Informal Urban Settlements and Cholera Risk in Dar es Salaam, Tanzania

PubMed Central

Penrose, Katherine; de Castro, Marcia Caldas; Werema, Japhet; Ryan, Edward T.

2010-01-01

Background As a result of poor economic opportunities and an increasing shortage of affordable housing, much of the spatial growth in many of the world's fastest-growing cities is a result of the expansion of informal settlements where residents live without security of tenure and with limited access to basic infrastructure. Although inadequate water and sanitation facilities, crowding and other poor living conditions can have a significant impact on the spread of infectious diseases, analyses relating these diseases to ongoing global urbanization, especially at the neighborhood and household level in informal settlements, have been infrequent. To begin to address this deficiency, we analyzed urban environmental data and the burden of cholera in Dar es Salaam, Tanzania. Methodology/Principal Findings Cholera incidence was examined in relation to the percentage of a ward's residents who were informal, the percentage of a ward's informal residents without an improved water source, the percentage of a ward's informal residents without improved sanitation, distance to the nearest cholera treatment facility, population density, median asset index score in informal areas, and presence or absence of major roads. We found that cholera incidence was most closely associated with informal housing, population density, and the income level of informal residents. Using data available in this study, our model would suggest nearly a one percent increase in cholera incidence for every percentage point increase in informal residents, approximately a two percent increase in cholera incidence for every increase in population density of 1000 people per km2 in Dar es Salaam in 2006, and close to a fifty percent decrease in cholera incidence in wards where informal residents had minimally improved income levels, as measured by ownership of a radio or CD player on average, in comparison to wards where informal residents did not own any items about which they were asked. In this study, the range of access to improved sanitation and improved water sources was quite narrow at the ward level, limiting our ability to discern relationships between these variables and cholera incidence. Analysis at the individual household level for these variables would be of interest. Conclusions/Significance Our results suggest that ongoing global urbanization coupled with urban poverty will be associated with increased risks for certain infectious diseases, such as cholera, underscoring the need for improved infrastructure and planning as the world's urban population continues to expand. PMID:20300569

Urban morphological determinants of temperature regulating ecosystem services in African cities: the case of Dar es Salaam, Tanzania

NASA Astrophysics Data System (ADS)

Cavan, Gina; Lindley, Sarah; Kibassa, Deusdedit; Shemdoe, Riziki; Capuano, Paolo; De Paola, Francesco; Renner, Florian; Pauleit, Stephan

2013-04-01

Urban green structure provides important regulating ecosystem services, such as temperature and flood regulation, and thus, has the potential to increase the resilience of African cities to climate change. Green structures within urban areas are not only limited to discrete units associated with recreational parks, agricultural areas and open spaces: they also exist within zones which have other primary functions, such as church yards, along transport routes, and within residential areas. Differing characteristics of urban areas can be conceptualised and subsequently mapped through the idea of urban morphology types. Urban morphology types are classifications which combine facets of urban form and function. When mapped, UMT units provide biophysically relevant meso-scale geographical zones which can be used as the basis for understanding climate-related impacts and adaptations. For example, they support the assessment of urban temperature patterns and the temperature regulating services provided by urban green structures. There are some examples of the use of UMTs for assessing regulating ecosystem services in European cities but little similar knowledge is available in an African context. This paper outlines the concept of urban morphology types (UMTs) and how they were applied to African case study cities (Cavan et al., 2012). It then presents the methods used to understand temperature regulating ecosystem services across an example African case study city, including (i) a GIS-based assessment of urban green structures, and (ii) applying an energy balance model to estimate current and future surface temperatures under climate change projections. The assessment is carried out for Dar es Salaam, Tanzania. Existing evidence suggests increases in both mean and extreme temperatures in the city. Historical analysis of the number of hot days per year suggests a rise from a maximum of 47 days per year in the period 1961-87 to 72 days per year in 2003-2011 (Giugni et al., 2012). Mean temperatures in the climate zone are estimated to increase by at least 1°C between 1971-2000 and 2021-2050(CSIR, 2012). Dar es Salaam is represented using around 1700 UMT units mapped across 43 UMT categories for the year 2008. Modelled surface temperature profiles for the city are presented, including an assessment of the potential impact of changing green structure cover within selected UMT categories. Provisional recommendations are made concerning the potential contribution of green structures as a climate adaptation response to the increasing temperatures in Dar es Salaam, which could be relevant for other African cities in similar climate zones. References Cavan, G., Lindley, S., Yeshitela, K., Nebebe, A., Woldegerima, T., Shemdoe, R., Kibassa, D., Pauleit, S., Renner, R., Printz, A., Buchta, K., Coly, A., Sall, F., Ndour, N. M., Ouédraogo, Y., Samari, B. S., Sankara, B. T., Feumba, R. A., Ngapgue, J. N., Ngoumo, M. T., Tsalefac, M., Tonye, E. (2012) CLUVA deliverable D2.7 Green infrastructure maps for selected case studies and a report with an urban green infrastructure mapping methodology adapted to African cities. http://www.cluva.eu/deliverables/CLUVA_D2.7.pdf. Accessed 18/12/12. CSIR (2012) CLUVA deliverable D1.5 Regional climate change simulations available for the selected areas http://www.cluva.eu/deliverables/CLUVA_D1.5.pdf. Accessed 8/1/13. Giugni, M., Adamo, P., Capuano, P., De Paola, F., Di Ruocco, A., Giordano, S., Iavazzo, P., Sellerino, M., Terracciano, S., Topa, M. E. (2012) CLUVA deliverable D.1.2 Hazard scenarios for test cities using available data. http://www.cluva.eu/deliverables/CLUVA_D1.2.pdf. Accessed 8/1/13

Cholera Mortality during Urban Epidemic, Dar es Salaam, Tanzania, August 16, 2015–January 16, 20161

PubMed Central

Massay, Amani Elibariki; Narra, Rupa; Mghamba, Janneth; Mohamed, Ahmed Abade; Kishimba, Rogath Saika; Urio, Loveness John; Rusibayamila, Neema; Magembe, Grace; Bakari, Muhammud; Gibson, James J.; Eidex, Rachel Barwick; Quick, Robert E.

2017-01-01

In 2015, a cholera epidemic occurred in Tanzania; most cases and deaths occurred in Dar es Salaam early in the outbreak. We evaluated cholera mortality through passive surveillance, burial permits, and interviews conducted with decedents’ caretakers. Active case finding identified 101 suspected cholera deaths. Routine surveillance had captured only 48 (48%) of all cholera deaths, and burial permit assessments captured the remainder. We interviewed caregivers of 56 decedents to assess cholera management behaviors. Of 51 decedents receiving home care, 5 (10%) used oral rehydration solution after becoming ill. Caregivers reported that 51 (93%) of 55 decedents with known time of death sought care before death; 16 (29%) of 55 delayed seeking care for >6 h. Of the 33 (59%) community decedents, 20 (61%) were said to have been discharged from a health facility before death. Appropriate and early management of cholera cases can reduce the number of cholera deaths. PMID:29155665

Work from waste.

PubMed

Eliah, E

2000-01-01

In Tanzania, rural residents are seeking better opportunities in the capital city of Dar-es-Salaam. This migration has generated problems, such as unplanned housing, low water supplies, and unemployment. In view of the competition in food processing, Mwanaidi Msosa and other members of the Kisutu Women Development Trust (KIWODET) sought financial returns in trash collecting. This paper reports how women workers are cleaning up their city, and breaking new ground in small-scale private sector employment. In 1998, 20 home-based workers from the KIWODET started ridding the city, as well as neighboring areas, of trash in exchange for money. When the Dar-es-Salaam City Commission privatized urban trash collection and street cleaning, KIWODET tendered with other contractors and organizations to operate in their neighborhood. Such an approach not only made the city cleaner, but has also created an estimate of 1000 new jobs. In addition, recycling was introduced as an attractive side-business.

Homicide death in Dar es Salaam, Tanzania 2005.

PubMed

Outwater, Anne H; Campbell, Jacquelyn C; Mgaya, Edward; Abraham, Alison G; Kinabo, Linna; Kazaura, Method; Kub, Joan

2008-12-01

Violence disproportionately affects low- and middle-income countries. Deeper understanding is needed in areas where little research has occurred. The objectives of the study were to: (a) ascertain rate of homicide death; (b) describe the victims and circumstances surrounding their deaths in Dar es Salaam, Tanzania in 2005. This study was developed by adapting the WHO/CDC Injury Surveillance Guidelines (Holder et al., 2001). Data on 12 variables were collected on all homicide deaths. Descriptive statistics and hypothesis tests were done when appropriate. Age standardised, age-specific and cause-specific mortality rates are presented. The overall homicide rate was 12.57 (males and females respectively: 22.26 and 2.64). Homicide deaths were 93.4% male, mostly unemployed, with a mean age of 28.2 years. Most deaths occurred in urban areas. Mob violence was the cause of 57% of deaths. The risk of homicide death for males was greater than the world average, but for females it was less. Most homicides were committed by community members policing against thieves.

A tool box for operational mosquito larval control: preliminary results and early lessons from the Urban Malaria Control Programme in Dar es Salaam, Tanzania

PubMed Central

Fillinger, Ulrike; Kannady, Khadija; William, George; Vanek, Michael J; Dongus, Stefan; Nyika, Dickson; Geissbühler, Yvonne; Chaki, Prosper P; Govella, Nico J; Mathenge, Evan M; Singer, Burton H; Mshinda, Hassan; Lindsay, Steven W; Tanner, Marcel; Mtasiwa, Deo; de Castro, Marcia C; Killeen, Gerry F

2008-01-01

Background As the population of Africa rapidly urbanizes, large populations could be protected from malaria by controlling aquatic stages of mosquitoes if cost-effective and scalable implementation systems can be designed. Methods A recently initiated Urban Malaria Control Programme in Dar es Salaam delegates responsibility for routine mosquito control and surveillance to modestly-paid community members, known as Community-Owned Resource Persons (CORPs). New vector surveillance, larviciding and management systems were designed and evaluated in 15 city wards to allow timely collection, interpretation and reaction to entomologic monitoring data using practical procedures that rely on minimal technology. After one year of baseline data collection, operational larviciding with Bacillus thuringiensis var. israelensis commenced in March 2006 in three selected wards. Results The procedures and staff management systems described greatly improved standards of larval surveillance relative to that reported at the outset of this programme. In the first year of the programme, over 65,000 potential Anopheles habitats were surveyed by 90 CORPs on a weekly basis. Reaction times to vector surveillance at observations were one day, week and month at ward, municipal and city levels, respectively. One year of community-based larviciding reduced transmission by the primary malaria vector, Anopheles gambiae s.l., by 31% (95% C.I. = 21.6–37.6%; p = 0.04). Conclusion This novel management, monitoring and evaluation system for implementing routine larviciding of malaria vectors in African cities has shown considerable potential for sustained, rapidly responsive, data-driven and affordable application. Nevertheless, the true programmatic value of larviciding in urban Africa can only be established through longer-term programmes which are stably financed and allow the operational teams and management infrastructures to mature by learning from experience. PMID:18218148

keep your models up-to-date: connecting community mapping data to complex urban flood modelling

NASA Astrophysics Data System (ADS)

Winsemius, Hessel; Eilander, Dirk; Ward, Philip; Diaz Loaiza, Andres; Iliffe, Mark; Mawanda, Shaban; Luo, Tianyi; Kimacha, Nyambiri; Chen, Jorik

2017-04-01

The world is urbanizing rapidly. According to the United Nation's World Urbanization Prospect, 50% of the global population already lives in urban areas today. This number is expected to grow to 66% by 2050. The rapid changes in these urban environments go hand in hand with rapid changes in natural hazard risks, in particular in informal unplanned neighbourhoods. In Dar Es Salaam - Tanzania, flood risk dominates and given the rapid changes in the city, continuous updates of detailed street level hazard and risk mapping are needed to adequately support decision making for urban planning, infrastructure design and disaster response. Over the past years, the Ramani Huria and Zuia Mafuriko projects have mapped the most flood prone neighbourhoods, including roads, buildings, drainage and land use and contributed data to the open-source OpenStreetMap database. In this contribution, we will demonstrate how we mobilize these contributed data to establish dynamic flood models for Dar Es Salaam and keep these up-to-date by making a direct link between the data, and model schematization. The tools automatically establish a sound 1D drainage network as well as a high resolution terrain dataset, by fusing the OpenStreetMap data with existing lower resolution terrain data such as the globally available satellite based SRTM 30. It then translates these fully automatically into the inputs required for the D-HYDRO modeling suite. Our tools are built such that community and stakeholder knowledge can be included in the model details through workshops with the tools so that missing essential information about the city's details can be augmented on-the-fly. This process creates a continuous dialogue between members of the community that collect data, and stakeholders requiring data for flood models. Moreover, used taxonomy and data filtering can be configured to conditions in other cities, making the tools generic and scalable. The tools are made available open-source.

Constraints on good child-care practices and nutritional status in urban Dar-es-Salaam, Tanzania.

PubMed

Kulwa, Kissa B M; Kinabo, Joyce L D; Modest, Beata

2006-09-01

Care is increasingly being recognized as a crucial input to child health and nutrition, along with food security, availability of health services, and a healthy environment. Although significant gains have been made in the fight against malnutrition in Tanzania, the nutritional status of preschool children in urban areas is not improving. To assess child-care practices and the nutritional status of infants and young children with the aim of improvingfeeding practices and child nutritional status. A cross-sectional study was undertaken in urban Dar-es-Salaam, Tanzania. The study involved 100 randomly selected mothers of children 6 to 24 months old from households in Ilala Municipality, one of the three municipalities that constitute the Dar-es-Salaam City Council. Data were collected by a structured questionnaire, spot-check observations, and anthropometric measurements. The prevalence rates of stunting, underweight, wasting, and morbidity were 43%, 22%, 3%, and 80%, respectively. The prevalence of exclusive breastfeeding was very low (9%), and most stunted children (88%) were not exclusively breastfed for the first 6 months. The mean age at which complementary foods and fluids were introduced was 3.26 +/- 1.12 months (range, 1 to 5 months). The fluids given were mainly water and thin cereal-based porridge. More than half of the households practiced good hygiene. Most of the psychosocial practices (e.g., caregiver's attention, affection, and involvement in child feeding, hygiene, health care, and training) were performed by mothers, except for cooking and feeding the children and child training, which were done mostly by alternative caregivers. Nearly half of the mothers (44%) worked out of the home. The mean number of working hours per day was long (10.32 +/- 2.13), necessitating the use of alternative caregivers. A negative correlation was found between height-for-age z-scores and the number of hours mothers worked outside the home. The prevalence rates of chronic malnutrition and morbidity are high, and child-feeding practices are inadequate in this urban population. Maternal employment and educational characteristics constrain good child-care practices, and alternative caregivers are taking a more important role in child care as mothers join the work force. We recommend that formative research be conducted to study the actual practices of caregivers in order to form the basis for a child-care education program. There is also a need to strengthen national health system support for improved child feeding.

Consumption of commercially produced snack foods and sugar-sweetened beverages during the complementary feeding period in four African and Asian urban contexts.

PubMed

Pries, Alissa M; Huffman, Sandra L; Champeny, Mary; Adhikary, Indu; Benjamin, Margaret; Coly, Aminata Ndeye; Diop, El Hadji Issakha; Mengkheang, Khin; Sy, Ndèye Yaga; Dhungel, Shrid; Feeley, Alison; Vitta, Bineti; Zehner, Elizabeth

2017-10-01

The availability and consumption of commercially produced foods and beverages have increased across low-income and middle-income countries. This cross-sectional survey assessed consumption of commercially produced foods and beverages among children 6-23 months of age, and mothers' exposure to promotions for these products. Health facility-based interviews were conducted among 218 randomly sampled mothers utilizing child health services in Dakar, Senegal; 229 in Dar es Salaam, Tanzania; 228 in Kathmandu Valley, Nepal; and 222 in Phnom Penh, Cambodia. In the day prior to the interview, 58.7% of 6-23-month-olds in Dakar, 23.1% in Dar es Salaam, 74.1% in Kathmandu Valley, and 55.0% in Phnom Penh had consumed a commercially produced snack food. In the previous week, the majority of children in Dakar (79.8%), Kathmandu Valley (91.2%), and Phnom Penh (80.6%) had consumed such products. Consumption of commercially produced sugar-sweetened beverages was noted among 32.0% of Phnom Penh, 29.8% of Dakar, 23.1% of Dar es Salaam, and 16.2% of Kathmandu Valley children. Maternal education was negatively associated with commercial snack food consumption in Dakar and Kathmandu Valley. Children of Phnom Penh mothers in the lowest wealth tercile were 1.5 times more likely to consume commercial snack food products, compared to wealthier mothers. These snack consumption patterns during the critical complementary feeding period demand attention; such products are often high in added sugars and salt, making them inappropriate for infants and young children. © 2017 John Wiley & Sons Ltd.

Does Personalized Water and Hand Quality Information Affect Attitudes, Behavior, and Health in Dar es Salaam, Tanzania?

NASA Astrophysics Data System (ADS)

Davis, J.; Pickering, A.; Horak, H.; Boehm, A.

2008-12-01

Tanzania (TZ) has one of the highest rates of child mortality due to enteric disease in the world. NGOs and local agencies have introduced numerous technologies (e.g., chlorine tablets, borewells) to increase the quantity and quality of water in Dar es Salaam, the capital of Tanzania, in hopes of reducing morbidity and mortality of waterborne disease. The objective of the present study is to determine if providing personalized information about water quality and hand surface quality, as determined by concentrations of enterococci and E. coli, results in improved health and water quality in households. A cohort study was completed in June-September 2008 in 3 communities ranging from urban to per-urban in Dar es Salaam, Tanzania to achieve our objective. The study consisted of 4 cohorts that were visited 4 times over the 3 month study. One cohort received no information about water and hand quality until the end of the summer, while the other groups received either just information on hand surface quality, just information on water quality, and information on both hand surface and water quality after the first (baseline) household visit. We report concentrations of enterococci and E. coli in water sources (surface waters and bore wells), water stored in households, and environmental waters were children and adults swim and bathe. In addition, we report concentrations of enterococci and E. coli on hands of caregivers and children in households. Preliminary results of surveys on health and perceptions of water quality and illness from the households are provided. Ongoing work will integrate the microbiological and sociological data sets to determine if personalized information interventions resulted in changes in health, water quality in the household, or perceptions of water quality, quantity and relation to human health. Future work will analyze DNA samples from hands and water for human-specific Bacteroides bacteria which are only present in human feces. Our study has the potential to provide empirical evidence to promote large scale monitoring and education campaigns in Africa to improve health and reduce the burden of waterborne disease.

Institutional evolution of a community-based programme for malaria control through larval source management in Dar es Salaam, United Republic of Tanzania.

PubMed

Chaki, Prosper P; Kannady, Khadija; Mtasiwa, Deo; Tanner, Marcel; Mshinda, Hassan; Kelly, Ann H; Killeen, Gerry F

2014-06-25

Community-based service delivery is vital to the effectiveness, affordability and sustainability of vector control generally, and to labour-intensive larval source management (LSM) programmes in particular. The institutional evolution of a city-level, community-based LSM programme over 14 years in urban Dar es Salaam, Tanzania, illustrates how operational research projects can contribute to public health governance and to the establishment of sustainable service delivery programmes. Implementation, management and governance of this LSM programme is framed within a nested set of spatially-defined relationships between mosquitoes, residents, government and research institutions that build upward from neighbourhood to city and national scales. The clear hierarchical structure associated with vertical, centralized management of decentralized, community-based service delivery, as well as increasingly clear differentiation of partner roles and responsibilities across several spatial scales, contributed to the evolution and subsequent growth of the programme. The UMCP was based on the principle of an integrated operational research project that evolved over time as the City Council gradually took more responsibility for management. The central role of Dar es Salaam's City Council in coordinating LSM implementation enabled that flexibility; the institutionalization of management and planning in local administrative structures enhanced community-mobilization and funding possibilities at national and international levels. Ultimately, the high degree of program ownership by the City Council and three municipalities, coupled with catalytic donor funding and technical support from expert overseas partners have enabled establishment of a sustainable, internally-funded programme implemented by the National Ministry of Health and Social Welfare and supported by national research and training institutes.

Institutional evolution of a community-based programme for malaria control through larval source management in Dar es Salaam, United Republic of Tanzania

PubMed Central

2014-01-01

Background Community-based service delivery is vital to the effectiveness, affordability and sustainability of vector control generally, and to labour-intensive larval source management (LSM) programmes in particular. Case description The institutional evolution of a city-level, community-based LSM programme over 14 years in urban Dar es Salaam, Tanzania, illustrates how operational research projects can contribute to public health governance and to the establishment of sustainable service delivery programmes. Implementation, management and governance of this LSM programme is framed within a nested set of spatially-defined relationships between mosquitoes, residents, government and research institutions that build upward from neighbourhood to city and national scales. Discussion and evaluation The clear hierarchical structure associated with vertical, centralized management of decentralized, community-based service delivery, as well as increasingly clear differentiation of partner roles and responsibilities across several spatial scales, contributed to the evolution and subsequent growth of the programme. Conclusions The UMCP was based on the principle of an integrated operational research project that evolved over time as the City Council gradually took more responsibility for management. The central role of Dar es Salaam’s City Council in coordinating LSM implementation enabled that flexibility; the institutionalization of management and planning in local administrative structures enhanced community-mobilization and funding possibilities at national and international levels. Ultimately, the high degree of program ownership by the City Council and three municipalities, coupled with catalytic donor funding and technical support from expert overseas partners have enabled establishment of a sustainable, internally-funded programme implemented by the National Ministry of Health and Social Welfare and supported by national research and training institutes. PMID:24964790

Habitat characterization and spatial distribution of Anopheles sp. mosquito larvae in Dar es Salaam (Tanzania) during an extended dry period

PubMed Central

Sattler, Michael A; Mtasiwa, Deo; Kiama, Michael; Premji, Zul; Tanner, Marcel; Killeen, Gerry F; Lengeler, Christian

2005-01-01

Introduction By 2030, more than 50% of the African population will live in urban areas. Controlling malaria reduces the disease burden and further improves economic development. As a complement to treated nets and prompt access to treatment, measures targeted against the larval stage of Anopheles sp. mosquitoes are a promising strategy for urban areas. However, a precise knowledge of the geographic location and potentially of ecological characteristics of breeding sites is of major importance for such interventions. Methods In total 151 km2 of central Dar es Salaam, the biggest city of Tanzania, were systematically searched for open mosquito breeding sites. Ecologic parameters, mosquito larvae density and geographic location were recorded for each site. Logistic regression analysis was used to determine the key ecological factors explaining the different densities of mosquito larvae. Results A total of 405 potential open breeding sites were examined. Large drains, swamps and puddles were associated with no or low Anopheles sp. larvae density. The probability of Anopheles sp. larvae to be present was reduced when water was identified as "turbid". Small breeding sites were more commonly colonized by Anopheles sp. larvae. Further, Anopheles gambiae s.l. larvae were found in highly organically polluted habitats. Conclusions Clear ecological characteristics of the breeding requirements of Anopheles sp. larvae could not be identified in this setting. Hence, every stagnant open water body, including very polluted ones, have to be considered as potential malaria vector breeding sites. PMID:15649333

Evaluation of buparvaquone (BUTA-Kel KELA, Belgium) as a treatment of East Coast fever in cattle, in the peri-urban of Dar Es Salaam city, Tanzania.

PubMed

Mbwambo, H A; Magwisha, H B; Mfinanga, J M

2006-06-30

Evaluation trials of the efficacy of buparvaquone (BUTA-kel KELA Laboratoria, N.V. Belgium), as a treatment of field cases of Theileria parva infection (East Coast fever - ECF) were carried out on 63 cattle in the peri-urban of Dar Es Salaam city, Tanzania, during the period November 2004 to August 2005. Thirty-two cattle (56%) received single-dose treatment (2.5 mg buparvaquone per kg body weight), while two and three-dose treatment with interval(s) of 48 h was given to 33% and 11% of total treated cattle, respectively; 38 cattle (60.3%) were treated at an early stage of the disease, while 25 cattle (39.7%) were treated at an advanced stage of the disease. The rectal body temperature of 90.5% of buparvaquone-treated cattle dropped to normal values (37.5-39.5 degrees C) by day 7 of treatment, and by day 15 of treatment 96.8% of treated cattle showed normal values. Pulmonary signs were observed in 8/68 (11.8%) of total ECF diagnosed cattle and were successfully treated, albeit with parvaquone plus frusemide (Fruvexon); were not included in final evaluation of the efficacy of BUTA-kel. The present evaluation trials record a recovery rate of 95.2%. Buparvaquone (BUTA-kel KELA Laboratoria, N.V. Belgium), therefore, records another efficacious and valuable alternative treatment against East Coast fever in Tanzania.

Urbanisation, poverty and sexual behaviour: the tale of five African cities.

PubMed

Greif, Meredith J; Dodoo, F Nii-Amoo; Jayaraman, Anuja

2011-01-01

The question of how urbanisation and poverty are linked in sub-Saharan Africa is an increasingly pressing one. The urban character of the HIV epidemic in sub-Saharan Africa exacerbates concern about the urbanisation - poverty relationship. Recent empirical work has linked urban poverty, and particularly slum residence, to risky sexual behaviour in Kenya's capital city, Nairobi. This paper explores the generalisability of these assertions about the relationship between urban poverty and sexual behaviour using Demographic and Health Survey data from five African cities: Accra (Ghana), Dar-es-Salaam (Tanzania), Harare (Zimbabwe), Kampala (Uganda) and Nairobi (Kenya). The study affirms that, although risky behaviour varies across the five cities, slum residents demonstrate riskier sexual behaviour compared with non-slum residents. There is earlier sexual debut, lower condom usage and more multiple sexual partners among women residing in slum households regardless of setting, suggesting a relatively uniform effect of urban poverty on sexual risk behaviour.

Mapping Urban Tree Canopy Cover Using Fused Airborne LIDAR and Satellite Imagery Data

NASA Astrophysics Data System (ADS)

Parmehr, Ebadat G.; Amati, Marco; Fraser, Clive S.

2016-06-01

Urban green spaces, particularly urban trees, play a key role in enhancing the liveability of cities. The availability of accurate and up-to-date maps of tree canopy cover is important for sustainable development of urban green spaces. LiDAR point clouds are widely used for the mapping of buildings and trees, and several LiDAR point cloud classification techniques have been proposed for automatic mapping. However, the effectiveness of point cloud classification techniques for automated tree extraction from LiDAR data can be impacted to the point of failure by the complexity of tree canopy shapes in urban areas. Multispectral imagery, which provides complementary information to LiDAR data, can improve point cloud classification quality. This paper proposes a reliable method for the extraction of tree canopy cover from fused LiDAR point cloud and multispectral satellite imagery data. The proposed method initially associates each LiDAR point with spectral information from the co-registered satellite imagery data. It calculates the normalised difference vegetation index (NDVI) value for each LiDAR point and corrects tree points which have been misclassified as buildings. Then, region growing of tree points, taking the NDVI value into account, is applied. Finally, the LiDAR points classified as tree points are utilised to generate a canopy cover map. The performance of the proposed tree canopy cover mapping method is experimentally evaluated on a data set of airborne LiDAR and WorldView 2 imagery covering a suburb in Melbourne, Australia.

Architectural design led approach to sustainable tourism for the waterfront development of Kunduchi in Tanzania

NASA Astrophysics Data System (ADS)

Leus, M.; Winkels, P.; Hannes, E.

2018-04-01

In Kunduchi, located in the Kinondoni district of the Dar es Salaam Region, it is of vital importance for the lives and livelihoods of the indigenous people to preserve the typical ecosystems and ensure the identity and economic resilience of these areas. The problem statement is as follows: In what way can sustainable tourism in Kunduchi serve as an engine for economic and social empowerment? How can Kunduchi be an inspiring example for the development of the coast of Dar Es Salaam in Tanzania that is threatened by large-scale tourist infrastructure? How to design sustainable solutions with respect for the local community and the local traditions? Firstly, a theoretical framework that connects sustainable tourism with the sustainable development of coastal areas is defined. Assumptions made on the basis of the literature review provide parameters that play an important role in the architectural concepts. Secondly, a research by design is presented in order to analyze and evaluate different scenarios to outline the opportunities of sustainable tourism on site of Kunduchi. Sustainable waterfront development is an obvious subtitle since the subtle spatial integration of these projects in the urban and water related context of Dares Salaam is of major importance.

Pattern of childhood falls in a low-income setting: a cross-sectional study in Dar es Salaam.

PubMed

Kamala, Benjamin; Wilson, Michael L; Hasselberg, Marie

2011-12-01

The objective was to determine patterns and circumstances of childhood falls in a low-income setting in Dar es Salaam, Tanzania. This cross sectional study is based on a household survey conducted in July 2009. A total of 3927 children up to age 18 from 1928 households in 15 sampled wards were surveyed through a structured questionnaire. The current study includes information regarding fall occurrence, socio-demographic and economic factors. Data were analysed using chi-square, t-test and logistic regression. Male children had 42% higher odds of falls compared to females, and rural residents had more than two times higher odds compared to urban residents. Falls occurred three times more among age group 1-4 and two times more among age group 5-9 compared to those between 15 and 18 years. Most falls occurred outdoors (62%) while playing (51%) with boys being over-represented. Females and children aged 1-4 years fell more from stairs whereas most infants fell from furniture. Male gender, younger age groups and rural residence were significant factors for fall injuries. The circumstances in which these falls occur also differ significantly. Intervention efforts should emphasise these patterns.

Integrating ICT into Teaching and Learning at the University of Dar es Salaam

ERIC Educational Resources Information Center

Mtebe, Joel S.; Dachi, Hilary; Raphael, Christina

2011-01-01

Since 1985, Tanzania has been undergoing significant political and economic changes from a centralized to a more market-oriented and globally connected economy. The University of Dar es Salaam (UDSM) has responded to these changes by reviewing its legal status, vision, and functions, particularly those related to research, teaching, and public…

Students' Experiences and Challenges of Blended Learning at the University of Dar Es Salaam, Tanzania

ERIC Educational Resources Information Center

Mtebe, Joel S.; Raphael, Christina

2013-01-01

Recent developments in Information and Communication Technologies (ICTs), especially eLearning, have heightened the need for University of Dar es Salaam (UDSM) to supplement on-campus face-to-face delivery as well as meeting increased students' enrolments through blended distance learning. Since 2008, the University has been offering three…

A Decade of Technology Enhanced Learning at the University of Dar es Salaam, Tanzania: Challenges, Achievements, and Opportunities

ERIC Educational Resources Information Center

Mtebe, Joel S.; Raphael, Christina

2017-01-01

For a decade past, integration of technology in teaching and learning has been received with both apprehension and skeptism from academics and student majority at the University of Dar es Salaam (UDSM). The study recounts real, professional and practical experiences, challenges, and opportunities of integrating educational technologies using…

Provision of Vocational Skills Education to Orphans: Lessons from Orphanage Centres in Dar es Salaam City, Tanzania

ERIC Educational Resources Information Center

Meli, Benjamin Mbeba

2015-01-01

This paper utilises data from a study that investigated the efficacy of vocational skills training provided to orphans from three orphanages in Temeke District, Dar es Salaam. The three orphanage centres that were studied are Kurasini National Children Home, Saudia and Don Bosco Vocational Centre. The sample comprised of 45 orphans, an official…

The use of LiDAR-derived high-resolution DSM and intensity data to support modelling of urban flooding

NASA Astrophysics Data System (ADS)

Aktaruzzaman, Md.; Schmitt, Theo G.

2011-11-01

This paper addresses the issue of a detailed representation of an urban catchment in terms of hydraulic and hydrologic attributes. Modelling of urban flooding requires a detailed knowledge of urban surface characteristics. The advancement in spatial data acquisition technology such as airborne LiDAR (Light Detection and Ranging) has greatly facilitated the collection of high-resolution topographic information. While the use of the LiDAR-derived Digital Surface Model (DSM) has gained popularity over the last few years as input data for a flood simulation model, the use of LiDAR intensity data has remained largely unexplored in this regard. LiDAR intensity data are acquired along with elevation data during the data collection mission by an aircraft. The practice of using of just aerial images with RGB (Red, Green and Blue) wavebands is often incapable of identifying types of surface under the shadow. On the other hand, LiDAR intensity data can provide surface information independent of sunlight conditions. The focus of this study is the use of intensity data in combination with aerial images to accurately map pervious and impervious urban areas. This study presents an Object-Based Image Analysis (OBIA) framework for detecting urban land cover types, mainly pervious and impervious surfaces in order to improve the rainfall-runoff modelling. Finally, this study shows the application of highresolution DSM and land cover maps to flood simulation software in order to visualize the depth and extent of urban flooding phenomena.

How Children Living in Poor Areas of Dar Es Salaam, Tanzania Perceive Their Own Multiple Intelligences

ERIC Educational Resources Information Center

Dixon, Pauline; Humble, Steve; Chan, David W.

2016-01-01

This study was carried out with 1,857 poor children from 17 schools, living in low-income areas of Dar Es Salaam, Tanzania. All children took the "Student Multiple Intelligences Profile" (SMIP) questionnaire as part of a bigger project that gathered data around concepts and beliefs of talent. This paper sets out two aims, first to…

Practical Use of ICT in Science and Mathematics Teachers' Training at Dar es Salaam University College of Education: An Analysis of Prospective Teachers' Technological Pedagogical Content Knowledge

ERIC Educational Resources Information Center

Kafyulilo, Ayoub C.

2010-01-01

This study investigated the ways through which pre-service science and mathematics teachers at Dar es Salaam University College of Education (DUCE) can acquire competencies for integrating technology pedagogy and content in teaching. Specifically the study investigated the preservice teachers' ICT integration competencies; practices that can be…

National and Global: A History of Scholars' Experiences with Research at the University of Dar Es Salaam, Tanzania (1961-Present)

ERIC Educational Resources Information Center

Jamison, Amy J.

2010-01-01

In this dissertation, I draw on research carried out at the University of Dar es Salaam (UDSM), Tanzania in 2008 to examine Tanzanian academics' experience with research throughout the history of this institution. This dissertation is designed as an historical case study and investigates how economic and political changes in Tanzania's…

Claiming territory: medical mission, interreligious revivalism, and the spatialization of health interventions in urban Tanzania.

PubMed

Dilger, Hansjörg

2014-01-01

Over the past decades, new religious actors have become involved in the provision of medical care in urban Tanzania. Muslim revivalist organizations and neo-Pentecostal churches in particular have established a range of health interventions that are tied to revisionist claims about religion, spirituality, and politics in society. In this article I discuss medical mission in Dar es Salaam in the light of (post)colonial histories of health service provision as well as with regard to inter- and intradenominational contestations over health and well-being, a morally acceptable life, and political participation. I argue that the nature of the inscription of revivalist organizations in urban space through health interventions depends on their structural location and their respective members' social and economic capital. I also show that the ongoing transformations of urban space through medical mission have become reflective of, as well as are triggering, moral interpretations of history and social inequality in contemporary Tanzania.

Intimate Partner Violence and the Association with HIV Risk Behaviors among Young Men in Dar Es Salaam, Tanzania

ERIC Educational Resources Information Center

Maman, Suzanne; Yamanis, Thespina; Kouyoumdjian, Fiona; Watt, Melissa; Mbwambo, Jessie

2010-01-01

There is growing evidence of the association between gender-based violence and HIV from the perspective and experiences of women. The purpose of this study is to examine these associations from the perspective of young men living in Dar es Salaam, Tanzania. A community-based sample of 951 men were interviewed, of whom 360 had sex in the past 6…

Factors Contributing to the Accumulation of Primary Teacher's Debts to the Government of Tanzania: A Case Study for Dar Es Salaam Region

ERIC Educational Resources Information Center

Kombo, Ibun

2015-01-01

This paper presents the findings of the study which was conducted to determine factors contributing to the accumulation of primary school teacher's debts to the Government of Tanzania, a case study of Dar es Salaam Region in its three municipalities namely, Ilala, Kinondoni and Temeke. Data was obtained through sampling method which also helped to…

Seasonal changes in the larvel populations of Aedes aegypti in two biotopes in Dar es Salaam, Tanzania

PubMed Central

Trpis, Milan

1972-01-01

The seasonal dynamics of larval populations of Aedes aegypti was studied in two different biotopes in Dar es Salaam, Tanzania. The first biotope was located on the Msasani peninsula on the coast 6 km north of Dar es Salaam, where A. aegypti breeds exclusively in coral rock holes. The population dynamics was studied during both the rainy and the dry season. Seasonal changes in the density of A. aegypti larvae depend primarily on variation in rainfall. The population of larvae dropped to zero only for a short time during the driest period while the adult population was maintained at a low level. The second biotope was in an automobile dump in a Dar es Salaam suburb, where A. aegypti breeds in artificial containers such as tires, automobile parts, tins, coconut shells, and snail shells. The greater part of the A. aegypti population of this biotope is maintained in the egg stage during the dry season. It serves as a focal point for breeding during the dry season: with the coming of the rains, the population expands into the surrounding residential areas. More than 70% of the larval population developed in tires, 20% in tins, 5% in coconut shells, and 1% in snail shells. PMID:4539415

Effects of LiDAR point density and landscape context on estimates of urban forest biomass

NASA Astrophysics Data System (ADS)

Singh, Kunwar K.; Chen, Gang; McCarter, James B.; Meentemeyer, Ross K.

2015-03-01

Light Detection and Ranging (LiDAR) data is being increasingly used as an effective alternative to conventional optical remote sensing to accurately estimate aboveground forest biomass ranging from individual tree to stand levels. Recent advancements in LiDAR technology have resulted in higher point densities and improved data accuracies accompanied by challenges for procuring and processing voluminous LiDAR data for large-area assessments. Reducing point density lowers data acquisition costs and overcomes computational challenges for large-area forest assessments. However, how does lower point density impact the accuracy of biomass estimation in forests containing a great level of anthropogenic disturbance? We evaluate the effects of LiDAR point density on the biomass estimation of remnant forests in the rapidly urbanizing region of Charlotte, North Carolina, USA. We used multiple linear regression to establish a statistical relationship between field-measured biomass and predictor variables derived from LiDAR data with varying densities. We compared the estimation accuracies between a general Urban Forest type and three Forest Type models (evergreen, deciduous, and mixed) and quantified the degree to which landscape context influenced biomass estimation. The explained biomass variance of the Urban Forest model, using adjusted R2, was consistent across the reduced point densities, with the highest difference of 11.5% between the 100% and 1% point densities. The combined estimates of Forest Type biomass models outperformed the Urban Forest models at the representative point densities (100% and 40%). The Urban Forest biomass model with development density of 125 m radius produced the highest adjusted R2 (0.83 and 0.82 at 100% and 40% LiDAR point densities, respectively) and the lowest RMSE values, highlighting a distance impact of development on biomass estimation. Our evaluation suggests that reducing LiDAR point density is a viable solution to regional-scale forest assessment without compromising the accuracy of biomass estimates, and these estimates can be further improved using development density.

Surface characteristics modeling and performance evaluation of urban building materials using LiDAR data.

PubMed

Li, Xiaolu; Liang, Yu

2015-05-20

Analysis of light detection and ranging (LiDAR) intensity data to extract surface features is of great interest in remote sensing research. One potential application of LiDAR intensity data is target classification. A new bidirectional reflectance distribution function (BRDF) model is derived for target characterization of rough and smooth surfaces. Based on the geometry of our coaxial full-waveform LiDAR system, the integration method is improved through coordinate transformation to establish the relationship between the BRDF model and intensity data of LiDAR. A series of experiments using typical urban building materials are implemented to validate the proposed BRDF model and integration method. The fitting results show that three parameters extracted from the proposed BRDF model can distinguish the urban building materials from perspectives of roughness, specular reflectance, and diffuse reflectance. A comprehensive analysis of these parameters will help characterize surface features in a physically rigorous manner.

Effects of LiDAR point density and landscape context on the retrieval of urban forest biomass

NASA Astrophysics Data System (ADS)

Singh, K. K.; Chen, G.; McCarter, J. B.; Meentemeyer, R. K.

2014-12-01

Light Detection and Ranging (LiDAR), as an alternative to conventional optical remote sensing, is being increasingly used to accurately estimate aboveground forest biomass ranging from individual tree to stand levels. Recent advancements in LiDAR technology have resulted in higher point densities and better data accuracies, which however pose challenges to the procurement and processing of LiDAR data for large-area assessments. Reducing point density cuts data acquisition costs and overcome computational challenges for broad-scale forest management. However, how does that impact the accuracy of biomass estimation in an urban environment containing a great level of anthropogenic disturbances? The main goal of this study is to evaluate the effects of LiDAR point density on the biomass estimation of remnant forests in the rapidly urbanizing regions of Charlotte, North Carolina, USA. We used multiple linear regression to establish the statistical relationship between field-measured biomass and predictor variables (PVs) derived from LiDAR point clouds with varying densities. We compared the estimation accuracies between the general Urban Forest models (no discrimination of forest type) and the Forest Type models (evergreen, deciduous, and mixed), which was followed by quantifying the degree to which landscape context influenced biomass estimation. The explained biomass variance of Urban Forest models, adjusted R2, was fairly consistent across the reduced point densities with the highest difference of 11.5% between the 100% and 1% point densities. The combined estimates of Forest Type biomass models outperformed the Urban Forest models using two representative point densities (100% and 40%). The Urban Forest biomass model with development density of 125 m radius produced the highest adjusted R2 (0.83 and 0.82 at 100% and 40% LiDAR point densities, respectively) and the lowest RMSE values, signifying the distance impact of development on biomass estimation. Our evaluation suggests that reducing LiDAR point density is a viable solution to regional-scale forest biomass assessment without compromising the accuracy of estimation, which may further be improved using development density.

Physical partner violence, women’s economic status and help-seeking behaviour in Dar es Salaam and Mbeya, Tanzania

PubMed Central

Vyas, Seema; Mbwambo, Jessie

2017-01-01

ABSTRACT Background: Women’s responses to partner violence are influenced by a complex constellation of factors including: psychological attachment to the partner; context of the abuse; and structural factors, all of which shape available options for women outside of the relationship. Objective: To describe women’s responses to physical partner violence; and to understand the role of women’s economic resources on their responses. Methods: Cross-sectional data from Dar es Salaam and Mbeya, Tanzania. Multivariate logistic regression was used to explore the relationship between women’s economic resources and their responses to violence. Results: In both sites, among physically abused women, over one-half experienced severe violence; approximately two-thirds had disclosed the violence; and approximately 40% had sought help. Abused women were more likely to have sought help from health services, the police and religious leaders in Dar es Salaam, and from local leaders in Mbeya. Economic resources did not facilitate women’s ability to leave violent partners in Dar es Salaam. In Mbeya, women who jointly owned capital assets were less likely to have left. In both sites, women’s sole ownership of capital assets facilitated help-seeking. Conclusion: Although support services are being scaled-up in Tanzania, efforts are needed to increase the acceptability of accessing such services. PMID:28485667

Exclusive breast-feeding is rarely practised in rural and urban Morogoro, Tanzania.

PubMed

Shirima, R; Greiner, T; Kylberg, E; Gebre-Medhin, M

2001-04-01

To investigate and compare feeding practices among infants of less than 7 months of age in a rural and an urban area in Tanzania. Cross-sectional, questionnaire-based interview of mothers and focus group discussions with extension workers and community leaders. Eleven villages in a rural district and 10 wards in an urban district in the Morogoro region, Tanzania, west of Dar es Salaam. Probability samples of mothers with infants of less than 7 months of age from each area). Exclusive breast-feeding was rarely practised in either the rural or urban areas investigated. However, the urban mothers initiated breast-feeding earlier, discarded colostrum less frequently, breast-fed exclusively for a longer period, gave breast milk as the first feed more often and delayed the introduction of solid foods for longer than their rural counterparts. The rural mothers, on the other hand, breast-fed their previous infants slightly longer than the urban mothers. The better performance of urban mothers could be partly due to sustained breast-feeding support in hospital settings and other campaigns which may not have reached the rural areas. In both the rural and urban areas more efforts are needed to encourage exclusive breast-feeding, to avoid premature complementation and, in the case of the urban areas, to protect extended breast-feeding.

Characteristics and geographic distribution of HIV-positive women diagnosed with cervical cancer in Dar es Salaam, Tanzania.

PubMed

Lovgren, Kathleen; Soliman, Amr S; Ngoma, Twalib; Kahesa, Crispin; Meza, Jane

2016-10-01

Cervical cancer is the leading incident cancer and the main cause of cancer-related mortality among women in sub-Saharan Africa. Furthermore, HIV-infected women are at a higher risk of developing cervical cancer than HIV-negative women. The purpose of this study was to distinguish differences in characteristics of HIV-positive and HIV-negative patients with cervical cancer in Dar es Salaam, Tanzania. The HIV status of cervical cancer patients diagnosed and/or treated at Ocean Road Cancer Institute in Dar es Salaam, Tanzania, during the period 2007-2011 was abstracted from the medical records. Additional abstracted information included patient's name, age, place of residence, occupation, education, marital status, age at marriage, gravidity, and screening clinic visit results. Ocean Road Cancer Institute patients came from two sources: the screening clinic followed by treatment clinic or the treatment clinic without prior screening. HIV-positive and HIV-negative patients were compared regarding the above-listed clinical and epidemiologic factors. Multivariable analysis was also performed to assess the risk factors associated with cervical cancer treatment without prior screening at Ocean Road Cancer Institute. HIV-positive cervical cancer patients tended to be younger, with higher education and lower parity. Patients screened for cervical cancer prior to treatment were more likely to be HIV-positive (OR: 2.09, 95% CI: 1.36, 3.21), less likely to have higher disease stages (OR: 0.64, 95% CI: 0.43, 0.94), and less likely to reside outside of Dar es Salaam (OR: 0.44, 95% CI: 0.30, 0.65). Screening for cervical cancer at Ocean Road Cancer Institute is utilised by more HIV-positive patients from Dar es Salaam. Future studies should focus on identifying the reasons for lower utilisation of screening by HIV-negative patients and patients from other distant rural regions in Tanzania. © The Author(s) 2016.

Sociocultural factors that reduce risks of homicide in Dar es Salaam: a case control study

PubMed Central

Kibusi, Stephen Matthew; Ohnishi, Mayumi; Outwater, Anne; Seino, Kaoruko; Kizuki, Masashi; Takano, Takehito

2013-01-01

Objectives This study was performed to examine the potential contributions of sociocultural activities to reduce risks of death by homicide. Methods This study was designed as a case control study. Relatives of 90 adult homicide victims in Dar es Salaam Region, Tanzania, in 2005 were interviewed. As controls, 211 participants matched for sex and 5-year age group were randomly selected from the same region and interviewed regarding the same contents. Results Bivariate analysis revealed significant differences between victims and controls regarding educational status, occupation, family structure, frequent heavy drinking, hard drug use and religious attendance. Conditional logistic regression analysis indicated that the following factors were significantly related to not becoming victims of homicide: being in employment (unskilled labour: OR=0.04, skilled labour: OR=0.07, others: OR=0.04), higher educational status (OR=0.02), residence in Dar es Salaam after becoming an adult (compared with those who have resided in Dar es Salaam since birth: OR=3.95), living with another person (OR=0.07), not drinking alcohol frequently (OR=0.15) and frequent religious service attendance (OR=0.12). Conclusions Frequent religious service attendance, living in the same place for a long time and living with another person were shown to be factors that contribute to preventing death by homicide, regardless of place of residence and neighbourhood environment. Existing non-structural community resources and social cohesive networks strengthen individual and community resilience against violence. PMID:23322260

Determinants of acceptance of cervical cancer screening in Dar es Salaam, Tanzania.

PubMed

Kahesa, Crispin; Kjaer, Susanne; Mwaiselage, Julius; Ngoma, Twalib; Tersbol, Britt; Dartell, Myassa; Rasch, Vibeke

2012-12-19

To describe how demographic characteristics and knowledge of cervical cancer influence screening acceptance among women living in Dar es Salaam, Tanzania. Multistage cluster sampling was carried out in 45 randomly selected streets in Dar es Salaam. Women between the ages of 25-59 who lived in the sampled streets were invited to a cervical cancer screening; 804 women accepted and 313 rejected the invitation. Information on demographic characteristics and knowledge of cervical cancer were obtained through structured questionnaire interviews. Women aged 35-44 and women aged 45-59 had increased ORs of 3.52 and 7.09, respectively, for accepting screening. Increased accepting rates were also found among single women (OR 2.43) and among women who had attended primary or secondary school (ORs of 1.81 and 1.94). Women who had 0-2 children were also more prone to accept screening in comparison with women who had five or more children (OR 3.21). Finally, knowledge of cervical cancer and awareness of the existing screening program were also associated with increased acceptance rates (ORs of 5.90 and 4.20). There are identifiable subgroups where cervical cancer screening can be increased in Dar es Salaam. Special attention should be paid to women of low education and women of high parity. In addition, knowledge and awareness raising campaigns that goes hand in hand with culturally acceptable screening services will likely lead to an increased uptake of cervical cancer screening.

Understanding the Unique Equatorial Density Irregularities

DTIC Science & Technology

2015-04-01

3 Bahir Dar, 79 ETHIOPIA EOARD GRANT #FA8655-13-1-3052 Report Date: April 2015 Final Report from 15 June 2013 to 30 March 2015 Air Force...ADDRESS(ES) Bahir Dar University Peda Straight, Region 3 Bahir Dar, 79 ETHIOPIA 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 9. SPONSORING/MONITORING...satellite signal receivers and others in collaboration with institutions outside Ethiopia . This effort provided some support for the installation of the

Real-time vehicle emissions monitoring using a compact LiDAR system and conventional instruments: first results of an experimental campaign in a suburban area in southern Italy

NASA Astrophysics Data System (ADS)

Parracino, Stefano; Richetta, Maria; Gelfusa, Michela; Malizia, Andrea; Bellecci, Carlo; De Leo, Leonardo; Perrimezzi, Carlo; Fin, Alessandro; Forin, Marco; Giappicucci, Francesca; Grion, Massimo; Marchese, Giuseppe; Gaudio, Pasquale

2016-10-01

Urban air pollution causes deleterious effects on human health and the environment. To meet stringent standards imposed by the European Commission, advanced measurement methods are required. Remote sensing techniques, such as light detection and ranging (LiDAR), can be a valuable option for evaluating particulate matter (PM), emitted by vehicles in urban traffic, with high sensitivity and in shorter time intervals. Since air quality problems persist not only in large urban areas, a measuring campaign was specifically performed in a suburban area of Crotone, Italy, using both a compact LiDAR system and conventional instruments for real-time vehicle emissions monitoring along a congested road. First results reported in this paper show a strong dependence between variations of LiDAR backscattering signals and traffic-related air pollution levels. Moreover, time-resolved LiDAR data averaged in limited regions, directly above conventional monitoring stations at the border of an intersection, were found to be linearly correlated to the PM concentration levels with a correlation coefficient between 0.75 and 0.84.

Uvulectomy, a traditional surgical procedure in Tanzania.

PubMed

Manni, J J

1984-02-01

Uvulectomy is carried out by traditional healers of Tanzania. The Department of Otorhinolaryngology of the Muhimbili Medical Centre, University of Dar es Salaam, has regularly treated patients who suffered complications arising from this procedure. In April 1980 the author attended the practice of a traditional healer (mganga) in Dar es Salaam and saw many uvulectomies performed. The procedure is described and its indications and complications reviewed. The study illustrates that knowledge and comprehension of traditional medicine is important for the medical profession in those countries where traditional medical procedures are still in use.

Schistosoma, other helminth infections, and associated risk factors in preschool-aged children in urban Tanzania

PubMed Central

Hella, Jerry; Knopp, Stefanie; Nassoro, Tatu; Shija, Neema; Aziz, Fatma; Mhimbira, Francis; Schindler, Christian; Mwingira, Upendo; Mandalakas, Anna M.; Manji, Karim; Tanner, Marcel; Utzinger, Jürg; Fenner, Lukas

2017-01-01

Background Despite the high prevalence of helminth infections among preschool-aged children, control programs in sub-Saharan countries primarily focus on school-aged populations. We assessed the prevalence of helminth infections and determined risk factors for infection among preschool-aged children in the urban setting of Dar es Salaam, Tanzania. Methodology Starting in October 2015, we conducted a 12-month prospective study among tuberculosis (TB)-exposed children under the age of 5 years and unexposed controls from neighboring households. At the time of recruitment, we collected medical histories, assessed development and cognitive functions, and performed medical examinations. We performed full blood cell counts and screened for HIV and malaria. Point-of-care circulating cathodic antigen (POC-CCA), urine filtration, Kato-Katz, FLOTAC, and Baermann tests were employed to detect helminth infections in urine and stool. Helminth infections were stratified for Schistosoma and other helminths to identify risk factors, using logistic regression. Principal findings We included 310 children with a median age of 26 months (inter quartile range 17–42 months) in the study. Among these, 189 were TB-exposed and 121 TB-unexposed. Two thirds of the children were anemic (hemoglobin level <11 g/dl) and the HIV prevalence was 1.3%. Schistosoma spp. was the predominant helminth species (15.8%; 95% confidence interval [CI] 12.1–20.3%). Other helminth infections were less frequent (9.0%, 95% CI 6.3–12.8%). Poor hygiene, use of household water sources, and TB-exposure were not associated with helminth infection. Development and cognitive scores did not significantly differ in helminth-infected and uninfected peers, but hemoglobin levels were significantly lower in helminth-infected children (10.1 g/dl vs. 10.4 g/dl, p = 0.027). Conclusions/significance In Dar es Salaam, a city with more than 4 million inhabitants, the prevalence of Schistosoma spp. infection among preschool-aged children was unexpectedly high. Setting-specific interventions that target preschool-aged children and urban settlements should be considered to reduce the transmission of Schistosoma and other helminth infections and to improve children’s health. PMID:29108003

Detecting understory plant invasion in urban forests using LiDAR

NASA Astrophysics Data System (ADS)

Singh, Kunwar K.; Davis, Amy J.; Meentemeyer, Ross K.

2015-06-01

Light detection and ranging (LiDAR) data are increasingly used to measure structural characteristics of urban forests but are rarely used to detect the growing problem of exotic understory plant invaders. We explored the merits of using LiDAR-derived metrics alone and through integration with spectral data to detect the spatial distribution of the exotic understory plant Ligustrum sinense, a rapidly spreading invader in the urbanizing region of Charlotte, North Carolina, USA. We analyzed regional-scale L. sinense occurrence data collected over the course of three years with LiDAR-derived metrics of forest structure that were categorized into the following groups: overstory, understory, topography, and overall vegetation characteristics, and IKONOS spectral features - optical. Using random forest (RF) and logistic regression (LR) classifiers, we assessed the relative contributions of LiDAR and IKONOS derived variables to the detection of L. sinense. We compared the top performing models developed for a smaller, nested experimental extent using RF and LR classifiers, and used the best overall model to produce a predictive map of the spatial distribution of L. sinense across our country-wide study extent. RF classification of LiDAR-derived topography metrics produced the highest mapping accuracy estimates, outperforming IKONOS data by 17.5% and the integration of LiDAR and IKONOS data by 5.3%. The top performing model from the RF classifier produced the highest kappa of 64.8%, improving on the parsimonious LR model kappa by 31.1% with a moderate gain of 6.2% over the county extent model. Our results demonstrate the superiority of LiDAR-derived metrics over spectral data and fusion of LiDAR and spectral data for accurately mapping the spatial distribution of the forest understory invader L. sinense.

Aerosols in coastal and inland areas in the equatorial African belt.

PubMed

Ssenyonga, Taddeo; Muyimbwa, Dennis; Okullo, Willy; Chen, Yi-Chun; Frette, Øvyind; Hamre, Børge; Steigen, Andreas; Dahlback, Arne; Stamnes, Jakob J

2014-05-10

Aerosols affect the climate directly through absorption and reflection of sunlight back to space and indirectly by acting as cloud condensation nuclei. This paper is based on more than three decades of satellite data (1979-1994 and 1996-2012) from total ozone mapping spectrometer (TOMS) and ozone monitoring instrument (OMI), which have provided measurements of backscattered radiances in the wavelength range from 331 to 380 nm. These data have been used to determine the aerosol climatology and to investigate the influence of the aerosol index (AI) on the ultraviolet index (UVI) in coastal land areas in Serrekunda (13.28°N, 16.34°W), The Gambia, and Dar-es-Salaam (6.8°S, 39.26°E), Tanzania, as well as in inland areas in Kampala (0.19°N, 32.34°E), Uganda. Heavy aerosol loadings were found to occur in the dry seasons at all three locations. To reduce the influence of clouds, we disregarded TOMS and OMI data for days during which the UV reflectivity was larger than 9% and investigated the correlation of the AI with the UVI for the remaining days at the three locations. We found a high correlation coefficient of 0.82 for Serrekunda, but poor correlation for Kampala and Dar-es-Salaam. The average AI for Serrekunda was found to be about three times higher than that for Kampala or Dar-es-Salaam, and a positive trend was found for the AI in Kampala and Dar-es-Salaam, whereas a negative trend was found for the AI in Serrekunda.

Sociodemographic variations in communication on sexuality and HIV/AIDS with parents, family members and teachers among in-school adolescents: a multi-site study in Tanzania and South Africa.

PubMed

Namisi, Francis Sande; Flisher, Alan J; Overland, Simon; Bastien, Sheri; Onya, Hans; Kaaya, Sylvia; Aarø, Leif Edvard

2009-06-01

To identify with whom in-school adolescents preferred to communicate about sexuality, and to study adolescents' communication on HIV/AIDS, abstinence and condoms with parents/guardians, other adult family members, and teachers. Data were obtained from a baseline questionnaire survey carried out in South Africa (Cape Town and Mankweng) and Tanzania (Dar es Salaam) in early 2004. We analysed data for 14,944 adolescents from 80 randomly selected schools. The mean ages were as follows: Cape Town, 13.38 years (standard deviation (SD) 1.15); Mankweng, 13.94 years (SD 1.35); and Dar es Salaam, 12.94 years (SD 1.31). Adolescent females preferred to receive sexuality information from their mothers, while among males there was a higher preference for fathers in two sites. Thirty-seven per cent, 41% and 29% reported never or hardly ever communicating about sexuality with parents, other adult family members, and teachers, respectively. "Silence'' was more prevalent in Dar es Salaam than in the other two sites. The odds of "never or hardly ever'' communicating with parents in Dar es Salaam were higher among girls than among boys (p < 0.01). For the two South African sites, boys had significantly higher odds of experiencing silence than did girls (both p < 0.001), and socioeconomic status was positively associated with parent-adolescent sexuality communication. In the logistic regression models, explained variation (Nagelkerke's R(2)) across sites ranged from 0.013 to 0.032. In all three sites, a substantial proportion of adolescents reported not communicating with their parents about HIV/AIDS, abstinence, or condoms. The low proportion of explained variation in sexuality communication implies that silence is common across sociodemographic subgroups.

Interventions That Increase Enrolment of Women in Higher Education: The University of Dar es Salaam, Tanzania

ERIC Educational Resources Information Center

Kilango, Nasero Charles; Qin, Yu Hai; Nyoni, Watende Pius; Senguo, Richard Allen

2017-01-01

Gender equality and equity has long been a focus area in Tanzanian government, encouraging the increased recruitment of female students in to higher education. This article investigates the effectiveness of affirmative action policy interventions that introduced and designed to increase female students' enrolment at the University of Dar es…

Family perceptions of intellectual disability: Understanding and support in Dar es Salaam

PubMed Central

2012-01-01

When attempting to understand the construct of intellectual disability in different contexts, speaking to family members in addition to the individual with the disability may provide new insight about understandings of and responses to intellectual disability in society and may help to identify the forms of support that are available or needed to ensure the quality of life of people with disabilities. This article outlines and discusses interviews that were conducted in Dar es Salaam, Tanzania, with family members of children and adults with intellectual disabilities. These interviews explore how families came to understand that their child had an intellectual disability; the availability of family support; and family hopes and dreams for the future, and were a part of a wider exploratory study that gathered insight from individuals with disabilities, families, and other providers of support to explore understandings and perceptions of disability in Dar es Salaam. Understanding family experiences will help researchers, policy makers, non-governmental organisations, and others to identify family strengths and family support needs which can ultimately improve family quality of life and the quality of life of the member with a disability. PMID:28729979

Vijana Vijiweni II: a cluster-randomized trial to evaluate the efficacy of a microfinance and peer health leadership intervention for HIV and intimate partner violence prevention among social networks of young men in Dar es Salaam.

PubMed

Kajula, Lusajo; Balvanz, Peter; Kilonzo, Mrema Noel; Mwikoko, Gema; Yamanis, Thespina; Mulawa, Marta; Kajuna, Deus; Hill, Lauren; Conserve, Donaldson; Reyes, Heathe Luz McNaughton; Leatherman, Sheila; Singh, Basant; Maman, Suzanne

2016-02-03

Intimate partner violence (IPV) and sexually transmitted infections (STIs), including HIV, remain important public health problems with devastating health effects for men and women in sub-Saharan Africa. There have been calls to engage men in prevention efforts, however, we lack effective approaches to reach and engage them. Social network approaches have demonstrated effective and sustained outcomes on changing risk behaviors in the U.S. Our team has identified and engaged naturally occurring social networks comprised mostly of young men in Dar es Salaam in an intervention designed to jointly reduce STI incidence and the perpetration of IPV. These stable networks are locally referred to as "camps." In a pilot study we demonstrated the feasibility and acceptability of a combined microfinance and peer health leadership intervention within these camp-based peer networks. We are implementing a cluster-randomized trial to evaluate the efficacy of an intervention combining microfinance with health leadership training in 60 camps in Dar es Salaam, Tanzania. Half of the camps have been randomized to the intervention arm, and half to a control arm. The camps in the intervention arm will receive a combined microfinance and health leadership intervention for a period of two years. The camps in the control arm will receive a delayed intervention. We have enrolled 1,258 men across the 60 study camps. Behavioral surveys will be conducted at baseline, 12-months post intervention launch and 30-month post intervention launch and biological samples will be drawn to test for Neisseria gonorrhea (NG), Chlamydia trachomatis (CT), and Trichomonas vaginalis (TV) at baseline and 30-months. The primary endpoints for assessing intervention impact are IPV perpetration and STI incidence. This is the first cluster-randomized trial targeting social networks of men in sub-Saharan Africa that jointly addresses HIV and IPV perpetration and has both biological and behavioral endpoints. Effective approaches to engage men in HIV and IPV prevention are needed in low resource, high prevalence settings like Tanzania. If we determine that this approach is effective, we will examine how to adapt and scale up this approach to other urban, sub-Saharan African settings. Clinical Trials.gov: NCT01865383 . Registration date: May 24, 2013.

Access to HIV prevention services among gender based violence survivors in Tanzania

PubMed Central

Mboya, Beati; Temu, Florence; Awadhi, Bayoum; Ngware, Zubeda; Ndyetabura, Elly; Kiondo, Gloria; Maridadi, Janneth

2012-01-01

Introduction Currently, Tanzania's HIV prevalence is 5.7%. Gender inequality and Gender Based Violence (GBV) are among factors fuelling the spread of HIV in Tanzania. This study was conducted to assess universal access to HIV prevention services among GBV survivors in Iringa and Dar-es-Salaam where HIV prevalence is as high as 14.7% and 9% respectively compared to a national average of 5.7%. Methods In 2010, a mixed methods study using triangulation model was conducted in Iringa and Dar-es-Salaam regions to represent rural and urban settings respectively. Questionnaires were administered to 283 randomly selected survivors and 37 health providers while 28 in-depth interviews and 16 focus group discussions were conducted among various stakeholders. Quantitative data was analyzed in SPSS by comparing descriptive statistics while qualitative data was analyzed using thematic framework approach. Results Counseling and testing was the most common type of HIV prevention services received by GBV survivors (29%). Obstacles for HIV prevention among GBV survivors included: stigma, male dominance culture and fear of marital separation. Bribery in service delivery points, lack of confidentiality, inadequate GBV knowledge among health providers, and fear of being involved in legal matters were mentioned to be additional obstacles to service accessibility by survivors. Reported consequences of GBV included: psychological problems, physical trauma, chronic illness, HIV infection. Conclusion GBV related stigma and cultural norms are obstacles to HIV services accessibility. Initiation of friendly health services, integration of GBV into HIV services and community based interventions addressing GBV related stigma and cultural norms are recommended. PMID:23467278

Relationships matter: contraceptive choices among HIV-positive women in Tanzania.

PubMed

Nyanja, Tabitha Alexandria Njeri; Tulinius, Charlotte

2017-07-01

Efforts to eliminate mother-to-child transmission of HIV in Tanzania are guided by a four-prong strategy advocated by the World Health Organization (WHO). Prong 2, prevention of unintended pregnancies among women living with HIV, has, however, received the least attention and contraceptive use to prevent unintended pregnancies remains low. This study explored the perceived barriers to the use of modern methods of contraception, and factors influencing contraceptive choice among HIV-positive women in urban Dar-es-Salaam, Tanzania. A qualitative multi-site study was conducted, utilising in-depth interviews and focus group discussions with 37 sexually active HIV-positive women aged between 20 and 44 years, attending three health facilities within Dar-es-Salaam. The theoretical framework was a patient centred model. Four barriers were identified: the influence of the women's spousal relationships; personal beliefs and the relationship of these in understanding her disease; the influence of the social demands on the woman and her relationships; and the importance of a woman's relationship with her healthcare provider/healthcare system. Being the bearers of bad news (HIV-positive status) the pregnant women experienced conflicts, violence, abandonment and rejection. The loss in negotiating power for the women was in relation to their intimate partners, but also in the patient-healthcare provider relationship. The role of the male partner as a barrier to contraceptive use cannot be understated. Therefore, the results suggest that healthcare providers should ensure patient-focused education and provide support that encompasses the importance of their relationships. Additional research is required to elucidate the functional association between contraceptive choices and personal and social relationships.

Access to HIV prevention services among gender based violence survivors in Tanzania.

PubMed

Mboya, Beati; Temu, Florence; Awadhi, Bayoum; Ngware, Zubeda; Ndyetabura, Elly; Kiondo, Gloria; Maridadi, Janneth

2012-01-01

Currently, Tanzania's HIV prevalence is 5.7%. Gender inequality and Gender Based Violence (GBV) are among factors fuelling the spread of HIV in Tanzania. This study was conducted to assess universal access to HIV prevention services among GBV survivors in Iringa and Dar-es-Salaam where HIV prevalence is as high as 14.7% and 9% respectively compared to a national average of 5.7%. In 2010, a mixed methods study using triangulation model was conducted in Iringa and Dar-es-Salaam regions to represent rural and urban settings respectively. Questionnaires were administered to 283 randomly selected survivors and 37 health providers while 28 in-depth interviews and 16 focus group discussions were conducted among various stakeholders. Quantitative data was analyzed in SPSS by comparing descriptive statistics while qualitative data was analyzed using thematic framework approach. Counseling and testing was the most common type of HIV prevention services received by GBV survivors (29%). Obstacles for HIV prevention among GBV survivors included: stigma, male dominance culture and fear of marital separation. Bribery in service delivery points, lack of confidentiality, inadequate GBV knowledge among health providers, and fear of being involved in legal matters were mentioned to be additional obstacles to service accessibility by survivors. Reported consequences of GBV included: psychological problems, physical trauma, chronic illness, HIV infection. GBV related stigma and cultural norms are obstacles to HIV services accessibility. Initiation of friendly health services, integration of GBV into HIV services and community based interventions addressing GBV related stigma and cultural norms are recommended.

Assessment of seismic loading on structures based on airborne LiDAR data from the Kalochori urban area (N. Greece)

NASA Astrophysics Data System (ADS)

Rovithis, Emmanouil; Kirtas, Emmanouil; Marini, Eleftheria; Bliziotis, Dimitris; Maltezos, Evangelos; Pitilakis, Dimitris; Makra, Konstantia; Savvaidis, Alexandros

2016-08-01

Airborne LiDAR monitoring integrated with field data is employed to assess the fundamental period and the seismic loading of structures composing an urban area under prescribed earthquake scenarios. Α piecewise work-flow is adopted by combining geometrical data of the building stock derived from a LiDAR-based 3D city model, structural data from in-situ inspections on representative city blocks and results of soil response analyses. The procedure is implemented in the residential area of Kalochori, (west of Thessaloniki in Northern Greece). Special attention is paid to the in-situ inspection of the building stock in order to discriminate recordings between actual buildings and man-made constructions that do not conform to seismic design codes and to acquire additional building stock data on structural materials, typologies and number of stories which is not feasible by the LiDAR process. The processed LiDAR and field data are employed to compute the fundamental period of each building by means of code-defined formulas. Knowledge of soil conditions in the Kalochoti area allows for soil response analyses to obtain free-field at ground surface under earthquake scenarios with varying return period. Upon combining the computed vibrational characteristics of the structures with the free-field response spectra, the seismic loading imposed on the structures of the urban area under investigation is derived for each one of the prescribed seismic motions. Results are presented in GIS environment in the form of spatially distributed spectral accelerations with direct implications in seismic vulnerability studies of an urban area.

A Hierarchical Object-oriented Urban Land Cover Classification Using WorldView-2 Imagery and Airborne LiDAR data

NASA Astrophysics Data System (ADS)

Wu, M. F.; Sun, Z. C.; Yang, B.; Yu, S. S.

2016-11-01

In order to reduce the “salt and pepper” in pixel-based urban land cover classification and expand the application of fusion of multi-source data in the field of urban remote sensing, WorldView-2 imagery and airborne Light Detection and Ranging (LiDAR) data were used to improve the classification of urban land cover. An approach of object- oriented hierarchical classification was proposed in our study. The processing of proposed method consisted of two hierarchies. (1) In the first hierarchy, LiDAR Normalized Digital Surface Model (nDSM) image was segmented to objects. The NDVI, Costal Blue and nDSM thresholds were set for extracting building objects. (2) In the second hierarchy, after removing building objects, WorldView-2 fused imagery was obtained by Haze-ratio-based (HR) fusion, and was segmented. A SVM classifier was applied to generate road/parking lot, vegetation and bare soil objects. (3) Trees and grasslands were split based on an nDSM threshold (2.4 meter). The results showed that compared with pixel-based and non-hierarchical object-oriented approach, proposed method provided a better performance of urban land cover classification, the overall accuracy (OA) and overall kappa (OK) improved up to 92.75% and 0.90. Furthermore, proposed method reduced “salt and pepper” in pixel-based classification, improved the extraction accuracy of buildings based on LiDAR nDSM image segmentation, and reduced the confusion between trees and grasslands through setting nDSM threshold.

Adolescents' Communication with Parents, Other Adult Family Members and Teachers on Sexuality: Effects of School-Based Interventions in South Africa and Tanzania.

PubMed

Namisi, Francis; Aarø, Leif Edvard; Kaaya, Sylvia; Kajula, Lusajo J; Kilonzo, Gad P; Onya, Hans; Wubs, Annegreet; Mathews, Catherine

2015-12-01

Cluster-randomized controlled trials were carried out to examine effects on sexual practices of school-based interventions among adolescents in three sites in sub-Saharan Africa. In this publication, effects on communication about sexuality with significant adults (including parents) and such communication as a mediator of other outcomes were examined. Belonging to the intervention group was significantly associated with fewer reported sexual debuts in Dar es Salaam only (OR 0.648). Effects on communication with adults about sexuality issues were stronger for Dar es Salaam than for the other sites. In Dar, increase in communication with adults proved to partially mediate associations between intervention and a number of social cognition outcomes. The hypothesized mediational effect of communication on sexual debut was not confirmed. Promoting intergenerational communication on sexuality issues is associated with several positive outcomes and therefore important. Future research should search for mediating factors influencing behavior beyond those examined in the present study.

Comparison of LiDAR-derived data and high resolution true color imagery for extracting urban forest cover

Treesearch

Aaron E. Maxwell; Adam C. Riley; Paul Kinder

2013-01-01

Remote sensing has many applications in forestry. Light detection and ranging (LiDAR) and high resolution aerial photography have been investigated as means to extract forest data, such as biomass, timber volume, stand dynamics, and gap characteristics. LiDAR return intensity data are often overlooked as a source of input raster data for thematic map creation. We...

Dental caries in relation to diet, saliva and cariogenic microorganisms in Tanzanians of selected age groups.

PubMed

Mazengo, M C; Tenovuo, J; Hausen, H

1996-06-01

The relationship between diet and dental caries in a Tanzanian population was studied. Mutans streptococci, lactobacilli, yeasts, salivary flow rate as well as buffer effect were also analyzed. A random sample of 12-, 35-44- and 65- to 74- year olds was drawn from Msongola (rural) and Ukombozi (urban), Dar-es-Salaam. The mean of two 24-h recalls was used for the assessment of food intake. The percentage of those with at least one carious tooth ranged from 30% in the 12-year-olds to 80% in the oldest age group. The mean number of decayed teeth (DT) increased significantly with age (P = 0.000) but was not significantly associated with the area of residence. DT increased significantly (P = 0.048) with the number of snacks per day and was also associated with dietary sucrose (P = 0.025), total carbohydrates (P = 0.002) and fiber (P = 0.002). Among salivary variables lactobacilli (P = 0.000) correlated positively with DT. Our study did not reveal any strong association between total energy intake and dental caries in rural or urban populations in Tanzania but snacking and sucrose intake were significantly associated with caries, in particular in the urban area.

The use of social media among adolescents in Dar es Salaam and Mtwara, Tanzania.

PubMed

Pfeiffer, Constanze; Kleeb, Matthis; Mbelwa, Alice; Ahorlu, Collins

2014-05-01

Social media form part of the rapid worldwide digital development that is re-shaping the life of many young people. While the use of social media by youths is increasingly researched in the North, studies about youth in the South are missing. It therefore remains unclear how social media can be included in interventions that aim at informing young people in many countries of the global South about sexual and reproductive health. This paper presents findings of a mixed-methods study of young people's user behaviour on the internet and specifically of social media as a platform for sexual health promotion in Tanzania. The study used questionnaires with 60 adolescents and in-depth interviews with eight students aged 15 to 19 years in Dar es Salaam, and in Mtwara, Southern Tanzania. Findings show that youth in Dar es Salaam and Mtwara access the internet mainly through mobile phones. Facebook is by far the most popular internet site. Adolescents highlighted their interest in reproductive and sexual health messages and updates being delivered through humorous posts, links and clips, as well as by youth role models like music stars and actors that are entertaining and reflect up-to-date trends of modern youth culture. Copyright © 2014 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

Synergistic Use of WorldView-2 Imagery and Airborne LiDAR Data for Urban Land Cover Classification

NASA Astrophysics Data System (ADS)

Wu, M. F.; Sun, Z. C.; Yang, B.; Yu, S. S.

2017-02-01

There are lots of challenges for deriving urban land cover types for high resolution optical imagery because of spectral similarity of different objects, mixed pixels, shadows of buildings and large tree crowns. In order to reduce these uncertainties, recently, it’s a trend of the classification of urban land cover from multi-source sensors in the field of urban remote sensing. In this study, a hierarchical support vector machine (SVM) classification method was applied to the urban land cover mapping, using the WorldView-2 imagery and airborne Light Detection and Ranging (LiDAR) data. The results showed that: (1) The overall accuracy (OA) and overall kappa (OK) were 72.92% and 0.66 for WorldView-2 imagery alone; while the OA and OK were improved up to 89.44% and 0.87 for the synergistic use of the two types of data source. (2) Buildings and road/parking lots extracted from fused data were more precision and well-shaped. The two classes from fused data were optimally classified with higher producer’s accuracy and user’s accuracy than WorldView-2 imagery alone. The trees were also easily separated from the grasslands when the airborne LiDAR data was added. (3) The fused data could reduce the phenomenon of different spectral character of the complex and detailed objects. It was also helpful to address the problem of shadows from the high-rise buildings. The results from this study indicate that the synergistic use of high resolution optical imagery and airborne LiDAR data can be an efficient approach to improving the classification of urban land cover.

Uncertainties in mapping forest carbon in urban ecosystems.

PubMed

Chen, Gang; Ozelkan, Emre; Singh, Kunwar K; Zhou, Jun; Brown, Marilyn R; Meentemeyer, Ross K

2017-02-01

Spatially explicit urban forest carbon estimation provides a baseline map for understanding the variation in forest vertical structure, informing sustainable forest management and urban planning. While high-resolution remote sensing has proven promising for carbon mapping in highly fragmented urban landscapes, data cost and availability are the major obstacle prohibiting accurate, consistent, and repeated measurement of forest carbon pools in cities. This study aims to evaluate the uncertainties of forest carbon estimation in response to the combined impacts of remote sensing data resolution and neighborhood spatial patterns in Charlotte, North Carolina. The remote sensing data for carbon mapping were resampled to a range of resolutions, i.e., LiDAR point cloud density - 5.8, 4.6, 2.3, and 1.2 pt s/m 2 , aerial optical NAIP (National Agricultural Imagery Program) imagery - 1, 5, 10, and 20 m. Urban spatial patterns were extracted to represent area, shape complexity, dispersion/interspersion, diversity, and connectivity of landscape patches across the residential neighborhoods with built-up densities from low, medium-low, medium-high, to high. Through statistical analyses, we found that changing remote sensing data resolution introduced noticeable uncertainties (variation) in forest carbon estimation at the neighborhood level. Higher uncertainties were caused by the change of LiDAR point density (causing 8.7-11.0% of variation) than changing NAIP image resolution (causing 6.2-8.6% of variation). For both LiDAR and NAIP, urban neighborhoods with a higher degree of anthropogenic disturbance unveiled a higher level of uncertainty in carbon mapping. However, LiDAR-based results were more likely to be affected by landscape patch connectivity, and the NAIP-based estimation was found to be significantly influenced by the complexity of patch shape. Copyright © 2016 Elsevier Ltd. All rights reserved.

The pattern of mucocutaneous disorders in HIV-infected children attending care and treatment centres in Dar es Salaam, Tanzania.

PubMed

Panya, Millembe F; Mgonda, Yassin M; Massawe, Augustine W

2009-07-14

HIV/AIDS is associated with a wide range of mucocutaneous disorders some of which are useful in the clinical staging and prognosis of the syndrome. There is paucity of information regarding the prevalence and pattern of mucocutaneous disorders among HIV infected children attending paediatric Care and Treatment Centres (CTC) in Dar es Salaam. To determine the prevalence and pattern of mucocutaneous disorders among HIV infected children attending public paediatric 'Care and Treatment Centres' in Dar es Salaam. This was a cross sectional descriptive study involving public paediatric 'Care and Treatment Centres' in Dar es Salaam. Clinical information was obtained using a questionnaire. Dermatological examination was carried out in daylight. Investigations were taken as appropriate. Data was analysed using the Statistical Package for Social Sciences (SPSS) program version 10.0. Chi-squared and Fisher's exact tests were utilized. A p-value of less than 0.05 was considered statistically significant. Three hundred and forty seven HIV infected children (52% males) attending CTCs were recruited into the study. Mucocutaneous disorders were encountered in 85% of them. There was no gender difference in the prevalence of the infective mucocutaneous disorders but males had a higher prevalence of non-infective/inflammatory dermatoses (58%) than females (42%) (p = 0.02). Overall, mucocutaneous disorders (infective + non infective) were more prevalent in advanced stages of HIV disease. Children with advanced HIV disease had a significantly increased frequency of fungal and viral infections (43% and 25% respectively than those with less advanced disease; 24% and 13% respectively (p = 0.01). Seventy four percent of the HIV-infected children with mucocutaneous disorders were already on ART. Mucocutaneous disorders among HIV infected children attending Care and Treatment Centres are common and highly variable. Comprehensive management should also emphasize on the management of mucocutaneous disorders.

Social networks of men who have sex with men and their implications for HIV/STI interventions: results from a cross-sectional study using respondent-driven sampling in a large and a small city in Tanzania.

PubMed

Ross, Michael W; Larsson, Markus; Jacobson, Jerry; Nyoni, Joyce; Agardh, Anette

2016-11-18

Men who have sex with men (MSM) in sub-Saharan Africa remain hidden and hard to reach for involvement in HIV and sexually transmitted infection (STI) services. The aim of the current study was to describe MSM social networks in a large and a small Tanzanian city in order to explore their utility for peer-based healthcare interventions. Data were collected through respondent-driven sampling (RDS) in Dar es Salaam (n=197) and in Tanga (n=99) in 2012 and 2013, using 5 and 4 seeds, respectively. All results were adjusted for RDS sampling design. Mean personal network size based on the number of MSM who were reported by the participants, as known to them was 12.0±15.5 in Dar es Salaam and 7.6±8.1 in Tanga. Mean actual RDS network size was 39.4±31.4 in Dar es Salaam and 25.3±9.7 in Tanga. A majority (97%) reported that the person from whom they received the recruitment coupon was a sexual partner, close friend or acquaintance. Homophile in recruitment patterns (selective affiliation) was present for age, gay openness, and HIV status in Dar es Salaam, and for sexual identification in Tanga. The personal network sizes and existence of contacts between recruiter and referral indicate that it is possible to use peer-driven interventions to reach MSM for HIV/STI interventions in larger and smaller sub-Saharan African cities. The study was reviewed and approved by the University of Texas Health Science Center's Institutional Review Board (HSC-SPH-10-0033) and the Tanzanian National Institute for Medical Research (NIMR/HQ/R.8a/Vol. IX/1088). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Numerical simulation of groundwater flow in Dar es Salaam Coastal Plain (Tanzania)

NASA Astrophysics Data System (ADS)

Luciani, Giulia; Sappa, Giuseppe; Cella, Antonella

2016-04-01

They are presented the results of a groundwater modeling study on the Coastal Aquifer of Dar es Salaam (Tanzania). Dar es Salaam is one of the fastest-growing coastal cities in Sub-Saharan Africa, with with more than 4 million of inhabitants and a population growth rate of about 8 per cent per year. The city faces periodic water shortages, due to the lack of an adequate water supply network. These two factors have determined, in the last ten years, an increasing demand of groundwater exploitation, carried on by quite a number of private wells, which have been drilled to satisfy human demand. A steady-state three dimensional groundwater model has been set up by the MODFLOW code, and calibrated with the UCODE code for inverse modeling. The aim of the model was to carry out a characterization of groundwater flow system in the Dar es Salaam Coastal Plain. The inputs applied to the model included net recharge rate, calculated from time series of precipitation data (1961-2012), estimations of average groundwater extraction, and estimations of groundwater recharge, coming from zones, outside the area under study. Parametrization of the hydraulic conductivities was realized referring to the main geological features of the study area, based on available literature data and information. Boundary conditions were assigned based on hydrogeological boundaries. The conceptual model was defined in subsequent steps, which added some hydrogeological features and excluded other ones. Calibration was performed with UCODE 2014, using 76 measures of hydraulic head, taken in 2012 referred to the same season. Data were weighted on the basis of the expected errors. Sensitivity analysis of data was performed during calibration, and permitted to identify which parameters were possible to be estimated, and which data could support parameters estimation. Calibration was evaluated based on statistical index, maps of error distribution and test of independence of residuals. Further model analysis was performed after calibration, to test model performance under a range of variations of input variables.

Putting the genie back in the bottle? Availability and presentation of oral artemisinin compounds at retail pharmacies in urban Dar-es-Salaam

PubMed Central

Kachur, S Patrick; Black, Carolyn; Abdulla, Salim; Goodman, Catherine

2006-01-01

Background Recently global health advocates have called for the introduction of artemisinin-containing antimalarial combination therapies to help curb the impact of drug-resistant malaria in Africa. Retail trade in artemisinin monotherapies could undermine efforts to restrict this class of medicines to more theoretically sound combination treatments. Methods This paper describes a systematic search for artemisinin-containing products at a random sample of licensed pharmacies in Dar-es-Salaam, Tanzania in July 2005. Results Nineteen different artemisinin-containing oral pharmaceutical products, including one co-formulated product, one co-packaged product, and 17 monotherapies were identified. All but one of the products were legally registered and samples of each product were obtained without a prescription. Packaging and labeling of the products seldom included local language or illustrated instructions for low-literate clients. Packaging and inserts compared reasonably well with standards recommended by the national regulatory authority with some important exceptions. Dosing instructions were inconsistent, and most recommended inadequate doses based on international standards. None of the monotherapy products mentioned potential benefits of combining the treatment with another antimalarial drug. Conclusion The findings confirm the widespread availability of artemisinin monotherapies that led the World Health Organization to call for the voluntary withdrawal of these drugs in malaria-endemic countries. As the global public health community gathers resources to deploy artemisinin-containing combination therapies in Africa, planners should be mindful that these drugs will coexist with artemisinin monotherapies in an already well-established market place. In particular, regulatory authorities should be incorporated urgently into the process of planning for rational deployment of artemisinin-containing antimalarial combination therapies. PMID:16569252

Patient satisfaction with HIV/AIDS care at private clinics in Dar es Salaam, Tanzania.

PubMed

Miller, James S; Mhalu, Aisa; Chalamilla, Guerino; Siril, Hellen; Kaaya, Silvia; Tito, Justina; Aris, Eric; Hirschhorn, Lisa R

2014-01-01

Health system responsiveness (HSR) measures quality of care from the patient's perspective, an important component of ensuring adherence to medication and care among HIV patients. We examined HSR in private clinics serving HIV patients in Dar es Salaam, Tanzania. We surveyed 640 patients, 18 or older receiving care at one of 10 participating clinics, examining socioeconomic factors, HIV regimen, and self-reported experience with access and care at the clinic. Ordered logistic regression, adjusted for clustering of the clinic sites, was used to measure the relationships between age, gender, education, site size, and overall quality of care rating, as well as between the different HSR domains and overall rating. Overall, patients reported high levels of satisfaction with care received. Confidentiality, communication, and respect were particularly highly rated, while timeliness received lower ratings despite relatively short wait times, perhaps indicating high expectations when receiving care at a private clinic. Respect, confidentiality, and promptness were significantly associated with overall rating of health care, while provider skills and communication were not significantly associated. Patients reported that quality of service and confidentiality, rather than convenience of location, were the most important factors in their choice of a clinic. Site size (patient volume) was also positively correlated with patient satisfaction. Our findings suggest that, in the setting of urban private-sector clinics, flexible clinics hours, prompt services, and efforts to improve respect, privacy and confidentiality may prove more helpful in increasing visit adherence than geographic accessibility. While a responsive health system is valuable in its own right, more work is needed to confirm that improvements in HSR in fact lead to improved adherence to care.

Body-art practices among undergraduate medical university students in dar es salaam, Tanzania, 2014.

PubMed

Chacha, Chacha Emmanuel; Kazaura, Method R

2015-01-01

Body-art practices are increasing among adolescents and young adults. Although substantial data are available in developed countries, little has been documented about body-art practices in developing countries. To determine the magnitude, types and reasons for practicing body-art practices among undergraduate medical University students in Dar es Salaam, Tanzania. A cross-sectional descriptive study was conducteed among undergraduate University students in Dar es Salaam involving 536 respondents from two Universities. We used a self-administered questionnaire to collect data. Analyses were based on summary measures and bivariate analyses. While 7.5% of undergraduate students reported having tattoos, 20% reported having body puncturing or piercing. Body piercing is reported more among female university undergraduate students than their male counterparts. Reported main reasons for undergoing body-art include "a mark of beauty," 24%, "just wanted one," 18% and "a mark of femininity or masculinity," 17%. The majority (98%) of students were aware that unsafe body-art practices may lead to contracting HIV and more than half (52%) reported awareness of the risk of Hepatitis B infection. Despite high awareness of the potential risks involved in unsafe body arts that include tattoo and piercing, these practices are increasing among adolescents and young adults. There is need to have educational and counseling efforts so as to minimize associated health risks.

"If really we are committed things can change, starting from us": Healthcare providers' perceptions of postpartum care and its potential for improvement in low-income suburbs in Dar es Salaam, Tanzania.

PubMed

Pallangyo, Eunice N; Mbekenga, Columba; Källestål, Carina; Rubertsson, Christine; Olsson, Pia

2017-03-01

To explore healthcare providers' perceptions of the current postpartum care (PPC) practice and its potential for improvement at governmental health institutions in low-resource suburbs in Dar es Salaam, Tanzania. Qualitative design, using focus group discussions (8) and qualitative content analysis. Healthcare institutions (8) at three levels of governmental healthcare in Ilala and Temeke suburbs, Dar es Salaam. Registered, enrolled and trained nurse-midwives (42); and medical and clinical officers (13). The healthcare providers perceived that PPC was suboptimal and that they could have prevented maternal deaths. PPC was fragmented at understaffed institutions, lacked guidelines and was organized in a top-down structure of leadership. The participants called for improvement of: organization of space, time, resources, communication and referral system; providers' knowledge; and supervision and feedback. Their motivation to enhance PPC quality was high. The HCP awareness of the suboptimal quality of PPC, its potential for promoting health and their willingness to engage in improving care are promising for the implementation of interventions to improve quality of care. Provision of guidelines, sensitization of providers to innovate and maximize utilization of existing resources, and supportive supervision and feedback are likely to contribute to the sustainability of any improvement. Copyright © 2016 Elsevier B.V. All rights reserved.

Tree Canopy Cover Mapping Using LiDAR in Urban Barangays of Cebu City, Central Philippines

NASA Astrophysics Data System (ADS)

Ejares, J. A.; Violanda, R. R.; Diola, A. G.; Dy, D. T.; Otadoy, J. B.; Otadoy, R. E. S.

2016-06-01

This paper investigates tree canopy cover mapping of urban barangays (smallest administrative division in the Philippines) in Cebu City using LiDAR (Light Detection and Ranging). Object-Based Image Analysis (OBIA) was used to extract tree canopy cover. Multi-resolution segmentation and a series of assign-class algorithm in eCognition software was also performed to extract different land features. Contextual features of tree canopies such as height, area, roundness, slope, length-width and elliptic fit were also evaluated. The results showed that at the time the LiDAR data was collected (June 24, 2014), the tree cover was around 25.11 % (or 15,674,341.8 m2) of the city's urban barangays (or 62,426,064.6 m2). Among all urban barangays in Cebu City, Barangay Busay had the highest cover (55.79 %) while barangay Suba had the lowest (0.8 %). The 16 barangays with less than 10 % tree cover were generally located in the coastal area, presumably due to accelerated urbanization. Thirty-one barangays have tree cover ranging from 10.59--27.3 %. Only 3 barangays (i.e., Lahug, Talamban, and Busay) have tree cover greater than 30 %. The overall accuracy of the analysis was 96.6 % with the Kappa Index of Agreement or KIA of 0.9. From the study, a grouping can be made of the city's urban barangays with regards to tree cover. The grouping will be useful to urban planners not only in allocating budget to the tree planting program of the city but also in planning and creation of urban parks and playgrounds.

Semi-automatic building extraction in informal settlements from high-resolution satellite imagery

NASA Astrophysics Data System (ADS)

Mayunga, Selassie David

The extraction of man-made features from digital remotely sensed images is considered as an important step underpinning management of human settlements in any country. Man-made features and buildings in particular are required for varieties of applications such as urban planning, creation of geographical information systems (GIS) databases and Urban City models. The traditional man-made feature extraction methods are very expensive in terms of equipment, labour intensive, need well-trained personnel and cannot cope with changing environments, particularly in dense urban settlement areas. This research presents an approach for extracting buildings in dense informal settlement areas using high-resolution satellite imagery. The proposed system uses a novel strategy of extracting building by measuring a single point at the approximate centre of the building. The fine measurement of the building outlines is then effected using a modified snake model. The original snake model on which this framework is based, incorporates an external constraint energy term which is tailored to preserving the convergence properties of the snake model; its use to unstructured objects will negatively affect their actual shapes. The external constrained energy term was removed from the original snake model formulation, thereby, giving ability to cope with high variability of building shapes in informal settlement areas. The proposed building extraction system was tested on two areas, which have different situations. The first area was Tungi in Dar Es Salaam, Tanzania where three sites were tested. This area is characterized by informal settlements, which are illegally formulated within the city boundaries. The second area was Oromocto in New Brunswick, Canada where two sites were tested. Oromocto area is mostly flat and the buildings are constructed using similar materials. Qualitative and quantitative measures were employed to evaluate the accuracy of the results as well as the performance of the system. The qualitative and quantitative measures were based on visual inspection and by comparing the measured coordinates to the reference data respectively. In the course of this process, a mean area coverage of 98% was achieved for Dar Es Salaam test sites, which globally indicated that the extracted building polygons were close to the ground truth data. Furthermore, the proposed system saved time to extract a single building by 32%. Although the extracted building polygons are within the perimeter of ground truth data, visually some of the extracted building polygons were somewhat distorted. This implies that interactive post-editing process is necessary for cartographic representation.

Mathematisches Bewusstsein

NASA Astrophysics Data System (ADS)

Kaenders, Rainer; Kvasz, Ladislav

Wenn jemand sagt, dass ein Bus um 9 Uhr abfährt - weiß man es dann? Angenommen, man ist darüber unterrichtet, dass die Busse unter der Woche immer zur vollen Stunde abfahren - von 7 Uhr morgens bis 7 Uhr abends, weiß man es dann mit dem Wissen um diese allgemeine Regel besser, dass der Bus um 9 Uhr abfährt? Macht es einen Unterschied, ob man den Fahrplan erstellt, den Bus lenkt oder nur mitfährt, um sich dieser Tatsache bewusst zu sein?

Multispectral LiDAR Data for Land Cover Classification of Urban Areas

PubMed Central

Morsy, Salem; Shaker, Ahmed; El-Rabbany, Ahmed

2017-01-01

Airborne Light Detection And Ranging (LiDAR) systems usually operate at a monochromatic wavelength measuring the range and the strength of the reflected energy (intensity) from objects. Recently, multispectral LiDAR sensors, which acquire data at different wavelengths, have emerged. This allows for recording of a diversity of spectral reflectance from objects. In this context, we aim to investigate the use of multispectral LiDAR data in land cover classification using two different techniques. The first is image-based classification, where intensity and height images are created from LiDAR points and then a maximum likelihood classifier is applied. The second is point-based classification, where ground filtering and Normalized Difference Vegetation Indices (NDVIs) computation are conducted. A dataset of an urban area located in Oshawa, Ontario, Canada, is classified into four classes: buildings, trees, roads and grass. An overall accuracy of up to 89.9% and 92.7% is achieved from image classification and 3D point classification, respectively. A radiometric correction model is also applied to the intensity data in order to remove the attenuation due to the system distortion and terrain height variation. The classification process is then repeated, and the results demonstrate that there are no significant improvements achieved in the overall accuracy. PMID:28445432

Multispectral LiDAR Data for Land Cover Classification of Urban Areas.

PubMed

Morsy, Salem; Shaker, Ahmed; El-Rabbany, Ahmed

2017-04-26

Airborne Light Detection And Ranging (LiDAR) systems usually operate at a monochromatic wavelength measuring the range and the strength of the reflected energy (intensity) from objects. Recently, multispectral LiDAR sensors, which acquire data at different wavelengths, have emerged. This allows for recording of a diversity of spectral reflectance from objects. In this context, we aim to investigate the use of multispectral LiDAR data in land cover classification using two different techniques. The first is image-based classification, where intensity and height images are created from LiDAR points and then a maximum likelihood classifier is applied. The second is point-based classification, where ground filtering and Normalized Difference Vegetation Indices (NDVIs) computation are conducted. A dataset of an urban area located in Oshawa, Ontario, Canada, is classified into four classes: buildings, trees, roads and grass. An overall accuracy of up to 89.9% and 92.7% is achieved from image classification and 3D point classification, respectively. A radiometric correction model is also applied to the intensity data in order to remove the attenuation due to the system distortion and terrain height variation. The classification process is then repeated, and the results demonstrate that there are no significant improvements achieved in the overall accuracy.

Invasive Shrub Mapping in an Urban Environment from Hyperspectral and LiDAR-Derived Attributes.

PubMed

Chance, Curtis M; Coops, Nicholas C; Plowright, Andrew A; Tooke, Thoreau R; Christen, Andreas; Aven, Neal

2016-01-01

Proactive management of invasive species in urban areas is critical to restricting their overall distribution. The objective of this work is to determine whether advanced remote sensing technologies can help to detect invasions effectively and efficiently in complex urban ecosystems such as parks. In Surrey, BC, Canada, Himalayan blackberry ( Rubus armeniacus ) and English ivy ( Hedera helix ) are two invasive shrub species that can negatively affect native ecosystems in cities and managed urban parks. Random forest (RF) models were created to detect these two species using a combination of hyperspectral imagery, and light detection and ranging (LiDAR) data. LiDAR-derived predictor variables included irradiance models, canopy structural characteristics, and orographic variables. RF detection accuracy ranged from 77.8 to 87.8% for Himalayan blackberry and 81.9 to 82.1% for English ivy, with open areas classified more accurately than areas under canopy cover. English ivy was predicted to occur across a greater area than Himalayan blackberry both within parks and across the entire city. Both Himalayan blackberry and English ivy were mostly located in clusters according to a Local Moran's I analysis. The occurrence of both species decreased as the distance from roads increased. This study shows the feasibility of producing highly accurate detection maps of plant invasions in urban environments using a fusion of remotely sensed data, as well as the ability to use these products to guide management decisions.

Rapid urban malaria appraisal (RUMA) in sub-Saharan Africa

PubMed Central

Wang, Shr-Jie; Lengeler, Christian; Smith, Thomas A; Vounatsou, Penelope; Cissé, Guéladio; Diallo, Diadie A; Akogbeto, Martin; Mtasiwa, Deo; Teklehaimanot, Awash; Tanner, Marcel

2005-01-01

Background The rapid urban malaria appraisal (RUMA) methodology aims to provide a cost-effective tool to conduct rapid assessments of the malaria situation in urban sub-Saharan Africa and to improve the understanding of urban malaria epidemiology. Methods This work was done in Yopougon municipality (Abidjan), Cotonou, Dar es Salaam and Ouagadougou. The study design consists of six components: 1) a literature review, 2) the collection of available health statistics, 3) a risk mapping, 4) school parasitaemia surveys, 5) health facility-based surveys and 6) a brief description of the health care system. These formed the basis of a multi-country evaluation of RUMA's feasibility, consistency and usefulness. Results A substantial amount of literature (including unpublished theses and statistics) was found at each site, providing a good overview of the malaria situation. School and health facility-based surveys provided an overview of local endemicity and the overall malaria burden in different city areas. This helped to identify important problems for in-depth assessment, especially the extent to which malaria is over-diagnosed in health facilities. Mapping health facilities and breeding sites allowed the visualization of the complex interplay between population characteristics, health services and malaria risk. However, the latter task was very time-consuming and required special expertise. RUMA is inexpensive, costing around 8,500–13,000 USD for a six to ten-week period. Conclusion RUMA was successfully implemented in four urban areas with different endemicity and proved to be a cost-effective first approach to study the features of urban malaria and provide an evidence basis for planning control measures. PMID:16153298

Semi-Automated Approach for Mapping Urban Trees from Integrated Aerial LiDAR Point Cloud and Digital Imagery Datasets

NASA Astrophysics Data System (ADS)

Dogon-Yaro, M. A.; Kumar, P.; Rahman, A. Abdul; Buyuksalih, G.

2016-09-01

Mapping of trees plays an important role in modern urban spatial data management, as many benefits and applications inherit from this detailed up-to-date data sources. Timely and accurate acquisition of information on the condition of urban trees serves as a tool for decision makers to better appreciate urban ecosystems and their numerous values which are critical to building up strategies for sustainable development. The conventional techniques used for extracting trees include ground surveying and interpretation of the aerial photography. However, these techniques are associated with some constraints, such as labour intensive field work and a lot of financial requirement which can be overcome by means of integrated LiDAR and digital image datasets. Compared to predominant studies on trees extraction mainly in purely forested areas, this study concentrates on urban areas, which have a high structural complexity with a multitude of different objects. This paper presented a workflow about semi-automated approach for extracting urban trees from integrated processing of airborne based LiDAR point cloud and multispectral digital image datasets over Istanbul city of Turkey. The paper reveals that the integrated datasets is a suitable technology and viable source of information for urban trees management. As a conclusion, therefore, the extracted information provides a snapshot about location, composition and extent of trees in the study area useful to city planners and other decision makers in order to understand how much canopy cover exists, identify new planting, removal, or reforestation opportunities and what locations have the greatest need or potential to maximize benefits of return on investment. It can also help track trends or changes to the urban trees over time and inform future management decisions.

Localized Segment Based Processing for Automatic Building Extraction from LiDAR Data

NASA Astrophysics Data System (ADS)

Parida, G.; Rajan, K. S.

2017-05-01

The current methods of object segmentation and extraction and classification of aerial LiDAR data is manual and tedious task. This work proposes a technique for object segmentation out of LiDAR data. A bottom-up geometric rule based approach was used initially to devise a way to segment buildings out of the LiDAR datasets. For curved wall surfaces, comparison of localized surface normals was done to segment buildings. The algorithm has been applied to both synthetic datasets as well as real world dataset of Vaihingen, Germany. Preliminary results show successful segmentation of the buildings objects from a given scene in case of synthetic datasets and promissory results in case of real world data. The advantages of the proposed work is non-dependence on any other form of data required except LiDAR. It is an unsupervised method of building segmentation, thus requires no model training as seen in supervised techniques. It focuses on extracting the walls of the buildings to construct the footprint, rather than focussing on roof. The focus on extracting the wall to reconstruct the buildings from a LiDAR scene is crux of the method proposed. The current segmentation approach can be used to get 2D footprints of the buildings, with further scope to generate 3D models. Thus, the proposed method can be used as a tool to get footprints of buildings in urban landscapes, helping in urban planning and the smart cities endeavour.

Fast Surface Reconstruction and Segmentation with Terrestrial LiDAR Range Data

DTIC Science & Technology

2009-05-18

UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) University of California at Berkeley,Department of Electrical Engineering and Computer...Sciences,Berkeley,CA,94720 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S...ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION /AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13

Urbanization in Africa since independence.

PubMed

Tarver, J D

1994-01-01

Over 185 million inhabitants were added to the urban areas of Africa between 1950 and 1990. Botswana, Lesotho, Namibia, South Africa, and Swaziland is the most highly urbanized, with 55% in 1990; while less than a quarter of Eastern Africa's population is living in urban centers. By the year 2015 more than half of Africa's population will be living in urban areas. Many parts of Africa have suffered prolonged droughts, overgrazing, locust infestations, and desertification. Millions have become refugees from natural disasters, political oppression, and rural poverty. The large exodus from Africa's rural areas has gone to cities but the large cities have attracted disproportionately large numbers of destitute migrants. Alexandria (1 million), Cairo (2.4 million) and the Witwatersrand in South Africa were the only African urban agglomerations with at least one million inhabitants in 1950. By 1990 the two Egyptian cities together had 12.7 million inhabitants and the Witwatersrand some 5 million, whereas the other 25 urban agglomerations with a million inhabitants each in 1990 had a total population of about 51 million. Lagos, Kinshasa, and Algiers ranged from 3 to 7.7 million. The capitals are the largest cities in at least 54 of the 59 countries and territories. Lagos, Nairobi, and Dar es Salaam are disproportionately larger than the next most populous cities in their countries. The 28 urban agglomerations with at least one million inhabitants had a total population of 70 million in 1990, and are projected to reach 100 million in the year 2000. Overall, Africa's urban population is projected to increase by approximately 135 million in the 1990-2000 decade (from 217 million to 352 million). About 105 million of the growth probably will occur in the smaller urban centers. The total African urban population is likely to reach one billion inhabitants within the next 50 years. It stood at 32 million in 1950. Presently, the United Nations projects 912 million urban residents (57% of the total population) by 2025.

Tracking Geomorphic Signatures of Watershed Suburbanization with Multi-Temporal LiDAR

EPA Science Inventory

Urban development practices redistribute surface materials through filling, grading and terracing, causing drastic changes to the geomorphic organization of the landscape. Many studies document the hydrologic, biologic, or geomorphic consequences of urbanization using space-for-t...

Invasive Shrub Mapping in an Urban Environment from Hyperspectral and LiDAR-Derived Attributes

PubMed Central

Chance, Curtis M.; Coops, Nicholas C.; Plowright, Andrew A.; Tooke, Thoreau R.; Christen, Andreas; Aven, Neal

2016-01-01

Proactive management of invasive species in urban areas is critical to restricting their overall distribution. The objective of this work is to determine whether advanced remote sensing technologies can help to detect invasions effectively and efficiently in complex urban ecosystems such as parks. In Surrey, BC, Canada, Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix) are two invasive shrub species that can negatively affect native ecosystems in cities and managed urban parks. Random forest (RF) models were created to detect these two species using a combination of hyperspectral imagery, and light detection and ranging (LiDAR) data. LiDAR-derived predictor variables included irradiance models, canopy structural characteristics, and orographic variables. RF detection accuracy ranged from 77.8 to 87.8% for Himalayan blackberry and 81.9 to 82.1% for English ivy, with open areas classified more accurately than areas under canopy cover. English ivy was predicted to occur across a greater area than Himalayan blackberry both within parks and across the entire city. Both Himalayan blackberry and English ivy were mostly located in clusters according to a Local Moran’s I analysis. The occurrence of both species decreased as the distance from roads increased. This study shows the feasibility of producing highly accurate detection maps of plant invasions in urban environments using a fusion of remotely sensed data, as well as the ability to use these products to guide management decisions. PMID:27818664

Urban topography for flood modeling by fusion of OpenStreetMap, SRTM and local knowledge

NASA Astrophysics Data System (ADS)

Winsemius, Hessel; Donchyts, Gennadii; Eilander, Dirk; Chen, Jorik; Leskens, Anne; Coughlan, Erin; Mawanda, Shaban; Ward, Philip; Diaz Loaiza, Andres; Luo, Tianyi; Iceland, Charles

2016-04-01

Topography data is essential for understanding and modeling of urban flood hazard. Within urban areas, much of the topography is defined by highly localized man-made features such as roads, channels, ditches, culverts and buildings. This results in the requirement that urban flood models require high resolution topography, and water conveying connections within the topography are considered. In recent years, more and more topography information is collected through LIDAR surveys however there are still many cities in the world where high resolution topography data is not available. Furthermore, information on connectivity is required for flood modelling, even when LIDAR data are used. In this contribution, we demonstrate how high resolution terrain data can be synthesized using a fusion between features in OpenStreetMap (OSM) data (including roads, culverts, channels and buildings) and existing low resolution and noisy SRTM elevation data using the Google Earth Engine platform. Our method uses typical existing OSM properties to estimate heights and topology associated with the features, and uses these to correct noise and burn features on top of the existing low resolution SRTM elevation data. The method has been setup in the Google Earth Engine platform so that local stakeholders and mapping teams can on-the-fly propose, include and visualize the effect of additional features and properties of features, which are deemed important for topography and water conveyance. These features can be included in a workshop environment. We pilot our tool over Dar Es Salaam.

The underlying reasons for very high levels of bed net use, and higher malaria infection prevalence among bed net users than non-users in the Tanzanian city of Dar es Salaam: a qualitative study.

PubMed

Msellemu, Daniel; Shemdoe, Aloysia; Makungu, Christina; Mlacha, Yeromini; Kannady, Khadija; Dongus, Stefan; Killeen, Gerry F; Dillip, Angel

2017-10-23

Bed nets reduce malaria-related illness and deaths, by forming a protective barrier around people sleeping under them. When impregnated with long-lasting insecticide formulations they also repel or kill mosquitoes attempting to feed upon sleeping humans, and can even suppress entire populations of malaria vectors that feed predominantly upon humans. Nevertheless, an epidemiological study in 2012 demonstrated higher malaria prevalence among bed net users than non-users in urban Dar es Salaam, Tanzania. Focus group discussions were conducted with women from four selected wards of Dar es Salaam city, focusing on four major themes relating to bed net use behaviours: (1) reasons for bed net use, (2) reasons for not using bed nets, (3) stimuli or reminders for people to use a bed net (4) perceived reasons for catching malaria while using a bed net. An analytical method by framework grouping of relevant themes was used address key issues of relevance to the study objectives. Codes were reviewed and grouped into categories and themes. All groups said the main reason for bed net use was protection against malaria. Houses with well-screened windows, with doors that shut properly, and that use insecticidal sprays against mosquitoes, were said not to use bed nets, while frequent attacks from malaria was the main stimulus for people to use bed nets. Various reasons were mentioned as potential reasons that compromise bed net efficacy, the most common of which were: (1) bed net sharing by two or more people, especially if one occupant tends to come to bed late at night, and does not tuck in the net 71%; (2) one person shares the bed but does not use the net, moving it away from the side on which s/he sleeps 68%; (3) ineffective usage habits, called ulalavi, in which a sprawling sleeper either touches the net while sleeping up against it or leaves a limb hanging outside of it 68%. Less common reasons mentioned included: (1) Small bed nets which become un-tucked at night (31%); (2) Bed nets with holes large enough to allow mosquitoes to pass (28%); and (3) Going to bed late after already being bitten outdoors (24%). Behaviours associated with bed net use like; bed sharing, bed net non compliant-bedfellow, sleeping pattern like ulalavi and some physical bed net attributes compromise its effectiveness and supposedly increase of malaria infection to bed net users. While some well-screened houses looked to instigate low malaria prevalence to non-bed net users.

Vom Big Business zum Smart Business in der Energiewirtschaft

NASA Astrophysics Data System (ADS)

Klaus, Jürgen; Anthonijsz, Jos

Kaum eine Branche hat in den letzten zehn Jahren einen tiefgreifenderen Wandel erfahren als die Energiewirtschaft. Einstmals geprägt durch Großkonzerne, die flächendeckend alle Formen von Energiedienstleistungen erbracht haben, stellt sich heute eine gänzlich veränderte Landschaft dar. Nicht nur das es heute eine Vielzahl von Erzeugern gibt, die zunehmend dezentral aufgestellt sind, auch die klassischen Marktrollen wechseln: Erzeuger werden zu Händlern, Verbraucher werden zu Erzeugern. Darüber hinaus drängen heute neue, vormals branchenfremde, Marktteilnehmer in die Energiewirtschaft. Leicht nachzuvollziehen, dass es eine neue Art der Kommunikation braucht. Ziel ist alle Akteure zu vernetzen, um so neuartige Geschäftsmodelle zu ermöglichen. Das Internet of Things (IoT) und die Serviceplattformen bieten hierzu die geeignete Grundlage und Lösungen für neue und zukünftige Prozesse in der Energiebranche. Hierbei stehen auch Themen, wie Big Data, Datenformate, Datennutzung und -sicherheit im Fokus.

The Challenges of Providing Postpartum Education in Dar es Salaam, Tanzania: Narratives of Nurse-Midwives and Obstetricians.

PubMed

Mselle, Lilian Teddy; Aston, Megan; Kohi, Thecla W; Mbekenga, Columba; Macdonald, Danielle; White, Maureen; Price, Sheri; Tomblin Murphy, Gail; O'Hearn, Shawna; Jefferies, Keisha

2017-10-01

Postpartum education can save lives of mothers and babies in developing countries, and the World Health Organization recommends all mothers receive three postpartum consultations. More information is needed to better understand how postpartum education is delivered and ultimately improves postpartum health outcomes. The purpose of this qualitative study was to examine how postpartum care was delivered in three postnatal hospital clinics in Dar es Salaam, Tanzania. Semistructured interviews with 10 nurse-midwives and three obstetricians were conducted. Feminist poststructuralism guided the research process. Postpartum education was seen to be an urgent matter; there was a lack of supportive resources and infrastructure in the hospital clinics, and nurse-midwives and obstetricians had to negotiate conflicting health and traditional discourses using various strategies. Nurse-midwives and obstetricians are well positioned to deliver life-saving postpartum education; however, improvements are required including increased number of nurse-midwives and obstetricians.

Exploring the association between women's access to economic resources and intimate partner violence in Dar es Salaam and Mbeya, Tanzania.

PubMed

Vyas, Seema; Jansen, Henrica Afm; Heise, Lori; Mbwambo, Jessie

2015-12-01

The relationship between women's access to economic resources, e.g. employment or access to micro-credit, and experience of intimate partner violence is complex. Empirical evidence documents that in some settings women's employment is associated with higher risk of partner violence but in other settings with lower risk. Evidence also shows that these conflicting associations exist not only between countries but also within different country settings. Using two population-based data sets gathered in 2002 in contrasting Tanzania settings-Dar es Salaam and Mbeya-, we used multivariate logistic regression to examine the relationship between women's access to economic resources and partner violence. Two indicators of economic resources were examined: whether women earned money and whether women owned a business either with someone or exclusively. In Dar es Salaam we found evidence of a higher risk association among women who earned money and who owned a business exclusively by themselves and a lower risk association among women who owned a business with someone. We found no relationship between either indicator of economic resources and partner violence in Mbeya. Other factors were similarly associated with partner violence in both settings and the strongest associations found were related to the respondents' partners: refusal to give money; alcohol use and relationships with other women. The findings support the assertion that women's access to economic resources operate differently in different country settings, thus highlighting the need for targeted prevention efforts that are relevant for the context. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of High-resolution Aerial LiDAR Data in Calibration of a Two-dimensional Urban Flood Simulation

NASA Astrophysics Data System (ADS)

Piotrowski, J.; Goska, R.; Chen, B.; Krajewski, W. F.; Young, N.; Weber, L.

2009-12-01

In June 2008, the state of Iowa experienced an unprecedented flood event which resulted in an economic loss of approximately $2.88 billion. Flooding in the Iowa River corridor, which exceeded the previous flood of record by 3 feet, devastated several communities, including Coralville and Iowa City, home to the University of Iowa. Recognizing an opportunity to capture a unique dataset detailing the impacts of the historic flood, the investigators contacted the National Center for Airborne Laser Mapping (NCALM), which performed an aerial Light Detection and Ranging (LiDAR) survey along the Iowa River. The survey, conducted immediately following the flood peak, provided coverage of a 60-mile reach. The goal of the present research is to develop a process by which flood extents and water surface elevations can be accurately extracted from the LiDAR data set and to evaluate the benefit of such data in calibrating one- and two-dimensional hydraulic models. Whereas data typically available for model calibration include sparsely distributed point observations and high water marks, the LiDAR data used in the present study provide broad-scale, detailed, and continuous information describing the spatial extent and depth of flooding. Initial efforts were focused on a 10-mile, primarily urban reach of the Iowa River extending from Coralville Reservoir, a United States Army Corps of Engineers flood control project, downstream through the Coralville and Iowa City. Spatial extent and depth of flooding were estimated from the LiDAR data. At a given cross-sectional location, river channel and floodplain measurements were compared. When differences between floodplain and river channel measurements were less than a standard deviation of the vertical uncertainty in the LiDAR survey, floodplain measurements were classified as flooded. A flood water surface DEM was created using measurements classified as flooded. A two-dimensional, depth-averaged numerical model of a 10-mile reach of the Iowa River corridor was developed using the United States Bureau of Reclamation SRH-2D hydraulic modeling software. The numerical model uses an unstructured numerical mesh and variable surface roughness, assigned according to observed land use and cover. The numerical model was calibrated using inundation extents and water surface elevations derived from the LiDAR data. It was also calibrated using high water marks and land survey data collected daily during the 2008 flood. The investigators compared the two calibrations to evaluate the benefit of high-resolution LiDAR data in improving the accuracy of a two-dimensional urban flood simulation.

Promoting sexual and reproductive health among adolescents in southern and eastern Africa (PREPARE): project design and conceptual framework.

PubMed

Aarø, Leif Edvard; Mathews, Catherine; Kaaya, Sylvia; Katahoire, Anne Ruhweza; Onya, Hans; Abraham, Charles; Klepp, Knut-Inge; Wubs, Annegreet; Eggers, Sander Matthijs; de Vries, Hein

2014-01-18

Young people in sub-Saharan Africa are affected by the HIV pandemic to a greater extent than young people elsewhere and effective HIV-preventive intervention programmes are urgently needed. The present article presents the rationale behind an EU-funded research project (PREPARE) examining effects of community-based (school delivered) interventions conducted in four sites in sub-Saharan Africa. One intervention focuses on changing beliefs and cognitions related to sexual practices (Mankweng, Limpopo, South Africa). Another promotes improved parent-offspring communication on sexuality (Kampala, Uganda). Two further interventions are more comprehensive aiming to promote healthy sexual practices. One of these (Western Cape, South Africa) also aims to reduce intimate partner violence while the other (Dar es Salaam, Tanzania) utilises school-based peer education. A modified Intervention Mapping approach is used to develop all programmes. Cluster randomised controlled trials of programmes delivered to school students aged 12-14 will be conducted in each study site. Schools will be randomly allocated (after matching or stratification) to intervention and delayed intervention arms. Baseline surveys at each site are followed by interventions and then by one (Kampala and Limpopo) or two (Western Cape and Dar es Salaam) post-intervention data collections. Questionnaires include questions common for all sites and are partly based on a set of social cognition models previously applied to the study of HIV-preventive behaviours. Data from all sites will be merged in order to compare prevalence and associations across sites on core variables. Power is set to .80 or higher and significance level to .05 or lower in order to detect intervention effects. Intraclass correlations will be estimated from previous surveys carried out at each site. We expect PREPARE interventions to have an impact on hypothesized determinants of risky sexual behaviour and in Western Cape and Dar es Salaam to change sexual practices. Results from PREPARE will (i) identify modifiable cognitions and social processes related to risky sexual behaviour and (ii) identify promising intervention approaches among young adolescents in sub-Saharan cultures and contexts. Controlled Trials ISRCTN56270821 (Cape Town); Controlled Trials ISRCTN10386599 (Limpopo); Clinical Trials NCT01772628 (Kampala); Australian New Zealand Clinical Trials Registry ACTRN12613000900718 (Dar es Salaam).

Promoting sexual and reproductive health among adolescents in southern and eastern Africa (PREPARE): project design and conceptual framework

PubMed Central

2014-01-01

Background Young people in sub-Saharan Africa are affected by the HIV pandemic to a greater extent than young people elsewhere and effective HIV-preventive intervention programmes are urgently needed. The present article presents the rationale behind an EU-funded research project (PREPARE) examining effects of community-based (school delivered) interventions conducted in four sites in sub-Saharan Africa. One intervention focuses on changing beliefs and cognitions related to sexual practices (Mankweng, Limpopo, South Africa). Another promotes improved parent-offspring communication on sexuality (Kampala, Uganda). Two further interventions are more comprehensive aiming to promote healthy sexual practices. One of these (Western Cape, South Africa) also aims to reduce intimate partner violence while the other (Dar es Salaam, Tanzania) utilises school-based peer education. Methods/design A modified Intervention Mapping approach is used to develop all programmes. Cluster randomised controlled trials of programmes delivered to school students aged 12–14 will be conducted in each study site. Schools will be randomly allocated (after matching or stratification) to intervention and delayed intervention arms. Baseline surveys at each site are followed by interventions and then by one (Kampala and Limpopo) or two (Western Cape and Dar es Salaam) post-intervention data collections. Questionnaires include questions common for all sites and are partly based on a set of social cognition models previously applied to the study of HIV-preventive behaviours. Data from all sites will be merged in order to compare prevalence and associations across sites on core variables. Power is set to .80 or higher and significance level to .05 or lower in order to detect intervention effects. Intraclass correlations will be estimated from previous surveys carried out at each site. Discussion We expect PREPARE interventions to have an impact on hypothesized determinants of risky sexual behaviour and in Western Cape and Dar es Salaam to change sexual practices. Results from PREPARE will (i) identify modifiable cognitions and social processes related to risky sexual behaviour and (ii) identify promising intervention approaches among young adolescents in sub-Saharan cultures and contexts. Trial registrations Controlled Trials ISRCTN56270821 (Cape Town); Controlled Trials ISRCTN10386599 (Limpopo); Clinical Trials NCT01772628 (Kampala); Australian New Zealand Clinical Trials Registry ACTRN12613000900718 (Dar es Salaam). PMID:24438582

Infant and young child feeding practices among children under 2 years of age and maternal exposure to infant and young child feeding messages and promotions in Dar es Salaam, Tanzania.

PubMed

Vitta, Bineti S; Benjamin, Margaret; Pries, Alissa M; Champeny, Mary; Zehner, Elizabeth; Huffman, Sandra L

2016-04-01

There are limited data describing infant and young child feeding practices (IYCF) in urban Tanzania. This study assessed the types of foods consumed by children under 2 years of age and maternal exposure to promotions of these foods in Dar es Salaam, Tanzania. A cross-sectional survey was conducted among 305 mothers of children less than 24 months of age who attended child health services in October and November, 2014. Among infants less than 6 months of age, rates of exclusive breastfeeding were low (40.8%) and a high proportion (38.2%) received semi-solid foods. Continued breastfeeding among 20-23-month-olds was only 33.3%. Consumption of breastmilk substitutes was not prevalent, and only 3.9% of infants less than 6 months of age and 4.8% of 6-23 month-olds were fed formula. Among 6-23-month-olds, only 38.4% consumed a minimum acceptable diet (using a modified definition). The homemade complementary foods consumed by the majority of 6-23-month-olds (85.2%) were cereal-dominated and infrequently contained micronutrient-rich ingredients. Only 3.1% of 6-23-month-olds consumed commercially produced infant cereal on the day preceding the interview. In contrast, commercially produced snack foods were consumed by 23.1% of 6-23-month-olds. Maternal exposure to commercial promotions of breastmilk substitutes and commercially produced complementary foods was low (10.5% and 1.0%, respectively), while exposure to promotions of commercially produced snack foods was high (45.9%). Strategies are needed to improve IYCF practices, particularly with regard to exclusive and continued breastfeeding, increased dietary diversity and consumption of micronutrient-rich foods, and avoidance of feeding commercially produced snack foods. © 2016 The Authors. Maternal & Child Nutrition published by John Wiley & Sons Ltd.

Low utilization of health care services following screening for hypertension in Dar es Salaam (Tanzania): a prospective population-based study

PubMed Central

Bovet, Pascal; Gervasoni, Jean-Pierre; Mkamba, Mashombo; Balampama, Marianna; Lengeler, Christian; Paccaud, Fred

2008-01-01

Background Drug therapy in high-risk individuals has been advocated as an important strategy to reduce cardiovascular disease in low income countries. We determined, in a low-income urban population, the proportion of persons who utilized health services after having been diagnosed as hypertensive and advised to seek health care for further hypertension management. Methods A population-based survey of 9254 persons aged 25–64 years was conducted in Dar es Salaam. Among the 540 persons with high blood pressure (defined here as BP ≥ 160/95 mmHg) at the initial contact, 253 (47%) had high BP on a 4th visit 45 days later. Among them, 208 were untreated and advised to attend health care in a health center of their choice for further management of their hypertension. One year later, 161 were seen again and asked about their use of health services during the interval. Results Among the 161 hypertensive persons advised to seek health care, 34% reported to have attended a formal health care provider during the 12-month interval (63% public facility; 30% private; 7% both). Antihypertensive treatment was taken by 34% at some point of time (suggesting poor uptake of health services) and 3% at the end of the 12-month follow-up (suggesting poor long-term compliance). Health services utilization tended to be associated with older age, previous history of high BP, being overweight and non-smoking, but not with education or wealth. Lack of symptoms and cost of treatment were the reasons reported most often for not attending health care. Conclusion Low utilization of health services after hypertension screening suggests a small impact of a patient-centered screen-and-treat strategy in this low-income population. These findings emphasize the need to identify and address barriers to health care utilization for non-communicable diseases in this setting and, indirectly, the importance of public health measures for primary prevention of these diseases. PMID:19087300

An Investigation on the Sensitivity of the Parameters of Urban Flood Model

NASA Astrophysics Data System (ADS)

M, A. B.; Lohani, B.; Jain, A.

2015-12-01

Global climatic change has triggered weather patterns which lead to heavy and sudden rainfall in different parts of world. The impact of heavy rainfall is severe especially on urban areas in the form of urban flooding. In order to understand the effect of heavy rainfall induced flooding, it is necessary to model the entire flooding scenario more accurately, which is now becoming possible with the availability of high resolution airborne LiDAR data and other real time observations. However, there is not much understanding on the optimal use of these data and on the effect of other parameters on the performance of the flood model. This study aims at developing understanding on these issues. In view of the above discussion, the aim of this study is to (i) understand that how the use of high resolution LiDAR data improves the performance of urban flood model, and (ii) understand the sensitivity of various hydrological parameters on urban flood modelling. In this study, modelling of flooding in urban areas due to heavy rainfall is carried out considering Indian Institute of Technology (IIT) Kanpur, India as the study site. The existing model MIKE FLOOD, which is accepted by Federal Emergency Management Agency (FEMA), is used along with the high resolution airborne LiDAR data. Once the model is setup it is made to run by changing the parameters such as resolution of Digital Surface Model (DSM), manning's roughness, initial losses, catchment description, concentration time, runoff reduction factor. In order to realize this, the results obtained from the model are compared with the field observations. The parametric study carried out in this work demonstrates that the selection of catchment description plays a very important role in urban flood modelling. Results also show the significant impact of resolution of DSM, initial losses and concentration time on urban flood model. This study will help in understanding the effect of various parameters that should be part of a flood model for its accurate performance.

Current and historical land use influence soil-based ecosystem services in an urban landscape.

PubMed

Ziter, Carly; Turner, Monica G

2018-04-01

Urban landscapes are increasingly recognized as providing important ecosystem services (ES) to their occupants. Yet, urban ES assessments often ignore the complex spatial heterogeneity and land-use history of cities. Soil-based services may be particularly susceptible to land-use legacy effects. We studied indicators of three soil-based ES, carbon storage, water quality regulation, and runoff regulation, in a historically agricultural urban landscape and asked (1) How do ES indicators vary with contemporary land cover and time since development? (2) Do ES indicators vary primarily among land-cover classes, within land-cover classes, or within sites? (3) What is the relative contribution of urban land-cover classes to potential citywide ES provision? We measured biophysical indicators (soil carbon [C], available phosphorus [P], and saturated hydraulic conductivity [K s ]) in 100 sites across five land-cover classes, spanning an ~125-year gradient of time since development within each land-cover class. Potential for ES provision was substantial in urban green spaces, including developed land. Runoff regulation services (high K s ) were highest in forests; water quality regulation (low P) was highest in open spaces and grasslands; and open spaces and developed land (e.g., residential yards) had the highest C storage. In developed land covers, both C and P increased with time since development, indicating effects of historical land-use on contemporary ES and trade-offs between two important ES. Among-site differences accounted for a high proportion of variance in soil properties in forests, grasslands, and open space, while residential areas had high within-site variability, underscoring the leverage city residents have to improve urban ES provision. Developed land covers contributed most ES supply at the citywide scale, even after accounting for potential impacts of impervious surfaces. Considering the full mosaic of urban green space and its history is needed to estimate the kinds and magnitude of ES provided in cities, and to augment regional ES assessments that often ignore or underestimate urban ES supply. © 2018 by the Ecological Society of America.

An Improved Snake Model for Refinement of Lidar-Derived Building Roof Contours Using Aerial Images

NASA Astrophysics Data System (ADS)

Chen, Qi; Wang, Shugen; Liu, Xiuguo

2016-06-01

Building roof contours are considered as very important geometric data, which have been widely applied in many fields, including but not limited to urban planning, land investigation, change detection and military reconnaissance. Currently, the demand on building contours at a finer scale (especially in urban areas) has been raised in a growing number of studies such as urban environment quality assessment, urban sprawl monitoring and urban air pollution modelling. LiDAR is known as an effective means of acquiring 3D roof points with high elevation accuracy. However, the precision of the building contour obtained from LiDAR data is restricted by its relatively low scanning resolution. With the use of the texture information from high-resolution imagery, the precision can be improved. In this study, an improved snake model is proposed to refine the initial building contours extracted from LiDAR. First, an improved snake model is constructed with the constraints of the deviation angle, image gradient, and area. Then, the nodes of the contour are moved in a certain range to find the best optimized result using greedy algorithm. Considering both precision and efficiency, the candidate shift positions of the contour nodes are constrained, and the searching strategy for the candidate nodes is explicitly designed. The experiments on three datasets indicate that the proposed method for building contour refinement is effective and feasible. The average quality index is improved from 91.66% to 93.34%. The statistics of the evaluation results for every single building demonstrated that 77.0% of the total number of contours is updated with higher quality index.

An Efficient Method for Automatic Road Extraction Based on Multiple Features from LiDAR Data

NASA Astrophysics Data System (ADS)

Li, Y.; Hu, X.; Guan, H.; Liu, P.

2016-06-01

The road extraction in urban areas is difficult task due to the complicated patterns and many contextual objects. LiDAR data directly provides three dimensional (3D) points with less occlusions and smaller shadows. The elevation information and surface roughness are distinguishing features to separate roads. However, LiDAR data has some disadvantages are not beneficial to object extraction, such as the irregular distribution of point clouds and lack of clear edges of roads. For these problems, this paper proposes an automatic road centerlines extraction method which has three major steps: (1) road center point detection based on multiple feature spatial clustering for separating road points from ground points, (2) local principal component analysis with least squares fitting for extracting the primitives of road centerlines, and (3) hierarchical grouping for connecting primitives into complete roads network. Compared with MTH (consist of Mean shift algorithm, Tensor voting, and Hough transform) proposed in our previous article, this method greatly reduced the computational cost. To evaluate the proposed method, the Vaihingen data set, a benchmark testing data provided by ISPRS for "Urban Classification and 3D Building Reconstruction" project, was selected. The experimental results show that our method achieve the same performance by less time in road extraction using LiDAR data.

Identifying conservation priorities and management strategies based on ecosystem services to improve urban sustainability in Harbin, China

PubMed Central

2018-01-01

Rapid urbanization and agricultural development has resulted in the degradation of ecosystems, while also negatively impacting ecosystem services (ES) and urban sustainability. Identifying conservation priorities for ES and applying reasonable management strategies have been found to be effective methods for mitigating this phenomenon. The purpose of this study is to propose a comprehensive framework for identifying ES conservation priorities and associated management strategies for these planning areas. First, we incorporated 10 ES indicators within a systematic conservation planning (SCP) methodology in order to identify ES conservation priorities with high irreplaceability values based on conservation target goals associated with the potential distribution of ES indicators. Next, we assessed the efficiency of the ES conservation priorities for meeting the designated conservation target goals. Finally, ES conservation priorities were clustered into groups using a K-means clustering analysis in an effort to identify the dominant ES per location before formulating management strategies. We effectively identified 12 ES priorities to best represent conservation target goals for the ES indicators. These 12 priorities had a total areal coverage of 13,364 km2 representing 25.16% of the study area. The 12 priorities were further clustered into five significantly different groups (p-values between groups < 0.05), which helped to refine management strategies formulated to best enhance ES across the study area. The proposed method allows conservation and management plans to easily adapt to a wide variety of quantitative ES target goals within urban and agricultural areas, thereby preventing urban and agriculture sprawl and guiding sustainable urban development. PMID:29682412

Identifying conservation priorities and management strategies based on ecosystem services to improve urban sustainability in Harbin, China.

PubMed

Qu, Yi; Lu, Ming

2018-01-01

Rapid urbanization and agricultural development has resulted in the degradation of ecosystems, while also negatively impacting ecosystem services (ES) and urban sustainability. Identifying conservation priorities for ES and applying reasonable management strategies have been found to be effective methods for mitigating this phenomenon. The purpose of this study is to propose a comprehensive framework for identifying ES conservation priorities and associated management strategies for these planning areas. First, we incorporated 10 ES indicators within a systematic conservation planning (SCP) methodology in order to identify ES conservation priorities with high irreplaceability values based on conservation target goals associated with the potential distribution of ES indicators. Next, we assessed the efficiency of the ES conservation priorities for meeting the designated conservation target goals. Finally, ES conservation priorities were clustered into groups using a K-means clustering analysis in an effort to identify the dominant ES per location before formulating management strategies. We effectively identified 12 ES priorities to best represent conservation target goals for the ES indicators. These 12 priorities had a total areal coverage of 13,364 km 2 representing 25.16% of the study area. The 12 priorities were further clustered into five significantly different groups ( p -values between groups < 0.05), which helped to refine management strategies formulated to best enhance ES across the study area. The proposed method allows conservation and management plans to easily adapt to a wide variety of quantitative ES target goals within urban and agricultural areas, thereby preventing urban and agriculture sprawl and guiding sustainable urban development.

Knowledge and attitudes towards obesity among primary school children in Dar es Salaam, Tanzania.

PubMed

Njelekela, Marina A; Muhihi, Alfa; Mpembeni, Rose N M; Anaeli, Amani; Chillo, Omary; Kubhoja, Sulende; Lujani, Benjamin; Ngarashi, Davis; Maghembe, Mwanamkuu

2015-01-01

Childhood obesity has increased over the past two decades. Child obesity is likely to persist through adulthood and increases the risk of non-communicable diseases (NCDs) later in life. This study assessed knowledge and attitudes towards obesity among primary school children in Dar es Salaam, Tanzania. A cross-sectional study was conducted in randomly selected primary schools in Dar es Salaam. A structured questionnaire was used to assess the knowledge and attitudes. Anthropometric and blood pressure measurements were taken using standard procedures. A total of 446 children were included in the analysis. The mean age of the participants was 11.1 ± 2.0 years. The mean body mass index (BMI), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were 16.6 ± 4.0 kg/m(2), 103.9 ± 10.3 mmHg and 65.6 ± 8.2 mmHg, respectively. Prevalence of obesity (defined as BMI >95(th) percentile for age and sex) was 5.2%. Half of the children (51.1%) had heard about obesity from teachers at school (20%), radio (19.4%) and books/newspaper (17.3%). Less than half (45.4%) had knowledge about the risk factors for childhood obesity and correctly defined obesity (44.6%). However, a good number of the children (72.1%) were aware that they can be affected by obesity. Majority of them had negative attitude towards obesity and various factors leading to or resulting from childhood obesity. Knowledge about childhood obesity among primary school children is moderate and have negative attitude towards obesity. Integrating educational programs early in primary schools may be an effective strategy to impact knowledge about obesity and other non-communicable diseases early in childhood.

Infant feeding practices among HIV-positive women in Dar es Salaam, Tanzania, indicate a need for more intensive infant feeding counselling.

PubMed

Young, Sera L; Israel-Ballard, Kiersten A; Dantzer, Emily A; Ngonyani, Monica M; Nyambo, Margaret T; Ash, Deborah M; Chantry, Caroline J

2010-12-01

To assess feeding practices of infants born to HIV-positive women in Dar es Salaam, Tanzania. These data then served as a proxy to evaluate the adequacy of current infant feeding counselling. A cross-sectional survey of infant feeding behaviours. Four clinics in greater Dar es Salaam in early 2008. A total of 196 HIV-positive mothers of children aged 6-10 months recruited from HIV clinics. Initiation of breast-feeding was reported by 95·4 % of survey participants. In the entire sample, 80·1 %, 34·2 % and 13·3 % of women reported exclusive breast-feeding (EBF) up to 2, 4 and 6 months, respectively. Median duration of EBF among women who ever breast-fed was 3 (interquartile range (IQR): 2·1, 4·0) months. Most non-breast-milk foods fed to infants were low in nutrient density. Complete cessation of breast-feeding occurred within 14 d of the introduction of non-breast-milk foods among 138 of the 187 children (73·8 %) who had ever received any breast milk. Of the 187 infants in the study who ever received breast milk, 19·4 % received neither human milk nor any replacement milks for 1 week or more (median duration of no milk was 14 (IQR: 7, 152) d). Infant feeding practices among these HIV-positive mothers resulted in infants receiving far less breast milk and more mixed complementary feeds than recommended, thus placing them at greater risk of both malnutrition and HIV infection. An environment that better enables mothers to follow national guidelines is urgently needed. More intensive infant feeding counselling programmes would very likely increase rates of optimal infant feeding.

Effect of improved access to antiretroviral therapy on clinical characteristics of patients enrolled in the HIV care and treatment clinic, at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania.

PubMed

Mugusi, Sabina F; Mwita, Julius C; Francis, Joel M; Aboud, Said; Bakari, Muhammad; Aris, Eric A; Swai, Andrew B; Mugusi, Ferdinand M; Pallangyo, Kisali; Sandstrom, Eric

2010-05-28

Sub-Saharan Africa has been severely affected by the HIV and AIDS pandemic. Global efforts at improving care and treatment has included scaling up use of antiretroviral therapy (ART). In Tanzania, HIV care and treatment program, including the provision of free ART started in 2004 with a pilot program at Muhimbili National Hospital in Dar es Salaam. This study describes the socio-demographic and clinical features of patients enrolled at the care and treatment clinic at MNH, Dar es Salaam, Tanzania. A cross-sectional study looking at baseline characteristics of patients enrolled at the HIV clinic at MNH between June 2004-Dec 2005 compared to those enrolled between 2006 and September 2008. Of all enrolled patients, 2408 (58.5%) were used for analysis. More females than males were attending the clinic. Their baseline median CD4 cell count was low (136 cells/microl) with 65.7% having below 200 cells/microl. Females had higher CD4 cell counts (150 cells/microl) than males (109 cells/microl) p < 0.001). The most common presenting features were skin rash and/or itching (51.6%); progressive weight loss (32.7%) and fever (23.4). Patients enrolled earlier at the clinic (2004-5) were significantly more symptomatic and had significantly lower CD4 cell count (127 cells/microl) compared to CD4 of 167 cells/microl in those seen later (2006-8) (p < 0.001). Patients enrolled to the MNH HIV clinic were predominantly females, and presented with advanced immune-deficiency. Improved access to HIV care and treatment services seems to be associated with patients' early presentation to the clinics in the course of HIV disease.

Asymptomatic bacteriuria and concomitant presence of other micro-organisms in urine of pregnant women in Dar es Salaam -- Tanzania.

PubMed

Mtimavalye, L A; Runyoro, D E; Massawe, F N; Mhalu, F S; Kanyawana, J Z

1983-09-01

This study was designed to determine the prevalence of significant bacteriuria in pregnancy in Dar es Salaam as well as attempt to find out whether bacteriuria has any effects on the mother and baby. Of 1007 pregnant women studied for asymptomatic bacteriuria, a significant bacteriuria rate of 6.3% was revealed. Escherichia coli was the predominant organism, making up 47.6% of the total organisms isolated. Schistosoma hematobium was present in 8.7%, T. vaginalis in 14%, yeast cells were found in the urine of 9.1% and the microfilariae of Wuchereria bancrofti were found in 1 specimen. 66.2% had no abnormality in their urine. It is recommended on the basis of this study that all women found to have significant bacteriuria in 1 cultured urine sample should be treated. There was a significant relationship noted between significant bacteriuria and the passing of S. hematobium in the urine. There was also a significant correlation between the presence of T. vaginalis and yeast cells in the urine. On the basis of laboratory sensitivity studies it was also found that the antimicrobial agents of choice for treating urinary tract infections in Dar es Salaam where E. coli and Klebsiella erogenes are the predominant organisms are nitrofurantoin, nalidixic acid and co-trimoxazole. The socioeconomic status of the bacteriuric and control group was divided into 4 groups according to take home pay; results show no significant increase of bacteriuria in any of the groups. It was not possible to follow up the effects of the presence of micro-organisms in urine during pregnancy because once a woman was found to have a positive culture she was treated.

Elevated blood pressure among primary school children in Dar es salaam, Tanzania: prevalence and risk factors.

PubMed

Muhihi, Alfa J; Njelekela, Marina A; Mpembeni, Rose N M; Muhihi, Bikolimana G; Anaeli, Amani; Chillo, Omary; Kubhoja, Sulende; Lujani, Benjamin; Maghembe, Mwanamkuu; Ngarashi, Davis

2018-02-13

Whilst the burden of non-communicable diseases is increasing in developing countries, little data is available on blood pressure among Tanzanian children. This study aimed at determining the blood pressure profiles and risk factors associated with elevated blood pressure among primary school children in Dar es Salaam, Tanzania. We conducted a cross sectional survey among 446 children aged 6-17 years from 9 randomly selected primary schools in Dar es Salaam. We measured blood pressure using a standardized digital blood pressure measuring machine (Omron Digital HEM-907, Tokyo, Japan). We used an average of the three blood pressure readings for analysis. Elevated blood pressure was defined as average systolic or diastolic blood pressure ≥ 90th percentile for age, gender and height. The proportion of children with elevated blood pressure was 15.2% (pre-hypertension 4.4% and hypertension 10.8%). No significant gender differences were observed in the prevalence of elevated BP. Increasing age and overweight/obese children were significantly associated with elevated BP (p = 0.0029 and p < 0.0001) respectively. Similar associations were observed for age and overweight/obesity with hypertension. (p = 0.0506 and p < 0.0001) respectively. In multivariate analysis, age above 10 years (adjusted RR = 3.63, 95% CI = 1.03-7.82) was significantly and independently associated with elevated BP in this population of school age children. We observed a higher proportion of elevated BP in this population of school age children. Older age and overweight/obesity were associated with elevated BP. Assessment of BP and BMI should be incorporated in school health program in Tanzania to identify those at risk so that appropriate interventions can be instituted before development of associated complications.

Comparing Perceptions with Actual Reports of Close Friend's HIV Testing Behavior Among Urban Tanzanian Men.

PubMed

Mulawa, Marta; Yamanis, Thespina J; Balvanz, Peter; Kajula, Lusajo J; Maman, Suzanne

2016-09-01

Men have lower rates of HIV testing and higher rates of AIDS-related mortality compared to women in sub-Saharan Africa. To assess whether there is an opportunity to increase men's uptake of testing by correcting misperceptions about testing norms, we compare men's perceptions of their closest friend's HIV testing behaviors with the friend's actual testing self-report using a unique dataset of men sampled within their social networks (n = 59) in Dar es Salaam, Tanzania. We examine the accuracy and bias of perceptions among men who have tested for HIV (n = 391) and compare them to the perceptions among men who never tested (n = 432). We found that testers and non-testers did not differ in the accuracy of their perceptions, though non-testers were strongly biased towards assuming that their closest friends had not tested. Our results lend support to social norms approaches designed to correct the biased misperceptions of non-testers to promote men's HIV testing.

Comparing Perceptions with Actual Reports of Close Friend’s HIV Testing Behavior Among Urban Tanzanian Men

PubMed Central

Yamanis, Thespina J.; Balvanz, Peter; Kajula, Lusajo J.; Maman, Suzanne

2016-01-01

Men have lower rates of HIV testing and higher rates of AIDS-related mortality compared to women in sub-Saharan Africa. To assess whether there is an opportunity to increase men’s uptake of testing by correcting misperceptions about testing norms, we compare men’s perceptions of their closest friend’s HIV testing behaviors with the friend’s actual testing self-report using a unique dataset of men sampled within their social networks (n = 59) in Dar es Salaam, Tanzania. We examine the accuracy and bias of perceptions among men who have tested for HIV (n = 391) and compare them to the perceptions among men who never tested (n = 432). We found that testers and non-testers did not differ in the accuracy of their perceptions, though non-testers were strongly biased towards assuming that their closest friends had not tested. Our results lend support to social norms approaches designed to correct the biased misperceptions of non-testers to promote men’s HIV testing. PMID:26880322

Efficacy of Waterless Hand Hygiene Compared with Handwashing with Soap: A Field Study in Dar es Salaam, Tanzania

PubMed Central

Pickering, Amy J.; Boehm, Alexandria B.; Mwanjali, Mathew; Davis, Jennifer

2010-01-01

Effective handwashing with soap requires reliable access to water supplies. However, more than three billion persons do not have household-level access to piped water. This research addresses the challenge of improving hand hygiene within water-constrained environments. The antimicrobial efficacy of alcohol-based hand sanitizer, a waterless hand hygiene product, was evaluated and compared with handwashing with soap and water in field conditions in Dar es Salaam, Tanzania. Hand sanitizer use by mothers resulted in 0.66 and 0.64 log reductions per hand of Escherichia coli and fecal streptococci, respectively. In comparison, handwashing with soap resulted in 0.50 and 0.25 log reductions per hand of E. coli and fecal streptococci, respectively. Hand sanitizer was significantly better than handwashing with respect to reduction in levels of fecal streptococci (P = 0.01). The feasibility and health impacts of promoting hand sanitizer as an alternative hand hygiene option for water-constrained environments should be assessed. PMID:20134005

Understanding Household Behavioral Risk Factors for Diarrheal Disease in Dar es Salaam: A Photovoice Community Assessment

PubMed Central

Badowski, Natalie; Castro, Cynthia M.; Montgomery, Maggie; Pickering, Amy J.; Mamuya, Simon; Davis, Jennifer

2011-01-01

Whereas Tanzania has seen considerable improvements in water and sanitation infrastructure over the past 20 years, the country still faces high rates of childhood morbidity from diarrheal diseases. This study utilized a qualitative, cross-sectional, modified Photovoice method to capture daily activities of Dar es Salaam mothers. A total of 127 photographs from 13 households were examined, and 13 interviews were conducted with household mothers. The photographs and interviews revealed insufficient hand washing procedures, unsafe disposal of wastewater, uncovered household drinking water containers, a lack of water treatment prior to consumption, and inappropriate toilets for use by small children. The interviews revealed that mothers were aware and knowledgeable of the risks of certain household practices and understood safer alternatives, yet were restricted by the perceived impracticality and financial constraints to make changes. The results draw attention to the real economic and behavioral challenges faced in reducing the spread of disease. PMID:21969836

Automatic 3D Building Detection and Modeling from Airborne LiDAR Point Clouds

ERIC Educational Resources Information Center

Sun, Shaohui

2013-01-01

Urban reconstruction, with an emphasis on man-made structure modeling, is an active research area with broad impact on several potential applications. Urban reconstruction combines photogrammetry, remote sensing, computer vision, and computer graphics. Even though there is a huge volume of work that has been done, many problems still remain…

INS/GPS/LiDAR Integrated Navigation System for Urban and Indoor Environments Using Hybrid Scan Matching Algorithm

PubMed Central

Gao, Yanbin; Liu, Shifei; Atia, Mohamed M.; Noureldin, Aboelmagd

2015-01-01

This paper takes advantage of the complementary characteristics of Global Positioning System (GPS) and Light Detection and Ranging (LiDAR) to provide periodic corrections to Inertial Navigation System (INS) alternatively in different environmental conditions. In open sky, where GPS signals are available and LiDAR measurements are sparse, GPS is integrated with INS. Meanwhile, in confined outdoor environments and indoors, where GPS is unreliable or unavailable and LiDAR measurements are rich, LiDAR replaces GPS to integrate with INS. This paper also proposes an innovative hybrid scan matching algorithm that combines the feature-based scan matching method and Iterative Closest Point (ICP) based scan matching method. The algorithm can work and transit between two modes depending on the number of matched line features over two scans, thus achieving efficiency and robustness concurrently. Two integration schemes of INS and LiDAR with hybrid scan matching algorithm are implemented and compared. Real experiments are performed on an Unmanned Ground Vehicle (UGV) for both outdoor and indoor environments. Experimental results show that the multi-sensor integrated system can remain sub-meter navigation accuracy during the whole trajectory. PMID:26389906

INS/GPS/LiDAR Integrated Navigation System for Urban and Indoor Environments Using Hybrid Scan Matching Algorithm.

PubMed

Gao, Yanbin; Liu, Shifei; Atia, Mohamed M; Noureldin, Aboelmagd

2015-09-15

This paper takes advantage of the complementary characteristics of Global Positioning System (GPS) and Light Detection and Ranging (LiDAR) to provide periodic corrections to Inertial Navigation System (INS) alternatively in different environmental conditions. In open sky, where GPS signals are available and LiDAR measurements are sparse, GPS is integrated with INS. Meanwhile, in confined outdoor environments and indoors, where GPS is unreliable or unavailable and LiDAR measurements are rich, LiDAR replaces GPS to integrate with INS. This paper also proposes an innovative hybrid scan matching algorithm that combines the feature-based scan matching method and Iterative Closest Point (ICP) based scan matching method. The algorithm can work and transit between two modes depending on the number of matched line features over two scans, thus achieving efficiency and robustness concurrently. Two integration schemes of INS and LiDAR with hybrid scan matching algorithm are implemented and compared. Real experiments are performed on an Unmanned Ground Vehicle (UGV) for both outdoor and indoor environments. Experimental results show that the multi-sensor integrated system can remain sub-meter navigation accuracy during the whole trajectory.

Teachers' Questioning Techniques in Advanced Level Chemistry Lessons: A Tanzanian Perspective

ERIC Educational Resources Information Center

Kira, Ernest; Komba, Sotco; Kafanabo, Eugenia; Tilya, Frank

2013-01-01

This study investigated the extent to which teachers' questioning techniques and the way teachers handled students' responses facilitated students' learning and promoted their thinking skills. The study focused on three secondary schools in Dar es Salaam. The data collection process involved classroom observations during chemistry lessons and…

Tanzanian Students' Attitudes toward English

ERIC Educational Resources Information Center

Hilliard, Amanda

2015-01-01

Although much research has been conducted on language policy and its effects in Tanzania, few studies have focused directly on the attitudes and opinions of Tanzanian students and teachers. For this project, 153 secondary students and 28 secondary school teachers from three secondary schools in Dar es Salaam were surveyed. Overall, both students…

Codeswitching and the Exclusivity of Social Identities: Some Data from Campus Kiswahili.

ERIC Educational Resources Information Center

Blommaert, Jan

1992-01-01

The macro-dimension of code switching is examined as observed in a sociolect of Swahili used by academic staff from the University of Dar es Salaam. It is argued that the specific sociohistoric background of Tanzanian society accounts for the social valency of Campus Kiswahili. (Author/LB)

Modeling the effects of urban expansion on natural capital stocks and ecosystem service flows: A case study in the Puget Sound, Washington, USA

USGS Publications Warehouse

Zank, Ben; Bagstad, Kenneth J.; Voigt, Brian; Villa, Ferdinando

2016-01-01

Urban expansion and its associated landscape modifications are important drivers of changes in ecosystem service (ES). This study examined the effects of two alternative land use-change development scenarios in the Puget Sound region of Washington State on natural capital stocks and ES flows. Land-use change model outputs served as inputs to five ES models developed using the Artificial Intelligence for Ecosystem Services (ARIES) platform. While natural capital stocks declined under managed (1.3–5.8%) and unmanaged (2.8–11.8%) development scenarios, ES flows increased by 18.5–56% and 23.2–55.7%, respectively. Human development of natural landscapes reduced their capacity for service provision, while simultaneously adding beneficiaries, particularly along the urban fringe. Using global and local Moran’s I, we identified three distinct patterns of change in ES due to projected landuse change. For services with location-dependent beneficiaries – open space proximity, viewsheds, and flood regulation – urbanization led to increased clustering and hot-spot intensities. ES flows were greatest in the managed land-use change scenario for open space proximity and flood regulation, and in the unmanaged land-use change scenario for viewsheds—a consequence of the differing ES flow mechanisms underpinning these services. We observed a third pattern – general declines in service provision – for carbon storage and sediment retention, where beneficiaries in our analysis were not location dependent. Contrary to past authors’ finding of ES declines under urbanization, a more nuanced analysis that maps and quantifies ES provision, beneficiaries, and flows better identifies gains and losses for specific ES beneficiaries as urban areas expand.

Estimating the relationship between urban 3D morphology and land surface temperature using airborne LiDAR and Landsat-8 Thermal Infrared Sensor data

NASA Astrophysics Data System (ADS)

Lee, J. H.

2015-12-01

Urban forests are known for mitigating the urban heat island effect and heat-related health issues by reducing air and surface temperature. Beyond the amount of the canopy area, however, little is known what kind of spatial patterns and structures of urban forests best contributes to reducing temperatures and mitigating the urban heat effects. Previous studies attempted to find the relationship between the land surface temperature and various indicators of vegetation abundance using remote sensed data but the majority of those studies relied on two dimensional area based metrics, such as tree canopy cover, impervious surface area, and Normalized Differential Vegetation Index, etc. This study investigates the relationship between the three-dimensional spatial structure of urban forests and urban surface temperature focusing on vertical variance. We use a Landsat-8 Thermal Infrared Sensor image (acquired on July 24, 2014) to estimate the land surface temperature of the City of Sacramento, CA. We extract the height and volume of urban features (both vegetation and non-vegetation) using airborne LiDAR (Light Detection and Ranging) and high spatial resolution aerial imagery. Using regression analysis, we apply empirical approach to find the relationship between the land surface temperature and different sets of variables, which describe spatial patterns and structures of various urban features including trees. Our analysis demonstrates that incorporating vertical variance parameters improve the accuracy of the model. The results of the study suggest urban tree planting is an effective and viable solution to mitigate urban heat by increasing the variance of urban surface as well as evaporative cooling effect.

Food, Aid, and Education in East Africa: Repackaging the Conversation

ERIC Educational Resources Information Center

Stambach, Amy

2016-01-01

This paper examines students' food perspectives in three rapidly diversifying contemporary contexts: a university setting in Kigali, Rwanda where students help to prepare Chinese dumplings; a school garden and canteen in Nairobi, Kenya where students jostle for bowls of beans and rice; and a fast-food restaurant in Dar es Salaam, Tanzania, where…

Anxiety and depression strongly associated with sexual risk behaviors among networks of young men in Dar es Salaam, Tanzania.

PubMed

Hill, Lauren M; Maman, Suzanne; Kilonzo, Mrema Noel; Kajula, Lusajo Joel

2017-02-01

This study tested the association between mental health scores and sexual risk behaviors among male members of social groups known as "camps" in Dar es Salaam, Tanzania. Anxiety and depression were measured using the HSCL-25 and condom use and sexual partner concurrency were assessed through self-report. A total of 1113 sexually active men with an average age of 27 years were included in the analyses. Higher anxiety and depression scores were significantly associated with both condom use (Anxiety AOR = 0.58, 95% CI: 0.44, 0.77; Depression AOR = 0.60, 95% CI: 0.47, 0.77) and concurrency (Anxiety AOR = 2.32, 95% CI: 1.73, 3.12; Depression AOR = 2.08, 95% CI: 1.60, 2.70). The results of this study provide information salient to the development of effective HIV prevention interventions targeting populations with high burdens of anxiety and depression. The feasibility and effect of integrating mental health promotion activities into HIV prevention interventions should be explored.

Hopefulness Fosters Affective and Cognitive Constructs for Actions to Cope and Enhance Quality of Life among People Living with HIV in Dar Es Salaam, Tanzania.

PubMed

Siril, Hellen; Fawzi, Mary C Smith; Todd, Jim; Wyatt, Monique; Kilewo, Japheth; Ware, Norma; Kaaya, Sylvia

The aims of this study were to describe how people living with HIV (PLWH) perceive hope and illustrate implications for HIV care and treatment. This is a qualitative study done to explore perceptions and meanings of hope among PLWH attending care and treatment clinics in Dar es Salaam, Tanzania. In all, 10 focus group discussions and 9 in-depth interviews were conducted. People living with HIV described the following 3 dimensions of hope: cognitive, positive emotions, and normalization. Being cognizant of the effectiveness of antiretroviral treatment (ART) often led to positive emotions, such as feeling comforted or strengthened, which in turn was related to positive actions toward normalizing life. Improved treatment outcomes facilitated hope, while persistent health problems, such as ART side effects, were sources of negative emotions contributing to loss of hope among PLWH. Hope motivated positive health-seeking behaviors, including adherence to ART, and this may guide interventions to help PLWH cope and live positively with HIV.

Prevalence and Risk Factors for Overweight and Obesity among HIV-Infected Adults in Dar es Salaam, Tanzania.

PubMed

Semu, Helen; Zack, Rachel M; Liu, Enju; Hertzmark, Ellen; Spiegelman, Donna; Sztam, Kevin; Hawkins, Claudia; Chalamila, Guerino; Muya, Aisa; Siril, Hellen; Mwiru, Ramadhani; Mtasiwa, Deo; Fawzi, Wafaie

2016-11-01

Overweight and obesity are increasingly prevalent among HIV-infected populations. We describe their prevalence and associated risk factors among HIV-infected adults in Dar es Salaam, Tanzania. A cross-sectional study was conducted to determine the proportion of patients who were overweight or obese at enrollment to care and treatment centres from 2004 to 2011. Multivariate relative risk regression models were fit to identify risk factors.  A total of 53 825 patients were included in the analysis. In all, 16% of women and 8% of men were overweight, while 7% and 2% were obese, respectively. In multivariate analyses, older age, higher CD4 count, higher hemoglobin levels, female sex, and being married were associated with obesity and overweight. World Health Organization HIV disease stage, tuberculosis history, and previous antiretroviral therapy were inversely associated with obesity and overweight. Overweight and obesity were highly prevalent among HIV-infected patients. Screening for overweight and obesity and focused interventions should be integrated into HIV care. © The Author(s) 2014.

Canopy rainfall partitioning across an urbanization gradient in forest structure as characterized by terrestrial LiDAR

NASA Astrophysics Data System (ADS)

Mesta, D. C.; Van Stan, J. T., II; Yankine, S. A.; Cote, J. F.; Jarvis, M. T.; Hildebrandt, A.; Friesen, J.; Maldonado, G.

2017-12-01

As urbanization expands, greater forest area is shifting from natural stand structures to urban stand structures, like forest fragments and landscaped tree rows. Changes in forest canopy structure have been found to drastically alter the amount of rainwater reaching the surface. However, stormwater management models generally treat all forest structures (beyond needle versus broadleaved) similarly. This study examines the rainfall partitioning of Pinus spp. canopies along a natural-to-urban forest gradient and compares these to canopy structural measurements using terrestrial LiDAR. Throughfall and meteorological observations were also used to estimate parameters of the commonly-used Gash interception model. Preliminary findings indicate that as forest structure changed from natural, closed canopy conditions to semi-closed canopy fragments and, ultimately, to exposed urban landscaping tree rows, the interchange between throughfall and rainfall interception also changed. This shift in partitioning between throughfall and rainfall interception may be linked to intuitive parameters, like canopy closure and density, as well as more complex metrics, like the fine-scale patterning of gaps (ie, lacunarity). Thus, results indicate that not all forests of the same species should be treated the same by stormwater models. Rather, their canopy structural characteristics should be used to vary their hydrometeorological interactions.

Community-owned resource persons for malaria vector control: enabling factors and challenges in an operational programme in Dar es Salaam, United Republic of Tanzania

PubMed Central

2011-01-01

Background Community participation in vector control and health services in general is of great interest to public health practitioners in developing countries, but remains complex and poorly understood. The Urban Malaria Control Program (UMCP) in Dar es Salaam, United Republic of Tanzania, implements larval control of malaria vector mosquitoes. The UMCP delegates responsibility for routine mosquito control and surveillance to community-owned resource persons (CORPs), recruited from within local communities via the elected local government. Methods A mixed method, cross-sectional survey assessed the ability of CORPs to detect mosquito breeding sites and larvae, and investigated demographic characteristics of the CORPs, their reasons for participating in the UMCP, and their work performance. Detection coverage was estimated as the proportion of wet habitats found by the investigator which had been reported by CORP. Detection sensitivity was estimated as the proportion of wet habitats found by the CORPS which the investigator found to contain Anopheles larvae that were also reported to be occupied by the CORP. Results The CORPs themselves perceived their role as professional rather than voluntary, with participation being a de facto form of employment. Habitat detection coverage was lower among CORPs that were recruited through the program administrative staff, compared to CORPs recruited by local government officials or health committees (Odds Ratio = 0.660, 95% confidence interval = [0.438, 0.995], P = 0.047). Staff living within their areas of responsibility had > 70% higher detection sensitivity for both Anopheline (P = 0.016) and Culicine (P = 0.012): positive habitats compared to those living outside those same areas. Discussion and conclusions Improved employment conditions as well as involving the local health committees in recruiting individual program staff, communication and community engagement skills are required to optimize achieving effective community participation, particularly to improve access to fenced compounds. A simpler, more direct, less extensive community-based surveillance system in the hands of a few, less burdened, better paid and maintained program personnel may improve performance and data quality. PMID:21955856

Placental Pathology Associated with Household Air Pollution in a Cohort of Pregnant Women from Dar es Salaam, Tanzania.

PubMed

Wylie, Blair J; Matechi, Emmanuel; Kishashu, Yahya; Fawzi, Wafaie; Premji, Zul; Coull, Brent A; Hauser, Russ; Ezzati, Majid; Roberts, Drucilla J

2017-01-01

Smoke from the burning of biomass fuels has been linked with adverse pregnancy outcomes such as low birth weight, stillbirth, and prematurity. To identify potential underlying mechanisms of adverse perinatal outcomes, we explored the association of placental pathology with household air pollution in pregnant women from urban/periurban Tanzania who cook predominantly with charcoal. Between 2011 and 2013, we measured personal exposures to fine particulate matter (PM2.5) and carbon monoxide (CO) over 72 hr among a cohort of Tanzanian pregnant women. Placentas were collected after delivery for examination. Placental pathologies of inflammatory, hypoxic, ischemic/hypertensive, infectious and thrombotic etiologies were diagnosed, blinded to exposure levels. Using multiple logistic regression, we explored the association of PM2.5 and CO exposure with placental pathology. One hundred sixteen women had personal air exposure measurements and placental histopathology available for analysis. PM2.5 and CO exposures were moderate [geometric means (GSD) were 40.5 μg/m3 (17.3) and 2.21 ppm (1.47) respectively]; 88.6% of PM2.5 measurements exceeded World Health Organization air quality guidelines. We observed an increase in the odds (per 1-unit increase in exposure on the ln-scale) of fetal thrombotic vasculopathy (FTV) both with increasing PM2.5 [adjusted odds ratio (aOR) = 5.5; 95% CI: 1.1, 26.8] and CO measurements (aOR = 2.5; 95% CI: 1.0, 6.4) in adjusted models only. FTV also was more common among pregnancies complicated by stillbirth or low birth weight. Fetal thrombosis may contribute to the adverse outcomes associated with household air pollution from cook stoves during pregnancy. Larger studies are necessary for confirmation. Citation: Wylie BJ, Matechi E, Kishashu Y, Fawzi W, Premji Z, Coull BA, Hauser R, Ezzati M, Roberts D. 2017. Placental pathology associated with household air pollution in a cohort of pregnant women from Dar es Salaam, Tanzania. Environ Health Perspect 125:134-140; http://dx.doi.org/10.1289/EHP256.

Tracking geomorphic signatures of watershed suburbanization with multi-temporal LiDAR

USGS Publications Warehouse

Jones, Daniel K.; Baker, Matthew E.; Miller, Andrew J.; Jarnagin, S. Taylor; Hogan, Dianna M.

2014-01-01

Urban development practices redistribute surface materials through filling, grading, and terracing, causing drastic changes to the geomorphic organization of the landscape. Many studies document the hydrologic, biologic, or geomorphic consequences of urbanization using space-for-time comparisons of disparate urban and rural landscapes. However, no previous studies have documented geomorphic changes from development using multiple dates of high-resolution topographic data at the watershed scale. This study utilized a time series of five sequential light detection and ranging (LiDAR) derived digital elevation models (DEMs) to track watershed geomorphic changes within two watersheds throughout development (2002–2008) and across multiple spatial scales (0.01–1 km2). Development-induced changes were compared against an undeveloped forested watershed during the same time period. Changes in elevations, slopes, hypsometry, and surface flow pathways were tracked throughout the development process to assess watershed geomorphic alterations. Results suggest that development produced an increase in sharp topographic breaks between relatively flat surfaces and steep slopes, replacing smoothly varying hillslopes and leading to greater variation in slopes. Examinations of flowpath distributions highlight systematic modifications that favor rapid convergence in unchanneled upland areas. Evidence of channel additions in the form of engineered surface conduits is apparent in comparisons of pre- and post-development stream maps. These results suggest that topographic modification, in addition to impervious surfaces, contributes to altered hydrologic dynamics observed in urban systems. This work highlights important considerations for the use of repeat LiDAR flights in analyzing watershed change through time. Novel methods introduced here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during development and help guide future research directions for development-based watershed studies.

Point‐of‐sale promotion of breastmilk substitutes and commercially produced complementary foods in Cambodia, Nepal, Senegal and Tanzania

PubMed Central

Pereira, Catherine; Sweet, Lara; Khin, Mengkheang; Ndiaye Coly, Aminata; Sy Gueye, Ndeye Yaga; Adhikary, Indu; Dhungel, Shrid; Makafu, Cecilia; Zehner, Elizabeth; Huffman, Sandra L.

2016-01-01

Abstract In order to assess the prevalence of point‐of‐sale promotions of infant and young child feeding products in Phnom Penh, Cambodia; Kathmandu Valley, Nepal; Dakar Department, Senegal; and Dar es Salaam, Tanzania, approximately 30 retail stores per site, 121 in total, were visited. Promotional activity for breastmilk substitutes (BMS) and commercially produced complementary foods in each site were recorded. Point‐of‐sale promotion of BMS occurred in approximately one‐third of sampled stores in Phnom Penh and Dakar Department but in 3.2% and 6.7% of stores in Kathmandu Valley and Dar es Salaam, respectively. Promotion of commercially produced complementary foods was highly prevalent in Dakar Department with half of stores having at least one promotion, while promotions for these products occurred in 10% or less of stores in the other three sites. While promotion of BMS in stores is legal in Senegal, it is prohibited in Cambodia without prior permission of the Ministry of Health/Ministry of Information and prohibited in both Nepal and Tanzania. Strengthening legislation in Senegal and enforcing regulations in Cambodia could help to prevent such promotion that can negatively affect breastfeeding practices. Key messages Even in countries such as Cambodia, Nepal and Tanzania where point‐of‐sale promotion is restricted, promotions of BMS were observed (in nearly one‐third of stores in Phnom Penh and less than 10% in Dar es Salaam and Kathmandu).Limited promotion of commercially produced complementary foods was evident (less than 10% of stores had a promotion for such foods), except in Dakar Department, where promotions were found in half of stores.Efforts are needed to strengthen monitoring, regulation and enforcement of restrictions on the promotion of BMS.Manufacturers and distributors should take responsibility for compliance with national regulations and global policies pertaining to the promotion of breastmilk substitutes. PMID:27061961

Oral health status of handicapped primary school pupils in Dar es Salaam, Tanzania.

PubMed

Simon, E N M; Matee, M I; Scheutz, F

2008-03-01

There is hardly any information regarding oral health status of handicapped primary school pupils in Tanzania. Determination of their oral health status could help in planning sustainable intervention programmes for this disadvantaged group. To determine caries and periodontal status and treatment needs of handicapped primary school pupils in Dar es Salaam, Tanzania. A descriptive cross-sectional study. Uhuru Mchanganyiko and Buguruni special schools, Dar es Salaam. The sample consisted of 179 (55.8%) males and 142 (44.2%) females aged between 7 and 22 years. Majority (71%) were deaf followed by blind (17.8%) and mentally retarded (8.7%). Six (1.9%) pupils were both deaf and blind, while one (0.3%) pupil was blind and mentally retarded. Forty one (12.8%) pupils had at least one decayed deciduous tooth, with the mean (dmfs) ranging from 0.25 to 3.24. The deaf had the highest mean decayed surfaces, followed by the mentally retarded and the blind. There was only one (0.3%) pupil who had a filled deciduous tooth. Thirty three (10.3%) pupils had decayed permanent teeth and 31 (9.7%) had missing permanent teeth. None of the decayed permanent teeth were restored. The blind had the lowest mean deciduous surfaces (DS) scores of between 0 and 1.0. In the mentally retarded group the mean DS ranged from 0.25 to 1.75. About 73.5% of the studied group had bleeding of the gums, with the blind having the highest mean bleeding index scores (p < 0.001) and about 82.8% of the pupils had calculus, with highest mean scores mainly among the blind (p = 0.008). The caries prevalence among handicapped primary school pupils was quite low. However, there was relatively high level of gingival bleeding and calculus. Regarding treatment needs, 23% required dental fillings mainly of one and two surface restorations and 82% required scaling and polishing. Despite these treatment needs these pupils had not received any dental attention.

Effect of Improved access to Antiretroviral Therapy on clinical characteristics of patients enrolled in the HIV care and treatment clinic, at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania

PubMed Central

2010-01-01

Background Sub-Saharan Africa has been severely affected by the HIV and AIDS pandemic. Global efforts at improving care and treatment has included scaling up use of antiretroviral therapy (ART). In Tanzania, HIV care and treatment program, including the provision of free ART started in 2004 with a pilot program at Muhimbili National Hospital in Dar es Salaam. This study describes the socio-demographic and clinical features of patients enrolled at the care and treatment clinic at MNH, Dar es Salaam, Tanzania. Methods A cross-sectional study looking at baseline characteristics of patients enrolled at the HIV clinic at MNH between June 2004 - Dec 2005 compared to those enrolled between 2006 and September 2008. Results Of all enrolled patients, 2408 (58.5%) were used for analysis. More females than males were attending the clinic. Their baseline median CD4 cell count was low (136 cells/μl) with 65.7% having below 200 cells/μl. Females had higher CD4 cell counts (150 cells/μl) than males (109 cells/μl) p < 0.001). The most common presenting features were skin rash and/or itching (51.6%); progressive weight loss (32.7%) and fever (23.4). Patients enrolled earlier at the clinic (2004-5) were significantly more symptomatic and had significantly lower CD4 cell count (127 cells/μl) compared to CD4 of 167 cells/μl in those seen later (2006-8) (p < 0.001). Conclusion Patients enrolled to the MNH HIV clinic were predominantly females, and presented with advanced immune-deficiency. Improved access to HIV care and treatment services seems to be associated with patients' early presentation to the clinics in the course of HIV disease. PMID:20509892

Managing Urban Water: Opportunities and Limitations of the Ecosystem Services Framework

NASA Astrophysics Data System (ADS)

Hamel, P.; Keeler, B.; Donahue, M.; Hobbie, S. E.; Finlay, J. C.; Brauman, K. A.; Vogl, A.

2015-12-01

Traditionally applied to rural environments, the concept of ES is gaining traction in urban areas, overlapping with a number of existing management frameworks in engineering, policy science, political ecology, or urban planning. Given this overlap, it is legitimate to question the value added by the ES concept, either as a theoretical or practical framework. This is particularly the case for urban water management, where new paradigms in engineering and socio-hydrology are increasingly bringing a social dimension to problem solving. In this talk, I will illustrate key opportunities and limitations of the ES framework with a focus on the service of stormwater retention. Drawing from examples in the Global North and South (including Melbourne, Australia, and Cape Town, South Africa), I will show that the ES lens allows: i) an explicit linkage between beneficiaries and grey and green infrastructure, which improves visibility and credibility of techniques valuing urban nature; ii) an improved understanding of tradeoffs and synergies between services, even in regions with limited environmental or socio-economic data; and iii) the development of powerful visualization techniques, enhancing communication with a broad range of stakeholders. These strengths make ES assessments a powerful tool to raise awareness or assist urban planners in realizing their vision of green cities. However, in cities like Melbourne with high capacity and innovative governance, I will argue that the instrumental use of ES is limited and may even be detrimental; limitations of the ES framework, which include a perceived partiality and vagueness, may be used by detractors to undermine the work of urban planners envisioning a greener city. To conclude the talk, I will present the work that the Natural Capital Project is conducting on the application of the ES concept for global indicators of sustainable development, thereby supporting the monitoring and implementation of urban Sustainable Development Goals.

Inappropriate Use of Antibiotics and Its Associated Factors among Urban and Rural Communities of Bahir Dar City Administration, Northwest Ethiopia

PubMed Central

Gebeyehu, Endalew; Bantie, Laychiluh; Azage, Muluken

2015-01-01

Background Inappropriate use of antibiotics in the community plays a role in the emergence and spread of bacteria resistant to antibiotics which threatens human health significantly. The present study was designed to determine inappropriate use of antibiotics and its associated factors among urban and rural communities of Bahir Dar city administration. Methods A comparative cross sectional study design was conducted in urban and rural kebeles of Bahir Dar city administration from February 1 to March 28, 2014. A total of 1082 participants included in the study using a systematic random sampling technique. Data was collected using pre-tested and structured questionnaire. Data was coded and entered into SPSSS version 16 for statistical analysis. Bivariate and multivariate logistic regression model were used to identify factors associated with inappropriate use of antibiotics. Results Inappropriate use of antibiotics was 30.9% without significant difference between urban (33.1%) and rural (29.2%) communities. From the inappropriate antibiotic use practice, self-medication was 18.0% and the remaining (12.9%) was for family member medication. Respiratory tract symptoms (74.6%), diarrhea (74.4%), and physical injury/wound (64.3%) were the three main reasons that the communities had used antibiotics inappropriately. Factors associated with inappropriate use of antibiotics were low educational status, younger age, unsatisfaction with the health care services, engagement with a job, and low knowledge on the use of antibiotic preparations of human to animals. Conclusions Inappropriate use of antibiotic exists in the study area with no significant difference between urban and rural communities. The study indicated an insight on what factors that intervention should be made to reduce inappropriate use of antibiotics in the community. Interventions that consider age groups, educational status, common health problems and their jobs together with improvement of health care services should be areas of focus to reduce inappropriate use of antibiotics. PMID:26379031

Inappropriate Use of Antibiotics and Its Associated Factors among Urban and Rural Communities of Bahir Dar City Administration, Northwest Ethiopia.

PubMed

Gebeyehu, Endalew; Bantie, Laychiluh; Azage, Muluken

2015-01-01

Inappropriate use of antibiotics in the community plays a role in the emergence and spread of bacteria resistant to antibiotics which threatens human health significantly. The present study was designed to determine inappropriate use of antibiotics and its associated factors among urban and rural communities of Bahir Dar city administration. A comparative cross sectional study design was conducted in urban and rural kebeles of Bahir Dar city administration from February 1 to March 28, 2014. A total of 1082 participants included in the study using a systematic random sampling technique. Data was collected using pre-tested and structured questionnaire. Data was coded and entered into SPSSS version 16 for statistical analysis. Bivariate and multivariate logistic regression model were used to identify factors associated with inappropriate use of antibiotics. Inappropriate use of antibiotics was 30.9% without significant difference between urban (33.1%) and rural (29.2%) communities. From the inappropriate antibiotic use practice, self-medication was 18.0% and the remaining (12.9%) was for family member medication. Respiratory tract symptoms (74.6%), diarrhea (74.4%), and physical injury/wound (64.3%) were the three main reasons that the communities had used antibiotics inappropriately. Factors associated with inappropriate use of antibiotics were low educational status, younger age, unsatisfaction with the health care services, engagement with a job, and low knowledge on the use of antibiotic preparations of human to animals. Inappropriate use of antibiotic exists in the study area with no significant difference between urban and rural communities. The study indicated an insight on what factors that intervention should be made to reduce inappropriate use of antibiotics in the community. Interventions that consider age groups, educational status, common health problems and their jobs together with improvement of health care services should be areas of focus to reduce inappropriate use of antibiotics.

Undernutrition among HIV-positive children in Dar es Salaam, Tanzania: antiretroviral therapy alone is not enough.

PubMed

Sunguya, Bruno F; Poudel, Krishna C; Otsuka, Keiko; Yasuoka, Junko; Mlunde, Linda B; Urassa, David P; Mkopi, Namala P; Jimba, Masamine

2011-11-16

The prevalence of HIV/AIDS has exacerbated the impact of childhood undernutrition in many developing countries, including Tanzania. Even with the provision of antiretroviral therapy, undernutrition among HIV-positive children remains a serious problem. Most studies to examine risk factors for undernutrition have been limited to the general population and ART-naive HIV-positive children, making it difficult to generalize findings to ART-treated HIV-positive children. The objectives of this study were thus to compare the proportions of undernutrition among ART-treated HIV-positive and HIV-negative children and to examine factors associated with undernutrition among ART-treated HIV-positive children in Dar es Salaam, Tanzania. From September to October 2010, we conducted a cross-sectional survey among 213 ART-treated HIV-positive and 202 HIV-negative children in Dar es Salaam, Tanzania. We measured the children's anthropometrics, socio-demographic factors, food security, dietary habits, diarrhea episodes, economic status, and HIV clinical stage. Data were analyzed using both univariate and multivariate methods. ART-treated HIV-positive children had higher rates of undernutrition than their HIV-negative counterparts. Among the ART-treated HIV-positive children, 78 (36.6%) were stunted, 47 (22.1%) were underweight, and 29 (13.6%) were wasted. Households of ART-treated HIV-positive children exhibited lower economic status, lower levels of education, and higher percentages of unmarried caregivers with higher unemployment rates. Food insecurity was prevalent in over half of ART-treated HIV-positive children's households. Furthermore, ART-treated HIV-positive children were more likely to be orphaned, to be fed less frequently, and to have lower body weight at birth compared to HIV-negative children.In the multivariate analysis, child's HIV-positive status was associated with being underweight (AOR = 4.61, 95% CI 1.38-15.36 P = 0.013) and wasting (AOR = 9.62, 95% CI 1.72-54.02, P = 0.010) but not with stunting (AOR = 0.68, 95% CI 0.26-1.77, P = 0.428). Important factors associated with underweight status among ART-treated HIV-positive children included hunger (AOR = 9.90, P = 0.022), feeding frequency (AOR = 0.02, p < 0.001), and low birth weight (AOR = 5.13, P = 0.039). Factors associated with wasting among ART-treated HIV-positive children were diarrhea (AOR = 22.49, P = 0.001) and feeding frequency (AOR = 0.03, p < 0.001). HIV/AIDS is associated with an increased burden of child underweight status and wasting, even among ART-treated children, in Dar es Salaam, Tanzania. In addition to increasing coverage of ART among HIV-positive children, interventions to ameliorate poor nutrition status may be necessary in this and similar settings. Such interventions should aim at promoting adequate feeding patterns, as well as preventing and treating diarrhea.

Registration of Laser Scanning Point Clouds: A Review.

PubMed

Cheng, Liang; Chen, Song; Liu, Xiaoqiang; Xu, Hao; Wu, Yang; Li, Manchun; Chen, Yanming

2018-05-21

The integration of multi-platform, multi-angle, and multi-temporal LiDAR data has become important for geospatial data applications. This paper presents a comprehensive review of LiDAR data registration in the fields of photogrammetry and remote sensing. At present, a coarse-to-fine registration strategy is commonly used for LiDAR point clouds registration. The coarse registration method is first used to achieve a good initial position, based on which registration is then refined utilizing the fine registration method. According to the coarse-to-fine framework, this paper reviews current registration methods and their methodologies, and identifies important differences between them. The lack of standard data and unified evaluation systems is identified as a factor limiting objective comparison of different methods. The paper also describes the most commonly-used point cloud registration error analysis methods. Finally, avenues for future work on LiDAR data registration in terms of applications, data, and technology are discussed. In particular, there is a need to address registration of multi-angle and multi-scale data from various newly available types of LiDAR hardware, which will play an important role in diverse applications such as forest resource surveys, urban energy use, cultural heritage protection, and unmanned vehicles.

Automatic registration of optical imagery with 3d lidar data using local combined mutual information

NASA Astrophysics Data System (ADS)

Parmehr, E. G.; Fraser, C. S.; Zhang, C.; Leach, J.

2013-10-01

Automatic registration of multi-sensor data is a basic step in data fusion for photogrammetric and remote sensing applications. The effectiveness of intensity-based methods such as Mutual Information (MI) for automated registration of multi-sensor image has been previously reported for medical and remote sensing applications. In this paper, a new multivariable MI approach that exploits complementary information of inherently registered LiDAR DSM and intensity data to improve the robustness of registering optical imagery and LiDAR point cloud, is presented. LiDAR DSM and intensity information has been utilised in measuring the similarity of LiDAR and optical imagery via the Combined MI. An effective histogramming technique is adopted to facilitate estimation of a 3D probability density function (pdf). In addition, a local similarity measure is introduced to decrease the complexity of optimisation at higher dimensions and computation cost. Therefore, the reliability of registration is improved due to the use of redundant observations of similarity. The performance of the proposed method for registration of satellite and aerial images with LiDAR data in urban and rural areas is experimentally evaluated and the results obtained are discussed.

Registration of Laser Scanning Point Clouds: A Review

PubMed Central

Cheng, Liang; Chen, Song; Xu, Hao; Wu, Yang; Li, Manchun

2018-01-01

The integration of multi-platform, multi-angle, and multi-temporal LiDAR data has become important for geospatial data applications. This paper presents a comprehensive review of LiDAR data registration in the fields of photogrammetry and remote sensing. At present, a coarse-to-fine registration strategy is commonly used for LiDAR point clouds registration. The coarse registration method is first used to achieve a good initial position, based on which registration is then refined utilizing the fine registration method. According to the coarse-to-fine framework, this paper reviews current registration methods and their methodologies, and identifies important differences between them. The lack of standard data and unified evaluation systems is identified as a factor limiting objective comparison of different methods. The paper also describes the most commonly-used point cloud registration error analysis methods. Finally, avenues for future work on LiDAR data registration in terms of applications, data, and technology are discussed. In particular, there is a need to address registration of multi-angle and multi-scale data from various newly available types of LiDAR hardware, which will play an important role in diverse applications such as forest resource surveys, urban energy use, cultural heritage protection, and unmanned vehicles. PMID:29883397

Perceptions of impact: Invasive alien plants in the urban environment.

PubMed

Potgieter, Luke J; Gaertner, Mirijam; O'Farrell, Patrick J; Richardson, David M

2018-06-08

Many alien plant species are introduced to urban areas to create, augment or restore ecosystem services (ES). However, many of these species spread beyond original plantings, sometimes causing negative effects on existing ES or creating novel ecosystem disservices (EDS). An understanding of the perceptions of urban residents regarding invasive alien plants (IAPs) and the ES and EDS they provide is needed for the effective prioritisation of IAP management efforts in cities. Using the city of Cape Town, South Africa as a case study, we conducted questionnaire-based surveys (online and face-to-face) to determine the perceptions of urban residents regarding IAPs and their capacity to provide ES and EDS. Most urban residents perceive IAPs negatively (i.e. agreeing that they create EDS), but many recognise their importance in providing ES. Although most residents are not opposed to the management of IAPs, such actions are not perceived as a high priority relative to other environmental problems. Socio-demographic variables such as age, education, environmental awareness, and ethnicity shape urban residents' perceptions of IAPs. Older, more educated respondents were more likely to perceive IAPs negatively, while respondents with greater environmental awareness were aware of the benefits provided by IAPs. This study highlights the need to integrate public perceptions into the planning and management of IAPs and emphasises the importance of including ES assessments into the decision-making process, particularly in urban areas. Copyright © 2018 Elsevier Ltd. All rights reserved.

Artisan Training and Employment Outcomes in Tanzania

ERIC Educational Resources Information Center

Bennell, Paul; Mukyanuzi, Faustin; Kasogela, Maurice; Mutashubirwa, Francis; Klim, Mikkel

2006-01-01

This article presents the main findings of a tracer survey of graduates from two artisan training centres in Tanzania, which was undertaken in early 2002. The two institutions are the Chang'ombe Regional Vocational Training and Service Centre (RVTSC) in Dar es Salaam and the Iringa RVTSC, which are owned and managed by the Vocational Education and…

Self Evaluation: A Case Study of a School in Dar Es Salaam, Tanzania

ERIC Educational Resources Information Center

Kokeyo, Carolyne Adhiambo; Oluoch, John

2015-01-01

External evaluation of schools purpose to monitor delivery of education with a view to ensuring adherence to stipulated curriculum and set standards as well as efficient and effective quality education. However, school improvement scholars in developed economies now argue that schools must take their own initiative to assess the extent to which…

Learner Diversity in Inclusive Classrooms: The Interplay of Language of Instruction, Gender and Disability

ERIC Educational Resources Information Center

Possi, Mwajabu K.; Milinga, Joseph Reginard

2017-01-01

The research was conducted to look into learner diversity in inclusive classrooms focusing on language of instruction, gender and disability issues, and their implications for education practices. A qualitative research approach was used to obtain data addressing the research problem from two inclusive secondary schools in Dar es Salaam region,…

ICT Accessibility and Usability to Support Learning of Visually-Impaired Students in Tanzania

ERIC Educational Resources Information Center

Eligi, Innosencia; Mwantimwa, Kelefa

2017-01-01

The main objective of this study was to assess the accessibility and usability of Information and Communication Technology facilities to facilitate learning among visually-impaired students at the University of Dar es Salaam (UDSM). The study employed a mixed methods design in gathering, processing and analysing quantitative and qualitative data.…

Marketing of Information in the Water Sector in Tanzania: A Strategy for MAJIDOC.

ERIC Educational Resources Information Center

Michael, Benedict P.

1992-01-01

Outlines a strategy for marketing the information products and services of the Water and Sanitation Information and Documentation Centre (MAJIDOC) of the Water Resources Institute in Dar es Salaam, Tanzania. Objectives of the marketing strategy are explained, ideas for internal and external promotion are described, and a budget plan is included.…

Who Sinned? Parents' Knowledge of the Causes of Disability in Tanzania

ERIC Educational Resources Information Center

Tungaraza, Frida D.

2012-01-01

This study aimed at finding out from parents what they knew to be the causes of their children's disabilities. One hundred and twenty six parents from four regions, namely Dar es Salaam, Dodoma, Kilimanjaro and Morogoro were involved in this study. Data was collected through interview, narratives and observation. It was obvious from the findings…

Accurate evaluation of sensitivity for calibration between a LiDAR and a panoramic camera used for remote sensing

NASA Astrophysics Data System (ADS)

García-Moreno, Angel-Iván; González-Barbosa, José-Joel; Ramírez-Pedraza, Alfonso; Hurtado-Ramos, Juan B.; Ornelas-Rodriguez, Francisco-Javier

2016-04-01

Computer-based reconstruction models can be used to approximate urban environments. These models are usually based on several mathematical approximations and the usage of different sensors, which implies dependency on many variables. The sensitivity analysis presented in this paper is used to weigh the relative importance of each uncertainty contributor into the calibration of a panoramic camera-LiDAR system. Both sensors are used for three-dimensional urban reconstruction. Simulated and experimental tests were conducted. For the simulated tests we analyze and compare the calibration parameters using the Monte Carlo and Latin hypercube sampling techniques. Sensitivity analysis for each variable involved into the calibration was computed by the Sobol method, which is based on the analysis of the variance breakdown, and the Fourier amplitude sensitivity test method, which is based on Fourier's analysis. Sensitivity analysis is an essential tool in simulation modeling and for performing error propagation assessments.

On Feature Extraction from Large Scale Linear LiDAR Data

NASA Astrophysics Data System (ADS)

Acharjee, Partha Pratim

Airborne light detection and ranging (LiDAR) can generate co-registered elevation and intensity map over large terrain. The co-registered 3D map and intensity information can be used efficiently for different feature extraction application. In this dissertation, we developed two algorithms for feature extraction, and usages of features for practical applications. One of the developed algorithms can map still and flowing waterbody features, and another one can extract building feature and estimate solar potential on rooftops and facades. Remote sensing capabilities, distinguishing characteristics of laser returns from water surface and specific data collection procedures provide LiDAR data an edge in this application domain. Furthermore, water surface mapping solutions must work on extremely large datasets, from a thousand square miles, to hundreds of thousands of square miles. National and state-wide map generation/upgradation and hydro-flattening of LiDAR data for many other applications are two leading needs of water surface mapping. These call for as much automation as possible. Researchers have developed many semi-automated algorithms using multiple semi-automated tools and human interventions. This reported work describes a consolidated algorithm and toolbox developed for large scale, automated water surface mapping. Geometric features such as flatness of water surface, higher elevation change in water-land interface and, optical properties such as dropouts caused by specular reflection, bimodal intensity distributions were some of the linear LiDAR features exploited for water surface mapping. Large-scale data handling capabilities are incorporated by automated and intelligent windowing, by resolving boundary issues and integrating all results to a single output. This whole algorithm is developed as an ArcGIS toolbox using Python libraries. Testing and validation are performed on a large datasets to determine the effectiveness of the toolbox and results are presented. Significant power demand is located in urban areas, where, theoretically, a large amount of building surface area is also available for solar panel installation. Therefore, property owners and power generation companies can benefit from a citywide solar potential map, which can provide available estimated annual solar energy at a given location. An efficient solar potential measurement is a prerequisite for an effective solar energy system in an urban area. In addition, the solar potential calculation from rooftops and building facades could open up a wide variety of options for solar panel installations. However, complex urban scenes make it hard to estimate the solar potential, partly because of shadows cast by the buildings. LiDAR-based 3D city models could possibly be the right technology for solar potential mapping. Although, most of the current LiDAR-based local solar potential assessment algorithms mainly address rooftop potential calculation, whereas building facades can contribute a significant amount of viable surface area for solar panel installation. In this paper, we introduce a new algorithm to calculate solar potential of both rooftop and building facades. Solar potential received by the rooftops and facades over the year are also investigated in the test area.

Integration of LIDAR Data Into a Municipal GIS to Study Solar Radiation

NASA Astrophysics Data System (ADS)

Africani, P.; Bitelli, G.; Lambertini, A.; Minghetti, A.; Paselli, E.

2013-04-01

Identifying the right roofs to install solar panels inside a urban area is crucial for both private citizens and the whole local population. The aim is not easy because a lot of consideration must be made: insolation, orientation of the surface, size of the surface, shading due to topography, shading due to taller buildings next the surface, shading due to taller vegetation and other possible problems typical of urban areas like the presence of chimneys. Accuracy of data related to the analyzed surfaces is indeed fundamental, and also the detail of geometric models used to represent buildings and their roofs. The complexity that these roofs can reach is elevated. This work uses LiDAR data to obtain, with a semi-automatic technique, the full geometry of each roof part complementing the pre-existing building data in the municipal cartography. With this data is possible to evaluate the placement of solar panels on roofs of a whole city analyzing the solar potential of each building in detail. Other traditional techniques, like photogrammetry, need strong manual editing effort in order to identify slopes and insert vector on surfaces at the right height. Regarding LiDAR data, in order to perform accurate modelling, it is necessary to obtain an high density point cloud. The method proposed can also be used as a fast and linear workflow process for an area where LiDAR data are available and a municipal cartography already exist: LiDAR data can be furthermore successfully used to cross-check errors in pre-existent digital cartography that can remain otherwise hidden.

Extraction of Urban Trees from Integrated Airborne Based Digital Image and LIDAR Point Cloud Datasets - Initial Results

NASA Astrophysics Data System (ADS)

Dogon-yaro, M. A.; Kumar, P.; Rahman, A. Abdul; Buyuksalih, G.

2016-10-01

Timely and accurate acquisition of information on the condition and structural changes of urban trees serves as a tool for decision makers to better appreciate urban ecosystems and their numerous values which are critical to building up strategies for sustainable development. The conventional techniques used for extracting tree features include; ground surveying and interpretation of the aerial photography. However, these techniques are associated with some constraint, such as labour intensive field work, a lot of financial requirement, influences by weather condition and topographical covers which can be overcome by means of integrated airborne based LiDAR and very high resolution digital image datasets. This study presented a semi-automated approach for extracting urban trees from integrated airborne based LIDAR and multispectral digital image datasets over Istanbul city of Turkey. The above scheme includes detection and extraction of shadow free vegetation features based on spectral properties of digital images using shadow index and NDVI techniques and automated extraction of 3D information about vegetation features from the integrated processing of shadow free vegetation image and LiDAR point cloud datasets. The ability of the developed algorithms shows a promising result as an automated and cost effective approach to estimating and delineated 3D information of urban trees. The research also proved that integrated datasets is a suitable technology and a viable source of information for city managers to be used in urban trees management.

The CLUVA project: Climate-change scenarios and their impact on urban areas in Africa

NASA Astrophysics Data System (ADS)

Di Ruocco, Angela; Weets, Guy; Gasparini, Paolo; Jørgensen, Gertrud; Lindley, Sarah; Pauleit, Stephan; Vahed, Anwar; Schiano, Pasquale; Kabisch, Sigrun; Vedeld, Trond; Coly, Adrien; Tonye, Emmanuel; Touré, Hamidou; Kombe, Wilbard; Yeshitela, Kumelachew

2013-04-01

CLUVA (CLimate change and Urban Vulnerability in Africa; http://www.cluva.eu/) is a 3 years project, funded by the European Commission in 2010. Its main objective is the estimate of the impacts of climate changes in the next 40 years at urban scale in Africa. The mission of CLUVA is to develop methods and knowledge to assess risks cascading from climate-changes. It downscales IPCC climate projections to evaluate threats to selected African test cities; mainly floods, sea-level rise, droughts, heat waves and desertification. The project evaluates and links: social vulnerability; vulnerability of in-town ecosystems and urban-rural interfaces; vulnerability of urban built environment and lifelines; and related institutional and governance dimensions of adaptation. A multi-scale and multi-disciplinary quantitative, probabilistic, modelling is applied. CLUVA brings together climate experts, risk management experts, urban planners and social scientists with their African counterparts in an integrated research effort focusing on the improvement of the capacity of scientific institutions, local councils and civil society to cope with climate change. The CLUVA approach was set-up in the first year of the project and developed as follows: an ensemble of eight global projections of climate changes is produced for east and west Africa until 2050 considering the new IPCC (International Panel on Climate Changes; http://www.ipcc.ch/) scenarios. These are then downscaled to urban level, where territorial modeling is required to compute hazard effects on the vulnerable physical system (urban ecosystems, informal settlements, lifelines such as transportation and sewer networks) as well as on the social context, in defined time frames, and risk analysis is then employed to assess expected consequences. An investigation of the existing urban planning and governance systems and its interface with climate risks is performed. With the aid of the African partners, the developed approach is currently being applied to selected African case studies: Addis Ababa - Ethiopia; Dar es Salaam - Tanzania, Douala - Cameroun; Ouagadougou - Burkina Faso, St. Louis - Senegal. The poster will illustrate the CLUVA's framework to assess climate-change-related risks at an urban scale in Africa, and will report on the progresses of selected case studies to demonstrate feasibility of a multi-scale and multi-risk quantitative approach for risk management.

Multiple health benefits of urban tree canopy: The mounting evidence for a green prescription

Treesearch

Jared M. Ulmer; Kathleen L. Wolf; Desiree R. Backman; Raymond L. Tretheway; Cynthia JA Blain; Jarlath PM O’Neil-Dunne; Lawrence D. Frank

2016-01-01

The purpose of this study was to enhance the understanding of the health-promoting potential of trees in an urbanized region of the United States. This was done using high-resolution LiDAR and imagery data to quantify tree cover within 250 m of the residence of 7910 adult participants in the California Health Interview Survey, then testing for main and mediating...

Instructor Support Services: An Inevitable Critical Success Factor in Blended Learning in Higher Education in Tanzania

ERIC Educational Resources Information Center

Raphael, Christina; Mtebe, Joel S.

2016-01-01

The adoption of blended learning to widen access, reduce cost, and improve the quality of education is becoming prevalent in higher education in sub-Saharan Africa and Tanzania in particular. University of Dar es Salaam and the Open University of Tanzania offer various blended learning courses using Moodle system via regional centres scattered…

The health-related microbiological quality of bottled drinking water sold in Dar es Salaam, Tanzania.

PubMed

Kassenga, Gabriel R

2007-03-01

The consumption of bottled and plastic-bagged drinking water in Tanzania has increased largely because of the deteriorating quality of tap water. It is uncertain whether these water products are safe for drinking. In this study, the microbiological quality of bottled and plastic-bagged drinking water sold in Dar es Salaam, Tanzania, was investigated. One hundred and thirty samples representing 13 brands of bottled water collected from shops, supermarkets and street vendors were analysed for total coliform and faecal coliform organisms as well as heterotrophic bacteria. These were compared with 61 samples of tap water. Heterotrophic bacteria were detected in 92% of the bottled water samples analysed. Total and faecal coliform bacteria were present in 4.6% and 3.6%, respectively, of samples analysed with a tendency for higher contamination rates in plastic-bagged drinking water. Microbiological quality of tap water was found to be worse compared with bottled water, with 49.2% and 26.2% of sampling points showing the presence of total coliform and faecal coliform organisms, respectively. The results suggest caution and vigilance to avert outbreaks of waterborne diseases from these types of drinking water.

Medicalization and morality in a weak state: health, hygiene and water in Dar Es Salaam, Tanzania.

PubMed

Obrist, Brigit

2004-04-01

Inspired by Foucault, many studies have examined the medicalization of everyday life in Western societies. This paper reconsiders potentials and limitations of this concept in an African city. Grounded in ethnographic research in Dar es Salaam, Tanzania, it concentrates on cleanliness, health and water in a lower middle-class neighbourhood. The findings show that women are familiar with professional health development discourses emphasizing cleanliness as a high value linked to bodily and domestic health. These discourses have been diffused in schools, clinics and other institutions during the colonial and socialist period. Women not only refer to these discourses, they try to reproduce them in daily practice and even demand them. This coercive yet voluntary nature of institutionalized discourses points to 'paradoxes of medicalization' also found in Western societies. It acquires, however, different meanings in a weak state like contemporary Tanzania which hardly manages to institutionalize medicalization through professional practice. Under such conditions, women who choose to follow health development discourses suffer a heavier practical, intellectual and emotional burden than those who are less committed. This may at least partly explain why many women assume a pragmatic stance towards the medicalization of everyday life.

Raster Vs. Point Cloud LiDAR Data Classification

NASA Astrophysics Data System (ADS)

El-Ashmawy, N.; Shaker, A.

2014-09-01

Airborne Laser Scanning systems with light detection and ranging (LiDAR) technology is one of the fast and accurate 3D point data acquisition techniques. Generating accurate digital terrain and/or surface models (DTM/DSM) is the main application of collecting LiDAR range data. Recently, LiDAR range and intensity data have been used for land cover classification applications. Data range and Intensity, (strength of the backscattered signals measured by the LiDAR systems), are affected by the flying height, the ground elevation, scanning angle and the physical characteristics of the objects surface. These effects may lead to uneven distribution of point cloud or some gaps that may affect the classification process. Researchers have investigated the conversion of LiDAR range point data to raster image for terrain modelling. Interpolation techniques have been used to achieve the best representation of surfaces, and to fill the gaps between the LiDAR footprints. Interpolation methods are also investigated to generate LiDAR range and intensity image data for land cover classification applications. In this paper, different approach has been followed to classifying the LiDAR data (range and intensity) for land cover mapping. The methodology relies on the classification of the point cloud data based on their range and intensity and then converted the classified points into raster image. The gaps in the data are filled based on the classes of the nearest neighbour. Land cover maps are produced using two approaches using: (a) the conventional raster image data based on point interpolation; and (b) the proposed point data classification. A study area covering an urban district in Burnaby, British Colombia, Canada, is selected to compare the results of the two approaches. Five different land cover classes can be distinguished in that area: buildings, roads and parking areas, trees, low vegetation (grass), and bare soil. The results show that an improvement of around 10 % in the classification results can be achieved by using the proposed approach.

Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology

PubMed Central

Chase, Arlen F.; Fisher, Christopher T.; Leisz, Stephen J.; Weishampel, John F.

2012-01-01

The application of light detection and ranging (LiDAR), a laser-based remote-sensing technology that is capable of penetrating overlying vegetation and forest canopies, is generating a fundamental shift in Mesoamerican archaeology and has the potential to transform research in forested areas world-wide. Much as radiocarbon dating that half a century ago moved archaeology forward by grounding archaeological remains in time, LiDAR is proving to be a catalyst for an improved spatial understanding of the past. With LiDAR, ancient societies can be contextualized within a fully defined landscape. Interpretations about the scale and organization of densely forested sites no longer are constrained by sample size, as they were when mapping required laborious on-ground survey. The ability to articulate ancient landscapes fully permits a better understanding of the complexity of ancient Mesoamerican urbanism and also aids in modern conservation efforts. The importance of this geospatial innovation is demonstrated with newly acquired LiDAR data from the archaeological sites of Caracol, Cayo, Belize and Angamuco, Michoacán, Mexico. These data illustrate the potential of technology to act as a catalytic enabler of rapid transformational change in archaeological research and interpretation and also underscore the value of on-the-ground archaeological investigation in validating and contextualizing results. PMID:22802623

Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology.

PubMed

Chase, Arlen F; Chase, Diane Z; Fisher, Christopher T; Leisz, Stephen J; Weishampel, John F

2012-08-07

The application of light detection and ranging (LiDAR), a laser-based remote-sensing technology that is capable of penetrating overlying vegetation and forest canopies, is generating a fundamental shift in Mesoamerican archaeology and has the potential to transform research in forested areas world-wide. Much as radiocarbon dating that half a century ago moved archaeology forward by grounding archaeological remains in time, LiDAR is proving to be a catalyst for an improved spatial understanding of the past. With LiDAR, ancient societies can be contextualized within a fully defined landscape. Interpretations about the scale and organization of densely forested sites no longer are constrained by sample size, as they were when mapping required laborious on-ground survey. The ability to articulate ancient landscapes fully permits a better understanding of the complexity of ancient Mesoamerican urbanism and also aids in modern conservation efforts. The importance of this geospatial innovation is demonstrated with newly acquired LiDAR data from the archaeological sites of Caracol, Cayo, Belize and Angamuco, Michoacán, Mexico. These data illustrate the potential of technology to act as a catalytic enabler of rapid transformational change in archaeological research and interpretation and also underscore the value of on-the-ground archaeological investigation in validating and contextualizing results.

Octree-based indexing for 3D pointclouds within an Oracle Spatial DBMS

NASA Astrophysics Data System (ADS)

Schön, Bianca; Mosa, Abu Saleh Mohammad; Laefer, Debra F.; Bertolotto, Michela

2013-02-01

A large proportion of today's digital datasets have a spatial component. The effective storage and management of which poses particular challenges, especially with light detection and ranging (LiDAR), where datasets of even small geographic areas may contain several hundred million points. While in the last decade 2.5-dimensional data were prevalent, true 3-dimensional data are increasingly commonplace via LiDAR. They have gained particular popularity for urban applications including generation of city-scale maps, baseline data disaster management, and utility planning. Additionally, LiDAR is commonly used for flood plane identification, coastal-erosion tracking, and forest biomass mapping. Despite growing data availability, current spatial information systems do not provide suitable full support for the data's true 3D nature. Consequently, one system is needed to store the data and another for its processing, thereby necessitating format transformations. The work presented herein aims at a more cost-effective way for managing 3D LiDAR data that allows for storage and manipulation within a single system by enabling a new index within existing spatial database management technology. Implementation of an octree index for 3D LiDAR data atop Oracle Spatial 11g is presented, along with an evaluation showing up to an eight-fold improvement compared to the native Oracle R-tree index.

Habitat productivity and pyrethroid susceptibility status of Aedes aegypti mosquitoes in Dar es Salaam, Tanzania.

PubMed

Mathias, Leah; Baraka, Vito; Philbert, Anitha; Innocent, Ester; Francis, Filbert; Nkwengulila, Gamba; Kweka, Eliningaya J

2017-06-09

Aedes aegypti (Diptera: Culicidae) is the main vector of the dengue virus globally. Dengue vector control is mainly based on reducing the vector population through interventions, which target potential breeding sites. However, in Tanzania, little is known about this vector's habitat productivity and insecticide susceptibility status to support evidence-based implementation of control measures. The present study aimed at assessing the productivity and susceptibility status of A. aegypti mosquitoes to pyrethroid-based insecticides in Dar es Salaam, Tanzania. An entomological assessment was conducted between January and July 2015 in six randomly selected wards in Dar es Salaam, Tanzania. Habitat productivity was determined by the number of female adult A. aegypti mosquitoes emerged per square metre. The susceptibility status of adult A. aegypti females after exposure to 0.05% deltamethrin, 0.75% permethrin and 0.05% lambda-cyhalothrin was evaluated using the standard WHO protocols. Mortality rates were recorded after 24 h exposure and the knockdown effect was recorded at the time points of 10, 15, 20, 30, 40, 50 and 60 min to calculate the median knockdown times (KDT 50 and KDT 95 ). The results suggest that disposed tyres had the highest productivity, while water storage tanks had the lowest productivity among the breeding habitats Of A. aegypti mosquitoes. All sites demonstrated reduced susceptibility to deltamethrin (0.05%) within 24 h post exposure, with mortalities ranging from 86.3 ± 1.9 (mean ± SD) to 96.8 ± 0.9 (mean ± SD). The lowest and highest susceptibilities were recorded in Mikocheni and Sinza wards, respectively. Similarly, all sites demonstrated reduced susceptibility permethrin (0.75%) ranging from 83.1 ± 2.1% (mean ± SD) to 96.2 ± 0.9% (mean ± SD), in Kipawa and Sinza, respectively. Relatively low mortality rates were observed in relation to lambda-cyhalothrin (0.05%) at all sites, ranging from 83.1 ± 0.7 (mean ± SD) to 86.3 ± 1.4 (mean ± SD). The median KDT 50 for deltamethrin, permethrin and lambda-cyhalothrin were 24.9-30.3 min, 24.3-34.4 min and 26.7-32.8 min, respectively. The KDT 95 were 55.2-90.9 min for deltamethrin, 54.3-94.6 min for permethrin and 64.5-69.2 min for lambda-cyhalothrin. The productive habitats for A. aegypti mosquitoes found in Dar es Salaam were water storage containers, discarded tins and tyres. There was a reduced susceptibility of A. aegypti to and emergence of resistance against pyrethroid-based insecticides. The documented differences in the resistance profiles of A. aegypti mosquitoes warrants regular monitoring the pattern concerning resistance against pyrethroid-based insecticides and define dengue vector control strategies.

Demand-based urban forest planning using high-resolution remote sensing and AHP

NASA Astrophysics Data System (ADS)

Kolanuvada, Srinivasa Raju; Mariappan, Muneeswaran; Krishnan, Vani

2016-05-01

Urban forest planning is important for providing better urban ecosystem services and conserve the natural carbon sinks inside the urban area. In this study, a demand based urban forest plan was developed for Chennai city by using Analytical Hierarchy Process (AHP) method. Population density, Tree cover, Air quality index and Carbon stocks are the parameters were considered in this study. Tree cover and Above Ground Biomass (AGB) layers were prepared at a resolution of 1m from airborne LiDAR and aerial photos. The ranks and weights are assigned by the spatial priority using AHP. The results show that, the actual status of the urban forest is not adequate to provide ecosystem services on spatial priority. From this perspective, we prepared a demand based plan for improving the urban ecosystem.

Impact of the Spatial Arrangement of Agricultural Land Use on Ecosystems Services and Peri-Urban Livelihoods at the Landscape Scale.

NASA Astrophysics Data System (ADS)

Inkoom, J. N.; Fürst, C.

2014-12-01

The relationship between agricultural land uses (ALU) and their impact on ecosystems services (ES) including biodiversity conservation is complex. This complexity has been augmented by isolated research on the impact of ALU on the landscape's capacity to provide ES in most climatically vulnerable areas of Sub-Saharan Africa. Though a considerable number of studies emphasise the nexus between specific land use types and their impact on ES, a sufficient modelling basis for an empirical consideration of spatial interactions between different agricultural land uses at the landscape scale within peri-urban areas in Sub-Saharan Africa is consistently missing. The need to assess and address significant issues regarding size, shape, spatial location, and interactivity of different land use patches in assessing land use interactions and their impact on ecosystem service provision necessitated this investigation. To formulate a methodology to correspond to this complexity, ES obtained from a characteristically agricultural and urbanizing landscapes were mapped using analytical hierarchical processes and management expert approaches. Further, landscape metrics and mean enrichment factor approaches are explored as neighbourhood assessment tools aimed at assessing the mutual impact gradient of agricultural and adjacent urban land uses on ES provision. Implementation is undertaken in GISCAME using a 2012 rapideye image classification and primary data collected on selected ES from local farmers within the VEA catchment of Upper East, Ghana. The outcome aims to provide the understanding of expected trade-offs and synergies varying ALU could pose to current and potential ES provision within urbanizing landscapes. Policy implications for observed trade-offs and synergies of ALU interaction on ES, rural livelihoods, and food security are communicated to farmers and decision makers. Keywords: Agricultural land use, neighbourhood interaction, ecosystems services, livelihoods, GISCAME.

Remote measurement of surface roughness, surface reflectance, and body reflectance with LiDAR.

PubMed

Li, Xiaolu; Liang, Yu

2015-10-20

Light detection and ranging (LiDAR) intensity data are attracting increasing attention because of the great potential for use of such data in a variety of remote sensing applications. To fully investigate the data potential for target classification and identification, we carried out a series of experiments with typical urban building materials and employed our reconstructed built-in-lab LiDAR system. Received intensity data were analyzed on the basis of the derived bidirectional reflectance distribution function (BRDF) model and the established integration method. With an improved fitting algorithm, parameters involved in the BRDF model can be obtained to depict the surface characteristics. One of these parameters related to surface roughness was converted to a most used roughness parameter, the arithmetical mean deviation of the roughness profile (R_a), which can be used to validate the feasibility of the BRDF model in surface characterizations and performance evaluations.

Three-Dimensional Reconstruction and Solar Energy Potential Estimation of Buildings

NASA Astrophysics Data System (ADS)

Chen, Y.; Li, M.; Cheng, L.; Xu, H.; Li, S.; Liu, X.

2017-12-01

In the context of the construction of low-carbon cities, green cities and eco-cities, the ability of the airborne and mobile LiDAR should be explored in urban renewable energy research. As the main landscape in urban environment, buildings have large regular envelopes could receive a huge amount of solar radiation. In this study, a relatively complete calculation scheme about building roof and façade solar utilization potential is proposed, using building three-dimensional geometric feature information. For measuring the city-level building solar irradiance, the precise three-dimensional building roof and façade models should be first reconstructed from the airborne and mobile LiDAR, respectively. In order to obtaining the precise geometric structure of building facades from the mobile LiDAR data, a new method for structure detection and the three-dimensional reconstruction of building façades from mobile LiDAR data is proposed. The method consists of three steps: the preprocessing of façade points, the detection of façade structure, the restoration and reconstruction of building façade. As a result, the reconstruction method can effectively deal with missing areas caused by occlusion, viewpoint limitation, and uneven point density, as well as realizing the highly complete 3D reconstruction of a building façade. Furthermore, the window areas can be excluded for more accurate estimation of solar utilization potential. After then, the solar energy utilization potential of global building roofs and facades is estimate by using the solar irradiance model, which combine the analysis of the building shade and sky diffuse, based on the analysis of the geometrical structure of buildings.

Insecticide resistance mechanisms associated with different environments in the malaria vector Anopheles gambiae: a case study in Tanzania.

PubMed

Nkya, Theresia E; Akhouayri, Idir; Poupardin, Rodolphe; Batengana, Bernard; Mosha, Franklin; Magesa, Stephen; Kisinza, William; David, Jean-Philippe

2014-01-25

Resistance of mosquitoes to insecticides is a growing concern in Africa. Since only a few insecticides are used for public health and limited development of new molecules is expected in the next decade, maintaining the efficacy of control programmes mostly relies on resistance management strategies. Developing such strategies requires a deep understanding of factors influencing resistance together with characterizing the mechanisms involved. Among factors likely to influence insecticide resistance in mosquitoes, agriculture and urbanization have been implicated but rarely studied in detail. The present study aimed at comparing insecticide resistance levels and associated mechanisms across multiple Anopheles gambiae sensu lato populations from different environments. Nine populations were sampled in three areas of Tanzania showing contrasting agriculture activity, urbanization and usage of insecticides for vector control. Insecticide resistance levels were measured in larvae and adults through bioassays with deltamethrin, DDT and bendiocarb. The distribution of An. gambiae sub-species and pyrethroid target-site mutations (kdr) were investigated using molecular assays. A microarray approach was used for identifying transcription level variations associated to different environments and insecticide resistance. Elevated resistance levels to deltamethrin and DDT were identified in agriculture and urban areas as compared to the susceptible strain Kisumu. A significant correlation was found between adult deltamethrin resistance and agriculture activity. The subspecies Anopheles arabiensis was predominant with only few An. gambiae sensu stricto identified in the urban area of Dar es Salaam. The L1014S kdr mutation was detected at elevated frequency in An gambiae s.s. in the urban area but remains sporadic in An. arabiensis specimens. Microarrays identified 416 transcripts differentially expressed in any area versus the susceptible reference strain and supported the impact of agriculture on resistance mechanisms with multiple genes encoding pesticide targets, detoxification enzymes and proteins linked to neurotransmitter activity affected. In contrast, resistance mechanisms found in the urban area appeared more specific and more related to the use of insecticides for vector control. Overall, this study confirmed the role of the environment in shaping insecticide resistance in mosquitoes with a major impact of agriculture activities. Results are discussed in relation to resistance mechanisms and the optimization of resistance management strategies.

Utilization of cervical cancer screening services and its associated factors among primary school teachers in Ilala Municipality, Dar es Salaam, Tanzania.

PubMed

Kileo, Neema Minja; Michael, Denna; Neke, Nyasule Majura; Moshiro, Candida

2015-12-15

Worldwide cervical cancer is one of the more common forms of carcinoma among women, causing high morbidity and high mortality. Despite being a major health problem in Tanzania, screening services for cervical cancer are very limited, and uptake of those services is low. We therefore conducted a study to investigate utilization of cancer screening services, and its associated factors among female primary school teachers in Ilala Municipality, Dar es Salaam. We conducted a cross-sectional study between May - August 2011 which involved 110 primary schools in Ilala Municipality in Dar es Salaam. Five hundred and twelve female primary school teachers were sampled using a two-stage cluster sampling procedure. Data on utilization of cervical cancer and risk factors were collected using a self-administered questionnaire. Proportional utilization of cervical cancer screening services was identified through a self report. Risk factors for services utilization were assessed using logistic regression analyses. Out of 512 female primary school teachers, only 108 (21 %) reported to ever been screened for cervical cancer. Utilization of cervical cancer screening services was 28 % among those aged 20-29, 22 % among married and 24 % among those with higher level of education. Women were more likely to utilize the cancer-screening service if they were multiparous (age-adjusted OR = 3.05, 95 % CI 1.15-8.06, P value 0.025), or reported more than one lifetime sexual partner (age-adjusted OR 2.17, 95 % CI 1.04-4.54, P value 0.038), or did not involve their spouse in making health decisions (adjusted OR 3.56, 95 % CI 2.05-6.18, P value <0.001). The study has demonstrated low level of utilization of cervical cancer screening service among female primary school teachers in Ilala munipality. Female primary school teachers with more than one previous pregnancy and those with more than one life-time sex partners were more likely to report utilization of the service. Spouse or partners support was an important factor in the utilization of cervical cancer screening service amongst the study population.

Evaluation of self-care practices and emotional distress among people with Type 2 diabetes mellitus in Dar es Salaam, Tanzania.

PubMed

Mosha, Theobald C E; Rashidi, Heri

2009-01-01

This study was conducted to determine self-care practices and diabetes related emotional distress among people with Type 2 diabetes mellitus in Dar es Salaam, Tanzania. A cross sectional survey-involving 121 Types 2 diabetics was conducted in 4 diabetic clinics located in Dar es Salaam. Anthropometric and biomedical measurements namely weight, height, waist, hip, mid-upper arm circumference, blood pressure and fasting blood glucose were measured. Self-care practices and diabetic related emotion distress were evaluated by using validated instruments. Results revealed that, the average fasting plasma glucose was 11.2 ± 5.5 mmol/l, blood pressure was 134.7/86.1 mm/Hg and the mean BMI for males and females were 25.0 ± 4.3 and 27.0 ± 5.1 kg/m(2), respectively. Subject's self-care score for general diet, specific diet, physical exercise, foot-care and medication were 4.6 ± 2.4, 3.7 ± 1.5, 3.4 ± 1.8, 3.6 ± 2.8 and 5.5 ± 2.8 days per week, respectively. Self-monitoring of blood glucose was irregular and only 46.3% of the subjects tested their levels of blood glucose at least once in between the appointments (90 days). Low income was the major limitation for complying with the self-care practices related to diet, blood glucose testing and medication. It is recommended that, the Government of Tanzania should in the short run subsidize the prices of diabetes drugs, remove all taxes on the glucose test kits and establish a national diabetes program that would coordinate and oversee provision of the basic services such as screening, glucose testing, medication, counseling and management of the condition. In the long run, the government should establish a preventive public health program in order to curtail the escalation of diabetes. Further research should be conducted to determine how factors such as socio-cultural and demographic, self-care, and psychosocial distress interact to determine biomedical outcomes such as blood pressure, blood glucose and body mass index.

Food insecurity and coping strategies among people living with HIV in Dar es Salaam, Tanzania.

PubMed

Semali, Innocent A; Edwin, Tuzie; Mboera, Leonard E G

2011-10-01

Food insecurity and malnutrition seriously impedes efforts to control HIV/AIDS in resource poor countries. This study was carried out to assess food security, and coping strategies among people living with HIV/AIDS (PLHIV) attending Care and Treatment Centre (CTC) in Dar es Salaam, Tanzania. A structured questionnaire was used to interview randomly selected adults (18 years) who were HIV positive who have just been eligible for anti-retroviral treatment (ART) in a CTC or one who has started ART but not more than four weeks has elapsed. A total of 446 (females=67.9%; males= 32.1%) people living with HIV/AIDS attending CTC were interviewed. About three quarters (73.1%) of the respondents were 25-44 years old and most (43.9%) were married. Two thirds (66.7%) of the respondents had primary school education. Seventy percent reported to have a regular income and 63.7% with a monthly income of less than US$ 154. More than half (52.2%) of the respondents were food insecure. Food insecurity was similar in both males (54.6%) and females (51.2%). However, food insecurity was least (48.2%) among those who were single and highest (57.7%) among those cohabiting. Low level of food insecurity was associated with having completed primary education (Adjusted OR=0.27; 95% CI, 0.09-0.82) and high income (>US $154) (OR=0.10; 95% CI, 0.01-0.67). Reporting two or less meals increased the likelihood of food insecurity (OR=4.2; 95% CI1.7-9.8). Low frequency of meals was significantly more prevalent (18.6%) among those. 45 years than among 35-44 years old respondents (6.7%) (P=0.04). Borrowing money (55.8%) and taking less preferred foods (53.3%) were the most common coping strategies. In conclusion, food insecurity is a significant problem among people living with HIV in Dar es Salaam which might significantly affect compliance to care and support. The study suggests that counselling of PLHIV before anti-retroviral treatment programmes should devise special strategies targeting those with low education, low income and low frequency of meals.

Experiences of social harm and changes in sexual practices among volunteers who had completed a phase I/II HIV vaccine trial employing HIV-1 DNA priming and HIV-1 MVA boosting in Dar es Salaam, Tanzania.

PubMed

Tarimo, Edith A M; Munseri, Patricia; Aboud, Said; Bakari, Muhammad; Mhalu, Fred; Sandstrom, Eric

2014-01-01

Volunteers in phase I/II HIV vaccine trials are assumed to be at low risk of acquiring HIV infection and are expected to have normal lives in the community. However, during participation in the trials, volunteers may encounter social harm and changes in their sexual behaviours. The current study aimed to study persistence of social harm and changes in sexual practices over time among phase I/II HIV vaccine immunogenicity (HIVIS03) trial volunteers in Dar es Salaam, Tanzania. A descriptive prospective cohort study was conducted among 33 out of 60 volunteers of HIVIS03 trial in Dar es Salaam, Tanzania, who had received three HIV-1 DNA injections boosted with two HIV-1 MVA doses. A structured interview was administered to collect data. Analysis was carried out using SPSS and McNemars' chi-square (χ2) was used to test the association within-subjects. Participants reported experiencing negative comments from their colleagues about the trial; but such comments were less severe during the second follow up visits (χ2 = 8.72; P<0.001). Most of the comments were associated with discrimination (χ2 = 26.72; P<0.001), stigma (χ2 = 6.06; P<0.05), and mistrust towards the HIV vaccine trial (χ2 = 4.9; P<0.05). Having a regular sexual partner other than spouse or cohabitant declined over the two follow-up periods (χ2 = 4.45; P<0.05). Participants in the phase I/II HIV vaccine trial were likely to face negative comments from relatives and colleagues after the end of the trial, but those comments decreased over time. In this study, the inherent sexual practice of having extra sexual partners other than spouse declined over time. Therefore, prolonged counselling and support appears important to minimize risky sexual behaviour among volunteers after participation in HIV Vaccine trials.

Modeling individual trees in an urban environment using dense discrete return LIDAR

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Madhurima; van Aardt, Jan A. N.; van Leeuwen, Martin

2015-05-01

The urban forest is becoming increasingly important in the contexts of urban green space, carbon sequestration and offsets, and socio-economic impacts. This has led to a recent increase in attention being paid to urban environmental management. Tree biomass, specifically, is a vital indicator of carbon storage and has a direct impact on urban forest health and carbon sequestration. As an alternative to expensive and time-consuming field surveys, remote sensing has been used extensively in measuring dynamics of vegetation and estimating biomass. Light detection and ranging (LiDAR) has proven especially useful to characterize the three dimensional (3D) structure of forests. In urban contexts however, information is frequently required at the individual tree level, necessitating the proper delineation of tree crowns. Yet, crown delineation is challenging for urban trees where a wide range of stress factors and cultural influences affect growth. In this paper high resolution LiDAR data were used to infer biomass based on individual tree attributes. A multi-tiered delineation algorithm was designed to extract individual tree-crowns. At first, dominant tree segments were obtained by applying watershed segmentation on the crown height model (CHM). Next, prominent tree top positions within each segment were identified via a regional maximum transformation and the crown boundary was estimated for each of the tree tops. Finally, undetected trees were identified using a best-fitting circle approach. After tree delineation, individual tree attributes were used to estimate tree biomass and the results were validated with associated field mensuration data. Results indicate that the overall tree detection accuracy is nearly 80%, and the estimated biomass model has an adjusted-R2 of 0.5.

DTMs Assessment to the Definition of Shallow Landslides Prone Areas

NASA Astrophysics Data System (ADS)

Martins, Tiago D.; Oka-Fiori, Chisato; Carvalho Vieira, Bianca; Montgomery, David R.

2017-04-01

Predictive methods have been developed, especially since the 1990s, to identify landslide prone areas. One of the examples it is the physically based model SHALSTAB (Shallow Landsliding Stability Model), that calculate the potential instability for shallow landslides based on topography and physical soil properties. Normally, in such applications in Brazil, the Digital Terrain Model (DTM), is obtained mainly from conventional contour lines. However, recently the LiDAR (Light Detection and Ranging) system has been largely used in Brazil. Thus, this study aimed to evaluate different DTM's, generated from conventional data and LiDAR, and their influence in generating susceptibility maps to shallow landslides using SHALSTAB model. For that were analyzed the physical properties of soil, the response of the model when applying conventional topographical data and LiDAR's in the generation of DTM, and the shallow landslides susceptibility maps based on different topographical data. The selected area is in the urban perimeter of the municipality of Antonina (PR), affected by widespread landslides in March 2011. Among the results, it was evaluated different LiDAR data interpolation, using GIS tools, wherein the Triangulation/Natural Neighbor presented the best performance. It was also found that in one of evaluation indexes (Scars Concentration), the LiDAR derived DTM presented the best performance when compared with the one originated from contour lines, however, the Landslide Potential index, has presented a small increase. Consequently, it was possible to assess the DTM's, and the one derived from LiDAR improved very little the certitude percentage. It is also noted a gap in researches carried out in Brazil on the use of products generated from LiDAR data on geomorphological analysis.

Inside and around the roman town of Grumentum: the contribution of LiDAR and historical air photography

NASA Astrophysics Data System (ADS)

Cianciarulo, Dario; Guariglia, Annibale; Lasaponara, Rosa; Masini, Nicola

2013-04-01

The papers deals with the integration of aerial laser scanning, multitemporal satellite and aerial dataset to provide information on the 'forma urbis' of the Grumentum roman town, to detect new archaeological features in its close surrounding and to analyze changes of the landscape over the time. Grumentum is an ancient town, 50 km south of Potenza (Southern Italy), located near the 'Via Herculea' connecting Venusia, in the north est of Basilicata, with Heraclea in the Ionian coast. The first settlement date back to the 6th century BC. Then, it was resettled by the Romans in the 3rd century BC. The town, which evidences a long history from the Republican age to late Antiquity (III BC-V AD), is characterized by the typical urban pattern of 'cardi' and 'decumani'. Its excavated ruins include a large amphitheatre, a theatre, the thermae, the Forum and some temples. LiDAR data, adequately filtered, classified and post processed by using geostatistics methods(Lasaponara et al. 2012), enabled to detect features linked to tombs under a dense vegetation located close to the urban perimeter. The analysis of historical air photos, draped over the ground surface obtained from the LiDAR survey, put in evidence some unknown crop-marks linked to roman urban fabric. Finally, the same photos along with the satellite multitemporal dataset allowed us to reconstruct the recent history of the landscape from the Agrarian Reform, in the 50s, up today. Reference Lasaponara R., Masini N., Holmgren R., Backe Forsberg Y., Integration of aerial and satellite remote sensing for archaeological investigations: a case study of the Etruscan site San Giovenale, Journal of Geophysics and Engineering, vol. 9, S26-S39, doi:10.1088/1742-2132/9/4/S26

An approach for combining airborne LiDAR and high-resolution aerial color imagery using Gaussian processes

NASA Astrophysics Data System (ADS)

Liu, Yansong; Monteiro, Sildomar T.; Saber, Eli

2015-10-01

Changes in vegetation cover, building construction, road network and traffic conditions caused by urban expansion affect the human habitat as well as the natural environment in rapidly developing cities. It is crucial to assess these changes and respond accordingly by identifying man-made and natural structures with accurate classification algorithms. With the increase in use of multi-sensor remote sensing systems, researchers are able to obtain a more complete description of the scene of interest. By utilizing multi-sensor data, the accuracy of classification algorithms can be improved. In this paper, we propose a method for combining 3D LiDAR point clouds and high-resolution color images to classify urban areas using Gaussian processes (GP). GP classification is a powerful non-parametric classification method that yields probabilistic classification results. It makes predictions in a way that addresses the uncertainty of real world. In this paper, we attempt to identify man-made and natural objects in urban areas including buildings, roads, trees, grass, water and vehicles. LiDAR features are derived from the 3D point clouds and the spatial and color features are extracted from RGB images. For classification, we use the Laplacian approximation for GP binary classification on the new combined feature space. The multiclass classification has been implemented by using one-vs-all binary classification strategy. The result of applying support vector machines (SVMs) and logistic regression (LR) classifier is also provided for comparison. Our experiments show a clear improvement of classification results by using the two sensors combined instead of each sensor separately. Also we found the advantage of applying GP approach to handle the uncertainty in classification result without compromising accuracy compared to SVM, which is considered as the state-of-the-art classification method.

An Ecosystem-Service Approach to Evaluate the Role of Non-Native Species in Urbanized Wetlands

PubMed Central

Yam, Rita S. W.; Huang, Ko-Pu; Hsieh, Hwey-Lian; Lin, Hsing-Juh; Huang, Shou-Chung

2015-01-01

Natural wetlands have been increasingly transformed into urbanized ecosystems commonly colonized by stress-tolerant non-native species. Although non-native species present numerous threats to natural ecosystems, some could provide important benefits to urbanized ecosystems. This study investigated the extent of colonization by non-native fish and bird species of three urbanized wetlands in subtropical Taiwan. Using literature data the role of each non-native species in the urbanized wetland was evaluated by their effect (benefits/damages) on ecosystem services (ES) based on their ecological traits. Our sites were seriously colonized by non-native fishes (39%–100%), but <3% by non-native birds. Although most non-native species could damage ES regulation (disease control and wastewater purification), some could be beneficial to the urbanized wetland ES. Our results indicated the importance of non-native fishes in supporting ES by serving as food source to fish-eating waterbirds (native, and migratory species) due to their high abundance, particularly for Oreochromis spp. However, all non-native birds are regarded as “harmful” species causing important ecosystem disservices, and thus eradication of these bird-invaders from urban wetlands would be needed. This simple framework for role evaluation of non-native species represents a holistic and transferable approach to facilitate decision making on management priority of non-native species in urbanized wetlands. PMID:25860870

Effects of seasonal change and seawater intrusion on water quality for drinking and irrigation purposes, in coastal aquifers of Dar es Salaam, Tanzania

NASA Astrophysics Data System (ADS)

Sappa, Giuseppe; Ergul, Sibel; Ferranti, Flavia; Sweya, Lukuba Ngalya; Luciani, Giulia

2015-05-01

Groundwater is the major source to meet domestic, industrial and agricultural needs in the city of Dar es Salaam, Tanzania. However, population growth, increasing urbanization, industrialization and tourism, and climatic changes have caused an intensive exploitation of groundwater resources leading the aquifers become more vulnerable to seawater intrusion. The aim of this study is to examine the variations of groundwater chemistry (as resulting from natural and anthropogenic inputs) depending on seasonal changes, in order to evaluate water quality for drinking and irrigation purposes. Physical and chemical data come from the analysis of groundwater samples, collected from 72 wells, used for the evaluation of water quality parameters, during a year of monitoring. Pattern diagrams, geochemical modeling techniques and Principal Component Analysis (PCA) have been used to identify the main factors influencing groundwater composition. Based on the hydrochemistry, the groundwater was classified into three types: (a) Na-Cl, (b) Ca-Cl, (c) mixed Ca-Na-HCO3-Cl (d) mixed Ca-Mg-Cl-SO4. The geochemical modeling results show that groundwater chemistry is mainly influenced by evaporation process, as it is suggested by the increase of Na and Cl ions concentrations. According to irrigation water quality assessment diagrams of USDA, most water samples from dry and rainy seasons, distributed in category C2-S1, C3-S1, C3-S2, C4-S2 highlighting medium to very high salinity hazard and low to medium sodium content class. PCA evidenced the role of seawater intrusion, evaporation process and anthropogenic pollution (i.e. high NO3 levels due to agricultural activities), as the major factors that influenced the water chemistry, and hence the water quality. Based on Pearson correlation matrix, the presence of high correlations (>0.8) among Na, Cl, Mg and SO4, in association with EC, were interpreted as the seawater intrusion effects. In this area groundwater quality is generally low, and often exceeds permissible limits of standard guideline values of WHO and FAO, referred to EC and chloride values. The high salinity and the groundwater level depletion create serious problems for current use of water supplies as well as future exploitation.

Community-based environmental management for malaria control: evidence from a small-scale intervention in Dar es Salaam, Tanzania.

PubMed

Castro, Marcia C; Tsuruta, Atsuko; Kanamori, Shogo; Kannady, Khadija; Mkude, Sixbert

2009-04-08

Historically, environmental management has brought important achievements in malaria control and overall improvements of health conditions. Currently, however, implementation is often considered not to be cost-effective. A community-based environmental management for malaria control was conducted in Dar es Salaam between 2005 and 2007. After community sensitization, two drains were cleaned followed by maintenance. This paper assessed the impact of the intervention on community awareness, prevalence of malaria infection, and Anopheles larval presence in drains. A survey was conducted in neighbourhoods adjacent to cleaned drains; for comparison, neighbourhoods adjacent to two drains treated with larvicides and two drains under no intervention were also surveyed. Data routinely collected by the Urban Malaria Control Programme were also used. Diverse impacts were evaluated through comparison of means, odds ratios (OR), logistic regression, and time trends calculated by moving averages. Individual awareness of health risks and intervention goals were significantly higher among sensitized neighbourhoods. A reduction in the odds of malaria infection during the post-cleaning period in intervention neighbourhoods was observed when compared to the pre-cleaning period (OR = 0.12, 95% CI 0.05-0.3, p < 0.001). During the post-cleaning period, a higher risk of infection (OR = 1.7, 95% CI 1.1-2.4, p = 0.0069) was observed in neighbourhoods under no intervention compared to intervention ones. Eighteen months after the initial cleaning, one of the drains was still clean due to continued maintenance efforts (it contained no waste materials and the water was flowing at normal velocity). A three-month moving average of the percentage of water habitats in that drain containing pupae and/or Anopheles larvae indicated a decline in larval density. In the other drain, lack of proper resources and local commitment limited success. Although environmental management was historically coordinated by authoritarian/colonial regimes or by industries/corporations, its successful implementation as part of an integrated vector management framework for malaria control under democratic governments can be possible if four conditions are observed: political will and commitment, community sensitization and participation, provision of financial resources for initial cleaning and structural repairs, and inter-sectoral collaboration. Such effort not only is expected to reduce malaria transmission, but has the potential to empower communities, improve health and environmental conditions, and ultimately contribute to poverty alleviation and sustainable development.

EnviroAtlas - New York, NY - One Meter Resolution Urban Land Cover Data (2008) Web Service

EPA Pesticide Factsheets

This EnviroAtlas web service supports research and online mapping activities related to EnviroAtlas (https://www.epa.gov/enviroatlas ). The New York, NY EnviroAtlas Meter-scale Urban Land Cover (MULC) Data were generated by the University of Vermont Spatial Analysis Laboratory (SAL) under the direction of Jarlath O'Neil-Dunne as part of the United States Forest Service Urban Tree Canopy (UTC) assessment program. Seven classes were mapped using LiDAR and high resolution orthophotography: Tree Canopy, Grass/Shrub, Bare Soil, Water, Buildings, Roads/Railroads, and Other Paved Surfaces. These data were subsequently merged to fit with the EPA classification. The SAL project covered the five boroughs within the NYC city limits. However the EPA study area encompassed that area plus a 1 kilometer buffer. Additional land cover for the buffer area was generated from United States Department of Agriculture (USDA) National Agricultural Imagery Program (NAIP) four band (red, green, blue, and near infrared) aerial photography at 1 m spatial resolution from July, 2011 and LiDAR from 2010. Six land cover classes were mapped: water, impervious surfaces, soil and barren land, trees, grass-herbaceous non-woody vegetation, and agriculture. An accuracy assessment of 600 completely random and 55 stratified random photo interpreted reference points yielded an overall User's fuzzy accuracy of 87 percent. The area mapped is the US Census Bureau's 2010 Urban Statistical Area for New Yor

Measuring urban tree loss dynamics across residential landscapes.

PubMed

Ossola, Alessandro; Hopton, Matthew E

2018-01-15

The spatial arrangement of urban vegetation depends on urban morphology and socio-economic settings. Urban vegetation changes over time because of human management. Urban trees are removed due to hazard prevention or aesthetic preferences. Previous research attributed tree loss to decreases in canopy cover. However, this provides little information about location and structural characteristics of trees lost, as well as environmental and social factors affecting tree loss dynamics. This is particularly relevant in residential landscapes where access to residential parcels for field surveys is limited. We tested whether multi-temporal airborne LiDAR and multi-spectral imagery collected at a 5-year interval can be used to investigate urban tree loss dynamics across residential landscapes in Denver, CO and Milwaukee, WI, covering 400,705 residential parcels in 444 census tracts. Position and stem height of trees lost were extracted from canopy height models calculated as the difference between final (year 5) and initial (year 0) vegetation height derived from LiDAR. Multivariate regression models were used to predict number and height of tree stems lost in residential parcels in each census tract based on urban morphological and socio-economic variables. A total of 28,427 stems were lost from residential parcels in Denver and Milwaukee over 5years. Overall, 7% of residential parcels lost one stem, averaging 90.87 stems per km 2 . Average stem height was 10.16m, though trees lost in Denver were taller compared to Milwaukee. The number of stems lost was higher in neighborhoods with higher canopy cover and developed before the 1970s. However, socio-economic characteristics had little effect on tree loss dynamics. The study provides a simple method for measuring urban tree loss dynamics within and across entire cities, and represents a further step toward high resolution assessments of the three-dimensional change of urban vegetation at large spatial scales. Published by Elsevier B.V.

A graph signal filtering-based approach for detection of different edge types on airborne lidar data

NASA Astrophysics Data System (ADS)

Bayram, Eda; Vural, Elif; Alatan, Aydin

2017-10-01

Airborne Laser Scanning is a well-known remote sensing technology, which provides a dense and highly accurate, yet unorganized point cloud of earth surface. During the last decade, extracting information from the data generated by airborne LiDAR systems has been addressed by many studies in geo-spatial analysis and urban monitoring applications. However, the processing of LiDAR point clouds is challenging due to their irregular structure and 3D geometry. In this study, we propose a novel framework for the detection of the boundaries of an object or scene captured by LiDAR. Our approach is motivated by edge detection techniques in vision research and it is established on graph signal filtering which is an exciting and promising field of signal processing for irregular data types. Due to the convenient applicability of graph signal processing tools on unstructured point clouds, we achieve the detection of the edge points directly on 3D data by using a graph representation that is constructed exclusively to answer the requirements of the application. Moreover, considering the elevation data as the (graph) signal, we leverage aerial characteristic of the airborne LiDAR data. The proposed method can be employed both for discovering the jump edges on a segmentation problem and for exploring the crease edges on a LiDAR object on a reconstruction/modeling problem, by only adjusting the filter characteristics.

Comparative studies of the efficacy of parvaquone and parvaquone-plus-frusemide in the treatment of Theileria parva infection (East Coast fever) in cattle.

PubMed

Mbwambo, H A; Sudi, F F; Mkonyi, P A; Mfinanga, J M; Mella, E S; Ngovi, C J

2002-09-26

Comparative studies of the efficacy of parvaquone (Parvexon) and parvaquone-plus-frusemide (Fruvexon) Bimeda Chemicals, Ireland, were done on 60 naturally infected cases of East Coast fever (ECF; Theileria parva infection in cattle). Small-scale dairy farmers in the peri-urban of Dar Es Salaam city reported ECF-suspected cases from March to mid-October 2001 and were treated with the two drugs alternately, as were diagnosed positive for ECF. Four sub-groups of 15 cattle each (early stage, 15; advanced stage, 15) were treated with parvaquone and parvaquone-plus-frusemide. Twenty-eight out of 30 (93.3%) cattle treated with parvaquone-plus-frusemide were cured, so do 24 out of 30 (80.0%) cattle treated with parvaquone without frusemide. Early diagnosis and prompt management of pulmonary signs, which accounted for 30.0% of total ECF cases is advised in order to improve cure rates. Unlike parvaquone without frusemide (Parvexon), parvaquone-plus-frusemide (Fruvexon) proved useful in the management of pulmonary signs, hence, a drug of choice in the treatment of ECF cases that are accompanied by or are likely to manifest pulmonary signs.

A Framework for Land Cover Classification Using Discrete Return LiDAR Data: Adopting Pseudo-Waveform and Hierarchical Segmentation

NASA Technical Reports Server (NTRS)

Jung, Jinha; Pasolli, Edoardo; Prasad, Saurabh; Tilton, James C.; Crawford, Melba M.

2014-01-01

Acquiring current, accurate land-use information is critical for monitoring and understanding the impact of anthropogenic activities on natural environments.Remote sensing technologies are of increasing importance because of their capability to acquire information for large areas in a timely manner, enabling decision makers to be more effective in complex environments. Although optical imagery has demonstrated to be successful for land cover classification, active sensors, such as light detection and ranging (LiDAR), have distinct capabilities that can be exploited to improve classification results. However, utilization of LiDAR data for land cover classification has not been fully exploited. Moreover, spatial-spectral classification has recently gained significant attention since classification accuracy can be improved by extracting additional information from the neighboring pixels. Although spatial information has been widely used for spectral data, less attention has been given to LiDARdata. In this work, a new framework for land cover classification using discrete return LiDAR data is proposed. Pseudo-waveforms are generated from the LiDAR data and processed by hierarchical segmentation. Spatial featuresare extracted in a region-based way using a new unsupervised strategy for multiple pruning of the segmentation hierarchy. The proposed framework is validated experimentally on a real dataset acquired in an urban area. Better classification results are exhibited by the proposed framework compared to the cases in which basic LiDAR products such as digital surface model and intensity image are used. Moreover, the proposed region-based feature extraction strategy results in improved classification accuracies in comparison with a more traditional window-based approach.

Access, Use and Perceptions of Teachers and Students towards Mobile Phones as a Tool for Teaching and Learning in Tanzania

ERIC Educational Resources Information Center

Kafyulilo, Ayoub

2014-01-01

This study explored the access, use and perceptions of teachers and students towards mobile phones as a tool for facilitating teaching and learning beyond the classroom walls. A total of 29 pre-service teachers and four college instructors from Dar es salaam University College of Education (DUCE) as well as 12 in-service teachers and 40 students…

Introduction of Information Science into Library Training in Eastern Africa. Expert Meeting (Dar es Salaam, Tanzania, February 26-29, 1980).

ERIC Educational Resources Information Center

Abidi, S. A. H.; Moeller, T.

In 1978 a team of three people was formed to survey the existing library training facilities in East Africa and to suggest possibilities as to how the elements of information science could be introduced either into existing programs or into special courses organized for the purpose. The team submitted its report to a joint meeting of the…

Leveraging strong social ties among young men in Dar es Salaam: A pilot intervention of microfinance and peer leadership for HIV and gender-based violence prevention.

PubMed

Maman, Suzanne; Kajula, Lusajo; Balvanz, Peter; Kilonzo, Mrema; Mulawa, Marta; Yamanis, Thespina

2016-12-01

Gender inequality is at the core of the HIV patterns that are evident in sub-Saharan Africa. Gender-based violence (GBV) and lack of economic opportunity are important structural determinants of HIV risk. We piloted a microfinance and health promotion intervention among social networks of primarily young men in Dar es Salaam. Twenty-two individuals participated in the microfinance component and 30 peer leaders were recruited and trained in the peer health leadership component. We collected and analysed observational data from trainings, monitoring data on loan repayment, and reports of peer conversations to assess the feasibility and acceptability of the intervention. Eighteen of the loan recipients (82%) paid back their loans, and of these 15 (83%) received a second, larger loan. Among the loan defaulters, one died, one had chronic health problems, and two disappeared, one of whom was imprisoned for theft. The majority of conversations reported by peer health leaders focused on condoms, sexual partner selection, and HIV testing. Few peer leaders reported conversations about GBV. We demonstrated the feasibility and acceptability of this innovative HIV and GBV prevention intervention. The lessons learned from this pilot have informed the implementation of a cluster-randomised trial of the microfinance and peer health leadership intervention.

'It makes the patient's spirit weaker': tuberculosis stigma and gender interaction in Dar es Salaam, Tanzania.

PubMed

Miller, C; Huston, J; Samu, L; Mfinanga, S; Hopewell, P; Fair, E

2017-11-01

Dar es Salaam, Tanzania. To describe tuberculosis (TB) related stigma and to understand how it interacts with gender to affect access to care. Eight focus group discussions were held among 48 TB patients and their household members, and a thematic content analysis was carried out. The main components of stigma were fear, self-isolation, ostracization, loss of status in the community, and discrimination by providers. Participants described the cultural context in which stigma operated as characterized by a general lack of health knowledge, cultural beliefs about TB, and engendered beliefs about disease in general. Both genders described some similar effects of stigma, including relationship difficulties and specifically challenges forming new relationships, but many effects of stigma were distinct by gender: women described challenges including assumptions about promiscuity and infidelity, as well as rejection by partners, while men described survival challenges. Stigma acted as a barrier to care through a cyclical pattern of stigma and fear, leading to health-seeking delays, with resulting continued transmission and poor health outcomes that further reinforced stigma. TB-related stigma is prevalent in this setting and operates differently for men and women. Interventions designed to increase case detection must address stigma and its interaction with gender.

Establishing an Anaesthesia and Intensive Care partnership and aiming for national impact in Tanzania.

PubMed

Ulisubisya, Mpoki; Jörnvall, Henrik; Irestedt, Lars; Baker, Tim

2016-03-18

Anaesthesia and Intensive Care is a neglected specialty in low-income countries. There is an acute shortage of health workers - several low-income countries have less than 1 anaesthesia provider per 100,000 population. Only 1.5% of hospitals in Africa have the intensive care resources needed for managing patients with sepsis. Health partnerships between institutions in high and low-income countries have been proposed as an effective way to strengthen health systems. The aim of this article is to describe the origin and conduct of a health partnership in Anaesthesia and Intensive Care between institutions in Tanzania and Sweden and how the partnership has expanded to have an impact at regional and national levels.The Muhimbili-Karolinska Anaesthesia and Intensive Care Collaboration was initiated in 2008 on the request of the Executive Director of Muhimbili National Hospital in Dar es Salaam. The partnership has conducted training courses, exchanges, research projects and introduced new equipment, routines and guidelines. The partnership has expanded to include all hospitals in Dar es Salaam. Through the newly formed Life Support Foundation, the partnership has had a national impact assisting the reanimation of the Society of Anaesthesiologists of Tanzania and has seen a marked increase of the number of young doctors choosing a residency in Anaesthesia and Intensive Care.

Damage Assessment for Disaster Relief Efforts in Urban Areas Using Optical Imagery and LiDAR Data

NASA Astrophysics Data System (ADS)

Bahr, Thomas

2014-05-01

Imagery combined with LiDAR data and LiDAR-derived products provides a significant source of geospatial data which is of use in disaster mitigation planning. Feature rich building inventories can be constructed from tools with 3D rooftop extraction capabilities, and two dimensional outputs such as DSMs and DTMs can be used to generate layers to support routing efforts in Spatial Analyst and Network Analyst workflows. This allows us to leverage imagery and LiDAR tools for disaster mitigation or other scenarios. Software such as ENVI, ENVI LiDAR, and ArcGIS® Spatial and Network Analyst can therefore be used in conjunction to help emergency responders route ground teams in support of disaster relief efforts. This is exemplified by a case study against the background of the magnitude 7.0 earthquake that struck Haiti's capital city of Port-au-Prince on January 12, 2010. Soon after, both LiDAR data and an 8-band WorldView-2 scene were collected to map the disaster zone. The WorldView-2 scene was orthorectified and atmospherically corrected in ENVI prior to use. ENVI LiDAR was used to extract the DSM, DTM, buildings, and debris from the LiDAR data point cloud. These datasets provide a foundation for the 2D portion of the analysis. As the data was acquired over an area of dense urbanization, the majority of ground surfaces are roads, and standing buildings and debris are actually largely separable on the basis of elevation classes. To extract the road network of Port-au-Prince, the LiDAR-based feature height information was fused with the WorldView-2 scene, using ENVI's object-based feature extraction approach. This road network was converted to a network dataset for further analysis by the ArcGIS Network Analyst. For the specific case of Haiti, the distribution of blue tarps, used as accommodations for refugees, provided a spectrally distinct target. Pure blue tarp pixel spectra were selected from the WorldView-2 scene and input as a reference into ENVI's Spectral Angle Mapper (SAM) classification routine, together with a water-shadow mask to prevent false positives. The resulting blue tarp shape file was input into the ArcGIS Point Density tool, a feature of the Spatial Analyst toolbox. The final distribution map shows the density of blue tarps in Port-au-Prince and can be used to roughly delineate camps of refugees. Analogous, a debris density map was generated after separating the debris elevation class. The combination of this debris density map with the road network allowed to construct an intact road network of Port-au-Prince within the ArcGIS Network Analyst. Moderate density debris was used as a cost-increase barrier feature of the network dataset, and high density debris was used as a total obstruction barrier feature. Based on this information, two hypothetical routing scenarios were analyzed. One involved routing a ground team between two different refugee concentration zones. For the other, potential helicopter landing zones were computed from the LiDAR-derived products and added as facility features to the Network Analyst. Routes from the helicopter landing zones to refugee concentration access points were solved using closest facility logic, again making use of the obstructed network.

[Not Available].

PubMed

Sendrós Madroño, José M

2016-06-03

La atención nutricional en el paciente oncohematológico debe formar parte del tratamiento global del paciente. Las alteraciones debidas a la localización de la neoplasia y los efectos secundarios del tratamiento oncoespecífico muchas veces dificultan o impiden la alimentación oral. Esto puede dar lugar a una desnutrición y es de gran importancia su detección, valoración e intervención temprana. El primer paso en la intervención nutricional es el consejo dietético. Este artículo muestra qué aspectos deben tenerse en cuenta para poder elaborar un consejo dietético y la importancia de que este sea individualizado. Se describen como ejemplo cuatro situaciones especiales, donde es necesario trasladar las recomendaciones nutricionales a un plan dietético. También se incide en el uso de los probióticos en pacientes inmunocomprometidos.

Spectral Lidar Analysis and Terrain Classification in a Semi-Urban Environment

DTIC Science & Technology

2017-03-01

MONITORING AGENCY REPORT NUMBER 11 . SUPPLEMENTARY NOTES The views expressed in this thesis are those of the author and do not reflect the official policy... Apollo 15, 16, 17 Laser Altimeters ...............................................6 3. Clementine...35 11 . Cloud-Aerosol LiDAR and Infrared Pathfinder Satellite Observations

Nutritional status and birth outcomes of adolescent pregnant girls in Morogoro, Coast, and Dar es Salaam regions, Tanzania.

PubMed

Shirima, Candida P; Kinabo, Joyce L

2005-01-01

Studies that link adolescence pregnancies, nutritional status, and birth outcomes in Tanzania are scarce. We examined the nutritional status and birth outcomes of pregnant adolescent girls from rural and urban areas of three regions in Tanzania. The study was carried out in the regions of Dar es Salaam (Chamazi and Gezaulole dispensaries and Round Table Maternity Home), Coast (Tumbi Regional Hospital and Mlandizi Health Center), and Morogoro (Regional Hospital, Uhuru Clinic, and Mlali Health Center). One hundred eighty pregnant adolescent girls ages 15 to 19 y were recruited and interviewed, and their nutritional status measurements were taken at the seven health facilities. Information concerning date of birth, marital status, educational status, sex education, and income status was collected with a structured questionnaire. Height, weight, and mid-upper arm circumference were measured according to standard techniques. Hemoglobin concentration was measured with a hemoglobinometer and the HemoCue technique. Nutritional status was assessed by body mass index, and hemoglobin concentration was determined by cutoff points of the World Health Organization. Suitable statistical analysis was done with SPSS 9.0. Weekly weight gain during pregnancy was measured in 123 subjects who kept their appointments and reported back after 2 wk. Fifty-seven subjects did not keep their appointments and were lost to follow-up. Records of infants' birth weights and mode of delivery were obtained from 50 subjects who delivered at the study sites. The height of about 54% of the subjects was shorter than 151 cm, suggestive of short maternal height. Severe wasting was observed in 27% of subjects. Mean weekly weight gain during pregnancy was 317 +/-110 g (-500 to 500 g). No significant differences were observed between rural and urban settings. Mean infant birth weight was 2600 +/- 480 g. About 48% of infants had low birth weight (<2500 g) and only 14% of infants had birth weight greater than 3000 g. About 14% of infants were born by cesarean section. Nearly 86% of the pregnant adolescent girls were anemic. A hemoglobin concentration below 7 g/dL was observed in 5% of subjects. Most subjects (55%) had hemoglobin concentrations from 7 to lower than 10 g/dL. There was a weak correlation between infant birth weight and weekly weight gain of the girls during pregnancy (r = 0.36, P < or = 0.01). However, a strong correlation was observed between birth weight and hemoglobin level of adolescent girls during pregnancy (r = 0.67, P = 0.01). Short stature was observed to contribute toward cesarean delivery (P = 0.05) because more cesarean deliveries were performed in short girls (<151 cm tall). The nutritional status of pregnant adolescent girls in the study areas was poor and resulted in poor pregnancy outcome. Girls should be educated about reproductive health at the primary level of education.

Hypertension in Sub-Saharan Africa: Cross-Sectional Surveys in Four Rural and Urban Communities

PubMed Central

Hendriks, Marleen E.; Wit, Ferdinand W. N. M.; Roos, Marijke T. L.; Brewster, Lizzy M.; Akande, Tanimola M.; de Beer, Ingrid H.; Mfinanga, Sayoki G.; Kahwa, Amos M.; Gatongi, Peter; Van Rooy, Gert; Janssens, Wendy; Lammers, Judith; Kramer, Berber; Bonfrer, Igna; Gaeb, Esegiel; van der Gaag, Jacques; Rinke de Wit, Tobias F.; Lange, Joep M. A.; Schultsz, Constance

2012-01-01

Background Cardiovascular disease (CVD) is the leading cause of adult mortality in low-income countries but data on the prevalence of cardiovascular risk factors such as hypertension are scarce, especially in sub-Saharan Africa (SSA). This study aims to assess the prevalence of hypertension and determinants of blood pressure in four SSA populations in rural Nigeria and Kenya, and urban Namibia and Tanzania. Methods and Findings We performed four cross-sectional household surveys in Kwara State, Nigeria; Nandi district, Kenya; Dar es Salaam, Tanzania and Greater Windhoek, Namibia, between 2009–2011. Representative population-based samples were drawn in Nigeria and Namibia. The Kenya and Tanzania study populations consisted of specific target groups. Within a final sample size of 5,500 households, 9,857 non-pregnant adults were eligible for analysis on hypertension. Of those, 7,568 respondents ≥18 years were included. The primary outcome measure was the prevalence of hypertension in each of the populations under study. The age-standardized prevalence of hypertension was 19.3% (95%CI:17.3–21.3) in rural Nigeria, 21.4% (19.8–23.0) in rural Kenya, 23.7% (21.3–26.2) in urban Tanzania, and 38.0% (35.9–40.1) in urban Namibia. In individuals with hypertension, the proportion of grade 2 (≥160/100 mmHg) or grade 3 hypertension (≥180/110 mmHg) ranged from 29.2% (Namibia) to 43.3% (Nigeria). Control of hypertension ranged from 2.6% in Kenya to 17.8% in Namibia. Obesity prevalence (BMI ≥30) ranged from 6.1% (Nigeria) to 17.4% (Tanzania) and together with age and gender, BMI independently predicted blood pressure level in all study populations. Diabetes prevalence ranged from 2.1% (Namibia) to 3.7% (Tanzania). Conclusion Hypertension was the most frequently observed risk factor for CVD in both urban and rural communities in SSA and will contribute to the growing burden of CVD in SSA. Low levels of control of hypertension are alarming. Strengthening of health care systems in SSA to contain the emerging epidemic of CVD is urgently needed. PMID:22427857

Comparative study of building footprint estimation methods from LiDAR point clouds

NASA Astrophysics Data System (ADS)

Rozas, E.; Rivera, F. F.; Cabaleiro, J. C.; Pena, T. F.; Vilariño, D. L.

2017-10-01

Building area calculation from LiDAR points is still a difficult task with no clear solution. Their different characteristics, such as shape or size, have made the process too complex to automate. However, several algorithms and techniques have been used in order to obtain an approximated hull. 3D-building reconstruction or urban planning are examples of important applications that benefit of accurate building footprint estimations. In this paper, we have carried out a study of accuracy in the estimation of the footprint of buildings from LiDAR points. The analysis focuses on the processing steps following the object recognition and classification, assuming that labeling of building points have been previously performed. Then, we perform an in-depth analysis of the influence of the point density over the accuracy of the building area estimation. In addition, a set of buildings with different size and shape were manually classified, in such a way that they can be used as benchmark.

Improving the Effectiveness of Speaker Verification Domain Adaptation With Inadequate In-Domain Data

DTIC Science & Technology

2017-08-20

Improving the Effectiveness of Speaker Verification Domain Adaptation With Inadequate In-Domain Data Bengt J. Borgström1, Elliot Singer1, Douglas...ll.mit.edu.edu, dar@ll.mit.edu, es@ll.mit.edu, omid.sadjadi@nist.gov Abstract This paper addresses speaker verification domain adaptation with...contain speakers with low channel diversity. Existing domain adaptation methods are reviewed, and their shortcomings are discussed. We derive an

An HIV/AIDS Knowledge Scale for Adolescents: Item Response Theory Analyses Based on Data from a Study in South Africa and Tanzania

ERIC Educational Resources Information Center

Aaro, Leif E.; Breivik, Kyrre; Klepp, Knut-Inge; Kaaya, Sylvia; Onya, Hans E.; Wubs, Annegreet; Helleve, Arnfinn; Flisher, Alan J.

2011-01-01

A 14-item human immunodeficiency virus/acquired immunodeficiency syndrome knowledge scale was used among school students in 80 schools in 3 sites in Sub-Saharan Africa (Cape Town and Mankweng, South Africa, and Dar es Salaam, Tanzania). For each item, an incorrect or don't know response was coded as 0 and correct response as 1. Exploratory factor…

EnviroAtlas - New York, NY - One Meter Resolution Urban Land Cover Data (2008)

EPA Pesticide Factsheets

The New York, NY EnviroAtlas Meter-scale Urban Land Cover (MULC) Data were generated by the University of Vermont Spatial Analysis Laboratory (SAL) under the direction of Jarlath O'Neil-Dunne as part of the United States Forest Service Urban Tree Canopy (UTC) assessment program. Seven classes were mapped using LiDAR and high resolution orthophotography: Tree Canopy, Grass/Shrub, Bare Soil, Water, Buildings, Roads/Railroads, and Other Paved Surfaces. These data were subsequently merged to fit with the EPA classification. The SAL project covered the five boroughs within the NYC city limits. However the EPA study area encompassed that area plus a 1 kilometer buffer. Additional land cover for the buffer area was generated from United States Department of Agriculture (USDA) National Agricultural Imagery Program (NAIP) four band (red, green, blue, and near infrared) aerial photography at 1 m spatial resolution from July, 2011 and LiDAR from 2010. Six land cover classes were mapped: water, impervious surfaces, soil and barren land, trees, grass-herbaceous non-woody vegetation, and agriculture. An accuracy assessment of 600 completely random and 55 stratified random photo interpreted reference points yielded an overall User's fuzzy accuracy of 87 percent. The area mapped is the US Census Bureau's 2010 Urban Statistical Area for New York City plus a 1 km buffer. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAt

Modelling Mean Albedo of Individual Roofs in Complex Urban Areas Using Satellite Images and Airborne Laser Scanning Point Clouds

NASA Astrophysics Data System (ADS)

Kalantar, B.; Mansor, S.; Khuzaimah, Z.; Sameen, M. Ibrahim; Pradhan, B.

2017-09-01

Knowledge of surface albedo at individual roof scale is important for mitigating urban heat islands and understanding urban climate change. This study presents a method for quantifying surface albedo of individual roofs in a complex urban area using the integration of Landsat 8 and airborne LiDAR data. First, individual roofs were extracted from airborne LiDAR data and orthophotos using optimized segmentation and supervised object based image analysis (OBIA). Support vector machine (SVM) was used as a classifier in OBIA process for extracting individual roofs. The user-defined parameters required in SVM classifier were selected using v-fold cross validation method. After that, surface albedo was calculated for each individual roof from Landsat images. Finally, thematic maps of mean surface albedo of individual roofs were generated in GIS and the results were discussed. Results showed that the study area is covered by 35% of buildings varying in roofing material types and conditions. The calculated surface albedo of buildings ranged from 0.16 to 0.65 in the study area. More importantly, the results indicated that the types and conditions of roofing materials significantly effect on the mean value of surface albedo. Mean albedo of new concrete, old concrete, new steel, and old steel were found to be equal to 0.38, 0.26, 0.51, and 0.44 respectively. Replacing old roofing materials with new ones should highly prioritized.

Identification of fine scale and landscape scale drivers of urban aboveground carbon stocks using high-resolution modeling and mapping.

PubMed

Mitchell, Matthew G E; Johansen, Kasper; Maron, Martine; McAlpine, Clive A; Wu, Dan; Rhodes, Jonathan R

2018-05-01

Urban areas are sources of land use change and CO 2 emissions that contribute to global climate change. Despite this, assessments of urban vegetation carbon stocks often fail to identify important landscape-scale drivers of variation in urban carbon, especially the potential effects of landscape structure variables at different spatial scales. We combined field measurements with Light Detection And Ranging (LiDAR) data to build high-resolution models of woody plant aboveground carbon across the urban portion of Brisbane, Australia, and then identified landscape scale drivers of these carbon stocks. First, we used LiDAR data to quantify the extent and vertical structure of vegetation across the city at high resolution (5×5m). Next, we paired this data with aboveground carbon measurements at 219 sites to create boosted regression tree models and map aboveground carbon across the city. We then used these maps to determine how spatial variation in land cover/land use and landscape structure affects these carbon stocks. Foliage densities above 5m height, tree canopy height, and the presence of ground openings had the strongest relationships with aboveground carbon. Using these fine-scale relationships, we estimate that 2.2±0.4 TgC are stored aboveground in the urban portion of Brisbane, with mean densities of 32.6±5.8MgCha -1 calculated across the entire urban land area, and 110.9±19.7MgCha -1 calculated within treed areas. Predicted carbon densities within treed areas showed strong positive relationships with the proportion of surrounding tree cover and how clumped that tree cover was at both 1km 2 and 1ha resolutions. Our models predict that even dense urban areas with low tree cover can have high carbon densities at fine scales. We conclude that actions and policies aimed at increasing urban carbon should focus on those areas where urban tree cover is most fragmented. Copyright © 2017 Elsevier B.V. All rights reserved.

Monitoring the effects of land cover change on the supply of ecosystem services in an urban region: A study of Santiago-Valparaíso, Chile

PubMed Central

de la Barrera, Francisco; Salazar, Alejandro; Inostroza, Luis

2017-01-01

Mankind’s quest for well-being results in continuous pressure to transform landscapes, with said transformation driven by land use changes, urbanization, production activity, and protective measures in addition to climate variability and other environmental drivers. The relationship between anthropogenic landscape changes and the provision of ecosystem services (ES) is a topic of increasing interest in Latin America. In Chile, land cover changes due to increased urbanization and forestry, and expansion of agricultural land, in addition to conservation initiatives as a part of land planning, have been intensive in the last few decades. In this study, the effects of anthropogenic landscape changes on the supply of ES were analyzed for the urban region of Santiago-Valparaiso (Chile) using a method based on expert consultation and land cover change assessment. A pool of experts scored the potential of specific land covers to provide certain ES. The results enabled calculation and mapping of changes in the potential of the landscape to supply ES. The aforementioned changes over a period of 15 years were evaluated. The results indicate a tenuous balance between positive and negative changes to the supply of ES derived from land cover changes. Understanding and reporting how these processes occur in urban regions contributes to the conservation of valuable landscapes through spatial planning tools, especially in areas close to housing developments and sensitive ecosystems. PMID:29136016

Monitoring the effects of land cover change on the supply of ecosystem services in an urban region: A study of Santiago-Valparaíso, Chile.

PubMed

Montoya-Tangarife, Claudia; de la Barrera, Francisco; Salazar, Alejandro; Inostroza, Luis

2017-01-01

Mankind's quest for well-being results in continuous pressure to transform landscapes, with said transformation driven by land use changes, urbanization, production activity, and protective measures in addition to climate variability and other environmental drivers. The relationship between anthropogenic landscape changes and the provision of ecosystem services (ES) is a topic of increasing interest in Latin America. In Chile, land cover changes due to increased urbanization and forestry, and expansion of agricultural land, in addition to conservation initiatives as a part of land planning, have been intensive in the last few decades. In this study, the effects of anthropogenic landscape changes on the supply of ES were analyzed for the urban region of Santiago-Valparaiso (Chile) using a method based on expert consultation and land cover change assessment. A pool of experts scored the potential of specific land covers to provide certain ES. The results enabled calculation and mapping of changes in the potential of the landscape to supply ES. The aforementioned changes over a period of 15 years were evaluated. The results indicate a tenuous balance between positive and negative changes to the supply of ES derived from land cover changes. Understanding and reporting how these processes occur in urban regions contributes to the conservation of valuable landscapes through spatial planning tools, especially in areas close to housing developments and sensitive ecosystems.

Rapid, high-resolution measurement of leaf area and leaf orientation using terrestrial LiDAR scanning data

USDA-ARS?s Scientific Manuscript database

The rapid evolution of high performance computing technology has allowed for the development of extremely detailed models of the urban and natural environment. Although models can now represent sub-meter-scale variability in environmental geometry, model users are often unable to specify the geometr...

Overweight, obesity and perceptions about body weight among primary schoolchildren in Dar es Salaam, Tanzania.

PubMed

Mpembeni, Rose N M; Muhihi, Alfa J; Maghembe, Mwanamkuu; Ngarashi, Davis; Lujani, Benjamin; Chillo, Omary; Kubhoja, Sulende; Anaeli, Amani; Njelekela, Marina A

2014-10-01

The increasing prevalence of overweight and obesity among children has become a public health concern both in developing and developed countries. Previous research studies have shown that favourable perception of one's body weight is an important factor in weight control. This study determined prevalence of overweight and obesity and assessed perception about body weight among primary schoolchildren in Dar es Salaam, Tanzania. In this cross sectional study, nine schools were selected randomly from a list of all primary schools in Dar es Salaam. A structured questionnaire was used to collect data on socio-demographic characteristics and lifestyle information including perception about body weight. Height and weight were measured following standard procedures. Chi- square tests and multiple logistic regressions were used to determine factors which influence perceptions about body weight. A total of 446 children were included into the study. The mean body mass index (BMI) was 16.6 ± 4.0 kg/m2 (16.1 ± 4.0 for males and 17.0 ± 4.0 for females). Prevalence of overweight and obesity was 9.8% and 5.2%, respectively. The prevalence of overweight and obesity was significantly higher among girls, 13.1% and 6.3% compared to boys with 6.3% and 3.8% overweight and obese respectively (P=0.0314). Overall, the prevalence of overweight and obesity was 15.0% (10.1% among boys and 19.4% among girls). One-third (33.3%) of the children perceived their body weight as overweight or obese. Among overweight and obese children, 35.4% had unfavourable perception of their body weights. There was a statistically significant difference between perceived body weight and actual body weight as indicated by BMI for both boys and girls (P < 0.05). Age of the child (AOR = 0.55 95% CI 0.36-0.85) and area of residence (COR = 0.64 95% CI 0.44-0.95) were found to be significant predictors of favourable perception of one's body weight. In conclusion, the prevalence of overweight and obesity is not very high in this population. However over a third of overweight and obese children, had unfavourable perception of their body weights. We recommend targeted educational programmes about overweight and obesity and the associated health effects in order to instil a behaviour of self consciousness on overweight and obesity among children in Tanzania.

Informing new or improved vector control tools for reducing the malaria burden in Tanzania: a qualitative exploration of perceptions of mosquitoes and methods for their control among the residents of Dar es Salaam.

PubMed

Makungu, Christina; Stephen, Stephania; Kumburu, Salome; Govella, Nicodem J; Dongus, Stefan; Hildon, Zoe Jane-Lara; Killeen, Gerry F; Jones, Caroline

2017-10-11

The effectiveness of malaria prevention with long-lasting insecticidal nets and indoor residual spraying is limited by emerging insecticide resistance, evasive mosquito behaviours that include outdoor biting, sub-optimal implementation and inappropriate use. New vector control interventions are required and their potential effectiveness will be enhanced if existing household perceptions and practices are integrated into intervention design. This qualitative descriptive study used focus groups discussions, in-depth interviews and photovoice methods to explore mosquito control perceptions and practices among residents in four study sites in Dar es Salaam, Tanzania. Mosquitoes were perceived as a growing problem, directly attributed to widespread environmental deterioration and lack of effective mosquito control interventions. Malaria and nuisance biting were perceived as the main problem caused by mosquitoes. Breeding sites were clearly distinguished from resting sites but residents did not differentiate between habitats producing malaria vector mosquitoes and others producing mostly nuisance mosquitoes. The most frequently mentioned protection methods in the wealthiest locations were bed nets, aerosol insecticide sprays, window screens, and fumigation, while bed nets were most frequently mentioned and described as 'part of the culture' in the least wealthy locations. Mosquito-proofed housing was consistently viewed as desirable, but considered unaffordable outside wealthiest locations. Slapping and covering up with clothing were most commonly used to prevent biting outdoors. Despite their utility outdoors, topical repellents applied to the skin were considered expensive, and viewed with suspicion due to perceived side effects. Improving the local environment was the preferred method for preventing outdoor biting. Affordability, effectiveness, availability, practicality, as well as social influences, such as government recommendations, socialization and internalization (familiarization and habit) were described as key factors influencing uptake. Outdoor transmission is widely accepted as an obstacle to malaria elimination. Larval source management, targeting both malaria vectors and nuisance-biting mosquitoes, is the preferred method for mosquito control among the residents of Dar es Salaam and should be prioritized for development alongside new methods for outdoor personal protection. Even if made available, effective and affordable, these additional interventions may require time and user experience to achieve positive reputations and trustworthiness.

A qualitative study of perceived risk for HIV transmission among police officers in Dar es Salaam, Tanzania

PubMed Central

2013-01-01

Background Understanding people’s views about HIV transmission by investigating a specific population may help to design effective HIV prevention strategies. In addition, knowing the inherent sexual practices of such a population, as well as the risky circumstances that may facilitate HIV transmission, is crucial for the said strategies to become effective. In this article, we report how police officers in Dar es Salaam, Tanzania, perceived the problem of HIV and AIDS in their local context, particularly in relation to unsafe sexual practices. The study was done with the view to recommending ways by which HIV transmission could be minimised within the police force. Methods The study was conducted among members of the police force in Dar es Salaam, Tanzania. Eight focus group discussions (FGDs) were conducted, with a total of 66 participants who were mixed in terms of age, gender, and marital status. Some of these were caregivers to patients with AIDS. Data were analysed using the interpretive description approach. Results The participants believed that both individual sexual behaviour and work-related circumstances were sources of HIV infection. They also admitted that they were being tempted to engage in risky sexual practices because of the institutional rules that prohibit officers from getting married during their training and for three years after. Nevertheless, as members of the Police Force, they stressed the fact that the risky sexual behaviour that exposes them to HIV is not limited to the force; it is rather a common problem that is faced by the general population. However, they complained, the nature of their job exposes them to road accident victims, subjecting them further to possible infection, especially when they have to handle these road accident casualties without proper protective gear. Conclusion Individual sexual behaviour and job-related circumstances are worth investigating if proper advice is to be given to the police regarding HIV prevention strategies. In order to improve the lives of these police officers, there is a need to review the existing institutional rules and practices to accommodate individual sexual needs. In addition, improving their working environment may minimize the risk of HIV transmission from handling casualties in emergency situations. PMID:23984994

Sexual behaviour, contraceptive knowledge and use among female undergraduates’ students of Muhimbili and Dar es Salaam Universities, Tanzania: a cross-sectional study

PubMed Central

2014-01-01

Background The rate of premarital sexual activity, unwanted pregnancies and illegal abortions remain higher among university students. This calls for understanding the knowledge on contraceptive use and sexual behaviours among this high risk group if the incidence of unintended pregnancy, illegal abortions and high sexual risky behaviour are to be minimized. This study aimed to assess ssexual behaviour, contraceptive knowledge and use among female undergraduates’ students of Muhimbili and Dar es Salaam Universities in Tanzania. Methods A cross-sectional analytic study was conducted among undergraduate female students in the two Universities located in Dar es Salaam region, Tanzania. The study period was from June 2013 to October 2013. A self-administered questionnaire was given to 281 students. Of these, 253 were retrieved, giving a response rate of 90%. Data was analyzed using Statistical Package for Social Science (SPSS) for Windows version 17.0. Descriptive statistics were summarized. The chi square test was used to examine relationship between various sociodemographic and sexual behaviours variables with contraceptive use. A P-value of less than 0.05 was considered statistically significant. Results Results showed that majority (70.4%) of the students have had sexual intercourse. All participants had knowledge of contraception. More than half, 148 (58.5%) of sexually active women reported ever used contraception before while 105 (41.5%) were current contraceptive users. Majority (74.7%) of the sexually active group started sexual activity at young age (19–24 years). Condom, 221(24.3%) and pills, 153 (16.8%) were the known contraceptive methods. The most popular method of contraception used were condoms, withdrawal and periodic abstinence. The main sources of information about contraception were from friends, radio and school (39.5%, 36% and 24%) respectively. Forty (15.8%) women had pregnancies. Of these, 11 (27%) have had unwanted pregnancies among which 54.6% have had induced abortion. Marital status, age at first sex, ever had sex, ever been pregnant and unwanted pregnancies were associated with use of contraception. Conclusions Most of the student’s had knowledge of contraception. However, rate of contraception use is still low. Majority of the respondent were sexually active, with the majority started sexual activity at young age. This needs advocacy for adolescence reproductive health education to promote the use of the available contraceptive services amongst university students. PMID:25099502

A pilot study to evaluate incorporating eye care for children into reproductive and child health services in Dar-es-Salaam, Tanzania: a historical comparison study

PubMed Central

2014-01-01

Background Many blinding eye conditions of childhood are preventable or treatable, particularly in developing countries. However, primary eye care (PEC) for children is poorly developed, leading to unnecessary visual loss. Activities for control by health workers entail interventions for systemic conditions (measles, vitamin A deficiency), identification and referral of children with sight threatening conditions and health education for caregivers. This pilot study evaluated integrating a package of activities to promote child eye health into Reproductive and Child Health (RCH) services in Dar-es-Salaam, Tanzania. Methods Design: historical comparison study. Fifteen Clinical Officers and 15 nurses in 15 randomly selected RCH clinics were trained in PEC for children in July 2010. They were given educational materials (poster and manual) and their supervisors were orientated. Knowledge and practices were assessed before and 3 weeks after training. One year later their knowledge and practices were compared with a different group of 15 Clinical Officers and 15 nurses who had not been trained. Results Before training staff had insufficient knowledge to identify, treat and refer children with eye diseases, even conjunctivitis. Some recommended harmful practices or did not know that cataract requires urgent referral. Eye examination, vitamin A supplementation of mothers after delivery and cleaning the eyes at birth with instillation of antibiotics (Crede’s prophylaxis) were not routine, and there were no eye-specific educational materials. Three weeks after training several clinics delivering babies started Crede’s prophylaxis, vitamin A supplementation of women after delivery increased from 83.7% to 100%, and all staff included eye conditions in health education sessions. At one year, trained staff were more likely to correctly describe, diagnose and treat conjunctivitis (z=2.34, p=0.04)(30%-vs-60.7%). Mystery mothers observed health education sessions in 7/10 RCH clinics with trained staff, five (71.4%) of which included eye conditions. Conclusions Primary eye care for children in Dar-es-Salaam is inadequate but training RCH staff can improve knowledge in the short term and change practices. Attendance by mothers and their children is high in RCH clinics, making them ideal for delivery of PEC. Ongoing supportive supervision is required to maintain knowledge and practices, as well as systems to track referrals. PMID:24932133

Medication challenges for patients with severe mental illness: experience and views of patients, caregivers and mental health care workers in Dar es Salaam, Tanzania.

PubMed

Iseselo, Masunga K; Ambikile, Joel Seme

2017-01-01

Management of patients with mental disorders is inadequate in the majority of low and middle income countries. The main treatment modality for patients with severe mental disorders in these countries is mainly pharmacological approach. Patients face many challenges in meeting medication needs. In this context, high percentages of individuals who have severe mental disorders are not treated. Regular and adequate supplies of appropriate, safe and affordable medications are some of the important aspects required for provision of quality mental health services. Psychotropic medications are an important component of holistic care that provides treatment options for those suffering from mental illnesses. In Tanzania, mental health services face many challenges including inadequate mental health care providers, infrastructure, and medication supply. Relapse is a common problem among patients attending mental health facilities. This study is aimed at exploring views and experiences of patients, caregivers and mental health care providers on the psychotropic medication in Dar es Salaam, Tanzania. A qualitative study was conducted, involving two focus group discussions with seven and nine caregivers in each group. Eleven in-depth interviews with four patients and seven mental health care providers at Temeke Municipality, Dar es Salaam, were conducted. Convenient sampling procedure was used to select participants for the study. Discussion and interview guides were used during data collection. Interviews were audio-recorded in Kiswahili with all study participants. The recorded interviews were transcribed and qualitative content thematic analysis was used to analyze data after translation. Four themes were identified. These include attitudes of patients towards psychotropic medication, availability of psychotropic medications, financial concerns towards psychotropic medications, and coverage of free treatment policy. The availability and affordability of psychotropic medications to patients are big problems. This was partly attributed to insufficient funds to support the budget of health facilities and technical challenges contributed by both the health facilities and other stakeholders. To improve mental health services in the country, it is important to ensure adequate supply of psychotropic medications in the health facilities. Access to psychotropic medications is essential in addressing the public health problem of untreated mental illnesses. These findings call for the government and other stakeholders to increase funding for essential psychotropic medications.

Sexual behaviour, contraceptive knowledge and use among female undergraduates' students of Muhimbili and Dar es Salaam Universities, Tanzania: a cross-sectional study.

PubMed

Somba, Magreat J; Mbonile, Milline; Obure, Joseph; Mahande, Michael J

2014-08-07

The rate of premarital sexual activity, unwanted pregnancies and illegal abortions remain higher among university students. This calls for understanding the knowledge on contraceptive use and sexual behaviours among this high risk group if the incidence of unintended pregnancy, illegal abortions and high sexual risky behaviour are to be minimized. This study aimed to assess ssexual behaviour, contraceptive knowledge and use among female undergraduates' students of Muhimbili and Dar es Salaam Universities in Tanzania. A cross-sectional analytic study was conducted among undergraduate female students in the two Universities located in Dar es Salaam region, Tanzania. The study period was from June 2013 to October 2013. A self-administered questionnaire was given to 281 students. Of these, 253 were retrieved, giving a response rate of 90%. Data was analyzed using Statistical Package for Social Science (SPSS) for Windows version 17.0. Descriptive statistics were summarized. The chi square test was used to examine relationship between various sociodemographic and sexual behaviours variables with contraceptive use. A P-value of less than 0.05 was considered statistically significant. Results showed that majority (70.4%) of the students have had sexual intercourse. All participants had knowledge of contraception. More than half, 148 (58.5%) of sexually active women reported ever used contraception before while 105 (41.5%) were current contraceptive users. Majority (74.7%) of the sexually active group started sexual activity at young age (19-24 years). Condom, 221(24.3%) and pills, 153 (16.8%) were the known contraceptive methods. The most popular method of contraception used were condoms, withdrawal and periodic abstinence. The main sources of information about contraception were from friends, radio and school (39.5%, 36% and 24%) respectively. Forty (15.8%) women had pregnancies. Of these, 11 (27%) have had unwanted pregnancies among which 54.6% have had induced abortion. Marital status, age at first sex, ever had sex, ever been pregnant and unwanted pregnancies were associated with use of contraception. Most of the student's had knowledge of contraception. However, rate of contraception use is still low. Majority of the respondent were sexually active, with the majority started sexual activity at young age. This needs advocacy for adolescence reproductive health education to promote the use of the available contraceptive services amongst university students.

Prevalence of Cryptosporidium parvum/hominis, Entamoeba histolytica and Giardia lamblia among Young Children with and without Diarrhea in Dar es Salaam, Tanzania.

PubMed

Tellevik, Marit G; Moyo, Sabrina J; Blomberg, Bjørn; Hjøllo, Torunn; Maselle, Samuel Y; Langeland, Nina; Hanevik, Kurt

2015-01-01

Although enteroparasites are common causes of diarrheal illness, few studies have been performed among children in Tanzania. This study aimed to investigate the prevalence of Cryptosporidium parvum/hominis, Entamoeba histolytica and Giardia lamblia among young children in Dar es Salaam, Tanzania, and identify risk factors for infection. We performed an unmatched case-control study among children < 2 years of age in Dar es Salaam, recruited from August 2010 to July 2011. Detection and identification of protozoans were done by PCR techniques on DNA from stool specimens from 701 cases of children admitted due to diarrhea at the three study hospitals, and 558 controls of children with no history of diarrhea during the last month prior to enrollment. The prevalence of C. parvum/hominis was 10.4% (84.7% C. hominis), and that of G. lamblia 4.6%. E. histolytica was not detected. The prevalence of Cryptosporidium was significantly higher in cases (16.3%) than in controls (3.1%; P < 0.001; OR = 6.2; 95% CI: 3.7-10.4). G. lamblia was significantly more prevalent in controls (6.1%) than in cases (3.4%; P = 0.027; OR = 1.8; 95% CI: 1.1-3.1). Cryptosporidium infection was found more often in HIV-positive (24.2%) than in HIV-negative children (3.9%; P < 0.001; OR = 7.9; 95% CI: 3.1-20.5), and was also associated with rainfall (P < 0.001; OR = 2.41; 95% CI: 1.5-3.8). Among cases, stunted children had significantly higher risk of being infected with Cryptosporidium (P = 0.011; OR = 2.12; 95% CI: 1.2-3.8). G. lamblia infection was more prevalent in the cool season (P = 0.004; OR = 2.2; 95% CI: 1.3-3.8), and more frequent among cases aged > 12 months (P = 0.003; OR = 3.5; 95% CI: 1.5-7.8). Among children aged 7-12 months, those who were breastfed had lower prevalence of G. lamblia infection than those who had been weaned (P = 0.012). Cryptosporidium infection is common among young Tanzanian children with diarrhea, particularly those living with HIV, and infection is more frequent during the rainy season. G. lamblia is frequently implicated in asymptomatic infections, but rarely causes overt diarrheal illness, and its prevalence increases with age.

Islet cell autoantibodies in African patients with Type 1 and Type 2 diabetes in Dar es Salaam Tanzania: a cross sectional study

PubMed Central

Lutale, JJK; Thordarson, H; Holm, PI; Eide, GE; Vetvik, K

2007-01-01

Background The aim of the present study was to assess the occurrence of glutamic acid decarboxylase autoantibodies (GADA) and insulinoma antigen 2 autoantibodies (IA2A) among patients of African origin in Dar es Salaam, Tanzania and to compare the occurrence of autoimmune mediated Type 1 diabetes with findings previously reported from the same place and from other African diabetic populations. Methods Two hundred and forty five patients from the diabetic clinic at Muhimbili Hospital were recruited for a cross sectional study. Patients were clinically classified into groups with Type 1 (T1D) and Type 2 diabetes (T2D); there were 94 patients with T1D and 151 with T2D. Autoantibodies for GAD and IA2 were measured with an assay based on radioligand binding. Fasting and random blood glucose, HbA1c, and C-peptide levels were also determined. Results Of the patients with T1D, 28 (29.8%) were GADA positive and 20 (21.3%) were IA2A positive. The overall occurrence of any autoantibody was 42.6%. The GAD and IA2 autoantibodies were detected more frequently among patients with T1D than among patients with T2D (P < 0.001). A higher autoantibody prevalence was observed with combined GADA and IA2A measurements compared to individual autoantibody measurements; 40 (42.6%) patients with T1D versus 11 (7.3%) with T2D had at least one positive autoantibody titer. There was no correlation between duration of disease and detection of autoantibodies in patients with T1D. There was a strong association with family history of diabetes among the autoantibody positive versus autoantibody negative patients with T1D (p < 0.01). Conclusion The prevalence of GAD and IA2 autoantibodies among African patients with T1D in Dar es Salaam was the same as that reported previously for South Africa and Ethiopia. It was much higher than the prevalence of islet cell autoantibodies (ICA) reported from the same clinic about 15 years ago. For unknown reasons the prevalence of pancreatic related autoantibodies in this African population is lower than the prevalence found among Caucasian populations. PMID:17963519

Ecosystem services and urban greenways: What's the public's perspective?

Treesearch

Lincoln R. Larson; Samuel J. Keith; Mariela Fernandez; Jeffrey C. Hallo; C. Scott Shafer; Viniece Jennings

2016-01-01

Ecosystem services (ES) are an important tool for quantifying the value of nature, yet there are often disconnects between services defined and measured by scientists and those that are realized and appreciated by the general public. Our study explored public perceptions of urban ES by examining benefits associated with greenways in two U.S. cities. Respondents (n =460...

25 Jahre - Institut fuer Geodaesie, Teil 2: Forschungsarbeiten und Veroeffentlichungen (25 Years - Institute of Geodesy, Part 2: Research Areas and Publications)

DTIC Science & Technology

2000-01-01

Georg von Neumayer" dar. Der geo- ddtische Beitrag zu dern interdisziplinlren Forschungsprojekt. ,,Massenhaushalt und Dyna - mik" umnfasst im wesentlichen...zu robustifizieren. Es sind dabei zwei Entwicklungslinien festzustellen. Die eine ver- sucht, die in der Statistik entwickelte Theorie auf geodaitische...Hampel, F.R.: Contributions to the theory of robust estimation. Ph.D. Thesis, University of California, Berkeley, 1968, Hampel, F.R.: A general qualitative

Using Adult Mosquitoes to Transfer Insecticides to Aedes Aegypti Larval Habitats

DTIC Science & Technology

2009-07-14

Playa , a municipality belonging to Ciudad de La Habana, Cuba. Rev Panam Salud Publica Pan Am J Public Health 19:379–384. 33. Harrington LC, et al...United Kingdom; bLaboratorio de Salud Publica, Iquitos, Peru; cIfakara Health Institute, Dar es Salaam, United Republic of Tanzania; dVector Group...Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom; eNaval Medical Research Center Detachment, United States Navy, Lima , Peru; and f

Leveraging strong social ties among young men in Dar es Salaam: A pilot intervention of microfinance and peer leadership for HIV and gender-based violence prevention

PubMed Central

Maman, Suzanne; Kajula, Lusajo; Balvanz, Peter; Kilonzo, Mrema Noel; Mulawa, Marta; Yamanis, Thespina

2015-01-01

Gender inequality is at the core of the HIV patterns that are evident in sub-Saharan Africa. Gender-based violence (GBV) and lack of economic opportunity are important structural determinants of HIV risk. We piloted a microfinance and health promotion intervention among social networks of primarily young men in Dar es Salaam. Twenty-two individuals participated in the microfinance component and 30 peer leaders were recruited and trained in the peer health leadership component. We collected and analyzed observational data from trainings, monitoring data on loan repayment, and reports of peer conversations to assess the feasibility and acceptability of the intervention. Eighteen of the loan recipients (82%) paid back their loans, and of these 15 (83%) received a second, larger loan. Among the loan defaulters, one died, one had chronic health problems, and two disappeared, one of whom was imprisoned for theft. The majority of conversations reported by peer health leaders focused on condoms, sexual partner selection and HIV testing. Few peer leaders reported conversations about GBV. We demonstrated the feasibility and acceptability of this innovative HIV and GBV prevention intervention. The lessons learned from this pilot have informed the implementation of a cluster-randomized trial of the microfinance and peer health leadership intervention. PMID:26588115

Lubricant use and condom use during anal sex in men who have sex with men in Tanzania.

PubMed

Romijnders, Kim Agj; Nyoni, Joyce E; Ross, Michael W; McCurdy, Sheryl A; Mbwambo, Jessie; Kok, Gerjo; Crutzen, Rik

2016-12-01

The lack of data on condom and lubricant use among African men who have sex with men (MSM) hinders prevention efforts. We describe use, knowledge, and access to lubricants in Dar es Salaam and Tanga, Tanzania. Data were collected in 2012 and 2013 from a cross-sectional survey of 200 MSM in Dar es Salaam and 100 MSM in Tanga, Tanzania. The most common reason for not using condoms was dislike of condoms. Two-thirds of the men reported always using a lubricant for anal sex. Results showed that: fewer men who have sex with both men and women (MSMW) know about lubricants; more MSM look for, have difficulty finding, and find lubricants to be expensive; and MSM use lubricants to facilitate penetration. MSMW commonly receive their lubricants from their sexual partner, while MSM got them from friends and pharmacies. HIV-negative MSM used lubricants to facilitate penetration and reduce pain. HIV-positive MSM are likely to get their lubricants from pharmacies or friends. MSMW use Vaseline® significantly more than MSM as a lubricant. Results suggest that HIV prevention knowledge among MSM is greater, so HIV prevention efforts should emphasise carrying water-based lubricant among MSMW. Consequently, there is an opportunity to co-market condoms and water-based lubricants. © The Author(s) 2016.

Role of traditional healers in psychosocial support in caring for the orphans: a case of Dar-es Salaam City, Tanzania.

PubMed

Kayombo, Edmund J; Mbwambo, Zakaria H; Massila, Mariam

2005-07-29

Orphans are an increasing problem in developing countries particularly in Africa; due to the HIV/AIDS pandemic; and needs collective effort in intervention processes by including all stakeholders right from the grass roots level. This paper attempts to present the role of traditional healers in psychosocial support for orphan children in Dar-es-Salaam City with special focus on those whose parents have died because of HIV/AIDS. Six traditional healers who were involved in taking care of orphans were visited at their "vilinge" (traditional clinics). In total they had 72 orphans, 31 being boys and 41 being girls with age range from 3 years to 19. It was learned that traditional healers, besides providing remedies for illnesses/diseases of orphans, they also provided other basic needs. Further, they even provided psychosocial support allowing children to cope with orphan hood life with ease. Traditional healers are living within communities at the grass roots level; and appear unnoticed hidden forces, which are involved in taking care of orphans. This role of traditional healers in taking care of orphans needs to be recognised and even scaling it up by empowering them both in financial terms and training in basic skills of psychosocial techniques in how to handle orphans, in order to reduce discrimination and stigmatisation in the communities where they live.

Red blood cell indices and prevalence of hemoglobinopathies and glucose 6 phosphate dehydrogenase deficiencies in male Tanzanian residents of Dar es Salaam.

PubMed

Mwakasungula, Solomon; Schindler, Tobias; Jongo, Said; Moreno, Elena; Kamaka, Kasimu; Mohammed, Mgeni; Joseph, Selina; Rashid, Ramla; Athuman, Thabit; Tumbo, Anneth Mwasi; Hamad, Ali; Lweno, Omar; Tanner, Marcel; Shekalaghe, Seif; Daubenberger, Claudia A

2014-01-01

Hemoglobinopathies, disorders of hemoglobin structure and production, are one of the most common monogenic disorders in humans. Glucose 6 phosphate dehydrogenase deficiency (G6PD) is an inherited enzymopathy resulting in increased oxygen stress susceptibility of red blood cells. The distributions of these genetic traits in populations living in tropical and subtropical regions where malaria has been or is still present are thought to result from survival advantage against severe life threatening malaria disease. 384 male Tanzanian volunteers residing in Dar es Salaam were typed for G6PD, sickle cell disease and α-thalassemia. The most prominent red blood cell polymorphism was heterozygous α(+)-thalassemia (37.8%), followed by the G6PD(A) deficiency (16.4%), heterozygous sickle cell trait (15.9%), G6PD(A-) deficiency (13.5%) and homozygous α(+)-thalassemia (5.2%). 35%, 45%, 17% and 3% of these volunteers were carriers of wild type gene loci, one, two or three of these hemoglobinopathies, respectively. We find that using a cut off value of 28.6 pg. for mean corpuscular hemoglobin (MCH), heterozygous α(+)-thalassemia can be predicted with a sensitivity of 84% and specificity of 72% in this male population. All subjects carrying homozygous α(+)-thalassemia were identified based on their MCH value < 28.6 pg.

From multifunctionality to multiple ecosystem services? A conceptual framework for multifunctionality in green infrastructure planning for urban areas.

PubMed

Hansen, Rieke; Pauleit, Stephan

2014-05-01

Green infrastructure (GI) and ecosystem services (ES) are promoted as concepts that have potential to improve environmental planning in urban areas based on a more holistic understanding of the complex interrelations and dynamics of social-ecological systems. However, the scientific discourses around both concepts still lack application-oriented frameworks that consider such a holistic perspective and are suitable to mainstream GI and ES in planning practice. This literature review explores how multifunctionality as one important principle of GI planning can be operationalized by approaches developed and tested in ES research. Specifically, approaches developed in ES research can help to assess the integrity of GI networks, balance ES supply and demand, and consider trade-offs. A conceptual framework for the assessment of multifunctionality from a social-ecological perspective is proposed that can inform the design of planning processes and support stronger exchange between GI and ES research.

Edge-to-Stem Variability in Wet-Canopy Evaporation From an Urban Tree Row

NASA Astrophysics Data System (ADS)

Van Stan, John T.; Norman, Zachary; Meghoo, Adrian; Friesen, Jan; Hildebrandt, Anke; Côté, Jean-François; Underwood, S. Jeffrey; Maldonado, Gustavo

2017-11-01

Evaporation from wet-canopy (E_C) and stem (E_S) surfaces during rainfall represents a significant portion of municipal-to-global scale hydrologic cycles. For urban ecosystems, E_C and E_S dynamics play valuable roles in stormwater management. Despite this, canopy-interception loss studies typically ignore crown-scale variability in E_C and assume (with few indirect data) that E_S is generally {<}2% of total wet-canopy evaporation. We test these common assumptions for the first time with a spatially-distributed network of in-canopy meteorological monitoring and 45 surface temperature sensors in an urban Pinus elliottii tree row to estimate E_C and E_S under the assumption that crown surfaces behave as "wet bulbs". From December 2015 through July 2016, 33 saturated crown periods (195 h of 5-min observations) were isolated from storms for determination of 5-min evaporation rates ranging from negligible to 0.67 mm h^{-1}. Mean E_S (0.10 mm h^{-1}) was significantly lower (p < 0.01) than mean E_C (0.16 mm h^{-1}). But, E_S values often equalled E_C and, when scaled to trunk area using terrestrial lidar, accounted for 8-13% (inter-quartile range) of total wet-crown evaporation (E_S+E_C scaled to surface area). E_S contributions to total wet-crown evaporation maximized at 33%, showing a general underestimate (by 2-17 times) of this quantity in the literature. Moreover, results suggest wet-crown evaporation from urban tree rows can be adequately estimated by simply assuming saturated tree surfaces behave as wet bulbs, avoiding problematic assumptions associated with other physically-based methods.

Insecticide resistance mechanisms associated with different environments in the malaria vector Anopheles gambiae: a case study in Tanzania

PubMed Central

2014-01-01

Background Resistance of mosquitoes to insecticides is a growing concern in Africa. Since only a few insecticides are used for public health and limited development of new molecules is expected in the next decade, maintaining the efficacy of control programmes mostly relies on resistance management strategies. Developing such strategies requires a deep understanding of factors influencing resistance together with characterizing the mechanisms involved. Among factors likely to influence insecticide resistance in mosquitoes, agriculture and urbanization have been implicated but rarely studied in detail. The present study aimed at comparing insecticide resistance levels and associated mechanisms across multiple Anopheles gambiae sensu lato populations from different environments. Methods Nine populations were sampled in three areas of Tanzania showing contrasting agriculture activity, urbanization and usage of insecticides for vector control. Insecticide resistance levels were measured in larvae and adults through bioassays with deltamethrin, DDT and bendiocarb. The distribution of An. gambiae sub-species and pyrethroid target-site mutations (kdr) were investigated using molecular assays. A microarray approach was used for identifying transcription level variations associated to different environments and insecticide resistance. Results Elevated resistance levels to deltamethrin and DDT were identified in agriculture and urban areas as compared to the susceptible strain Kisumu. A significant correlation was found between adult deltamethrin resistance and agriculture activity. The subspecies Anopheles arabiensis was predominant with only few An. gambiae sensu stricto identified in the urban area of Dar es Salaam. The L1014S kdr mutation was detected at elevated frequency in An gambiae s.s. in the urban area but remains sporadic in An. arabiensis specimens. Microarrays identified 416 transcripts differentially expressed in any area versus the susceptible reference strain and supported the impact of agriculture on resistance mechanisms with multiple genes encoding pesticide targets, detoxification enzymes and proteins linked to neurotransmitter activity affected. In contrast, resistance mechanisms found in the urban area appeared more specific and more related to the use of insecticides for vector control. Conclusions Overall, this study confirmed the role of the environment in shaping insecticide resistance in mosquitoes with a major impact of agriculture activities. Results are discussed in relation to resistance mechanisms and the optimization of resistance management strategies. PMID:24460952

Geometric validation of a mobile laser scanning system for urban applications

NASA Astrophysics Data System (ADS)

Guan, Haiyan; Li, Jonathan; Yu, Yongtao; Liu, Yan

2016-03-01

Mobile laser scanning (MLS) technologies have been actively studied and implemented over the past decade, as their application fields are rapidly expanding and extending beyond conventional topographic mapping. Trimble's MX-8, as one of the MLS systems in the current market, generates rich survey-grade laser and image data for urban surveying. The objective of this study is to evaluate whether Trimble MX-8 MLS data satisfies the accuracy requirements of urban surveying. According to the formula of geo-referencing, accuracies of navigation solution and laser scanner determines the accuracy of the collected LiDAR point clouds. Two test sites were selected to test the performance of Trimble MX-8. Those extensive tests confirm that Trimble MX-8 offers a very promising tool to survey complex urban areas.

Developpement et application d'un systeme mobile de laser terrestre pour quantifier le bilan sedimentaire des plages

NASA Astrophysics Data System (ADS)

Van-Wierts, Stefanie

Au Québec maritime, l'érosion côtière est une problématique d'envergure, notamment sur les côtes de formations meubles. Les plages ont un rôle de zone tampon ayant comme fonction naturelle d'absorber l'énergie des vagues et donc d'assurer l'équilibre de certains écosystèmes et le maintien de l'écoumène en réduisant l'érosion de la côte. Les méthodes d'acquisition conventionnelles ne permettent pas de quantifier convenablement les changements morphosédimentaires d'une plage à l'échelle des cellules hydrosédimentaires. Le manque de méthode d'acquisition fiable et de données quantitatives mène à une surestimation ou à une sous-estimation de la disponibilité sédimentaire d'un système côtier. Pour contrer ces lacunes et afin de minimiser les coûts d'acquisition, un nouveau système mobile de LiDAR terrestre a été mis en place, permettant d'acquérir des données topographiques de l'estran, de la haute plage et des falaises. Le système multicapteurs comprend un LiDAR, un système de navigation à haute précision (IMU et D-GPS) et une caméra. L'ensemble des instruments et capteurs sont montés sur un véhicule de type tout-terrain. Le système a été évalué sur la zone côtière de la péninsule de Manicouagan. La comparaison des données LiDAR avec 1 050 points de référence géopositionnés au D-GPS montre une erreur verticale moyenne de 0,1 m sur les secteurs de plage. Les résultats montrent que le volume sédimentaire moyen des plages devant les zones où la ligne de rivage présente un ouvrage de protection en enrochement (12 m 3/m) est plus de trois fois plus faible que devant les secteurs à l'état naturel (35,5 m3/m). La moyenne des secteurs en transition, constituant les segments où une zone artificielle et une zone naturelle se chevauchent présentent un volume moyen de 28 m3/m. Aussi, les plages devant les secteurs anthropisés sont en moyenne près de 2 fois plus étroites (12,7 m) que devant les secteurs naturels (25,4 m). Un indice de bilan sédimentaire des plages a été testé et il constitue un excellent proxy pour évaluer la disponibilité sédimentaire des plages ainsi qu'identifier les secteurs déficitaires. La réalisation d'une couverture complète au LiDAR a permis de constater que des profils de plage réalisés à un intervalle de plus de 200 m sur des côtes diversifiées mènent à des résultats significativement différents de la réalité. Par contre, il semble que l'intervalle des profils à peu d'impact sur de longs secteurs de plages uniformes.

Use of LiDAR for calculating solar irradiance on roofs and façades of buildings at city scale: Methodology, validation, and analysis

NASA Astrophysics Data System (ADS)

Cheng, Liang; Xu, Hao; Li, Shuyi; Chen, Yanming; Zhang, Fangli; Li, Manchun

2018-04-01

As the rate of urbanization continues to accelerate, the utilization of solar energy in buildings plays an increasingly important role in sustainable urban development. For this purpose, we propose a LiDAR-based joint approach for calculating the solar irradiance incident on roofs and façades of buildings at city scale, which includes a methodology for calculating solar irradiance, the validation of the proposed method, and analysis of its application. The calculation of surface irradiance on buildings may then inform photovoltaic power generation simulations, architectural design, and urban energy planning. Application analyses of the proposed method in the experiment area found that: (1) Global and direct irradiations vary significantly by hour, day, month and season, both following the same trends; however, diffuse irradiance essentially remains unchanged over time. (2) Roof irradiation, but not façade irradiation, displays distinct time-dependent patterns. (3) Global and direct irradiations on roofs are highly correlated with roof aspect and slope, with high global and direct irradiations observed on roofs of aspect 100-250° and slopes of 0-60°, whereas diffuse irradiation on roofs is only affected by roof slope. (4) The façade of a building receives higher levels of global and direct irradiations if facing southeast, south, and southwest; however, diffuse irradiation remains constant regardless of façade orientation.

Real-time full-motion color Flash lidar for target detection and identification

NASA Astrophysics Data System (ADS)

Nelson, Roy; Coppock, Eric; Craig, Rex; Craner, Jeremy; Nicks, Dennis; von Niederhausern, Kurt

2015-05-01

Greatly improved understanding of areas and objects of interest can be gained when real time, full-motion Flash LiDAR is fused with inertial navigation data and multi-spectral context imagery. On its own, full-motion Flash LiDAR provides the opportunity to exploit the z dimension for improved intelligence vs. 2-D full-motion video (FMV). The intelligence value of this data is enhanced when it is combined with inertial navigation data to produce an extended, georegistered data set suitable for a variety of analysis. Further, when fused with multispectral context imagery the typical point cloud now becomes a rich 3-D scene which is intuitively obvious to the user and allows rapid cognitive analysis with little or no training. Ball Aerospace has developed and demonstrated a real-time, full-motion LIDAR system that fuses context imagery (VIS to MWIR demonstrated) and inertial navigation data in real time, and can stream these information-rich geolocated/fused 3-D scenes from an airborne platform. In addition, since the higher-resolution context camera is boresighted and frame synchronized to the LiDAR camera and the LiDAR camera is an array sensor, techniques have been developed to rapidly interpolate the LIDAR pixel values creating a point cloud that has the same resolution as the context camera, effectively creating a high definition (HD) LiDAR image. This paper presents a design overview of the Ball TotalSight™ LIDAR system along with typical results over urban and rural areas collected from both rotary and fixed-wing aircraft. We conclude with a discussion of future work.

Automatic tree parameter extraction by a Mobile LiDAR System in an urban context.

PubMed

Herrero-Huerta, Mónica; Lindenbergh, Roderik; Rodríguez-Gonzálvez, Pablo

2018-01-01

In an urban context, tree data are used in city planning, in locating hazardous trees and in environmental monitoring. This study focuses on developing an innovative methodology to automatically estimate the most relevant individual structural parameters of urban trees sampled by a Mobile LiDAR System at city level. These parameters include the Diameter at Breast Height (DBH), which was estimated by circle fitting of the points belonging to different height bins using RANSAC. In the case of non-circular trees, DBH is calculated by the maximum distance between extreme points. Tree sizes were extracted through a connectivity analysis. Crown Base Height, defined as the length until the bottom of the live crown, was calculated by voxelization techniques. For estimating Canopy Volume, procedures of mesh generation and α-shape methods were implemented. Also, tree location coordinates were obtained by means of Principal Component Analysis. The workflow has been validated on 29 trees of different species sampling a stretch of road 750 m long in Delft (The Netherlands) and tested on a larger dataset containing 58 individual trees. The validation was done against field measurements. DBH parameter had a correlation R2 value of 0.92 for the height bin of 20 cm which provided the best results. Moreover, the influence of the number of points used for DBH estimation, considering different height bins, was investigated. The assessment of the other inventory parameters yield correlation coefficients higher than 0.91. The quality of the results confirms the feasibility of the proposed methodology, providing scalability to a comprehensive analysis of urban trees.

Automatic tree parameter extraction by a Mobile LiDAR System in an urban context

PubMed Central

Lindenbergh, Roderik; Rodríguez-Gonzálvez, Pablo

2018-01-01

In an urban context, tree data are used in city planning, in locating hazardous trees and in environmental monitoring. This study focuses on developing an innovative methodology to automatically estimate the most relevant individual structural parameters of urban trees sampled by a Mobile LiDAR System at city level. These parameters include the Diameter at Breast Height (DBH), which was estimated by circle fitting of the points belonging to different height bins using RANSAC. In the case of non-circular trees, DBH is calculated by the maximum distance between extreme points. Tree sizes were extracted through a connectivity analysis. Crown Base Height, defined as the length until the bottom of the live crown, was calculated by voxelization techniques. For estimating Canopy Volume, procedures of mesh generation and α-shape methods were implemented. Also, tree location coordinates were obtained by means of Principal Component Analysis. The workflow has been validated on 29 trees of different species sampling a stretch of road 750 m long in Delft (The Netherlands) and tested on a larger dataset containing 58 individual trees. The validation was done against field measurements. DBH parameter had a correlation R2 value of 0.92 for the height bin of 20 cm which provided the best results. Moreover, the influence of the number of points used for DBH estimation, considering different height bins, was investigated. The assessment of the other inventory parameters yield correlation coefficients higher than 0.91. The quality of the results confirms the feasibility of the proposed methodology, providing scalability to a comprehensive analysis of urban trees. PMID:29689076

Peer network influence on intimate partner violence perpetration among urban Tanzanian men.

PubMed

Mulawa, Marta I; Kajula, Lusajo J; Maman, Suzanne

2018-04-01

Male perpetration of intimate partner violence (IPV) against women in Tanzania is widespread. Theory and empirical evidence suggest peer networks may play an important role in shaping IPV perpetration, although research on this topic in sub-Saharan Africa is limited. Grounded in social learning theory, social influence theory, and the theory of gender and power, the purpose of this study was to examine whether and how peer networks influence men's perpetration of IPV in Dar es Salaam, Tanzania. We conducted in-depth interviews (n = 40) with a sub-sample of 20 men enrolled in the control condition of an ongoing cluster-randomised controlled trial. We purposively sampled participants who previously reported perpetrating physical IPV. To analyse the data, we generated narrative summaries and conducted thematic and interpretative coding. We saw no evidence that men self-selected into peer networks with certain values or behaviours. Rather, men described several mechanisms through which their peers influenced the perpetration of IPV, including: (1) the internalisation of peer network norms, (2) pressure to conform to peer network norms and (3) the direct involvement of peers in shaping couple power dynamics. Our findings suggest that peer networks influence men's perpetration of IPV and should be targeted in future programmes and interventions.

Urban fire risk control: House design, upgrading and replanning

PubMed Central

Mbuya, Elinorata Celestine

2018-01-01

Urbanisation leads to house densification, a phenomenon experienced in both planned and unplanned settlements in cities in developing countries. Such densification limits fire brigade access into settlements, thereby aggravating fire disaster risks. In this article, we assess the fire exposure and risks in residences in informal areas of Mchikichini ward, in Dar es Salaam City, Tanzania. We rely on interviews of residents and government officials to obtain background on the occurrence and causes of fire accidents, policy provisions and regulations, and experiences with fire outbreaks and coping strategies, as well as on observations and measurements of house transformations, spatial quality and indoor real life. Our findings suggest that fire risks arise from both inappropriate structural characteristics and unsound behavioural practices. This includes unsafe electric practices by residents, poor capacity of residents to fight fires once started, limited access to structures by firefighting equipment because of flouting of planning regulations and inadequate awareness of local government leaders of the magnitude of fire risks. Potential changes to reduce fire risks in the settlement include the installation of firefighting systems, restriction of cooking to designated spaces, use of safer cooking energy sources and lighting means, improvements of vehicle access routes to neighbourhoods, capacity building at the grass root level and the establishment of community-based fire risk management.

An improved mosquito electrocuting trap that safely reproduces epidemiologically relevant metrics of mosquito human-feeding behaviours as determined by human landing catch.

PubMed

Govella, Nicodem J; Maliti, Deodatus F; Mlwale, Amos T; Masallu, John P; Mirzai, Nosrat; Johnson, Paul C D; Ferguson, Heather M; Killeen, Gerry F

2016-09-13

Reliable quantification of mosquito host-seeking behaviours is required to determine the efficacy of vector control methods. For malaria, the gold standard approach remains the risky human landing catch (HLC). Here compare the performance of an improved prototype of the mosquito electrocuting grid trap (MET) as a safer alternative with HLC for measuring malaria vector behaviour in Dar es Salaam, Tanzania. Mosquito trapping was conducted at three sites within Dar es Salaam representing a range of urbanicity over a 7-month period (December 2012-July 2013, 168 sampling nights). At each site, sampling was conducted in a block of four houses, with two houses being allocated to HLC and the other to MET on each night of study. Sampling was conducted both indoors and outdoors (from 19:00 to 06:00 each night) at all houses, with trapping method (HLC and MET) being exchanged between pairs of houses at each site using a crossover design. The MET caught significantly more Anopheles gambiae sensu lato than the HLC, both indoors (RR [95 % confidence interval (CI)]) = 1.47 [1.23-1.76], P < 0.0001 and outdoors = 1.38 [1.14-1.67], P < 0.0001). The sensitivity of MET compared with HLC did not detectably change over the course of night for either An. gambiae s.l. (OR [CI]) = 1.01 [0.94-1.02], P = 0.27) or Culex spp. (OR [CI]) = 0.99 [0.99-1.0], P = 0.17) indoors and declined only slightly outdoors: An. gambiae s.l. (OR [CI]) = 0.92 [0.86-0.99], P = 0.04), and Culex spp. (OR [CI]) = 0.99 [0.98-0.99], P = 0.03). MET-based estimates of the proportions of mosquitoes caught indoors (P i ) or during sleeping hours (P fl ), as well as the proportion of human exposure to bites that would otherwise occurs indoors (π i ), were statistically indistinguishable from those based on HLC for An. gambiae s.l. (P = 0.43, 0.07 and 0.48, respectively) and Culex spp. (P = 0.76, 0.24 and 0.55, respectively). This improved MET prototype is highly sensitive tool that accurately quantifies epidemiologically-relevant metrics of mosquito biting densities, behaviours and human exposure distribution.

Translucent Procedures, Abstraction without Opacity

DTIC Science & Technology

1993-10-01

Justi1ficatilon By- Distribut •c._/ rAviiii andi or Dist Sp• ialI I ..da A Guillermo Rozas Mazo (1931-1990). c~uyo desco de dar a sus hijos la cducaci6n... que dI no pudo recibir. con este trabajo realizo. Lo proinetido es deuda. Acknowledgments There are many people to whom I owe my sanity and to whom I...constant value). This expression gives us the value of the last unknown. 4. Once the residual system is solved, compute the value of the eliminated un

Estimating KC-137 Aircraft Ownership Costs in the Brazilian Air Force

DTIC Science & Technology

1997-06-01

Cycle Costing A-1 M manpower m meter Maint. Maintenance Mainten. Maintenance O&S Operation and Support OPAC Online Public Access Catalog PAMAGL Parque ...1.2 e 1.3. ))as informag6es quanto a pagarnento dar~o urn pouco de trabaiho, mas creio que podern ser conseguidas na tesouraria do Parque . N~o basta...pela Base na manutengo das aeronaves (e que n~o sejam fornecidos pelo Parque ), tais como gaxetas, componentes eletr6nicos, brocas, produtos qufmicos, etc

Al-Shebab: An Al-Qaeda Affiliate Case Study (2Rev)

DTIC Science & Technology

2017-10-01

explosives and car bombs . Al-Shebab’s joining Al-Qaeda had mutual benefits: AQ’s presence in East Africa dates to Osama Bin Laden’s time in Sudan...1992–1996) and the establishment of cells that perpetrated the August 7, 1998 bombings of the U.S. embassies in Nairobi, Kenya, and Dar es Salaam...to build an emirate in the Gedo region, but the project was crushed by Ethiopian forces after AIAI perpetrated several bombings in Ethiopia.25 The

Nocturnal haemoglobin oxygen desaturation in urban and rural East African paediatric cohorts with and without sickle cell anaemia: a cross-sectional study.

PubMed

L'Esperance, V S; Ekong, T; Cox, S E; Makani, J; Newton, C R; Soka, D; Komba, A; Kirkham, F J; Hill, C M

2016-04-01

Low haemoglobin oxygen saturation (SpO2) predicts complications in children with sickle cell anaemia (SCA) in the North but there are few data from Africa, where the majority of the patients reside. We measured daytime and overnight SpO2 in children with SCA in routine follow-up clinic, and controls without symptoms of SCA, comparing rural (Kilifi, Kenya) and urban (Dar-es-Salaam, Tanzania) cohorts. Daytime SpO2 was lower in 65 Tanzanian children with SCA (TS; median 97 (IQR 94-100)%); p<0.0001) than in 113 Kenyan children with SCA (KS; 99 (98-100)%) and 20 Tanzanian controls (TC; 100 (98-100)%). Compared with 95 Kenyan children with SCA, in 54 Tanzanian children with SCA and 19 TC who returned for overnight oximetry, mean (KS 99.0 (96.7-99.8)%; TS 97.9 (95.4-99.3)%; TC 98.4 (97.5-99.1)%; p=0.01) and minimum nocturnal SpO2 (92 (86-95)%; 87 (78.5-91)%; 90 (83.5-93)% p=0.0001) were lower. The difference between children with SCA persisted after adjustment for haemoglobin (p=0.004). Urban Tanzanian children, with and without SCA, experience greater exposure to low daytime and night-time SpO2 compared with rural Kenyan children with SCA. Possible explanations include differences in the prevalence of obstructive sleep apnoea or asthma, alterations in the oxyhaemoglobin desaturation curve or cardiovascular compromise, for example, to shunting at atrial or pulmonary level secondary to increased pulmonary artery pressure. The fact that non-SCA siblings in the urban area are also affected suggests that environmental exposures, for example, air pollution, nutrition or physical exercise, may play a role. Further studies should determine aetiology and clinical relevance for the SCA phenotype in children resident in Africa. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Lymphatic filariasis patient identification in a large urban area of Tanzania: An application of a community-led mHealth system.

PubMed

Mwingira, Upendo; Chikawe, Maria; Mandara, Wilfred Lazarus; Mableson, Hayley E; Uisso, Cecilia; Mremi, Irene; Malishee, Alpha; Malecela, Mwele; Mackenzie, Charles D; Kelly-Hope, Louise A; Stanton, Michelle C

2017-07-01

Lymphatic filariasis (LF) is best known for the disabling and disfiguring clinical conditions that infected patients can develop; providing care for these individuals is a major goal of the Global Programme to Eliminate LF. Methods of locating these patients, knowing their true number and thus providing care for them, remains a challenge for national medical systems, particularly when the endemic zone is a large urban area. A health community-led door-to-door survey approach using the SMS reporting tool MeasureSMS-Morbidity was used to rapidly collate and monitor data on LF patients in real-time (location, sex, age, clinical condition) in Dar es Salaam, Tanzania. Each stage of the phased study carried out in the three urban districts of city consisted of a training period, a patient identification and reporting period, and a data verification period, with refinements to the system being made after each phase. A total of 6889 patients were reported (133.6 per 100,000 population), of which 4169 were reported to have hydrocoele (80.9 per 100,000), 2251 lymphoedema-elephantiasis (LE) (43.7 per 100,000) and 469 with both conditions (9.1 per 100,000). Kinondoni had the highest number of reported patients in absolute terms (2846, 138.9 per 100,000), followed by Temeke (2550, 157.3 per 100,000) and Ilala (1493, 100.5 per 100,000). The number of hydrocoele patients was almost twice that of LE in all three districts. Severe LE patients accounted for approximately a quarter (26.9%) of those reported, with the number of acute attacks increasing with reported LE severity (1.34 in mild cases, 1.78 in moderate cases, 2.52 in severe). Verification checks supported these findings. This system of identifying, recording and mapping patients affected by LF greatly assists in planning, locating and prioritising, as well as initiating, appropriate morbidity management and disability prevention (MMDP) activities. The approach is a feasible framework that could be used in other large urban environments in the LF endemic areas.

Clustering of Multispectral Airborne Laser Scanning Data Using Gaussian Decomposition

NASA Astrophysics Data System (ADS)

Morsy, S.; Shaker, A.; El-Rabbany, A.

2017-09-01

With the evolution of the LiDAR technology, multispectral airborne laser scanning systems are currently available. The first operational multispectral airborne LiDAR sensor, the Optech Titan, acquires LiDAR point clouds at three different wavelengths (1.550, 1.064, 0.532 μm), allowing the acquisition of different spectral information of land surface. Consequently, the recent studies are devoted to use the radiometric information (i.e., intensity) of the LiDAR data along with the geometric information (e.g., height) for classification purposes. In this study, a data clustering method, based on Gaussian decomposition, is presented. First, a ground filtering mechanism is applied to separate non-ground from ground points. Then, three normalized difference vegetation indices (NDVIs) are computed for both non-ground and ground points, followed by histograms construction from each NDVI. The Gaussian function model is used to decompose the histograms into a number of Gaussian components. The maximum likelihood estimate of the Gaussian components is then optimized using Expectation - Maximization algorithm. The intersection points of the adjacent Gaussian components are subsequently used as threshold values, whereas different classes can be clustered. This method is used to classify the terrain of an urban area in Oshawa, Ontario, Canada, into four main classes, namely roofs, trees, asphalt and grass. It is shown that the proposed method has achieved an overall accuracy up to 95.1 % using different NDVIs.

Mapping Urban Ecosystem Services Using High Resolution Aerial Photography

NASA Astrophysics Data System (ADS)

Pilant, A. N.; Neale, A.; Wilhelm, D.

2010-12-01

Ecosystem services (ES) are the many life-sustaining benefits we receive from nature: e.g., clean air and water, food and fiber, cultural-aesthetic-recreational benefits, pollination and flood control. The ES concept is emerging as a means of integrating complex environmental and economic information to support informed environmental decision making. The US EPA is developing a web-based National Atlas of Ecosystem Services, with a component for urban ecosystems. Currently, the only wall-to-wall, national scale land cover data suitable for this analysis is the National Land Cover Data (NLCD) at 30 m spatial resolution with 5 and 10 year updates. However, aerial photography is acquired at higher spatial resolution (0.5-3 m) and more frequently (1-5 years, typically) for most urban areas. Land cover was mapped in Raleigh, NC using freely available USDA National Agricultural Imagery Program (NAIP) with 1 m ground sample distance to test the suitability of aerial photography for urban ES analysis. Automated feature extraction techniques were used to extract five land cover classes, and an accuracy assessment was performed using standard techniques. Results will be presented that demonstrate applications to mapping ES in urban environments: greenways, corridors, fragmentation, habitat, impervious surfaces, dark and light pavement (urban heat island). Automated feature extraction results mapped over NAIP color aerial photograph. At this scale, we can look at land cover and related ecosystem services at the 2-10 m scale. Small features such as individual trees and sidewalks are visible and mappable. Classified aerial photo of Downtown Raleigh NC Red: impervious surface Dark Green: trees Light Green: grass Tan: soil

The Registration and Segmentation of Heterogeneous Laser Scanning Data

NASA Astrophysics Data System (ADS)

Al-Durgham, Mohannad M.

Light Detection And Ranging (LiDAR) mapping has been emerging over the past few years as a mainstream tool for the dense acquisition of three dimensional point data. Besides the conventional mapping missions, LiDAR systems have proven to be very useful for a wide spectrum of applications such as forestry, structural deformation analysis, urban mapping, and reverse engineering. The wide application scope of LiDAR lead to the development of many laser scanning technologies that are mountable on multiple platforms (i.e., airborne, mobile terrestrial, and tripod mounted), this caused variations in the characteristics and quality of the generated point clouds. As a result of the increased popularity and diversity of laser scanners, one should address the heterogeneous LiDAR data post processing (i.e., registration and segmentation) problems adequately. Current LiDAR integration techniques do not take into account the varying nature of laser scans originating from various platforms. In this dissertation, the author proposes a methodology designed particularly for the registration and segmentation of heterogeneous LiDAR data. A data characterization and filtering step is proposed to populate the points' attributes and remove non-planar LiDAR points. Then, a modified version of the Iterative Closest Point (ICP), denoted by the Iterative Closest Projected Point (ICPP) is designed for the registration of heterogeneous scans to remove any misalignments between overlapping strips. Next, a region-growing-based heterogeneous segmentation algorithm is developed to ensure the proper extraction of planar segments from the point clouds. Validation experiments show that the proposed heterogeneous registration can successfully align airborne and terrestrial datasets despite the great differences in their point density and their noise level. In addition, similar testes have been conducted to examine the heterogeneous segmentation and it is shown that one is able to identify common planar features in airborne and terrestrial data without resampling or manipulating the data in any way. The work presented in this dissertation provides a framework for the registration and segmentation of airborne and terrestrial laser scans which has a positive impact on the completeness of the scanned feature. Therefore, the derived products from these point clouds have higher accuracy as seen in the full manuscript.

Geomorphic floodplain with organic matter (biomass) estimates for Fanno Creek, Oregon

USGS Publications Warehouse

Sobieszczyk, Steven

2011-01-01

Fanno Creek is a tributary to the Tualatin River and flows though parts of the southwest Portland metropolitan area. The stream is heavily influenced by urban runoff and shows characteristic flashy streamflow and poor water quality commonly associated with urban streams. This data set represents the geomorphic floodplain as derived from light detection and ranging (LiDAR) data and aerial photographic imagery. The floodplain represents current conditions including both anthropogenic alterations and natural historic floodplain features. The floodplain dataset is divided into 13 reach segments and attributed with corresponding organic material load estimates for each reach.

Automatic 3d Building Model Generations with Airborne LiDAR Data

NASA Astrophysics Data System (ADS)

Yastikli, N.; Cetin, Z.

2017-11-01

LiDAR systems become more and more popular because of the potential use for obtaining the point clouds of vegetation and man-made objects on the earth surface in an accurate and quick way. Nowadays, these airborne systems have been frequently used in wide range of applications such as DEM/DSM generation, topographic mapping, object extraction, vegetation mapping, 3 dimensional (3D) modelling and simulation, change detection, engineering works, revision of maps, coastal management and bathymetry. The 3D building model generation is the one of the most prominent applications of LiDAR system, which has the major importance for urban planning, illegal construction monitoring, 3D city modelling, environmental simulation, tourism, security, telecommunication and mobile navigation etc. The manual or semi-automatic 3D building model generation is costly and very time-consuming process for these applications. Thus, an approach for automatic 3D building model generation is needed in a simple and quick way for many studies which includes building modelling. In this study, automatic 3D building models generation is aimed with airborne LiDAR data. An approach is proposed for automatic 3D building models generation including the automatic point based classification of raw LiDAR point cloud. The proposed point based classification includes the hierarchical rules, for the automatic production of 3D building models. The detailed analyses for the parameters which used in hierarchical rules have been performed to improve classification results using different test areas identified in the study area. The proposed approach have been tested in the study area which has partly open areas, forest areas and many types of the buildings, in Zekeriyakoy, Istanbul using the TerraScan module of TerraSolid. The 3D building model was generated automatically using the results of the automatic point based classification. The obtained results of this research on study area verified that automatic 3D building models can be generated successfully using raw LiDAR point cloud data.

Weakly Supervised Segmentation-Aided Classification of Urban Scenes from 3d LIDAR Point Clouds

NASA Astrophysics Data System (ADS)

Guinard, S.; Landrieu, L.

2017-05-01

We consider the problem of the semantic classification of 3D LiDAR point clouds obtained from urban scenes when the training set is limited. We propose a non-parametric segmentation model for urban scenes composed of anthropic objects of simple shapes, partionning the scene into geometrically-homogeneous segments which size is determined by the local complexity. This segmentation can be integrated into a conditional random field classifier (CRF) in order to capture the high-level structure of the scene. For each cluster, this allows us to aggregate the noisy predictions of a weakly-supervised classifier to produce a higher confidence data term. We demonstrate the improvement provided by our method over two publicly-available large-scale data sets.

Acting within an increasingly confined space: A qualitative study of sexual behaviours and healthcare needs among men who have sex with men in a provincial Tanzanian city.

PubMed

Larsson, Markus; Mohamed Shio, Jasmine; Ross, Michael W; Agardh, Anette

2017-01-01

To explore risk perceptions, sexual practices and healthcare needs among men who have sex with men in the provincial city of Tanga in northern Tanzania. Previous research suggests that HIV/STIs are increasing problems for this population. Yet, few studies have been conducted outside the urban area of Dar es Salaam, which has limited our knowledge about the HIV/STI risk factors and healthcare needs among men who have sex with men who live outside major metropolitan areas. During three months in 2013, 10 in-depth interviews with men who have sex with men were conducted in Tanga. Data were interpreted through qualitative content analysis. The theme that emerged was labelled "Acting within an increasingly confined space". The theme reflects the interference of stigma in men's lives, and in the face of potential discrimination, men perceived their sexual and healthcare choices as limited. This created obstacles for forming romantic and sexual relationships, insisting on consistent condom use with sexual partners, maintaining open and conducive relationships with family, and accessing healthcare services when required. Sexual stigma is a concern as it contributes to HIV/STI risk-related behaviours among men who have sex with men. Priority should be given to programmes that support same-sex practicing men in their efforts to make informed choices regarding their sexual health. Creating safe cyber networks provides an opportunity to reach this population with targeted sexual health education messages. Such programmes might be even more urgent in smaller towns and rural areas where gay specific initiatives are more limited than in urban areas.

Acting within an increasingly confined space: A qualitative study of sexual behaviours and healthcare needs among men who have sex with men in a provincial Tanzanian city

PubMed Central

Mohamed Shio, Jasmine; Ross, Michael W.; Agardh, Anette

2017-01-01

Objective To explore risk perceptions, sexual practices and healthcare needs among men who have sex with men in the provincial city of Tanga in northern Tanzania. Previous research suggests that HIV/STIs are increasing problems for this population. Yet, few studies have been conducted outside the urban area of Dar es Salaam, which has limited our knowledge about the HIV/STI risk factors and healthcare needs among men who have sex with men who live outside major metropolitan areas. Method During three months in 2013, 10 in-depth interviews with men who have sex with men were conducted in Tanga. Data were interpreted through qualitative content analysis. Results The theme that emerged was labelled “Acting within an increasingly confined space”. The theme reflects the interference of stigma in men’s lives, and in the face of potential discrimination, men perceived their sexual and healthcare choices as limited. This created obstacles for forming romantic and sexual relationships, insisting on consistent condom use with sexual partners, maintaining open and conducive relationships with family, and accessing healthcare services when required. Conclusions Sexual stigma is a concern as it contributes to HIV/STI risk-related behaviours among men who have sex with men. Priority should be given to programmes that support same-sex practicing men in their efforts to make informed choices regarding their sexual health. Creating safe cyber networks provides an opportunity to reach this population with targeted sexual health education messages. Such programmes might be even more urgent in smaller towns and rural areas where gay specific initiatives are more limited than in urban areas. PMID:28817626

Prolonged sexual abstinence after childbirth: gendered norms and perceived family health risks. Focus group discussions in a Tanzanian suburb.

PubMed

Mbekenga, Columba K; Pembe, Andrea B; Darj, Elisabeth; Christensson, Kyllike; Olsson, Pia

2013-01-15

Prolonged sexual abstinence after childbirth is a socio-cultural practice with health implications, and is described in several African countries, including Tanzania. This study explored discourses on prolonged postpartum sexual abstinence in relation to family health after childbirth in low-income suburbs of Dar es Salaam, Tanzania. Data for the discourse analysis were collected through focus group discussions with first-time mothers and fathers and their support people in Ilala, Dar es Salaam, Tanzania. In this setting, prolonged sexual abstinence intended at promoting child health was the dominant discourse in the period after childbirth. Sexual relations after childbirth involved the control of sexuality for ensuring family health and avoiding the social implications of non-adherence to sexual abstinence norms. Both abstinence and control were emphasised more with regard to women than to men. Although the traditional discourse on prolonged sexual abstinence for protecting child health was reproduced in Ilala, some modern aspects such as the use of condoms and other contraceptives prevailed in the discussion. Discourses on sexuality after childbirth are instrumental in reproducing gender-power inequalities, with women being subjected to more restrictions and control than men are. Thus, interventions that create openness in discussing sexual relations and health-related matters after childbirth and mitigate gendered norms suppressing women and perpetuating harmful behaviours are needed. The involvement of males in the interventions would benefit men, women, and children through improving the gender relations that promote family health.

Prevalence of STI symptoms and high levels of stigma in STI healthcare among men who have sex with men in Dar es Salaam, Tanzania: a respondent-driven sampling study.

PubMed

Ross, Michael W; Larsson, Markus; Nyoni, Joyce E; Agardh, Anette

2017-08-01

Symptoms of sexually transmitted infections (STIs), whether they are presented for treatment or diagnosis, and how they are received by the clinician where they are presented, may be concomitants of stigma associated with homosexuality in homophobic climates. We analyzed respondent-driven sampling data from a study on 200 young men who have sex with men (MSM) in Dar es Salaam, Tanzania to examine sample prevalence, treatment and clinician response to 10 symptoms potentially associated with STIs. Survey measures included 10 self-reported STI symptoms, further specified according to location (genital, anal, oral), further specified according to place of diagnosis, place of, treatment whether there was pharmacy treatment or self-medication, healthcare worker (HCW) inquiries about source of infection and whether the HCW was polite. Most common symptoms reported were genital pain, burning urination, genital itching/burning, penile discharge, and groin swelling. Anal symptoms had the lowest proportion of treatment at public clinics and among the highest proportion of pharmacy treatment; anal sores had the highest proportion of self-medication. HCWs were reported as not being polite in response to 71-90% of the symptoms, (median = 82%). The findings suggest that stigma and negative HCW response are barriers to public clinic treatment for MSM in Tanzania and that these may have implications for both STI treatment and the HIV cascade.

Pollution of water sources due to poor waste management--the case of Dar-es-Salaam.

PubMed

Makule, D E

2000-01-01

Pollution of water sources for the city of Dar-es-Salaam originates from haphazard disposal of solid wastes, discharge of untreated or inadequately treated wastewater to water sources, lack of standard sanitary facilities and poor hygienic practices. Contaminated water used for human consumption can lead to serious health problems e.g. cholera, typhoid, skin diseases, etc., which, in turn, leads to reduced working hours/manpower. This has a direct effect to production output which can lead to a deterioration of local community welfare. Having realised this as a problem, the Government of Tanzania stipulated, in its water policy of 1991, the need for protection of water sources. In achieving this goal, proper waste management was singled out to be of vital importance. Due to economic hardships, however, budget allocation by the central Government could not cover the costs needed for proper handling of waste. This left Tanzania with no alternative other than heavy reliance on donor and bilateral organisations for financial support of programmes. Nevertheless, these sources of funds proved to be unreliable for many different reasons. To deal with these problems, the Government currently emphasises involving local community and NGOs, the formation of stakeholder funds and organisations, and involvement of the private sector. Other efforts are intensification of education programmes to create more awareness to the local communities on the need for protection of water sources. Although at its infancy level, the system is showing some signs of improvement.

Early Cenozoic tropical climate: report from the Tanzania Onshore Paleogene Integrated Coring (TOPIC) workshop

NASA Astrophysics Data System (ADS)

Pearson, P. N.; Hudson, W.

2014-12-01

We are currently developing a proposal for a new International Continental Scientific Drilling Program (ICDP) project to recover a stratigraphic and paleoclimatic record from the full succession of Eocene hemipelagic sediments that are now exposed on land in southern Tanzania. Funding for a workshop was provided by ICDP, and the project was advertised in the normal way. A group of about 30 delegates assembled in Dar-es-Salaam for 3 intensive days of discussion, project development, and proposal writing. The event was hosted by the Tanzania Petroleum Development Corporation (TPDC) and was attended by several geologists, geochemists, geophysicists, and micropaleontologists from TPDC and the University of Dar-es-Salaam. International delegates were from Canada, Germany, India, Ireland, Italy, the Netherlands, United Kingdom, and United States (and we also have project partners from Australia, Belgium, and Sweden who were not able to attend). Some of the scientists are veterans of previous scientific drilling in the area, but over half are new on the scene, mostly having been attracted by Tanzania's reputation for world-class paleoclimate archives. Here we outline the broad aims of the proposed drilling and give a flavor of the discussions and the way our proposal developed during the workshop. A video of the workshop with an introduction to the scientific goals and interviews of many of the participants is available at http://vimeo.com/107911777.

Prolonged sexual abstinence after childbirth: gendered norms and perceived family health risks. Focus group discussions in a Tanzanian suburb

PubMed Central

2013-01-01

Background Prolonged sexual abstinence after childbirth is a socio-cultural practice with health implications, and is described in several African countries, including Tanzania. This study explored discourses on prolonged postpartum sexual abstinence in relation to family health after childbirth in low-income suburbs of Dar es Salaam, Tanzania. Methods Data for the discourse analysis were collected through focus group discussions with first-time mothers and fathers and their support people in Ilala, Dar es Salaam, Tanzania. Results In this setting, prolonged sexual abstinence intended at promoting child health was the dominant discourse in the period after childbirth. Sexual relations after childbirth involved the control of sexuality for ensuring family health and avoiding the social implications of non-adherence to sexual abstinence norms. Both abstinence and control were emphasised more with regard to women than to men. Although the traditional discourse on prolonged sexual abstinence for protecting child health was reproduced in Ilala, some modern aspects such as the use of condoms and other contraceptives prevailed in the discussion. Conclusion Discourses on sexuality after childbirth are instrumental in reproducing gender-power inequalities, with women being subjected to more restrictions and control than men are. Thus, interventions that create openness in discussing sexual relations and health-related matters after childbirth and mitigate gendered norms suppressing women and perpetuating harmful behaviours are needed. The involvement of males in the interventions would benefit men, women, and children through improving the gender relations that promote family health. PMID:23316932

Risk factors associated with the incidence rate of clinical mastitis in smallholder dairy cows in the Dar es Salaam region of Tanzania.

PubMed

Kivaria, F M; Noordhuizen, J P T M; Msami, H M

2007-05-01

Smallholder dairy herds around the Dar es Salaam region of Tanzania supply 86% of raw milk consumed by the city dwellers. Previous studies have indicated that clinical mastitis is an important disease affecting smallholder dairy cows and an 18-month questionnaire-based longitudinal field-study was conducted between July 2003 and March 2005 to elucidate risk factors associated with the incidence. A total of 6057 quarter-level observations from 317 lactating cows on 87 randomly selected smallholder dairy herds were analysed at the quarter and cow level using logistic and Poisson regression models, respectively. At the quarter level, the average incidence rate of clinical mastitis was 38.4 cases per 100 quarter-years at risk whereas at the cow level the incidence rate was 43.3 cases per 100 cow-years at risk. The incidence was significantly (P< or =0.001) associated with cow factors (body condition score, parity, stage of lactation, and udder consistency), housing (floor type) conditions and milking (cow and udder preparation) practices. It was concluded that the extrapolation of the classic ten-point mastitis control plan into smallholder dairy herds should be undertaken cautiously. An integrated approach to dairy extension should focus more on the creation of mastitis awareness among smallholder producers and on the improvement of animal nutrition and reproduction indices-factors that may also have a direct impact on milk yield.

Parental education as an indicator of socioeconomic status: improving quality of data by requiring consistency across measurement occasions.

PubMed

Aarø, Leif Edvard; Flisher, Alan J; Kaaya, Sylvia; Onya, Hans; Namisi, Francis S; Wubs, Annegreet

2009-06-01

Adolescents' reports of parents' education are sometimes used as indicators of socioeconomic status in surveys of health behaviour. The quality of such measurements is questionable. We hypothesized that consistent reporting of parents' education across measurement occasions in prospective panel studies indicates a higher quality of data than single or inconsistent reports. A multi-site, prospective panel study (three measurement occasions) was carried out among adolescents in Cape Town and Mankweng (South Africa), and Dar es Salaam (Tanzania). Analyses were based on data from students participating at baseline and with a valid code for school number (n = 15,684). For Cape Town and Dar es Salaam students, the associations between parents' education and an alternative indicator of socioeconomic status (both measured at baseline) increased with increasing consistency of reports about parents' education across measurement occasions. For Cape Town, the associations of father's education with a range of behavioural and social cognition variables were significantly stronger among ;;consistent'' than among other students. The pattern was the same for mother's education, but with fewer significant interaction effects. Requiring consistency of reports across data-collection occasions may, under the right combination of circumstances, make a difference. Insignificant and "close to zero'' associations may turn out to be at least moderately strong and statistically significant. When applying indicators of socioeconomic status, such as parents' highest level of completed education, it is most advantageous to use data from prospective panel studies, and to check for consistency of answers across measurement occasions.

Temporal changes in potential regulating ecosystem services driven by urbanization

NASA Astrophysics Data System (ADS)

Ferreira, Carla; Amorim, Inês; Pires, Evanilton; Kalantari, Zahra; Walsh, Rory; Ferreira, António

2017-04-01

Ecosystem services (ES) are understood to be the capacity of the landscape of a particular area to provide goods and services to society. In terms of human benefits, four categories of ES are usually considered: provisioning (e.g. seafood), regulating (e.g. climate regulation, air quality, water purification and natural hazard protection), supporting (e.g. maintenance of biodiversity), and cultural (e.g. recreation). The potential supply of ecosystem services has receive increasing interest as a tool for natural resource management. Nevertheless, the capacity to supply ES depends on biophysical conditions, as well as climate and land-use changes, induced by human activities. This study aims to investigate the potential for regulating ecosystem service supply of a Portuguese peri-urban catchment, and attempts to understand the temporal changes in ES over the last decades driven by urbanization. The study was developed in Ribeira dos Covões catchment (6.2 km2), in Portugal. Due to its proximity to Coimbra, a major city in the central region of Portugal, the catchment has undergone major land-use changes over the last half-century. Since 1958, the agricultural area, comprising mainly olives and arable land, has declined from 48% to 4%, due to increases in urban land (from 8% to 40%) and forest (from 44% to 53%), as well as a temporary creation of open spaces (from 0% to 3%). The nature of forest cover also changed, from native species, such as oaks (Quercus sp.), to commercial timber plantations, mostly of Pinus pinaster L. and Eucaliptus globulus L.. Urbanization became more pronounced after 1973, exhibiting a discontinuous pattern until 1995, and then later more continuous urban areas through the infilling of areas between the earlier urban cores. Quantification of regulating ES in the study catchment was achieved using GIS techniques, in order to gain a spatial dimension of ES distribution (Burkhard et al., 2009). Mapping ecosystem service capacities at a 5×5m resolution involved the use of CORINE land cover data and aerial photographs, available for the years 1958, 1973, 1979, 1990, 1995, 2002, 2007 and 2012. The resulting land-use maps include 11 land cover classes: equipment and infrastructure, discontinuous urban fabric, continuous urban fabric, natural areas with shrubs and herbaceous plants, softwoods, hardwoods, mixed forest, permanent crops, arable land, bare soil and water bodies. Quantitative assessment of regulating services of these land-use classes was achieved based on interviews with 31 experts. Each expert prepared a matrix using a scale from "0" to "5", where "0" refers to the land cover as having no capacity to provide regulating services, while 5 indicates that the land cover provides a wide range of ecosystem services. A final matrix was prepared based on mean values of all the experts. This matrix was then integrated with the land-use maps of different years to generate a spatially explicit potential ecosystem service supply model. The results showed decreasing ecosystem regulation services over time, mainly due to increasing urban area but also changes on forest types. The methodology used can be easily applied to test distinct urbanization scenarios, thus, providing a valuable support for urban planning.

Improved quality of management of eclampsia patients through criteria based audit at Muhimbili National Hospital, Dar es Salaam, Tanzania. Bridging the quality gap.

PubMed

Kidanto, Hussein Lesio; Wangwe, Peter; Kilewo, Charles D; Nystrom, Lennarth; Lindmark, Gunnila

2012-11-21

Criteria-based audits (CBA) have been used to improve clinical management in developed countries, but have only recently been introduced in the developing world. This study discusses the use of a CBA to improve quality of care among eclampsia patients admitted at a University teaching hospital in Dar es Salaam Tanzania. The prevalence of eclampsia in MNH is high (≈6%) with the majority of cases arriving after start of convulsions. In 2004-2005 the case-fatality rate in eclampsia was 5.1% of all pregnant women admitted for delivery (MNH obstetric data base). A criteria-based audit (CBA) was used to evaluate the quality of care for eclamptic mothers admitted at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania after implementation of recommendations of a previous audit. A CBA of eclampsia cases was conducted at MNH. Management practices were evaluated using evidence-based criteria for appropriate care. The Ministry of Health (MOH) guidelines, local management guidelines, the WHO manual supplemented by the WHO Reproductive Health Library, standard textbooks, the Cochrane database and reviews in peer reviewed journals were adopted. At the initial audit in 2006, 389 case notes were assessed and compared with the standards, gaps were identified, recommendations made followed by implementation. A re-audit of 88 cases was conducted in 2009 and compared with the initial audit. There was significant improvement in quality of patient management and outcome between the initial and re-audit: Review of management plan by senior staff (76% vs. 99%; P=0.001), urine for albumin test (61% vs. 99%; P=0.001), proper use of partogram to monitor labour (75% vs. 95%; P=0.003), treatment with steroids for lung maturity (2.0% vs. 24%; P=0.001), Caesarean section within 2 hours of decision (33% vs. 61%; P=0.005), full blood count (28% vs. 93%; P=0.001), serum urea and creatinine (44% vs. 86%; P=0.001), liver enzymes (4.0% vs. 86%; P=0.001), and specialist review within 2 hours of admission (25% vs. 39%; P=0.018). However, there was no significant change in terms of delivery within 24 hours of admission (69% vs. 63%; P=0.33). There was significant reduction of maternal deaths (7.7% vs. 0%; P=0.001). CBA is applicable in low resource setting and can help to improve quality of care in obstetrics including management of pre-eclampsia and eclampsia.

Job satisfaction and turnover intentions among health care staff providing services for prevention of mother-to-child transmission of HIV in Dar es Salaam, Tanzania.

PubMed

Naburi, Helga; Mujinja, Phares; Kilewo, Charles; Orsini, Nicola; Bärnighausen, Till; Manji, Karim; Biberfeld, Gunnel; Sando, David; Geldsetzer, Pascal; Chalamila, Guerino; Ekström, Anna Mia

2017-09-06

Option B+ for the prevention of mother-to-child transmission (PMTCT) of HIV (i.e., lifelong antiretroviral treatment for all pregnant and breastfeeding mothers living with HIV) was initiated in Tanzania in 2013. While there is evidence that this policy has benefits for the health of the mother and the child, Option B+ may also increase the workload for health care providers in resource-constrained settings, possibly leading to job dissatisfaction and unwanted workforce turnover. From March to April 2014, a questionnaire asking about job satisfaction and turnover intentions was administered to all nurses at 36 public-sector health facilities offering antenatal and PMTCT services in Dar es Salaam, Tanzania. Multivariable logistic regression models were used to identify factors associated with job dissatisfaction and intention to quit one's job. Slightly over half (54%, 114/213) of the providers were dissatisfied with their current job, and 35% (74/213) intended to leave their job. Most of the providers were dissatisfied with low salaries and high workload, but satisfied with workplace harmony and being able to follow their moral values. The odds of reporting to be globally dissatisfied with one's job were high if the provider was dissatisfied with salary (adjusted odds ratio (aOR) 5.6, 95% CI 1.2-26.8), availability of protective gear (aOR 4.0, 95% CI 1.5-10.6), job description (aOR 4.3, 95% CI 1.2-14.7), and working hours (aOR 3.2, 95% CI 1.3-7.6). Perceiving clients to prefer PMTCT Option B+ reduced job dissatisfaction (aOR 0.2, 95% CI 0.1-0.8). The following factors were associated with providers' intention to leave their current job: job stability dissatisfaction (aOR 3.7, 95% CI 1.3-10.5), not being recognized by one's superior (aOR 3.6, 95% CI 1.7-7.6), and poor feedback on the overall unit performance (aOR 2.7, 95% CI 1.3-5.8). Job dissatisfaction and turnover intentions are comparatively high among nurses in Dar es Salaam's public-sector maternal care facilities. Providing reasonable salaries and working hours, clearer job descriptions, appropriate safety measures, job stability, and improved supervision and feedback will be key to retaining satisfied PMTCT providers and thus to sustain successful implementation of Option B+ in Tanzania.

Climate change induced heat wave hazard in eastern Africa: Dar Es Salaam (Tanzania) and Addis Ababa (Ethiopia) case study

NASA Astrophysics Data System (ADS)

Capuano, Paolo; Sellerino, Mariangela; Di Ruocco, Angela; Kombe, Wilbard; Yeshitela, Kumelachew

2013-04-01

Last decades, new records were set in the world for tornadoes, drought, wind, floods, wildfires and hot temperatures, testifying unusual weather and climate patterns with increasing frequency and intensity of extreme weather events. Extreme heat events are natural hazards affecting many regions in the world, nevertheless limited work has been done on the analysis and effects of extreme heat events in Africa, that is considered a continent particularly vulnerable to the effects of climate change. In fact, the increase of temperature expected in the African continent during the 21st century is larger than the global mean warming, being about 3° to 4° C, about 1.5 times the global temperature increase (Christensen et al., 2007; Gualdi et al., 2012), with the subtropical regions projected to warm more than the tropical regions. Observations and downscaled model simulations (RCP4.5 and RCP8.5 IPCC scenarios) are analyzed to describe heat wave characteristics in Dar es Salaam (Tanzania) and Addis Ababa (Ethiopia), spanning the last five decades as well as that projected for the 21st century. Observed data are daily maximum and minimum temperature collected in the period 1961-2011; downscaled model simulations span up to 2050. Heat waves are defined following a peak over threshold approach by statistical comparison to historical meteorological baselines (site dependent), using a fixed absolute threshold. Projected future warming in the Dar es Salaam and Addis Ababa shows a further increase in the heat waves parameters. Heat wave duration and hot days number are strictly correlated showing that the temperature rise could generate not only an increase of heat waves number but mainly a longer average duration, that can strongly affect the resilience capacity of the population, particularly the elder people. In fact, the impacts of heat waves on the society are determined also by temporal duration (Stephenson, 2008), in addition to their frequency, in fact the capacity of adaptation can be reduced with prolonged exposure to high temperature and humidity. The expected persistence of long-lived heat waves lasting approximately 1.5-2 weeks is clearly longer with respect to the climatological period (1961-1990). During 100 years, short lived but more intense waves are more than doubled in duration. It is evident the needs for the national health services to develop strategies for the mitigation of the heat wave effects, to enhance the resilience of the population, particularly the elder people.

Developing a Method to Mask Trees in Commercial Multispectral Imagery

NASA Astrophysics Data System (ADS)

Becker, S. J.; Daughtry, C. S. T.; Jain, D.; Karlekar, S. S.

2015-12-01

The US Army has an increasing focus on using automated remote sensing techniques with commercial multispectral imagery (MSI) to map urban and peri-urban agricultural and vegetative features; however, similar spectral profiles between trees (i.e., forest canopy) and other vegetation result in confusion between these cover classes. Established vegetation indices, like the Normalized Difference Vegetation Index (NDVI), are typically not effective in reliably differentiating between trees and other vegetation. Previous research in tree mapping has included integration of hyperspectral imagery (HSI) and LiDAR for tree detection and species identification, as well as the use of MSI to distinguish tree crowns from non-vegetated features. This project developed a straightforward method to model and also mask out trees from eight-band WorldView-2 (1.85 meter x 1.85 meter resolution at nadir) satellite imagery at the Beltsville Agricultural Research Center in Beltsville, MD spanning 2012 - 2015. The study site included tree cover, a range of agricultural and vegetative cover types, and urban features. The modeling method exploits the product of the red and red edge bands and defines accurate thresholds between trees and other land covers. Results show this method outperforms established vegetation indices including the NDVI, Soil Adjusted Vegetation Index, Normalized Difference Water Index, Simple Ratio, and Normalized Difference Red Edge Index in correctly masking trees while preserving the other information in the imagery. This method is useful when HSI and LiDAR collection are not possible or when using archived MSI.

LiDAR and 2D Electrical Resistivity Tomography as a Supplement of Geomorphological Investigations in Urban Areas: a Case Study from the City of Wrocław (SW Poland)

NASA Astrophysics Data System (ADS)

Kasprzak, Marek; Traczyk, Andrzej

2014-06-01

In urbanized areas, particularly in lowland terrains and floors of large river valleys, the natural land configuration is often hard to recognize due to a long history of human activity. Accordingly, archaeological works in cities, which supply knowledge on settlement conditions, are usually accompanied by geological and geomophological research. Lately, data from light detection and ranging (LiDAR) have become a valuable source of information on urban land configuration. Geophysical methods are also becoming increasingly popular in background studies. The paper presents a method of using and linking these sources of spatial information about landforms in such areas. The main aim is to identify to what extent these complementary sources of data and the proposed method can be used in such a specific environment to reconstruct natural, buried terrain morphology. The city of Wrocław in Central Europe serves as an example. To this end geomorphometric studies were conducted with the use of digital elevation models (DEMs) based on LiDAR scanning and derivated land-surface parameters—SAGA Wetness Index, Channel Network Base Level and Altitude above Channel Network. The study also involved determining morphological edges and measurements of the meanders of the Odra, as well as expanding information on the spatial distribution of alluvia and the structure of slope breaks. To this end, geophysical measurements were conducted using the Two-Dimensional Electrical Resistivity Tomography method. Additionally, five typical sequences of man-made ground present within the perimeter of the city were distinguished. As a result, a map of the main landforms of Wrocław is presented. Finally, we argue that although high resolution DEM and derivate land-surface parameters are very useful in terrain analysis, places with thick man-made ground or strongly levelled areas must be recognized by geoarchaeological excavations or geological bore holes. The geophysical survey is useful to identify buried morphological edges and older relief elements in open areas.

Assessment of physicochemical characteristics and hygienic practices along the value chain of raw fruit juice vended in Dar es Salaam City, Tanzania.

PubMed

Nonga, Hezron E; Simforian, Edeltruds A; Ndabikunze, Bernadette K

2014-10-01

Fresh fruit juice is an essential component of human diet and there is considerable evidence of health and nutritional benefits. However, nature of the fruits used in juicing and unhygienic processes in the value chain may cause poor quality of juice. This cross- sectional study was conducted to assess physicochemical characteristics and hygienic practices along the value chain of raw fruit juice vended in Dar es Salaam, Tanzania. A total of 90 juice vendors were interviewed. Ninety juice samples were collected and analysed for physicochemical quality. The pH of juices ranged between 2.7 and 6.4, acidity 0.01% and 1.3% and, total soluble solids ranged between -1.5 and 18.04 °Brix. Most juices (67.8%) had -Brix levels below Codex recommended values classified as weak and watery. Juices were made of mango, passion, tamarind, sugar cane and mixture of these fruits sourced from open markets in the city. Water for washing of fruits and dilution of juices was from deep wells (53.3%) and taps (46.7%). About one third (37.8%) of the juice vendors didn't wash the fruits before juicing and 44.4% didn't boil water for juice dilution. Juice extraction was done by kitchen blenders, boiling in water and squeezing by simple machines. Juice pasteurization was not done. The majority of vendors (78.9%) stored juices in plastic buckets and juice was sold in glass cups, reused plastic bottles and disposable cups. Vending sites were restaurants, bus stands and along roadsides. The majority of premises (78.9%) were in unhygienic condition that likely encouraged or introduced contaminants to the juices. It is concluded that, the overall handling, preparation practices and physicochemical quality of raw fruit juices vended in Dare es Salaam City are poor. The government should educate the vendors on food safety and hygiene as well as enforcing regular monitoring of the quality of street fruit juices.

Trends in Terrorism, Threats to the United States and the Future of the Terrorism Risk Insurance Act

DTIC Science & Technology

2005-01-01

radicalism has emerged that appears to be based on the spreading phenomenon of anti-globalization (AG). The AG movement has had an impact on at least...such as those that were witnessed in Kenya and Tanzania in 19981 and New York and Washington, D.C., three years later.5 3 For an excellent overview of...this period, see Rashid, 2000, chapter 10. 4 The attacks in Kenya and Tanzania-which were against the U.S. embassies in Nairobi and Dar es Salaam-are

Group Occupational Health Service in a Developing Country

PubMed Central

de Glanville, H.

1970-01-01

In 1967 an experimental group occupational health service was set up in Dar es Salaam to provide direct service to industrial firms. Larger companies were visited by a doctor, smaller firms in rotation by auxiliaries. After three years 65 companies had joined with over 15,000 employees, and workers were attending the group dispensaries at a rate of over 250,000 visits a year. Such an approach through direct service to the working community appears to be more appropriate to a developing country than a purely advisory central occupational health unit. PMID:5483327

Intergration of LiDAR Data with Aerial Imagery for Estimating Rooftop Solar Photovoltaic Potentials in City of Cape Town

NASA Astrophysics Data System (ADS)

Adeleke, A. K.; Smit, J. L.

2016-06-01

Apart from the drive to reduce carbon dioxide emissions by carbon-intensive economies like South Africa, the recent spate of electricity load shedding across most part of the country, including Cape Town has left electricity consumers scampering for alternatives, so as to rely less on the national grid. Solar energy, which is adequately available in most part of Africa and regarded as a clean and renewable source of energy, makes it possible to generate electricity by using photovoltaics technology. However, before time and financial resources are invested into rooftop solar photovoltaic systems in urban areas, it is important to evaluate the potential of the building rooftop, intended to be used in harvesting the solar energy. This paper presents methodologies making use of LiDAR data and other ancillary data, such as high-resolution aerial imagery, to automatically extract building rooftops in City of Cape Town and evaluate their potentials for solar photovoltaics systems. Two main processes were involved: (1) automatic extraction of building roofs using the integration of LiDAR data and aerial imagery in order to derive its' outline and areal coverage; and (2) estimating the global solar radiation incidence on each roof surface using an elevation model derived from the LiDAR data, in order to evaluate its solar photovoltaic potential. This resulted in a geodatabase, which can be queried to retrieve salient information about the viability of a particular building roof for solar photovoltaic installation.

Innovative urban forestry governance in Melbourne?: Investigating "green placemaking" as a nature-based solution.

PubMed

Gulsrud, Natalie Marie; Hertzog, Kelly; Shears, Ian

2018-02-01

A nature-based approach to climate resilience aims to challenge and re-frame conventional environmental management methods by refocusing solutions from technological strategies to socio-ecological principles such as human well-being and community-based governance models, thereby improving and legitimizing the delivery of ecosystem services (ES). There are, however, many challenges to applying a socio-ecological agenda to urban climate resilience and thereby re-framing ES delivery as community and people focused, a knowledge gap extensively outlined in the environmental governance literature. In this paper, we aim to contribute to this re-assesment of urban environmental governance by examining the City of Melbourne's approach to urban re-naturing governance from a place-based perspective. Here we focus on the city's internationally-acclaimed urban forest strategy (UFS), investigating how and to which extent the governance arrangements embedded within the UFS draw strength from diverse perspectives and allow for institutional arrangements that support "situated" reflexive decision making and co-creation. We find that Melbourne's UFS governance process fosters green placemaking by re-focusing climate adaptation solutions from technological strategies to situated socio-ecological principles such as human well-being and community-based decision making. In this sense, this case provides valuable insight for the broader UGI governance field regarding the opportunities and challenges associated with a socio-cultural approach to urban re-naturing and ES delivery. Copyright © 2017 Elsevier Inc. All rights reserved.

Distinct clinical characteristics and helminth co-infections in adult tuberculosis patients from urban compared to rural Tanzania.

PubMed

Sikalengo, George; Hella, Jerry; Mhimbira, Francis; Rutaihwa, Liliana K; Bani, Farida; Ndege, Robert; Sasamalo, Mohamed; Kamwela, Lujeko; Said, Khadija; Mhalu, Grace; Mlacha, Yeromin; Hatz, Christoph; Knopp, Stefanie; Gagneux, Sébastien; Reither, Klaus; Utzinger, Jürg; Tanner, Marcel; Letang, Emilio; Weisser, Maja; Fenner, Lukas

2018-03-24

Differences in rural and urban settings could account for distinct characteristics in the epidemiology of tuberculosis (TB). We comparatively studied epidemiological features of TB and helminth co-infections in adult patients from rural and urban settings of Tanzania. Adult patients (≥ 18 years) with microbiologically confirmed pulmonary TB were consecutively enrolled into two cohorts in Dar es Salaam, with ~ 4.4 million inhabitants (urban), and Ifakara in the sparsely populated Kilombero District with ~ 400 000 inhabitants (rural). Clinical data were obtained at recruitment. Stool and urine samples were subjected to diagnose helminthiases using Kato-Katz, Baermann, urine filtration, and circulating cathodic antigen tests. Differences between groups were assessed by χ 2 , Fisher's exact, and Wilcoxon rank sum tests. Logistic regression models were used to determine associations. Between August 2015 and February 2017, 668 patients were enrolled, 460 (68.9%) at the urban and 208 (31.1%) at the rural site. Median patient age was 35 years (interquartile range [IQR]: 27-41.5 years), and 454 (68%) were males. Patients from the rural setting were older (median age 37 years vs. 34 years, P = 0.003), had a lower median body mass index (17.5 kg/m 2 vs. 18.5 kg/m 2 , P <  0.001), a higher proportion of recurrent TB cases (9% vs. 1%, P <  0.001), and in HIV/TB co-infected patients a lower median CD4 cell counts (147 cells/μl vs. 249 cells/μl, P = 0.02) compared to those from urban Tanzania. There was no significant difference in frequencies of HIV infection, diabetes mellitus, and haemoglobin concentration levels between the two settings. The overall prevalence of helminth co-infections was 22.9% (95% confidence interval [CI]: 20.4-27.0%). The significantly higher prevalence of helminth infections at the urban site (25.7% vs. 17.3%, P = 0.018) was predominantly driven by Strongyloides stercoralis (17.0% vs. 4.8%, P <  0.001) and Schistosoma mansoni infection (4.1% vs. 16.4%, P <  0.001). Recurrent TB was associated with living in a rural setting (adjusted odds ratio [aOR]: 3.97, 95% CI: 1.16-13.67) and increasing age (aOR: 1.06, 95% CI: 1.02-1.10). Clinical characteristics and helminth co-infections pattern differ in TB patients in urban and rural Tanzania. The differences underline the need for setting-specific, tailored public health interventions to improve clinical management of TB and comorbidities.

Heavy metal levels of pasture grasses in metropolitan area

NASA Astrophysics Data System (ADS)

Luilo, G. B.; Othman, O. C.

2003-05-01

Urban agriculture is becoming an important lucrative activity in Dar es Salaam City even though the city is subject to traffic and industrial pollution pressures. Poor planning has left only limited spaces, particularly road reserves, for cultivation and foraging animals. While there is increasing road traffic no study bas been conducted determine levels of trace metals in pasture grasses. This study, therefore, reports on the levels of cadmium, manganese, lead and zinc of cynodon grasses in road vicinity in the city. Results show that the trace metal levels (ppm ± SDE) in Cynodon grass species were: Cd (0.24 ± 0.06-2.58 ± 0.15), Mn (41.5 ± 13.6-345.0 ± 124.3), Pb (1.15 ± 0.64-25.53 ± 1.29) and Zn (25.97 ± 3.69-95.36 ± 19.61). The mean levels of lead and zinc varied exponentially with distance off the road up to 15 m distance. Lead and zinc levels correlated with average daily traffic in the roads while cadmium and manganese did not. This suggests that lead and zinc in grasses owe their sources from the passing motor vehicles in agreement with other reported studies. It is recommended that pasture grasses in road vicinities must not be used for foraging dairy cattle and goats for public health reasons.

Maternal exposure to carbon monoxide and fine particulate matter during pregnancy in an urban Tanzanian cohort

PubMed Central

WYLIE, Blair J.; KISHASHU, Yahya; MATECHI, Emmanuel; ZHOU, Zheng; COULL, Brent; ABIOYE, Ajibola Ibraheem; DIONISIO, Kathie L.; MUGUSI, Ferdinand; PREMJI, Zul; FAWZI, Wafaie; HAUSER, Russ; EZZATI, Majid

2016-01-01

Low birth weight contributes to as many as 60% of all neonatal deaths; exposure during pregnancy to household air pollution has been implicated as a risk factor. Between 2011 and 2013, we measured personal exposures to carbon monoxide (CO) and fine particulate matter (PM2.5) in 239 pregnant women in Dar es Salaam, Tanzania. CO and PM2.5 exposures during pregnancy were moderately high (geometric means 2.0 ppm and 40.5 μg/m3); 87% of PM2.5 measurements exceeded WHO air quality guidelines Median and high (75th centile) CO exposures were increased for those cooking with charcoal and kerosene versus kerosene alone in quantile regression. High PM2.5 exposures were increased with charcoal use. Outdoor cooking reduced median PM2.5 exposures. For PM2.5, we observed a 0.15 kilogram reduction in birth weight per interquartile increase in exposure (23.0 μg/m3) in multivariable linear regression; this finding was of borderline statistical significance (95% confidence interval −0.30, 0.00 kilograms; p=0.05). PM2.5 was not significantly associated with birth length or head circumference nor were CO exposures associated with newborn anthropometrics. Our findings contribute to the evidence that exposure to household air pollution, and specifically fine particulate matter, may adversely affect birth weight. PMID:26880607

Understanding women's experiences of distress during pregnancy in Dar es Salaam, Tanzania.

PubMed

Kaaya, S F; Mbwambo, J K; Fawzi, M C Smith; Van Den Borne, H; Schaalma, H; Leshabari, M T

2010-01-01

Several studies show depression is common during pregnancy. However, there is limited information in Tanzania on the magnitude of perceived distress during pregnancy and meanings ascribed to such distress. A descriptive survey collected data using unstructured interviews from 12 traditional practitioners and 10 peri-urban women with previous pregnancy related mental health concerns identified using a depression vignette. The objectives were to describe the sources and characteristics of distress during pregnancy, and idioms of distress that could inform cultural adaptation of depression screening tools. Narrative analysis showed an emergent category of "problematic pregnancies" framed women's recollections of prolonged periods of sadness. This experience was qualified using various idioms of distress that were differentially emphasized depending on informant's perceived causes of health concern. The idiom kusononeka was consistently used to describe extreme sadness across causal categories and clustered with at least two typical features of major depression. This suggested existence of a construct with similarities to biomedical criteria for depression. "Thinking too much" emerged as a distinctive expression associated with prolonged sadness. Distinctive expressions of social functioning impairments were identified that can inform depression severity assessments. In conclusion, contextual inquiry into experiences of psychological distress showed distinct local idioms that clustered in patterns similar to symptoms of biomedical depressive episodes. Further studies to assess the utility of local idioms of distress and distress related functional impairment in depression assessment tools are warranted.

[Concept of "opinion leader": Recommendations of the Committee on Ethics and Transparency in the Medical-Industry Relationship (CETREMI) of the National Academy of Medicine (ANM)].

PubMed

Burgos, Rubén; Aguilar-Salinas, Carlos Alberto; Barile-Fabris, Leonor; Rangel-Fraustro, Manuel Sigfrido; Arrieta, Óscar; Campillo, Carlos; Celis, Miguel Ángel; Llata, Manuel de la; Domínguez, Judith; Halabe, José; Islas, Sergio; Jasso, Luis; Lifshitz, Alberto; Moreno, Mucio; Plancarte, Ricardo; Reyes, Alejandro; Soda, Antonio; Verástegui, Emma; Sotelo, Julio

2017-01-01

La relación que involucra al médico y la industria abarca un espectro amplio de formas, para lo cual se requiere una exposición clara y transparente de términos y principios. Uno de los objetivos primordiales de la industria es contar con un respaldo académico que le permita dar a conocer las características y las propiedades de sus productos -eficacia, eficiencia y seguridad- con el propósito de ser prescritos y usados. Los fines de la industria son la venta de sus productos, el reconocimiento como empresas de prestigio y la ganancia económica. Implícitamente, para CETREMI el principio de mayor importancia en esta relación es indudablemente el beneficio del enfermo.

Building capacity for providing canopy cover and canopy height at FIA plot locations using high-resolution imagery and leaf-off LiDAR

Treesearch

Rachel Riemann; Jarlath O' Neil-Dunne; Greg C. Liknes

2012-01-01

Tree canopy cover and canopy height information are essential for estimating volume, biomass, and carbon; defining forest cover; and characterizing wildlife habitat. The amount of tree canopy cover also influences water quality and quantity in both rural and urban settings. Tree canopy cover and canopy height are currently collected at FIA plots either in the field or...

The Application of LiDAR to Assessment of Rooftop Solar Photovoltaic Deployment Potential in a Municipal District Unit

PubMed Central

Nguyen, Ha T.; Pearce, Joshua M.; Harrap, Rob; Barber, Gerald

2012-01-01

A methodology is provided for the application of Light Detection and Ranging (LiDAR) to automated solar photovoltaic (PV) deployment analysis on the regional scale. Challenges in urban information extraction and management for solar PV deployment assessment are determined and quantitative solutions are offered. This paper provides the following contributions: (i) a methodology that is consistent with recommendations from existing literature advocating the integration of cross-disciplinary competences in remote sensing (RS), GIS, computer vision and urban environmental studies; (ii) a robust methodology that can work with low-resolution, incomprehensive data and reconstruct vegetation and building separately, but concurrently; (iii) recommendations for future generation of software. A case study is presented as an example of the methodology. Experience from the case study such as the trade-off between time consumption and data quality are discussed to highlight a need for connectivity between demographic information, electrical engineering schemes and GIS and a typical factor of solar useful roofs extracted per method. Finally, conclusions are developed to provide a final methodology to extract the most useful information from the lowest resolution and least comprehensive data to provide solar electric assessments over large areas, which can be adapted anywhere in the world. PMID:22666044

Characterizing Urban Volumetry Using LIDAR Data

NASA Astrophysics Data System (ADS)

Santos, T.; Rodrigues, A. M.; Tenedório, J. A.

2013-05-01

Urban indicators are efficient tools designed to simplify, quantify and communicate relevant information for land planners. Since urban data has a strong spatial representation, one can use geographical data as the basis for constructing information regarding urban environments. One important source of information about the land status is imagery collected through remote sensing. Afterwards, using digital image processing techniques, thematic detail can be extracted from those images and used to build urban indicators. Most common metrics are based on area (2D) measurements. These include indicators like impervious area per capita or surface occupied by green areas, having usually as primary source a spectral image obtained through a satellite or airborne camera. More recently, laser scanning data has become available for large-scale applications. Such sensors acquire altimetric information and are used to produce Digital Surface Models (DSM). In this context, LiDAR data available for the city is explored along with demographic information, and a framework to produce volumetric (3D) urban indexes is proposed, and measures like Built Volume per capita, Volumetric Density and Volumetric Homogeneity are computed.

Microbial Efficacy of Waterless Hand Hygiene in Dar es Salaam, Tanzania

NASA Astrophysics Data System (ADS)

Pickering, A.; Boehm, A.; Davis, J.

2008-12-01

Millions of people die from diarrheal and respiratory diseases every year due to lack of proper sanitation, hygiene, and access to clean water. The act of handwashing with soap has been found to effectively reduce both diarrheal and respiratory illness, however, handwashing at critical times (i.e. after using the toilet, before preparing food) remains infrequent around the world. This research investigates the potential for alcohol- based hand sanitizer (ABHS) to be an effective and appropriate hand hygiene option in developing countries. A study was conducted to assess the microbiological effectiveness of ABHS, as compared to handwashing with soap and water, in field conditions in Dar es Salaam, Tanzania. A total of 205 participants, including mothers, nurses, students, and teachers, were introduced to ABHS, given a standardized amount (2ml) of product, and instructed on how to use the product correctly. Hand samples were obtained using the hand rinse method before and after the use of ABHS from 152 participants. The other 53 participants were hand sampled before and after handwashing with a non-antimicrobial liquid soap and clean water (prior to using ABHS). Visual inspections of the hands were performed before hand sampling to record the level of dirt on the hands. All hand samples were processed and analyzed by membrane filtration for concentrations of two microbial indicators, enterococci and E. coli. User perceptions of the product and willingness to pay are also documented. The results of this study provide valuable insight on the prospective of promoting ABHS in developing countries and water scarce areas.

Criteria-based audit on management of eclampsia patients at a tertiary hospital in Dar es Salaam, Tanzania

PubMed Central

Kidanto, Hussein Lesio; Mogren, Ingrid; Massawe, Siriel N; Lindmark, Gunilla; Nystrom, Lennarth

2009-01-01

Background Criteria-based audits have been used to improve clinical management in developed countries, but have only recently been introduced in the developing world. This study discusses the introduction of a criteria-based audit in a tertiary hospital in an African setting, assesses the quality of care among eclampsia patients and discusses possible interventions in order to improve the quality of care. Methods We conducted a criteria based audit of 389 eclampsia patients admitted to Muhimbili National Hospital (MNH), Dar es Salaam Tanzania between April 14, 2006 and December 31, 2006. Cases were assessed using evidence-based criteria for appropriate care. Results Antepartum, intrapartum and postpartum eclampsia constituted 47%, 41% and 12% of the eclampsia cases respectively. Antepartum eclampsia was mostly (73%) preterm whereas the majority (71%) of postpartum eclampsia cases ware at term. The case fatality rate for eclampsia was 7.7%. Medical histories were incomplete, the majority (75%) of management plans were not reviewed by specialists in obstetrics, specialist doctors live far from the hospital and do not spend nights in hospital even when they are on duty, monitoring of patients on magnesium sulphate was inadequate, and important biochemical tests were not routinely done. Two thirds of the patient scheduled for caesarean section did not undergo surgery within agreed time. Conclusion Potential areas for further improvement in quality of emergency care for eclampsia relate to standardizing management guidelines, greater involvement of specialists in the management of eclampsia and continued medical education on current management of eclampsia for junior staff. PMID:19323846

Eclampsia in Dar es Salaam, Tanzania -- incidence, outcome, and the role of antenatal care.

PubMed

Urassa, David P; Carlstedt, Anders; Nyström, Lennarth; Massawe, Siriel N; Lindmark, Gunilla

2006-01-01

In order to assess the effectiveness of antenatal care for prevention of eclampsia, a retrospective case-control study was performed at the Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania. All women with eclampsia seen at MNH during 1999-2000 and controls without eclampsia were included. The study used a labor ward database and antenatal cards of eclamptic women and non-eclamptic controls. For each of the 741 eclamptic women who delivered at MNH, two non-eclamptic controls were chosen from the database. For 399 of the eclampsia cases and 420 non-eclamptic controls, the antenatal records could be traced and compared. Main outcome measures. Maternal and perinatal mortality, detection of antenatal risk factors, appropriate referrals, and incidence of eclampsia. Hospital and population-based incidences of eclampsia were 200/10,000 and 67/10,000, respectively. The case-fatality rate for eclampsia was 5.0% for women who delivered at MNH and 16% for those referred to MNH after being delivered elsewhere. The risk of low birth weight and perinatal death was significantly increased in eclamptic women (odds ratio = 6 and 10, respectively). The screening coverage for signs of pre-eclampsia was >85%, except for proteinuria (33%). Fewer than 50% of the women who developed eclampsia had been referred from the ANC clinic and <10% were admitted to the antenatal ward at MNH before onset of eclamptic fits. The current practice of antenatal care is insufficient as a prevention strategy for eclampsia in a low-resource setting with high incidence of eclampsia.

Capture-recapture analysis of East Coast fever in smallholder dairy herds in the Dar es Salaam region of Tanzania.

PubMed

Kivaria, F M; Noordhuizen, J P T M

2010-05-01

The prevalence of and case fatality rate due to East Coast fever (ECF) were estimated in 1402 dairy cattle in 87 small herds in the Dar es Salaam region of Tanzania, from January 2003 to January 2005 using a capture-recapture method. Information on clinical cases and deaths due to ECF were obtained from farm records and from a questionnaire-based cross-sectional survey conducted between July 2003 and March 2005 as part of longitudinal studies of bovine mastitis in these herds. The number of clinical cases identified was 567 (from farm records) and 496 (from the questionnaire), and the number of deaths recorded were 305 (from farm records) and 251 (from the questionnaire). In all, 450 clinical cases and 191 deaths due to ECF were identified from the two sources, giving an observed prevalence of 32% (CI(95%) 30-35%) and observed case fatality rate of 42% (CI(95%) 38-47%). Following application of the capture-recapture method, the estimated number of clinical cases and deaths was 625 (CI(95%) 617-633) and 401 (CI(95%) 384-418), respectively. The respective prevalence and case fatality rates were 45% (CI(95%) 41-48%) and 64% (CI(95%) 60-68%). The estimates obtained using the capture-recapture method are higher than those identified by traditional cross-sectional studies conducted in the same study area, and probably provide a more accurate epidemiological picture of ECF in this region of Tanzania. Copyright 2009 Elsevier Ltd. All rights reserved.

Sampling Migrants from their Social Networks: The Demography and Social Organization of Chinese Migrants in Dar es Salaam, Tanzania.

PubMed

Merli, M Giovanna; Verdery, Ashton; Mouw, Ted; Li, Jing

2016-07-01

The streams of Chinese migration to Africa are growing in tandem with rising Chinese investments and trade flows in and to the African continent. In spite of the high profile of this phenomenon in the media, there are few rich and broad descriptions of Chinese communities in Africa. Reasons for this include the rarity of official statistics on foreign-born populations in African censuses, the absence of predefined sampling frames required to draw representative samples with conventional survey methods and difficulties to reach certain segments of this population. Here, we use a novel network-based approach, Network Sampling with Memory, which overcomes the challenges of sampling 'hidden' populations in the absence of a sampling frame, to recruit a sample of recent Chinese immigrants in Dar es Salaam, Tanzania and collect information on the demographic characteristics, migration histories and social ties of members of this sample. These data reveal a heterogeneous Chinese community composed of "state-led" migrants who come to Africa to work on projects undertaken by large Chinese state-owned enterprises and "independent" migrants who come on their own accord to engage in various types of business ventures. They offer a rich description of the demographic profile and social organization of this community, highlight key differences between the two categories of migrants and map the structure of the social ties linking them. We highlight needs for future research on inter-group differences in individual motivations for migration, economic activities, migration outcomes, expectations about future residence in Africa, social integration and relations with local communities.

Perpetration and Victimization of Intimate Partner Violence Among Young Men and Women in Dar es Salaam, Tanzania

PubMed Central

Mulawa, Marta; Kajula, Lusajo J.; Yamanis, Thespina J.; Balvanz, Peter; Kilonzo, Mrema N.; Maman, Suzanne

2016-01-01

We describe and compare the baseline rates of victimization and perpetration of three forms of intimate partner violence (IPV)—psychological, physical, and sexual—among sexually active men (n = 1,113) and women (n = 226) enrolled in an ongoing cluster-randomized HIV and gender-based violence prevention trial in Dar es Salaam, Tanzania. IPV was measured using a modified version of the World Health Organization Violence Against Women instrument. We assess the degree to which men and women report overlapping forms of IPV victimization and perpetration. Sociodemographic and other factors associated with increased risk of victimization and perpetration of IPV are examined. Within the last 12 months, 34.8% of men and 35.8% of women reported any form of IPV victimization. Men were more likely than women to report perpetrating IPV (27.6% vs. 14.6%, respectively). We also found high rates of co-occurrence of IPV victimization and perpetration with 69.7% of male perpetrators and 81.8% of female perpetrators also reporting victimization during the last year. Among men, having ever consumed alcohol and experiencing childhood violence were associated with increased risk of most forms of IPV. Younger women were more likely to report perpetrating IPV than older women. We found evidence of gender symmetry with regard to most forms of IPV victimization, but men reported higher rates of IPV perpetration than women. Given the substantial overlap between victimization and perpetration reported, our findings suggest that IPV may be bidirectional within relationships in this setting and warrant further investigation. Implications for interventions are discussed. PMID:26802044

Sampling Migrants from their Social Networks: The Demography and Social Organization of Chinese Migrants in Dar es Salaam, Tanzania

PubMed Central

Merli, M. Giovanna; Verdery, Ashton; Mouw, Ted; Li, Jing

2016-01-01

The streams of Chinese migration to Africa are growing in tandem with rising Chinese investments and trade flows in and to the African continent. In spite of the high profile of this phenomenon in the media, there are few rich and broad descriptions of Chinese communities in Africa. Reasons for this include the rarity of official statistics on foreign-born populations in African censuses, the absence of predefined sampling frames required to draw representative samples with conventional survey methods and difficulties to reach certain segments of this population. Here, we use a novel network-based approach, Network Sampling with Memory, which overcomes the challenges of sampling ‘hidden’ populations in the absence of a sampling frame, to recruit a sample of recent Chinese immigrants in Dar es Salaam, Tanzania and collect information on the demographic characteristics, migration histories and social ties of members of this sample. These data reveal a heterogeneous Chinese community composed of “state-led” migrants who come to Africa to work on projects undertaken by large Chinese state-owned enterprises and “independent” migrants who come on their own accord to engage in various types of business ventures. They offer a rich description of the demographic profile and social organization of this community, highlight key differences between the two categories of migrants and map the structure of the social ties linking them. We highlight needs for future research on inter-group differences in individual motivations for migration, economic activities, migration outcomes, expectations about future residence in Africa, social integration and relations with local communities. PMID:27746912

Barriers and promoters of home-based pasteurization of breastmilk among HIV-infected mothers in greater Dar es Salaam, Tanzania.

PubMed

Young, Sera; Leshabari, Sebalda; Arkfeld, Chaele; Singler, Jennifer; Dantzer, Emily; Israel-Ballard, Kiersten; Mashio, Clara; Maternowska, Catherine; Chantry, Caroline

2013-06-01

For the past decade, heat-treating breastmilk has been an infant feeding option recommended by the World Health Organization as a strategy to reduce vertical transmission. However, little is known about field experiences with it. Our primary objective was to explore the barriers and promoters of the implementation of breastmilk pasteurization, "flash-heating" (FH), in the real-world setting of Dar es Salaam, Tanzania. Nineteen in-depth interviews were conducted with participants in a home-based infant feeding counseling intervention in which FH was promoted after 6 months of exclusive breastfeeding. Additionally, three focus group discussions were conducted with peer counselors. Interviews were transcribed, translated, and coded independently using NVivo 8 software (QSR International). Data were analyzed using the socioecological framework. Information and support provided by peer counselors were the most important promoters of initiation and continuation of FH; this impacted individual-, interpersonal-, and institutional-level promoters of success. Other promoters included perceived successful breastmilk expression, infant health after initiation of FH, and the inability to pay for replacement milks. Stigma was the most important barrier and cut across all levels of the framework. Other barriers included doubt about the safety or importance of pasteurized breastmilk, difficulties with expressing milk (often attributed to poor diet), and competing responsibilities. The most common suggestion for improving the uptake and duration of FH was community education. Given the acknowledged role of breastmilk pasteurization in the prevention of vertical transmission, further implementation research is needed. A multilevel intervention addressing barriers to FH would likely improve uptake.

Climate change induced risk analysis of Addis Ababa city (Ethiopia)

NASA Astrophysics Data System (ADS)

Jalayer, Fatemeh; Herslund, Lise; Cavan, Gina; Printz, Andreas; Simonis, Ingo; Bucchignani, Edoardo; Jean-Baptiste, Nathalie; Hellevik, Siri; Fekade, Rebka; Nebebe, Alemu; Woldegerima, Tekle; Workalemahu, Liku; Workneh, Abraham; Yonas, Nebyou; Abebe Bekele, Essete; Yeshitela, Kumelachew

2013-04-01

CLUVA (CLimate change and Urban Vulnerability in Africa; http://www.cluva.eu/) is a 3 years project, funded by the European Commission in 2010. Its objective is to develop context-centered methods to assess vulnerability and increase knowledge on managing climate related risks and to estimate the impacts of climate changes in the next 40 years at urban scale in Africa. The project downscales IPCC climate projections to evaluate threats to selected African test cities; mainly floods, sea-level rise, droughts, heat waves, desertification. It also evaluates and links: social vulnerability; urban green structures and ecosystem services; urban-rural interfaces; vulnerability of urban built environment and lifelines; and related institutional and governance dimensions of adaptation. CLUVA combines assessment approaches to investigate how cities, communities and households can resist and cope with, as well as recover from climate induced hazards. This multi-scale and multi-disciplinary qualitative, quantitative and probabilistic approach of CLUVA is currently being applied to selected African test cities (Addis Ababa - Ethiopia; Dar es Salaam - Tanzania; Douala - Cameroun; Ouagadougou - Burkina Faso; St. Louis - Senegal). In particular, the poster will report on the progresses of the Addis Ababa case study. Addis Ababa, the largest city in Ethiopia, is exposed to heat waves, drought, and, more recently, to flash floods. Due to undulating topography, poor waste management and the absence of sustainable storm water management, Addis Ababa is prone to severe flood events during the rainy seasons. Metropolitan Addis Ababa is crossed by several small watercourses. Torrential rains, very common during the rainy season, cause a sudden rise in the flow of these water courses, inundating and damaging the settlements along their banks and affecting the livelihood of the local population. The combination of climate change and development pressures are expected to exacerbate the current situation. The CLUVA research team - composed of climate and environmental scientists, engineers, risk management experts, urban planners and social scientists from both European and African institutions - has started to produce research outputs suitable for use in evidence-based planning activities in the case study cities. Indeed, climate change projections at 8 km resolution are ready for regions containing each of the case study cities; a preliminary hazard assessment for floods, drought and heat waves has already been performed, based on historical data; urban morphology and related green structures have been characterized; preliminary findings in social vulnerability have been achieved; a GIS based identification of Urban Residential hotspots to flooding is completed; and the vulnerability of informal settlements to flooding has been evaluated for one of the hotspots identified (Little Akaki case study area). Furthermore, a set of indicators relevant for Addis Ababa has been selected by local stakeholders to identify especially vulnerable, high risk areas and communities and an investigation of existing urban planning and governance systems and its interface with climate risks and vulnerability is ongoing. Evidence from the CLUVA project is being used to develop the next Master Plan for the Addis Ababa metropolitan area.

Urban Classification Techniques Using the Fusion of LiDAR and Spectral Data

DTIC Science & Technology

2012-09-01

Photogrammetry and Remote Sensing, 62, 43–63. Stein, D., Beaven, S., Hoff, L., Winter, E., Schaum, A., & Stocker, A. (2002). Anomaly detection from...TECHNIQUES USING THE FUSION OF LIDAR AND SPECTRAL DATA by Justin E. Mesina September 2012 Thesis Advisor: Richard C . Olsen Second...from shadow anomalies . The fused results however, were not as accurate in differentiating trees from grasses as using only spectral results. Overall the

Integrating terrestrial LiDAR and stereo photogrammetry to map the Tolay lakebed in northern San Francisco Bay

USGS Publications Warehouse

Woo, Isa; Storesund,; Takekawa, John Y.; Gardiner, Rachel J.; Ehret,

2009-01-01

The Tolay Creek Watershed drains approximately 3,520 ha along the northern edge of San Francisco Bay. Surrounded by a mosaic of open space conservation easements and public wildlife areas, it is one of the only watersheds in this urbanized estuary that is protected from its headwaters to the bay. Tolay Lake is a seasonal, spring-fed lake found in the upper watershed that historically extended over 120 ha. Although the lakebed was farmed since the early 1860s, the majority of the lakebed was recently acquired by the Sonoma County Regional Parks Department to restore its natural habitat values. As part of the restoration planning process, we produced a digital elevation model (DEM) of the historic extent of Tolay Lake by integrating terrestrial LiDAR (light detection and ranging) and stereo photogrammetry datasets, and real-time kinematic (RTK) global positioning system (GPS) surveys. We integrated the data, generated a DEM of the lakebed and upland areas, and analyzed errors. The accuracy of the composite DEM was verified using spot elevations obtained from the RTK GPS. Thus, we found that by combining photogrammetry, terrestrial LiDAR, and RTK GPS, we created an accurate baseline elevation map to use in watershed restoration planning and design.

LiDAR Scan Matching Aided Inertial Navigation System in GNSS-Denied Environments

PubMed Central

Tang, Jian; Chen, Yuwei; Niu, Xiaoji; Wang, Li; Chen, Liang; Liu, Jingbin; Shi, Chuang; Hyyppä, Juha

2015-01-01

A new scan that matches an aided Inertial Navigation System (INS) with a low-cost LiDAR is proposed as an alternative to GNSS-based navigation systems in GNSS-degraded or -denied environments such as indoor areas, dense forests, or urban canyons. In these areas, INS-based Dead Reckoning (DR) and Simultaneous Localization and Mapping (SLAM) technologies are normally used to estimate positions as separate tools. However, there are critical implementation problems with each standalone system. The drift errors of velocity, position, and heading angles in an INS will accumulate over time, and on-line calibration is a must for sustaining positioning accuracy. SLAM performance is poor in featureless environments where the matching errors can significantly increase. Each standalone positioning method cannot offer a sustainable navigation solution with acceptable accuracy. This paper integrates two complementary technologies—INS and LiDAR SLAM—into one navigation frame with a loosely coupled Extended Kalman Filter (EKF) to use the advantages and overcome the drawbacks of each system to establish a stable long-term navigation process. Static and dynamic field tests were carried out with a self-developed Unmanned Ground Vehicle (UGV) platform—NAVIS. The results prove that the proposed approach can provide positioning accuracy at the centimetre level for long-term operations, even in a featureless indoor environment. PMID:26184206

LiDAR Scan Matching Aided Inertial Navigation System in GNSS-Denied Environments.

PubMed

Tang, Jian; Chen, Yuwei; Niu, Xiaoji; Wang, Li; Chen, Liang; Liu, Jingbin; Shi, Chuang; Hyyppä, Juha

2015-07-10

A new scan that matches an aided Inertial Navigation System (INS) with a low-cost LiDAR is proposed as an alternative to GNSS-based navigation systems in GNSS-degraded or -denied environments such as indoor areas, dense forests, or urban canyons. In these areas, INS-based Dead Reckoning (DR) and Simultaneous Localization and Mapping (SLAM) technologies are normally used to estimate positions as separate tools. However, there are critical implementation problems with each standalone system. The drift errors of velocity, position, and heading angles in an INS will accumulate over time, and on-line calibration is a must for sustaining positioning accuracy. SLAM performance is poor in featureless environments where the matching errors can significantly increase. Each standalone positioning method cannot offer a sustainable navigation solution with acceptable accuracy. This paper integrates two complementary technologies-INS and LiDAR SLAM-into one navigation frame with a loosely coupled Extended Kalman Filter (EKF) to use the advantages and overcome the drawbacks of each system to establish a stable long-term navigation process. Static and dynamic field tests were carried out with a self-developed Unmanned Ground Vehicle (UGV) platform-NAVIS. The results prove that the proposed approach can provide positioning accuracy at the centimetre level for long-term operations, even in a featureless indoor environment.

Automatic building extraction from LiDAR data fusion of point and grid-based features

NASA Astrophysics Data System (ADS)

Du, Shouji; Zhang, Yunsheng; Zou, Zhengrong; Xu, Shenghua; He, Xue; Chen, Siyang

2017-08-01

This paper proposes a method for extracting buildings from LiDAR point cloud data by combining point-based and grid-based features. To accurately discriminate buildings from vegetation, a point feature based on the variance of normal vectors is proposed. For a robust building extraction, a graph cuts algorithm is employed to combine the used features and consider the neighbor contexture information. As grid feature computing and a graph cuts algorithm are performed on a grid structure, a feature-retained DSM interpolation method is proposed in this paper. The proposed method is validated by the benchmark ISPRS Test Project on Urban Classification and 3D Building Reconstruction and compared to the state-art-of-the methods. The evaluation shows that the proposed method can obtain a promising result both at area-level and at object-level. The method is further applied to the entire ISPRS dataset and to a real dataset of the Wuhan City. The results show a completeness of 94.9% and a correctness of 92.2% at the per-area level for the former dataset and a completeness of 94.4% and a correctness of 95.8% for the latter one. The proposed method has a good potential for large-size LiDAR data.

Collection and analysis of wind data for the evaluation of Wildland-Urban Interface Fire Dynamics Simulator

NASA Astrophysics Data System (ADS)

Espina, Chad Edward Obedoza

The Wildland Urban-Interface Fire Dynamics Simulator (WFDS) is a computer code that is currently being developed by the National Institute of Standards and Technology (NIST). WFDS has the capability of simulating wildland fire behavior with prescribed elements such vegetative and structural fuel, topography, and weather conditions. In this initial stage of the research, support for the development of WFDS focuses on the evaluation of a wind flow simulation on a very complex, outdoor terrain. This effort is preceded by the fabrication, installation and testing of wind-sensing equipment. Foremost, wind data gathered from different sites using various instruments are compared and evaluated. The data gathered in the Trails community of Rancho Bernardo is then presented and compared to select WFDS simulations. Systems consisting of a wind vane and anemometer are currently installed in the Trails community of Rancho Bernardo. They were installed by Professor Fletcher J. Miller and me using a lift that is attached to a telescoping crane. These instruments will gather the wind data needed to show the behavioral patterns of winds influenced by the topography and obstructions such as trees and houses. They are currently installed on top of light posts. These light posts were picked based on the path of the fire influenced by the Santa Ana winds that ravaged the community in 2007. The data from these instruments were graphically represented using a Matlab code that was developed specifically for the data sets. The Matlab graphing utility plots wind speed and wind direction along with matching polar plots. Other main features also include the ability to set a time range and compare two sites in one plot. There are other wind instruments currently being tested and being analyzed to ensure correct data is being recorded. These instruments will also expand to a wider range the wind data-gathering capabilities vertically. A Sound Detecting and Ranging (SoDAR) unit gathers wind speed and direction from the sound waves, initially emitted by the SoDAR to the atmosphere, that are reflected by the air flow above the unit. Wind data has been compared to the SoDAR unit with data from instruments installed on a meteorological tower operated by the National Oceanic and Atmospheric Administration (NOAA) located in northern California. Two more SoDARs are currently in Texas where initially they were deployed 400 meters apart of each other at an airfield. Also in the same airfield, the wind instrument of an Unmanned Aerial Vehicle (UAV) SuperBat was tested and compared to the SoDARs. Lastly, a self-contained wind instrument (Wind Dart) on a UAV that was developed by the University of Colorado was tested. The instrument was used while attached to the UAV Spectra. A static test was also done in San Diego State University's low speed wind tunnel. The wind data comparison from the SoDAR and meteorological tower in Lodi, California showed close tracking to each other both in wind speed and direction. The comparison of the wind data gathered by the two SoDARs in Texas also showed close tracking to each other. As for the Wind Dart, the data gathered from the instrument and UAV Spectra are not conclusive enough to validate the abilities of the Wind Dart. The experimental procedure in testing the Wind Dart on a moving platform must be further developed. Before the aerial test of the Wind Dart, it was first tested at San Diego State University's low speed tunnel. The detected wind speed by the Wind Dart closely matches the prescribed wind speed of the wind tunnel. The data between the UAV SuperBat and SoDARs showed close tracking. Data collected by the Rancho Bernardo wind instruments shows cyclical wind patterns in the neighborhood. Initial evaluation of select WFDS simulations show data that mimics data gathered from the field.

Occurrence, compositional distribution, and toxicity assessment of pyrethroid insecticides in sediments from the fluvial systems of Chaohu Lake, Eastern China.

PubMed

Wang, Ji-Zhong; Bai, Ya-Shu; Wu, Yakton; Zhang, Shuo; Chen, Tian-Hu; Peng, Shu-Chuan; Xie, Yu-Wei; Zhang, Xiao-Wei

2016-06-01

Surface sediment-associated synthetic pyrethroid insecticides (SPs) are known to pose high risks to the benthic organisms in Chaohu Lake, a shallow lake of Eastern China. However, the pollution status of the lake's tributaries and estuaries is still unknown. The present study was conducted to investigate the occurrence, compositional distribution, and toxicity of 12 currently used SPs in the surface sediments from four important tributaries, as well as in the sediment cores at their estuaries, using GC-MS for quantification. All SPs selected were detectable, with cypermethrin, es/fenvalerate, and permethrin dominant in both surface and core sediments, suggesting that these compounds were extensively applied. Urban samples contained the highest summed concentrations of the 12 SPs analyzed (Σ12SP) in both surface and core sediments compared with rural samples, suggesting that urban areas near aquatic environments posed high risks for SPs. The mean concentration of Σ12SP in surface sediments of each river was generally higher than that found in core sediments from its corresponding estuary, perhaps implying recent increases in SP usage. Surface sediments were significantly dominated by cypermethrin and permethrin, whereas core sediments were dominated by permethrin and es/fenvalerate. The compositional distributions demonstrated a spatial variation for surface sediments because urban sediments generally contained greater percentages of permethrin and cypermethrin, but rural sediments had significant levels of es/fenvalerate and cypermethrin. In all sediment cores, the percentage of permethrin gradually increased, whereas es/fenvalerate tended to decrease, from the bottom sediments to the top, indicating that the former represented fresh input, whereas the latter represented historical residue. Most urban samples would be expected to be highly toxic to benthic organisms due to the residue of SPs based on a calculation of toxic units (TUs) using toxicity data of the amphipod Hyalella azteca. However, low TU values were found for the samples from rural areas. These results indicate that the bottom sediments were exposed to high risk largely by the residual SPs from urban areas. The summed TUs were mostly attributable to cypermethrin, followed by λ-cyhalothrin and es/fenvalerate. Despite permethrin contributing ∼28.7 % of the Σ12SP concentration, it only represented 6.34 % of the summed TUs. Therefore, our results suggest that high levels of urbanization can increase the accumulation of SPs in aquatic environments.

Buildings classification from airborne LiDAR point clouds through OBIA and ontology driven approach

NASA Astrophysics Data System (ADS)

Tomljenovic, Ivan; Belgiu, Mariana; Lampoltshammer, Thomas J.

2013-04-01

In the last years, airborne Light Detection and Ranging (LiDAR) data proved to be a valuable information resource for a vast number of applications ranging from land cover mapping to individual surface feature extraction from complex urban environments. To extract information from LiDAR data, users apply prior knowledge. Unfortunately, there is no consistent initiative for structuring this knowledge into data models that can be shared and reused across different applications and domains. The absence of such models poses great challenges to data interpretation, data fusion and integration as well as information transferability. The intention of this work is to describe the design, development and deployment of an ontology-based system to classify buildings from airborne LiDAR data. The novelty of this approach consists of the development of a domain ontology that specifies explicitly the knowledge used to extract features from airborne LiDAR data. The overall goal of this approach is to investigate the possibility for classification of features of interest from LiDAR data by means of domain ontology. The proposed workflow is applied to the building extraction process for the region of "Biberach an der Riss" in South Germany. Strip-adjusted and georeferenced airborne LiDAR data is processed based on geometrical and radiometric signatures stored within the point cloud. Region-growing segmentation algorithms are applied and segmented regions are exported to the GeoJSON format. Subsequently, the data is imported into the ontology-based reasoning process used to automatically classify exported features of interest. Based on the ontology it becomes possible to define domain concepts, associated properties and relations. As a consequence, the resulting specific body of knowledge restricts possible interpretation variants. Moreover, ontologies are machinable and thus it is possible to run reasoning on top of them. Available reasoners (FACT++, JESS, Pellet) are used to check the consistency of the developed ontologies, and logical reasoning is performed to infer implicit relations between defined concepts. The ontology for the definition of building is specified using the Ontology Web Language (OWL). It is the most widely used ontology language that is based on Description Logics (DL). DL allows the description of internal properties of modelled concepts (roof typology, shape, area, height etc.) and relationships between objects (IS_A, MEMBER_OF/INSTANCE_OF). It captures terminological knowledge (TBox) as well as assertional knowledge (ABox) - that represents facts about concept instances, i.e. the buildings in airborne LiDAR data. To assess the classification accuracy, ground truth data generated by visual interpretation and calculated classification results in terms of precision and recall are used. The advantages of this approach are: (i) flexibility, (ii) transferability, and (iii) extendibility - i.e. ontology can be extended with further concepts, data properties and object properties.

From the litter up and the sky down: Perspectives on urban ...

EPA Pesticide Factsheets

The structure of the urban forest represents the complex product of local biophysical conditions, socio-economic milieu, people preferences and management with rare counterparts in rural forests. However, urban forest structure, as similarly observed in rural forests, affects key ecological and hydrological processes as well as the plethora of organisms regulating these processes. This seminar talk will firstly present key mechanisms regulating urban eco-hydrological processes “from a litter up” perspective. In particular, fine scale effects of urban forest structure upon i) organic matter decomposition, and comminution, ii) community-assembly of decomposers, detritivores, and ecosystem engineers (i.e. bacteria, litter-dwelling macrofauna, ants), and iii) stormwater runoff infiltration and interception will be discussed. The second part of this intervention will look at the structure of the urban forest “from a sky down” perspective. Recent findings from large scale LiDAR investigations will be presented to discuss social and biophysical drivers affecting urban forest structure at sub-continental scale, as well as short-term tree loss dynamics across residential landscapes, and how these can potentially affect eco-hydrological processes at large scale. Urban forest structure, as similarly observed in rural forests, affects key ecological and hydrological processes as well as the plethora of organisms regulating these processes.

Elderly suicide trends in the context of transforming China, 1987–2014

PubMed Central

Zhong, Bao-Liang; Chiu, Helen F. K.; Conwell, Yeates

2016-01-01

In the context of rapid ageing, understanding the time-trend of elderly suicide (ES) could inform China’s efforts on suicide prevention. We examined time-trends in Chinese ES rates (ESRs) from 1987 to 2014, a period of profound social changes. Suicide rates by residence (rural/urban), gender, and 5-year age-group (65+) in 1987–2014 were provided by the Chinese Ministry of Health. Time-trends were analyzed with joinpoint analysis. The time-trend of national ESRs was downward (average annual percent change [AAPC] = −3.7, P < 0.001): 76.6/100000 in 1987 and 30.2/100000 in 2014. However, the time-trend of corresponding percentages of ESs among the total suicides was monotonically increasing (AAPC = 3.4, P < 0.001): 16.9% in 1987 to 41.2% in 2014. The time-trends in ESRs of both rural and urban men and women were decreasing, but only the rural trends were significant (P < 0.001). Rural-urban and male-female differences in ESRs were decreasing over time (slope = −4.2 and −3.0, P ≤ 0.006), but the rural-urban and male-female ESR differences in 2014 remained large (16.3/100000 and 9.8/100000, P < 0.001). While national ESRs decreased significantly during the past three decades, the current ESR remains high in China. Further, the age-pattern of Chinese suicide is transitioning to elderly predominance. ES, particularly rural ES, should be a public health priority in China. PMID:27886219

Multiple health benefits of urban tree canopy: The mounting evidence for a green prescription.

PubMed

Ulmer, Jared M; Wolf, Kathleen L; Backman, Desiree R; Tretheway, Raymond L; Blain, Cynthia Ja; O'Neil-Dunne, Jarlath Pm; Frank, Lawrence D

2016-11-01

The purpose of this study was to enhance the understanding of the health-promoting potential of trees in an urbanized region of the United States. This was done using high-resolution LiDAR and imagery data to quantify tree cover within 250m of the residence of 7910 adult participants in the California Health Interview Survey, then testing for main and mediating associations between tree cover and multiple health measures. The results indicated that more neighborhood tree cover, independent from green space access, was related to better overall health, primarily mediated by lower overweight/obesity and better social cohesion, and to a lesser extent by less type 2 diabetes, high blood pressure, and asthma. These findings suggest an important role for trees and nature in improving holistic population health in urban areas. Copyright © 2016 Elsevier Ltd. All rights reserved.

Downwind effects on an arid dunefield from an evolving urbanised area

NASA Astrophysics Data System (ADS)

Hernández-Calvento, L.; Jackson, D. W. T.; Medina, R.; Hernández-Cordero, A. I.; Cruz, N.; Requejo, S.

2014-12-01

The impacts of urbanised zones on aeolian dynamics are little understood, particularly within arid areas. This study examines the large-scale influence of a growing tourist resort in Gran Canaria Island, Spain, on the sedimentary dynamics of an arid dunefield. Direct downwind effects from the urban area on the dune field surface are modelled for pre-growth and post-growth phases of the urban development. The geomorphological changes observed in the area stretching from the shoreline to the inland transgressive dune field were documented through aerial photographic and LiDAR evidence. Impacts of the urban growth on airflow, as well as those induced by tourists in the upper beach zone (de-vegetation), are examined through analysis of topographic changes. These impacts on the system are shown to have been synergistic in driving the development of a composite dune ridge, formed by the coalescence of smaller dunes into a distinctive aeolian accumulation ridge.

A Web-GIS Procedure Based on Satellite Multi-Spectral and Airborne LIDAR Data to Map the Road blockage Due to seismic Damages of Built-Up Urban Areas

NASA Astrophysics Data System (ADS)

Costanzo, Antonio; Montuori, Antonio; Silva, Juan Pablo; Silvestri, Malvina; Musacchio, Massimo; Buongiorno, Maria Fabrizia; Stramondo, Salvatore

2016-08-01

In this work, a web-GIS procedure to map the risk of road blockage in urban environments through the combined use of space-borne and airborne remote sensing sensors is presented. The methodology concerns (1) the provision of a geo-database through the integration of space-borne multispectral images and airborne LiDAR data products; (2) the modeling of building vulnerability, based on the corresponding 3D geometry and construction time information; (3) the GIS-based mapping of road closure due to seismic- related building collapses based on the building characteristic height and the width of the road. Experimental results, gathered for the Cosenza urban area, allow demonstrating the benefits of both the proposed approach and the GIS-based integration of multi-platforms remote sensing sensors and techniques for seismic road assessment purposes.

Patterns and trends in urban biodiversity and landscape design

Treesearch

Norbert Müller; Maria Ignatieva; Charles H. Nilon; Peter Werner; Wayne C. Zipperer

2013-01-01

Urbanization destroys or modifi es native habitats and creates new ones with its infrastructure. Because of these changes, urban landscapes favor non-native and native species that are generalists. Nevertheless, cities reveal a great variety of habitats and species, and, especially in temperate cities, the diversity of vascular plants and birds can be higher than in...

Can smartphones and tablets improve the management of childhood illness in Tanzania? A qualitative study from a primary health care worker's perspective.

PubMed

Shao, Amani Flexson; Rambaud-Althaus, Clotilde; Swai, Ndeniria; Kahama-Maro, Judith; Genton, Blaise; D'Acremont, Valerie; Pfeiffer, Constanze

2015-04-02

The impact of the Integrated Management of Childhood Illness (IMCI) strategy has been less than anticipated because of poor uptake. Electronic algorithms have the potential to improve quality of health care in children. However, feasibility studies about the use of electronic protocols on mobile devices over time are limited. This study investigated constraining as well as facilitating factors that influence the uptake of a new electronic Algorithm for Management of Childhood Illness (ALMANACH) among primary health workers in Dar es Salaam, Tanzania. A qualitative approach was applied using in-depth interviews and focus group discussions with altogether 40 primary health care workers from 6 public primary health facilities in the three municipalities of Dar es Salaam, Tanzania. Health worker's perceptions related to factors facilitating or constraining the uptake of the electronic ALMANACH were identified. In general, the ALMANACH was assessed positively. The majority of the respondents felt comfortable to use the devices and stated that patient's trust was not affected. Most health workers said that the ALMANACH simplified their work, reduced antibiotic prescription and gave correct classification and treatment for common causes of childhood illnesses. Few HWs reported technical challenges using the devices and complained about having had difficulties in typing. Majority of the respondents stated that the devices increased the consultation duration compared to routine practice. In addition, health system barriers such as lack of staff, lack of medicine and lack of financial motivation were identified as key reasons for the low uptake of the devices. The ALMANACH built on electronic devices was perceived to be a powerful and useful tool. However, health system challenges influenced the uptake of the devices in the selected health facilities.

Risk factors for anaemia among HIV infected children attending HIV care and treatment clinic at Muhimbili National Hospital in Dar es Salaam, Tanzania.

PubMed

Makubi, Abel N; Mugus, Ferdinand; Magesa, Pius M; Roberts, David; Quaresh, Amrana

2012-01-01

There is paucity of data describing the risk factors for anaemia among HIV infected children in Tanzania. This cross sectional study aimed at determining the contributing factors for anaemia among HIV-infected children attending Muhimbili National Hospital in Dar es Salaam. Both univariate and multivariate logistic regression analyses were performed to identify possible factors associated with anaemia in HIV-infected children. In this study a total of 75 (44%) patients among 167 recruited HIV children aged 6 months to 59 months were found to be anaemic (Hg<11 g/dl). Multivariate logistic regression demonstrated that not being on HAART (OR 3.40, 95%CI (1.20-9.60), having CD4% <25% (OR 2.30, 95%CI (1.20-34.60), having a history of tuberculosis (TB) (OR 3.23, 95%CI (1.10-9.70) and having hookworm infestation (OR 5.97, 95%CI (1.92-18.4) were independent risk factors for anaemia among HIV infected children. The analyses also showed that being HIV positive for ≥ 2.5 years resulted into a low risk of severe anaemia compared to being HIV positive for < 2.5 years. Taking multivitamins (OR 0.07, 95%, CI (0.020-0.30) and antihelminthics (OR 0.27, 95%CI (0.10-0.74) were also protective against anaemia in children. Similar factors (with exception of using antihelmintics) were associated with severe anaemia. In conclusion the factors associated with anaemia in HIV infected children were multifactorial in nature. Efforts to correct anaemia in HIV infected children should include use of HAART and treatment of infections such as TB and hookworms.

Maternal Dietary L-Arginine and Adverse Birth Outcomes in Dar es Salaam, Tanzania.

PubMed

Darling, Anne Marie; McDonald, Chloe R; Urassa, Willy S; Kain, Kevin C; Mwiru, Ramadhani S; Fawzi, Wafaie W

2017-09-01

The amino acid arginine is a physiological precursor to nitric oxide, which is a key mediator of embryonic survival, fetal growth, and pregnancy maintenance. We evaluated the association between consumption of the amino acid arginine and the rate of adverse birth outcomes using data from a double-blind, randomized, placebo-controlled micronutrient supplementation trial among pregnant women in Dar es Salaam, Tanzania (2001-2004). Dietary intakes of arginine were assessed using repeated 24-hour recalls that were administered throughout pregnancy. Participants (n = 7,591) were monitored by research midwives throughout follow-up to assess pregnancy outcomes. Cubic-restricted splines and multivariable log-Poisson regression with empirical standard errors were used to estimate the continuous and categorical associations between arginine intake and adverse birth outcomes. Compared with women within the lowest quintile of arginine intake, those within the highest quintile had 0.79 times the risk of preterm birth before 37 weeks (95% confidence interval: 0.63, 1.00; P = 0.03). The continuous associations of arginine intake with preterm birth before 37 weeks and with preterm birth before 34 weeks were characterized by an initial rapid decrease in risk with increasing intake (P for nonlinearity < 0.01). Arginine intake was not associated with fetal loss or giving birth to infants who were born small for their gestational ages. This data suggest that the association between dietary arginine intake and preterm birth warrants further investigation. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Prevalence and risk factors for skin diseases among antiretroviral-naïve HIV-infected pregnant women in Dar es Salaam, Tanzania.

PubMed

Shayo, Grace A; Moshiro, Candida; Spiegelman, Donna; Mugusi, Ferdinand M; Chalamilla, Guerino; Msamanga, Gernard; Hawkins, Claudia; Fawzi, Wafaie

2014-10-01

Reduced cell-mediated immunity associated with pregnancy may cause a flaring or exacerbation of some skin conditions. Little is known about the magnitude of and risk factors for skin diseases among human immunodeficiency virus (HIV)-infected antiretroviral therapy-naïve pregnant women. Cross-sectional study of 1078 HIV-infected antiretroviral therapy-naïve pregnant women was conducted in Dar es Salaam, Tanzania. Skin diagnoses were mainly clinical. Log-binomial regression models were used to explore factors associated with the outcomes. About 84% of the women were in World Health Organization (WHO) HIV stage I. Median CD4(+) count was 405 × 10(6)  cells/l. The prevalence of any skin disease was 18%. Fungal infections (11%), genital ulcers (7%), and viral infections (5%) were the most common skin conditions. Skin infections were 2.64 times more common in HIV stage III (95% CI 1.51-4.62) compared to stage I. Fungal infections were 1.77 times common among single, divorced, and widowed women than among married women (95% CI 1.16-2.69), 2.8 times common among women in HIV stage III (95% CI 1.18-6.64) compared to stage I. Genital ulcers were significantly more common among women whose source of income was their own compared with those who got full support from partners, and among WHO HIV stage III disease compared to stage I. The burden of skin diseases was relatively low. Advanced HIV stage was associated with a range of skin conditions. CD4(+) cell count was not related to skin infection prevalence. © 2014 The International Society of Dermatology.

Sexual behavior and condom use among male students in Dar-Es-Salaam, Tanzania with emphasis on contact with barmaids.

PubMed

Maswanya, Edward S; Moji, Kazuhiko; Yamamoto, Taro; Aoyagi, Kiyoshi; Yahata, Yuichiro; Takemoto, Tai-Ichiro

2012-03-01

The objective of this quantitative study was to identifying factors that influence young men to participate in risky sexual behavior that place them at risk of HIV infection, as young people are at higher risk for HIV infection than adults. A cross-sectional study design that employed face-to-face interview questionnaire to identify socio-demographic characteristics, sexual behavior, knowledge of HIV, STD, attitudes towards condoms was administered to 175 sexually active male students between 17 and 24 years old in college settings of Dar-es-Salaam city, Tanzania. In the previous 12 months, 80% of students had at least one steady sex partner (girlfriend), 71% had sex with a barmaid, 33% had sex with a casual partner and 83% had multiple sex partners. Condoms had been used at some time by 83% of students, and in the latest sexual encounter by 56%. However, only 37%, 22%, and 11% consistently used condoms during sex with girlfriends, casual partners and barmaids, respectively. Condom use was least popular during sex with barmaids, and 94% and 91% of students had experienced oral and anal sex with barmaids, respectively. STD infection was reported by 42% of students. Sex with barmaids was associated with alcohol and illicit drug intake, sex under their respective influences, and STD infection. Despite the high prevalence of these risky behaviors, 64% of students replied that they were at low or no risk of HIV infection. Our findings suggest that HIV prevention programs for male students should emphasize risks associated with multiple sexual partners, and sex with barmaids and casual partners, to increase the risk perception of HIV/AIDS. Condom use needs to be promoted.

Detection of CTX-M-15 beta-lactamases in Enterobacteriaceae causing hospital- and community-acquired urinary tract infections as early as 2004, in Dar es Salaam, Tanzania.

PubMed

Manyahi, Joel; Moyo, Sabrina J; Tellevik, Marit Gjerde; Ndugulile, Faustine; Urassa, Willy; Blomberg, Bjørn; Langeland, Nina

2017-04-17

The spread of Extended Spectrum β-lactamases (ESBLs) among Enterobacteriaceae and other Gram-Negative pathogens in the community and hospitals represents a major challenge to combat infections. We conducted a study to assess the prevalence and genetic makeup of ESBL-type resistance in bacterial isolates causing community- and hospital-acquired urinary tract infections. A total of 172 isolates of Enterobacteriaceae were collected in Dar es Salaam, Tanzania, from patients who met criteria of community and hospital-acquired urinary tract infections. We used E-test ESBL strips to test for ESBL-phenotype and PCR and sequencing for detection of ESBL genes. Overall 23.8% (41/172) of all isolates were ESBL-producers. ESBL-producers were more frequently isolated from hospital-acquired infections (32%, 27/84 than from community-acquired infections (16%, 14/88, p < 0.05). ESBL-producers showed high rate of resistance to ciprofloxacin (85.5%), doxycycline (90.2%), gentamicin (80.5%), nalidixic acid (84.5%), and trimethoprim-sulfamethoxazole (85.4%). Furthermore, 95% of ESBL-producers were multi-drug resistant compared to 69% of non-ESBL-producers (p < 0.05). The distribution of ESBL genes were as follows: 29/32 (90.6%) bla CTX-M-15 , two bla SHV-12 , and one had both bla CTX-M-15 and bla SHV-12 . Of 29 isolates carrying bla CTX-M-15 , 69% (20/29) and 31% (9/29) were hospital and community, respectively. Bla SHV-12 genotypes were only detected in hospital-acquired infections. bla CTX-M-15 is a predominant gene conferring ESBL-production in Enterobacteriaceae causing both hospital- and community-acquired infections in Tanzania.

Barriers and Promoters of Home-Based Pasteurization of Breastmilk Among HIV-Infected Mothers in Greater Dar es Salaam, Tanzania

PubMed Central

Leshabari, Sebalda; Arkfeld, Chaele; Singler, Jennifer; Dantzer, Emily; Israel-Ballard, Kiersten; Mashio, Clara; Maternowska, Catherine; Chantry, Caroline

2013-01-01

Abstract Background For the past decade, heat-treating breastmilk has been an infant feeding option recommended by the World Health Organization as a strategy to reduce vertical transmission. However, little is known about field experiences with it. Our primary objective was to explore the barriers and promoters of the implementation of breastmilk pasteurization, “flash-heating” (FH), in the real-world setting of Dar es Salaam, Tanzania. Subjects and Methods Nineteen in-depth interviews were conducted with participants in a home-based infant feeding counseling intervention in which FH was promoted after 6 months of exclusive breastfeeding. Additionally, three focus group discussions were conducted with peer counselors. Interviews were transcribed, translated, and coded independently using NVivo 8 software (QSR International). Data were analyzed using the socioecological framework. Results Information and support provided by peer counselors were the most important promoters of initiation and continuation of FH; this impacted individual-, interpersonal-, and institutional-level promoters of success. Other promoters included perceived successful breastmilk expression, infant health after initiation of FH, and the inability to pay for replacement milks. Stigma was the most important barrier and cut across all levels of the framework. Other barriers included doubt about the safety or importance of pasteurized breastmilk, difficulties with expressing milk (often attributed to poor diet), and competing responsibilities. The most common suggestion for improving the uptake and duration of FH was community education. Conclusions Given the acknowledged role of breastmilk pasteurization in the prevention of vertical transmission, further implementation research is needed. A multilevel intervention addressing barriers to FH would likely improve uptake. PMID:23131094

Homicide of children in Dar es Salaam, Tanzania.

PubMed

Outwater, Anne H; Mgaya, Edward; Campbell, Jacqueline C; Becker, Stan; Kinabo, Linna; Menick, Daniel Mbassa

2010-12-01

Although data are sparse, it has been estimated that the highest rates of homicide death amongst children are in Africa. Little information is available on ages 0-14 years. No known quantitative surveillance of early neonaticide (killed at less than one week) has been conducted previously in Africa. A Violent Death Survey following WHO/CDC Guidelines was completed in Dar es Salaam region, Tanzania (population 2.845 million) in 2005. Qualitative and quantitative data were gathered and analyzed. The overall age adjusted rate of discarded and killed children in DSM was 2.05 per 100,000. The rate of early neonaticide was 27.7 per 100,000 while the rate of homicide incidence for children older than one week was 0.54 per 100,000 The overall estimated homicide rate for Africa of children under age 15 was 4.53 per 100,000. The rate in DSM was closer to the estimated global rate of 1.7 per 100,000. The results in DSM show that broad age groupings such as "< 1 year", "0-4 years" and "0-14 years" may mask a high incidence of neonaticide and an otherwise low incidence of murdered children. The print media provided good in-depth coverage for a few cases but it is not known if the reported cases are representative. Eighty percent of homicides of children in DSM were neonaticides. Since it is believed that the forces behind neonaticide are fundamentally different than homicides of older children, it is suggested that data of future surveys be parsed to include neonates, until the phenomenon is more clearly understood and addressed. Further understanding of the mother and father of the deceased is needed. Continued surveillance data collection is important to expand the sample size.

Homicide of children in Dar es Salaam, Tanzania, 2005

PubMed Central

Outwater, Anne; Mgaya, Edward; Campbell, Jacquelyn C.; Becker, Stan; Kinabo, Linna; Menick, Daniel Mbassa

2014-01-01

Background Although data are sparse, it has been estimated that the highest rates of homicide death amongst children are in Africa. Little information is available on ages 0 -< 15 years. No reliable quantitative surveillance analysis of neonaticide (killed at less than one week) has been done. Methods A Violent Death Survey following WHO/CDC Guidelines was completed in Dar es Salaam region, Tanzania (DSM) (population 2.845 million) in 2005. Qualitative and quantitative data were gathered and analyzed using mixed methods techniques. Results The overall age adjusted rate of discarded and killed children in DSM was 2.05. The rate of neonaticide was 27.7 per 100,000) while the rate of homicide incidence for children > one day was Discussion The overall estimated homicide rate for Africa of children under age 15 was 4.53 per 100,000, whereas. The estimated global rate is 1.7 per 100,000 closer to DSM‘s rate. The results in DSM show that broad age groupings such as ” <1 year” or “0–4 years” or “0 – <15 years” may mask a high incidence of neonaticide and an otherwise low incidence of murdered children. The print media provided good in-depth coverage for a few cases but it is not known if the reported cases are representative. Conclusion Eighty percent of homicides of children in DSM are neonaticides. Since it is believed that the forces behind neonaticide are fundamentally different than homicides of older children, it is suggested that data of future surveys be parsed to include neonates, until the phenomenon is more clearly understood and addressed. Further understanding of the mother and father of the deceased is needed. Continued surveillance data collection is important to expand the sample size. PMID:22066333

Enhancing the application of effective malaria interventions in Africa through training.

PubMed

Ijumba, Jasper N; Kitua, Andrew Y

2004-08-01

Africa bears more than 90% of the entire global malaria disease burden. Surprisingly, even with the current renewed interest in malaria prevention and control and the enabling environment resulting from the Roll Back Malaria initiative and the political commitment made by the African Presidents at the Abuja Summit, there are still no significant initiatives for strengthening capacity for malaria control through training within the African continent itself. The Center for Enhancement of Effective Malaria Interventions (CEEMI) has been established in Dar es Salaam, Tanzania for results-oriented training. It is intended to provide the needed skills for identifying and solving malaria control problems and providing incentives to malaria control workers in their work performance. The intention is to produce implementers with leadership skills for planning and managing malaria control activities and who can use strategic thinking in improving their work performance. To sustain political commitment and support and to sensitize the community on malaria issues, the CEEMI, in collaboration with the Ministry of Health (National Malaria Control Program), the Institute of Journalism and Mass Communication of the University of Dar es Salaam, and the Commonwealth Broadcasting Association have already conducted malaria seminars for Tanzanian Members of Parliament and journalists from Kenya, Malawi, Tanzania, and Uganda. Additionally, a diploma course in health communication is being developed for journalists and for the same purpose. Also being developed is a training module for "Council Malaria Focal Person." This is aimed at complementing the Roll Back Malaria initiative to meet the Abuja targets of reducing morbidity and mortality due to malaria by 50% by 2010. Copyright 2004 The American Society of Tropical Medicine and Hygiene

Predicting biotic community response to urbanization using high-resolution landuse/landcover data

EPA Science Inventory

Under EPA’s Green Infrastructure Initiative, research activities are underway to evaluate the effectiveness of green infrastructure in mitigating the effects of urbanization and stormwater impacts on stream biota and habitat. Preliminary analyses, using impervious cover es...

Estimating the Limits of Infiltration in the Urban Appalachian Plateau

NASA Astrophysics Data System (ADS)

Lavin, S. M.; Bain, D.; Hopkins, K. G.; Pfeil-McCullough, E. K.; Copeland, E.

2014-12-01

Green infrastructure in urbanized areas commonly uses infiltration systems, such as rain gardens, swales and trenches, to convey surface runoff from impervious surfaces into surrounding soils. However, precipitation inputs can exceed soil infiltration rates, creating a limit to infiltration-based storm water management, particularly in urban areas covered by impervious surfaces. Given the limited availability and varied quality of soil infiltration rate data, we synthesized information from national databases, available field test data, and applicable literature to characterize soil infiltration rate distributions, focusing on Allegheny County, Pennsylvania as a case study. A range of impervious cover conditions was defined by sampling available GIS data (e.g., LiDAR and street edge lines) with analysis windows placed randomly across urbanization gradients. Changes in effective precipitation caused by impervious cover were calculated across these gradients and compared to infiltration rate distributions to identify thresholds in impervious coverage where these limits are exceeded. Many studies have demonstrated the effects of urbanization on infiltration, but the identification of these thresholds will clarify interactions between impervious cover and soil infiltration. These methods can help identify sections of urban areas that require augmentation of infiltration-based systems with additional infrastructural strategies, especially as green infrastructure moves beyond low impact development towards more frequent application during infilling of existing urban systems.

Evidence of social network influence on multiple HIV risk behaviors and normative beliefs among young Tanzanian men

PubMed Central

Mulawa, Marta; Yamanis, Thespina J.; Hill, Lauren; Balvanz, Peter; Kajula, Lusajo J.; Maman, Suzanne

2016-01-01

Research on network-level influences on HIV risk behaviors among young men in sub-Saharan Africa is severely lacking. One significant gap in the literature that may provide direction for future research with this population is understanding the degree to which various HIV risk behaviors and normative beliefs cluster within men’s social networks. Such research may help us understand which HIV-related norms and behaviors have the greatest potential to be changed through social influence. Additionally, few network-based studies have described the structure of social networks of young men in sub-Saharan Africa. Understanding the structure of men’s peer networks may motivate future research examining the ways in which network structures shape the spread of information, adoption of norms, and diffusion of behaviors. We contribute to filling these gaps by using social network analysis and multilevel modeling to describe a unique dataset of mostly young men (n= 1,249 men and 242 women) nested within 59 urban social networks in Dar es Salaam, Tanzania. We examine the means, ranges, and clustering of men’s HIV-related normative beliefs and behaviors. Networks in this urban setting varied substantially in both composition and structure and a large proportion of men engaged in risky behaviors including inconsistent condom use, sexual partner concurrency, and intimate partner violence perpetration. We found significant clustering of normative beliefs and risk behaviors within these men’s social networks. Specifically, network membership explained between 5.78 and 7.17% of variance in men’s normative beliefs and between 1.93 and 15.79% of variance in risk behaviors. Our results suggest that social networks are important socialization sites for young men and may influence the adoption of norms and behaviors. We conclude by calling for more research on men’s social networks in Sub-Saharan Africa and map out several areas of future inquiry. PMID:26874081

Evidence of social network influence on multiple HIV risk behaviors and normative beliefs among young Tanzanian men.

PubMed

Mulawa, Marta; Yamanis, Thespina J; Hill, Lauren M; Balvanz, Peter; Kajula, Lusajo J; Maman, Suzanne

2016-03-01

Research on network-level influences on HIV risk behaviors among young men in sub-Saharan Africa is severely lacking. One significant gap in the literature that may provide direction for future research with this population is understanding the degree to which various HIV risk behaviors and normative beliefs cluster within men's social networks. Such research may help us understand which HIV-related norms and behaviors have the greatest potential to be changed through social influence. Additionally, few network-based studies have described the structure of social networks of young men in sub-Saharan Africa. Understanding the structure of men's peer networks may motivate future research examining the ways in which network structures shape the spread of information, adoption of norms, and diffusion of behaviors. We contribute to filling these gaps by using social network analysis and multilevel modeling to describe a unique dataset of mostly young men (n = 1249 men and 242 women) nested within 59 urban social networks in Dar es Salaam, Tanzania. We examine the means, ranges, and clustering of men's HIV-related normative beliefs and behaviors. Networks in this urban setting varied substantially in both composition and structure and a large proportion of men engaged in risky behaviors including inconsistent condom use, sexual partner concurrency, and intimate partner violence perpetration. We found significant clustering of normative beliefs and risk behaviors within these men's social networks. Specifically, network membership explained between 5.78 and 7.17% of variance in men's normative beliefs and between 1.93 and 15.79% of variance in risk behaviors. Our results suggest that social networks are important socialization sites for young men and may influence the adoption of norms and behaviors. We conclude by calling for more research on men's social networks in Sub-Saharan Africa and map out several areas of future inquiry. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of point-of-care ultrasound on clinical decision-making at an urban emergency department in Tanzania.

PubMed

Reynolds, Teri Ann; Amato, Stas; Kulola, Irene; Chen, Chuan-Jay Jeffrey; Mfinanga, Juma; Sawe, Hendry Robert

2018-01-01

Point of care ultrasound (PoCUS) is an efficient, inexpensive, safe, and portable imaging modality that can be particularly useful in resource-limited settings. However, its impact on clinical decision making in such settings has not been well studied. The objective of this study is to describe the utilization and impact of PoCUS on clinical decision making at an urban emergency department in Dar es Salaam, Tanzania. This was a prospective descriptive cross-sectional study of patients receiving PoCUS at Muhimbili National Hospital's Emergency Medical Department (MNH EMD). Data on PoCUS studies during a period of 10 months at MNH EMD was collected on consecutive patients during periods when research assistants were available. Data collected included patient age and sex, indications for ultrasound, findings, interpretations, and provider-reported diagnostic impression and disposition plan before and after PoCUS. Descriptive statistics, including medians and interquartile ranges, and counts and percentages, are reported. Pearson chi squared tests and p-values were used to evaluate categorical data for significant differences. PoCUS data was collected for 986 studies performed on 784 patients. Median patient age was 32 years; 56% of patients were male. Top indications for PoCUS included trauma, respiratory presentations, and abdomino-pelvic pain. The most frequent study types performed were eFAST, cardiac, and obstetric or gynaecologic studies. Overall, clinicians reported that the use of PoCUS changed either diagnostic impression or disposition plan in 29% of all cases. Rates of change in diagnostic impression or disposition plan increased to 45% in patients for whom more than one PoCUS study type was performed. In resource-limited emergency care settings, PoCUS can be utilized for a wide range of indications and has substantial impact on clinical decision making, especially when more than one study type is performed.

Utilization of toothpaste and fluoride content in toothpaste manufactured in Tanzania.

PubMed

Kikwilu, Emil N; Frencken, Jo E; Mulder, Jan

2008-10-01

To determine the use of toothpaste, the reasons behind its irregular use, the cost perceptions, and the fluoride concentrations in locally manufactured toothpaste. A total of 978 dental patients attending 13 dental clinics for 2 weeks in June 2007 completed a pre-tested questionnaire on toothpaste use. Toothpaste was collected from shops in Dar es Salaam and analyzed at the laboratory of the Dental School in Amsterdam. Logistic regression was applied to determine the relative importance of independent variables on usage and perceptions about the cost of toothpaste. Eighty-six percent of respondents used toothpaste daily. Of the 130 who used toothpaste less than once a day, 57.7% gave financial reasons for their irregular use. Toothpaste was perceived as expensive by 34.8% of respondents. Urban residents were five times more likely than rural residents to use toothpaste. Younger respondents were more likely than older respondents: to perceive toothpaste as important, to brush their teeth, to use toothpaste, and to brush their teeth regularly. All toothpaste manufactured in Tanzania had free fluoride concentrations below 400 ppm. Most respondents used toothpaste regularly and one-third regarded it as expensive. Toothpaste manufactured in Tanzania had free fluoride concentrations below the optimum levels for dental caries prevention. For a well-functioning Basic Package of Oral Care, the authority responsible for oral health has to take measures aimed at lowering the price of toothpaste, and toothpaste manufacturers have to ensure that their products have the optimal fluoride concentration for dental caries prevention.

Prevalence of post-traumatic stress disorder in children: the case of the Mbagala bomb blasts in Tanzania.

PubMed

Messo, Innocent Nasson

2013-05-01

In April 2009, military bombs stockpiled in Mbagala, Dar es Salaam, exploded uncontrollably, landing in the neighbourhood killing 26 people, injuring about 600 and destroying 9049 homes. This must have been a terrible experience, with psychological consequences. The purpose of this study was to investigate the prevalence of Post-Traumatic Stress Disorder (PTSD) among the children involved in the bomb blasts. It was hypothesized that children would not exhibit PTSD symptoms, as well as not showing sex differences in exhibiting PTSD symptoms. The study findings show 93% of children bomb survivors had PTSD symptoms, with no sex differences in the PTSD reported.

Assessing stream bank condition using airborne LiDAR and high spatial resolution image data in temperate semirural areas in Victoria, Australia

NASA Astrophysics Data System (ADS)

Johansen, Kasper; Grove, James; Denham, Robert; Phinn, Stuart

2013-01-01

Stream bank condition is an important physical form indicator for streams related to the environmental condition of riparian corridors. This research developed and applied an approach for mapping bank condition from airborne light detection and ranging (LiDAR) and high-spatial resolution optical image data in a temperate forest/woodland/urban environment. Field observations of bank condition were related to LiDAR and optical image-derived variables, including bank slope, plant projective cover, bank-full width, valley confinement, bank height, bank top crenulation, and ground vegetation cover. Image-based variables, showing correlation with the field measurements of stream bank condition, were used as input to a cumulative logistic regression model to estimate and map bank condition. The highest correlation was achieved between field-assessed bank condition and image-derived average bank slope (R2=0.60, n=41), ground vegetation cover (R=0.43, n=41), bank width/height ratio (R=0.41, n=41), and valley confinement (producer's accuracy=100%, n=9). Cross-validation showed an average misclassification error of 0.95 from an ordinal scale from 0 to 4 using the developed model. This approach was developed to support the remotely sensed mapping of stream bank condition for 26,000 km of streams in Victoria, Australia, from 2010 to 2012.

The Early Detection of the Emerald Ash Borer (eab) Using Multi-Source Remotely Sensed Data

NASA Astrophysics Data System (ADS)

Hu, B.; Naveed, F.; Tasneem, F.; Xing, C.

2018-04-01

The objectives of this study were to exploit the synergy of hyperspectral imagery, Light Detection And Ranging (LiDAR) and high spatial resolution data and their synergy in the early detection of the EAB (Emerald Ash Borer) presence in trees within urban areas and to develop a framework to combine information extracted from multiple data sources. To achieve these, an object-oriented framework was developed to combine information derived from available data sets to characterize ash trees. Within this framework, an advanced individual tree delineation method was developed to delineate individual trees using the combined high-spatial resolution worldview-3 imagery was used together with LiDAR data. Individual trees were then classified to ash and non-ash trees using spectral and spatial information. In order to characterize the health state of individual ash trees, leaves from ash trees with various health states were sampled and measured using a field spectrometer. Based on the field measurements, the best indices that sensitive to leaf chlorophyll content were selected. The developed framework and methods were tested using worldview-3, airborne LiDAR data over the Keele campus of York University Toronto Canada. Satisfactory results in terms of individual tree crown delineation, ash tree identification and characterization of the health state of individual ash trees. Quantitative evaluations is being carried out.

Unsupervised building detection from irregularly spaced LiDAR and aerial imagery

NASA Astrophysics Data System (ADS)

Shorter, Nicholas Sven

As more data sources containing 3-D information are becoming available, an increased interest in 3-D imaging has emerged. Among these is the 3-D reconstruction of buildings and other man-made structures. A necessary preprocessing step is the detection and isolation of individual buildings that subsequently can be reconstructed in 3-D using various methodologies. Applications for both building detection and reconstruction have commercial use for urban planning, network planning for mobile communication (cell phone tower placement), spatial analysis of air pollution and noise nuisances, microclimate investigations, geographical information systems, security services and change detection from areas affected by natural disasters. Building detection and reconstruction are also used in the military for automatic target recognition and in entertainment for virtual tourism. Previously proposed building detection and reconstruction algorithms solely utilized aerial imagery. With the advent of Light Detection and Ranging (LiDAR) systems providing elevation data, current algorithms explore using captured LiDAR data as an additional feasible source of information. Additional sources of information can lead to automating techniques (alleviating their need for manual user intervention) as well as increasing their capabilities and accuracy. Several building detection approaches surveyed in the open literature have fundamental weaknesses that hinder their use; such as requiring multiple data sets from different sensors, mandating certain operations to be carried out manually, and limited functionality to only being able to detect certain types of buildings. In this work, a building detection system is proposed and implemented which strives to overcome the limitations seen in existing techniques. The developed framework is flexible in that it can perform building detection from just LiDAR data (first or last return), or just nadir, color aerial imagery. If data from both LiDAR and aerial imagery are available, then the algorithm will use them both for improved accuracy. Additionally, the proposed approach does not employ severely limiting assumptions thus enabling the end user to apply the approach to a wider variety of different building types. The proposed approach is extensively tested using real data sets and it is also compared with other existing techniques. Experimental results are presented.

Focusing on the big picture: urban vegetation and eco ...

EPA Pesticide Factsheets

Trees and vegetation can be key components of urban green infrastructure and green spaces such as parks and residential yards. Large trees, characterized by broad canopies, and high leaf and stem volumes, can intercept a substantial amount of stormwater while promoting evapotranspiration and reducing stormwater runoff and pollutant loads. Urban vegetation cover, height, and volume are likely to be affected not only by local climatic characteristics, but also by complex socio-economic dynamics resulting from management practices and resident’s preferences. We examine the benefits provided by private greenspace and present preliminary findings related to the climatic and socio-economic drivers correlated with structural complexity of residential urban vegetation. We use laser (LiDAR) and multispectral remotely-sensed data collected throughout 1400+ neighborhoods and 1.2+ million residential yards across 8 US cities to carry out this analysis. We discuss principles and opportunities to enhance stormwater management using residential greenspace, as well as the larger implications for decentralized stormwater management at city-wide scale. We discuss principles and opportunities to enhance stormwater management using residential greenspace, as well as the larger implications for decentralized stormwater management at city-wide scale.

A new tent trap for sampling exophagic and endophagic members of the Anopheles gambiae complex.

PubMed

Govella, Nicodemus J; Chaki, Prosper P; Geissbuhler, Yvonne; Kannady, Khadija; Okumu, Fredros; Charlwood, J Derek; Anderson, Robert A; Killeen, Gerry F

2009-07-14

Mosquito sampling methods are essential for monitoring and evaluating malaria vector control interventions. In urban Dar es Salaam, human landing catch (HLC) is the only method sufficiently sensitive for monitoring malaria-transmitting Anopheles. HLC is labour intensive, cumbersome, hazardous, and requires such intense supervision that is difficulty to sustain on large scales. Novel tent traps were developed as alternatives to HLC. The Furvela tent, designed in Mozambique, incorporates a CDC Light trap (LT) components, while two others from Ifakara, Tanzania (designs A and B) require no electricity or moving parts. Their sensitivity for sampling malaria vectors was compared with LT and HLC over a wide range of vector abundances in rural and urban settings in Tanzania, with endophagic and exophagic populations, respectively, using randomised Latin-square and cross- over experimental designs. The sensitivity of LTs was greater than HLC while the opposite was true of Ifakara tent traps (crude mean catch of An. gambiae sensu lato relative to HLC = 0.28, 0.65 and 1.30 for designs A, B and LT in a rural setting and 0.32 for design B in an urban setting). However, Ifakara B catches correlated far better to HLC (r2 = 0.73, P < 0.001) than any other method tested (r2 = 0.04, P = 0.426 and r2 = 0.19, P = 0.006 for Ifakara A and LTs respectively). Only Ifakara B in a rural setting with high vector density exhibited constant sampling efficiency relative to HLC. The relative sensitivity of Ifakara B increased as vector densities decreased in the urban setting and exceeded that of HLC at the lowest densities. None of the tent traps differed from HLC in terms of the proportions of parous mosquitoes (P >or= 0.849) or An. gambiae s.l. sibling species (P >or= 0.280) they sampled but both Ifakara A and B designs failed to reduce the proportion of blood-fed mosquitoes caught (Odds ratio [95% Confidence Interval] = 1.6 [1.2, 2.1] and 1.0 [0.8, 1.2], P = 0.002 and 0.998, respectively), probably because of operator exposure while emptying the trap each morning. The Ifakara B trap may have potential for monitoring and evaluating a variety of endophagic and exophagic Afrotropical malaria vectors, particularly at low but epidemiologically relevant population densities. However, operator exposure to mosquito bites remains a concern so additional modifications or protective measures will be required before this design can be considered for widespread, routine use.

Regionalstatistik

NASA Astrophysics Data System (ADS)

Eppmann, Helmut; Fürnrohr, Michael

Viele Aufgaben in Politik, Wirtschaft und Gesellschaft erfordern nicht nur globale, sondern auch regionale Lösungen. Die Regionalstatistik ist deshalb unentbehrlich für viele Planungs- und Entscheidungsprozesse. Ihren Ausbau und ihre Nutzung zu fördern, hat sich der Ausschuss für Regionalstatistik der Deutschen Statistischen Gesellschaft zum Ziel gesetzt. Dieses Kapitel stellt zunächst einige Grundlagen der Regionalstatistik und die Aufgaben des Ausschusses dar. Es folgen das umfangreiche regionalstatistische Datenangebot der Statistischen Ämter des Bundes und der Länder und seine Nutzung. Ein ergänzender Abschnitt ist der Arbeit des Instituts für Bau-, Stadt- und Raumforschung gewidmet. Das Kapitel schließt mit einem Ausblick auf die Weiterentwicklung des regionalstatistischen Datenangebotes aus Sicht der amtlichen Statistik.

Being forced to become your own Doctor - Men who have Sex with Men's Experiences of Stigma in the Tanzanian Healthcare System.

PubMed

Larsson, Markus; Ross, Michael W; Månsson, Sven-Axel; Nyoni, Joyce; Shio, Jasmine; Agardh, Anette

2016-01-01

To acquire a deepened understanding of how stigma in healthcare affects health-seeking behaviours of same-sex practising men in Tanzania. In-depth interviews with twelve men were conducted in Dar es Salaam, 2012. Data were interpreted through qualitative content analysis. Narratives revealed that men's healthcare perceptions were shaped by previous encounters, rumours in gay community, norms and legislation around homosexuality. Fears of exposure aggravated men's possibilities of giving full anamnesis and detached them from formal healthcare services. Stigma in healthcare might lead to severe public health problems due to perceived exclusion from the health system by sexual minorities.

3D turbulence measurements using three intersecting Doppler LiDAR beams: validation against sonic anemometry

NASA Astrophysics Data System (ADS)

Carbajo Fuertes, Fernando; Valerio Iungo, Giacomo; Porté-Agel, Fernando

2013-04-01

Nowadays communities of researchers and industry in the wind engineering and meteorology sectors demand extensive and accurate measurements of atmospheric boundary layer turbulence for a better understanding of its role in a wide range of onshore and offshore applications: wind resource evaluation, wind turbine wakes, meteorology forecast, pollution and urban climate studies, etc. Atmospheric turbulence has been traditionally investigated through sonic anemometers installed on meteorological masts. However, the setup and maintenance of instrumented masts is generally very costly and the available location for the measurements is limited by the fixed position and height of the facility. In order to overcome the above-mentioned shortcomings, a measurement technique is proposed, based on the reconstruction of the three-dimensional velocity vector from simultaneous measurements of three intersecting Doppler wind LiDARs. This measuring technique presents the main advantage of being able to measure the wind velocity at any point in space inside a very large volume, which can be set and optimized for each test. Furthermore, it is very flexible regarding its transportation, installation and operation in any type of terrain. On the other hand, LiDAR measurements are strongly affected by the aerosol concentration in the air, precipitation, and the spatial and temporal resolution is poorer than that of a sonic anemometer. All this makes the comparison between these two kinds of measurements a complex task. The accuracy of the technique has been assessed by this study against sonic anemometer measurements carried out at different heights on the KNMI's meteorological mast at Cabauw's experimental site for atmospheric research (CESAR) in the Netherlands. An early uncertainty analysis shows that one of the most important parameters to be taken into account is the relative angles between the intersecting laser beams, i.e., the position of each LiDAR on the terrain and their elevation and azimuth angles. Following this analysis, different LiDAR layouts have been tested, e.g., one vertical beam and the other two almost horizontal, all three equidistant with the same elevation angle, etc. Preliminary results show different degrees of agreement between the proposed technique and the sonic anemometers depending on the LiDARs layout, which is in agreement with the uncertainty analysis carried out. The best configurations show a good agreement for the three components of the velocity and turbulence spectra, thus proving the ability of the technique to measure accurately atmospheric turbulence, consolidating it as a very interesting alternative to meteorological masts for many different applications.

Mobile LiDAR Measurement for Aerosol Investigation in South-Central Hebei, China

NASA Astrophysics Data System (ADS)

qin, kai; Wu, Lixin; Zheng, Yunhui; Wong Man, Sing; Wang, Runfeng; Hu, Mingyu; Lang, Hongmei; Wang, Luyao; Bai, Yang; Rao, Lanlan

2016-04-01

With the rapid industrialization and urbanization in China during the last decades, the increasing anthropogenic pollutant emissions have significantly caused serious air pollution problems which are adversely influencing public health. Hebei is one of the most air polluted provinces in China. In January 2013, an extremely severe and persistent haze episode with record-breaking PM2.5 outbreak affecting hundreds of millions of people occurred over eastern and northern China. During that haze episode, 7 of the top 10 most polluted cities in China were located in the Hebei Province according to the report of China's Ministry of Environmental Protection. To investigate and the spatial difference and to characterize the vertical distribution of aerosol in different regions of south-central Hebei, mobile measurements were carried out using a mini micro pulse LiDAR system (model: MiniMPL) in March 2014. The mobile LiDAR kit consisting of a MiniMPL, a vibration reduction mount, a power inverter, a Windows surface tablet and a GPS receiver were mounted in a car watching though the sunroof opening. For comparison, a fixed measurement using a traditional micro pulse LiDAR system (model: MPL-4B) was conducted simultaneously in Shijiazhuang, the capital of Hebei Province. The equipped car was driven from downtown Shijiazhuang by way of suburban and rural area to downtown Cangzhou, Handan, and Baoding respectively at almost stable speed around 100Km per hour along different routes which counted in total more than 1000Km. The results can be summarized as: 1) the spatial distribution of total aerosol optical depth along the measurement routes in south-central Hebei was controlled by local terrain and population in general, with high values in downtown and suburban in the plain areas, and low values in rural areas along Taihang mountain to the west and Yan mountain to the north; 2) obviously high AODs were obtained at roads crossing points, inside densely populated area and nearby industrial emission sources; 3) under the heavy polluted condition, the height of planetary boundary layer (PBL) reduced to 500m. This experimental measurement suggests that mobile LiDAR is capable of detecting the time and area dependent air pollution episode in regional scale. Especially, LiDAR offers active remote sensing of aerosol vertical properties, which makes it feasible to detect the PBL evolution playing a crucial role in the haze formation. With regular weekly/monthly/quarterly mobile detection, some hidden emission sources could be detected and the air pollution local pattern would be revealed.

Implicit Shape Models for Object Detection in 3d Point Clouds

NASA Astrophysics Data System (ADS)

Velizhev, A.; Shapovalov, R.; Schindler, K.

2012-07-01

We present a method for automatic object localization and recognition in 3D point clouds representing outdoor urban scenes. The method is based on the implicit shape models (ISM) framework, which recognizes objects by voting for their center locations. It requires only few training examples per class, which is an important property for practical use. We also introduce and evaluate an improved version of the spin image descriptor, more robust to point density variation and uncertainty in normal direction estimation. Our experiments reveal a significant impact of these modifications on the recognition performance. We compare our results against the state-of-the-art method and get significant improvement in both precision and recall on the Ohio dataset, consisting of combined aerial and terrestrial LiDAR scans of 150,000 m2 of urban area in total.

Epigenetische Aspekte bei Karzinomen der Kopf-Hals-Region

PubMed Central

Schmezer, Peter; Plass, Christoph

2009-01-01

Zusammenfassung Plattenepithelkarzinome der Kopf-Hals-Region (HNSCC) zählen seit Jahren zu den weltweit häufigsten Krebsarten. Trotz vieler Bemühungen hat sich das 5-Jahres-Überleben bei Patienten mit HNSCC kaum verbessert. Um einen Fortschritt zu erzielen, ist es notwendig, die der Erkrankung zugrunde liegenden biologischen Prozesse besser zu verstehen. Neben den bekannten genetischen Veränderungen haben molekular-zytogenetische Untersuchungen bei HNSCC gezeigt, dass es weitere Veränderungen gibt, die mit Vermehrung und Verlust chromosomaler Bereiche einhergehen, für die jedoch die krankheitsverursachenden Gene bisher nicht identifiziert wurden. Darüberhinaus haben jüngste Forschungsergebnisse verdeutlicht, dass epigenetische Modifikationen wie die DNA Methylierung eine wichtige Rolle spielen. So konnte gezeigt werden, dass bei HNSCC eine Reihe von Genen (z.B. das Tumorsuppressorgen CDKN2A sowie DAPK1, MGMT, TIMP3, TCF21, und C/EBPα) hypermethylierte Bereiche in regulatorischen DNA Sequenzen aufweisen, wodurch ihre Expression verringert oder unterbunden wird. Die Hypermethylierung solcher Gene könnte als Biomarker zur Früherkennung von HNSCC genutzt werden und nicht zuletzt dadurch zur Verbesserung von Prävention und Therapieerfolg beitragen. PMID:18483718

Predictable waves of sequential forest degradation and biodiversity loss spreading from an African city.

PubMed

Ahrends, Antje; Burgess, Neil D; Milledge, Simon A H; Bulling, Mark T; Fisher, Brendan; Smart, James C R; Clarke, G Philip; Mhoro, Boniface E; Lewis, Simon L

2010-08-17

Tropical forest degradation emits carbon at a rate of approximately 0.5 Pgxy(-1), reduces biodiversity, and facilitates forest clearance. Understanding degradation drivers and patterns is therefore crucial to managing forests to mitigate climate change and reduce biodiversity loss. Putative patterns of degradation affecting forest stocks, carbon, and biodiversity have variously been described previously, but these have not been quantitatively assessed together or tested systematically. Economic theory predicts a systematic allocation of land to its highest use value in response to distance from centers of demand. We tested this theory to see if forest exploitation would expand through time and space as concentric waves, with each wave targeting lower value products. We used forest data along a transect from 10 to 220 km from Dar es Salaam (DES), Tanzania, collected at two points in time (1991 and 2005). Our predictions were confirmed: high-value logging expanded 9 kmxy(-1), and an inner wave of lower value charcoal production 2 kmxy(-1). This resource utilization is shown to reduce the public goods of carbon storage and species richness, which significantly increased with each kilometer from DES [carbon, 0.2 Mgxha(-1); 0.1 species per sample area (0.4 ha)]. Our study suggests that tropical forest degradation can be modeled and predicted, with its attendant loss of some public goods. In sub-Saharan Africa, an area experiencing the highest rate of urban migration worldwide, coupled with a high dependence on forest-based resources, predicting the spatiotemporal patterns of degradation can inform policies designed to extract resources without unsustainably reducing carbon storage and biodiversity.

“I didn’t know that…” patient perceptions of print information, education, and communication related to HIV/AIDS treatment

PubMed Central

STONE, COSBY A.; SIRIL, HELLEN; NAMPANDA, EMERENSIANA; GARCIA, MARIA E.; TITO, JUSTINA; NAMBIAR, DEVAKI; CHALAMILLA, GUERINO; KAAYA, SYLVIA F.

2017-01-01

Improving health literacy is a necessary intervention for people with chronic health conditions to ensure adherence with long or life therapies and increase participation in self-care. While adherence is a multifactorial process, increasing health literacy among HIV-infected patients at all stages of living with HIV has been shown to improve treatment outcomes. In the era of rapid scale up of HIV care and treatment, little has been done to evaluate the utility of IEC materials for increasing patient health literacy and how patients perceive such materials. Four patient-oriented print IEC brochures in Swahili were designed to be read at the clinic waiting areas and also carried home by patients to supplement the knowledge received from routine counselling during clinic visits. Brochures detail antiretroviral therapy and address common myths, side effects, types and management of opportunistic infections, and prevention of mother to child transmission of HIV. We conducted focus group discussions with HIV-infected patients to explore patient perceptions of IEC materials in the urban congested HIV care setting of Dar es Salaam, Tanzania. Groups of participants were recruited from eight public PEPFAR-supported HIV care and treatment centres in the city (N=50). In this paper we present the results of those focus group discussions and introduce the print IEC materials as a pilot intervention in a Swahili-speaking setting where a need for additional health literacy exists. Further evaluation of these materials will follow as the data becomes available. PMID:25566605

Ecologists can enable communities to implement malaria vector control in Africa

PubMed Central

Mukabana, W Richard; Kannady, Khadija; Kiama, G Michael; Ijumba, Jasper N; Mathenge, Evan M; Kiche, Ibrahim; Nkwengulila, Gamba; Mboera, Leonard; Mtasiwa, Deo; Yamagata, Yoichi; van Schayk, Ingeborg; Knols, Bart GJ; Lindsay, Steven W; de Castro, Marcia Caldas; Mshinda, Hassan; Tanner, Marcel; Fillinger, Ulrike; Killeen, Gerry F

2006-01-01

Background Integrated vector management (IVM) for malaria control requires ecological skills that are very scarce and rarely applied in Africa today. Partnerships between communities and academic ecologists can address this capacity deficit, modernize the evidence base for such approaches and enable future scale up. Methods Community-based IVM programmes were initiated in two contrasting settings. On Rusinga Island, Western Kenya, community outreach to a marginalized rural community was achieved by University of Nairobi through a community-based organization. In Dar es Salaam, Tanzania, Ilala Municipality established an IVM programme at grassroots level, which was subsequently upgraded and expanded into a pilot scale Urban Malaria Control Programme with support from national academic institutes. Results Both programmes now access relevant expertise, funding and policy makers while the academic partners benefit from direct experience of community-based implementation and operational research opportunities. The communities now access up-to-date malaria-related knowledge and skills for translation into local action. Similarly, the academic partners have acquired better understanding of community needs and how to address them. Conclusion Until sufficient evidence is provided, community-based IVM remains an operational research activity. Researchers can never directly support every community in Africa so community-based IVM strategies and tactics will need to be incorporated into undergraduate teaching programmes to generate sufficient numbers of practitioners for national scale programmes. Academic ecologists at African institutions are uniquely positioned to enable the application of practical environmental and entomological skills for malaria control by communities at grassroots level and should be supported to fulfil this neglected role. PMID:16457724

Occurrence of nitrate in Tanzanian groundwater aquifers: A review

NASA Astrophysics Data System (ADS)

Elisante, Eliapenda; Muzuka, Alfred N. N.

2017-03-01

More than 25 % of Tanzanian depends on groundwater as the main source of water for drinking, irrigation and industrial activities. The current trend of land use may lead to groundwater contamination and thus increasing risks associated with the usage of contaminated water. Nitrate is one of the contaminants resulting largely from anthropogenic activities that may find its way to the aquifers and thus threatening the quality of groundwater. Elevated levels of nitrate in groundwater may lead to human health and environmental problems. The current trend of land use in Tanzania associated with high population growth, poor sanitation facilities and fertilizer usage may lead to nitrate contamination of groundwater. This paper therefore aimed at providing an overview of to what extent human activities have altered the concentration of nitrate in groundwater aquifers in Tanzania. The concentration of nitrate in Tanzanian groundwater is variable with highest values observable in Dar es Salaam (up to 477.6 mg/l), Dodoma (up to 441.1 mg/l), Tanga (above 100 mg/l) and Manyara (180 mg/l). Such high values can be attributed to various human activities including onsite sanitation in urban centres and agricultural activities in rural areas. Furthermore, there are some signs of increasing concentration of nitrate in groundwater with time in some areas in response to increased human activities. However, reports on levels and trends of nitrate in groundwater in many regions of the country are lacking. For Tanzania to appropriately address the issue of groundwater contamination, a deliberate move to determine nitrate concentration in groundwater is required, as well as protection of recharge basins and improvement of onsite sanitation systems.

Line segment extraction for large scale unorganized point clouds

NASA Astrophysics Data System (ADS)

Lin, Yangbin; Wang, Cheng; Cheng, Jun; Chen, Bili; Jia, Fukai; Chen, Zhonggui; Li, Jonathan

2015-04-01

Line segment detection in images is already a well-investigated topic, although it has received considerably less attention in 3D point clouds. Benefiting from current LiDAR devices, large-scale point clouds are becoming increasingly common. Most human-made objects have flat surfaces. Line segments that occur where pairs of planes intersect give important information regarding the geometric content of point clouds, which is especially useful for automatic building reconstruction and segmentation. This paper proposes a novel method that is capable of accurately extracting plane intersection line segments from large-scale raw scan points. The 3D line-support region, namely, a point set near a straight linear structure, is extracted simultaneously. The 3D line-support region is fitted by our Line-Segment-Half-Planes (LSHP) structure, which provides a geometric constraint for a line segment, making the line segment more reliable and accurate. We demonstrate our method on the point clouds of large-scale, complex, real-world scenes acquired by LiDAR devices. We also demonstrate the application of 3D line-support regions and their LSHP structures on urban scene abstraction.

Urban Density Indices Using Mean Shift-Based Upsampled Elevetion Data

NASA Astrophysics Data System (ADS)

Charou, E.; Gyftakis, S.; Bratsolis, E.; Tsenoglou, T.; Papadopoulou, Th. D.; Vassilas, N.

2015-04-01

Urban density is an important factor for several fields, e.g. urban design, planning and land management. Modern remote sensors deliver ample information for the estimation of specific urban land classification classes (2D indicators), and the height of urban land classification objects (3D indicators) within an Area of Interest (AOI). In this research, two of these indicators, Building Coverage Ratio (BCR) and Floor Area Ratio (FAR) are numerically and automatically derived from high-resolution airborne RGB orthophotos and LiDAR data. In the pre-processing step the low resolution elevation data are fused with the high resolution optical data through a mean-shift based discontinuity preserving smoothing algorithm. The outcome is an improved normalized digital surface model (nDSM) is an upsampled elevation data with considerable improvement regarding region filling and "straightness" of elevation discontinuities. In a following step, a Multilayer Feedforward Neural Network (MFNN) is used to classify all pixels of the AOI to building or non-building categories. For the total surface of the block and the buildings we consider the number of their pixels and the surface of the unit pixel. Comparisons of the automatically derived BCR and FAR indicators with manually derived ones shows the applicability and effectiveness of the methodology proposed.

Assessing acceptability of parents/guardians of adolescents towards introduction of sex and reproductive health education in schools at Kinondoni Municipal in Dar es Salaam city.

PubMed

Mbonile, Lumuli; Kayombo, Edmund J

2008-04-01

To assess acceptability of parents/guardians of adolescents towards the introduction of sex and reproductive health education in the community and schools. A multi-stage random sampling technique was used to get 150 participants for this study. A structured questionnaire was used to interview the sampled participants and was supplemented with guided focus group discussion in Kinondoni Municipality of Dar es Salaam, Tanzania. The analysis of the findings shows that there is a mixed feeling on the introduction of sex and reproductive health education in schools. Participants strongly supported that they should talk with their adolescents about sexuality and reproductive health (88.6%) but their culture prohibits them from doing so (76.7%). Also supported that condoms could protect against HIV/AIDS and sexually transmitted infections (82%), but strongly opposed the use of condoms to their adolescents because it would encourage promiscuity (78%). When the data were analysed by faith of the religions of the participants, 64% were in favour of introducing sex education and reproductive health, but were opposed to use of condoms to their adolescents. All participants were against vijiweni, which were recreation centres for the youths because they taught bad manners to their adolescents. The preferred source of information about sex education and reproductive health should be from the parents/guardians (86%), religious leaders (70%), media (62%), health workers (61%) and school teachers (59%). All in all the will of introduction of sex education and reproductive health in the community is there but the approach need to be worked out carefully by taking into account of the cultural and religious factors. Parents/guardians, religious leaders and traditional charismatic leaders should take part in designing the programme and even being involved in teaching it. The other option is to lump together sex education and reproductive health education in science especially in biology which is already in place in Tanzania education programmes.

Causes, magnitude and management of burns in under-fives in district hospitals in Dar es Salaam, Tanzania.

PubMed

Justin-Temu, M; Rimoy, G; Premji, Z; Matemu, G

2008-04-01

To determine the causes, magnitude and management of burns in children under five years of age who were admitted in the district hospitals of Dar es Salaam City, Tanzania. In this study, a total of 204 under fives were enrolled. Questionnaires were used to elicit if the parent/caretaker had the knowledge of the cause of the burns, what was done immediately after burn injury, first aid given immediately after burn, source of the knowledge of first aid and when the child was taken to the hospital. Also the questionnaire was cited with data on the management of burns in the hospitals through observation and checking the treatment files. Forty nine percent were males while 50.5% were females. Most of the children (54.9%) were aged between 1-2 years. 78.4% had scalds while 21.6% had flame burns. No children were found to have burns caused by chemicals or electricity. Most of the burns (97.5%) occurred accidentally, although some (2.5%) were intentional. 68.6% of these burn injuries occurred in the kitchen. Immediately after burn 87.3% of the children had first aid applied on their wounds while 12.7% didn't apply anything. Of the agents used, honey was the most used (32.8%) followed by cold water (16.7%). The source of knowledge on these agents was from relatives and friends (72.5%), schools (7%), media (6%) and medical personnel (14%). The study further revealed that analgesics, intravenous fluids, antiseptics and antibiotics were the drugs used for treatment of burns in the hospital and that there was no specialized unit for burns in the hospitals. Causes of childhood burns are largely preventable requiring active social/medical education and public enlighten campaigns on the various methods of prevention. The government to see to it that hospitals have specialized units for managing burn cases and also the socio-economic status of its people be improved.

Knowledge, attitude and acceptability of spermicidal contraception among university students in Dar es Salaam.

PubMed

Mwambete, Kennedy D; Mogasa, C

2007-04-01

The aim of this study was to assess the knowledge, acceptability and attitude towards the use of spermicides among students of University of Dar es Salaam (UDSM). This was a descriptive cross-sectional study conducted over four-month period among UDSM students. A random sample of students was recruited from all three university campus namely University College of Land and Architectural Studies (UCLAS), Muhimbili University College of Health Sciences (MUCHS) and Mlimani Campus (MC). Questionnaires with both closed and open end-questions were used for data collection in which knowledge, attitude, and acceptability of spermicides were determined. The collected data were analyzed using SPSS/PC+ version 10.0, 1999 computer package. A total of 300 students participated in this study, out of which 154 (513%) were females and 146 (48.7%) males. Majority of the students 276 (92%) had poor knowledge of spermicidal products, and out of these, 146 (53%) were absolutely unable to describe the use of spermicides. Ninety-three percent of the students had never used spermicides. Of those who had never used spermicides, 84 (30%) said because they used other contraceptive means, 50 (17.8%) said they are expensive, 29 (10.3%) attributed this to unavailability of the products, 3 (1.1%) to fear of "contracting" cancer and 13(4.6%) to the unreliability. Furthermore, a few who had used them didn't trust the products as ideal means of contraception. The respondents had poor knowledge of spermicides. Spermicides were not accepted by the students because of the presumed side-effects, being very expensive and unreliable for contraception purpose. However, the respondents accepted spermicides usage as an ideal alternative to condom and effective means for a female-controlled method to prevent/reduce unwanted pregnancy and HIV risk. The study recommends that the Government/responsible authorities should encourage spermicides usage, particularly when coupled with microbicides, in reduction of unplanned pregnancies, sexually transmitted diseases (STDs) and HIV infection inclusive.

Cervical pre-malignant lesions in HIV infected women attending Care and Treatment Centre in a tertiary hospital, Dar es Salaam, Tanzania.

PubMed

Balandya, Belinda S; Pembe, Andrea B; Mwakyoma, Henry A

2011-09-01

The aims of this study was to determine proportion of HIV infected women with cervical pre-malignant lesions; and compare the use of Visual Inspection of the cervix after application of Acetic acid (VIA) and Papanicolau (Pap) smear in screening for cervical premalignant lesions in HIV positive women attending Care and Treatment Centre (CTC) at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania. A total of 316 women aged 18-70 years had a Pap smear taken for cytology, followed by spraying onto the cervix with 4% acetic acid and then inspecting it. Cytology was considered negative when there was no Cervical Intraepithelial Neoplasia (CIN) lesion reported from the Pap smear taken, and positive if CIN lesion 1, 2 or 3 was reported. Detection of a well-defined, opaque acetowhite lesion close to the squamocolumnar junction or close to the external cervical os constituted a positive VIA. Out of 316 women, 132 women had acetowhite lesions on VIA, making the proportion of abnormal cervical lesions to be 42.4%. One hundred and one out of 312 women (32.4%) had CIN lesions detected on Pap smear. The proportion of agreement between these two tests was 0.3. The proportion of agreement was moderate in women with advanced WHO HIV clinical stage of the disease and in women not on ART (Anti Retroviral Therapy). Women with CD-4 count less than 200 cells/mm3 had more abnormal cervical lesions. There is considerable proportion of HIV positive women with premalignant lesions of the cervix. Considering the proportion of HIV women with abnormal lesions and the difficulty in logistics of doing Pap smear in low resource settings, these results supports the recommendation to introduce screening of premalignant lesions of the cervix using VIA to all HIV infected women.

Induced abortion, pregnancy loss and intimate partner violence in Tanzania: a population based study.

PubMed

Stöckl, Heidi; Filippi, Veronique; Watts, Charlotte; Mbwambo, Jessie K K

2012-03-05

Violence by an intimate partner is increasingly recognized as an important public and reproductive health issue. The aim of this study is to investigate the extent to which physical and/or sexual intimate partner violence is associated with induced abortion and pregnancy loss from other causes and to compare this with other, more commonly recognized explanatory factors. This study analyzes the data of the Tanzania section of the WHO Multi-Country Study on Women's Health and Domestic Violence, a large population-based cross-sectional survey of women of reproductive age in Dar es Salaam and Mbeya, Tanzania, conducted from 2001 to 2002. All women who answered positively to at least one of the questions about specific acts of physical or sexual violence committed by a partner towards her at any point in her life were considered to have experienced intimate partner violence. Associations between self reported induced abortion and pregnancy loss with intimate partner violence were analysed using multiple regression models. Lifetime physical and/or sexual intimate partner violence was reported by 41% and 56% of ever partnered, ever pregnant women in Dar es Salaam and Mbeya respectively. Among the ever pregnant, ever partnered women, 23% experienced involuntary pregnancy loss, while 7% reported induced abortion. Even after adjusting for other explanatory factors, women who experienced intimate partner violence were 1.6 (95%CI: 1.06,1.60) times more likely to report an pregnancy loss and 1.9 (95%CI: 1.30,2.89) times more likely to report an induced abortion. Intimate partner violence had a stronger influence on induced abortion and pregnancy loss than women's age, socio-economic status, and number of live born children. Intimate partner violence is likely to be an important influence on levels of induced abortion and pregnancy loss in Tanzania. Preventing intimate partner violence may therefore be beneficial for maternal health and pregnancy outcomes. © 2012 Stöckl et al; licensee BioMed Central Ltd.

Prevalence and prognostic implications of anaemia and iron deficiency in Tanzanian patients with heart failure.

PubMed

Makubi, Abel; Hage, Camilla; Lwakatare, Johnson; Mmbando, Bruno; Kisenge, Peter; Lund, Lars H; Rydén, Lars; Makani, Julie

2015-04-01

To determine the prevalence, correlates and prognostic implications of anaemia and iron deficiency (ID) in patients with heart failure (HF) in Tanzania. This was a cross-sectional and prospective observational study conducted at Muhimbili National Hospital in Dar es Salaam, Tanzania. Patients were ≥ 18 years of age, with HF defined according to the Framingham criteria. The primary outcome was anaemia and the secondary outcome was a composite of hospitalisation for HF or all-cause mortality. A total of 401 HF patients (median age 56 years, IQR 41-67 years; women 51%) were included. The prevalence of anaemia was 57%. The overall prevalence of ID was 49% distributed as 69% versus 21% in subjects with and without anaemia (p < 0.001). Normocytic anaemia was seen in 18% of the patients while none had macrocytic anaemia. The risk of having anaemia was positively associated with residency outside Dar es Salaam (OR 1.72 (95% CI 1.02 to 2.89); p = 0.038), atrial fibrillation (4.12 (1.60 to 10.61); p=0.003), LVEF < 45% (2.70 (1.57 to 4.67); p < 0.001) and negatively (ORs per unit decrease) with creatinine clearance (0.98 (0.97 to 0.99); p = 0.012) and total cholesterol (0.78 (0.63 to 0.98); p = 0.029). One-year survival free from a composite endpoint was 70%. The presence of ID anaemia increased the likelihood for an event (HR 2.67; 95% CI 1.39 to 5.07; p = 0.003), while anaemia without ID did not influence the risk. ID anaemia was common in Tanzanian patients with HF and was independently associated with the risk for hospitalisation or death. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Factors for change in maternal and perinatal audit systems in Dar es Salaam hospitals, Tanzania.

PubMed

Nyamtema, Angelo S; Urassa, David P; Pembe, Andrea B; Kisanga, Felix; van Roosmalen, Jos

2010-06-03

Effective maternal and perinatal audits are associated with improved quality of care and reduction of severe adverse outcome. Although audits at the level of care were formally introduced in Tanzania around 25 years ago, little information is available about their existence, performance, and practical barriers to their implementation. This study assessed the structure, process and impacts of maternal and perinatal death audit systems in clinical practice and presents a detailed account on how they could be improved. A cross sectional descriptive study was conducted in eight major hospitals in Dar es Salaam in January 2009. An in-depth interview guide was used for 29 health managers and members of the audit committees to investigate the existence, structure, process and outcome of such audits in clinical practice. A semi-structured questionnaire was used to interview 30 health care providers in the maternity wards to assess their awareness, attitude and practice towards audit systems. The 2007 institutional pregnancy outcome records were reviewed. Overall hospital based maternal mortality ratio was 218/100,000 live births (range: 0 - 385) and perinatal mortality rate was 44/1000 births (range: 17 - 147). Maternal and perinatal audit systems existed only in 4 and 3 hospitals respectively, and key decision makers did not take part in audit committees. Sixty percent of care providers were not aware of even a single action which had ever been implemented in their hospitals because of audit recommendations. There were neither records of the key decision points, action plan, nor regular analysis of the audit reports in any of the facilities where such audit systems existed. Maternal and perinatal audit systems in these institutions are poorly established in structure and process; and are less effective to improve the quality of care. Fundamental changes are urgently needed for successful audit systems in these institutions.

Induced abortion, pregnancy loss and intimate partner violence in Tanzania: a population based study

PubMed Central

2012-01-01

Background Violence by an intimate partner is increasingly recognized as an important public and reproductive health issue. The aim of this study is to investigate the extent to which physical and/or sexual intimate partner violence is associated with induced abortion and pregnancy loss from other causes and to compare this with other, more commonly recognized explanatory factors. Methods This study analyzes the data of the Tanzania section of the WHO Multi-Country Study on Women's Health and Domestic Violence, a large population-based cross-sectional survey of women of reproductive age in Dar es Salaam and Mbeya, Tanzania, conducted from 2001 to 2002. All women who answered positively to at least one of the questions about specific acts of physical or sexual violence committed by a partner towards her at any point in her life were considered to have experienced intimate partner violence. Associations between self reported induced abortion and pregnancy loss with intimate partner violence were analysed using multiple regression models. Results Lifetime physical and/or sexual intimate partner violence was reported by 41% and 56% of ever partnered, ever pregnant women in Dar es Salaam and Mbeya respectively. Among the ever pregnant, ever partnered women, 23% experienced involuntary pregnancy loss, while 7% reported induced abortion. Even after adjusting for other explanatory factors, women who experienced intimate partner violence were 1.6 (95%CI: 1.06,1.60) times more likely to report an pregnancy loss and 1.9 (95%CI: 1.30,2.89) times more likely to report an induced abortion. Intimate partner violence had a stronger influence on induced abortion and pregnancy loss than women's age, socio-economic status, and number of live born children. Conclusions Intimate partner violence is likely to be an important influence on levels of induced abortion and pregnancy loss in Tanzania. Preventing intimate partner violence may therefore be beneficial for maternal health and pregnancy outcomes. PMID:22390254

High sero-prevalence of hepatitis B virus and human immunodeficiency virus infections among pregnant women attending antenatal clinic at Temeke municipal health facilities, Dar es Salaam, Tanzania: a cross sectional study.

PubMed

Manyahi, Joel; Msigwa, Yohannes; Mhimbira, Francis; Majigo, Mtebe

2017-04-07

Hepatitis B virus (HBV) and Human immunodeficiency virus (HIV) infection in pregnancy is associated with direct effect of pregnancy and potential viral transmission from mother to newborn. In Tanzania very little in known on prevalence of HBV infection and their associated factors among pregnant women in lower health facilities. The main objective of the study was to determine the prevalence of HBsAg, HIV and HBV-HIV co-infection among pregnant women attending antenatal clinics in Dar es Salaam. This cross sectional study was conducted in three Temeke municipal health-care facilities between May 2014 and June 2014. A total of 249 pregnant women attending antenatal clinic (ANC) were consecutively enrolled in the study. A data collection tool was used to extract socio-demographic characteristics from ANC card. Commercial ARCHITECT® ci4100™ was used to assess HBsAg status and liver function (Alanine amino-transferase (ALAT). HIV status was determined by anti-HIV antibody test. Of 249 pregnant women enrolled the median age was 25 years (IQR 22-30) and most of them were married (72.4%). The overall prevalence of HBsAg and HIV were 8.03% (95% CI: 5.0-12.1%) and 17.2% (95% CI: 12.8-22.5%), respectively. HBV/HIV co-infection rate was 2.8% (95% CI; 1.3-5.4%). HBsAg positive rate was significantly high in women who were HIV positive (p < 0.05). Being employed /student were less associated with HBV infection (aOR 0.35, 95% CI 0.13-0.95). Only 3 (15%) of pregnant women with HBsAg positive had abnormal ALAT. High prevalence of HBV and HIV infections among pregnant women were reported in this setting thus calls for the national expansion of the integration of prevention of mother-to-child transmission (PMTCT) services for HBV infection.

Prevalence and Predictors of Human Immunodeficiency Virus and Selected Sexually Transmitted Infections Among People Who Inject Drugs in Dar es Salaam, Tanzania: A New Focus to Get to Zero.

PubMed

Mmbaga, Elia John; Moen, Kåre; Makyao, Neema; Leshabari, Melkizedeck

2017-02-01

Previous studies in Tanzania indicated that human immunodeficiency virus (HIV) prevalence among people who inject drugs (PWIDs) could be as high as 40%. We aim to provide data on the prevalence of HIV and sexually transmitted infection among PWIDs to inform national plans to get to zero. Respondent-driven sampling was used to collect drug use, and sexual practices data among PWIDs aged 15 years and older. Blood samples were examined for HIV, herpes simplex virus type 2, syphilis, and hepatitis B. A total of 620 PWIDs with a median age of 32 (interquartile range, 17-52) participated in the study. Their use of drugs had typically started during adolescence. The prevalence of HIV was found to be 15.5%, whereas that of herpes simplex type 2 was 43.3%. Associated with an increased likelihood of HIV infection was being a female (adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.0-3.6), sharing of syringes (aOR, 2.4; 95% CI, 1.1-6.1), used syringes hidden in public places (aOR, 5.1; 95% CI, 1.3-10.2), and having had a genital ulcer during the last 12 months before this survey. On the other hand, being educated, use of noninjectable drugs, access (aOR, 0.5; 95% CI, 0.2-0.8), and use of clean syringes (aOR, 0.3; 95% CI, 0.1-0.6) were associated with decreased likelihood of HIV infection. The prevalence of HIV infection among PWIDs in Dar es Salaam is 3 times higher than that in the general population. Behavioral and biological risk factors contribute to HIV transmission and needs to be addressed to be able to get to zero.

Methadone Treatment for HIV Prevention—Feasibility, Retention, and Predictors of Attrition in Dar es Salaam, Tanzania: A Retrospective Cohort Study

PubMed Central

Lambdin, Barrot H.; Masao, Frank; Chang, Olivia; Kaduri, Pamela; Mbwambo, Jessie; Magimba, Ayoub; Sabuni, Norman; Bruce, R. Douglas

2014-01-01

Background. People who inject drugs (PWID) in Dar es Salaam, Tanzania, have an estimated human immunodeficiency virus (HIV) prevalence of 42%–50% compared with 6.9% among the general population. Extensive evidence supports methadone maintenance to lower morbidity, mortality, and transmission of HIV and other infectious diseases among PWID. In 2011, the Tanzanian government launched the first publicly funded methadone clinic on the mainland of sub-Saharan Africa at Muhimbili National Hospital. Methods. We conducted a retrospective cohort study of methadone-naive patients enrolling into methadone maintenance treatment. Kaplan-Meier survival curves were constructed to assess retention probability. Proportional hazards regression models were used to evaluate the association of characteristics with attrition from the methadone program. Results. Overall, 629 PWID enrolled into methadone treatment during the study. At 12 months, the proportion of clients retained in care was 57% (95% confidence interval [CI], 53%–62%). Compared with those receiving a low dose (<40 mg), clients receiving a medium (40–85 mg) (adjusted hazard ratio [aHR], 0.50 [95% CI, .37–.68]) and high (>85 mg) (aHR, 0.41 [95% CI, .29–.59]) dose of methadone had a lower likelihood of attrition, adjusting for other characteristics. Older clients (aHR, 0.53 per 10 years [95% CI, .42–.69]) and female clients (aHR, 0.50 [95% CI, .28–.90]) had a significantly lower likelihood of attrition, whereas clients who reported a history of sexual abuse (aHR, 2.84 [95% CI, 1.24–6.51]) had a significantly higher likelihood of attrition. Conclusions. Patient retention in methadone maintenance is comparable to estimates from programs in North America, Europe, and Asia. Future implementation strategies should focus on higher doses and flexible dosing strategies to optimize program retention and strengthened efforts for clients at higher risk of attrition. PMID:24855149

Identifying Programmatic Gaps: Inequities in Harm Reduction Service Utilization among Male and Female Drug Users in Dar es Salaam, Tanzania

PubMed Central

Lambdin, Barrot H.; Bruce, R. Douglas; Chang, Olivia; Nyandindi, Cassian; Sabuni, Norman; Zamudio-Haas, Sophia; McCurdy, Sheryl; Masao, Frank; Ivo, Yovin; Msami, Amani; Ubuguy, Omar; Mbwambo, Jessie

2013-01-01

Introduction Current estimates suggest an HIV prevalence of 42% among people who inject drugs (PWIDs) in Dar es Salaam, while HIV prevalence is estimated to be 8.8% among the general population in the city. To address the HIV epidemic in this population, the government of Tanzania began establishing HIV prevention, treatment and care services including outreach and medication assisted treatment (MAT) for PWIDs in 2010. We assessed gender inequities in utilization of outreach and MAT services and evaluated differences in HIV risk behaviors between female and male PWIDs. Materials and Methods Routine outreach data between December 2010 to mid-August 2012 and baseline data on clients enrolling in methadone from February 2011 to August 2012 were utilized. Binomial regression was used to estimate adjusted relative risk estimates comparing females to males. Results From December 2010 to August 2012, 8,578 contacts were made to drug users; among them 1,898 were injectors. A total of 453 injectors were eligible and referred to MAT, of which, 443 enrolled in treatment. However, regarding total outreach contacts, outreach to PWID, referral to MAT and enrollment in MAT, 8% or less of drug users accessing services were women. In contrast, weighted estimations from surveys suggest that 34% of PWIDs are female, and this approximation is similar to recent population size estimations. Overall, 43% of traditional outreach workers conducting outreach with drug users were female. Though reporting higher levels of condom usage, female PWID were more likely to report multiple sex partners, anal sex, commercial sex work and struggle under a higher burden of addiction, mental disorders and abuse. Conclusions Services have not been mobilized adequately to address the clear needs of females who inject drugs. A clear and urgent need exists for women-centered strategies that effectively engage female PWID into HIV prevention services. PMID:23825620

Women's preferences regarding infant or maternal antiretroviral prophylaxis for prevention of mother-to-child transmission of HIV during breastfeeding and their views on Option B+ in Dar es Salaam, Tanzania.

PubMed

Ngarina, Matilda; Tarimo, Edith A M; Naburi, Helga; Kilewo, Charles; Mwanyika-Sando, Mary; Chalamilla, Guerino; Biberfeld, Gunnel; Ekstrom, Anna Mia

2014-01-01

The WHO 2010 guidelines for prevention of mother-to-child transmission (PMTCT) of HIV recommended prophylactic antiretroviral treatment (ART) either for infants (Option A) or mothers (Option B) during breastfeeding for pregnant women with a CD4 count of >350 cell/µL in low-income countries. In 2012, WHO proposed that all HIV-infected pregnant women should receive triple ART for life (B+) irrespective of CD4 count. Tanzania has recently switched from Option A to B+, with a few centers practicing B. However, more information on the real-life feasibility of these options is needed. This qualitative study explored women's preferences for Option A vs B and their views on Option B+ in Dar es Salaam, Tanzania. We conducted four focus group discussions with a total of 27 pregnant women with unknown HIV status, attending reproductive and child health clinics, and 31 in-depth interviews among HIV-infected pregnant and post-delivery women, 17 of whom were also asked about B+. Most participants were in favor of Option B compared to A. The main reasons for choosing Option B were: HIV-associated stigma, fear of drug side-effects on infants and difficult logistics for postnatal drug adherence. Some of the women asked about B+ favored it as they agreed that they would eventually need ART for their own survival. Some were against B+ anticipating loss of motivation after protecting the child, fearing drug side-effects and not feeling ready to embark on lifelong medication. Some were undecided. Option B was preferred. Since Tanzania has recently adopted Option B+, women with CD4 counts of >350 cell/µL should be counseled about the possibility to "opt-out" from ART after cessation of breastfeeding. Drug safety and benefits, economic concerns and available resources for laboratory monitoring and evaluation should be addressed during B+ implementation to enhance long-term feasibility and effectiveness.

High Prevalence of Faecal Carriage of ESBL-Producing Enterobacteriaceae among Children in Dar es Salaam, Tanzania.

PubMed

Tellevik, Marit G; Blomberg, Bjørn; Kommedal, Øyvind; Maselle, Samuel Y; Langeland, Nina; Moyo, Sabrina J

2016-01-01

Faecal carriage of ESBL-producing bacteria is a potential risk for transmission and infection. Little is known about faecal carriage of antibiotic resistance in Tanzania. This study aimed to investigate the prevalence of faecal carriage of ESBL-producing Enterobacteriaceae and to identify risk factors for carriage among young children in Tanzania. From August 2010 to July 2011, children below 2 years of age were recruited in Dar es Salaam, including healthy community children (n = 250) and children hospitalized due to diarrhoea (n = 250) or other diseases (n = 103). ChromID ESBL agar and ChromID CARBA SMART agar were used for screening. Antimicrobial susceptibility testing was performed by the disk diffusion method. ESBL genotypes were identified by Real-Time PCR and sequencing. The overall prevalence of ESBL carriage was 34.3% (207/ 603). The prevalence of ESBL carriage was significantly higher among hospitalized children (50.4%), compared to community children (11.6%; P < 0.001; OR = 7.75; 95% CI: 4.99-12.03). We found high prevalence of Multidrug-resistance (94%) among Escherichia coli and Klebsiella pneumoniae isolates. No resistance to carbapenems was detected. For the majority of isolates (94.7%) we detected a blaCTX-M-15-like gene. In addition, the plasmid mediated AmpC beta-lactamase CMY-2 was detected for the first time in Tanzania. ESBL prevalence was significantly higher among HIV positive (89.7%) than HIV negative (16.9%) children (P = 0.001; OR = 9.99; 95% CI: 2.52-39.57). Use of antibiotics during the past 14 days and age below 1 year was also associated with ESBL carriage. We report a high rate of faecal carriage of ESBL-producing Enterobacteriaceae among children below 2 years of age in Tanzania, particularly those with HIV-infection. Resistance to a majority of the available antimicrobials commonly used for children in Tanzania leaves few treatment options for infections when caused by these bacteria.

Quantitative market survey of non-woody plants sold at Kariakoo Market in Dar es Salaam, Tanzania.

PubMed

Posthouwer, Chantal; Veldman, Sarina; Abihudi, Siri; Otieno, Joseph N; van Andel, Tinde R; de Boer, Hugo J

2018-04-30

In Tanzania, traditional medicine plays a significant role in health care and local economies based on the harvesting, trade and sale of medicinal plant products. The majority of this plant material is said to originate from wild sources, and both traditional healers and vendors are concerned about the increasing scarcity of certain species. A market survey of non-powdered, non-woody medicinal plants was conducted at Kariakoo Market in Dar es Salaam, the major hub for medicinal plant trade in Tanzania, to assess sustainability of traded herbal medicine. For this study, fresh and dried herbs, seeds and fruits were collected and interviews were conducted to obtain information on vernacular names, preparation methods, monthly sales, uses and prices. Bundles of herbal medicine offered for sale were weighed and counted to calculate the value and volumes of daily stock at the market. A total of 71 medicinal plant products belonging to 62 to 67 different species from at least 41 different plant families were identified. We identified 45 plant products to species level, 20 products to genus level and four to family level. Plant species most encountered at the market were Suregada zanzibariensis, Myrothamnus flabellifolia and Sclerocarya birrea. The major use categories reported by the vendors were ritual purposes, digestive disorders and women's health. Annual sales are estimated to be in excess of 30 t and close to 200,000 USD, and trade in herbal medicine at Kariakoo Market provides subsistence income to many local vendors. A large diversity of wild-harvested plant species is traded as medicinal products in Tanzania, including species listed on CITES Appendices. Identifying and monitoring temporal changes in availability per season and from year to year will reveal which species are most affected by this trade, and help relevant authorities in Tanzania to find alternative sources of income for dependent stakeholders and initiate targeted efforts to protect threatened plant species. Copyright © 2018. Published by Elsevier B.V.

Sexual behavior and condom use in female students in Dar-es-Salaam, Tanzania: differences by steady and casual partners.

PubMed

Maswanya, E S; Moji, K; Aoyagi, K; Takemoto, T

2011-06-01

In Tanzania female youth are increasingly becoming at greater risk of sexually transmitted HIV infection, whereby more than 80% cases occur through un-protected sex. The objective of this study was to examine related-factors which influence female students to have risky sexual contacts with casual partners including condom use and sex with sugar daddies. A cross section study involving face-to-face interview was conducted regarding sexual behavior among 219 sexually-debuted female students aged between 18 and 24 years who were attending high schools and colleges in Dar-es-salaam, Tanzania. Eighty-three percent had at least one boyfriend in the past 12 months, 57% had engaged in sex with a "sugar daddy", and 24% had engaged in sex with a casual partner other than a sugar daddy. Sixty-nine percent had ever used a condom, and 66% had used a condom during their most recent sexual encounter. Thirty-two percent reported always using a condom during sex with their boyfriends, whereas only 2% always used a condom with a sugar daddy. Decision-making about condom use during sex with boyfriends was made by couples together (48%) or by the girls alone (34%), whereas the decision during sex with a sugar daddy was predominantly made by the male partner (79%). Data were analyzed using Statistical Package for Social Sciences (SPSS) version 9.5 for frequencies, cross-tabulations and chi-squired test and statistical significance set at p<0.05. The study highlighted risk factors for female students towards HIV infection. Receiving money and/or presents were the major motivations for having sex irrelevant with types of sex partners. Although most female's students disagreed in principle to have sex in exchange for money or presents, sex with sugar daddies was common among female students and was a major risk factor for HIV infection. Based on the findings, recommendations for improvement in prevention programs among female youth within Tanzanian context are discussed.

Hot-spot analysis applied to the identification of potential high and low regulating, providing and cultural ecosystem services in Vilnius Region (Lithuania)

NASA Astrophysics Data System (ADS)

Pereira, Paulo; Daniel, Depellegrin; Egarter-Vigl, Lukas; Cerda, Artemi; Estebaranz, Ferran; Misiune, Ieva

2017-04-01

Ecosystem services (ES) potential assessment is crucial for a correct territorial planning at different scales of analysis (Depellegrin et al., 2016). In urban and peri-urban areas, sprawl, grazing and unsustainable agriculture practices contributed to land degradation and de decrease of the quality and quantity of the services provided by these areas (Eldridge and Delgado-Baquerizo, 2017; Favretto et al., 2017). In order to understand the spatial pattern of these impacts, mapping ES potential is key to understand the areas that need to be restored and protected for an unsustainable use (Brevik et al., 2016; Egarter-Vigl et al., 2017; Pereira et al., 2017). Hot-spot analysis is a good method to identify clusters of areas with high and low capacity for ES capacity. This analysis is very useful to detect homogeneous areas, where ES have high or low quality. The objective of this work is to apply a hot-spot analysis to detect areas with high/low capacity for Regulating, Provision, Cultural and Total ES in Vilnius region. ES potential was carried out based on the matrix developed by Burkhard et al. (2009), which ranks ES capacity from 0= no capacity to 5=very high relevant capacity to a different land use type. The results showed that regulating, providing and cultural and total ES have a significant dispersed (low-clustered) pattern: Regulating (Z-score=-19.28, p<0.001), Providing (Z-score=-29.28, p<0.001) Cultural (Z-score=-8.13, p<0.001) and Total (Z-score=-22.46, p<0.001). This shows that ES capacity in Vilnius area is extremely fragmented and there is a lack of connectivity between the areas with high capacity of ES. There is lack of green corridors and connectivity between green areas is attributed to the urban sprawl observed in Vilnius area (Pereira et al., 2014). References Brevik, E., Calzolari, C., Miller, B., Pereira, P., Kabala, C., Baumgarten, A., Jordán, A. (2016) Historical perspectives and future needs in soil mapping, classification and pedological modelling, Geoderma, 264, Part B, 256-274. Burkhard B, Kroll F, Müller F, Windhorst W. 2009. Landscapes' capacities to provide ecosystem services- a concept for land-cover based assessments. Landscape Online. 15, 1-22. Depellegrin, D.A., Pereira, P., Misiune, I., Egarter-Vigl, L. Mapping Ecosystem Services potential in Lithuania. International Journal of Sustainable Development and World Ecology, 23, 441-455. Egarter-Vigl, L., Depellegrin, D., Pereira, P., De Groot, D., Tappeiner, U. (2017) Mapping the ecosystem service delivery chain: Capacity, flow, and demand pertaining to aesthetic experiences in mountain landscapes, Science of the Total Environment, 574, 442-436. Eldridge, D.J., Delgado-Baquerizo, M. (2017) Continental-scale impacts of livestock grazing on ecosystem supporting and regulating services. Land Degradation and Development. DOI: 10.1002/ldr.2668 Favretto, N., Lueding, E., Stringer, L., Dougill, A.J. (2017) Valuing ecosystem services in semi-arid rangelands through stochastic simulation. Land Degradation and Development. DOI: 10.1002/ldr.2590 Pereira, P., Brevik, E., Munoz-Rojas, M., Miller, B., Smetanova, A., Depellegrin, D., Misiune, I., Novara, A., Cerda, A. (2017) Soil mapping and process modelling for sustainable land management. In: Pereira, P., Brevik, E., Munoz-Rojas, M., Miller, B. (Eds.) Soil mapping and process modelling for sustainable land use management (Elsevier Publishing House) ISBN: 9780128052006 Pereira, P., Monkevicius, A., Siarova, A. (2014) Public perception of the Environmental, Social and Economic impacts of Urban Sprawl in Vilnius, Societal Studies, 6, 256 - 290.

English(es) in Urban Contexts: Politics, Pluralism, and Possibilities

ERIC Educational Resources Information Center

Kirkland, David E.

2010-01-01

English as taught in city schools does not always reflect the Englishes city students travel with. Their urban English landscape is enriched by a procession of many voices that march in various directions in, around, and through the monuments of the city. These languages--Englishes, in this case--which have been traded on through various public…

a Point Cloud Classification Approach Based on Vertical Structures of Ground Objects

NASA Astrophysics Data System (ADS)

Zhao, Y.; Hu, Q.; Hu, W.

2018-04-01

This paper proposes a novel method for point cloud classification using vertical structural characteristics of ground objects. Since urbanization develops rapidly nowadays, urban ground objects also change frequently. Conventional photogrammetric methods cannot satisfy the requirements of updating the ground objects' information efficiently, so LiDAR (Light Detection and Ranging) technology is employed to accomplish this task. LiDAR data, namely point cloud data, can obtain detailed three-dimensional coordinates of ground objects, but this kind of data is discrete and unorganized. To accomplish ground objects classification with point cloud, we first construct horizontal grids and vertical layers to organize point cloud data, and then calculate vertical characteristics, including density and measures of dispersion, and form characteristic curves for each grids. With the help of PCA processing and K-means algorithm, we analyze the similarities and differences of characteristic curves. Curves that have similar features will be classified into the same class and point cloud correspond to these curves will be classified as well. The whole process is simple but effective, and this approach does not need assistance of other data sources. In this study, point cloud data are classified into three classes, which are vegetation, buildings, and roads. When horizontal grid spacing and vertical layer spacing are 3 m and 1 m respectively, vertical characteristic is set as density, and the number of dimensions after PCA processing is 11, the overall precision of classification result is about 86.31 %. The result can help us quickly understand the distribution of various ground objects.

EnviroAtlas -- Memphis, TN (2012) -- One Meter Resolution Urban Land Cover Data Web Service

EPA Pesticide Factsheets

This EnviroAtlas web service supports research and online mapping activities related to EnviroAtlas (https://www.epa.gov/enviroatlas ). The Memphis, TN EnviroAtlas One Meter-scale Urban Land Cover (MULC) dataset comprises 2,733 km2 around the city of Memphis, surrounding towns, and rural areas. These leaf-on LC data and maps were derived from 1-m pixel, four-band (red, green, blue, and near-infrared) aerial photography acquired from the United States Department of Agriculture (USDA) National Agriculture Imagery Program (NAIP) on four dates in 2012: June 15, June 18, June 21 and June 23, and one date in 2013: July 12. Three separate LiDAR (Light Detection and Ranging) data sets collected on February 19, 2009 00e2?? August 2, 2010, December 1-2, 2011 and January 23-24, 2012 were integrated for Shelby Co., TN, Crittenden Co., AR, and DeSoto Co, MS. Five MULC classes were mapped directly from the NAIP and LiDAR data: Water, Impervious, Soil, Trees, and Grass/Herbaceous. Agriculture was derived from USDA Common Land Unit (CLU) data. Woody and emergent wetlands were copied from existing National Wetlands Inventory (NWI) data. Analysis of a random sampling of 612 photo-interpreted land cover reference points yielded an overall users accuracy of 86.9%. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-u

EnviroAtlas -- Memphis, TN (2012) -- One Meter Resolution Urban Land Cover Data

EPA Pesticide Factsheets

The Memphis, TN EnviroAtlas One Meter-scale Urban Land Cover (MULC) dataset comprises 2,733 km2 around the city of Memphis, surrounding towns, and rural areas. These leaf-on LC data and maps were derived from 1-m pixel, four-band (red, green, blue, and near-infrared) aerial photography acquired from the United States Department of Agriculture (USDA) National Agriculture Imagery Program (NAIP) on four dates in 2012: June 15, June 18, June 21 and June 23, and one date in 2013: July 12. Three separate LiDAR (Light Detection and Ranging) data sets collected on February 19, 2009 00e2?? August 2, 2010, December 1-2, 2011 and January 23-24, 2012 were integrated for Shelby Co., TN, Crittenden Co., AR, and DeSoto Co, MS. Five MULC classes were mapped directly from the NAIP and LiDAR data: Water, Impervious, Soil, Trees, and Grass/Herbaceous. Agriculture was derived from USDA Common Land Unit (CLU) data. Woody and emergent wetlands were copied from existing National Wetlands Inventory (NWI) data. Analysis of a random sampling of 612 photo-interpreted land cover reference points yielded an overall users accuracy of 86.9%. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as do

Monitoring Urban Stream Restoration Efforts in Relation to Flood Behavior Along Minebank Run, Towson, MD

NASA Astrophysics Data System (ADS)

Lee, G.; Miller, A. J.

2017-12-01

Urban stream restoration efforts are commonly undertaken to combat channel degradation and restore natural stream hydrology. We examine changes in flood patterns along an approximately 1.5-mile reach of Minebank Run, located in Towson, MD, by comparing pre-restoration morphology from surveys conducted in 2001, post-restoration morphology in 2007, and current conditions in 2017 following damage to the restoration project from persistent flooding. Hydraulic modeling was conducted in HEC-RAS 2D using three alternative scenarios: 1) topographic contours from a 2001 survey of pre-restoration topography combined with 2005 LiDAR, 2) 2007 survey combined with 2005 LiDAR data representing the post-restoration channel morphology, and 3) a March 2017 DEM of current channel conditions. The 2017 DEM was created using Structure from Motion (SfM) from high resolution 4K video collected via Unmanned Aerial Vehicle (UAV) flights at a resolution of 0.05 meters. Flood hydrographs from a USGS stream gage located within the study reach as well as a simulated hydrograph of the 100-year storm event were routed through the pre-restoration, post-restoration, and current modeled terrain and analyzed for changes in water-surface elevation and depth, inundation extent, 2-d velocity fields, and translation vs. attenuation of the flood wave to assess the net impact on potential flood hazards. In addition, our study demonstrates that SfM is a quick and inexpensive method for collecting topographic data for hydrologic modeling, assessing stream characteristics including channel bed roughness, and for examining short term changes of channel morphology at a very fine scale.

Fusion of LIDAR Data and Multispectral Imagery for Effective Building Detection Based on Graph and Connected Component Analysis

NASA Astrophysics Data System (ADS)

Gilani, S. A. N.; Awrangjeb, M.; Lu, G.

2015-03-01

Building detection in complex scenes is a non-trivial exercise due to building shape variability, irregular terrain, shadows, and occlusion by highly dense vegetation. In this research, we present a graph based algorithm, which combines multispectral imagery and airborne LiDAR information to completely delineate the building boundaries in urban and densely vegetated area. In the first phase, LiDAR data is divided into two groups: ground and non-ground data, using ground height from a bare-earth DEM. A mask, known as the primary building mask, is generated from the non-ground LiDAR points where the black region represents the elevated area (buildings and trees), while the white region describes the ground (earth). The second phase begins with the process of Connected Component Analysis (CCA) where the number of objects present in the test scene are identified followed by initial boundary detection and labelling. Additionally, a graph from the connected components is generated, where each black pixel corresponds to a node. An edge of a unit distance is defined between a black pixel and a neighbouring black pixel, if any. An edge does not exist from a black pixel to a neighbouring white pixel, if any. This phenomenon produces a disconnected components graph, where each component represents a prospective building or a dense vegetation (a contiguous block of black pixels from the primary mask). In the third phase, a clustering process clusters the segmented lines, extracted from multispectral imagery, around the graph components, if possible. In the fourth step, NDVI, image entropy, and LiDAR data are utilised to discriminate between vegetation, buildings, and isolated building's occluded parts. Finally, the initially extracted building boundary is extended pixel-wise using NDVI, entropy, and LiDAR data to completely delineate the building and to maximise the boundary reach towards building edges. The proposed technique is evaluated using two Australian data sets: Aitkenvale and Hervey Bay, for object-based and pixel-based completeness, correctness, and quality. The proposed technique detects buildings larger than 50 m2 and 10 m2 in the Aitkenvale site with 100% and 91% accuracy, respectively, while in the Hervey Bay site it performs better with 100% accuracy for buildings larger than 10 m2 in area.

Virtuelle Kraftwerke für Smart Markets

NASA Astrophysics Data System (ADS)

Dürr, Thomas; Heyne, Jean-Christoph

In den zurückliegenden Jahren haben insbesondere zwei Trends die Stromversorgung bestimmt: der starke Anstieg der dezentralen und der Ausbau der regenerativen Stromerzeugung, die vor allem in den Verteilnetzen stattfinden. Angesichts dieser Entwicklung gewinnen virtuelle Kraftwerke (VK) immer mehr an Bedeutung. In der frühen Phase waren VK insbesondere eine Möglichkeit, kleine dezentrale Erzeuger zu einer größeren Einheit zu bündeln und sie so marktfähig zu machen. Heute werden sie - überwacht und gesteuert über ein Dezentrales Energie-Management-System (DEMS) - gemeinsam mit Demand Response betrieben, also dem Reagieren eines Energieabnehmers auf Marktpreise. Das Demand Side Management soll zur Flexibilisierung der Industrie beitragen. Da der Ausbau der Übertragungsnetze nur schleppend vorankommt, kann die Nutzung von lastseitiger Flexibilität einen wichtigen Beitrag zur Versorgungssicherheit leisten. Im zweiten Teil des Beitrags geht es um die Entwicklung der Märkte. Großes Interesse besteht immer noch an der Regelenergie, zumal der Bedarf bis 2050 deutlich steigen wird. Die Spotmärkte Intraday und Day-Ahead wachsen kontinuierlich, deshalb werden sie für VK immer wichtiger. Am Ende gibt der Beitrag einen Ausblick auf die künftige Entwicklung, in der Regelenergie- und Spotmärkte noch eine Rolle spielen, aber andere Geschäftsmodelle wichtiger werden. Darüber hinaus geht es um langfristige Entwicklungen, die z. B. zusätzliche Serviceleistungen durch VK betreffen.

Towards a comprehensive and realistic risk evaluation of engineered nanomaterials in the urban water system

NASA Astrophysics Data System (ADS)

Duester, Lars; Burkhardt, Michael; Gutleb, Arno; Kaegi, Ralf; Macken, Ailbhe; Meermann, Björn; von der Kammer, Frank

2014-06-01

The European COoperation in Science and Technology (COST) Action ES1205 on the transfer of Engineered Nano materials from wastewater Treatment and stormwatEr to Rivers (ENTER) aims to create and to maintain a trans European network among scientists. This perspective article delivers a brief overview on the status quo at the beginning of the project by addressing the following aspects on engineered nano materials (ENMs) in the urban systems: i) ENMs that need to be considered on a European level; ii) uncertainties on production-volume estimations; iii) fate of selected ENMs during waste water transport and treatment; iv) analytical strategies for ENM analysis; v) ecotoxicity of ENMs, and vi) future needs. These six step stones deliver the derivation of the position of the ES1205 network at the beginning of the projects runtime, by defining six fundamental aspects that should be considered in future discussions on risk evaluation of ENMs in urban water systems.

Toward a comprehensive and realistic risk evaluation of engineered nanomaterials in the urban water system

PubMed Central

Duester, Lars; Burkhardt, Michael; Gutleb, Arno C.; Kaegi, Ralf; Macken, Ailbhe; Meermann, Björn; von der Kammer, Frank

2014-01-01

The European COoperation in Science and Technology (COST) Action ES1205 on the transfer of Engineered Nano materials from wastewater Treatment and stormwatEr to Rivers (ENTER) aims to create and to maintain a trans European network among scientists. This perspective article delivers a brief overview on the status quo at the beginning of the project by addressing the following aspects on engineered nano materials (ENMs) in the urban systems: (1) ENMs that need to be considered on a European level; (2) uncertainties on production-volume estimations; (3) fate of selected ENMs during waste water transport and treatment; (4) analytical strategies for ENM analysis; (5) ecotoxicity of ENMs, and (6) future needs. These six step stones deliver the derivation of the position of the ES1205 network at the beginning of the projects runtime, by defining six fundamental aspects that should be considered in future discussions on risk evaluation of ENMs in urban water systems. PMID:25003102

Being forced to become your own Doctor – Men who have Sex with Men’s Experiences of Stigma in the Tanzanian Healthcare System

PubMed Central

Larsson, Markus; Ross, Michael W.; Månsson, Sven-Axel; Nyoni, Joyce; Shio, Jasmine; Agardh, Anette

2016-01-01

Objective To acquire a deepened understanding of how stigma in healthcare affects health-seeking behaviours of same-sex practising men in Tanzania. Methods In-depth interviews with twelve men were conducted in Dar es Salaam, 2012. Data were interpreted through qualitative content analysis. Results Narratives revealed that men’s healthcare perceptions were shaped by previous encounters, rumours in gay community, norms and legislation around homosexuality. Fears of exposure aggravated men’s possibilities of giving full anamnesis and detached them from formal healthcare services. Conclusions Stigma in healthcare might lead to severe public health problems due to perceived exclusion from the health system by sexual minorities. PMID:28491204

Benchmarking urban flood models of varying complexity and scale using high resolution terrestrial LiDAR data

NASA Astrophysics Data System (ADS)

Fewtrell, Timothy J.; Duncan, Alastair; Sampson, Christopher C.; Neal, Jeffrey C.; Bates, Paul D.

2011-01-01

This paper describes benchmark testing of a diffusive and an inertial formulation of the de St. Venant equations implemented within the LISFLOOD-FP hydraulic model using high resolution terrestrial LiDAR data. The models are applied to a hypothetical flooding scenario in a section of Alcester, UK which experienced significant surface water flooding in the June and July floods of 2007 in the UK. The sensitivity of water elevation and velocity simulations to model formulation and grid resolution are analyzed. The differences in depth and velocity estimates between the diffusive and inertial approximations are within 10% of the simulated value but inertial effects persist at the wetting front in steep catchments. Both models portray a similar scale dependency between 50 cm and 5 m resolution which reiterates previous findings that errors in coarse scale topographic data sets are significantly larger than differences between numerical approximations. In particular, these results confirm the need to distinctly represent the camber and curbs of roads in the numerical grid when simulating surface water flooding events. Furthermore, although water depth estimates at grid scales coarser than 1 m appear robust, velocity estimates at these scales seem to be inconsistent compared to the 50 cm benchmark. The inertial formulation is shown to reduce computational cost by up to three orders of magnitude at high resolutions thus making simulations at this scale viable in practice compared to diffusive models. For the first time, this paper highlights the utility of high resolution terrestrial LiDAR data to inform small-scale flood risk management studies.

Urban forest topographical mapping using UAV LIDAR

NASA Astrophysics Data System (ADS)

Putut Ash Shidiq, Iqbal; Wibowo, Adi; Kusratmoko, Eko; Indratmoko, Satria; Ardhianto, Ronni; Prasetyo Nugroho, Budi

2017-12-01

Topographical data is highly needed by many parties, such as government institution, mining companies and agricultural sectors. It is not just about the precision, the acquisition time and data processing are also carefully considered. In relation with forest management, a high accuracy topographic map is necessary for planning, close monitoring and evaluating forest changes. One of the solution to quickly and precisely mapped topography is using remote sensing system. In this study, we test high-resolution data using Light Detection and Ranging (LiDAR) collected from unmanned aerial vehicles (UAV) to map topography and differentiate vegetation classes based on height in urban forest area of University of Indonesia (UI). The semi-automatic and manual classifications were applied to divide point clouds into two main classes, namely ground and vegetation. There were 15,806,380 point clouds obtained during the post-process, in which 2.39% of it were detected as ground.

DART: Recent Advances in Remote Sensing Data Modeling With Atmosphere, Polarization, and Chlorophyll Fluorescence

NASA Technical Reports Server (NTRS)

Gastellu-Etchegorry, Jean-Phil; Lauret, Nicolas; Yin, Tiangang; Landier, Lucas; Kallel, Abdelaziz; Malenovsky, Zbynek; Bitar, Ahmad Al; Aval, Josselin; Benhmida, Sahar; Qi, Jianbo;

Association between salt and hypertension in rural and urban populations of low to middle income countries: a systematic review and meta-analysis of population based studies.

PubMed

Subasinghe, Asvini K; Arabshahi, Simin; Busingye, Doreen; Evans, Roger G; Walker, Karen Z; Riddell, Michaela A; Thrift, Amanda G

2016-01-01

The prevalence of hypertension, the greatest contributor to mortality globally, is increasing in low-and-middle income countries (LMICs). In urban regions of LMICs, excessive salt intake is associated with increased risk of hypertension. We aimed to determine whether this is the case in rural regions as well. We performed a meta-analysis of studies in rural and urban areas of LMICs in which the association of salt and hypertension were assessed using multivariable models. We identified 18 studies with a total of 134,916 participants. The prevalence of high salt intake ranged from 21.3% to 89.5% in rural and urban populations. When salt was analysed as a continuous variable, a greater impact of salt on hypertension was found in urban (n=4) (pooled effect size (ES) 1.42, 95% CI 1.19, 1.69) than in rural populations (n=4) (pooled ES 1.07, 95% CI 1.04, 1.10, p for difference <0.001). In studies where salt was analysed continuously, a greater impact of salt on hypertension was observed in lean rural populations (BMI <23 kg/m2) than in non-lean rural populations (BMI >=23 kg/m2, p for difference <0.001). The prevalence of high salt intake is similar in rural and urban regions. Excessive salt intake has a greater impact on the prevalence of hypertension in urban than rural regions. BMI appears to modify the relationship between salt and hypertension in rural populations.

Assessing social vulnerability in African urban context. The challenge to cope with climate change induced hazards by communities and households

NASA Astrophysics Data System (ADS)

Kabisch, Sigrun; Jean-Baptiste, Nathalie

2013-04-01

Social vulnerability assessment remains central in discourses on global climatic change and takes a more pertinent meaning considering that natural disasters in African countries continue to deeply affect human settlements and destroys human livelihoods. In recent years, in particular large territories and growing cities have experienced severe weather events. Among them are river and flash floods, affecting the social and economic assets of local populations. The impact of the damage related to floods is not only perceptible during seasonal events but also during unexpected larger disasters which place a particular burden on local population and institutions to adapt effectively to increasing climatic pressures. Important features for social vulnerability assessment are the increasing severity of the physical damages, the shortcoming of social and technical infrastructure, the complexity of land management/market, the limited capacity of local institutions and last but not least the restricted capacities of local population to resist these events. Understanding vulnerability implies highlighting and interlinking relevant indicators and/or perceptions encompassed in four main dimensions: social, institutional, physical and attitudinal vulnerability. Case studies in Dar es Salaam, Ouagadougou and Addis Ababa were carried out to obtain insights into the context-related conditions, behavior routines and survival networks in urban areas in west and east Africa. Using a combination of tools (e.g. focus group discussions, transect walks, interviews) we investigated in close cooperation with African partners how households and communities are being prepared to cope with, as well as to recover from floods. A comprehensive process of dealing with floods can be described based on sequential attributes concerning i) Anticipation before a flood occurs, ii) Resistance and coping activities during a flood event and, iii) Recovery and reconstruction afterwards. A participatory approach at household level provides detailed knowledge about the preparedness, the susceptibility and the coping capacities of identified community including its leaders and members. Assessing and ranking the weaknesses and limitations help strengthen awareness and initiate measures for improving coping capacities to social vulnerability in case of flooding. Examples of social vulnerability and the spectrum of coping activities are demonstrated through to use of empirical research results.

Emotional Triggers and Psychopathology Associated with Suicidal Ideation in Urban Children with Elevated Aggressive-Disruptive Behavior

ERIC Educational Resources Information Center

Wyman, Peter A.; Gaudieri, Patricia A.; Schmeelk-Cone, Karen; Cross, Wendi; Brown, C. Hendricks; Sworts, Luke; West, Jennifer; Burke, Katharine C.; Nathan, Janaki

2009-01-01

8.6% suicidal ideation (SI) was found among 349 urban 6-9 year olds in the top tercile of aggressive-disruptive behavior. SI was associated with more self-reported depression, ODD, conduct problems, and ADHD symptoms (ES 0.70-0.97) and 3.5-5 times more clinically significant symptoms. Parents rated more symptoms in older children associated with…

Homeland Security Planning for Urban Area Schools

DTIC Science & Technology

2008-03-01

about the safety and well-being of their families while they are at the scene and this may affect their job performance . Butler , et al recommend...TITLE AND SUBTITLE Homeland Security Planning for Urban Area Schools 6. AUTHOR(S) Craig Gjelsten 5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME...S) AND ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943-5000 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING /MONITORING AGENCY

Mapping bundles of ecosystem services reveals distinct types of multifunctionality within a Swedish landscape.

PubMed

Queiroz, Cibele; Meacham, Megan; Richter, Kristina; Norström, Albert V; Andersson, Erik; Norberg, Jon; Peterson, Garry

2015-01-01

Ecosystem services (ES) is a valuable concept to be used in the planning and management of social-ecological landscapes. However, the understanding of the determinant factors affecting the interaction between services in the form of synergies or trade-offs is still limited. We assessed the production of 16 ES across 62 municipalities in the Norrström drainage basin in Sweden. We combined GIS data with publically available information for quantifying and mapping the distribution of services. Additionally, we calculated the diversity of ES for each municipality and used correlations and k-means clustering analyses to assess the existence of ES bundles. We found five distinct types of bundles of ES spatially agglomerated in the landscape that could be explained by regional social and ecological gradients. Human-dominated landscapes were highly multifunctional in our study area and urban densely populated areas were hotspots of cultural services.

Investigating impacts of natural and human-induced environmental changes on hydrological processes and flood hazards using a GIS-based hydrological/hydraulic model and remote sensing data

NASA Astrophysics Data System (ADS)

Wang, Lei

Natural and human-induced environmental changes have been altering the earth's surface and hydrological processes, and thus directly contribute to the severity of flood hazards. To understand these changes and their impacts, this research developed a GIS-based hydrological and hydraulic modeling system, which incorporates state-of-the-art remote sensing data to simulate flood under various scenarios. The conceptual framework and technical issues of incorporating multi-scale remote sensing data have been addressed. This research develops an object-oriented hydrological modeling framework. Compared with traditional lumped or cell-based distributed hydrological modeling frameworks, the object-oriented framework allows basic spatial hydrologic units to have various size and irregular shape. This framework is capable of assimilating various GIS and remotely-sensed data with different spatial resolutions. It ensures the computational efficiency, while preserving sufficient spatial details of input data and model outputs. Sensitivity analysis and comparison of high resolution LIDAR DEM with traditional USGS 30m resolution DEM suggests that the use of LIDAR DEMs can greatly reduce uncertainty in calibration of flow parameters in the hydrologic model and hence increase the reliability of modeling results. In addition, subtle topographic features and hydrologic objects like surface depressions and detention basins can be extracted from the high resolution LiDAR DEMs. An innovative algorithm has been developed to efficiently delineate surface depressions and detention basins from LiDAR DEMs. Using a time series of Landsat images, a retrospective analysis of surface imperviousness has been conducted to assess the hydrologic impact of urbanization. The analysis reveals that with rapid urbanization the impervious surface has been increased from 10.1% to 38.4% for the case study area during 1974--2002. As a result, the peak flow for a 100-year flood event has increased by 20% and the floodplain extent has expanded by about 21.6%. The quantitative analysis suggests that the large regional detentions basins have effectively offset the adverse effect of increased impervious surface during the urbanization process. Based on the simulation and scenario analyses of land subsidence and potential climate changes, some planning measures and policy implications have been derived for guiding smart urban growth and sustainable resource development and management to minimize flood hazards.

AGI's Boulder Operation

ERIC Educational Resources Information Center

Romey, William D.

1972-01-01

Environmental Studies for Urban Youth (ES) for first grade through college and the primary concerns of the Earth Science Teacher Preparation Project (ESTPP), both developed by the AGI's Earth Science Education Program, are considered. (PR)

Blue-Green Solutions in Urban Development

NASA Astrophysics Data System (ADS)

Karlsson, Caroline; Kalantari, Zahra

2017-04-01

With the ongoing urbanisation and increasing pressure for new housing and infrastructure, the nexus of developing compact, energy-efficient and yet liveable and sustainable cities is urgent to address. In this context, blue-green spaces and related ecosystem services (ES) are critical resources that need to be integrated in policy and planning of urban. Among the ES provided by blue-green spaces, regulating ES such as water retention and purification are particularly important in urban areas, affecting water supply and quality, related cultural ES and biodiversity, as well as cities potential to adapt to climate change. Blue-green infrastructure management is considered a sustainable way to reducing negative effects of urbanisation, such as decreasing flood risks, as well as adapting to climate change for example by controlling increasing flood and drought risks. Blue-green infrastructure management can for example create multifunctional surfaces with valuable environmental and social functions and generally handle greenways and ecological networks as important ecosystem service components, for example for stormwater regulation in a sustainable urban drainage system. The Norrström drainage basin (22,000 km2) is a large demonstrator for Blue-green infrastructure management. Both urbanisation and agriculture are extensive within this basin, which includes the Swedish capital Stockholm and is part of the fertile Swedish belt. Together, the relatively high population density combined with agricultural and industrial activities in this region imply large eutrophication and pollution pressures, not least transferred through storm runoff to both inland surface waters and the coastal waters of the Baltic Sea. The ecosystems of this basin provide highly valued but also threatened services. For example, Lake Mälaren is the single main freshwater supply for the Swedish capital Stockholm, as well as a key nutrient retention system that strongly mitigates waterborne nutrient loads to the Baltic Sea a function that is in turn threatened by climate change. Large socio-economic values are also at stake here with regard to ecosystem regulation of both flood and drought risks, again threatened by both climate change and human development activities within the Norrström basin itself.

Urban ergonomics: an ongoing study of city signs and maps.

PubMed

Alves, Patricia; Arezes, Pedro

2012-01-01

The purpose of this study is to assess whether the existing signals in three European cities were developed according usability principles and ergonomic aspects for the citizen. City maps and signals will be tested using efficiency, effectiveness and user's satisfaction criteria. Among the urban areas are the center of Paris-FR, assumed to be well signalized, the historical center of Guimarães-PT and Chorweiler, Cologne-DE, a residential neighborhood of modern urbanism characterized by the extensive use of vegetation, the landscape homogeneity, and, consequently, by the difficult navigation.

Assessing the urban solar energy resource potential of Davao City, Philippines, using LiDAR Digital Surface Model (DSM) and GRASS GIS

NASA Astrophysics Data System (ADS)

Teves, Justine; Sola, Eula Fae; Pintor, Ben Hur; Ang, Ma. Rosario Concepcion

2016-10-01

Solar energy is emerging as one of the top options for renewable energy sources in the Philippines, with largescale solar photovoltaic (PV) farms being built all over the country. Solar energy resource in the urban environment has great potential in making a city self-sustaining, but has not been fully explored for the country. In order to represent its potential, reliable resource assessment should be done. This study aims to assess the available solar energy resource in Davao City, a trade and commerce hub in southern Philippines. The functions of GRASS GIS, specifically the r.sun module, in modelling incoming solar radiation is discussed, along with the use of a one-meter LiDAR Digital Surface Model (DSM) and Linke Turbidity coefficients as inputs. The average Julian day of each month was used to compute the Global Horizontal Irradiation (GHI) values under clear-sky or cloudless conditions. To account for the effects of the clouds in the study area, the clear-sky indices (Kc) were computed using data from solar recording stations of the Bureau of Soils and Water Management (BSWM) found within and around the region. These were multiplied to the modelled clear-sky GHI rasters to get the real-sky GHI. The results show that the city's average GHI potential ranges from 2693.79 Wh/m2 and 4453.13 Wh/m2. Average values are particularly higher around the months of March and April, while lower values are seen in the months of November and January. Areas with higher potential are seen in the southern portion of the city, consistent in built-up areas.

Integrated Use of Remote Sensed Data and Numerical Cartography for the Generation of 3d City Models

NASA Astrophysics Data System (ADS)

Bitelli, G.; Girelli, V. A.; Lambertini, A.

2018-05-01

3D city models are becoming increasingly popular and important, because they constitute the base for all the visualization, planning, management operations regarding the urban infrastructure. These data are however not available in the majority of cities: in this paper, the possibility to use geospatial data of various kinds with the aim to generate 3D models in urban environment is investigated. In 3D modelling works, the starting data are frequently the 3D point clouds, which are nowadays possible to collect by different sensors mounted on different platforms: LiDAR, imagery from satellite, airborne or unmanned aerial vehicles, mobile mapping systems that integrate several sensors. The processing of the acquired data and consequently the obtainability of models able to provide geometric accuracy and a good visual impact is limited by time, costs and logistic constraints. Nowadays more and more innovative hardware and software solutions can offer to the municipalities and the public authorities the possibility to use available geospatial data, acquired for diverse aims, for the generation of 3D models of buildings and cities, characterized by different level of detail. In the paper two cases of study are presented, both regarding surveys carried out in Emilia Romagna region, Italy, where 2D or 2.5D numerical maps are available. The first one is about the use of oblique aerial images realized by the Municipality for a systematic documentation of the built environment, the second concerns the use of LiDAR data acquired for other purposes; in the two tests, these data were used in conjunction with large scale numerical maps to produce 3D city models.

Trends in traffic fatalities in Mexico: examining progress on the decade of action for road safety 2011-2020.

PubMed

Cervantes-Trejo, Arturo; Leenen, Iwin; Fabila-Carrasco, John Stewart; Rojas-Vargas, Roy

2016-11-01

We explore demographic, temporal and geographic patterns of 256,588 road traffic fatalities from 1998 to 2013 in Mexico, in context of UN´s decade of action for road safety 2010-2020 (DARS). Combined traffic mortality data and population counts were analyzed using mixed-effects logistic regression, distinguishing sex-age groups, vulnerable and protected road users, and municipal size. Rapid growth from 1998 to 2008 in traffic mortality rates has been reversed since 2009. Most deaths averted are among young male protected road users (reduction of 0.95 fatalities per 100,000 per year in males 12-49). In spite of a steady decrease over the full study period, mortality rates remain high in vulnerable road users over 50, with a high mortality rate of 26 per 100,000 males over 75 years in 2013. Progress on the reduction of deaths advances in Mexico, in line with DARS targets. National road safety efforts require strengthening. Initiatives should target vulnerable road users, specifically adults >50 years in urban areas. Strengthening of drink driving programs aimed at young drivers/occupants is promising.

Application of Earth Sciencés Technology in Mapping the of Brazilian Coast: Localization, Analysis & Monitoring of the Archaeological Sites with Remote Sensing & LiDAR

NASA Astrophysics Data System (ADS)

Thompson Alves de Souza, Carlos Eduardo

Application of Earth Sciencés Technology in Mapping the of Brazilian Coast: Localization, Analysis & Monitoring of the Archaeological Sites with Remote Sensing & LiDAR Carlos Eduardo Thompson Alves de Souza cethompsoniii@hotmail.com Archaeologist Member of the European Association of Archaeologists B.A.Archaeology MA.Remote Sensing Abstract The Archaeological Research in Urban Environment with the Air Light Detection and Ranging is problematic for the Overlay Layers mixed with contexts concerning the Interpretation of Archaeological Data. However, in the Underwater Archaeology the results are excellent. This paper considers the application of Remote Sensing and Air Light Detection and Ranging (LIDAR) as separate things as well as Land Archaeology and the Underwater Archaeology. European Archaeologists know very little about Brazil and the article presents an Overview of Research in Brazil with Remote Sensing in Archaeology and Light Detection and Ranging in Land Archaeology and Underwater Archaeology, because Brazil has Continental Dimensions. Braziliańs Methodology for Location, Analysis and Monitoring of Archaeological Sites is necessarily more Complex and Innovative and therefore can serve as a New Paradigm for other archaeologists involved in the Advanced Management Heritage.

Vernal Pools Detection Using High-Resolution LiDAR Data and Aerial Imagery in Hubbardston, Massachusetts

NASA Astrophysics Data System (ADS)

Jiang, Jiaxin

Vernal pool refers to temporary or semi-permanent pools that occur in surface depressions without permanent inlets or outlets. Because they periodically dry out, vernal pools are free of fish and essential to amphibians, some reptiles, birds, and mammals for breeding habitats. In Massachusetts, vernal pool habitats are found in woodland depressions, swales or kettle holes where water is contained for at least two months in most years. However, vernal pools are delicate ecosystems. These systems are fragile to human activities such as urbanization. Understanding the current situation of vernal pools helps city planners make wiser decisions. This study focuses on identifying vernal pools in the state of Massachusetts with high-resolution light detection and ranging (LiDAR) data and aerial imagery. By using high-resolution light detection and ranging data, aerial imagery, land use data, the MassDEP Hydrography layer and the Soil Survey Geographic Database, the approach located over 1800 potential vernal pools in a 108 km 2 study area in Massachusetts. The assessment of the study result shows the commission rate was 5.6% and omission rate was 7.1%. This method provides an efficient way of locating vernal pools over large areas.

Surface Fitting Filtering of LIDAR Point Cloud with Waveform Information

NASA Astrophysics Data System (ADS)

Xing, S.; Li, P.; Xu, Q.; Wang, D.; Li, P.

2017-09-01

Full-waveform LiDAR is an active technology of photogrammetry and remote sensing. It provides more detailed information about objects along the path of a laser pulse than discrete-return topographic LiDAR. The point cloud and waveform information with high quality can be obtained by waveform decomposition, which could make contributions to accurate filtering. The surface fitting filtering method with waveform information is proposed to present such advantage. Firstly, discrete point cloud and waveform parameters are resolved by global convergent Levenberg Marquardt decomposition. Secondly, the ground seed points are selected, of which the abnormal ones are detected by waveform parameters and robust estimation. Thirdly, the terrain surface is fitted and the height difference threshold is determined in consideration of window size and mean square error. Finally, the points are classified gradually with the rising of window size. The filtering process is finished until window size is larger than threshold. The waveform data in urban, farmland and mountain areas from "WATER (Watershed Allied Telemetry Experimental Research)" are selected for experiments. Results prove that compared with traditional method, the accuracy of point cloud filtering is further improved and the proposed method has highly practical value.

New Late Gene, dar, Involved in DNA Replication of Bacteriophage T4 I. Isolation, Characterization, and Genetic Location.

PubMed

Wu, J R; Yeh, Y C

1975-05-01

Suppressors of gene 59-defective mutants were isolated by screening spontaneous, temperature-sensitive (ts) revertants of the amber mutant, amC5, in gene 59. Six ts revertants were isolated. No gene 59-defective ts recombinant was obtained by crossing each ts revertant with the wild type, T4D. However, suppressors of gene 59-defective mutants were obtained from two of these ts revertants. These suppressor mutants are referred to as dar (DNA arrested restoration). dar mutants specifically restored the abnormalities, both in DNA synthesis and burst size, caused by gene 59-defective mutants to normal levels. It is unlikely that dar mutants are nonsense suppressors since theý failed to suppress amber mutations in 11 other genes investigated. The genetic expression of dar is controlled by gene 55; therefore, dar is a late gene. The genetic location of dar has been mapped between genes 24 and 25, a region contiguous to late genes. dar appears to be another nonessential gene of T4 since burst sizes of dar were almost identical to those of the wild type. Mutations in dar did not affect genetic recombination and repair of UV-damaged DNA, but caused a sensitivity to hydroxyurea in progeny formation. The effect of the dar mutation on host DNA degradation cannot account for its hydroxyurea sensitivity. dar mutant alleles were recessive to the wild-type allele as judged by restoration of arrested DNA synthesis. The possible mechanisms for the suppression of defects in gene 59 are discussed.

Predictable waves of sequential forest degradation and biodiversity loss spreading from an African city

PubMed Central

Burgess, Neil D.; Milledge, Simon A. H.; Bulling, Mark T.; Fisher, Brendan; Smart, James C. R.; Clarke, G. Philip; Mhoro, Boniface E.; Lewis, Simon L.

2010-01-01

Tropical forest degradation emits carbon at a rate of ~0.5 Pg·y−1, reduces biodiversity, and facilitates forest clearance. Understanding degradation drivers and patterns is therefore crucial to managing forests to mitigate climate change and reduce biodiversity loss. Putative patterns of degradation affecting forest stocks, carbon, and biodiversity have variously been described previously, but these have not been quantitatively assessed together or tested systematically. Economic theory predicts a systematic allocation of land to its highest use value in response to distance from centers of demand. We tested this theory to see if forest exploitation would expand through time and space as concentric waves, with each wave targeting lower value products. We used forest data along a transect from 10 to 220 km from Dar es Salaam (DES), Tanzania, collected at two points in time (1991 and 2005). Our predictions were confirmed: high-value logging expanded 9 km·y−1, and an inner wave of lower value charcoal production 2 km·y−1. This resource utilization is shown to reduce the public goods of carbon storage and species richness, which significantly increased with each kilometer from DES [carbon, 0.2 Mg·ha−1; 0.1 species per sample area (0.4 ha)]. Our study suggests that tropical forest degradation can be modeled and predicted, with its attendant loss of some public goods. In sub-Saharan Africa, an area experiencing the highest rate of urban migration worldwide, coupled with a high dependence on forest-based resources, predicting the spatiotemporal patterns of degradation can inform policies designed to extract resources without unsustainably reducing carbon storage and biodiversity. PMID:20679200

Sources of salinity and urban pollution in the Quaternary sand aquifers of Dar es Salaam, Tanzania

NASA Astrophysics Data System (ADS)

Walraevens, Kristine; Mjemah, Ibrahimu Chikira; Mtoni, Yohana; Van Camp, Marc

2015-02-01

Groundwater is globally important for human consumption, and changes in quality can have serious consequences. The study area is within a coastal aquifer where groundwater quality is influenced by various potential sources of salinity that determine the composition of water extracted from wells. Groundwater chemistry data from the aquifer have been acquired to determine the geochemical conditions and processes that occur in this area and assess their implications for aquifer susceptibility. Analysis of groundwater samples shows that the dominant watertype is mostly NaCl with pH < 7 in both aquifers (i.e. upper and lower) except for the shallow wells where CaHCO3 prevails with pH ⩾ 7, and boreholes located near the Indian Ocean, where coral reef limestone deposits are located and the watertype evolves towards CaHCO3. In the lower aquifer, Cl- is higher than in the upper aquifer. The origin of salinity in the area is strongly influenced by groundwater ascending from deep marine Miocene Spatangid Shales through faults, seawater incursion on the border of the Indian Ocean, and throughout, there is some salinity within the Quaternary aquifer, especially in intercalated deltaic clays in the fluviatile deposits, showing some marine influences. The seawater intrusion is linked to the strongly increasing groundwater exploitation since 1997. Another process that plays a major role to the concentration of major ions in the groundwater is calcite dissolution. Next to geogenic salinity and seawater intrusion, anthropogenic pollution as well is affecting groundwater quality in the aquifer. An important result of this study is the observation of high nitrate concentrations, that call for improved sanitation in the area, where domestic sewage with on-site sanitation (mainly pit latrines) also threatens the groundwater resource.

Headache in a nonclinical population in Dar es Salaam, Tanzania. A community-based study.

PubMed

Matuja, W B; Mteza, I B; Rwiza, H T

1995-05-01

Headache is a common symptom that constitutes a major health problem to all countries in the world with a variable prevalence from about 20.2% in the African population to about 80% in populations of the civilized world. Community-based studies in African populations are still scanty, and the impact on health facility utilization and sickness absence from work is unknown. After a simple random selection, 1540 urban workers and students of higher education completed a standardized self-administered questionnaire on headache. A total of 815 (52%), (620 (51%) men, 195 (60%) women) admitted to having suffered a headache requiring medication or medical consultation in the last year. Of these, 366 (23.7%) had recurrent headache not attributable to systemic disease. Of the total with recurrent headache, there was a significant preponderance of women over men with sex prevalence of 28.9% and 22.4%, respectively (X2 P = 0.0001). Combined vascular-muscular-type of headache exceeded all types of headache, accounting for 35.8% of cases, followed by migraine accounting for 30.8% of cases. Organic disease was rare, accounting for 8.5% of cases, and psychogenic causes of headache were even rarer at less than 1.2% of cases. Within 2 months of onset of recurrent headaches, over 32% of sufferers had utilized the health facility at their place of work or study. A significant number of cases (175) had an average of 11.3 lost work days per year in comparison to a control group of 154 persons with an average of 5.7 lost work days per year for reasons other than headache (X2 P = 0.0005).(ABSTRACT TRUNCATED AT 250 WORDS)

Intensity-Duration-Frequency (IDF) rainfall curves, for data series and climate projection in African cities.

PubMed

De Paola, Francesco; Giugni, Maurizio; Topa, Maria Elena; Bucchignani, Edoardo

2014-01-01

Changes in the hydrologic cycle due to increase in greenhouse gases cause variations in intensity, duration, and frequency of precipitation events. Quantifying the potential effects of climate change and adapting to them is one way to reduce urban vulnerability. Since rainfall characteristics are often used to design water structures, reviewing and updating rainfall characteristics (i.e., Intensity-Duration-Frequency (IDF) curves) for future climate scenarios is necessary (Reg Environ Change 13(1 Supplement):25-33, 2013). The present study regards the evaluation of the IDF curves for three case studies: Addis Ababa (Ethiopia), Dar Es Salaam (Tanzania) and Douala (Cameroon). Starting from daily rainfall observed data, to define the IDF curves and the extreme values in a smaller time window (10', 30', 1 h, 3 h, 6 h, 12 h), disaggregation techniques of the collected data have been used, in order to generate a synthetic sequence of rainfall, with statistical properties similar to the recorded data. Then, the rainfall pattern of the three test cities was analyzed and IDF curves were evaluated. In order to estimate the contingent influence of climate change on the IDF curves, the described procedure was applied to the climate (rainfall) simulations over the time period 2010-2050, provided by CMCC (Centro Euro-Mediterraneo sui Cambiamenti Climatici). The evaluation of the IDF curves allowed to frame the rainfall evolution of the three case studies, considering initially only historical data, then taking into account the climate projections, in order to verify the changes in rainfall patterns. The same set of data and projections was also used for evaluating the Probable Maximum Precipitation (PMP).

Calculation of the overlap factor for scanning LiDAR based on the tridimensional ray-tracing method.

PubMed

Chen, Ruiqiang; Jiang, Yuesong; Wen, Luhong; Wen, Donghai

2017-06-01

The overlap factor is used to evaluate the LiDAR light collection ability. Ranging LiDAR is mainly determined by the optical configuration. However, scanning LiDAR, equipped with a scanning mechanism to acquire a 3D coordinate points cloud for a specified target, is essential in considering the scanning effect at the same time. Otherwise, scanning LiDAR will reduce the light collection ability and even cannot receive any echo. From this point of view, we propose a scanning LiDAR overlap factor calculation method based on the tridimensional ray-tracing method, which can be applied to scanning LiDAR with any special laser intensity distribution, any type of telescope (reflector, refractor, or mixed), and any shape obstruction (i.e., the reflector of a coaxial optical system). A case study for our LiDAR with a scanning mirror is carried out, and a MATLAB program is written to analyze the laser emission and reception process. Sensitivity analysis is carried out as a function of scanning mirror rotation speed and detector position, and the results guide how to optimize the overlap factor for our LiDAR. The results of this research will have a guiding significance in scanning LiDAR design and assembly.

Immunogenicity and Protective Efficacy of the DAR-901 Booster Vaccine in a Murine Model of Tuberculosis

PubMed Central

Lahey, Timothy; Laddy, Dominick; Hill, Krystal; Schaeffer, Jacqueline; Hogg, Alison; Keeble, James; Dagg, Belinda; Ho, Mei Mei; Arbeit, Robert D.; von Reyn, C. Fordham

2016-01-01

Background The development of a novel tuberculosis vaccine is a leading global health priority. SRL172, an inactivated, whole-cell mycobacterial vaccine, was safe, immunogenic and reduced the incidence of culture-confirmed tuberculosis in a phase III trial in HIV-infected and BCG immunized adults in Tanzania. Here we describe the immunogenicity and protective efficacy of DAR-901, a booster vaccine against tuberculosis manufactured from the same seed strain using a new scalable method. Methods We evaluated IFN-γ responses by ELISpot and antibody responses by enzyme linked immunosorbent assay in C57BL/6 and BALB/c mice after three doses of DAR-901. In an aerosol challenge model, we evaluated the protective efficacy of the DAR-901 booster in C57BL/6 mice primed with BCG and boosted with two doses of DAR-901 at 4 dosage levels in comparison with homologous BCG boost. Results DAR-901 vaccination elicited IFN-γ responses to mycobacterial antigen preparations derived from both DAR-901 and Mycobacterium tuberculosis. DAR-901 immunization enhanced antibody responses to DAR-901 but not Mycobacterium tuberculosis lysate or purified protein derivative. Among animals primed with BCG, boosting with DAR-901 at 1 mg provided greater protection against aerosol challenge than a homologous BCG boost (lungs P = 0.036, spleen P = 0.028). Conclusions DAR-901 induces cellular and humoral immunity and boosts protection from M. tuberculosis compared to a homologous BCG boost. PMID:27997597

CONHECIMENTO DA LEI GERAL DE SAÚDE – RESPEITO ÀS TRANSFUSÕES SANGUÍNEAS EM MÉDICOS E PACIENTES TESTEMUNHAS DE JEOVÁ DO HOSPITAL DR. DARÍO CONTRERAS DA REPÚBLICA DOMINICANA

PubMed Central

SANTANA, ELSA DÍAZ

2010-01-01

Este estudo avalia quanto o corpo médico do Hospital Dr. Darío Contreras de República Dominicana conhece, respeita, informa e aplica a Lei Geral de Saúde em relação aos direitos do paciente Testemunha de Jeová de negar-se a ser transfundido (respeito a sua autonomia); também se os Testemunhas de Jeová conhecem a Lei Geral de Saúde e até que ponto têm se beneficiado diante dessa proposição. O estudo revelou que nem médicos, nem Testemunhas de Jeová conhecem de fato essa lei. PMID:20689657

Status of Women in Physics in Tanzania Since 2002

NASA Astrophysics Data System (ADS)

Samiji, M. E.

2009-04-01

Seeing a need for more teachers in the sciences, including physics, the Tanzanian government upgraded two teachers' training colleges to become constituent colleges of the University of Dar es Salaam. The government has also been aware of the underrepresentation of women in a number of programs, notably science and engineering. The university created two programs—the Pre-Entry Program and the Female Undergraduate Scholarship Program (FUSP)—to facilitate female enrollment in science courses. In 2007 the physics department, in collaboration with the UNESCO Basic Science Program, conducted a workshop for physics teachers in secondary schools. Of 31 participants, six were female. As a result of these efforts, the number of female students who show interest in physics and other fields of science has increased by 5% since 2002.

Evaluating Public Health Interventions: 3. The Two-Stage Design for Confounding Bias Reduction-Having Your Cake and Eating It Two.

PubMed

Spiegelman, Donna; Rivera-Rodriguez, Claudia L; Haneuse, Sebastien

2016-07-01

In public health evaluations, confounding bias in the estimate of the intervention effect will typically threaten the validity of the findings. It is a common misperception that the only way to avoid this bias is to measure detailed, high-quality data on potential confounders for every intervention participant, but this strategy for adjusting for confounding bias is often infeasible. Rather than ignoring confounding altogether, the two-phase design and analysis-in which detailed high-quality confounding data are obtained among a small subsample-can be considered. We describe the two-stage design and analysis approach, and illustrate its use in the evaluation of an intervention conducted in Dar es Salaam, Tanzania, of an enhanced community health worker program to improve antenatal care uptake.

S2k-Leitlinie zum Gebrauch von Präparationen zur lokalen Anwendung auf der Haut (Topika).

PubMed

Wohlrab, Johannes; Staubach, Petra; Augustin, Matthias; Eisert, Lisa; Hünerbein, Andreas; Nast, Alexander; Reimann, Holger; Strömer, Klaus; Mahler, Vera

2018-03-01

Diese Leitlinie richtet sich an Assistenz- und Fachärzte der Dermatologie sowie an Kostenträger und politische Entscheidungsgremien. Die Leitlinie wurde im formellen Konsensusverfahren (S2k) von Dermatologen unter Einbindung von Apothekern erstellt. Die Leitlinie stellt allgemeine Aspekte der Pharmakokinetik sowie der regulatorischen Begrifflichkeiten dar. Es werden Empfehlungen zur Indikation von Magistralrezepturen sowie deren Qualitätssicherung gegeben. Die Bedeutung der galenischen Grundlagen und die Problematik bei einer Substitution gegeneinander verschiedener Grundlagen werden dargestellt. Die Leitlinie umfasst Kriterien zur Auswahl einer adäquaten Grundlage sowie spezifische Aspekte zur Therapieplanung. Die Leitlinie gibt Empfehlungen zum Management bei Unverträglichkeiten gegenüber Bestandteilen der Grundlagen oder Hilfsstoffe. © 2018 The Authors | Journal compilation © Blackwell Verlag GmbH, Berlin.

Prevention of mother-to-child transmission of HIV-1 through breastfeeding by treating mothers with triple antiretroviral therapy in Dar es Salaam, Tanzania: the Mitra Plus study.

PubMed

Kilewo, Charles; Karlsson, Katarina; Ngarina, Matilda; Massawe, Augustine; Lyamuya, Eligius; Swai, Andrew; Lipyoga, Rosina; Mhalu, Fred; Biberfeld, Gunnel

2009-11-01

The main aim of this study was to reduce breast-milk transmission of HIV-1 by treating HIV-1-infected women with highly active antiretroviral therapy (HAART) during breastfeeding. Mitra Plus was an open-label, nonrandomized, prospective cohort study. HIV-1-infected pregnant women in Dar es Salaam were treated with zidovudine (ZDV) + lamivudine (3TC) + nevirapine (NVP). NVP was later replaced by nelfinavir for mothers with CD4 cell counts >200 cells per microliter or with adverse reaction to NVP. HAART was initiated at 34 weeks of gestation. For women with symptomatic HIV infection or CD4 cell counts below 200 cells per microliter, HAART was started earlier if possible. Treatment of the mothers was stopped at 6 months except for those mothers who needed HAART for their own health. The infants received ZDV + 3TC for 1 week after birth. Mothers were advised to exclusively breastfeed and to wean abruptly between 5 and 6 months. Transmission of HIV-1 was analyzed using the Kaplan-Meier survival technique. Cox regression was used for comparison with the breastfeeding population of the Petra trial arm A. There were 441 infants included in the analysis of HIV-1 transmission. The cumulative transmission of HIV-1 was 4.1 % [95% confidence interval (CI): 2.2 to 6.0] at 6 weeks, 5.0% (95% CI: 2.9 to 7.1) at 6 months, and 6.0% (95% CI: 3.7 to 8.3) at 18 months after delivery. The cumulative risk of HIV transmission between 6 weeks and 6 months was 1.0% and between 6 months and 18 months 1.1%. The cumulative HIV infection or death rate was 8.6% (95% CI: 6.0 to 11.2) at 6 months and 13.6% (95% CI: 10.3 to 16.9) at 18 months after delivery. Viral load at enrollment and duration of HAART before delivery were significantly associated with transmission but CD4 cell count at enrollment was not. The median time of breastfeeding was 24 weeks. The transmission in the Mitra Plus study was about half of the transmission in the breastfeeding population in the Petra trial arm A at 6 months after delivery (adjusted relative hazard = 0.49, P < 0.001). The combined outcome HIV infection or death was significantly lower in the Mitra Plus study than in the breastfeeding population in the Petra trial arm A at 18 months (adjusted relative hazard = 0.61, P = 0.007). NVP-related mucocutaneous rash was demonstrated in 6.5% of 429 NVP-exposed women. The incidence of NVP-related grade 3 or 4 hepatotoxicity was low (0.5%). HAART given to HIV-infected mothers in late pregnancy and during breastfeeding resulted in a low postnatal HIV transmission similar to that previously demonstrated in the Mitra study in Dar es Salaam using infant prophylaxis with 3TC during breastfeeding. The extended maternal prophylaxis with HAART for prevention of mother-to-child transmission of HIV-1 for breastfeeding mothers who do not need HAART for their own health should be further evaluated and compared with the use of infant postnatal antiretroviral prophylaxis regarding safety and cost-effectiveness.

Analysis of long-term climate change on per capita water demand in urban versus suburban areas in the Portland metropolitan area, USA

NASA Astrophysics Data System (ADS)

Parandvash, G. Hossein; Chang, Heejun

2016-07-01

We investigated the impacts of long-term climate variability and change on per capita water demand in urban and suburban service areas that have different degrees of development density in the Portland metropolitan area, USA. Together with historical daily weather and water production data, socioeconomic data such as population and unemployment rate were used to estimate daily per capita water demand in the two service areas. The structural time series regression model results show that the sensitivity of per capita water demand to both weather and unemployment rate variables is higher in suburban areas than in urban areas. This is associated with relatively higher proportional demand by the residential sector in the suburban area. The estimated coefficients of the historical demand model were used to project the mid-21st century (2035-2064) per capita water demand under three climate change scenarios that represent high (HadGEM2-ES), medium (MIROC5), and low (GFDL) climate changes. Without climate adaptation, compared to the historical period between 1983 and 2012, per capita water demand is projected to increase by 10.6% in the 2035-2064 period under the HadGEM2-ES in suburban areas, while per capita demand is projected to increase by 4.8% under the same scenario in urban areas. Our findings have implications for future urban water resource management and land use planning in the context of climate variability and change. A tight integration between water resource management and urban planning is needed for preparing for climate adaptation in municipal water planning and management.

Characterization and Higher-Order Structure Assessment of an Interchain Cysteine-Based ADC: Impact of Drug Loading and Distribution on the Mechanism of Aggregation.

PubMed

Guo, Jianxin; Kumar, Sandeep; Chipley, Mark; Marcq, Olivier; Gupta, Devansh; Jin, Zhaowei; Tomar, Dheeraj S; Swabowski, Cecily; Smith, Jacquelynn; Starkey, Jason A; Singh, Satish K

2016-03-16

The impact of drug loading and distribution on higher order structure and physical stability of an interchain cysteine-based antibody drug conjugate (ADC) has been studied. An IgG1 mAb was conjugated with a cytotoxic auristatin payload following the reduction of interchain disulfides. The 2-D LC-MS analysis shows that there is a preference for certain isomers within the various drug to antibody ratios (DARs). The physical stability of the unconjugated monoclonal antibody, the ADC, and isolated conjugated species with specific DAR, were compared using calorimetric, thermal, chemical denaturation and molecular modeling techniques, as well as techniques to assess hydrophobicity. The DAR was determined to have a significant impact on the biophysical properties and stability of the ADC. The CH2 domain was significantly perturbed in the DAR6 species, which was attributable to quaternary structural changes as assessed by molecular modeling. At accelerated storage temperatures, the DAR6 rapidly forms higher molecular mass species, whereas the DAR2 and the unconjugated mAb were largely stable. Chemical denaturation study indicates that DAR6 may form multimers while DAR2 and DAR4 primarily exist in monomeric forms in solution at ambient conditions. The physical state differences were correlated with a dramatic increase in the hydrophobicity and a reduction in the surface tension of the DAR6 compared to lower DAR species. Molecular modeling of the various DAR species and their conformers demonstrates that the auristatin-based linker payload directly contributes to the hydrophobicity of the ADC molecule. Higher order structural characterization provides insight into the impact of conjugation on the conformational and colloidal factors that determine the physical stability of cysteine-based ADCs, with implications for process and formulation development.

LiDAR and IFSAR-Based Flood Inundation Model Estimates for Flood-Prone Areas of Afghanistan

NASA Astrophysics Data System (ADS)

Johnson, W. C.; Goldade, M. M.; Kastens, J.; Dobbs, K. E.; Macpherson, G. L.

2014-12-01

Extreme flood events are not unusual in semi-arid to hyper-arid regions of the world, and Afghanistan is no exception. Recent flashfloods and flashflood-induced landslides took nearly 100 lives and destroyed or damaged nearly 2000 homes in 12 villages within Guzargah-e-Nur district of Baghlan province in northeastern Afghanistan. With available satellite imagery, flood-water inundation estimation can be accomplished remotely, thereby providing a means to reduce the impact of such flood events by improving shared situational awareness during major flood events. Satellite orbital considerations, weather, cost, data licensing restrictions, and other issues can often complicate the acquisition of appropriately timed imagery. Given the need for tools to supplement imagery where not available, complement imagery when it is available, and bridge the gap between imagery based flood mapping and traditional hydrodynamic modeling approaches, we have developed a topographic floodplain model (FLDPLN), which has been used to identify and map river valley floodplains with elevation data ranging from 90-m SRTM to 1-m LiDAR. Floodplain "depth to flood" (DTF) databases generated by FLDPLN are completely seamless and modular. FLDPLN has been applied in Afghanistan to flood-prone areas along the northern and southern flanks of the Hindu Kush mountain range to generate a continuum of 1-m increment flood-event models up to 10 m in depth. Elevation data used in this application of FLDPLN included high-resolution, drone-acquired LiDAR (~1 m) and IFSAR (5 m; INTERMAP). Validation of the model has been accomplished using the best available satellite-derived flood inundation maps, such as those issued by Unitar's Operational Satellite Applications Programme (UNOSAT). Results provide a quantitative approach to evaluating the potential risk to urban/village infrastructure as well as to irrigation systems, agricultural fields and archaeological sites.

Simulation of Satellite, Airborne and Terrestrial LiDAR with DART (I):Waveform Simulation with Quasi-Monte Carlo Ray Tracing

NASA Technical Reports Server (NTRS)

Gastellu-Etchegorry, Jean-Philippe; Yin, Tiangang; Lauret, Nicolas; Grau, Eloi; Rubio, Jeremy; Cook, Bruce D.; Morton, Douglas C.; Sun, Guoqing

2016-01-01

Light Detection And Ranging (LiDAR) provides unique data on the 3-D structure of atmosphere constituents and the Earth's surface. Simulating LiDAR returns for different laser technologies and Earth scenes is fundamental for evaluating and interpreting signal and noise in LiDAR data. Different types of models are capable of simulating LiDAR waveforms of Earth surfaces. Semi-empirical and geometric models can be imprecise because they rely on simplified simulations of Earth surfaces and light interaction mechanisms. On the other hand, Monte Carlo ray tracing (MCRT) models are potentially accurate but require long computational time. Here, we present a new LiDAR waveform simulation tool that is based on the introduction of a quasi-Monte Carlo ray tracing approach in the Discrete Anisotropic Radiative Transfer (DART) model. Two new approaches, the so-called "box method" and "Ray Carlo method", are implemented to provide robust and accurate simulations of LiDAR waveforms for any landscape, atmosphere and LiDAR sensor configuration (view direction, footprint size, pulse characteristics, etc.). The box method accelerates the selection of the scattering direction of a photon in the presence of scatterers with non-invertible phase function. The Ray Carlo method brings traditional ray-tracking into MCRT simulation, which makes computational time independent of LiDAR field of view (FOV) and reception solid angle. Both methods are fast enough for simulating multi-pulse acquisition. Sensitivity studies with various landscapes and atmosphere constituents are presented, and the simulated LiDAR signals compare favorably with their associated reflectance images and Laser Vegetation Imaging Sensor (LVIS) waveforms. The LiDAR module is fully integrated into DART, enabling more detailed simulations of LiDAR sensitivity to specific scene elements (e.g., atmospheric aerosols, leaf area, branches, or topography) and sensor configuration for airborne or satellite LiDAR sensors.

Using Remote Sensing to Visualize and Extract Building Inventories of Urban Areas for Disaster Planning and Response

NASA Astrophysics Data System (ADS)

Lang, A. F.; Salvaggio, C.

2016-12-01

Climate change, skyrocketing global population, and increasing urbanization have set the stage for more so-called "mega-disasters." We possess the knowledge to mitigate and predict the scope of these events, and recent advancements in remote sensing can inform these efforts. Satellite and aerial imagery can be obtained anywhere of interest; unmanned aerial systems can be deployed quickly; and improved sensor resolutions and image processing techniques allow close examination of the built environment. Combined, these technologies offer an unprecedented ability for the disaster community to visualize, assess, and communicate risk. Disaster mitigation and response efforts rely on an accurate representation of the built environment, including knowledge of building types, structural characteristics, and juxtapositions to known hazards. The use of remote sensing to extract these inventory data has come far in the last five years. Researchers in the Digital Imaging and Remote Sensing (DIRS) group at the Rochester Institute of Technology are meeting the needs of the disaster community through the development of novel image processing methods capable of extracting detailed information of individual buildings. DIRS researchers have pioneered the ability to generate three-dimensional building models from point cloud imagery (e.g., LiDAR). This method can process an urban area and recreate it in a navigable virtual reality environment such as Google Earth within hours. Detailed geometry is obtained for individual structures (e.g., footprint, elevation). In a recent step forward, these geometric data can now be combined with imagery from other sources, such as high resolution or multispectral imagery. The latter ascribes a spectral signature to individual pixels, suggesting construction material. Ultimately, these individual building data are amassed over an entire region, facilitating aggregation and risk modeling analyses. The downtown region of Rochester, New York is presented as a case study. High resolution optical, LiDAR, and multi-spectral imagery was captured of this region. Using the techniques described, these imagery sources are combined and processed to produce a holistic representation of the built environment, inclusive of individual building characteristics.

Study on environmental test technology of LiDAR used for vehicle

NASA Astrophysics Data System (ADS)

Wang, Yi; Yang, Jianfeng; Ou, Yong

2018-03-01

With the development of intelligent driving, the LiDAR used for vehicle plays an important role in it, in some extent LiDAR is the key factor of intelligent driving. And environmental adaptability is one critical factor of quality, it relates success or failure of LiDAR. This article discusses about the environment and its effects on LiDAR used for vehicle, it includes analysis of any possible environment that vehicle experiences, and environmental test design.

Post-donation telephonic interview of blood donors providing an insight into delayed adverse reactions: First attempt in India.

PubMed

Tiwari, Aseem K; Aggarwal, Geet; Dara, Ravi C; Arora, Dinesh; Srivastava, Khushboo; Raina, Vimarsh

2017-04-01

Blood donor experiences both immediate adverse reactions (IAR) and delayed adverse reactions (DAR). With limited published data available on the incidence of DAR, a study was conducted to estimate incidence and profile of DAR through telephonic interview. Study was conducted over a 45-day period for consecutive volunteer whole blood donations at tertiary care hospital. Donors were divided into first-time, repeat and regular and were monitored for IAR. They were given written copy of post-donation advice. Donors were contacted telephonically three weeks post-donation and enquired about general wellbeing and specific DAR in accordance with a standard n international (International Society of Blood Transfusion) standard format. Donors participated in the study of which 1.6% donors experienced an IAR. Much larger number reported DAR (10.3% vs.1.6% p<0.0001). Further, DAR was presented as a variegated profile with bruise, painful arms and fatigue being the commonest. DARs were more common in females than males (25% vs. 10.3%, p<0.02). Localized DAR like bruise and painful arms were more common in younger donors (age <50 years) whereas systemic DAR like fatigue was common in older donors (>50 years). First time (12.3%) and repeat donors (13.5%) had similar frequency of DAR but were lower among regular donors (6.7%). DARs are more common than IAR and are of different profile. Post-donation interview has provided an insight into donor experiences and can be used as a valuable tool in donor hemovigilance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estimation of the fraction of absorbed photosynthetically active radiation (fPAR) in maize canopies using LiDAR data and hyperspectral imagery.

PubMed

Qin, Haiming; Wang, Cheng; Zhao, Kaiguang; Xi, Xiaohuan

2018-01-01

Accurate estimation of the fraction of absorbed photosynthetically active radiation (fPAR) for maize canopies are important for maize growth monitoring and yield estimation. The goal of this study is to explore the potential of using airborne LiDAR and hyperspectral data to better estimate maize fPAR. This study focuses on estimating maize fPAR from (1) height and coverage metrics derived from airborne LiDAR point cloud data; (2) vegetation indices derived from hyperspectral imagery; and (3) a combination of these metrics. Pearson correlation analyses were conducted to evaluate the relationships among LiDAR metrics, hyperspectral metrics, and field-measured fPAR values. Then, multiple linear regression (MLR) models were developed using these metrics. Results showed that (1) LiDAR height and coverage metrics provided good explanatory power (i.e., R2 = 0.81); (2) hyperspectral vegetation indices provided moderate interpretability (i.e., R2 = 0.50); and (3) the combination of LiDAR metrics and hyperspectral metrics improved the LiDAR model (i.e., R2 = 0.88). These results indicate that LiDAR model seems to offer a reliable method for estimating maize fPAR at a high spatial resolution and it can be used for farmland management. Combining LiDAR and hyperspectral metrics led to better performance of maize fPAR estimation than LiDAR or hyperspectral metrics alone, which means that maize fPAR retrieval can benefit from the complementary nature of LiDAR-detected canopy structure characteristics and hyperspectral-captured vegetation spectral information.

From the Sierra to the Cities: The Urban Campaign of the Shining Path

DTIC Science & Technology

1992-01-01

AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS( ES ) Rand Corporation,1776 Main Street...PO Box 2138,Santa Monica,CA,90407-2138 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS( ES ) 10...indeed turned out to be correct. See " Que pasa con Sendero Luminoso?" QueHacer, No. 29, June 1984, pp. 34-38. 4Richard Webb and Graciela Fernandez

Civilian Skills for African Military Officers to Resolve the Infrastructure, Economic Development, and Stability Crisis in Sub-Saharan Africa

DTIC Science & Technology

2011-03-01

AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Army War College,Strategic... projects build - ing Chinese infrastructure in both rural and urban ar- eas.53 The Chinese model thus instills a lifelong dedica- tion to and...Studies Institute,122 Forbes Avenue,Carlisle,PA,17013 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES

Media: A Line of Operation for Urban Combat on the Operational Level

DTIC Science & Technology

2007-05-09

coverage of events. Although bloggers may not be trained journalists, they do have an impact on media coverage. As the media reporters submit stori the...day’s events, bloggers around the world provide commentary on the topic and sometim even further investigate the facts of the report. Stories that...not address blog r es of es eports or blogg g dium ers as a legitimate form of media. Bloggers and blog pages are primarily commentary on

An Algorithm to Identify and Localize Suitable Dock Locations from 3-D LiDAR Scans

DTIC Science & Technology

2013-05-10

Locations from 3-D LiDAR Scans 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Graves, Mitchell Robert 5d. PROJECT NUMBER...Ranging ( LiDAR ) scans. A LiDAR sensor is a sensor that collects range images from a rotating array of vertically aligned lasers. Our solution leverages...Algorithm, Dock, Locations, Point Clouds, LiDAR , Identify 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a

Association between anaemia and infections (HIV, malaria and hookworm) among children admitted at Muhimbili National Hospital.

PubMed

Magesa, A S; Magesa, P M

2012-09-01

Anaemia is the major cause of morbidity and mortality in paediatric age with much aetiology. The magnitude of childhood anaemia has been inadequately studied at Muhimbili National Hospital (MNH). The study was aimed at determining the frequency of anaemia and associated infections in patients admitted in general paediatric wards at MNH in Dar es Salaam. This was a descriptive cross-sectional study. This was conducted at MNH in general paediatric wards from 20th August, 2009 to 15th December, 2009. Patients, aged 1-84 months, consecutively admitted were recruited in the study. After informed verbal consent from the guardian or parent was obtained, information on demographic and clinical characteristics was collected from the parent or guardian. Physical examination and laboratory tests on blood ; stool samples for hookworm screening; blood slides for malaria parasites; Human Immunodeficiency Virus (HIV) screening; and blood peripheral smears were done on all subjects. Additional information was taken from medical files. Data management: The prevalence of anemia was determined as a percentage of all paediatric patients recruited during the time of data collection. All information was recorded using questionnaires and analysis was done using SPSS version 13.0. A p value of < 0.05 was considered statistically significant. A total of 315 children were assessed. The frequency of anaemia was 79.4%. This is much higher than the WHO prevalence of 67.6% in Africa for anaemia to be taken as a disease of public health importance. The proportion of malaria was 7.9%, HIV seropositive was 10.2% and hookworm was 1.0% of all admissions. There was an increased risk of anaemia in patients with HIV seropositive and or malaria although this was not statistically significant (RR > 1.0, p > 0.05). Anaemia in paediatric patients admitted at MNH is a disease of high public health importance in Dar es Salaam and may well carry a high burden in the rest of the country. Other risk factors of anaemia should be investigated with a goal of reducing the burden of anaemia.

Glycaemic control in type 1 diabetes mellitus among children and adolescents in a resource limited setting in Dar es Salaam - Tanzania.

PubMed

Noorani, Mariam; Ramaiya, Kaushik; Manji, Karim

2016-05-31

Type 1 Diabetes Mellitus is a rapidly growing problem in Tanzania. Children and adolescents with type 1 diabetes have previously been found to have poor glycaemic control and high prevalence of complications. Strict glycaemic control reduces the incidence and progression of chronic complications. The aim of this study was to identify the factors associated with glycaemic control among children and adolescents. A cross sectional study was done at the diabetes clinic for children and adolescents. Data on socioeconomic, demographic and diabetes specific variables including adherence, diabetes knowledge, caregivers knowledge and their involvement in the care of the child was obtained. Glycaemic control was assessed by measuring glycosylated hemoglobin. (HbA1C). Linear regression analysis was done to determine factors associated with glycaemic control Seventy-five participants were recruited into the study (51 % males). The mean HbA1c was 11.1 ± 2.1 %. Children aged <10 years were found to have a significantly better glycaemic control (9.8 %) as compared to 10-14 year olds (11.5 %) and >14 year olds (11.4 %) (P value = 0.022). Sixty-eight percent of patients had good adherence to insulin while adherence to blood glucose monitoring regimen was 48 % and to diet control was 28 %. Younger age, having the mother as the primary caregiver, better caregiver knowledge of diabetes, better adherence to blood glucose monitoring regimen and diabetes duration of less than 1 year were associated with better glycaemic control. In multivariate analysis, age, adherence to blood glucose monitoring regimen and the mother as the primary caregiver were found to independently predict glycaemic control (R(2) = 0.332, p value = 0.00). Children and adolescents with type 1 diabetes in Dar es Salaam have poor glycaemic control. In order to improve metabolic control, adherence to blood glucose monitoring should be encouraged and caregivers encouraged to participate in care of their children especially the adolescents.

Masculine attitudes of superiority deter men from accessing antiretroviral therapy in Dar es Salaam, Tanzania.

PubMed

Nyamhanga, Tumaini M; Muhondwa, Eustace P Y; Shayo, Rose

2013-10-22

This article presents part of the findings from a larger study that sought to assess the role that gender relations play in influencing equity regarding access and adherence to antiretroviral therapy (ART). Review of the literature has indicated that, in Southern and Eastern Africa, fewer men than women have been accessing ART, and the former start using ART late, after HIV has already been allowed to advance. The main causes for this gender gap have not yet been fully explained. To explore how masculinity norms limit men's access to ART in Dar es Salaam. This article is based on a qualitative study that involved the use of focus group discussions (FGDs). The study employed a stratified purposive sampling technique to recruit respondents. The study also employed a thematic analysis approach. Overall, the study's findings revealed that men's hesitation to visit the care and treatment clinics signifies the superiority norm of masculinity that requires men to avoid displaying weakness. Since men are the heads of families and have higher social status, they reported feeling embarrassed at having to visit the care and treatment clinics. Specifically, male respondents indicated that going to a care and treatment clinic may raise suspicion about their status of living with HIV, which in turn may compromise their leadership position and cause family instability. Because of this tendency towards 'hiding', the few men who register at the public care and treatment clinics do so late, when HIV-related signs and symptoms are already far advanced. This study suggests that the superiority norm of masculinity affects men's access to ART. Societal expectations of a 'real man' to be fearless, resilient, and emotionally stable are in direct conflict with expectations of the treatment programme that one has to demonstrate health-promoting behaviour, such as promptness in attending the care and treatment clinic, agreeing to take HIV tests, and disclosing one's status of living with HIV to at least one's spouse or partner. Hence, there is a need for HIV control agencies to design community-based programmes that will stimulate dialogue on the deconstruction of masculinity notions.

Masculine attitudes of superiority deter men from accessing antiretroviral therapy in Dar es Salaam, Tanzania

PubMed Central

Nyamhanga, Tumaini M.; Muhondwa, Eustace P.Y.; Shayo, Rose

2013-01-01

Background This article presents part of the findings from a larger study that sought to assess the role that gender relations play in influencing equity regarding access and adherence to antiretroviral therapy (ART). Review of the literature has indicated that, in Southern and Eastern Africa, fewer men than women have been accessing ART, and the former start using ART late, after HIV has already been allowed to advance. The main causes for this gender gap have not yet been fully explained. Objective To explore how masculinity norms limit men's access to ART in Dar es Salaam. Design This article is based on a qualitative study that involved the use of focus group discussions (FGDs). The study employed a stratified purposive sampling technique to recruit respondents. The study also employed a thematic analysis approach. Results Overall, the study's findings revealed that men's hesitation to visit the care and treatment clinics signifies the superiority norm of masculinity that requires men to avoid displaying weakness. Since men are the heads of families and have higher social status, they reported feeling embarrassed at having to visit the care and treatment clinics. Specifically, male respondents indicated that going to a care and treatment clinic may raise suspicion about their status of living with HIV, which in turn may compromise their leadership position and cause family instability. Because of this tendency towards ‘hiding’, the few men who register at the public care and treatment clinics do so late, when HIV-related signs and symptoms are already far advanced. Conclusion This study suggests that the superiority norm of masculinity affects men's access to ART. Societal expectations of a ‘real man’ to be fearless, resilient, and emotionally stable are in direct conflict with expectations of the treatment programme that one has to demonstrate health-promoting behaviour, such as promptness in attending the care and treatment clinic, agreeing to take HIV tests, and disclosing one's status of living with HIV to at least one's spouse or partner. Hence, there is a need for HIV control agencies to design community-based programmes that will stimulate dialogue on the deconstruction of masculinity notions. PMID:24152373

Improvements in Health-related Quality of Life among Methadone Maintenance Clients in Dar es Salaam, Tanzania

PubMed Central

Ubuguyu, Omary; Tran, Olivia C.; Bruce, R. Douglas; Masao, Frank; Nyandindi, Cassian; Sabuni, Norman; McCurdy, Sheryl; Mbwambo, Jessie

2016-01-01

Background Injection of heroin has become widespread in Dar es Salaam, Tanzania and is spreading throughout the country. To prevent potential bridging of HIV epidemics, the Tanzanian government established a methadone maintenance treatment (MMT) clinic in February 2011. We assess the effect of MMT on health-related quality of life (HRQOL) and examine factors, particularly HIV infection and methadone dose, associated with changes in HRQOL. Methods This study utilized routine data on clients enrolling in methadone from February 2011 to April 2012 at Muhimbili National Hospital. Change in physical (PCS) and mental health (MCS) composite scores, as measured by the SF-12 tool, were the primary outcomes. Backward stepwise linear regression, with a criterion of p<0.2 was used to identify baseline exposure variables for inclusion in multivariable models, while adjusting for baseline scores. Results A total of 288 MMT clients received baseline and follow-up assessments. Mean methadone dose administered was 45 mg (SD±25) and 76(27%) were confirmed HIV-positive. Significant improvements were observed in PCS and MCS, with mean increases of 15.7 and 3.3, respectively. In multivariable models, clients who had previous poly-substance use with cocaine [p=0.040] had a significantly higher mean change in PCS. Clients who were living with HIV [p=0.002]; satisfied with current marital situation [p=0.045]; had a history of suicidal thoughts [p=0.021]; and previously experienced cognitive difficulties [p=0.012] had significantly lower mean change in PCS. Clients with shorter history of heroin use [p=0.012] and who received higher methadone doses [p=0.028] had significantly higher mean change in MCS, compared to their counterparts. Discussion Aspects of mental and physical health, risk behaviors and quality of life among drug users are intertwined and complex. Our research revealed positive short-term effects of MMT on HRQOL and highlights the importance of sustained retention for optimal benefits. Comprehensive supportive services in addition to provision of methadone are needed to address the complex health needs of people who inject drugs. PMID:27017376

Evaluation of a community health worker intervention and the World Health Organization's Option B versus Option A to improve antenatal care and PMTCT outcomes in Dar es Salaam, Tanzania: study protocol for a cluster-randomized controlled health systems implementation trial.

PubMed

Sando, David; Geldsetzer, Pascal; Magesa, Lucy; Lema, Irene Andrew; Machumi, Lameck; Mwanyika-Sando, Mary; Li, Nan; Spiegelman, Donna; Mungure, Ester; Siril, Hellen; Mujinja, Phares; Naburi, Helga; Chalamilla, Guerino; Kilewo, Charles; Ekström, Anna Mia; Fawzi, Wafaie W; Bärnighausen, Till W

2014-09-15

Mother-to-child transmission of HIV remains an important public health problem in sub-Saharan Africa. As HIV testing and linkage to PMTCT occurs in antenatal care (ANC), major challenges for any PMTCT option in developing countries, including Tanzania, are delays in the first ANC visit and a low overall number of visits. Community health workers (CHWs) have been effective in various settings in increasing the uptake of clinical services and improving treatment retention and adherence. At the beginning of this trial in January 2013, the World Health Organization recommended either of two medication regimens, Option A or B, for prevention of mother-to-child transmission of HIV (PMTCT). It is still largely unclear which option is more effective when implemented in a public healthcare system. This study aims to determine the effectiveness, cost-effectiveness, acceptability, and feasibility of: (1) a community health worker (CWH) intervention and (2) PMTCT Option B in improving ANC and PMTCT outcomes. This study is a cluster-randomized controlled health systems implementation trial with a two-by-two factorial design. All 60 administrative wards in the Kinondoni and Ilala districts in Dar es Salaam were first randomly allocated to either receiving the CHW intervention or not, and then to receiving either Option B or A. Under the standard of care, facility-based health workers follow up on patients who have missed scheduled appointments for PMTCT, first through a telephone call and then with a home visit. In the wards receiving the CHW intervention, the CHWs: (1) identify pregnant women through home visits and refer them to antenatal care; (2) provide education to pregnant women on antenatal care, PMTCT, birth, and postnatal care; (3) routinely follow up on all pregnant women to ascertain whether they have attended ANC; and (4) follow up on women who have missed ANC or PMTCT appointments. ClinicalTrials.gov: EJF22802. Registration date: 14 May 2013.

Mapping of Mycobacterium tuberculosis Complex Genetic Diversity Profiles in Tanzania and Other African Countries

PubMed Central

Mbugi, Erasto V.; Katale, Bugwesa Z.; Streicher, Elizabeth M.; Keyyu, Julius D.; Kendall, Sharon L.; Dockrell, Hazel M.; Michel, Anita L.; Rweyemamu, Mark M.; Warren, Robin M.; Matee, Mecky I.; van Helden, Paul D.; Couvin, David; Rastogi, Nalin

2016-01-01

The aim of this study was to assess and characterize Mycobacterium tuberculosis complex (MTBC) genotypic diversity in Tanzania, as well as in neighbouring East and other several African countries. We used spoligotyping to identify a total of 293 M. tuberculosis clinical isolates (one isolate per patient) collected in the Bunda, Dar es Salaam, Ngorongoro and Serengeti areas in Tanzania. The results were compared with results in the SITVIT2 international database of the Pasteur Institute of Guadeloupe. Genotyping and phylogeographical analyses highlighted the predominance of the CAS, T, EAI, and LAM MTBC lineages in Tanzania. The three most frequent Spoligotype International Types (SITs) were: SIT21/CAS1-Kili (n = 76; 25.94%), SIT59/LAM11-ZWE (n = 22; 7.51%), and SIT126/EAI5 tentatively reclassified as EAI3-TZA (n = 18; 6.14%). Furthermore, three SITs were newly created in this study (SIT4056/EAI5 n = 2, SIT4057/T1 n = 1, and SIT4058/EAI5 n = 1). We noted that the East-African-Indian (EAI) lineage was more predominant in Bunda, the Manu lineage was more common among strains isolated in Ngorongoro, and the Central-Asian (CAS) lineage was more predominant in Dar es Salaam (p-value<0.0001). No statistically significant differences were noted when comparing HIV status of patients vs. major lineages (p-value = 0.103). However, when grouping lineages as Principal Genetic Groups (PGG), we noticed that PGG2/3 group (Haarlem, LAM, S, T, and X) was more associated with HIV-positive patients as compared to PGG1 group (Beijing, CAS, EAI, and Manu) (p-value = 0.03). This study provided mapping of MTBC genetic diversity in Tanzania (containing information on isolates from different cities) and neighbouring East African and other several African countries highlighting differences as regards to MTBC genotypic distribution between Tanzania and other African countries. This work also allowed underlining of spoligotyping patterns tentatively grouped within the newly designated EAI3-TZA lineage (remarkable by absence of spacers 2 and 3, and represented by SIT126) which seems to be specific to Tanzania. However, further genotyping information would be needed to confirm this specificity. PMID:27149626

Risk and protective factors for relapse among individuals with schizophrenia: a qualitative study in Dar es Salaam, Tanzania.

PubMed

Sariah, Adellah E; Outwater, Anne H; Malima, Khadija I Y

2014-08-30

Relapse in people with schizophrenia is a major challenge for mental health service providers in Tanzania and other countries. Approximately 10% of people with schizophrenia are re-admitted due to relapse at Muhimbili National Hospital (MNH) Psychiatric Unit each month. Relapse brings about negative effects and it results in a huge burden to patients, their families, the mental health sector and the country's economy. So far no study has been done to address relapse in Tanzania. The purpose of the study was to explore perspectives on risk and protective factors influencing relapse of people with schizophrenia and their caregivers attending Muhimbili National Hospital Psychiatric Out-patient Department, Dar es Salaam, Tanzania. A qualitative study was conducted, involving in-depth interviews of seven people with schizophrenia who are out-patients and their seven family caregivers at MNH. Purposive sampling procedure was used to select participants for the study. Audio recorded in-depth interviews in Swahili language were conducted with all study participants. The recorded information was transcribed and analyzed using NVivo 9 computer assisted qualitative data analysis software. Personal risk and protective factors for relapse, environmental risk and protective factors for relapse and suggestions to reduce relapse were the main themes that emerged from this study. People with schizophrenia and their caregivers (all of whom were relatives) perceived non adherence to antipsychotic medication as a leading risk factor of relapse; other risks included poor family support, stressful life events and substance use. Family support, adherence to antipsychotic medication, employment and religion were viewed as protective factors. Participants suggested strengthening mental health psycho-education sessions and community home visits conducted by mental health nurses to help reduce relapse. Other suggestions included strengthening the nurse-patient therapeutic relationship in provision of mental health care. This study calls for improvement in mental health care service delivery to individuals with schizophrenia. Establishing a curricular in mental health nursing that aims to produce competent mental health nurse force would improve nursing practice in mental health care service delivery.

Vulnerability Assessment Using LIDAR Data in Silang-Sta Rosa Subwatershed, Philippines

NASA Astrophysics Data System (ADS)

Bragais, M. A.; Magcale-Macandog, D. B.; Arizapa, J. L.; Manalo, K. M.

2016-10-01

Silang-Sta. Rosa Subwatershed is experiencing rapid urbanization. Its downstream area is already urbanized and the development is moving fast upstream. With the rapid land conversion of pervious to impervious areas and increase frequency of intense rainfall events, the downstream of the watershed is at risk of flood hazard. The widely used freeware HEC-RAS (Hydrologic Engineering Center- River Analysis System) model was used to implement the 2D unsteady flow analysis to develop a flood hazard map. The LiDAR derived digital elevation model (DEM) with 1m resolution provided detailed terrain that is vital for producing reliable flood extent map that can be used for early warning system. With the detailed information from the simulation like areas to be flooded, the predicted depth and duration, we can now provide specific flood forecasting and mitigation plan even at community level. The methodology of using 2D unsteady flow modelling and high resolution DEM in a watershed can be replicated to other neighbouring watersheds specially those areas that are not yet urbanized so that their development will be guided to be flood hazard resilient. LGUs all over the country will benefit from having a high resolution flood hazard map.

Mitigating the effects of landscape development on streams in urbanizing watersheds

USGS Publications Warehouse

Hogan, Dianna M.; Jarnagin, S. Taylor; Loperfido, John V.; Van Ness, Keith

2013-01-01

This collaborative study examined urbanization and impacts on area streams while using the best available sediment and erosion control (S&EC) practices in developing watersheds in Maryland, United States. During conversion of the agricultural and forested watersheds to urban land use, land surface topography was graded and vegetation was removed creating a high potential for sediment generation and release during storm events. The currently best available S&EC facilities were used during the development process to mitigate storm runoff water quality, quantity, and timing before entering area streams. Detailed Geographic Information System (GIS) maps were created to visualize changing land use and S&EC practices, five temporal collections of LiDAR (light detection and ranging) imagery were used to map the changing landscape topography, and streamflow, physical geomorphology, and habitat data were used to assess the ability of the S&EC facilities to protect receiving streams during development. Despite the use of the best available S&EC facilities, receiving streams experienced altered flow, geomorphology, and decreased biotic community health. These impacts on small streams during watershed development affect sediment and nutrient loads to larger downstream aquatic ecosystems such as the Chesapeake Bay.

LiDAR utility for natural resource managers

Treesearch

Andrew Thomas Hudak; Jeffrey Scott Evans; Alistair Mattthew Stuart Smith

2009-01-01

Applications of LiDAR remote sensing are exploding, while moving from the research to the operational realm. Increasingly, natural resource managers are recognizing the tremendous utility of LiDAR-derived information to make improved decisions. This review provides a cross-section of studies, many recent, that demonstrate the relevance of LiDAR across a suite of...

LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter.

PubMed

Liu, Wanli

2017-03-08

The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated.

Registration of Aerial Optical Images with LiDAR Data Using the Closest Point Principle and Collinearity Equations.

PubMed

Huang, Rongyong; Zheng, Shunyi; Hu, Kun

2018-06-01

Registration of large-scale optical images with airborne LiDAR data is the basis of the integration of photogrammetry and LiDAR. However, geometric misalignments still exist between some aerial optical images and airborne LiDAR point clouds. To eliminate such misalignments, we extended a method for registering close-range optical images with terrestrial LiDAR data to a variety of large-scale aerial optical images and airborne LiDAR data. The fundamental principle is to minimize the distances from the photogrammetric matching points to the terrestrial LiDAR data surface. Except for the satisfactory efficiency of about 79 s per 6732 × 8984 image, the experimental results also show that the unit weighted root mean square (RMS) of the image points is able to reach a sub-pixel level (0.45 to 0.62 pixel), and the actual horizontal and vertical accuracy can be greatly improved to a high level of 1/4⁻1/2 (0.17⁻0.27 m) and 1/8⁻1/4 (0.10⁻0.15 m) of the average LiDAR point distance respectively. Finally, the method is proved to be more accurate, feasible, efficient, and practical in variety of large-scale aerial optical image and LiDAR data.

Retrieving aboveground biomass of wetland Phragmites australis (common reed) using a combination of airborne discrete-return LiDAR and hyperspectral data

NASA Astrophysics Data System (ADS)

Luo, Shezhou; Wang, Cheng; Xi, Xiaohuan; Pan, Feifei; Qian, Mingjie; Peng, Dailiang; Nie, Sheng; Qin, Haiming; Lin, Yi

2017-06-01

Wetland biomass is essential for monitoring the stability and productivity of wetland ecosystems. Conventional field methods to measure or estimate wetland biomass are accurate and reliable, but expensive, time consuming and labor intensive. This research explored the potential for estimating wetland reed biomass using a combination of airborne discrete-return Light Detection and Ranging (LiDAR) and hyperspectral data. To derive the optimal predictor variables of reed biomass, a range of LiDAR and hyperspectral metrics at different spatial scales were regressed against the field-observed biomasses. The results showed that the LiDAR-derived H_p99 (99th percentile of the LiDAR height) and hyperspectral-calculated modified soil-adjusted vegetation index (MSAVI) were the best metrics for estimating reed biomass using the single regression model. Although the LiDAR data yielded a higher estimation accuracy compared to the hyperspectral data, the combination of LiDAR and hyperspectral data produced a more accurate prediction model for reed biomass (R2 = 0.648, RMSE = 167.546 g/m2, RMSEr = 20.71%) than LiDAR data alone. Thus, combining LiDAR data with hyperspectral data has a great potential for improving the accuracy of aboveground biomass estimation.

A General-purpose Framework for Parallel Processing of Large-scale LiDAR Data

NASA Astrophysics Data System (ADS)

Li, Z.; Hodgson, M.; Li, W.

2016-12-01

Light detection and ranging (LiDAR) technologies have proven efficiency to quickly obtain very detailed Earth surface data for a large spatial extent. Such data is important for scientific discoveries such as Earth and ecological sciences and natural disasters and environmental applications. However, handling LiDAR data poses grand geoprocessing challenges due to data intensity and computational intensity. Previous studies received notable success on parallel processing of LiDAR data to these challenges. However, these studies either relied on high performance computers and specialized hardware (GPUs) or focused mostly on finding customized solutions for some specific algorithms. We developed a general-purpose scalable framework coupled with sophisticated data decomposition and parallelization strategy to efficiently handle big LiDAR data. Specifically, 1) a tile-based spatial index is proposed to manage big LiDAR data in the scalable and fault-tolerable Hadoop distributed file system, 2) two spatial decomposition techniques are developed to enable efficient parallelization of different types of LiDAR processing tasks, and 3) by coupling existing LiDAR processing tools with Hadoop, this framework is able to conduct a variety of LiDAR data processing tasks in parallel in a highly scalable distributed computing environment. The performance and scalability of the framework is evaluated with a series of experiments conducted on a real LiDAR dataset using a proof-of-concept prototype system. The results show that the proposed framework 1) is able to handle massive LiDAR data more efficiently than standalone tools; and 2) provides almost linear scalability in terms of either increased workload (data volume) or increased computing nodes with both spatial decomposition strategies. We believe that the proposed framework provides valuable references on developing a collaborative cyberinfrastructure for processing big earth science data in a highly scalable environment.

Genomic Characterization of DArT Markers Based on High-Density Linkage Analysis and Physical Mapping to the Eucalyptus Genome

PubMed Central

Petroli, César D.; Sansaloni, Carolina P.; Carling, Jason; Steane, Dorothy A.; Vaillancourt, René E.; Myburg, Alexander A.; da Silva, Orzenil Bonfim; Pappas, Georgios Joannis; Kilian, Andrzej; Grattapaglia, Dario

2012-01-01

Diversity Arrays Technology (DArT) provides a robust, high throughput, cost-effective method to query thousands of sequence polymorphisms in a single assay. Despite the extensive use of this genotyping platform for numerous plant species, little is known regarding the sequence attributes and genome-wide distribution of DArT markers. We investigated the genomic properties of the 7,680 DArT marker probes of a Eucalyptus array, by sequencing them, constructing a high density linkage map and carrying out detailed physical mapping analyses to the Eucalyptus grandis reference genome. A consensus linkage map with 2,274 DArT markers anchored to 210 microsatellites and a framework map, with improved support for ordering, displayed extensive collinearity with the genome sequence. Only 1.4 Mbp of the 75 Mbp of still unplaced scaffold sequence was captured by 45 linkage mapped but physically unaligned markers to the 11 main Eucalyptus pseudochromosomes, providing compelling evidence for the quality and completeness of the current Eucalyptus genome assembly. A highly significant correspondence was found between the locations of DArT markers and predicted gene models, while most of the 89 DArT probes unaligned to the genome correspond to sequences likely absent in E. grandis, consistent with the pan-genomic feature of this multi-Eucalyptus species DArT array. These comprehensive linkage-to-physical mapping analyses provide novel data regarding the genomic attributes of DArT markers in plant genomes in general and for Eucalyptus in particular. DArT markers preferentially target the gene space and display a largely homogeneous distribution across the genome, thereby providing superb coverage for mapping and genome-wide applications in breeding and diversity studies. Data reported on these ubiquitous properties of DArT markers will be particularly valuable to researchers working on less-studied crop species who already count on DArT genotyping arrays but for which no reference genome is yet available to allow such detailed characterization. PMID:22984541

Bridging gaps: On the performance of airborne LiDAR to model wood mouse-habitat structure relationships in pine forests.

PubMed

Jaime-González, Carlos; Acebes, Pablo; Mateos, Ana; Mezquida, Eduardo T

2017-01-01

LiDAR technology has firmly contributed to strengthen the knowledge of habitat structure-wildlife relationships, though there is an evident bias towards flying vertebrates. To bridge this gap, we investigated and compared the performance of LiDAR and field data to model habitat preferences of wood mouse (Apodemus sylvaticus) in a Mediterranean high mountain pine forest (Pinus sylvestris). We recorded nine field and 13 LiDAR variables that were summarized by means of Principal Component Analyses (PCA). We then analyzed wood mouse's habitat preferences using three different models based on: (i) field PCs predictors, (ii) LiDAR PCs predictors; and (iii) both set of predictors in a combined model, including a variance partitioning analysis. Elevation was also included as a predictor in the three models. Our results indicate that LiDAR derived variables were better predictors than field-based variables. The model combining both data sets slightly improved the predictive power of the model. Field derived variables indicated that wood mouse was positively influenced by the gradient of increasing shrub cover and negatively affected by elevation. Regarding LiDAR data, two LiDAR PCs, i.e. gradients in canopy openness and complexity in forest vertical structure positively influenced wood mouse, although elevation interacted negatively with the complexity in vertical structure, indicating wood mouse's preferences for plots with lower elevations but with complex forest vertical structure. The combined model was similar to the LiDAR-based model and included the gradient of shrub cover measured in the field. Variance partitioning showed that LiDAR-based variables, together with elevation, were the most important predictors and that part of the variation explained by shrub cover was shared. LiDAR derived variables were good surrogates of environmental characteristics explaining habitat preferences by the wood mouse. Our LiDAR metrics represented structural features of the forest patch, such as the presence and cover of shrubs, as well as other characteristics likely including time since perturbation, food availability and predation risk. Our results suggest that LiDAR is a promising technology for further exploring habitat preferences by small mammal communities.

4D Near Real-Time Environmental Monitoring Using Highly Temporal LiDAR

NASA Astrophysics Data System (ADS)

Höfle, Bernhard; Canli, Ekrem; Schmitz, Evelyn; Crommelinck, Sophie; Hoffmeister, Dirk; Glade, Thomas

2016-04-01

The last decade has witnessed extensive applications of 3D environmental monitoring with the LiDAR technology, also referred to as laser scanning. Although several automatic methods were developed to extract environmental parameters from LiDAR point clouds, only little research has focused on highly multitemporal near real-time LiDAR (4D-LiDAR) for environmental monitoring. Large potential of applying 4D-LiDAR is given for landscape objects with high and varying rates of change (e.g. plant growth) and also for phenomena with sudden unpredictable changes (e.g. geomorphological processes). In this presentation we will report on the most recent findings of the research projects 4DEMON (http://uni-heidelberg.de/4demon) and NoeSLIDE (https://geomorph.univie.ac.at/forschung/projekte/aktuell/noeslide/). The method development in both projects is based on two real-world use cases: i) Surface parameter derivation of agricultural crops (e.g. crop height) and ii) change detection of landslides. Both projects exploit the "full history" contained in the LiDAR point cloud time series. One crucial initial step of 4D-LiDAR analysis is the co-registration over time, 3D-georeferencing and time-dependent quality assessment of the LiDAR point cloud time series. Due to the high amount of datasets (e.g. one full LiDAR scan per day), the procedure needs to be performed fully automatically. Furthermore, the online near real-time 4D monitoring system requires to set triggers that can detect removal or moving of tie reflectors (used for co-registration) or the scanner itself. This guarantees long-term data acquisition with high quality. We will present results from a georeferencing experiment for 4D-LiDAR monitoring, which performs benchmarking of co-registration, 3D-georeferencing and also fully automatic detection of events (e.g. removal/moving of reflectors or scanner). Secondly, we will show our empirical findings of an ongoing permanent LiDAR observation of a landslide (Gresten, Austria) and an agricultural maize crop stand (Heidelberg, Germany). This research demonstrates the potential and also limitations of fully automated, near real-time 4D LiDAR monitoring in geosciences.

Applicability of Aerial Green LiDAR to a Large River in the Western United States

NASA Astrophysics Data System (ADS)

Conner, J. T.; Welcker, C. W.; Cooper, C.; Faux, R.; Butler, M.; Nayegandhi, A.

2013-12-01

In October 2012, aerial green LiDAR data were collected in the Snake River (within Idaho and Oregon) to test this emerging technology in a large river with poor water clarity. Six study areas (total of 30 river miles spread out over 250 river miles) were chosen to represent a variety of depths, channel types, and surface conditions to test the accuracy, depth penetration, data density of aerial green LiDAR. These characteristics along with cost and speed of acquisition were compared to other bathymetric survey techniques including rod surveys (total station and RTK-GPS), single-beam sonar, and multibeam echosounder (MBES). The green LiDAR system typically measured returns from the riverbed through 1-2 meters of water, which was less than one Secchi depth. However, in areas with steep banks or aquatic macrophytes, LiDAR returns from the riverbed were less frequent or non-existent. In areas of good return density, depths measured from green LiDAR data corresponded well with previously collected data sets from traditional bathymetric survey techniques. In such areas, the green LiDAR point density was much higher than both rod and single beam sonar surveys, yet lower than MBES. The green LiDAR survey was also collected more efficiently than all other methods. In the Snake River, green LiDAR does not provide a method to map the entire riverbed as it only receives bottom returns in shallow water, typically at the channel margins. However, green LiDAR does provide survey data that is an excellent complement to MBES, which is more effective at surveying the deeper portions of the channel. In some cases, the green LiDAR was able to provide data in areas that the MBES could not, often due to issues with navigating the survey boat in shallow water. Even where both MBES and green LiDAR mapped the river bottom, green LiDAR often provides more accurate data through a better angle of incidence and less shadowing than the MBES survey. For one MBES survey in 2013, the green LiDAR data was used to create a map of shallow hazards to be avoided during the survey for the safety of the crew and the MBES equipment. While green LiDAR does not provide a single solution to all large river surveying problems, when combined with MBES it allows for more complete, more efficient, and safer surveys in a large river.

A multiscale curvature algorithm for classifying discrete return LiDAR in forested environments

Treesearch

Jeffrey S. Evans; Andrew T. Hudak

2007-01-01

One prerequisite to the use of light detection and ranging (LiDAR) across disciplines is differentiating ground from nonground returns. The objective was to automatically and objectively classify points within unclassified LiDAR point clouds, with few model parameters and minimal postprocessing. Presented is an automated method for classifying LiDAR returns as ground...

LiDAR - An emerging tool for geological applications

USGS Publications Warehouse

Stoker, Jason M.

2012-01-01

Over the past five to ten years the use and applicability of light detection and ranging (LiDAR) technology has increased dramatically. As a result, more and more LiDAR data now are being collected across the country for a wide range of applications, and LiDAR currently is the technology of choice for high resolution terrain model creation, 3-D city and infrastructure modeling, forestry, and a wide range of scientific applications. LiDAR is a key technology for geological applications both within and outside the U.S. Geological Survey, and efforts are underway to try to collect high resolution LiDAR data for the entire United States (https://pubs.usgs.gov/fs/2012/3089/pdf/fs2012-3089.pdf).

Dynamic inundation mapping of Hurricane Harvey flooding in the Houston metro area using hyper-resolution modeling and quantitative image reanalysis

NASA Astrophysics Data System (ADS)

Noh, S. J.; Lee, J. H.; Lee, S.; Zhang, Y.; Seo, D. J.

2017-12-01

Hurricane Harvey was one of the most extreme weather events in Texas history and left significant damages in the Houston and adjoining coastal areas. To understand better the relative impact to urban flooding of extreme amount and spatial extent of rainfall, unique geography, land use and storm surge, high-resolution water modeling is necessary such that natural and man-made components are fully resolved. In this presentation, we reconstruct spatiotemporal evolution of inundation during Hurricane Harvey using hyper-resolution modeling and quantitative image reanalysis. The two-dimensional urban flood model used is based on dynamic wave approximation and 10 m-resolution terrain data, and is forced by the radar-based multisensor quantitative precipitation estimates. The model domain includes Buffalo, Brays, Greens and White Oak Bayous in Houston. The model is simulated using hybrid parallel computing. To evaluate dynamic inundation mapping, we combine various qualitative crowdsourced images and video footages with LiDAR-based terrain data.

Estimating the vegetation canopy height using micro-pulse photon-counting LiDAR data.

PubMed

Nie, Sheng; Wang, Cheng; Xi, Xiaohuan; Luo, Shezhou; Li, Guoyuan; Tian, Jinyan; Wang, Hongtao

2018-05-14

The upcoming space-borne LiDAR satellite Ice, Cloud and land Elevation Satellite-2 (ICESat-2) is scheduled to launch in 2018. Different from the waveform LiDAR system onboard the ICESat, ICESat-2 will use a micro-pulse photon-counting LiDAR system. Thus new data processing algorithms are required to retrieve vegetation canopy height from photon-counting LiDAR data. The objective of this paper is to develop and validate an automated approach for better estimating vegetation canopy height. The new proposed method consists of three key steps: 1) filtering out the noise photons by an effective noise removal algorithm based on localized statistical analysis; 2) separating ground returns from canopy returns using an iterative photon classification algorithm, and then determining ground surface; 3) generating canopy-top surface and calculating vegetation canopy height based on canopy-top and ground surfaces. This automatic vegetation height estimation approach was tested to the simulated ICESat-2 data produced from Sigma Space LiDAR data and Multiple Altimeter Beam Experimental LiDAR (MABEL) data, and the retrieved vegetation canopy heights were validated by canopy height models (CHMs) derived from airborne discrete-return LiDAR data. Results indicated that the estimated vegetation canopy heights have a relatively strong correlation with the reference vegetation heights derived from airborne discrete-return LiDAR data (R 2 and RMSE values ranging from 0.639 to 0.810 and 4.08 m to 4.56 m respectively). This means our new proposed approach is appropriate for retrieving vegetation canopy height from micro-pulse photon-counting LiDAR data.

Remote sensing of Sonoran Desert vegetation structure and phenology with ground-based LiDAR

USGS Publications Warehouse

Sankey, Joel B.; Munson, Seth M.; Webb, Robert H.; Wallace, Cynthia S.A.; Duran, Cesar M.

2015-01-01

Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of LiDAR to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat LiDAR scans of perennial plant canopies over the course of one year had high precision. LiDAR measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of LiDAR vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by LiDAR was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using LiDAR over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat LiDAR measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.

Temporal transferability of LiDAR-based imputation of forest structure attributes

Treesearch

Patrick A. Fekety; Michael J. Falkowski; Andrew T. Hudak

2015-01-01

Forest inventory and planning decisions are frequently informed by LiDAR data. Repeated LiDAR acquisitions offer an opportunity to update forest inventories and potentially improve forest inventory estimates through time. We leveraged repeated LiDAR and ground measures for a study area in northern Idaho, U.S.A., to predict (via imputation) - across both space and time-...

Relationship between LiDAR-derived forest canopy height and Landsat images

Treesearch

Cristina Pascual; Antonio Garcia-Abril; Warren B. Cohen; Susana Martin-Fernandez

2010-01-01

The mean and standard deviation (SD) of light detection and ranging (LiDAR)-derived canopy height are related to forest structure. However, LiDAR data typically cover a limited area and have a high economic cost compared with satellite optical imagery. Optical images may be required to extrapolate LiDAR height measurements across a broad landscape. Different spectral...

LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter

PubMed Central

Liu, Wanli

2017-01-01

The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated. PMID:28282897

Automation of lidar-based hydrologic feature extraction workflows using GIS

NASA Astrophysics Data System (ADS)

Borlongan, Noel Jerome B.; de la Cruz, Roel M.; Olfindo, Nestor T.; Perez, Anjillyn Mae C.

2016-10-01

With the advent of LiDAR technology, higher resolution datasets become available for use in different remote sensing and GIS applications. One significant application of LiDAR datasets in the Philippines is in resource features extraction. Feature extraction using LiDAR datasets require complex and repetitive workflows which can take a lot of time for researchers through manual execution and supervision. The Development of the Philippine Hydrologic Dataset for Watersheds from LiDAR Surveys (PHD), a project under the Nationwide Detailed Resources Assessment Using LiDAR (Phil-LiDAR 2) program, created a set of scripts, the PHD Toolkit, to automate its processes and workflows necessary for hydrologic features extraction specifically Streams and Drainages, Irrigation Network, and Inland Wetlands, using LiDAR Datasets. These scripts are created in Python and can be added in the ArcGIS® environment as a toolbox. The toolkit is currently being used as an aid for the researchers in hydrologic feature extraction by simplifying the workflows, eliminating human errors when providing the inputs, and providing quick and easy-to-use tools for repetitive tasks. This paper discusses the actual implementation of different workflows developed by Phil-LiDAR 2 Project 4 in Streams, Irrigation Network and Inland Wetlands extraction.

Improving Measurement of Forest Structural Parameters by Co-Registering of High Resolution Aerial Imagery and Low Density LiDAR Data

PubMed Central

Huang, Huabing; Gong, Peng; Cheng, Xiao; Clinton, Nick; Li, Zengyuan

2009-01-01

Forest structural parameters, such as tree height and crown width, are indispensable for evaluating forest biomass or forest volume. LiDAR is a revolutionary technology for measurement of forest structural parameters, however, the accuracy of crown width extraction is not satisfactory when using a low density LiDAR, especially in high canopy cover forest. We used high resolution aerial imagery with a low density LiDAR system to overcome this shortcoming. A morphological filtering was used to generate a DEM (Digital Elevation Model) and a CHM (Canopy Height Model) from LiDAR data. The LiDAR camera image is matched to the aerial image with an automated keypoints search algorithm. As a result, a high registration accuracy of 0.5 pixels was obtained. A local maximum filter, watershed segmentation, and object-oriented image segmentation are used to obtain tree height and crown width. Results indicate that the camera data collected by the integrated LiDAR system plays an important role in registration with aerial imagery. The synthesis with aerial imagery increases the accuracy of forest structural parameter extraction when compared to only using the low density LiDAR data. PMID:22573971

Malaria control in Tanzania

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yhdego, M.; Majura, P.

A review of the malaria control programs and the problem encountered in the United Republic of Tanzania since 1945 to the year 1986 is discussed. Buguruni, one of the squatter areas in the city of Dar es Salaam, is chosen as a case study in order to evaluate the economic advantage of engineering methods for the control of malaria infection. Although the initial capital cost of engineering methods may be high, the cost effectiveness requires a much lower financial burden of only about Tshs. 3 million compared with the conventional methods of larviciding and insecticiding which requires more than Tshs.more » 10 million. Finally, recommendations for the adoption of engineering methods are made concerning the upgrading of existing roads and footpaths in general with particular emphasis on drainage of large pools of water which serve as breeding sites for mosquitoes.« less

Validating LiDAR Derived Estimates of Canopy Height, Structure and Fractional Cover in Riparian Areas: A Comparison of Leaf-on and Leaf-off LiDAR Data

NASA Astrophysics Data System (ADS)

Wasser, L. A.; Chasmer, L. E.; Taylor, A.; Day, R.

2010-12-01

Characterization of riparian buffers is integral to understanding the landscape scale impacts of disturbance on wildlife and aquatic ecosystems. Riparian buffers may be characterized using in situ plot sampling or via high resolution remote sensing. Field measurements are time-consuming and may not cover a broad range of ecosystem types. Further, spectral remote sensing methods introduce a compromise between spatial resolution (grain) and area extent. Airborne LiDAR can be used to continuously map and characterize riparian vegetation structure and composition due to the three-dimensional reflectance of laser pulses within and below the canopy, understory and at the ground surface. The distance between reflections (or ‘returns’) allows for detection of narrow buffer corridors at the landscape scale. There is a need to compare leaf-off and leaf-on surveyed LiDAR data with in situ measurements to assess accuracy in landscape scale analysis. These comparisons are particularly important considering increased availability of leaf-off surveyed LiDAR datasets. And given this increased availability, differences between leaf-on and leaf-off derived LiDAR metrics are largely unknown for riparian vegetation of varying composition and structure. This study compares the effectiveness of leaf-on and leaf-off LiDAR in characterizing riparian buffers of varying structure and composition as compared to field measurements. Field measurements were used to validate LiDAR derived metrics. Vegetation height, canopy cover, density and overstory and understory species composition were recorded in 80 random plots of varying vegetation type, density and structure within a Pennsylvania watershed (-77.841, 40.818). Plot data were compared with LiDAR data collected during leaf on and leaf off conditions to determine 1) accuracy of LiDAR derived metrics compared to field measures and 2) differences between leaf-on and leaf-off LiDAR metrics. Results illustrate that differences exist between metrics derived from leaf on and leaf-off surveyed LiDAR. There is greater variability between the two datasets within taller deciduous and mixed (conifer and deciduous) vegetation compared to shorter deciduous and mixed vegetation. Differences decrease as stand density increases for both mixed and deciduous forests. LiDAR derived canopy height is more sensitive to understory vegetation as stand density decreases making measurement of understory vegetation in the field important in the validation process. Finally, while leaf-on LiDAR is often preferred for vegetation analysis, results suggest that leaf-off LiDAR may be sufficient to categorize vegetation into height classes to be used for landscape scale habitat models.

Three-dimensional canopy fuel loading predicted using upward and downward sensing LiDAR systems

Treesearch

Nicholas S. Skowronski; Kenneth L. Clark; Matthew Duveneck; John. Hom

2011-01-01

We calibrated upward sensing profiling and downward sensing scanning LiDAR systems to estimates of canopy fuel loading developed from field plots and allometric equations, and then used the LiDAR datasets to predict canopy bulk density (CBD) and crown fuel weight (CFW) in wildfire prone stands in the New Jersey Pinelands. LiDAR-derived height profiles were also...

Demystifying LiDAR technologies for temperate rainforest in the Pacific Northwest

Treesearch

Rhonda Mazza; Demetrios Gatziolis

2013-01-01

Light detection and ranging (LiDAR), also known as airborne laser scanning, is a rapidly emerging technology for remote sensing. Used to help map, monitor, and assess natural resources, LiDAR data were first embraced by forestry professionals in Scandinavia as a tool for conducting forest inventories in the mid to late 1990s. Thus early LiDAR theory and applications...

Remote sensing based detection of forested wetlands: An evaluation of LiDAR, aerial imagery, and their data fusion

NASA Astrophysics Data System (ADS)

Suiter, Ashley Elizabeth

Multi-spectral imagery provides a robust and low-cost dataset for assessing wetland extent and quality over broad regions and is frequently used for wetland inventories. However in forested wetlands, hydrology is obscured by tree canopy making it difficult to detect with multi-spectral imagery alone. Because of this, classification of forested wetlands often includes greater errors than that of other wetlands types. Elevation and terrain derivatives have been shown to be useful for modelling wetland hydrology. But, few studies have addressed the use of LiDAR intensity data detecting hydrology in forested wetlands. Due the tendency of LiDAR signal to be attenuated by water, this research proposed the fusion of LiDAR intensity data with LiDAR elevation, terrain data, and aerial imagery, for the detection of forested wetland hydrology. We examined the utility of LiDAR intensity data and determined whether the fusion of Lidar derived data with multispectral imagery increased the accuracy of forested wetland classification compared with a classification performed with only multi-spectral image. Four classifications were performed: Classification A -- All Imagery, Classification B -- All LiDAR, Classification C -- LiDAR without Intensity, and Classification D -- Fusion of All Data. These classifications were performed using random forest and each resulted in a 3-foot resolution thematic raster of forested upland and forested wetland locations in Vermilion County, Illinois. The accuracies of these classifications were compared using Kappa Coefficient of Agreement. Importance statistics produced within the random forest classifier were evaluated in order to understand the contribution of individual datasets. Classification D, which used the fusion of LiDAR and multi-spectral imagery as input variables, had moderate to strong agreement between reference data and classification results. It was found that Classification A performed using all the LiDAR data and its derivatives (intensity, elevation, slope, aspect, curvatures, and Topographic Wetness Index) was the most accurate classification with Kappa: 78.04%, indicating moderate to strong agreement. However, Classification C, performed with LiDAR derivative without intensity data had less agreement than would be expected by chance, indicating that LiDAR contributed significantly to the accuracy of Classification B.

A DArT marker genetic map of perennial ryegrass (Lolium perenne L.) integrated with detailed comparative mapping information; comparison with existing DArT marker genetic maps of Lolium perenne, L. multiflorum and Festuca pratensis.

PubMed

King, Julie; Thomas, Ann; James, Caron; King, Ian; Armstead, Ian

2013-07-03

Ryegrasses and fescues (genera, Lolium and Festuca) are species of forage and turf grasses which are used widely in agricultural and amenity situations. They are classified within the sub-family Pooideae and so are closely related to Brachypodium distachyon, wheat, barley, rye and oats. Recently, a DArT array has been developed which can be used in generating marker and mapping information for ryegrasses and fescues. This represents a potential common marker set for ryegrass and fescue researchers which can be linked through to comparative genomic information for the grasses. A F2 perennial ryegrass genetic map was developed consisting of 7 linkage groups defined by 1316 markers and deriving a total map length of 683 cM. The marker set included 866 DArT and 315 gene sequence-based markers. Comparison with previous DArT mapping studies in perennial and Italian ryegrass (L. multiflorum) identified 87 and 105 DArT markers in common, respectively, of which 94% and 87% mapped to homoeologous linkage groups. A similar comparison with meadow fescue (F. pratensis) identified only 28 DArT markers in common, of which c. 50% mapped to non-homoelogous linkage groups. In L. perenne, the genetic distance spanned by the DArT markers encompassed the majority of the regions that could be described in terms of comparative genomic relationships with rice, Brachypodium distachyon, and Sorghum bicolor. DArT markers are likely to be a useful common marker resource for ryegrasses and fescues, though the success in aligning different populations through the mapping of common markers will be influenced by degrees of population interrelatedness. The detailed mapping of DArT and gene-based markers in this study potentially allows comparative relationships to be derived in future mapping populations characterised using solely DArT markers.

Estimating impervious cover and riparian zone condition in New England watersheds.

EPA Science Inventory

Under EPA’s Green Infrastructure Initiative, research activities are underway to evaluate the effectiveness of green infrastructure in mitigating the effects of urbanization and stormwater impacts on stream biota and habitat. Preliminary analyses, using impervious cover es...

DArT Markers Effectively Target Gene Space in the Rye Genome

PubMed Central

Gawroński, Piotr; Pawełkowicz, Magdalena; Tofil, Katarzyna; Uszyński, Grzegorz; Sharifova, Saida; Ahluwalia, Shivaksh; Tyrka, Mirosław; Wędzony, Maria; Kilian, Andrzej; Bolibok-Brągoszewska, Hanna

2016-01-01

Large genome size and complexity hamper considerably the genomics research in relevant species. Rye (Secale cereale L.) has one of the largest genomes among cereal crops and repetitive sequences account for over 90% of its length. Diversity Arrays Technology is a high-throughput genotyping method, in which a preferential sampling of gene-rich regions is achieved through the use of methylation sensitive restriction enzymes. We obtained sequences of 6,177 rye DArT markers and following a redundancy analysis assembled them into 3,737 non-redundant sequences, which were then used in homology searches against five Pooideae sequence sets. In total 515 DArT sequences could be incorporated into publicly available rye genome zippers providing a starting point for the integration of DArT- and transcript-based genomics resources in rye. Using Blast2Go pipeline we attributed putative gene functions to 1101 (29.4%) of the non-redundant DArT marker sequences, including 132 sequences with putative disease resistance-related functions, which were found to be preferentially located in the 4RL and 6RL chromosomes. Comparative analysis based on the DArT sequences revealed obvious inconsistencies between two recently published high density consensus maps of rye. Furthermore we demonstrated that DArT marker sequences can be a source of SSR polymorphisms. Obtained data demonstrate that DArT markers effectively target gene space in the large, complex, and repetitive rye genome. Through the annotation of putative gene functions and the alignment of DArT sequences relative to reference genomes we obtained information, that will complement the results of the studies, where DArT genotyping was deployed, by simplifying the gene ontology and microcolinearity based identification of candidate genes. PMID:27833625

DArT Markers Effectively Target Gene Space in the Rye Genome.

PubMed

Gawroński, Piotr; Pawełkowicz, Magdalena; Tofil, Katarzyna; Uszyński, Grzegorz; Sharifova, Saida; Ahluwalia, Shivaksh; Tyrka, Mirosław; Wędzony, Maria; Kilian, Andrzej; Bolibok-Brągoszewska, Hanna

2016-01-01

Large genome size and complexity hamper considerably the genomics research in relevant species. Rye ( Secale cereale L.) has one of the largest genomes among cereal crops and repetitive sequences account for over 90% of its length. Diversity Arrays Technology is a high-throughput genotyping method, in which a preferential sampling of gene-rich regions is achieved through the use of methylation sensitive restriction enzymes. We obtained sequences of 6,177 rye DArT markers and following a redundancy analysis assembled them into 3,737 non-redundant sequences, which were then used in homology searches against five Pooideae sequence sets. In total 515 DArT sequences could be incorporated into publicly available rye genome zippers providing a starting point for the integration of DArT- and transcript-based genomics resources in rye. Using Blast2Go pipeline we attributed putative gene functions to 1101 (29.4%) of the non-redundant DArT marker sequences, including 132 sequences with putative disease resistance-related functions, which were found to be preferentially located in the 4RL and 6RL chromosomes. Comparative analysis based on the DArT sequences revealed obvious inconsistencies between two recently published high density consensus maps of rye. Furthermore we demonstrated that DArT marker sequences can be a source of SSR polymorphisms. Obtained data demonstrate that DArT markers effectively target gene space in the large, complex, and repetitive rye genome. Through the annotation of putative gene functions and the alignment of DArT sequences relative to reference genomes we obtained information, that will complement the results of the studies, where DArT genotyping was deployed, by simplifying the gene ontology and microcolinearity based identification of candidate genes.

Heterodimerization with beta2-adrenergic receptors promotes surface expression and functional activity of alpha1D-adrenergic receptors.

PubMed

Uberti, Michelle A; Hague, Chris; Oller, Heide; Minneman, Kenneth P; Hall, Randy A

2005-04-01

The alpha1D-adrenergic receptor (alpha1D-AR) is a G protein-coupled receptor (GPCR) that is poorly trafficked to the cell surface and largely nonfunctional when heterologously expressed by itself in a variety of cell types. We screened a library of approximately 30 other group I GPCRs in a quantitative luminometer assay for the ability to promote alpha1D-AR cell surface expression. Strikingly, these screens revealed only two receptors capable of inducing robust increases in the amount of alpha1D-AR at the cell surface: alpha1B-AR and beta2-AR. Confocal imaging confirmed that coexpression with beta2-AR resulted in translocation of alpha1D-AR from intracellular sites to the plasma membrane. Additionally, coimmunoprecipitation studies demonstrated that alpha1D-AR and beta2-AR specifically interact to form heterodimers when coexpressed in HEK-293 cells. Ligand binding studies revealed an increase in total alpha1D-AR binding sites upon coexpression with beta2-AR, but no apparent effect on the pharmacological properties of the receptors. In functional studies, coexpression with beta2-AR significantly enhanced the coupling of alpha1D-AR to norepinephrine-stimulated Ca2+ mobilization. Heterodimerization of beta2-AR with alpha1D-AR also conferred the ability of alpha1D-AR to cointernalize upon beta2-AR agonist stimulation, revealing a novel mechanism by which these different adrenergic receptor subtypes may regulate each other's activity. These findings demonstrate that the selective association of alpha1D-AR with other receptors is crucial for receptor surface expression and function and also shed light on a novel mechanism of cross talk between alpha1- and beta2-ARs that is mediated through heterodimerization and cross-internalization.

Important LiDAR metrics for discriminating forest tree species in Central Europe

NASA Astrophysics Data System (ADS)

Shi, Yifang; Wang, Tiejun; Skidmore, Andrew K.; Heurich, Marco

2018-03-01

Numerous airborne LiDAR-derived metrics have been proposed for classifying tree species. Yet an in-depth ecological and biological understanding of the significance of these metrics for tree species mapping remains largely unexplored. In this paper, we evaluated the performance of 37 frequently used LiDAR metrics derived under leaf-on and leaf-off conditions, respectively, for discriminating six different tree species in a natural forest in Germany. We firstly assessed the correlation between these metrics. Then we applied a Random Forest algorithm to classify the tree species and evaluated the importance of the LiDAR metrics. Finally, we identified the most important LiDAR metrics and tested their robustness and transferability. Our results indicated that about 60% of LiDAR metrics were highly correlated to each other (|r| > 0.7). There was no statistically significant difference in tree species mapping accuracy between the use of leaf-on and leaf-off LiDAR metrics. However, combining leaf-on and leaf-off LiDAR metrics significantly increased the overall accuracy from 58.2% (leaf-on) and 62.0% (leaf-off) to 66.5% as well as the kappa coefficient from 0.47 (leaf-on) and 0.51 (leaf-off) to 0.58. Radiometric features, especially intensity related metrics, provided more consistent and significant contributions than geometric features for tree species discrimination. Specifically, the mean intensity of first-or-single returns as well as the mean value of echo width were identified as the most robust LiDAR metrics for tree species discrimination. These results indicate that metrics derived from airborne LiDAR data, especially radiometric metrics, can aid in discriminating tree species in a mixed temperate forest, and represent candidate metrics for tree species classification and monitoring in Central Europe.

Diversity Arrays Technology (DArT) for Pan-Genomic Evolutionary Studies of Non-Model Organisms

PubMed Central

James, Karen E.; Schneider, Harald; Ansell, Stephen W.; Evers, Margaret; Robba, Lavinia; Uszynski, Grzegorz; Pedersen, Niklas; Newton, Angela E.; Russell, Stephen J.; Vogel, Johannes C.; Kilian, Andrzej

2008-01-01

Background High-throughput tools for pan-genomic study, especially the DNA microarray platform, have sparked a remarkable increase in data production and enabled a shift in the scale at which biological investigation is possible. The use of microarrays to examine evolutionary relationships and processes, however, is predominantly restricted to model or near-model organisms. Methodology/Principal Findings This study explores the utility of Diversity Arrays Technology (DArT) in evolutionary studies of non-model organisms. DArT is a hybridization-based genotyping method that uses microarray technology to identify and type DNA polymorphism. Theoretically applicable to any organism (even one for which no prior genetic data are available), DArT has not yet been explored in exclusively wild sample sets, nor extensively examined in a phylogenetic framework. DArT recovered 1349 markers of largely low copy-number loci in two lineages of seed-free land plants: the diploid fern Asplenium viride and the haploid moss Garovaglia elegans. Direct sequencing of 148 of these DArT markers identified 30 putative loci including four routinely sequenced for evolutionary studies in plants. Phylogenetic analyses of DArT genotypes reveal phylogeographic and substrate specificity patterns in A. viride, a lack of phylogeographic pattern in Australian G. elegans, and additive variation in hybrid or mixed samples. Conclusions/Significance These results enable methodological recommendations including procedures for detecting and analysing DArT markers tailored specifically to evolutionary investigations and practical factors informing the decision to use DArT, and raise evolutionary hypotheses concerning substrate specificity and biogeographic patterns. Thus DArT is a demonstrably valuable addition to the set of existing molecular approaches used to infer biological phenomena such as adaptive radiations, population dynamics, hybridization, introgression, ecological differentiation and phylogeography. PMID:18301759

La Observación Sistemática de Vecindarios: El caso de Chile y sus perspectivas para Trabajo Social

PubMed Central

Sanhueza, Guillermo E.; Delva, Jorge; Andrade, Fernando H.; Grogan-Kaylor, Andrew; Bares, Cristina; Castillo, Marcela

2012-01-01

El estudio acerca de las características de los vecindarios y sus efectos sobre las personas ha llegado a ser un área de creciente atención por parte de investigadores de diversas disciplinas en países desarrollados. Aunque actualmente existen diversas metodologías para estudiar efectos del vecindario, una de las más utilizadas es la Observación Sistemática de Vecindarios –Systematic Social Observation SSO, en inglés—porque permite recolectar información acerca de diversas características del entorno físico, social, ambiental y económico de los vecindarios donde se aplica. El objetivo de este artículo es (i) dar a conocer sumariamente algunas investigaciones influyentes sobre efectos del vecindario en Estados Unidos, ii) describir cómo se diseñó e implementó la Observación Sistemática de Vecindarios en la ciudad de Santiago de Chile, iii) señalar algunos facilitadores y obstaculizadores de la implementación del proyecto y, finalmente iv) enunciar posibles contribuciones y limitaciones que esta metodología ofrecería al trabajo social en Chile. PMID:24791060

Werner-Syndrom. Eine prototypische Form der segmentalen Progerie

PubMed Central

Lessel, D.; Oshima, J.; Kubisch, C.

2013-01-01

Das Werner-Syndrom ist eine segmental progeroide Erkrankung mit Beginn in der Adoleszenz oder im frühen Erwachsenenalter. Typische Symptome, die zum vorgealterten Phänotyp beitragen, sind ein post-pubertär auftretender Kleinwuchs, Katarakte, eine vorzeitige Ergrauung/Ausdünnung des Haupthaars, sklerodermieähnliche Hautveränderungen und eine regionale Atrophie des subkutanen Fettgewebes. Darüber hinaus kommt es früh und gehäuft zu „Alterserkrankungen“ wie z. B. einem Diabetes mellitus Typ 2, einer Osteoporose, einer Atherosklerose sowie verschiedenen malignen Tumoren. Das Werner-Syndrom wird autosomal- rezessiv vererbt und ist durch Mutationen im Werner-Gen (WRN) bedingt. Es wurden bis heute mehr als 70 über das gesamte Gen verteilte Mutationen identifiziert, die typischerweise zu einem Verlust der Genfunktion führen. WRN kodiert für eine RecQ-Typ- Helikase, die u. a. an der DNA-Reparatur und der Aufrechterhaltung der DNA-Integrität beteiligt ist, was sich in einer erhöhten genetischen Instabilität in Patientenzellen wider-spiegelt. Trotz der relativen Seltenheit ist die Analyse des Werner-Syndroms von allgemeiner Bedeutung, um die Rolle der DNA-Stabilität und Integrität für das Altern sowie die Entwicklung altersassoziierter Erkrankungen besser zu verstehen. PMID:25309043

LiDAR for data efficiency.

DOT National Transportation Integrated Search

2011-09-30

This report documents the AHMCT research project: LiDAR for Data Efficiency for the Washington State Department of Transportation (WSDOT). The research objective was to evaluate mobile LiDAR technology to enhance safety, determine efficiency ga...

Diversity arrays technology: a generic genome profiling technology on open platforms.

PubMed

Kilian, Andrzej; Wenzl, Peter; Huttner, Eric; Carling, Jason; Xia, Ling; Blois, Hélène; Caig, Vanessa; Heller-Uszynska, Katarzyna; Jaccoud, Damian; Hopper, Colleen; Aschenbrenner-Kilian, Malgorzata; Evers, Margaret; Peng, Kaiman; Cayla, Cyril; Hok, Puthick; Uszynski, Grzegorz

2012-01-01

In the last 20 years, we have observed an exponential growth of the DNA sequence data and simular increase in the volume of DNA polymorphism data generated by numerous molecular marker technologies. Most of the investment, and therefore progress, concentrated on human genome and genomes of selected model species. Diversity Arrays Technology (DArT), developed over a decade ago, was among the first "democratizing" genotyping technologies, as its performance was primarily driven by the level of DNA sequence variation in the species rather than by the level of financial investment. DArT also proved more robust to genome size and ploidy-level differences among approximately 60 organisms for which DArT was developed to date compared to other high-throughput genotyping technologies. The success of DArT in a number of organisms, including a wide range of "orphan crops," can be attributed to the simplicity of underlying concepts: DArT combines genome complexity reduction methods enriching for genic regions with a highly parallel assay readout on a number of "open-access" microarray platforms. The quantitative nature of the assay enabled a number of applications in which allelic frequencies can be estimated from DArT arrays. A typical DArT assay tests for polymorphism tens of thousands of genomic loci with the final number of markers reported (hundreds to thousands) reflecting the level of DNA sequence variation in the tested loci. Detailed DArT methods, protocols, and a range of their application examples as well as DArT's evolution path are presented.

Shipborne LiDAR system for coastal change monitoring

NASA Astrophysics Data System (ADS)

Kim, chang hwan; Park, chang hong; Kim, hyun wook; hyuck Kim, won; Lee, myoung hoon; Park, hyeon yeong

2016-04-01

Coastal areas, used as human utilization areas like leisure space, medical care, ports and power plants, etc., are regions that are continuously changing and interconnected with oceans and land and the sea level has risen by about 8cm (1.9mm / yr) due to global warming from 1964 year to 2006 year in Korea. Coastal erosion due to sea-level rise has caused the problem of marine ecosystems and loss of tourism resources, etc. Regular monitoring of coastal erosion is essential at key locations with such volatility. But the survey method of land mobile LiDAR (light detection and ranging) system has much time consuming and many restrictions. For effective monitoring beach erosion, KIOST (Korea Institute of Ocean Science & Technology) has constructed a shipborne mobile LiDAR system. The shipborne mobile LiDAR system comprised a land mobile LiDAR (RIEGL LMS-420i), an INS (inertial navigation system, MAGUS Inertial+), a RTKGPS (LEICA GS15 GS25), and a fixed platform. The shipborne mobile LiDAR system is much more effective than a land mobile LiDAR system in the measuring of fore shore areas without shadow zone. Because the vessel with the shipborne mobile LiDAR system is continuously moved along the shoreline, it is possible to efficiently survey a large area in a relatively short time. Effective monitoring of the changes using the constructed shipborne mobile LiDAR system for seriously eroded coastal areas will be able to contribute to coastal erosion management and response.

Highly reproducible surface-enhanced Raman scattering-active Au nanostructures prepared by simple electrodeposition: origin of surface-enhanced Raman scattering activity and applications as electrochemical substrates.

PubMed

Choi, Suhee; Ahn, Miri; Kim, Jongwon

2013-05-24

The fabrication of effective surface-enhanced Raman scattering (SERS) substrates has been the subject of intensive research because of their useful applications. In this paper, dendritic gold (Au) rod (DAR) structures prepared by simple one-step electrodeposition in a short time were examined as an effective SERS-active substrate. The SERS activity of the DAR surfaces was compared to that of other nanostructured Au surfaces with different morphologies, and its dependence on the structural variation of DAR structures was examined. These comparisonal investigations revealed that highly faceted sharp edge sites present on the DAR surfaces play a critical role in inducing a high SERS activity. The SERS enhancement factor was estimated to be greater than 10(5), and the detection limit of rhodamine 6G at DAR surfaces was 10(-8)M. The DAR surfaces exhibit excellent spot-to-spot and substrate-to-substrate SERS enhancement reproducibility, and their long-term stability is very good. It was also demonstrated that the DAR surfaces can be effectively utilized in electrochemical SERS systems, wherein a reversible SERS behavior was obtained during the cycling to cathodic potential regions. Considering the straightforward preparation of DAR substrates and the clean nature of SERS-active Au surfaces prepared in the absence of additives, we expect that DAR surfaces can be used as cost-effective SERS substrates in analytical and electrochemical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Fusing Social Media and Mobile Analytics for Urban Sense-Making

DTIC Science & Technology

2017-05-09

AFRL-AFOSR-JP-TR-2017-0037 Fusing Social Media and Mobile Analytics for Urban Sense-Making Archan Misra SINGAPORE MANAGEMENT UNIVERSITY Final Report...CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-14-1-0002 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) Archan Misra 5d.   PROJECT NUMBER 5e.  TASK...NUMBER 5f.  WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) SINGAPORE MANAGEMENT UNIVERSITY 81 VICTORIA STREET SINGAPORE, 188065 SG 8

Development of a regional LiDAR field plot strategy for Oregon and Washington

Treesearch

Arvind Bhuta; Leah Rathbun

2015-01-01

The National Forest System (NFS) Pacific Northwest Region (R6) has been flying LiDAR on a per project basis. Additional field data was also collected in situ to many of these LiDAR projects to aid in the development of predictive models and estimate values which are unattainable through LiDAR data alone (e.g. species composition, tree volume, and downed woody material...

Optimizing variable radius plot size and LiDAR resolution to model standing volume in conifer forests

Treesearch

Ram Kumar Deo; Robert E. Froese; Michael J. Falkowski; Andrew T. Hudak

2016-01-01

The conventional approach to LiDAR-based forest inventory modeling depends on field sample data from fixed-radius plots (FRP). Because FRP sampling is cost intensive, combining variable-radius plot (VRP) sampling and LiDAR data has the potential to improve inventory efficiency. The overarching goal of this study was to evaluate the integration of LiDAR and VRP data....

Processing LiDAR Data to Predict Natural Hazards

NASA Technical Reports Server (NTRS)

Fairweather, Ian; Crabtree, Robert; Hager, Stacey

2008-01-01

ELF-Base and ELF-Hazards (wherein 'ELF' signifies 'Extract LiDAR Features' and 'LiDAR' signifies 'light detection and ranging') are developmental software modules for processing remote-sensing LiDAR data to identify past natural hazards (principally, landslides) and predict future ones. ELF-Base processes raw LiDAR data, including LiDAR intensity data that are often ignored in other software, to create digital terrain models (DTMs) and digital feature models (DFMs) with sub-meter accuracy. ELF-Hazards fuses raw LiDAR data, data from multispectral and hyperspectral optical images, and DTMs and DFMs generated by ELF-Base to generate hazard risk maps. Advanced algorithms in these software modules include line-enhancement and edge-detection algorithms, surface-characterization algorithms, and algorithms that implement innovative data-fusion techniques. The line-extraction and edge-detection algorithms enable users to locate such features as faults and landslide headwall scarps. Also implemented in this software are improved methodologies for identification and mapping of past landslide events by use of (1) accurate, ELF-derived surface characterizations and (2) three LiDAR/optical-data-fusion techniques: post-classification data fusion, maximum-likelihood estimation modeling, and hierarchical within-class discrimination. This software is expected to enable faster, more accurate forecasting of natural hazards than has previously been possible.

Improving LiDAR Data Post-Processing Techniques for Archaeological Site Management and Analysis: A Case Study from Canaveral National Seashore Park

NASA Astrophysics Data System (ADS)

Griesbach, Christopher

Methods used to process raw Light Detection and Ranging (LiDAR) data can sometimes obscure the digital signatures indicative of an archaeological site. This thesis explains the negative effects that certain LiDAR data processing procedures can have on the preservation of an archaeological site. This thesis also presents methods for effectively integrating LiDAR with other forms of mapping data in a Geographic Information Systems (GIS) environment in order to improve LiDAR archaeological signatures by examining several pre-Columbian Native American shell middens located in Canaveral National Seashore Park (CANA).

The first genetic map of pigeon pea based on diversity arrays technology (DArT) markers.

PubMed

Yang, Shi Ying; Saxena, Rachit K; Kulwal, Pawan L; Ash, Gavin J; Dubey, Anuja; Harper, John D I; Upadhyaya, Hari D; Gothalwal, Ragini; Kilian, Andrzej; Varshney, Rajeev K

2011-04-01

With an objective to develop a genetic map in pigeon pea (Cajanus spp.), a total of 554 diversity arrays technology (DArT) markers showed polymorphism in a pigeon pea F(2) mapping population of 72 progenies derived from an interspecific cross of ICP 28 (Cajanus cajan) and ICPW 94 (Cajanus scarabaeoides). Approximately 13% of markers did not conform to expected segregation ratio. The total number of DArT marker loci segregating in Mendelian manner was 405 with 73.1% (P > 0.001) of DArT markers having unique segregation patterns. Two groups of genetic maps were generated using DArT markers. While the maternal genetic linkage map had 122 unique DArT maternal marker loci, the paternal genetic linkage map has a total of 172 unique DArT paternal marker loci. The length of these two maps covered 270.0 cM and 451.6 cM, respectively. These are the first genetic linkage maps developed for pigeon pea, and this is the first report of genetic mapping in any grain legume using diversity arrays technology.

On the impact of a refined stochastic model for airborne LiDAR measurements

NASA Astrophysics Data System (ADS)

Bolkas, Dimitrios; Fotopoulos, Georgia; Glennie, Craig

2016-09-01

Accurate topographic information is critical for a number of applications in science and engineering. In recent years, airborne light detection and ranging (LiDAR) has become a standard tool for acquiring high quality topographic information. The assessment of airborne LiDAR derived DEMs is typically based on (i) independent ground control points and (ii) forward error propagation utilizing the LiDAR geo-referencing equation. The latter approach is dependent on the stochastic model information of the LiDAR observation components. In this paper, the well-known statistical tool of variance component estimation (VCE) is implemented for a dataset in Houston, Texas, in order to refine the initial stochastic information. Simulations demonstrate the impact of stochastic-model refinement for two practical applications, namely coastal inundation mapping and surface displacement estimation. Results highlight scenarios where erroneous stochastic information is detrimental. Furthermore, the refined stochastic information provides insights on the effect of each LiDAR measurement in the airborne LiDAR error budget. The latter is important for targeting future advancements in order to improve point cloud accuracy.

Comparison of Precision of Biomass Estimates in Regional Field Sample Surveys and Airborne LiDAR-Assisted Surveys in Hedmark County, Norway

NASA Technical Reports Server (NTRS)

Naesset, Erik; Gobakken, Terje; Bollandsas, Ole Martin; Gregoire, Timothy G.; Nelson, Ross; Stahl, Goeran

2013-01-01

Airborne scanning LiDAR (Light Detection and Ranging) has emerged as a promising tool to provide auxiliary data for sample surveys aiming at estimation of above-ground tree biomass (AGB), with potential applications in REDD forest monitoring. For larger geographical regions such as counties, states or nations, it is not feasible to collect airborne LiDAR data continuously ("wall-to-wall") over the entire area of interest. Two-stage cluster survey designs have therefore been demonstrated by which LiDAR data are collected along selected individual flight-lines treated as clusters and with ground plots sampled along these LiDAR swaths. Recently, analytical AGB estimators and associated variance estimators that quantify the sampling variability have been proposed. Empirical studies employing these estimators have shown a seemingly equal or even larger uncertainty of the AGB estimates obtained with extensive use of LiDAR data to support the estimation as compared to pure field-based estimates employing estimators appropriate under simple random sampling (SRS). However, comparison of uncertainty estimates under SRS and sophisticated two-stage designs is complicated by large differences in the designs and assumptions. In this study, probability-based principles to estimation and inference were followed. We assumed designs of a field sample and a LiDAR-assisted survey of Hedmark County (HC) (27,390 km2), Norway, considered to be more comparable than those assumed in previous studies. The field sample consisted of 659 systematically distributed National Forest Inventory (NFI) plots and the airborne scanning LiDAR data were collected along 53 parallel flight-lines flown over the NFI plots. We compared AGB estimates based on the field survey only assuming SRS against corresponding estimates assuming two-phase (double) sampling with LiDAR and employing model-assisted estimators. We also compared AGB estimates based on the field survey only assuming two-stage sampling (the NFI plots being grouped in clusters) against corresponding estimates assuming two-stage sampling with the LiDAR and employing model-assisted estimators. For each of the two comparisons, the standard errors of the AGB estimates were consistently lower for the LiDAR-assisted designs. The overall reduction of the standard errors in the LiDAR-assisted estimation was around 40-60% compared to the pure field survey. We conclude that the previously proposed two-stage model-assisted estimators are inappropriate for surveys with unequal lengths of the LiDAR flight-lines and new estimators are needed. Some options for design of LiDAR-assisted sample surveys under REDD are also discussed, which capitalize on the flexibility offered when the field survey is designed as an integrated part of the overall survey design as opposed to previous LiDAR-assisted sample surveys in the boreal and temperate zones which have been restricted by the current design of an existing NFI.

Re-evaluating estimates of impervious cover and riparian zone condition in New England watersheds

EPA Science Inventory

Under EPA’s Green Infrastructure Initiative, research activities are underway to evaluate the effectiveness of green infrastructure in mitigating the effects of urbanization and stormwater impacts on stream biota and habitat. Preliminary analyses, using impervious cover es...

The Benefits of Restoration in Urbanizing Watersheds: Developing Value Indicators and Understanding Social Barriers and Opportunities

EPA Science Inventory

Ecological restoration can reestablish ecosystem services (ES) that provide important social benefits, but managers with limited funds and resources are forced to prioritize potential restoration sites. Prioritizing restoration sites based on ecological functioning and expected ...

Creating Ecosystem Services Indices with EnviroAtlas Metrics

EPA Science Inventory

To support the well-being of future generations, ecosystem services (ES) need to be fully understood and evaluated by decision-makers. Geospatial tools, such as the EnviroAtlas, allow decision-makers, urban planners, public health professionals, and other stakeholders to view and...

High Density LiDAR and Orthophotography in UXO Wide Area Assessment

DTIC Science & Technology

2008-01-01

4 Figure 2. Helicopter-Mounted LiDAR and Orthophoto Sensor Equipment...4 Figure 3. LiDAR and Orthophoto System Installed on Helicopter........................................ 6 Figure 4. Kirtland Precision...17 Figure 11. Orthophoto Data Density Results

Cloning, sequence, and disruption of the Saccharomyces diastaticus DAR1 gene encoding a glycerol-3-phosphate dehydrogenase.

PubMed Central

Wang, H T; Rahaim, P; Robbins, P; Yocum, R R

1994-01-01

The Saccharomyces diastaticus DAR1 gene was cloned by complementation in an Escherichia coli strain auxogrophic for glycerol-3-phosphate. DAR1 encodes an NADH-dependent dihydroxyacetone phosphate reductase (sn-glycerol-3-phosphate dehydrogenase [G3PDase; EC 1.1.1.8]) homologous to several other eukaryotic G3PDases. DAR1 is distinct from GUT2, which encodes a glucose-repressed mitochondrial G3PDase, but is identical to GPD1 from S. cerevisiae, a close relative of S. diastaticus. The level of DAR1-encoded G3PDase was increased about threefold in a medium of high osmolarity. Disruption of DAR1 in a haploid S. cerevisiae was not lethal but led to a decrease in cytoplasmic NADH-dependent G3PDase activity, an increase in osmotic sensitivity, and a 25% reduction in glycerol secretion from cells grown anaerobically on glucose. PMID:7961476

Cloning, sequence, and disruption of the Saccharomyces diastaticus DAR1 gene encoding a glycerol-3-phosphate dehydrogenase.

PubMed

Wang, H T; Rahaim, P; Robbins, P; Yocum, R R

1994-11-01

The Saccharomyces diastaticus DAR1 gene was cloned by complementation in an Escherichia coli strain auxogrophic for glycerol-3-phosphate. DAR1 encodes an NADH-dependent dihydroxyacetone phosphate reductase (sn-glycerol-3-phosphate dehydrogenase [G3PDase; EC 1.1.1.8]) homologous to several other eukaryotic G3PDases. DAR1 is distinct from GUT2, which encodes a glucose-repressed mitochondrial G3PDase, but is identical to GPD1 from S. cerevisiae, a close relative of S. diastaticus. The level of DAR1-encoded G3PDase was increased about threefold in a medium of high osmolarity. Disruption of DAR1 in a haploid S. cerevisiae was not lethal but led to a decrease in cytoplasmic NADH-dependent G3PDase activity, an increase in osmotic sensitivity, and a 25% reduction in glycerol secretion from cells grown anaerobically on glucose.

Achieving Accuracy Requirements for Forest Biomass Mapping: A Data Fusion Method for Estimating Forest Biomass and LiDAR Sampling Error with Spaceborne Data

NASA Technical Reports Server (NTRS)

Montesano, P. M.; Cook, B. D.; Sun, G.; Simard, M.; Zhang, Z.; Nelson, R. F.; Ranson, K. J.; Lutchke, S.; Blair, J. B.

2012-01-01

The synergistic use of active and passive remote sensing (i.e., data fusion) demonstrates the ability of spaceborne light detection and ranging (LiDAR), synthetic aperture radar (SAR) and multispectral imagery for achieving the accuracy requirements of a global forest biomass mapping mission. This data fusion approach also provides a means to extend 3D information from discrete spaceborne LiDAR measurements of forest structure across scales much larger than that of the LiDAR footprint. For estimating biomass, these measurements mix a number of errors including those associated with LiDAR footprint sampling over regional - global extents. A general framework for mapping above ground live forest biomass (AGB) with a data fusion approach is presented and verified using data from NASA field campaigns near Howland, ME, USA, to assess AGB and LiDAR sampling errors across a regionally representative landscape. We combined SAR and Landsat-derived optical (passive optical) image data to identify forest patches, and used image and simulated spaceborne LiDAR data to compute AGB and estimate LiDAR sampling error for forest patches and 100m, 250m, 500m, and 1km grid cells. Forest patches were delineated with Landsat-derived data and airborne SAR imagery, and simulated spaceborne LiDAR (SSL) data were derived from orbit and cloud cover simulations and airborne data from NASA's Laser Vegetation Imaging Sensor (L VIS). At both the patch and grid scales, we evaluated differences in AGB estimation and sampling error from the combined use of LiDAR with both SAR and passive optical and with either SAR or passive optical alone. This data fusion approach demonstrates that incorporating forest patches into the AGB mapping framework can provide sub-grid forest information for coarser grid-level AGB reporting, and that combining simulated spaceborne LiDAR with SAR and passive optical data are most useful for estimating AGB when measurements from LiDAR are limited because they minimized forest AGB sampling errors by 15 - 38%. Furthermore, spaceborne global scale accuracy requirements were achieved. At least 80% of the grid cells at 100m, 250m, 500m, and 1km grid levels met AGB density accuracy requirements using a combination of passive optical and SAR along with machine learning methods to predict vegetation structure metrics for forested areas without LiDAR samples. Finally, using either passive optical or SAR, accuracy requirements were met at the 500m and 250m grid level, respectively.

Downstream of downtown: urban wastewater as groundwater recharge

NASA Astrophysics Data System (ADS)

Foster, S. S. D.; Chilton, P. J.

Wastewater infiltration is often a major component of overall recharge to aquifers around urban areas, especially in more arid climates. Despite this, such recharge still represents only an incidental (or even accidental) byproduct of various current practices of sewage effluent handling and wastewater reuse. This topic is reviewed through reference to certain areas of detailed field research, with pragmatic approaches being identified to reduce the groundwater pollution hazard of these practices whilst attempting to retain their groundwater resource benefit. Since urban sewage effluent is probably the only `natural resource' whose global availability is steadily increasing, the socioeconomic importance of this topic for rapidly developing urban centres in the more arid parts of Asia, Africa, Latin America and the Middle East will be apparent. L'infiltration des eaux usées est souvent la composante essentielle de toute la recharge des aquifères des zones urbaines, particulièrement sous les climats les plus arides. Malgré cela, une telle recharge ne constitue encore qu'un sous-produit incident, ou même accidentel, de pratiques courantes variées du traitement de rejets d'égouts et de réutilisation d'eaux usées. Ce sujet est passé en revue en se référant à certaines régions étudiées en détail, par des approches pragmatiques reconnues pour permettre de réduire les risques de pollution des nappes dues à ces pratiques tout en permettant d'en tirer profit pour leur ressource en eau souterraine. Puisque les effluents d'égouts urbains sont probablement la seule « ressource naturelle » dont la disponibilité globale va croissant constamment, l'importance socio-économique de ce sujet est évidente pour les centres urbains à développement rapide de l'Asie, de l'Afrique, de l'Amérique latine et du Moyen-Orient. La infiltración de aguas residuales es a menudo un componente principal de la recarga total en acuíferos ubicados en torno a zonas urbanas, especialmente en los climas más áridos. A pesar de ello, dicho componente todavía es una consecuencia secundaria (o incluso accidental) de diversas prácticas asociadas con la manipulación de las aguas residuales y con la reutilitzación de aguas depuradas. Este tema se revisa mediante referencias a ciertas áreas en las que existen investigación detallada de campo, identificando enfoques pragmáticos con el fin de reducir el riesgo de contaminación de las aguas subterráneas por tales prácticas, a la vez tratando de conservar los beneficios para los recursos del acuífero. Dado que los efluentes de aguas residuales urbanas son probablemente la única `fuente natural' cuya disponibilidad global se halla en del aumento, la importancia socioeconómica de este tema será evidente para los centros urbanos de rápido desarrollo en Asia, Latinoamérica y Oriente Medio.

A GUI visualization system for airborne lidar image data to reconstruct 3D city model

NASA Astrophysics Data System (ADS)

Kawata, Yoshiyuki; Koizumi, Kohei

2015-10-01

A visualization toolbox system with graphical user interfaces (GUIs) was developed for the analysis of LiDAR point cloud data, as a compound object oriented widget application in IDL (Interractive Data Language). The main features in our system include file input and output abilities, data conversion capability from ascii formatted LiDAR point cloud data to LiDAR image data whose pixel value corresponds the altitude measured by LiDAR, visualization of 2D/3D images in various processing steps and automatic reconstruction ability of 3D city model. The performance and advantages of our graphical user interface (GUI) visualization system for LiDAR data are demonstrated.

How much does the time lag between wildlife field-data collection and LiDAR-data acquisition matter for studies of animal distributions? A case study using bird communities

Treesearch

Kerri T. Vierling; Charles E. Swift; Andrew T. Hudak; Jody C. Vogeler; Lee A. Vierling

2014-01-01

Vegetation structure quantified by light detection and ranging (LiDAR) can improve understanding of wildlife occupancy and species-richness patterns. However, there is often a time lag between the collection of LiDAR data and wildlife data. We investigated whether a time lag between the LiDAR acquisition and field-data acquisition affected mapped wildlife distributions...

Demonstration of LiDAR and Orthophotography for Wide Area Assessment at Pueblo Precision Bombing Range #2, Colorado

DTIC Science & Technology

2008-01-01

Figure 11. Screenshot of OrthoPro seam lines (pink), tiles (blue), and photos (green)................ 26 Figure 12. Calibration craters (existing...with aerial targets for the orthophotography data collection, 1 per data collection tile (1 sq km). For the Phase I data collection, 9 LiDAR ground...Orthophotography data were collected concurrently with the LiDAR data collection. Based on the LiDAR flight line spacing parameters, the orthophoto images were

Development and validation of the Dimensional Anhedonia Rating Scale (DARS) in a community sample and individuals with major depression.

PubMed

Rizvi, Sakina J; Quilty, Lena C; Sproule, Beth A; Cyriac, Anna; Michael Bagby, R; Kennedy, Sidney H

2015-09-30

Anhedonia, a core symptom of Major Depressive Disorder (MDD), is predictive of antidepressant non-response. In contrast to the definition of anhedonia as a "loss of pleasure", neuropsychological studies provide evidence for multiple facets of hedonic function. The aim of the current study was to develop and validate the Dimensional Anhedonia Rating Scale (DARS), a dynamic scale that measures desire, motivation, effort and consummatory pleasure across hedonic domains. Following item selection procedures and reliability testing using data from community participants (N=229) (Study 1), the 17-item scale was validated in an online study with community participants (N=150) (Study 2). The DARS was also validated in unipolar or bipolar depressed patients (n=52) and controls (n=50) (Study 3). Principal components analysis of the 17-item DARS revealed a 4-component structure mapping onto the domains of anhedonia: hobbies, food/drink, social activities, and sensory experience. Reliability of the DARS subscales was high across studies (Cronbach's α=0.75-0.92). The DARS also demonstrated good convergent and divergent validity. Hierarchical regression analysis revealed the DARS showed additional utility over the Snaith-Hamilton Pleasure Scale (SHAPS) in predicting reward function and distinguishing MDD subgroups. These studies provide support for the reliability and validity of the DARS. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Combined effect of pulse density and grid cell size on predicting and mapping aboveground carbon in fast-growing Eucalyptus forest plantation using airborne LiDAR data.

PubMed

Silva, Carlos Alberto; Hudak, Andrew Thomas; Klauberg, Carine; Vierling, Lee Alexandre; Gonzalez-Benecke, Carlos; de Padua Chaves Carvalho, Samuel; Rodriguez, Luiz Carlos Estraviz; Cardil, Adrián

2017-12-01

LiDAR remote sensing is a rapidly evolving technology for quantifying a variety of forest attributes, including aboveground carbon (AGC). Pulse density influences the acquisition cost of LiDAR, and grid cell size influences AGC prediction using plot-based methods; however, little work has evaluated the effects of LiDAR pulse density and cell size for predicting and mapping AGC in fast-growing Eucalyptus forest plantations. The aim of this study was to evaluate the effect of LiDAR pulse density and grid cell size on AGC prediction accuracy at plot and stand-levels using airborne LiDAR and field data. We used the Random Forest (RF) machine learning algorithm to model AGC using LiDAR-derived metrics from LiDAR collections of 5 and 10 pulses m -2 (RF5 and RF10) and grid cell sizes of 5, 10, 15 and 20 m. The results show that LiDAR pulse density of 5 pulses m -2 provides metrics with similar prediction accuracy for AGC as when using a dataset with 10 pulses m -2 in these fast-growing plantations. Relative root mean square errors (RMSEs) for the RF5 and RF10 were 6.14 and 6.01%, respectively. Equivalence tests showed that the predicted AGC from the training and validation models were equivalent to the observed AGC measurements. The grid cell sizes for mapping ranging from 5 to 20 also did not significantly affect the prediction accuracy of AGC at stand level in this system. LiDAR measurements can be used to predict and map AGC across variable-age Eucalyptus plantations with adequate levels of precision and accuracy using 5 pulses m -2 and a grid cell size of 5 m. The promising results for AGC modeling in this study will allow for greater confidence in comparing AGC estimates with varying LiDAR sampling densities for Eucalyptus plantations and assist in decision making towards more cost effective and efficient forest inventory.

Deformity Angular Ratio Describes the Severity of Spinal Deformity and Predicts the Risk of Neurologic Deficit in Posterior Vertebral Column Resection Surgery.

PubMed

Wang, Xiao-Bin; Lenke, Lawrence G; Thuet, Earl; Blanke, Kathy; Koester, Linda A; Roth, Michael

2016-09-15

Retrospective review of prospectively collected data. To assess the value of the deformity angular ratio (DAR, maximum Cobb measurement divided by number of vertebrae involved) in evaluating the severity of spinal deformity, and predicting the risk of neurologic deficit in posterior vertebral column resection (PVCR). Although the literature has demonstrated that PVCR in spinal deformity patients has achieved excellent outcomes, it is still high risk neurologically. This study, to our knowledge, is the largest series of PVCR patients from a single center, evaluating deformity severity, and potential neurologic deficit risk. A total of 202 consecutive pediatric and adult patients undergoing PVCRs from November 2002 to September 2014 were reviewed. The DAR (coronal DAR, sagittal DAR, and total DAR) was used to evaluate the complexity of the deformity. The incidence of spinal cord monitoring (SCM) events was 20.5%. Eight patients (4.0%) had new neurologic deficits. Patients with a high total DAR (≥25) were significantly younger (20.3 vs. 29.0 yr, P = 0.001), had more severe coronal and sagittal deformities, were more myelopathic (33.3% vs. 11.7%, P = 0.000), needed larger vertebral resections (1.8 vs. 1.3, P = 0.000), and had a significantly higher rate of SCM events than seen in the low total DAR (<25) patients (41.1% vs. 10.8%; P = 0.000). Patients with a high sagittal DAR (≥15) also had a significantly higher rate of SCM events (34.0% vs. 15.1%, P = 0.005) and a greater chance of neurologic deficits postoperatively (12.5% vs. 0, P = 0.000). For patients undergoing a PVCR, the DAR can be used to quantify the angularity of the spinal deformity, which is strongly correlated to the risk of neurologic deficits. Patients with a total DAR greater than or equal to 25 or sagittal DAR greater than or equal to 15 are at much higher risk for intraoperative SCM events and new neurologic deficits. 3.

Let’s agree on the casing of Lidar

USGS Publications Warehouse

Deering, Carol; Stoker, Jason M.

2014-01-01

Is it lidar, Lidar, LiDAR, LIDAR, LiDar, LiDaR, or liDAR? A comprehensive review of the scientific/technical literature reveals seven different casings of this short form for light detection and ranging. And there could be more.

Infrastructure Investment Protection with LiDAR

DOT National Transportation Integrated Search

2012-10-15

The primary goal of this research effort was to explore the wide variety of uses of LiDAR technology and to evaluate their : applicability to NCDOT practices. NCDOT can use this information about LiDAR in determining how and when the : technology can...

Assessing LiDAR elevation data for KDOT applications.

DOT National Transportation Integrated Search

2013-02-01

LiDAR-based elevation surveys are a cost-effective means for mapping topography over large areas. LiDAR : surveys use an airplane-mounted or ground-based laser radar unit to scan terrain. Post-processing techniques are : applied to remove vegetation ...

47 CFR 25.164 - Milestones.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

47 CFR 25.164 - Milestones.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

47 CFR 25.164 - Milestones.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

47 CFR 25.164 - Milestones.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Milestones. (a) Licensees of geostationary orbit satellite systems other than DBS and DARS satellite systems.... (b) Licensees of non-geostationary orbit satellite systems other than DBS and DARS satellite systems... both non-geostationary orbit satellites and geostationary orbit satellites, other than DBS and DARS...

LiDAR for Air Quality Measurements

DOT National Transportation Integrated Search

2017-02-02

The overall goal of this research is to investigate a unique light detection and ranging (LiDAR) technology for ambient air quality measurement of particulate matter. The ODU team has recently received a state-of-the-art elastic LiDAR from NASA Langl...

Applications of High-Resolution LiDAR Data for the Christina River Basin CZO

NASA Astrophysics Data System (ADS)

Hicks, N. S.; Aufdenkampe, A. K.; Hicks, S. D.

2011-12-01

High-resolution LiDAR data allows for fine scale geomorphic assessment over relatively large spatial extents. Previously available DEMs with a resolution of ten meters or more did not provide adequate resolution for geomorphic characterization of small streams and watersheds or the identification of changes in stream morphology over time. High-resolution LiDAR data for a portion of the Christina River Basin Critical Zone Observatory (CRB-CZO) was obtained during both leaf-off and leaf-on time periods in 2010. Topographic data from these flights is being analyzed with the intent of geomorphic applications such as stream morphology, sediment transport studies, and the evaluation of alluvial deposits. These data and resultant products will also be used in hydrologic and biogeochemical modeling and in biologic and biogeochemical studies of these streams, which are long-term study sites. The LiDAR data also facilitate informed instrument placement and will be used for vegetation studies. The LiDAR data for the CRB-CZO has been used to create a variety of LiDAR based topographic data products including TINs and 0.5-m DEMs. LiDAR derived slope and elevation products were combined with LiDAR intensity images to identify stream channel boundaries and stream centerlines for third through first-order streams. High-resolution slope data also aided in floodplain characterization of these small streams. These high precision stream channel and floodplain characterizations would not have been otherwise possible without extensive field surveying. Future LiDAR flights will allow for the identification of changes in channel morphology over time in low order basins. These characterizations are of particular interest in comparisons between forested and meadow reaches, and in studying the effects of changes in land-use on channel morphology. High-resolution LiDAR data allow for the generation of surface characterizations of importance to a wide range of interdisciplinary researchers.

Deflation-activated receptors, not classical inflation-activated receptors, mediate the Hering-Breuer deflation reflex.

PubMed

Yu, Jerry

2016-11-01

Many airway sensory units respond to both lung inflation and deflation. Whether those responses to opposite stimuli come from one sensor (one-sensor theory) or more than one sensor (multiple-sensor theory) is debatable. One-sensor theory is commonly presumed in the literature. This article proposes a multiple-sensor theory in which a sensory unit contains different sensors for sensing different forces. Two major types of mechanical sensors operate in the lung: inflation- and deflation-activated receptors (DARs). Inflation-activated sensors can be further divided into slowly adapting receptors (SARs) and rapidly adapting receptors (RARs). Many SAR and RAR units also respond to lung deflation because they contain DARs. Pure DARs, which respond to lung deflation only, are rare in large animals but are easily identified in small animals. Lung deflation-induced reflex effects previously attributed to RARs should be assigned to DARs (including pure DARs and DARs associated with SARs and RARs) if the multiple-sensor theory is accepted. Thus, based on the information, it is proposed that activation of DARs can attenuate lung deflation, shorten expiratory time, increase respiratory rate, evoke inspiration, and cause airway secretion and dyspnea.

The application of LiDAR to investigate foredune morphology and vegetation

NASA Astrophysics Data System (ADS)

Doyle, Thomas B.; Woodroffe, Colin D.

2018-02-01

LiDAR (Light Detection and Ranging) has been used to investigate coastal landform morphology, evolution, and change for almost a decade. Repeated airborne LiDAR surveys can provide the scientific community with significant observations of how shorelines have evolved, which may then enable forecasts of future patterns of change. However, there have been few studies that have considered the application of this new technology to the specific study of foredune morphology and vegetation. The accuracy and appropriateness of airborne LiDAR needs to be assessed, particularly where the density of vegetation may obscure the underlying topography, prior to interpreting derived geomorphic features. This study: i) tests the vertical accuracy of airborne LiDAR in 37 foredune systems along the coast of south-eastern Australia, and ii) demonstrates that it can be used to describe foredune morphology and vegetation in considerable detail. There was a strong correlation between the remotely-sensed LiDAR-derived elevation and field topographic and vegetation surveys (R2 = 0.96). A protocol for obtaining foredune geomorphic and botanical parameters is described. It enables widespread biogeomorphic characterisation along coasts for which LiDAR data is available, which can benefit both coastal managers and researchers alike.

Georeferenced LiDAR 3D vine plantation map generation.

PubMed

Llorens, Jordi; Gil, Emilio; Llop, Jordi; Queraltó, Meritxell

2011-01-01

The use of electronic devices for canopy characterization has recently been widely discussed. Among such devices, LiDAR sensors appear to be the most accurate and precise. Information obtained with LiDAR sensors during reading while driving a tractor along a crop row can be managed and transformed into canopy density maps by evaluating the frequency of LiDAR returns. This paper describes a proposed methodology to obtain a georeferenced canopy map by combining the information obtained with LiDAR with that generated using a GPS receiver installed on top of a tractor. Data regarding the velocity of LiDAR measurements and UTM coordinates of each measured point on the canopy were obtained by applying the proposed transformation process. The process allows overlap of the canopy density map generated with the image of the intended measured area using Google Earth(®), providing accurate information about the canopy distribution and/or location of damage along the rows. This methodology was applied and tested on different vine varieties and crop stages in two important vine production areas in Spain. The results indicate that the georeferenced information obtained with LiDAR sensors appears to be an interesting tool with the potential to improve crop management processes.

Parenting practices and styles associated with adolescent sexual health in Dar es Salaam, Tanzania.

PubMed

Kajula, Lusajo J; Darling, Nancy; Kaaya, Sylvia F; De Vries, Hein

2016-11-01

Parenting styles and practices are suggested to be important predictors of adolescent sexual health, mostly in Europe and North America. Limited research has been conducted on these processes in Sub-Saharan Africa, which has different patterns of adolescent sexual behavior and family traditions. This study qualitatively explored parenting practices and styles associated with adolescent sexual health in Tanzania, with 12 adolescents and 12 parents of adolescents. The themes we identified from the data included parental monitoring, preventive, and punitive behaviors. Parents were reported to use mostly punitive behaviors to correct or prohibit sexual behavior; parents also set clear rules about appropriate sexual behavior (e.g., modesty and abstinence). Parents were also reported to closely monitor their adolescent children's friendships and sexual behavior to minimize sexual behavior. However, some parents also engaged in positive preventive practices aimed at protecting their adolescent children.

Disparities in mental health outcomes among lung cancer survivors associated with ruralness of residence.

PubMed

Andrykowski, Michael A; Steffens, Rachel F; Bush, Heather M; Tucker, Thomas C

2014-04-01

Healthy People 2020 identifies elimination of health disparities as a key aim. Rural residence is associated with disparities in cancer screening, physical morbidity, and survival. The present study aimed to identify potential disparities in mental health (MH) outcomes (e.g., anxiety and depression symptoms, distress) in lung cancer (LC) survivors associated with ruralness of residence. Lung cancer survivors (LC group; n = 193; mean age = 63.1 years; mean time since diagnosis = 15.6 months) were recruited from the population-based SEER Kentucky Cancer Registry. LC survivors completed a telephone interview and questionnaire assessing MH outcomes. U.S. Department of Agriculture Rural-Urban Continuum Codes were used to identify Rural (n = 117) and Urban (n = 76) LC survivors. A healthy comparison (HC) group was recruited (n = 152) and completed a questionnaire assessing MH outcomes. Across six MH indices, Rural LC survivors reported poorer MH relative to Urban LC survivors with a mean effect size (ES) of 0.43 SD in unadjusted analyses and 0.29 SD in analyses adjusted for education and physical comorbidity. Comparison of the LC and HC groups revealed significant Ruralness × Group interactions for five of six MH indices. The Rural LC group reported poorer MH than the Rural HC group with a mean ES of 0.51 SD. The MH of Urban LC and HC groups did not differ (mean ES = 0.00 SD). Rural residence is a risk factor for poorer MH outcomes for LC survivors. The MH of Rural LC survivors may be more negatively impacted by cancer diagnosis and treatment than the MH of Urban LC survivors. Copyright © 2013 John Wiley & Sons, Ltd.

Assessing LiDAR elevation data for KDOT applications : [technical summary].

DOT National Transportation Integrated Search

2013-02-01

LiDAR-based elevation surveys : are a cost-effective means for : mapping topography over large : areas. LiDAR surveys use an : airplane-mounted or ground-based : laser radar unit to scan terrain. : Post-processing techniques are : applied to remove v...

Effects of LiDAR point density, sampling size and height threshold on estimation accuracy of crop biophysical parameters.

PubMed

Luo, Shezhou; Chen, Jing M; Wang, Cheng; Xi, Xiaohuan; Zeng, Hongcheng; Peng, Dailiang; Li, Dong

2016-05-30

Vegetation leaf area index (LAI), height, and aboveground biomass are key biophysical parameters. Corn is an important and globally distributed crop, and reliable estimations of these parameters are essential for corn yield forecasting, health monitoring and ecosystem modeling. Light Detection and Ranging (LiDAR) is considered an effective technology for estimating vegetation biophysical parameters. However, the estimation accuracies of these parameters are affected by multiple factors. In this study, we first estimated corn LAI, height and biomass (R² = 0.80, 0.874 and 0.838, respectively) using the original LiDAR data (7.32 points/m²), and the results showed that LiDAR data could accurately estimate these biophysical parameters. Second, comprehensive research was conducted on the effects of LiDAR point density, sampling size and height threshold on the estimation accuracy of LAI, height and biomass. Our findings indicated that LiDAR point density had an important effect on the estimation accuracy for vegetation biophysical parameters, however, high point density did not always produce highly accurate estimates, and reduced point density could deliver reasonable estimation results. Furthermore, the results showed that sampling size and height threshold were additional key factors that affect the estimation accuracy of biophysical parameters. Therefore, the optimal sampling size and the height threshold should be determined to improve the estimation accuracy of biophysical parameters. Our results also implied that a higher LiDAR point density, larger sampling size and height threshold were required to obtain accurate corn LAI estimation when compared with height and biomass estimations. In general, our results provide valuable guidance for LiDAR data acquisition and estimation of vegetation biophysical parameters using LiDAR data.

Modeling marbled murrelet (Brachyramphus marmoratus) habitat using LiDAR-derived canopy data

USGS Publications Warehouse

Hagar, Joan C.; Eskelson, Bianca N.I.; Haggerty, Patricia K.; Nelson, S. Kim; Vesely, David G.

2014-01-01

LiDAR (Light Detection And Ranging) is an emerging remote-sensing tool that can provide fine-scale data describing vertical complexity of vegetation relevant to species that are responsive to forest structure. We used LiDAR data to estimate occupancy probability for the federally threatened marbled murrelet (Brachyramphus marmoratus) in the Oregon Coast Range of the United States. Our goal was to address the need identified in the Recovery Plan for a more accurate estimate of the availability of nesting habitat by developing occupancy maps based on refined measures of nest-strand structure. We used murrelet occupancy data collected by the Bureau of Land Management Coos Bay District, and canopy metrics calculated from discrete return airborne LiDAR data, to fit a logistic regression model predicting the probability of occupancy. Our final model for stand-level occupancy included distance to coast, and 5 LiDAR-derived variables describing canopy structure. With an area under the curve value (AUC) of 0.74, this model had acceptable discrimination and fair agreement (Cohen's κ = 0.24), especially considering that all sites in our sample were regarded by managers as potential habitat. The LiDAR model provided better discrimination between occupied and unoccupied sites than did a model using variables derived from Gradient Nearest Neighbor maps that were previously reported as important predictors of murrelet occupancy (AUC = 0.64, κ = 0.12). We also evaluated LiDAR metrics at 11 known murrelet nest sites. Two LiDAR-derived variables accurately discriminated nest sites from random sites (average AUC = 0.91). LiDAR provided a means of quantifying 3-dimensional canopy structure with variables that are ecologically relevant to murrelet nesting habitat, and have not been as accurately quantified by other mensuration methods.

Valuating Ecosystem Services of Urban Ponds - case study from Bangladesh

NASA Astrophysics Data System (ADS)

Carle, Nina

2016-04-01

A climate risk assessment for the city of Barisal was carried out by a consultancy firm, financed by KfW Development Bank of Germany. Due to high dependencies on natural capital of people in developing countries they are facing high vulnerability when it comes to changes of the asset category 'natural capital' (here: urban ponds), whether due to the exposition on climate (change) related impacts, implemented measures or land use change. With a closer view on the city's assets, the question remained open to the author 1) Under current conditions, what is the demand for ecosystem services (ES) 2) What is the value of the benefits and the how much is the contribution to the city's welfare? 3) What are the future changes in the demand for ES? And what are the future changes on the supply side (pressures and threats to the ecosystem)? Methodology: The City of Barisal in Bangladesh has a calculated number of around 10.000 urban rain-fed ponds,representing 6.5% of the city area, which represents a huge natural water supply and gives the city its characteristic face. In August 2015 a user survey was conducted in the city of Barisal, in every ward (administrative unit), to determine the demand for ecosystem services related to urban ponds, evaluating over 600 ponds. The findings will present the huge variation of provisioning ecosystem services and an important regulating service, related to economic and domestic use, in a spatial resolution. It will be shown, how the importance of ES changes, by changing the unit of analysis (families or ponds or the city) and the importance for the livelihood of pond owners and users. A relationship between pond area(m2) and number of users was detected, also the role of compensation payments for the pond owners by the users. It will be shown how natural capital, privately and publicly owned,contributes in an important way in buffering unequal distribution of societies resources in the short- and long-run. However society's demand for ES will change in the future, as climate models indicate a change in precipitation patterns for Barisal. Climate change is operating multisectoral and therefore all assets have to be considered to detect the potential damage. This research can show the pathways of people depending on natural captital in developing countries, sharpening the view for vulnerable groups. Furthermore the research can deliver a contribution to the discussion on (financial) investments to build resilient futures.

Object-based habitat mapping using very high spatial resolution multispectral and hyperspectral imagery with LiDAR data

NASA Astrophysics Data System (ADS)

Onojeghuo, Alex Okiemute; Onojeghuo, Ajoke Ruth

2017-07-01

This study investigated the combined use of multispectral/hyperspectral imagery and LiDAR data for habitat mapping across parts of south Cumbria, North West England. The methodology adopted in this study integrated spectral information contained in pansharp QuickBird multispectral/AISA Eagle hyperspectral imagery and LiDAR-derived measures with object-based machine learning classifiers and ensemble analysis techniques. Using the LiDAR point cloud data, elevation models (such as the Digital Surface Model and Digital Terrain Model raster) and intensity features were extracted directly. The LiDAR-derived measures exploited in this study included Canopy Height Model, intensity and topographic information (i.e. mean, maximum and standard deviation). These three LiDAR measures were combined with spectral information contained in the pansharp QuickBird and Eagle MNF transformed imagery for image classification experiments. A fusion of pansharp QuickBird multispectral and Eagle MNF hyperspectral imagery with all LiDAR-derived measures generated the best classification accuracies, 89.8 and 92.6% respectively. These results were generated with the Support Vector Machine and Random Forest machine learning algorithms respectively. The ensemble analysis of all three learning machine classifiers for the pansharp QuickBird and Eagle MNF fused data outputs did not significantly increase the overall classification accuracy. Results of the study demonstrate the potential of combining either very high spatial resolution multispectral or hyperspectral imagery with LiDAR data for habitat mapping.

Applicability Analysis of Cloth Simulation Filtering Algorithm for Mobile LIDAR Point Cloud

NASA Astrophysics Data System (ADS)

Cai, S.; Zhang, W.; Qi, J.; Wan, P.; Shao, J.; Shen, A.

2018-04-01

Classifying the original point clouds into ground and non-ground points is a key step in LiDAR (light detection and ranging) data post-processing. Cloth simulation filtering (CSF) algorithm, which based on a physical process, has been validated to be an accurate, automatic and easy-to-use algorithm for airborne LiDAR point cloud. As a new technique of three-dimensional data collection, the mobile laser scanning (MLS) has been gradually applied in various fields, such as reconstruction of digital terrain models (DTM), 3D building modeling and forest inventory and management. Compared with airborne LiDAR point cloud, there are some different features (such as point density feature, distribution feature and complexity feature) for mobile LiDAR point cloud. Some filtering algorithms for airborne LiDAR data were directly used in mobile LiDAR point cloud, but it did not give satisfactory results. In this paper, we explore the ability of the CSF algorithm for mobile LiDAR point cloud. Three samples with different shape of the terrain are selected to test the performance of this algorithm, which respectively yields total errors of 0.44 %, 0.77 % and1.20 %. Additionally, large area dataset is also tested to further validate the effectiveness of this algorithm, and results show that it can quickly and accurately separate point clouds into ground and non-ground points. In summary, this algorithm is efficient and reliable for mobile LiDAR point cloud.

Advances in animal ecology from 3D ecosystem mapping with LiDAR

NASA Astrophysics Data System (ADS)

Davies, A.; Asner, G. P.

2015-12-01

The advent and recent advances of Light Detection and Ranging (LiDAR) have enabled accurate measurement of 3D ecosystem structure. Although the use of LiDAR data is widespread in vegetation science, it has only recently (< 14 years) been applied to animal ecology. Despite such recent application, LiDAR has enabled new insights in the field and revealed the fundamental importance of 3D ecosystem structure for animals. We reviewed the studies to date that have used LiDAR in animal ecology, synthesising the insights gained. Structural heterogeneity is most conducive to increased animal richness and abundance, and increased complexity of vertical vegetation structure is more positively influential than traditionally measured canopy cover, which produces mixed results. However, different taxonomic groups interact with a variety of 3D canopy traits and some groups with 3D topography. LiDAR technology can be applied to animal ecology studies in a wide variety of environments to answer an impressive array of questions. Drawing on case studies from vastly different groups, termites and lions, we further demonstrate the applicability of LiDAR and highlight new understanding, ranging from habitat preference to predator-prey interactions, that would not have been possible from studies restricted to field based methods. We conclude with discussion of how future studies will benefit by using LiDAR to consider 3D habitat effects in a wider variety of ecosystems and with more taxa to develop a better understanding of animal dynamics.

Airborne LiDAR reflective linear feature extraction for strip adjustment and horizontal accuracy determination.

DOT National Transportation Integrated Search

2009-02-01

ODOT's Office of Aerial Engineering (OAE) has been using an Opetch 30/70 ALTM airborne LiDAR system for about four years. The introduction of LiDAR technology was a major development towards improving the mapping operations. The overall experiences a...

Stationary LiDAR for traffic and safety applications - vehicles interpretation and tracking.

DOT National Transportation Integrated Search

2014-01-01

The goal of the T-Scan project is to develop a data processing module for a novel LiDAR-based traffic scanner to collect highly accurate microscopic traffic data at road intersections. : T-Scan uses Light Detection and Ranging (LiDAR) technology that...

Estimation of forest aboveground biomass and uncertainties by integration of field measurements, airborne LiDAR, and SAR and optical satellite data in Mexico.

PubMed

Urbazaev, Mikhail; Thiel, Christian; Cremer, Felix; Dubayah, Ralph; Migliavacca, Mirco; Reichstein, Markus; Schmullius, Christiane

2018-02-21

Information on the spatial distribution of aboveground biomass (AGB) over large areas is needed for understanding and managing processes involved in the carbon cycle and supporting international policies for climate change mitigation and adaption. Furthermore, these products provide important baseline data for the development of sustainable management strategies to local stakeholders. The use of remote sensing data can provide spatially explicit information of AGB from local to global scales. In this study, we mapped national Mexican forest AGB using satellite remote sensing data and a machine learning approach. We modelled AGB using two scenarios: (1) extensive national forest inventory (NFI), and (2) airborne Light Detection and Ranging (LiDAR) as reference data. Finally, we propagated uncertainties from field measurements to LiDAR-derived AGB and to the national wall-to-wall forest AGB map. The estimated AGB maps (NFI- and LiDAR-calibrated) showed similar goodness-of-fit statistics (R 2 , Root Mean Square Error (RMSE)) at three different scales compared to the independent validation data set. We observed different spatial patterns of AGB in tropical dense forests, where no or limited number of NFI data were available, with higher AGB values in the LiDAR-calibrated map. We estimated much higher uncertainties in the AGB maps based on two-stage up-scaling method (i.e., from field measurements to LiDAR and from LiDAR-based estimates to satellite imagery) compared to the traditional field to satellite up-scaling. By removing LiDAR-based AGB pixels with high uncertainties, it was possible to estimate national forest AGB with similar uncertainties as calibrated with NFI data only. Since LiDAR data can be acquired much faster and for much larger areas compared to field inventory data, LiDAR is attractive for repetitive large scale AGB mapping. In this study, we showed that two-stage up-scaling methods for AGB estimation over large areas need to be analyzed and validated with great care. The uncertainties in the LiDAR-estimated AGB propagate further in the wall-to-wall map and can be up to 150%. Thus, when a two-stage up-scaling method is applied, it is crucial to characterize the uncertainties at all stages in order to generate robust results. Considering the findings mentioned above LiDAR can be used as an extension to NFI for example for areas that are difficult or not possible to access.

Use of demand for and spatial flow of ecosystem services to identify priority areas.

PubMed

Verhagen, Willem; Kukkala, Aija S; Moilanen, Atte; van Teeffelen, Astrid J A; Verburg, Peter H

2017-08-01

Policies and research increasingly focus on the protection of ecosystem services (ESs) through priority-area conservation. Priority areas for ESs should be identified based on ES capacity and ES demand and account for the connections between areas of ES capacity and demand (flow) resulting in areas of unique demand-supply connections (flow zones). We tested ways to account for ES demand and flow zones to identify priority areas in the European Union. We mapped the capacity and demand of a global (carbon sequestration), a regional (flood regulation), and 3 local ESs (air quality, pollination, and urban leisure). We used Zonation software to identify priority areas for ESs based on 6 tests: with and without accounting for ES demand and 4 tests that accounted for the effect of ES flow zone. There was only 37.1% overlap between the 25% of priority areas that encompassed the most ESs with and without accounting for ES demand. The level of ESs maintained in the priority areas increased from 23.2% to 57.9% after accounting for ES demand, especially for ESs with a small flow zone. Accounting for flow zone had a small effect on the location of priority areas and level of ESs maintained but resulted in fewer flow zones without ES maintained relative to ignoring flow zones. Accounting for demand and flow zones enhanced representation and distribution of ESs with local to regional flow zones without large trade-offs relative to the global ES. We found that ignoring ES demand led to the identification of priority areas in remote regions where benefits from ES capacity to society were small. Incorporating ESs in conservation planning should therefore always account for ES demand to identify an effective priority network for ESs. © 2016 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

Large Scale Textured Mesh Reconstruction from Mobile Mapping Images and LIDAR Scans

NASA Astrophysics Data System (ADS)

Boussaha, M.; Vallet, B.; Rives, P.

2018-05-01

The representation of 3D geometric and photometric information of the real world is one of the most challenging and extensively studied research topics in the photogrammetry and robotics communities. In this paper, we present a fully automatic framework for 3D high quality large scale urban texture mapping using oriented images and LiDAR scans acquired by a terrestrial Mobile Mapping System (MMS). First, the acquired points and images are sliced into temporal chunks ensuring a reasonable size and time consistency between geometry (points) and photometry (images). Then, a simple, fast and scalable 3D surface reconstruction relying on the sensor space topology is performed on each chunk after an isotropic sampling of the point cloud obtained from the raw LiDAR scans. Finally, the algorithm proposed in (Waechter et al., 2014) is adapted to texture the reconstructed surface with the images acquired simultaneously, ensuring a high quality texture with no seams and global color adjustment. We evaluate our full pipeline on a dataset of 17 km of acquisition in Rouen, France resulting in nearly 2 billion points and 40000 full HD images. We are able to reconstruct and texture the whole acquisition in less than 30 computing hours, the entire process being highly parallel as each chunk can be processed independently in a separate thread or computer.

A tool for assessing ecological status of forest ecosystem

NASA Astrophysics Data System (ADS)

Rahman Kassim, Abd; Afizzul Misman, Muhammad; Azahari Faidi, Mohd; Omar, Hamdan

2016-06-01

Managers and policy makers are beginning to appreciate the value of ecological monitoring of artificially regenerated forest especially in urban areas. With the advent of more advance technology in precision forestry, high resolution remotely sensed data e.g. hyperspectral and LiDAR are becoming available for rapid and precise assessment of the forest condition. An assessment of ecological status of forest ecosystem was developed and tested using FRIM campus forest stand. The forest consisted of three major blocks; the old growth artificially regenerated native species forests, naturally regenerated forest and recent planted forest for commercial timber and other forest products. Our aim is to assess the ecological status and its proximity to the mature old growth artificially regenerated stand. We used airborne LiDAR, orthophoto and thirty field sampling quadrats of 20x20m for ground verification. The parameter assessments were grouped into four broad categories: a. forest community level-composition, structures, function; landscape structures-road network and forest edges. A metric of parameters and rating criteria was introduced as indicators of the forest ecological status. We applied multi-criteria assessment to categorize the ecological status of the forest stand. The paper demonstrates the application of the assessment approach using FRIM campus forest as its first case study. Its potential application to both artificially and naturally regenerated forest in the variety of Malaysian landscape is discussed