**3. Autoimmunity**

There is also a high degree of overlap between autoimmune diseases and IEI in the context of genetic linkages and causes [44]. The molecular mechanisms responsible for the immune dysregulation in patients with IEI still are not fully recognized [45]. The usage of genetic analysis and a better understanding of the involved immune regulatory and signaling mechanisms is revealing the complex relationships between IEI syndromes and autoimmune diseases [44]. In the past, IEI and autoimmune diseases were considered as opposites; now, we know that genetic mutations may affect multiple immune cells and molecules, and in consequence IEI does not exclude autoimmunity. Furthermore, autoimmune diseases often coexist with some IEI [46].

The potential mechanisms associated with the pathogenesis of autoimmunity include impaired B cell differentiation and germ-center reactions, altered T cell central or peripheral tolerance, uncontrolled lymphocyte proliferation and differentiation, disturbances in Treg/Th17 balance, dysfunctional complement and innate immune activation, and the defective clearance of the infectious agents [45,46].

A French national study by Fischer et al. includes all types of IEI and autoimmune manifestations. The study demonstrated that autoimmunity is a significant component of clinical presentation of all types of IEI: one or more autoimmune and inflammatory manifestations were noted in 26.2% of 2183 retrospectively screened IEI patients, with a risk of onset throughout the patient's lifetime. The risk of autoimmune cytopenia (AIC) was at least 120 times higher than in the general population; among children the risk of inflammatory bowel disease (IBD) was 80 times higher, while the risk of arthritis was 40 times higher. The risk of other autoimmune complications was approximately 10 times higher. Autoimmune manifestations occurred in patients with all types of IEI; however, patients with T-cell defects or CVID had, statistically speaking, the highest risk for autoimmunity [47].

The signs and symptoms of most rheumatic diseases are classified in international American College of Rheumatology (ACR) or European League Against Rheumatism (EU-LAR) criteria. The management of autoimmunity in patients with IEI is often challenging because immune dysregulation, as well as permanent inflammation, may influence the diagnostic process. Moreover, when assessing a patient with IEI for possible autoimmunity, it is important to consider a broad differential diagnosis, because infectious diseases, adverse

effects of medications, and malignancies can mimic autoimmune processes.  Clinicians must be aware of the characteristic clinical features of autoimmune diseases among IEI patients. These include polyautoimmunity, which is defined as the presence of more than one autoimmune disease in a single patient and early onset autoimmunity (the presence of autoimmune disease at any age that is earlier than usual) [46]. Some IEI are associated with specific autoimmune diseases, and the awareness of these patterns also allows clinicians to monitor patients more effectively.

During evaluation of a patient with IEI and suspected autoimmunity, some laboratory tests are needed. This includes a complete blood count with differential, acute phase reactants, autoantibodies, serologies, flow cytometry, cytokine analysis, levels of complement, human leukocyte antigen (HLA) typing, and comprehensive endocrine and/or metabolic panels [48].

On the other hand, laboratory tests may help to catch patients with IEI among heterogenous group of patients with already diagnosed autoimmunity. Immune phenotyping and immunoglobulin (Ig) levels are indispensable. The ratio of naïve and memory T cells (CD45RA/CD45RO) may differentiate patients with late-onset or profound combined immunodeficiency disorders [49–52].

In addition, specific subsets of T and B cells have been linked to IEI with autoimmunity. These include the expansion of TCRαβ CD4−CD8− (double-negative) T cells in autoimmune lymphoproliferative syndrome (ALPS), CD19hi21lo B cells in CVID with autoimmunity, an abnormal count of Treg in Tregopathies, Th17 cells in STAT1 GOF patients, and expanding follicular helper T cells (Tfh) in CTLA4 and LRBA deficiency. Changes in these subsets may also predict the progression of autoimmune complications or a response to therapy [52,53].

Primary antibody deficiencies (PADs) are the most common inherited IEI in humans, with recurrent infections as a predominant presenting complaint. However, various types of PADs are also associated with inflammatory disorders, granulomatous lesions, lymphoproliferative diseases, and cancer. Several studies have reported that PAD patients are predisposed to autoimmune complications [47,54].

X-linked agammaglobulinemia (XLA), also known as Bruton agammaglobulinemia, is the prototype antibody deficiency [55]. Function-loss mutations in Bruton's tyrosine kinase (BTK) lead to a block in B-cell maturation, a near total absence of B cells in the periphery, and severe reductions in serum immunoglobulins. Surprisingly, most patients with XLA have a small number of B cells, or "leaky B cells", in the peripheral blood [54,56]. Patients with XLA are rather at a low risk of autoimmune or inflammatory diseases compared with other IEI patients, but several studies suggest that some XLA patients show symptoms with similar diagnostic features to rheumatoid arthritis (RA), IBD, alopecia, enteropathy, autoimmune hemolytic anemia (AIHA), immune thrombocytopenic purpura (ITP), neutropenia, and Kawasaki disease [54,57–59]. These patients are not expected to produce autoantibodies; however, surprisingly, the "leaky" production of autoantibodies and defects in B-cell central tolerance has been reported [54,60,61].

Autoimmune diseases occur in 20–30% of CVID patients. The most reportable are autoimmune cytopenias such as ITP, AIHA, and Evans syndrome; however, organ-specific and systemic autoimmune diseases are also described [45,62–64].

It is worth mentioning that it is not uncommon that autoimmune complications are the first or the only clinical manifestation of CVID during diagnostics [54,65].

A cohort study on CVID patients with immune cytopenia showed higher levels of serum immunoglobulin, CD19hi B cells, and T CD4 effector T cells, accompanied by reduced naïve T cells [45,66]. Moreover, according to several studies, Treg frequency and their functional characteristics are disturbed in CVID patients [54,67–69], which may result in elevated levels of activated T cells; autoimmunity; and chronic inflammation. Defects in Tregs are also correlated with the expansion of CD21low B cells in CVID patients with autoimmunity [70–72]. In a study by Boileau et al., the serum IgG level in CVID patients with autoimmunity (cytopenia and others) was greater than in CVID patients without autoimmunity [66]. Other studies revealed that CVID patients with autoimmunity have higher levels of IgM compared with non-autoimmune phenotypes [73,74]. On the other hand, markedly depressed serum immunoglobulin levels have been reported in patients with RA, Sjogren's syndrome (SS), and systemic lupus erythematosus (SLE), prompting suspicion of IEI [75,76].

Autoantibodies circulating in the serum and/or plasma, as well as the immune complex deposits containing autoantibodies and complement, are essential diagnostic tools in most autoimmune diseases. In patients with hypogammaglobulinemia (i.e., CVID, XLA etc.) and some types of CIDs, diagnostic tests that are based on antibodies may be not useful and provide false-negative results. For example, the diagnosis of definite autoimmune hepatitis (AIH) in CVID patients is definitely challenging. According to the European Association for the Study of the Liver (EASL), both histologic evidence of moderate to severe interface hepatitis and the positivity of the typical autoantibodies are required to make an AIH diagnosis [77,78]. It is not surprising that CVID patients generally may not have autoantibodies, even in the case of noticeable autoimmune complications.

However, in a study by Tahiat et al. among 299 IEI patients with a dominance of PAD (27.8%) and CID (26.1%), autoantibodies were found in 32.4% of all IEI patients, compared with 15.8% of healthy subjects. Anti-nuclear antibodies (ANA) (10.0%), transglutaminase antibody (TGA) (8.4%), RBC antibodies (6.7%), anti-smooth muscle antibody (ASMA) (5.4%), and ASCA (5.0%) were the most common autoantibodies. The authors have concluded that considering the association of some autoimmune diseases with certain PIDs, screening for corresponding autoantibodies would be recommended. However, due to the low positive predictive value of the autoantibodies, the results should be interpreted with caution in patients with IEI [79].

Oppositely, the production of specific antibodies may by impaired even when the level of main classes of immunoglobulins is normal in specific antibody deficiency (SAD). Consequently, most autoantibodies are not found in these patients [48,80,81]. In sIgAD, as well as in CVID with IgA deficiency, it is obvious that there is a lack of antibodies in this immunoglobulin class (for example, tissue transglutaminase IgA–tTg IgA). On the other hand, among patients during IRT, exogenous Ig may interfere with some of the special immunologic tests. That is why it is worth considering if some screening tests such as autoantibodies should be performed before the therapy is being initiated or the serum should be frozen for future testing [48].

Some IEI patients are constantly negative for disease-specific autoantibodies, and in the case of clinical suspicion of autoimmune disease, other diagnostic methods should be considered. Medical imaging is often a part of the clinical evaluation of patients with suspected autoimmune disorder. In the case of IEI patients, some difficulties may appear at this point too. In particular types of IEI there is a problem with radiosensitivity, which limits the use of medical radiation for the diagnosis of autoimmunity [82–84]. Genetic instability, defective DNA repair, and a predisposition to malignancy are associated with specific types of IEI. A-T and NBS are well-defined IEI connected with defective DNA repair [85], where patients might be sensitive to radiation. X-ray exposure should be limited to diagnostic purposes only when it is medically necessary because patients should be protected from unnecessary medical techniques that incorporate radiation. Substitution with magnetic resonance imaging (MRI) or ultrasound is desirable [48].

Histopathological examination is sometimes crucial and clinically indicated in a diagnostic process. Diagnostic challenges may occur here as well. In IEI patients, as an effect of immunoglobulins and immune cells deficiency, affected tissue can have a different histological appearance in comparison to healthy individuals [48,78,86–88].

Since autoimmune cytopenia (AIC) is a common finding in IEI patients, Westermann-Clark et al. evaluated 154 pediatric patients with AIC in the context of IEI. Splenomegaly, short stature, and recurrent or chronic infections were common clinical features among

patients with AIC and IEI. IEI patients were more likely to have AIHA or Evans syndrome than AIC-only patients. Patients with both IEI and AIC more often had low CD3 and CD8 cells; low IgA and IgG levels; and a higher prevalence of autoantibodies to red blood cells, platelets, or neutrophils. AIC diagnosis preceded IEI diagnosis by 3 years on average, except among those with partial DiGeorge syndrome [89]. The early detection of patients with comorbid IEI and AIC may improve treatment outcomes.

The main molecular defects and common autoimmune complications among IEI are summarized in Table 2.

**Table 2.** Common autoimmune presentation in inborn errors of immunity (IEI).

Abbreviations: AD—Addison's disease; AIC—autoimmune cytopenia; AIHA—autoimmune hemolytic anemia; AIT—autoimmune thyroid disease; AN—autoimmune neutropenia; ALPS—autoimmune lymphoproliferative syndrome; APECED—autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy; APLA—antiphospholipid antibodies; CD—celiac disease; CVID—common variable immunodeficiency; GN—glomerulonephritis; GOF—gain-of-function; IBD—inflammatory bowel disease; IUIS—International Union of Immunological Societies; JIA—juvenile idiopathic arthritis; IPEX—immune dysregulation, polyendocrinopathy, enteropathy, and X-linked syndrome; ITP—immune thrombocytopenia; MS – multiple sclerosis; RA—rheumatoid arthritis; SLE—systemic lupus erythematosus; and T1D—type 1 diabetes.


*Supporting open minds since 2005*

Numerical Modeling and Computer Simulation http://dx.doi.org/10.5772/intechopen.77641 Edited by Dragan M. Cvetković and Gunvant A.Birajdar

#### Contributors

Ghazala Ashraf, Khalid Saifullah Syed, Muhammad Ishaq, Stephen Kirkup, Javad Yazdani, Babacar Leye, Léon Matar Tine, Mamadou Sy, Marwa Ben Said-Romdhane, Sondes Skander-Mustapha, Ilhem Slama-Belkhodja, Akhilanand Chaurasia, Saman Ishrat, M. Husain Khan, Bakrim Fadwa, El Maroufy Hamid, Ait Mousse Hassan, Goharik Petrosyan

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**1. Introduction**

The journey of exploring acid and base starts long before, but in the last century the advancement was remarkable. In 1890, Wilhelm Ostwald electronically measured hydrogen [1]. Svante Arrhenius won the Noble prize in 1903 for the theory of ionization [2]. In 1908, Henderson and Black showed that bicarbonate and phosphate equilibrated with CO2 at normal body temperature in different solution [3]. In 1923, Bronsted first put forward the idea of acid as a substance that ionizes in solution and donate hydrogen and the base accepts the hydrogen from the solution [4]. Bronsted, Henderson and Van Slyke described acid-base balance in the early part of nineteenth century [5]. Handerson invented bicarbonate as the most important buffer system of the body, and Hasselbalch first measured the real blood pH in the early part of nineteenth century [6–8]. In 1909, S. P. S. Sorensen developed the pH scale [8]. Later Hasselbalch-Henderson developed an equation that helped in relating pH to the blood bicarbonate and PCO2 [7, 9, 10]. In the early 1980s, scientists introduced electrodes specific for each ion. Thereafter, serum electrolyte and the anion gap measurement become routine tools for assessing acidosis.

Acidosis has fatal consequences like CNS damage. Even death is not uncommon. Acidosis is characterized by a decrease in pH, and this change is rapidly

corrected by the body buffer systems. Many clinical conditions develop acidosis, as well as ionic derangements and the only correction of the underlying cause can resolve it. There are equal numbers of cations and anions in the blood and among them there are some unmeasured anions. These unmeasured anions can contribute in the clinically important anion gap. In a healthy individual, there is an acceptable range of normal anion gap. But some conditions can increase or decrease this gap. Increased anion gap usually represents metabolic acidosis. Albumin and many other confounding factors influence the anion gap derangements. Accuracy in measuring anion gap is critically important for the evaluation of acidosis.


**5. Conclusions**

In this work, we combined UAV infrared thermography with laboratory tests to investigate how to more efficiently and accurately analyze the high-temperature stability and water stability of asphalt pavements during the paving process, which resulted in the following conclusions.

**Author Contributions:** Writing—original draft, W.C. and K.W.; data curation, W.C. and K.W.; software, Z.F., X.X. and B.X.; methodology, W.H., X.Z., S.W., X.X. and G.H.; validation, S.W., L.N., K.C., Z.F. and T.C.; formal analysis, G.H., L.N., K.C. and T.C.; project administration, W.H. and B.X.; investigation, J.W. and X.Z.; supervision, J.W. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the National Key R&D Program of China (grant number 2018YFB1600100), the Shandong Natural Science Foundation Committee (ZR2020QE271, ZR2020KE024), the Shandong Provincial Natural Science Foundation (grant number ZR2020QE272), the Shandong Jianzhu University Doctoral research foundation (grant number X18073Z).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data sharing is not applicable for this article.

**Acknowledgments:** The authors would like to thank the staff at Shandong Transportation Research Institute for their support.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


Perspective Chapter: A Perspective on the Resettlement of Maasai Communities from the Ngorongoro Landscape in Tanzania

*Franco P. Mbise*

## **Abstract**

Tanzania is endowed with an abundance of natural resources, and the country has set aside more than 30% of its land for conservation. The Ngorongoro district is where both the Ngorongoro Conservation Area (NCA) and the Loliondo Game Controlled Area (LGCA) are located. Sometimes, it is confusing when talking about Ngorongoro as a region and the NCA as a conservation area. The NCA is an example of a diverse landscape in which humans (the Maasai tribe) and their livestock coexist with wildlife, but crop farming is prohibited. According to current projections, the Maasai population at NCA is approximately 120,000 people. And there are approximately 45,200 livestock. The increase in people is proportional to the increase in livestock, as the Maasai who live in the Ngorongoro landscape rely solely on animal husbandry as their main source of income. In the NCA, human and livestock population growth have a significant impact on wildlife and their habitat. To alleviate the pressure on the landscape, the Tanzanian government took the initiative to seek Maasai willing to relocate to another area, in this case, Handeni district in Tanga region.

**Keywords:** landscape conservation, Maasai, quality of life, resettlement, Tanzania

## **1. Introduction**

The International Union for Conservation of Nature (IUCN) has defined six Protected Areas Management Categories that describe protected areas (PAs) and their management planning through the World Commission on Protected Areas (WCPA). This includes sustainable use areas set aside to protect important ecological processes, species, and ecosystems while also providing cultural, scientific, educational, recreational, and visitor opportunities and strictly protected areas set aside to protect biodiversity and only used for scientific research and monitoring [1].

The Yellowstone National Park in the United States, Kruger National Park in South Africa, and Serengeti National Park in Tanzania are all well-known parks with great conservation histories. Protected areas around the world have become the only way

to protect species and their habitats. As the human population grows, these protected areas are increasingly encroached upon by locals, degrading and destroying these pristine wildlife habitats. Recently, the focus of wildlife conservation has shifted to single species, particularly endangered species. The main concern is to protect the entire ecosystem, as this will protect all species. True, threatened and endangered species require extra care in conservation. This initiative should be handled with extreme caution without losing sight of the importance of conserving the entire ecosystem, which in turn conserves all species. Nowadays, conservationists understand that without local communities, the paradigm of sustainable conservation will fade away. Communities living within or adjacent to protected areas play a critical role in achieving this goal. When people in a community care about conservation, it costs the government less to protect protected areas [2–5]. A major issue arises when the two actors are required to distribute accrued benefits equally, and benefit sharing is the demand for tangible benefits to local communities living within or near protected areas. Benefit sharing that is equitable will improve mutual understanding between local communities and conservation stakeholders. Benefits devoted to the construction of schools, hospitals, water wells, and roads appear to be less tangible to locals because what they really want is direct cash flow in their pockets. For example, in western Serengeti, the construction of schools became a motivator for poaching. Because conservationists build schools, parents must pay school fees and uniforms to send their children to these schools. Many PAs in Africa followed the Yellowstone conventional and exclusionary principle of a top-down approach, which was used during the formation of the world's oldest national park in 1872. As a result, many PAs have prioritized biodiversity and ecosystem services over social and cultural issues that are important to local communities. Poaching is an immediate option for covering these costs. In this scenario, helping societies is not always perceived as such, but rather as a threat to biodiversity [6–9].

Tanzania is endowed with an abundance of natural resources, and the country has set aside more than 30% of its land for conservation. This 30% is where 22 national parks are located; 16 game reserves; 38 game-controlled areas; 13 wildlife management areas; and 28 forest reserves. About 20% of the Tanzanian revenue comes from tourism. Therefore, fostering conservation initiatives is of paramount importance for the future conservation activities of the country. The government of Tanzania has made significant contributions to achieving the conservation vision that was laid down by Mwalimu Julius K. Nyerere [10], who was the first Tanzanian president and the father of the nation after independence in 1961 and until his retirement in 1985.

The Mwalimu conservation vision was manifested during the Arusha Manifesto in 1961, and it states:

The survival of our wildlife is a matter of grave concern to all of us in Africa. These wild creatures amid the wild places they inhabit are not only important as a source of wonder and inspiration, but are an integral part of our natural resources and our future livelihood and wellbeing. In accepting the trusteeship of our wildlife we solemnly declare that we will do everything in our power to make sure that our children's grand-children will be able to enjoy this rich and precious inheritance. The conservation of wildlife and wild places calls for specialist knowledge, trained manpower and money, and we look to other nations to co-operate with us in this important task - the success or failure of which not only affects the continent of Africa but the rest of the world as well.

The Mwalimu conservation vision was a first-of-its-kind, symbolic plan that was put into action in a strong way. Its goal was to protect and care for Tanzania's *Perspective Chapter: A Perspective on the Resettlement of Maasai Communities... DOI: http://dx.doi.org/10.5772/intechopen.108633*

beautiful wildlife as a top national heritage [10]. In the pursuit of conservation initiatives to make this wildlife conservation paradigm come true, during 2020, the country made a substantive recategorization of protected areas, making a total of 22 national parks from only one national park, the Serengeti, since 1959. The recategorization process upgraded the status of six game reserves to a more protected category, that of a national park. The newly established national parks are: Nyerere, Burigi-Chato, Kigosi, Ibanda-Kyerwa, Rumanyika-Karagwe, and Ugalla River [11].

## **2. Ngorongoro landscape**

Ngorongoro Conservation Area (NCA) is classified as category V by the IUCN. Category V is defined as an area with distinct ecological, biological, cultural, and scenic value as a result of long-term human–nature interaction. As a result, the area and its associated features are protected and preserved. The NCA is an example of a diverse landscape in which humans (the Maasai tribe) coexist with wildlife. The Maasai of the Ngorongoro Crater were evicted from Serengeti, the Maasai name for an endless plain. The Maasai were evicted from the Serengeti plains by colonial rule in 1959, and the area was gazetted as a national park [8, 12]. As a conservation model, colonial rule used "fines and fences," an approach that excluded people from conservation efforts, resulting in hostility between the two actors [2]. Following that, the Maasai were relocated to the Ngorongoro landscape, and they remained there since their exodus from the Serengeti plain. They had a population of about 3000 people when they relocated to NCA. They joined a small group of local Maasai at NCA landscape. According to current projections, their population on the landscape is around 120,000 people (**Figure 1**). The increase in people is proportional to the increase in livestock, as the Maasai who live in the Ngorongoro landscape rely solely on animal husbandry as their main source of income (**Figures 1** and **2**). The 1959 Ngorongoro Conservation Ordinance strictly prohibits farming in the area (**Figure 3**) [13, 14]. As the human population grows, it becomes a burden on our mother earth. Not only that, but given the constraints imposed on the Maasai, who are limited to only one source of economic activity (animal husbandry). As a result, the government was forced to take some steps in order to secure arable land in Handeni, Tanga region (**Figure 4**). Furthermore, because they lived in the Ngorongoro landscape, the 1959 Ngorongoro Conservation Ordinance prohibited them from constructing modern homes. Given the restrictions put in place to protect the landscape's beauty, these restrictions hurt the Maasai people.

In the NCA, human and livestock population growth has a significant impact on wildlife and their habitats (**Figures 1** and **5**). Human population growth and associated activities result in significant changes in land use in any landscape (**Figure 1**). As a result, wildlife's available vegetation and habitat ranges are shrinking [15–17]. The lion population, for example, has declined significantly in the NCA (**Figure 5**). Because of increased human activity, the Serengeti National Park is now a source of predators, while the protected areas surrounding it are sinks [15]. The human population is rapidly growing in the area (**Figure 1**). As the human population grows, so does the demand for land for livestock grazing (**Figure 2**), farming, and settlement. As a result, wildlife habitats are deteriorating and being displaced by other activities [18, 19]. Some writers stated in the Cattle Complex Theory, in the context of pastoralists and their livestock, that it was difficult to draw a line between a herd of

#### **Figure 1.**

*Human population projections for the Ngorongoro conservation area from 1960 to 2020.*

#### **Figure 2.**

*Livestock population (cattle, sheep, and goats) projections for the Ngorongoro conservation area from 1960 to 2020.*

cattle and the cattle herder (difficulty distinguishing master from slave). Eventually, they concluded that cattle are in charge in African pastoralism because herders try to meet their needs for food, water, space, and disease protection [20]. The Ngorongoro district currently has approximately 419,355 hectares suitable for cattle grazing. Tanzania has 12, 513 villages, but only 648 villages have been authorized to dedicate their land for grazing [20].

Human population growth in many African countries has increased the demand for land use and natural resource exploitation significantly. As the human population grows, especially in Africa, wild prey species such as wildebeest are depleted (**Figure 6**) and natural habitats are displaced; these habitats are now limited to small patches [21]. As a result, a proper management structure and policy designed to conserve natural habitats and their species is urgently required [22, 23]. When humans dominate the areas surrounding protected areas, their activities have a huge negative impact on wildlife [21]. In Algonquin Park, Canada, for example, the wolf population was severely persecuted when the animals crossed the park border [24]. Because of human population growth and the expansion of agricultural activities for global food security, biodiversity is

*Perspective Chapter: A Perspective on the Resettlement of Maasai Communities... DOI: http://dx.doi.org/10.5772/intechopen.108633*

#### **Figure 3.**

*The Maasai people' current home, with red highlights outside the crater.*

**Figure 4.** *Resettlement zone in light green.*

currently facing a significant challenge. Anthropogenic activities have significantly altered land cover and land use, which has a negative impact on biodiversity in any ecosystem [25]. For example, in the Serengeti ecosystem, large carnivore populations are higher in the Serengeti National Park than in the Loliondo Game Controlled Area (LGCA) [26], whereas large carnivore abundance was similar in the two areas in previous decades (**Figure 5**) [18]. This shift is the result of an increase in pastoral community populations that live within the LGCA with their livestock.

**Figure 5.** *Lion population status in the Ngorongoro conservation area for the two periods (2000–2017) [15].*

#### **Figure 6.**

*Wildebeest population decline in the Ngorongoro conservation area from 1960 to 2020.*

Tanzania's government, through the Ministry of Natural Resources and Tourism, is doing everything possible to keep the Mwalimu vision of protecting wild places alive for present and future generations. Today, high attention is focused on the decline and extinction of species, habitats, and entire ecosystems. The most serious attention is given to the loss of biodiversity due to species extinction. Therefore, on the good will of the government of Tanzania to make sure that its people live in a peaceful place with freedom to legally perform daily economic activities, the Maasai were voluntarily asked to register and relocate to Handeni, Tanga. In the new home, the government built modern homes and provided infrastructure for social services such as hospitals, water wells, electricity supply, and road networks, to mention a few. The exercise is still in progress as many people are still willing to relocate to the area (**Figure 7**). The public is still unaware of the number of new houses that are expected to be built, but it may be determined by how many people are willing to relocate to the area. I understand how difficult it is to relocate 120,000 people, and because the exercise is based on individual willingness to relocate, it is anticipated that not all Maasai will leave the NCA landscape (personal observation).

*Perspective Chapter: A Perspective on the Resettlement of Maasai Communities... DOI: http://dx.doi.org/10.5772/intechopen.108633*

**Figure 7.** *The current housing style of the Maasai people at Ngorongoro.*

## **3. Livestock depredation and human attack incidences in the Ngorongoro landscape**

Globally, wildlife habitats are gradually shrinking as a result of anthropogenic activities and human population growth [23]. Because of an increased human population, the edges of protected areas are gradually shrinking, resulting in an increased demand for land for settlement and farming. Such demands have a negative impact on biodiversity conservation by encroaching on arable and fertile lands adjacent to protected areas [27]. As a result of habitat degradation, frequent interactions between humans and wildlife have increased [21, 23]. Because human population control in Africa is poor, there is a strong correlation between the increase in human population and the extinction of wildlife [28, 29]. Large carnivores and humans have a long history of conflict, with human attacks and livestock depredation [30, 31]. Human attacks and livestock predation have resulted in carnivore retaliation [31, 32]. This conflict must be addressed using all available means in order to gain conservation support for large carnivores from local people who interact with these species [23, 33]. For example, a study of the feeding and seasonal preferences of lions (*Panthera leo*) in Kenya's Tsavo National Park discovered that livestock depredation increased during the dry season [34]. In contrast to the dry season, when most herds of prey are found around water points, carnivores' prey is evenly distributed across the habitat during the wet season. This facilitates predation because lions can hide near water sources and prey on approaching herds [34]. However, chasing individuals during the wet season requires more effort and energy due to the abundance of shallow water points. When predators find it difficult to hunt wild prey, they turn to easier prey, such as livestock [34]. Furthermore, it was discovered that livestock depredation

increased during the wet season in the Tsholotsho Communal Land and Ngamo Forest adjacent to Hwange National Park in Zimbabwe [35]. Communities usually grow crops during the wet season. During this time, their livestock is moved away from the crop fields to graze near protected areas where there are more wild carnivores [35]. When dealing with livestock depredation, coexistence measures are easier to implement in a community than human attacks. It is frequently possible to provide conservation incentives that boost local morale and increase their willingness to accept losses as a result of the incentives. It is, however, impossible to provide incentives that compensate for human attacks and/or killings. Ideally, studies should be conducted to educate people on how to avoid human attacks based on the circumstances surrounding previous attacks. The study's findings will be used to propose various strategies for harmonious coexistence between humans and carnivores as well as to support their conservation. Tanzania's conservation stakeholders' primary goal is to reduce the carnivore population adjacent to many networks of protected areas. Retaliatory killings will increase if people have negative attitudes toward large carnivores. Large carnivores require large home ranges, and because protected areas are shrinking due to anthropogenic activities, they end up living close to human-dominated areas.

The situation in the Ngorongoro landscape is threatening people's lives due to frequent incidents of human attacks and/or livestock depredation. Normal lives of people living in the landscape have been jeopardized, especially for schoolchildren, who now attend school in comparison to previous generations when many Tanzanians did not. When students arrive at school in the morning, they are vulnerable to predator attacks.  With the new home in Handeni, the constraints that would have resulted in an illiterate society in the future are now a thing of the past.

## **4. Improving the quality of the Maasai people with modern homes and farming opportunities**

A large number of Maasai communities have voluntarily registered to relocate to the newly established homes in Tanga's Handeni district [36, 37]. It is time to educate the public about the distinctions between the NCA and the LGCA) in the Loliondo and Sale divisions. According to the IUCN, NCA are classified as category V. However, the Wildlife Division is in charge of the LGCA. It is a gazetted area with defined boundaries where people are permitted to live. A permit or license is required to exploit or harvest wildlife resources. Some species are not hunted, for example, rhinos and giraffes, as well as there is wildlife control for crop or livestock protection. So, the NCA only lets people visit for photography, while the LGCA lets people visit for both photography and trophy hunting.

When discussing the Ngorongoro district, where both the NCA and the LGCA are located, it is common to become confused. As a result, they are found in the same district but play different roles in terms of wildlife conservation and tourism businesses. Tanzania's government believes that they have the right to protect their people from any danger. In this context, the government defines the danger as human attacks, livestock depredation, and a poor quality of life [31, 38] as well as the consequences of raising an illiterate generation because most children do not attend school due to fear of lion attacks [39]. Tanzania's government has taken steps to build houses in the Tanga region (Handeni district) (**Figure 4**). The Handeni

## *Perspective Chapter: A Perspective on the Resettlement of Maasai Communities... DOI: http://dx.doi.org/10.5772/intechopen.108633*

district appears to be the ideal location for Maasai people and livestock in order to alleviate current pressures on the well-known NCA [40, 41]. The presence of NCA contributes to a higher percentage of tourism revenue generated by tourism activities. As a result, the Tanzanian government has determined that the only way to protect the status and scenic beauty of the NCA is to ask the Maasai people to relocate to a safe place (Handeni district) that is free of human attacks caused by large carnivores and/or livestock depredation. The artifact of constructing new modern homes in better conditions than existing traditional houses is in accordance with the country's goal of continuously improving the quality of life of its people. As a result, the majority of Tanzanians see the government's actions as beneficial to Maasai communities. Maasai people in NCA currently live in boma houses made of poles and cow dung and thatched with grass or occasionally covered with plastic [42] (**Figure 3**). The conservation policy that governs the NCA prohibits the Maasai from engaging in farming activities [43, 44]. The only advantage they have is free pasture, and the remainder of their food should come from nearby districts [43, 45]. The new home, Handeni, on the other hand, has no such restrictions. In this anticipation, it is a good opportunity for each household to have a good house made of bricks and roofed with iron sheets (**Figure 8**). Furthermore, they will have a backyard to grow food crops such as maize and vegetables to supplement their diet. What a fantastic opportunity!

Nevertheless, this opportunity may prove difficult during their initial days in their new home. For centuries, the Maasai have been pastoralists, relying on livestock husbandry for a living. Outside the NCA, the Maasai practice both livestock husbandry and subsistence farming, like in the LGCA [17]. Since the Maasai from NCA have not done farming before, they will need help and training from extension officers from the Ministry of Agriculture.

**Figure 8.** *The new housing style of the Maasai people at Handeni.*

## **5. Conclusion**

Given the current unprecedented increase in human population, now is the time for conservationists and policymakers to rethink and find immediate solutions to conserve and protect biodiversity. If we do not plan for the future, the natural wonders we enjoy today will be lost and our grandchildren will blame us for irresponsible actions. As the Mwalimu (the father of Tanzania) vision emphasizes, the loss of these magnificent wild places and their creatures will affect not only the African continent but also the entire world. As a result, Tanzania's decision to willingly allow the Maasai to relocate to freedom land was the millennia decision ever made in conservation initiatives. For instance, according to the Martin Oleikayo, the head of Msomera Village, said that "the resettlement plan is good for the whole country." He also said that "all citizens benefit from the money made by tourism in the conservation area" [36]. A bold decision on economic potential due to the area's growing human population will result in a medium- and eventually high-income populace. With the present climate change and population pressures, it will aggravate poverty in the region [46]. However, the Maasai resettlement may have some drawbacks. It is very likely that moving out of the area where you have lived since you were a child will cause some discomfort. The trade-offs that are being thought of here are ones in which the option of moving is better than the option of staying on their ancestral land.

## **Author details**

Franco P. Mbise Department of Biology, The University of Dodoma, Dodoma, Tanzania

\*Address all correspondence to<EMAIL_ADDRESS><EMAIL_ADDRESS>
© 2022 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Perspective Chapter: A Perspective on the Resettlement of Maasai Communities... DOI: http://dx.doi.org/10.5772/intechopen.108633*

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Section 2


**1. Introduction**

When imaging an object through a scattering medium, the transmitted light is consisted by the ballistic light and the scattered light [1]. The ballistic light that carries the object information migrates through the scattering medium without deviating from the forward direction. The scattered light that has been scattered randomly in all directions loses the object information and undermines the imaging quality [2]. Most methods only use the ballistic light for imaging, and the scattered light is suppressed by employing a short time gate based on nonlinear phenomena [3–6]. However, these methods are only effective for the weak scattering medium. When imaging through a highly scattering medium, almost all the light has been scattered randomly. In order to solve this problem, some methods that use the scattered light for imaging have recently been proposed. These include computational ghost imaging [7,8], wavefront shaping [9,10], speckle correlation [11–13], and optical transmission matrix (TM) [14–17].

Generally speaking, imaging 3D objects that are hidden behind scattering media is a challenging work. On one hand, compared with the traditional one-way imaging through a scattering medium

where the light wave has only been distorted once, imaging an object that hidden behind scattering media is more difficult since the light wave has gone through a round-trip distortion: On the way in for the illumination and on the way out for the detection. In such a case, the information of the object seemingly cannot be recovered. On the other hand, two-dimensional (2D) imaging only needs to recover the intensity (amplitude) features of the object. Three-dimensional (3D) imaging is much more difficult, as both the intensity (amplitude) and the morphological (phase) features of the object should be recovered.

Although a lot of methods have ever been proposed, they are not effective for imaging 3D objects hidden behind highly scattering media. For example, the computational ghost imaging method cannot achieve round-trip imaging through scattering media because the information of the illumination wave is lost via the on-the-way-in distortion [18]. The wavefront shaping method only can image the 2D intensity object as the phase information of the object cannot be recovered, and due to the scanning process, its imaging speed is also restricted [19]. Similarly, the speckle correlation method relies on the inherent correlations in scattered speckle patterns, which makes it only applied to thin opaque layers, as the field-of-view is inversely proportional to the scattering medium thickness [12]. Different from the above methods, the optical transmission matrix (TM) can inherently characterize the scattering medium by giving the relationship between the input optical field and the output optical field [14]. Theoretically, it has the ability to recover the information of the object without loss and achieve the 3D complex amplitude imaging. Recently, this method has shown potential in focusing [15], delivering imaging [16], controlling transmitted energy [20], multispectral control [21], and acoustically modulated light [22]. However, generally speaking, they all belong to the cases working in the transmission imaging mode where the light is only distorted once. More recently, we also show that a 2D intensity object, which is completely hidden behind a scattering medium, can be imaged directly from the distorted output optical field [23]. Nevertheless, to the best of our knowledge, using the TM method to recover the complex amplitude information of the object that is hidden behind highly scattering media has not yet been reported.

In this paper, we show in principle that based on the round-trip TM, it is possible to recover the complex amplitude information of the object that is hidden behind scattering media. The imaging method and experiment setup are introduced, and a simple virtual complex amplitude object has also been constructed to verify the effectiveness of our method. The experiment results show that not only the amplitude but also the phase information of the object can be recovered.

#### **2. Principle**

As shown in Figure 1, when a target object is hidden behind a scattering medium, an active light is used to illuminate the object. In such a case, the incident plane wave has gone through a round-trip distortion, and the optical field reflected by the object can be expressed as

$$R(\xi,\eta) = S(\xi,\eta) \* O(\xi,\eta),\tag{1}$$

where the '\*' operation indicates that the corresponding (*ξ*, *η*) elements are multiplied. *O*(*ξ*, *η*) is the complex amplitude of the target object, and *S*(*ξ*, *η*) is the complex field distribution of the illumination wave which is seriously distorted due to the on-the-way-in process via the scattering medium. Based on these definitions, the final output optical field can be expressed as

$$E(\mathbf{x}, y) = \sum\_{\vec{\xi}, \eta} K\_{\mathcal{R} \to E}(\mathbf{x}, y; \underline{\xi}, \eta) \* \mathcal{R}(\underline{\xi}, \eta). \tag{2}$$

The *KR*→*E*(*x*, *y*; *ξ*, *η*) is a traditional one-way TM of scattering media, which has given the relationship between the reflected optical field *R*(*ξ*, *η*) and the output optical field *E*(*x*, *y*) [15].

**Figure 1.** Schematic of imaging an object hidden behind a scattering medium.

As long as *KR*→*E*(*x*, *y*; *ξ*, *η*) is measured in advance, the reflected optical field *R*(*ξ*, *η*) can be recovered from *E*(*x*, *y*) directly [16]. Nevertheless, the object *O*(*ξ*, *η*) cannot be recovered yet since *S*(*ξ*, *η*) is still unknown. To overcome this problem, specially, we construct a new TM

$$T\_{O \to E}(\mathbf{x}, \mathbf{y}; \underline{\mathbf{y}}, \boldsymbol{\eta}) = K\_{R \to E}(\mathbf{x}, \mathbf{y}; \underline{\mathbf{y}}, \boldsymbol{\eta}) \, \* \, \mathcal{S}(\underline{\mathbf{y}}, \boldsymbol{\eta}) \tag{3}$$

as the round-trip TM of the scattering medium. It can be seen from Equation (3) that, different from the traditional one-way TM *KR*→*E*(*x*, *y*; *ξ*, *η*), this new TM *TO*→*E*(*x*, *y*; *ξ*, *η*) has additionally recorded the complex field distribution *S*(*ξ*, *η*) of the distorted illumination wave. In this way, Equation (2) can also be expressed as

$$E(\mathbf{x}, y) = \sum\_{\vec{\xi}, \eta} T\_{O \to E}(\mathbf{x}, y; \vec{\xi}, \eta) \* O(\vec{\xi}, \eta). \tag{4}$$

Now, once the *TO*→*E*(*x*, *y*; *ξ*, *η*) is measured, the relationship between *O*(*ξ*, *η*) and *E*(*x*, *y*) can be given directly.

Furthermore, for the convenience of calculation, the Equation (4) is converted to the matrix form as

$$E(\mathbf{x}, \mathbf{y}) = T\_{O \to E}(\mathbf{x}, \mathbf{y}; \boldsymbol{\xi}, \boldsymbol{\eta}) \times O(\boldsymbol{\xi}, \boldsymbol{\eta}), \tag{5}$$

where the ' × ' represents a multiplication operation between two matrices. In this way, the object information *O*(*ξ*, *η*) can be recovered directly from the distorted output optical field *E*(*x*, *y*) by the inverse operation:

$$O\_{\rm rec}(\xi,\eta) = T\_{O \to E}(\mathbf{x}, y; \xi, \eta)^{-1} \times E(\mathbf{x}, y),\tag{6}$$

where *TO*→*E*(*x*, *y*; *ξ*, *η*) −1 is the inverse matrix (or pseudoinverse matrix for any (*ξ*, *η*)/(*x*, *y*) segments ratio) of .

#### **3. Experimental Study**

#### *3.1. Measure the Round-Trip TM*

Before imaging the object, the round-trip TM *TO*→*E*(*x*, *y*; *ξ*, *η*) of the scattering medium should be measured in advance.

The experimental setup is shown in Figure 2. A He-Ne laser with a wavelength of 632.8 nm is split into two by a beam splitter (BS1). The transmitted beam is reflected off by a mirror, after being reflected at a second beam splitter (BS2), the beam is distorted via the scattering medium to illuminate the DMD, then, the beam reflected by the DMD is distorted again via the scattering medium to generate the output wave. Meanwhile, the beam reflected by BS1, with the wave front being modulated by the LCVR, is used as the reference wave. At last, the output wave and the reference wave are combined to form an interference image at the CCD. In this way, the complex field distribution (both the amplitude and the phase) of the output wave can be acquired by using the phase-shifting digital holography technology [24].

**Figure 2.** Experimental setup. Scattering medium (a 220-grit and a 1500-grit Thorlabs Optics ground-glass diffuser are stacked together to enhance the scattering ability), DMD: digital micromirror devices (ViALUX, V-7001VIS, 1024 × 768 pixels), LCVR: liquid crystal variable retarder (Meadowlark Optics, D5020), CCD (Hamamatsu, C13440-20CU, 2048 × 2048 segments (pixels), the central 400 × 300 segments are used for imaging), L#: lens, P#: polarizer, BS#: beam splitter, A: attenuation film, M: mirror.

To acquire the round-trip TM, we divide the DMD into 64 × 48 segments (the size of each segment: 219 μm × 219 μm) and turn on only one segment in sequence. The sketch map of the measured *TO*→*E*(*x*, *y*; *ξ*, *η*) are shown in Figure 3a,b for the amplitude part and the phase part, respectively (Two-dimensional input DMD segments (*ξ*, *η*) and output CCD segments (*x*, *y*) are both stretched to one-dimensional to facilitate the computation, and only part of the DMD segments and CCD segments are shown). What we want to emphasize is that the measured *TO*→*E*(*x*, *y*; *ξ*, *η*) has the ability to overcome the round-trip distortion simultaneously without information loss, which is owing to the fact that it not only has played the role of the one-way TM, but has also recorded the complex field distribution of the distorted illumination wave.

**Figure 3.** Sketch map of the measured round-trip TM *TO*→*E*(*x*, *y*; *ξ*, *η*). Amplitude (**a**) and corresponding phase (**b**), respectively. Color bar: phase in radian.

#### *3.2. Imaging the Object*

After the *TO*→*E*(*x*, *y*; *ξ*, *η*) is measured, the system is ready to image the target object. In order to test the imaging quality precisely, we don't capture the image of a natural real object directly. Instead, a binary complex amplitude object which consists of the characters part and the background part, is constructed by a phase-only-modulation spatial light modulator (SLM: Meadowlark Optics, P1920-0635-HDMI, 1920 × 1152 pixels) using two phase masks *O*(1) SLM(*ξ*, *η*) and *O*(2) SLM(*ξ*, *η*) [15,16]. The mask *O*(1) SLM(*ξ*, *η*) is a plane phase whose amplitude = 1 and phase = π. The mask *O*(2) SLM(*ξ*, *η*) is obtained by flipping the phase of *O*(1) SLM(*ξ*, *η*) from π to 2π/3 for the characters part, and from π to -π/3 for the background part. As a result, a virtual 3D complex amplitude object *O*(2) SLM(*ξ*, *η*) − *O*(1) SLM(*ξ*, *η*)

can be constructed, which corresponds to the characters part with amplitude = 1 and phase = π/3 [as shown in Figure 4a], as well as the background part with amplitude = √3 and phase = −π/6 [as shown in Figure 4b], respectively.

**Figure 4.** Complex amplitude object constructed by the SLM using two phase masks *O*(1) SLM(*ξ*, *η*) and *O*(2) SLM(*ξ*, *η*). (**a**) amplitude = 1 and phase = π/3 for the characters part, (**b**) amplitude = √3 and phase = −π/6 for the background part.

Next, we will perform the imaging, and the SLM is located at the same place after removing the DMD. To match the size of the DMD segment (219 μm × 219 μm) used for measuring the round-trip TM of the scattering medium, the SLM is divided into 80 × 48 segments (the size of each segment 220 μm × 220 μm), and the central 18 × 14 segments are used to construct the complex amplitude object *O*(2) SLM(*ξ*, *η*) − *O*(1) SLM(*ξ*, *η*) whose amplitude and phase are shown in Figure 5a1,a2, respectively. The corresponding output optical field *E*(2) CCD(*x*, *y*) − *E*(1) CCD(*x*, *y*) is shown in Figure 5b1,b2 for the amplitude and the phase, respectively, where *E*(1) CCD(*x*, *y*) and *E*(2) CCD(*x*, *y*) are the output optical field correspond to the *O*(1) SLM(*ξ*, *η*) and *O*(2) SLM(*ξ*, *η*), respectively. It can be seen from Figure 5b1,b2 that the information of the object *O*(2) SLM(*ξ*, *η*) − *O*(1) SLM(*ξ*, *η*) has indeed been seriously destroyed, and it is impossible to image the object directly.

**Figure 5.** Imaging the complex amplitude object. (**a1**,**a2**) Amplitude and phase of the object *O*(2) SLM(*ξ*, *η*) − *O*(1) SLM(*ξ*, *η*), respectively. (**b1**,**b2**) Amplitude and phase of the corresponding output optical filed *E*(2) CCD(*x*, *y*) − *E*(1) CCD(*x*, *y*), respectively. (**c1**,**c2**) Amplitude and phase of the recovered object, respectively. (**d1**) Section profiles corresponding to the lines in (**a1**,**c1**); (**d2**) section profiles corresponding to the lines in (**a2**,**c2**). Scale bars indicate 400 μm in (**b1**,**b2**) and 600 μm in (**a1**,**a2**,**c1**,**c2**). Gray bar: amplitude. Color bar: phase in radian.

Finally, with the round-trip TM *TO*→*E*(*x*, *y*; *ξ*, *η*) being measured previously, according to Equation (6), the object information can be recovered directly from the distorted output optical field *E*(2) CCD(*x*, *y*) − *E*(1) CCD(*x*, *y*) by the inverse operation:

$$\mathcal{O}\_{\rm rec}(\xi,\eta) = T\_{\rm O \to E}(\mathbf{x}, y; \xi, \eta)^{-1} \times \left[ \mathcal{E}\_{\rm CCD}^{(2)}(\mathbf{x}, y) - \mathcal{E}\_{\rm CCD}^{(1)}(\mathbf{x}, y) \right]. \tag{7}$$

The results are shown in Figure 5c1,c2 for the amplitude and the phase, respectively. The section profiles in Figure 5d1, corresponding to the lines in Figure 5a1,c1, show that the amplitude of the object can be recovered; Similarly, the section profiles in Figure 5d2, corresponding to the lines in Figure 5a2,c2, show that the phase of the object can also be recovered well.

#### *3.3. Verify the Effectiveness of the Round-Trip TM*

In this part, to verify the effectiveness of our round-trip TM method, we will show that the illumination wave is indeed seriously distorted (for simplicity, only the amplitude is tested, and it can be predicted that the phase will get the same result). In such a case, the traditional one-way TM is ineffective.

Firstly, we have recorded the intensity (amplitude) distribution of the illumination wave (corresponding to *S*(*ξ*, *η*) in Figure 1) by placing a CCD in the place of the DMD, the result is shown in Figure 6a. It is seen that the originally uniformed incident light is seriously distorted due to the on-the-way-in process via the scattering medium. Furthermore, we multiply the amplitude of the object [shown in Figure 6b] by Figure 6a to indicate the amplitude of the reflected wave indirectly (corresponding to *R*(*ξ*, *η*) in Figure 1). The result is shown in Figure 6c. It is seen that the amplitude information of the object [*O*(*ξ*, *η*)] is completely submerged. This means that, even adopting the traditional one-way imaging method using the one-way TM, Figure 6c might be the best recovery result instead of the Figure 5c1 which could be obtained adopting our round-trip imaging method using the round-trip TM.

**Figure 6.** (**a**) Intensity (amplitude) distribution of the illumination wave. (**b**) Amplitude of the object. (**c**) Amplitude of the reflected wave. Scale bar: 550 μm.

#### **4. Discussion**

The pre-processing of our method is relatively complicated, as the round-trip TM of a scattering medium should be measured prior to image the object, which will usually take a few minutes. However, this is just a one-time procedure, once calibrated, the TM is effective continuously as long as the medium has not been disturbed.

Our method is effective for imaging through the thick scattering medium, and it does not involve any scanning operations during the imaging process. Therefore, it probably has potential applications in some new fields. On one hand, one can monitor the target through an apparently opaque screen (used as a barrier), while it is incapable of being observed by it. On the other hand, instead of as a barrier which undermines the imaging ability, a scattering medium can also be used actively as an imaging sensor. For example, the single multimode optical fiber, as a scattering medium due to the mode dispersion, could potentially open up new, less invasive forms of endoscopy to perform high-resolution imaging of tissues out of reach of current conventional endoscopes [19,25,26].

At present, the preliminary result shows that our method has the ability to recover the complex amplitude information of the object. However, as an early study, no real 3D object has been tested yet. In fact, many problems should be further resolved when imaging a real 3D object. For example, the 2π ambiguity problem when there is an abrupt change in surface height of the object. This problem could can be solved if the size of the DMD segment that used to measure the TM is further reduced.