10.3: Common Musculoskeletal Conditions
Now that we have reviewed the basic anatomy of the musculoskeletal system, let’s review common musculoskeletal conditions that a nurse may find on assessment.
Osteoporosis
Osteoporosis is a disease that thins and weakens bones, causing them to become fragile and break easily. See Figure \(\PageIndex{1}\) [1] for an illustration comparing the top right image of normal bone to the bottom right image of bone with osteoporosis. Osteoporosis is common in older women and often occurs in the hip, spine, and wrist. To keep bones strong, patients at risk are educated to eat a diet rich in calcium and vitamin D, participate in weight-bearing exercise, and avoid smoking. If needed, medications such as bisphosphonates and calcitonin are used to treat severe osteoporosis. [2]
Fracture
A fracture is the medical term for a broken bone. There are many different types of fractures commonly caused by sports injuries, falls, and car accidents. Additionally, people with osteoporosis are at higher risk for fractures from minor injuries due to weakening of the bones. See Figure \(\PageIndex{2}\) [3] for an illustration of different types of fractures. For example, if the broken bone punctures the skin, it is called an open fracture . Symptoms of a fracture include the following:
- Intense pain
- Deformity (i.e., the limb looks out of place)
- Swelling, bruising, or tenderness around the injury
- Numbness and tingling of the extremity distal to the injury
- Difficulty moving a limb
A suspected fracture requires immediate medical attention and an X-ray to determine if the bone is broken. Treatment includes a cast or splint. In severe fractures, surgery is performed to place plates, pins, or screws in the bones to keep them in place as they heal. [4]
Hip Fracture
A hip fracture, commonly referred to as a “broken hip,” is actually a fracture of the femoral neck. See Figure \(\PageIndex{3}\) [5] for an image of a hip fracture. Hip fractures are typically caused by a fall, especially in older adults with preexisting osteoporosis. Symptoms of a hip fracture after a fall include the following:
- Pain
- An inability to lift, move, or rotate the affected leg
- An inability to stand or put weight on the affected leg
- Bruising and swelling around the hip
- The injured leg appears shorter than the other leg
- The injured leg is rotated outwards [6]
Hip fractures typically require surgical repair within 48 hours of the injury. In approximately half of the cases of hip fractures, hip replacement is needed. See more information about hip replacement under the “Osteoarthritis” section below. In other cases, the fracture is fixed with surgery called Open Reduction Internal Fixation (ORIF) where the surgeon makes an incision to realign the bones, and then they are internally fixated (i.e., held together) with hardware like metal pins, plates, rods, or screws. After the bone heals, this hardware isn’t removed unless additional symptoms occur. After surgery, the patient will need mobility assistance for a prolonged period of time from family members or in a long-term care facility, and the reduced mobility can result in additional falls if protective measures are not put into place. Additionally, hip fractures are also associated with life-threatening complications, such as pneumonia, infected pressure injuries, and blood clots that can move to the lungs causing pulmonary embolism. [7]
Osteoarthritis
Osteoarthritis (OA) is the most common type of arthritis associated with aging and wear and tear of the articular cartilage that covers the surfaces of bones at a synovial joint. OA causes the cartilage to gradually become thinner, and as the cartilage layer wears down, more pressure is placed on the bones. The joint responds by increasing production of the synovial fluid for more lubrication, but this can cause swelling of the joint cavity. The bone tissue underlying the damaged articular cartilage also responds by thickening and causing the articulating surface of the bone to become rough or bumpy. As a result, joint movement results in pain and inflammation. In early stages of OA, symptoms may be resolved with mild activity that warms up the joint. However, in advanced OA, the affected joints become more painful and difficult to use, resulting in decreased mobility. There is no cure for osteoarthritis, but several treatments can help alleviate the pain. Treatments may include weight loss, low-impact exercise, and medications such as acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), and celecoxib. For severe cases of OA, joint replacement surgery may be required. [8]
See Figure \(\PageIndex{4}\) [9] for an image comparing a normal joint to one with osteoarthritis and another type of arthritis called rheumatoid arthritis. (Rheumatoid arthritis is further explained under the “Joint Replacement” subsection.)
Joint Replacement
Arthroplasty , the medical term for joint replacement surgery, is an invasive procedure requiring extended recovery time, so conservative treatments such as lifestyle changes and medications are attempted before surgery is performed. See Figure \(\PageIndex{5}\) [10] for an illustration of joint replacement surgery. This type of surgery involves replacing the articular surfaces of the bones with prosthesis (artificial components). For example, in hip arthroplasty, the worn or damaged parts of the hip joint, including the head and neck of the femur and the acetabulum of the pelvis, are removed and replaced with artificial joint components. The replacement head for the femur consists of a rounded ball attached to the end of a shaft that is inserted inside the femur. The acetabulum of the pelvis is reshaped and a replacement socket is fitted into its place. [11]
Hip Replacement
Hip replacement is surgery for people with severe hip damage often caused by osteoarthritis or a hip fracture. During a hip replacement operation, the surgeon removes damaged cartilage and bone from the hip joint and replaces them with artificial parts. [12]
The most common complication after surgery is hip dislocation. Because a man-made hip is smaller than the original joint, the ball may easily come out of its socket. Some general rules of thumb when caring for patients during the recovery period are as follows:
- Patients should not cross their legs or ankles when they are sitting, standing, or lying down.
- Patients should not lean too far forward from their waist or pull their leg up past their waist. This bending is called hip flexion. Avoid hip flexion greater than 90 degrees. [13]
For more information about patient education after a hip replacement surgery, read the following article from Medline Plus: How to Take Care of Your New Hip Joint
Rheumatoid Arthritis
Rheumatoid arthritis (RA) is a type of arthritis that causes pain, swelling, stiffness, and loss of function in joints due to inflammation caused by an autoimmune disease. See Figure \(\PageIndex{6}\) [14] for an illustration of RA in the hands causing inflammation and a common deformity of the fingers. It often starts in middle age and is more common in women. RA is different from osteoarthritis because it is an autoimmune disease, meaning it is caused by the immune system attacking the body’s own tissues. [15] In rheumatoid arthritis, the joint capsule and synovial membrane become inflamed. As the disease progresses, the articular cartilage is severely damaged, resulting in joint deformation, loss of movement, and potentially severe disability. There is no known cure for RA, so treatments are aimed at alleviating symptoms. Medications such as nonsteroidal anti-inflammatory drugs (NSAIDS), corticosteroids, and antirheumatic drugs such as methotrexate are commonly used to treat rheumatoid arthritis. [16]
Gout
Gout is a type of arthritis that causes swollen, red, hot, and stiff joints due to the buildup of uric acid. It typically first attacks the big toe. See Figure \(\PageIndex{7}\) [17] for an illustration of gout in the joint of the big toe. Uric acid usually dissolves in the blood, passes through the kidneys, and is eliminated in urine, but gout occurs when uric acid builds up in the body and forms painful, needle-like crystals in joints. Gout is treated with lifestyle changes such avoiding alcohol and food high in purines, as well as administering antigout medications, such as allopurinol and colchicine. [18]
Vertebral Disorders
The spine is composed of many vertebrae stacked on top of one another, forming the vertebral column. There are several disorders that can occur in the vertebral column causing curvature of the spine such as kyphosis, lordosis, and scoliosis. See Figure \(\PageIndex{8}\) [19] for an illustration of kyphosis, lordosis, and scoliosis.
Kyphosis is a curving of the spine that causes a bowing or rounding of the back, often referred to as a “buffalo hump” that can lead to a hunchback or slouching posture. Kyphosis can be caused by osteoarthritis, osteoporosis, or other conditions. Pain in the middle or lower back is the most common symptom. Treatment depends upon the cause, the severity of pain, and the presence of any neurological symptoms. [20]
Lordosis is the inward curve of the lumbar spine just above the buttocks. A small degree of lordosis is normal, especially during the third trimester of pregnancy. Too much curving of the lower back is often called swayback. Most of the time, lordosis is not treated if the back is flexible because it is not likely to progress or cause problems. [21]
Scoliosis causes a sideways curve of the spine. It commonly develops in late childhood and the early teens when children grow quickly. Symptoms of scoliosis include leaning to one side and having uneven shoulders and hips. Treatment depends on the patient’s age, the amount of expected additional growth, the degree of curving, and whether the curve is temporary or permanent. Patients with mild scoliosis might only need checkups to monitor if the curve is getting worse, whereas others may require a brace or have surgery. [22]
Sprains and Strains
A strain is a stretched or torn muscle or tendon. Tendons are tissues that connect muscle to bone. See Figure \(\PageIndex{10}\) [28] for an image of a strained tendon. Strains can happen suddenly from an injury or develop over time due to chronic overuse. Symptoms include pain, muscle spasms, swelling, and trouble moving the muscle.
Treatment of sprains and strains is often referred to with the mnemonic RICE that stands for Resting the injured area, Icing the area, Compressing the area with an ACE bandage or other device, and Elevating the affected limb. Medications such as acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs) may also be used. [29]
Knee Injuries and Arthroscopic Surgery
Knee injuries are common. Because the knee joint is primarily supported by muscles and ligaments, injuries to any of these structures will result in pain or knee instability. Arthroscopic surgery has greatly improved the surgical treatment of knee injuries and reduced subsequent recovery times. This procedure involves a small incision and the insertion of an arthroscope, a pencil-thin instrument that allows for visualization of the joint interior. Small surgical instruments are inserted via additional incisions to remove or repair ligaments and other joint structures. [30]
Contracture
A contracture develops when the normally elastic tissues are replaced by inelastic, fiber-like tissue. This inelastic tissue makes it difficult to stretch the area and prevents normal movement.
Contractures occur in the skin, the tissues underneath, and the muscles, tendons, and ligaments surrounding a joint. They affect the range of motion and function in a specific body part and can be painful. See Figure \(\PageIndex{11}\) [31] for an image of severe contracture of the wrist that occurred after a burn injury.
Contracture can be caused by any of the following:
- Brain and nervous system disorders, such as cerebral palsy or stroke
- Inherited disorders, such as muscular dystrophy
- Nerve damage
- Reduced use (for example, from lack of mobility)
- Severe muscle and bone injuries
- Scarring after traumatic injury or burns
Treatments may include exercises, stretching, or applying braces and splints. [32]
Foot Drop
Foot drop is the inability to raise the front part of the foot due to weakness or paralysis of the muscles that lift the foot. As a result, individuals with foot drop often scuff their toes along the ground when walking or bend their knees to lift their foot higher than usual to avoid the scuffing. Foot drop is a symptom of an underlying problem and can be temporary or permanent, depending on the cause. The prognosis for foot drop depends on the cause. Foot drop caused by trauma or nerve damage usually shows partial or complete recovery, but in progressive neurological disorders, foot drop will be a symptom that is likely to continue as a lifelong disability. Treatment depends on the specific cause of foot drop. The most common treatment is to support the foot with lightweight leg braces. See Figure \(\PageIndex{12}\) 33] for an image of a patient with foot drop treated with a leg brace. Exercise therapy to strengthen the muscles and maintain joint motion also helps to improve a patient’s gait. [34]
- “ Osteoporosis Effect and Locations.jpg ” by BruceBlaus is licensed under CC BY-SA 4.0 ↵
- MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2020, Aug 14]. Osteoporosis; [reviewed 2017, Mar 15; cited 2020, Sep 18]. https://medlineplus.gov/osteoporosis.html ↵
- “ 612 Types of Fractures.jpg ” by OpenStax is licensed under CC BY 4.0 ↵
- MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2020, Apr 20]. Fractures; [reviewed 2016, Mar 15; cited 2020, Sep 18]. https://medlineplus.gov/fractures.html ↵
- “ Cdm hip fracture 343.jpg ” by Booyabazooka is licensed under CC BY-SA 3.0 ↵
- NHS (UK). (2019, October 3). Hip fracture. https://www.nhs.uk/conditions/hip-fracture/ ↵
- This work is a derivative of Anatomy & Physiology by OpenStax and is licensed under CC BY 4.0 . Access for free at https://openstax.org/books/anatomy-and-physiology/pages/1-introduction ↵
- This work is a derivative of Anatomy & Physiology by OpenStax and is licensed under CC BY 4.0 . Access for free at https://openstax.org/books/anatomy-and-physiology/pages/1-introduction ↵
- “ Osteoarthritis and rheumatoid arthritis - Normal joint Osteoarthr -- Smart-Servier.jpg ” by Laboratoires Servier is licensed under CC BY-SA 3.0 ↵
- “ Replacement surgery - Shoulder total hip and total knee replacement -- Smart-Servier.jpg ” by Laboratoires Servier is licensed under CC BY-SA 3.0 ↵
- This work is a derivative of Anatomy & Physiology by OpenStax and is licensed under CC BY 4.0 . Access for free at https://openstax.org/books/anatomy-and-physiology/pages/1-introduction ↵
- MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2020, Aug 21]. Hip replacement; [reviewed 2016, Aug 31; cited 2020, Sep 18]. https://medlineplus.gov/hipreplacement.html ↵
- A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M., Inc.; c1997-2020. Taking care of your new hip joint; [updated 2020, Sep 16; cited 2020, Sep 18]. https://medlineplus.gov/ency/patientinstructions/000171.htm ↵
- “ Rheumatoid arthritis -- Smart- Servier (cropped).jpg ” by Laboratoires Servier is licensed under CC BY-SA 3.0 ↵
- MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2020, Aug 14]. Rheumatoid arthritis; [reviewed 2018, May 2; cited 2020, Sep 18]. https://medlineplus.gov/rheumatoidarthritis.html ↵
- This work is a derivative of Anatomy & Physiology by OpenStax and is licensed under CC BY 4.0 . Access for free at https://openstax.org/books/anatomy-and-physiology/pages/1-introduction ↵
- “ Gout Signs and Symptoms.jpg ” by www.scientificanimations.com/ is licensed under CC BY 4.0 ↵
- This work is a derivative of Anatomy and Physiology by Boundless.com and is licensed under CC BY-SA 4.0 ↵
- “ Vertebral column disorders - Normal Scoliosis Lordosis Kyphosis -- Smart-Servier.jpg ” by Laboratoires Servier is licensed under CC BY-SA 3.0 ↵
- A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M., Inc.; c1997-2020. Kyphosis; [updated 2020, Sep 16; cited 2020, Sep 18]. https://medlineplus.gov/ency/article/001240.htm ↵
- A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M., Inc.; c1997-2020. Lordosis - lumbar; [updated 2020, Sep 16; cited 2020, Sep 18]. https://medlineplus.gov/ency/article/003278.htm ↵
- MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2020, Apr 29]. Scoliosis; [reviewed 2016, Oct 18; cited 2020, Sep 18]. https://medlineplus.gov/scoliosis.html ↵
- “ AnterDisAPMark.png ” by James Heilman, MD is licensed under CC BY-SA 4.0 ↵
- MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2019, Feb 7]. Dislocations; [reviewed 2016, Oct 26; cited 2020, Sep 18]. https://medlineplus.gov/dislocations.html ↵
- “813 Clubfoot.jpg” by OpenStax is licensed under CC BY 3.0 ↵
- A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M., Inc.; c1997-2020. Club foot; [updated 2020, Sep 16; cited 2020, Sep 18]. https://medlineplus.gov/ency/article/001228.htm ↵
- “Ankle sprain -- Smart-Servier.jpg” by Laboratoires Servier is licensed under CC BY-SA 3.0 ↵
- “3D Medical Animation Depicting Strain-Tendon.jpg” by https://www.scientificanimations.com is licensed under CC BY-SA 4.0 ↵
- A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M., Inc.; c1997-2020. Sprains and strains; [updated 2020, Jun 17; reviewed 2017, Jan 3; cited 2020, Sep 18]. https://medlineplus.gov/sprainsandstrains.html ↵
- This work is a derivative of Anatomy & Physiology by OpenStax and is licensed under CC BY 4.0 . Access for free at https://openstax.org/books/anatomy-and-physiology/pages/1-introduction ↵
- “Complications of Hypertrophic Scarring.png” by Aarabi, S., Longaker, M. T., & Gurtner, G. C. is licensed under CC BY 3.0 ↵
- A.D.A.M. Medical Encyclopedia [Internet]. Atlanta (GA): A.D.A.M., Inc.; c1997-2020. Contracture deformity; [updated 2020, Sep 16; cited 2020, Sep 18]. https://medlineplus.gov/ency/article/003185.htm ↵
- “AFO brace for foot drop.JPG” by Pagemaker787 is licensed under CC BY-SA 4.0 ↵
- National Institute of Neurological Disorders and Stroke. (2019, March 27). Foot drop information page . https://www.ninds.nih.gov/Disorders/All-Disorders/Foot-Drop-Information-Page ↵


3.3: Discussion- What Research Have You Done Lately?
In your life outside of school, think about some investigation you’ve done to satisfy your own curiosity. (Keep in mind the difference between “homework questions” and “research questions” as noted in What Is Research? )
- What was your research question?
- What kind of information did you have to gather in order to answer it?
- What sources did you use to gather the information?
- Were you successful in answering the question?
- And, if you’re willing to share, what was your answer?
Post 1: For your first post, answer the first 4 bullet points (and the last, if you’re willing).
Your post should be at least 150-200 words. It doesn’t have to be grammatically perfect, but should use standard English (no text-speak, please) and normal capitalization rules.
Posts 2 and 3: Respond to at least two of your classmates’ posts.
Responses are weighed as heavily as your initial posting, and should be roughly as long (150-200 words) when combined. Responses should indicate you’ve read your classmates’ posts carefully. Include specific details from the post you’re responding to in your reply.
Contributors and Attributions
- Composition II. Authored by : Janet Zepernick. Provided by : Pittsburg State University. Located at : http://www.pittstate.edu/ . Project : Kaleidoscope Open Course Initiative. License : CC BY: Attribution


7.4: Low Energy Electron Diffraction
Low energy electron diffraction (LEED) is a very powerful technique that allows for the characterization of the surface of materials. Its high surface sensitivity is due to the use of electrons with energies between 20-200 eV, which have wavelengths equal to 2.7 – 0.87 Å (comparable to the atomic spacing). Therefore, the electrons can be elastically scattered easily by the atoms in the first few layers of the sample. Its features, such as little penetration of low–energy electrons have positioned it as one of the most common techniques in surface science for the determination of the symmetry of the unit cell (qualitative analysis) and the position of the atoms in the crystal surface (quantitative analysis).
History: Davisson and Germer Experiment
In 1924 Louis de Brogile postulated that all forms of matter, such as electrons, have a wave-particle nature. Three years later after this postulate, the American physicists Clinton J. Davisson and Lester H. Germer (Figure \(\PageIndex{1}\)) proved experimentally the wave nature of electrons at Bell Labs in New York, see Figure 1. At that time, they were investigating the distribution-in-angle of the elastically scattered electrons (electrons that have suffered no loss of kinetic energy) from the (111) face of a polycrystalline nickel, material composed of many randomly oriented crystals.
The experiment consisted of a beam of electrons from a heated tungsten filament directed against the polycrystalline nickel and an electron detector, which was mounted on an arc to observe the electrons at different angles. During the experiment, air entered in the vacuum chamber where the nickel was, producing an oxide layer on its surface. Davisson and Clinton reduced the nickel by heating it at high temperature. They did not realize that the thermal treatment changed the polycrystalline nickel to a nearly monocrystalline nickel, material composed of many oriented crystals. When they repeated the experiment, it was a great surprise that the distribution-in-angle of the scattered electrons manifested sharp peaks at certain angles. They soon realized that these peaks were interference patterns, and, in analogy to X-ray diffraction, the arrangement of atoms and not the structure of the atoms was responsible for the pattern of the scattered electrons.
The results of Davisson and Germer were soon corroborated by George Paget Thomson, J. J. Thomson’s son. In 1937, both Davisson and Thomson were awarded with the Nobel Prize in Physics for their experimental discovery of the electron diffraction by crystals. It is noteworthy that 31 years after J. J. Thomson showed that the electron is a particle, his son showed that it is also a wave.
Although the discovery of low-energy electron diffraction was in 1927, it became popular in the early 1960’s, when the advances in electronics and ultra-high vacuum technology made possible the commercial availability of LEED instruments. At the beginning, this technique was only used for qualitative characterization of surface ordering. Years later, the impact of computational technologies allowed the use of LEED for quantitative analysis of the position of atoms within a surface. This information is hidden in the energetic dependence of the diffraction spot intensities, which can be used to construct a LEED I-V curve.
Principles and Diffraction Patterns
Electrons can be considered as a stream of waves that hit a surface and are diffracted by regions with high electron density (the atoms). The electrons in the range of 20 to 200 eV can penetrate the sample for about 10 Å without loosing energy. Because of this reason, LEED is especially sensitive to surfaces, unlike X-ray diffraction, which gives information about the bulk-structure of a crystal due to its larger mean free path (around micrometers). Table \(\PageIndex{1}\) compares general aspects of both techniques.
| Low Energy Electron Diffraction | X-ray Diffraction |
| Surface structure determination (high surface sensitivity) | Bulk structures determination |
| Sample single crystal | Sample single-crystal or polycrystalline |
| Sample must be have an oriented surface, sensitive to impurities | Surface impurities not important |
| Experiment in ultra-high vacuum | Experiment usually at atmospheric pressure |
| Experiment done mostly at constant incidence angle and variable wavelength (electron energy) | Constant wavelength and variable incidence angle |
| Diffraction pattern consists of beams visible at almost all energies | Diffraction pattern consists of beams flashing out at specific wavelengths and angles |
Like X-ray diffraction, electron diffraction also follows the Bragg’s law, see Figure \(\PageIndex{2}\) , where λ is the wavelength, a is the atomic spacing, d is the spacing of the crystal layers, θ is the angle between the incident beam and the reflected beam, and n is an integer. For constructive interference between two waves, the path length difference (2a sinθ / 2d sinθ) must be an integral multiple of the wavelength.
In LEED, the diffracted beams impact on a fluorescent screen and form a pattern of light spots (Figure \(\PageIndex{3}\) a), which is a to-scale version of the reciprocal lattice of the unit cell. The reciprocal lattice is a set of imaginary points, where the direction of a vector from one point to another point is equal to the direction of a normal to one plane of atoms in the unit cell (real space). For example, an electron beam penetrates a few 2D-atomic layers, Figure \(\PageIndex{3}\) b), so the reciprocal lattice seen by LEED consists of continues rods and discrete points per atomic layer, see Figure \(\PageIndex{3}\) c. In this way, LEED patterns can give information about the size and shape of the real space unit cell, but nothing about the positions of the atoms. To gain this information about atomic positions, analysis of the spot intensities is required. For further information about reciprocal lattice and crystals refer to Crystal Structure and An Introduction to Single-Crystal X-Ray Crystallography.
Thanks to the hemispheric geometry of the green screen of LEED, we can observe the reciprocal lattice without distortion. It is important to take into account that the separation of the points in the reciprocal lattice and the real interplanar distance are inversely proportional, which means that if the atoms are more widely spaced, the spots in the pattern get closer and vice versa. In the case of superlattices, a periodic structure composed of layers of two materials, new points arise in addition to the original diffraction pattern.
LEED Experimental Equipment
The typical diagram of a LEED system is shown in Figure \(\PageIndex{4}\). This system sends an electron beam to the surface of the sample, which comes from an electron gun behind a transparent hemispherical fluorescent screen. The electron gun consists of a heated cathode and a set of focusing lenses which send electrons at low energies. The electrons collide with the sample and diffract in different directions depending on the surface. Once diffracted, they are directed to the fluorescent screen. Before colliding with the screen, they must pass through four different grids (known as retarding grids), which contain a central hole through which the electron gun is inserted. The first grid is the nearest one to the sample and is connected to earth ground. A negative potential is applied to the second and third grids, which act as suppressor grids, given that they repel all electrons coming from non–elastic diffractions. These grids perform as filters, which only allow the highest–energy electrons to pass through; the electrons with the lowest energies are blocked in order to prevent a bad resolution image. The fourth grid protects the phosphor screen, which possesses positive charge from the negative grids. The remaining electrons collide with the luminescent screen, creating a phosphor glow (left side of Figure \(\PageIndex{4}\)), where the light intensity depends on the electron intensity.
For conventional systems of LEED, it is necessary a method of data acquisition. In the past, the general method for analyzing the diffraction pattern was to manually take several dozen pictures. After the development of computers, the photographs were scanned and digitalized for further analysis through computational software. Years later, the use of the charge–coupled device (CCD) camera was incorporated, allowing rapid acquisition, the possibility to average frames during the acquisition in order to improve the signal, the immediate digitalization and channeling of LEED pattern. In the case of the IV curves, the intensities of the points are extracted making use of special algorithms. Figure \(\PageIndex{5}\) shows a commercial LEED spectrometer with the CCD camera, which has to be in an ultra-high vacuum vessel.
LEED Applications
We have previously talked about the discovery of LEED and its principles, along with the experimental setup of a LEED system. It was also mentioned that LEED provides qualitative and quantitative surface analysis. In the following section, we will discuss the most common applications of LEED and the information that one can obtain with this technique.
Study of Adsorbates on the Surface and Disorder Layers
ne of the principal applications of LEED is the study of adsorbates on catalysts, due to its high surface sensitivity. In order to illustrate the application of LEED in the study of adsorbates. As an example, Figure \(\PageIndex{6}\) a shows the surface of Cu (100) single crystal, the pristine material. This surface was cleaned carefully by various cycles of sputtering with ions of argon, followed by annealing. The LEED patter of Cu (100) presents four well-defined spots corresponding to its cubic unit cell.
Figure \(\PageIndex{6}\) b shows the LEED pattern after the growth of graphene on the surface of Cu (100) at 800 °C, we can observe the four spots that correspond to the surface of Cu (100) and a ring just outside these spots, which correspond to the domains of graphene with four different primary rotational alignments with respect to the Cu (100) substrate lattice, see Figure \(\PageIndex{7}\). When increasing the temperature of growth of graphene to 900 °C, we can observe a ring of twelve spots (as seen in Figure \(\PageIndex{6}\) c), which indicates that the graphene has a much higher degree of rotational order. Only two domains are observed with an alignment of one of the lattice vectors to one of the Cu (100) surface lattice vectors, given that graphene has a hexagonal geometry, so that only one vector can coincide with the cubic lattice of Cu (100).
One possible explanation for the twelve spots observed at 900 ˚C is that when the temperature of all domains is increased the four different domains observed at 800 ˚C, may possess enough energy to adopt the two orientations in which the vectors align with the surface lattice vector of Cu (100). In addition, at 900 ˚C, a decrease in the size and intensity of the Cu (100) spots is observed, indicating a larger coverage of the copper surface by the domains of graphene.
When the oxygen is chemisorbed on the surface of Cu (100), the new spots correspond to oxygen, Figure \(\PageIndex{8}\) a. Once graphene is allowed to grow on the surface with oxygen at 900 ˚C, the LEED pattern turns out different: the twelve spots corresponding to graphene domains are not observed due to nucleation of graphene domains in the presence of oxygen in multiple orientations, Figure \(\PageIndex{8}\) b.
A way to study the disorder of the adsorbed layers is through the LEED–IV curves, see Figure \(\PageIndex{9}\). In this case, the intensities are in relation to the angle of the electron beam. The spectrum of Cu (100) with only four sharp peaks shows a very organized surface. In the case of the graphene sample growth over the copper surface, twelve peaks are shown, which correspond to the main twelve spots of the LEED pattern. These peaks are sharp, which indicate an high level of order. For the case of the sample of graphene growth over copper with oxygen, the twelve peaks widen, which is an effect of the increase of disorder in the layers.
Structure Determination
As previously mentioned, LEED–IV curves may give us exact information about the position of the atoms in a crystal. These curves are related to a variation of intensities of the diffracted electron (spots) with the energy of the electron beam. The process of determination of the structure by this technique works as ‘proof and error’ and consists of three main parts: the measurement of the intensity spectra, the calculations for various models of atomic positions and the search for the best-fit structure which is determined by an R-factor.
The first step consists of obtaining the experimental LEED pattern and all the electron beam intensities for every spot of the reciprocal lattice in the pattern. Theoretical LEED–IV curves are calculated for a large number of geometrical models and these are compared with the experimental curves. The agreement is quantified by means of a reliability factor or R–factor. The closest this value to zero is, the more perfect the agreement between experimental and theoretical curves. In this way, the level of precision of the crystalline structure will depend on the smallest R–factor that can be achieved.
Pure metals with pure surfaces allow R–factor values of around 0.1. When moving to more complex structures, these values increase. The main reason for this gradually worse agreement between theoretical and experimental LEED-IV curves lies in the approximations in conventional LEED theory, which treats the atoms as perfect spheres with constant scattering potential in between. This description results in inaccurate scattering potential for more open surfaces and organic molecules. In consequence, a precision of 1-2 pm can be achieved for atoms in metal surfaces, whereas the positions of atoms within organic molecules are typically determined within ±10-20 pm. The values of the R-factor are usually between 0.2 and 0.5, where 0.2 represents a good agreement, 0.35 a mediocre agreement and 0.5 a poor agreement.
Figure \(\PageIndex{10}\) shows an example of a typical LEED–IV curve for Ir (100), which has a quasi-hexagonal unit cell. One can observe the parameters used to calculate the theoretical LEED–IV curve and the best-fitted curve obtained experimentally, which has an R–factor value of 0.144. The model used is also shown.


11.3: Interpretive Case Research Exemplar
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Perhaps the best way to learn about interpretive case research is to examine an illustrative example. One such example is Eisenhardt’s (1989) study of how executives make decisions in high-velocity environments (HVE). Readers are advised to read the original paper published in Academy of Management Journal before reading the synopsis in this chapter. In this study, Eisenhardt examined how executive teams in some HVE firms make fast decisions, while those in other firms cannot, and whether faster decisions improve or worsen firm performance in such environments. HVE was defined as one where demand, competition, and technology changes so rapidly and discontinuously that the information available is often inaccurate, unavailable or obsolete. The implicit assumptions were that it is hard to make fast decisions with inadequate information in HVE, and fast decisions may not be efficient and may result in poor firm performance.
Reviewing the prior literature on executive decision-making, Eisenhardt found several patterns, although none of these patterns were specific to high-velocity environments. The literature suggested that in the interest of expediency, firms that make faster decisions obtain input from fewer sources, consider fewer alternatives, make limited analysis, restrict user participation in decision-making, centralise decision-making authority, and have limited internal conflicts. However, Eisenhardt contended that these views may not necessarily explain how decision makers make decisions in high-velocity environments, where decisions must be made quickly and with incomplete information, while maintaining high decision quality.
To examine this phenomenon, Eisenhardt conducted an inductive study of eight firms in the personal computing industry. The personal computing industry was undergoing dramatic changes in technology with the introduction of the UNIX operating system, RISC architecture, and 64KB random access memory in the 1980s, increased competition with the entry of IBM into the personal computing business, and growing customer demand with double-digit demand growth, and therefore fit the profile of the high-velocity environment. This was a multiple case design with replication logic, where each case was expected to confirm or disconfirm inferences from other cases. Case sites were selected based on their access and proximity to the researcher, however, all of these firms operated in the high-velocity personal computing industry in California’s Silicon Valley area. The collocation of firms in the same industry and the same area ruled out any ‘noise’ or variance in dependent variables (decision speed or performance) attributable to industry or geographic differences.
The study employed an embedded design with multiple levels of analysis: decision (comparing multiple strategic decisions within each firm), executive teams (comparing different teams responsible for strategic decisions), and the firm (overall firm performance). Data was collected from five sources:
Initial interviews with Chief Executive Officers . CEOs were asked questions about their firm’s competitive strategy, distinctive competencies, major competitors, performance, and recent/ongoing major strategic decisions. Based on these interviews, several strategic decisions were selected in each firm for further investigation. Four criteria were used to select decisions: the decisions must involve the firm’s strategic positioning, the decisions must have high stakes, the decisions must involve multiple functions, and the decisions must be representative of strategic decision-making process in that firm.
Interviews with divisional heads . Each divisional head was asked sixteen open-ended questions, ranging from their firm’s competitive strategy, functional strategy, top management team members, frequency and nature of interaction with team, typical decision-making processes, how each of the decisions were made, and how long it took them to make those decisions. Interviews lasted between one and a half and two hours, and sometimes extended to four hours. To focus on facts and actual events rather than respondents’ perceptions or interpretations, a ‘courtroom’ style questioning was employed, such as ‘When did this happen?’, ‘What did you do?’, etc. Interviews were conducted by two people, and the data was validated by cross-checking facts and impressions made by the interviewer and notetaker. All interview data was recorded, however notes were also taken during each interview, which ended with the interviewer’s overall impressions. Using a ‘24-hour rule’, detailed field notes were completed within 24 hours of the interview, so that some data or impressions were not lost to recall.
Questionnaires . Executive team members at each firm were asked to complete a survey questionnaire that captured quantitative data on the extent of conflict and power distribution in their firm.
Secondary data . Industry reports and internal documents such as demographics of the executive teams responsible for strategic decisions, financial performance of firms, and so forth, were examined.
Personal observation . Lastly, the researcher attended a one-day strategy session and a weekly executive meeting at two firms in her sample.
Data analysis involved a combination of quantitative and qualitative techniques. Quantitative data on conflict and power were analysed for patterns across firms/decisions. Qualitative interview data was combined into decision climate profiles, using profile traits (e.g., impatience) mentioned by more than one executive. For within-case analysis, decision stories were created for each strategic decision by combining executive accounts of the key decision events into a timeline. For cross-case analysis, pairs of firms were compared for similarities and differences, categorised along variables of interest such as decision speed and firm performance. Based on these analyses, tentative constructs and propositions were derived inductively from each decision story within firm categories. Each decision case was revisited to confirm the proposed relationships. The inferred propositions were compared with findings from the existing literature to examine differences, and to generate new insights from the case findings. Finally, the validated propositions were synthesised into an inductive theory of strategic decision-making by firms in high-velocity environments.
Inferences derived from this multiple case research contradicted several decision-making patterns expected from the existing literature. First, fast decision-makers in high-velocity environments used more information, and not less information as suggested by the previous literature. However, these decision-makers used more real-time information—an insight not available from prior research—which helped them identify and respond to problems, opportunities, and changing circumstances faster. Second, fast decision-makers examined more—not fewer—alternatives. However, they considered these multiple alternatives in a simultaneous manner, while slower decision-makers examined fewer alternatives in a sequential manner. Third, fast decision-makers did not centralise decision-making or restrict inputs from others as the literature suggested. Rather, these firms used a two-tiered decision process in which experienced counsellors were asked for inputs in the first stage, followed by a rapid comparison and decision selection in the second stage. Fourth, fast decision-makers did not have less conflict—as expected from the literature—but employed better conflict resolution techniques to reduce conflict and improve decision-making speed. Finally, fast decision-makers exhibited superior firm performance by virtue of their built-in cognitive, emotional, and political processes that led to rapid closure of major decisions.


1.12: Types of Public Speaking
The art of public speaking remains a communication skill that remains in high demand. The concept public speaking applies generally to situations in which a message gets communicated to a wider (most often live) audience. More specifically, public speaking can be classified based on the method the speaker used to construct the message. Speakers can present their ideas in the form of an impromptu, manuscript, memorized, or extemporaneous speech.
Home Impromptu speaking is unplanned, unrehearsed, and unscripted. Sometimes, an impromptu speech might arise when the speaker has no time to prepare and has to speak in a completely improvised manner, but in other situations, impromptu speaking may involve characteristically short preparation times like a few minutes. Speakers most often give impromptu speeches without notes, and will succeed if they remain spontaneous, engaging, and confident. They must have a knack for thinking quickly on a moment’s notice. Impromptu speakers face the challenge of staying on topic while keeping the “flow” of their conversational style going to maintain the audience’s attention. Regardless of the varying needs of one’s career or industry, impromptu speaking opportunities arise frequently, such as when one is called upon to explain a project, product, or process to members of management or constituent groups. Speakers that can respond with relevant information in an organized and timely manner have a greater chance of establishing credibility to their audience.
Manuscript speaking remains one of the most formal speaking styles since the speaker reads from an entirely pre-written script. Manuscript speeches frequent large, formal settings, such as commencement ceremonies or political affairs, and may utilize teleprompters to allow the speaker to maintain eye contact with the audience. Herein lies the drawback of this type of speech. Instead of interacting with the audience, keeping the speech fresh and engaging, manuscript speeches can feel canned or inauthentic to the audience.
Home Memorized speeches share similarities to the pre-written manuscript speech, but unlike the manuscript speech, the speaker memorizes the speech as though it contained lines from a Shakespearean play and recites them, verbatim, to the audience instead of reading it. Memorization has its pitfalls, however, as the speaker may forget a “line” and need to rely on improvisation techniques to fill in the gaps in memory.
Home Extemporaneous speaking differs from impromptu in that it allows for much more preparation and structure without relying on memorization. Extemporaneous speakers utilize an outline to serve as the foundation for a persuasive or informational speech, which provides a roadmap (but not a complete script) for the speaker to follow. In addition, extemporaneous speeches often contain a structure similar to the classic five-paragraph essay, with an introduction, main points, and a conclusion that reinforces a thesis or central idea. Speaking extemporaneously ultimately means speaking fluidly, yet with extensive preparation achieved through research. For the vast majority of topics, structuring a speech using an extemporaneous format provides the best of all worlds: a presentation with well-prepared information and defined structure, but with enough flexibility to remain conversational and fluid.


4.8: Background- Filtering with a Weighted Running Average
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The advantage of the running average approach to filtering is that it’s really easy to see why it reduces high-frequency fluctuations: Any little “uppies and downies” within the set of points being averaged together will cancel each other out. Imagine that we applied a running average filter to raw EEG, using a running average width of 50 ms (e.g., 5 points on either side of the current point if we have one point every 5 ms). If the EEG has a 20 Hz sine wave in it, there will be exactly one cycle of the sine wave in 50 ms, and the positive and negative sides of the sine wave will cancel each other out.
The disadvantage of the running average filter is that it’s a bit crude. Imagine that we had a 101-point running average filter (the number is always odd because we have the current point plus an equal number of points on either side). The filtered value at time point t would be just as influenced by time point t-50 as by point t-1 . Instead of giving all 101 points equal weight, it would make more sense to give nearby points greater weight than more distant points. That’s actually quite easy to do.
This weighted running average approach to filtering is illustrated in Figure 4.3. We start by defining a weighting function , which indicates how much weight each of the surrounding time points will have. For example, rather than having a 7-point running average in which each of the 7 points has equal weight, the 7-point weighting function shown in Figure 4.3 gives the greatest weight to the current point, and then the weights fall off for more distant points. The filtered value at time t is computed by taking each of the 7 points (t-3 through t+3), multiplying the unfiltered value at each point by the corresponding value from the weighting function, and the summing these weighted values.
A standard 7-point running average could be computed in the same way. Our weighting function would have a value of 1/7 at each of the 7 points. The filtered value at time t would then be computed by taking 1/7 times the voltage at each of the 7 points and then summing these values together. That’s identical to taking the average of the 7 points.
I hope that you can still see how this more sophisticated version of the running average filter will tend to attenuate high frequencies: Uppies and downies during the set of points being averaged together will tend to cancel each other out.
You may be wondering how this weighted running average approach is related to filtering with an impulse response function. The answer is beautifully simple: The weighting function is simply the mirror image of the impulse response function. And if the impulse response function is symmetrical (which is usually the case), the weighting function is exactly the same as the impulse response function. Also, because the weighting function is just the mirror image of the impulse response function, you can compute the frequency response function by applying the Fourier transform to the mirror image of the weighting function.
The only real difference between filtering with an impulse response function and filtering with a weighting function is conceptual: the impulse response approach tells you how the unfiltered value at time t will influence the filtered values at the surrounding time points (because the unfiltered value at time t is replaced by a scaled copy of the impulse response function), whereas the weighted running average approach tells you how the filtered value at time t is influenced by the unfiltered values at the surround points (because the filtered value at time t is the weighted sum of the surrounding time points).
Thinking about filtering in terms of the weighting function should help you understand an important consequence of filtering: Filtering inevitably reduces temporal resolution (no matter how the filtering is implemented). The filtered value at a given time point is influenced by the surrounding time points, so the voltage you see at 100 ms is now influenced by the voltages at 95 ms, 105 ms, etc. And the weighting function shows you exactly how much impact the preceding and subsequent time points will have on the filtered value at a given time point. The wider the weighting function, the more you are filtering your data, and the more temporal precision you have lost. This is a very clear example of the principle that increasing the precision in the frequency domain (by limiting the set of frequencies that are in the filter output) decreases the precision in the time domain (by causing the filtered value at a given time point to be influenced by a wider range of time points from the unfiltered data).


30.19: Plant Sensory Systems and Responses - Blue Light Response
- Differentiate among blue light responses of plants
Phototropism is the directional bending of a plant toward or away from a light source of blue wavelengths of light. Positive phototropism is growth toward a light source, while negative phototropism (also called skototropism) is growth away from light. Several proteins use blue light to control various physiological processes in the plant.
Phototropins and Physiological Responses
Phototropins are protein-based receptors responsible for mediating the phototropic response in plants. Like all plant photoreceptors, phototropins consist of a protein portion and a light-absorbing portion, called the chromophore, which senses blue wavelengths of light. Phototropins belong to a class of proteins called flavoproteins because the chromophore is a covalently-bound molecule of flavin.
Phototropins control other physiological responses including leaf opening and closing, chloroplast movement, and the opening of stomata. However, of all responses controlled by phototropins, phototropism has been studied the longest and is the best understood.
Phototropism and Auxin
In 1880, Charles Darwin and his son Francis first described phototropism as the bending of seedlings toward light. Darwin observed that light was perceived by the the apical meristem (tip of the plant), but that the plant bent in response in a different part of the plant. The Darwins concluded that the signal had to travel from the apical meristem to the base of the plant, where it bent.
In 1913, Peter Boysen-Jensen conducted an experiment that demonstrated that a chemical signal produced in the plant tip was responsible for the plant’s bending response at the base. He cut off the tip of a seedling, covered the cut section with a permeable layer of gelatin, and then replaced the tip. The seedling bent toward the light when illuminated even though the layer of gelatin was present. However, when impermeable mica flakes were inserted between the tip and the cut base, the seedling did not bend.
A refinement of Boysen-Jensen’s experiment showed that the signal traveled on the shaded side of the seedling. When the mica plate was inserted on the illuminated side, the plant still bent toward the light. Therefore, the chemical signal from the sunlight, which is blue wavelengths of light, was a growth stimulant; the phototropic response involved faster cell elongation on the shaded side than on the illuminated side, causing the plant to bend. We now know that as light passes through a plant stem, it is diffracted and generates phototropin activation across the stem. Most activation occurs on the lit side, causing the plant hormones indole acetic acid (IAA) or auxin to accumulate on the shaded side. Stem cells elongate under the influence of IAA.
Cryptochromes
Cryptochromes are another class of blue-light absorbing photoreceptors. Their chromophores also contain a flavin-based chromophore. Cryptochromes set the plant’s circadian rhythm (the 24-hour activity cycle) using blue light receptors. There is some evidence that cryptochromes work by sensing light-dependent redox reactions and that, together with phototropins, they mediate the phototropic response.
Key Points
- In addition to phototropism, phototropins sense blue light to control leaf opening and closing, chloroplast movement, and the opening of stomata.
- When phototropins are activated by blue light, the hormone auxin accumulates on the shaded side of the plant, triggering elongation of stem cells and phototropism.
- Cryptochromes sense blue light-dependent redox reactions to control the circadian rhythm of plants.
Key Terms
- skototropism : growth or movement away from light
- phototropin : any of a class of photoreceptor flavoproteins that mediate phototropism in higher plants
- auxin : a class of plant growth hormones that is responsible for elongation in phototropism and gravitropism and for other growth processes in the plant life cycle
- cryptochrome : any of several light-sensitive flavoproteins, in the protoreceptors of plants, that regulate germination, elongation, and photoperiodism


8.4: Parts of a Good Presentation
- Identify key features of a good presentation
Like reverse engineering a product, we can distill the key features of a good presentation by looking at presentation evaluation scorecards. Refer to Table 1 for a sample class presentation grading rubric.
| Table 1. Presentation Grading Rubric | |||
|---|---|---|---|
| Criteria | Rating | Pts | |
| Overall communication effectiveness. Presentation reflects thoughtful planning (content) and development (structure) and engaged delivery (style) | 10 pts (Full Marks) | 0 pts (No Marks) | 10 pts |
| Presenter has a unique voice and compelling message. | 10 pts (Full Marks) | 0 pts (No Marks) | 10 pts |
| Presentation reflects learning. Content reflects knowledge and thoughtful development of subject. Speaker applies communication concepts learned and/or incorporates relevant terminology. Points are supported by credible sources/data. | 50 pts (Full Marks) | 0 pts (No Marks) | 50 pts |
| Slides reflect thoughtful design. Slides reflect an understanding of and ability to apply design best practices (i.e., 10-20-30 rule; “bullet points kill”) | 20 pts (Full Marks) | 0 pts (No Marks) | 20 pts |
| Presentation meets stated requirements. Presentation meets subject matter, research, length & formatting (including citation) requirements. | 10 pts (Full Marks) | 0 pts (No Marks) | 10 pts |
| Total Points: 100 |
At the macro level, the key elements of a good presentation are content, organization, and delivery. There are both substance and style aspects of content. Substance elements include the originality and significance of your idea, the quality of your research and analysis, clarity and potential impact of your recommendations. Style aspects of content include confidence and credibility, both of which have a significant impact on how you—and your message—are received.
Good organization starts with a strong opening and continues in a logical and well-supported manner throughout the presentation, leading to a close that serves as a resolution of the problem or a summary of the situation you’ve presented. The audience experiences good organization as a sense of flow—an inevitable forward movement to a satisfying close. This forward momentum also requires audiences to have a certain level of technical and information-management competency. To the latter point, good presentation requires a presenter to put thought into information design, from the structure and content of slides to the transitions between individual points, slides and topics.
Delivery entails a range of factors from body language and word choice to vocal variety. In this category, your audience is responding to your personality and professionalism. For perspective, one of the three evaluation categories on the official Toastmasters speaker evaluation form is “As I Saw You;” in parentheses: “approach, position, personal appearance, facial expression, gestures and detracting mannerisms.” A good presenter has a passion for the subject and an ability to convey and perhaps elicit that emotion in the audience. Audience engagement—through eye contact, facial expression, perhaps the use of gestures or movement—also contributes to an effective presentation. However, to the point in the Toastmasters evaluation, gestures, movement other mannerisms can be distracting (see Module 7: Public Speaking for more on this). What works: natural (not staged) movement that reinforces communication of your idea.
With those key features and presentation-evaluation criteria in mind, let’s add a disclaimer. The reality is that your features won’t matter if you don’t deliver one essential benefit: relevance.
Whether you think in Toastmasters terminology—”What’s in it for me? (WIIFM)” from the audience perspective—or put yourself in the audience’s position and ask “So what?,” it’s a question that you need to answer early. We’ll get into this more in the next section as we discuss presentation planning.
Contributors and Attributions
- Parts of a Good Presentation. Authored by : Nina Burokas. Provided by : Lumen Learning. License : CC BY: Attribution
- Modification of WIIFM. Authored by : Nathan Stephens. Located at : https://flic.kr/p/dEFKQS . License : CC BY-SA: Attribution-ShareAlike


36.3: The Naive and Delusional Farmer
After reading this passage, I wonder if this guy was actually as delusional as he sounds? Now a days you never really hear anything great about America anymore, at least not in the way this guy talked about our country. So to me, reading this was a bit strange, he was literally “gassing up” America. This sounds like a story about the American dream, in the eyes of Farmer James. This land is everything he dreamed of. But then towards the end of this passage, he starts to contradict himself and maybe, just maybe, may not feel as great about America as he did at first. Let’s look at some examples of why I think this man was kind of delusional. But I do respect his positivity and outlook on life…
“We have no princes, for whom we toil, starve, and bleed; we are the most perfect society now existing in the world” (19).
The use of the word “perfect” makes me feel uncomfortable for many reasons.
- There is literally no such thing as perfect
- The society was NOT perfect, there were lots of slavery, racism and more
- Many people starve, bleed and more in America as well.
This quote shows that when he first moves to America, he is baffled at how “perfect” it is. He loves this country and everything it stands for.
Another quote used in this text to highlight Farmer James’s thoughts on the country is, “The American is a new man, who acts upon new principles; he must therefore entertain ideas, and form new opinions” (21).
This quote right here represents how Farmer James feels towards the freedom and opportunities this country holds. He came from a country where everyone is ruled under a king and queen and there are only peasants who don’t have many opportunities. So as you can imagine, Farmer James is very impressed and excited about the new life he hopes to build for himself. He looks at America as a new and fresh beginning for him and his family.
How does Letters celebrate, construct, or consolidate a seemingly coherent and positive American national identity?
This book written by Farmer James, shows a lot of positivity towards the country and how amazing it is for all these new settlers. They are granted with so many options, new life styles, jobs, freedom and more. This passage nicely paints a picture of how much freedom America grants its people. It gives it an independent and strong identity, it shows how fortunate we Americans are, to have all this freedom and all these rights.
In what ways does it undermine or destabilize this national identity (even as it seems to celebrate it)?
By giving an unrealistic view of this country. At first James gives his readers a bias view on America. He only talks about the great things at first and how amazing this country is. But we need to remember, we are only seeing what THIS guy likes. We aren’t shown what other guys like Farmer James feel about America. They may not feel the same way as him or agree that it is a perfect society. The biased interpretation of this country is what destabilizes the national identity he tries to show his readers. We can’t believe only one side of a story. Or believe what just one person says.
And ironically, at the end of this passage, James concludes that he still loves this country other than, sharing land with Native Americas, racism/slavery and the war. The more he lives in America, he realizes it isn’t as perfect as it’s made out to be/how he believed it to be.
I almost feel bad for this guy, he was so hyped up about America and his new journey in life, only to realize his beloved country isn’t as great as it seems to be. The first time he starts to realize this is when he runs into the slave inside the cage while walking through the woods. We see Farmer James’s compassion and kindness towards the slaves when he tries to help this poor guy. “…with trembling hands I guided it to the quivering lips of the wretched sufferer” (31). This tragic event that James had to witness was probably when he finally understood, America isn’t as great as it seemed to be.
Poor James.


3.2: Naming binary ionic compounds
Binary ionic compounds are compounds composed of monoatomic cations and monoatomic anions. For example, NaCl is a binary ionic compound composed of monoatomic cations Na + and monoatomic anions Cl - . Another example is CaCl 2 composed of monoatomic cations Ca 2 + and monoatomic anions Cl - .
Charge on monoatomic ions
Nonmetals and metalloids of group 14 to group 17 usually form monoatomic anions. The charge on the anions is equal to the group number minus eighteen. For example, halogens in group 17 have charge: 17-18 = -1, oxygen in group 16 has charge: 16-18 = -2, and nitrogen in group 15 has charge: 15-18 = -3. Metals usually form cations: metals of group 1 from +1, metals of group 2 form +2, and aluminum of group 13 form +3 charge on cations, as shown in Fig. 3.2.1. Other metals have variable charges in compounds. The charge of the metals having variable charge can be calculated from the compound's chemical formula because the total –ve charge should be equal to the total +ve charge to make the compound neutral.
calculate the charge of iron ion in FeCl 2 ?
Solution
Three are two chloride anions, each with a -1 charge, making a total of -2. So the charge on cation has to be +2 to balance the negative charge. Answer: Fe 2 + .
Calculate the charge on an iron ion in Fe 2 O 3 ?
Solution
There are three oxygen anions, each with a -2 charge, making -6. So the total charge on two iron atoms should be +6, i.e., the charge on iron atoms is +3. Answer: Fe 3 + .
Names of monoatomic ions
Name of a monoatomic anion
The name of a monoatomic anion is the element's name with the last syllable replaced with –ide ion. For example, Cl - is a chloride ion, O 2- is an oxide ion, N 3- is a nitride ion, S 2- is sulfide ion, and C 4- is a carbide ion, derived from the element names chlorine, oxygen, nitrogen, sulfur, and carbon, respectively.
Name of a monoatomic cation having a fixed charge
Alkali metals have +1, alkaline earth metals have +2, and aluminum has +3 charge. Their name is the name of the element ending with ion. For example, Na + is a sodium ion, Ca 2 + is a calcium ion, and Al 3 + is an aluminum ion.
Name of a monoatomic cation having a variable charge
The names of the cations that have a variable charge is the name of the element followed by charge in roman numeral enclosed in small bracts and ending with ion. For example, Fe 2 + is an iron(II) ion, and Fe 3 + is an iron(III) ion, Cu + is a copper(I) ion, and Cu 2 + is a copper(II) ion.
The ions that are important in body fluids include sodium ion (Na + ), potassium ion (K + ), calcium ion (Ca 2 + ), magnesium ion (Mg 2 + ), and chloride ion (Cl - ), as shown in Fig. 3.2.2. Na + is present in fluids inside the cells. It regulates and controls body fluids. K + is present in fluids outside the cells and regulates body fluids and cell functions. Ca 2 + and Ma 2 + are present in the body fluids outside the cells, where Ca 2 + is needed for muscle contraction, Mg 2 + is needed for muscle contraction, nerve control, and enzymes. Cl - is primarily present to balance the charge of the cations in the body fluids.
Writing the formula of a binary ionic compounds
The formula of an ionic compound is the symbol of the cation element with a subscript number followed by the symbol of the anion element with a subscript number. The formula shows the simplest whole-number ratio of the constituent elements in the subscripts, such that the total positive charge is equal to the total negative charge.script on the right of the symbols tell the number if they're more than one atom of the element.
The rules are illustrated in Fig. 3.2.3:
- Write cation followed by anion with charges,
- swap the charge as a subscript of the opposite ion,
- simplify the subscript to the simplest whole-number ratio,
- use the simplified subscript in the final formula, and
- do not write the subscript if it is one.
Writing the names of an ionic compound from the formula
Writing the name of ionic compounds of cations with fixed charge
If the cation has a fixed charge in compounds, the name starts with the name of the element of the cation, followed by the name of the anion without the world ion at the end. For example, KI is potassium iodide, and CaCl 2 is calcium chloride.
Writing the name of ionic compounds of cations with variable charge
Write the name of the cation, including the charge in roman numerals enclosed in small brackets but without the word ion at the end, followed by the name of the anion, without ion at the end. For example, FeCl 2 is iron(II) chloride, and Fe 2 O 3 is iron(III) oxide. Additional examples are given in Table 1.
Silver, zinc, and cadmium cations have fixed changes: Ag + , Zn 2 + , and Cd 2 + . Names of these cations are the names of the element with or without charge shown in roman numerals, both ways it is correct.
| Example# | Formula | Name of the cation | Name of the anion | Name of the compound |
|---|---|---|---|---|
| 1 | NaCl | Sodium ion | Chloride ion | Sodium chloride |
| 2 | Al 2 O 3 | Aluminum ion | Oxide ion | Aluminum oxide |
| 3 | FeCl 3 | Iron(III) ion | Chloride ion | Iron(III) chloride |
| 4 | CuO | Copper(II) ion | Oxide ion | Copper(II) oxide |
| 5 | AgCl |
Silver(I) ion, or Silver ion |
Chloride ion |
Silver(I) chloride, or Silver chloride |


2.4: Expected Versus Unexpected Findings
Table \(\PageIndex{1}\)a compares expected and unexpected findings when performing a general survey assessment. These findings are included in documentation regarding the general survey assessment.
| Assessment | Expected Findings | Unexpected Findings (notify provider if a new finding*) |
|---|---|---|
| Signs of distress | No signs of distress | Unresponsive, difficulty breathing, confused, moaning, or grimacing |
| Mood and appearance |
Calm and cooperative
Responds appropriately to questions Appears stated age |
Mood is depressed, anxious, or agitated
Signs of suspected substance use disorder are present, such as the scent of alcohol |
| Orientation | Alert and oriented to person, place, and time | Unable to provide name, location, or day |
| Hygiene | Well groomed. Clothing is appropriate for weather | Unkempt appearance or inappropriate clothing according to the weather |
| Family dynamics | Family members demonstrate mutual respect, trust, and caring |
Family members communicate in an unfriendly, disrespectful, or hostile manner
Signs of suspected abuse are present |
| Speech and communication | Speech is clear and understandable; patient follows instructions appropriately | Speech is garbled or difficult to understand; unable to respond appropriately to questions or follow commands |
| Range of motion | Moves all extremities equally bilaterally with good posture | New facial drooping or altered/unequal movement of extremities |
| Mobility | Gait is smooth and even and can maintain balance without assistance. If present, assistive devices are used appropriately and this is documented | Gait is shuffling, staggering, or limping. Balance is impaired; assistive devices like a cane or walker are not used appropriately |
| Nutrition | BMI within normal range | BMI out of range. Unexplained weight loss or gain has occurred |
| Fluid status | Moist mucous membranes | Dry skin and dry mucous membranes; sunken eyes in adults; sunken fontanel in infants |
| CRITICAL CONDITIONS to report immediately: | Newly unresponsive or altered mental status; difficulty breathing; vital signs out of range; skin is cool, clammy, or cyanotic |


6.2: Courses Dashboard - Viewing and Accessing Course Assignments
Assignments
When you log into ADAPT, you are taken to the “My Courses” dashboard, where you should see the courses you have registered for. You can navigate to a course by clicking on the course title, which takes you to the Course dashboard. In the course dashboard (See Figure 6.2.1), you will see:
- Assignments
- Group – the course grade category
- Available from – the date the assignment is available
- Due – due date
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Status – Indicates information about the assignment:
- Upcoming – the assignment isn’t available.
- Open – The assignment is open, and you can submit responses.
- Late - You may still submit responses, but there may be a late penalty.
- Closed - The assignment is past due, and you may no longer submit responses. However, you can still view the questions.
- Submitted – shows you the number of questions you have submitted for an assignment.
- Score
- Z-Score
You can filter the assignments in your course dashboard by using the drop-down menus under the course name (See (Figure \(\PageIndex{1}\))). You can also sort your view by clicking the up or down triangle to the left of the criteria you want to sort: group, available from, due, statut, and submitted.
Assignment Information
Clicking on an assignment title in the Course dashboard brings you to the assignment, where you will see the assignment information and questions. The assignment information includes the following:
- A description of the assignment
- Total number of points
- Number of questions
- Allowed attempts
- Assignment due date
- Late policy and final submission date.
The question information provided in the assignment includes the questions, date and time of your last submissions, question points, score, and solution (if available).
Types of Assignments
ADAPT is an online homework platform with a variety of assignment types, with each type representing a different assessment style and ways you will submit answers. The four general assignments in ADAPT are Real Time Graded, Delayed Grading, Learning Tree, or Clicker Assessments.
Here is a brief description of each assignment type:
- Real Time: Real-time assessments generally contain automatically graded questions and provide instant feedback about whether your submission was correct.
- Delayed Graded: these assignments generally contain questions that require extra grading by your instructor and will not provide immediate feedback once you’ve submitted a response. You will not see a grade for these assignments until the instructor releases them.
- Learning Tree: a learning tree assignment contains real-time graded (auto-graded) questions with targeted support materials to help you learn how to solve the problem.
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Clicker Assignments: these assignments are often used in class to get feedback about your learning. They can be automatically graded, and you will receive instructions from your instructor about how to interact with these assignments.


5.4: Mobile Learning - A Tentative Step Towards Utopia?
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During Spring 2007, I was invited to the 16th International World Wide Web Conference in Banff, Canada. I was there to take part in two separate tracks, although the topic was the same—how the mobile phone might help close the digital divide in the developing world. My talk on the first day was more general, discussing the delivery of targeted information—health messages, wildlife alerts, or market prices, for example—via text message (SMS)—and the importance of understanding the complex cultural issues which surround technology adoption in places like sub-Saharan Africa, where I have done most of my conservation, development and technology work. On the second day I sat on an expert panel discussing something a little more specific—access to the Internet via mobile devices under the conditions faced by a developing country.
I started my panel discussion with a short description of what I considered to be Utopia, the ideal conditions under which we’d all like to be working. It went something like this: “Everybody, everywhere wirelessly communicating and accessing a whole range of personally relevant information whenever they like, using a wide variety of compatible devices at high speed and low cost.”
This, of course, isn’t realistic anywhere, let alone in many developing countries, at least not yet. But the specific problems of web delivery in these places are not dissimilar to those faced by anyone looking to work with mobile technologies in the developing world. And, as you would expect, the m-learning community is not exempt. Ageing handsets, limited functionality, lack of bandwidth, issues of literacy and cost are just some of the barriers, and there are many. It is these barriers that I propose to discuss a little later in this chapter.
But for now let’s imagine that we are living in Utopia and almost anything is possible. The sky’s the limit! What would that look like? Given a high-end mobile device—mobile phones, personal digital assistants (PDAs), pocket PCs, and even things like iPods—what could we do? More to the point, what would students require it to do to make their learning experience more engaging, enjoyable, and productive, assuming these are key objectives? Would their mobile learning experience be largely based on video lectures? Collaboration with other students via online blogs and wikis? Playing games and “learning by doing”? Schooling in a virtual world with virtual classmates, teachers and desks? Pitting students against one another through online spelling and math competitions? Mobile-delivered examinations? All of these? More?
Some of these things, of course, are already happening. The University of California in Berkeley recently began posting entire lectures on YouTube and, of course, YouTube content is accessible via mobile devices. A lecturer at Bradford University in the UK early last year went as far as abolishing traditional lectures altogether in favour of podcasts, in his words “freeing up more time for smaller group teaching”. And children can learn to count, spell or even play guitar using Javabased mobile games, downloadable from the Internet or directly onto their phones via a carrier portal.


5.11: Hellenistic Period
Historians today consider the death of Alexander to be the end point of the Classical Period and the beginning of the Hellenistic Period. That moment, for historians, also marks the end of the polis as the main unit of organization in the Greek world. While city-states continued to exist, the main unit of organization from that point on was the great Hellenistic kingdoms. These kingdoms, encompassing much greater territory than the Greek world had before Alexander, contributed to the thorough Hellenization of the Eastern Mediterranean and the Middle East. The age of the Hellenistic kingdoms also coincided with the rise of Rome as a military power in the West. Ultimately, the Hellenistic kingdoms were conquered and absorbed by Rome.
Hellenistic Kingdoms
Although Alexander had several children from his different wives, he did not leave an heir old enough to take power upon his death. Indeed, his only son, Alexander IV, was only born several months after his father’s death. Instead, Alexander’s most talented generals turned against each other in a contest for the control of the empire that they had helped create.
These Wars of the Diadochi , as they are known in modern scholarship, ended with a partition of Alexander’s empire into a number of kingdoms, each ruled by dynasties. Of these, the four most influential dynasties which retained power for the remainder of the Hellenistic Age, were the following: Seleucus, who took control of Syria and the surrounding areas, thus creating the Seleucid Empire ; Antigonus Monophthalmos, the One-Eyed, who took over the territory of Asia Minor and northern Syria, establishing the Antigonid Dynasty ; the Attalid Dynasty, which took power over the Kingdom of Pergamon , after the death of its initial ruler, Lysimachus, a general of Alexander; and Ptolemy, Alexander’s most influential general, who took control over Egypt, establishing the Ptolemaic Dynasty .
The most imperialistic of Alexander’s successors, Seleucus I Nicator took Syria, swiftly expanding his empire to the east to encompass the entire stretch of territory from Syria to India. At its greatest expanse, this territory’s ethnic diversity was similar to that of Alexander’s original empire, and Seleucus adopted the same policy of ethnic unity as originally practiced by Alexander; some of Seleucus’ later successors, however, attempted to impose Hellenization on some of the peoples under their rule. These successors had difficulties holding on to Seleucus’ conquests. A notable exception, Antiochus III, attempted to expand the Empire into Anatolia and Greece in the early second century BCE but was ultimately defeated by the Romans. The empire’s story for the remainder of its existence is one of almost constant civil wars and increasingly declining territories. The Seleucids seem to have had a particularly antagonistic relationship with their Jewish subjects, going so far as to outlaw Judaism in 168 BCE. The Jewish holiday Hannukah celebrates a miracle that occurred following the historical victory of the Jews, led by Judah Maccabee, over the Seleucids in 165 BCE. Shortly afterwards, the Seleucids had to allow autonomy to the Jewish state; it achieved full independence from Seleucid rule in 129 BCE. In 63 BCE, the Roman general Pompey finally conquered the small remnant of the Seleucid Empire, making it into the Roman province of Syria.
Antigonus Monophthalmos, Seleucus’ neighbor, whose holdings included Macedonia, Asia Minor, and the northwestern portion of Syria, harbored ambitious plans that rivaled those of Seleucus. Antigonus’ hopes of reuniting all of Alexander’s original empire under his own rule, however, were never realized as Antigonus died in battle in 301 BCE. The greatest threat to the Antigonids, however, came not from the Seleucid Empire, but from Rome with whom they waged three Macedonian Wars between 214 and 168 BCE. The Roman defeat of king Perseus in 168 BCE at the Battle of Pydna marked the end of the Third Macedonian War , and the end of an era, as control over Greece was now in Roman hands.
The smallest and least imperialistic of the successor states, the kingdom of Pergamon, was originally part of a very short-lived empire established by Lysimachus, one of Alexander’s generals. Lysimachus originally held Macedonia and parts of Asia Minor and Thrace but had lost all of these territories by the time of his death in 281 BCE. One of his officers, Philetaerus, however, took over the city of Pergamon, establishing there the Attalid dynasty that transformed Pergamon into a small and successful kingdom. The final Attalid king, Attalus III, left his kingdom to Rome in his will in 133 BCE.
Lasting from the death of Alexander in 323 BCE to the death of Cleopatra VII in 30 BCE, the Ptolemaic kingdom proved to be the longest lasting and most successful of the kingdoms carved from Alexander’s initial empire. Its founder, Ptolemy I Soter , was a talented general, as well as an astronomer, philosopher, and historian, who wrote his own histories of Alexander’s campaigns. Aiming to make Alexandria the new Athens of the Mediterranean, Ptolemy spared no expense in building the Museaum, an institution of learning and research that included, most famously, the Great Library , and worked tirelessly to attract scholars and cultured elite to his city. Subsequent Ptolemies continued these works so that Alexandria held its reputation as a cultural capital into Late Antiquity. One example of a particularly impressive scientific discovery is the work of Eratosthenes, the head librarian at the Great Library in the second half of the third century BCE, who accurately calculated the earth’s circumference. But while the Ptolemies brought with them Greek language and culture to Egypt, they were also profoundly influenced by Egyptian customs. Portraying themselves as the new Pharaohs, the Ptolemies even adopted the Egyptian royal custom of brother-sister marriages, a practice that eventually percolated down to the general populace as well. Unfortunately, brother-sister marriages did not prevent strife for power within the royal family. The last of the Ptolemaic rulers, Cleopatra VII, first married and ruled jointly with her brother Ptolemy XIII. After defeating him in a civil war, she then married another brother, Ptolemy XIV, remaining his wife until his death, possibly from sisterly poisoning. Best known for her affairs with Julius Caesar and, after Caesar’s death, with Marcus Antonius, Cleopatra teamed with Marcus Antonius in a bid for the Roman Empire. The last surviving ruler who was descended from one of Alexander’s generals, she was finally defeated by Octavian, the future Roman emperor Augustus, in 30 BCE.
The history of the successor states that resulted from the carving of Alexander’s empire shows the imperialistic drive of Greek generals, while also demonstrating the instability of their empires. Historians do not typically engage in counter-factual speculations, but it is very likely that, had he lived longer, Alexander would have seen his empire unravel, as no structure was really in place to hold it together. At the same time, the clash of cultures that Alexander’s empire and the successor states produced resulted in the spread of Greek culture and language further than ever before; simultaneously, it also introduced the Greeks to other peoples, thus bringing foreign customs—such as the brother-sister marriages in Egypt—into the lives of the Greeks living outside the original Greek world.
Hellenistic Culture
The Hellenistic kingdoms spread Greek language, culture, and art all over the areas of Alexander’s former conquests. Furthermore, many Hellenistic kings, especially the Ptolemies, were patrons of art and ideas. Thus the Hellenistic era saw the flourishing of art and architecture, philosophy, medical and scientific writing, and even translations of texts of other civilizations into Greek. The undisputed center for these advances was Alexandria.
Combining the practical with the ambitious, the Pharos , or Lighthouse, of Alexandria was one of the most famous examples of Hellenistic architecture and has remained a symbol of the city to the present day. Constructed in 280 BCE, it was considered to be one of the Seven Wonders of the Ancient World and was one of the tallest buildings in the world at the time. While its practical purpose was to guide ships into the harbor at night, it also exemplified the bold advances and experimental spirit of Hellenistic architecture. Indeed, it was located on a man-made mole off the coast of the city. The building comprised three layers, the top one of which housed the furnace that produced the light.
The structure of the Pharos shows an interest in straight lines and orderly shapes, while its function symbolized the ability of man to subdue the sea, even by night. Similarly, both the scientific and medical texts from the Hellenistic Period reveal a fascination with an ordered universe and an interest in discovering how it worked. Herophilus of Chalcedon , for instance, pioneered dissection in the early third BCE and was especially interested in the human brain and the nervous system. The mathematician Euclid, who lived and worked in Alexandria during the reign of Ptolemy I (323 – 283 BCE), wrote the Elements , an encyclopedic work of mathematics that effectively created the discipline of geometry. Going a step further than Euclid in his research, the third-century BCE scientist and inventor Archimedes of Syracuse specialized in applying mathematical concepts to create such devices as a screw pump and a variety of war machines, including the heat ray.
The same fascination with studying the order of the universe appears in Hellenistic philosophy and stems ultimately from the philosophy of Aristotle (384 – 322 BCE), considered to be the last Classical Greek philosopher. Aristotle was a prolific polymath, who wrote on political theory, poetry, music, and a variety of sciences, to list just some of his interests. Engrossed in seeing all disciplines as part of a larger world order, Aristotle specifically argued for empiricism, that is, the belief that knowledge is acquired from sensory experiences rather than from intuition. In the sciences, for instance, this approach required experiments and the careful gathering of data. While Aristotle’s influence on the Hellenistic philosophers is undeniable, the alternate theories that some of the philosophers developed regarding the structure of the universe and the place of humanity in it differs drastically from Aristotle’s view. For instance, Skepticism , especially as formulated by Pyrrho in the third century BCE, argued that it was impossible to reach any accurate conclusions about the world and the key to happiness was to stop trying. Cynic philosophers , starting in the fourth century BCE, advocated the ascetic life of simplicity and freedom from possessions. A related philosophy, Stoicism , argued for letting go of all emotions and developing a self-control that would allow one to live in accordance to nature. On the other hand, the third-century philosophy of Epicureanism argued for the absence of pain as the ultimate goal in life and saw the universe as ruled by random chance, separate from the intervention of the gods. All of these philosophies, and many others that co-existed with them, aimed to provide a coherent system that made sense of the world and provided a purpose for human life.
Finally, in a testament to the deep influence of the Hellenistic language culture on the conquered regions, the Hellenistic Period saw the translation of texts of other civilizations into Greek. One particularly influential example was the translation of the Hebrew Old Testament into Greek. Jews formed a significant minority of the population of Alexandria , the capital of Ptolemaic Egypt, as well as other major cities around the Mediterranean, such as Antioch. By the third century BCE, these Jews appear to have largely lost the knowledge of Hebrew; thus, a translation of the sacred texts into Greek was necessary. In addition, as later legend has it, Ptolemy II Philadelphus allegedly commissioned seventy-two scholars to translate the Old Testament into Greek for his Royal Library. Whether indeed solicited by Ptolemy II or not, the translation was likely completed over the course of the third throughfirst centuries BCE. Named after the legendary seventy-two (or, in some versions, seventy) translators, the text was titled the Septuagint . The completion of this translation showed the thorough Hellenization of even the Jews, who had largely kept themselves apart from mainstream culture of the cities in which they lived.


19: Urogenital System Infections
The urogenital system is a combination of the urinary tract and reproductive system. Because both systems are open to the external environment, they are prone to infections. Some infections are introduced from outside, whereas others result from imbalances in the microbiota of the urogenital tract.
Urinary tract infections (UTIs) are one the most common bacterial infections worldwide, affecting over 100 million people each year. During 2007 in the United States, doctor office visits for UTIs exceeded 10 million, and an additional 2–3 million emergency department visits were attributed to UTIs. Sexually transmitted infections (STIs) also primarily affect the urogenital system and are an important cause of patient morbidity. The Centers for Disease Control and Prevention (CDC) estimates that there are approximately 20 million new cases of reportable STIs annually in the United States, half of which occur in people aged 15–24 years old. When STIs spread to the reproductive organs, they can be associated with severe morbidity and loss of fertility.
Because males and females have different urogenital anatomy, urogenital infections may affect males and females differently. In this chapter, we will discuss the various microbes that cause urogenital disease and the factors that contribute to their pathogenicity.
Chapter Outline
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- 19.1: Bacterial Infections of the Reproductive System
- Gonorrhea is caused by N. gonorrhoeae, which can cause infection of the reproductive and urinary tracts and is associated with symptoms of urethritis. If left untreated, it can progress to epididymitis, salpingitis, and pelvic inflammatory disease and enter the bloodstream to infect other sites in the body.


8.11: Recording a Macro
Learning Objectives
- Use a macro to add a filter to column headers
- Use a macro to remove duplicates
- Use a macro to select blank rows
In business, you may have spreadsheets filled with data from different departments, divisions or even other companies requiring updating, reformatting or cleaning up on a regular basis. There are a few macros examples that help make this repetitive work easier.
These next spreadsheet actions are created from the View > Macros > Record macro path.
Adding Filters to Column Headers
Each quarter you receive a spreadsheet filled with information. To make it easier to sort data you’d like to add filters to each new spreadsheet. Here are the steps to follow to make a macro for this:
- Open worksheet > View > Macros > Record Macro
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In
Record Macro
dialogue box;
- Type in macro name with no spaces or by using _ to connect words (e.g. Filter_Macro).
- Create a shortcut key (optional). If you do choose one, make sure it isn’t Ctrl + C, Ctrl + V, or other already existing shortcut keys.
- Decide where to store the macro recording.
- Add a description (optional) to help identify the functions done by the macro and click OK . The macro is now recording.
- Highlight the entire row of column headers > Data tab > Filter button.
- Go back to View > Macros > Stop Recording . This macro is now available to use on the next set of data needing filters added.
- Run macro: To run the macro on the new set of data open the data, go to View > Macros > View Macros . A dialog box will open then select the macro for adding filters and click Run .
Watch this short video to see these tasks done in sequence and used on a fresh data set.
Remove Duplicates
Spreadsheet data is often filled with duplicate information and needs to be sorted through in order to be useful. For this example, a single list of the salespeople is needed from the large data set. To start recording the macro, follow the order in the example for recording above, then follow these steps:
- Highlight the column containing the Salesperson names. Right click > copy OR use Ctrl + C
- Open a new tab > select a cell > right click and paste OR Ctrl + V
- Click Data tab > Remove Duplicates button
- Go back to View > Macros > Stop Recording . This macro is now available to use on the next set of data needing duplicates reduced.
- Run macro: To run the macro on the new set of data open the data then go to View > Macros > View Macros . A dialog box will open, select the macro for removing duplicates and click Run .
Watch the short video to see these tasks done sequence and used on a fresh data set.
Selecting Blank Rows
Many times, a worksheet or data set is filled with blank rows that can stop a successful analysis of the data or cause errors in formulas. In order to clean up a data set with a macro, follow these steps.
Like with the other functions, open the spreadsheet and set up a macro for recording. An alternative way to quickly record is to select the record button at the bottom left corner of the Excel window to start.
- Create a new column > label it Empty (or another name). Make sure it has a filter added in the header.
- In the first cell, type in the function that counts how many values are in the list of arguments, that function is = COUNTA(B4:G4) your table range and press the Enter key.
- With the H4 cell highlighted, pull the corner down the entire column covering all the rows.
- Click filter arrow in “ Empty ” header and deselect “ All ” the select “ 0 ” and press OK .
- Select all the rows that are “ 0 ” > right click delete
- Click filter arrow in “ Empty ” header, then select Clear filter from “Empty” and data rows appear with no empty rows.
- Go back to View, Macros and Stop Recording . Alternatively, click the little square in the bottom left corner to stop the recording. This macro is now available to use on the next set of data needing duplicates reduced.
- Run macro: To run the macro on the new set of data open the data, go to View > Macros > View Macros . A dialog box will open, select the macro for selecting blank rows and click Run .
Watch the short video to see these tasks done in sequence and used on a fresh data set.
Practice Questions
Note
Unlike other actions, running a macro cannot be reversed with the Ctrl + Z (Cmnd+Z) short-cut or the Undo arrow so make sure you have a copy of the original data worksheet before running a macro for the first time.
Macros take a little practice to get used to, but once you use them more frequently, you will see the variety of things that a macro can accomplish. Remember, a macro allows you to record operations and re-use the sequence of mouse actions or keystrokes of anything you can do in Excel with keystrokes or a mouse. Start using them and see how far you can go.
Contributors and Attributions
- Recording a Macro. Authored by : Sherri Pendleton. Provided by : Lumen Learning. License : CC BY: Attribution