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Excreta Disposal in Dar-es-salaam  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The sociocultural and socioeconomic situation of sanitation in Dar-es-Salaam (Dsm), Tanzania, was studied with explicit emphasis on pit-latrines. Without considering the sociocultural conditions, the so-called best solution might not be the right one. Therefore, in order to achieve the intended goal, a literature review, a questionnaire survey, and personal visits to the chosen study areas were done. In total, 207 household questionnaires were filled in 16 areas of the city. Interviewers did ...

Chaggu, E.; Mashouri, D.; Buuren, J. C. L.; Sanders, W. T. M.; Lettinga, G.

2002-01-01

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A Browning process : The case of Dar es Salaam city  

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The study is about how green spaces and structures of Dar es Salaam city, quantitatively and qualitatively, are browning out. It also tries to explore the different reasons behind the browning tendency, and what it means to the function of the city and to the daily form of life of the inhabitants. Finally there is a discussion about how to counteract the tendency by involving the inhabitants in planning procedures following the communicative approach to planning. The main investigations have ...

Mng Ong O, Othmar Simtali

2005-01-01

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Prevalence and Determinants of Obesity among Primary School Children in Dar es Salaam, Tanzania.  

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Childhood obesity has increased dramatically and has become a public health concern worldwide. Childhood obesity is likely to persist through adulthood and may lead to early onset of NCDs. However, there is paucity of data on obesity among primary school children in Tanzania. This study assessed the prevalence and determinants of obesity among primary school children in Dar es Salaam. A cross sectional study was conducted among school age children in randomly selected schools in Dar es Salaam...

2013-01-01

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Epidemiological Studies on Bovine Mastitis in Smallholder Dairy Herds in the Dar es Salaam Region, Tanzania  

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Recently the number of milking cows has increased substantially in the Dar es Salaam region due to an increasing demand for fresh milk in this densely populated urban centre. It is estimated that there are 1,765 smallholder dairy herds with 8,233 improved dairy animals in and around the Dar es Salaam region. Urban and peri-urban smallholder dairying is viewed as an agricultural activity that provides a regular and stable income to the household and is considered to be a forerunner of further...

2006-01-01

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Potential of solar power in electricity production in Dar es Salaam, Tanzania : focus on households and paybacks  

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The purpose of this work was to study the opportunities and challenges of using solar power by solar photovoltaic (PV) in production of electricity for households in Dar es Salaam, Tanzania. Dar es Salaam has plenty of sunshine throughout the year making it a perfect candidate for solar PV electrification. Data collected for this work was done mainly by conducting interviews with different levels of households, private and government institutes, literature from books, web pages and previou...

Kibbassa, Mwilumbwa

2010-01-01

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Rapid Urban Malaria Appraisal (RUMA) II: Epidemiology of urban malaria in Dar es Salaam (Tanzania)  

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Abstract Background The thinking behind malaria research and control strategies stems largely from experience gained in rural areas and needs to be adapted to the urban environment. Methods A rapid assessment of urban malaria was conducted in Dar es Salaam in June-August, 2003 using a standard Rapid Urban Malaria Appraisal (RUMA) methodology. This study was part of a multi-site study in sub-Saharan Africa supported by the Roll Back Malaria Partnership. Re...

2006-01-01

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Storage, Collection and Disposal of Kariakoo Market Wastes in Dar Es Salaam, Tanzania  

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In many developing countries, the market is still the most important source of commerce for traders and provisions for the general public. The transmission of disease in the market place involves factors relating to the host, the agent and the environment. This study examines the quality of solid waste management in Kariakoo market, Dar es Salaam. The main problems identified were poor market design and lack of a well organized waste storage, collection and disposal systems. Two-thirds of the...

Yhdego, Michael

2011-01-01

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

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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 insuffi...

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

2011-01-01

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A Review of Traffic Congestion in Dar es Salaam City from the Physical Planning Perspective  

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Traffic congestion is one of the major problems facing Dar es Salaam City and is attributed by a number of factors including rapid population increase, inadequate and poor road infrastructure, city structure, rapid increase in number of cars and lack of physical plan to control city development. The city is already implementing a number of strategies in order to minimize traffic congestion. However, many of the strategies are focusing on improving the capacity of roads in terms of increasing ...

2013-01-01

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Predictors of breastfeeding cessation among HIV-infected women in Dar es Salaam,Tanzania  

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This paper examines predictors of breastfeeding cessation among a cohort of human immunodeficiency virus (HIV)-infected women. This was a prospective follow-up study of HIV-infected women who participated in a randomized micronutrient supplementation trial conducted in Dar es Salaam, Tanzania. 795 HIV-infected Tanzanian women with singleton newborns were utilized from the cohort for this analysis. The proportion of women breastfeeding declined from 95% at 12 months to 11% at 24 months. The mu...

Petraro, Paul; Duggan, Christopher; Msamanga, Gernard; Peterson, Karen E.; Spiegelman, Donna; Fawzi, Wafaie

2011-01-01

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A Review of Traffic Congestion in Dar es Salaam City from the Physical Planning Perspective  

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Full Text Available Traffic congestion is one of the major problems facing Dar es Salaam City and is attributed by a number of factors including rapid population increase, inadequate and poor road infrastructure, city structure, rapid increase in number of cars and lack of physical plan to control city development. The city is already implementing a number of strategies in order to minimize traffic congestion. However, many of the strategies are focusing on improving the capacity of roads in terms of increasing number of lanes, proposing new overpasses and underpasses at the main road intersections and improving public transport. These strategies cannot fully overcome the congestion problems in Dar es Salaam on their own unless efforts are made to redistribute services and community infrastructure. The latter can be achieved through physical planning, which has the potential of influencing trip generation and travel patterns and traffic volume in specific roads. Therefore to minimize traffic congestion in the Dar es Salaam both strategies for improving road capacity, public transport and physical planning solutions ought to be applied together.

Robert B. Kiunsi

2013-01-01

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Prevalence and determinants of obesity among primary school children in Dar es Salaam, Tanzania  

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Background Childhood obesity has increased dramatically and has become a public health concern worldwide. Childhood obesity is likely to persist through adulthood and may lead to early onset of NCDs. However, there is paucity of data on obesity among primary school children in Tanzania. This study assessed the prevalence and determinants of obesity among primary school children in Dar es Salaam. Methods A cross sectional study was conducted among school age children in randomly selected schools in Dar es Salaam. Anthropometric and blood pressure measurements were taken using standard procedures. Body Mass Index (BMI) was calculated as weight in kilograms divided by the square of height in meters (kg/m2). Child obesity was defined as BMI at or above 95th percentile for age and sex. Socio-demographic characteristics of children were determined using a structured questionnaire. Logistic regression was used to determine association between independent variables with obesity among primary school children in Dar es Salaam. Results A total of 446 children were included in the analysis. The mean age of the participants was 11.1±2.0 years and 53.1% were girls. The mean BMI, SBP and DBP were 16.6±4.0 kg/m2, 103.9±10.3mmHg and 65.6±8.2mmHg respectively. The overall prevalence of child obesity was 5.2% and was higher among girls (6.3%) compared to boys (3.8%). Obese children had significantly higher mean values for age (p=0.042), systolic and diastolic blood pressures (all pchild obesity. Conclusions The prevalence of childhood obesity in this population was found to be low. However, children from urban schools and girls were proportionately more obese compared to their counterparts. Primary preventive measures for childhood obesity should start early in childhood and address socioeconomic factors of parents contributing to childhood obesity.

2013-01-01

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

DEFF Research Database (Denmark)

ABSTRACT: OBJECTIVE: To describe how demographic characteristics and knowledge of cervical cancer influence screening acceptance among women living in Dar es Salaam, Tanzania. METHODS: 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. RESULTS: 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 (ORs 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). CONCLUSION: 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.

Kahesa, Crispin; Kjaer, Susanne

2012-01-01

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

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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. PMID:24908469

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

2014-06-01

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Modeling Urban Growth Spatial Dynamics: Case studies of Addis Ababa and Dar es Salaam  

Science.gov (United States)

Rapid urbanization, and consequently, the dramatic spatial expansion of mostly informal urban areas increases the vulnerability of African cities to the effects of climate change such as sea level rise, more frequent flooding, droughts and heat waves. The EU FP 7 funded project CLUVA (Climate Change and Urban Vulnerability in Africa, www.cluva.eu) aims to develop strategies for minimizing the risks of natural hazards caused by climate change and to improve the coping capacity of African cities. Green infrastructure may play a particular role in climate change adaptation by providing ecosystem services for flood protection, stormwater retention, heat island moderation and provision of food and fuel wood. In this context, a major challenge is to gain a better understanding of the spatial and temporal dynamics of the cities and how these impact on green infrastructure and hence their vulnerability. Urban growth scenarios for two African cities, namely Addis Ababa, Ethiopia and Dar es Salaam, Tanzania, were developed based on a characterization of their urban morphology. A population growth driven - GIS based - disaggregation modeling approach was applied. Major impact factors influencing the urban dynamics were identified both from literature and interviews with local experts. Location based factors including proximity to road infrastructure and accessibility, and environmental factors including slope, surface and flood risk areas showed a particular impact on urban growth patterns. In Addis Ababa and Dar es Salaam, population density scenarios were modeled comparing two housing development strategies. Results showed that a densification scenario significantly decreases the loss of agricultural and green areas such as forests, bushland and sports grounds. In Dar es Salaam, the scenario of planned new settlements with a population density of max. 350 persons per hectare would lead until 2025 to a loss of agricultural land (-10.1%) and green areas (-6.6%). On the other hand, 12.4% of agricultural land and 16.1% of green areas would be lost in the low density development scenario of unplanned settlements of max. 150 persons per hectare. Relocating the population living in flood prone areas in the case of Addis Ababa and keeping those areas free from further settlements in the case of Dar es Salaam would result in even lower losses (agricultural land: -10.0%, green areas: -5.6%) as some flood prone areas overlap with agricultural/ green areas. The scenario models introduced in this research can be used by planners as tools to understand and manage the different outcomes of distinctive urban development strategies on growth patterns and how they interact with different climate change drivers such as loss of green infrastructure and effects such as frequent flooding hazards. Due to the relative simplicity of their structure and the single modeling environment, the models can be transferred to similar cities with minor modifications accommodating the different conditions of each city. Already, in Addis Ababa the results of the model will be used in the current revision of the Master plan of the city. Keywords: GIS, modeling, Urban Dynamics, Dar es Salaam, Addis Ababa, urbanization

Buchta, Katja; Abo El Wafa, Hany; Printz, Andreas; Pauleit, Stephan

2013-04-01

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Climate change induced risk analysis of Dar es Salaam city (Tanzania)  

Science.gov (United States)

CLUVA (CLimate change and Urban Vulnerability in Africa; http://www.cluva.eu/) is a 3 years project, funded by the European Commission in 2010. The main objective of CLUVA is to develop context-centered methods and knowledge to be applied to African cities to assess vulnerabilities and increase knowledge on managing climate related risks. The project estimates the impacts of climate changes in the next 40 years at urban scale and downscales IPCC climate projections to evaluate specific threats to selected African test cities. These are mainly from floods, sea-level rise, droughts, heat waves, and desertification. The project 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. The 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 present preliminary findings for the Dar es Salaam case study. Dar es Salaam, which is Tanzania's largest coastal city, is exposed to floods, coastal erosion, droughts and heat waves, and highly vulnerable to impacts as a result of ineffective urban planning (about 70% unplanned settlements), poverty and lack of basic infrastructure (e.g. lack of or poor quality storm water drainage systems). Climate change could exacerbate the current situation increasing hazard-exposure alongside the impacts of development pressures which act to increase urban vulnerability for example because of informal (unregulated) urbanization. The CLUVA research team - composed of climate and environmental scientists, 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 through interdisciplinary methods and analysis. Climate change projections at 8 km resolution are ready for regions containing each of the case study cities; a preliminary hazard assessment for floods, droughts and heat waves has been performed, based on historical data; urban morphology and related green structures have been characterized; preliminary findings in social vulnerability provide insights how communities and households can resist and cope with, as well as recover from climate induced hazards; vulnerability of informal settlements to floods has been assessed for a case study area (Suna sub ward) and a GIS based identification of urban residential hotspots to flooding is completed. Furthermore, a set of indicators has been identified and the most relevant for Dar es Salaam has been selected by local stakeholders to identify particular vulnerable high risk areas and communities. An investigation of the existing urban planning and governance system and its interface with climate risks and vulnerability has inter-alia suggested severe institutional deficits including over-centralized institutions for disaster risk management and climate change adaptation. A multi-risk framework considering climate-related hazards, and physical and social fragilities has been set up.

Topa, Maria Elena; Herslund, Lise; Cavan, Gina; Printz, Andreas; Simonis, Ingo; Bucchignani, Edoardo; Jean-Baptiste, Nathalie; Hellevik, Siri; Johns, Regina; Kibassa, Deusdedit; Kweka, Clara; Magina, Fredrick; Mangula, Alpha; Mbuya, Elinorata; Uhinga, Guido; Kassenga, Gabriel; Kyessi, Alphonce; Shemdoe, Riziki; Kombe, Wilbard

2013-04-01

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Rapid Urban Malaria Appraisal (RUMA II: Epidemiology of urban malaria in Dar es Salaam (Tanzania  

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Full Text Available Abstract Background The thinking behind malaria research and control strategies stems largely from experience gained in rural areas and needs to be adapted to the urban environment. Methods A rapid assessment of urban malaria was conducted in Dar es Salaam in June-August, 2003 using a standard Rapid Urban Malaria Appraisal (RUMA methodology. This study was part of a multi-site study in sub-Saharan Africa supported by the Roll Back Malaria Partnership. Results Overall, around one million cases of malaria are reported every year by health facilities. However, school surveys in Dar es Salaam during a dry spell in 2003 showed that the prevalence of malaria parasites was low: 0.8%, 1.4%, 2.7% and 3.7% in the centre, intermediate, periphery and surrounding rural areas, respectively. Health facilities surveys showed that only 37/717 (5.2% of presenting fever cases and 22/781 (2.8% of non-fever cases were positive by blood slide. As a result, malaria-attributable fractions for fever episodes were low in all age groups and there was an important over-reporting of malaria cases. Increased malarial infection rates were seen in persons who travelled to rural areas within the past three months. A remarkably high coverage of insecticide-treated nets and a corresponding reduction in malarial infection risk were found. Conclusion The number of clinical malaria cases was much lower than routine reporting suggested. Improved malaria diagnosis and re-defined clinical guidelines are urgently required to avoid over-treatment with antimalarials.

Manane Lusinge

2006-04-01

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Identification of diarrheagenic Escherichia coli isolated from infants and children in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Relatively few studies have been done in Tanzania to detect and classify diarrheagenic Escherichia coli (DEC strains among children with diarrhea. This study aimed at investigating DEC among children in Dar es Salaam aged less than five years hospitalized due to acute/persistent diarrhea. Methods DEC were isolated from stool samples collected from two hundred and eighty children with acute/persistent diarrhea at Muhimbili National Hospital and Ilala and Mwananyamala Municipal Hospitals in Dar es Salaam. A multiplex PCR system method was used to detect a species specific gene for E.coli and ten different virulence genes for detection of five pathogroups of DEC namely enteroaggregative- (EAEC, enteropathogenic- (EPEC, enterotoxigenic- (ETEC, enteroinvasive- (EIEC and enterohemorghagic- Escherichia coli (EHEC. Results Sixty-four patients (22.9% harbored DEC. Forty-one of them (14.6% were categorized as EAEC. Most of the EAEC (82.9% were classified as typical EAEC possessing the aggR gene, and 92.6% carried the aat gene. Isolates from thirteen patients were EPEC (4.6% and most of these (92.3% were typical EPEC with both eae and bfpA genes. Ten isolates were identified as ETEC (3.6% with only the heat stable toxin; either st1a or st1b but not both. Age wise, EAEC and EPEC were significantly more prevalent among the age group 0–6 months (p stx1 and stx2 and EIEC (ial were not detected in this study group. Conclusion The results show a high proportion of DEC among Tanzanian children with diarrhea, with typical EAEC and typical EPEC predominating. The use of primers for both variants of ST1 (st1a and st1b increased the sensitivity for detection of ETEC strains.

Matee Mecky I

2007-08-01

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BUS BAY PERFORMANCE AND ITS INFLUENCE ON THE CAPACITY OF ROAD NETWORK IN DAR ES SALAAM  

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Full Text Available One of major problems facing motorists in Dar es Salaam city today is congestion. Bus bays have a significant influence on the capacity of a roadway because they interfere with passing vehicles primarily when buses maneuver to pull into and out of bus bays. Bus bay stops will also interfere with vehicles movement if bus demand exceeds the bus bay capacity resulting in some buses waiting in the travel lane until the buses occupying the bay exit the bay. This paper presents the results of a study which was carried out to evaluate the bus bay performance and its influence on the capacity of the roadway network in the city of Dar es Salaam. The case study area covered 11 bus stops along Morogoro road from Ubungo to Magomeni Mapipa. Capacity of bus bays was studied using procedure outlined in the Transit Capacity and Quality of Service Manual of 2003. This enabled the researcher to determine parameters such as dwell times and clearance times which are major determinants of bus stop capacity. The results indicate that only 18% of the bus bay stops studied did not have adequate capacity to cater for the available demand. 9% did not have adequate capacity during peak hours but the capacity was adequate during off-peak hours. The remaining 73% of bus bay stops possess adequate capacity all the time. Although most bus bay stops studied possess adequate capacity, severe congestion was observed at these locations. This is due to erratic behavior of bus drivers who do not utilize the provided space for them to drop off and pick up passengers. Clearly, this is an area that requires more strict enforcement in order to ease the congestion problem in the city by operating the existing capacity more efficiently."

Nurdin K. Mushule

2012-01-01

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Flooding, flood risks and coping strategies in urban informal residential areas: the case of Keko Machungwa, Dar es Salaam, Tanzania  

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This article presents findings from a study carried out in Keko Machungwa informal settlement in Dar es Salaam under the auspices of the Disaster Management Training Centre of Ardhi University, Tanzania. The settlement has experienced frequent flooding in the past five years, and this study explores the causes, risks, extent of flooding and coping strategies of residents as well as municipality and city officials. Key methods employed in capturing empirical evidence included mapping of zones ...

Tumpale Sakijege; John Lupala; Shaaban Sheuya

2012-01-01

 
 
 
 
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Age specific aetiological agents of diarrhoea in hospitalized children aged less than five years in Dar es Salaam, Tanzania  

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Background This study aimed to determine the age-specific aetiologic agents of diarrhoea in children aged less than five years. The study also assessed the efficacy of the empiric treatment of childhood diarrhoea using Integrated Management of Childhood Illness (IMCI) guidelines. Methods This study included 280 children aged less than 5 years, admitted with diarrhoea to any of the four major hospitals in Dar es Salaam. Bacterial pathogens were identified using conventional methods. Enzyme Li...

Moyo, Sabrina J.; Njølstad, Gro; Matee, Mecky I.; Kitundu, Jesse; Myrmel, Helge; Mylvaganam, Haima; Maselle, Samwel Y.; Langeland, Nina

2011-01-01

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Community-Based Environmental Management for Malaria Control: Evidence from a Small-Scale Intervention in Dar es Salaam, Tanzania  

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Background: 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 awa...

2009-01-01

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Community-Based Environmental Management for Malaria Control: Evidence from a small-scale intervention in Dar es Salaam, Tanzania.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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, prev...

2009-01-01

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background 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 inte...

2009-01-01

25

Window screening, ceilings and closed eaves as sustainable ways to control malaria in Dar es Salaam, Tanzania  

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Abstract Background Malaria transmission in Africa occurs predominantly inside houses where the primary vectors prefer to feed. Human preference and investment in blocking of specific entry points for mosquitoes into houses was evaluated and compared with known entry point preferences of the mosquitoes themselves. Methods Cross-sectional household surveys were conducted in urban Dar es Salaam, Tanzania to estimate usage levels of available options for house proo...

Ogoma Sheila B; Kannady Khadija; Sikulu Maggy; Chaki Prosper P; Govella Nicodem J; Mukabana Wolfgang R; Killeen Gerry F

2009-01-01

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Interdependence of domestic malaria prevention measures and mosquito-human interactions in urban Dar es Salaam, Tanzania  

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Abstract Background Successful malaria vector control depends on understanding behavioural interactions between mosquitoes and humans, which are highly setting-specific and may have characteristic features in urban environments. Here mosquito biting patterns in Dar es Salaam, Tanzania are examined and the protection against exposure to malaria transmission that is afforded to residents by using an insecticide-treated net (ITN) is estimated. Methods Mosquito biti...

Geissbühler Yvonne; Chaki Prosper; Emidi Basiliana; Govella Nicodemus J; Shirima Rudolf; Mayagaya Valeliana; Mtasiwa Deo; Mshinda Hassan; Fillinger Ulrike; Lindsay Steven W; Kannady Khadija; de Castro Marcia; Tanner Marcel; Killeen Gerry F

2007-01-01

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Resettling Displaced Residents from Regularized Settlements in Dar es Salaam City, Tanzania : The case of Community Infrastructure Upgrading Program (CIUP)  

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This research seeks to examine the process of displacement and resettlement of residents who had been affected by regularization process within Manzese and Buguruni wards in Dar es Salaam City, Tanzania. It aimed at analyzing the issues and opportunities faced by the affected residents during regularization. The regularization which involves two processes, tenure and physical upgrading has been extensively used in solving problems associated with unplanned and informal settlements within deve...

Magembe-mushi, Dawah Lulu

2011-01-01

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Identification of diarrheagenic Escherichia coli isolated from infants and children in Dar es Salaam, Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Relatively few studies have been done in Tanzania to detect and classify diarrheagenic Escherichia coli (DEC) strains among children with diarrhea. This study aimed at investigating DEC among children in Dar es Salaam aged less than five years hospitalized due to acute/persistent diarrhea. Methods DEC were isolated from stool samples collected from two hundred and eighty children with acute/persistent diarrhea at Muhimbili National H...

2007-01-01

29

Knowledge of mosquitos in relation to public and domestic control activities in the cities of Dar es Salaam and Tanga.  

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A study of community awareness of mosquitos and related subjects in the residential areas of two Tanzanian cities (Dar es Salaam and Tanga) showed that residents were well aware of mosquitos. Almost all claimed to use some form of domestic mosquito control product for their personal protection, and many spend a significant portion of the household income on this. The problems of nuisance-biting and malaria transmission are usually not separated and are considered to be the result of poor envi...

Stephens, C.; Masamu, E. T.; Kiama, M. G.; Keto, A. J.; Kinenekejo, M.; Ichimori, K.; Lines, J.

1995-01-01

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Transportation Conditions and Access to Services in a Context of Urban Sprawl and Deregulation. The Case of Dar es Salaam  

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Major deficiencies in urbanisation and transportation systems are reinforcing patterns of social and urban segregation in Dar es Salaam, Tanzania's largest city. Analysis of the 1993 Human Resources Development Survey shows that there are numerous obstacles to the daily travel of the city's inhabitants, notably the poor. These barriers weigh heavily on schedules, complicate access to services ever further, limit the use of urban space, and place considerable pressure on household budgets. Con...

Diaz Olvera, Lourdes; Plat, Didier; Pochet, Pascal

2003-01-01

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Improving quality of perinatal care through clinical audit : a study from a tertiary hospital in Dar es Salaam, Tanzania  

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Perinatal audit has been tested and proved an important tool for reduction of perinatal mortality and assessment of quality of perinatal care. At Muhimbili National Hospital (MNH), a tertiary hospital in Dar es salaam, Tanzania we performed a retrospective cross-sectional study using data from an obstetrics database to classify all perinatal deaths during 1999-2003. We also determined the prevalence of anaemia in pregnancy and its impact on perinatal outcome. Furthermore, we conducted a perin...

Kidanto, Hussein L.

2009-01-01

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Exploring Sustainable Urban Food Provisioning: The Case of Eggs in Dar es Salaam  

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Full Text Available Global food supply is dominated by transnational corporations, which have great power and are widely critiqued for the negative environmental and social impacts of their operations. Many argue that this industrial food system is unsustainable, yet its expansion seems inevitable and alternatives are seen as incapable of feeding the world’s growing and increasingly urban population. Since much of the world’s future population growth is going to happen in the cities of the developing world, they have become the frontline for the expansion of the industrial food system, raising the serious challenge of ensuring food security for residents. This paper, based on a qualitative study of patterns of egg provisioning in Dar es Salaam, explores whether existing patterns of food supply in this rapidly growing city, of over four million people, provide workable alternatives. Eggs are an important source of nutrition and patterns of egg supply offer a lens through which to explore the sustainability of different modes of provisioning. A range of non-corporate provisioning patterns, based on small-scale enterprises, are found to have social, economic and environmental advantages, challenging assumptions that corporate food chains are necessary, or desirable, to feed cities sustainably.

Marc C. A. Wegerif

2014-06-01

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The management of depressed skull fractures in children at Muhimbili Medical Centre, Dar es Salaam, Tanzania.  

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Thirty eight consecutive children with depressed fracture of the skull admitted to the Paediatric Surgical Unit (PSU) of Muhimbili Medical Centre (MMC), Dar es Salaam between January 1986 to May 1992 were studied. There were 22 boys and 16 girls. Age range was from birth to 10 years. A fall of one form or another accounted for 25 (65.00%) patients. Falling from a sister's or mother's back occurred in 4 (10.5%) patients, while falling from trees was a cause in 8 (21%) patients. Objects hitting on the head accounted for 6 (15.8%) patients. The objects included stones in 3 and falling coconut fruits in three. Traffic motor accidents accounted for 5 (13.2%) patients. In 35 (92.1%) patients, the fractures were closed while in 3 (7.9%) they were open. The fractures were located in the frontal or parietal bone in 27 (76.3%) patients. The 3 coconut fractures were located at the sagittal area. Only 4 (10.5%) patients had focal neurological signs. Convulsions were recorded in 3 patients while loss of consciousness was observed in 4 patients. Surgery was performed on 22 (57.9%) patients while conservative approach was practised in 16 (42.1%). The indications for surgery were cosmetics in 15 patients, compound fracture in 3 patients, focal neurological deficit in 2 patients, and torn dura presenting with Pseudo-meningocele in 2 patients. PMID:8306906

Mlay, S M; Sayi, E N

1993-05-01

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Patterns of sexually transmitted infections in adolescents and youth in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Syndromic management of STIs has been advocated as simplified and cheap approach. Youth have been reported to be at increased risk of acquiring STIs which can facilitate HIV transmission. We have investigated the relationship between the syndromic management and specific aetiology diagnosis and its relationship with HIV infection and health seeking behaviour among youth attending a reproductive health clinic in Dar es Salaam, Tanzania. Methods Between September 1998 and February 1999 among 1895 adolescents and youth below 25 years seen in the clinic 199 (10.5% were randomly selected and consented to participate in the study. A standard questionnaire was administered. Blood and vaginal or urethral specimens were taken and investigated for STI causative agents. Results Among a total of 199 studied adolescents and youth 22.6 % were teenagers, with fewer females 17.8% than males; 27.5% (p Conclusion The burden of STIs in this youth population is large indicating that youth are at increased risk of STIs and will certainly require youth friendly clinics. There is a need to refine the current syndromic management guidelines.

Swai Andrew

2006-02-01

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Assessing urban fire risk in the central business district of Dar es Salaam, Tanzania  

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Full Text Available Buildings as infrastructure along with people’s lives need protection against fire outbreaks. Knowledge on the use of installed facilities is essential in tackling There emergencies, otherwise their installation becomes meaningless. Lack of such knowledge could hamper escape from There hazards and thwart attempts to contain there outbreaks at their preliminary stage. THis study, carried out in the Central Business District of Dar es Salaam City, assessed urban there risk with respect to public awareness on the use of #re #ghting facilities and preparedness in the event of #re outbreaks. Public buildings with at least four storeys or 2000m2 floor space were surveyed. According to the Fire and Rescue Act of 2007, such buildings have to be provided with adequate means of escape and #re #ghting facilities. Data was collected through observation and interviews with building managers, users and key informants. The study revealed high there disaster risk in most buildings of the study area, as 60% of the buildings’ users do not know how to operate the facilities, and 41% are not aware of the available escape means in case of there outbreak. Worse still, only 29% had received training within the past five years, and 68% had never been trained.

Yohannes Kachenje

2010-04-01

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Characterization of Salmonella species from water bodies in Dar-Es-Salaam city, Tanzania  

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Full Text Available Background: Water-borne diseases are the most common cause of illness and death among the poor population from developing countries. The majority of the people are inadequately aware that aquatic environment is a major source of salmonellosis. Dar es Salaam city is among the cities with most of its population live in squatter. Typhoid fever ranks second with 14.3% of all notifiable disease cases in the city. The city experience water scarcity which forces water wells and rivers to become the main sources of water for domestic use and livestock. This study therefore, characterized Salmonella strains from different water bodies of city as possible sources for enteric diseases endemicity. Methods: The Salmonella Chromogenic Agar (SC Agar and Kligler Iron Agar (KIA media were used for isolation and enumeration of the strains. The inoculated cultures were incubated at 370C for 24 hours. Salmonella colonies were confirmed by magenta colorations and hydrogen sulfide production on SC Agar and KIA Agar, respectively. The Analytical Profile Index 20 Enterobacteriaceae kit (API 20E kit was used to identify Salmonella species. Results: Based on the API 20E kit, the  identified Salmonella species from different water bodies were Salmonella ser. paratyphi A (96.9%, Salmonella cholelaesuis spp choleraesuis (99.5% and Salmonella typhi (99.9%. Conclusion: This study shows that shallow wells and rivers which are mainly used by the city dwellers were highly contaminated with Salmonella and were more contaminated than deep wells and marine water bodies. This warrants further investigation on the disease mapping in the urban and peri-urban areas.

Eliningaya Kweka

2013-01-01

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Skinning the goat and pulling the load: transactional sex among youth in Dar es Salaam, Tanzania.  

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Transactional sex has been associated with risk of HIV infection in a number of studies throughout sub-Saharan Africa. Urban young women are economically vulnerable and at heightened risk of HIV infection in Tanzania; yet there are few studies that have explored relationship dynamics, including transactional sex, in this setting. This paper sheds light on the broader context of sexual relationships among youth at risk for HIV, how transactional sex plays out in these relationships, and how the transactional nature of relationships affects women's risk for HIV. We conducted 60 in depth interviews and 14 focus group discussions with young men and women, 16-24 years old, in Dar es Salaam, Tanzania. These data guided the development of a community based HIV and violence prevention intervention for young men. Youth described the exchange of sex for money or other material goods in all types of sexual relationships. While the exchange was explicit in casual relationships, young women voiced material and monetary expectations from their committed partners as well. Young men described their pursuit of multiple partners as sexually motivated, while women sought multiple partners for economic reasons. Young men were aware of the expectations of material support from partners, and acknowledged that their ability to provide for a partner affected both the longevity and exclusivity of their relationships. Youth described a deep mistrust of the motivations and commitment of their sexual partners. Furthermore, young women's financial dependence on men impacted their ability to negotiate safe sexual behaviors in both casual and committed relationships. Programs designed to reduce HIV risk among Tanzanian youth need to take into account the transactional component of sexual relationships and how such exchanges differ according to partner type. PMID:17851993

Maganja, R K; Maman, S; Groves, A; Mbwambo, J K

2007-09-01

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

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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. PMID:24499337

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

2014-09-01

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Mosquito control in Dar es Salaam. I. Assessment of Culex quinquefasciatus breeding sites prior to intervention.  

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In preparation for a trial polystyrene beads and pyriproxyfen for the control of Culex quinquefasciatus mosquitoes, surveys of their breeding were carried out in two contrasting areas of Dar es Salaam, Mikocheni and Ilala, during the dry season. Sanitation structures (latrines, soakage pits, septic tanks and cess pits) were the most profilic breeding places, totalling 780 in Mikocheni and 1544 in Ilala. Those in Mikocheni were estimated to contain about 1.4 times more mosquito pupae, per site, than in such structures in Ilala. This was both because a higher proportion of sites contained visible water and because sites with water were more likely to contain pupae in Mikocheni. The relative importance of the different types of structure, in terms of productivity, was the same in both areas. Although septic tanks and cess pits made up only 10.5% of the on-site sanitation structures in Ilala, they contained 53% of the total number of pupae in enclosed sites; they were therefore particularly important targets for treatment with polystyrene beads. A survey during the rainy season of sites in Ilala revealed little change in the proportion that were wet, or in the frequency of breeding in those with visible water. The number, type and area of open breeding sites varied greatly between the two study areas. In Mikocheni the area of open breeding sites was 100 times greater than in Ilala, with 97% of the 13,000 m2 being flooded grassland. In Ilala all but four of the sixty-six open breeding sites were puddles of sullage water derived from bathrooms.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7787221

Chavasse, D C; Lines, J D; Ichimori, K; Marijani, J

1995-04-01

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CHARACTERIZATION OF SALMONELLA SPECIES FROM WATER BODIES IN DAR-ES-SALAAM CITY, TANZANIA  

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Full Text Available Background: Water-borne diseases are the most common cause of illness and death among the poor population from developing countries. The majority of the people are inadequately aware that aquatic environment is a major source of salmonellosis. Dar es Salaam city is among the cities with most of its population live in squatter. Typhoid fever ranks second with 14.3% of all notifiable disease cases in the city. The city experience water scarcity which forces water wells and rivers to become the main sources of water for domestic use and livestock. This study therefore, characterized Salmonella strains from different water bodies of city as possible sources for enteric diseases endemicity. Methods: The Salmonella Chromogenic Agar (SC Agar and Kligler Iron Agar (KIA media were used for isolation and enumeration of the strains. The inoculated cultures were incubated at 370C for 24 hours. Salmonella colonies were confirmed by magenta colorations and hydrogen sulfide production on SC Agar and KIA Agar, respectively. The Analytical Profile Index 20 Enterobacteriaceae kit (API 20E kit was used to identify Salmonella species. Results: Based on the API 20E kit, the identified Salmonella species from different water bodies were Salmonella ser. paratyphi A (96.9%, Salmonella cholelaesuis spp choleraesuis (99.5% and Salmonella typhi (99.9%. Conclusion: This study shows that shallow wells and rivers which are mainly used by the city dwellers were highly contaminated with Salmonella and were more contaminated than deep wells and marine water bodies. This warrants further investigation on the disease mapping in the urban and peri-urban areas.

Eliningaya Kweka

2013-03-01

 
 
 
 
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Window screening, ceilings and closed eaves as sustainable ways to control malaria in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Malaria transmission in Africa occurs predominantly inside houses where the primary vectors prefer to feed. Human preference and investment in blocking of specific entry points for mosquitoes into houses was evaluated and compared with known entry point preferences of the mosquitoes themselves. Methods Cross-sectional household surveys were conducted in urban Dar es Salaam, Tanzania to estimate usage levels of available options for house proofing against mosquito entry, namely window screens, ceilings and blocking of eaves. These surveys also enabled evaluation of household expenditure on screens and ceilings and the motivation behind their installation. Results Over three quarters (82.8% of the 579 houses surveyed in Dar es Salaam had window screens, while almost half (48.9% had ceilings. Prevention of mosquito entry was cited as a reason for installation of window screens and ceilings by 91.4% (394/431 and 55.7% (127/228 of respondents, respectively, but prevention of malaria was rarely cited (4.3%, 22/508. The median cost of window screens was between US $ 21-30 while that of ceilings was between US $301-400. The market value of insecticide-treated nets, window screening and ceilings currently in use in the city was estimated as 2, 5 and 42 million US$. More than three quarters of the respondents that lacked them said it was too expensive to install ceilings (82.2% or window screens (75.5%. Conclusion High coverage and spending on screens and ceilings implies that these techniques are highly acceptable and excellent uptake can be achieved in urban settings like Dar es Salaam. Effective models for promotion and subsidization should be developed and evaluated, particularly for installation of ceilings that prevent entry via the eaves, which are the most important entry point for mosquitoes that cause malaria, a variety of neglected tropical diseases and the nuisance which motivates uptake.

Chaki Prosper P

2009-09-01

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Interdependence of domestic malaria prevention measures and mosquito-human interactions in urban Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Successful malaria vector control depends on understanding behavioural interactions between mosquitoes and humans, which are highly setting-specific and may have characteristic features in urban environments. Here mosquito biting patterns in Dar es Salaam, Tanzania are examined and the protection against exposure to malaria transmission that is afforded to residents by using an insecticide-treated net (ITN is estimated. Methods Mosquito biting activity over the course of the night was estimated by human landing catch in 216 houses and 1,064 residents were interviewed to determine usage of protection measures and the proportion of each hour of the night spent sleeping indoors, awake indoors, and outdoors. Results Hourly variations in biting activity by members of the Anopheles gambiae complex were consistent with classical reports but the proportion of these vectors caught outdoors in Dar es Salaam was almost double that of rural Tanzania. Overall, ITNs confer less protection against exophagic vectors in Dar es Salaam than in rural southern Tanzania (59% versus 70%. More alarmingly, a biting activity maximum that precedes 10 pm and much lower levels of ITN protection against exposure (38% were observed for Anopheles arabiensis, a vector of modest importance locally, but which predominates transmission in large parts of Africa. Conclusion In a situation of changing mosquito and human behaviour, ITNs may confer lower, but still useful, levels of personal protection which can be complemented by communal transmission suppression at high coverage. Mosquito-proofing houses appeared to be the intervention of choice amongst residents and further options for preventing outdoor transmission include larviciding and environmental management.

Mshinda Hassan

2007-09-01

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The spectrum of dermatological disorders among primary school children in Dar es Salaam  

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Full Text Available Abstract Background Dermatologic disorders are common in many countries but the spectrum varies greatly. Many studies have reported a significant burden of skin diseases in school children. The objective of this study was to determine the current spectrum of dermatological disorders in primary school children in Dar es Salaam city. Methods Primary school children were recruited by multistage sampling. Detailed interview, dermatological examination and appropriate laboratory investigations were performed. Data was analyzed using the 'Statistical Package for Social Sciences' (SPSS program version 10.0 and EPI6. A p-value of Results A total of 420 children were recruited (51% males; mean age 11.4 ± 2.8 years; range 6-19 years. The overall point prevalence of any skin disorder was 57.3% and it was 61.9% and 52.6% in males and females respectively (p = 0.05. Infectious dermatoses accounted for 30.4% with superficial fungal infections (dermatophytoses and pityriasis versicolor being the commonest (20%. Dermatophytoses were diagnosed in 11.4% (48/420; the prevalence in males and females being 12.6% and 10.1% respectively (p = 0.41 and higher (21.8% in the age-group 6-10 years (p = 0.045. Fungal cultures were positive in 42/48 children (88%. All three dermatophyte genera were isolated. Tinea capitis was the commonest disease among culture-positive dermatophytoses (30/42; 71.4% with an overall prevalence of 7.1% (30/420 followed by tinea pedis (11/42; 26.1% whose overall prevalence was 2.6%. Microsporum canis was common in tinea capitis (14/30; 46.7% followed by Trichophyton violaceum (6/30; 20%. Trichophyton rubrum was common in tinea pedis (5/11; 45.5%. Thirty six children (8.6% had pityriasis versicolor which was more prevalent (6/27; 22.l2% in the age group 16-19 years (p = 0.0004. The other common infectious dermatoses were pyodermas (4% and pediculosis capitis (3.6%. Common non-infectious dermatoses were: acne vulgaris (36.4%, non-specific dermatoses (10.7%, non-specific ulcers (5% and atopic eczema (2.6%. Rare conditions (prevalence Conclusions Skin disorders are common in primary school children; infectious dermatoses are still rampant and many children do not seek medical assistance.

Mgonda Yassin M

2010-12-01

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A first insight into the genetic diversity of Mycobacterium tuberculosis in Dar es Salaam, Tanzania, assessed by spoligotyping  

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Full Text Available Abstract Background Tanzania has a high tuberculosis incidence, and genotyping studies of Mycobacterium tuberculosis in the country are necessary in order to improve our understanding of the epidemic. Spoligotyping is a potentially powerful genotyping method due to fast generation of genotyping results, high reproducibility and low operation costs. The recently constructed SpolDB4 database and the model-based program 'Spotclust' can be used to assign isolates to families, subfamilies and variants. The results of a study can thus be analyzed in a global context. Results One hundred forty-seven pulmonary isolates from consecutive tuberculosis patients in Dar es Salaam were spoligotyped. SpolDB4 and 'Spotclust' were used to assign isolates to families, subfamilies and variants. The CAS (37%, LAM (22% and EAI (17% families were the most abundant. Despite the dominance of these three families, diversity was high due to variation within M. tuberculosis families. Of the obtained spoligopatterns, 64% were previously unrecorded. Conclusion Spoligotyping is useful to gain an overall understanding of the local TB epidemic. This study demonstrates that the extensive TB epidemic in Dar es Salaam, Tanzania is caused by a few successful M. tuberculosis families, dominated by the CAS family. Import of strains was a minor problem.

Mfinanga Sayoki GM

2006-09-01

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Primary antimicrobial resistance among Mycobacterium tuberculosis isolates from HIV seropositive and HIV seronegative patients in Dar es Salaam Tanzania  

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Full Text Available Abstract Background The United Republic of Tanzania is one of the 22 high M. tuberculosis burden countries. Data collected between 2002 and 2007 indicate that the global prevalence of drug-resistant M. tuberculosis including MDR vary greatly. The varied drug-resistance patterns make continuous surveillance of drug resistance an essential component of tuberculosis control program. Findings M. tuberculosis isolates were obtained from consenting adult tuberculosis patients involved in a placebo-controlled study to evaluate the efficacy of multivitamin supplements on response to anti-Tb treatment in Dar es Salaam, Tanzania. Antimicrobial susceptibility testing was done on four antimicrobial agents namely streptomycin, isoniazid, ethambutol and rifampicin. HIV testing and CD4+ T lymphocytes enumeration were also done. A total of 280 M. tuberculosis isolates from 191 (68% males and 89 (32% female patients with no previous history of anti-tuberculosis treatment exceeding 4 weeks in the previous 12 months were tested. Among these, 133 (47% patients were HIV seropositive. Fourteen (5.0% isolates were resistant to any of the anti-tuberculosis drugs. The prevalence of primary resistance was 5.0%, 0.7%, 0.4% and 0% for isoniazid, streptomycin, rifampicin and ethambutol respectively. One isolate (0.4% was MDR, with resistance to isoniazid, streptomycin and rifampicin. Conclusion M. Tb primary resistance rate in a selected population in Dar es Salaam Tanzania is low and efforts should be undertaken to support the Tuberculosis program.

Bosch Ronald

2008-07-01

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A call for parental monitoring to improve condom use among secondary school students in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background The number of people newly infected with human immunodeficiency virus (HIV has been decreasing in sub-Saharan Africa, but prevalence of the infection remains unacceptably high among young people. Despite the alarming pervasiveness of the virus, young people in this region continue to engage in risky sexual behaviors including unprotected sexual intercourse. In developed countries, parents can play important roles in protecting young people from such behaviors, but evidence regarding the impact of parental involvement is still limited in sub-Saharan Africa. Therefore, we conducted this study to examine the magnitude of risky sexual behaviors and the association of parental monitoring and parental communication with condom use at last sexual intercourse among secondary school students in Dar es Salaam, Tanzania. Methods We conducted this cross-sectional study among 2,217 male and female students aged 15 to 24 years from 12 secondary schools in Dar es Salaam. From October to November 2011, we collected data using a self-administered questionnaire. Multiple logistic regression analyses were conducted to examine the association of parental monitoring and parental communication with condom use at last sexual intercourse, adjusting for potential confounders. Results A total of 665 (30.3% secondary school students reported being sexually active within the year prior to data collection. Among them, 41.7% had multiple sexual partners, 10.5% had concurrent sexual partners, and 41.1% did not use a condom at last sexual intercourse. A higher level of parental monitoring was associated with increased likelihood of condom use at last sexual intercourse among male students (AOR: 1.56, 95% CI: 1.05-2.32; p?=?0.03 but not among female students (AOR: 1.54, 95% CI: 0.71-3.37; p?=?0.28. The association between parental communication and condom use at last sexual intercourse among both male and female students was not statistically significant. Conclusions A high level of parental monitoring is associated with more consistent condom use among male students in Dar es Salaam, Tanzania -- many of whom have engaged in high-risk sexual behaviors such as multiple sexual partnerships, concurrent sexual partnerships, and unprotected sexual intercourse in the past one year. Interventions should thus be strengthened to reduce multiple sexual partnerships, concurrent sexual partnerships, and to improve parental monitoring among such students toward increasing condom use.

Mlunde Linda B

2012-12-01

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Community-based surveillance of malaria vector larval habitats: a baseline study in urban Dar es Salaam, Tanzania  

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Full Text Available Abstract Background As the population of Africa rapidly urbanizes it may be possible to protect large populations from malaria by controlling aquatic stages of mosquitoes. Here we present a baseline evaluation of the ability of community members to detect mosquito larval habitats with minimal training and supervision in the first weeks of an operational urban malaria control program. Methods The Urban Malaria Control Programme of Dar es Salaam recruited and provided preliminary training to teams of Community-Owned Resource Persons (CORPs who performed weekly surveys of mosquito breeding sites. Two trained mosquito biologists accompanied each of these teams for one week and evaluated the sensitivity of this system for detecting potential Anopheles habitats. Results Overall, 42.4% of 986 habitats surveyed by an inspection team had previously been identified by CORPs. Agricultural habitats were detected less often than other habitats (30.8% detected, Odds Ratio [95%CI] = 0.46 [0.29–0.73], P = 0.001. Non-agricultural artificial habitats were less suitable than other habitats (29.3% occupancy, OR = 0.69 [0.46–1.03], P = 0.066 but still constituted 45% (169/289 of occupied habitats because of their abundance (51 % of all habitats. Conclusion The levels of coverage achieved by modestly trained and supported CORPs at the start of the Dar es Salaam UMCP were insufficient to enable effective suppression of malaria transmission through larval control. Further operational research is required to develop surveillance systems that are practical, affordable, effective and acceptable so that community-based integrated vector management can be implemented in cities across Africa.

Fillinger Ulrike

2006-06-01

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

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Full Text Available Abstract Background 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. Methods 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. Results 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 , 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 . Conclusion 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.

Sunguya Bruno F

2011-11-01

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Low quality of routine microscopy for malaria at different levels of the health system in Dar es Salaam  

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Full Text Available Abstract Background Laboratory capacity to confirm malaria cases in Tanzania is low and presumptive treatment of malaria is being practiced widely. In malaria endemic areas WHO now recommends systematic laboratory testing when suspecting malaria. Currently, the use of Rapid Diagnostic Tests (RDTs is recommended for the diagnosis of malaria in lower level peripheral facilities, but not in health centres and hospitals. In this study, the following parameters were evaluated: (1 the quality of routine microscopy, and (2 the effects of RDT implementation on the positivity rate of malaria test results at three levels of the health system in Dar es Salaam, Tanzania. Methods During a baseline cross-sectional survey, routine blood slides were randomly picked from 12 urban public health facilities in Dar es Salaam, Tanzania. Sensitivity and specificity of routine slides were assessed against expert microscopy. In March 2007, following training of health workers, RDTs were introduced in nine public health facilities (three hospitals, three health centres and three dispensaries in a near-to-programmatic way, while three control health facilities continued using microscopy. The monthly malaria positivity rates (PR recorded in health statistics registers were collected before (routine microscopy and after (routine RDTs the intervention in all facilities. Results At baseline, 53% of blood slides were reported as positive by the routine laboratories, whereas only 2% were positive by expert microscopy. Sensitivity of routine microscopy was 71.4% and specificity was 47.3%. Positive and negative predictive values were 2.8% and 98.7%, respectively. Median parasitaemia was only three parasites per 200 white blood cells (WBC by routine microscopy compared to 1226 parasites per 200 WBC by expert microscopy. Before RDT implementation, the mean test positivity rates using routine microscopy were 43% in hospitals, 62% in health centres and 58% in dispensaries. After RDT implementation, mean positivity rates using routine RDTs were 6%, 7% and 8%, respectively. The sensitivity and specificity of RDTs using expert microscopy as reference were 97.0% and 96.8%. The positivity rate of routine microscopy remained the same in the three control facilities: 71% before versus 72% after. Two cross-sectional health facility surveys confirmed that the parasite rate in febrile patients was low in Dar es Salaam during both the rainy season (13.6% and the dry season (3.3%. Conclusions The quality of routine microscopy was poor in all health facilities, regardless of their level. Over-diagnosis was massive, with many false positive results reported as very low parasitaemia (1 to 5 parasites per 200 WBC. RDTs should replace microscopy as first-line diagnostic tool for malaria in all settings, especially in hospitals where the potential for saving lives is greatest.

Mtasiwa Deo

2011-11-01

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

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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

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

2013-04-01

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Air pollution in southern Africa: The case of motor vehicle exhaust contribution in Dar Es Salaam city  

International Nuclear Information System (INIS)

The aim of this study was to review air pollution problems in the Southern Africa region and establish the quality of ambient air in Dar Es Salaam city in Tanzania with respect to three vehicular pollutants which are sulphur dioxide (SO2), nitrogen dioxide (NO2) and suspended particulate matters (SPM). These pollutants were measured in eight different locations in Dar-Es Salaam city which are Fire, Morocco, Tazara, Kariakoo, Ubungo, Posta, UCLAS, and Akiba. With the exception of South Africa and Botswana, other countries in the Southern Africa Region which include Tanzania, Mozambique, Malawi. Zambia, Zimbabwe. Angola and Namibia do not have air pollution standards, and regular air pollution monitoring is not carried out in these countries. Diesel fueled vehicles in South Africa are responsible for one third of all smog-forming nitrogen dioxides and almost two-thirds of all particulate pollution emitted by all vehicles. The measurement methods used in Dar Es Salaam study were pararosaniline method for SO2, Saltzman for measuring nitrogen dioxide, and filtration method for suspended particulate matters. The following was observed from the analysis: Hourly sulphur dioxide concentration ranged from 558 -1385 ?g/m3. These measured values were above the recommended WHO guidelines with an hourly objective value of 350 ?g/m3. Hourly nitrogen dioxide concentration was found to range from 18 to 53 ?g/m3. The maximum hourly nitrogen dioxide concentration at 53 ?g/m3 was below the recommended WHO guidelines with a value of 200 ?g/m3. The hourly suspended particulate matter (SPM) was found to range from 744 to 1161 ?g/m3. The measured suspended particulate matter concentrations were above the recommended hourly maximum value by WHO guidelines which is 230?g/m3. The correlation coefficient of pollutants and the number of vehicles counted for different sampling points was determined and found to be fair reasonable with a value of 0.906 for suspended particulate matter (SPM), 0.64 for nitrogen dioxide (NO2) and 0.74 for sulphur dioxide (SO2). Gaussian , model NO2 predictions were comparable to the measured NO2 concentration. The average ratio of model calculated and measured concentrations is 0.60. The correlation coefficient between the measured concentrations and those predicted by the model was found to be 0.6. Remedial measures recommended include development of exhaust pipe emission standards and enforcing them in all countries in the Southern Africa Region. Annual check up of emission levels of SO2 and SPM for motor vehicles is recommended. It is further recommended that imported used vehicles should be tested for emission level prior to their registration, and regular ambient air pollutants levels monitoring activities be introduced in cities and municipalities within the Southern Africa Region for selected gaseous pollutants which should include SO2, NO2, and SPM. (author)

2005-06-01

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Health and Oral Health related knwoledge, attitudes and behaviors - a study of secondary school students in Dar es Salaam, Tanzania. A cross sectional study of 16-20 year old students  

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Aim: To assess the socio-demographic distribution, relationship and levels of health and oral health related knowledge, attitudes and behaviors among secondary school students in Dar-es-Salaam region, Tanzania.

Nyamuryekunge, Kasusu Klint

2012-01-01

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Knowledge among drug dispensers and antimalarial drug prescribing practices in public health facilities in Dar es Salaam  

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Full Text Available Appolinary AR Kamuhabwa,1 Richard Silumbe21Unit of Pharmacology and Therapeutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, 2Pharmacy Council, Dar es Salaam, TanzaniaBackground: Irrational prescribing and dispensing of antimalarials has been identified as a contributing factor in the emergence of malaria parasites resistant to existing antimalarial drugs. Factors that contribute to such irrational prescribing and dispensing should therefore be identified to address this problem. The aim of this study was to assess irrational antimalarial drug dispensing and prescribing practices in public health facilities.Methods: A descriptive-retrospective cross-sectional study was conducted between January and June 2011 in order to assess prescribing and dispensing practices for antimalarial drugs in three public hospitals and nine health centers in Dar es Salaam, Tanzania. Thirty-two drug dispensers were interviewed using a structured questionnaire. A total of 4,320 prescriptions for the period January to December 2010 were collected and assessed for antimalarial drug prescribing patterns.Results: The majority (84.6% of drug dispensers had poor knowledge regarding the basic information required from patients before dispensing artemether-lumefantrine. Seventeen of 32 drug dispensers did not know the basic information that should be given to patients in order to increase absorption of artemether-lumefantrine after oral intake. Most drug dispensers also showed limited knowledge about the dosage and contraindications for artemether-lumefantrine. Eighty-seven percent of all prescriptions contained artemether-lumefantrine as the only antimalarial drug, 77.1% contained at least one analgesic, and 26.9% contained at least one antibiotic, indicating unnecessary use of analgesics and antibiotics with antimalarial drugs. A substantial number of prescriptions contained antimalarial drugs that have already been declared ineffective for the treatment of malaria in Tanzania, providing additional evidence of inadequate knowledge among health care workers concerning treatment policy.Conclusion: Despite the government's efforts to increase public awareness regarding use of artemether-lumefantrine as first-line treatment for uncomplicated malaria, there is still irrational prescribing, dispensing, and use of this combination. Based on the results of this study, it is proposed that regular on-the-job training and continuing education be provided to drug dispensers and prescribers in public health facilities.Keywords: artemether-lumefantrine, drug dispensers, malaria, prescribing, knowledge

Kamuhabwa AA

2013-09-01

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

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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.

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

2008-12-01

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Prevalence of enteropathogenic viruses and molecular characterization of group A rotavirus among children with diarrhea in Dar es Salaam Tanzania  

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Full Text Available Abstract Background Different groups of viruses have been shown to be responsible for acute diarrhea among children during their first few years of life. Epidemiological knowledge of viral agents is critical for the development of effective preventive measures, including vaccines. Methods In this study we determined the prevalence of the four major enteropathogenic viruses – rotavirus, norovirus, adenovirus and astrovirus – was determined in 270 stool samples collected from children aged 0 – 60 months who were admitted with diarrhea in four hospitals in Dar es Salaam, Tanzania, using commercially available ELISA kits. In addition, the molecular epidemiology of group A rotavirus was investigated using reverse transcriptase multiplex polymerase chain reaction (RT-PCR. Results At least one viral agent was detected in 87/270 (32.2% of the children. The prevalence of rotavirus, norovirus, adenovirus and astrovirus was 18.1%, 13.7%, 2.6% and 0.4%, respectively. In most cases (62.1% of viruses were detected in children aged 7–12 months. The G and P types (VP7 and VP4 genotypes respectively were further investigated in 49 rotavirus ELISA positive samples. G9 was the predominant G type (81.6%, followed by G1 (10.2% and G3 (0.2%. P[8] was the predominant P type (83.7%, followed by P[6] (0.4% and P[4] (0.2%. The following G and P types were not detected in this study population; G2, G4, G8 G10, P[9], P[10] and P[11]. The dominating G/P combination was G9P[8], accounting for 39 (90.7% of the 43 fully characterized strains. Three (6.1% of the 49 rotavirus strains could not be typed. Conclusion Nearly one third of children with diarrhea admitted to hospitals in Dar es Salaam had one of the four viral agents. The predominance of rotavirus serotype G9 may have implication for rotavirus vaccination in Tanzania.

Maselle Samwel Y

2007-12-01

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

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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.

2013-01-01

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The Importance of Drains for the Larval Development of Lymphatic Filariasis and Malaria Vectors in Dar es Salaam, United Republic of Tanzania  

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Lymphatic filariasis and malaria are endemic in Dar es Salaam and partially share common vectors, but no synergy exists between their control programs. The vast majority of mosquito breeding habitats in the city is human-made, and therefore could be mitigated through the implementation of a community-based vector control program accompanied by an educational campaign to sensitize the population and promote behavior change. Of particular importance are clogged drains and ditches with stagnant ...

Castro, Marcia C.; Kanamori, Shogo; Kannady, Khadija; Mkude, Sigsbert; Killeen, Gerry F.; Fillinger, Ulrike

2010-01-01

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Monitoring mosquitoes in urban Dar es Salaam: Evaluation of resting boxes, window exit traps, CDC light traps, Ifakara tent traps and human landing catches  

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Abstract Background Ifakara tent traps (ITT) are currently the only sufficiently sensitive, safe, affordable and practical method for routine monitoring host-seeking mosquito densities in Dar es Salaam. However, it is not clear whether ITT catches represent indoors or outdoors biting densities. ITT do not yield samples of resting, fed mosquitoes for blood meal analysis. Methods Outdoors mosquito sampling methods, namely human landing catch (HLC), ITT (Design B) ...

Govella Nicodem J; Chaki Prosper P; Mpangile John M; Killeen Gerry F

2011-01-01

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Achieving high coverage of larval-stage mosquito surveillance: challenges for a community-based mosquito control programme in urban Dar es Salaam, Tanzania  

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Abstract Background Preventing malaria by controlling mosquitoes in their larval stages requires regular sensitive monitoring of vector populations and intervention coverage. The study assessed the effectiveness of operational, community-based larval habitat surveillance systems within the Urban Malaria Control Programme (UMCP) in urban Dar es Salaam, Tanzania. Methods Cross-sectional surveys were carried out to assess the ability of community-owned resource per...

Chaki Prosper P; Govella Nicodem J; Shoo Bryson; Hemed Abdullah; Tanner Marcel; Fillinger Ulrike; Killeen Gerry F

2009-01-01

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

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Abstract 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)...

Chaki Prosper P; Dongus Stefan; Fillinger Ulrike; Kelly Ann; Killeen Gerry F

2011-01-01

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

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Abstract 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)...

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

2008-01-01

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

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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 orpha...

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

2005-01-01

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The Importance of Drains for the Larval Development of Lymphatic Filariasis and Malaria Vectors in Dar es Salaam, United Republic of Tanzania  

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Background: Dar es Salaam has an extensive drain network, mostly with inadequate water flow, blocked by waste, causing flooding after rainfall. The presence of Anopheles and Culex larvae is common, which is likely to impact the transmission of lymphatic filariasis and malaria by the resulting adult mosquito populations. However, the importance of drains as larval habitats remains unknown. Methodology: Data on mosquito larval habitats routinely collected by the Urban Malaria Control Progra...

Kanamori, Shogo; Kannady, Khadija; Mkude, Sigsbert; Killeen, Gerry F.; Fillinger, Ulrike; Konradsen, Flemming; Castro, Marcia C.

2010-01-01

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Balancing collective responsibility, individual opportunities and risks: a qualitative study on how police officers reason around volunteering in an HIV vaccine trial in Dar es Salaam, Tanzania  

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Abstract Background Results from HIV vaccine trials on potential volunteers will contribute to global efforts to develop an HIV vaccine. The purpose of this study among police officers in Dar es Salaam, Tanzania, was to explore the underlying reasons that induce people to enrol in an HIV vaccine trial. Methods We conducted discussions with eight focus groups, containing a total of 66 police officers. The information collected was analyzed using interpretive desc...

Am, Tarimo Edith; Thorson Anna; Kohi Thecla W; Mwami Joachim; Bakari Muhammad; Sandström Eric; Kulane Asli

2010-01-01

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Urban schistosomiasis and soil transmitted helminthiases in young school children in Dar es Salaam and Tanga, Tanzania, after a decade of anthelminthic intervention  

DEFF Research Database (Denmark)

Rapid urbanization in resource poor countries often results in expansion of unplanned settlements with overcrowding and inadequate sanitation. These conditions potentially support transmission of schistosomiasis and soil transmitted helminths (STH), but knowledge on the occurrence, transmission and control of these infections in urban settings is limited. The present study assessed the status of urinary schistosomiasis and STH across two different-sized cities in Tanzania - Dar es Salaam and Tanga - after a decade of anthelminthic intervention. Primary school children were examined for parasite eggs in urine and stool. Questionnaires were administered to the children, and observations were made on the urban environments. The burden of urinary schistosomiasis and STH was found to be low in both cities (overall 1.2% in Dar es Salaam and 0.3% in Tanga for urinary schistosomiasis; overall <1% in Dar es Salaam and 1-2% in Tanga for each STH infection), and the identified cases showed no clear pattern of spatial distribution. The findings indicated that a marked decrease in prevalence of these infections had occurred in the two cities during recent years. The observed promising developments appeared to have been accomplished by implementation of drug based intervention programs, in combination with environmental change (fewer snail habitats) and generally improved levels of hygiene. Continued efforts, including anthelminthic treatment and health education, are important to maintain these positive achievements.

Simonsen, Paul Erik

2014-01-01

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

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Full Text Available Abstract 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.

Tanner Marcel

2005-01-01

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Aetiology of deafness among children at the Buguruni School for the Deaf in Dar es Salaam, Tanzania.  

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To identify the causes of deafness, 354 pupils attending the Buguruni School for the Deaf in Dar es Salaam, Tanzania, were studied. Of these children 205 were boys and 149 were girls, a sex ratio of 1.4:1. The onset of deafness was congenital in 36 (10.2%) and acquired in 318 (89.8%). Among the children with acquired deafness, the cause was unknown in 77 (24.2%); meningitis in 76 (23.9%), ototoxicity in 66 (20.8%), mumps in 53 (16.7%) febrile convulsions in five (1.5%), otitis media in 28 (8.8%) and measles in 13 (4.1%). Among the children with congenital deafness, only ten (27.8%) were identified before the age of 2 years. The findings indicate that most (75.8%) of the causes of acquired deafness are preventable through immunisation, early diagnosis and proper treatment of ear infections and avoidance of prescription of ototoxic drugs. This emphasizes the need for programmes aimed at improving the health services at primary levels of health care which will in turn prevent deafness. PMID:9466225

Minja, B M

1998-01-01

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Prevalence of otitis media, hearing impairment and cerumen impaction among school children in rural and urban Dar es Salaam, Tanzania.  

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Eight hundred and two (802) primary school children in rural and urban Dar es Salaam, Tanzania, were examined to determine the prevalence of otitis media, hearing impairment and cerumen impaction by otoscopy and pure tone audiometry. Ear disease was found in 222 (27.7%) of the children. One hundred and twenty six (15.7%) had cerumen impaction, 70 (8.7%) had sensorineural hearing loss and 21 (2.6%) had chronic suppurative otitis media. Cerumen impaction was found in 20.45% of the rural school children and in 14.8% of the urban school children. This difference in prevalence between the two groups was not statistically significant. The prevalence of chronic suppurative otitis media (COM) was 9.44% among the rural school children and 1.3% among the urban school children, the difference being statistically significant (P < 0.001). Sensorineural hearing impairment was found in 14.1% of the rural school children and in 7.7% of the urban children, this also being statistically significant (P < 0.05). The low prevalence of chronic suppurative otitis media among the urban school children is ascribed to better medical services which facilitate early diagnosis and treatment of acute otitis media. This emphasizes the need to improve the health services in the rural areas so that acute otitis media is diagnosed and treated at the primary level of health care. This will in turn prevent hearing impairment due to chronic suppurative otitis media. PMID:8884404

Minja, B M; Machemba, A

1996-09-01

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Adolescent girls, illegal abortions and "sugar-daddies" in Dar es Salaam: vulnerable victims and active social agents  

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Adolescent girls' early sexual activity, early pregnancy, induced abortions and the increase in HIV infections have become major concerns in Sub-Saharan Africa. Efforts, though, to understand their sexual behaviour and to prevent reproductive health problems are almost non-existent. Adolescent girls are normally seen as victims and easy preys of (often older and married) men's sexual exploitation. This article, which is based on a qualitative study of 51 adolescent girls who had just had an illegal abortion in Dar es Salaam, Tanzania, reveals that these girls are not only victims but also willing preys and active social agents engaging in high-risk sexual behaviour. In order to get material benefits they expose themselves to serious health risks, including induced abortion - without realising their own vulnerability. In our study, one out of four girls had more than one partner at the time they became pregnant, and many counted on an illegally induced abortion if they got pregnant. Even if adolescents are nowallowed free access to family planning information, education and services, our study shows that this remains in the realm of theory rather than practice. Moreover, most adolescent girls are not aware about their right to such services. The paper concludes that the vulnerability of adolescent girls increases without the recognition that sexuality education and contraceptive services do not constitute a licence to practice illicit sex - but rather a means to create more mature and responsible attitudes and to increase sexual and reproductive health.

Silberschmidt, Margrethe; Rasch, V

2001-01-01

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Smear microscopy and culture conversion rates among smear positive pulmonary tuberculosis patients by HIV status in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Tanzania ranks 15th among the world's 22 countries with the largest tuberculosis burden and tuberculosis has continued to be among the major public health problems in the country. Limited data, especially in patients co infected with HIV, are available to predict the duration of time required for a smear positive pulmonary tuberculosis patient to achieve sputum conversion after starting effective treatment. In this study we assessed the sputum smear and culture conversion rates among HIV positive and HIV negative smear positive pulmonary tuberculosis patients in Dar es Salaam Methods The study was a prospective cohort study which lasted for nine months, from April to December 2008 Results A total of 502 smear positive pulmonary tuberculosis patients were recruited. HIV test results were obtained for 498 patients, of which 33.7% were HIV positive. After two weeks of treatment the conversion rate by standard sputum microscopy was higher in HIV positive(72.8% than HIV negative(63.3% patients by univariate analysis(P = 0.046, but not in multivariate analysis. Also after two weeks of treatment the conversion rate by fluorescence microscopy was higher in HIV positive (72.8% than in HIV negative(63.2% patients by univariate analysis (P = 0.043 but not in the multivariate analysis. The conversion rates by both methods during the rest of the treatment period (8, 12, and 20 weeks were not significantly different between HIV positive and HIV negative patients. With regards to culture, the conversion rate during the whole period of the treatment (2, 8, 12 and 20 weeks were not significantly different between HIV positive and HIV negative patients. Conclusion Conversion rates of standard smear microscopy, fluorescence microscopy and culture did not differ between HIV positive and HIV negative pulmonary tuberculosis patients.

Mfinanga Sayoki G

2010-07-01

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Bacteria isolated from bloodstream infections at a tertiary hospital in Dar es Salaam, Tanzania: antimicrobial resistance of isolates  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english OBJECTIVES: A bloodstream infection (BSI) is a life-threatening condition. We studied the causative agents of BSIs and antimicrobial susceptibility patterns of bacterial isolates at Muhimbili National Hospital (MNH) in Dar es Salaam, Tanzania. METHODS: A retrospective analysis of blood culture resul [...] ts obtained at MNH from January 2005 to December 2009 was done. Blood culture isolates judged to be clinically significant and antimicrobial susceptibility results of the bacteria were included. The frequencies and proportions of bacteria isolated and antimicrobial susceptibility results were analysed and compared using Pearson's chi-square test and Fisher's exact test where applicable, or the Mann-Whitney U-test. RESULTS: A total of 13 833 blood cultures were performed. Bacterial pathogens were detected in 1 855 (13.4%), Gram-positive bacteria (1 523; 82.1%) being significantly more prevalent than Gramnegative bacteria (332; 17.9%) (p=0.008). The most common bacterial pathogens isolated were coagulase-negative staphylococci (CoNS) (1 250; 67.4%), S. aureus (245; 13.2%), Escherichia coli (131; 7%) and Klebsiella spp. (130; 7.0%). All bacteria isolated showed high resistance to penicillin G (70.6%), tetracycline (63.8%), cefotaxime (62.5%) and ampicillin (62.3%). Moderate to high resistance was seen against chloramphenicol (45.2%), erythromycin (35.0%), ciprofloxacin (29.3%), co-trimoxazole (25.0%) and gentamicin (23.5%). Of S. aureus isolates, 23.3% were resistant to methicillin. CONCLUSION: CoNS accounted for two-thirds of the bacterial pathogens isolated. High-level resistance was seen to first-line and inexpensive antimicrobial agents. Routine screening for extendedspectrum beta-lactamase production and methicillin resistance among Gram-negative rods and S. aureus from blood cultures should be instituted to monitor spread of multidrug-resistant isolates.

S, Moyo; S, Aboud; M, Kasubi; S Y, Maselle.

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

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Full Text Available Abstract Background 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. Methods 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. Results 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 Anopheles larvae indicated a decline in larval density. In the other drain, lack of proper resources and local commitment limited success. Conclusion 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.

Kannady Khadija

2009-04-01

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

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Full Text Available Abstract 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.

Lindmark Gunilla

2009-03-01

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The Importance of Drains for the Larval Development of Lymphatic Filariasis and Malaria Vectors in Dar es Salaam, United Republic of Tanzania  

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Background Dar es Salaam has an extensive drain network, mostly with inadequate water flow, blocked by waste, causing flooding after rainfall. The presence of Anopheles and Culex larvae is common, which is likely to impact the transmission of lymphatic filariasis and malaria by the resulting adult mosquito populations. However, the importance of drains as larval habitats remains unknown. Methodology Data on mosquito larval habitats routinely collected by the Urban Malaria Control Program (UMCP) and a special drain survey conducted in 2006 were used to obtain a typology of habitats. Focusing on drains, logistic regression was used to evaluate potential factors impacting the presence of mosquito larvae. Spatial variation in the proportion of habitats that contained larvae was assessed through the local Moran's I indicator of spatial association. Principal Findings More than 70% of larval habitats in Dar es Salaam were human-made. Aquatic habitats associated with agriculture had the highest proportion of Anopheles larvae presence and the second highest of Culex larvae presence. However, the majority of aquatic habitats were drains (42%), and therefore, 43% (1,364/3,149) of all culicine and 33% (320/976) of all anopheline positive habitats were drains. Compared with drains where water was flowing at normal velocity, the odds of finding Anopheles and Culex larvae were 8.8 and 6.3 (p<0.001) times larger, respectively, in drains with stagnant water. There was a positive association between vegetation and the presence of mosquito larvae (p<0.001). The proportion of habitats with mosquito larvae was spatially correlated. Conclusion Restoring and maintaining drains in Dar es Salaam has the potential to eliminate more than 40% of all potential mosquito larval habitats that are currently treated with larvicides by the UMCP. The importance of human-made larval habitats for both lymphatic filariasis and malaria vectors underscores the need for a synergy between on-going control efforts of those diseases.

Castro, Marcia C.; Kanamori, Shogo; Kannady, Khadija; Mkude, Sigsbert; Killeen, Gerry F.; Fillinger, Ulrike

2010-01-01

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Investigations on the prevalence of bovine tuberculosis and brucellosis in dairy cattle in Dar es Salaam region and in zebu cattle in Lugoba area, Tanzania.  

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A study between August 1995 and December 1997 included 343 dairy cattle on 20 farms in the Dar es Salaam region and 2289 zebu cattle on 39 bomas in the Lugoba area (coast region). The aim was to establish the prevalence of bovine tuberculosis (Mycobacterium bovis) and bovine brucellosis (Brucella abortus). In the single intradermal tuberculin test (SIT), 0.9% (3/343) of the animals in Dar es Salaam tested positive and 1.2% (4/343) were doubtful. Positive reactors were found in 10% (2/20) of the farms. In the Lugoba area, 0.6% (14/2206) were positive and 6.8% (149/2206) doubtful, positive cases being found in 21% (8/39) of all bomas. In the slow agglutination test (SAT) for B. abortus, 14.1% (48/341) of the serum samples reacted positively in Dar es Salaam and 2.3% (8/341) were doubtful. Positive SAT reactors were identified on 25% (5/20) of the dairy cattle farms. In the Lugoba area, 12.3% (273/2221) proved to be positive SAT reactors and doubtful reactions were observed in 2.9% (64/2221). SAT-positive animals were detected on 87% (34/39) of all bomas. The prevalence in single herds in Dar es Salaam varied from 4.3% to 5.3% for the SIT and from 2.2% to 50% for the SAT. The prevalence in single herds in Lugoba area was between 1.1% and 2.9% for SIT and from 1.4% up to 62.1% for SAT. The two cattle populations differed significantly (p < 0.001) in the prevalence of both bovine tuberculosis and bovine brucellosis. Two cows that were positive reactors were slaughtered and subjected to post-mortem examination, and organ samples were bacteriologically cultured. The occurrence of Mycobacterium tuberculosis was confirmed by polymerase chain reaction (PCR) in both cows. PMID:10907285

Weinhäupl, I; Schöpf, K C; Khaschabi, D; Kapaga, A M; Msami, H M

2000-06-01

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Roadside concentration of gaseous and particulate matter pollutants and risk assessment in Dar-es-Salaam, Tanzania.  

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This study used manual air sampling method to assess the contribution of road traffic to air pollution level in Dar-es-Salaam City, Tanzania. Samples were collected from 11 different sites. Parameters measured were: sulphur dioxide using pararosaniline method, nitrogen dioxide using saltzman method, particulate matter and particulate lead using filtration method and atomic absorption spectrometric method, respectively. Results showed that hourly average sulphur dioxide concentration range from 127 to 1385 microg/m3. The measured values of sulphur dioxide were above the recommended WHO guidelines with an hourly objective value of 350 microg/m3 at 87% of the sampling sites. The hourly average nitrogen dioxide concentration ranged from 18 to 53 microg/m3. The maximum hourly nitrogen dioxide concentration at 53 microg/m3 was below the WHO guideline value of 200 microg/m3. The hourly average suspended particulate matter (SPM) ranged from 98 to 1161 microg/m3, exceeding the recommended value of 230 microg/m3 by WHO at 87% of the sampling sites. The hourly average lead concentration was found to range from 0.60 to 25.6 microg/m3, exceeding again the WHO guideline value of 1.5 microg/m3 at 83% of the sampling sites. Results predicted by Gaussian model when compared with the measured values were found to have a correlation coefficient of 0.8, signifying a good correlation. The risk assessment was undertaken considering the people who spend a significant portion of their time near the roads, such as the Uhuru primary school pupils and the adult population who reside by the roadside. The unit risk realised was 18.2 x 10(-6) for adult population and 2.2 x 10(-6) for pupils, both scenarios showing risk higher than the United Sates of America Environmental Protection Agency (USEPA) acceptable limit of 1 x 10(-6). Considering the magnitude of the problem at hand, this study recommends an introduction of mandatory emission tests of SPM, lead and sulphur dioxide (SO2). The study further recommends the introduction of continuous and/or regular air quality monitoring and the use non-leaded petrol in Tanzania. PMID:15931998

Jackson, Msafiri M

2005-05-01

77

Attitudes, beliefs and norms relating to contraceptive use among young migrant and non-migrant adults in urban Dar es Salaam, Tanzania.  

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The young urban population of Tanzania is growing rapidly, primarily due to rural-urban migration. More information is needed on the challenges facing young adult urban women and men in using family planning (FP). The purpose of this study is to identify perceptions, interpersonal and familial attitudes, and sociocultural norms regarding FP among young adults (18-25 years) in Dar es Salaam, Tanzania, comparing responses by sex, marital status and migration status. We conducted 12 focus groups with young adult men and women (n=74) in Dar es Salaam in December 2009. Participants knew of modern contraceptive methods, but had serious concerns about side effects. Single men and women preferred condoms. Female migrants stated that traditional methods were ineffective, yet commonly used in rural areas. Men's desires for more children frequently led female migrants not to use FP, while many married long-term residents used FP discreetly. Single women sometimes received the support of their parents/boyfriends to access and use contraception. Findings highlight differences in experiences among young adult men and women based on their migrant and marital status at the individual, interpersonal and normative levels. Future efforts to promote FP should engage existing social support systems and cultivate new ones in response to barriers. PMID:24156247

Irani, Laili; Speizer, Ilene; Barrington, Clare

2013-01-01

78

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

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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.

2014-01-01

79

Trace metal pollution and its influence on the community structure of soft bottom molluscs in intertidal areas of the Dar es Salaam coast, Tanzania  

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The influence of trace metal pollution on the community structure of soft bottom molluscs was investigated in intertidal areas of the Dar es Salaam coast. Significant enrichment of As, Mn, Mo, Sb, and Zn in sediments was recorded. Redundancy analysis indicated that trace metal pollution contributed 68% of the variation in community structure. Monte Carlo permutation test showed that As and Sb contributed significantly to variation in species composition. T-value biplots and van Dobben circles showed that the gastropods Acteon fortis, Assiminea ovata, and Littoraria aberrans, were negatively affected by As and Sb, while the bivalve Semele radiata and the gastropod Conus litteratus were only negatively affected by As. Bioaccumulation of As, Cd, Cu, Mo and Zn occurred in the bivalve Mactra ovalina and the gastropod Polinices mammilla. This calls for regular monitoring and management measures.

2012-03-01

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Participatory mapping of target areas to enable operational larval source management to suppress malaria vector mosquitoes in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Half of the population of Africa will soon live in towns and cities where it can be protected from malaria by controlling aquatic stages of mosquitoes. Rigorous but affordable and scaleable methods for mapping and managing mosquito habitats are required to enable effective larval control in urban Africa. Methods A simple community-based mapping procedure that requires no electronic devices in the field was developed to facilitate routine larval surveillance in Dar es Salaam, Tanzania. The mapping procedure included (1 community-based development of sketch maps and (2 verification of sketch maps through technical teams using laminated aerial photographs in the field which were later digitized and analysed using Geographical Information Systems (GIS. Results Three urban wards of Dar es Salaam were comprehensively mapped, covering an area of 16.8 km2. Over thirty percent of this area were not included in preliminary community-based sketch mapping, mostly because they were areas that do not appear on local government residential lists. The use of aerial photographs and basic GIS allowed rapid identification and inclusion of these key areas, as well as more equal distribution of the workload of malaria control field staff. Conclusion The procedure developed enables complete coverage of targeted areas with larval control through comprehensive spatial coverage with community-derived sketch maps. The procedure is practical, affordable, and requires minimal technical skills. This approach can be readily integrated into malaria vector control programmes, scaled up to towns and cities all over Tanzania and adapted to urban settings elsewhere in Africa.

Dongus Stefan

2007-09-01

 
 
 
 
81

Organic liquids storage tanks volatile organic compounds (VOCS) emissions dispersion and risk assessment in developing countries: the case of Dar-es-Salaam City, Tanzania.  

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The emission estimation of nine volatile organic compounds (VOCs) from eight organic liquids storage tanks companies in Dar-es-Salaam City Tanzania has been done by using US EPA standard regulatory storage tanks emission model (TANKS 4.9b). Total VOCs atmospheric emission has been established to be 853.20 metric tones/yr. It has been established further that petrol storage tanks contribute about 87% of total VOCs emitted, while tanks for other refined products and crude oil were emitting 10% and 3% of VOCs respectively. Of the eight sources (companies), the highest emission value from a single source was 233,222.94 kg/yr and the lowest single source emission value was 6881.87 kg/yr. The total VOCs emissions estimated for each of the eight sources were found to be higher than the standard level of 40,000 kg/yr per source for minor source according to US EPA except for two sources, which were emitting VOCs below the standard level. The annual emissions per single source for each of the VOCs were found to be below the US EPA emissions standard which is 2,000 kg/yr in all companies except the emission of hexane from company F1 which was slightly higher than the standard. The type of tanks used seems to significantly influence the emission rate. Vertical fixed roof tanks (VFRT) emit a lot more than externally floating roof tanks (EFRT) and internally floating roof tanks (IFRT). The use of IFRT and EFRT should be encouraged especially for storage of petrol which had highest atmospheric emission contribution. Model predicted atmospheric emissions are less than annual losses measured by companies in all the eight sources. It is possible that there are other routes for losses beside atmospheric emissions. It is therefore important that waste reduction efforts in these companies are directed not only to reducing atmospheric emissions, but also prevention of the spillage and leakage of stored liquid and curbing of the frequently reported illegal siphoning of stored products. Emission rates for benzene, toluene, and xylene were used as input to CALPUFF air dispersion model for the calculation of spatial downwind concentrations from area sources. By using global positioning system (GPS) and geographical information system (GIS) the spatial benzene concentration contributed by organic liquid storage tanks has been mapped for Dar-es-Salaam City. Highest concentrations for all the three toxic pollutants were observed at Kigamboni area, possibly because the area is located at the wind prevailing direction from the locations of the storage tanks. The model predicted concentrations downwind from the sources were below tolerable concentrations by WHO and US-OSHA. The highest 24 hrs averaging time benzene concentration was used for risk assessment in order to determine maximum carcinogenic risk amongst the population exposed at downwind. Established risk for adult and children at 2.9x10(-3) and 1.9x10(-3) respectively, are higher than the acceptable US-EPA risk of 1x10(-6). It is very likely that the actual VOCs concentrations in some urban areas in Tanzania including Dar-es-Salaam City are much higher than the levels reported in this study when other sources such as petrol stations and motor vehicles on the roads are considered. Tanzania Government therefore need to put in place: an air quality policy and legislation, establish air quality guidelines and acquire facilities which will enable the implementation of air quality monitoring and management programmes. PMID:16779602

Jackson, Msafiri M

2006-05-01

82

The burden of co-existing dermatological disorders and their tendency of being overlooked among patients admitted to muhimbili national hospital in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Skin diseases are underestimated and overlooked by most clinicians despite being common in clinical practice. Many patients are hospitalized with co-existing dermatological conditions which may not be detected and managed by the attending physicians. The objective of this study was to determine the burden of co-existing and overlooked dermatological disorders among patients admitted to medical wards of Muhimbili National hospital in Dar es Salaam. Study design and settings A hospital-based descriptive cross-sectional study conducted at Muhimbili National hospital in Dar es Salaam, Tanzania. Methods Patients were consecutively recruited from the medical wards. Detailed interview to obtain clinico-demographic characteristics was followed by a complete physical examination. Dermatological diagnoses were made mainly clinically. Appropriate confirmatory laboratory investigations were performed where necessary. Data was analyzed using the 'Statistical Package for Social Sciences' (SPSS program version 10.0. A p-value of Results Three hundred and ninety patients admitted to medical wards were enrolled into the study of whom, 221(56.7% were females. The mean age was 36.7 ± 17.9 (range 7-84 years. Overall, 232/390 patients (59.5% had co-existing dermatological disorders with 49% (191/390 having one, 9% (36/390 two and 5 patients (1% three. A wide range of co-existing skin diseases was encountered, the most diverse being non-infectious conditions which together accounted for 36.4% (142/390 while infectious dermatoses accounted for 31.5% (123/390. The leading infectious skin diseases were superficial fungal infections accounting for 18%. Pruritic papular eruption of HIV/AIDS (PPE and seborrheic eczema were the most common non-infectious conditions, each accounting for 4.3%. Of the 232/390 patients with dermatological disorders, 191/232 (82.3% and 154/232 (66.3% had been overlooked by their referring and admitting doctors respectively. Conclusion Dermatological disorders are common among patients admitted to medical wards and many are not detected by their referring or admitting physicians. Basic dermatological education should be emphasized to improve knowledge and awareness among clinicians.

Chale Pauline NF

2011-04-01

83

Declining HIV-1 prevalence and incidence among Police Officers - a potential cohort for HIV vaccine trials, in Dar es Salaam, Tanzania  

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Background A safe effective and affordable HIV vaccine is the most cost effective way to prevent HIV infection worldwide. Current studies of HIV prevalence and incidence are needed to determine potentially suitable cohorts for vaccine studies. The prevalence and incidence of HIV-1 infection among the police in Dar es Salaam in 1996 were 13.8% and 19.6/1000 PYAR respectively. This study aimed at determining the current prevalence and incidence of HIV in a police cohort 10 years after a similar study was conducted. Methods Police officers in Dar es Salaam, Tanzania were prospectively enrolled into the study from 2005 and followed-up in an incidence study three years later. HIV infection was determined by two sequential enzyme linked immunosorbent assays (ELISAs) in the prevalence study and discordant results between two ELISAs were resolved by a Western blot assay. Rapid HIV assays (SD Bioline and Determine) were used for the incidence study. Results A total of 1,240 police participated in the HIV prevalence study from August 2005 to November 2008. Of these, 1101 joined the study from August 2005-September 2007 and an additional 139 were recruited between October 2007 to November 2008 while conducting the incidence study. A total of 726 (70%) out of the 1043 eligible police participated in the incidence study. The overall HIV-1 prevalence was 65/1240 (5.2%). Females had a non-statistically significant higher prevalence of HIV infection compared to males 19/253, (7.5%) vs. 46/987 (4.7%) respectively (p?=?0.07). The overall incidence of HIV-1 was 8.4 per 1000 PYAR (95% CI 4.68-14.03), and by gender was 8.8 and 6.9 per 1000 PYAR, among males and females respectively, (p?=?0.82). Conclusions The HIV prevalence and incidence among the studied police has declined over the past 10 years, and therefore this cohort is better suited for phase I/II HIV vaccine studies than for efficacy trials.

2013-01-01

84

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  

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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.

2014-01-01

85

Sanitary inspection of wells using risk-of-contamination scoring indicates a high predictive ability for bacterial faecal pollution in the peri-urban tropical lowlands of Dar es Salaam, Tanzania  

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The sanitary inspection of wells was performed according to World Health Organization (WHO) procedures using risk-of-contamination (ROC) scoring to determine the capacity of ROC scoring to predict bacterial faecal pollution of well water in the peri-urban tropical lowlands of Dar es Salaam, Tanzania. The analysis was based on a selection of wells representing environments with low to high presumptive faecal pollution risk and a multi-parametric data set of bacterial indicators, generating a c...

Mushi, Douglas; Byamukama, Denis; Kirschner, Alexander K. T.; Mach, Robert L.; Brunner, K.; Farnleitner, Andreas H.

2012-01-01

86

The contribution of ineffective urban planning practices to disaster and disaster risks accumulation in urban areas: the case of former Kunduchi quarry site in Dar es Salaam, Tanzania  

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Full Text Available This study examined the link between urban planning practices and disaster risks. The study used the former Kunduchi Quarry Site within the City of Dar es Salaam to demonstrate how laxity in enforcing the laid down planning rules, regulations and procedures facilitates the accumulation and occurrence of disaster risks and disasters in urban areas. This undermines one of the central roles of urban planning, which is to protect the lives of people from disaster risks and disasters. In exploring this, the study specifically focused on understanding the rules, regulations and procedures of planning in Tanzania; the extent to which they are followed and, where they are not followed, their implications for disaster risks and disasters; the coping initiatives adopted by local communities to reduce risks and their level of success or failure; and finally the drawing of lessons and recommendations for disaster risk reduction in urban areas. Strongly emerging from this study is the finding that although planning rules and regulations do exist, they are not enforced. As a result urban communities suffer from disaster risks and disasters caused by unregulated activities. The study analyzed the coping initiatives that urban communities apply to reduce disaster risks in their areas. It noted that, while a range of “coping” responses could be observed, these are not lasting solutions to the disaster risks being faced. Sustainable solutions seem to be known by the local community but they are not adopted for fear of compromising or undermining their existing livelihood strategies.

Benedict F. Malele

2009-04-01

87

An Evaluation of Male Involvement on the Programme for PMTCT of HIV/AIDS: A Case Study of Ilala Municipality in Dar es Salaam, Tanzania  

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Full Text Available Male involvement in the programme on Prevention of Mother to Child Transmission (PMTCT of HIV/AIDS is investigated in Ilala Municipality, Dar es Salaam region in Tanzania. Knowledge, attitude, communication behaviors among partners, awareness, and how they affect the uptake of the PMTCT services are among the factors considered. A sample of 192 study units was used. Structured, administered questionnaires and in-depth interviews were used as data collection instruments. Questions relating to uptake of PMTCT and associated factors such as outlined in theintroduction were asked. Data were analyzed by using SPSS Chi-Square test and logistic regression modules were used in the analysis. Significant relationships between knowledge/attitudes and follow up to the uptake of PMTCT services were observed. The study revealed that communication barriers between pregnant women and their husband/partners are the limiting factors of follow up to uptake and utilization of PMTCT services.Logistic Regression Analysis shows that all the limiting factors of knowledge, attitude, and communication behaviors among partners have had a greater chance of influencing a follow up to the uptake of PMTCT services. HIV/AIDS education aimed at increasing knowledge and PMTCT awareness among clients/partners within the community is still low. Stigmatization is singled out as a matter to be addressed. PMTCT utilization acceptance requires a change of cultural attitude in the community.

RRJ Akarro

2011-01-01

88

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

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Full Text Available Abstract 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.

Massila Mariam

2005-07-01

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The problem of illegally induced abortion: results from a hospital-based study conducted at district level in Dar es Salaam  

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Illegal abortion is known to be a major contributor to maternal mortality. The objective of the study was firstly to identify women with illegally induced abortion, (IA) and to compare them with women admitted with a spontaneous abortion (SA) or receiving antenatal care (AC), and secondly to describe the circumstances which characterized the abortion. The population of this cross-sectional questionnaire study comprised patients from Temeke District Hospital, Dar es Salaam, Tanzania. After an in-depth confidential interview, 603 women with incomplete abortion were divided into two groups: 362 women with IA and 241 with SA. They were compared with 307 AC women. IA women were significantly younger, more often better educated, unmarried, nulliparous and students than AC women. Regarding civil-status, educational level, proportion of nullipara and proportion of students, SA patients were similar to AC women. These results lend support to the assumption that the in-depth confidential interview made it possible to distinguish IA women from SA women.

Rasch, V; Muhammad, H

2000-01-01

90

Balancing collective responsibility, individual opportunities and risks: a qualitative study on how police officers reason around volunteering in an HIV vaccine trial in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Results from HIV vaccine trials on potential volunteers will contribute to global efforts to develop an HIV vaccine. The purpose of this study among police officers in Dar es Salaam, Tanzania, was to explore the underlying reasons that induce people to enrol in an HIV vaccine trial. Methods We conducted discussions with eight focus groups, containing a total of 66 police officers. The information collected was analyzed using interpretive description. Results The results showed that participants were motivated to participate in the trial by altruism, and that the participants experienced some concerns about their participation. They stated that altruism in the fight against HIV infection was the main reason for enrolling in the trial. However, young participants were seriously concerned about a possible loss of close relationships if they enrolled in the HIV vaccine trial. Both men and women feared the effect of the trial on their reproductive biology, and they feared interference with pregnancy norms. They were unsure about risks such as the risks of acquiring HIV infection and of suffering physical harm, and they were unsure of the intentions of the researchers conducting the trial. Further, enrolling in the trial required medical examination, and this led some participants to fear that unknown diseases would be revealed. Other participants, however, saw an opportunity to obtain free health services. Conclusions We have shown that specific fears are important concerns when recruiting volunteers to an HIV vaccine trial. More knowledge is needed to determine participants' views and to ensure that they understand the conduct of the trial and the reasons it is being carried out.

Bakari Muhammad

2010-05-01

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

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Full Text Available Abstract 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.

Govella Nico J

2008-01-01

92

Achieving high coverage of larval-stage mosquito surveillance: challenges for a community-based mosquito control programme in urban Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Preventing malaria by controlling mosquitoes in their larval stages requires regular sensitive monitoring of vector populations and intervention coverage. The study assessed the effectiveness of operational, community-based larval habitat surveillance systems within the Urban Malaria Control Programme (UMCP in urban Dar es Salaam, Tanzania. Methods Cross-sectional surveys were carried out to assess the ability of community-owned resource persons (CORPs to detect mosquito breeding sites and larvae in areas with and without larviciding. Potential environmental and programmatic determinants of habitat detection coverage and detection sensitivity of mosquito larvae were recorded during guided walks with 64 different CORPs to assess the accuracy of data each had collected the previous day. Results CORPs reported the presence of 66.2% of all aquatic habitats (1,963/2,965, but only detected Anopheles larvae in 12.6% (29/230 of habitats that contained them. Detection sensitivity was particularly low for late-stage Anopheles (2.7%, 3/111, the most direct programmatic indicator of malaria vector productivity. Whether a CORP found a wet habitat or not was associated with his/her unfamiliarity with the area (Odds Ratio (OR [95% confidence interval (CI] = 0.16 [0.130, 0.203], P Conclusions Accessibility of habitats in urban settings presents a major challenge because the majority of compounds are fenced for security reasons. Furthermore, CORPs under-reported larvae especially where larvicides were applied. This UMCP system for larval surveillance in cities must be urgently revised to improve access to enclosed compounds and the sensitivity with which habitats are searched for larvae.

Shoo Bryson

2009-12-01

93

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

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Full Text Available Abstract 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.

Black Carolyn

2006-03-01

94

Informal support to first-parents after childbirth: a qualitative study in low-income suburbs of Dar es Salaam, Tanzania  

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Full Text Available Abstract Background In Tanzania, and many sub-Saharan African countries, postpartum health programs have received less attention compared to other maternity care programs and therefore new parents rely on informal support. Knowledge on how informal support is understood by its stakeholders to be able to improve the health in families after childbirth is required. This study aimed to explore discourses on health related informal support to first-time parents after childbirth in low-income suburbs of Dar es Salaam, Tanzania. Methods Thirteen focus group discussions with first-time parents and female and male informal supporters were analysed by discourse analysis. Results The dominant discourse was that after childbirth a first time mother needed and should be provided with support for care of the infant, herself and the household work by the maternal or paternal mother or other close and extended family members. In their absence, neighbours and friends were described as reconstructing informal support. Informal support was provided conditionally, where poor socio-economic status and non-adherence to social norms risked poor support. Support to new fathers was constructed as less prominent, provided mainly by older men and focused on economy and sexual matters. The discourse conveyed stereotypic gender roles with women described as family caretakers and men as final decision-makers and financial providers. The informal supporters regulated the first-time parents' contacts with other sources of support. Conclusions Strong and authoritative informal support networks appear to persist. However, poverty and non-adherence to social norms was understood as resulting in less support. Family health in this context would be improved by capitalising on existing informal support networks while discouraging norms promoting harmful practices and attending to the poorest. Upholding stereotypic notions of femininity and masculinity implies great burden of care for the women and delimited male involvement. Men's involvement in reproductive and child health programmes has the potential for improving family health after childbirth. The discourses conveyed contradicting messages that may be a source of worry and confusion for the new parents. Recognition, respect and raising awareness for different social actors' competencies and limitations can potentially create a health-promoting environment among families after childbirth.

Mbekenga Columba K

2011-11-01

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Seroprevalence of human immunodeficiency virus, hepatitis B and C viruses and syphilis infections among blood donors at the Muhimbili National Hospital in Dar Es Salaam, Tanzania  

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Full Text Available Abstract Background According to the latest Tanzanian National AIDS Control Programme (NACP report a total of 147,271 individuals donated blood during the year 2002. However, blood safety remains an issue of major concern in transfusion medicine in Tanzania where national blood transfusion services and policies, appropriate infrastructure, trained personnel and financial resources are inadequate. Most of the donated blood is screened for HIV alone. Methods We determined among blood donors at Muhimbili National Hospital (MNH, the seroprevalence of human immunodeficiency virus (HIV, hepatitis C virus (HCV, hepatitis B surface antigen (HBsAg and syphilis by donor type, sex and age and to determine association, if any, in the occurrence of the pathogens. The sample included 1599 consecutive donors, 1424(89.1% males and 175 (10.9% females, who donated blood between April 2004 and May, 2005. Most of them 1125 (70.4% were replacement donors and a few 474 (29.6% voluntary donors. Their age (in years ranged from 16 to 69, and most (72.2% were between 20–39 years. Results Two hundred and fifty four (15.9% of the donated blood had serological evidence of infection with at least one pathogen and 28 (1.8% had multiple infections. The current seroprevalence of HIV, HBsAg, HCV and syphilis among blood donors at MNH in Dar es Salaam was found to be 3.8%, 8.8%, 1.5% and 4.7%, respectively. Respective seroprevalences among HIV seronegative blood donors were 8.7% for HBV, 1.6% for HCV and 4.6% for syphilis. The differences in the prevalence of HIV and syphilis infections between replacement and voluntary donors were statistically significant (P 2 = 58.5 df = 5, P Conclusion The high (15.9% seroprevalence of blood-borne infections in blood donated at MNH calls for routine screening of blood donors for HBV, HCV, HIV and syphilis and for strict selection criteria of donors, with emphasis on getting young voluntary donors and for establishment of strict guidelines for blood transfusions.

Lyamuya Eligius F

2006-01-01

96

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  

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Background 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. Methods and Results 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 (?2) 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 (?2?=?8.72; P<0.001). Most of the comments were associated with discrimination (?2?=?26.72; P<0.001), stigma (?2?=?6.06; P<0.05), and mistrust towards the HIV vaccine trial (?2?=?4.9; P<0.05). Having a regular sexual partner other than spouse or cohabitant declined over the two follow-up periods (?2?=?4.45; P<0.05). Conclusion 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.

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

2014-01-01

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"For someone who's rich, it's not a problem". Insights from Tanzania on diabetes health-seeking and medical pluralism among Dar es Salaam's urban poor  

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Abstract The prevalence of chronic non-communicable disease, such as type 2 diabetes mellitus (T2DM), is rising worldwide. In Africa, T2DM is primarily affecting those living in urban areas and increasingly affecting the poor. Diabetes management among urban poor is an area of research that has received little attention. Based on ethnographic fieldwork in Dar es Salam, the causes and conditions for diabetes management in Tanzania have been examined. In this paper, we focus on the st...

2010-01-01

98

"For someone who's rich, it's not a problem". Insights from Tanzania on Diabetes Health-Seeking and Medical Pluralism among Dar es Salaam's Urban Poor.  

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The prevalence of chronic non-communicable disease, such as type 2 diabetes mellitus (T2DM), is rising worldwide. In Africa, T2DM is primarily affecting those living in urban areas and increasingly affecting the poor. Diabetes management among urban poor is an area of research that has received little attention. Based on ethnographic fieldwork in Dar es Salam, the causes and conditions for diabetes management in Tanzania have been examined. In this paper, we focus on the structural context of...

2010-01-01

99

"For someone who's rich, it's not a problem". Insights from Tanzania on diabetes health-seeking and medical pluralism among Dar es Salaam's urban poor  

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The prevalence of chronic non-communicable disease, such as type 2 diabetes mellitus (T2DM), is rising worldwide. In Africa, T2DM is primarily affecting those living in urban areas and increasingly affecting the poor. Diabetes management among urban poor is an area of research that has received little attention. Based on ethnographic fieldwork in Dar es Salam, the causes and conditions for diabetes management in Tanzania have been examined. In this paper, we focus on the structural context of...

2010-01-01

100

Seroprevalence of hepatitis B and C viral co-infections among children infected with human immunodeficiency virus attending the paediatric HIV care and treatment center at Muhimbili National Hospital in Dar-es-Salaam, Tanzania  

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Full Text Available Abstract Background With increased availability of antibiotics and antifungal agents hepatitis B virus (HBV and hepatitis C virus (HCV infections are becoming a cause for significant concern in HIV infected children. We determined the seroprevalence and risk factors for HBV and HCV among HIV infected children aged 18 months to 17 years, attending the Paediatric HIV Care and Treatment Center (CTC at Muhimbili National Hospital (MNH in Dar-es-Salaam, Tanzania. Methods Investigations included; interviews, physical examination and serology for HBsAg, IgG antibodies to HCV and alanine aminotransferase (ALT levels. HIV serostatus and CD4 counts were obtained from patient records. Results 167 HIV infected children, 88(52.7% males and 79(47.3% females were enrolled. The overall prevalence of hepatitis co-infection was 15%, with the seroprevalence of HBV and HCV being 1.2% and 13.8%, respectively. Hepatitis virus co-infection was not associated with any of the investigated risk factors and there was no association between HBV and HCV. Elevated ALT was associated with hepatitis viral co-infection but not with ART usage or immune status. Conclusion The high seroprevalence (15% of hepatitis co-infection in HIV infected children attending the Paediatrics HIV CTC at the MNH calls for routine screening of hepatitis viral co-infection and modification in the management of HIV infected children.

Munubhi Emmanuel K

2007-11-01

 
 
 
 
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The perceptions on male circumcision as a preventive measure against HIV infection and considerations in scaling up of the services: a qualitative study among police officers in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background In recent randomized controlled trials, male circumcision has been proven to complement the available biomedical interventions in decreasing HIV transmission from infected women to uninfected men. Consequently, Tanzania is striving to scale-up safe medical male circumcision to reduce HIV transmission. However, there is a need to investigate the perceptions of male circumcision in Tanzania using specific populations. The purpose of the present study was to assess the perceptions of male circumcision in a cohort of police officers that also served as a source of volunteers for a phase I/II HIV vaccine (HIVIS-03 trial in Dar es Salaam, Tanzania. Methods In-depth interviews with 24 men and 10 women were conducted. Content analysis informed by the socio-ecological model was used to analyze the data. Results Informants perceived male circumcision as a health-promoting practice that may prevent HIV transmission and other sexually transmitted infections. They reported male circumcision promotes sexual pleasure, confidence and hygiene or sexual cleanliness. They added that it is a religious ritual and a cultural practice that enhances the recognition of manhood in the community. However, informants were concerned about the cost involved in male circumcision and cleanliness of instruments used in medical and traditional male circumcision. They also expressed confusion about the shame of undergoing circumcision at an advanced age and pain that could emanate after circumcision. The participants advocated for health policies that promote medical male circumcision at childhood, specifically along with the vaccination program. Conclusions The perceived benefit of male circumcision as a preventive strategy to HIV and other sexually transmitted infections is important. However, there is a need to ensure that male circumcision is conducted under hygienic conditions. Integrating male circumcision service in the routine childhood vaccination program may increase its coverage at early childhood. The findings from this investigation provide contextual understanding that may assist in scaling-up male circumcision in Tanzania.

Tarimo Edith AM

2012-07-01

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Breastfeeding ans sexuality after childbirth in Dar es Salaam, Tanzania  

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Background: Kubemenda is a word in Kiswahili and a conception that the infants? health will be negatively affected if the mother has sexual intercourse during the breastfeeding period. Aim: The aim of this study is to explore if nurses experience concerns among parents about sexuality during the breastfeeding period related to kubemenda. Furthermore, to investigate the nurses own perception and knowledge about kubemenda and if general information is given to the parents about breastfeeding...

Hansen, Ruby; Hormaza?bal Contreras, Anahi?

2012-01-01

103

Visualising improvement and innovation potential : the case of sustainable building in Dar es Salaam  

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BackgroundResearch shows that building supply chains in many countries could account for as much as 40% of the man made carbon emissions. Most building growth is taking place in Third World countries. Concrete is the most widely used building material. In many countries, as for example in Tanzania concrete blocks are the most widely used building material. Cement is the most expensive component and also has the highest carbon footprint. Earlier research indicates that there is a sub...

2012-01-01

104

Masculine attitudes of superiority deter men from accessing antiretroviral therapy in Dar es Salaam, Tanzania  

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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. ...

Nyamhanga, Tumaini M.; Muhondwa, Eustace P. Y.; Rose Shayo

2013-01-01

105

Drug use in pregnancy: Knowledge of drug dispensers and pregnant women in Dar es Salaam, Tanzania  

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More than 90% of pregnant women take prescription or non-prescription drugs at some time during pregnancy. In general, unless absolutely necessary, drugs should not be used during pregnancy because many of them are harmful to the fetus. Appropriate dispensing is one of the steps for rational drug use; so, it is necessary that drug dispensers should have relevant and updated knowledge and skills regarding drug use in pregnancy. To assess the knowledge of drug dispensers and pregnant women rega...

Kamuhabwa, Appolinary; Jalal, Rashida

2011-01-01

106

Child trafficking in Tanzania:Experiences of Trafficked Girls in Dar es Salaam  

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This study focuses on the experiences of trafficked children in Tanzania. Trafficking of children deprives them of human rights and freedoms; it may also pose a public health risk. Migration of children who are fostered by extended family is a long-standing customary practice in Tanzania, but while the circumstances of fostering have changed, given increasing rural poverty and the impact of the HIV/AIDS, this has not been recognized in Tanzanian society. The government enacted the Anti-Traffi...

2011-01-01

107

Child trafficking in Tanzania: Experiences of Trafficked Girls in Dar es Salaam  

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This study focuses on the experiences of trafficked children in Tanzania. Trafficking of children deprives them of human rights and freedoms; it may also pose a public health risk. Migration of children who are fostered by extended family is a long-standing customary practice in Tanzania, but while the circumstances of fostering have changed, given increasing rural poverty and the impact of the HIV/AIDS, this has not been recognized in Tanzanian society. The government enacted the Anti-Traffi...

2011-01-01

108

Antimicrobial Activity of Medicated Soaps Commonly Used By Dar es Salaam Residents in Tanzania.  

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An in vitro evaluation of the anti-microbial activity of medicated soaps was conducted using ditch-plate and hand washing techniques. Strains of reference microbes namely Candida albicans (ATCC90028), Staphylococcus aureus (ATCC25923), Pseudomonas aureginosa (ATCC27853) and Escherichia coli (ATCC25922) were tested at three different soaps' concentrations (1.0, 4.0 and 8.0 mg/ml). A total of 16 medicated soaps were assayed for their antimicrobial efficacy. Of these, 13 were medicated and 3 non-medicated soaps, which served as control. Ciprofloxacin and ketaconazole were employed as positive controls. Label disclosure for the soaps' ingredients and other relevant information were absorbed. The most common antimicrobial active ingredients were triclosan, trichloroxylenol and trichlorocarbanilide. ANOVA for means of zones of inhibition revealed variability of antimicrobial activity among the medicated soaps. Positive correlation (r=0.318; Psoaps' concentrations was evidenced. Hand washing frequencies positively correlated with microbial counts. Roberts(®) soap exhibited the largest zone of inhibition (34 mm) on S. aureus. Candida albicans was the least susceptible microbe. Regency(®) and Dalan(®) exhibited the least zone of inhibition on the tested bacteria. Protex(®), Roberts(®), Family(®) and Protector(®) were equally effective (Psoaps have satisfactory antibacterial activity; though lack antifungal effect with exception of Linda(®) liquid soap. The hand washing technique has proved to be inappropriate for evaluation of soaps' antimicrobial efficacy due to presence of the skin microflora. PMID:22131630

Mwambete, K D; Lyombe, F

2011-01-01

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Antimicrobial Activity of Medicated Soaps Commonly Used By Dar es Salaam Residents in Tanzania  

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An in vitro evaluation of the anti-microbial activity of medicated soaps was conducted using ditch-plate and hand washing techniques. Strains of reference microbes namely Candida albicans (ATCC90028), Staphylococcus aureus (ATCC25923), Pseudomonas aureginosa (ATCC27853) and Escherichia coli (ATCC25922) were tested at three different soaps’ concentrations (1.0, 4.0 and 8.0 mg/ml). A total of 16 medicated soaps were assayed for their antimicrobial efficacy. Of these, 13 were medicated and 3 n...

2011-01-01

110

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

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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. PMID:20737827

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

2010-01-01

111

Introduction of a qualitative perinatal audit at Muhimbili National Hospital, Dar es Salaam, Tanzania  

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BACKGROUND: Perinatal death is a devastating experience for the mother and of concern in clinical practice. Regular perinatal audit may identify suboptimal care related to perinatal deaths and thus appropriate measures for its reduction. The aim of this study was to perform a qualitative perinatal audit of intrapartum and early neonatal deaths and propose means of reducing the perinatal mortality rate (PMR). METHODS: From 1st August, 2007 to 31st December, 2007 we conducted an audit of perina...

Kidanto, Hussein L.; Mogren, Ingrid; Roosmalen, Jos; Thomas, Angela N.; Massawe, Siriel N.; Nystro?m, Lennarth; Lindmark, Gunilla

2009-01-01

112

Introduction of a qualitative perinatal audit at Muhimbili National Hospital, Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Perinatal death is a devastating experience for the mother and of concern in clinical practice. Regular perinatal audit may identify suboptimal care related to perinatal deaths and thus appropriate measures for its reduction. The aim of this study was to perform a qualitative perinatal audit of intrapartum and early neonatal deaths and propose means of reducing the perinatal mortality rate (PMR. Methods From 1st August, 2007 to 31st December, 2007 we conducted an audit of perinatal deaths (n = 133 with birth weight 1500 g or more at Muhimbili National Hospital (MNH. The audit was done by three obstetricians, two external and one internal auditors. Each auditor independently evaluated the cases narratives. Suboptimal factors were identified in the antepartum, intrapartum and early neonatal period and classified into three levels of delay (community, infrastructure and health care. The contribution of each suboptimal factor to adverse perinatal outcome was identified and the case graded according to possible avoidability. Degree of agreement between auditors was assessed by the kappa coefficient. Results The PMR was 92 per 1000 total births. Suboptimal factors were identified in 80% of audited cases and half of suboptimal factors were found to be the likely cause of adverse perinatal outcome and were preventable. Poor foetal heart monitoring during labour was indirectly associated with over 40% of perinatal death. There was a poor to fair agreement between external and internal auditors. Conclusion There are significant areas of care that need improvement. Poor monitoring during labour was a major cause of avoidable perinatal mortality. This type of audit was a good starting point for quality assurance at MNH. Regular perinatal audits to identify avoidable causes of perinatal deaths with feed back to the staff may be a useful strategy to reduce perinatal mortality.

Thomas Angela N

2009-09-01

113

Preliminary investigation into the elemental profile of ambient particulate matter in Dar Es Salam, Tanzania as determined by high-energy polarized edxrf  

International Nuclear Information System (INIS)

The elemental concentration profile of particulate matter in the troposphere from the coast of Dar Es Salaam towards the inland in Tanzania was investigated. Particulates were collected from two sites by using a 0.4 ?m Nuclepore membrane filter in a single stage impactor, aligned at intervals of 0 km and 20 km from the coast line, for bulk analysis. The particulates were collected during the dry and rainy season between September 2004 and January 2005. The concentration of 20 elements (Si. K, Ca, Ti, V, Fe, Se, Sr, Cr, Ni, Mn, Cu, Zn, As, Cd, Ph, Sb, Al, S and Ci) from two sites were determined using high-energy polarised Energy Dispersive ?ray Fluorescence (EDXRF). Concentrations ranged between 2 ngm-3 and 3640 ngm-3. Possible sources for 20 elements were identified with specific focus on marine originated elements, by comparison of the results obtained with that available in open literature. Away from the coast, a gradual decrease in marine element concentration was observed 3640 ngm-3 to 2237 ngm-3. Weather conditions (micro-climate) information during sampling days were obtained from the Tanzania Meteorological Agency (TMA) and considered as a representatives of required site meteorological parameters. From the results, it was also noted that wind speed and direction influence the elemental particulate concentrations on the various sites.(Author)

2006-01-01

114

The extension of Ubungo power plant in Dar es Salaam, Tanzania, to a combined cycle - A prestudy  

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The report deals with the consequences concerning a future extension of Ubungo Power Plant. Today the power plant consists of four gas turbines, two of model General Electric LM6000 and two of model ABB Stal GT10 of which the latter were the ones focused on. In the report four different applications are presented; Simple two pressure system, Two pressure system with reheat, Two pressure system with heat exchange between feedwater and condensate, and single pressure system with an additional evaporating loop. The calculations are divided into three sections; thermodynamic calculations, calculations of the heat exchanger surface areas, and economic calculations. From the thermodynamic calculations the applications with the highest thermal efficiency was selected. The power output increased with about 55% and the thermal efficiency of the complete combined cycle is 48.2%. This is, of course, a theoretical value calculated without consideration to a number of losses that will decrease both the power output and the thermal efficiency. At part load (50% load assumed, i.e. one gas turbine is operating) the thermal efficiency is 46.7%. The economic calculations indicated that the extension is highly worthwhile in an economic point of view; both cases studied have a payback time of less than six years for full load operation, provided that the charging system which is to be imposed by the World Bank has come into force. 18 refs, 33 figs

Grinneland, L.; Oehrstroem, K.

1996-05-01

115

Nurse's recommendations to HIV positive mothers about breastfeeding : A qualitative study performed in Dar es Salaam, Tanzania  

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AIM: The aim of this study was to a) find out which recommendations are given by nurses regarding breastfeeding to HIV infected mothers, at Muhimbili hospital and the adherence of these, and (b) to find out the nurses’ opinions regarding the WHO recommendations and the parents’ adherence to these. The study will also look into if the nurses are aware of any changes in knowledge among the parents in an HIV context.METHOD: There were eight semi-structured interviews with open ended question...

2011-01-01

116

Barriers to and drivers for change : analysing causes for improvement potential in the building supply system in Dar es Salaam  

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Business excellence needs constant reinvention with current challenges being such as how to integrate Learnability, Innovability and Sustainability. This paper looks at learning based on Innovation Action Research with focus on process innovation with the purpose of highlighting sustainability challenges in business core processes. A system based process model in combination with sustainability indicators is used to describe a value network and the existing potential for improved sustainabili...

Isaksson, Raine; Hallencreutz, Jacob; Taylor, Neil

2010-01-01

117

Implementation of the National Environment Policy:A case of the Local Government Authorities in Dar Es Salaam City- Tanzania  

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The government of Tanzania, with the support of a wide range of donors is implementing Local Government Reform Programmes. The three municipal councils of Ilala, Temeke and Kinondoni are among the Local government institutions in the 1st phase of the programme. The programme is one of the decentralized measures to improve service delivery at the local level, which includes management of the environment. The programmes are aimed at replacing the former control and command system of central gov...

Mruma, Rosemary Oswald

2005-01-01

118

Community response to artemisinin-based combination therapy for childhood malaria: a case study from Dar es Salaam, Tanzania  

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Abstract Background New malaria treatment guidelines in Tanzania have led to the large-scale deployment of artemether-lumefantrine (Coartem®), popularly known as ALu or dawa mseto. Very little is known about how people in malaria endemic areas interpret policy makers' decision to replace existing anti-malarials, such as sulphadoxine-pyrimethamine (SP) with "new" treatment regimens, such as ALu or other formulations of ACT. This study was conducted...

2010-01-01

119

Community response to artemisinin-based combination therapy for childhood malaria: a case study from Dar es Salaam, Tanzania  

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Full Text Available Abstract Background New malaria treatment guidelines in Tanzania have led to the large-scale deployment of artemether-lumefantrine (Coartem®, popularly known as ALu or dawa mseto. Very little is known about how people in malaria endemic areas interpret policy makers' decision to replace existing anti-malarials, such as sulphadoxine-pyrimethamine (SP with "new" treatment regimens, such as ALu or other formulations of ACT. This study was conducted to examine community level understandings and interpretations of ALu's efficacy and side-effects. The paper specifically examines the perceived efficacy of ALu as articulated by the mothers of young children diagnosed with malaria and prescribed ALu. Methods Participant observation, six focus group discussions in two large villages, followed by interviews with a random sample of 110 mothers of children less than five years of age, who were diagnosed with malaria and prescribed ALu. Additionally, observations were conducted in two village dispensaries involving interactions between mothers/caretakers and health care providers. Results While more than two-thirds of the mothers had an overall negative disposition toward SP, 97.5% of them spoke favourably about ALu, emphasizing it's ability to help their children to rapidly recover from malaria, without undesirable side-effects. 62.5% of the mothers reported that they were spending less money dealing with malaria than previously when their child was treated with SP. 88% of the mothers had waited for 48 hours or more after the onset of fever before taking their child to the dispensary. Mothers' knowledge and reporting of ALu's dosage was, in many cases, inconsistent with the recommended dosage schedule for children. Conclusion Deployment of ALu has significantly changed community level perceptions of anti-malarial treatment. However, mothers continue to delay seeking care before accessing ALu, limiting the impact of highly subsidized rollout of the drug. Implementation of ACT-based treatment guidelines must be complemented with educational campaigns to insure that mothers seek prompt help for their children within 24 hours of the onset of fever. Improved communication between health care providers and mothers of sick children can facilitate better adherence to ALu's recommended dosage. Community level interpretations of anti-malarials are multifaceted; integrating knowledge of local beliefs and practices surrounding consumption of anti-malarials into programmatic goals can help to significantly improve malaria control interventions.

Nyato Daniel J

2010-02-01

120

Medium and long-term adherence to postabortion contraception among women having experienced unsafe abortion in Dar es Salaam, Tanzania  

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BACKGROUND: Postabortion contraceptive service is considered an effective means in addressing the problem of unsafe abortion; in spite this fact this component remains one of the weakest parts of postabortion care. In this context, the paper aims to describe the impact of a postabortion contraceptive service intervention among women admitted with complications from unsafe abortions and to explore the women's long-term contraceptive adherence. METHODS: 392 women having experienced unsafe abortion were identified by an empathetic approach and offered postabortion contraceptive service, which included counselling on HIV and condom use. Questionnaire interviews about contraceptive use were conducted at the time of inclusion and 12 months after the abortion. Additionally, in-depth interviews were performed 6-12 months after the abortion. RESULTS: Eighty-nine percent of the women accepted postabortion contraception. Follow-up information was obtained 12 months after the abortion among 59 percent of the women. Amongthese, 79 percent of the married women and 84 percent of the single women stated they were using contraception at 12 months. Condom use among the single women increased significantly during the 12 months follow up. CONCLUSION: Postabortion contraceptive services appear to be well accepted by women who are admitted with complications after an unsafe abortion and should thus be recognized as an important means in addressing the problem of unsafe abortion. In addition, counselling about HIV and condom use should be considered an essential aspect of postabortion care.

Rasch, Vibeke; Yambesi, Fortunata

2008-01-01

 
 
 
 
121

Impact of Community-Based Larviciding on the Prevalence of Malaria Infection in Dar es Salaam, Tanzania  

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Background: The use of larval source management is not prioritized by contemporary malaria control programs in sub-Saharan Africa despite historical success. Larviciding, in particular, could be effective in urban areas where transmission is focal and accessibility to Anopheles breeding habitats is generally easier than in rural settings. The objective of this study is to assess the effectiveness of a community-based microbial larviciding intervention to reduce the prevalence of malaria infec...

Maheu-giroux, Mathieu; Castro, Marcia C.

2013-01-01

122

Motivations and Deterrents to Take Part in an HIV Vaccine Trial: Experiences from Study Participants in Dar es Salaam, Tanzania  

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Background: As HIV infection continues to be a public health problem, development of an effective preventive HIV vaccine is a priority. For the ultimate development of an AIDS vaccine, clinical trials are being conducted throughout the world. However, the process of developing the vaccine does not only depend on identification of suitable trial candidates, but also requires knowledge of incentives to participate in the community where the trial is being conducted. Therefore, the studies prese...

Tarimo, Edith Andrew Mroso

2011-01-01

123

Evaluation of simple rapid HIV assays and development of national rapid HIV test algorithms in Dar es Salaam, Tanzania  

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Abstract Background Suitable algorithms based on a combination of two or more simple rapid HIV assays have been shown to have a diagnostic accuracy comparable to double enzyme-linked immunosorbent assay (ELISA) or double ELISA with Western Blot strategies. The aims of this study were to evaluate the performance of five simple rapid HIV assays using whole blood samples from HIV-infected patients, pregnant women, voluntary counseling and testing attendees and blood donors, and ...

Lyamuya Eligius F; Aboud Said; Urassa Willy K; Sufi Jaffer; Mbwana Judica; Ndugulile Faustin; Massambu Charles

2009-01-01

124

Evaluation of simple rapid HIV assays and development of national rapid HIV test algorithms in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Suitable algorithms based on a combination of two or more simple rapid HIV assays have been shown to have a diagnostic accuracy comparable to double enzyme-linked immunosorbent assay (ELISA or double ELISA with Western Blot strategies. The aims of this study were to evaluate the performance of five simple rapid HIV assays using whole blood samples from HIV-infected patients, pregnant women, voluntary counseling and testing attendees and blood donors, and to formulate an alternative confirmatory strategy based on rapid HIV testing algorithms suitable for use in Tanzania. Methods Five rapid HIV assays: Determine™ HIV-1/2 (Inverness Medical, SD Bioline HIV 1/2 3.0 (Standard Diagnostics Inc., First Response HIV Card 1–2.0 (PMC Medical India Pvt Ltd, HIV1/2 Stat-Pak Dipstick (Chembio Diagnostic System, Inc and Uni-Gold™ HIV-1/2 (Trinity Biotech were evaluated between June and September 2006 using 1433 whole blood samples from hospital patients, pregnant women, voluntary counseling and testing attendees and blood donors. All samples that were reactive on all or any of the five rapid assays and 10% of non-reactive samples were tested on a confirmatory Inno-Lia HIV I/II immunoblot assay (Immunogenetics. Results Three hundred and ninety samples were confirmed HIV-1 antibody positive, while 1043 were HIV negative. The sensitivity at initial testing of Determine, SD Bioline and Uni-Gold™ was 100% (95% CI; 99.1–100 while First Response and Stat-Pak had sensitivity of 99.5% (95% CI; 98.2–99.9 and 97.7% (95% CI; 95.7–98.9, respectively, which increased to 100% (95% CI; 99.1–100 on repeat testing. The initial specificity of the Uni-Gold™ assay was 100% (95% CI; 99.6–100 while specificities were 99.6% (95% CI; 99–99.9, 99.4% (95% CI; 98.8–99.7, 99.6% (95% CI; 99–99.9 and 99.8% (95% CI; 99.3–99.9 for Determine, SD Bioline, First Response and Stat-Pak assays, respectively. There was no any sample which was concordantly false positive in Uni-Gold™, Determine and SD Bioline assays. Conclusion An alternative confirmatory HIV testing strategy based on initial testing on either SD Bioline or Determine assays followed by testing of reactive samples on the Determine or SD Bioline gave 100% sensitivity (95% CI; 99.1–100 and 100% specificity (95% CI; 96–99.1 with Uni-Gold™ as tiebreaker for discordant results.

Mbwana Judica

2009-02-01

125

Reported heterosexual intercourse and related behaviours among primary school pupils in Kinondoni district, Dar es Salaam, Tanzania.  

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A cross-sectional questionnaire survey was conducted among 2820 pupils in 22 randomly selected primary schools in Kinondoni district, Tanzania. The objective was to identify the proportion of pupils who reported ever having had sexual intercourse, as well as sociodemographic and psychosocial factors and other sexual-related behaviours associated with heterosexual intercourse among pupils. About 13% (376) of participating pupils reported having had heterosexual intercourse. The proportion of pupils who reported doing so varied significantly by age, sex, school grade and parents' education. Regarding psychosocial factors, pupils who agreed that having sexual intercourse implies love for a partner and that sexual intercourse creates peer approval were significantly more likely to report having had heterosexual intercourse. Pupils who reported having a girl/boy friend, kissed a boy/girl, engaged in light petting, engaged in heavy petting or practised oral sex and anal sex were more likely to report ever having heterosexual intercourse. The implications for programme and intervention development are discussed. PMID:23140465

Kakoko, Deodatus C V

2013-01-01

126

Neonatal sepsis at Muhimbili National Hospital, Dar es Salaam, Tanzania; aetiology, antimicrobial sensitivity pattern and clinical outcome  

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Full Text Available Abstract Background Neonatal sepsis contributes significantly to morbidity and mortality among young infants. The aetiological agents as well as their susceptibility to antimicrobial agents are dynamic. This study determined aetiology, antimicrobial susceptibility and clinical outcome of neonatal sepsis at Muhimbili National Hospital. Methods Three hundred and thirty neonates admitted at the Muhimbili National Hospital neonatal ward between October, 2009 and January, 2010 were recruited. Standardized questionnaires were used to obtain demographic and clinical information. Blood and pus samples were cultured on MacConkey, blood and chocolate agars and bacteria were identified based on characteristic morphology, gram stain appearance and standard commercially prepared biochemical tests. Antimicrobial sensitivity testing was performed for ampicillin, cloxacillin, gentamicin, amikacin, cefuroxime and ceftriaxone on Mueller Hinton agar using the Kirby Bauer diffusion method. Results Culture proven sepsis was noted in 24% (74/330 of the study participants. Isolated bacterial pathogens were predominantly Staphylococcus aureus, Klebsiella spp and Escherichia coli. Klebsiella spp 32.7% (17/52 was the predominant blood culture isolate in neonates aged below seven days while Staphylococcus aureus 54.5% (12/22 was commonest among those aged above seven days. Staphylococcus aureus was the predominant pus swabs isolate for both neonates aged 0–6 days 42.2% (98/232 and 7–28 days 52.3% (34/65. Resistance of blood culture isolates was high to ampicillin 81.1% (60/74 and cloxacillin 78.4% (58/74, moderate to ceftriaxone 14.9% (11/74 and cefuroxime 18.9% (14/74, and low to amikacin 1.3% (1/74. Isolates from swabs had high resistance to ampicillin 89.9% (267/297 and cloxacillin 85.2 (253/297, moderate resistance to ceftriaxone 38.0% (113/297 and cefuroxime 36.0% (107/297, and low resistance to amikacin 4.7% (14/297. Sepsis was higher in neonates with fever and hypothermia (p=0.02, skin pustules (p Conclusions Staphylococcus aureus was predominant isolate followed by Klebsiella and Escherichia coli. There was high resistance to ampicillin and cloxacillin. Mortality rate due to neonatal sepsis was high in our setting. Routine antimicrobial surveillance should guide the choice of antibiotics for empirical treatment of neonatal sepsis.

Mhada Tumaini V

2012-10-01

127

Breast Cancer Knowledge, Beliefs, and Screening Practices among Women Seeking Care at District Hospitals in Dar es Salaam, Tanzania  

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BACKGROUND Limited disease awareness among women may impact breast cancer stage-at-diagnosis in Tanzania, reducing survival. This study assessed breast cancer knowledge, screening practices, and educational preferences among outpatients at Tanzanian government-supported hospitals. METHODS A convenience sample of women was surveyed regarding (1) knowledge/beliefs of breast cancer etiology, risk factors, symptoms, treatment, (2) early detection knowledge/practice, and (3) educational preferences. RESULTS Among 225 respondents, 98.2% knew of breast cancer; 22.2% knew someone affected by breast cancer. On average, 30% of risk factors and 51% of symptoms were identified. Most accepted one or more breast cancer myths. Among 126 aware of breast self-exam, 40% did not practice it; only 0.9% underwent regular clinical breast examinations despite 68% being aware of the procedure. Among treatments, 87% recognized surgery, 70% radiation, and fewer systemic therapy. Preferred educational sources were group sessions, television/radio, and meetings with breast cancer survivors. CONCLUSIONS This work reveals incomplete breast cancer awareness among Tanzanian women and promises to inform development of user-focused educational resources.

Morse, Emma Perry; Maegga, Bertha; Joseph, Gertrud; Miesfeldt, Susan

2014-01-01

128

Active case finding for tuberculosis among people who inject drugs on methadone treatment in Dar es Salaam, Tanzania.  

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SETTING Active case finding is a World Health Organization (WHO) endorsed strategy for improving tuberculosis (TB) case detection. Despite WHO recommendations for active case finding among people who inject drugs (PWID), few studies have been published. The historical focus of case finding has been in populations that are human immunodeficiency virus-positive, incarcerated or at higher occupational risk. OBJECTIVE We sought to examine the yield of active case finding among PWID newly started on methadone in Tanzania. DESIGN Of 222 methadone clients, 156 (70%) met with study administrators; 150 consented to participate, 139 (93%) of whom were male. The median age was 34 years. A symptom-based questionnaire was developed by the investigators and administered to every consenting patient by a native Swahili speaker. RESULTS Of the 150 patients surveyed, 16 (11%) had one or more TB symptoms and were referred for laboratory testing. Six new TB cases were identified in this active case finding program, with a prevalence of 4%. CONCLUSION This study presents the first data on TB prevalence in a population of PWID in Tanzania. This prevalence is 23 times that of the general Tanzanian TB prevalence of 0.2%. These results have significant implications for TB control. PMID:24902554

Gupta, A; Mbwambo, J; Mteza, I; Shenoi, S; Lambdin, B; Nyandindi, C; Doula, B I; Mfaume, S; Bruce, R D

2014-07-01

129

Oral manifestations of HIV infection in children and adults receiving highly active anti-retroviral therapy [HAART] in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background The aim of the study was to compare the prevalence and types of HIV-related oral lesions between children and adult Tanzanian patients on HAART with those not on HAART and to relate the occurrence of the lesions with anti-HIV drug regimen, clinical stage of HIV disease and CD4+ cell count. Methods Participants were 532 HIV infected patients, 51 children and 481 adults, 165 males and 367 females. Children were aged 2–17 years and adults 18 and 67 years. Participants were recruited consecutively at the Muhimbili National Hospital (MNH HIV clinic from October 2004 to September 2005. Investigations included; interviews, physical examinations, HIV testing and enumeration of CD4+ T cells. Results A total of 237 HIV-associated oral lesions were observed in 210 (39.5% patients. Oral candidiasis was the commonest (23.5%, followed by mucosal hyperpigmentation (4.7%. There was a significant difference in the occurrence of oral candidiasis (?2 = 4.31; df = 1; p = 0.03 and parotid enlargement (?2 = 36.5; df = 1; p = 0.04 between children and adults. Adult patients who were on HAART had a significantly lower risk of; oral lesions (OR = 0.32; 95% CI = 0.22 – 0.47; p = 0.005, oral candidiasis (OR = 0.28; 95% CI = 0.18 – 0.44; p = 0.003 and oral hairy leukoplakia (OR = 0.18; 95% CI = 0.04 – 0.85; p = 0.03. There was no significant reduction in occurrence of oral lesions in children on HAART (OR = 0.35; 95% CI = 0.11–1.14; p = 0.15. There was also a significant association between the presence of oral lesions and CD4+ cell count 3 (?2 = 52.4; df = 2; p = 0.006 and with WHO clinical stage (?2 = 121; df = 3; p = 0.008. Oral lesions were also associated with tobacco smoking (?2 = 8.17; df = 2; p = 0.04. Conclusion Adult patients receiving HAART had a significantly lower prevalence of oral lesions, particularly oral candidiasis and oral hairy leukoplakia. There was no significant change in occurrence of oral lesions in children receiving HAART. The occurrence of oral lesions, in both HAART and non-HAART patients, correlated with WHO clinical staging and CD4+ less than 200 cells/mm3.

Mikx Frans HM

2006-08-01

130

Cost and cost-effectiveness of community based and health facility based directly observed treatment of tuberculosis in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Identifying new approaches to tuberculosis treatment that are effective and put less demand to meagre health resources is important. One such approach is community based direct observed treatment (DOT. The purpose of the study was to determine the cost and cost effectiveness of health facility and community based directly observed treatment of tuberculosis in an urban setting in Tanzania. Methods Two alternative strategies were compared: health facility based directly observed treatment by health personnel and community based directly observed treatment by treatment supervisors. Costs were analysed from the perspective of health services, patients and community in the year 2002 in US $ using standard methods. Treatment outcomes were obtained from a randomised-controlled trial which was conducted alongside the cost study. Smear positive, smear negative and extra-pulmonary TB patients were included. Cost-effectiveness was calculated as the cost per patient successfully treated. Results The total cost of treating a patient with conventional health facility based DOT and community based DOT were $ 145 and $ 94 respectively. Community based DOT reduced cost by 35%. Cost fell by 27% for health services and 72% for patients. When smear positive and smear negative patients were considered separately, community DOT was associated with 45% and 19% reduction of the costs respectively. Patients used about $ 43 to follow their medication to health facility which is equivalent to their monthly income. Indirect costs were as important as direct costs, contributing to about 49% of the total patient's cost. The main reason for reduced cost was fewer number of visits to the TB clinic. Community based DOT was more cost-effective at $ 128 per patient successfully treated compared to $ 203 for a patient successfully treated with health facility based DOT. Conclusion Community based DOT presents an economically attractive option to complement health facility based DOT. This is particularly important in settings where TB clinics are working beyond capacity under limited resources.

Robberstad Bjarne

2005-07-01

131

Awareness of Rheumatic Heart Disease Prevention among Primary Health Care Providers and People Aged Nine Years and Above in Kinondoni Municipality Dar es salaam, Tanzania.  

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Acute Rheumatic Fever (ARF) is an autoimmune consequence of infection with Group A -haemolytic Streptococci (GAS). It causes an acute generalised inflammatory response and an illness that selectively affects the heart, joints, brain and skin. ARF leaves no lasting damage to the brain, joints or skin. However, damage to the heart valves, particularly the mitral and aortic valves, may persist after an acute episode has resolved. This involvement of the cardiac valves is known as Rheumatic Heart...

2011-01-01

132

Towards a GIS-T database design and implementation for public transit planning: the case study of Dar-Es-salaam metropolitan city, Tanzania.  

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In the last decade, we have witnessed tremendous advances and developments in the applications of Geographic Information Systems (GIS), in terms of technological hardware, software, methods, and data models. One of the applications that have attracted much attention in the use of GIS is the transportation sector mainly for planning, public transport routing, management and operations. This has made it important to have a unified or universal GIS-T standard data model, specifically, in the are...

2009-01-01

133

Cervical cytological changes in HIV-infected patients attending care and treatment clinic at Muhimbili National Hospital, Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Tanzania is among Sub-Saharan countries mostly affected by the HIV and AIDS pandemic, females being more vulnerable than males. HIV infected women appear to have a higher rate of persistent infection by high risk types of human papillomavirus (HPV strongly associated with high-grade squamous intraepithelial lesions (HSIL and invasive cervical carcinoma. Furthermore, although HIV infection and cervical cancer are major public health problems, the frequency and HIV/HPV association of cervical cancer and HSIL is not well documented in Tanzania, thus limiting the development of preventive and therapeutic strategies. Methods A prospective unmatched, case-control study of HIV-seropositive, ? 18 years of age and consenting non-pregnant patients attending the care and treatment center (CTC at Muhimbili National Hoospital (MNH as cases was done between 2005 and 2006. HIV seronegative, non-pregnant and consenting women recruited from the Cervical Cancer Screening unit (CCSU at ORCI were used as controls while those who did not consent to study participation and/or individuals under Results A total of 170 participants from the two centers were recruited including 50 HIV-seronegative controls were from the CCSU. Ages ranged from 20-66 years (mean 40.5 years for cases and 20-69 years (mean 41.6 years for controls. The age group 36-45 years was the most affected by HIV (39.2%, n = 47. Cervicitis, squamous intraepithelial lesions (SIL and carcinoma constituted 28.3% (n = 34, 38.3% (n = 46 and 5.8% (n = 7 respectively among cases, and 28% (n = 14, 34% (n = 17 and 2% (n = 1 for controls, although this was not statistically significant (P-value = 0.61. IHC showed that p53 was not detectable in HPV + Pap smears and cell blocks indicating possible degradation. Conclusions The frequency of SIL and carcinoma appeared to be higher among HIV-infected women on HAART compared to seronegative controls and as expected increased with age. HIV seropositive patients appeared to present earlier with SIL compared to those HIV seronegative suggesting a role of HIV in altering the natural history of HPV infection and cervical lesions. The absence of p53 immunoreactivity in HPV + lesions is indicative of the ability of HPV E6 proteins to interact with the tumor suppressor gene and pave way for viral-induced oncogenesis in the studied Tanzanian women.

Mwakigonja Amos R

2012-02-01

134

High Rate of Fatal Cases of Pediatric Septicemia Caused by Gram-Negative Bacteria with Extended-Spectrum Beta-Lactamases in Dar es Salaam, Tanzania  

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Extended-spectrum beta-lactamases (ESBLs) were present in high proportions of Escherichia coli (25% [9 of 36]) and Klebsiella pneumoniae isolates (17% [9 of 52]) causing pediatric septicemia at a tertiary hospital in Tanzania. Patients with septicemia due to ESBL-producing organisms had a significantly higher fatality rate than those with non-ESBL isolates (71% versus 39%, P = 0.039). This is the first report of the CTX-M-15 genotype of ESBLs on the African continent and the first observation...

2005-01-01

135

High Rate of Fatal Cases of Pediatric Septicemia Caused by Gram-Negative Bacteria with Extended-Spectrum Beta-lactamases in Dar es Salaam, Tanzania.  

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Extended-spectrum beta-lactamases (ESBLs) were present in high proportions of Escherichia coli (25% [9 of 36]) and Klebsiella pneumoniae isolates (17% [9 of 52]) causing pediatric septicemia at a tertiary hospital in Tanzania. Patients with septicemia due to ESBL-producing organisms had a significantly higher fatality rate than those with non-ESBL isolates (71% versus 39%, P = 0.039). This is the first report of the CTX-M-15 genotype of ESBLs on the African continent and the first observation...

2005-01-01

136

Challenges of caring for children with mental disorders: Experiences and views of caregivers attending the outpatient clinic at Muhimbili National Hospital, Dar es Salaam - Tanzania  

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Abstract Background It is estimated that world-wide up to 20?% of children suffer from debilitating mental illness. Mental disorders that pose a significant concern include learning disorders, hyperkinetic disorders (ADHD), depression, psychosis, pervasive development disorders, attachment disorders, anxiety disorders, conduct disorder, substance abuse and eating disorders. Living with such children can be very stressful for caregivers in the family. Therefore, determinatio...

2012-01-01

137

Challenges of Caring for Children with Mental Disorders: Experiences and Views of Caregivers Attending the Outpatient Clinic at Muhimbili National Hospital, Dar es Salaam - Tanzania.  

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It is estimated that world-wide up to 20?% of children suffer from debilitating mental illness. Mental disorders that pose a significant concern include learning disorders, hyperkinetic disorders (ADHD), depression, psychosis, pervasive development disorders, attachment disorders, anxiety disorders, conduct disorder, substance abuse and eating disorders. Living with such children can be very stressful for caregivers in the family. Therefore, determination of challenges of living with these ...

2012-01-01

138

Challenges of caring for children with mental disorders: Experiences and views of caregivers attending the outpatient clinic at Muhimbili National Hospital, Dar es Salaam - Tanzania  

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Full Text Available Abstract Background It is estimated that world-wide up to 20?% of children suffer from debilitating mental illness. Mental disorders that pose a significant concern include learning disorders, hyperkinetic disorders (ADHD, depression, psychosis, pervasive development disorders, attachment disorders, anxiety disorders, conduct disorder, substance abuse and eating disorders. Living with such children can be very stressful for caregivers in the family. Therefore, determination of challenges of living with these children is important in the process of finding ways to help or support caregivers to provide proper care for their children. The purpose of this study was to explore the psychological and emotional, social, and economic challenges that parents or guardians experience when caring for mentally ill children and what they do to address or deal with them. Methodology A qualitative study design using in-depth interviews and focus group discussions was applied. The study was conducted at the psychiatric unit of Muhimbili National Hospital in Tanzania. Two focus groups discussions (FGDs and 8 in-depth interviews were conducted with caregivers who attended the psychiatric clinic with their children. Data analysis was done using content analysis. Results The study revealed psychological and emotional, social, and economic challenges caregivers endure while living with mentally ill children. Psychological and emotional challenges included being stressed by caring tasks and having worries about the present and future life of their children. They had feelings of sadness, and inner pain or bitterness due to the disturbing behaviour of the children. They also experienced some communication problems with their children due to their inability to talk. Social challenges were inadequate social services for their children, stigma, burden of caring task, lack of public awareness of mental illness, lack of social support, and problems with social life. The economic challenges were poverty, child care interfering with various income generating activities in the family, and extra expenses associated with the child’s illness. Conclusion Caregivers of mentally ill children experience various psychological and emotional, social, and economic challenges. Professional assistance, public awareness of mental illnesses in children, social support by the government, private sector, and non-governmental organizations (NGOs are important in addressing these challenges.

Ambikile Joel

2012-07-01

139

Participatory mapping of target areas to enable operational larval source management to suppress malaria vector mosquitoes in Dar es Salaam, Tanzania  

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Abstract Background Half of the population of Africa will soon live in towns and cities where it can be protected from malaria by controlling aquatic stages of mosquitoes. Rigorous but affordable and scaleable methods for mapping and managing mosquito habitats are required to enable effective larval control in urban Africa. Methods A simple community-based mapping procedure that requires no electronic devices in the field was developed to facilitate routine larv...

Dongus Stefan; Nyika Dickson; Kannady Khadija; Mtasiwa Deo; Mshinda Hassan; Fillinger Ulrike; Drescher Axel W; Tanner Marcel; de Castro Marcia C; Killeen Gerry F

2007-01-01

140

Challenges of caring for children with mental disorders: Experiences and views of caregivers attending the outpatient clinic at Muhimbili National Hospital, Dar es Salaam - Tanzania  

Science.gov (United States)

Background It is estimated that world-wide up to 20?% of children suffer from debilitating mental illness. Mental disorders that pose a significant concern include learning disorders, hyperkinetic disorders (ADHD), depression, psychosis, pervasive development disorders, attachment disorders, anxiety disorders, conduct disorder, substance abuse and eating disorders. Living with such children can be very stressful for caregivers in the family. Therefore, determination of challenges of living with these children is important in the process of finding ways to help or support caregivers to provide proper care for their children. The purpose of this study was to explore the psychological and emotional, social, and economic challenges that parents or guardians experience when caring for mentally ill children and what they do to address or deal with them. Methodology A qualitative study design using in-depth interviews and focus group discussions was applied. The study was conducted at the psychiatric unit of Muhimbili National Hospital in Tanzania. Two focus groups discussions (FGDs) and 8 in-depth interviews were conducted with caregivers who attended the psychiatric clinic with their children. Data analysis was done using content analysis. Results The study revealed psychological and emotional, social, and economic challenges caregivers endure while living with mentally ill children. Psychological and emotional challenges included being stressed by caring tasks and having worries about the present and future life of their children. They had feelings of sadness, and inner pain or bitterness due to the disturbing behaviour of the children. They also experienced some communication problems with their children due to their inability to talk. Social challenges were inadequate social services for their children, stigma, burden of caring task, lack of public awareness of mental illness, lack of social support, and problems with social life. The economic challenges were poverty, child care interfering with various income generating activities in the family, and extra expenses associated with the child’s illness. Conclusion Caregivers of mentally ill children experience various psychological and emotional, social, and economic challenges. Professional assistance, public awareness of mental illnesses in children, social support by the government, private sector, and non-governmental organizations (NGOs) are important in addressing these challenges.

2012-01-01

 
 
 
 
141

THE EFFECT OF ENVIRONMENTAL REGULATIONS ON FINANCIAL PERFORMANCE IN TANZANIA: A SURVEY OF MANUFACTURING COMPANIES QUOTED ON THE DAR ES SALAAM STOCK EXCHANGE  

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Full Text Available There has been environmental pollution across the globe. Environmental activists are condemning manufacturing companies of environmental pollution. This has led to the establishment of environmental regulations and standards by government authorities across the globe. In complying with environmental regulations companies have found themselves incurring additional cost when compared to those companies which do not comply. However, the effect of compliance to environmental regulations on the financial performance is not clear. This study explores the effects of environmental compliance on the financial performance for listed manufacturing companies in Tanzania. Five listed manufacturing companies were surveyed to obtain data used for the purpose of this study. Specifically, the study intended to establish: the relationship between environmental compliance and financial performance and the effect of environmental compliance on the financial performance. Regression analysis was done to establish the relationship between environmental compliance and financial performance. Findings suggest that there is no significant relationship between environmental compliance and financial performance among listed manufacturing firms in Tanzania. This study concludes that environmental compliance has no significant effect on the financial performance for listed manufacturing firms in Tanzania.

Daniel Linus Naila

2013-01-01

142

Salaam Seizures (West Syndrome)  

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Three children suffering from salaam seizures are presented and discussed. 2-year and 4-month-old boy with congenital bilateral cataracts, severe mental retraction and typical EEG pattern. Spasms started, as he was one year old. There is no consanguinity of the parents. The mother was exposed to rubella in the 3rd or 4th month of pregnancy.

Dd, Farhoud; Ehsani, H.

1985-01-01

143

Comparative evaluation of the Ifakara tent trap-B, the standardized resting boxes and the human landing catch for sampling malaria vectors and other mosquitoes in urban Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Frequent, sensitive and accurate sampling of Anopheles mosquitoes is a prerequisite for effective management of malaria vector control programmes. The most reliable existing means to measure mosquito density is the human landing catch (HLC. However, the HLC technique raises major ethical concerns because of the necessity to expose humans to vectors of malaria and a variety of other pathogens. Furthermore, it is a very arduous undertaking that requires intense supervision, which is severely limiting in terms of affordability and sustainability. Methods A community-based, mosquito sampling protocol, using the Ifakara tent trap-B (ITT-B and standardized resting boxes (SRB, was developed and evaluated in terms of the number and sample composition of mosquitoes caught by each, compared to rigorously controlled HLC. Mosquitoes were collected once and three times every week by the HLC and the alternative methods, respectively, in the same time and location. Results Overall, the three traps caught 44,848 mosquitoes. The ITT-B, HLC and SRB caught 168, 143 and 46 Anopheles gambiae s.l. as well as 26,315, 13,258 and 4,791 Culex species respectively. The ITT-B was three- and five-times cheaper than the HLC per mosquito caught for An. gambiae and Cx. Species, respectively. Significant correlations between the numbers caught by HLC and ITT-B were observed for both An. gambiae s.l. (P Cx. species (P = 0.003. Correlation between the catches with HLC and SRB were observed for Cx. species (P An. gambiae s.l. (P = 0.195, presumably because of the low density of the latter. Neither ITT-B nor SRB exhibited any obvious density dependence for sampling the two species. Conclusion SRBs exhibited poor sensitivity for both mosquito taxa and are not recommended in this setting. However, this protocol is affordable and effective for routine use of the ITT-B under programmatic conditions. Nevertheless, it is recommended that the trap and the protocol be evaluated further at full programmatic scales to establish effectiveness under fully representative conditions of routine practice.

Kambi Said H

2009-08-01

144

Comparative evaluation of the Ifakara tent trap-B, the standardized resting boxes and the human landing catch for sampling malaria vectors and other mosquitoes in urban Dar es Salaam, Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Frequent, sensitive and accurate sampling of Anopheles mosquitoes is a prerequisite for effective management of malaria vector control programmes. The most reliable existing means to measure mosquito density is the human landing catch (HLC). However, the HLC technique raises major ethical concerns because of the necessity to expose humans to vectors of malaria and a variety of other pathogens. Furthermore, it is a very arduous undertaking that req...

Sikulu Maggy; Govella Nicodem J; Ogoma Sheila B; Mpangile John; Kambi Said H; Kannady Khadija; Chaki Prosper C; Mukabana Wolfgang R; Killeen Gerry F

2009-01-01

145

â??For someone whoâ??s rich, itâ??s not a problemâ?? : Insights from Tanzania on diabetes health-seeking and medical pluralism among Dar es Salaamâ??s urban poor  

DEFF Research Database (Denmark)

The prevalence of chronic non-communicable disease, such as type 2 diabetes mellitus (T2DM), is rising worldwide. In Africa, T2DM is primarily affecting those living in urban areas and increasingly affecting the poor. Diabetes management among urban poor is an area of research that has received little attention. Based on ethnographic fieldwork in Dar es Salam, the causes and conditions for diabetes management in Tanzania have been examined. In this paper, we focus on the structural context of diabetes services in Tanzania; the current status of biomedical and ethnomedical health care; and health-seeking among people with T2DM. We demonstrate that although Tanzania is actively developing its diabetes services, many people with diabetes and low socioeconomic status are unable to engage continuously in treatment. There are many challenges to be addressed to support people accessing diabetes health care services and improve diabetes management.

Kolling, Marie; Winkley, Kirsty

2010-01-01

146

Salaam DK a case study  

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Through methodological reflections based on critical discourse analysis, we intend this project to be an evaluation of Salaam DK’s ideological discourse, while investigating the festival’s relations to the socio-cultural context it exists in. From theories of ‘Otherness’ and stereotyping as formulated by Stuart Hall, concepts of power relation and ideology by Norman Fairclough and Teun A. van Dijk, and theories of ideology, we wish to explain the dynamics of and problematic reflection...

2008-01-01

147

La educación inclusiva es nuestra tarea  

Directory of Open Access Journals (Sweden)

Full Text Available La educación inclusiva es un tema que se ha venido trabajando desde hace relativamente pocos años en el Perú, pero en otros países se viene realizando desde hace muchos años. Por ello esta investigación busca dar a conocer todos aquellos elementos que son necesarios para lograr una inclusión adecuada de los niños, tomando como centro al niño, reconociéndolo como un ser humano integral que no solo aprende conceptos, sino también aprende a convivir e interactuar con su medio. Es aquí donde debemos tomar en cuenta el respeto a la diversidad que se debe dar en el aula, ya que al convivir se comparten experiencias con personas diferentes, como pueden ser los niños con necesidades especiales o simplemente con las de un niño regular. En esta investigación hemos querido resaltar la importancia de los roles de los agentes educativos para el buen desarrollo de la inclusión de los niños, siendo estos indispensables para lograrlo.

Meybol Calderón

2012-06-01

148

¿Es la muerte importante para la vida?  

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Full Text Available El fenómeno de muerte celular programada, o apoptosis, es actualmente uno de los más estudiados en el campo de la biomedicina; su importancia radica en que varias enfermedades, que afectan tanto al hombre como a los animales, son causadas por una alteración en este mecanismo fisiológico tan relevante, a tal grado que sin la existencia de este fenómeno fisiológico, la vida, como actualmente se conoce no sería posible. El propósito del presente trabajo es definir el fenómeno de apoptosis, describir cómo se regula y dar cuenta de algunas enfermedades causadas por su alteración, así como de las técnicas de detección.

Fernando Iván Flores Pérez

2002-01-01

149

Performance and acceptability of the FluoLED Easy (TM) module for tuberculosis fluorescence microscopy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

SETTING: Tuberculosis (TB) reference laboratory in Bangkok, Thailand, and two health centres in Dar es Salaam, Tanzania. OBJECTIVES: To assess the performance and user-friendliness of a light-emitting diode (LED) module (FluoLED Easy) for TB fluorescence microscopy (FM). DESIGN: Equivalence study vs. conventional FM in Bangkok using blinded re-reading; routine detection in the health centres in Dar es Salaam compared to Ziehl-Neelsen (ZN) over 2 years, with rechecking of FM smears. RESULTS: F...

Deun, A.; Chonde, T. M.; Gumusboga, M.; Rienthong, S.

2008-01-01

150

Direct Georeferencing of Stationary LiDAR  

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Unlike mobile survey systems, stationary survey systems are given very little direct georeferencing attention. Direct Georeferencing is currently being used in several mobile applications, especially in terrestrial and airborne LiDAR systems. Georeferencing of stationary terrestrial LiDAR scanning data, however, is currently performed indirectly through using control points in the scanning site. The indirect georeferencing procedure is often troublesome; the availability of control stations w...

Ahmed Mohamed; Benjamin Wilkinson

2009-01-01

151

Tri-Lateral Noor al Salaam High Concentration Solar Central Receiver Program  

Energy Technology Data Exchange (ETDEWEB)

This report documents the efforts conducted primarily under the Noor al Salaam (“Light of Peace”) program under DOE GRANT NUMBER DE-FC36-02GO12030, together with relevant technical results from a closely related technology development effort, the U.S./Israel Science and Technology Foundation (USISTF) High Concentration Solar Central Receiver program. These efforts involved preliminary design, development, and test of selected prototype power production subsystems and documentation of an initial version of the system definition for a high concentration solar hybrid/gas electrical power plant to be built in Zaafarana, Egypt as a first step in planned commercialization. A major part of the planned work was halted in 2007 with an amendment in October 2007 requiring that we complete the technical effort by December 31, 2007 and provide a final report to DOE within the following 90 days. This document summarizes the work conducted. The USISTF program was a 50/50 cost-shared program supported by the Department of Commerce through the U.S./Israel Science and Technology Commission (USISTC). The USISTC was cooperatively developed by President Clinton and the late Prime Minister Rabin of Israel "to encourage technological collaboration" and "support peace in the Middle East through economic development". The program was conducted as a follow-on effort to Israel's Magnet/CONSOLAR Program, which was an advanced development effort to design, fabricate, and test a solar central receiver and secondary optics for a "beam down" central receiver concept. The status of these hardware development programs is reviewed, since they form the basis for the Noor al Salaam program. Descriptions are provided of the integrated system and the major subsystems, including the heliostat, the high temperature air receiver, the power conversion unit, tower and tower reflector, compound parabolic concentrator, and the master control system. One objective of the USISTF program was to conduct marketing research, identify opportunities for use of this technology, and to the extent possible, secure an agreement leading to a pre-commercialization demonstration or prototype plant. This was accomplished with the agreement to conduct the Noor al Salaam program as a tri-lateral project between Egypt, Israel, and the U.S. The tri-lateral project was led by the University of Alabama in Huntsville (UAH); this included the Egyptian New and Renewable Energy Authority and the Israeli USISTC participants. This project, known was Noor al Salaam, was funded by the U.S. Agency for International Development (USAID) through the Department of Energy (DOE). The Egyptian activity was under the auspices of the Egyptian Ministry of Energy and Electricity, New and Renewable Energy Authority (NREA) as part of Egypt's plans for renewable energy development. The objective of the Noor al Salaam project was to develop the conditions necessary to obtain funding and construct and operate an approximately 10 to 20 Megawatt hybrid solar/natural gas demonstration power plant in Zaafarana, Egypt that could serve both as a test bed for advanced solar technology evaluations, and as a forerunner to commercial plant designs. This plant, termed Noor Al Salaam, or “Light of Peace”, reached the initial phase of system definition before being curtailed, in part by changes in USAID objectives, coupled with various delays that were beyond the scope of the program to resolve. The background of the USISTF technology development and pre-commercialization effort is provided in this report, together with documentation of the technology developments conducted under the Noor al Salaam program. It should be noted that only a relatively small part of the Noor al Salaam funding was expended over the approximately five years for which UAH was prime contractor before the program was ordered closed (Reference 1) so that the remaining funds could be returned to USAID.

Blackmon, James B

2008-03-31

152

¿Es la ocratoxina a una micotoxina mutagénica?  

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Full Text Available La ocratoxina A es una micotoxina producida por especies de los géneros Aspergillus y Penicillium que a través de los alimentos puede pasar al ser humano. Su órgano diana es el riñón pero también es hepatotóxica, inmunotóxica y teratogénica. Ha sido clasificada por la Agencia Internacional de Investigación contra el Cáncer (IARC como posible carcinógeno humano (clase 2B pero se desconoce si el mecanismo de acción transcurre a través de fenómenos genéticos o epigenéticos. En este artículo se revisan los datos de genotoxicidad y mutagenicidad de esta micotoxina. Aunque los primeros estudios en ensayos de reversión mutagénica con bacterias resultaron negativos, pronto se comprobó que administrada a animales de experimentación, la ocratoxina A inducía la formación de aductos especialmente en tejidos de riñón y vejiga urinaria de ratón. También se ha comprobado que esta micotoxina produce roturas monocatenarias en el ADN, da lugar a alteraciones cromosómicas e intercambios entre cromátidas hermanas e induce la síntesis de ADN fuera del período S, fenómeno indicativo de procesos de reparación. Se considera que la actividad genotóxica es dependiente de activación metabólica, en particular de varias isoformas P450, si bien los metabolitos genotóxicos no han sido aislados. Los últimos estudios realizados con ocratoxina A tritiada bajo diversas condiciones experimentales indican que el principal metabolito es el derivado monohidroxilado 4- (R ? hidroxi-ocratoxina A y que ni la ocratoxina A ni este metabolito forman aductos con el ADN, por lo que su actividad genotóxica estaría más relacionada con procesos de citotoxicidad y peroxidación lipídica, los cuales podrían dar lugar a moléculas reactivas con los ácidos nucleicos

L. Arbillaga

2004-01-01

153

APLICACIÓN DE DATOS LiDAR EN LA ESTIMACIÓN DEL VOLUMEN FORESTAL EN EL PARQUE METROPOLITANO BOSQUE SAN CARLOS / APPLICATION LiDAR DATA IN ESTIMATING FOREST VOLUME IN THE METROPOLITAN PARK SAN CARLOS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish RESUMEN La tecnología LiDAR es una de las fuentes de información geográfica que permite obtener puntos de coordenadas incluyendo la altura con mayor precisión. Una de las principales aplicaciones que tiene LiDAR es en el sector forestal, pero que en Colombia el poco desarrollo de este sector limita [...] explorar la conveniencia del uso de datos LiDAR para estimar recursos forestales. El presente trabajo explora el uso de datos LiDAR para la estimación del Volumen Forestal en el Parque Metropolitano Bosque San Carlos en Bogotá D.C. Se establece un marco de antecedentes con estudios similares, se analiza un grupo de herramientas informáticas para el manejo de los datos LiDAR y posteriormente, se establece un procedimiento metodológico para obtener un modelo de regresión que relacione los datos de altura normalizados, con la variable de campo de Volumen Forestal. Se realizan análisis de regresión apoyado en criterios de decisión estadísticos probando varios modelos para seleccionar las variables que mejor representen el fenómeno, se establece la prueba de bondad de ajuste tanto del modelo como de sus parámetros. Aunque el modelo que se obtiene no arrojo los resultados esperados en términos de la estimación del Volumen Forestal se analizan las causas de que eso ocurra. Finalmente, se valida el modelo aplicándolo para la totalidad de la zona de estudio y se representa geográficamente a través de un mapa temático. Abstract in english ABSTRACT LiDAR technology is a source of geographic information for obtaining coordinate points including height, with more accurately, one of the main applications is having LiDAR in forestry, but in Colombia the underdevelopment of this sector limits explore the convenience of using LiDAR data to [...] estimate forest resources. This paper explores the use of LiDAR data for estimating forest volume in Metropolitan Park Forest San Carlos in Bogota DC Establishing a framework for background with similar studies; analyze a group of tools to manage LiDAR data and subsequently establishing a methodological procedure for a regression model relating the standard height data, with variable field, forest volume. Regression analysis was performed on decision criteria supported statistical testing various models to select the variables that best represent the phenomenon, establishing the goodness of fit test of the model and its parameters. Although the model is obtained did not produce the expected results in terms of estimating forest volume examines the causes of that happening. Finally the model is validated by applying it to the entire study area and represented geographically through a thematic map.

Cristian Danilo, Martínez Tobón; Jhon Eric, Aunta Duarte; Jorge Alberto, Valero Fandiño.

154

UN ESTUDIANTE CONFLICTIVO PARA MUCHOS, ES EN REALIDAD UN PERSONAJE CON MUCHO QUE DAR  

Directory of Open Access Journals (Sweden)

Full Text Available In this written presents a history that is repeat year to year for some educators that have as a goal to formation in aspects of type scientific and also as corresponding to social values; there is also a reflection that leads to evidence of bias, prejudice and the exclusion that is made, in some cases in the classroom, to students that present some difficulties, aspect that affects the formation of the student, the learning and evaluation. In the same way is presented as a suggestion the inclusion of values in the classroom regardless the area of knowledge, based on of a pedagogical model and psychological currents that allow establish academic links and reflections in the formation of human being.

LEIDY NATALY MATEUS AGUILERA

2010-08-01

155

UN ESTUDIANTE CONFLICTIVO PARA MUCHOS, ES EN REALIDAD UN PERSONAJE CON MUCHO QUE DAR  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this written presents a history that is repeat year to year for some educators that have as a goal to formation in aspects of type scientific and also as corresponding to social values; there is also a reflection that leads to evidence of bias, prejudice and the exclusion that is made, in some cases in the classroom, to students that present some difficulties, aspect that affects the formation of the student, the learning and evaluation. In the same way is presented as a suggestion the inc...

2010-01-01

156

TALLER DE MOVIMIENTO-DANZA: DAR FORMA Y FIGURA AL MOVIMIENTO  

Directory of Open Access Journals (Sweden)

Full Text Available Resumen: Una taller de danza es una forma de enseñar la danza, de modo que lo más importante es utilizar el movimiento como “material” de creación o crear nuevos materiales para los fines de la propia danza. Los alumnos tienen que aprender que ellos mismos son capaces de dar forma al movimiento para sus propios fines. Abstract: The most important in a motion workshop in dance is using movement like “material” for creating or creating materials for dancing. Pupils should learn that they are able to give form to their own movement in order to reach individual aims.

Adrea Probst

2008-04-01

157

¿Qué es conducta?  

Directory of Open Access Journals (Sweden)

Full Text Available La definición de la Psicología como ciencia de la conducta adoptada por el Conductismo supone e implica a su vez una conceptualización clara y unívoca de dicho concepto. Pero tal definición se enfrenta con una serie de malentendidos tenaces que dificultan no sólo la comprensión de dicho concepto básico sino también, en consecuencia, la propia conceptualización conductista. El propósito del presente trabajo es intentar exponer algunos de estos malentendidos, entre los que destacan los errores categoriales groseros, los procesos de reificación abusiva, los razonamientos tautológicos disfrazados, la generalización imprudente del modelo médico al ámbito de la conducta y la confusión nefasta entre un fenómeno y su conceptualización. Para ello, y con un tono más didáctico que académico, se recurre a una serie de metáforas de la vida cotidiana: la parte escondida del iceberg no es más que iceberg, las piedras no caen por su propio peso, los hombres y las mujeres no mueren porque son mortales, el bacilo de Koch existe y la máscara no es el rostro.

Esteve Freixa i Baqué

2003-01-01

158

Freezing Human ES Cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Here we demonstrate how our lab freezes HuES human embryonic stem cell lines. A healthy, exponentially expanding culture is washed with PBS to remove residual media that could otherwise quench the Trypsin reaction. Warmed 0.05% Trypsin-EDTA is then added to cover the cells, and the plate allowed to incubate for up to 5 mins at room temperature. During this time cells can be observed rounding, and colonies lifting off the plate surface. Gentle repeated pipetting will remove cells and colon...

Trish, Erin; Dimos, John; Eggan, Kevin

2006-01-01

159

¿Qué es el neozapatismo?  

Directory of Open Access Journals (Sweden)

Full Text Available El levantamiento chiapaneco del primero de enero de 1994 descencadenó la movilización de varios sectores de la sociedad mexicana. Del repudio unánime a la guerra nació un amplio movimiento ciudadano y popular que ?sin compartir los medios tácticos de la lucha armada? convergió con el Ejército Zapatista de Liberación Nacional (EZLN en sus aspiraciones sociales y políticas: la lucha por la democracia, la justicia y la libertad. Por ser él, resulta pertinente calificarlo con el término de neozapatismo civil. Si sumamos a este conjunto de movilizaciones ciudadanas y populares el propio zapatismo armado ? advirtiendo su carácter «socio-políticomilitar »? obtendremos el neozapatismo en su sentido más amplio. Otra forma de entender el neozapatismo ?que desarrollaremos en la presente reflexión? es como un proceso dinámico constituido por una pluralidad de intereses, voluntades e identidades, que lo inscriben dentro de un campo de contradicciones y de tensiones no resueltas. Como primera premisa podemos apuntar que el neozapatismo no es ni homogéneo ni mucho menos monolítico, sino que, como lo mostraremos a continuación, tiene una naturaleza multifacética, polisémica y fluídica.

Willibald Sonnleitner

2000-01-01

160

Application of LiDAR technology for hydroelectric operations  

Energy Technology Data Exchange (ETDEWEB)

Airborne LiDAR technology that uses On the Fly GPS techniques with portable IMU systems has shown strong growth in the last five years. In 2007, Ontario Power Generation (OPG) developed a pilot project to introduce the concept of airborne LiDAR technology for mapping and hydrotechnical studies as a viable option for acquiring accurate elevation data in forested areas of Northern Ontario. LiDAR data have been collected on over 12,000 sq km for 19 river systems since 2008. This paper reported the review of the acquisition and data processing methodology for the application of LiDAR technology to hydroelectric operations. It focused on providing insight into using the technology for hydropower planning and operations and illustrated the benefits of LiDAR over case studies for hydroelectric applications. The LiDAR data sets illustrated the significant advantages for detail terrain mapping for OPG. This technology is still evolving. Data collection and review is ongoing.

McArdle, Steven; Grover, Patrick; Hellas, Neil [4DM Inc., Toronto, (Canada); Bryan, Nick; Kirkham, Allan; Lim, Sony [Ontario Power Generation, Toronto, (Canada)

2010-07-01

 
 
 
 
161

Trapped in decline: a sociological analysis of economic life in Mgeta, Uluguru mountains Tanzania.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The research for this thesis was carried out in Tanzania during the period 1985- 89 and focuses on the Mgeta division in the Uluguru mountains, Morogoro rural district. Research was also undertaken among migrants from the area living in Dar es Salaam where they traded in foodstuffs. I made a return visit to the area in November 1991 to look again at questions which arose during writing up. The research also reflects seven years' employment at the University of Dar es Salaam (1982-89). The Tan...

1993-01-01

162

Outlook for survivors of childhood in sub-Saharan Africa: adult mortality in Tanzania. Adult Morbidity and Mortality Project.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVE--To measure age and sex specific mortality in adults (15-59 years) in one urban and two rural areas of Tanzania. DESIGN--Reporting of all deaths occurring between 1 June 1992 and 31 May 1995. SETTING--Eight branches in Dar es Salaam (Tanzania's largest city), 59 villages in Morogoro rural district (a poor rural area), and 47 villages in Hai district (a more prosperous rural area). SUBJECTS--40,304 adults in Dar es Salaam, 69,964 in Hai, 50,465 in Morogoro rural. MAIN OUTCOME MEASURE...

Kitange, H. M.; Machibya, H.; Black, J.; Mtasiwa, D. M.; Masuki, G.; Whiting, D.; Unwin, N.; Moshiro, C.; Klima, P. M.; Lewanga, M.; Alberti, K. G.; Mclarty, D. G.

1996-01-01

163

A DArT platform for quantitative bulked segregant analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Bulked segregant analysis (BSA) identifies molecular markers associated with a phenotype by screening two DNA pools of phenotypically distinct plants for markers with skewed allele frequencies. In contrast to gel-based markers, hybridization-based markers such as SFP, DArT or SNP generate quantitative allele-frequency estimates. Only DArT, however, combines this advantage with low development and assay costs and the ability to be deployed for any plant spe...

Wenzl Peter; Raman Harsh; Wang Junping; Zhou Meixue; Huttner Eric; Kilian Andrzej

2007-01-01

164

Tree filtering for high density airborne LiDAR data:  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A high resolution Airborne LiDAR data creates better opportunity for an individual tree measurement and provides valuable results for more precise forest inventory. This paper presents tree filtering approach that able to separate dominant tree and undergrowth vegetation. The results can be used for a detailed individual tree measurement. This process is one of the main steps for a single tree extraction from the high resolution Airborne LiDAR data. The filtering technique lies on the fact th...

2008-01-01

165

Alternative Methodologies for LiDAR System Calibration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Over the last few years, LiDAR has become a popular technology for the direct acquisition of topographic information. In spite of the increasing utilization of this technology in several applications, its accuracy potential has not been fully explored. Most of current LiDAR calibration techniques are based on empirical and proprietary procedures that demand the system’s raw measurements, which may not be always available to the end-user. As a result, we can still observe systematic discrepa...

Ayman Habib; Ki In Bang; Ana Paula Kersting; Jacky Chow

2010-01-01

166

Assessing understory development in forest plantations using laser imaging detection and ranging (LiDAR) / Evaluación del desarrollo del sotobosque en plantaciones forestales mediante LiDAR  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Las plantaciones forestales deberían ser manejadas de forma que conserven biodiversidad al tiempo que provean bienes y servicios. Este es un desafío significativo pues las plantaciones tienden a reducir la riqueza de especies nativas. La presencia de un sotobosque desarrollado incrementa el valor de [...] las plantaciones como hábitat para la fauna nativa. En este trabajo desarrollamos un método sencillo para evaluar la disponibilidad de sotobosque en plantaciones forestales empleando imágenes LiDAR y RGB de alta resolución. En base a datos de campo, LiDAR e imágenes aéreas para rodales de Pinus radiata en Chile central, el modelo digital de copa (DCM), obtenido de sustraer el modelo digital de terreno (DTM) del modelo digital de superficie (DSM) es un predictor más confiable del desarrollo del sotobosque que variables como la pendiente del terreno, la exposición, la edad de la plantación y la altura del dosel de la plantación en situaciones en las cuales en dosel superior no está completamente cerrado. La correlación entre DCM y el sotobosque sin embargo decrece con la altura del dosel de la plantación, lo que hace de DCM un estimador conservador del desarrollo del sotobosque. El uso de DCM permitirá una evaluación rápida y costo/efectiva de la disponibilidad de hábitat para fauna nativa en plantaciones forestales. Abstract in english Forestry plantations are expected to be managed in ways to conserve biodiversity while producing goods and services. This goal implies a significant challenge as plantations tend to reduce species richness. The presence of well developed understory enhances the value of plantations as habitat for na [...] tive fauna. Here, we develop a straightforward method to assess the availability of understory in forestry stands using laser imaging detection and ranging (LiDAR) data and aerial RGB high resolution images. Based on field and airborne acquired data for Pinus radiata stands in central Chile, the digital crown model (DCM), derived from the subtraction of the digital terrain model (DTM) from the digital surface model (DSM) is a more reliable predictor of understory height that variables like terrain slope, aspect, plantation age and canopy height in forests and plantations which have not complete closed canopy. The correlation between DCM and understory though decreases while the actual height of the plantation canopy increases, rendering DCM a conservative estimate of understory development. The use of DCM will allow a fast and cost/effective estimate of habitat suitability in forestry plantations.

JAIME, HERNÁNDEZ; M. PAZ, ACUÑA; PATRICIO, CORVALÁN; JAVIER A, SIMONETTI.

167

The Role of "Kilimani Sesame" in the Healthy Development of Tanzanian Preschool Children  

Science.gov (United States)

"Kilimani Sesame," a media intervention that employs print, radio, and television, was developed to entertain and educate preschool children in Tanzania. This study examined the effects of a six-week intervention delivering "Kilimani Sesame" material to 223 children in the rural district of Kisarawe and the city of Dar es Salaam. Results offer…

Borzekowski, Dina L. G.; Macha, Jacob E.

2010-01-01

168

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background 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. Methods Novel tent traps were developed as alternatives t...

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

2009-01-01

169

CAUSATIVE FACTORS PUSHED WOMEN INTO DAR-UL-AMAN: A CASE STUDY OF DAR-UL-AMAN DISTRICT GUJRAT, PAKISTAN  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main purpose of the present research was to explore “the causative factors which forced the women to join Dar-ul-Aman in Gujrat, District Gujrat. Mostly the women in Dar-ul-Aman faced a number of issues, family pressure, personal choice, fear, personality issues and some other family related issues. For the present study, nine cases were sampled from targeted population through the purposive sampling technique and interview guide was administrated by the researchers c...

2013-01-01

170

Extraction of Mangrove Biophysical Parameters Using Airborne LiDAR  

Directory of Open Access Journals (Sweden)

Full Text Available Tree parameter determinations using airborne Light Detection and Ranging (LiDAR have been conducted in many forest types, including coniferous, boreal, and deciduous. However, there are only a few scientific articles discussing the application of LiDAR to mangrove biophysical parameter extraction at an individual tree level. The main objective of this study was to investigate the potential of using LiDAR data to estimate the biophysical parameters of mangrove trees at an individual tree scale. The Variable Window Filtering (VWF and Inverse Watershed Segmentation (IWS methods were investigated by comparing their performance in individual tree detection and in deriving tree position, crown diameter, and tree height using the LiDAR-derived Canopy Height Model (CHM. The results demonstrated that each method performed well in mangrove forests with a low percentage of crown overlap conditions. The VWF method yielded a slightly higher accuracy for mangrove parameter extractions from LiDAR data compared with the IWS method. This is because the VWF method uses an adaptive circular filtering window size based on an allometric relationship. As a result of the VWF method, the position measurements of individual tree indicated a mean distance error value of 1.10 m. The individual tree detection showed a kappa coefficient of agreement (K value of 0.78. The estimation of crown diameter produced a coefficient of determination (R2 value of 0.75, a Root Mean Square Error of the Estimate (RMSE value of 1.65 m, and a Relative Error (RE value of 19.7%. Tree height determination from LiDAR yielded an R2 value of 0.80, an RMSE value of 1.42 m, and an RE value of 19.2%. However, there are some limitations in the mangrove parameters derived from LiDAR. The results indicated that an increase in the percentage of crown overlap (COL results in an accuracy decrease of the mangrove parameters extracted from the LiDAR-derived CHM, particularly for crown measurements. In this study, the accuracy of LiDAR-derived biophysical parameters in mangrove forests using the VWF and IWS methods is lower than in coniferous, boreal, pine, and deciduous forests. An adaptive allometric equation that is specific for the level of tree density and percentage of crown overlap is a solution for improving the predictive accuracy of the VWF method.

Poonsak Miphokasap

2013-04-01

171

¿Quién es el paciente limítrofe?  

Directory of Open Access Journals (Sweden)

Full Text Available Diversos términos -límite, limítrofe, fronterizo y borderline parecen aludir al mismo paciente. No obstante, diferentes definiciones surgen tras la revisión del concepto. ¿Se refiere a un trastorno específico de la personalidad, a un síndrome clínico, a un nivel de funcionamiento intermedio entre la neurosis y la psicosis, a un subgrupo de los trastornos afectivos de la esquizofrenia o la epilepsia? En gran parte, la confusión proviene de dos enfoques diferentes que se esfuerzan por definir el concepto: el enfoque descriptivo que pone el énfasis en la sintomatología diagnostica frente al enfoque psicodinámico que destaca aspectos estructurales, dinámicos y de desarrollo como criterios diagnósticos. Estos dos enfoques aunque separados no dejan por ello de estar relacionados. Se han mantenido independientes porque las observaciones de ambos grupos provienen de contextos, metodologías y énfasis diferentes. Al contar con marcos teóricos y métodos distintos, sus conclusiones no pueden compararse aunque teóricamente pueden complementarse. El enfoque descriptivo, representado por el DSM-IV, ve el concepto limítrofe como uno de los muchos trastornos de la personalidad que son distintos entre sí, mientras que el enfoque psicodinámico de Kernberg lo considera como un nivel de funcionamiento psíquico o de organización yoica estable ?entre la neurótica y la psicótica? que puede dar cabida a distintos tipos de personalidades (dentro de este marco, se puede hablar de una personalidad narcisista con un nivel organizacional limítrofe...

Cristina Gómez de Cortés

2000-01-01

172

¿Que es la electroforesis capilar?  

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La electroforesis capilar (CE) es una técnica de separación basada en la diferente velocidad de migración de las distintas especies cargadas bajo la acción de un campo eléctrico. La separación se lleva a cabo en un capilar de sílice fundida de diámetro muy pequeño ( 10-200 ¿m). El uso de estos capilares tiene múltiples ventajas: a) los capilares son anticonvectivos en sí mismos, por lo tanto, no es necesaria la utilización de un gel soporte como medio; b) el calor generado al pas...

2007-01-01

173

Alternative Methodologies for LiDAR System Calibration  

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Full Text Available Over the last few years, LiDAR has become a popular technology for the direct acquisition of topographic information. In spite of the increasing utilization of this technology in several applications, its accuracy potential has not been fully explored. Most of current LiDAR calibration techniques are based on empirical and proprietary procedures that demand the system’s raw measurements, which may not be always available to the end-user. As a result, we can still observe systematic discrepancies between conjugate surface elements in overlapping LiDAR strips. In this paper, two alternative calibration procedures that overcome the existing limitations are introduced. The first procedure, denoted as “Simplified method”, makes use of the LiDAR point cloud from parallel LiDAR strips acquired by a steady platform (e.g., fixed wing aircraft over an area with moderately varying elevation. The second procedure, denoted as “Quasi-rigorous method”, can deal with non-parallel strips, but requires time-tagged LiDAR point cloud and navigation data (trajectory position only acquired by a steady platform. With the widespread adoption of LAS format and easy access to trajectory information, this data requirement is not a problem. The proposed methods can be applied in any type of terrain coverage without the need for control surfaces and are relatively easy to implement. Therefore, they can be used in every flight mission if needed. Besides, the proposed procedures require minimal interaction from the user, which can be completely eliminated after minor extension of the suggested procedure.

Jacky Chow

2010-03-01

174

¿Es posible el capitalismo sostenible?  

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Full Text Available ¿Es posible el capitalismo sostenible? En este artículo se analiza una evidencia relativa a esta pregunta, haciendo énfasis en algunos de los diferentes conceptos de "sostenibilidad" planteados por los verdes y por el sector empresarial. Se hace un breve recuento de las condiciones de sostenibilidad económica y se discute la "primera" contradicción del capitalismo y la naturaleza de la acumulación capitalista, además de un breve examen del proceso de formación de una crisis mundial en la década de los ochenta.

James O´Connor

2000-01-01

175

Nitrogen concentration estimation with hyperspectral LiDAR  

Science.gov (United States)

Agricultural lands have strong impact on global carbon dynamics and nitrogen availability. Monitoring changes in agricultural lands require more efficient and accurate methods. The first prototype of a full waveform hyperspectral Light Detection and Ranging (LiDAR) instrument has been developed at the Finnish Geodetic Institute (FGI). The instrument efficiently combines the benefits of passive and active remote sensing sensors. It is able to produce 3D point clouds with spectral information included for every point which offers great potential in the field of remote sensing of environment. This study investigates the performance of the hyperspectral LiDAR instrument in nitrogen estimation. The investigation was conducted by finding vegetation indices sensitive to nitrogen concentration using hyperspectral LiDAR data and validating their performance in nitrogen estimation. The nitrogen estimation was performed by calculating 28 published vegetation indices to ten oat samples grown in different fertilization conditions. Reference data was acquired by laboratory nitrogen concentration analysis. The performance of the indices in nitrogen estimation was determined by linear regression and leave-one-out cross-validation. The results indicate that the hyperspectral LiDAR instrument holds a good capability to estimate plant biochemical parameters such as nitrogen concentration. The instrument holds much potential in various environmental applications and provides a significant improvement to the remote sensing of environment.

Nevalainen, O.; Hakala, T.; Suomalainen, J.; Kaasalainen, S.

2013-10-01

176

A DArT platform for quantitative bulked segregant analysis  

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Full Text Available Abstract Background Bulked segregant analysis (BSA identifies molecular markers associated with a phenotype by screening two DNA pools of phenotypically distinct plants for markers with skewed allele frequencies. In contrast to gel-based markers, hybridization-based markers such as SFP, DArT or SNP generate quantitative allele-frequency estimates. Only DArT, however, combines this advantage with low development and assay costs and the ability to be deployed for any plant species irrespective of its ploidy level. Here we investigate the suitability of DArT for BSA applications using a barley array as an example. Results In a first test experiment, we compared two bulks of 40 Steptoe/Morex DH plants with contrasting pubescent leaves (mPub alleles on chromosome 3H. At optimized levels of experimental replication and marker-selection threshold, the BSA scan identified 433 polymorphic markers. The relative hybridization contrast between bulks accurately reflected the between-bulk difference in the frequency of the mPub allele (r = 0.96. The 'platform noise' of DArT assays, estimated by comparing two identical aliquots of a DNA mixture, was significantly lower than the 'pooling noise' reflecting the binomial sampling variance of the bulking process. The allele-frequency difference on chromosome 3H increased in the vicinity of mPub and peaked at the marker with the smallest distance from mPub (4.6 cM. In a validation experiment with only 20 plants per bulk we identified an aluminum (Al tolerance locus in a Dayton/Zhepi2 DH population on chromosome 4H with Conclusion DArT-BSA identifies genetic loci that influence phenotypic characters in barley with at least 5 cM accuracy and should prove useful as a generic tool for high-throughput, quantitative BSA in plants irrespective of their ploidy level.

Wang Junping

2007-06-01

177

¿Quién es el Dr. Alvarado?  

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Full Text Available Este texto, escrito por Arturo Jauretche, recupera la figura del Dr. Carlos Alberto Alvarado (1904-1986 quien, en tiempos en que Ramón Carrillo era secretario de Salud Pública de la Nación, dirige una campaña que logra controlar el paludismo en el noroeste argentino con una reducción muy importante del número de casos, alcanzando una amplia repercusión mundial. En 1955, el Dr. Alvarado es separado de su cargo por la Revolución Libertadora, momento en que la Organización Panamericana de la Salud lo designa asesor regional y entre 1959 y 1964 lo nombran jefe del programa de erradicación de la malaria de la Organización Mundial de la Salud, en Ginebra, Suiza. A su regreso al país en 1966, organiza el Plan de Salud Rural, creando para ello la figura del "agente sanitario" y la "ronda sanitaria" anticipándose a conceptos que varios años después se plasmarían en la Atención Primaria de la Salud. El texto de Jauretche fue publicado originalmente en 1967 en el libro Los profetas del odio, por la editorial de Arturo Peña Lillo, editor de los grandes títulos del "pensamiento nacional" argentino. Su reedición en la sección "Memoria e historia" es un modo de rendir homenaje a una de las figuras indiscutibles de la Salud Pública argentina.

Arturo Jauretche

2012-01-01

178

Diversity arrays technology (DArT) markers in apple for genetic linkage maps  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Diversity Arrays Technology (DArT) provides a high-throughput whole-genome genotyping platform for the detection and scoring of hundreds of polymorphic loci without any need for prior sequence information. The work presented here details the development and performance of a DArT genotyping array for apple. This is the first paper on DArT in horticultural trees. Genetic mapping of DArT markers in two mapping populations and their integration with other marker types showed that DArT is a powerf...

Schouten, Henk J.; Weg, W. Eric; Carling, Jason; Khan, Sabaz Ali; Mckay, Steven J.; Kaauwen, Martijn P. W.; Wittenberg, Alexander H. J.; Koehorst-van Putten, Herma J. J.; Noordijk, Yolanda; Gao, Zhongshan; Rees, D. Jasper G.; Dyk, Maria M.; Jaccoud, Damian; Considine, Michael J.; Kilian, Andrzej

2012-01-01

179

Estatinas en insuficiencia cardíaca: "dar o no dar" / Statins in heart failure: "to give or not to give" / Estatinas na insuficiência cardíaca: "dar ou não dar"  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in portuguese Pacientes com níveis de colesterol aumentados representam uma população em risco de sofrer eventos cardiovasculares e morte por doença vascular. As estatinas demonstraram ser efetivas em reduzir o colesterol e, portanto diminuir os eventos cardiovasculares em pacientes com doença arterial coronária [...] ou com alto risco de desenvolvêlas. Na insuficiência cardíaca crônica (ICC), baixos níveis de colesterol estão associados com o aumento da mortalidade. Este fenômeno, conhecido como epidemiologia inversa não se apresenta somente em IC, senão também em doenças críticas dos idoso. Uma possível explicação é a hipótese da endotoxina, a qual se refere que o colesterol cumpre uma função de "purificador" das endotoxinas.As estatinas não só diminuem o colesterol, mas também têm efeitos pleiotrópicos, como antiinflamatórios e melhoria da função endotelial. Faz-se necessário uma revisão nos mecanismos farmacológicos dos efeitos do tratamento com estatinas, para tratar de conciliar estes efeitos contraditórios. Neste trabalho revisaremos os efeitos prejudiciais e benéficos do tratamento com estatinas em modelos animais e em humanos com ICC. Faz-se necessário uma maior investigação no modelo de ICC em humanos. Abstract in spanish Pacientes con niveles de colesterol aumentados representan una población en riesgo de sufrir eventos cardiovasculares y muerte por enfermedad vascular. Las estatinas han demostrado ser efectivas en reducir el colesterol y por lo tanto disminuir los eventos cardiovasculares en pacientes con enfermeda [...] d arterial coronaria o con alto riesgo de desarrollarla. En insuficiencia cardíaca crónica (ICC), bajos niveles de colesterol están asociados con aumento de la mortalidad. Este fenómeno, conocido como epidemiología reversa no se presenta sólo en ICC, sino también en enfermedades críticas del anciano. Una posible explicación es la hipótesis de la endotoxina, la cual refiere que el colesterol cumple una función de"purificador" de las endotoxinas. Las estatinas no sólo disminuyen el colesterol, también tienen efectos pleiotrópicos, como antiinflamatorios y mejoría de la función endotelial. Se hace necesario revisar los mecanismos farmacológicos de los efectos del tratamiento con estatinas, para tratar de conciliar estos efectos contradictorios. En este trabajo revisaremos los efectos dañinos y beneficiosos del tratamiento con estatinas en modelos animales y en humanos con ICC. Se hace necesaria una mayor investigación en el modelo de ICC en humanos. Abstract in english Patients with increased cholesterol levels are at increased risk to experience cardiovascular events and to die from vascular disease. Statins have been proven to effectively reduce cholesterol levels and subsequently reduce cardiovascular events in patients with coronary artery disease or at increa [...] sed risk to develop coronary artery disease. However, in patients with chronic heart failure (CHF), low levels of cholesterol are related to increased mortality. This phenomenon of reverse epidemiology is not unique to CHF, but also exists in other critical disease and in the elderly in general as well. An important rationale has been provided by the endotoxin hypothesis, which suggests that cholesterol has an important scavenger function regarding harmful en dotoxins. Indeed, these lines of evidence predict a harmful effect of statin treatment in patients with CHF. However, statins not only lower cholesterol, but also have been reported to exhibit pleiotropic effects, including reduction of inflammation and improvement of endothelial function. In order to reconcile these contradictory lines of evidence, it is necessary to examine the pharmacological mechanisms of effects of statin treatment. In this review, we provide the available lines of evidence in animal models and humans predicting both harmful and beneficial effects of statin treatment in CHF. We emphasize the importance of additional research spe

Carlos Andrés, León; Silvia, Moro.

180

Portadores de VIH/SIDA e HCC: dar voz a relatos de sofrimento  

Scientific Electronic Library Online (English)

Full Text Available SciELO Portugal | Language: Portuguese Abstract in portuguese É inquestionável que o diagnóstico de se ser portador de uma doença crónica alberga muitas implicações. Contudo, o diagnóstico de Vírus da Imunodeficiência Humana (VIH)/ Síndrome da Imunodeficiência Adquirida (SIDA) tem um impacto particular na vida do portador, e nas relações com as pessoas para si [...] significativas, nomeadamente quando consideramos o estigma a ele associado. O contacto com estes sujeitos fez-nos perceber que mesmo quando estes são internados por complicações relacionadas com a hepatite, culpabilizam o VIH e não a Hepatite C Crónica (HCC). A principal implicação psicológica é a ansiedade, encontrada em todos os sujeitos, o que nos surpreendeu dado que a literatura coloca a depressão como sintoma psicológico mais frequentemente associado à infecção pelo VIH/SIDA, não se tendo encontrado idên­tica constatação em relação à HCC. A metodologia qualitativa utilizada visou dar a este trabalho um contorno exploratório, descritivo e analítico das experiências e vivências de 17 indivíduos portadores de VIH/SIDA e de HCC, a quem tentamos dar voz, na expressão do seu sofrimento físico, psicológico e social. Abstract in spanish Es incuestionable que serse portador de una enfermedad crónica engloba muchas implicaciones. Sin embargo, el diagnóstico del virus de la inmunodeficiencia humana (VIH) / Síndrome de inmunodeficiencia adquirida (SIDA) tiene un impacto particular en la vida del portador y en las relaciones con las per [...] sonas significativas, sobre todo considerando el estigma que está asociado a él. El contacto con estos sujetos permitió que entendiéramos que mismo cuando estos son internados debido a complicaciones relacionadas con la hepatitis, culpabilizan el VIH e no la hepatitis C Crónica (HCC). La principal implicación psicológica es la ansiedad, percibida en todos los sujetos, facto que nos sorprendió ya que la literatura coloca la depresión como síntoma psicológico más frecuentemente asociado a la infección por vía VIH/SIDA, no se verificando idéntica constatación relativamente a la HCC. La metodología cualitativa utilizada se fijó en dar a este trabajo un carácter exploratorio, descriptivo y analítico de las experiencias y vivencias de 17 sujetos portadores de VIH/SIDA y de HCC, a los cuales intentamos dar voz, en la expresión de su sufrimiento físico, psicológico y social. Abstract in english It is undeniable that being diagnosed with a chronic disease sets numerous implications. However, the diagnosis of Human Immunodeficiency Virus (HIV)/ Acquired Immune Deficiency Syndrome (AIDS) seems to have a particular impact on the person’s life and relationships, especially if considering the st [...] igma associated to it. Being in touch with these individuals made us realize that, even when hospitalized due to complications related to hepatitis, they tend to blame the HIV instead of the Chronic Hepatitis C (CHC). The main psychological condition found in all patients was, unexpec­tedly, anxiety, given the fact that literature places depression as the most frequent psychological symptom associated to HIV/AIDS, not having found any similar information relating to CHC. The qualitative methodology we applied meant to give this article an exploratory, descriptive and analytical outline of the experiences of 17 HIV/AIDS and CHC infected, to whom we gave voice to express their physical, psychological and social anguish.

Sofia Santanna, Gandra; Zélia, Teixeira.

 
 
 
 
181

LiDAR-Derived DEM and Raw Height Comparisons along Profile Corridor Gradients within a Forest  

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Full Text Available We compared field based and airborne LiDAR-derived profile corridor measurements across forest canopy types and terrain ranging from 37% to 49% slope. Both LiDAR-derived DEM and raw LiDAR point elevations were compared to field data. Primary objectives included examining whether canopy type or terrain slope influenced LiDAR-derived profile measurements. A secondary objective included comparing cable logging payloads based on field measured profile elevations to payloads based on LiDAR-derived elevations. Average RMSE elevation errors were slightly lower for profile point to LiDAR DEM values (0.43 m than profile point to nearest LiDAR elevation point (0.49 m with differences being larger when sites within forest clearings were removed from analysis. No statistically significant relationship existed between field measured ground slopes and associated profile point and LiDAR DEM elevation differences but a mild correlation existed when LiDAR raw point elevation differences were compared. Our payload analysis determined the limiting payload distance and had consistent results across study sites. The DEM-based profile outperformed the nearest point profile by 5% on average. Results suggest that forest analysts should consider using the nearest LiDAR DEM value rather than the nearest LiDAR point elevation for terrain heights at discrete locations, particularly when forest canopy occludes locations of interest.

Michael G. Wing

2013-04-01

182

R Band Photometry of X-Ray Selected BL Lacertae Objects: 1ES 0229+20, 1ES 0323+02, 1ES 0502+67, 1ES 0647+25, 1ES 0806+52, 1ES 0927+50, 1ES 1028+51, 1ES 1959+65 and 1ES 2344+51  

Energy Technology Data Exchange (ETDEWEB)

We present optical R band photometry for nine X-ray Einstein Slew Survey Sample BL Lacertae objects: 1ES 0323+022, 1ES 0502+675, 1ES 0647+250, 1ES 0806+524, 1ES 1028+511, 1ES 1959+650 and 1ES 2344+514. Two blazars 1ES 0229+200 and 1ES 0927+500 didn't show any detectable variability. They have all been observed with the ST-6 CCD camera attached to the Newtonian focus of the 70-cm meniscus telescope. These data provide optical information on sources that have been rarely observed in the optical band. Variability on long time scales within one magnitude in R band was detected for all of the observed objects except two. The largest variation was observed for 1ES 0502+675 and equals to {delta}R=1{sup m}{sub .}07.

Kurtanidze, Omar M.; Nikolashvili, Maria G.; Kapanadze, Bidzina Z.; Kimeridze, Givi N.; Sigua, Lorand A.; Urushadze, Tamriko V.; Goderidze, Eldar K

2004-06-01

183

R Band Photometry of X-Ray Selected BL Lacertae Objects: 1ES 0229+20, 1ES 0323+02, 1ES 0502+67, 1ES 0647+25, 1ES 0806+52, 1ES 0927+50, 1ES 1028+51, 1ES 1959+65 and 1ES 2344+51  

International Nuclear Information System (INIS)

We present optical R band photometry for nine X-ray Einstein Slew Survey Sample BL Lacertae objects: 1ES 0323+022, 1ES 0502+675, 1ES 0647+250, 1ES 0806+524, 1ES 1028+511, 1ES 1959+650 and 1ES 2344+514. Two blazars 1ES 0229+200 and 1ES 0927+500 didn't show any detectable variability. They have all been observed with the ST-6 CCD camera attached to the Newtonian focus of the 70-cm meniscus telescope. These data provide optical information on sources that have been rarely observed in the optical band. Variability on long time scales within one magnitude in R band was detected for all of the observed objects except two. The largest variation was observed for 1ES 0502+675 and equals to ?R=1m.07

2004-06-01

184

Development of a new digital subtraction angiography system DAR-2400  

International Nuclear Information System (INIS)

A new digital subtraction angiography system DAR-2400 has been developed. This system conforms to the trend of film-less diagnosis and interventional angiography developing rapidly in the field of the circulation system diagnosis. At the time of radiography and fluoroscopy, acquisition speed, spatial and temporal resolution, storage capacity of images have been improved. Also, new permanent image filing devices and other many functions have realized efficient examination. (author)

1990-01-01

185

Quantifying Ladder Fuels: A New Approach Using LiDAR  

Directory of Open Access Journals (Sweden)

Full Text Available We investigated the relationship between LiDAR and ladder fuels in the northern Sierra Nevada, California USA. Ladder fuels are often targeted in hazardous fuel reduction treatments due to their role in propagating fire from the forest floor to tree crowns. Despite their importance, ladder fuels are difficult to quantify. One common approach is to calculate canopy base height, but this has many potential sources of error. LiDAR may be a way forward to better characterize ladder fuels, but has only been used to address this question peripherally and in only a few instances. After establishing that landscape fuel treatments reduced canopy and ladder fuels at our site, we tested which LiDAR-derived metrics best differentiated treated from untreated areas. The percent cover between 2 and 4 m had the most explanatory power to distinguish treated from untreated pixels across a range of spatial scales. When compared to independent plot-based measures of ladder fuel classes, this metric differentiated between high and low levels of ladder fuels. These findings point to several immediate applications for land managers and suggest new avenues of study that could lead to possible improvements in the way that we model wildfire behavior across forested landscapes in the US.

Heather A. Kramer

2014-06-01

186

CONSTRUIR LAS COMPETENCIAS, ¿ES DARLE LA ESPALDA A LOS SABERES?  

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Full Text Available RESUMENUn enfoque por competencias no tiene porque ser, paradójicamente, más elitista que una pedagogía centrada en los saberes. ¿Cómo abordar el enfoque por competencias? Como una tentativa de modernizar el currículum, adaptado a la realidad contemporánea, en el campo del trabajo, de la ciudadanía o de la vida cotidiana. Es cierto que la ascensión de las competencias en el campo educativo va vinculada al mundo de la economía y del trabajo, pero también importa mostrar que, lejos de dar la espalda a los saberes, el enfoque por competencias les da una fuerza nueva, vinculándolas a las prácticas sociales, a las situaciones complejas, a los problemas, a los proyectos…ABSTRACTUn aproche par compétences ne será pas, paradoxalement, plus elitaire qu’ une pedagogie centrée sur les savoirs. Comment situer l’approche par compétences? Comme une tentative de moderniser le curriculum, de le adapter à la réalité contemporaine, dans le champ du  travail, de la citoyenneté on de la vie quotidienne. C’ est vrai que l’ascension des compétences dans le champ educatif va unit au monde de l’economie et du travail, mais aussi il importe montrer que, loin de tourner de dos aux savoirs, l’approche par compétences leur donne une forcé nouvelle, en les liant á de pratiques sociales, á des situations complexes, á des problemes, á des proyects…

Philippe Perrenoud

2011-03-01

187

Multipath Estimation in Urban Environments from Joint GNSS Receivers and LiDAR Sensors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, multipath error on Global Navigation Satellite System (GNSS) signals in urban environments is characterized with the help of Light Detection and Ranging (LiDAR) measurements. For this purpose, LiDAR equipment and Global Positioning System (GPS) receiver implementing a multipath estimating architecture were used to collect data in an urban environment. This paper demonstrates how GPS and LiDAR measurements can be jointly used to model the environment and obtain robust receivers....

Chen, Xin; Ali, Khurram; Dovis, Fabio

2012-01-01

188

¿Qué es la justicia global?  

Directory of Open Access Journals (Sweden)

Full Text Available Ya existen más libros y ensayos sobre "justicia global" en este milenio que en el anterior, al menos según lo que indican las computadoras. Algunos de los temas más amplios que se discuten hoy bajo el título "justicia global" se vienen tratando desde hace siglos, inclusive desde el principio de la civilización, pero se los discutía bajo distintos rótulos, tales como "justicia internacional", "ética internacional" y "la ley de las naciones". Este ensayo explora el significado de tal desplazamiento en la terminología. Un rasgo distintivo del marco filosófico asociado con la expresión "justicia global" es el hecho de destacar el análisis causal y moral del orden institucional global contra el trasfondo de sus alternativas viables y alcanzables. Dentro de este enfoque general de la justicia global, las diferentes concepciones de la justicia global diferirán en los criterios específicos de justicia global que proponen. No obstante ello, esos criterios coincidirán en enfatizar la cuestión sobre cómo funciona nuestro orden institucional global en comparación con sus alternativas viables y alcanzables, en lo que respecta a los intereses humanos fundamentales que resultan relevantes desde un punto de vista moral. Al extender el análisis institucional moral más allá del estado, esta pregunta centra la atención sobre de qué manera la incidencia masiva actual de la violencia y la pobreza extrema, y los profundos excesos de mortalidad y morbilidad que provocan, se pueden evitar -no sencillamente a través de una mejor conducta por parte de los gobiernos, en el plano interno y el internacional sino también, y de manera mucho más efectiva, a través de reformas institucionales globales que, entre otras cosas, mejorarían esa conducta gubernamental al modificar las opciones a disposición de los gobiernos y los incentivos que enfrentan.There are more books and essays on 'global justice' in this millennium already than in the preceding one, at least as far as computers can tell. Some of the broad topics currently debated under the heading of "global justice" have been discussed for centuries, back to the beginnings of civilization. But they were discussed under different labels, such as "international justice", "international ethics," and "the law of nations." This essay explores the significance of this shift in terminology. Distinctive of the philosophical framework associated with the increasingly prominent expression "global justice." is the focus on the causal and moral analysis of the global institutional order against the background of its feasible and reachable alternatives. Within this general global-justice approach, distinct conceptions of global justice will differ in the specific criteria of global justice they propose. But such criteria will coincide in their emphasis on the question of how well our global institutional order is doing, compared to its feasible and reachable alternatives, in regard to the fundamental human interests that matter from a moral point of view. Extending institutional moral analysis beyond the state, this question focuses attention on how today's massive incidence of violence and severe poverty, and the huge excesses of mortality and morbidity they cause might be avoided not merely through better government behavior, internally and internationally, but also, and much more effectively, through global institutional reforms that would, among other things, elevate such government behavior by modifying the options governments have and the incentives they face.

Thomas Pogge

2007-11-01

189

Applying the Moment Distance Framework to LiDAR Waveforms  

Science.gov (United States)

In the past decade or so, there have only been limited approaches formulated for the analysis of waveform LiDAR data. We illustrate how the Moment Distance (MD) framework can characterize the shape of the LiDAR waveforms using simple, computationally fast, geometric operations. We assess the relationship of the MD metrics to some key waveform landmarks - such as locations of peaks, power of returns, and pseudo-heights - using LVIS datasets acquired over a tropical forest in La Selva, Costa Rica in 1998 and 2005. We also apply the MD framework to 2003 LVIS data from Howland Forest, Maine. We also explore the effects of noise on the MD Index (MDI). Our results reveal that the MDI can capture important dynamics in canopy structure. Movement in the location of the peaks is detected by shifts in the MDI. Because this new approach responds to waveform shape, it is more sensitive to changes of location of peak returns than to the power of the return. Results also suggest a positive relationship between the MDI and the canopy pseudo-height.

Salas, E. L.; Aguilar-Amuchastegui, N.; Henebry, G. M.

2010-12-01

190

Remote Sensing | Free Full-Text | Ground Filtering Algorithms for Airborne LiDAR Data: A Review of Critical Issues  

...Ground Filtering Algorithms for Airborne LiDAR Data: A Review of Critical Issues This paper reviews LiDAR ground filtering algorithms used in the process ... We discuss critical issues for the development and application of LiDAR ground filtering algorithms, including filtering procedures for different feature types, ... Ground Filtering Algorithms for Airborne LiDAR Data: A Review of Critical Issues This paper reviews LiDAR ground filtering algorithms used in the ... We discuss critical issues for the development and application of LiDAR ground filtering algorithms, including filtering procedures for different feature types, ...

191

ES cell-derived neuroepithelial cell cultures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

ES cells have the potential to differentiate into cells from all germ layers, which makes them an attractive tool for the development of new therapies. In general, the differentiation of ES cells follows the concept to first generate immature progenitor cells, which then can be propagated and differentiated into mature cellular phenotypes. This also applies for ES cell-derived neurogenesis, in which the development of neural cells follows two major steps: First, the derivation and expansion o...

Karki, Shreeya; Pruszak, Jan; Isacson, Ole; Sonntag, Kai C.

2006-01-01

192

Mapping tree genera using discrete LiDAR and geometric tree metrics Mapeo del género de árboles usando LiDAR y métricas geométricas para árboles  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Maps of tree genera are useful in applications including forest inventory, urban planning, and the maintenance of utility transmission line infrastructure. We present a case study of using high density airborne LiDAR data for tree genera mapping along the right of way (ROW) of a utility transmission line corridor. Our goal was to identify single trees that showed or posed potential threats to transmission line infrastructure. Using the three dimensional mapping capability of LiDAR, we derived...

Connie Ko; Remmel, Tarmo K.; Gunho Sohn

2012-01-01

193

4D Terrestrial LiDAR Data Collection: Geomorphic and Hydraulic Applications (Invited)  

Science.gov (United States)

Terrestrial LiDAR, also known as T-LiDAR, ground-based LiDAR, or Terrestrial Laser Scanning, can provide great insights into some types of geomorphic and hydraulic studies, particularly when collected repeatedly over time. Because T-LiDAR collects a large amount of data on a set grid, oftentimes processes are inadvertently captured that are not part of the initial research question but can be important factors in their own right. In addition, though T-LiDAR is most often used at relatively small sites for high-precision scanning, it also can be used for relatively rapid meso-scale site measurements, albeit typically with less precision. Using examples from the Elwha River dam removals, WA, a canal experiment in NE, and several small river restoration sites in CA, we highlight several important and innovative uses of T-LiDAR measurements, including quick temporal scale changes in water surface features and larger temporal- and spatial-scale changes in reservoir deltaic deposits and longitudinal profile features. Also discussed will be some considerations for improving T-LiDAR error estimation and a comparison to other data collection techniques, including aerial LiDAR, structure-from-motion photogrammetry, and UAV- and plane-captured photogrammetry.

Minear, J. T.; Wright, S. A.; Kinzel, P. J.; Draut, A. E.; Logan, J.

2013-12-01

194

Canopy wake measurements using multiple scanning wind LiDARs  

Science.gov (United States)

Canopy wakes have been shown, in controlled wind tunnel experiments, to significantly affect the fluxes of momentum, heat and other scalars at the land and water surface over distances of ~O(1 km), see Markfort et al. (EFM, 2013). However, there are currently no measurements of the velocity field downwind of a full-scale forest canopy. Point-based anemometer measurements of wake turbulence provide limited insight into the extent and details of the wake structure, whereas scanning Doppler wind LiDARs can provide information on how the wake evolves in space and varies over time. For the first time, we present measurements of the velocity field in the wake of a tall patch of forest canopy. The patch consists of two uniform rows of 35-meter tall deciduous, plane trees, which border either side of the Allée de Dorigny, near the EPFL campus. The canopy is approximately 250 m long, and it is 35 m wide, along the direction of the wind. A challenge faced while making field measurements is that the wind rarely intersects a canopy normal to the edge. The resulting wake flow may be deflected relative to the mean inflow. Using multiple LiDARs, we measure the evolution of the wake due to an oblique wind blowing over the canopy. One LiDAR is positioned directly downwind of the canopy to measure the flow along the mean wind direction and the other is positioned near the canopy to evaluate the transversal component of the wind and how it varies with downwind distance from the canopy. Preliminary results show that the open trunk space near the base of the canopy results in a surface jet that can be detected just downwind of the canopy and farther downwind dissipates as it mixes with the wake flow above. A time-varying recirculation zone can be detected by the periodic reversal of the velocity vector near the surface, downwind of the canopy. The implications of canopy wakes for measurement and modeling of surface fluxes will be discussed.

Markfort, Corey D.; Carbajo Fuertes, Fernando; Valerio Iungo, Giacomo; Stefan, Heinz; Porté-Agel, Fernando

2014-05-01

195

Applicability of Aerial Green LiDAR to a Large River in the Western United States  

Science.gov (United States)

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.

Conner, J. T.; Welcker, C. W.; Cooper, C.; Faux, R.; Butler, M.; Nayegandhi, A.

2013-12-01

196

Registration of vehicle based panoramic image and LiDAR point cloud  

Science.gov (United States)

Higher quality surface information would be got when data from optical images and LiDAR were integrated, owing to the fact that optical images and LiDAR point cloud have unique characteristics that make them preferable in many applications. While most previous works focus on registration of pinhole perspective cameras to 2D or 3D LiDAR data. In this paper, a method for the registration of vehicle based panoramic image and LiDAR point cloud is proposed. Using the translation among panoramic image, single CCD image, laser scanner and Position and Orientation System (POS) along with the GPS/IMU data, precise co-registration between the panoramic image and the LiDAR point cloud in the world system is achieved. Results are presented under a real world data set collected by a new developed Mobile Mapping System (MMS) integrated with a high resolution panoramic camera, two laser scanners and a POS.

Chen, Changjun; Cao, Liang; Xie, Hong; Zhuo, Xiangyu

2013-10-01

197

Extraction of Urban Power Lines from Vehicle-Borne LiDAR Data  

Directory of Open Access Journals (Sweden)

Full Text Available Airborne LiDAR has been traditionally used for power line cruising. Nevertheless, data acquisition with airborne LiDAR is constrained by the complex environments in urban areas as well as the multiple parallel line structures on the same power line tower, which means it is not directly applicable to the extraction of urban power lines. Vehicle-borne LiDAR system has its advantages upon airborne LiDAR and this paper tries to utilize vehicle-borne LiDAR data for the extraction of urban power lines. First, power line points are extracted using a voxel-based hierarchical method in which geometric features of each voxel are calculated. Then, a bottom-up method for filtering the power lines belonging to each power line is proposed. The initial clustering and clustering recovery procedures are conducted iteratively to identify each power line. The final experiment demonstrates the high precision of this technique.

Liang Cheng

2014-04-01

198

El Buen Ordeño es muy Importante  

Directory of Open Access Journals (Sweden)

Full Text Available El ordeño es uno de los mayores trabajos de las fincas lecheras y es también uno de los más importantes. La forma en que se ordeña las vacas determina en gran parte la calidad de la leche e influye además sobre la cantidad de leche producida. Las vacas lecheras deben ser ordeñadas dos veces al día, a intervalos iguales.

Blackman Charles

1947-06-01

199

Latt\\`es maps and combinatorial expansion  

CERN Document Server

A Latt\\`es map $f\\colon \\hat{\\mathbb{C}}\\rightarrow \\hat{\\mathbb{C}}$ is a rational map that is obtained from a finite quotient of a conformal torus endomorphism. We characterize Latt\\`es maps by their combinatorial expansion behavior.

Yin, Qian

2011-01-01

200

LiDAR bore-sight calibration: a comparative study  

Science.gov (United States)

Within the AutoProbaDTM project, we plan to develop fast and fully automated techniques to derive topographic maps from full-waveform airborne LiDAR data, based on a probabilistic approach to modelling surfaces and data acquisition, solving inverse problems and handling uncertainty. Bayesian inference provides a rigorous framework for unsupervised reconstruction of the DEM and error propagation from the data to the end result, treating all quantities as random variables. Automatic sensor calibration plays a major role in this project. In fact, the overall accuracy and uncertainty obtained from the LiDAR technology depends on the assembly and calibration of the three system components: the GPS (Global Positioning System), the INS (Inertial Navigation System) and the laser-scanner device. Bore-sight angles are the angular offsets in X,Y and Z directions between the scanner frame and the INS frame measured at the centre of the INS body frame. In this paper we evaluate some of the principal bore-sight calibration methods and we propose a novel method based on the Bayesian inference to address this problem as well. The first contribution is to use not only the 3D points extracted from the raw waveforms but their uncertainty as well, and to apply a probabilistic surface matching with spatially variable point accuracy in order to obtain the attitude corrections. The second contribution consists of using all the flight lines, where most methods only use the calibration cross. This way we can also estimate the attitude drift and correct for temporal attitude variations as well. Finally, we use the probabilistic framework for error propagation and propose a probability distribution of the calibrated bore-sight angles.

Gonçalves, G. R.; Jalobeanu, A.

2011-12-01

 
 
 
 
201

A Kinetic Study of Anaerobic Biodegradation of Food and Fruit Residues during Biogas Generation Using Initial Rate Method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A kinetic study of biogas production from Urban Solid Waste (USW) generated in Dar es Salaam city (Tanzania) is presented. An experimental bioreactor simulating mesophilic conditions of most USW landfills was developed. The goal of the study was to generate the kinetic order of reaction with respect to biodegradable organic waste and use it to model biogas production from food residues mixed with fruit waste. Anaerobic biode...

William Wanasolo; Samwel Victor Manyele; John Makunza

2013-01-01

202

Self-care, foot problems and health in Tanzanian diabetic patients and comparisons with matched Swedish diabetic patients  

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The overall aim was to study self-care, foot problems and self-perceived health in 150 consecutively invited Tanzanian diabetic patients and to compare them with gender- and age-matched Swedish diabetic patients (n=150) from a middle Sweden area. The main study was cross-sectional and took place at a diabetes clinic in Dar es Salaam. All patients answered questions about their self-care satisfaction, diabetes knowledge and skills, and educational needs. Foot examination also included question...

Smide, Bibbi

2000-01-01

203

Common Mental Disorders and Risk Factors in Urban Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A cross sectional population based epidemiological survey of 899 adults aged between 15 and 59 was undertaken in two urban areas of demographic surveillance sites in Dar es Salaam, Tanzania, using the Clinical Interview Schedule Revised. Significantly higher rates were found among those who had experienced more than three severe life events in the last six months and relationship difficulties and death of a loved one.

Rachel Jenkins; Joseph Mbatia; Nicola Singleton; Bethany White

2010-01-01

204

Ten Tanzanian transplants: problems and perspectives.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A strategy of live related donor kidney transplantation coupled to the briefest possible preparatory period of haemodialysis was adopted as the most cost effective treatment for a selected group of 9 Tanzanian patients who received a total of 10 grafts. Patient and donor selection and preparation were carried out at Muhimbuli Medical Centre, Dar es Salaam, and the transplant procedure and first few months of follow-up were done at St. Thomas' Hospital, London. There was a high incidence of co...

Basinda, S. L.; Maro, E. E.; Mclarty, D. G.; Young, A. E.; Wing, A. J.

1988-01-01

205

Blood Culture Contamination in Tanzania, Malawi, and the United States: a Microbiological Tale of Three Cities?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We conducted retrospective, comparative analyses of contamination rates for cultures of blood obtained in the emergency rooms of Muhimbili National Hospital (MNH) in Dar es Salaam, Tanzania; Lilongwe Central Hospital (LCH) in central Malawi; and the Duke University Medical Center (DUMC) in the United States. None of the emergency room patients had indwelling intravascular devices at the time that the blood samples for cultures were obtained. In addition, we reviewed the contamination rates fo...

2006-01-01

206

Challenges and approaches to the integration of HIS:case studies from Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This research falls under the area of design and implementation of information systems in developing countries. I have studied the health information systems in Tanzania using case studies in Ilala Municipal, situated in Dar es Salaam city, and Tabora Municipal in the Tabora region. The purpose of the research was to study the challenges encountered by the health workers at the local level with regard to information collection, use and reporting. The focus of this thesis is on problems of fra...

Shidende, Nima H.

2005-01-01

207

Implementation of artemether-lumefantrine treatment policy for malaria at health facilities in Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

V Mugoyela1, O Minzi21Department of Medicinal Chemistry, 2Unit of Pharmacology and Therapeutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, Dar Es Salaam, TanzaniaBackground: The purpose of this study was to compare knowledge on the part of health workers in public and private health facilities about prescribing and dispensing of an artemether-lumefantrine combination, 3 years after moving from sulfadoxine-pyrimethamine to artemether-lumefantrine as a first-line t...

2011-01-01

208

Psychological effects of business trainings in Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This master thesis, as a part of a project on business trainings in Tanzania, investigates the effects of these trainings on change in mindset and soft skills of microentrepreneurs in Dar es Salaam. It focuses on following dimensions: Creativity, Individualism, Locus of Control, Need for Achievement, Dispositional Optimism and Trust/Relationship. The significant differences are found on the number of dimensions. Entrepreneurs who took part in the training have more internal locus of control, ...

?yniewska, Agnieszka Anna; Selezneva, Olga

2009-01-01

209

Waste is a resource:A study on the opportunities in a new solid waste management in Iringa municipality  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Municipal solid waste refers to waste in a solid form, produced in the daily day life of a society such as packaging, food scrapes, grass clippings, clothing, furniture, paper, electronics and so on. It is called municipal solid waste because it is in the responsibility of the local government and comes from our homes, schools, hospitals and businesses. It is produced 108 tons municipal solid waste in Iringa each day. Iringa district is located approximately 500km from Dar Es Salaam and 263...

Solberg, Eirin

2012-01-01

210

A method for cross-sector priority setting: gaps and hypotheses in malaria research  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study proposes a new priority setting method for identifying critical information gaps in a multisector system. The method uses graph-theoretical concepts and principles of systems theory in characterizing the underlying information structure of the system. Its application is illustrated in the context of malaria control in Tanzania, drawing on the findings of a workshop held in October 2003 in Dar es Salaam. The workshop identified two critical pathways, EVHA and EVHPA, which warrant be...

2004-01-01

211

Hydrogeological Investigations of Deep Coastal Aquifers, Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

ABSTRACT Borehole geophysical logging is viable method of determining the water quality and hydrogeological parameters of aquifers. A recent study was conducted to delineate the distribution of formation water salinity profile down to 600 meters below land surface of the Kimbiji coastal aquifer located 40 km south of the commercial capital, Dar es Salaam coastal plain in Tanzania. A hydrogeologic seismic cross section was also constructed. The borehole geophysical methods included short and l...

James, Apolkarpi Peter

2007-01-01

212

Gender-Related Differences in the Prevalence of Cardiovascular Disease Risk Factors and their Correlates in Urban Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Urban areas in Africa suffer a serious problem with dual burden of infectious diseases and emerging chronic diseases such as cardiovascular diseases (CVD) and diabetes which pose a serious threat to population health and health care resources. However in East Africa, there is limited literature in this research area. The objective of this study was to examine the prevalence of cardiovascular disease risk factors and their correlates among adults in Temeke, Dar es Salaam, Tanzania....

Njelekela, Marina A.; Mpembeni, Rose; Mligiliche, Nuru L.; Mtabaji, Jacob; Muhihi, Alfa; Spiegelman, Donna Lynn; Hertzmark, Ellen; Liu, Enju; Finkelstein, Julia Leigh; Fawzi, Wafaie W.; Willett, Walter C.

2009-01-01

213

An affordable, quality-assured community-based system for high-resolution entomological surveillance of vector mosquitoes that reflects human malaria infection risk patterns  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background More sensitive and scalable entomological surveillance tools are required to monitor low levels of transmission that are increasingly common across the tropics, particularly where vector control has been successful. A large-scale larviciding programme in urban Dar es Salaam, Tanzania is supported by a community-based (CB) system for trapping adult mosquito densities to monitor programme performance. Methodology An intensive and extensive CB s...

Chaki Prosper P; Mlacha Yeromin; Msellemu Daniel; Muhili Athuman; Malishee Alpha D; Mtema Zacharia J; Kiware Samson S; Zhou Ying; Lobo Neil F; Russell Tanya L; Dongus Stefan; Govella Nicodem J; Killeen Gerry F

2012-01-01

214

Human bite injuries in the oro-facial region at the Muhimbili National Hospital, Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Human bites in the maxillofacial region compromise function and aesthetics, resulting in social and psychological effects. There is paucity of information regarding human bite injuries in Tanzania. The aim of the study was to assess the occurrence, treatment modalities and prognosis of human bite injuries in the oro-facial region at the Muhimbili National Hospital Dar es Salaam, Tanzania. Methods In a prospective study the details of patients...

2008-01-01

215

Prevention of intimate partner violence : community and healthcare workers´ perceptions in urban Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: Intimate partner violence (IPV) against women is public health and human rights concern. The studies forming this thesis seek to understand healthcare worker and community attitudes and perceptions about IPV; their role in support, care and prevention of IPV, and the feasibility of introducing routine screening for IPV among women attending healthcare. Methods: Four interrelated studies were conducted in Temeke District, Dar es Salaam, Tanzania: 1) a content analysis of 16 in-dept...

Laisser, Rose Mjawa

2011-01-01

216

LiDAR Forest Inventory with Single-Tree, Double-, and Single-Phase Procedures  

International Nuclear Information System (INIS)

Light Detection and Ranging (LiDAR) data at 0.5-2 m postings were used with double-sample, stratified procedures involving single-tree relationships in mixed, and single species stands to yield sampling errors ranging from ±2.1% to ±11.5%. LiDAR samples were selected with focal filter procedures and heights computed from interpolated canopy and DEM surfaces. Tree dbh and height data were obtained at various ratios of LiDAR, ground samples for DGPS located ground plots. Dbh-height and ground-LiDAR height models were used to predict dbh and compute Phase 2 estimates of basal area and volume. Phase 1 estimates were computed using the species probability distribution from ground plots in each strata. Phase 2 estimates were computed by randomly assigning LiDAR heights to species groups using a Monte Carlo simulation for each ground plot. There was no statistical difference between volume estimates from 0.5 m and 1 m LiDAR densities. Volume estimates from single-phase LiDAR procedures utilizing existing tree attributes and height bias relationships were obtained with sampling errors of 1.8% to 5.5%.

2009-01-01

217

LiDAR Forest Inventory with Single-Tree, Double-, and Single-Phase Procedures  

Directory of Open Access Journals (Sweden)

Full Text Available Light Detection and Ranging (LiDAR data at 0.5–2?m postings were used with double-sample, stratified procedures involving single-tree relationships in mixed, and single species stands to yield sampling errors ranging from ±2.1% to ±11.5%. LiDAR samples were selected with focal filter procedures and heights computed from interpolated canopy and DEM surfaces. Tree dbh and height data were obtained at various ratios of LiDAR, ground samples for DGPS located ground plots. Dbh-height and ground-LiDAR height models were used to predict dbh and compute Phase 2 estimates of basal area and volume. Phase 1 estimates were computed using the species probability distribution from ground plots in each strata. Phase 2 estimates were computed by randomly assigning LiDAR heights to species groups using a Monte Carlo simulation for each ground plot. There was no statistical difference between volume estimates from 0.5?m and 1?m LiDAR densities. Volume estimates from single-phase LiDAR procedures utilizing existing tree attributes and height bias relationships were obtained with sampling errors of 1.8% to 5.5%.

Robert C. Parker

2009-01-01

218

Nos fios de Ariádne: cartografia da relação saúdetrabalho numa escola pública de Vitória-ES  

Directory of Open Access Journals (Sweden)

Full Text Available En los hilos de Ariadna: cartografía de la relación salud-trabajo en una escuela pública de Vitória-ES Se trata del estudio cualitativo abordando las relaciones entre salud y trabajo de los profesores de una escuela pública en la ciudad de Vitória, capital del estado de Espíritu Santo. Su objetivo fue cartografiar las vivencias de placer y sufrimiento de los docentes, principalmente las estrategias creadas para defenderse de las nocividades del ambiente de trabajo y producir salud. Afirma la insociabilidad entre modos de trabajar y modos de subjetivar, y constata que la deteriorización del sistema público de enseñanza ha producido sus efectos en el trabajo del profesorado, comprometiendo la salud de esos profesionales y causando, muchas veces, su alejamiento de las funciones por medio de licencias médicas o mismo abandono de la profesión. Busca dar visibilidades a las acciones que apuntan para la recreación del trabajo, mismo dentro de condiciones adversas.

Maria Elizabeth Barros de Barros

2007-01-01

219

Numerical study of ES-SAGD process  

Energy Technology Data Exchange (ETDEWEB)

Steam assisted gravity drainage (SAGD) processes have been used to produce bitumen reservoirs in Alberta for several years. Expanding solvent SAGD (ES-SAGD) was developed to improve the energy efficiency of SAGD processes by co-injecting small amounts of solvent with the steam. The solvent condenses with the steam along the boundary of the gas chamber and reduces the viscosity of the solvent bitumen mixture. This study conducted an SAGD baseline test and an ES-SAGD test within a 2-D high pressure-high temperature test facility. The ES-SAGD test was then history-matched. The effects of the solvent in the ES-SAGD process were analyzed and sensitivity studies were conducted to examine the effects of key parameters. Experimental results from the tests showed that the ES-SAGD process had higher recovery rates than the SAGD process. The co-injected solvent enhanced solution gas production, lowered residual oil saturation, and reduced the viscosity of the oil. The analyses showed that the solvent spread within the gas chamber. Sensitivity studies showed that gas convective mixing is an important factor in the ES-SAGD process. 14 refs., 5 tabs., 26 figs.

Deng, X.; Nasr, T. [Alberta Research Council, Edmonton, AB (Canada); Zhao, L. [Petro-Canada Oil and Gas Inc., Calgary, AB (Canada); Law, D.H.S. [Schlumberger Canada Ltd., Edmonton, AB (Canada). Reservoir Fluid Centre

2006-07-01

220

LiDAR Forest Inventory with Single-Tree, Double-, and Single-Phase Procedures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Light Detection and Ranging (LiDAR) data at 0.5–2?m postings were used with double-sample, stratified procedures involving single-tree relationships in mixed, and single species stands to yield sampling errors ranging from ±2.1% to ±11.5%. LiDAR samples were selected with focal filter procedures and heights computed from interpolated canopy and DEM surfaces. Tree dbh and height data were obtained at various ratios of LiDAR, ground samples for DGPS located gr...

Parker, Robert C.; Evans, David L.

2009-01-01

 
 
 
 
221

Transmission of intestinal schistosomiasis in Bahir Dar, northwest Ethiopia.  

Science.gov (United States)

Parasitological, malacological and transmission studies were made for a period of one year in the town of Bahir Dar, northwest Ethiopia. The overall prevalence of schistosomiasis mansoni in residents of Kebeles 8, 9 and 10 was 12%. The prevalence in Sertse Dengel school children was 45% and that in Dil Chibo school children was 32%. The peak prevalence in both sexes in school and non-school populations occurred in the age group 10-14 years. Intensity of infection showed a similar pattern of age variation as prevalence. Biomphalaria pfeifferi snail density peaked towards the end of the rainy season (September) in Lake Tana and around the middle of the dry season (January) on the shore of the River Abay. In September, infected snails were recovered from all collection sites. Of mice immersed in four water contact sites in September, schistosome infections developed in those immersed in three sites. Parasitological findings suggested that schistosomiasis infection rates depended on age and sex of individuals and geographical location of the place from the potentially infective water bodies. Snail population density and associated schistosomal infection in a human population depended on rainfall and associated ecological changes such as fluctuation in water level and vegetation density. As malacological findings and sentinel mouse immersion results indicated, it appeared that the main transmission season in Lake Tana region is towards the end of the rainy season although low level intermittent transmission may take place throughout the year. PMID:1954954

Erko, B; Tedla, S; Petros, B

1991-10-01

222

ES cell-derived neuroepithelial cell cultures.  

Science.gov (United States)

ES cells have the potential to differentiate into cells from all germ layers, which makes them an attractive tool for the development of new therapies. In general, the differentiation of ES cells follows the concept to first generate immature progenitor cells, which then can be propagated and differentiated into mature cellular phenotypes. This also applies for ES cell-derived neurogenesis, in which the development of neural cells follows two major steps: First, the derivation and expansion of immature neuroepithelial precursors and second, their differentiation into mature neural cells. A common method to produce neural progenitors from ES cells is based on embryoid body (EB) formation, which reveals the differentiation of cells from all germ layers including neuroectoderm. An alternative and more efficient method to induce neuroepithelial cell development uses stromal cell-derived inducing activity (SDIA), which can be achieved by co-culturing ES cells with skull bone marrow-derived stromal cells. Both, EB formation and SDIA, reveal the development of rosette-like structures, which are thought to resemble neural tube- and/or neural crest-like progenitors. The neural precursors can be isolated, expanded and further differentiated into specific neurons and glia cells using defined culture conditions. Here, we describe the generation and isolation of such rosettes in co-culture experiments with the stromal cell line MS5 (2-5). PMID:18704173

Karki, Shreeya; Pruszak, Jan; Isacson, Ole; Sonntag, Kai C

2006-12-01

223

ASTER GDEM validation using LiDAR data over coastal regions of Greenland  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Elevation data from airborne Light Detection and Ranging (LiDAR) campaigns are used in an attempt to evaluate the accuracy of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) global digital elevation model (GDEM) in Greenland.

Hvidegaard, Sine Munk; Sørensen, Louise Sandberg; Forsberg, Rene?

2011-01-01

224

Akkuraatheidseffek van LiDAR - datavermindering op digitale hoogtemodelle The effects of data reduction on remotely sensed LiDAR-based DEMs  

Directory of Open Access Journals (Sweden)

Full Text Available Digitale hoogtemodelle word in ’n verskeidenheid toepassings gebruik, nie net in die veld vanGeografie nie, maar dikwels in ’n interdissiplinêre konteks, byvoorbeeld omgewingsbestuur, bosbou en stadsmodellering.LiDAR-derived DEMs can take weeks to process, thus minimising the effectiveness of timely solutions. In order to reach realistic processing times, data sets need to be reduced. However, data reduction needs to be conducted with the minimum loss of accuracy. This study investigates the effects of data reduction on LiDAR-derived DEMs.

Jaco Immelman

2011-09-01

225

Automatic representation and reconstruction of DBM from LiDAR data using Recursive Minimum Bounding Rectangle  

Science.gov (United States)

Three-dimensional building models are important for various applications, such as disaster management and urban planning. The development of laser scanning sensor technologies has resulted in many different approaches for efficient building model generation using LiDAR data. Despite this effort, generation of these models lacks economical and reliable techniques that fully exploit the advantage of LiDAR data. Therefore, this research aims to develop a framework for fully-automated building model generation by integrating data-driven and model-driven methods using LiDAR datasets. The building model generation starts by employing LiDAR data for building detection and approximate boundary determination. The generated building boundaries are then integrated into a model-based processing strategy because LiDAR derived planes show irregular boundaries due to the nature of LiDAR point acquisition. The focus of the research is generating models for the buildings with right-angled-corners, which can be described with a collection of rectangles under the assumption that the majority of the buildings in urban areas belong to this category. Therefore, by applying the Minimum Bounding Rectangle (MBR) algorithm recursively, the LiDAR boundaries are decomposed into sets of rectangles for further processing. At the same time, the quality of the MBRs is examined to verify that the buildings, from which the boundaries are generated, are buildings with right-angled-corners. The parameters that define the model primitives are adjusted through a model-based boundary fitting procedure using LiDAR boundaries. The level of details in the final Digital Building Model is based on the number of recursions during the MBR processing, which in turn are determined by the LiDAR point density. The model-based boundary fitting improves the quality of the generated boundaries and as seen in experimental results, the quality depends on the average LiDAR point spacing. This research thus develops an approach which not only automates the building model generation, but also achieves the best accuracy of the model while utilizing only LiDAR data.

Kwak, Eunju; Habib, Ayman

2014-07-01

226

Investigating assumptions of crown archetypes for modelling LiDAR returns  

Digital Repository Infrastructure Vision for European Research (DRIVER)

LiDAR has the potential to derive canopy structural information such as tree height and leaf area index (LAI), via models of the LiDAR signal. Such models often make assumptions regarding crown shape to simplify parameter retrieval and crown archetypes are typically assumed to contain a turbid medium to account for within-crown scattering. However, these assumptions may make it difficult to relate derived structural parameters to measurable canopy properties. Here, we test the impact of crown...

Calders, K.; Lewis, P.; Disney, M.; Verbesselt, J.; Herold, M.

2013-01-01

227

SVM-Based Classification of Segmented Airborne LiDAR Point Clouds in Urban Areas  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Object-based point cloud analysis (OBPA) is useful for information extraction from airborne LiDAR point clouds. An object-based classification method is proposed for classifying the airborne LiDAR point clouds in urban areas herein. In the process of classification, the surface growing algorithm is employed to make clustering of the point clouds without outliers, thirteen features of the geometry, radiometry, topology and echo characteristics are calculated, a support vector machine (SVM) is ...

Jixian Zhang; Xiangguo Lin; Xiaogang Ning

2013-01-01

228

Diversity Arrays Technology (DArT) for whole-genome profiling of barley  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Diversity Arrays Technology (DArT) can detect and type DNA variation at several hundred genomic loci in parallel without relying on sequence information. Here we show that it can be effectively applied to genetic mapping and diversity analyses of barley, a species with a 5,000-Mbp genome. We tested several complexity reduction methods and selected two that generated the most polymorphic genomic representations. Arrays containing individual fragments from these representations generated DArT f...

Wenzl, Peter; Carling, Jason; Kudrna, David; Jaccoud, Damian; Huttner, Eric; Kleinhofs, Andris; Kilian, Andrzej

2004-01-01

229

Dar razón de la libertad en Kant y en Hegel  

Directory of Open Access Journals (Sweden)

Full Text Available El artículo analiza y confronta en perspectiva contemporánea los conceptos de razón y libertad en Kant y en Hegel. Refuta las interpretaciones corrientes de estos autores y pone de relieve la primacía de la libertad. Sólo por la existencia de la libertad es posible la razón. Tal es el famoso "bucle" reconocido por Kant: la razón es el fundamento (lógico de la libertad, mientras que ésta es la fundación (ontológica, efectivamente de la razón. Hegel estará sustancialmente de acuerdo con ese "bucle de retroalimentación", pero se esforzará por desarrollar dialécticamente lo que en el analítico Kant aparece como un conjunto de temas yuxtapuestos. En el filósofo suabo, ambos temas se encuentran incardinados en un movimiento mucho más amplio e integrador.The article analyses and confronts the concepts of reason and freedom in Kant and Hegel in a contemporary perspective. It refutes the current interpretations of these authors and makes relevant the priority of freedom. Reason is possible only because of the existence of freedom. Such the famous circle acknowledged by Kant: reason is the (logical grounding of freedom, whilst the latter is the (ontological, effective grounding of reason. Hegel will agree with that "circle of feedback", but will endeavour to develop dialectically what in the analytical Kant appears as a set of juxtaposed issues. In the swabian philosopher, both issues are incardinated in a much wider and integrated movement.

Félix Duque

2004-01-01

230

Dar razón de la libertad en Kant y en Hegel  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish El artículo analiza y confronta en perspectiva contemporánea los conceptos de razón y libertad en Kant y en Hegel. Refuta las interpretaciones corrientes de estos autores y pone de relieve la primacía de la libertad. Sólo por la existencia de la libertad es posible la razón. Tal es el famoso "bucle" [...] reconocido por Kant: la razón es el fundamento (lógico) de la libertad, mientras que ésta es la fundación (ontológica, efectivamente) de la razón. Hegel estará sustancialmente de acuerdo con ese "bucle de retroalimentación", pero se esforzará por desarrollar dialécticamente lo que en el analítico Kant aparece como un conjunto de temas yuxtapuestos. En el filósofo suabo, ambos temas se encuentran incardinados en un movimiento mucho más amplio e integrador. Abstract in english The article analyses and confronts the concepts of reason and freedom in Kant and Hegel in a contemporary perspective. It refutes the current interpretations of these authors and makes relevant the priority of freedom. Reason is possible only because of the existence of freedom. Such the famous circ [...] le acknowledged by Kant: reason is the (logical) grounding of freedom, whilst the latter is the (ontological, effective) grounding of reason. Hegel will agree with that "circle of feedback", but will endeavour to develop dialectically what in the analytical Kant appears as a set of juxtaposed issues. In the swabian philosopher, both issues are incardinated in a much wider and integrated movement.

Duque, Félix.

231

The first genetic map of pigeon pea based on diversity arrays technology (DArT) markers.  

Science.gov (United States)

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. PMID:21677394

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

232

¿Por qué Freud es de actualidad?  

Directory of Open Access Journals (Sweden)

Full Text Available Este texto pretende mostrar en forma condensada algunos de los lineamientos a partir de los cuales es posible sostener en qué sentido puede afirmarse que Freud y su descubrimiento del inconsciente y la pulsión, continúan siendo de actualidad para reflexionar acerca de los problemas contemporáneos.

Héctor Gallo.

2002-03-01

233

Independent evaluation of the SNODAS snow depth product using regional scale LiDAR-derived measurements  

Science.gov (United States)

Repeated Light Detection and Ranging (LiDAR) surveys are quickly becoming the de facto method for measuring spatial variability of montane snowpacks at high resolution. This study examines the potential of a 750 km2 LiDAR-derived dataset of snow depths, collected during the 2007 northern Colorado Cold Lands Processes Experiment (CLPX-2), as a validation source for an operational hydrologic snow model. The SNOw Data Assimilation System (SNODAS) model framework, operated by the US National Weather Service, combines a physically-based energy-and-mass-balance snow model with satellite, airborne and automated ground-based observations to provide daily estimates of snowpack properties at nominally 1 km resolution over the coterminous United States. Independent validation data is scarce due to the assimilating nature of SNODAS, compelling the need for an independent validation dataset with substantial geographic coverage. Within twelve distinctive 500 m × 500 m study areas located throughout the survey swath, ground crews performed approximately 600 manual snow depth measurements during each of the CLPX-2 LiDAR acquisitions. This supplied a dataset for constraining the uncertainty of upscaled LiDAR estimates of snow depth at the 1 km SNODAS resolution, resulting in a root-mean-square difference of 13 cm. Upscaled LiDAR snow depths were then compared to the SNODAS-estimates over the entire study area for the dates of the LiDAR flights. The remotely-sensed snow depths provided a more spatially continuous comparison dataset and agreed more closely to the model estimates than that of the in situ measurements alone. Finally, the results revealed three distinct areas where the differences between LiDAR observations and SNODAS estimates were most drastic, suggesting natural processes specific to these regions as causal influences on model uncertainty.

Hedrick, A.; Marshall, H.-P.; Winstral, A.; Elder, K.; Yueh, S.; Cline, D.

2014-06-01

234

LiDAR Applications in Resource Geology and Benefits for Land Management  

Science.gov (United States)

The US Forest Service (US Department of Agriculture) manages a broad range of geologic resources and hazards on National Forests and Grass Lands throughout the United States. Resources include rock and earth materials, groundwater, caves and paleontological resources, minerals, energy resources, and unique geologic areas. Hazards include landslides, floods, earthquakes, volcanic eruptions, and naturally hazardous materials (e.g., asbestos, radon). Forest Service Geologists who address these issues are Resource Geologists. They have been exploring LiDAR as a revolutionary tool to efficiently manage all of these hazards and resources. However, most LiDAR applications for management have focused on timber and fuels management, rather than landforms. This study shows the applications and preliminary results of using LiDAR for managing geologic resources and hazards on public lands. Applications shown include calculating sediment budgets, mapping and monitoring landslides, mapping and characterizing borrow pits or mines, determining landslide potential, mapping faults, and characterizing groundwater dependent ecosystems. LiDAR can be used to model potential locations of groundwater dependent ecosystems with threatened or endangered plant species such as Howellia aquatilis. This difficult to locate species typically exists on the Mendocino National Forest within sag ponds on landslide benches. LiDAR metrics of known sites are used to model potential habitat. Thus LiDAR can link the disciplines of geology, hydrology, botany, archaeology and others for enhanced land management. As LiDAR acquisition costs decrease and it becomes more accessible, land management organizations will find a wealth of applications with potential far-reaching benefits for managing geologic resources and hazards.

Mikulovsky, R. P.; De La Fuente, J. A.

2013-12-01

235

Estimating FPAR of maize canopy using airborne discrete-return LiDAR data.  

Science.gov (United States)

The fraction of absorbed photosynthetically active radiation (FPAR) is a key parameter for ecosystem modeling, crop growth monitoring and yield prediction. Ground-based FPAR measurements are time consuming and labor intensive. Remote sensing provides an alternative method to obtain repeated, rapid and inexpensive estimates of FPAR over large areas. LiDAR is an active remote sensing technology and can be used to extract accurate canopy structure parameters. A method to estimating FPAR of maize from airborne discrete-return LiDAR data was developed and tested in this study. The raw LiDAR point clouds were processed to separate ground returns from vegetation returns using a filter method over a maize field in the Heihe River Basin, northwest China. The fractional cover (fCover) of maize canopy was computed using the ratio of canopy return counts or intensity sums to the total of returns or intensities. FPAR estimation models were established based on linear regression analysis between the LiDAR-derived fCover and the field-measured FPAR (R(2) = 0.90, RMSE = 0.032, p < 0.001). The reliability of the constructed regression model was assessed using the leave-one-out cross-validation procedure and results show that the regression model is not overfitting the data and has a good generalization capability. Finally, 15 independent field-measured FPARs were used to evaluate accuracy of the LiDAR-predicted FPARs and results show that the LiDAR-predicted FPAR has a high accuracy (R(2) = 0.89, RMSE = 0.034). In summary, this study suggests that the airborne discrete-return LiDAR data could be adopted to accurately estimate FPAR of maize. PMID:24663850

Luo, Shezhou; Wang, Cheng; Xi, Xiaohuan; Pan, Feifei

2014-03-10

236

Airborne Light Detection and Ranging (LiDAR) for Individual Tree Stem Location, Height, and Biomass Measurements  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Light Detection and Ranging (LiDAR) remote sensing has demonstrated potential in measuring forest biomass. We assessed the ability of LiDAR to accurately estimate forest total above ground biomass (TAGB) on an individual stem basis in a conifer forest in the US Pacific Northwest region using three different computer software programs and compared results to field measurements. Software programs included FUSION, TreeVaW, and watershed segmentation. To assess the accuracy of LiDAR TAGB estimati...

Curtis Edson; Wing, Michael G.

2011-01-01

237

Validation of the high-throughput marker technology DArT using the model plant Arabidopsis thaliana  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Diversity Arrays Technology (DArT) is a microarray-based DNA marker technique for genome-wide discovery and genotyping of genetic variation. DArT allows simultaneous scoring of hundreds of restriction site based polymorphisms between genotypes and does not require DNA sequence information or site-specific oligonucleotides. This paper demonstrates the potential of DArT for genetic mapping by validating the quality and molecular basis of the markers, using the model plant Arabidopsis thaliana. ...

Wittenberg, A. H. J.; Lee, T. A. J.; Cayla, C.; Kilian, A.; Visser, R. G. F.; Schouten, H. J.

2005-01-01

238

Maternal delays in utilizing institutional delivery services, Bahir Dar, Ethiopia  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: Timely referrals and access to appropriate health care had a great impact on reduction to maternal deaths and disabilities. Maternal delay is one of the contributing factors for high maternal mortality in developing countries. Maternal delays were categorized into three levels: delay in making the decision for seeking care, delay in arrival at a health facility, and delay in receiving adequate treatment. They have been named first, second, and third delay maternal delays; respectively. This study was aimed at assessing maternal delays in utilizing institutional delivery service sin Bahir Dar, North-Western Ethiopia. Methods: A cross sectional facility based study was conducted on a sample of 422 women attending at a public health facility for delivery services. The sample size was determined by using single population proportion formula and the study participants were selected by using a systematic random sampling method. Data were collected by means of a pre-tested, standardized questionnaire; analysis was carried out using SPSS version 16. Results: Data was collected from 410 laboring mothers. First delay, 155 (37.8% of mothers was delayed in decision making for seeking care from the public health facility and the mean delay was 8 hours. Delay in seeking emergency obstetric care [EOC] was about seven fold among illiterate mothers (AOR, 6.71; 95%CI, 3.66 -12.29 than literate mothers; the odds of delay for EOC were three times more likely among mother were unable to make decisions by their own (AOR, 3.30; 95%CI, 1.25 -7.20 than those mothers who made the decisions of their own. Unemployed mothers were 4 times more likely to have the maternal delay in seeking EOC (AOR, 3.94; 95%CI, 2.36 -6.57 than employed mothers. Second delay, 130 (31.7% of mothers had transportation problems in reaching health care facilities. Predictors in the first maternal delay were also the major contributing factors for this delay. The third delay, after their arrival at health facilities, 126 (30.7% mothers reported that they did not get the services on time; the mean waiting time for getting the service was 4 hours. Conclusions: Many mothers were not getting institutional delivery care services in a timely manner, due to the “three maternal delays”. Mothers’ literacy, decision making power and employment status were the main predictors for delivery service utilization. Hence, emphasis should be given for awareness creation on the risks of maternal delays, designing income generating mechanism, women empowering for in decision making and ambulance services should be strengthened.

Worku Awoke

2013-06-01

239

La Neurociencia Computacional hoy: I. Qué es y por qué es difícil su estudio  

Directory of Open Access Journals (Sweden)

Full Text Available La Neurociencia Computacional es una disciplina consolidada, con más de 20 años de desarrollo, y que emplea técnicas muy diversas para entender diferentes computaciones cerebrales. Aquí se introduce brevemente mediante dos artículos. En el primero, “Qué es y por qué es difícil su estudio”, se introducen de forma muy general cuáles son sus objetivos como ciencia y los problemas con los que se encuentra. En el segundo, mediante “Un ejemplo muy representativo en el campo” abordamos su metodología y destacamos la trascendencia que la Neurociencia Computacional está teniendo y tendrá dentro de las Neurociencias.

Jesús Cortés

2009-01-01

240

Evolutionary feature selection to estimate forest stand variables using LiDAR  

Science.gov (United States)

Light detection and ranging (LiDAR) has become an important tool in forestry. LiDAR-derived models are mostly developed by means of multiple linear regression (MLR) after stepwise selection of predictors. An increasing interest in machine learning and evolutionary computation has recently arisen to improve regression use in LiDAR data processing. Although evolutionary machine learning has already proven to be suitable for regression, evolutionary computation may also be applied to improve parametric models such as MLR. This paper provides a hybrid approach based on joint use of MLR and a novel genetic algorithm for the estimation of the main forest stand variables. We show a comparison between our genetic approach and other common methods of selecting predictors. The results obtained from several LiDAR datasets with different pulse densities in two areas of the Iberian Peninsula indicate that genetic algorithms perform better than the other methods statistically. Preliminary studies suggest that a lack of parametric conditions in field data and possible misuse of parametric tests may be the main reasons for the better performance of the genetic algorithm. This research confirms the findings of previous studies that outline the importance of evolutionary computation in the context of LiDAR analisys of forest data, especially when the size of fieldwork datatasets is reduced.

Garcia-Gutierrez, Jorge; Gonzalez-Ferreiro, Eduardo; Riquelme-Santos, Jose C.; Miranda, David; Dieguez-Aranda, Ulises; Navarro-Cerrillo, Rafael M.

2014-02-01

 
 
 
 
241

Development of LiDAR measurements for the German offshore test site  

International Nuclear Information System (INIS)

The paper introduces the content of the recently started joint research project 'Development of LiDAR measurements for the German Offshore Test Site' which has the objective to support other research projects at the German offshore test site 'alpha ventus'. The project has started before the erection of the offshore wind farm and one aim is to give recommendations concerning LiDAR technology useable for offshore measurement campaigns and data analysis. The work is organized in four work packages. The work package LiDAR technology deals with the specification, acquisition and calibration of a commercial LiDAR system for the measurement campaigns. Power curve measurements are dedicated to power curve assessment with ground-based LiDAR using standard statistical methods. Additionally, it deals with the development of new methods for the measurement of non-steady short-term power curves. Wind field research aims at the development of wake loading simulation methods of wind turbines and the exploration of loading control strategies and nacelle-based wind field measurement techniques. Finally, dissemination of results to the industry takes place in work package Technology transfer

2008-05-01

242

Specular and diffuse object extraction from a LiDAR derived Digital Surface Model (DSM)  

Science.gov (United States)

This paper intents to investigate the indifferent behaviour quantitatively of target objects of interest due to specular and diffuse reflectivity based on generated LiDAR DSM of the study site in Ampang, Kuala Lumpur. The LiDAR data to be used was initially checked for its reliability and accuracy. The point cloud LiDAR data was converted to raster to allow grid analysis of the next process of generating the DSM and DTM. Filtering and masking were made removing the features of interest (i.e. building and tree) and other unwanted above surface features. A normalised DSM and object segmentation approach were conducted on the trees and buildings separately. Error assessment and findings attained were highlighted and documented. The result of LiDAR verification certified that the data is reliable and useable. The RMSE obtained is within the tolerance value of horizontal and vertical accuracy (x, y, z) i.e. 0.159 m, 0.211 m 0.091 m respectively. Building extraction inclusive of roof top based on slope and contour analysis undertaken indicate the capability of the approach while single tree extraction through aspect analysis appears to preserve the accuracy of the extraction accordingly. The paper has evaluated the suitable methods of extracting non-ground features and the effective segmentation of the LiDAR data.

Saraf, N. M.; Hamid, J. R. A.; Kamaruddin, M. H.

2014-02-01

243

Abnormal fb Es enhancements in equatorial Es layers during magnetic storms of solar cycle 23  

Science.gov (United States)

We have analyzed the behavior of blanketing frequency of the Es layer (fb Es) occurring at an equatorial station covering the days before, during and subsequent to 24 intense and very intense magnetic storms (Dst?-100nT) that occurred during the solar cycle 23. The fb Es was measured by digital ionosonde over São Luís, Brazil (2.33° S, 44.2° W, dip: -4.5°). Our analysis shows that there are significant changes in the fb Es, mainly during the recovery phase of magnetic storms, characterized by occurrence of peaks that exceed the ambient background values. Also, these peaks are associated to other types of sporadic E layer than the Esq (a non-blanketing layer detected due the plasma irregularities in the equatorial electrojet), which in turn means competing mechanisms. The results are discussed in terms of the statistics of the abnormal enhancement taking into account the phase of the magnetic storm.

Resende, L. C. A.; Denardini, C. M.; Batista, I. S.

2013-09-01

244

EMI Execution Service (EMI-ES) Specification  

CERN Multimedia

This document provides the interface specification, including related data models such as state model, activity description, resource and activity information, of an execution service, matching the needs of the EMI production middleware stack composed of ARC, gLite and UNICORE components. This service therefore is referred to as the EMI Execution Service (or “ES” for short). This document is a continuation of the work previously know as the GENEVA, then AGU (“ARC, gLite UNICORE”), then PGI execution service. As a starting point, the v0.42 of the “PGI Execution Service Specification” (doc15839) was used.

Schuller, B

2010-01-01

245

Martha senn: cuando la vida es creación  

Directory of Open Access Journals (Sweden)

Full Text Available Martha Senn es tal vez la cantante lírica colombiana de mayor reconocimiento mundial. En estas páginas se hace una semblanza de su vida profesional, resaltando los giros en su trayectoria. Su vida ha sido una búsqueda permanente de respuestas a sus propias indagaciones vitales sobre el sentido de lo social, asociado con lo que mejor sabe hacer: cantar. Al final queda formulado un principio fundamental en las palabras de la propia Martha: la necesidad de utilizar la música como herramienta de transformación social.

Carlos Hernando Dueñas Montaño

2012-04-01

246

Genetic linkage mapping in an F2 perennial ryegrass population using DArT markers  

DEFF Research Database (Denmark)

Perennial ryegrass is the principal forage grass species used in temperate agriculture. In recent years, significant efforts have been made to develop molecular marker strategies to allow cost-effective characterization of a large number of loci simultaneously. One such strategy involves using DArT markers, and a DArT array has recently been developed for the Lolium-Festuca complex. In this study, we report the first use of the DArTFest array to generate a genetic linkage map based on 326 markers in a Lolium perenne F2 population, consisting of 325 genotypes. For proof of concept, the map was used to identify QTL associated with differences in crown rust susceptibility, caused by the fungal biotroph, Puccinia coronata.

Tomaszewski, Céline; Byrne, Stephen

2012-01-01

247

LiDAR remote sensing observations for forest assessment and recovery responses following disturbance  

Science.gov (United States)

LiDAR data covering 400 km2 in the Cowal and Trossacs Forest District, Scotland, U.K., were used to provide a low cost solution to update the database of public forests and to produce multi-scale cartographic products for supporting management decisions in the event of forest disturbance such as infestation or wind damage. All parameter estimates were directly obtained from the LiDAR data without the necessity of field calibration. This was achieved using a hybrid approach integrating current stand models for Sitka spruce (Picea sitchensis bong. Carr) and LiDAR analysis. More conventional field methods offer percentage sampling, permitting only a proportion of stands to be surveyed each year and aiming to represent stand-level conditions. The use of LiDAR is advantageous in allowing a complete observation-based assessment throughout the forest and greatly-improved spatial representation of important forest parameters. Time-series analysis was performed using LiDAR data collected in the past 10 years. This analysis allowed us to establish growth trajectories in the forest stands, automatically discriminating areas of growth, those whose growth had been affected by disease and the occurrence of windthrow gaps. The results were compared to the cartography produced by the Forest District after a severe wind storm that affected the area in 2012. This analysis showed the ability of LiDAR to create a more precise location and extent of catastrophic damage and windthrow gaps. In addition, once windthrow has occurred, progression of further damage in existing canopy gaps can be observed. This approach additionally allows the impact of disease on forest growth and subsequent recovery response to be monitored.

Rosette, J.; Suárez, J.; Fonweben, J.; North, P.

2013-12-01

248

Improving Species Diversity and Biomass Estimates of Tropical Dry Forests Using Airborne LiDAR  

Directory of Open Access Journals (Sweden)

Full Text Available The spatial distribution of plant diversity and biomass informs management decisions to maintain biodiversity and carbon stocks in tropical forests. Optical remotely sensed data is often used for supporting such activities; however, it is difficult to estimate these variables in areas of high biomass. New technologies, such as airborne LiDAR, have been used to overcome such limitations. LiDAR has been increasingly used to map carbon stocks in tropical forests, but has rarely been used to estimate plant species diversity. In this study, we first evaluated the effect of using different plot sizes and plot designs on improving the prediction accuracy of species richness and biomass from LiDAR metrics using multiple linear regression. Second, we developed a general model to predict species richness and biomass from LiDAR metrics for two different types of tropical dry forest using regression analysis. Third, we evaluated the relative roles of vegetation structure and habitat heterogeneity in explaining the observed patterns of biodiversity and biomass, using variation partition analysis and LiDAR metrics. The results showed that with increasing plot size, there is an increase of the accuracy of biomass estimations. In contrast, for species richness, the inclusion of different habitat conditions (cluster of four plots over an area of 1.0 ha provides better estimations. We also show that models of plant diversity and biomass can be derived from small footprint LiDAR at both local and regional scales. Finally, we found that a large portion of the variation in species richness can be exclusively attributed to habitat heterogeneity, while biomass was mainly explained by vegetation structure.

José Luis Hernández-Stefanoni

2014-05-01

249

LiDAR data and SAR imagery acquired by an unmanned helicopter for rapid landslide investigation  

Science.gov (United States)

When earthquakes or heavy rainfall hits a landslide prone area, initial actions require estimation of the size of damage to people and infrastructure. This includes identifying the number and size of newly collapsed or expanded landslides, and appraising subsequent risks from remobilization of landslides and debris materials. In inapproachable areas, the UAV (Unmanned Aerial Vehicles) is likely to be of greatest use. In addition, repeat monitoring of sites after the event is a way of utilizing UAVs, particularly in terms of cost and convenience. In this study, LiDAR (SkEyesBox MP-1) data and SAR (Nano SAR) imagery, acquired over 0.5 km2 landslide prone area, are presented to assess the practicability of using unmanned helicopters (in this case a 10 year old YAMAHA RMAX G1) in these situations. LiDAR data was taken in July 2012, when tree foliage covered the ground surface. However, imagery was of sufficient quality to identify and measure landslide features. Nevertheless, LiDAR data obtained by a manned helicopter in the same area in August 2008 was more detailed, reflecting the function of the LiDAR scanner. On the other hand, 2 m resolution Nano SAR imagery produced reasonable results to elucidate hillslope condition. A quick method for data processing without loss of image quality was also investigated. In conclusion, the LiDAR scanner and UAV employed here could be used to plan immediate remedial activity of the area, before LiDAR measurement with a manned helicopter can be organized. SAR imagery from UAV is also available for this initial activity, and can be further applied to long term monitoring.

Kasai, M.; Tanaka, Y.; Yamazaki, T.

2012-12-01

250

Estimating stem volume and biomass of Pinus koraiensis using LiDAR data.  

Science.gov (United States)

The objective of this study was to estimate the stem volume and biomass of individual trees using the crown geometric volume (CGV), which was extracted from small-footprint light detection and ranging (LiDAR) data. Attempts were made to analyze the stem volume and biomass of Korean Pine stands (Pinus koraiensis Sieb. et Zucc.) for three classes of tree density: low (240 N/ha), medium (370 N/ha), and high (1,340 N/ha). To delineate individual trees, extended maxima transformation and watershed segmentation of image processing methods were applied, as in one of our previous studies. As the next step, the crown base height (CBH) of individual trees has to be determined; information for this was found in the LiDAR point cloud data using k-means clustering. The LiDAR-derived CGV and stem volume can be estimated on the basis of the proportional relationship between the CGV and stem volume. As a result, low tree-density plots had the best performance for LiDAR-derived CBH, CGV, and stem volume (R (2) = 0.67, 0.57, and 0.68, respectively) and accuracy was lowest for high tree-density plots (R (2) = 0.48, 0.36, and 0.44, respectively). In the case of medium tree-density plots accuracy was R (2) = 0.51, 0.52, and 0.62, respectively. The LiDAR-derived stem biomass can be predicted from the stem volume using the wood basic density of coniferous trees (0.48 g/cm(3)), and the LiDAR-derived above-ground biomass can then be estimated from the stem volume using the biomass conversion and expansion factors (BCEF, 1.29) proposed by the Korea Forest Research Institute (KFRI). PMID:20182905

Kwak, Doo-Ahn; Lee, Woo-Kyun; Cho, Hyun-Kook; Lee, Seung-Ho; Son, Yowhan; Kafatos, Menas; Kim, So-Ra

2010-07-01

251

Detailed Hydrographic Feature Extraction from High-Resolution LiDAR Data  

Energy Technology Data Exchange (ETDEWEB)

Detailed hydrographic feature extraction from high-resolution light detection and ranging (LiDAR) data is investigated. Methods for quantitatively evaluating and comparing such extractions are presented, including the use of sinuosity and longitudinal root-mean-square-error (LRMSE). These metrics are then used to quantitatively compare stream networks in two studies. The first study examines the effect of raster cell size on watershed boundaries and stream networks delineated from LiDAR-derived digital elevation models (DEMs). The study confirmed that, with the greatly increased resolution of LiDAR data, smaller cell sizes generally yielded better stream network delineations, based on sinuosity and LRMSE. The second study demonstrates a new method of delineating a stream directly from LiDAR point clouds, without the intermediate step of deriving a DEM. Direct use of LiDAR point clouds could improve efficiency and accuracy of hydrographic feature extractions. The direct delineation method developed herein and termed “mDn”, is an extension of the D8 method that has been used for several decades with gridded raster data. The method divides the region around a starting point into sectors, using the LiDAR data points within each sector to determine an average slope, and selecting the sector with the greatest downward slope to determine the direction of flow. An mDn delineation was compared with a traditional grid-based delineation, using TauDEM, and other readily available, common stream data sets. Although, the TauDEM delineation yielded a sinuosity that more closely matches the reference, the mDn delineation yielded a sinuosity that was higher than either the TauDEM method or the existing published stream delineations. Furthermore, stream delineation using the mDn method yielded the smallest LRMSE.

Danny L. Anderson

2012-05-01

252

Optimisation of LiDAR derived terrain models for river flow modelling  

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Full Text Available Airborne LiDAR (Light Detection And Ranging combines cost efficiency, high degree of automation, high point density of typically 1–10 points per m2 and height accuracy of better than ±15 cm. For all these reasons LiDAR is particularly suitable for deriving precise Digital Terrain Models (DTM as geometric basis for hydrodynamic-numerical (HN simulations. The application of LiDAR for river flow modelling requires a series of preprocessing steps. Terrain points have to be filtered and merged with river bed data, e.g. from echo sounding. Then, a smooth Digital Terrain Model of the Watercourse (DTM-W needs to be derived, preferably considering the random measurement error during surface interpolation. In a subsequent step, a hydraulic computation mesh has to be constructed. Hydraulic simulation software is often restricted to a limited number of nodes and elements, thus, data reduction and data conditioning of the high resolution LiDAR DTM-W becomes necessary. We will present a DTM thinning approach based on adaptive TIN refinement which allows a very effective compression of the point data (more than 95% in flood plains and up to 90% in steep areas while preserving the most relevant topographic features (height tolerance ±20 cm. Traditional hydraulic mesh generators focus primarily on physical aspects of the computation grid like aspect ratio, expansion ratio and angle criterion. They often neglect the detailed shape of the topography as provided by LiDAR data. In contrast, our approach considers both the high geometric resolution of the LiDAR data and additional mesh quality parameters. It will be shown that the modelling results (flood extents, flow velocities, etc. can vary remarkably by the availability of surface details. Thus, the inclusion of such geometric details in the hydraulic computation meshes will gain importance for river flow modelling in the future.

G. Mandlburger

2008-12-01

253

Optimisation of LiDAR derived terrain models for river flow modelling  

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Full Text Available Airborne LiDAR (Light Detection And Ranging combines cost efficiency, high degree of automation, high point density of typically 1–10 points per m2 and height accuracy of better than ±15 cm. For all these reasons LiDAR is particularly suitable for deriving precise Digital Terrain Models (DTM as geometric basis for hydrodynamic-numerical (HN simulations. The application of LiDAR for river flow modelling requires a series of preprocessing steps. Terrain points have to be filtered and merged with river bed data, e.g. from echo sounding. Then, a smooth Digital Terrain Model of the Watercourse (DTM-W needs to be derived, preferably considering the random measurement error during surface interpolation. In a subsequent step, a hydraulic computation mesh has to be constructed. Hydraulic simulation software is often restricted to a limited number of nodes and elements, thus, data reduction and data conditioning of the high resolution LiDAR DTM-W becomes necessary. We will present a DTM thinning approach based on adaptive TIN refinement which allows a very effective compression of the point data (more than 95% in flood plains and up to 90% in steep areas while preserving the most relevant topographic features (height tolerance ±20 cm. Traditional hydraulic mesh generators focus primarily on physical aspects of the computation grid like aspect ratio, expansion ratio and angle criterion. They often neglect the detailed shape of the topography as provided by LiDAR data. In contrast, our approach considers both the high geometric resolution of the LiDAR data and additional mesh quality parameters. It will be shown that the modelling results (flood extents, flow velocities, etc. can vary remarkably by the availability of surface details. Thus, the inclusion of such geometric details in the hydraulic computation meshes is gaining importance in river flow modelling.

G. Mandlburger

2009-08-01

254

Detection of large above ground biomass variability in lowland forest ecosystems by airborne LiDAR  

Science.gov (United States)

Quantification of tropical forest Above Ground Biomass (AGB) over large areas as input for Reduced Emissions from Deforestation and forest Degradation (REDD+) projects and climate change models is challenging. This is the first study which attempts to estimate AGB and its variability across large areas of tropical lowland forests in Central Kalimantan (Indonesia) through correlating airborne Light Detection and Ranging (LiDAR) to forest inventory data. Two LiDAR height metrics were analysed and regression models could be improved through the use of LiDAR point densities as input (R2 = 0.88; n = 52). Surveying with a LiDAR point density per square meter of 2-4 resulted in the best cost-benefit ratio. We estimated AGB for 600 km of LiDAR tracks and showed that there exists a considerable variability of up to 140% within the same forest type due to varying environmental conditions. Impact from logging operations and the associated AGB losses dating back more than 10 yr could be assessed by LiDAR but not by multispectral satellite imagery. Comparison with a Landsat classification for a 1 million ha study area where AGB values were based on site specific field inventory data, regional literature estimates, and default values by the Intergovernmental Panel on Climate Change (IPCC) showed an overestimation of 46%, 102%, and 137%, respectively. The results show that AGB overestimation may lead to wrong GHG emission estimates due to deforestation in climate models. For REDD+ projects this leads to inaccurate carbon stock estimates and consequently to significantly wrong REDD+ based compensation payments.

Jubanski, J.; Ballhorn, U.; Kronseder, K.; Franke, J.; Siegert, F.

2012-08-01

255

Detection of large above ground biomass variability in lowland forest ecosystems by airborne LiDAR  

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Full Text Available Quantification of tropical forest Above Ground Biomass (AGB over large areas as input for Reduced Emissions from Deforestation and forest Degradation (REDD+ projects and climate change models is challenging. This is the first study which attempts to estimate AGB and its variability across large areas of tropical lowland forests in Central Kalimantan (Indonesia through correlating airborne Light Detection and Ranging (LiDAR to forest inventory data. Two LiDAR height metrics were analysed and regression models could be improved through the use of LiDAR point densities as input (R2 = 0.88; n = 52. Surveying with a LiDAR point density per square meter of 2–4 resulted in the best cost-benefit ratio. We estimated AGB for 600 km of LiDAR tracks and showed that there exists a considerable variability of up to 140% within the same forest type due to varying environmental conditions. Impact from logging operations and the associated AGB losses dating back more than 10 yr could be assessed by LiDAR but not by multispectral satellite imagery. Comparison with a Landsat classification for a 1 million ha study area where AGB values were based on site specific field inventory data, regional literature estimates, and default values by the Intergovernmental Panel on Climate Change (IPCC showed an overestimation of 46%, 102%, and 137%, respectively. The results show that AGB overestimation may lead to wrong GHG emission estimates due to deforestation in climate models. For REDD+ projects this leads to inaccurate carbon stock estimates and consequently to significantly wrong REDD+ based compensation payments.

J. Jubanski

2012-08-01

256

Development of a UAV-LiDAR System with Application to Forest Inventory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present the development of a low-cost Unmanned Aerial Vehicle-Light Detecting and Ranging (UAV-LiDAR) system and an accompanying workflow to produce 3D point clouds. UAV systems provide an unrivalled combination of high temporal and spatial resolution datasets. The TerraLuma UAV-LiDAR system has been developed to take advantage of these properties and in doing so overcome some of the current limitations of the use of this technology within the forestry industry. A modified processing workf...

Luke Wallace; Arko Lucieer; Christopher Watson; Darren Turner

2012-01-01

257

Variogram maps from LiDAR data as fingerprints of surface morphology on scree slopes  

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Full Text Available Herein, an aerial LiDAR topographic dataset is analysed and interpolated by means of geostatistical techniques in order to examine the morphology of a scree slope area in the Eastern Italian Alps. The LiDAR-derived digital terrain model (DTM is analysed using variogram maps as spatial continuity indexes. This allowed for evaluation of the reproduction of spatial variability of topography and for the characterization and comparison of different morphological features occurring in the study site. The results indicate that variogram maps efficiently synthesise the spatial variability of topography in a local search window, representing suitable "fingerprints" of surface morphology.

S. Trevisani

2009-02-01

258

Using airborne LiDAR and USGS DEM data for assessing rock glaciers and glaciers  

Science.gov (United States)

Varying topographic and geologic conditions affect the location of rock glaciers. Despite being found worldwide, rock glaciers are often confused with glacier counterparts or other periglacial landforms. Light detection and ranging (LiDAR) data, because of its accuracy and resolution, may help the assessment of topographic variables needed to form rock glaciers or help reveal unique characteristics to enhance regional, automatic mapping. The objectives of this paper are to compare the elevation, slope, aspect, hillshade, and curvature for 1 m LiDAR and 10 m US Geological Survey (USGS) Digital Elevation Models (DEMs) from the Andrews and Taylor Glaciers with the Taylor Rock Glacier in Colorado. The utility of these data sources will be assessed for landform discrimination and to evaluate the uncertainty between the DEMs. According to the LiDAR data, the Taylor Rock Glacier exists at a lower elevation and has a gentler slope compared to the glaciers. Each landform has steep areas from which snow and debris are delivered. The Andrews Glacier has the most northern aspect, which helps maintain it through snow accumulation and reduced insolation. Glaciers exhibit a concave mean curvature, whereas the Taylor Rock Glacier has a convex mean curvature. The fine resolution of the LiDAR data clearly identifies some distinct characteristics. On the Taylor Rock Glacier, ridges, furrows, and a pronounced front slope were easily identifiable on the LiDAR DEM, whereas crevasses, the boundary between snow and debris covered surfaces, and a lateral moraine were detectable near the Andrews Glacier. The accuracy assessment revealed that at a common 10 m resolution, the USGS DEM estimated a maximum elevation about 150 m greater compared to the LiDAR data in areas of rugged topography surrounding the landforms. A comparison of root mean squared errors (RMSE) between the LiDAR and USGS DEMs showed that the Taylor Rock Glacier has the lowest RMSE for the elevation and the curvature variables. As a result, readily available USGS DEMs may better for analysis to characterize the topographic setting of landforms at the regional scale. At the fine scale, however, the micro-topography of rock glaciers is illuminated much more clearly on the LiDAR data, making it an ideal, yet costly source, for feature extraction.

Janke, Jason R.

2013-08-01

259

DArT markers: diversity analyses and mapping in Sorghum bicolor  

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Full Text Available Abstract Background The sequential nature of gel-based marker systems entails low throughput and high costs per assay. Commonly used marker systems such as SSR and SNP are also dependent on sequence information. These limitations result in high cost per data point and significantly limit the capacity of breeding programs to obtain sufficient return on investment to justify the routine use of marker-assisted breeding for many traits and particularly quantitative traits. Diversity Arrays Technology (DArT™ is a cost effective hybridisation-based marker technology that offers a high multiplexing level while being independent of sequence information. This technology offers sorghum breeding programs an alternative approach to whole-genome profiling. We report on the development, application, mapping and utility of DArT™ markers for sorghum germplasm. Results A genotyping array was developed representing approximately 12,000 genomic clones using PstI+BanII complexity with a subset of clones obtained through the suppression subtractive hybridisation (SSH method. The genotyping array was used to analyse a diverse set of sorghum genotypes and screening a Recombinant Inbred Lines (RIL mapping population. Over 500 markers detected variation among 90 accessions used in a diversity analysis. Cluster analysis discriminated well between all 90 genotypes. To confirm that the sorghum DArT markers behave in a Mendelian manner, we constructed a genetic linkage map for a cross between R931945-2-2 and IS 8525 integrating DArT and other marker types. In total, 596 markers could be placed on the integrated linkage map, which spanned 1431.6 cM. The genetic linkage map had an average marker density of 1/2.39 cM, with an average DArT marker density of 1/3.9 cM. Conclusion We have successfully developed DArT markers for Sorghum bicolor and have demonstrated that DArT provides high quality markers that can be used for diversity analyses and to construct medium-density genetic linkage maps. The high number of DArT markers generated in a single assay not only provides a precise estimate of genetic relationships among genotypes, but also their even distribution over the genome offers real advantages for a range of molecular breeding and genomics applications.

Parh Dipal K

2008-01-01

260

Monitoring Automotive Particulate Matter Emissions with LiDAR: A Review  

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Full Text Available Automotive particulate matter (PM causes deleterious effects on health and visibility. Physical and chemical properties of PM also influence climate change. Roadside remote sensing of automotive emissions is a valuable option for assessing the contribution of individual vehicles to the total PM burden. LiDAR represents a unique approach that allows measuring PM emissions from in-use vehicles with high sensitivity. This publication reviews vehicle emission remote sensing measurements using ultraviolet LiDAR and transmissometer systems. The paper discusses the measurement theory and documents examples of how these techniques provide a unique perspective for exhaust emissions of individual and groups of vehicles.

Claudio Mazzoleni

2010-04-01

 
 
 
 
261

Ground Filtering Algorithms for Airborne LiDAR Data: A Review of Critical Issues  

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Full Text Available This paper reviews LiDAR ground filtering algorithms used in the process of creating Digital Elevation Models. We discuss critical issues for the development and application of LiDAR ground filtering algorithms, including filtering procedures for different feature types, and criteria for study site selection, accuracy assessment, and algorithm classification. This review highlights three feature types for which current ground filtering algorithms are suboptimal, and which can be improved upon in future studies: surfaces with rough terrain or discontinuous slope, dense forest areas that laser beams cannot penetrate, and regions with low vegetation that is often ignored by ground filters.

Kaiguang Zhao

2010-03-01

262

¿Un país pobre podrá dar Bienestar a sus Animales?  

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Full Text Available ResumenLa verdad absoluta es que los animales de producción y especialmente los perros y gatos en los países en desarrollo están propensos a sufrir actos de negligencia humana. Las mascotas padecen de la pobreza del mismo modo que lo hacen sus dueños. En un País como Bolivia con grandes zonas empobrecidas y extensos barrios periurbanos que se debaten en la miseria, los animales están vulnerables a la desnutrición,enfermedades y sobre todo al abandono.El bienestar animal ha sido definido por la Organización Mundial de Sanidad Animal(OIE como la manera en que los animales se enfrentan con el medio ambiente y que incluye su sanidad, sus percepciones, su estado anímico y otros efectos positivos o negativos que influyen sobre los mecanismos físicos y psíquicos del animal .Lamentablemente en países del llamado “Tercer Mundo” esta definición cae en saco roto.

Parrilla, Guillermo.

2007-12-01

263

Transit timing analysis of the exoplanets TrES-1 and TrES-2  

CERN Document Server

The aim of this work is a detailed analysis of transit light curves from TrES-1 and TrES-2, obtained over a period of three to four years, in order to search for variabilities in observed mid-transit times and to set limits for the presence of additional third bodies. Using the IAC 80cm telescope, we observed transits of TrES-1 and TrES-2 over several years. Based on these new data and previously published work, we studied the observed light curves and searched for variations in the difference between observed and calculated (based on a fixed ephemeris) transit times. To model possible transit timing variations, we used polynomials of different orders, simulated O-C diagrams corresponding to a perturbing third mass and sinusoidal fits. For each model we calculated the chi-squared residuals and the False Alarm Probability (FAP). For TrES-1 we can exclude planetary companions (>1 M_earth) in the 3:2 and 2:1 MMRs having high FAPs based on our transit observations from ground. Additionally, the presence of a ligh...

Rabus, M; Alonso, R; Belmonte, J A; Almenara, J M

2009-01-01

264

Geometrical parameters of E+S pairs  

Science.gov (United States)

Local environmental conditions (i.e., density and angular momentum properties of protogalactic clouds) are thought to be factors affecting the ultimate morphology of a galaxy. The existence of significant numbers of mixed morphology (E/SO+S) pairs of galaxies would represent a direct challenge to this idea unless all early-type components are formed by mergers. The authors wished to isolate candidate E+S pairs for detailed study. The authors have observed 22 pairs of mixed morphology galaxies (containing at least one early-type component) selected from a catalog of Sulentic (1988: unpublished) based upon the ESO sky survey. The observed sample and relevant morphological and interaction characteristics are summarized in tabular form. The authors report the relevant geometrical properties of the galaxies in another table. They list the maximum values measured for the ellipticity and the a(4)/a shape parameter together with the total measured twisting along the profile beyond the seeing disk (they set an inner limit of 3 arcsed). An asterisk indicates objects in which a(4)/a is neither predominantly boxy nor disky. They found a large number of true mixed pairs with 13/22 E+S pairs in the present sample. The remaining objects include 5 disk pairs (composed of SO and S members) and 3 early-type pairs comprising E and SO members. They estimate that between 25 and 50 percent of the pairs in any complete sample will be of the E+S type. This suggests that 100 to 200 such pairs exist on the sky brighter than m sub pg = 16.0. They found no global evidence for a difference between E members of this sample and those in more general samples (e.g., Bender et al. 1989). In particular, they found that about 30 percent of the early-type galaxies cannot be classified either predominantly boxy or disky because the a(4)/a profile shows both of these features at a comparable level or does not show any significant trend. Isophotal twisting is observed with a range and distribution consistent with general samples (delta PA between 0 to 70 degrees). Two spirals show significant twisting in their bulge components. They observed two early-type components with shell structure and at least 6 objects with twisting values greater than about 30 degrees.

Rampazzo, Roberto; Sulentic, Jack W.

1990-01-01

265

KML-Based Access and Visualization of High Resolution LiDAR Topography  

Science.gov (United States)

Over the past decade, there has been dramatic growth in the acquisition of LiDAR (Light Detection And Ranging) high-resolution topographic data for earth science studies. Capable of providing digital elevation models (DEMs) more than an order of magnitude higher resolution than those currently available, LiDAR data allow earth scientists to study the processes that contribute to landscape evolution at resolutions not previously possible yet essential for their appropriate representation. These datasets also have significant implications for earth science education and outreach because they provide an accurate representation of landforms and geologic hazards. Unfortunately, the massive volume of data produced by LiDAR mapping technology can be a barrier to their use. To make these data available to a larger user community, we have been exploring the use of Keyhole Markup Language (KML) and Google Earth to provide access to LiDAR data products and visualizations. LiDAR digital elevation models are typically delivered in a tiled format that lends itself well to a KML-based distribution system. For LiDAR datasets hosted in the GEON OpenTopography Portal (www.opentopography.org) we have developed KML files that show the extent of available LiDAR DEMs and provide direct access to the data products. Users interact with these KML files to explore the extent of the available data and are able to select DEMs that correspond to their area of interest. Selection of a tile loads a download that the user can then save locally for analysis in their software of choice. The GEON topography system also has tools available that allow users to generate custom DEMs from LiDAR point cloud data. This system is powerful because it enables users to access massive volumes of raw LiDAR data and to produce DEM products that are optimized to their science applications. We have developed a web service that converts the custom DEM models produced by the system to a hillshade that is delivered to the user as a KML groundoverlay. The KML product enables users to quickly and easily visualize the DEMs in Google Earth. By combining internet-based LiDAR data processing with KML visualization products, users are able to execute computationally intensive data sub-setting, processing and visualization without having local access to computing resources, GIS software, or data processing expertise. Finally, GEON has partnered with the US Geological Survey to generate region-dependant network linked KML visualizations for large volumes of LiDAR derived hillshades of the Northern San Andreas fault system. These data, acquired by the NSF-funded GeoEarthScope project, offer an unprecedented look at active faults in the northern portion of the San Andreas system. Through the region-dependant network linked KML, users can seamlessly access 1 meter hillshades (both 315 and 45 degree sun angles) for the full 1400 square kilometer dataset, without downloading huge volumes of data. This type of data access has great utility for users ranging from earthquake scientists to K-12 educators who wish to introduce cutting edge real world data into their earth science lessons.

Crosby, C. J.; Blair, J. L.; Nandigam, V.; Memon, A.; Baru, C.; Arrowsmith, J. R.

2008-12-01

266

Contratación Electrónica: ¿Es necesaria una convención internacional ?  

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Full Text Available La Convención de Viena sobre Compraventa internacional de Mercaderías llenó un vacío de marras en relación con la regulación sustantiva de compraventas internacionales. Sin embargo, su aplicación por parte de los operadores internacionales del comercio ha coincidido en las últimas dos décadas con el uso cada vez más frecuente de las tecnologías de la información en los negocios y ello ha hecho que las soluciones, en un principio eficaces y suficientes, no lo sean hoy en un mundo comercial sin barreras. ¿Es necesaria una Convención sobre contratación electrónica para suprimir los obstáculos jurídicos de la utilización de los medios modernos de comunicación? Cuál sería el contenido y alcance de este instrumento y cómo se relacionaría con los demás instrumentos sustantivos existentes? La respuesta a estas preguntas y más en el presente artículo.

Daniel Peña Valenzuela

2002-01-01

267

Histogramming system for the ES-1010 computer  

International Nuclear Information System (INIS)

A system of subroutines for operation with 1- and 2-dimensional distributions on the ES-1010 computer is described. The 1-dimensional distribution is represented as a histogram, the 2-dimensional one - as a table or as a scattering diagrams. Subroutines provide such opportunities as booking and deleting, filling and clearing distributions, arithmetic operations with them, distinguishing part of the distribution and compressing it, and printing them on the computer printer with arbitrary printer line. All subroutines are written in the FORTRAN-IV language and can be called from the program written in FORTRAN or in ASSEMBLER language. This system can be implemented on all computers that offer the FORTRAN-IV computer

1980-01-01

268

El Pseudo-Hiepes es Bernardo Polo  

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Full Text Available Nearly fifteen years ago, the author proposed the name Pseudo-Hiepes to refer to a then anonymous painter whom certain Italian art historians had called the Master of the Lombard Fruit Bowl. At the time, he argued for an Aragonese origin in the later part of the century. A signed work has finally been discovered and is published here. The artist was indeed from Zaragoza, and his name is Bernardo Polo.

Hace unos quince años, el autor propuso el apodo Pseudo-Hiepes para identificar al pintor anónimo a quien algunos entendidos italianos habían bautizado como Maestro del Frutero lombardo. En aquel entonces, argumentó que debía tratarse de un artista aragonés, de la segunda mitad de siglo. Por fin ha aparecido una obra firmada que se presenta aquí. Efectivamente, el artista era zaragozano y su nombre es Bernardo Polo.

Jordan, William B.

2009-12-01

269

PHOEBE: PHysics Of Eclipsing BinariEs  

Science.gov (United States)

PHOEBE (PHysics Of Eclipsing BinariEs) is a modeling package for eclipsing binary stars, built on top of the widely used WD program (Wilson & Devinney 1971). This introductory paper overviews most important scientific extensions (incorporating observational spectra of eclipsing binaries into the solution-seeking process, extracting individual temperatures from observed color indices, main-sequence constraining and proper treatment of the reddening), numerical innovations (suggested improvements to WD's Differential Corrections method, the new Nelder & Mead's downhill Simplex method) and technical aspects (back-end scripter structure, graphical user interface). While PHOEBE retains 100 % WD compatibility, its add-ons are a powerful way to enhance WD by encompassing even more physics and solution reliability.

Prsa, Andrej; Matijevic, Gal; Latkovic, Olivera; Vilardell, Francesc; Wils, Patrick

2011-06-01

270

Geometrical parameters of E+S pairs  

International Nuclear Information System (INIS)

Local environmental conditions (i.e., density and angular momentum properties of protogalactic clouds) are thought to be factors affecting the ultimate morphology of a galaxy. The existence of significant numbers of mixed morphology (E/SO+S) pairs of galaxies would represent a direct challenge to this idea. The authors have observed 22 pairs of mixed morphology galaxies selected from a catalog of Sulentic (1988: unpublished) based upon the ESO sky survey. The observed sample and relevant morphological and interaction characteristics are summarized in tabular form. The authors list the maximum values measured for the ellipticity and the a(4)/a shape parameter together with the total measured twisting along the profile beyond the seeing disk (they set an inner limit of 3 arcsed). An asterisk indicates objects in which a(4)/a is neither predominantly boxy nor disky. They found a large number of true mixed pairs with 13/22 E+S pairs in the present sample. The remaining objects include 5 disk pairs (composed of SO and S members) and 3 early-type pairs comprising E and SO members. They estimate that between 25 and 50 percent of the pairs in any complete sample will be of the E+S type. This suggests that 100 to 200 such pairs exist on the sky brighter than m sub pg = 16.0. They found no global evidence for a difference between E members of this sample and those in more general samples (e.g., Bender et al. 1989). In particular, they found that about 30 percent of the early-type galaxies cannot be classified either predominantly boxy or disky

1990-11-01

271

Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology.  

Science.gov (United States)

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

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

2012-08-01

272

High-throughput genotyping of hop (Humulus lupulus L.) utilising diversity arrays technology (DArT).  

Science.gov (United States)

Implementation of molecular methods in hop (Humulus lupulus L.) breeding is dependent on the availability of sizeable numbers of polymorphic markers and a comprehensive understanding of genetic variation. However, use of molecular marker technology is limited due to expense, time inefficiency, laborious methodology and dependence on DNA sequence information. Diversity arrays technology (DArT) is a high-throughput cost-effective method for the discovery of large numbers of quality polymorphic markers without reliance on DNA sequence information. This study is the first to utilise DArT for hop genotyping, identifying 730 polymorphic markers from 92 hop accessions. The marker quality was high and similar to the quality of DArT markers previously generated for other species; although percentage polymorphism and polymorphism information content (PIC) were lower than in previous studies deploying other marker systems in hop. Genetic relationships in hop illustrated by DArT in this study coincide with knowledge generated using alternate methods. Several statistical analyses separated the hop accessions into genetically differentiated North American and European groupings, with hybrids between the two groups clearly distinguishable. Levels of genetic diversity were similar in the North American and European groups, but higher in the hybrid group. The markers produced from this time and cost-efficient genotyping tool will be a valuable resource for numerous applications in hop breeding and genetics studies, such as mapping, marker-assisted selection, genetic identity testing, guidance in the maintenance of genetic diversity and the directed breeding of superior cultivars. PMID:21243330

Howard, E L; Whittock, S P; Jakše, J; Carling, J; Matthews, P D; Probasco, G; Henning, J A; Darby, P; Cerenak, A; Javornik, B; Kilian, A; Koutoulis, A

2011-05-01

273

Object-Based Classification of Abandoned Logging Roads under Heavy Canopy Using LiDAR  

Directory of Open Access Journals (Sweden)

Full Text Available LiDAR-derived slope models may be used to detect abandoned logging roads in steep forested terrain. An object-based classification approach of abandoned logging road detection was employed in this study. First, a slope model of the study site in Marin County, California was created from a LiDAR derived DEM. Multiresolution segmentation was applied to the slope model and road seed objects were iteratively grown into candidate objects. A road classification accuracy of 86% was achieved using this fully automated procedure and post processing increased this accuracy to 90%. In order to assess the sensitivity of the road classification to LiDAR ground point spacing, the LiDAR ground point cloud was repeatedly thinned by a fraction of 0.5 and the classification procedure was reapplied. The producer’s accuracy of the road classification declined from 79% with a ground point spacing of 0.91 to below 50% with a ground point spacing of 2, indicating the importance of high point density for accurate classification of abandoned logging roads.

Jason Sherba

2014-05-01

274

Airborne hyperspectral and LiDAR data integration for weed detection  

Science.gov (United States)

Agriculture uses 70% of global available fresh water. However, ca. 50-70% of water used by cultivated plants, the rest of water transpirated by the weeds. Thus, to define the distribution of weeds is very important in precision agriculture and horticulture as well. To survey weeds on larger fields by traditional methods is often time consuming. Remote sensing instruments are useful to detect weeds in larger area. In our investigation a 3D airborne laser scanner (RIEGL LMS-Q680i) was used in agricultural field near Sopron to scouting weeds. Beside the airborne LiDAR, hyperspectral imaging system (AISA DUAL) and air photos helped to investigate weed coverage. The LiDAR survey was carried out at early April, 2012, before sprouting of cultivated plants. Thus, there could be detected emerging of weeds and direction of cultivation. However airborne LiDAR system was ideal to detect weeds, identification of weeds at species level was infeasible. Higher point density LiDAR - Terrestrial laser scanning - systems are appropriate to distinguish weed species. Based on the results, laser scanner is an effective tool to scouting of weeds. Appropriate weed detection and mapping systems could contribute to elaborate water and herbicide saving management technique. This publication was supported by the OTKA project K 105789.

Tamás, János; Lehoczky, Éva; Fehér, János; Fórián, Tünde; Nagy, Attila; Bozsik, Éva; Gálya, Bernadett; Riczu, Péter

2014-05-01

275

Genetic Essentialism, Neuroessentialism, and Stigma: Commentary on Dar-Nimrod and Heine (2011)  

Science.gov (United States)

Dar-Nimrod and Heine (2011) presented a masterfully broad review of the implications of genetic essentialism for understandings of human diversity. This commentary clarifies the reasons that essentialist thinking has problematic social consequences and links genetic forms of essentialism to those invoking neural essences. The mounting evidence…

Haslam, Nick

2011-01-01

276

Effects of atmospheric stability on the evolution of wind turbine wakes: Volumetric LiDAR scans  

Science.gov (United States)

Aerodynamic optimization of wind farm layout is a fundamental task to reduce wake effects on downstream wind turbines, thus to maximize wind power harvesting. However, downstream evolution and recovery of wind turbine wakes are strongly affected by the characteristics of the incoming atmospheric boundary layer (ABL) flow, like the vertical profiles of the mean wind velocity and the turbulence intensity, which are in turn affected by the ABL stability regime. Therefore, the characterization of the variability of wind turbine wakes under different ABL stability regimes becomes fundamental to better predict wind power harvesting and improve wind farm efficiency. To this aim, wind velocity measurements of the wake produced by a 2 MW Enercon E-70 wind turbine were performed with three scanning Doppler wind Light Detection and Ranging (LiDAR) instruments. One LiDAR was typically devoted to the characterization of the incoming wind, in particular wind velocity, shear and turbulence intensity at the height of the rotor disc. The other two LiDARs performed scans in order to characterize the wake velocity field produced by the tested wind turbine. The main challenge in performing field measurements of wind turbine wakes is represented by the varying wind conditions, and by the consequent adjustments of the turbine yaw angle needed to maximize power production. Consequently, taking into account possible variations of the relative position between LiDAR measurement volume and wake location, different LiDAR measurement procedures were carried out in order to perform 2-D and 3-D characterizations of the mean wake velocity field. However, larger measurement volumes and higher spatial resolution require longer sampling periods; thus, to investigate wake turbulence tests were also performed by staring the LiDAR laser beam over fixed directions and with the maximum sampling frequency. Furthermore, volumetric scans of the wind turbine wake were performed under different wind conditions via two simultaneous LiDARs. Through the evaluation of the minimum wake velocity deficit as a function of the downstream distance, it is shown that the stability regime of the ABL has a significant effect on the wake evolution; specifically the wake recovers faster under convective conditions. This result suggests that atmospheric inflow conditions, and particularly thermal stability, should be considered for improved wake models and predictions of wind power harvesting.

Valerio Iungo, Giacomo; Porté-Agel, Fernando

2014-05-01

277

Development and mapping of DArT markers within the Festuca - Lolium complex  

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Full Text Available Abstract Background Grasses are among the most important and widely cultivated plants on Earth. They provide high quality fodder for livestock, are used for turf and amenity purposes, and play a fundamental role in environment protection. Among cultivated grasses, species within the Festuca-Lolium complex predominate, especially in temperate regions. To facilitate high-throughput genome profiling and genetic mapping within the complex, we have developed a Diversity Arrays Technology (DArT array for five grass species: F. pratensis, F. arundinacea, F. glaucescens, L. perenne and L. multiflorum. Results The DArTFest array contains 7680 probes derived from methyl-filtered genomic representations. In a first marker discovery experiment performed on 40 genotypes from each species (with the exception of F. glaucescens for which only 7 genotypes were used, we identified 3884 polymorphic markers. The number of DArT markers identified in every single genotype varied from 821 to 1852. To test the usefulness of DArTFest array for physical mapping, DArT markers were assigned to each of the seven chromosomes of F. pratensis using single chromosome substitution lines while recombinants of F. pratensis chromosome 3 were used to allocate the markers to seven chromosome bins. Conclusion The resources developed in this project will facilitate the development of genetic maps in Festuca and Lolium, the analysis on genetic diversity, and the monitoring of the genomic constitution of the Festuca × Lolium hybrids. They will also enable marker-assisted selection for multiple traits or for specific genome regions.

Studer Bruno

2009-10-01

278

ES FUNDAMENTAL LA HERMENÉUTICA / Is Hermeneutics Fundamental  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish RESUMEN Se interroga el fundamento de la hermenéutica del texto y lo que significa retomarla a la letra en filosofía y en teología. Una hermenéutica es fundamental si se afinca en un modo de existencia adecuado a su propósito, de modo que se diferencie mejor y sea identificada claramente. La hermené [...] utica protestante del sentido del texto y la hermenéutica judía del cuerpo de la letra serán sustituidas aquí por una hermenéutica católica del texto del cuerpo, en una tentativa al menos programática. Abstract in english ABSTRACT The article inquires into the basis of textual hermeneutics and what it means to apply it literally in philosophy and theology. Hermeneutics is fundamental if it is grounded in a mode of existence that is adequate to its purpose, so that it is better differentiated and clearly identified. T [...] he Protestant hermeneutics of the meaning of the text and the Jewish hermeneutics of the body of the letter are here replaced by a Catholic hermeneutics of the text of the body, in an attempt that is at least programmatic.

EMMANUEL, FALQUE.

279

Review Essay: Gibt es eine qualitative Netzwerkanalyse?  

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Full Text Available Die sozialwissenschaftliche Netzwerkanalyse hat sich in den 1970er Jahren formiert und seitdem als ein eigenes empirisches Paradigma für die Analyse sozialer Beziehungssysteme etabliert. In diesem Beitrag werden der theoretisch-methodologische Standort der Netzwerkanalyse ("strukturale Analyse" und die verschiedenen Formen der Netzwerkanalyse vorgestellt. Die strukturale Analyse argumentiert, dass soziale Akteure und soziale Beziehungen in Netzwerke eingebettet sind und dass das Handeln und Wahrnehmen von Akteuren und die Performanz sozialer Beziehungen durch die Netzwerkstruktur beeinflusst werden. Seit den 1990er Jahren sind in die strukturale Analyse Konzepte wie das der agency, dasjenige des Diskurses und das der Symbolorientierung aufgenommen worden und haben die strukturale Analyse damit geöffnet. Hieran schließt ein Trend der zunehmenden Aufnahme qualitativer Verfahren in die Netzwerkanalyse an. Diese dienen insbesondere der Einbeziehung der Akteursperspektive in die Netzwerkanalyse, der Exploration von Netzwerken sowie der verstehenden Analyse der Netzwerkdynamiken. Der von Betina HOLLSTEIN und Florian STRAUS herausgegebene Band "Qualitative Netzwerkanalyse" versammelt zwanzig überwiegend empirische Beiträge, die die Leistungsfähigkeit der Kombination quantitativer und qualitativer Verfahren in der Netzwerkanalyse in verschiedenen Anwendungsfeldern belegen. In diesem Beitrag wird untersucht, wie es gelingt, die Perspektive der strukturalen Analyse hierbei umzusetzen und weiterzuentwickeln. Aus dieser Rezensionsperspektive wird die Selbstpositionierung der "qualitativen Netzwerkanalyse" innerhalb der Netzwerkanalyse beurteilt. URN: urn:nbn:de:0114-fqs0701287

Rainer Diaz-Bone

2007-01-01

280

Hydrodynamic Aspects at Vitória Bay Mouth, ES  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Entender o comportamento hidrodinâmico e o transporte de MPS é de grande importância em regiões portuárias como o Porto de Vitória, localizado na Baía de Vitória, Vitória-ES, Brasil. A Baía de Vitória, é um estuário que nunca foi alvo de pesquisas sistemáticas de análise temporal com objetivo de ide [...] ntificar suas características hidrodinâmicas e de troca de MPS. Assim, esse estudo visa investigar os fluxos de sal e MPS na desembocadura do estuário da baía de Vitória, através da compreensão da variação temporal da salinidade, temperatura e correntes ao longo da coluna d'água e na seção transversal do canal. Os resultados mostraram que a desembocadura estuarina tendeu a apresentar uma estratificação parcial nos períodos de quadratura e pouca estratificação no período de sizígia. O padrão de circulação neste trecho do estuário é influenciado principalmente pela maré, com pequena influência da descarga fluvial. Em relação ao MPS, a desembocadura do estuário mostrou uma tendência de baixa concentração, com os maiores valores ocorrendo durante a estação seca. Uma forte relação momentânea foi observada entre os fluxos de MPS e sal. Apesar de todos os dados terem sido coletados na desembocadura do estuário, o sistema mostrou uma importação de sal em todos os ciclos e importação de MPS em três dos quatro ciclos de maré estudados. Assim a Baía de Vitória não está exportando MPS para a plataforma adjacente. Abstract in english Understading the hydrodynamic behavior and suspended particulated matter (SPM) transport are of great importance in port regions such as Vitória Harbor, which is located at Vitória Bay, Vitória – ES, Brazil. Vitória Bay is an estuary that has not been systematically assessed through a temporal analy [...] sis in order to identify its hydrodynamics characteristics and SPM exchange. This study aims to investigate salt and suspended particulate matter flux at the estuarine mouth of Vitória Bay by understanding the temporal variation of salinity, temperature and tidal currents within the water column and at the channel crosssection. Results showed that the estuarine mouth tended to present partial stratification periods during neap tides and little stratification in spring tides. The circulation pattern was mainly influenced by the tide, with little influence from river discharge. With regard to the SPM, the mouth of the estuary tended to show low concentrations, with the highest values occurring during the dry season. A close relationship between momentary discharge, SPM and salt fluxes was observed. Despite all the data was collected at the mouth of the estuary, the system showed an importation trend of salt in all cycles and SPM importation for three of the four studied tidal cycles. Thus, Vitoria Bay is not exporting SPM to the adjacent inner shelf.

FLÁVIA A.A., GARONCE; VALÉRIA S., QUARESMA.

 
 
 
 
281

O Édipo de Foucault não é o de Freud/El Edipo de Foucault no es de Freud  

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Full Text Available O Édipo, como o homem que sabia demais, era por isso o homem da ignorância. Foucault, diferente de Freud, estabelece um Édipo historicizado no tempo da passagem da forma jurídica do “regime de provas” à do “sistema de inquérito”, culminando no que chamou de o “exame” – nome lacônico que dá às ciências humanas. Porém, não há como mencionar a tragédia sofocliana sem tocar na hermenêutica psicanalítica, e sobre isso Foucault é implacável: a Psicanálise é um dispositivo discursivo de poder, uma ciência disciplinar, contendora do desejo. Mas a Psicanálise não deve ser emparelhada à Psiquiatria, por exemplo. A “razão” freudiana reside justamente numa tensão paradoxal entre dar voz à singularidade e, ao mesmo tempo, reafirmar universais históricos da cultura. Édipo não é uma nosografia, mas o que detém um “saber que não se sabe”: o do inconsciente. Se ele é o homem do inconsciente em Freud, em Foucault ele será o da ignorância. Nisso, ambos se confluem: o homem moderno para sempre está “dissolvido”. Edipo, como el hombre que sabía demasiado, era el hombre de la ignorancia. Foucault, a diferencia de Freud, establece un Edipo historizado en el tiempo de la pasaje de la forma jurídica del "régimen de pruebas" al “sistema de averiguación", que culmina en lo que él llamó la "examem" - nombre lacónico que él da a las humanidades. Sin embargo, no se menciona la tragedia de Sófocles, sin tocar en la hermenéutica del psicoanálisis, y Foucault es implacable: el psicoanálisis es un dispositivo discursivo del poder, una ciencia disciplinar, contendiente del deseo. Pero el psicoanálisis no debería ser emparejados a la psiquiatría, por ejemplo. La "razón" freudiana reside en una tensión paradójica entre dar voz a la singularidad y, al mismo tiempo, reafirmar los universales históricos de la cultura. Edipo no es una nosografia, pero lo que tiene un "saber que no se sabe": el inconsciente. Si él es el hombre del inconsciente en Freud, en Foucault él será de la ignorancia. En este sentido, ambos confluyen: el hombre moderno para siempre está "disuelto".

Marcelo Ricardo Pereira

2010-03-01

282

Capabilities of the bathymetric Hawk Eye LiDAR for coastal habitat mapping: A case study within a Basque estuary  

Science.gov (United States)

The bathymetric LiDAR system is an airborne laser that detects sea bottom at high vertical and horizontal resolutions in shallow coastal waters. This study assesses the capabilities of the airborne bathymetric LiDAR sensor (Hawk Eye system) for coastal habitat mapping in the Oka estuary (within the Biosphere Reserve of Urdaibai, SE Bay of Biscay, northern Spain), where water conditions are moderately turbid. Three specific objectives were addressed: 1) to assess the data quality of the Hawk Eye LiDAR, both for terrestrial and subtidal zones, in terms of height measurement density, coverage, and vertical accuracy; 2) to compare bathymetric LiDAR with a ship-borne multibeam echosounder (MBES) for different bottom types and depth ranges; and 3) to test the discrimination potential of LiDAR height and reflectance information, together with multi-spectral imagery (three visible and near infrared bands), for the classification of 22 salt marsh and rocky shore habitats, covering supralittoral, intertidal and subtidal zones. The bathymetric LiDAR Hawk Eye data enabled the generation of a digital elevation model (DEM) of the Oka estuary, at 2 m of horizontal spatial resolution in the terrestrial zone (with a vertical accuracy of 0.15 m) and at 4 m within the subtidal, extending a water depth of 21 m. Data gaps occurred in 14.4% of the area surveyed with the LiDAR (13.69 km 2). Comparison of the LiDAR system and the MBES showed no significant mean difference in depth. However, the Root Mean Square error of the former was high (0.84 m), especially concentrated upon rocky (0.55-1.77 m) rather than in sediment bottoms (0.38-0.62 m). The potential of LiDAR topographic variables and reflectance alone for discriminating 15 intertidal and submerged habitats was low (with overall classification accuracy between 52.4 and 65.4%). In particular, reflectance retrieved for this case study has been found to be not particularly useful for classification purposes. The combination of the LiDAR-based DEM and derived topographical features with the near infrared and visible bands has permitted the mapping of 22 supralittoral, intertidal and subtidal habitats of the Oka estuary, with high overall classification accuracies of between 84.5% and 92.1%, using the maximum likelihood algorithm. The airborne bathymetric Hawk Eye LiDAR, although somewhat limited by water turbidity and wave breaking, provides unique height information obscured from topographic LiDAR and acoustic systems, together with an improvement of the habitat mapping reliability in the complex and dynamic coastal fringe.

Chust, Guillem; Grande, Maitane; Galparsoro, Ibon; Uriarte, Adolfo; Borja, Ángel

2010-10-01

283

DArT markers: diversity analyses, genomes comparison, mapping and integration with SSR markers in Triticum monococcum  

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Full Text Available Abstract Background Triticum monococcum (2n = 2x = 14 is an ancient diploid wheat with many useful traits and is used as a model for wheat gene discovery. DArT (Diversity Arrays Technology employs a hybridisation-based approach to type thousands of genomic loci in parallel. DArT markers were developed for T. monococcum to assess genetic diversity, compare relationships with hexaploid genomes, and construct a genetic linkage map integrating DArT and microsatellite markers. Results A DArT array, consisting of 2304 hexaploid wheat, 1536 tetraploid wheat, 1536 T. monococcum as well as 1536 T. boeoticum representative genomic clones, was used to fingerprint 16 T. monococcum accessions of diverse geographical origins. In total, 846 polymorphic DArT markers were identified, of which 317 were of T. monococcum origin, 246 of hexaploid, 157 of tetraploid, and 126 of T. boeoticum genomes. The fingerprinting data indicated that the geographic origin of T. monococcum accessions was partially correlated with their genetic variation. DArT markers could also well distinguish the genetic differences amongst a panel of 23 hexaploid wheat and nine T. monococcum genomes. For the first time, 274 DArT markers were integrated with 82 simple sequence repeat (SSR and two morphological trait loci in a genetic map spanning 1062.72 cM in T. monococcum. Six chromosomes were represented by single linkage groups, and chromosome 4Am was formed by three linkage groups. The DArT and SSR genetic loci tended to form independent clusters along the chromosomes. Segregation distortion was observed for one third of the DArT loci. The Ba (black awn locus was refined to a 23.2 cM region between the DArT marker locus wPt-2584 and the microsatellite locus Xgwmd33 on 1Am; and the Hl (hairy leaf locus to a 4.0 cM region between DArT loci 376589 and 469591 on 5Am. Conclusion DArT is a rapid and efficient approach to develop many new molecular markers for genetic studies in T. monococcum. The constructed genetic linkage map will facilitate localisation and map-based cloning of genes of interest, comparative mapping as well as genome organisation and evolution studies between this ancient diploid species and other crops.

Huttner Eric

2009-09-01

284

Quantifying spatial distribution of snow depth errors from LiDAR using Random Forests  

Science.gov (United States)

There is increasing need to characterize the distribution of snow in complex terrain using remote sensing approaches, especially in isolated mountainous regions that are often water-limited, the principal source of terrestrial freshwater, and sensitive to climatic shifts and variations. We apply intensive topographic surveys, multi-temporal LiDAR, and Random Forest modeling to quantify snow volume and characterize associated errors across seven land cover types in a semi-arid mountainous catchment at a 1 and 4 m spatial resolution. The LiDAR-based estimates of both snow-off surface topology and snow depths were validated against ground-based measurements across the catchment. Comparison of LiDAR-derived snow depths to manual snow depth surveys revealed that LiDAR based estimates were more accurate in areas of low lying vegetation such as shrubs (RMSE = 0.14 m) as compared to areas consisting of tree cover (RMSE = 0.20-0.35 m). The highest errors were found along the edge of conifer forests (RMSE = 0.35 m), however a second conifer transect outside the catchment had much lower errors (RMSE = 0.21 m). This difference is attributed to the wind exposure of the first site that led to highly variable snow depths at short spatial distances. The Random Forest modeled errors deviated from the field measured errors with a RMSE of 0.09-0.34 m across the different cover types. Results show that snow drifts, which are important for maintaining spring and summer stream flows and establishing and sustaining water-limited plant species, contained 30 × 5-6% of the snow volume while only occupying 10% of the catchment area similar to findings by prior physically-based modeling approaches. This study demonstrates the potential utility of combining multi-temporal LiDAR with Random Forest modeling to quantify the distribution of snow depth with a reasonable degree of accuracy. Future work could explore the utility of Terrestrial LiDAR Scanners to produce validation of snow-on surface elevations.

Tinkham, W.; Smith, A. M.; Marshall, H.; Link, T. E.; Falkowski, M. J.; Winstral, A. H.

2013-12-01

285

Importance of High-Resolution LiDAR Data in Modeling Runoff Levels Over Impervious Surfaces  

Science.gov (United States)

Directly connected impervious areas collect and deliver unfiltered runoff to modified and impacted waterways. Modeling water flow over the landscape is an effective method of observing drainage patterns and predicting pollutant and sediment loadings. Improved models applying high-resolution elevation data can identify key areas with high pollutant output. This is a crucial issue in the Lake Tahoe Basin where lakeshore urban development has increased and lake clarity has been declining for years. This study aims to evaluate an integrated LiDAR and GIS-based modeling approach that uses a fine-scaled ground surface and impervious surface connectivity to predict the pollutant load in the Lake Tahoe Basin This study produced a fine-scaled surface model of nine subset catchments in the South Tahoe basin, including areas of low (below 20%), medium (30% to 50%) and high (above 50%) impervious surface cover. Our method integrated LiDAR, multispectral imagery, and GIS data to develop accurate terrain models, hydrologic routing, and directly connected impervious area layers for the Lake Tahoe basin. The high-density ground and object elevation data collected using Light Detection and Ranging (LiDAR) creates an accurate picture of water flow over the land, and obstacles to the flow such as buildings. High-resolution LiDAR data was obtained from the Round 10 Lake Tahoe Southern Nevada Public Land Management capital program from the year 2010. This data was processed to create a digital elevation model of the ground surface. Land use classification used object height information from the LiDAR cloud, NAIP 4-band images with 1-meter resolution and a normalized difference vegetation index image derived from the NAIP imagery. The US Army Core of Engineers hydrologic modeling system (HEC-HMS) will be used to model runoff. Based on long-term simulations the effect of directly connected impervious area on rainfall-runoff characteristics for the South Lake Tahoe catchments will be evaluated. Similar scenarios will be run on data derived from 10-meter resolution USGS elevation models. Regression analyses will be used to compare the simulation results derived using LiDAR data inputs to the results obtained using lower-resolution USGS elevation models and to observed monitoring data.

Melosh, C.; Rao, M.

2013-12-01

286

LA EUTANASIA NO ES UN ACTO MÉDICO  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in portuguese Neste artigo expõem-se os argumentos pelos quais o médico está juridicamente impedido de matar os seus pacientes. Dentre outras razões, os médicos não matam seus pacientes porque "matar" não é um ato médico terapêutico. Não restabelece a saúde nem preserva a vida. Se o Estado deseja a eutanásia e o [...] suicídio assistido, não existe nenhuma razão que impeça os familiares dos pacientes os levem ao cabo. Eles, não o médico, devem responder pelo ato ante a sociedade e as suas próprias consciências. Além disso, o artigo revisa de modo claro e conciso a sentencia C-239/97 da Corte Constitucional e explica porquê alguns artigos do projeto da lei 05/07 do Senado não se ajustam a ela e, portanto, são inconstitucionais. Abstract in spanish En este artículo se exponen los argumentos por los cuales el médico está jurídica y éticamente impedido para matar a sus pacientes. Entre otras razones, los médicos no matan a sus pacientes porque "matar" no es un acto médico terapéutico. No restablece la salud y tampoco preserva la vida. Si el Esta [...] do quiere la eutanasia y el suicidio asistido, no hay ninguna razón constitucional que impida realizar el acto eutanásico a los familiares de los pacientes enfermos. Son ellos, y no el médico, quienes deben responder ante la sociedad y ante sus propias conciencias por ello. El artículo, además, revisa de manera clara y precisa la sentencia C-239/97 de la Corte Constitucional, y explica por qué algunos artículos del proyecto de Ley 05/07 del Senado no se ajustan a ella y son, por tanto, inconstitucionales. Abstract in english This paper deals with the legal and moral reasons that prevent the physician from taking a patient's life. Among other reasons, medical doctors do not "kill" their patients because "killing" is not a therapeutic medical act. It does not reestablish the patient's previous state of health, nor does it [...] preserve life. If the state wants to allow euthanasia or assisted suicide, there is no constitutional reason why the relatives of a patient who is ill cannot euthanize or assist the patient in committing suicide. It is they, not the physician, who must answer to society and their own consciences for doing so. The article also offers a clear and precise look at Sentence C-239/97 issued by the Constitutional Court of Colombia and analyses the reasons why some of the articles in Senate Bill 05/07 are inconsistent with that sentence and, therefore, are unconstitutional.

Jorge, Merchán-Price.

287

High frequency of partial DIIIa and DAR alleles found in sickle cell disease patients suggests increased risk of alloimmunization to RhD.  

Science.gov (United States)

We have set out to determine the frequency of DIIIa and DAR alleles among sickle cell disease (SCD) patients. These D variants permit the unexpected development of antibodies to RhD among individuals who are otherwise classified as RhD+. DNA samples from 130 SCD patients were tested for 455A>C (specific for DIIIa), 602C>G, 667T>G (common for both DIIIa and DAR) and 1025T>C (specific for DAR) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequence analysis. The PCR-RFLP showed that 12 (9.2%) of the SCD patients were carrying DIIIa and DAR alleles. Genomic DNA analysis performed by sequence showed that three samples were heterozygous DIIIa (2.3%), seven heterozygous DAR (4.6%) and two (1.5%) samples carried a partial D with four mutations: 455A>C (heterozygous), 602C>G and 667T>G (homozygous) and 1025T>C (heterozygous), indicating compound heterozygosity for one DIIIa allele and one DAR allele. The predicted phenotypes of eight (6.2%) SCD patients were DIIIa, DAR and DIIIa/DAR. Three patients were anti-D immunized (DAR, n = 1; DIIIa/DAR, n = 2). These findings suggest that SCD patients who are candidates for chronic transfusion may benefit from genotyping for DIIIa and DAR to prevent alloimmunization. PMID:15713129

Castilho, L; Rios, M; Rodrigues, A; Pellegrino, J; Saad, S T O; Costa, F F

2005-02-01

288

Landslide investigation using LiDAR data acquired by an unmanned helicopter  

Science.gov (United States)

In this study, LiDAR data acquired over 0.5 km2 landslide prone area by an unmanned helicopter is presented. The data was taken in summer 2012 and 2013, when tree foliage covered the ground surface. Imagery was of sufficient quality to identify and measure landslide features. These data together with LiDAR data obtained by a manned helicopter in the same area in August 2008 were examined to find active slopes on landslides during the period from 2008 to 2013. Morphological characteristics of these slopes were also analyzed to utilize the notion to discover active but hiding landslides in the region. In inapproachable areas, the UAV (Unmanned Aerial Vehicles) is likely to be of greatest use. In addition, this study showed that repeat monitoring of sites is a way of utilizing UAVs, particularly in terms of cost and convenience.

Kasai, M.; Tanaka, Y.; Marutani, T.; Saito, Y.

2013-12-01

289

Cosmogenic Records in 18 Ordinary Chondrites from the Dar Al Gani Region, Libya. 1; Noble Gases  

Science.gov (United States)

In the last decade thousands of meteorites have been recovered from hot deserts in the Sahara and Oman. One of the main meteorite concentration surfaces in the Sahara is the Dar al Gani plateau in Libya, which covers a total area of 8000 km2. More than 1000 meteorites have been reported from this area. The geological setting, meteorite pairings and the meteorite density of the Dar al Gani (DaG) field are described in more detail in [1]. In this work we report concentrations of the noble gas isotopes of He, Ne, Ar as well as 84Kr and 132Xe in 18 DaG meteorites. In a separate paper we will report the cosmogenic radionuclides [2]. We discuss the thermal history and cosmic-ray exposure (CRE) history of these meteorites, and evaluate the effects of the hot desert environment on the noble gas record.

Schultz, L.; Franke, L.; Welten, K. C.; Nishiizumi, K.; Jull, A. J. T.

2003-01-01

290

Characterization of the OPAL obscurant penetrating LiDAR in various degraded visual environments  

Science.gov (United States)

The OPAL obscurant penetrating LiDAR was developed by Neptec and characterized in various degraded visual environments (DVE) over the past five years. Quantitative evaluations of obscurant penetration were performed using the Defence RD Canada - Valcartier (DRDC Valcartier) instrumented aerosol chamber for obscurants such as dust and fog. Experiments were done with the sensor both at a standoff distance and totally engulfed in the obscurants. Field trials were also done to characterize the sensor in snow conditions and in smoke. Finally, the OPAL was also mounted on a Bell 412 helicopter to characterize its dust penetration capabilities, in environment such as Yuma Proving Ground. The paper provides a summary of the results of the OPAL evaluations demonstrating it to be a true "see through" obscurant penetrating LiDAR and explores commercial applications of the technology.

Trickey, Evan; Church, Philip; Cao, Xiaoying

2013-05-01

291

Biogenini? amin? kaupimasis Lietuvoje išaugintose daržov?se  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Biogenini? amin? (putrescino, histamino, kadaverino, tiramino) kiekiai nustatyti šviežiose daržov?se: morkose, bulv?se, raudonuosiuose burok?liuose, geltonvais?se saldžiosiose paprikose, žiediniuose kop?stuose, brokoliuose, špinatuose, pomidoruose ir pomidor? ke?upuose. Didžiausias tiramino lygis (330,8–491,1 mg kg-1) nustatytas brokoliuose, putrescino (27,8–35,7 mg kg-1) – pomidoruose, histamino (50,2–84,2 mg kg-1) – burok?liuose. Darbe pateikti biogenini? amin? ...

2007-01-01

292

Estimating Volume, Biomass, and Carbon in Hedmark County, Norway Using a Profiling LiDAR  

Science.gov (United States)

A profiling airborne LiDAR is used to estimate the forest resources of Hedmark County, Norway, a 27390 square kilometer area in southeastern Norway on the Swedish border. One hundred five profiling flight lines totaling 9166 km were flown over the entire county; east-west. The lines, spaced 3 km apart north-south, duplicate the systematic pattern of the Norwegian Forest Inventory (NFI) ground plot arrangement, enabling the profiler to transit 1290 circular, 250 square meter fixed-area NFI ground plots while collecting the systematic LiDAR sample. Seven hundred sixty-three plots of the 1290 plots were overflown within 17.8 m of plot center. Laser measurements of canopy height and crown density are extracted along fixed-length, 17.8 m segments closest to the center of the ground plot and related to basal area, timber volume and above- and belowground dry biomass. Linear, nonstratified equations that estimate ground-measured total aboveground dry biomass report an R(sup 2) = 0.63, with an regression RMSE = 35.2 t/ha. Nonstratified model results for the other biomass components, volume, and basal area are similar, with R(sup 2) values for all models ranging from 0.58 (belowground biomass, RMSE = 8.6 t/ha) to 0.63. Consistently, the most useful single profiling LiDAR variable is quadratic mean canopy height, h (sup bar)(sub qa). Two-variable models typically include h (sup bar)(sub qa) or mean canopy height, h(sup bar)(sub a), with a canopy density or a canopy height standard deviation measure. Stratification by productivity class did not improve the nonstratified models, nor did stratification by pine/spruce/hardwood. County-wide profiling LiDAR estimates are reported, by land cover type, and compared to NFI estimates.

Nelson, Ross; Naesset, Erik; Gobakken, T.; Gregoire, T.; Stahl, G.

2009-01-01

293

Quantifying Dynamics in Tropical Peat Swamp Forest Biomass with Multi-Temporal LiDAR Datasets  

Directory of Open Access Journals (Sweden)

Full Text Available Tropical peat swamp forests in Indonesia store huge amounts of carbon and are responsible for enormous carbon emissions every year due to forest degradation and deforestation. These forest areas are in the focus of REDD+ (reducing emissions from deforestation, forest degradation, and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks projects, which require an accurate monitoring of their carbon stocks or aboveground biomass (AGB. Our study objective was to evaluate multi-temporal LiDAR measurements of a tropical forested peatland area in Central Kalimantan on Borneo. Canopy height and AGB dynamics were quantified with a special focus on unaffected, selective logged and burned forests. More than 11,000 ha were surveyed with airborne LiDAR in 2007 and 2011. In a first step, the comparability of these datasets was examined and canopy height models were created. Novel AGB regression models were developed on the basis of field inventory measurements and LiDAR derived height histograms for 2007 (r2 = 0.77, n = 79 and 2011 (r2 = 0.81, n = 53, taking the different point densities into account. Changes in peat swamp forests were identified by analyzing multispectral imagery. Unaffected forests accumulated on average 20 t/ha AGB with a canopy height increase of 2.3 m over the four year time period. Selective logged forests experienced an average AGB loss of 55 t/ha within 30 m and 42 t/ha within 50 m of detected logging trails, although the mean canopy height increased by 0.5 m and 1.0 m, respectively. Burned forests lost 92% of the initial biomass. These results demonstrate the great potential of repetitive airborne LiDAR surveys to precisely quantify even small scale AGB and canopy height dynamics in remote tropical forests, thereby featuring the needs of REDD+.

Florian Siegert

2013-05-01

294

NASA Goddard’s LiDAR, Hyperspectral and Thermal (G-LiHT Airborne Imager  

Directory of Open Access Journals (Sweden)

Full Text Available The combination of LiDAR and optical remotely sensed data provides unique information about ecosystem structure and function. Here, we describe the development, validation and application of a new airborne system that integrates commercial off the shelf LiDAR hyperspectral and thermal components in a compact, lightweight and portable system. Goddard’s LiDAR, Hyperspectral and Thermal (G-LiHT airborne imager is a unique system that permits simultaneous measurements of vegetation structure, foliar spectra and surface temperatures at very high spatial resolution (~1 m on a wide range of airborne platforms. The complementary nature of LiDAR, optical and thermal data provide an analytical framework for the development of new algorithms to map plant species composition, plant functional types, biodiversity, biomass and carbon stocks, and plant growth. In addition, G-LiHT data enhance our ability to validate data from existing satellite missions and support NASA Earth Science research. G-LiHT’s data processing and distribution system is designed to give scientists open access to both low- and high-level data products (http://gliht.gsfc.nasa.gov, which will stimulate the community development of synergistic data fusion algorithms. G-LiHT has been used to collect more than 6,500 km2 of data for NASA-sponsored studies across a broad range of ecoregions in the USA and Mexico. In this paper, we document G-LiHT design considerations, physical specifications, instrument performance and calibration and acquisition parameters. In addition, we describe the data processing system and higher-level data products that are freely distributed under NASA’s Data and Information policy.

Vuong Ly

2013-08-01

295

Strategies for minimizing sample size for use in airborne LiDAR-based forest inventory  

Science.gov (United States)

Recently airborne Light Detection And Ranging (LiDAR) has emerged as a highly accurate remote sensing modality to be used in operational scale forest inventories. Inventories conducted with the help of LiDAR are most often model-based, i.e. they use variables derived from LiDAR point clouds as the predictive variables that are to be calibrated using field plots. The measurement of the necessary field plots is a time-consuming and statistically sensitive process. Because of this, current practice often presumes hundreds of plots to be collected. But since these plots are only used to calibrate regression models, it should be possible to minimize the number of plots needed by carefully selecting the plots to be measured. In the current study, we compare several systematic and random methods for calibration plot selection, with the specific aim that they be used in LiDAR based regression models for forest parameters, especially above-ground biomass. The primary criteria compared are based on both spatial representativity as well as on their coverage of the variability of the forest features measured. In the former case, it is important also to take into account spatial auto-correlation between the plots. The results indicate that choosing the plots in a way that ensures ample coverage of both spatial and feature space variability improves the performance of the corresponding models, and that adequate coverage of the variability in the feature space is the most important condition that should be met by the set of plots collected.

Junttila, Virpi; Finley, Andrew O.; Bradford, John B.; Kauranne, Tuomo

2013-01-01

296

Recovery of Forest Canopy Parameters by Inversion of Multispectral LiDAR Data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We describe the use of Bayesian inference techniques, notably Markov chain Monte Carlo (MCMC) and reversible jump MCMC (RJMCMC) methods, to recover forest structural and biochemical parameters from multispectral LiDAR (Light Detection and Ranging) data. We use a variable dimension, multi-layered model to represent a forest canopy or tree, and discuss the recovery of structure and depth profiles that relate to photochemical properties. We first demonstrate how simple vegetation indices such as...

Andrew Wallace; Caroline Nichol; Iain Woodhouse

2012-01-01

297

Step by step error assessment in braided river sediment budget using airborne LiDAR data  

Science.gov (United States)

Sequential airborne LiDAR surveys were used to reconstruct the sediment budget of a 7-km-long braided river channel in southeastern France following a 14-year return period flood and to improve its accuracy step by step. Data processing involved (i) surface matching of the sequential point clouds, (ii) spatially distributed propagation of uncertainty based on surface conditions of the channel, and (iii) water depth subtraction from the digital elevation models based on water depths measured in the field. The respective influence of each processing step on sediment budget computation was systematically documented. This showed that surface matching and water depth subtraction both have a considerable effect on the net sediment budget. Although DEM of difference thresholding based on uncertainty analysis on absolute elevation values had a smaller effect on the sediment budget, this step is crucial for the production of a comprehensive map of channel deformations. A large independent data set of RTK-GPS checkpoints was used to control the quality of the LiDAR altimetry. The results showed that high density (7–9 points/m2) airborne LiDAR surveys can provide a very high level of detection of elevation changes on the exposed surfaces of the channel, with a 95% confidence interval level of detection between 19 and 30 cm. Change detection from LiDAR data revealed that 54% of the pre-flood active channel was reworked by the flood. The braided channel pattern was highly disturbed by the flood owing to the occurrence of several channel avulsions.

Lallias-Tacon, S.; Liébault, F.; Piégay, H.

2014-06-01

298

Extracting More Data from LiDAR in Forested Areas by Analyzing Waveform Shape  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Light Detection And Ranging (LiDAR) in forested areas is used for constructing Digital Terrain Models (DTMs), estimating biomass carbon and timber volume and estimating foliage distribution as an indicator of tree growth and health. All of these purposes are hindered by the inability to distinguish the source of returns as foliage, stems, understorey and the ground except by their relative positions. The ability to separate these returns would improve all analyses significantly. Furthermore, ...

Thomas Adams; Peter Beets; Christopher Parrish

2012-01-01

299

DARS (Decoys As the Reference State) Potentials for Protein-Protein Docking  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Decoys As the Reference State (DARS) is a simple and natural approach to the construction of structure-based intermolecular potentials. The idea is generating a large set of docked conformations with good shape complementarity but without accounting for atom types, and using the frequency of interactions extracted from these decoys as the reference state. In principle, the resulting potential is ideal for finding near-native conformations among structures obtained by docking, and can be combi...

Chuang, Gwo-yu; Kozakov, Dima; Brenke, Ryan; Comeau, Stephen R.; Vajda, Sandor

2008-01-01

300

DArT markers for the rye genome - genetic diversity and mapping  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Implementation of molecular breeding in rye (Secale cereale L.) improvement programs depends on the availability of high-density molecular linkage maps. However, the number of sequence-specific PCR-based markers available for the species is limited. Diversity Arrays Technology (DArT) is a microarray-based method allowing for detection of DNA polymorphism at several thousand loci in a single assay without relying on DNA sequence information. The ob...

Bolibok-Br?goszewska Hanna; Heller-Uszy?ska Katarzyna; Wenzl Peter; Uszy?ski Grzegorz; Kilian Andrzej; Rakoczy-Trojanowska Monika

2009-01-01

 
 
 
 
301

New possibilities for damage prediction from tunnel subsidence using aerial LiDAR data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Computation modelling has not been fully exploited for predicting building damage due to tunnel-induced subsidence, because of the expense and time required to create computational meshes for the vast quantity of buildings that may be impacted along a tunnel’s route. A possible circumvention of such a resource commitment lies in the exploitation of remote sensing data in the form of aerial laser scans (also know as Light Detection and Ranging – LiDAR). This paper presents work accomplish...

2010-01-01

302

New DArT markers for oat provide enhanced map coverage and global germplasm characterization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Genomic discovery in oat and its application to oat improvement have been hindered by a lack of genetic markers common to different genetic maps, and by the difficulty of conducting whole-genome analysis using high-throughput markers. This study was intended to develop, characterize, and apply a large set of oat genetic markers based on Diversity Array Technology (DArT). Results Approximately 19,000 genomic clones were isolated from complexit...

2009-01-01

303

Accuracy and Precision of Terrestrial LiDAR for Ground Deformation Monitoring  

Science.gov (United States)

With controlled experiments and multiple occupations of a field site at Waimea Bay, Oahu, we are assessing the accuracy and precision for geodetic applications of the Optech ILRIS 3-D, a near-infrared (1.2 micron wavelength) Terrestrial-LiDAR (T-LiDAR) system. For the controlled experiments, we have built a stable table with a grid of peg holes and estimated static offsets and translations of a geodetic target (a Leica GPS antenna and radome). We scan the radome from variable distances (50 -1000 m) and with variable spot spacing. We use the 3D point cloud data to model the phase center of the radome by fitting all data points to a spherical model in a local co-ordinate frame. Preliminary results show that from over 1400 individual scans with spot-spacing ranging from 2 mm to 20 mm and over distances of 100-180 meters, the phase center of the radome derived from T-LiDAR measurements and solid modeling is achieved with better than 2-4 mm standard deviation. At the field site we have conducted more than 30 scans over a period of 3 months of an area with dimensions ranging from ~300 - 1000 m. While the beach face changes significantly during this time period, the area behind the beach does not allowing us to analyze the multiple natural and human-made targets there for their stability at a variety of distances and weather conditions.

Aryal, A.; Brooks, B. A.; Foster, J. H.

2007-12-01

304

ASTER GDEM validation using LiDAR data over coastal regions of Greenland  

DEFF Research Database (Denmark)

Elevation data from airborne Light Detection and Ranging (LiDAR) campaigns are used in an attempt to evaluate the accuracy of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) global digital elevation model (GDEM) in Greenland. The LiDAR elevation data set is characterized by a high spatial resolution of about 1 m and elevation accuracy of 20â??30 cm root mean square error (RMSE). The LiDAR data sets used were acquired during ice-monitoring campaigns carried out from 2003 to 2008. The study areas include ice-free regions, local ice caps and the ice sheet margin. A linear error of 15â??65 m was derived, which is far greater than the 20-m product specification. This estimation is biased by both the seasonal and the climatic changes in local ice caps because the ASTER GDEM was computed from imagery acquired in the period 2000â??2009. High sloping areas along the coastal regions of Greenland and the effect of the number of scenes used to generate the ASTER GDEM as well as relief are associatedwith the GDEM accuracy.

Hvidegaard, Sine Munk; Sørensen, Louise Sandberg

2011-01-01

305

Use of LiDAR data in hydroelectric reservoir clearing assessment  

Energy Technology Data Exchange (ETDEWEB)

Reservoirs have many purposes including water storage for hydroelectric projects, agriculture and irrigation, and floodwater control. Most reservoirs use natural geological features such as river valleys, combined with man-made dams and dykes to impound water for controlled release. Thus, the project for which the reservoir was created receives benefit from water storage and release that would not be available without this control. However, subsequent flooding of the reservoir can cause significant environmental impacts that have to be mitigated. In order to balance terrestrial, aquatic, socio-economic, and operational needs, a plan is needed. This paper reviewed one effective method to quantify the amount of deforestation required to create a water reservoir. It discussed Newfoundland's Lower Churchill Project and the development of multiple case scenarios for accurate clearing requirements using light detection and ranging (LiDAR) data and high resolution geo-referenced orthophotographs. A reservoir clearing assessment using the LiDAR digital elevation model and orthophotographic data was explained. It was concluded that LiDAR data was a very valuable tool for assessment purposes. However, it does not replace the requirement of field reconnaissance, or detailed field surveying during construction. Using GPS and maps created from the data, the field task is rendered much more cost and time effective. 12 figs.

Tucker, K.B.; Cooper, J. [Newfoundland and Labrador Hydro, St. John' s, NL (Canada)

2007-07-01

306

A Comparison of Two Open Source LiDAR Surface Classification Algorithms  

Directory of Open Access Journals (Sweden)

Full Text Available With the progression of LiDAR (Light Detection and Ranging towards a mainstream resource management tool, it has become necessary to understand how best to process and analyze the data. While most ground surface identification algorithms remain proprietary and have high purchase costs; a few are openly available, free to use, and are supported by published results. Two of the latter are the multiscale curvature classification and the Boise Center Aerospace Laboratory LiDAR (BCAL algorithms. This study investigated the accuracy of these two algorithms (and a combination of the two to create a digital terrain model from a raw LiDAR point cloud in a semi-arid landscape. Accuracy of each algorithm was assessed via comparison with >7,000 high precision survey points stratified across six different cover types. The overall performance of both algorithms differed by only 2%; however, within specific cover types significant differences were observed in accuracy. The results highlight the accuracy of both algorithms across a variety of vegetation types, and ultimately suggest specific scenarios where one approach may outperform the other. Each algorithm produced similar results except in the ceanothus and conifer cover types where BCAL produced lower errors.

Danny G Marks

2011-03-01

307

Phylogenetic Relationships between Four Salix L. Species Based on DArT Markers  

Directory of Open Access Journals (Sweden)

Full Text Available The objectives of this study were to evaluate the usefulness of DArT markers in genotypic identification of willow species and describe genetic relationships between four willow species: Salix viminalis, S. purpurea, S. alba and S. triandra. The experimental plant material comprised 53 willow genotypes of these four species, which are popularly grown in Poland. DArT markers seem to identify Salix species with a high degree of accuracy. As a result, the examined species were divided into four distinct groups which corresponded to the four analyzed species. In our study, we observed that S. triandra was very different genetically from the other species, including S. alba which is generally classified into the same subgenus of Salix. The above corroborates the findings of other authors who relied on molecular methods to reveal that the classification of S. triandra to the subgenus Salix was erroneous. The Principal Coordinate Analysis (PCoA and the neighbor-joining dendrogram also confirmed the clear division of the studied willow genotypes into four clusters corresponding to individual species. This confirmed the usefulness of DArT markers in taxonomic analyses and identification of willow species.

Jerzy A. Przyborowski

2013-12-01

308

Aerial LiDAR Based Analysis of a Degraded Fault Scarp in Stewart Valley, Nevada  

Science.gov (United States)

Normal fault scarp morphology has been examined by numerous authors who have used slope angle versus height of scarp profiles to derive the relative age of the whole scarp. Recently, both aerial and ground-based LiDAR have been used to analyse fault scarp geometries, replacing traditional labour intensive techniques that are typically performed in the field on well developed relatively unmodified scarps. Here we present scarp morphology age analysis of a low (less than 2.5 m maximum height), significantly degraded fault scarp that is part of the Stateline Fault System in Stewart Valley, Nevada. We use aerial LiDAR as a method to measure profiles of the scarp and we demonstrate techniques to scrutinize scarp profiles for evidence of localized non-diffusive processes. These processes are often difficult to recognize by more traditional methods and can introduce significant variance in scarp slope/height plots for relative age if not identified and removed. We find that LiDAR offers great potential for relative age comparisons between fault scarps of significant morphologic degradation. Such comparisons are one of the goals of our project as these comparisons will help provide a more rigorous determination of rupture histories throughout the Stateline Fault System.

D'Arcy, K.; Guest, B.

2011-12-01

309

Algorithm for Extracting Digital Terrain Models under Forest Canopy from Airborne LiDAR Data  

Directory of Open Access Journals (Sweden)

Full Text Available Extracting digital elevationmodels (DTMs from LiDAR data under forest canopy is a challenging task. This is because the forest canopy tends to block a portion of the LiDAR pulses from reaching the ground, hence introducing gaps in the data. This paper presents an algorithm for DTM extraction from LiDAR data under forest canopy. The algorithm copes with the challenge of low data density by generating a series of coarse DTMs by using the few ground points available and using trend surfaces to interpolate missing elevation values in the vicinity of the available points. This process generates a cloud of ground points from which the final DTM is generated. The algorithm has been compared to two other algorithms proposed in the literature in three different test sites with varying degrees of difficulty. Results show that the algorithm presented in this paper is more tolerant to low data density compared to the other two algorithms. The results further show that with decreasing point density, the differences between the three algorithms dramatically increased from about 0.5m to over 10m.

Almasi S. Maguya

2014-07-01

310

Four-dimensional surface deformation analysis, snow volume calculation, and fault mapping with Ground Based Tripod LiDAR  

Science.gov (United States)

Ground-based tripod or terrestrial LiDAR (T-LiDAR) has the potential to significantly advance science and hazard assessments in a broad number of research disciplines using remotely collected ultra-high resolution (centimeter to subcentimeter) and accurate (~4 mm) digital imagery of the scanned target. This can be accomplished at distances from 3 to >800 meters, depending on the instrument and target's infrared reflective properties. Scientific analysis of the ultra-high resolution T-LiDAR imagery is through the direct analysis of three-dimensional datasets to calculate target dimensions, volume, and area; alternatively, repeated surveys of the target, differential four-dimensional time-series analysis can be used to evaluate volume change, target stability, surface displacements, or change-detection. Three examples are given that show a range of scientific T-LiDAR application to earth science research: (1) fault mapping at Yucca Flat, Nev.; (2) snow volume calculations in the central Sierra Nevada, Calif.; and (3) hazard mitigation and change-detection and hazard mitigation for the June 1, 2005, Laguna Beach Landslide, southern Calif. The fault-mapping example is a static analysis of many detailed (1- to 5-cm spot spacing) T-LiDAR scans collected on the Nevada Test Site at Yucca Flat at a crater created by an underground nuclear test. The analysis identifies and maps centimeter-level fractures and faults in and near the crater. The level of detail of the T-LiDAR-generated fault and fracture database enhances existing fracture maps. The snow-volume calculation example is a differential analysis of three T-LiDAR surveys at the U.C. Berkeley Central Sierra Snow Lab between March and June 2004. The surveys were aligned and differenced to calculate spatially varying snow volumes. These volumes were combined with water-density measurements to estimate the total water volume. The change detection and hazard-assessment example analyzes repeated T-LiDAR imagery following the June 1, 2005, Laguna Beach Landslide to assess hillslope and structure stability of the slide and the immediate surroundings, and to evaluate T-LiDAR as a hazards response tool. There were no land-surface changes within the landslide after the initial T-LiDAR survey (10 to 21 days after the event) other than minor small-scale readjustments, property recovery efforts, and monitoring within the landslide. T-LiDAR provided direct measurements for the full surrounding region and confirmed that many of the nearby homes were not moving during this time period and could be reinhabited.

Bawden, G. W.; Schmitz, S.; Howle, J. F.; Laczniak, R. J.; Bowers, J.; Osterhuber, R.; Irvine, P.

2005-12-01

311

Analysis of DAR(1)/D/s Queue with Quasi-Negative Binomial-II as Marginal Distribution  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we consider the arrival process of a multiserver queue governed by a discrete autoregressive process of order 1 [DAR(1)] with Quasi-Negative Binomial Distribution-II as the marginal distribution. This discrete time multiserver queueing system with autoregressive arrivals is more suitable for modeling the Asynchronous Transfer Mode(ATM) multiplexer queue with Variable Bit Rate (VBR) coded teleconference traffic. DAR(1) is described by a few parameters and it is easy to match the ...

Kanichukattu Korakutty Jose; Bindu Abraham

2011-01-01

312

A method for parameterising roughness and topographic sub-grid scale effects in hydraulic modelling from LiDAR data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

High resolution airborne laser data provide new ways to explore the role of topographic complexity in hydraulic modelling parameterisation, taking into account the scale-dependency between roughness and topography. In this paper, a complex topography from LiDAR is processed using a spatially and temporally distributed method at a fine resolution. The surface topographic parameterisation considers the sub-grid LiDAR data points above and below a reference DEM, hereafter named as topographic co...

Casas, A.; Lane, S. N.; Yu, D.; Benito, G.

2010-01-01

313

Detection of large above-ground biomass variability in lowland forest ecosystems by airborne LiDAR  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Quantification of tropical forest above-ground biomass (AGB) over large areas as input for Reduced Emissions from Deforestation and forest Degradation (REDD+) projects and climate change models is challenging. This is the first study which attempts to estimate AGB and its variability across large areas of tropical lowland forests in Central Kalimantan (Indonesia) through correlating airborne light detection and ranging (LiDAR) to forest inventory data. Two LiDAR height metrics were analysed, ...

Jubanski, J.; Ballhorn, U.; Kronseder, K.; Franke, J.; Siegert, F.

2013-01-01

314

Semi-Supervised Methods to Identify Individual Crowns of Lowland Tropical Canopy Species Using Imaging Spectroscopy and LiDAR  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Our objective is to identify and map individuals of nine tree species in a Hawaiian lowland tropical forest by comparing the performance of a variety of semi-supervised classifiers. A method was adapted to process hyperspectral imagery, LiDAR intensity variables, and LiDAR-derived canopy height and use them to assess the identification accuracy. We found that semi-supervised Support Vector Machine classification using tensor summation kernel was superior to supervised classification, with dem...

Jean-Baptiste Féret; Asner, Gregory P.

2012-01-01

315

Investigation of genetic diversity and population structure of common wheat cultivars in northern China using DArT markers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background In order to help establish heterotic groups of Chinese northern wheat cultivars (lines), Diversity arrays technology (DArT) markers were used to investigate the genetic diversity and population structure of Chinese common wheat (Triticum aestivum L.). Results In total, 1637 of 7000 DArT markers were polymorphic and scored with high confidence among a collection of 111 lines composed mostly of cultivars and breeding lines from norther...

Zhang LiYi; Liu DongCheng; Guo XiaoLi; Yang WenLong; Sun JiaZhu; Wang DaoWen; Sourdille Pierre; Zhang AiMin

2011-01-01

316

Development of diversity array technology (DArT) markers for assessment of population structure and diversity in Aegilops tauschii  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Aegilops tauschii Coss. is the D-genome donor to hexaploid bread wheat (Triticum aestivum) and is the most promising wild species as a genetic resource for wheat breeding. To study the population structure and diversity of 81 Ae. tauschii accessions collected from various regions of its geographical distribution, the genomic representation of these lines were used to develop a diversity array technology (DArT) marker array. This Ae. tauschii array and a previously developed DArT wheat array w...

Sohail, Quahir; Shehzad, Tariq; Kilian, Andrezj; Eltayeb, Amin Elsadig; Tanaka, Hiroyuki; Tsujimoto, Hisashi

2012-01-01

317

Algorithmic Foundation and Software Tools for Extracting Shoreline Features from Remote Sensing Imagery and LiDAR Data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents algorithmic components and corresponding software routines for extracting shoreline features from remote sensing imagery and LiDAR data. Conceptually, shoreline features are treated as boundary lines between land objects and water objects. Numerical algorithms have been identified and de-vised to segment and classify remote sensing imagery and LiDAR data into land and water pixels, to form and enhance land and water objects, and to trace and vectorize the boundaries betwee...

Hongxing Liu; Lei Wang; Sherman, Douglas J.; Qiusheng Wu; Haibin Su

2011-01-01

318

Las interculturalidad-es, identidad-es y el diálogo de saberes  

Directory of Open Access Journals (Sweden)

Full Text Available En este artículo argumentamos que en el plano epistemológico el proceso de interculturalizar sólo se puede construir desde una revaloración de la identidad individual y social, mediante la cual los sujetos sociales cuestionen la colonialidad del saber. Una revaloración que permita a estos sujetos re-negociar los elementos de la auto y hetero identificación, que hasta ahora reproducen las jerarquías y dualidades impuestas desde el colonialismo a través de una violencia simbólica que lleva a lasubvaloración de la propia identidad.Se analiza también cómo la escuela históricamente ha sido un aparato de reproducción del Estado y del ?status quo ?, pero curiosamente, es desde este ámbito desde el cual han surgido más propuestas sólidas de interculturalidad en la práctica. Estas propuestas se han expandido a otrosplanos en los que se construye y se reconstruye conocimiento, ya sea a través de procesos pedagógicos conscientes (educación popular/pedagogías insumisas, u otras formas cotidianas, incluso procesos inconscientes de construir, reconstruir, descubrir, redescubrir y compartir conocimientos y saberes. Es importante resaltar que, el diálogo de saberes, en la práctica reconoce la resignificación de estas mismas prácticas, lo que nos permitirá acercarnos -o al menos visualiza un posible debate entre el hacer y el decir de la interculturalización o de la interculturalidad, que poco a poco vienen abonando a lo que hoy se ha dado por llamar diálogo intercultural.

Sonia Comboni Salinas

2013-01-01

319

Analysis of the Influence of Plot Size and LiDAR Density on Forest Structure Attribute Estimates  

Directory of Open Access Journals (Sweden)

Full Text Available This paper assesses the combined effect of field plot size and LiDAR density on the estimation of four forest structure attributes: volume, total biomass, basal area and canopy cover. A total of 21 different plot sizes were considered, obtained by decreasing the field measured plot radius value from 25 to 5 m with regular intervals of 1 m. LiDAR data densities were simulated by randomly removing LiDAR pulses until reaching nine different density values. In order to avoid influence of the digital terrain model spatial resolution, eight different resolutions were considered (from 0.25 to 2 m grid size and tested. A set of per-plot LiDAR metrics was extracted for each parameter combination. Prediction models of forest attributes were defined using forward stepwise ordinary least-square regressions. Results show that the highest R2 values are reached by combining large plot sizes and high LiDAR data density values. However, plot size has a greater effect than LiDAR point density. In general, minimum plot areas of 500–600 m2 are needed for volume, biomass and basal area estimates, and of 300–400 m2 for canopy cover. Larger plot sizes do not significantly increase the accuracy of the models, but they increase the cost of fieldwork.

Luis A. Ruiz

2014-05-01

320

Analysis of full-waveform LiDAR data for forestry applications: a review of investigations and methods  

Directory of Open Access Journals (Sweden)

Full Text Available The goal of this review is to present leading examples of current methodologies for extracting forest characteristics from full-waveform LiDAR data. Four key questions are addressed: (i does full-waveform LiDAR provide advantages over discrete-return laser sensors; (ii will full-waveform LiDAR provide valid results in support of forest inventory operations and allow for a decrease in ground sampling efforts; (iii is the use of full-waveform LiDAR data cost effective; and (iv what is the scope of the applied methods (i.e., is full-waveform LiDAR accurate for different forest compositions, structures, and densities, and is it sensitive to leaf-off/leaf-on conditions? Key forest structure characteristics can be estimated with significant accuracy using full-waveform metrics, although methodologies and their corresponding accuracies differ. For example, some processing methods are valid at the plot scale, whereas other procedures perform well at the regional scale; to be effective, certain LiDAR data analyses require a minimum point density, whereas other methods perform well using large-footprint sensors. Therefore, it is important to match processing methods with the appropriate scale and scope. The aim of this paper is to provide the forest research community and remote sensing technology developers with an overview of existing methods for inferring key forest characteristics, including their applicability and performance.

Pirotti F

2011-06-01

 
 
 
 
321

LiDAR Sampling Density for Forest Resource Inventories in Ontario, Canada  

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Full Text Available Over the past two decades there has been an abundance of research demonstrating the utility of airborne light detection and ranging (LiDAR for predicting forest biophysical/inventory variables at the plot and stand levels. However, to date there has been little effort to develop a set of protocols for data acquisition and processing that would move governments or the forest industry towards cost-effective implementation of this technology for strategic and tactical (i.e., operational forest resource inventories. The goal of this paper is to initiate this process by examining the significance of LiDAR data acquisition (i.e., point density for modeling forest inventory variables for the range of species and stand conditions representing much of Ontario, Canada. Field data for approximately 200 plots, sampling a broad range of forest types and conditions across Ontario, were collected for three study sites. Airborne LiDAR data, characterized by a mean density of 3.2 pulses m?2 were systematically decimated to produce additional datasets with densities of approximately 1.6 and 0.5 pulses m?2. Stepwise regression models, incorporating LiDAR height and density metrics, were developed for each of the three LiDAR datasets across a range of forest types to estimate the following forest inventory variables: (1 average height (R2(adj = 0.75–0.95; (2 top height (R2(adj = 0.74–0.98; (3 quadratic mean diameter (R2(adj = 0.55–0.85; (4 basal area (R2(adj = 0.22–0.93; (5 gross total volume (R2(adj = 0.42–0.94; (6 gross merchantable volume (R2(adj = 0.35–0.93; (7 total aboveground biomass (R2(adj = 0.23–0.93; and (8 stem density (R2(adj = 0.17–0.86. Aside from a few cases (i.e., average height and density for some stand types, no decimation effect was observed with respect to the precision of the prediction of the majority of forest variables, which suggests that a mean density of 0.5 pulses m?2 is sufficient for plot and stand level modeling under these diverse forest conditions across Ontario.

Dave Etheridge

2012-03-01

322

Flood Risk Mapping Using LiDAR for Annapolis Royal, Nova Scotia, Canada  

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Full Text Available A significant portion of the Canadian Maritime coastline has been surveyed with airborne Light Detection and Ranging (LiDAR. The purpose of these surveys has been to map the risk of flooding from storm surges and projected long-term sea?level rise from climate change and to include projects in all three Maritime Provinces: Prince Edward Island, New Brunswick, and Nova Scotia. LiDAR provides the required details in order to map the flood inundation from 1 to 2 m storm surge events, which cause coastal flooding in many locations in this region when they occur at high tide levels. The community of Annapolis Royal, Nova Scotia, adjacent to the Bay of Fundy, has been surveyed with LiDAR and a 1 m DEM (Digital Elevation Model was constructed for the flood inundation mapping. Validation of the LiDAR using survey grade GPS indicates a vertical accuracy better than 30 cm. A benchmark storm, known as the Groundhog Day storm (February 1–3, 1976, was used to assess the flood maps and to illustrate the effects of different sea-level rise projections based on climate change scenarios if it were to re-occur in 100 years time. Near shore bathymetry has been merged with the LiDAR and local wind observations used to model the impact of significant waves during this benchmark storm. Long-term (ca. greater than 30 years time series of water level observations from across the Bay of Fundy in Saint John, New Brunswick, have been used to estimate return periods of water levels under present and future sea-level rise conditions. Results indicate that under current sea-level rise conditions this storm has a 66 year return period. With a modest relative sea-level (RSL rise of 80 cm/century this decreases to 44 years and, with a possible upper limit rise of 220 cm/century, this decreases further to 22 years. Due to the uncertainty of climate change scenarios and sea-level rise, flood inundation maps have been constructed at 10 cm increments up to the 9 m contour which represents an upper flood limit estimate in 100 years, based on the highest predicted tide, plus a 2 m storm surge and a RSL of 220 cm/century.

Tim L. Webster

2010-09-01

323

Estimating forest snow accumulation with LiDAR derived canopy metrics, southern Sierra Nevada, California  

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Water resources from mountain snow-melt are becoming more difficult to predict as demand for them increases. Thus more effective methods of determining the spatial and temporal distribution of mountain snow is of utmost importance, particularly in forested terrain where remote sensing is limited by canopy cover and few sensor networks exist. We present an analysis of LiDAR derived digital elevation and canopy surface models as emerging metrics for quantifying snow depth accumulation in forest covered terrain. Our analysis compares hourly snow depth sensor measurements, collected over four water years from 26 stratified locations, to canopy metrics measured with airborne scanning LiDAR and effective LAI measured in-situ, using LAI - 2000 and hemispheric photos. The period of record represents dry, normal, and wet years where peak mean snow depths were 73 - 165% of the 30 year April 1st mean. Normalized fractional totals were calculated at each location for the 20 largest monthly continuous precipitation events. Mean values within a 2- 40 m radius of six site specific canopy characteristics: mean canopy height, standard deviation of canopy height, canopy surface ratio, fractional canopy cover, and coefficient of variation were determined from 1 m gridded LiDAR surface models at each snow sensor location. In all cases at least twice the variability was present at radii 2 m, estimated from LiDAR altimetry, and effective LAI, estimated from in-situ measurements, were also determined for each location. The predictive capacity of canopy metrics for snow depth variability was found to be dependent on the radius of integration with the highest coefficients of determination at radii between 8 - 12 m. When compared to mean fractional snow accumulation at all sensors, we found: r2 and p in parenthesis, mean canopy height (0.58, < 0.001), standard deviation (0.51, < 0.001), canopy to ground surface ratio (0.48, < 0.001) and fractional canopy cover (0.45, < 0.001) showed the highest coefficients of determination and maximum canopy height (0.40, < 0.001), coefficient of variation (0.38, < 0.001) minimum gap distance (0.25, < 0.001) and both methods of effective LAI (0.38, 0.002 and 0.27, 0.01) the lowest. These metrics, measured as part of a single or ongoing airborne snow observation campaign, provide a basis for estimating snow depth accumulation in locations where few ground measurements are made and limited direct LiDAR snow depth altimetry is available.

Kirchner, P.; Bales, R. C.; Painter, T. H.

2013-12-01

324

DArT markers for the rye genome - genetic diversity and mapping  

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Full Text Available Abstract Background Implementation of molecular breeding in rye (Secale cereale L. improvement programs depends on the availability of high-density molecular linkage maps. However, the number of sequence-specific PCR-based markers available for the species is limited. Diversity Arrays Technology (DArT is a microarray-based method allowing for detection of DNA polymorphism at several thousand loci in a single assay without relying on DNA sequence information. The objective of this study was the development and application of Diversity Arrays technology for rye. Results Using the PstI/TaqI method of complexity reduction we created a rye diversity panel from DNA of 16 rye varieties and 15 rye inbred lines, including parents of a mapping population consisting of 82 recombinant inbred lines. The usefulness of a wheat diversity panel for identification of DArT markers for rye was also demonstrated. We identified 1022 clones that were polymorphic in the genotyped ILs and varieties and 1965 clones that differentiated the parental lines L318 and L9 and segregated in the mapping population. Hierarchical clustering and ordination analysis were performed based on the 1022 DArT markers to reveal genetic relationships between the rye varieties and inbred lines included in the study. Chromosomal location of 1872 DArT markers was determined using wheat-rye addition lines and 1818 DArT markers (among them 1181 unique, non-cosegregating were placed on a genetic linkage map of the cross L318 × L9, providing an average density of one unique marker every 2.68 cM. This is the most saturated rye linkage map based solely on transferable markers available at the moment, providing rye breeders and researches with a better choice of markers and a higher probability of finding polymorphic markers in the region of interest. Conclusion The Diversity Arrays Technology can be efficiently and effectively used for rye genome analyses - assessment of genetic similarity and linkage mapping. The 11520-clone rye genotyping panel with several thousand markers with determined chromosomal location and accessible through an inexpensive genotyping service is a valuable resource for studies on rye genome organization and in molecular breeding of the species.

Kilian Andrzej

2009-12-01

325

Seagrass Identification Using High-Resolution 532nm Bathymetric LiDAR and Hyperspectral Imagery  

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Seagrass provides vital habitat for marine fisheries and is a key indicator species of coastal ecosystem vitality. Monitoring seagrass is therefore an important environmental initiative, but measuring details of seagrass distribution over large areas via remote sensing has proved challenging. Developments in airborne bathymetric light detection and ranging (LiDAR) provide great potential in this regard. Traditional bathymetric LiDAR systems have been limited in their ability to map within the shallow water zone (< 1 m) where seagrass is typically present due to limitations in receiver response and laser pulse length. Emergent short-pulse width bathymetric LiDAR sensors and waveform processing algorithms enable depth measurements in shallow water environments previously inaccessible. This 3D information of the benthic layer can be applied to detect seagrass and characterize its distribution. Researchers with the National Center for Airborne Laser Mapping (NCALM) at the University of Houston (UH) and the Coastal and Marine Geospatial Sciences Lab (CMGL) of the Harte Research Institute at Texas A&M University-Corpus Christi conducted a coordinated airborne and boat-based survey of the Redfish Bay State Scientific Area as part of a collaborative study to investigate the capabilities of bathymetric LiDAR and hyperspectral imaging for seagrass mapping. Redfish Bay, located along the middle Texas coast of the Gulf of Mexico, is a state scientific area designated for the purpose of protecting and studying native seagrasses. Redfish Bay is part of the broader Coastal Bend Bays estuary system recognized by the US Environmental Protection Agency (EPA) as a national estuary of significance. For this survey, UH acquired high-resolution discrete-return and full-waveform bathymetric data using their Optech Aquarius 532 nm green LiDAR. In a separate flight, UH collected 2 sets of hyperspectral imaging data (1.2-m pixel resolution and 72 bands, and 0.6m pixel resolution and 36 bands) with their CASI 1500 hyperspectral sensor. The ground survey was conducted by CMGL. The team used an airboat to collect in-situ radiometer measurements of sky irradiance and surface water reflectance at different locations in the bay. The team also collected water samples, GPS position, and depth. A follow-up survey was conducted to acquire ground-truth data of benthic type at over 80 locations within the bay. Two complementary approaches were developed to detect and map the seagrass cover over the study area - automated classification algorithms were validated with high spatial resolution hyperspectral imagery, and a continuous wavelet based signal processing and pulse broadening analysis of the digitized returns was performed with the full waveform of the bathymetric LiDAR. The two approaches were compared to the collected ground truth data of seagrass type, height, and location. Results of the evaluation will be presented, along with a preliminary discussion of the fusion of the LiDAR and hyperspectral imagery for improved overall classification accuracy.

Pan, Z.; Prasad, S.; Starek, M. J.; Fernandez Diaz, J. C.; Glennie, C. L.; Carter, W. E.; Shrestha, R. L.; Singhania, A.; Gibeaut, J. C.

2013-12-01

326

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

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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.

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

2013-04-01

327

Precise BAC targeting of genetically polymorphic mouse ES cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The use of bacterial artificial chromosomes (BACs) provides a consistent and high targeting efficiency of homologous recombination in embryonic stem (ES) cells, facilitated by long stretches of sequence homology. Here, we introduce a BAC targeting method which employs restriction fragment length polymorphisms (RFLPs) in targeted polymorphic C57BL/6/Cast/Ei F1 mouse ES cell lines to identify properly targeted ES cell clones. We demonstrate that knockout alleles can be generated either by targe...

2011-01-01

328

Automatic building extraction using LiDAR and aerial photographs / Extração automática de edificações usando LiDAR e fotografias aéreas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Este artigo apresenta uma abordagem para a extração automática de edificações usando dados LiDAR e fotografias aéreas de um sistema com múltiplos sensores posicionados na mesma plataforma. A abordagem de extração automática de edificações é composta por etapas de segmentação, análise e classificação [...] , baseadas em análise de imagens com base em objetos. Na etapa de segmentação foram usados os métodos Chessboard, fatiamento do constraste e multirresolução. As primitivas de segmentação, como escala, forma, integridade, brilho e parâmetros estatísticos, foram usadas para determinar os valores-limite para a classificação na etapa de análise. A classificação baseada em regras foi realizada com regras de decisão definidos com base nas primitivas de determinado objeto e regras fuzzy. Neste estudo, preferiu-se a classificação hierárquica. Primeiramente, foram geradas as classes de vegetação e solo e então foi extraída a classe de edifícações. O NDVI, declividade, e as imagens Hough foram gerados e usados para evitar confundir a classe edificações com outras classes. As imagens de intensidade geradas a partir dos dados LiDAR e operações morfológicas foram utilizados para melhorar a precisão da classe de edifícações. A abordagem proposta alcançou uma exatidão de aproximadamente 93% para a classe alvo em um bairro suburbano, que era a área de estudo. Além disso, as análises de integralidade (96,73%) e correção (95,02%) foram realizadas através da comparação dos edifícios automaticamente extraídos e dados de referência. Abstract in english This paper presents an automatic building extraction approach using LiDAR data and aerial photographs from a multi-sensor system positioned at the same platform. The automatic building extraction approach consists of segmentation, analysis and classification steps based on object-based image analysi [...] s. The chessboard, contrast split and multi-resolution segmentation methods were used in the segmentation step. The determined object primitives in segmentation, such as scale parameter, shape, completeness, brightness, and statistical parameters, were used to determine threshold values for classification in the analysis step. The rule-based classification was carried out with defined decision rules based on determined object primitives and fuzzy rules. In this study, hierarchical classification was preferred. First, the vegetation and ground classes were generated; the building class was then extracted. The NDVI, slope and Hough images were generated and used to avoid confusing the building class with other classes. The intensity images generated from the LiDAR data and morphological operations were utilized to improve the accuracy of the building class. The proposed approach achieved an overall accuracy of approximately 93% for the target class in a suburban neighborhood, which was the study area. Moreover, completeness (96.73%) and correctness (95.02%) analyses were performed by comparing the automatically extracted buildings and reference data.

Melis, Uzar; Naci, Yastikli.

329

Analysis of elevation changes detected from multi-temporal LiDAR surveys in forested landslide terrain in western Oregon  

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We examined elevation changes detected from two successive sets of Light Detection and Ranging (LiDAR) data in the northern Coast Range of Oregon. The first set of LiDAR data was acquired during leafon conditions and the second set during leaf-off conditions. We were able to successfully identify and map active landslides using a differential digital elevation model (DEM) created from the two LiDAR data sets, but this required the use of thresholds (0.50 and 0.75 m) to remove noise from the differential elevation data, visual pattern recognition of landslideinduced elevation changes, and supplemental QuickBird satellite imagery. After mapping, we field-verified 88 percent of the landslides that we had mapped with high confidence, but we could not detect active landslides with elevation changes of less than 0.50 m. Volumetric calculations showed that a total of about 18,100 m3 of material was missing from landslide areas, probably as a result of systematic negative elevation errors in the differential DEM and as a result of removal of material by erosion and transport. We also examined the accuracies of 285 leaf-off LiDAR elevations at four landslide sites using Global Positioning System and total station surveys. A comparison of LiDAR and survey data indicated an overall root mean square error of 0.50 m, a maximum error of 2.21 m, and a systematic error of 0.09 m. LiDAR ground-point densities were lowest in areas with young conifer forests and deciduous vegetation, which resulted in extensive interpolations of elevations in the leaf-on, bare-earth DEM. For optimal use of multi-temporal LiDAR data in forested areas, we recommend that all data sets be flown during leaf-off seasons.

Burns, W. J.; Coe, J. A.; Kaya, B. S.; Ma, L.

2010-01-01

330

Extracting More Data from LiDAR in Forested Areas by Analyzing Waveform Shape  

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Full Text Available Light Detection And Ranging (LiDAR in forested areas is used for constructing Digital Terrain Models (DTMs, estimating biomass carbon and timber volume and estimating foliage distribution as an indicator of tree growth and health. All of these purposes are hindered by the inability to distinguish the source of returns as foliage, stems, understorey and the ground except by their relative positions. The ability to separate these returns would improve all analyses significantly. Furthermore, waveform metrics providing information on foliage density could improve forest health and growth estimates. In this study, the potential to use waveform LiDAR was investigated. Aerial waveform LiDAR data were acquired for a New Zealand radiata pine plantation forest, and Leaf Area Density (LAD was measured in the field. Waveform peaks with a good signal-to-noise ratio were analyzed and each described with a Gaussian peak height, half-height width, and an exponential decay constant. All parameters varied substantially across all surface types, ruling out the potential to determine source characteristics for individual returns, particularly those with a lower signal-to-noise ratio. However, pulses on the ground on average had a greater intensity, decay constant and a narrower peak than returns from coniferous foliage. When spatially averaged, canopy foliage density (measured as LAD varied significantly, and was found to be most highly correlated with the volume-average exponential decay rate. A simple model based on the Beer-Lambert law is proposed to explain this relationship, and proposes waveform decay rates as a new metric that is less affected by shadowing than intensity-based metrics. This correlation began to fail when peaks with poorer curve fits were included.

Peter Beets

2012-03-01

331

Quantification of glacial and ground surface velocities from repeat terrestrial LiDAR scans  

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Repeat terrestrial LiDAR scans of moving surfaces (e.g. around faults, glaciers, mass movements, etc.) collected at different times offer the opportunity to quantify surface velocities in high resolution. This study presents a new approach for quantifying surface velocities from remote sensing data. Emphasis is placed on the interpretation of terrestrial LiDAR grid point cloud (GPC) data, but the technique presented is also applicable to other (RASTER) remote sensing datasets. The method used consists of investigating two or more temporally variable GPCs referred as a raw and displaced/deformed scans. A user-defined grid is defined on the raw and deformed scans and the center point of each grid is identified. A search window size is determined for comparison between the two scans. Elevations in both scans are then converted to a reference elevation and a normalized cross correlation is applied between the images for pattern recognition. The focal points of the raw image and correlated deformed location are used to prepare an affine transformation for that grid. This procedure is applied on all the grids to prepare the spatial distribution of the affine transformation. Finally, the affine transformation is extended to calculate the horizontal components of surface deformation. These components are used to prepare the spatial distribution of the displacement distance and angle between each grid on each scan. The routine was applied to a series of synthetic (test) datasets and to repeat LiDAR scans (ILRIS-LR) of the Rhone glacier, Switzerland collected in August 2011. Results from the synthetic tests indicate the approach provides a robust reconstruction of spatially non-uniform velocity fields on scans with different surface characteristics. For the Rhone glacier data both temporal and spatial variations in surface velocities were recovered across a large portion of the glacier at centimeter scale. Temporal variations in the glacier surface velocity were resolved from scans collected multiple times a day over the course of a week.

Shahzad, F.; Ehlers, T. A.

2012-04-01

332

Fusing Hyperspectral and LiDAR data from CAO-VSWIR for Increased Data Dimensionality  

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The use of multi-sensor platforms for scientific data collection requires precise co-location in order to gain maximum data dimensionality for Earth system research. The different types of collection mechanisms of the sensors (e.g., scanning and pushbroom) can make it difficult to precisely match data from multiple sensors, even when the sensors are flown on the same aircraft at the same time. To overcome these problems, the Carnegie Airborne Observatory (CAO) AToMS sensor suite uses a method that maximizes the match between the Light Detection and Ranging (LiDAR), Visible-to-Near Infrared (VNIR), and Visible-to-Shortwave Infrared (VSWIR) sensors. This is done by generating an intensity image from the LiDAR data that serves as a base on which the spectrometers (VNIR and VSWIR) are matched using ground control points (GCPs). To do so, we employ the use of automated tie point matching in the overlap regions of the spectrometers to improve the co-location between flightlines. The combination of the GCPs and tie points produce data that is used to build camera models for the VNIR and VSWIR spectrometers such that they will match the LiDAR data. The result produces a matched hyper-dimensional data set with great scientific information content. We compare the data dimensionality of two contrasting scenes - a built environment at Stanford University and a lowland tropical forest in Amazonia. Principal components analysis revealed 336 dimensions (degrees of freedom) in the Stanford case, and 218 dimensions in the Amazon. The Amazon case presents what could be the highest level of remotely sensed data dimensionality ever reported for a forested ecosystem. Simulated misalignment of data streams reduced the effective information content by up to 48%, highlighting the critical role of achieving high precision when undertaking multi-sensor fusion. The instrumentation and methods described here are a pathfinder for future airborne applications undertaken by the National Ecological Observatory Network (NEON) and other organizations.

Knapp, D. E.; Asner, G. P.; Boardman, J. W.; Kennedy-Bowdoin, T.; Eastwood, M.; Anderson, C.; Martin, R. E.; Green, R. O.

2012-12-01

333

Classification of breaklines derived from airborne LiDAR data for geomorphological activity mapping  

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Airborne LiDAR surveys provide 3D high-resolution elevation information for area-wide applications. Due to the capability of LiDAR to penetrate vegetation cover highly accurate digital terrain models (DTMs) can be derived also for forested areas. Breaklines derived from LiDAR DTMs mark regions of slope discontinuities, describing the main characteristics of a terrain surface in an efficient manner. Breaklines are often used for DTM enhancement but also for the detection and interpretation of geomorphologically relevant landforms such as landslides, torrents, erosion scraps and tectonic faults. Because of human activities geomorphologic landforms are often disturbed and reshaped i.e. by construction of roads, skiing slopes, drainage channels and surface mining. Therefore, DTMs contain both, anthropogenic and geomorphologic discontinuities. This significantly disturbs morphometric analysis and causes problems for automatic landform mapping algorithms. In this research an automatic breakline detection method is applied in an alpine region with high relief variation containing surface discontinuities such as torrents, creeping slope failure, and landslides, which are reshaped by anthropogenic activities. Regions of high curvature are classified and vectorised in order to derive 3D breaklines. These are further filtered and classified based on object-based properties such as their size, shape and slope to separate natural i.e. geomorphologic relevant and anthropogenic structures. The classification result is compared to reference map data indicating a high reliability of the classification quality. After the removal of anthropogenic breaklines the remaining natural breaklines are used to compute line density maps using a moving window approach. These density maps point out areas of different relief energy and assist to delineate areas of geomorphologic relevance. These areas are also of most interest to identify geomorphological landforms. The methodology presented contributes to enhance automated geomorphological mapping and process interpretation tasks in regions with high relief energy.

Rutzinger, Martin; Höfle, Bernhard; Vetter, Michael; Stötter, Johann; Pfeifer, Norbert

2010-05-01

334

Molecular multi-effect screening of environmental pollutants using the MolDarT.  

Science.gov (United States)

Molecular effect detection is a useful approach for ecotoxicological screening of chemicals. We show here the application of the molecular DarT (MolDarT), where the expression of selected target genes is detected in short-term (120 h) exposed developing zebrafish (Danio rerio), thus allowing subacute multi-effect compound screening. The genes metallothionein 2 (mt2), cytochrome P450 1A1 (cyp1a1), and recombination activation gene 1 (rag1) are used as endpoints that describe detoxification/metal toxicity (mt2), detoxification/PAH toxicity (cyp1a1), and acquired immune system disruption (rag1). Each gene's developmental expression was studied in unexposed zebrafish during 4 to 120 h past fertilization (hpf), and all three genes were found to be expressed at 120 hpf. Furthermore, mt2 transcripts were present at high levels at 4 hpf, indicating a maternal transfer. For positive toxicity controls, freshly fertilized zebrafish eggs were exposed for 120 hpf to ZnSO(4), 1,5-dimethylnaphthalene (DMN) and CdCl(2). Exposure to 100 and 200 microM ZnSO(4) significantly induced mt2; 10 microM DMN and 20 microM DMN resulted in significantly increased cyp1a1 abundance; and 5 and 10 microM CdCl(2) significantly reduced rag1 expression levels. Furthermore, we analysed these target genes for their expression in zebrafish eggs from a previous exposure study. The eggs were exposed for 120 hpf to the environmental pollutants estradiol (E2), ethinylestradiol (EE2), nonylphenol (NP), atrazine, cyproconazol, and bisphenol A (BPA) and found differential expression of the three genes. Exposure to the (xeno-)estrogenic compound NP (0.75 microM) significantly lowered mt2 expression. This study shows the potential of short-term in vivo multi-effect screenings within one single subacute exposure using the MolDarT. PMID:18214934

Liedtke, Anja; Muncke, Jane; Rüfenacht, Karin; Eggen, Rik I L

2008-02-01

335

¿Qué es lo que es Órfico en los Orphica?: La poesía atribuida a Orfeo  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish Después de la reciente publicación de numerosos textos poéticos rápidamente considerados de inspiración órfica, ha llegado el momento de tener una mirada crítica sobre una clasificación en la que las motivaciones no son siempre explícitas. Es la ocasión de interrogar sobre el rol cultual de estos nu [...] evos textos, sobre el status del orfismo como movimiento religioso en la época clásica, sobre las funciones asumidas por la figura heroica de Orfeo y sobre el papel jugado por las prácticas de la escritura dentro de la composición poética órfica. Abstract in english After the publication in recent years of various poetical texts considered as inspired by Orphism, time has come to have a critical look to such a classification; its reasons are far from clear. That offers an occasion to question the cultic role of these new texts, the status of Orphism as a religi [...] ous movement in classical Greece , the functions assumed by Orpheus as a hero and a founder, and the role played by writing in the composition of Orphic poems.

Calame, Claude.

336

Sensors | Special Issue : LiDAR for 3D City Modeling  

...Agronomy Algorithms Animals Antibiotics Antibodies Antioxidants Applied Sciences Arts Atmosphere Atoms Axioms Behavioral Sciences Bioengineering Biology Biomedicines Biomolecules Biosensors Brain Sciences Buildings Cancers Catalysts ...to the development of LiDAR data processing algorithms and software tools, including segmentation and filtering, generation of digital surface models (DSMs) ... Hence, it is based on a reliable 3D segmentation algorithm, detecting planar faces in a point cloud. This segmentation is of ... We describe the theoretical background, the segmentation algorithm, the outline detection, and the modeling approach, and we present and discuss ...

337

Landslide displacement vectors derived from multi-temporal topographic LiDAR data  

Science.gov (United States)

Information about slope geometry and kinematics of landslides is essential for hazard assessment, monitoring and planning of protection and mitigation measures. Especially for remote and inaccessible slopes, subsurface data (e.g. boreholes, tunnels, investigation adits) are often not available and thus the deformation characteristics must be derived from surface displacement data. In recent years, multi-temporal topographic LiDAR (Light Detection and Ranging) data became an increasingly improved tool for detecting topographic surface deformations. In this context, LiDAR-based change detection is commonly applied for quantifying surface elevation changes. Advanced change detection methods derive displacement vectors with direction and velocities of slope movements. To extract displacement vectors from LiDAR raster data (i) an approach based on feature tracking by image correlation and (ii) an approach based on feature tracking by vectors breaklines are investigated. The image correlation method is based on the IMCORR software (National Snow and Ice Data Center, University of Colorado, Boulder), implemented in a SAGA GIS module. The image correlation algorithm is based on a normalized cross-covariance method. The algorithm searches tie points in two feature rasters derived from a digital surface model acquired at different time stamps. The method assesses automatically the displacement rates and directions of distinct terrain features e.g. displaced mountain ridges or striking boulders. In contrast the vector-based breakline methods require manual selection of tie points. The breaklines are the product of vectorized curvature raster images and extracting the "upper terrain edges" (topographic ridges) and "lower terrain edges" (topographic depressions). Both methods were tested on simulated terrain with determined displacement rates in order to quantify i) the accuracy ii) the minimum detectable movement rates iii) the influence of terrain characteristics iv) the influence of input raster cell size and v) the influence of method parameter settings. Both methods were applied to investigate the development of an active rockslide in high mountain terrain. As a result, both methods yield reasonable data in order to differentiate between landslide areas and stable terrain as well as document the kinematic development of different sub-slabs within the landslide masses (featuring different movement directions and rates). Limitations are given for areas with large displacements and complex bedrock deformation, where automatic feature-tracking lead to wrong correlation results and tie points do not coincide with real displaced features. For complex deformation mechanism only the analysis method based on breaklines and manual tie point identification is suitable for vector extraction. Automated spatial analyses of topographic LiDAR data are a fundamental support to answer a variety of morphological-geological and monitoring questions.

Fey, Christine; Rutzinger, Martin; Bremer, Magnus; Prager, Christoph; Zangerl, Christian

2014-05-01

338

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

Science.gov (United States)

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.

Aktaruzzaman, Md.; Schmitt, Theo G.

2011-10-01

339

Investigation of genetic diversity and population structure of common wheat cultivars in northern China using DArT markers  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background In order to help establish heterotic groups of Chinese northern wheat cultivars (lines, Diversity arrays technology (DArT markers were used to investigate the genetic diversity and population structure of Chinese common wheat (Triticum aestivum L.. Results In total, 1637 of 7000 DArT markers were polymorphic and scored with high confidence among a collection of 111 lines composed mostly of cultivars and breeding lines from northern China. The polymorphism information content (PIC of DArT markers ranged from 0.03 to 0.50, with an average of 0.40, with P > 80 (reliable markers. With principal-coordinates analysis (PCoA of DArT data either from the whole genome or from the B-genome alone, all lines fell into one of two major groups reflecting 1RS/1BL type (1RS/1BL and non-1RS/1BL. Evidence of geographic clustering of genotypes was also observed using DArT markers from the A genome. Cluster analysis based on the unweighted pair-group method with algorithmic mean suggested the existence of two subgroups within the non-1RS/1BL group and four subgroups within the 1RS/1BL group. Furthermore, analysis of molecular variance (AMOVA revealed highly significant (P Conclusion These results provide valuable information for selecting crossing parents and establishing heterotic groups in the Chinese wheat-breeding program.

Wang DaoWen

2011-05-01

340

Development and mapping of DArT markers within the Festuca - Lolium complex  

DEFF Research Database (Denmark)

Background Grasses are among the most important and widely cultivated plants on Earth. They provide high quality fodder for livestock, are used for turf and amenity purposes, and play a fundamental role in environment protection. Among cultivated grasses, species within the Festuca-Lolium complex predominate, especially in temperate regions. To facilitate high-throughput genome profiling and genetic mapping within the complex, we have developed a Diversity Arrays Technology (DArT) array for five grass species: F. pratensis, F. arundinacea, F. glaucescens, L. perenne and L. multiflorum. Results The DArTFest array contains 7680 probes derived from methyl-filtered genomic representations. In a first marker discovery experiment performed on 40 genotypes from each species (with the exception of F. glaucescens for which only 7 genotypes were used), we identified 3884 polymorphic markers. The number of DArT markers identified in every single genotype varied from 821 to 1852. To test the usefulness of DArTFest array for physical mapping, DArT markers were assigned to each of the seven chromosomes of F. pratensis using single chromosome substitution lines while recombinants of F. pratensis chromosome 3 were used to allocate the markers to seven chromosome bins. Conclusion The resources developed in this project will facilitate the development of genetic maps in Festuca and Lolium, the analysis on genetic diversity, and the monitoring of the genomic constitution of the Festuca Ã? Lolium hybrids. They will also enable marker-assisted selection for multiple traits or for specific genome regions.

Kopecký, David; Bartos, Jan

2009-01-01

 
 
 
 
341

Algorithmic Foundation and Software Tools for Extracting Shoreline Features from Remote Sensing Imagery and LiDAR Data  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents algorithmic components and corresponding software routines for extracting shoreline features from remote sensing imagery and LiDAR data. Conceptually, shoreline features are treated as boundary lines between land objects and water objects. Numerical algorithms have been identified and de-vised to segment and classify remote sensing imagery and LiDAR data into land and water pixels, to form and enhance land and water objects, and to trace and vectorize the boundaries between land and water ob-jects as shoreline features. A contouring routine is developed as an alternative method for extracting shore-line features from LiDAR data. While most of numerical algorithms are implemented using C++ program-ming language, some algorithms use available functions of ArcObjects in ArcGIS. Based on VB .NET and ArcObjects programming, a graphical user’s interface has been developed to integrate and organize shoreline extraction routines into a software package. This product represents the first comprehensive software tool dedicated for extracting shorelines from remotely sensed data. Radarsat SAR image, QuickBird multispectral image, and airborne LiDAR data have been used to demonstrate how these software routines can be utilized and combined to extract shoreline features from different types of input data sources: panchromatic or single band imagery, color or multi-spectral image, and LiDAR elevation data. Our software package is freely available for the public through the internet.

Qiusheng Wu

2011-04-01

342

Exact scattering solutions in an energy sudden (ES) representation  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we lay down the theoretical foundations for computing exact scattering wave functions in a reference frame which moves in unison with the system internal coordinates. In this frame the (internal) coordinates appear to be fixed and its adoption leads very naturally (in zeroth order) to the energy sudden (ES) approximation (and the related infinite order sudden (IOS) method). For this reason we call the new representation for describing the exact dynamics of a many channel scattering problem, the ES representation. Exact scattering solutions are derived in both time dependent and time independent frameworks for the representation and many interesting results in these frames are established. It is shown, e.g., that in a time dependent frame the usual Schroedinger propagator factorizes into internal Hamiltonian, ES, and energy correcting propagators. We also show that in a time independent frame the full Green's functions can be similarly factorized. Another important feature of the new representation is that it forms a firm foundation for seeking corrections to the ES approximation. Thus, for example, the singularity which arises in conventional perturbative expansions of the full Green's functions (with the ES Green's function as the zeroth order solution) is avoided in the ES representation. Finally, a number of both time independent and time dependent ES correction schemes are suggested.

Chang, B.; Eno, L.; Rabitz, H.

1983-04-01

343

IMMUNE REGULATING ES-PRODUCTS IN PARASITIC NEMATODES  

DEFF Research Database (Denmark)

Excretory/secretory (ES) products are molecules including various proteins produced by parasitic nematodes including larval A. simplex which is occurring in numerous marine fish hosts. The function of these substances and their effect on host physiology has not been fully described. The present work elucidates the effect of ES substances on the fish immune system by measuring immune gene expression in spleen and liver of rainbow trout (Oncorhynchus mykiss) injected intraperitoneally with ES products isolated from A. simplex third stage larvae. The overall gene expression profile of exposed fish showed a generalized down-regulation of the immune genes tested, suggesting a role of ES proteins in minimizing the immune reaction of rainbow trout against invading nematodes. We also tested the enzymatic activity of the ES proteins and found that lipase, esterase lipase, valine and cysteine arylamidases, naphthol-AS-BI-phosphohydrolase and a-galactosidase activities were present in the ES solution. This type of hydrolytic enzyme activity may play a role in nematode penetration of host tissue. Based on the notion that A. simplex ES-proteins may have an immune-depressive effect, it could also be suggested that worm enzymes directly target host immune effector molecules which would add to the decreased host immune responses and increased worm survival.

Bahlool, Qusay Zuhair Mohammad; Buchmann, Kurt

344

Rainfall and wind circulation in coastal Tanzania  

Energy Technology Data Exchange (ETDEWEB)

The prevailing macro-scale and local components of circulation over East Africa are considered. Using detailed data for the wind circulation at the surface and 850 mb for Dar es Salaam, Tanzania the importance of local diurnally-varying land- and sea-breezes is illustrated. There is a marked change in wind direction at the surface in all seasons such that mean three-hourly data clearly depict a regular alternation between land- and sea-breezes. These are superimposed on an interact with the prevailing trade wind circulation to produce different timings of rainfall through the day and night at the different seasons.

Summer, G.N.

1982-01-01

345

Forty years of '  

...” When it emerged in 1972 the book was hailed in Dar-es-Salaam as “probably the greatest book event in Africa since Frantz Fanon.” Wole Soyinka, the African novelist went further. He suggested that Rodney was one of the first “solidly ideologically situated intellectuals ever to look ... Like Frantz Fanon’s Wretched of the Earth and Paulo Freire’s Pedagogy of the Oppressed, How Europe Underdeveloped Africa remains one of the most compelling and persuasive books to emerge from the bowels of critical resistance to the exploitation of small countries. If Rodney were to ...

346

Analysis of Ozone (O3) and Erythemal UV (EUV) measured by TOMS in the equatorial African belt  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We presented time series of total ozone column amounts (TOCAs) and erythemal UV (EUV) doses derived from measurements by TOMS (Total Ozone Mapping Spectrometer) instruments on board the Nimbus-7 (N7) and the Earth Probe (EP) satellites for three locations within the equatorial African belt for the period 1979 to 2000. The locations were Dar-es-Salaam (6.8° S, 39.26° E) in Tanzania, Kampala (0.19° N, 32.34° E) in Uganda, and Serrekunda (13.28° N, 16.34° W) in Gambia. Equatorial Africa ha...

Taddeo Ssenyonga; Stamnes, Jakob J.; Arne Dahlback; Andreas Steigen; Willy Okullo; Øyvind Frette

2010-01-01

347

Water-l News #4  

...YEAR, UNWire, June 9, 2003 5) & nbsp 200 TOWNS TO GET WATER, The Monitor (Kampala), June 5, 2003 6) & nbsp INTERNATIONAL NETWORK PROPOSES ALTERNATIVES FOR ...GOOD HYGIENE WITH CAREFUL WATER USAGE: ENV MINISTER, Channel News Asia, June, 3, 2003 8) & nbsp GIVING THE POOR BETTER ACCESS ...TO GROUNDWATER, IWMI, June 2003 9) & nbsp WORLD BANK PROVIDES US $250 MILLION TO FIGHT POVERTY, UN Integrated Regional Information Networks, May 30, 2003 ...JAPAN TO SPEND TSH 6.6 BILLION ON WATER PROJECTS, Business Times (Dar es Salaam), May 30, 2003 11) ...

348

Analysis of Ozone (O3) and Erythemal UV (EUV) measured by TOMS in the equatorial African belt  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english We presented time series of total ozone column amounts (TOCAs) and erythemal UV (EUV) doses derived from measurements by TOMS (Total Ozone Mapping Spectrometer) instruments on board the Nimbus-7 (N7) and the Earth Probe (EP) satellites for three locations within the equatorial African belt for the p [...] eriod 1979 to 2000. The locations were Dar-es-Salaam (6.8º S, 39.26º E) in Tanzania, Kampala (0.19º N, 32.34º E) in Uganda, and Serrekunda (13.28º N, 16.34º W) in Gambia. Equatorial Africa has high levels of UV radiation, and because ozone shields UV radiation from reaching the Earth's surface, there is a need to monitor TOCAs and EUV doses. In this paper we investigated the trend of TOCAs and EUV doses, the effects of annual and solar cycles on TOCAs, as well as the link between lightning and ozone production in the equatorial African belt. We also compared clear-sky simulated EUV doses with the corresponding EUV doses derived from TOMS measurements. The TOCAs were found to vary in the ranges 243 DU - 289 DU, 231 DU - 286 DU, and 236 DU - 296 DU, with mean values of 266.9 DU, 260.9 DU, and 267.8 DU for Dar-es-Salaam, Kampala and Serrekunda, respectively. Daily TOCA time series indicated that Kampala had the lowest TOCA values, which we attributed to the altitude effect. There were two annual ozone peaks in Dar-es-Salaam and Kampala, and one annual ozone peak in Serrekunda. The yearly TOCA averages showed an oscillation within a five-year period. We also found that the EUV doses were stable at all three locations for the period 1979-2000, and that Kampala and Dar-es-Salaam were mostly cloudy throughout the year, whereas Serrekunda was mostly free from clouds. It was also found that clouds were among the major factors determining the level of EUV reaching the Earth´s surface. Finally, we noted that during rainy seasons, horizontal advection effects augmented by lightning activity may be responsible for enhanced ozone production in the tropics.

Ssenyonga, Taddeo; Stamnes, Jakob J; Dahlback, Arne; Steigen, Andreas; Okullo, Willy; Frette, Øyvind.

349

¿Es el plagio una sorpresa? ¿Acaso tiene clase?  

Directory of Open Access Journals (Sweden)

Full Text Available Entendemos que no es posible abordar en un espacio editorial el vasto tema del plagio, sus implicaciones y temas conexos presente en libros, artículos científicos, historias, películas, frases, logotipos, inventos, marcas, colores de productos e ideas entre otros muchos temas desarrollados por el ser humano. Este mal es muy antiguo, pero parafraseando términos de los infectólogos, hoy día se encuentra en plena reemergencia. Al patógeno de esta epidemia le favorece indiscutiblemente la moderna vía de transmisión global que es el internet, ya que través de la red, el cibernauta dispone de toneladas de información; la mayoría gratuita.

Marco González T.

2011-12-01

350

Retrieval of Forest Aboveground Biomass and Stem Volume with Airborne Scanning LiDAR  

Directory of Open Access Journals (Sweden)

Full Text Available Airborne scanning LiDAR is a promising technique for efficient and accuratebiomass mapping due to its capacity for direct measurement of the three-dimensionalstructure of vegetation. A combination of individual tree detection (ITD and an area-basedapproach (ABA introduced in Vastaranta et al. [1] to map forest aboveground biomass(AGB and stem volume (VOL was investigated. The main objective of this study was totest the usability and accuracy of LiDAR in biomass mapping. The nearest neighbourmethod was used in the ABA imputations and the accuracy of the biomass estimation wasevaluated in the Finland, where single tree-level biomass models are available. The relativeroot-mean-squared errors (RMSEs in plot-level AGB and VOL imputation were 24.9%and 26.4% when field measurements were used in training the ABA. When ITDmeasurements were used in training, the respective accuracies ranged between 28.5%–34.9%and 29.2%–34.0%. Overall, the results show that accurate plot-level AGB estimates can beachieved with the ABA. The reduction of bias in ABA estimates in AGB and VOL wasencouraging when visually corrected ITD (ITDvisual was used in training. We conclude that itis not feasible to use ITDvisual in wall-to-wall forest biomass inventory, but it could provide acost-efficient application for acquiring training data for ABA in forest biomass mapping.

Petteri Alho

2013-05-01

351

Numerical modeling of the airflow around a forest edge using LiDAR-derived forest heigths  

DEFF Research Database (Denmark)

A 3D methodology to quantify the effect of forests on the mean wind flow field is presented. The methodology is based on the treatment of forest raw data of light detection and ranging (LiDAR) scans, and a computational fluid dynamics (CFD) method based on a Reynolds-averaged Navier-Stokes (RaNS) approach using the kâ??e turbulence model with a corresponding canopy model. The example site investigated is a forest edge located on the Falster island in Denmark, where a measurement campaign was conducted. The LiDAR scans are used in order to obtain the forest heights, which served as input to the numerical CFD model. A sensitivity analysis with regards to the resolution of the structured forest height grid obtained from the implemented digital elevation model (DEM) was carried out. CFD calculations were conducted with the forest height grid taken as input and the complete methodology results are finally briefly compared to the wind measurements of the site with regards to the calculated wind field prediction accuracy.

Boudreault, Louis-Etienne; Dellwik, Ebba

352

Point Spread Function (PSF) noise filter strategy for geiger mode LiDAR  

Science.gov (United States)

LiDAR is an efficient optical remote sensing technology that has application in geography, forestry, and defense. The effectiveness is often limited by signal-to-noise ratio (SNR). Geiger mode avalanche photodiode (APD) detectors are able to operate above critical voltage, and a single photoelectron can initiate the current surge, making the device very sensitive. These advantages come at the expense of requiring computationally intensive noise filtering techniques. Noise is a problem which affects the imaging system and reduces the capability. Common noise-reduction algorithms have drawbacks such as over aggressive filtering, or decimating in order to improve quality and performance. In recent years, there has been growing interest on GPUs (Graphics Processing Units) for their ability to perform powerful massive parallel processing. In this paper, we leverage this capability to reduce the processing latency. The Point Spread Function (PSF) filter algorithm is a local spatial measure that has been GPGPU accelerated. The idea is to use a kernel density estimation technique for point clustering. We associate a local likelihood measure with every point of the input data capturing the probability that a 3D point is true target-return photons or noise (background photons, dark-current). This process suppresses noise and allows for detection of outliers. We apply this approach to the LiDAR noise filtering problem for which we have recognized a speed-up factor of 30-50 times compared to traditional sequential CPU implementation.

Smith, O'Neil; Stark, Robert; Smith, Philip; St. Romain, Randall; Blask, Steven

2013-05-01

353

Airborne LiDAR detection of postglacial faults and Pulju moraine in Palojärvi, Finnish Lapland  

Science.gov (United States)

Postglacial faults (PGFs) are indicative of young tectonic activity providing crucial information for nuclear repository studies. Airborne LiDAR (Light Detection And Ranging) data revealed three previously unrecognized late- or postglacial faults in northernmost Finnish Lapland. Under the canopies of mountain birch (Betula pubescens ssp. czerepanovii) we also found clusters of the Pulju moraine, typically found on the ice-divide zone of the former Fennoscandian ice sheet (FIS), to be spatially associated with the fault-scarps. Tilt derivative (TDR) filtered LiDAR data revealed the previously unknown Palojärvi fault that, by the NE–SW orientation parallels with the well documented Lainio-Suijavaara PGF in northern Sweden. This suggests that PGFs are more extensive features than previously recognized. Two inclined diamond drill holes verified the fractured system of the Palojärvi fault and revealed clear signs of postglacial reactivation. Two other previously unrecognized PGFs, the W–E trending Paatsikkajoki fault and the SE–NW trending Kultima fault, differ from the Palojärvi faulting in orientation and possibly also with regard to age. The Pulju moraine, a morphological feature showing transitions from shallow (< 2-m-high) circular/arcuate ridges to sinusoidal/anastomosing esker networks was found to be concentrated within 6 km from the Kultima fault-scarp. We advocate that some of the past seismic events took place under the retreating wet-base ice sheet and the increased pore-water pressure triggered the sediment mass flows and formation of the Pulju moraine–esker landscape.

Sutinen, Raimo; Hyvönen, Eija; Middleton, Maarit; Ruskeeniemi, Timo

2014-04-01

354

Genetic diversity of carotenoid-rich bananas evaluated by Diversity Arrays Technology (DArT  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid content was analyzed spectrophotometrically and genetic variability was estimated using 653 DArT markers. The average carotenoid content was 4.73 µg.g-1, and ranged from 1.06 µg.g-1 for the triploid Nanica (Cavendish group to 19.24 µg.g-1 for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 µg.g-1. The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00. DArT analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank.

Edson P. Amorim

2009-01-01

355

Genetic diversity of carotenoid-rich bananas evaluated by Diversity Arrays Technology (DArT)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid co [...] ntent was analyzed spectrophotometrically and genetic variability was estimated using 653 DArT markers. The average carotenoid content was 4.73 µg.g-1, and ranged from 1.06 µg.g-1 for the triploid Nanica (Cavendish group) to 19.24 µg.g-1 for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 µg.g-1). The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00). DArT analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank.

Amorim, Edson P.; Vilarinhos, Alberto D.; Cohen, Kelly O.; Amorim, Vanusia B.O.; Santos-Serejo, Janay A. dos; Silva, Sebastião Oliveira e; Pestana, Kátia N.; Santos, Vânia J. dos; Paes, Norma S.; Monte, Damares C.; Reis, Ronaldo V. dos.

356

3D modeling of pylon from airborne LiDAR data  

Science.gov (United States)

Extracting three-dimensional model of the pylon from aerial LIght Detection And Ranging (LiDAR) point clouds automatically is one of the key techniques for digitization and visualization of smart grid facilities. This paper presents a model-driven three-dimensional pylon modeling method using airborne LiDAR data. On the basis of in-depth study of the actual structure of the pylon and the characteristics of point clouds data, a conceptual model of pylon is constructed, in which the pylon is divided into three parts as pylon foot, pylon body and pylon head. Parameters of the model such as position and orientation are defined. In this approach, a complicated pylon is divided into three relatively simple parts firstly. Then different parts of the pylon are reconstructed with different strategies. Finally, model parts are assembled to a complete pylon model using the position and direction information. Results of experiments on the point clouds data from Southern Power Grid show that the precision of extracted pylon orientation and position reached centimeter-level, the accuracy of pylon head classification is higher than 95%, and the pylon model fits well with pylon points. It suggests that the proposed approach can achieve the goal of semi-automatic three-dimensional modeling of the pylon effectively.

Chen, Zhipeng; Lan, Zenrong; Long, Huaping; Hu, Qingwu

2014-05-01

357

Topographic and Thermal Investigations of Active Pahoehoe Lava Flows Using Coupled LiDAR/FLIR Datasets  

Science.gov (United States)

Pahoehoe lava flows consist of multiple overlapping and interfingering lobes and exhibit morphologically diverse surfaces characterized by channels, smooth-surfaced sheets, and numerous, small networks of interconnected pahoehoe toes. In order to analyze the different pahoehoe emplacement regimes, we have acquired simultaneous high-resolution topographic and thermal measurements of advancing and inflating flow lobes at high temporal frequency. These datasets allow the creation of flow lobe maps at regular intervals during flow emplacement that document morphologic, thermal, and morphometric characteristics of individual pahoehoe elements (e.g., pahoehoe toes) as well as compound pahoehoe features (e.g., toe networks, channels with lateral levees). These datasets reveal patterns in flow behavior and provide quantitative documentation of flow emplacement processes. Field investigations were conducted in February and March, 2012 on tube-fed pahoehoe flows in the Puu Oo flow field, Kilauea Volcano, Hawaii. We utilized a ground-based, full-waveform scanning LiDAR and FLIR SC645 thermal infrared camera, supplemented by high-definition video and time-lapse photography. The LiDAR scanner is capable of acquiring rapid, successive scans with reproducible 5 mm resolution data at a rate of 300 kHz. The FLIR camera acquires calibrated thermal images in the 7.5 - 13 mm range; the object temperature range is -20°C to +2000°C, with a thermal sensitivity of FLIR system provides rapid acquisition of high-resolution spatial and high-precision thermal datasets for advancing pahoehoe flows.

Crown, D. A.; Anderson, S. W.; Finnegan, D. C.; LeWinter, A. L.; Ramsey, M.

2012-12-01

358

Quantitative analysis of woodpecker habitat using high-resolution airborne LiDAR estimates of forest structure and composition.  

Energy Technology Data Exchange (ETDEWEB)

Light detection and ranging (LiDAR) technology has the potential to radically alter the way researchers and managers collect data on wildlife–habitat relationships. To date, the technology has fostered several novel approaches to characterizing avian habitat, but has been limited by the lack of detailed LiDAR-habitat attributes relevant to species across a continuum of spatial grain sizes and habitat requirements. We demonstrate a novel three-step approach for using LiDAR data to evaluate habitat based on multiple habitat attributes and accounting for their influence at multiple grain sizes using federally endangered red-cockaded woodpecker (RCW; Picoides borealis) foraging habitat data from the Savannah River Site (SRS) in South Carolina, USA.

Garabedian, James E. [Department of Forestry and Environmental Resources, North Carolina State University; McGaughey, Robert J. [Pacific Northwest Research Station, USDA Forest Service, University of Washington; Reutebuch, Stephen E. [Southern Research Station, USDA Forest Service, Bent Creek Experimental Forest; et al, et al

2014-01-28

359

A New Spectroscopic and Photometric Analysis of the Transiting Planet Systems TrES-3 and TrES-4  

CERN Multimedia

We report new spectroscopic and photometric observations of the parent stars of the recently discovered transiting planets TrES-3 and TrES-4. A detailed abundance analysis based on high-resolution spectra yields [Fe/H] $= -0.19\\pm 0.08$, $T_\\mathrm{eff} = 5650\\pm 75$ K, and $\\log g = 4.4\\pm 0.1$ for TrES-3, and [Fe/H] $= +0.14\\pm 0.09$, $T_\\mathrm{eff} = 6200\\pm 75$ K, and $\\log g = 4.0\\pm0.1$ for TrES-4. The accuracy of the effective temperatures is supported by a number of independent consistency checks. The spectroscopic orbital solution for TrES-3 is improved with our new radial-velocity measurements of that system, as are the light-curve parameters for both systems based on newly acquired photometry for TrES-3 and a reanalysis of existing photometry for TrES-4. We have redetermined the stellar parameters taking advantage of the strong constraint provided by the light curves in the form of the normalized separation $a/R_\\star$ (related to the stellar density) in conjunction with our new temperatures and m...

Sozzetti, A; Charbonneau, D; Winn, J N; Korzennik, S G; Holman, M J; Latham, D W; Laird, J B; Fernández, J; O'Donovan, F T; Mandushev, G; Dunham, E; Everett, M E; Esquerdo, G A; Rabus, M; Belmonte, J A; Deeg, H J; Brown, T N; Hidas, M G; Baliber, N

2008-01-01

360

Airborne Light Detection and Ranging (LiDAR for Individual Tree Stem Location, Height, and Biomass Measurements  

Directory of Open Access Journals (Sweden)

Full Text Available Light Detection and Ranging (LiDAR remote sensing has demonstrated potential in measuring forest biomass. We assessed the ability of LiDAR to accurately estimate forest total above ground biomass (TAGB on an individual stem basis in a conifer forest in the US Pacific Northwest region using three different computer software programs and compared results to field measurements. Software programs included FUSION, TreeVaW, and watershed segmentation. To assess the accuracy of LiDAR TAGB estimation, stem counts and heights were analyzed. Differences between actual tree locations and LiDAR-derived tree locations using FUSION, TreeVaW, and watershed segmentation were 2.05 m (SD 1.67, 2.19 m (SD 1.83, and 2.31 m (SD 1.94, respectively, in forested plots. Tree height differences from field measured heights for FUSION, TreeVaW, and watershed segmentation were ?0.09 m (SD 2.43, 0.28 m (SD 1.86, and 0.22 m (2.45 in forested plots; and 0.56 m (SD 1.07 m, 0.28 m (SD 1.69 m, and 1.17 m (SD 0.68 m, respectively, in a plot containing young conifers. The TAGB comparisons included feature totals per plot, mean biomass per feature by plot, and total biomass by plot for each extraction method. Overall, LiDAR TAGB estimations resulted in FUSION and TreeVaW underestimating by 25 and 31% respectively, and watershed segmentation overestimating by approximately 10%. LiDAR TAGB underestimation occurred in 66% and overestimation occurred in 34% of the plot comparisons.

Michael G. Wing

2011-11-01

 
 
 
 
361

Using LiDAR to Estimate Total Aboveground Biomass of Redwood Stands in the Jackson Demonstration State Forest, Mendocino, California  

Science.gov (United States)

The overall objective of this study is to develop a method for estimating total aboveground biomass of redwood stands in Jackson Demonstration State Forest, Mendocino, California using airborne LiDAR data. LiDAR data owing to its vertical and horizontal accuracy are increasingly being used to characterize landscape features including ground surface elevation and canopy height. These LiDAR-derived metrics involving structural signatures at higher precision and accuracy can help better understand ecological processes at various spatial scales. Our study is focused on two major species of the forest: redwood (Sequoia semperirens [D.Don] Engl.) and Douglas-fir (Pseudotsuga mensiezii [Mirb.] Franco). Specifically, the objectives included linear regression models fitting tree diameter at breast height (dbh) to LiDAR derived height for each species. From 23 random points on the study area, field measurement (dbh and tree coordinate) were collected for more than 500 trees of Redwood and Douglas-fir over 0.2 ha- plots. The USFS-FUSION application software along with its LiDAR Data Viewer (LDV) were used to to extract Canopy Height Model (CHM) from which tree heights would be derived. Based on the LiDAR derived height and ground based dbh, a linear regression model was developed to predict dbh. The predicted dbh was used to estimate the biomass at the single tree level using Jenkin's formula (Jenkin et al 2003). The linear regression models were able to explain 65% of the variability associated with Redwood's dbh and 80% of that associated with Douglas-fir's dbh.

Rao, M.; Vuong, H.

2013-12-01

362

Modelling stand biomass fractions in Galician Eucalyptus globulus plantations by use of different LiDAR pulse densities  

Energy Technology Data Exchange (ETDEWEB)

Aims of study: To evaluate the potential use of canopy height and intensity distributions, determined by airborne LiDAR, for the estimation of crown, stem and aboveground biomass fractions. To assess the effects of a reduction in LiDAR pulse densities on model precision. Area of study: The study area is located in Galicia, NW Spain. The forests are representative of Eucalyptus globulus stands in NW Spain, characterized by low-intensity silvicultural treatments and by the presence of tall shrub. Material and methods: Linear, multiplicative power and exponential models were used to establish empirical relationships between field measurements and LiDAR metrics. A random selection of LiDAR returns and a comparison of the prediction errors by LiDAR pulse density factor were performed to study a possible loss of fit in these models. Main results: Models showed similar goodness-of-fit statistics to those reported in the international literature. R2 ranged from 0.52 to 0.75 for stand crown biomass, from 0.64 to 0.87 for stand stem biomass, and from 0.63 to 0.86 for stand aboveground biomass. The RMSE/MEAN 100 of the set of fitted models ranged from 17.4% to 28.4%. Models precision was essentially maintained when 87.5% of the original point cloud was reduced, i.e. a reduction from 4 pulses m{sup 2} to 0.5 pulses m{sup 2}. Research highlights: Co