5.2: Sources for Californias Water
California's limited water supply comes from two main sources: surface water, or water that travels or gathers on the ground, like rivers, streams, and lakes; and groundwater, which is water that is pumped out from the ground. The primary contributor for these sources is rainfall and California’s snowpack. Because both surficial and ground water are becoming either unreliable or depleted, California has had to begin producing a small amount of desalinated water, water that was once sea water, but has been purified. As an example, Catalina Island’s water comes from combination of underground aquifers and a desalination plant. While that plant helps supplement the lack of natural water supply, Catalina is still unable to meet the annual water needs of the island – making a steady supply of rain essential.
Ground Water
Groundwater is a critical component for California’s water supply. During a normal year, 30% of the state's water supply originates from groundwater (underground water). In times of intense drought, groundwater consumption can rise to 60% or more. Over 850,000,000 acre-feet (276,973,717,105,760 gallons) of water is stored in California's 450 known groundwater reservoirs; however, not all the water is usable. California's water situation presents a complex challenge. Groundwater, despite its wider distribution compared to surface water concentrated in the north, faces significant limitations. Firstly, over half is unusable due to poor quality, potentially from natural minerals or accumulated pollutants. Secondly, centuries of rapid extraction have caused saltwater intrusion, contaminating remaining water with salt, and making it unsuitable for many uses. Finally, pumping groundwater, especially from deeper wells, can be expensive due to the high energy demands. These limitations highlight the need for a balanced approach to water management in California.
The largest groundwater reservoirs are found in the Central Valley. The majority of the supply there is in the form of runoff that seeps into the aquifer. Freshwater is usually found in deposits of gravel, silt, and sand. Below these deposits lies a layer of deep sediment, a relic of the era when the Pacific Ocean covered the area.
The large quantity of water beneath the surface has given rise to the misconception that groundwater is a sort of renewable resource that can be limitlessly tapped. Calculations assuming that groundwater usage is sustainable if the rate of removal equals the rate of recharge are often incorrect because of ignoring changes in water consumption and water renewal.
While the volume of groundwater in California is very large, aquifers can be over drafted when groundwater is removed more rapidly than it is replenished. Overdraft occurs where the average annual amount of groundwater extraction exceeds the long-term average annual supply of water to the basin. Effects of overdraft can include seawater intrusion, land subsidence, groundwater depletion, and/or chronic lowering of groundwater levels. In 1999, it was estimated that the average annual overdrafting was around 2,200,000 acre-feet (716,873,150,156 gallons) across the state, with 800,000 acre-feet (260,681,145,511 gallons) in the Central Valley. Since 1999, overdrafting has significantly increased, causing further strain and concern for California’s water storage. Satellite measurements found that in just the combined Sacramento and San Joaquin River basins, including the Central Valley, overdrafting between 2011 and 2014 was 12,000,000 acre-feet (3,910,217,182,669 gallons) of water per year… that is nearly 4 trillion gallons of water.
Groundwater-related subsidence is the subsidence (or the sinking) of land resulting from groundwater extraction. It is a growing problem in the developing world as cities increase in population and water use, without adequate pumping regulation and enforcement. One estimate has 80% of serious U.S. land subsidence problems associated with the excessive extraction of groundwater, making it a growing problem throughout the world.
Groundwater can be considered one of the last free resources, as anyone who can afford to drill can usually draw up merely according to their ability to pump (depending on local regulations). However, as seen in the figure, pumping-induced drawdown causes a depression of the groundwater surface around the production well. This can ultimately affect a large region by making it more difficult and expensive to pump the deeper water. Thus, the extraction of groundwater becomes a tragedy of the commons, with resulting economic consequences.
The arid areas of the world are requiring more and more water for growing populations and agriculture. In the San Joaquin Valley of California, groundwater pumping for crops has occurred for generations. This has resulted in the entire valley sinking an extraordinary amount, as much as 28 feet, as shown in figure 5.2. This has not come without consequences. Any large-scale change of topography, no matter how slight it may seem, has the potential to drastically change the surface-water hydrology. This has happened in the Joaquin Valley and other regions of the world, such as New Orleans and Bangkok.
Surficial Water
California has ten major drainage basins defined for convenience of water management. These basins are divided from one another by the crests of mountains. From north to south the basins are: North Coast, Sacramento River, North Lahontan, San Francisco Bay, San Joaquin River, Central Coast, Tulare Lake, South Lahontan, South Coast, and Colorado River regions. Each region incorporates watersheds from many rivers of similar clime. Many of the drainage basins are extremely altered, with hydroelectric power generation happening in much of the upper portion of these watersheds.
The Central Valley watershed, which incorporates the Sacramento River, San Joaquin River, and Tulare Lake regions, is the largest in California, draining over a third of the state – 60,000 square miles (160,000 km2) – and producing nearly half the total runoff. The Sierra Nevada snowpack feeds Central Valley River systems and is a critical source of water in the state's long dry season when little if any precipitation falls. Up to 30 percent of California's water supply is from snowpack, and most of the California's hydroelectricity is also generated from the Sierra Nevada snowpack. More generally, in the US one of the largest uses of fresh water is withdrawal for the energy sector. Much of California's extensive reservoir and aqueduct system is designed to store and capture runoff from the Central Valley watershed. As this infrastructure ages, dam removal in California has become more widespread—a process that has been largely successful. The Sacramento and San Joaquin Rivers converge at the Sacramento–San Joaquin River Delta, a large fresh-water estuary where much of the state's water supply is withdrawn. The Central Valley watershed provides most of the water for Northern and Central California, as well as a significant chunk of Southern California's usage.
A proposed project by the Project Authority aims to divert water from the Sacramento River, upstream of the Delta, for storage in a new reservoir located 14 miles away. Existing canals would be used to transport the water. Construction is tentatively scheduled to begin in mid-2024, with operations targeted to start by 2030. The estimated cost of $3.9 billion would be funded through a combination of local, state, and federal public money. Significantly, the project has already secured funding from California's Proposition 1 water bond ($816 million) and the U.S. Department of Agriculture ($449 million). The U.S. Bureau of Reclamation is also a key partner.
The new reservoir would be incorporated into the existing California State Water Project (SWP). While economic benefits are estimated around $260 million annually, operation costs are projected to be between $10 million and $20 million. Based on a "beneficiary pays" principle, approximately 30 public water agencies, irrigation districts, counties, and cities in California have expressed tentative financial commitment to the project.
The North Coast watershed receives the highest annual precipitation of any California watershed. It incorporates many large river systems such as the Klamath, Smith, Trinity, and Eel, and produces over a third of the runoff in the state. With the notable exceptions of the Trinity Dam complex that transfers water from the Trinity River into the Sacramento River and Scott Dam that transfers water from the Eel River into the Russian River, most of the North Coast watersheds are relatively undeveloped, some have federal Wild and Scenic status that protect them from development; the northern coastal rivers provide water for salmonid habitat, carbon-sequestering forests, and local communities; some are within the influence of tribal water and fishing rights. Water flowing in these watersheds and into the Pacific Ocean is critical for sensitive, threatened, and endangered salmonids. There have been proposals to create additional inter-basin transfers from North Coast rivers to increase water supplies in the rest of California, but these projects have been rejected due to presumed environmental harm.
The Colorado River originates more than 1,000 miles (1,600 km) from California in the Rocky Mountains of Colorado and Wyoming and forms the state's southeastern border in the Mojave Desert. Unlike the other California watersheds, essentially all the water flowing in the Colorado River originates outside the state. The Colorado River is a critical source of irrigation and urban water for southern California, providing between 55 and 65 percent of the total supply.
The Central and South Coast watersheds include the most populous regions of California – the San Francisco Bay Area, Los Angeles, and San Diego – but have relatively little natural runoff, requiring the importation of water from other parts of the state.
Rivers of the Lahontan watersheds in eastern California are part of the high desert Great Basin and do not drain to the Pacific. Most of the water is used locally in eastern California and western Nevada for irrigation. The Owens River of the South Lahontan region, however, is a principal source of water for Los Angeles.
|
Hydrologic Region |
Annual Precipitation |
Annual Runoff |
|---|---|---|
|
North Coast |
55,900,000 acre-feet (69.0 km 3 ) |
28,900,000 acre-feet (35.6 km 3 ) |
|
Sacramento River |
52,400,000 acre-feet (64.6 km 3 ) |
22,400,000 acre-feet (27.6 km 3 ) |
|
North Lahontan |
6,000,000 acre-feet (7.4 km 3 ) |
1,900,000 acre-feet (2.3 km 3 ) |
|
San Francisco Bay |
5,500,000 acre-feet (6.8 km 3 ) |
1,200,000 acre-feet (1.5 km 3 ) |
|
San Joaquin River |
21,800,000 acre-feet (26.9 km 3 ) |
7,900,000 acre-feet (9.7 km 3 ) |
|
Central Coast |
12,300,000 acre-feet (15.2 km 3 ) |
2,500,000 acre-feet (3.1 km 3 ) |
|
Tulare Lake |
13,900,000 acre-feet (17.1 km 3 ) |
3,300,000 acre-feet (4.1 km 3 ) |
|
South Lahontan |
9,300,000 acre-feet (11.5 km 3 ) |
1,300,000 acre-feet (1.6 km 3 ) |
|
South Coast |
10,800,000 acre-feet (13.3 km 3 ) |
1,200,000 acre-feet (1.5 km 3 ) |
|
Colorado River |
4,300,000 acre-feet (5.3 km 3 ) |
200,000 acre-feet (0.25 km 3 ) |
Figure 5.4: California’s Main Watersheds & Annual Precipitation/Runoff Rates. [5]
Rain & Snowfall
Rain typically falls in California mostly during the winter and spring months, from October through May, with more rain falling on the northern half of the state than the southern. Approximately 75 percent of the total precipitation volume occurs north of Sacramento, while 75 percent of the total water demand is in the south. With very rare exceptions, summers are dry throughout the state. Precipitation falling as snow in the Sierra and other mountain ranges feeds the network of reservoirs and surface water sources that supply the state; a low rainfall or light snowfall year can result in drought.
Rivers in northern and coastal California are mainly rain fed, peaking from January to April and falling to very low levels between June and November. Snowmelt has a significant influence on the Sierra Nevada rivers from east of Sacramento to east of Bakersfield, which typically peak between April and July. Snowmelt is also the primary water source for the Colorado River which supplies southern California.
Annual precipitation in California is highly variable, with a statewide average of 22.9 inches (58.2 cm) of precipitation per year. However, recorded precipitation totals can fluctuate heavily from year to year because of atmospheric conditions and climate change. El Niño–Southern Oscillation often has a significant effect on the state's precipitation, with generally higher precipitation during El Niño periods. In addition, climate change has impacted California's precipitation patterns in recent years with effects including more rapid snowmelt, more frequent heatwaves, and drier conditions across the state. California precipitation and snowpack are measured by the state of California by "water year", which runs from October 1 to September 30.
From late 2022 through spring 2024, California experienced a relentless barrage of atmospheric rivers. These concentrated bands of moisture in the atmosphere unleashed record-breaking rainfall, causing widespread problems. Excessive rain overwhelmed rivers and streams, triggering extensive flooding in the Central Valley, Salinas Valley, and the Santa Cruz Mountains.
Desalinization
In response to water shortages in the state, some water districts are looking to desalination to provide water for residents. Supporters view seawater desalination as a more reliable water source, since it draws its water from the ocean and thus, is not affected by periods of drought like other sources of water are. Another incentive for desalination is the ability for localities to be more self-sufficient with their water supply, thus improving their drought resilience. However, desalination has been the subject of scrutiny by opponents, who believe that the costs and possible environmental effects of desalination are indicators that California should continue to pursue other alternatives.
Below is a photo of the desalination plants on Catalina Island, which produce 40% of the island’s drinking water.
Although the response to desalination has been mixed, some areas of California are moving forward with seawater desalination. As an example, in December 2015, Poseidon Water completed the construction of the Claude "Bud" Lewis Carlsbad Desalination Plant, in Carlsbad California. This facility, which was approved by the San Diego Water Authority, is responsible for providing water for about 8% of San Diego County's water by the year 2020. The facility cost $1 billion to build and is the largest desalination facility in the Western Hemisphere producing up to 50 million gallons (190,000 m3) of water per day. This plans also uses approximately 35 megawatts (MW) to produce 50 million gallons of water per day. This translates to roughly 246,156 megawatt hours (MWh) of electricity used per year. As of December 2015, there are 6 additional seawater desalination plants currently in operation in the state of California. As of 2022, there are 12 active desalination plants.
[1] Image by Wikimedia is licensed under a CC-BY-SA 4.0 license .
[2] Image by Wikimedia is licensed under a CC-BY-SA 4.0 license .
[3] Image by Wikimedia is licensed under a CC-BY-SA 4.0 license .
[4] Graphic by Jeremy Patrich
[5]
[6]


36.4: Bisphosphonates, Calcium Preparations, Vitamin D, and Estrogen Receptor Modulators
By the end of this section, you should be able to:
- 36.4.1 Identify the characteristics of bisphosphates, calcium, vitamin D, and estrogen receptor modulator drugs used to treat osteoporosis.
- 36.4.2 Explain the indications, actions, adverse reactions, and interactions of bisphosphates, calcium, vitamin D, and estrogen receptor modulator drugs used to treat osteoporosis.
- 36.4.3 Describe nursing implications of bisphosphates, calcium, vitamin D, and estrogen receptor modulator drugs used to treat osteoporosis.
- 36.4.4 Explain the client education related to bisphosphates, calcium, vitamin D, and estrogen receptor modulator drugs used to treat osteoporosis.
Bisphosphonates, calcium preparations, vitamin D, and estrogen receptor modulators may seem out of context in this chapter; however, they are included because of their effects on postmenopausal clients who no longer produce sufficient estrogen and are at increased risk of osteopenia and osteoporosis. Osteopenia is a condition in which bone mass is decreased, causing bones to become weaker. Osteoporosis is a condition in which bone mass has decreased to the point that bones become brittle and are much more likely to fracture (Fink, 2019; Zareef & Jackson, 2021; National Institutes of Health, 2022).
(See Thyroid and Parathyroid Disorder Drugs for more information regarding bisphosphonates, calcium preparations, and vitamin D.)
Bisphosphonates
Bisphosphonates are a category of drugs used to prevent and treat osteoporosis in postmenopausal clients. Vitamin D and calcium may be used as an adjunct with bisphosphonate therapy. Weight-bearing exercises, such as walking for 30 minutes several days a week, should be included as part of client education. Routine bone density testing should be scheduled to determine the effectiveness of the drug therapy (Ganesan et al., 2022).
Table 36.16 lists common bisphosphonates and typical routes and dosing for adult clients.
| Drug | Routes and Dosage Ranges |
|---|---|
|
Alendronate
( Fosamax ) |
10 mg orally once daily or 70 mg orally once weekly. |
|
Ibandronate
( Boniva ) |
Oral:
150 mg once monthly.
IV: 3 mg every 3 months. |
|
Risedronate
( Actonel ) |
5 mg orally once daily, or 35 mg once weekly, or 150 mg once monthly. |
|
Zoledronic acid
( Reclast ) |
5 mg IV once every 12 months or 24 months for treatment of osteoporosis. |
Adverse Effects and Contraindications
Adverse effects of bisphosphonates include decreased serum calcium and serum phosphate levels, arthralgia, myalgia, stomach pain, difficulty swallowing, heartburn, and irritation or pain of the esophagus. One major adverse effect from bisphosphonate therapy is osteonecrosis of the jaw (Madhumati & Gonegandla, 2020). The bisphosphonate accumulates in the jaw at a higher rate than in other bones and causes increased new bone formation. As a result, the older bone lacks sufficient blood supply and begins to die or become necrosed. This complication occurs more often in clients with cancer and in those who have invasive dental procedures. Thus, invasive dental procedures should not be performed while a client is receiving bisphosphonates.
Contraindications to bisphosphonates include any esophageal abnormality that prevents adequate and timely emptying of the stomach. Additionally, bisphosphonates should not be used if the client is unable to sit up or stand for at least 30 minutes after taking the medication, to reduce the risk of esophageal irritation. Severe renal insufficiency is another instance where bisphosphonates should not be used.
Table 36.17 is a drug prototype table for bisphosphonates featuring alendronate. It lists drug class, mechanism of action, adult dosage, indications, therapeutic effects, drug and food interactions, adverse effects, and contraindications.
|
Drug Class
Bisphosphonates Mechanism of Action Inhibits normal and abnormal bone resorption |
Drug Dosage
10 mg orally once daily or 70 mg orally once weekly (may vary depending on indication). |
|
Indications
Prevention and treatment of osteoporosis in postmenopausal clients For the treatment of osteoporosis in males, Paget’s disease, and glucocorticoid-induced osteoporosis Therapeutic Effects Increases bone density |
Drug Interactions
Calcium Antacids Aspirin Nonsteroidal anti-inflammatory drugs (NSAIDs) Food Interactions No significant interactions unless food or beverages (except water) are taken within 30 minutes of drug Avoid orange juice for at least 2 hours after taking |
|
Adverse Effects
Decreased serum calcium and serum phosphate levels Arthralgia Myalgia Stomach pain Difficulty swallowing Heartburn Irritation or pain of the esophagus Osteonecrosis of the jaw |
Contraindications
Esophageal abnormalities that prevent adequate and timely emptying of the stomach Inability of client to sit up or stand for at least 30 minutes after taking the medication (to reduce risk of esophageal irritation) Severe renal insufficiency |
Calcium Preparations
Calcium, the most abundant mineral in the body, is necessary for bone development and bone maintenance. In fact, about 98% of the body’s calcium is stored in the bones. Calcium from food and supplements is absorbed by both active transport and passive diffusion across the intestinal mucosa. Vitamin D is essential for calcium absorption and for maintaining adequate calcium levels. Estrogen is also important for maintaining bone health; thus, during menopause when females produce less estrogen, they have a considerable risk of developing osteopenia and osteoporosis (National Institutes of Health, 2022).
Food sources of calcium include dairy, salmon, dark green vegetables (broccoli, kale, spinach), and other foods with high levels of oxalic acid such as sweet potatoes, rhubarb, and beans. Calcium supplements vary widely as to their source and the amount of calcium contained in the tablets (National Institutes of Health, 2022).
Calcium supplements include calcium acetate , calcium citrate , calcium gluconate , and calcium chloride . Calcium supplements used to treat osteoporosis and osteopenia are administered orally; dosages depend on the specific type of calcium supplement being prescribed and the reason for its use. Calcium carbonate and calcium citrate are the two most common forms of calcium used in supplements. Calcium has varying rates of absorption depending on the specific supplement, an individual’s level of stomach acid, and the fat content in a meal eaten when a calcium supplement is taken. The greater the fat content, the less calcium is absorbed. Calcium gluconate and calcium chloride are administered intravenously and used for serious and life-threatening acute hypocalcemia, hyperkalemia, and certain cardiac emergencies. See Fluids and Electrolytes, Vitamins, Minerals, and Alternative Therapies for more information about calcium and Vitamin D.
Adverse Effects and Contraindications
Adverse effects of calcium supplements are usually GI related and include abdominal pain, gas, bloating, constipation, and nausea. Hypercalcemia can lead to poor muscle tone, renal insufficiency, weight loss, fatigue, polyuria, and heart arrhythmias.
Contraindications and precautions are necessary depending on the client’s chronic diseases and other medications being taken. Clients with heart disease and renal disease may need closer monitoring of calcium levels. Calcium supplements generally decrease stomach acid necessary for the metabolism and absorption of other medications. Levothyroxine is one example; it should be taken at least 30 minutes prior to or 2 hours after calcium. So a complete medication history is important in planning calcium supplementation.
Vitamin D
Along with calcium supplements, vitamin D should be taken either as a separate supplement or included in the calcium supplement. The best source of vitamin D is sunlight. The appropriate amount of time for sun exposure is determined by the skin type based on Fitzpatrick’s skin typing, which ranges from I (fair skin that burns easily) to VI (skin that is always tan) (National Institutes of Health, 2022; Sakamoto, 2019; Zareef & Jackson, 2021). The use of sunscreen during sun exposure is controversial as far as the effect on vitamin D; however, the client should take care to avoid sunburn (AIM at Melanoma Foundation, n.d.).
Other sources of vitamin D include fatty fish (such as trout, salmon, tuna, and mackerel) and fish liver oils and fortified foods such as milk and cereals (National Institutes of Health, 2022).
Estrogen Receptor Modulators
Estrogen receptor modulators (ERMs) are not hormones. They are estrogen receptor site agonists or antagonists. ERMs possess some of the positive effects of estrogen and have fewer adverse effects. Raloxifene and toremifene are the drugs discussed in this section.
Raloxifene
Raloxifene is used to prevent and treat postmenopausal osteoporosis by increasing bone density. Contraindications include allergy, pregnancy, and lactation. Caution should be used for clients with a history of deep vein thrombosis and/or smoking because of the risk of clot development. Adverse effects are like those of estrogen and can include skin rash and edema. Raloxifene dosage is 60 mg daily orally.
Table 36.18 is a drug prototype table for estrogen receptor modulators featuring raloxifene . It lists drug class, mechanism of action, adult dosage, indications, therapeutic effects, drug and food interactions, adverse effects, and contraindications.
|
Drug Class
Estrogen receptor modulator Mechanism of Action Binds to estrogen receptors with either activation of estrogenic pathways (agonism) or blockade of estrogenic pathways (antagonism) |
Drug Dosage
60 mg orally once daily. Supplemental calcium and/or vitamin D should be added to the diet if daily intake is inadequate. |
|
Indications
Prevention and treatment of osteoporosis in postmenopausal clients Therapeutic Effects Increases bone density |
Drug Interactions
Cholestyramine Warfarin Systemic estrogens Use with caution with certain other highly protein-bound drugs such as diazepam, diazoxide, and lidocaine Food Interactions No significant interactions |
|
Adverse Effects
Venous thromboembolism Skin rash Edema Hot flashes Leg cramps Nausea Arthralgia Rhinitis |
Contraindications
Allergy Pregnancy and lactation History of deep vein thrombosis, pulmonary embolism, or retinal vein thrombosis and/or smoking because of the risk of clot development |
FDA Black Box Warning
Raloxifene
Raloxifene may cause increased risk of venous thromboembolism and death from stroke in clients with a history of venous thrombosis, documented coronary heart disease, or at increased risk for major coronary events.
Toremifene
Toremifene is used to treat clients who have estrogen receptor–positive advanced breast cancer. Toremifene works by binding to estrogen receptors, which prevents cancer cells from developing. Contraindications include allergy to the drug, pregnancy and lactation, and hypercalcemia. Caution must be used in prescribing toremifene to clients with renal or hepatic dysfunction or bone marrow suppression. Adverse effects are like menopausal symptoms, which were discussed in Review of the Female Reproductive System.
Table 36.19 is a drug prototype table for estrogen receptor modulators featuring toremifene . It lists drug class, mechanism of action, adult dosage, indications, therapeutic effects, drug and food interactions, adverse effects, and contraindications.
|
Drug Class
Estrogen receptor modulator Mechanism of Action Binds to estrogen receptors, which prevents cancer cells from developing |
Drug Dosage
60 mg orally once daily. Supplemental calcium and/or vitamin D should be added to the diet if daily intake is inadequate. |
|
Indications
Treatment for female clients who have estrogen receptor–positive advanced breast cancer Therapeutic Effects Prevents cancer cells from growing and spreading |
Drug Interactions
Thiazide diuretics Drugs that prolong QT interval (quinidine, procainamide, disopyramide, amiodarone, sotalol, ibutilide, dofetilide) Strong CYP3A4 enzyme inducers, such as dexamethasone, phenytoin, carbamazepine, rifampin, rifabutin, phenobarbital, St. John’s wort Food Interactions Grapefruit or grapefruit juice |
|
Adverse Effects
Venous thromboembolism Hot flashes Nausea and vomiting Fatigue Depression Lethargy Anorexia Arthritis Pulmonary embolism Myocardial infarction |
Contraindications
Allergy Pregnancy and lactation Prolonged QT interval Renal or hepatic impairment |
FDA Black Box Warning
Toremifene
Toremifene may cause QT prolongation, which could result in a type of ventricular tachycardia called torsade de pointes, which may result in syncope, seizure, and/or death.
Nursing Implications
The nurse should do the following for clients who are taking bisphosphonates, calcium preparations, vitamin D, or estrogen receptor modulators:
- Perform a physical assessment and determine the reason for the specific drug therapy.
- Assess past medical history and family history for osteoporosis, hypocalcemia, and vitamin D deficiency.
- Assess the client’s ability to understand and follow medication regimen.
- Determine pregnancy and lactation status.
- Assess smoking history and use of alcohol.
- Obtain necessary diagnostic and laboratory testing, such as bone density, calcium and vitamin D levels, and electrocardiogram.
- Assess diet and exercise patterns.
- Provide client teaching regarding the drug and when to call the health care provider. See below for client teaching guidelines.
Client Teaching Guidelines
The client taking a bisphosphonate, calcium, vitamin D, or an estrogen receptor modulator should:
- Understand the medication’s purpose, side effects, contraindications, precautions, and any signs and symptoms to report that require immediate attention.
- Know how to manage the side effects of the specific drug therapy.
- Know the medication dosage and route and be able to self-administer correctly (e.g., drink at least 6–8 ounces of water with bisphosphonate and remain standing or sitting upright for 30 minutes after taking the medication).
- Maintain weight-bearing exercise of 30 minutes 3–5 times weekly to increase bone strength.
- Include foods high in calcium in diet: leafy green vegetables, salmon, dairy, sweet potatoes, rhubarb, and beans.
- Understand drug, food, or herbal interactions with the specific medication.
- Verbalize the importance of follow-up appointments and diagnostic testing to manage the medication regimen.
The client taking a bisphosphonate, calcium, vitamin D, or an estrogen receptor modulator should not:
- Take bisphosphonates at the same time as other medications or supplements.
- Take calcium supplements with a high-fat meal.


15.20E: Leprosy
- Describe the causative agents of leprosy: Mycobacterium leprae and Mycobacterium lepromatosis
Leprosy, also known as Hansen’s disease (HD), is a chronic disease caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Named after physician Gerhard Armauer Hansen, leprosy is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract. Skin lesions are the primary external sign. Left untreated, leprosy can be progressive, causing permanent damage to the skin, nerves, limbs, and eyes.
Diagnosis
Diagnosis in the U.S. is often delayed because healthcare providers are unaware of leprosy and its symptoms. Early diagnosis and treatment prevents nerve involvement, the hallmark of leprosy, and the disability it causes. There are many kinds of leprosy, but there are common symptoms, including:
- Runny nose
- Dry scalp
- Eye problems
- Skin lesions
- Muscle weakness
- Reddish skin
- Smooth, shiny, diffuse thickening of skin on the face, ears, and hands
- Loss of sensation in fingers and toes
- Thickening of peripheral nerves
- Flat nose due to destruction of nasal cartilage
There is also phonation and resonation of sound during speech. Often there is atrophy of the testes and impotency.
Causative Agents
Mycobacterium leprae and Mycobacterium lepromatosis are the causative agents of leprosy. M. lepromatosis is a comparatively recently identified mycobacterium that was isolated from a fatal case of diffuse lepromatous leprosy in 2008. An intracellular, acid-fast bacterium, M. leprae is aerobic and rod-shaped, and is surrounded by the waxy cell membrane coating characteristic of Mycobacterium species. Due to extensive loss of genes necessary for independent growth, M. leprae and M. lepromatosis are obligate pathogens, and are unculturable in the laboratory, a factor that leads to difficulty in definitively identifying the organism under a strict interpretation of Koch’s postulates. The use of non-culture-based techniques such as molecular genetics has allowed for alternative establishment of causation.
Routes of Infection
M. leprae is usually spread from person to person in respiratory droplets. Studies have shown that leprosy can be transmitted to humans through contact with armadillos, too. Leprosy is not known to be either sexually transmitted or highly infectious after treatment. Approximately 95% of people are naturally immune, and sufferers are no longer infectious after as little as two weeks of treatment. In 1988, Jacinto Convit was nominated for the Nobel Prize in Medicine for developing a vaccine to fight leprosy using a combination of tuberculosis (TB) vaccines with Mycobacterium Leprae. A number of synthetic pharmaceuticals that are effective against leprosy have now been identified, allowing doctors a flexible choice of treatments.
Key Points
- Left untreated, leprosy can be progressive, causing permanent damage to the skin, nerves, limbs, and eyes.
- M. leprae and M. lepromatosis are obligate pathogens, and are unculturable in the laboratory, a factor that leads to difficulty in definitively identifying the organism under a strict interpretation of Koch’s postulates.
- There is now a vaccination and extensive pharmaceutical options for treatment and prevention of leprosy.
Key Terms
- leprosy : Leprosy, also known as Hansen’s disease (HD), is a chronic disease caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis.
- mycobacterium : Any of many rod-shaped, aerobic bacteria, of the genus Mycobacterium, that cause diseases such as tuberculosis and leprosy


4.11: Introduction to Narration
What you’ll learn to do: examine characteristics of writing narratives
Narrative writing can be a powerful addition to your writing toolkit. Humans seem to hunger for stories, and so narrative may be the most well-received of rhetorical devices. We use stories to educate and to entertain: They often feel friendlier than lists of facts or citations of scientific studies.
As Philip Pullman said,
After nourishment, shelter and companionship, stories are the thing we need most in the world.
Contributors and Attributions
CC licensed content, Shared previously
- Narration. Provided by : Boundless. Located at : courses.lumenlearning.com/boundless-writing/chapter/types-of-rhetorical-modes/. License : CC BY: Attribution
- Image of open book. Authored by : Tumisu. Provided by : Pixabay. Located at : pixabay.com/illustrations/storytelling-story-telling-tale-4203628/. License : Other . License Terms : pixabay.com/service/terms/#license


47.4A: Measuring Biodiversity
- Explain how DNA barcoding aids in measuring biodiversity
Measuring Biodiversity
The technologies of molecular genetics, data processing, and data storage are maturing to the point where cataloging the planet’s species in an accessible way is close to feasible. DNA barcoding is one molecular genetic method, which takes advantage of the rapid evolution in a mitochondrial gene present in eukaryotes, to identify species using the sequence of portions of the gene. Plants may be barcoded using a combination of chloroplast genes.
DNA Barcoding
DNA barcoding is a taxonomic method that uses a short genetic marker in an organism’s DNA to identify it as belonging to a particular species. It differs from molecular phylogeny in that the main goal is not to determine patterns of relationship, but to identify an unknown sample in terms of a preexisting classification. The most commonly-used barcode region for animals, at least, is a segment of approximately 600 base pairs of the mitochondrial gene cytochrome oxidase I (COI).
Applications include, for example, identifying plant leaves (even when flowers or fruit are not available), identifying insect larvae (which may have fewer diagnostic characters than adults and are frequently less well-known), identifying the diet of an animal (based on its stomach contents or feces), and identifying products in commerce (for example, herbal supplements or wood).
Rapid, mass-sequencing machines make the molecular genetics portion of the work relatively inexpensive and quick. Computer resources store and make available the large volumes of data. Projects are currently underway to use DNA barcoding to catalog museum specimens, which have already been named and studied, as well as testing the method on less studied groups. As of mid-2012, close to 150,000 named species had been barcoded. Early studies suggest there are significant numbers of undescribed species that looked too much like sibling species to previously be recognized as different. These now can be identified with DNA barcoding.
Numerous computer databases now provide information about named species and a framework for adding new species. However, as already noted, at the present rate of description of new species, it will take close to 500 years before the complete catalog of life is known. Many, perhaps most, species on the planet do not have that much time.
There is also the problem of understanding which species known to science are threatened and to what degree they are threatened. This task is carried out by the non-profit IUCN (International Union for Conservation of Nature) which maintains the Red List: an online listing of endangered species categorized by taxonomy, type of threat, and other criteria. The Red List is supported by scientific research. In 2011, the list contained 61,000 species, all with supporting documentation.
Key Points
- DNA barcoding is a taxonomic method that uses a short genetic marker in an organism’s DNA to identify it as belonging to a particular species.
- Barcoding allows us to classify organisms that would otherwise be difficult to identify, such as in situations where only part of an organism is available, or is too immature to identify by conventional methods.
- At the present rate of description of new species, it will take close to 500 years before the complete catalog of life is known; however, most species will be extinct before this time.
- Even with barcoding, it is difficult to know which species are threatened and to what degree they are threatened, a task carried out by the non-profit IUCN (International Union for Conservation of Nature).
Key Terms
- barcoding : a taxonomic method that uses a short genetic marker in an organism’s DNA to identify it as belonging to a particular species
- phylogeny : the evolutionary history of an organism
- taxonomy : the science of finding, describing, classifying and naming organisms


16: RC and L/R Time Constants
This chapter explores the response of capacitors and inductors to sudden changes in DC voltage (called a transient voltage), when wired in series with a resistor. Unlike resistors, which respond instantaneously to applied voltage, capacitors and inductors react over time as they absorb and release energy.
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- 16.2: Capacitor Transient Response
- Because capacitors store energy in the form of an electric field, they tend to act like small secondary-cell batteries, being able to store and release electrical energy. A fully discharged capacitor maintains zero volts across its terminals, and a charged capacitor maintains a steady quantity of voltage across its terminals, just like a battery.
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- 16.8: Solving for Unknown Time
- Sometimes it is necessary to determine the length of time that a reactive circuit will take to reach a predetermined value. This is especially true in cases where we’re designing an RC or L/R circuit to perform a precise timing function. To calculate this, we need to modify our “Universal time constant formula.”