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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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Transportation and access to urban services in Dar es Salaam  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Transportation in Dar es Salaam is particularly difficult. Statistical data drawn from the 1993 Human Resources Development Survey confirm that in unplanned settlements, transportation conditions and access to urban services are less favourable than in the rest of the city. The poverty of a majority of city inhabitants, the low quality of urban passenger transport and poor accessibility result in daily mobility reduced to the immediate neighbourhood, while in turn tends to perpetuate poverty.

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

2002-01-01

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A Browning process : The case of Dar es Salaam city  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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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Seasonal variation of water-soluble inorganic species in the coarse and fine atmospheric aerosols at Dar es Salaam, Tanzania  

International Nuclear Information System (INIS)

from our water-soluble ions study strongly suggests that biomass burning and secondary aerosols make a significant contribution to fine particulate mass in Dar es Salaam atmosphere. Thus, burning of waste and biomass are thought to be the major causes for the atmospheric particulate pollution in Dar es Salaam during the dry season.

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Child Labour in Urban Agriculture: The Case of Dar es Salaam, Tanzania.  

Science.gov (United States)

Urban agriculture in Dar es Salaam was found to use child labor of both children with parents of higher and lower socioeconomic status (SES). Discusses policy implications and calls for the education of parents of lower SES not to expect an economic contribution from their children's labor, and the education of children about their rights. (LZ)

Mlozi, Malongo R. S.

1995-01-01

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Towards sustainable ground water management in Dar Es Salaam city, Tanzania  

International Nuclear Information System (INIS)

Groundwater pollution in urban areas is a worldwide growing environmental problem in this millennium. Many major cities in the world depend on groundwater for water supplies. However, urbanization processes threaten its quality. The problem is more pronounced in urban areas in developing countries like Tanzania, which are characterized with inadequate infrastructure for waste management. In Tanzania, the situation is more threatening in Dar Es Salaam City, which experiences acute deficiency in infrastructure provision: housing, water supply, sanitation, transportation and energy. The existing challenge is to protect groundwater resources amidst rapid growing Dar Es Salaam city, of which failure can lead to escalating costs for provision of drinking water with overall results of decreased public health conditions. A research conducted from 1997 to 2002, revealed that almost 50% of the water supply in Dar Es Salaam city comes from groundwater and that groundwater is being threatened by indiscriminate disposal practices of both domestic and industrial wastes. For example about 88% of the urban population use on-site sanitation systems, which discharge partially treated sewage to the groundwater. About 60 tonnes/day of chemical oxygen demand (COD) are transported to the groundwater through domestic sewage. Analysis of groundwater quality in the city indicated that the unconfined aquifer is starting to degrade. For instance, more than 40% of groundwater samples analysed fohan 40% of groundwater samples analysed for nitrate, chloride and faecal coliform bacteria, did not comply with the national standards for drinking water. Recognising the fact that demand for groundwater is on the increase in the city and that the aquifers have shown signs of degradation, a groundwater management plan is required to ensure sustainable utilization of the resource. This paper discusses the groundwater situation in Dar Es Salaam city and finally puts forward measures towards establishment of a management strategy. (author)

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Early Postpartum Concerns of Mothers in Dar-es-Salaam, Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study was designed to assess Tanzanian women's perceptions of their concerns during the early postpartum period and explore the relationship of these concerns to parity, experience with child care, age, marital status, religion and tribe. The Lazarus and Folkman (1984) stress, appraisal, and coping framework guided the study. A convenience sample of 100 mothers with uncomplicated vaginal deliveries were selected from Dar-Es- Salaam. By means of a card-sort, mothers sorted items as "worri...

Lugina, H. I.

1992-01-01

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Science.gov (United States)

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 ppreventive measures for childhood obesity should start early in childhood and address socioeconomic factors of parents contributing to childhood obesity. PMID:24094276

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.

Rasch, Vibeke

2012-01-01

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

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Full Text Available 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 (OR 3.21. Finally, knowledge of cervical cancer and awareness of the existing screening program were also associated with increased acceptance rates (ORs of 5.90 and 4.20. 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

2012-12-01

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Basic analysis of climate and urban bioclimate of Dar es Salaam, Tanzania  

Science.gov (United States)

Better understanding of urban microclimate and bioclimate of any city is imperative today when the world is constrained by both urbanisation and global climate change. Urbanisation generally triggers changes in land cover and hence influencing the urban local climate. Dar es Salaam city in Tanzania is one of the fast growing cities. Assessment of its urban climate and the human biometeorological conditions was done using the easily available synoptic meteorological data covering the period 2001-2011. In particular, the physiologically equivalent temperature (PET) was calculated using the RayMan software and results reveal that the afternoon period from December to February (DJF season) is relatively the most thermal stressful period to human beings in Dar es Salaam where PET values of above 35 °C were found. Additionally, the diurnal cycle of the individual meteorological elements that influence the PET index were analysed and found that air temperature of 30-35 °C dominate the afternoon period from 12:00 to 15:00 hours local standard time at about 60 % of occurrence. The current results, though considered as preliminary to the ongoing urban climate study in the city, provide an insight on how urban climate research is of significant importance in providing useful climatic information for ensuring quality of life and wellbeing of city dwellers.

Ndetto, Emmanuel L.; Matzarakis, Andreas

2013-10-01

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

Science.gov (United States)

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

2014-05-01

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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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Diagnosis and Treatment of Tuberculosis Among Children at an HIV Care Program in Dar es Salaam, Tanzania.  

Science.gov (United States)

Diagnosis and treatment of tuberculosis is challenging in children with human immunodeficiency virus (HIV) infection. We describe the clinical features, diagnostic testing results, tuberculosis and HIV treatment and clinical outcomes of 57 HIV-infected children diagnosed with tuberculosis at the DarDar Pediatric Program in Dar es Salaam, Tanzania. In this cohort, tuberculosis was common, microbiologic studies were frequently negative and mortality was high. PMID:24945878

Adams, Lisa V; McQuillan, Thomas; Naburi, Helga E; Lyatuu, Goodluck; Ippolito, Matthew M; Saunders, Andrew; Kiravu, Anna; Palumbo, Paul; von Reyn, C Fordham

2014-12-01

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Planning the unplanned : incorporating agriculture as an urban land use into the Dar es Salaam master plan and beyond  

DEFF Research Database (Denmark)

Despite significant contributions to human health, livelihoods and food security, urban agriculture in Dar es Salaam has received relatively little political support from central and local government due to its informal state. As a result, many urban farmers' experience insecurity of land access and ownership, and are unable to invest in the improvement of their land, inputs and infrastructure. Although there have been several attempts by various international and foreign organizations to legitimize and institutionalize urban agriculture in Dar es Salaam, very little has changed politically over the past 30 years. This study focuses on the current incorporation of urban agriculture into the Dar es Salaam 2012-2032 Master Plan (still unapproved as of June 2013), and examines how local and central governments legitimize the practice of urban agriculture. It also looks at how greater acceptance, or institutionalization, can take place through formalized processes. The past and present legitimization processes for urban agriculture in Dar es Salaam, and their intended and unintended outcomes, provide an in-depth analysis for this case study. It argues that the sustainability of urban agriculture is largely dependent on political commitment from both local and central government. Legitimization of the practice through policy and rules and regulations can facilitate the further institutionalization of urban agriculture, especially in land use planning. However, it can also further marginalize urban farmers who cultivate open spaces within the city. Nonetheless, urban agriculture will continue to persist, adapting and innovating under the pressures of urbanization. © 2013 International Institute for Environment and Development (IIED).

Halloran, Afton Marian Szasz; Magid, Jakob

2013-01-01

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

DEFF Research Database (Denmark)

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 waste consists of vegetable matter. Proposals for improved design of storage and collection facilities are described. Experiments revealed wastes from the market are readily decomposable by composting. A change in the design of covered markets and improvements in waste handling are essential to reduce the potential health hazards in developing countries.

Yhdego, Michael

1992-01-01

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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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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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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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Acceptance of contraceptives among women who had an unsafe abortion in Dar es Salaam  

DEFF Research Database (Denmark)

OBJECTIVE: To assess the need for post-abortion contraception and to determine if women who had an unsafe abortion will use a contraceptive method to avoid repeated unwanted pregnancies and STDs/HIV. METHOD: Women attending Temeke Municipal Hospital, Dar es Salaam, after an unsafe abortion or an induced abortion performed at the hospital (n=788) were counselled about contraception and the risk of contracting STDs/HIV. A free ward-based contraceptive service was offered and the women were asked to return for follow-up. RESULTS: Participants (90%) accepted the post-abortion contraceptive service. Of these, 86% stated they were still using contraception 1-6 months after discharge. Initially, 55% of the women accepted to use condoms either alone or as part of double protection. After 1-6 months this proportion had dropped to 18%. Single women were significantly more likely to use condoms. CONCLUSION: High-quality contraceptive service counselling can induce women to use contraception after having had an unsafe abortion. The results of our study are encouraging and should be used to convince policy makers of the need to implement such services at municipal level to reduce the number of repeated unsafe abortions.

Rasch, Vibeke; Massawe, Siriel

2004-01-01

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The role of local government in promoting sustainable urban agriculture in Dar es Salaam and Copenhagen  

DEFF Research Database (Denmark)

As a multifunctional activity and land use, urban agriculture supports a range of objectives, from urban greening to food security. However, it is often left out of urban policy. As a result of the highly contextual and cross-cutting nature of urban agriculture, there are relatively few comprehensive and formalized regulatory tools to draw from. Different cities around the world are now deciding how to fit urban agriculture into the urban agenda; however, in many places urban agriculture continues to operate in the absence of legitimization due to its relatively mobile and dynamic nature. This article looks at the importance of local and central governments in promoting sustainable urban agriculture. Through participatory action research, it examines the cases of Dar es Salaam, Tanzania and Copenhagen, Denmark to understand stakeholder interactions, as well as present and future barriers to the conservation of existing urban agriculture and future initiatives. The findings suggest that municipal recognition and institutional support for urban agriculture is an important component in increasing the sustainability of related initiatives. Local and central government plays a role in the legitimization and institutionalization of urban agriculture through the facilitation of multi-stakeholder processes, policy development and the conservation and allocation of land. © 2013 Taylor & Francis.

Halloran, Afton Marian Szasz; Magid, Jakob

2013-01-01

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Prevalence, Perceived Factors and Knowledge on Effects of Tobacco Use on Oral Health Among Secondary School Students in Dar es salaam  

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At the time of the conception of this study there was scant information on self reported prevalence, knowledge on detrimental effects on oral health and factors influencing tobacco use among secondary school students in Dar es Salaam region. To determine the prevalence, perceived factors that may lead and /or deter secondary school students to use tobacco and knowledge on effects of tobacco use on oral health among secondary school students in Dar es Salaam. This was a descriptive cross-secti...

Kabulwa, Msafiri Nicodemus

2011-01-01

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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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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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Factors for change in maternal and perinatal audit systems in Dar es Salaam hospitals, Tanzania  

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Full Text Available Abstract Background Effective maternal and perinatal audits are associated with improved quality of care and reduction of severe adverse outcome. Although audits at the level of care were formally introduced in Tanzania around 25 years ago, little information is available about their existence, performance, and practical barriers to their implementation. This study assessed the structure, process and impacts of maternal and perinatal death audit systems in clinical practice and presents a detailed account on how they could be improved. Methods A cross sectional descriptive study was conducted in eight major hospitals in Dar es Salaam in January 2009. An in-depth interview guide was used for 29 health managers and members of the audit committees to investigate the existence, structure, process and outcome of such audits in clinical practice. A semi-structured questionnaire was used to interview 30 health care providers in the maternity wards to assess their awareness, attitude and practice towards audit systems. The 2007 institutional pregnancy outcome records were reviewed. Results Overall hospital based maternal mortality ratio was 218/100,000 live births (range: 0 - 385 and perinatal mortality rate was 44/1000 births (range: 17 - 147. Maternal and perinatal audit systems existed only in 4 and 3 hospitals respectively, and key decision makers did not take part in audit committees. Sixty percent of care providers were not aware of even a single action which had ever been implemented in their hospitals because of audit recommendations. There were neither records of the key decision points, action plan, nor regular analysis of the audit reports in any of the facilities where such audit systems existed. Conclusions Maternal and perinatal audit systems in these institutions are poorly established in structure and process; and are less effective to improve the quality of care. Fundamental changes are urgently needed for successful audit systems in these institutions.

Kisanga Felix

2010-06-01

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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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Risk factors for VIA positivity and determinants of screening attendances in Dar es Salaam, Tanzania  

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ABSTRACT: BACKGROUND: Tanzania is among the countries in the world where the cervical cancer incidence is estimated to be highest. Acknowledging an increase in the burden of cervical cancer, VIA was implemented as a regional cervical cancer screening strategy in Tanzania in 2002. With the aim of describing risk factors for VIA positivity and determinants of screening attendances in Tanzania, this paper present the results from a comparative analysis performed among women who are reached and not reached by the screening program". METHODS: 14 107 women aged 25--59 enrolled in a cervical cancer screening program in Dar es Salaam in the period 2002 -- 2008. The women underwent VIA examination and took part in a structured questionnaire interview. Socioeconomic characteristics, sexual behavior, HIV status and high-risk (HR) HPV infection were determined in a subpopulation of 890 who participated and 845 who did not participate in the screening. RESULTS: Being widowed/separated OR=1.41 (95% CI: 1.17-1.66), of high parity OR=3.19 (95% CI: 1.84-5.48) of low education OR= 4.30 (95% CI: 3.50-5.31) and married at a young age OR=2.17 (95% CI: 1.37-3.07) were associated with being VIA positive. Women who participated in the screening were more likely to be HIV positive OR= 1.59 (95% CI. 1.14-2.25) in comparison with women who had never attended screening, while no difference was found in the prevalence of HR-HPV infection among women who had attended screening and women who had not attended screening. CONCLUSION: Women who are widowed/separated, of high parity, of low education and married at a young age are more likely to be VIA positive and thus at risk of developing cervical cancer. The study further documents that a referral linkage between the HIV care and treatment program and the cervical cancer screening program is in place in the setting studied, where HIV positive were more likely to participate in the cervical cancer screening program than HIV negative women.

Rasch, Vibeke

2012-01-01

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Factors associated with different patterns of nonadherence to HIV care in Dar es Salaam, Tanzania.  

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Health system responsiveness (HSR), a measure of patient health care experience, may influence adherence to HIV/AIDS care and be an important predictor of outcomes. We studied the relationship between HSR, patient factors, and visit nonadherence in 16 President's Emergency Plan for AIDS Relief-supported HIV/AIDS clinics in Dar es Salaam. An HSR survey was administered in 2009, and all clinic visits 1 year following the interviews were analyzed for 720 patients on antiretrovirals (ARVs). Definitions of visit nonadherence were (1) low visit constancy ([VC], no visit in ?1 quarter), (2) gaps in care (>60 days between visits), (3) no visit in last quarter (VLQ). The relationships between factors were analyzed using multivariate analysis with adjusted odds ratio (AOR) and 95% confidence intervals (CI) reported. Few patients were nonadherent using VLQ (14%) and VC (28%). Gaps in care were more common (49.6%) and associated with younger age (AOR: 3.86 [2.02-7.40]), no explanation of side effects (AOR: 2.21 [1.49-3.28]), and shorter antiretroviral therapy (ART) duration (0-3 months AOR: 1.49 [1.09-2.03]; 3-6 months AOR: 2.44 [1.40-4.25]). No VLQ was associated with younger age (AOR: 3.40 [1.63-7.07]), poor health care worker (HCW) communication (AOR: 4.83 [1.39-16.78]), and less time on ART (0-3 months AOR: 5.04 [2.47-10.30]; 3-6 months AOR: 3.09 [1.72-5.57]). Younger age, poor HCW communication, and shorter ART duration also predicted lower VC, as did higher patient-HCW ratios. The rates of visit nonadherence differed based on the definitions used. Younger age, shorter time on ART, and poor HCW communication predicted lower adherence regardless of the definition. More work is needed to understand the relationship between HSR, patient factors, and different patterns of visit nonadherence and their impact on ART outcomes. PMID:23269515

Poles, Gabriela; Li, Michelle; Siril, Hellen; Mhalu, Aisa; Hawkins, Claudia; Kaaya, Sylvia; Aris, Eric; Chalamilla, Guerino; Hirschhorn, Lisa R

2014-01-01

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

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Full Text Available Background: This article presents part of the findings from a larger study that sought to assess the role that gender relations play in influencing equity regarding access and adherence to antiretroviral therapy (ART. Review of the literature has indicated that, in Southern and Eastern Africa, fewer men than women have been accessing ART, and the former start using ART late, after HIV has already been allowed to advance. The main causes for this gender gap have not yet been fully explained. Objective: To explore how masculinity norms limit men's access to ART in Dar es Salaam. Design: This article is based on a qualitative study that involved the use of focus group discussions (FGDs. The study employed a stratified purposive sampling technique to recruit respondents. The study also employed a thematic analysis approach. Results: Overall, the study's findings revealed that men's hesitation to visit the care and treatment clinics signifies the superiority norm of masculinity that requires men to avoid displaying weakness. Since men are the heads of families and have higher social status, they reported feeling embarrassed at having to visit the care and treatment clinics. Specifically, male respondents indicated that going to a care and treatment clinic may raise suspicion about their status of living with HIV, which in turn may compromise their leadership position and cause family instability. Because of this tendency towards ‘hiding’, the few men who register at the public care and treatment clinics do so late, when HIV-related signs and symptoms are already far advanced. Conclusion: This study suggests that the superiority norm of masculinity affects men's access to ART. Societal expectations of a ‘real man’ to be fearless, resilient, and emotionally stable are in direct conflict with expectations of the treatment programme that one has to demonstrate health-promoting behaviour, such as promptness in attending the care and treatment clinic, agreeing to take HIV tests, and disclosing one's status of living with HIV to at least one's spouse or partner. Hence, there is a need for HIV control agencies to design community-based programmes that will stimulate dialogue on the deconstruction of masculinity notions.

Tumaini M. Nyamhanga

2013-10-01

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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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Risk factors for VIA positivity and determinants of screening attendances in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Tanzania is among the countries in the world where the cervical cancer incidence is estimated to be highest. Acknowledging an increase in the burden of cervical cancer, VIA was implemented as a regional cervical cancer screening strategy in Tanzania in 2002. With the aim of describing risk factors for VIA positivity and determinants of screening attendances in Tanzania, this paper present the results from a comparative analysis performed among women who are reached and not reached by the screening program”. Methods 14 107 women aged 25–59 enrolled in a cervical cancer screening program in Dar es Salaam in the period 2002 – 2008. The women underwent VIA examination and took part in a structured questionnaire interview. Socioeconomic characteristics, sexual behavior, HIV status and high-risk (HR HPV infection were determined in a subpopulation of 890 who participated and 845 who did not participate in the screening. Results Being widowed/separated OR=1.41 (95% CI: 1.17-1.66, of high parity OR=3.19 (95% CI: 1.84-5.48 of low education OR= 4.30 (95% CI: 3.50-5.31 and married at a young age OR=2.17 (95% CI: 1.37-3.07 were associated with being VIA positive. Women who participated in the screening were more likely to be HIV positive OR= 1.59 (95% CI. 1.14-2.25 in comparison with women who had never attended screening, while no difference was found in the prevalence of HR-HPV infection among women who had attended screening and women who had not attended screening. Conclusion Women who are widowed/separated, of high parity, of low education and married at a young age are more likely to be VIA positive and thus at risk of developing cervical cancer. The study further documents that a referral linkage between the HIV care and treatment program and the cervical cancer screening program is in place in the setting studied, where HIV positive were more likely to participate in the cervical cancer screening program than HIV negative women.

Kahesa Crispin

2012-12-01

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

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This study was designed to determine the prevalence of significant bacteriuria in pregnancy in Dar es Salaam as well as attempt to find out whether bacteriuria has any effects on the mother and baby. Of 1007 pregnant women studied for asymptomatic bacteriuria, a significant bacteriuria rate of 6.3% was revealed. Escherichia coli was the predominant organism, making up 47.6% of the total organisms isolated. Schistosoma hematobium was present in 8.7%, T. vaginalis in 14%, yeast cells were found in the urine of 9.1% and the microfilariae of Wuchereria bancrofti were found in 1 specimen. 66.2% had no abnormality in their urine. It is recommended on the basis of this study that all women found to have significant bacteriuria in 1 cultured urine sample should be treated. There was a significant relationship noted between significant bacteriuria and the passing of S. hematobium in the urine. There was also a significant correlation between the presence of T. vaginalis and yeast cells in the urine. On the basis of laboratory sensitivity studies it was also found that the antimicrobial agents of choice for treating urinary tract infections in Dar es Salaam where E. coli and Klebsiella erogenes are the predominant organisms are nitrofurantoin, nalidixic acid and co-trimoxazole. The socioeconomic status of the bacteriuric and control group was divided into 4 groups according to take home pay; results show no significant increase of bacteriuria in any of the groups. It was not possible to follow up the effects of the presence of micro-organisms in urine during pregnancy because once a woman was found to have a positive culture she was treated. PMID:12340188

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

1983-09-01

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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  

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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)

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

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Full Text Available Abstract 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 Linked Immunosorbent Assay (ELISA and agglutination assay were used to detect viruses and intestinal protozoa, respectively. Antimicrobial susceptibility was determined using Kirby-Bauer disk diffusion method. Results At least one of the searched pathogens was detected in 67.1% of the cases, and mixed infections were detected in 20.7% of cases. Overall, bacteria and viruses contributed equally accounting for 33.2% and 32.2% of all the cases, respectively, while parasites were detected in 19.2% patients. Diarrhoeagenic Escherichia coli (DEC was the most common enteric pathogen, isolated in 22.9% of patients, followed by Cryptosporidium parvum (18.9%, rotavirus (18.1% and norovirus (13.7%. The main cause of diarrhoea in children aged 0 to 6 months were bacteria, predominantly DEC, while viruses predominated in the 7-12 months age group. Vibrio cholerae was isolated mostly in children above two years. Shigella spp, V. cholerae and DEC showed moderate to high rates of resistance to erythromycin, ampicillin, chloramphenicol and tetracycline (56.2-100%. V. cholerae showed full susceptibility to co-trimoxazole (100%, while DEC and Shigella showed high rate of resistance to co-trimoxazole; 90.6% and 93.3% respectively. None of the bacterial pathogens isolated showed resistance to ciprofloxacin which is not recommended for use in children. Cefotaxime resistance was found only in 4.7% of the DEC. Conclusion During the dry season, acute watery diarrhoea is the most common type of diarrhoea in children under five years in Dar es Salaam and is predominantly due to DEC, C. parvum, rotaviruses and noroviruses. Constant antibiotic surveillance is warranted as bacteria were highly resistant to various antimicrobial agents including co-trimoxazole and erythromycin which are currently recommended for empiric treatment of diarrhoea.

Myrmel Helge

2011-02-01

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

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

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

2013-04-01

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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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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...

Rrj, Akarro

2011-01-01

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Prevalence of obesity and associated risk factors among adults in Kinondoni municipal district, Dar es Salaam Tanzania  

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Full Text Available Abstract Background Obesity is on the rise worldwide, not sparing developing countries. Both demographic and socio-economic factors play parts in obesity causation. Few surveys have been conducted in Tanzania to determine the magnitude of obesity and its association with these risk factors. This study aimed at determining the prevalence of obesity and its associated risk factors among adults aged 18 - 65 years in Kinondoni municipality, Dar es Salaam, Tanzania from April 2007 to April 2008. Methods Random sampling of households was performed. Interviews and anthropometric measurement were carried out to eligible and consenting members of the selected households. Obesity was defined using Body Mass Index (BMI. Results Out of 1249 subjects recruited, 814 (65.2% were females. The overall prevalence of obesity was 19.2% (240/1249. However, obesity was significantly more prevalent in women (24.7% than men (9%, p Conclusion This study revealed a higher prevalence of obesity among Kinondoni residents than previously reported in other parts of the country. Independent predictors of obesity in the population studied were increasing age, marriage and cohabitation, high SES, female sex and less vigorous physical activities.

Mugusi Ferdinand M

2011-05-01

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

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

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

2005-01-01

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Maintenance of Sensitivity of the T-SPOT.TB Assay after Overnight Storage of Blood Samples, Dar es Salaam, Tanzania.  

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Background. T-SPOT.TB is an interferon gamma release assay for detecting Mycobacterium tuberculosis infection. The requirement to process within 8 hours is constraining, deters use, and leads to invalid results. Addition of T Cell Xtend reagent may allow delayed processing, but has not been extensively field tested. Design. Consecutive AFB smear positive adult tuberculosis patients were prospectively recruited in Dar es Salaam, Tanzania. Patients provided a medical history, 1-3 sputum samples for culture and 1 blood sample which was transported to the laboratory under temperature-controlled conditions. After overnight storage, 25??L of T Cell Xtend reagent was added per mL of blood, and the sample was tested using T-SPOT.TB. Results. 143 patients were enrolled: 57 patients were excluded because temperature control was not maintained, 19 patients were excluded due to red blood cell contamination, and one did not provide a sputum sample for culture. Among 66 evaluable patients, overall agreement between T-SPOT.TB and culture was 95.4% (95%CI; 87.1-99.0%) with Kappa value 0.548. Sensitivity of T-SPOT.TB when using T Cell Xtend reagent was 96.8% (95%CI; 88.8-99.6%). Conclusions. When T Cell Xtend reagent is added to specimens held overnight at recommended temperatures, T-SPOT.TB is as sensitive as the standard assay in patients with tuberculosis. PMID:22567274

Talbot, Elizabeth A; Maro, Isaac; Ferguson, Katherine; Adams, Lisa V; Mtei, Lillian; Matee, Mecky; von Reyn, C Fordham

2012-01-01

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Efficacy of waterless hand hygiene compared with handwashing with soap: a field study in Dar es Salaam, Tanzania.  

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

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

2010-02-01

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Personal protection against mosquitoes in Dar es Salaam, Tanzania, by using a kerosene oil lamp to vaporize transfluthrin.  

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The effectiveness of a cheap and easy method of household protection against Culex quinquefasciatus Say and other mosquitoes (Diptera: Culicidae) was investigated in Dar es Salaam, Tanzania. Kerosene-burning lamps (korobois) were modified to heat and vaporize transfluthrin, a volatile pyrethroid insecticide. When transfluthrin was added to fuel of the lamp, protection against biting was poor unless a very high concentration of insecticide was used. A modified lamp (= vaporizing koroboi) was designed to overcome this problem by mixing the insecticide with vegetable oil and heating it to 120 degrees C in a tin held just above the flame. The concentration of 0.1% transfluthrin in vegetable oil gave 50-75% reduction in biting, a similar degree of protection to that obtained from burning a mosquito coil containing a synthetic pyrethroid (0.25% d-allethrin) and significantly better protection than a locally bought coil (brand 'White Crane', probably containing DDT). Greater protection (consistently > 90%) was achieved with a higher concentration of transfluthrin (0.5%) in the vegetable oil. This modified lamp is simple, cheap and employs locally available technology. With further development, and due regard to inhalation toxicity of the vaporized materials, it may offer a more cost-effective alternative to a mosquito coil as a means of personal protection, and a useful complement to a net for the early part of the evening before bedtime. PMID:12243228

Pates, H V; Line, J D; Keto, A J; Miller, J E

2002-09-01

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Obesity, Overweight, and Perceptions about Body Weight among Middle-Aged Adults in Dar es Salaam, Tanzania  

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Background. Prevalence of obesity is increasing throughout the world at an alarming rate. Appropriate perception of one's own body weight is important for improved weight control behavior. This study was conducted to determine the prevalence of overweight and obesity and assess perception of body weight among middle aged adults in Dar es Salaam, Tanzania. Methods. Structured questionnaire was used to collect sociodemographic and lifestyle information including perception about body weight. Anthropometric measurements were taken by a trained person following standard procedures. Results. Prevalence of obesity was 13% and 36% among men and women, respectively. There was significant gender difference in perception of body weight (12% and 25% of men and women perceived their body weight as overweight). Only 2% of women perceived themselves as obese whereas none of the men did so. Among overweight men, only 22% perceived themselves as overweight/obese compared to 38% of overweight women who perceived themselves as overweight/obese. Overall, majority of the participants (87%) were willing to lose weight. Conclusions. There is a great difference between perceived and actual body weight with men underestimating their body weight more than women. Educational programs regarding overweight and obesity and the associated health consequences are highly recommended in Tanzania. PMID:24527261

Muhihi, Alfa J.; Njelekela, Marina A.; Mpembeni, Rose; Mwiru, Ramadhani S.; Mligiliche, Nuru; Mtabaji, Jacob

2012-01-01

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Sexual Motivation, Sexual Transactions and Sexual Risk Behaviors in Men who have Sex with Men in Dar es Salaam, Tanzania.  

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Understanding the associations between sexual motivation and sexual risk behaviors of men who have sex with men (MSM) is critical for developing effective HIV prevention interventions. To examine these associations, we employed data from a survey of 200 MSM in Dar es Salaam, Tanzania, recruited through respondent driven sampling. Results showed that 44.5 % of surveyed participants most often looked for love/affection when having sex, and 36.5 % most often looked for money. Money-motivated MSM were more likely to identify themselves as bisexual, more likely to have anal sex, and had significantly higher numbers of partners of both sexes. Those who most often looked for love/affection were less likely to ask for condom use, to actually use a condom, and to use lubrication in anal sex. MSM with different sexual motivations had dissimilar sexual risk behaviors. Tailored health interventions for each group to reduce these sexual risks for STIs/HIV prevention are needed. PMID:24890184

Bui, Thanh C; Nyoni, Joyce E; Ross, Michael W; Mbwambo, Jessie; Markham, Christine M; McCurdy, Sheryl A

2014-12-01

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

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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.

2010-12-01

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

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

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Full Text Available 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 by severity of flooding, interviews with households, sub-ward leaders, and municipal and city officials. Non-participant observation, primarily taking photographs, complemented these methods. Laboratory tests of water samples taken from shallow wells in the settlement were performed to establish the level of pollution. In addition, records of prevalence of water-borne diseases were gathered from a dispensary within the settlement to corroborate flooding events, water pollution and occurrence of such diseases. Findings show that flooding is contributed to by the lack of a coordinated stormwater drainage system; haphazard housing development within the valley; and blocking of the water stream by haphazard dumping of solid waste and construction. Risks associated with flooding include water and air pollution, diseases, waterlogging and blocked accessibility. The most common coping strategies at household level are use of sandbags and tree logs; raised pit latrines and doorsteps; provision of water outlet pipes above plinth level; construction of embankments, protection walls and elevation of house foundations; seasonal displacement; and boiling and chemical treatment of water. Recommendations for future action at household, community and city level are made.

Tumpale Sakijege

2012-06-01

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Critical Analysis of the Challenges of Solid Waste Management Initiatives in Keko Machungwa Informal Settlement, Dar es Salaam  

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Full Text Available Solid waste is inevitable because by nature every human activity generates a certain amount of solid waste. The rate of solid waste generated tends to increase with the increase in population. Despite existence of various efforts on solid waste collection, still the quantity of solid waste collected is small compared to the solid waste generated. The situation is even worse in unplanned settlements of developing countries, where, ineffective solid waste collection is contributed to by haphazard solid waste disposal and hence environmental pollution. Therefore, having an effective and efficient solid waste management system is a major challenge in cities of developing countries, and thus more consulted efforts are needed. This paper presents finding based on the study carried out in Keko Machungwa informal settlement in Dar es Salaam, Tanzania. The study explored challenges facing solid waste management initiatives in Keko Machungwa and recommended measures for improvement. Data for this study was collected through documentary review, household interviews, focus group discussions, physical observations and official interviews. The analysis reveals that solid waste generated in Keko Machungwa is 16 tones per day, among those, only 4.56 (less than 50% are collected. About 11.44 tones of uncollected waste are illegally dumped into a seasonal stream and in different vacant lots hence causing blockage of the seasonal stream. Different groups engaged in solid waste collection are deterred by many challenges. The challenges include: lack of cooperation among the existing solid waste collection organs, inaccessibility in some places, low public participation, financial constraints and unwillingness of local community to pay for solid waste collection fees. The paper recommends four options on how solid waste management, particularly collection in Keko Machungwa can be enhanced. 1 Alliance among the existing organ, 2 placing dust-bins in different points within the settlement, 3 linking the fees of solid waste collection to other public services and 4 education and awareness creation campaigns accompanied by community stakeholder consultations.

Samson Elisha Kasala

2014-09-01

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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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Microalbuminuria among Type 1 and Type 2 diabetic patients of African origin in Dar Es Salaam, Tanzania  

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Full Text Available Abstract Background The prevalences and risk factors of microalbuminuria are not full described among black African diabetic patients. This study aimed at determining the prevalence of microalbuminuria among African diabetes patients in Dar es Salaam, Tanzania, and relate to socio-demographic features as well as clinical parameters. Methods Cross sectional study on 91 Type 1 and 153 Type 2 diabetic patients. Two overnight urine samples per patient were analysed. Albumin concentration was measured by an automated immunoturbidity assay. Average albumin excretion rate (AER was used and were categorised as normalbuminuria (AER 200 ug/min. Information obtained also included age, diabetes duration, sex, body mass index, blood pressure, serum total cholesterol, high-density and low-density lipoprotein cholesterol, triglycerides, serum creatinine, and glycated hemoglobin A1c. Results Overall prevalence of microalbuminuria was 10.7% and macroalbuminuria 4.9%. In Type 1 patients microalbuminuria was 12% and macroalbuminuria 1%. Among Type 2 patients, 9.8% had microalbuminuria, and 7.2% had macroalbuminuria. Type 2 patients with abnormal albumin excretion rate had significantly longer diabetes duration 7.5 (0.2–24 yrs than those with normal albumin excretion rate 3 (0–25 yrs, p No significant differences in body mass index, glycaemic control, and cholesterol levels was found among patients with normal compared with those with elevated albumin excretion rate either in Type 1 or Type 2 patients. A stepwise multiple linear regression analysis among Type 2 patients, revealed AER (natural log AER as the dependent variable to be predicted by [odds ratio (95% confidence interval] diabetes duration 0.090 (0.049, 0.131, p Conclusion The prevalence of micro and macroalbuminuria is higher among African Type 1 patients with relatively short diabetes duration compared with prevalences among Caucasians. In Type 2 patients, the prevalence is in accordance with findings in Caucasians. The present study detects, however, a much lower prevalence than previously demonstrated in studies from sub-Saharan Africa. Abnormal AER was significantly related to diabetes duration and systolic blood pressure.

Thordarson Hrafnkell

2007-01-01

62

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

63

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

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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 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. PMID:24495630

Mwakitalu, Mbutolwe E; Malecela, Mwele N; Mosha, Franklin W; Simonsen, Paul E

2014-05-01

64

Investigating seawater intrusion due to groundwater pumping with schematic model simulations: The example of the Dar es Salaam coastal aquifer in Tanzania  

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Water supply requirements in Dar es Salaam city (Tanzania) are rising rapidly by population growth and groundwater is increasingly used to fullfill the needs. The groundwater is taken from the Dar es Salaam Quaternary coastal aquifer (DQCA), stretching inland from the coastline. As thousands of wells have been drilled in the coastal strip and pumping rates are uncontrolled, seawater intrusion is deteriorating the quality of fresh groundwater. To investigate the response of the fresh/salt water interface to coastal pumping, simulations with a schematic two-dimensional cross-sectional model have been done. Depending on the depth of the wells in the 150 m thick DQCA and their distance from the coastline, different pathways of seawater intrusion and shifts of the interface can be recognized. The local presence of a semi-pervious layer can have a significant impact on the fresh/salt water distribution. Although the modeled section is not related to a specific location along the coastline but rather represents an average aquifer buildup, the results of the simulations can be used to formulate recommendations when drilling new wells and for a better monitoring of the salinisation process along the coast. It proves that even simple schematic models can give meaningful contributions.

Van Camp, Marc; Mtoni, Yohana; Mjemah, Ibrahimu C.; Bakundukize, Charles; Walraevens, Kristine

2014-08-01

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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. PMID:24964790

2014-01-01

66

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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Full Text Available 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 and resting boxes (RB were conducted in parallel with indoors sampling using HLC, Centers for Disease Control and Prevention miniature light traps (LT and RB as well as window exit traps (WET in urban Dar es Salaam, rotating them thirteen times through a 3 × 3 Latin Square experimental design replicated in four blocks of three houses. This study was conducted between 6th May and 2rd July 2008, during the main rainy season when mosquito biting densities reach their annual peak. Results The mean sensitivities of indoor RB, outdoor RB, WET, LT, ITT (Design B and HLC placed outdoor relative to HLC placed indoor were 0.01, 0.005, 0.036, 0.052, 0.374, and 1.294 for Anopheles gambiae sensu lato (96% An. gambiae s.s and 4% An. arabiensis, respectively, and 0.017, 0.053, 0.125, 0.423, 0.372 and 1.140 for Culex spp, respectively. The ITT (Design B catches correlated slightly better to indoor HLC (r2 = 0.619, P 2 = 0.231, P = 0.001 than outdoor HLC (r2 = 0.423, P 2 = 0.228, P = 0.001 for An. gambiae s.l. and Culex spp respectively but the taxonomic composition of mosquitoes caught by ITT does not match those of the indoor HLC (?2 = 607.408, degrees of freedom = 18, P An. gambiae caught indoors was unaffected by the use of an LLIN in that house. Conclusion The RB, WET and LT are poor methods for surveillance of malaria vector densities in urban Dar es Salaam compared to ITT and HLC but there is still uncertainty over whether the ITT best reflects indoor or outdoor biting densities. The particular LLIN evaluated here failed to significantly reduce house entry by An. gambiae s.l. suggesting a negligible repellence effect.

Mpangile John M

2011-03-01

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

International Nuclear Information System (INIS)

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.

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Determinants of previous HIV testing and knowledge of partner's HIV status among men attending a voluntary counseling and testing clinic in Dar es Salaam, Tanzania.  

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Voluntary Counseling and Testing (VCT) remains low among men in sub-Saharan Africa. The factors associated with previous HIV testing and knowledge of partner's HIV status are described for 9,107 men who visited the Muhimbili University College of Health Sciences' VCT site in Dar es Salaam, Tanzania, between 1997 and 2008. Data are from intake forms administered to clients seeking VCT services. Most of the men (64.5%) had not previously been tested and 75% were unaware of their partner's HIV status. Multivariate logistic regression revealed that age, education, condom use, and knowledge of partner's HIV status were significant predictors of previous HIV testing. Education, number of sexual partners, and condom use were also associated with knowledge of partner's HIV status. The low rate of VCT use among men underscores the need for more intensive initiatives to target men and remove the barriers that prevent HIV disclosure. PMID:23221684

Conserve, Donaldson; Sevilla, Luis; Mbwambo, Jessie; King, Gary

2013-11-01

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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

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Adolescent girls with illegally induced abortion in Dar es Salaam: the discrepancy between sexual behaviour and lack of access to contraception  

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This article reports on a study of induced abortion among adolescent girls in Dar es Salaam, Tanzania, who were admitted to a district hospital in Dar es Salaam because of an illegally induced abortion in 1997. In the quantitative part of the study, 197 teenage girls (aged 14-19) were asked for socio-economic details, contraceptive knowledge/use, age at first intercourse and number of sexual partners. In the qualitative part, 51 teenage girls were interviewed in-depth about their relationships with their partners, sexual behaviour, contraceptive use and reasons for non-use, and why they became pregnant. The girls were sexually active at an early age and having sex mainly with men older than themselves. Although most of the girls were in love with and enjoyed sex with their partners, they also entered these relationships to obtain money or gifts in exchange for sex. Most were not using contraception or condoms though they were also at risk of STDs and HIV. These girls were getting pregnant expecting their boyfriends to marry them, or because they did not think they could become pregnant or failed to use contraception correctly. Most adolescent girls are not aware of the 1994 Tanzanian policy that gave them the right to seek family planning services and in practice these services are not being provided. There is a need for youth-friendly family planning services and to make abortion safe and legal, in order to reduce unwanted pregnancies and abortion-related complications and deaths among adolescent girls.

Rasch, V; Silberschmidt, Margrethe

2000-01-01

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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

72

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

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

Kidanto Hussein

2012-11-01

73

Ready to Use Therapeutic Foods (RUTF improves undernutrition among ART-treated, HIV-positive children in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background HIV/AIDS is associated with an increased burden of undernutrition among children even under antiretroviral therapy (ART. To treat undernutrition, WHO endorsed the use of Ready to Use Therapeutic Foods (RUTF that can reduce case fatality and undernutrition among ART-naïve HIV-positive children. However, its effects are not studied among ART-treated, HIV-positive children. Therefore, we examined the association between RUTF use with underweight, wasting, and stunting statuses among ART-treated HIV-positive children in Dar es Salaam, Tanzania. Methods This cross-sectional study was conducted from September-October 2010. The target population was 219 ART-treated, HIV-positive children and the same number of their caregivers. We used questionnaires to measure socio-economic factors, food security, RUTF-use, and ART-duration. Our outcome variables were underweight, wasting, and stunting statuses. Results Of 219 ART-treated, HIV-positive children, 140 (63.9% had received RUTF intervention prior to the interview. The percentages of underweight and wasting among non-RUTF-receivers were 12.4% and 16.5%; whereas those of RUTF-receivers were 3.0% (P?=?0.006 and 2.8% (P?=?0.001, respectively. RUTF-receivers were less likely to have underweight (Adjusted Odd Ratio (AOR =0.19, CI: 0.04, 0.78, and wasting (AOR?=?0.24, CI: 0.07, 0.81, compared to non RUTF-receivers. Among RUTF receivers, children treated for at least four months (n?=?84 were less likely to have underweight (P?=?0.049, wasting (P?=?0.049 and stunting (P? Conclusions Among HIV-positive children under ART, the provision of RUTF for at least four months was associated with low proportions of undernutrition status. RUTF has a potential to improve undernutrition among HIV-positive children under ART in the clinical settings in Dar es Salaam, Tanzania.

Sunguya Bruno F

2012-08-01

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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. PMID:24932133

2014-01-01

75

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

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Impact of the change from an injectable to a fully oral regimen on patient adherence to ambulatory tuberculosis treatment in Dar es Salaam, Tanzania.  

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In a comparative study conducted among outpatients at tuberculosis clinics in the Ilala and Kinondoni districts of Dar es Salaam, no difference in patient compliance was recorded between streptomycin injection and an all-oral treatment regimen. An all-oral regimen was considered desirable because of concerns about injection-related human immunodeficiency virus (HIV) transmission, the high cost of streptomycin, and the staff time involved in providing injections; on the other hand, it was unclear whether patients would accept a change to oral ethambutol. In Kinondoni District, where an average of 127 tuberculosis patients are expected daily, 95.9% of the expected patients attended in the initial phase when streptomycin was still given, 97.1% in the transition period, and 95.7% once the oral regimen had been fully implemented. In Ilala, where there was no baseline survey due to nonavailability of streptomycin, attendance was 91.8% of expected when the oral regimen was put into place. Encouraged by these findings, Tanzania's national tuberculosis control program has replaced streptomycin injection with oral ethambutol administration. It is speculated that the shorter clinic waiting times involved in this regimen have helped to maintain a high level of attendance. In this culture, at least, oral regimens do not appear to be perceived as less effective or important than injections. PMID:7579308

Chum, H J; Ilmolelian, G; Rieder, H L; Msangi, J; Mwinyi, N; Zwahlen, M; Enarson, D A; Ipuge, Y A

1995-08-01

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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

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Detection of pulmonary tuberculosis among patients with cough attending outpatient departments in Dar Es Salaam, Tanzania: does duration of cough matter?  

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Full Text Available Abstract Background According to WHO estimates, tuberculosis case detection rate in Tanzania is less than 50% and this poses a major challenge to control tuberculosis in the country. Currently, one of the defining criteria for suspecting tuberculosis is cough for two weeks or more. We wanted to find out whether the prevalence of tuberculosis was different in patients who reported cough for two weeks or more, compared to patients with cough for less than two weeks. Methods We conducted a cross sectional study in six health facilities in Dar es Salaam, between September and October 2007. All patients aged five years and above with cough were screened for pulmonary tuberculosis (PTB by smear microscopy. Patients were divided into two groups, those who coughed for less than two weeks ( Results A total of 65,530 patients attended outpatients department (OPD. Out of these, 2274 (3.5% patients reported cough. Among patients who reported cough, 2214 (97.4% remembered their cough duration. One thousand nine hundred and seventy three patients (89.1% coughed for ? 2 wks as compared to 241 (10.9% patients who coughed for Conclusion Detection of smear positive PTB among patients who coughed for less than two weeks was as high as for those who coughed for two weeks or more.

Wandwalo Eliud R

2009-07-01

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Polycyclic aromatic hydrocarbon (PAH) contamination of surface sediments and oysters from the inter-tidal areas of Dar es Salaam, Tanzania  

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Surface sediment and oyster samples from the inter-tidal areas of Dar es Salaam were analyzed for 23 polycyclic aromatic hydrocarbons (PAHs) including the 16 compounds prioritized by US-EPA using GC/MS. The total concentration of PAHs in the sediment ranged from 78 to 25,000 ng/g dry weight, while oyster concentrations ranged from 170 to 650 ng/g dry weight. Hazards due to sediment contamination were assessed using Equilibrium Partitioning Sediment Benchmarks and Threshold Effect Levels. Diagnostic indices and principle component analysis were used to identify possible sources. Interestingly, no correlation between sediment and oyster concentrations at the same sites was found. This is supported by completely different contamination patterns, suggesting different sources for both matrices. Hazard assessment revealed possible effects at six out of eight sites on the benthic communities and oyster populations. The contribution of PAH intake via oyster consumption to carcinogenic risks in humans seems to be low. - PAH contamination may pose hazards to benthos but limited risks to humans.

Gaspare, Lydia; Machiwa, John F. [Department of Aquatic Environment and Conservation, University of Dar es Salaam, P.O. Box 60091, Dar es Salaam (Tanzania, United Republic of); Mdachi, S.J.M. [Department of Chemistry, University of Dar es Salaam, P.O. Box 35062, Dar es Salaam (Tanzania, United Republic of); Streck, Georg [UFZ Helmholtz Centre for Environmental Research Leipzig-Halle, Department of Effect-Directed Analysis, Permoserstrasse 15, 04318 Leipzig (Germany); Brack, Werner [UFZ Helmholtz Centre for Environmental Research Leipzig-Halle, Department of Effect-Directed Analysis, Permoserstrasse 15, 04318 Leipzig (Germany)], E-mail: werner.brack@ufz.de

2009-01-15

80

Anemia at the Initiation of Tuberculosis Therapy Is Associated with Delayed Sputum Conversion among Pulmonary Tuberculosis Patients in Dar-es-Salaam, Tanzania  

Science.gov (United States)

Background Pulmonary tuberculosis and anemia are both prevalent in Tanzania. There is limited and inconsistent literature on the association between anemia and sputum conversion following tuberculosis treatment. Methods Newly diagnosed sputum smear positive pulmonary tuberculosis patients aged ?15 years initiating on standard anti tuberculosis therapy were recruited from 14 of 54 tuberculosis clinics in Dar es Salaam. Patients were receiving medication according to the recommended short course Directly Observed Therapy (DOT) strategy and were followed up prospectively until completion of treatment (six months). Patients were evaluated before initiation of TB treatment by performing the following; clinical history, physical examination, complete blood counts, serum biochemistry and sputum microscopy. Sputum smears were re-examined at two months of anti-tuberculosis therapy for presence of acid fast bacilli. Anemia was defined as hemoglobin <13 g/dl (males) or <12 g/dl (females). Log-binomial regression was used to assess the association between anemia and sputum conversion at two months. Results Of the 1245 patients included in the study, 86% were anemic and 7% were sputum smear positive at two months of anti-tuberculosis therapy. Anemic patients were three times more likely to have sputum positive smear as compared to non-anemic patients at two months (RR?=?3.05; 95% CI 1.11–8.40) p?=?0.03. The risk for sputum positive smear results increased with severity of anemia (P for trend <0.01). Conclusion Baseline anemia is associated with increased risk for persistent positive sputum smears at two months of tuberculosis treatment. Future studies should evaluate the mechanisms for TB-associated anemia as well as the role of intervention for anemia among TB patients. PMID:24642636

Nagu, Tumaini J.; Spiegelman, Donna; Hertzmark, Ellen; Aboud, Said; Makani, Julie; Matee, Mecky I.; Fawzi, Wafaie; Mugusi, Ferdinand

2014-01-01

 
 
 
 
81

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

82

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

83

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

84

Mosquito control in Dar es Salaam. II. Impact of expanded polystyrene beads and pyriproxyfen treatment of breeding sites on Culex quinquefasciatus densities.  

Science.gov (United States)

In two contrasting areas of Dar es Salaam (Ilala and Mikocheni) all enclosed breeding sites of Culex quinquefasciatus, such as latrines and septic tanks, were treated with a floating layer of expanded polystyrene beads. 7 months later checks in both study areas revealed only one site (from which the polystyrene had been removed during emptying) containing immature stages of Cx quinquefasciatus. Open breeding sites such as areas of flooded land and blocked drains were treated with pyriproxyfen (an insect growth regulator) at a concentration of 0.1 ppm. Emergence of Cx quinquefasciatus adults from these sites was inhibited for 4 weeks during the rainy season and for up to 11 weeks during the dry season. The problem of mosquito breeding sites caused by bathroom sullage water was addressed through a combination of health education and indirect pressure from the Urban Malaria Control Project (UMCP) via local community leaders. Households responsible for these sites were encouraged to eliminate them by diverting the water into an enclosed drainage structure, usually a pit latrine. After two weekly visits 64.7% of households had complied and 93.4% had complied after five visits. 5 months later, only 15.7% had reverted to allowing sullage water to collect into puddles. Densities of Cx quinquefasciatus adults dropped by 76.7% in Mikocheni and by 46.2% in Ilala following intervention, but increased by 84.9% and 25.6% in two untreated comparison areas. The reasons for differential success of the combined interventions in the two treated areas are discussed. PMID:7787222

Chavasse, D C; Lines, J D; Ichimori, K; Majala, A R; Minjas, J N; Marijani, J

1995-04-01

85

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

86

Risky behaviours among young people living with HIV attending care and treatment clinics in Dar Es Salaam, Tanzania: implications for prevention with a positive approach  

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Full Text Available Introduction: Prevention with a positive approach has been advocated as one of the main strategies to reduce new instances of HIV infection. Risky sexual behaviours among people living with HIV/AIDS are the cornerstone for this approach. Understanding the extent to which infected individuals practice risky behaviours is fundamental in designing appropriate population-specific interventions. With the HIV infection transmission rates remaining high among young people in sub-Saharan Africa, continued prevention among them remains a priority. This study therefore seeks to describe the magnitude and determinants of risky sexual behaviours among young people living with HIV. Methods: A cross-sectional study was conducted between June and July 2010 in selected Care and Treatment Clinics (CTCs in Dar Es Salaam, Tanzania. A total of 282 HIV-positive patients aged 15–24 were interviewed about their sexual behaviours using a questionnaire. Results: Prevalence of unprotected sex was 40.0% among young males and 37.5% among young females (p<0.001. Multiple sexual partnerships were reported by 10.6% of males and 15.9% of females (p<0.005. More than 50% of the participants did not know about the HIV status of their sexual partners. A large proportion of participants had minimal knowledge of transmission (46.7% males vs. 60.4% females and prevention (65.3% males vs. 73.4% females of sexually transmitted infections (STIs. Independent predictors of condom use included non-use of alcohol [adjusted odds ratio (AOR, 0.40 95% confidence interval (CI; 0.17–0.84] and younger age (15–19 years (AOR, 2.76, 95% CI: 1.05–7.27. Being on antiretroviral therapy (AOR, 0.38, 95% CI: 0.17–0.85 and not knowing partners’ HIV sero-status (AOR, 2.62, 95% CI: 1.14–5.10 predicted the practice of multiple sexual partnership. Conclusions: Unprotected sex and multiple sexual partnerships were prevalent among young people living with HIV. Less knowledge on STI and lack of HIV disclosure increased the vulnerability and risk for HIV transmission among young people. Specific intervention measures addressing alcohol consumption, risky sexual behaviours, and STI transmission and prevention knowledge should be integrated in the routine HIV/AIDS care and treatment offered to this age group.

Aisa Mhalu

2013-10-01

87

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

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Full Text Available Abstract Background Sub-Saharan Africa has been severely affected by the HIV and AIDS pandemic. Global efforts at improving care and treatment has included scaling up use of antiretroviral therapy (ART. In Tanzania, HIV care and treatment program, including the provision of free ART started in 2004 with a pilot program at Muhimbili National Hospital in Dar es Salaam. This study describes the socio-demographic and clinical features of patients enrolled at the care and treatment clinic at MNH, Dar es Salaam, Tanzania. Methods A cross-sectional study looking at baseline characteristics of patients enrolled at the HIV clinic at MNH between June 2004 - Dec 2005 compared to those enrolled between 2006 and September 2008. Results Of all enrolled patients, 2408 (58.5% were used for analysis. More females than males were attending the clinic. Their baseline median CD4 cell count was low (136 cells/?l with 65.7% having below 200 cells/?l. Females had higher CD4 cell counts (150 cells/?l than males (109 cells/?l p Conclusion Patients enrolled to the MNH HIV clinic were predominantly females, and presented with advanced immune-deficiency. Improved access to HIV care and treatment services seems to be associated with patients' early presentation to the clinics in the course of HIV disease.

Swai Andrew B

2010-05-01

88

‘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  

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

89

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

90

Homeowner's Architectural Responses to Crime in Dar Es Salaan : Its impacts and implications to urban architecture, urban design and urban management  

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HTML clipboardThis study is about Homeowner’s architectural responses to crime in Dar es Salaam Tanzania: its impacts and implications to urban architecture, urban design and urban management. The study explores and examines the processes through which homeowners respond to crimes of burglary, home robbery and fear of it using architectural or physical elements. The processes are explored and examined using case study methodology in three cases in Dar es Salaam. The cases are resident...

Bulamile, Ludigija Boniface

2009-01-01

91

New tools for public participation in urban planning - a case from Dar es Salaam  

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Full Text Available

Public Participation GIS har i efterhånden en del år været foreslået som et relevant redskab for bedre byplanlægning også i de hastigt voksende storbyer i udviklingslandene. Der synes dog ikke at være så mange eksempler på, at PPGIS er velintegreret i planprocessen. Denne artikel handler om nye tekniske muligheder for fælles kortlægning, registrering og deling af geografiske informationer gennem web-baserede services som f.eks. ArcGIS-Online. Vil sådanne kunne tages i anvendelse af berørte borgere og medvirke til en bedre byplanprocess og en forbedret retslig stilling for storbyens marginaliserede grupper, sådan som det har været foreslået?

Juma R Kiduanga

2012-04-01

92

Risk Factors of Surgical Site Infection at Muhimbili National Hospital, Dar es Salaam, Tanzania  

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Surgical site infection (SSI) is a common source of morbidity among operated patients. At Muhimbili National Hospital (MNH), studies indicate that the rate of SSI has been increasing over the past thirty years. The aim of this study was to determine the prevalence and factors associated with SSI among patients undergoing surgery at MNH. This was a hospital-based cross-sectional study. One hundred and eighteen patients who underwent surgical procedures in the surgical wards were recruited. Dem...

Akoko, L. O.; Mwanga, A. H.; Fredrick, F.; Mbembati, N. M.

2012-01-01

93

Factors Influencing Exclusive Breastfeeding Among HIV Positive Mothers at Ilala Municipality Dar es Salaam  

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Exclusive breast feeding practices to infants from birth to six months of age are declining as their age increases despite the associated benefits. Knowledge on the factors influencing exclusive breastfeeding among HIV positive mothers will create awareness on feeding practices that are risk to the infant’s health. To determine factors that influence exclusive breastfeeding among HIV positive mothers of infants aged 6-12 months old attending Reproductive and child Health clinic and care and...

Saka, Florence Jairus

2012-01-01

94

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

95

Urban Agriculture and Operational Mosquito Larvae Control: Mitigating Malaria Risk in Dar es Salaam, Tanzania  

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Global commitment, political will and financial support to reduce the burden of malaria, a disease which kills about one million people each year, have reached an unprecedented level. Although global malaria eradication appears to be a distant goal, there are promising efforts towards regional control and local elimination of the disease. Sub-Saharan Africa (SSA) is the region with the world’s highest malaria burden, as well as the world’s fastest growing cities. Rapid urbanisation brings...

Dongus, Stefan

2009-01-01

96

Anaemia in women of reproductive age in Tanzania : A study in Dar es Salaam  

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The overall aims of the study were to determine the prevalence of anaemia in women of reproductive age and to investigate the underlying causes, as well as assess the effectiveness of antenatal care (ANC) interventions for anaemia prevention. Consecutive pregnant women booking for ANC (n=2235) were screened for anaemia, followed up and screened again late in pregnancy. Basic ANC interventions included iron and folate supplementation, malaria chemoprophylaxis and referral of severe anaemia cas...

Massawe, Siriel Nanzia

2002-01-01

97

Ecology and Epidemiology of Integrated Malaria Vector Management in Dar es Salaam, Tanzania  

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Malaria remains one of the major contributors to the global burden of disease with approximately 70% of the clinical malaria attacks occurring in sub-Saharan Africa. Sub- Saharan Africa has the highest risk as ideal climatic conditions for transmission coincide with occurrence of some of the most efficient malaria vectors, namely Anopheles gambiae s.s., Anopheles arabiensis and Anopheles funestus.. Even though it is estimated that by the year 2030 more than 50% of the African population will ...

Geissbu?hler, Yvonne

2008-01-01

98

Risky sexual practices among youth attending a sexually transmitted infection clinic in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Youth have been reported to be at a higher risk of acquiring STIs with significant adverse health and social consequences. Knowledge on the prevailing risky practices is an essential tool to guide preventive strategies. Methods Youth aged between 18 and 25 years attending an STI clinic were recruited. Social, sexual and demographic characteristics were elicited using a structured standard questionnaire. Blood samples were tested for syphilis and HIV infections. Urethral, high vaginal and cervical swabs were screened for common STI agents. Results A total of 304 youth were studied with mean age of 21.5 and 20.3 years for males and females respectively. 63.5% of youth were seeking STI care. The mean age of coitache was 16.4 and 16.2 years for males and females respectively. The first sexual partner was significantly older in females compared to male youth (23.0 vs 16.8 years (p Conclusion Most female youth seen at the STI clinic had their first sexual intercourse with older males. Youth were engaging in high risk unprotected sexual practices which were predisposing them to STIs and unplanned pregnancies. There is a great need to establish more youth-friendly reproductive health clinics, encourage consistent and correct use of condoms, delay in sexual debut and avoid older sexual partners in females.

Mhalu F

2008-11-01

99

Avoidaee Perinatal Deaths as Seen at Muhimbili National Hospital, Dar-es-Salaam Tanzania.  

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In developing countries perinatal mortality is still very high and remains a challenge in the care of pregnant women. In a poor resource country like Tanzania knowing the avoidable causes of perinatal deaths can greatly have an impact on perinatal mortality and designing effective and measurable interventions with the available resources. To determine factors contributing to avoidable perinatal death at Muhimbili National Hospital from 1st November 2006 to 31st January 2007. This was a cross ...

Marandu, Simon

2007-01-01

100

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)

 
 
 
 
101

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

102

Managing Disposal of Unwanted Pharmaceuticals at Health Facilities in Tanzania: A Case of Dar es salaam Region Public Health Facilities  

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In the public sector medicines are the property of the state, for which strict accounting procedures to write-off the unwanted pharmaceutical stock are necessary (Public Finance Act & Regulations, 2004). This applies both to medicines that are procured through the normal channels and to donated medicines. For quite a long time, disposal of unwanted medicines e.g. especially expired pharmaceuticals in the country has not been done systematically and professionally due to a number of factors th...

Matiko, Damas

2011-01-01

103

Clinical and Echocardiographic Findings of Left Ventricular Diastolic Dysfunction Among Hypertensive Patients at Muhimbili National Hospital, Dar es Salaam  

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Hypertension is the commonest of the cardiovascular risk factors, whose prevalence in Tanzania is high between 20-30%, among rural and urban residents respectively. Uncontrolled hypertension leads to a number of structural changes in the heart which eventually cumulates into interstitial fibrosis, myocardial wall thickness and functional alteration such as diastolic dysfunction. Diastolic dysfunction is thought to be responsible for as many as 74% of cases of HF in hypertensive patients. Desp...

Sanga, Tulizo Shemu

2012-01-01

104

Equity in access to health care provision under the medicare security for small scale entrepreneurs in Dar es Salaam.  

Science.gov (United States)

The main objective of this study was to assess equity in access to health care provision under the Medicare Security for Small Scale Entrepreneurs (SSE). Methodological triangulation was used to an exploratory and randomized cross- sectional study in order to supplement information on the topic under investigation. Questionnaires were administered to 281 respondents and 6 Focus Group Discussions (FGDs) were held with males and females. Documentary review was also used. For quantitative aspect of the study, significant associations were measured using confidence intervals (95% CI) testing. Qualitative data were analyzed with assistance of Open code software. The results show that inequalities in access to health care services were found in respect to affordability of medical care costs, distance from home to health facilities, availability of drugs as well as medical equipments and supplies. As the result of existing inequalities some of clients were not satisfied with the provided health services. The study concludes by drawing policy and research implications of the findings. PMID:23120940

Urassa, J A E

2012-03-01

105

Prevalence and Factors Associated with Overweight and Obesity Among Primary School Children in Kinondoni District, Dar-es-salaam  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Urban Tanzania is currently experiencing nutrition transition- a globalization-related phenomenon that entails the progressive displacement of traditional diets richer in nutrients, in favour of the consumption of unhealthy foods; heavy in added sugar, saturated fat, and sodium and an increase in sedentary life style. Despite these trends little is known about childhood obesity in Tanzania. This study intended to determine prevalence of and factors associated with overweight and obesity among...

Mwaikambo, Sijenunu A.

2012-01-01

106

The Prevalence of Posttraumatic Stress Disorder and Associated Mental Health Problems Among Institutionalized Orphans in Dar es salaam, Tanzania  

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Orphanhood is becoming a more common experience for children in Tanzania, in part as a consequence of the AIDS pandemic, trauma and poverty. The number of orphans and risk of psychopathology has been steadily increasing even in regions where the AIDS epidemic has stabilized. Institutional care for orphaned children is uncommon in sub-Sahara Africa and seen as a last resort primarily as orphanages are often seen as a source of unhealthy psychological development and orphans’ ability to survi...

Myovela, Benjamin

2012-01-01

107

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

Directory of Open Access Journals (Sweden)

Full Text Available Abstract 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. Among these, 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

2008-07-01

108

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...

Janson, Johanna; Waka?ng, Emmy

2011-01-01

109

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

DEFF Research Database (Denmark)

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

110

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

Directory of Open Access Journals (Sweden)

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

111

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

Energy Technology Data Exchange (ETDEWEB)

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

112

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

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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...

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

2011-01-01

113

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

114

HIV Related Stigma, Depressive Morbidity and Treatment Adherence in Patients on Antiretroviral Therapy Attending the Mwanayamala Hospital, Dar es salaam  

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There are about 33 million people who are living with HIV and AIDS worldwide and approximately 67% are in sub Saharan African countries. In Tanzania 2 million people are living with HIV/AIDS and 30% of them are in need of antiretroviral treatment. Several studies highlighted some psychological experiences in people living HIV/AIDS including feelings of shame, guilt, helplessness, self-blame and self-isolation that suggest negative self-image and this negative self-image has influence on acces...

Rutayuga, Theonest

2011-01-01

115

Growth and Pubertal Development Among HIV Infected Children Aged 8-18 years in Dar es Salaam  

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Advances in management of HIV-infected infants and children have been remarkable, majority of infected children are now surviving into adolescence. Several studies have shown that growth and pubertal development is often impaired among children with HIV and AIDS. Abnormalities include early deficits in height and weight, and delay in skeletal maturation. Onset of menarche and pubertal development are also delayed. The magnitudes of delayed puberty among HIV infected children in Tanzania have ...

Mbwile, Gloria Reginald

2012-01-01

116

Nutritional support and care services for urban adult people living with HIV/AIDS :a case study from Dar es Salaam, Tanzania  

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It is well known that nutritional status plays an important role in preventing opportunisticinfections as it improves immunity system. Not so rnuch is known about how people livingwith HTV/AIDS manage their nutrition and thc difficulties encountered in accessing supportand other services necessary for maintaining their nutrition and health and improve quality ofli fe.In this study, persons with HIVIAIDS wcre asked to tell about nutrition support and careservices provided by both formal and in...

Mwapili, Neema Joshua

2006-01-01

117

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

Directory of Open Access Journals (Sweden)

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

118

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

119

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

Directory of Open Access Journals (Sweden)

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

120

Perceptions and beliefs on tuberculosis and the influence on health seeking behaviour. A qualitative study in Kinondoni district, Dar es Salaam.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background and goal Tuberculosis (TB) is one of the major health problems in the world. Early passive case detection and high treatment compliance is important for obtaining a successful TB control. One of the factors early case detection relies on is the human factor. The suspected TB case needs to recognize symptoms of TB and value them serious enough to report at a professional health facility. Cough for more than two weeks is considered to be TB suspect. The main goal of early case de...

Knutsen, Anne Kari

2010-01-01

 
 
 
 
121

Compliance to Occupational and Public Health Requirements and Associated Factors in Barbershops and Hair Dressing Salons, A Case of kinondoni Municipality, Dar es Salaam, Tanzania  

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Hairdressing and barbering industry is one of occupations which employ significant number of young men and women. This population can be exposed to number of occupational problems such as poor posture, joint pain, prolonged standing, long working hours, missed meals, as well as being subjected to physical injuries. These problems can be reduced if barbershops and hair dressing salons are highly complying with occupational and public health regulatory and operational requirements (OHS and PH) ...

Nshunju, Raphael Kyalakishaija

2012-01-01

122

IISD RS @ Fourth International Conference on Community-Based Adaptation to Climate Change - 25-27 February 2010 - Dar es Salaam - Tanzania  

...participants convened for a final day at the Fourth International Conference on CBA to Climate Change. In the morning, participants met in ...then met in a final session to chart the way forward on CBA activities, including the work to further develop the Global Initiative ... Friday, 26 February The Fourth International Conference on Community-Based Adaptation (CBA) to Climate Change went into its third day on Friday, 26 ...plenary session that focused on the scaling up and replication of best CBA practices. They also met in parallel thematic sessions on: ...

123

Ready to Use Therapeutic Foods (RUTF) improves undernutrition among ART-treated, HIV-positive children in Dar es Salaam, Tanzania  

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Abstract Background HIV/AIDS is associated with an increased burden of undernutrition among children even under antiretroviral therapy (ART). To treat undernutrition, WHO endorsed the use of Ready to Use Therapeutic Foods (RUTF) that can reduce case fatality and undernutrition among ART-naïve HIV-positive children. However, its effects are not studied among ART-treated, HIV-positive children. Therefore, we examined the association between RUTF use with underweight, wasting, ...

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

2012-01-01

124

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  

Directory of Open Access Journals (Sweden)

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

125

El biocontrol de Pseudomonas chlororaphis PCL1606 es debido al compuesto antifúngico producido por los genes dar  

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Pseudomonas chlororaphis PCL1606 es una rizobacteria con capacidad de biocontrol frente a Rosellinia necatrix, agente causal de la podredumbre radicular blanca y Fusarium oxysporum f. sp. radicis-lycorpersici, que causa la podredumbre de cuello y raices de las plantas de tomate. Esta bacteria se caracteriza por la producción del antibiótico antifúngico 2-hexil, 5-propil resorcinol (HPR). Para determinar las bases genéticas de la producción de HPR en P. chlororaphis PCL1606, se rastre?...

Caldero?n, Claudia E.; Carrio?n, Vi?ctor J.; Bonilla, Nuria; Vicente, Antonio; Cazorla, Francisco M.

2013-01-01

126

Prevalence of the Human Immunodeficiency Virus, other Sexually Transmitted Infections, and Health-Related Perceptions, Reflections, Experiences and Practices among Men having Sex with Men in Dar es Salaam  

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Men who have sex with Men (MSM) have been reported to be at higher risk of transmission and acquisition of HIV and other sexually transmitted infections (STI). Studies on HIV prevalence among MSM conducted in various African countries have revealed prevalence rates which are higher (2-20 times) than that of the general population. HIV-related research and programming in many parts of Africa including Tanzania have often failed to address anal sex in general and male-to-male penile-anal sex in...

Leshabari, M. T.; Mmbaga, Elia J.; Mpembeni, Rose; Moen, Kare

2013-01-01

127

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  

Directory of Open Access Journals (Sweden)

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

128

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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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...

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

2009-01-01

129

BOOKMARKS:  

to the staff of the Swedish Embassy in Dar es Salaam for assisting with the arrangements for ...the commissioning donors and interviews with key stakeholders in Dar es Salaam and outside. ...An inception visit to Dar es Salaam took place in early December 2009 to brief commissioning donors,

130

La "capacidad vial" del plan regulador chileno, ¿es lo suficientemente buena para dar forma a un entorno edificado sostenible?/ The "road capacity" of the chilean master plan is it good enough for shaping a sustainable built environment?  

Directory of Open Access Journals (Sweden)

Full Text Available The "road capacity" of the Chilean Master Plan is a tool developed to measure the capacity of streets in terms of supporting the size of vehicle flow. This tool considers topics such as land use, population density and street width. The purpose of this technique is to incorporate it to the Master Plan, as a town planning instrument, so as to cope with traffic forecasting and congestion. However, the technique does not embrace any sustainability concept, this is due to a disregard of any district ´s social or environmental needs. Therefore a sustainable urban development would doubtfully be reached. It is argued that some other approaches are required for shaping a sustainable built environment in which it is understood that the streets are a public space for people rather than a platform for moving vehicles only. This means, to promote accessibility as well as mobility. In this paper the author reviews borrowed concepts such as "carrying capacity" and "environmental capacity" from bioregionalist and ecological disciplines using a case study in outskirts of Santiago´s metro area./La "capacidad vial" del Plan Regulador chileno es una herramienta desarrollada para medir la capacidad de las calles en términos de apoyar el tamaño del flujo de vehículos. Esta herramienta considera temas como el uso de la tierra, la densidad de población y ancho de la calle. El propósito de esta técnica es su incorporación al Plan Maestro, como un instrumento de planificación de la ciudad, con el fin de hacer frente a la previsión del tráfico y la congestión. Sin embargo, la técnica no incluye ningún concepto de sostenibilidad. Por lo tanto un desarrollo urbano sostenible dudosamente sería alcanzado. Se argumenta que algunos otros enfoques son necesarios para dar forma a un medio ambiente sostenible integrado, en el que se entiende que las calles son un espacio público para las personas en lugar de una plataforma para mover los vehículos solamente. Esto significa, para promover la accesibilidad y la movilidad. En este trabajo la autora revisa conceptos prestados, tales como "la capacidad de carga" y "capacidad ambiental", desde el bioregionalist y disciplinas ecológicas mediante un estudio de caso en las afueras del área metropolitana de Santiago de Chile.

Cárdenas Jirón, Luz Alicia

2000-03-01

131

Evaluation  

CIP CSO DAC DAR DeNRM DESEMP ...UKAid Development Partner Group Democratic Republic of Congo Dar es Salaam Reliability of Power Supply exempli gratia ( ...instituutti (SDI), tietoyhteiskun- nan ja tieto-ja viestintätekniikkasektorin kehityshanke TANZICT, Dar es Salaamin

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Dar olhando a quem: estudo sobre o Projecto "Todo Homem é Meu Irmão" / Donner en regardant à qui on donne: Étude sur le projet "Tout homme est mon frère" / Do give looking at whom: Study on the project "Every man is my brother" / Dar mirando a quién: estudio acerca del Proyecto "Todo hombre es mi hermano"  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Portuguese Abstract in portuguese Este documento analisa o fenómeno da dádiva, através de um estudo de caso observado num diário português - o Jornal de Notícias. Este jornal acolhe, há várias décadas, o Projecto "Todo Homem é Meu Irmão". Este trabalho avalia quais os factores responsáveis pelos diferentes valores atribuídos aos dif [...] erentes beneficiários desse projecto. Conclui que são factores positivos a duração do pedido nas edições do jornal e o número de dependentes a cargo dos beneficiários. Conclui que são factores negativos a presença do beneficiário em categorias de rendimento superior assim como a autonomia de mobilidade. Os resultados mostram que o fenómeno da dádiva é complexo onde entram também, com influência, as características endógenas do beneficiário, para lá das dimensões que a literatura apontou previamente. Abstract in spanish Este documento analiza el fenómeno de la dádiva a través de un estudio de caso observado en un periódico portugués - el Jornal de Notícias. Ese periódico contiene, hace varias décadas, el Proyecto "Todo hombre es mi hermano". Este trabajo evalúa cuáles son los factores responsables por los diferente [...] s valores atribuidos a los distintos beneficiarios de ese proyecto. Se concluye que son factores positivos la duración del pedido en las ediciones del periódico y el número de dependientes a cargo de los beneficiarios. Además se concluye que son factores negativos la presencia del beneficiario en categorías de rendimiento superior así como la autonomía de movilidad. Los resultados muestran que el fenómeno de la dádiva es complejo donde entran también, con influencia, las características endógenas del beneficiario para más allá de las dimensiones que la literatura señaló previamente. Abstract in english This paper analyzes the gift phenomenon observing data from the Project "Every Man is my brother" (or Todo Homem é Meu Irmão). This Project has been supported by the Portuguese newspaper Jornal de Notícias for more than 30 years. This work evaluates which determinants influence the values given to e [...] ach case. This work concluded that the number of weeks for exposing each case in the pages of the newspaper and the number of children supported by each beneficiary positively influence the values that were given to this beneficiary. Higher individual incomes and self-mobility negatively influence the values that were given. These results show that the gift phenomenon is rather complex and it is also influenced by the endogenous characteristics of each receiver.

Paulo, Reis Mourão.

2013-07-01

133

WATER-L NEWS #4.pdf  

6 BILLION ON WATER PROJECTS, Business Times (Dar es Salaam), May 30, 2003 11) ...May 30, 2003 46) NILE BASIN POWER PROJECT LAUNCHED, Business Times (Dar es Salaam), May 30, ...None failed, but the citizens within the five cities rated poor Alburquerque, Boston,

134

Dar sem (se) perder  

Scientific Electronic Library Online (English)

Full Text Available SciELO Portugal | Language: Portuguese Abstract in portuguese Este estudo pretende fazer uma breve referência histórica sobre o parto através dos tempos e das culturas e o modo como ele foi sendo vivido. Actualmente e na nossa sociedade, o parto decorre geralmente em contexto hospitalar e é considerado maioritariamente um acto médico. Dada a difusão generaliza [...] da da utilização do analgésico epidural em partos eutócicos, pretendemos dar um contributo para a compreensão psicólogica do pedido ou da adesão à sugestão dos técnicos de saúde, da aplicação deste analgésico. Quais as razões expressas por puérperas face à utilização do analgésico epidural durante o parto? É esta a principal questão deste estudo exploratório. Abstract in english This is a brief historical review of the attitudes toward child labour throughout time and cultures. Labour nowadays is carried out in a hospital context, and it is considered mainly as a medical act. The epidural analgesic is now common in childbirth, and we discuss the psychological aspects of the [...] request for this analgesic and the attitudes towards the suggestions of the health technicians. Which are the reasons that parturient women invoke in relation to epidural analgesic through labour? This is the main question of this exploratory study.

Maria José, Gil.

135

Policy Innovation Systems for Clean Energy Security (PISCES)  

May 23, 2012 ... In Africa Bioenergy contribute up to. 80% of energy ... Studies, Nairobi. • Main \\Partners - University of Dar es. Salaam, Practical Action ... (A) = Adaptive \\Capacity. UKERC-PISCES .... water, land, soil, biodiversity and climate ...

136

Application of basic pharmacology and dispensing practice of antibiotics in accredited drug-dispensing outlets in Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OM Minzi,1 VS Manyilizu21Unit of Pharmacology and Therapeutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania, 2Logistics System Strengthening Unit, John Snow Inc, Dar es Salaam, TanzaniaBackground: Provision of pharmaceutical services in accredited drug-dispensing outlets (ADDOs) in Tanzania has not been reported. This study compared the antibiotics dispensing practice between ADDOs and part II shops, or duka la dawa baridi (DLDBs), in Tanzan...

Om, Minzi; Vs, Manyilizu

2013-01-01

137

LiDAR as a Web Service  

Digital Repository Infrastructure Vision for European Research (DRIVER)

LiDAR(Light Detection And Ranging) is a device, which works in a similar way as radar, but instead of radio waves, it uses light. We can use it as a mean to detect particles in the air (mainly air polution particles) or for measuring weather conditions. LiDAR with other supporting elements forms LiDAR system. In our example LiDAR system will be used remotely, in particular by remote user. Goals: a) To plan and project protocol for exchanging messages between client (user, costumer) and ...

Balija, Damir

2011-01-01

138

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

139

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

140

OBJECT RECONSTRUCTION FROM LiDAR POINTS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cilj diplomskega dela je rekonstruirati 3D model objekta (v našem primeru cerkve) s pomo?jo to?k, pridobljenih z laserskim prebirnikom LiDAR (ang. Light Detection and Ranging). V prvem delu diplomske naloge predstavimo tehnologijo LiDAR ter opišemo datote?ni format LAS, ki predstavlja standardni zapis podatkov LiDAR. V drugem podamo ve? tehnik geometrijskega modeliranja, pri ?emer podrobneje predstavimo najpogosteje uporabljene gradnike in funkcijonalnosti. V tem delu se osredoto?imo...

S?krabl, Marko

2011-01-01

 
 
 
 
141

Deformation monitoring and modeling based on LiDAR data for slope stability assessment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Lockergesteinssedimente reagieren mit zeitabhängigen Deformationen, wenn sie durch Einschnitte entlastet werden. Diese Zeitabhängigheit stellt eine Herausforderung, wenn es um die stabilitätsbewertung geht. Böschungsbrüche und Bodensenkungen beispielsweise werden nicht nur durch tiefgreifende Bauvorhaben und Bergbauaktivitäten ausgelöst, sondern auch durch geologische Setzungsprozesse. Sie stellen ein Problem dar, welches sich negativ auf die Umwelt, die Sicherheit des Menschen und die...

Hu, Hui

2013-01-01

142

Direct Georeferencing of Stationary LiDAR  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

143

Qué es la ética económica  

Directory of Open Access Journals (Sweden)

Full Text Available Al observar la renuencia de muchos practicantes de la actividad empresarial para emplear la palabra ética o tan siquiera para estar dispuestos a discutir sobre ética, en este ensayo se hace un esfuerzo por definir lo que debería ser la ética económica y empresarial. Se sugiere el énfasis sobre una “nueva práctica”, un enfoque que reconoce la prioridad de la practica sobre la teoría. El  centro de atención esta en el mejoramiento de la calidad ética al tomar decisiones y al emprender acciones. Debe distinguirse tres niveles: el nivel micro o del individuo, el meso o nivel de las firmas y organizaciones, y el nivel macro de las economías nacionales y transnacionales. También deben considerarse tres grupos de valores: personales, colectivos y generales. Siempre debe tenerse en mente las inter-relaciones entre estos niveles y valores. Se precisa de un modelo de cooperación entre la economía y la ética que pueda superar los problemas del idealismo o de reducir la ética a un aparato instrumental. Un enfoque basado en la toma de decisiones ofrece la mayor de las promesas. Al  mismo tiempo, debe enfrentarse el problema del pluralismo, problema que sólo podrá ser resuelto encontrando un consenso superpuesto. Lo simple de la pregunta -¿qué es la ética económica?- va de la mano con la dificultad de dar una respuesta clara y comprehensiva. Es sumamente confuso, colorido y variado lo que hoy se escucha en nombre de la “ética económica y empresarial”. Abundan las expectativas múltiples, e incluso contradictorias en este campo. Si bien soy muy consciente de estos problemas tratare, sin embargo, de dar algunas respuestas provisionales y, con suerte, aclaratorias a nuestra pregunta simple. Ellas tienen el color personal, influenciado por mi experiencia europeo-occidental, e inspiradas por mi esperanza de que los esfuerzos en el campo de la ética económica contribuyan a hacer frente a los grandes retos de nuestro tiempo de manera más inteligente y efectiva. Desde una perspectiva descriptiva y analítica, podríamos preguntar qué es, en realidad, la ética económica y empresarial aquí, en este país o en otros países del mundo. No lo voy a hacer, pues ya hay muchos artículos que resumen la situación de varios países (De George, 1987; Enderle, 1988 y 1991; Mahoney, 1990; Steinmann ylohr, 1991; van Luijk, 1990; y otros. Más bien, discutiré el tema de lo que debe ser la ética económica y empresarial y cómo puede esto justificarse.

Georges Enderle

1993-06-01

144

Direct Georeferencing of Stationary LiDAR  

Directory of Open Access Journals (Sweden)

Full Text Available 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 within the scanning range is not always possible. Also, field procedure can be laborious and involve extra equipment and target setups. In addition, the conventional method allows for possible human error due to target information bookkeeping. Additionally, the accuracy of this procedure varies according to the quality of the control used. By adding a dual GPS antenna apparatus to the scanner setup, thereby supplanting the use of multiple ground control points scattered throughout the scanning site, we mitigate not only the problems associated with indirect georeferencing but also induce a more efficient set up procedure while maintaining sufficient precision. In this paper, we describe a new method for determining the 3D absolute orientation of LiDAR point cloud using GPS measurements from two antennae firmly mounted on the optical head of a stationary LiDAR system. In this paper, the general case is derived where the orientation angles are not small; this case completes the theory of stationary LiDAR direct georeferencing. Simulation and real world field experimentation of the prototype implementation suggest a precision of about 0.05 degrees (~1 milli-radian for the three orientation angles.

Ahmed Mohamed

2009-12-01

145

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

146

User's manual of the MKENO-DAR code system  

International Nuclear Information System (INIS)

The computer code manual of MKENO-DAR which is a direct angular representation Monte Carlo code for criticality safety analysis is already issued as JAERI-M report, however, complex pre-stage data handlings and calculations by auxiliary programs are required before the execution of MKENO-DAR. The MKENO-DAR CODE SYSTEM widely spans a whole code system including MKENO-DAR and other pre-stage auxiliary programs. This report discusses the systematic treatment of the MKENO-DAR CODE SYSTEM and shows the simplified calculation technique from the user side of view. (author)

147

¿Cu?l es el sentido de la historia?  

Directory of Open Access Journals (Sweden)

Full Text Available En este texto se hace un repaso de la constitución de la historia y la historiografía y del planteamiento de algunos filósofos (de Voltaire a Fukuyama sobre este proceso constitutivo. El hilo conductor que sigue el texto pretende dar respuesta a la pregunta: ¿cuál es el sentido de la historia?Hacia el final, el autor ensaya una respuesta a la pregunta planteada desde la perspectiva de los países periféricos. Palabras claves: Historia, historiografía, fin de la historia, Occidente.

Javier Aldama Pinedo

2011-05-01

148

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

149

Aplicación del LiDAR aerotransportado a la determinación de la altura de grandes estructuras. Caso de estudio: Presas / Application of Airborne LiDAR to the Determination of the Height of Large Structures. Case Study: Dams  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish La mejor forma de calcular la altura de una presa es realizar una nivelación geométrica de precisión. No obstante, este método es demandante y costoso. La precisión de los datos obtenidos ha mejorado sustancialmente, esta tecnología puede proveer precisiones de 2 a 3 centímetros, más que suficiente [...] para determinar la altura de presa y utilizar ésta como dato de partida para cualquier actividad posterior que así lo requiera. La densidad de adquisición de los datos LiDAR (Light Detection and Ranging) es importante para establecer la bondad de los resultados. Finalmente, como los sistemas LiDAR aerotransportados están basados en alturas elipsoidales, es necesario transformarlas a ortométricas. Este trabajo muestra los resultados obtenidos usando un LiDAR de baja densidad (0.5 pts/m²) y su validación con observaciones GPS (Global Positioning System) en postproceso. Los resultados demuestran que se puede obtener una precisión del orden de 10-25 cm, suficiente para la mayoría de las actividades relacionadas con la ingeniería civil. Abstract in english The best way to determine the height of dams is to level the top of the dam applying a geometric leveling. Nevertheless this task is very demanding and expensive. The accuracy potential of LiDAR (Light Detection and Ranging) data has significantly improved. These systems can provide accuracy of 2-3 [...] cm level, which could be enough to be applied in the determination of the height of dams. The point acquisition density is an important factor involved in the process of determining the height using LiDAR technique. Finally, since the LiDAR technique is based on ellipsoidal heights, the coordinates must be transformed to the official orthometric system. This paper shows the results obtained using low density airborne LiDAR data (0.5 pts/m²) and their validation with post-processed GPS (Global Positioning System) observations. Test results have shown LiDAR can be accurate enough (10-25 cm) to determine the height and to be applied in many civil engineering activities.

Rubén, Martínez Marín; Juan Gregorio, Rejas Ayuga; Miguel, Marchamalo Sacristán.

2014-03-01

150

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

151

LiDAR Utility for Natural Resource Managers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Applications of LiDAR remote sensing are exploding, while moving from the research to the operational realm. Increasingly, natural resource managers are recognizing the tremendous utility of LiDAR-derived information to make improved decisions. This review provides a cross-section of studies, many recent, that demonstrate the relevance of LiDAR across a suite of terrestrial natural resource disciplines including forestry, fire and fuels, ecology, wildlife, geology, geomorphology, and surface ...

Alistair Matthew Stuart Smith; Andrew Thomas Hudak; Jeffrey Scott Evans

2009-01-01

152

Storage, manipulation, and visualization of LiDAR data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In recent years, three-dimensional (3D) data has become increasingly available, in part as a result of significant technological progresses in Light Detection and Ranging (LiDAR). LiDAR provides longitude and latitude information delivered in conjunction with a GPS device, and elevation information generated by a pulse or phase laser scanner, which together provide an effective way of acquiring accurate 3D information of a terrestrial or manmade feature. The main advantages of LiDAR over conv...

Scho?n, Bianca; Bertolotto, Michela; Laefer, Debra F.; Morrish, Sean

2009-01-01

153

DAR: A Modern Institutional Repository with a Scalability Twist  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Digital Assets Repository (DAR) is an Institutional Repository developed at the Bibliotheca Alexandrina to manage the full lifecycle of a digital asset: its creation and ingestion, its metadata management, storage and archival in addition to the necessary mechanisms for publishing and dissemination. DAR was designed with a focus on integrating DAR with different sources of digital objects and metadata in addition to integration with applications built on top of the repository. As a modern...

Mikhail, Youssef Bibliotheca Alexandrina; Adly, Noha Bibliotheca Alexandrina; Nagi, Magdy Bibliotheca Alexandrina

2012-01-01

154

LiDAR Utility for Natural Resource Managers  

Directory of Open Access Journals (Sweden)

Full Text Available Applications of LiDAR remote sensing are exploding, while moving from the research to the operational realm. Increasingly, natural resource managers are recognizing the tremendous utility of LiDAR-derived information to make improved decisions. This review provides a cross-section of studies, many recent, that demonstrate the relevance of LiDAR across a suite of terrestrial natural resource disciplines including forestry, fire and fuels, ecology, wildlife, geology, geomorphology, and surface hydrology. We anticipate that interest in and reliance upon LiDAR for natural resource management, both alone and in concert with other remote sensing data, will continue to rapidly expand for the foreseeable future.

Alistair Matthew Stuart Smith

2009-11-01

155

"The Dar Hamid Sons' Union". Understanding Political Development Among The Dar Hamid Agro-Pastoralists In North Kordofan, Sudan  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main theme In this thesis I explore the mobilization of a particular civil society organization among the Dar Hamid agro pastoralist people in northern Kordofan, western Sudan . The analysis is based upon information gathered from people living in the Dar Hamid homeland in northern Kordofan , and among Dar Hamid association elites in Khartoum. The fieldwork period was between June and December 2011. The mobilization of civil society organizations in the Sudan has been and continues...

Awadelseed, Adil

2012-01-01

156

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...

Donge, J. K.

1993-01-01

157

Processing LiDAR Data to Predict Natural Hazards  

Science.gov (United States)

ELF-Base and ELF-Hazards (wherein 'ELF' signifies 'Extract LiDAR Features' and 'LiDAR' signifies 'light detection and ranging') are developmental software modules for processing remote-sensing LiDAR data to identify past natural hazards (principally, landslides) and predict future ones. ELF-Base processes raw LiDAR data, including LiDAR intensity data that are often ignored in other software, to create digital terrain models (DTMs) and digital feature models (DFMs) with sub-meter accuracy. ELF-Hazards fuses raw LiDAR data, data from multispectral and hyperspectral optical images, and DTMs and DFMs generated by ELF-Base to generate hazard risk maps. Advanced algorithms in these software modules include line-enhancement and edge-detection algorithms, surface-characterization algorithms, and algorithms that implement innovative data-fusion techniques. The line-extraction and edge-detection algorithms enable users to locate such features as faults and landslide headwall scarps. Also implemented in this software are improved methodologies for identification and mapping of past landslide events by use of (1) accurate, ELF-derived surface characterizations and (2) three LiDAR/optical-data-fusion techniques: post-classification data fusion, maximum-likelihood estimation modeling, and hierarchical within-class discrimination. This software is expected to enable faster, more accurate forecasting of natural hazards than has previously been possible.

Fairweather, Ian; Crabtree, Robert; Hager, Stacey

2008-01-01

158

Freezing human ES cells.  

Science.gov (United States)

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 colonies from the plate surface. Trypsinized cells are placed in a standard conical tube containing pre-warmed hES cell media to quench remaining trypsin, and then spun. Cells are resuspended growth media at a concentration of approximately one million cells in one mL of media, a concentration such that one frozen aliquot is sufficient to resurrect a culture on a 10 cm plate. After cells are adequately resuspended, ice cold freezing media is added at equal volume. Cell suspensions are mixed thoroughly, aliquoted into freezing vials, and allowed to slowly freeze to -80 C over 24 hours. Frozen cells can then moved to the vapor phase of liquid nitrogen for long term storage, or remain at -80 for approximately six months. PMID:18704182

Trish, Erin; Dimos, John; Eggan, Kevin

2006-12-01

159

¿Es posible matizar el individualismo de John Locke?  

Directory of Open Access Journals (Sweden)

Full Text Available El interrogante del que este artículo pretende dar cuenta es si el individualismo de John Locke responde a la radicalidad con la que la corriente de interpretación más difundida intenta caracterizarlo. La conclusión que se alcanza luego de una amplia presentación de pruebas textuales, es que la necesaria matización del individualismo se deriva de la insistencia del autor en justificar el origen divino de los derechos y deberes. De este modo, en la medida en que se niegue que los hombres disponen de un derecho irrefrenable a seguir su deseo de autopreservación, es posible concluir que el Estado no existe para resguardar esos presuntos derechos individuales, sino para restaurar la ley de naturaleza que ya no sirve, como debería, para determinar los derechos y deberes de los hombres.

Diego A. Fernández Peychaux

2011-12-01

160

DETERMINATION OF UNCOVERED TERRAIN PARTS IN LiDAR DATA  

Digital Repository Infrastructure Vision for European Research (DRIVER)

LiDAR is an advance tehnology of a remote sensing, which allows fast and accurate acquisition of the data from the Earth's surface with the help of a laser beam. The laser beam reflects poorly from the areas covered with water. Also, various obstacles may hide some parts of the terrain. Because of this LiDAR systems often do not gather the whole parts of the terrain. Such LiDAR data sets may cause errors in later spatial analyses and therefore, it is important to detect and eliminate such unc...

Osojnik, Monika

2013-01-01

 
 
 
 
161

Pradini? klasi? mokini? daržovi? ir vaisi? vartojimo ypatumai  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pakankamas vaisi? ir daržovi? vartojimas – tai neabejotinas ger? sveikos mitybos ?pro?i? pagrindas. Vaisiai ir daržov?s ypa? svarb?s jaunam organizmui, nes j? pakankamas vartojimas vaikyst?je susij?s su sumažejusia rizika sirgti širdies bei kraujagysli? ligomis, tam tikromis v?žio formomis ir kitomis l?tin?mis neinfekcin?mis ligomis tiek jaunyst?je, tiek vyresniame amžoiuje. Moksliniais tyrimais ?rodyta, kad vaikai, vartojantys mažiau vaisi? ir daržovi?, yra lin...

Butkus, Gintautas

2014-01-01

162

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...

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

2010-01-01

163

Georeferenced LiDAR 3D Vine Plantation Map Generation  

Directory of Open Access Journals (Sweden)

Full Text Available The use of electronic devices for canopy characterization has recently been widely discussed. Among such devices, LiDAR sensors appear to be the most accurate and precise. Information obtained with LiDAR sensors during reading while driving a tractor along a crop row can be managed and transformed into canopy density maps by evaluating the frequency of LiDAR returns. This paper describes a proposed methodology to obtain a georeferenced canopy map by combining the information obtained with LiDAR with that generated using a GPS receiver installed on top of a tractor. Data regarding the velocity of LiDAR measurements and UTM coordinates of each measured point on the canopy were obtained by applying the proposed transformation process. The process allows overlap of the canopy density map generated with the image of the intended measured area using Google Earth®, providing accurate information about the canopy distribution and/or location of damage along the rows. This methodology was applied and tested on different vine varieties and crop stages in two important vine production areas in Spain. The results indicate that the georeferenced information obtained with LiDAR sensors appears to be an interesting tool with the potential to improve crop management processes.

Meritxell Queraltó

2011-06-01

164

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Los mapas de géneros de árboles son útiles para el inventario forestal, planificación urbana y el mantenimiento de la infraestructura de líneas de transmisión. Se presenta un estudio de caso de uso de datos LiDAR de alta densidad para el mapeo de géneros de árboles a lo largo del derecho de paso (RO [...] W) de un corredor de línea de transmisión. El objetivo de la investigación fue identificar árboles individuales que mostraban o poseían una amenaza potencial a la infraestructura de la línea de transmisión. Mediante el uso de mapas tridimensionales de LiDAR se derivaron métricas de árboles que están relacionadas con la geometría de éstos (formas del árbol). Por ejemplo, la dirección del crecimiento dominante de los árboles es útil para identificar árboles que crecen inclinados hacia las líneas de transmisión. También se derivaron otras métricas geométricas que son útiles para determinar los géneros de los árboles, tales como altura, forma de la copa, tamaño y estructura de ramas. El área de estudio se ubicó al norte de Thessalon, Ontario, Canadá, a lo largo de los principales corredores de ROW y en los bosques aledaños. Los atributos geométricos usados para la clasificación de los géneros fueron categorizados en cinco amplias clases: 1) líneas, 2) agrupamiento, 3) volúmenes, 4) amortiguamiento en 3D de puntos, y 5) forma general del árbol que provee parámetros como una entrada para el clasificador forestal aleatorio. Abstract in english 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 tree metrics that are related to the geometry of the trees (tree forms). For example, the dominant growth direction of trees is useful in identifying trees that are leaning towards transmission lines. We also derived other geometric indices that are useful in determining tree genera; these metrics included their height, crown shape, size, and branching structures. Our pilot study was situated north of Thessalon, Ontario, Canada along a major utility corridor ROW and surrounding woodlots. The geometric features used for general classification could be categorized into five broad categories related to: 1) lines, 2) clusters, 3) volumes, 4) 3D buffers of points, and 5) overall tree shape that provide parameters as an input for the Random Forest classifier.

Connie, Ko; Tarmo K, Remmel; Gunho, Sohn.

165

Fission barriers for 255Es, 256Es, and 255Fm  

International Nuclear Information System (INIS)

Fission coincidence data are presented for (d,pf), (t,pf), and (3He,df) reactions on a 254Es target. A possible resonance is observed in 255Es. Estimates for the height of the first peak of the fission barrier for 255Es, 256Es, and 255Fm are presented. The possibility of additional structure in the potential energy surface in the vicinity of the first peak of the fission barrier is discussed

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

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.

2013-12-01

168

National Policies towards Broadcasting in Tanzania.  

Science.gov (United States)

The main thesis of this paper, which uses Tanzania's broadcasting system--Radio Tanzania Dar Es Salaam (RTD)--as a case study, is that media systems reflect the political and economic systems of the nation within which they operate subject to certain constraints. This discussion includes: (1) the history of the country's broadcasting policy before…

Samwilu-Mwaffisi, M.

169

"Finding a Life" among Undocumented Congolese Refugee Children in Tanzania  

Science.gov (United States)

The majority of undocumented Congolese refugee children living in Dar es Salaam, Tanzania, experience extreme poverty and social exclusion, harassment and discrimination. Their fear of deportation, forcible removal to refugee camps and imprisonment is coupled with a strong feeling that they are unwelcome in Tanzania. These realities require that…

Mann, Gillian

2010-01-01

170

Addressing Climate-Related Challenges and Information Needs in Africa  

Science.gov (United States)

The Africa Climate Conference 2013 (ACC-2013), which was organized by the World Climate Research Programme, the African Climate Policy Center of the United Nations Economic Commission for Africa, and the University of Dar es Salaam, brought together more than 300 participants, including decision makers, representatives of research funding agencies, scientists from various disciplines, and practitioners from Africa and around the globe.

Shongwe, M. E.; Pirani, Anna; Bekele, Seleshi

2014-06-01

171

Language in Education in Eastern Africa.  

Science.gov (United States)

This volume contains the papers given at the first Eastern Africa Conference on Language and Linguistics, held in Dar es Salaam in December 1968, under the auspices of the Survey of Language Use and Language Teaching in Eastern Africa. The chief aim of the Conference was to bring together scholars and teachers working in Eastern Africa interested…

Gorman, T. P., Ed.

172

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

173

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

174

LiDAR error estimation with WAsP engineering  

International Nuclear Information System (INIS)

The LiDAR measurements, vertical wind profile in any height between 10 to 150m, are based on assumption that the measured wind is a product of a homogenous wind. In reality there are many factors affecting the wind on each measurement point which the terrain plays the main role. To model LiDAR measurements and predict possible error in different wind directions for a certain terrain we have analyzed two experiment data sets from Greece. In both sites LiDAR and met, mast data have been collected and the same conditions are simulated with RisOe/DTU software, WAsP Engineering 2.0. Finally measurement data is compared with the model results. The model results are acceptable and very close for one site while the more complex one is returning higher errors at higher positions and in some wind directions

175

LiDAR error estimation with WAsP engineering  

DEFF Research Database (Denmark)

The LiDAR measurements, vertical wind profile in any height between 10 to 150m, are based on assumption that the measured wind is a product of a homogenous wind. In reality there are many factors affecting the wind on each measurement point which the terrain plays the main role. To model LiDAR measurements and predict possible error in different wind directions for a certain terrain we have analyzed two experiment data sets from Greece. In both sites LiDAR and met. mast data have been collected and the same conditions are simulated with Riso/DTU software, WAsP Engineering 2.0. Finally measurement data is compared with the model results. The model results are acceptable and very close for one site while the more complex one is returning higher errors at higher positions and in some wind directions.

Bingöl, Ferhat; Mann, Jakob

2008-01-01

176

Alternative Methodologies for LiDAR System Calibration  

Directory of Open Access Journals (Sweden)

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

177

Raster Vs. Point Cloud LiDAR Data Classification  

Science.gov (United States)

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

El-Ashmawy, N.; Shaker, A.

2014-09-01

178

High Fidelity DEM Generation Based on LiDAR Data  

Directory of Open Access Journals (Sweden)

Full Text Available With favorable penetrability to vegetation, LiDAR data is an important data source to generate high precision DEM for reconnaissance and design of railway. To avoid the limitation of the LiDAR data-processing in keeping terrain feature and to satisfy the demand of the reconnaissance and design, this paper presents a high fidelity DEM production method, which successively uses the specialized software and the variety photogrammetry technology. The large scale results of production have proved that the method is feasible and useable. 

Xudong Lai

2012-08-01

179

Determining the half-lives of /sup 253/Es, /sup 254/Es, /sup 254m/Es, /sup 255/Es, /sup 257/Es, /sup 256/Fm  

Energy Technology Data Exchange (ETDEWEB)

Semiconductor alpha, gamma, and x-ray spectrometry has been used to identify einsteinium and fermium isotopes having mass numbers 253-257 in californium targets irradiated in the central channel of the high-flux SM-2 reactor. Half-life measurements have been made for /sup 253/Es, /sup 254/Es, /sup 254m/Es, /sup 255/Es, /sup 257/Es, /sup 256/Fm. The measurements are compared with published data.

Popov, Yu.S.; Timofeev, G.A.; Mishenev, V.B.; Kovantsev, V.N.; Elesin, A.A.

1988-03-01

180

Determining the half-lives of 253Es, 254Es, /sup 254m/Es, 255Es, 257Es, 256Fm  

International Nuclear Information System (INIS)

Semiconductor alpha, gamma, and x-ray spectrometry has been used to identify einsteinium and fermium isotopes having mass numbers 253-257 in californium targets irradiated in the central channel of the high-flux SM-2 reactor. Half-life measurements have been made for 253Es, 254Es, /sup 254m/Es, 255Es, 257Es, 256Fm. The measurements are compared with published data

 
 
 
 
181

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

182

Forest structures retrieval from LiDAR onboard ULA  

Science.gov (United States)

Following the United Nations Framework Convention on Climate Change, the assessment of forest carbon stock is one of the main elements for a better understanding of the carbon cycle and its evolution following the climate change. The forests sequester 80% of the continental biospheric carbon and this efficiency is a function of the tree species and the tree health. The airborne backscatter LiDAR onboard the ultra light aircraft (ULA) can provide the key information on the forest vertical structures and evolution in the time. The most important structural parameter is the tree top height, which is directly linked to the above-ground biomass using non-linear relationships. In order to test the LiDAR capability for retrieving the tree top height, the LiDAR ULICE (Ultraviolet LIdar for Canopy Experiment) has been used over different forest types, from coniferous (maritime pins) to deciduous (oaks, hornbeams ...) trees. ULICE works at the wavelength of 355 nm with a sampling along the line-of-sight between 15 and 75 cm. According to the LiDAR signal to noise ratio (SNR), two different algorithms have been used in our study. The first algorithm is a threshold method directly based on the comparison between the LiDAR signal and the noise distributions, while the second one used a low pass filter by fitting a Gaussian curve family. In this paper, we will present these two algorithms and their evolution as a function of the SNR. The main error sources will be also discussed and assessed for each algorithm. The results show that these algorithms have great potential for ground-segment of future space borne LiDAR missions dedicated to the forest survey at the global scale. Acknowledgements: the canopy LiDAR system ULICE has been developed by CEA (Commissariat à l'Energie Atomique). It has been deployed with the support of CNES (Centre National d'Etude Spariales) and ANR (Agence Nationale de la Recherche). We acknowledge the ULA pilots Franck Toussaint for logistical help during the ULA campaign.

Shang, Xiaoxia; Chazette, Patrick; Totems, Julien; Marnas, Fabien; Sanak, Joseph

2013-04-01

183

A DArT platform for quantitative bulked segregant analysis  

Directory of Open Access Journals (Sweden)

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

184

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.

185

Graph-based filtering of urban LiDAR data  

Science.gov (United States)

A graph-based approach for modeling and solving the LiDAR filtering problem in urban areas is established. Our method consists of three steps. In the first step we construct a graph-based representation of the LiDAR data, Delaunay triangulation or the KNN graph can be used in this step. An algorithm is introduced to label the edges of this graph. In this second step, we defined criteria to eliminate some of the graph edges, then we used a connected components algorithm to separate the graph representation into different components. Finally, these components are classified into terrain or objects. Different datasets with different characteristics have been used to analyze the performance of our method.

Belkhouche, Yassine; Buckles, Bill; Duraisamy, Prakash; Alam, Mohammad S.

2014-04-01

186

Monitoring coastal change using terrestrial LiDAR  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper describes recent applications by the British Geological Survey (BGS) of the technique of mobile terrestrial Light Detection And Ranging (LiDAR) surveying to monitor various geomorphological changes on English coasts and estuaries. These include cliff recession, landslides and flood defences, and are usually sited at remote locations undergoing dynamic processes with no fixed reference points. Advantages, disadvantages and some practical problems are discussed. The role of GPS in las...

Hobbs, P.; Gibson, A.; Jones, L.; Poulton, C.; Jenkins, G.; Pearson, S.; Freeborough, K.

2010-01-01

187

Management of products distribution for cooperative "Daržovi? centras"  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Object of the work: cooperative "Daržovi? centras". Subject of the work: distribution of goods. Work purpose: to prepare distribution strategy for organization and to provide for perfection of channel management. Tasks of the work: 1. To analyse goods distribution system; 2. To establish basic variants of formation for distribution channels; 3. To analyse elements of channel management; 4. To analyse channels of distribution for organization and formulate methodical substantiation; 5. To pr...

Dubinskaite?, Jurgita

2005-01-01

188

Rockfall hazard analysis using LiDAR and spatial modeling  

Science.gov (United States)

Rockfalls have been significant geohazards along the Canadian Class 1 Railways (CN Rail and CP Rail) since their construction in the late 1800s. These rockfalls cause damage to infrastructure, interruption of business, and environmental impacts, and their occurrence varies both spatially and temporally. The proactive management of these rockfall hazards requires enabling technologies. This paper discusses a hazard assessment strategy for rockfalls along a section of a Canadian railway using LiDAR and spatial modeling. LiDAR provides accurate topographical information of the source area of rockfalls and along their paths. Spatial modeling was conducted using Rockfall Analyst, a three dimensional extension to GIS, to determine the characteristics of the rockfalls in terms of travel distance, velocity and energy. Historical rockfall records were used to calibrate the physical characteristics of the rockfall processes. The results based on a high-resolution digital elevation model from a LiDAR dataset were compared with those based on a coarse digital elevation model. A comprehensive methodology for rockfall hazard assessment is proposed which takes into account the characteristics of source areas, the physical processes of rockfalls and the spatial attribution of their frequency and energy.

Lan, Hengxing; Martin, C. Derek; Zhou, Chenghu; Lim, Chang Ho

2010-05-01

189

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

Directory of Open Access Journals (Sweden)

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

190

LA DIETA MEDITERRÁNEA: ES CARDIOPROTECTIVA?  

Directory of Open Access Journals (Sweden)

Full Text Available La enfermedad coronaria es una de las principales causas de morbilidad y mortalidad en USA, la intervención de la dieta es una línea primaria en el tratamiento y prevención de la misma. El aumento de la evidencia científica muestra que la tradicional dieta mediterránea puede reducir los riesgos de una enfermedad cardiovascular, los beneficios cardiovasculares de esta dieta superan lo de las dietas de baja grasa prescriptas clásicamente, la carga de las enfermedades cardiovasculares es enorme, y los aportes nutricionales que puedan optimizar la salida cardiovascular son esenciales. Las evidencias clínicas apoyan el role de la dieta mediterránea en la salud cardiovascular, presentándose con mucho énfasis los efectos fisiológicos de los ácidos grasos omega -3. Se discuten las implicaciones en la práctica clínica y se enfocan futuras investigaciones.

Alfredo Arredondo Bruce

2007-01-01

191

El duelo es un trabajo  

Directory of Open Access Journals (Sweden)

Full Text Available Esta pregunta por lo nuevo en la atención en duelo invita a pensar en varias direcciones: qué hay de nuevo como oferta médica para ayudar a soportar la situación de pérdida que el duelo arrastra consigo, por un lado, pero por otro, qué hay de nuevo en el duelo? Es difícil saber si las condiciones de elaboración del duelo se modifican con las particularidades de una época o con las particularidades propias de cada modalidad de sufrimiento, igualmente existe una tesis que afirma que nuestra época no es ya la época de la muerte romántica más bien que la condición de guerra haría a su vez que las
coordenadas del duelo podrían pensarse de manera distinta, sin embargo detrás de lo nuevo siempre encontramos lo viejo: la muerte. Parafraseando el último verso de “Las Flores del Mal” de Baudelaire:

Clara Cecilia Mesa

2001-02-01

192

DAR O NO DAR PAPAYA: EL ROMPECABEZAS DE LA CONFIANZA INTERPERSONAL / THE PUZZLE OF INTERPERSONAL TRUST  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Un aspecto no suficientemente considerado en la solución del dilema social de la redistribución de la riqueza es el papel mediador de la confianza. En este artículo presento evidencia preliminar a este respecto. Posteriormente considero varios mecanismos que pueden explicar los niveles de confianza [...] interpersonal observados en 54 países incluidos en la quinta Encuesta Mundial de Valores (2005-2008). Los resultados de un modelo estadístico multivariado indican que las variables con mejor desempeño son el nivel de riqueza, la estabilidad política y, con un efecto negativo, la participación einclusión en los procesos de toma de decisión. Sin embargo, un análisis de los niveles de confianza interpersonal con base en las encuestas del Latinobarómetro realizadas entre 1996 y 2010 arroja resultados parcialmente distintos. Modelos posteriores podrían resolver esta disparidad tomando en cuenta la variedad de trayectorias históricas en cada región o modelando el efecto de los mecanismos derivados de la estructura social, económica y política de modo distinto. Abstract in english One aspect not sufficiently considered in solving the social dilemma of redistribution of wealth is the mediating role of trust. In this article, I present preliminary evidence in this regard. Later, I consider several mechanisms that may explain the observed levels of interpersonal trust in 54 coun [...] tries included in the fifth World Values ??Survey (2005-2008). The results of a multivariate statistical model indicate that the best performing variables are the level of wealth, political stability, with a negative effect , participation and inclusion in decision -making processes . However, an analysis of the levels of interpersonal trust based on surveys conducted between 1996 and Latinobarometer 2010 shows partly different results. Later models could resolve this disparity considering the variety of historical trajectories in each region or modeling the effect of mechanisms from social, economic and political structure differently.

Juan Gabriel, Gómez Albarello.

2014-04-01

193

DAR O NO DAR PAPAYA: EL ROMPECABEZAS DE LA CONFIANZA INTERPERSONAL / THE PUZZLE OF INTERPERSONAL TRUST  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Un aspecto no suficientemente considerado en la solución del dilema social de la redistribución de la riqueza es el papel mediador de la confianza. En este artículo presento evidencia preliminar a este respecto. Posteriormente considero varios mecanismos que pueden explicar los niveles de confianza [...] interpersonal observados en 54 países incluidos en la quinta Encuesta Mundial de Valores (2005-2008). Los resultados de un modelo estadístico multivariado indican que las variables con mejor desempeño son el nivel de riqueza, la estabilidad política y, con un efecto negativo, la participación einclusión en los procesos de toma de decisión. Sin embargo, un análisis de los niveles de confianza interpersonal con base en las encuestas del Latinobarómetro realizadas entre 1996 y 2010 arroja resultados parcialmente distintos. Modelos posteriores podrían resolver esta disparidad tomando en cuenta la variedad de trayectorias históricas en cada región o modelando el efecto de los mecanismos derivados de la estructura social, económica y política de modo distinto. Abstract in english One aspect not sufficiently considered in solving the social dilemma of redistribution of wealth is the mediating role of trust. In this article, I present preliminary evidence in this regard. Later, I consider several mechanisms that may explain the observed levels of interpersonal trust in 54 coun [...] tries included in the fifth World Values ??Survey (2005-2008). The results of a multivariate statistical model indicate that the best performing variables are the level of wealth, political stability, with a negative effect , participation and inclusion in decision -making processes . However, an analysis of the levels of interpersonal trust based on surveys conducted between 1996 and Latinobarometer 2010 shows partly different results. Later models could resolve this disparity considering the variety of historical trajectories in each region or modeling the effect of mechanisms from social, economic and political structure differently.

Juan Gabriel, Gómez Albarello.

194

Portable and Airborne Small Footprint LiDAR: Forest Canopy Structure Estimation of Fire Managed Plots  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study used an affordable ground-based portable LiDAR system to provide an understanding of the structural differences between old-growth and secondary-growth Southeastern pine. It provided insight into the strengths and weaknesses in the structural determination of portable systems in contrast to airborne LiDAR systems. Portable LiDAR height profiles and derived metrics and indices (e.g., canopy cover, canopy height) were compared among plots with different fire frequency and fire season...

Listopad, Claudia M. C. S.; Drake, Jason B.; Weishampel, John F.; Masters, Ron E.

2011-01-01

195

Lietuvos gyventoj? daržovi? ir vaisi? vartojimo ?pro?iai  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pateikiami tarptautinio NORBAGREEN tyrimo, kurio tikslas buvo ?vertinti daržovi? ir vaisi? vartojim? Šiaur?s Europos ir Baltijos valstyb?se, duomenys. Lietuvoje apklausti 1076 15-74 m. atsitiktinai pasirinkti žmon?s. Tyrimas atliktas pagal vienod?, specialiai šiam projektui parengt? klausimyn?, kurio tinkamumas ?vertintas Lietuvoje, Suomijoje ir Švedijoje. Lietuvos gyventojai daržoves valg? vidutiniškai 32, vaisius – 22 kartus per m?nes?. Kasdien valg? daržoves 61,4 p...

Petkevic?iene?, Janina; Kriauc?ioniene?, Vilma

2005-01-01

196

El duelo es un trabajo  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Esta pregunta por lo nuevo en la atención en duelo invita a pensar en varias direcciones: qué hay de nuevo como oferta médica para ayudar a soportar la situación de pérdida que el duelo arrastra consigo, por un lado, pero por otro, qué hay de nuevo en el duelo? Es difícil saber si las condiciones de elaboración del duelo se modifican con las particularidades de una época o con las particularidades propias de cada modalidad de sufrimiento, igualmente existe una tesis que afirma que nu...

Clara Cecilia Mesa.

2001-01-01

197

Airborne Dual-Wavelength LiDAR Data for Classifying Land Cover  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study demonstrated the potential of using dual-wavelength airborne light detection and ranging (LiDAR) data to classify land cover. Dual-wavelength LiDAR data were acquired from two airborne LiDAR systems that emitted pulses of light in near-infrared (NIR) and middle-infrared (MIR) lasers. The major features of the LiDAR data, such as surface height, echo width, and dual-wavelength amplitude, were used to represent the characteristics of land cover. Based on the major features of land co...

Cheng-Kai Wang; Yi-Hsing Tseng; Hone-Jay Chu

2014-01-01

198

Dia de Dar Gracias. Modulo Nivel Primario. (Day to Give Thanks. Module Primary Level.)  

Science.gov (United States)

Dia de Dar Gracias (Thanksgiving) is the subject of this primary level unit. The unit objectives are to: (1) know about El Dia de Dar Gracias as it is celebrated in the United States; (2) know how the Mayas celebrated it; (3) understand the context of the stories in the unit; (4) know about the main food used, the turkey; (5) distinguish other…

Espinoza, Delia; Lopez, Santiago, III

199

Flood Modeling Using a Synthesis of Multi-Platform LiDAR Data  

Directory of Open Access Journals (Sweden)

Full Text Available This study examined the utility of a high resolution ground-based (mobile and terrestrial Light Detection and Ranging (LiDAR dataset (0.2 m point-spacing supplemented with a coarser resolution airborne LiDAR dataset (5 m point-spacing for use in a flood inundation analysis. The techniques for combining multi-platform LiDAR data into a composite dataset in the form of a triangulated irregular network (TIN are described, and quantitative comparisons were made to a TIN generated solely from the airborne LiDAR dataset. For example, a maximum land surface elevation difference of 1.677 m and a mean difference of 0.178 m were calculated between the datasets based on sample points. Utilizing the composite and airborne LiDAR-derived TINs, a flood inundation comparison was completed using a one-dimensional steady flow hydraulic modeling analysis. Quantitative comparisons of the water surface profiles and depth grids indicated an underestimation of flooding extent, volume, and maximum flood height using the airborne LiDAR data alone. A 35% increase in maximum flood height was observed using the composite LiDAR dataset. In addition, the extents of the water surface profiles generated from the two datasets were found to be statistically significantly different. The urban and mountainous characteristics of the study area as well as the density (file size of the high resolution ground based LiDAR data presented both opportunities and challenges for flood modeling analyses.

Ryan M. Csontos

2013-09-01

200

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

 
 
 
 
201

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

Science.gov (United States)

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. Multipath amplitude and delay are estimated by means of LiDAR feature extraction and multipath mitigation architecture. The results show the feasibility of integrating the information provided by LiDAR sensors and GNSS receivers for multipath mitigation. PMID:23202177

Ali, Khurram; Chen, Xin; Dovis, Fabio; De Castro, David; Fernandez, Antonio J.

2012-01-01

202

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

Directory of Open Access Journals (Sweden)

Full Text Available 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. Multipath amplitude and delay are estimated by means of LiDAR feature extraction and multipath mitigation architecture. The results show the feasibility of integrating the information provided by LiDAR sensors and GNSS receivers for multipath mitigation.

Antonio J. Fernández

2012-10-01

203

¿Los médicos cuentan con herramientas suficientes para dar la orden de “no reanimar”? Aspectos bioéticos en la atención del paciente terminal  

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Full Text Available Antecedentes: en su formación profesional, los médicos no cuentan con la currícula necesaria para atender pacientes con enfermedades terminales. Objetivo: conocer si los médicos tienen los conocimientos básicos para evaluar los síntomas y condiciones generales del estado del paciente terminal. Material y método: estudio observacional en el que, previa firma del consentimiento informado, se aplicó un cuestionario semiestructurado del conocimiento que poseen los médicos de las escalas de evaluación general y síntomas más frecuentes en los pacientes terminales. Se realizó un análisis descriptivo con medidas de tendencia central. Se evaluaron 72 médicos de un hospital que da cuidados a pacientes geriátricos y con enfermedades discapacitantes. Resultados: 75% de los médicos atienden pacientes con en- fermedades crónicas y degenerativas, pero solamente 50% ha recibido algún tipo de adiestramiento en cuidados paliativos y casi siempre ha sido financiado por ellos mismos. No hay un programa institucional de enseñanza médica continua que los capacite en el manejo de los cuidados paliativos de pacientes terminales. Muchos de ellos poseen los conceptos generales de lo que es la medicina paliativa; sin embargo, cuando se requieren conocimientos específicos del área no son capaces de dar descripciones detalladas de los mismos, en especial de enfermedades terminales, ya sea renales, cardiacas, pulmonares o, incluso, demencias. Conclusión: los médicos no tienen la capacidad de dar la orden de “no reanimar”. Es necesario aplicar criterios generalizados para el establecimiento de normas de atención en cuidados pa- liativos a nivel institucional. Es urgente que el personal médico obtenga capacitación apropiada en dicha materia.

Jorge A Reyes Guerrero

2013-01-01

204

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

205

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%.

206

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

207

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 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

208

¿Qué es la justicia global?  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish 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 c [...] ivilización, 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. Abstract in english 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.

209

¿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

210

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

211

Procesamiento de datos LiDAR con ArcGIS Desktop 10  

Digital Repository Infrastructure Vision for European Research (DRIVER)

El presente trabajo pretende mostrar el procesamiento de los datos LiDAR mediante el uso del software de ESRI: ArcGIS Desktop 10. Para ello se aborda una breve introducción a la evolución del sensor LiDAR y las versiones de datos .las, así como un resumen de sus principales aplicaciones en la actualidad. Por otra parte, se incluye una aproximación al software existente para el tratamiento de datos LiDAR, recopilando una muestra significativa de herramientas orientadas al manejo de arch...

San Jose? Albacete, Antonio

2011-01-01

212

Using LiDAR data to define stream flow rating curves  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In remote locations, it is difficult to obtain stream flow information because of the difficulty making sufficient dis- charge measurements. In this study we investigate the feasibility to constrain a fluid mechanics-based flow model for defining stream flow rating curves with remotely sensed topographic data from airborne LiDAR scanning. A near infrared (NIR) LiDAR scan was carried out for an 8-m wide channel in northern Sweden. The topographic information from this NIR LiDAR scan along the ...

Nathanson, Marcus; Kean, Jason; Laudon, Hjalmar; Seibert, Jan; Grabs, Thomas; Lyon, Steve

2012-01-01

213

LiDAR-derived snowpack data sets from mixed conifer forests across the Western United States  

Science.gov (United States)

Light Detection and Ranging (LiDAR) offers the potential to measure snow depth and vegetation structure at high spatial resolution over large extents and thereby increase our ability to quantify snow water resources. Here we present airborne LiDAR data products at four Critical Zone Observatories (CZO) in the Western United States: Jemez River Basin, NM, Boulder Creek Watershed, CO, Kings River Experimental Watershed, CA, and Wolverton Basin, CA. We make publicly available snow depth data products (1 m2 resolution) derived from LiDAR with an estimated accuracy of <30 cm compared to limited in situ snow depth observations.

Harpold, A. A.; Guo, Q.; Molotch, N.; Brooks, P. D.; Bales, R.; Fernandez-Diaz, J. C.; Musselman, K. N.; Swetnam, T. L.; Kirchner, P.; Meadows, M. W.; Flanagan, J.; Lucas, R.

2014-03-01

214

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

215

Evaluation the Impact of a NGDO Social Entrepreneurship Course  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This is an evaluative study of students participating in the social entrepreneurship courses recently launched at the NDGO Action Aid Denmark’s training centre in Dar es Salaam, Tanzania. As proposed by the theory of planned behaviour, attitudes and intentions were used as predictors of future social entrepreneurial venture creation among the students. Data was collected through a survey distributed immediately after the courses and a follow-up survey distributed 2½-3 months later. The fol...

Larsen, Tanja Lærke

2013-01-01

216

Genital tract infections among HIV-infected pregnant women in Malawi, Tanzania and Zambia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this study was to compare the prevalence and factors associated with genital tract infections among HIV-infected pregnant women from African sites. Participants were recruited from Blantyre and Lilongwe, Malawi; Dar es Salaam, Tanzania; and Lusaka, Zambia. Genital tract infections were assessed at baseline. Of 2627 eligible women enrolled, 2292 were HIV-infected. Of these, 47.8% had bacterial vaginosis (BV), 22.4% had vaginal candidiasis, 18.8% had trichomoniasis, 8.5% had genital ...

Aboud, S.; Msamanga, G.; Read, J. S.; Mwatha, A.; Chen, Y. Q.; Potter, D.; Valentine, M.; Sharma, U.; Hoffmann, I.; Taha, T. E.; Goldenberg, R. L.; Fawzi, W. W.

2008-01-01

217

Reasons for Poor Adherence to Antiretroviral Therapy Postnatally in HIV-1 Infected Women Treated for their own Health: Experiences from the Mitra Plus Study in Tanzania.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In a study of prevention of mother-to-child transmission of HIV (PMTCT) by triple antiretroviral therapy (ART) in Dar es Salaam, Tanzania (the Mitra Plus study), retrospective viral load testing revealed a high and increasing frequency of detectable viral load during follow-up for two years postnatally in women given continuous ART for their own health suggesting poor adherence. This study explored women's own perceived barriers to adherence to ART post-delivery so as to identify ways to faci...

Ngarina, Matilda; Popenoe, Rebecca; Kilewo, Charles; Biberfeld, Gunnel; Ekstrom, Anna Mia

2013-01-01

218

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

219

Kierrätysmateriaalien käyttö tuotteen valmistuksessa  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of the thesis was to create a nice and pleasant outdoor recreation area for the volunteers working for Art in Tanzania in Dar es Salaam, Tanzania. Art in Tanzania organization offers volunteer work in Tanzania, Zanzibar and Ethiopia in sectors such as medical care, education and media production. The thesis was divided into two parts. The first part deals with the differences between the consumption cultures in Africa and Finland. Also information was gathered about traditiona...

Eskola, Anu

2010-01-01

220

Vitamins and Perinatal Outcomes Among HIV-Negative Women in Tanzania.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Prematurity and low birth weight are associated with high perinatal and infant mortality, especially in developing countries. Maternal micronutrient deficiencies may contribute to these adverse outcomes. In a double-blind trial in Dar es Salaam, Tanzania, we randomly assigned 8468 pregnant women (gestational age of fetus, 12 to 27 weeks) who were negative for human immunodeficiency virus infection to receive daily multivitamins (including multiples of the recommended dietary allowance) or pla...

Fawzi, Wafaie W.; Msamanga, Gernard I.; Urassa, Willy; Hertzmark, Ellen; Petraro, Paul; Willett, Walter C.; Spiegelman, Donna

2007-01-01

 
 
 
 
221

Common Mental Disorders and Risk Factors in Urban Tanzania  

Directory of Open Access Journals (Sweden)

Full Text Available 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

2010-06-01

222

ES strukt?rin? parama Lietuvos turizmui  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Magistro baigiamajame darbe išanalizuota ir ?vertinta ES strukt?rin?s paramos Lietuvos turizmui ?sisavinimo efektyvumas, iškeltos pagrindin?s ES strukt?rin?s paramos l?šas bei pateiki sprendimai joms spr?sti. Pirmojoje darbo dalyje teoriniu aspektu analizuojama turizmo infrastrukt?ra, ES strukt?rin?s paramos politikos turinys bei ES strukt?rin?s paramos vaidmuo šalies ekonomikai. Antrojoje darbo dalyje analizuojamas ES strukt?rin?s paramos Lietuvos bei apskri?i? turizmo ...

Lis?kute?, Rima

2014-01-01

223

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Przyborowski, Jerzy A.; Pawe? Sulima; Anna Kuszewska; Dariusz Za?uski; Andrzej Kilian

2013-01-01

224

Development of a molecular linkage map of pearl millet integrating DArT and SSR markers.  

Science.gov (United States)

Pearl millet is an important component of food security in the semi-arid tropics and is assuming greater importance in the context of changing climate and increasing demand for highly nutritious food and feed. Molecular tools have been developed and applied for pearl millet on a limited scale. However, the existing tool kit needs to be strengthened further for its routine use in applied breeding programs. Here, we report enrichment of the pearl millet molecular linkage map by exploiting low-cost and high-throughput Diversity Arrays Technology (DArT) markers. Genomic representation from 95 diverse genotypes was used to develop a DArT array with circa 7,000 clones following PstI/BanII complexity reduction. This array was used to genotype a set of 24 diverse pearl millet inbreds and 574 polymorphic DArT markers were identified. The genetic relationships among the inbred lines as revealed by DArT genotyping were in complete agreement with the available pedigree data. Further, a mapping population of 140 F(7) Recombinant Inbred Lines (RILs) from cross H 77/833-2 × PRLT 2/89-33 was genotyped and an improved linkage map was constructed by integrating DArT and SSR marker data. This map contains 321 loci (258 DArTs and 63 SSRs) and spans 1148 cM with an average adjacent-marker interval length of 3.7 cM. The length of individual linkage groups (LGs) ranged from 78 cM (LG 3) to 370 cM (LG 2). This better-saturated map provides improved genome coverage and will be useful for genetic analyses of important quantitative traits. This DArT platform will also permit cost-effective background selection in marker-assisted backcrossing programs as well as facilitate comparative genomics and genome organization studies once DNA sequences of polymorphic DArT clones are available. PMID:21476042

Supriya, A; Senthilvel, S; Nepolean, T; Eshwar, K; Rajaram, V; Shaw, R; Hash, C T; Kilian, A; Yadav, R C; Narasu, M L

2011-07-01

225

LiDAR data management pipeline; from spatial database population to web-application visualization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

While the existence of very large and scalable Database Management Systems (DBMSs) is well recognized, it is the usage and extension of these technologies to managing spatial data that has seen increasing amounts of research work in recent years. A focused area of this research work involves the handling of very high resolution Light Detection and Ranging (LiDAR) data. While LiDAR has many real world applications, it is usually the purview of organizations interested in capturing and monitori...

Lewis, Paul; Mc Elhinney, Conor P.; Mccarthy, Tim

2012-01-01

226

Modeling marbled murrelet (Brachyramphus marmoratus) habitat using LiDAR-derived canopy data  

Science.gov (United States)

LiDAR (Light Detection And Ranging) is an emerging remote-sensing tool that can provide fine-scale data describing vertical complexity of vegetation relevant to species that are responsive to forest structure. We used LiDAR data to estimate occupancy probability for the federally threatened marbled murrelet (Brachyramphus marmoratus) in the Oregon Coast Range of the United States. Our goal was to address the need identified in the Recovery Plan for a more accurate estimate of the availability of nesting habitat by developing occupancy maps based on refined measures of nest-strand structure. We used murrelet occupancy data collected by the Bureau of Land Management Coos Bay District, and canopy metrics calculated from discrete return airborne LiDAR data, to fit a logistic regression model predicting the probability of occupancy. Our final model for stand-level occupancy included distance to coast, and 5 LiDAR-derived variables describing canopy structure. With an area under the curve value (AUC) of 0.74, this model had acceptable discrimination and fair agreement (Cohen's ??=?0.24), especially considering that all sites in our sample were regarded by managers as potential habitat. The LiDAR model provided better discrimination between occupied and unoccupied sites than did a model using variables derived from Gradient Nearest Neighbor maps that were previously reported as important predictors of murrelet occupancy (AUC?=?0.64, ??=?0.12). We also evaluated LiDAR metrics at 11 known murrelet nest sites. Two LiDAR-derived variables accurately discriminated nest sites from random sites (average AUC?=?0.91). LiDAR provided a means of quantifying 3-dimensional canopy structure with variables that are ecologically relevant to murrelet nesting habitat, and have not been as accurately quantified by other mensuration methods.

Hagar, Joan C.; Eskelson, Bianca N. I.; Haggerty, Patricia K.; Nelson, S. Kim; Vesely, David G.

2014-01-01

227

Liofilizuotomis daržov?mis praturtinto jogurto kokyb?s tyrimai  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Magistrant?ros studij? baigiamajame darbe pateikiami jogurto, praturtinto liofilizuotomis daržov?mis, fizikini? rodikli? (klampumo, rišlumo, konsistencijos, tvirtumo ir r?gštingumo) bei juslini? savybi? tyrim? rezultatai. Darbo objektas – 3,5 % riebumo ekologiškas jogurtas, kuris buvo pagardintas liofilizuotomis daržov?mis, prieskoniniais augalais ir pievagrybiais. Buvo paruošti 6 jogurto su priedais variantai: I var. (kontrolinis) – be pried?; II var. – pomidor?, ?...

Botyriu?te?, Reda

2014-01-01

228

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

229

Airborne Dual-Wavelength LiDAR Data for Classifying Land Cover  

Directory of Open Access Journals (Sweden)

Full Text Available This study demonstrated the potential of using dual-wavelength airborne light detection and ranging (LiDAR data to classify land cover. Dual-wavelength LiDAR data were acquired from two airborne LiDAR systems that emitted pulses of light in near-infrared (NIR and middle-infrared (MIR lasers. The major features of the LiDAR data, such as surface height, echo width, and dual-wavelength amplitude, were used to represent the characteristics of land cover. Based on the major features of land cover, a support vector machine was used to classify six types of suburban land cover: road and gravel, bare soil, low vegetation, high vegetation, roofs, and water bodies. Results show that using dual-wavelength LiDAR-derived information (e.g., amplitudes at NIR and MIR wavelengths could compensate for the limitations of using single-wavelength LiDAR information (i.e., poor discrimination of low vegetation when classifying land cover.

Cheng-Kai Wang

2014-01-01

230

Area-Based Mapping of Defoliation of Scots Pine Stands Using Airborne Scanning LiDAR  

Directory of Open Access Journals (Sweden)

Full Text Available The mapping of changes in the distribution of insect-caused forest damage remains an important forest monitoring application and challenge. Efficient and accurate methods are required for mapping and monitoring changes in insect defoliation to inform forest management and reporting activities. In this research, we develop and evaluate a LiDAR-driven (Light Detection And Ranging approach for mapping defoliation caused by the Common pine sawfly (Diprion pini L.. Our method requires plot-level training data and airborne scanning LiDAR data. The approach is predicated on a forest canopy mask created by detecting forest canopy cover using LiDAR. The LiDAR returns that are reflected from the canopy (that is, returns > half of maximum plot tree height are used in the prediction of the defoliation. Predictions of defoliation are made at plot-level, which enables a direct integration of the method to operational forest management planning while also providing additional value-added from inventory-focused LiDAR datasets. In addition to the method development, we evaluated the prediction accuracy and investigated the required pulse density for operational LiDAR-based mapping of defoliation. Our method proved to be suitable for the mapping of defoliated stands, resulting in an overall mapping accuracy of 84.3% and a Cohen’s kappa coefficient of 0.68.

Hannu Hyyppä

2013-03-01

231

LiDAR: principles and forestry applications LiDAR: princípios e aplicações florestais  

Directory of Open Access Journals (Sweden)

Full Text Available One of the first areas investigated for commercial applications of LiDAR was for forest applications. Topography and forest coverage are of extreme importance for forest resources managers. Accurate information on trees height and density, besides being fundamental for planning, are hard to obtain by conventional methods. Laser scanning technology, as opposed to satellite images and aerial photographs, can concurrently map the ground and obtain estimates of trees height. The use of modeling associated with LiDAR data allows to obtain estimates of several other forest variables such as basal area, diameter, volume,�  biomass and fuel material. Besides these applications, LiDAR technology presents a great potential for planning forest harvesting activities, road construction and maintenance. However, there are great challenges to be overcome in developing technologies and computational applications more robust and reliable for modeling data from this type of sensor.

doi: 10.4336/2010.pfb.30.63.231

 
 
241

Measurement procedures for characterization of wind turbine wakes with scanning Doppler wind LiDARs  

Science.gov (United States)

The wake flow produced from an Enercon E-70 wind turbine is investigated through three scanning Doppler wind LiDARs. One LiDAR is deployed upwind to characterize the incoming wind, while the other two LiDARs are located downstream to carry out wake measurements. The main challenge in performing 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 the LiDAR measurement volume and wake location, different measuring techniques 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. The characterization of the wake recovery along the downwind direction is performed. Moreover, wake turbulence peaks are detected at turbine top-tip height, which can represent increased fatigue loads for downstream wind turbines within a wind farm.

Iungo, G. V.; Porté-Agel, F.

2013-05-01

242

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

243

Separation of Ground and Low Vegetation Signatures in LiDAR Measurements of Salt-Marsh Environments:  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Light detection and ranging (LiDAR) has been shown to have a great potential in the accurate characterization of forest systems; however, its application to salt-marsh environments is challenging because the characteristic short vegetation does not give rise to detectable differences between first and last LiDAR returns. Furthermore, the lack of precisely identifiable references (e.g., buildings, roads, etc.) in marsh areas makes the registration and bias correction of the LiDAR data much mor...

Wang, C.; Menenti, M.; Stoll, M. P.; Feola, A.; Belluco, E.; Marani, M.

2009-01-01

244

Geometric Calibration and Radiometric Correction of LiDAR Data and Their Impact on the Quality of Derived Products  

Digital Repository Infrastructure Vision for European Research (DRIVER)

LiDAR (Light Detection And Ranging) systems are capable of providing 3D positional and spectral information (in the utilized spectrum range) of the mapped surface. Due to systematic errors in the system parameters and measurements, LiDAR systems require geometric calibration and radiometric correction of the intensity data in order to maximize the benefit from the collected positional and spectral information. This paper presents a practical approach for the geometric calibration of LiDAR sys...

Wai-Yeung Yan; Ahmed Shaker; Habib, Ayman F.; Kersting, Ana P.

2011-01-01

245

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 s...

Pirotti F

2011-01-01

246

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.

Marinete Rosa Pereira Mascarello

2007-01-01

247

Positive Effekte für Intelligenz und Schulisches Lernen : wie stellt sich ein Training des induktiven Denkens dar und was bewirkt es bei Kindern und Jugendlichen? ; Ergebnisse einer Metaanalyse  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Während unter Ärzten die Bemühungen um die so genannte evidenzbasierte Medizin nur mühsam vorankommen, interessieren sich in der Praxis tätige Psychologinnen und Psychologen seit jeher für Untersuchungen, in denen die Effektivität ihrer Interventionsmaßnahmen überprüft wird. Im vorliegenden Beitrag wird ein Trainingskonzept vorgestellt und metaanalytisch auf seine Effektivität hin überprüft, das nahezu ausschließlich von Psychologen bei Kindern und Jugendlichen (und seit neue...

Klauer, Karl Josef

2003-01-01

248

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

249

European LiDAR Mapping Forum Un report dal futuro del 3D intelligente  

Directory of Open Access Journals (Sweden)

Full Text Available Circa 450 delegati provenienti da 45 paesi si sono riuniti per lo European LiDAR Mapping Forum (ELMFal Congress Palace nel centro di Salisburgo in Austria, dove si sono succedute presentazioni da parte diesperti leader a livello mondiale.Abstract About 450 delegates from 45 countries gathered for the European LiDAR Mapping Forum (ELMF at the Congress Palace in the center of Salzburg in Austria, with presentations by leading experts in the world. The topics on the use of LiDAR to support transport, urban modeling, coastal zone mapping, asset management, 3D visualization and GIS applications, have contributed to the success of the third ELMF (the first took place in 2012 from 4 to 5 December 2012. 

Redazione GEOmedia

2013-03-01

250

An algorithm of fast index constructing and neighbor searching for 3D LiDAR data  

Science.gov (United States)

As the 3D point-cloud data increase greatly with the development of data acquisition technology, it is an important prerequisite to establish an efficient index constructing and neighbor searching algorithm for point-cloud in data processing. In this paper, an efficient algorithm of index constructing and neighbor searching for 3D LiDAR data was proposed based on the combination of 3D grid, linear octree and Hash table. An experiment was conducted about the 3D LiDAR data and the result shows that the proposed method has higher efficiency of data index constructing and neighbor searching for 3D point-cloud acquired by mobile LiDAR.

Feng, YiCong; Cen, MinYi; Zhang, TongGang

251

¿Un país pobre podrá dar Bienestar a sus Animales?  

Directory of Open Access Journals (Sweden)

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

252

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

253

Portable and Airborne Small Footprint LiDAR: Forest Canopy Structure Estimation of Fire Managed Plots  

Directory of Open Access Journals (Sweden)

Full Text Available This study used an affordable ground-based portable LiDAR system to provide an understanding of the structural differences between old-growth and secondary-growth Southeastern pine. It provided insight into the strengths and weaknesses in the structural determination of portable systems in contrast to airborne LiDAR systems. Portable LiDAR height profiles and derived metrics and indices (e.g., canopy cover, canopy height were compared among plots with different fire frequency and fire season treatments within secondary forest and old growth plots. The treatments consisted of transitional season fire with four different return intervals: 1-yr, 2-yr, 3-yr fire return intervals, and fire suppressed plots. The remaining secondary plots were treated using a 2-yr late dormant season fire cycle. The old growth plots were treated using a 2-yr growing season fire cycle. Airborne and portable LiDAR derived canopy cover were consistent throughout the plots, with significantly higher canopy cover values found in 3-yr and fire suppressed plots. Portable LiDAR height profile and metrics presented a higher sensitivity in capturing subcanopy elements than the airborne system, particularly in dense canopy plots. The 3-dimensional structures of the secondary plots with varying fire return intervals were dramatically different to old-growth plots, where a symmetrical distribution with clear recruitment was visible. Portable LiDAR, even though limited to finer spatial scales and specific biases, is a low-cost investment with clear value for the management of forest canopy structure.

Claudia M.C.S. Listopad

2011-06-01

254

Investigating the spatial distribution of water levels in the Mackenzie Delta using airborne LiDAR  

Science.gov (United States)

Airborne light detection and ranging (LiDAR) data were used to map water level (WL) and hydraulic gradients (??H/??x) in the Mackenzie Delta. The LiDAR WL data were validated against eight independent hydrometric gauge measurements and demonstrated mean offsets from - 0??22 to + 0??04 m (??LiDAR-based WL gradients could be estimated with confidence over channel lengths exceeding 5-10 km where the WL change exceeded local noise levels in the LiDAR data. For the entire Delta, the LiDAR sample coverage indicated a rate of change in longitudinal gradient (??2H/??x) of 5??5 ?? 10-10 m m-2; therefore offering a potential means to estimate average flood stage hydraulic gradient for areas of the Delta not sampled or monitored. In the Outer Delta, within-channel and terrain gradient measurements all returned a consistent estimate of - 1 ?? 10-5 m m-1, suggesting that this is a typical hydraulic gradient for the downstream end of the Delta. For short reaches ( 0??1 m was observed at a channel constriction entering a meander bend, suggesting a localized modification of the channel hydraulics. Furthermore, water levels in the anabranch channels of the Peel River were almost 1 m higher than in Middle Channel of the Mackenzie River. This suggests: (i) the channels are elevated and have shallower bank heights in this part of the delta, leading to increased cross-delta and along-channel hydraulic gradients; and/or (ii) a proportion of the Peel River flow is lost to Middle Channel due to drainage across the delta through anastamosing channels. This study has demonstrated that airborne LiDAR data contain valuable information describing Arctic river delta water surface and hydraulic attributes that would be challenging to acquire by other means. ?? 2011 John Wiley & Sons, Ltd.

Hopkinson, C.; Crasto, N.; Marsh, P.; Forbes, D.; Lesack, L.

2011-01-01

255

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

256

MKENO-DAR: a direct angular representation Monte Carlo code for criticality safety analysis  

International Nuclear Information System (INIS)

Improving the Monte Carlo code MULTI-KENO, the MKENO-DAR (Direct Angular Representation) code has been developed for criticality safety analysis in detail. A function was added to MULTI-KENO for representing anisotropic scattering strictly. With this function, the scattering angle of neutron is determined not by the average scattering angle ?-bar of the Pl Legendre polynomial but by the random work operation using probability distribution function produced with the higher order Legendre polynomials. This code is avilable for the FACOM-M380 computer. This report is a computer code manual for MKENO-DAR. (author)

257

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

Directory of Open Access Journals (Sweden)

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

258

Monitoring Automotive Particulate Matter Emissions with LiDAR: A Review  

Directory of Open Access Journals (Sweden)

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

259

Parallel algorithm for linear feature detection from airborne LiDAR data  

Science.gov (United States)

Linear features from airport images correspond to runways, taxiways and roads. Detecting runways helps pilots to focus on runway incursions in poor visibility conditions. In this work, we attempt to detect linear features from LiDAR swath in near real time using parallel implementation on G5-based apple cluster called Xseed. Data from LiDAR swath is converted into a uniform grid with nearest neighbor interpolation. The edges and gradient directions are computed using standard edge detection algorithms such as Canny's detector. Edge linking and detecting straight-line features are described. Preliminary results on Reno, Nevada airport data are included.

Mareboyana, Manohar; Chi, Paul

2006-05-01

260

DArT markers: diversity analyses and mapping in Sorghum bicolor  

Directory of Open Access Journals (Sweden)

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

 
 
 
 
261

Modeling rating curves using remotely-sensed LiDAR data  

Science.gov (United States)

Discharge is important since it integrates water from across the landscape. In remote locations, however, it is often difficult to obtain accurate streamflow information because of the difficulty of obtaining the discharge measurements necessary to define stage-discharge relationships (rating curves). The aim of this study is to investigate the feasibility of defining rating curves indirectly using a fluid-mechanically based model constrained with topographic data from airborne LiDAR scanning. The study is carried out for a small 8-m wide channel in the boreal landscape of northern Sweden. Helicopter-mounted LiDAR data with an approximately 30-cm average point spacing was used to define the channel geometry above a low flow water surface along a 90-m long reach. The channel topography below the surface was estimated using the simple assumption of a flat bed. The roughness for the modeled reach was back-calculated from a single direct measurement of discharge. This topographic and roughness information was then used to calculate a rating curve using the method of Kean and Smith (JGR-Earth Surface, 2010). The rating curve from the LiDAR scan was compared with direct measurements of discharge, as well as with a calculated rating curve developed using more detailed topographic data from a ground survey. In general, there was good agreement between all three methods. The calculated rating curve based on the detailed ground survey was in the best agreement with the direct measurements. The LiDAR-based rating curve was in good agreement with the medium and high flow measurements, but deviated from the direct measurements at low flows. The discrepancy between the LiDAR-based rating curve and the low flow measurements is due to unresolved bed topography, which could not be detected by the scan because of the cover of water. This deficiency can be minimized by scanning during periods of extremely low flow. The results so far suggest that further studies using combined site surveys and LiDAR scans or various combinations of LiDAR scans (e.g., green LiDAR that can detect topographical variations through water) could be useful in generating the data needed to run such a fluid mechanically based model for generating rating curves. This opens a realm of possibility to remotely sense and monitor stream flows in natural channels in remote locations.

Nathanson, M.; Lyon, S. W.; Kean, J. W.; Grabs, T. J.; Seibert, J.; Laudon, H.

2010-12-01

262

Automatic detection of gravel bars in a river channel from airborne LiDAR-derived DTM  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Airborne Laser Scanning or LiDAR data are widely used nowadays in river valleys for topography and hydro-morphology. However, the large data sets of unprocessed 3D point clouds require some challenging treatment and end-users may prefer to deal with DTMs (Digital Terrain Models) derived from LiDAR surveys. Without any complementary data (such as field survey or photographs) detecting position and shape of gravel bars in a river is a demanding task, especially if done manually. This paper ...

Pe?nard, L.; Morel, M.

2012-01-01

263

Por qué el problema del hiato explicativo es realmente un problema para el fisicismo  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish En este artículo exploro el compatibilismo, el punto de vista según el cual la tesis del hiato o hueco explicativo entre lo fenoménico y lo físico es compatible con una metafísica fisicista. Defiendo que el argumento del dualismo de propiedades es un argumento incompatibilista más fuerte que el argu [...] mento de Jackson-Chalmers o el de Kripke y exploro críticamente algunos intentos recientes de replicar al mismo. La conclusión a la que llego es que una posición compatibilista capaz de dar una respuesta adecuada al argumento del dualismo de propiedades sigue todavía pendiente de articulación. Abstract in english In this paper I explore compatibilism, the view that the claim that there is an explanatory gap between the phenomenal and the physical is compatible with an overall physicalist metaphysics. I argue that the property dualism argument is an incompatibilist argument which is stronger than the Jackson- [...] Chalmers argument or Kripke's argument and I critically explore some recent attempts in the literature to deal with it. The conclusion is that a compatibilist view, one able to cope with the property dualism argument, is still pending.

David, Pineda.

264

The Earth System (ES-DOC) Project  

Science.gov (United States)

ESSI1.3 New Paradigms, Modelling, and International Collaboration Strategies for Earth System Sciences Earth System Documentation (ES-DOC) is an international project supplying tools & services in support of earth system documentation creation, analysis and dissemination. It is nurturing a sustainable standards based documentation eco-system that aims to become an integral part of the next generation of exa-scale dataset archives. ES-DOC leverages open source software and places end-user narratives at the heart of all it does. ES-DOC has initially focused upon nurturing the Earth System Model (ESM) documentation eco-system. Within this context ES-DOC leverages emerging documentation standards and supports the following projects: Coupled Model Inter-comparison Project Phase 5 (CMIP5); Dynamical Core Model Inter-comparison Project (DCMIP); National Climate Predictions and Projections Platforms Quantitative Evaluation of Downscaling Workshop. This presentation will introduce the project to a wider audience and demonstrate the range of tools and services currently available for use. It will also demonstrate how international collaborative efforts are essential to the success of ES-DOC.

Greenslade, Mark; Murphy, Sylvia; Treshansky, Allyn; DeLuca, Cecilia; Guilyardi, Eric; Denvil, Sebastien

2014-05-01

265

Visualization of High-Resolution LiDAR Topography in Google Earth  

Science.gov (United States)

The growing availability of high-resolution LiDAR (Light Detection And Ranging) topographic data has proven to be revolutionary for Earth science research. These data allow scientists to study the processes acting on the Earth’s surfaces at resolutions not previously possible yet essential for their appropriate representation. In addition to their utility for research, the data have also been recognized as powerful tools for communicating earth science concepts for education and outreach purposes. Unfortunately, the massive volume of data produced by LiDAR mapping technology can be a barrier to their use. To facilitate access to these powerful data for research and educational purposes, we have been exploring the use of Keyhole Markup Language (KML) and Google Earth to deliver LiDAR-derived visualizations. The OpenTopography Portal (http://www.opentopography.org/) is a National Science Foundation-funded facility designed to provide access to Earth science-oriented LiDAR data. OpenTopography hosts a growing collection of LiDAR data for a variety of geologic domains, including many of the active faults in the western United States. We have found that the wide spectrum of LiDAR users have variable scientific applications, computing resources, and technical experience and thus require a data distribution system that provides various levels of access to the data. For users seeking a synoptic view of the data, and for education and outreach purposes, delivering full-resolution images derived from LiDAR topography into the Google Earth virtual globe is powerful. The virtual globe environment provides a freely available and easily navigated viewer and enables quick integration of the LiDAR visualizations with imagery, geographic layers, and other relevant data available in KML format. Through region-dependant network linked KML, OpenTopography currently delivers over 20 GB of LiDAR-derived imagery to users via simple, easily downloaded KMZ files hosted at the Portal. This method provides seamlessly access to hillshaded imagery for both bare earth and first return terrain models with various angles of illumination. Seamless access to LiDAR-derived imagery in Google Earth has proven to be the most popular product available in the OpenTopography Portal. The hillshade KMZ files have been downloaded over 3000 times by users ranging from earthquake scientists to K-12 educators who wish to introduce cutting edge real world data into their earth science lessons. OpenTopography also provides dynamically generated KMZ visualizations of LiDAR data products produced when users choose to use the OpenTopography point cloud access and processing system. These Google Earth compatible products allow users to quickly visualize the custom terrain products they have generated without the burden of loading the data into a GIS environment. For users who have installed the Google Earth browser plug-in, these visualizations can be launched directly from the OpenTopography results page and viewed directly in the browser.

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

2009-12-01

266

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

267

EISCAT observations of a sequential Es layer  

International Nuclear Information System (INIS)

An experiment was carried out during the summer of 1982, using EISCAT incoherent scatter radar, to investigate sequential Es:layers of enhanced electron density in the ionospheric E-region. Results are presented for an event occurring on 30 July, and the observations compared in a simple way with those expected from the wind-shear theory. Comparisons are made with data available from ionograms from Tromso, Kiruna and Sodankyla, at which sites Es layers are also seen, though with differences that may be due to differences of wind direction. (author)

268

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

269

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

270

a Data Driven Method for Building Reconstruction from LiDAR Point Clouds  

Science.gov (United States)

Airborne laser scanning, commonly referred to as LiDAR, is a superior technology for three-dimensional data acquisition from Earth's surface with high speed and density. Building reconstruction is one of the main applications of LiDAR system which is considered in this study. For a 3D reconstruction of the buildings, the buildings points should be first separated from the other points such as; ground and vegetation. In this paper, a multi-agent strategy has been proposed for simultaneous extraction and segmentation of buildings from LiDAR point clouds. Height values, number of returned pulse, length of triangles, direction of normal vectors, and area are five criteria which have been utilized in this step. Next, the building edge points are detected using a new method named "Grid Erosion". A RANSAC based technique has been employed for edge line extraction. Regularization constraints are performed to achieve the final lines. Finally, by modelling of the roofs and walls, 3D building model is reconstructed. The results indicate that the proposed method could successfully extract the building from LiDAR data and generate the building models automatically. A qualitative and quantitative assessment of the proposed method is then provided.

Sajadian, M.; Arefi, H.

2014-10-01

271

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

272

DARS-RNP and QUASI-RNP: New statistical potentials for protein-RNA docking  

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Full Text Available Abstract Background Protein-RNA interactions play fundamental roles in many biological processes. Understanding the molecular mechanism of protein-RNA recognition and formation of protein-RNA complexes is a major challenge in structural biology. Unfortunately, the experimental determination of protein-RNA complexes is tedious and difficult, both by X-ray crystallography and NMR. For many interacting proteins and RNAs the individual structures are available, enabling computational prediction of complex structures by computational docking. However, methods for protein-RNA docking remain scarce, in particular in comparison to the numerous methods for protein-protein docking. Results We developed two medium-resolution, knowledge-based potentials for scoring protein-RNA models obtained by docking: the quasi-chemical potential (QUASI-RNP and the Decoys As the Reference State potential (DARS-RNP. Both potentials use a coarse-grained representation for both RNA and protein molecules and are capable of dealing with RNA structures with posttranscriptionally modified residues. We compared the discriminative power of DARS-RNP and QUASI-RNP for selecting rigid-body docking poses with the potentials previously developed by the Varani and Fernandez groups. Conclusions In both bound and unbound docking tests, DARS-RNP showed the highest ability to identify native-like structures. Python implementations of DARS-RNP and QUASI-RNP are freely available for download at http://iimcb.genesilico.pl/RNP/

Bujnicki Janusz M

2011-08-01

273

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

Science.gov (United States)

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 (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

274

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

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Full Text Available 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 demonstrable accuracy for at least eight out of nine species, and for all combinations of data types tested. We also found that the combination of hyperspectral imagery and LiDAR data usually improved species classification. Both LiDAR intensity and LiDAR canopy height proved useful for classification of certain species, but the improvements varied depending upon the species in question. Our results pave the way for target-species identification in tropical forests and other ecosystems.

Gregory P. Asner

2012-08-01

275

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

276

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 variation...

Rabus, M.; Deeg, H. J.; Alonso, R.; Belmonte, J. A.; Almenara, J. M.

2009-01-01

277

Distinguishing grass from ground using LiDAR: Techniques and applications  

Science.gov (United States)

Standard protocols exist for extracting bare-earth Digital Elevation Models (DEMs) from LiDAR point clouds that include trees and other large woody vegetation. Grasses and other herbaceous plants can also obscure the ground surface, yet methods for optimally distinguishing grass from ground to generate accurate LiDAR-based raster products for geomorphic and ecological applications are still under development. Developing such methods is important because LiDAR-based difference products (e.g. snow thickness) require accurate representations of the ground surface and because raster data for grass height and density have important applications in ecology. In this study, we developed and tested methods for constructing optimal bare-earth and grass height raster layers from LiDAR point clouds and compared the results to high-quality field-based measurements of grass height, density, and species type for nearly 1000 precisely geo-referenced locations collected during the acquisition of a >200 km^2 airborne LiDAR flight of the Valles Caldera National Preserve (New Mexico). In cases of partially bare ground (where the skewness of return heights above a plane fit to the lowest first returns is sufficiently large), a planar fit to the lowest first returns provides a good method of producing an accurate bare-earth DEM and the statistics of the first returns above that planar fit provide good estimates of the mean and variance of grass height. In areas of relatively thick grass cover, however, a fit to the lowest first returns yields a bare-earth DEM that may be a meter or more above the actual ground surface. Here we propose a method to solve this problem using field-measured correlations among the mean, variance, and skewness of grass heights. In this method, the variance and skewness of the differences between LiDAR first returns and a 10m^2 planar fit to the lowest first returns is used, together with field-based correlations of grass height statistics, to estimate the mean grass height. A bare-earth DEM that corrects for the effects of dense vegetation can then be constructed by subtracting the estimated mean grass height from the mean of the LiDAR first returns. We illustrate two applications of this method. First, spectral analysis of grass height raster products of Valles Caldera reveal fractal patterns that reflect the roles of geomorphology (e.g. height above active channel) and small-scale disturbances on grass growth and hence on the spatial variations in grass height. Second, snow thicknesses mapped by airborne LiDAR in the Valles Caldera systematically under-predict the actual snow thickness in riparian areas because the ground-surface in the snow-off DEM fails to represent the true ground surface in areas of tall, dense grass. By comparing a grass-corrected LiDAR-derived snow thickness map to the results of snow survey data acquired during the time of the snow-on LiDAR flight, we show that the techniques we developed minimize this problem.

Pelletier, J. D.; Swetnam, T.; Papuga, S. A.; Nelson, K.; Brooks, P. D.; Harpold, A. A.; Chorover, J.

2011-12-01

278

Estimating Above Ground Biomass using LiDAR in the Northcoast Redwood Forests  

Science.gov (United States)

In recent years, LiDAR (Light Intensity Detection Amplification and Ranging) is increasingly being used in estimating biophysical parameters related to forested environments. The main goal of the project is to estimate long-term biomass accumulation and carbon sequestration potential of the redwoods ecosystem. The project objectives are aimed at providing an assessment of carbon pools within the redwood ecosystem. Specifically, we intend to develop a relational model based on LiDAR-based canopy estimates and extensive ground-based measurements available for the old-growth redwood forest located within the Prairie Creek Redwoods State Park, CA. Our preliminary analysis involved developing a geospatial database, including LiDAR data collected in 2007 for the study site, and analyzing the data using USFS Fusion software. The study area comprised of a 12-acres section of coastal redwood (Sequoia sempervirens) in the Prairie Creek Redwoods State Park, located in Orick, CA. A series of analytical steps were executed using the USFS FUSION software to produce some intermediate data such as bare earth model, canopy height model, canopy coverage model, and canopy maxima treelist. Canopy maxima tree tops were compared to ground layer to determine height of tree tops. A total of over 1000 trees were estimated, and then with thinning (to eliminate errors due to low vegetation > 3 meters tall), a total of 950 trees were delineated. Ground measurements were imported as a point based shapefile and then compared to the treetop heights created from LiDAR data to the actual ground referenced data. The results were promising as most estimated treetops were within 1-3 meters of the ground measurements and generally within 3-5m of the actual tree height. Finally, we are in the process of applying some allometric equations to estimate above ground biomass using some of the LiDAR-derived canopy metrics.

Rao, M.; Stewart, E.

2010-12-01

279

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

280

LiDAR Segmentation using Suitable Seed Points for 3D Building Extraction  

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Effective building detection and roof reconstruction has an influential demand over the remote sensing research community. In this paper, we present a new automatic LiDAR point cloud segmentation method using suitable seed points for building detection and roof plane extraction. Firstly, the LiDAR point cloud is separated into "ground" and "non-ground" points based on the analysis of DEM with a height threshold. Each of the non-ground point is marked as coplanar or non-coplanar based on a coplanarity analysis. Commencing from the maximum LiDAR point height towards the minimum, all the LiDAR points on each height level are extracted and separated into several groups based on 2D distance. From each group, lines are extracted and a coplanar point which is the nearest to the midpoint of each line is considered as a seed point. This seed point and its neighbouring points are utilised to generate the plane equation. The plane is grown in a region growing fashion until no new points can be added. A robust rule-based tree removal method is applied subsequently to remove planar segments on trees. Four different rules are applied in this method. Finally, the boundary of each object is extracted from the segmented LiDAR point cloud. The method is evaluated with six different data sets consisting hilly and densely vegetated areas. The experimental results indicate that the proposed method offers a high building detection and roof plane extraction rates while compared to a recently proposed method.

Abdullah, S. M.; Awrangjeb, M.; Lu, G.

2014-08-01

 
 
 
 
281

Multi-component wind measurements of wind turbine wakes performed with three LiDARs  

Science.gov (United States)

Field measurements of the wake flow produced from the interaction between atmospheric boundary layer and a wind turbine are performed with three wind LiDARs. The tested wind turbine is a 2 MW Enercon E-70 located in Collonges, Switzerland. First, accuracy of mean values and frequency resolution of the wind measurements are surveyed as a function of the number of laser rays emitted for each measurement. Indeed, measurements performed with one single ray allow maximizing sampling frequency, thus characterizing wake turbulence. On the other hand, if the number of emitted rays is increased accuracy of mean wind is increased due to the longer sampling period. Subsequently, two-dimensional measurements with a single LiDAR are carried out over vertical sections of the wind turbine wake and mean wake flow is obtained by averaging 2D measurements consecutively performed. The high spatial resolution of the used LiDAR allows characterizing in details velocity defect present in the central part of the wake and its downstream recovery. Single LiDAR measurements are also performed by staring the laser beam at fixed directions for a sampling period of about ten minutes and maximizing the sampling frequency in order to characterize wake turbulence. From these tests wind fluctuation peaks are detected in the wind turbine wake at blade top-tip height for different downstream locations. The magnitude of these turbulence peaks is generally reduced by moving downstream. This increased turbulence level at blade top-tip height observed for a real wind turbine has been already detected from previous wind tunnel tests and Large Eddy simulations, thus confirming the presence of a source of dangerous fatigue loads for following wind turbines within a wind farm. Furthermore, the proper characterization of wind fluctuations through LiDAR measurements is proved by the detection of the inertial subrange from spectral analysis of these velocity signals. Finally, simultaneous measurements with two LiDARs are performed over the mean vertical symmetry plane of the wind turbine wake, while a third LiDAR measures the incoming wind over a vertical plane parallel to the mean wind direction and lying outside of the wake. One LiDAR is placed in proximity of the wind turbine location and measures pointing downstream, whereas a second LiDAR is located along the mean wind direction at a downstream distance of 6.5 diameters and measures pointing upstream. For these measurements axial and vertical velocity components are retrieved only for measurement points where the two laser beams result to be roughly orthogonal. Statistics of the two velocity components show in the near wake at hub height strong flow fluctuations with magnitudes about 30% of the mean value, and a gradual reduction for downstream distances larger than three rotor diameters.

Iungo, G. V.; Wu, Y.-T.; Porté-Agel, F.

2012-04-01

282

Comprehensive Utilization of Temporal and Spatial Domain Outlier Detection Methods for Mobile Terrestrial LiDAR Data  

Directory of Open Access Journals (Sweden)

Full Text Available Terrestrial LiDAR provides many disciplines with an effective and efficient means of producing realistic three-dimensional models of real world objects. With the advent of mobile terrestrial LiDAR, this ability has been expanded to include the rapid collection of three-dimensional models of large urban scenes. For all its usefulness, it does have drawbacks. One of the major problems faced by the LiDAR industry today is the automatic removal of outlying data points from LiDAR point clouds. This paper discusses the development and combined implementation of two methods of performing outlier detection in georeferenced point clouds. These methods made use of the raw data available from most time-of-flight mobile terrestrial LiDAR scanners in both the temporal and spatial domains. The first method involved a moving fixed interval smoother derived from the well-known position velocity acceleration Kalman Filter. The second method fitted a quadratic curved surface to sections of LiDAR data. The combined use of these routines is discussed through examples with real LiDAR data.

Baoxin Hu

2011-08-01

283

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

284

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

285

Characterization of Forest Ecosystems by combined Radiative Transfer Modeling for Imaging Spectrometer and LiDAR  

Science.gov (United States)

This research was motivated by the increased information dimensionality provided by current Earth Observation systems measuring the complex and dynamic medium of the vegetated surface of the Earth. Advanced and reliable algorithms that fully exploit this enhanced Earth Observation information are needed to deliver consistent data sets of the Earth vegetation condition describing its spatial distribution and change over time. Spectral observation provided by imaging spectrometers and the waveform from large-footprint LiDAR are now available from space for forest ecosystem studies. The imaging spectrometer data contains information about the biochemical composition of the canopy foliage, and is widely used to estimate biophysical canopy parameters such as LAI and fractional cover. LiDAR responds to the vertical distribution of scatters and permits inferences about the plant structures required to supply water and mechanical support to those surfaces. Various canopy height indices derived from LiDAR waveform have been successfully used to infer forest above-ground biomass and the characterization of canopy structure. The structure parameters derived from LiDAR data can improve the accuracy and robustness of canopy parameter retrieval from imaging spectrometer by reducing uncertainties related to the canopy structure. The specific information content, inherent to the observations of imaging spectrometry and LIDAR, assesses thus different but complementary characteristics of the complex vegetation canopy. The combination of these two information dimensions offers a unique and reliable canopy characterization including information relevant to different aspects of the biochemical and biophysical properties and thus understanding of processes within forest ecosystems. A comprehensive canopy characterization of a forest ecosystem is derived from the combined remote sensing signal of imaging spectrometry and large footprint LIDAR. The inversion of two linked physically based Radiative Transfer Models (RTM) provided the platform for synergistically exploiting the specific and independent information dimensions obtained by the two earth observation systems. The proposed research relies on a radiative transfer model adapted to imaging spectrometer data (GeoSAIL) and a LiDAR waveform model based on the same 3D canopy structure. Both the GeoSAIL and LiDAR waveform models have already been employed and validated to retrieve forest properties from Imaging Spectrometer and LiDAR data separately. As these models are based on the same basic physical concept and share common input parameters an interface between these models can be established, which allows for the generation of a Look Up Table (LUT) consisting of the simulated signatures of the Imaging Spectrometer and LiDAR as a function of a common forest stand parameterization. In the presented approach, the specific information content inherent to the observations of the respective sensor was not only able to complement the canopy characterization, but also helped to solve the ill-posed problem of the RTM inversion. A comprehensive data set including EO and field data has been available for the validation of the proposed earth observation concept over a mixed hardwood and softwood forest part of the Northern Experimental Forest (NEF), Howland, Maine (45°15'N, 68°45'W). The Laser Vegetation Imaging Sensor (LVIS) acquired full waveform data over the site in the summer of 2003 as part of a NASA Terrestrial Ecology Program aircraft campaign. Further the Compact High Resolution Imaging Spectrometer (CHRIS) on the ESA platform Proba data acquired imaging spectrometer data in 2006-08. As reference data every tree in a 200m by 150m area was measured for its location, dbh, and species in 1990, and was re-measured in 2003-2004 and 2006. The field data has been complemented by hemispherical photographs characterizing the canopy structure as well as with field spectrometer measurements of the optical properties for relevant scatters and background. The presented approach provides robust estimates

Koetz, B.; Sun, G.; Morsdorf, F.; Rubio, J.; Kimes, D.; Ranson, J.

2009-04-01

286

Automated Extraction of 3D Trees from Mobile LiDAR Point Clouds  

Science.gov (United States)

This paper presents an automated algorithm for extracting 3D trees directly from 3D mobile light detection and ranging (LiDAR) data. To reduce both computational and spatial complexities, ground points are first filtered out from a raw 3D point cloud via blockbased elevation filtering. Off-ground points are then grouped into clusters representing individual objects through Euclidean distance clustering and voxel-based normalized cut segmentation. Finally, a model-driven method is proposed to achieve the extraction of 3D trees based on a pairwise 3D shape descriptor. The proposed algorithm is tested using a set of mobile LiDAR point clouds acquired by a RIEGL VMX-450 system. The results demonstrate the feasibility and effectiveness of the proposed algorithm.

Yu, Y.; Li, J.; Guan, H.; Zai, D.; Wang, C.

2014-06-01

287

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

288

EMI Execution Service (EMI-ES) Specification  

CERN Document Server

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

289

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 <0.05°C at 30°C. An RTK GPS was used to acquire precise locations of scan positions and to georeference LiDAR point cloud data to real-world coordinates. The combined LiDAR/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

290

3D turbulence measurements in inhomogeneous boundary layers with three wind LiDARs  

Science.gov (United States)

One of the most challenging tasks in atmospheric anemometry is obtaining reliable turbulence measurements of inhomogeneous boundary layers at heights or in locations where is not possible or convenient to install tower-based measurement systems, e.g. mountainous terrain, cities, wind farms, etc. Wind LiDARs are being extensively used for the measurement of averaged vertical wind profiles, but they can only successfully accomplish this task under the limiting conditions of flat terrain and horizontally homogeneous flow. Moreover, it has been shown that common scanning strategies introduce large systematic errors in turbulence measurements, regardless of the characteristics of the flow addressed. From the point of view of research, there exist a variety of techniques and scanning strategies to estimate different turbulence quantities but most of them rely in the combination of raw measurements with atmospheric models. Most of those models are only valid under the assumption of horizontal homogeneity. The limitations stated above can be overcome by a new triple LiDAR technique which uses simultaneous measurements from three intersecting Doppler wind LiDARs. It allows for the reconstruction of the three-dimensional velocity vector in time as well as local velocity gradients without the need of any turbulence model and with minimal assumptions [EGU2013-9670]. The triple LiDAR technique has been applied to the study of the flow over the campus of EPFL in Lausanne (Switzerland). The results show the potential of the technique for the measurement of turbulence in highly complex boundary layer flows. The technique is particularly useful for micrometeorology and wind engineering studies.

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

2014-05-01

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? ...

Zaborskiene?, Gintare?; Garmiene?, Galina; Jasutiene?, Ina; S?alas?evic?iene?, Alvija

2007-01-01

292

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...

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

2009-01-01

293

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

294

Monitoring Automotive Particulate Matter Emissions with LiDAR: A Review  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ul...

Claudio Mazzoleni; Kuhns, Hampden D.; Hans Moosmüller

2010-01-01

295

Evaluating the benefits of Octree-based indexing for LiDAR data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In recent years the geospatial domain has seen a significant increase in the availability of very large three dimensional (3D) point datasets. These datasets originate from a variety of sources, such as for example Light Detection and Ranging (LiDAR) or meteorological weather recordings. Increasingly, a desire within the geospatial community has been expressed to exploit these types of 3D point data in a meaningful engineering context that goes beyond mere visualization. However, current Spat...

Mosa, Abu Saleh Mohammad; Schoen, Bianca; Bertolotto, Michela; et al

2012-01-01

296

"Dar-Al-Nodveh": The First Experience of Collective Wisdom in Managing Mecca City  

Directory of Open Access Journals (Sweden)

Full Text Available The history of Hejaz especially in one century before Islam was affected by Quraysh tribe. All political, social and economical changes were under the control of Quraysh leaders. Qsy Ibn Kalab was the most influential leader of this tribe during history. His unique courageous deeds have change Quraysh from some dispersed tribes to a unified effective tribe. Among such acts of this leader was foundation of "Dar-Al-Nodveh" which was very significant. Dar-Al-Nodveh guaranteed the success of all acts performed in Quraysh and other tribes. Leaders of Quraysh organized their important deeds within the framework of the making opportunities resulted in expansion of this city due to decisions made by elites of the city and consequently Mecca was turned into the biggest business republic of Arabestan. Even they leaded a part of commercial market of the world. They could keep that safe and dispelled all probable dangers. The question is that the idea for formation of this government city, "Dar-Al-Nodveh", is that how came to the mind of Qsy Ibn Kalab and how much was the influence of Dar-Al-Nodveh in Mecca and how did it gave identity to the city? It seems that the international conditions of that time and personality of Qsy Ibn Kalab had very significant influence on the future of the city of Mecca. His corrective actions did much in turning Mecca to a prominent city in peninsula. The present article aimed to study general formation process of this government city with emphasis on the role of Qsy Ibn Kalab.

Asghar Montazerol Ghaem

2013-01-01

297

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

298

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

299

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

300

Remote Sensing | Free Full-Text | GIS-Based Roughness Derivation for Flood Simulations: A Comparison of Orthophotos, LiDAR and Crowdsourced Geodata  

...GIS-Based Roughness Derivation for Flood Simulations: A Comparison of Orthophotos, LiDAR and Crowdsourced Geodata flood simulations based on different datasets: orthophotos, LiDAR data, ... Object-based image analysis is applied to orthophotos and LiDAR raster data in order to generate land cover maps, which enable a roughness ... The vertical vegetation structure within the LiDAR point cloud is used to derive an additional floodplain roughness map. Further roughness maps are ... The results based on roughness maps derived from LiDAR data and OpenStreetMap data are comparable, whereas the results of the other datasets ...

 
 
 
 
301

Drainage Structure Datasets and Effects on LiDAR-Derived Surface Flow Modeling  

Directory of Open Access Journals (Sweden)

Full Text Available With extraordinary resolution and accuracy, Light Detection and Ranging (LiDAR-derived digital elevation models (DEMs have been increasingly used for watershed analyses and modeling by hydrologists, planners and engineers. Such high-accuracy DEMs have demonstrated their effectiveness in delineating watershed and drainage patterns at fine scales in low-relief terrains. However, these high-resolution datasets are usually only available as topographic DEMs rather than hydrologic DEMs, presenting greater land roughness that can affect natural flow accumulation. Specifically, locations of drainage structures such as road culverts and bridges were simulated as barriers to the passage of drainage. This paper proposed a geospatial method for producing LiDAR-derived hydrologic DEMs, which incorporates data collection of drainage structures (i.e., culverts and bridges, data preprocessing and burning of the drainage structures into DEMs. A case study of GIS-based watershed modeling in South Central Nebraska showed improved simulated surface water derivatives after the drainage structures were burned into the LiDAR-derived topographic DEMs. The paper culminates in a proposal and discussion of establishing a national or statewide drainage structure dataset.

Ruopu Li

2013-12-01

302

Phylogenetic relationships between four Salix L. species based on DArT markers.  

Science.gov (United States)

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. PMID:24336112

Przyborowski, Jerzy A; Sulima, Pawe?; Kuszewska, Anna; Za?uski, Dariusz; Kilian, Andrzej

2013-01-01

303

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

304

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

305

High-Density LiDAR Mapping of the Ancient City of Mayapán  

Directory of Open Access Journals (Sweden)

Full Text Available A 2013 survey of a 40 square kilometer area surrounding Mayapán, Yucatan, Mexico used high-density LiDAR data to map prehispanic architecture and related natural features. Most of the area is covered by low canopy dense forest vegetation over karstic hilly terrain that impedes full coverage archaeological survey. We used LiDAR at 40 laser points per square meter to generate a bare earth digital elevation model (DEM. Results were evaluated with comparisons to previously mapped areas and with traditional archaeological survey methods for 38 settlement clusters outside of the city wall. Ground checking employed full coverage survey of selected 500 m grid squares, as well as documentation of the chronology and detail of new public and domestic settlement features and cenotes. Results identify the full extent of continued, contemporary Postclassic settlement (A.D. 1150–1450 outside of the city wall to at least 500 meters to the east, north, and west. New data also reveal an extensive modified landscape of terraformed residential hills, rejolladas, and dense settlement dating from Preclassic through Classic Periods. The LiDAR data also allow for the identification of rooms, benches, and stone property walls and lanes within the city.

Timothy Hare

2014-09-01

306

Motion Field Estimation for a Dynamic Scene Using a 3D LiDAR  

Directory of Open Access Journals (Sweden)

Full Text Available This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (LiDAR sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D LiDAR-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D LiDAR measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively.

Qingquan Li

2014-09-01

307

Effect of oral diacerein (DAR) in an experimental hip chondrolysis model.  

Science.gov (United States)

We aimed to reproduce the articular cartilage structural changes in a joint exposed to a metallic implant as in the adolescent pinned hip with persistent joint penetration and secondly, to test the effect of an interleukin inhibitor, diacerein (DAR) in the ensuing articular cartilage lesion. Twenty immature beagles were submitted to a surgical K-wire implantation in the hip with the material left in the joint space for 6 months. Twelve animals were sacrificed for histological and biochemical tests. Eight animals were sacrificed at 10 months (half of them treated with DAR) and analyzed by scanning electron microscopy (SEM) and biochemistry of the articular cartilage. Preoperative and monthly C3 and C4 complement and immunoglobulins serum levels were determined. The histological and the electrophoretic profile changes were significative at 6 months. At 10 months the migration profile (CaCl2) recovered to normal levels in the operated hip and the SEM scores for the acetabulum were similar to the non operated control hip after treatment. The serum level of IgA was elevated at the 4th and 6th month postoperatively. The persistence of a metallic implant resulted in degenerative changes parallel to that described for hip chondrolysis as a complication of in-situ pinning; and the cartilage lesion improved with DAR treatment. PMID:16705708

Kitadai, Humberto Ken; Takahashi, Hélio Kyoshi; Straus, Anita Hilda; Ibanez, José Fernando; Lucas, Ronald; Kitadai, Fábio Takashi; Milani, Carlo

2006-06-01

308

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 20–30 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 15–65 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 2000–2009. 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

309

Using Airborne LiDAR Technology to Analyze Landslide Hazards in Shih-men Watershed  

Science.gov (United States)

During the flood seasons between 2001 and 2005, Taiwan was devastated by typhoons such as Toraji, Nari, Aere, Haitang, Matsa, Talim, and Longwang. Those trigger massive failures at the upstream. Large amount of sediment was washed into Shih-men Reservoir and dramatically increased the turbidity, far exceeding the capacity of water treatment plants. Water shortage happened as a result, and the managing authority has already begun the watershed conservation management. Remote sensing applications on large-scale monitoring are now widely used around the world. Of them, airborne LiDAR technology is very accurate and has the greatest coverage, able to perform quick and high resolution scan to obtain the three dimensional information of the target. Therefore, this study used airborne LiDAR technology to measure Shih-men watershed to establish high-precision elevation data. In the meantime, through analysis of variance on data before and after the measurement, topological changes from typhoons or extreme rainfalls as well as the efficiency of sediment control facilities are assessed. Keyword: Shih-men Reservoir, LiDAR, digital elevation model, conservation management

Lin, B.-S.; Hsiao, C.-Y.; Leung, W.-Y.; Chi, S.-Y.

2012-04-01

310

Motion Field Estimation for a Dynamic Scene Using a 3D LiDAR.  

Science.gov (United States)

This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (LiDAR) sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D LiDAR-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D LiDAR measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively. PMID:25207868

Li, Qingquan; Zhang, Liang; Mao, Qingzhou; Zou, Qin; Zhang, Pin; Feng, Shaojun; Ochieng, Washington

2014-01-01

311

Geodetic imaging with airborne LiDAR: the Earth's surface revealed  

International Nuclear Information System (INIS)

The past decade has seen an explosive increase in the number of peer reviewed papers reporting new scientific findings in geomorphology (including fans, channels, floodplains and landscape evolution), geologic mapping, tectonics and faulting, coastal processes, lava flows, hydrology (especially snow and runoff routing), glaciers and geo-archaeology. A common genesis of such findings is often newly available decimeter resolution ‘bare Earth’ geodetic images, derived from airborne laser swath mapping, a.k.a. airborne LiDAR, observations. In this paper we trace nearly a half century of advances in geodetic science made possible by space age technology, such as the invention of short-pulse-length high-pulse-rate lasers, solid state inertial measurement units, chip-based high speed electronics and the GPS satellite navigation system, that today make it possible to map hundreds of square kilometers of terrain in hours, even in areas covered with dense vegetation or shallow water. To illustrate the impact of the LiDAR observations we present examples of geodetic images that are not only stunning to the eye, but help researchers to develop quantitative models explaining how terrain evolved to its present form, and how it will likely change with time. Airborne LiDAR technology continues to develop quickly, promising ever more scientific discoveries in the years ahead. (review article)

312

Geodetic imaging with airborne LiDAR: the Earth's surface revealed.  

Science.gov (United States)

The past decade has seen an explosive increase in the number of peer reviewed papers reporting new scientific findings in geomorphology (including fans, channels, floodplains and landscape evolution), geologic mapping, tectonics and faulting, coastal processes, lava flows, hydrology (especially snow and runoff routing), glaciers and geo-archaeology. A common genesis of such findings is often newly available decimeter resolution 'bare Earth' geodetic images, derived from airborne laser swath mapping, a.k.a. airborne LiDAR, observations. In this paper we trace nearly a half century of advances in geodetic science made possible by space age technology, such as the invention of short-pulse-length high-pulse-rate lasers, solid state inertial measurement units, chip-based high speed electronics and the GPS satellite navigation system, that today make it possible to map hundreds of square kilometers of terrain in hours, even in areas covered with dense vegetation or shallow water. To illustrate the impact of the LiDAR observations we present examples of geodetic images that are not only stunning to the eye, but help researchers to develop quantitative models explaining how terrain evolved to its present form, and how it will likely change with time. Airborne LiDAR technology continues to develop quickly, promising ever more scientific discoveries in the years ahead. PMID:23828665

Glennie, C L; Carter, W E; Shrestha, R L; Dietrich, W E

2013-08-01

313

Estimating Basin Snow Volume Using Aerial LiDAR and Binary Regression Trees (Invited)  

Science.gov (United States)

Snow cover derived from airborne LiDAR (Light Detection And Ranging) is combined with binary regression trees to improve the prediction of total basin snow volume for the Dry Creek Experimental Watershed (DCEW), ID. These methods are used to identify site-specific topographic controls on the spatial distribution of snow so that future point measurements of snow depth can be distributed through space efficiently. LiDAR is used to map snow cover by differencing the digital elevation models (DEMs) obtained from a snow-covered overflight and a snow-free overflight. Topographic parameters known to control snow distribution are calculated from the snow free LiDAR dataset. Here, mean vegetation height, slope, aspect, solar radiation, and elevation are used to predict snow depth via a binary regression tree using ten-fold cross-validation. The branches leading to the terminal nodes of the regression tree are used to segment the watershed into homogeneous snow distribution units. Preliminary results indicate that 23 statistically significant discrete units exist. Thus, during future field campaigns, point measurements of snow depth can be gathered and distributed throughout these units. Mean measured SWE/depth of each unit can be summed to determine the total basin snow volume. This method should decrease field time and improve the accuracy of basin snow volume estimates for watershed analyses.

Shallcross, A. T.; McNamara, J. P.; Flores, A. N.; Marshall, H.; Marks, D. G.; Glenn, N. F.

2010-12-01

314

LiDAR scan and smart piezo layer combined damage detection  

Science.gov (United States)

The motivation of this study is to determine a technique to completely describe the damage state of large deformed structures commonly found during forensic investigations. The combination of Laser Detecting and Ranging (LiDAR) and Piezoelectric (PZT) Sensing Technologies for damage quantification is suggested to generate the full-field description of large deformation of a plate. The test subject is a 16 inch by 16 inch aluminum plate subjected to different damage scenarios. LiDAR is a static scanning laser that provides a 3-dimensional picture of the object. Smart Layer is a commercial PZT actuator/sensor network system that generates stress waves for internal damage evaluation. Both techniques were applied to the test plate after damages are introduced. In order to effectively analyze the results, the images for each test were superimposed. Frequencies that depicted the best interpretation of damage in the direct path images were superimposed with the 3-dimensional LiDAR images. Four damage scenarios were imposed on an aluminum plate including saw cuts at different depths using an electric saw. The final damage is a severe bending of the plate. The bending of the specimen produced an image that located the most severe damage directly under the left hand portion and directly above the right hand portion of the bend.

Chen, Shenen; Chung, Howard; Park, Youngjin

2013-04-01

315

High resolution t-LiDAR scanning of an active bedrock fault scarp for palaeostress analysis  

Science.gov (United States)

Palaeostress analysis of an active bedrock normal fault scarp based on kinematic indicators is carried applying terrestrial laser scanning (t-LiDAR or TLS). For this purpose three key elements are necessary for a defined region on the fault plane: (i) the orientation of the fault plane, (ii) the orientation of the slickenside lineation or other kinematic indicators and (iii) the sense of motion of the hanging wall. We present a workflow to obtain palaeostress data from point cloud data using terrestrial laser scanning. The entire case-study was performed on a continuous limestone bedrock normal fault scarp on the island of Crete, Greece, at four different locations along the WNW-ESE striking Spili fault. At each location we collected data with a mobile terrestrial light detection and ranging system and validated the calculated three-dimensional palaeostress results by comparison with the conventional palaeostress method with compass at three of the locations. Numerous kinematics indicators for normal faulting were discovered on the fault plane surface using t-LiDAR data and traditional methods, like Riedel shears, extensional break-outs, polished corrugations and many more. However, the kinematic indicators are more or less unidirectional and almost pure dip-slip. No oblique reactivations have been observed. But, towards the tips of the fault, inclination of the striation tends to point towards the centre of the fault. When comparing all reconstructed palaeostress data obtained from t-LiDAR to that obtained through manual compass measurements, the degree of fault plane orientation divergence is around ±005/03 for dip direction and dip. The degree of slickenside lineation variation is around ±003/03 for dip direction and dip. Therefore, the percentage threshold error of the individual vector angle at the different investigation site is lower than 3 % for the dip direction and dip for planes, and lower than 6 % for strike. The maximum mean variation of the complete calculated palaeostress tensors is ±005/03. So, technically t-LiDAR measurements are in the error range of conventional compass measurements. The advantages is that remote palaeostress analysis is possible. Further steps in our research will be studying reactivated faults planes with multiple kinematic indicators or striations with t-LiDAR.

Reicherter, Klaus; Wiatr, Thomas; Papanikolaou, Ioannis; Fernández-Steeger, Tomas

2013-04-01

316

DArT markers for the rye genome - genetic diversity and mapping  

Directory of Open Access Journals (Sweden)

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

317

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

318

Multiple-LiDAR measurements of wind turbine wakes: effect of the atmospheric stability  

Science.gov (United States)

Aerodynamic design and optimization of a wind farm layout are mainly based on the evaluation of wind turbine wake recovery by moving downstream, and on the characterization of wake interactions within a wind farm. Indeed, the power production of downstream wind turbine rows is strictly affected by the cumulative wake produced by the turbines deployed upstream. Wind turbine wakes are dependent on their aerodynamic features, and being immersed in the atmospheric boundary layer (ABL), they are also affected by surface heterogeneity, e.g. site topography and surface coverage, and atmospheric stability. The ABL stability is typically classified as neutral, convective or stable. In a neutral ABL the mechanical turbulent production is the dominating phenomenon. Conversely, for a convective ABL the turbulent kinetic energy and vertical transport phenomena are enhanced by positive buoyancy. Finally, for a stable ABL, a lower turbulence level is typically observed with an increased wind shear. For the present campaign convective ABL was typically observed during day-time, and neutral ABL for early morning and sunset periods. The aim of the present work is the evaluation of the influence of the ABL stability on downstream evolution of wind turbine wakes, which is mainly controlled by different ABL turbulence characteristics. Field measurements of the wake produced from a 2 MW Enercon E-70 wind turbine were performed with three scanning Doppler wind LiDARs. The wind and atmospheric conditions were characterized through a sonic anemometer deployed in proximity of the wind turbine. One LiDAR was placed at a distance about 12 rotor diameters upstream of the turbine in order to characterize the incoming wind. Two additional LiDARs were typically used to perform wake measurements. Tests were performed over the wake vertical symmetry plane in order to characterize wake recovery. Measurements were also carried out over conical surfaces in order to investigate the wind turbine wake with varying wind direction, thus different turbine yaw angles. Moreover, a 3D characterization of the wind turbine wake was performed by scanning the LiDAR over a 3D measurement volume. However, the large sampling period required for the 3D scans does not allow the investigation of wake dynamics. The LiDAR measurements show that wake evolution is significantly affected by the stability conditions of the ABL, thus by the different turbulence characteristics of the incoming wind. In particular, a faster wake recovery is observed in the presence of an increased turbulence of the incoming wind and for more convective atmospheric flows.

Valerio Iungo, Giacomo; Porté-Agel, Fernando

2013-04-01

319

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

320

Kooperatin?s bendrov?s „Daržovi? centras“ produkt? pardavimo r?mimo strategijos formavimas  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The object of research – cooperative “Daržovi? centras”. The subject of research – promotion and forces having influence on it. The aim of the work – to prepare promotion strategy for cooperative “Daržovi? centras”. The tasks: 1) to estimate forces, influencing marketing and promotion strategy in organization; 2) to analyze theoretical aspects of promotion instrumentality and define relations between them; 3) to identify promotion strategy stages; 4) to analyze environmental...

Pranckevic?iu?te?, Jolanta

2005-01-01

 
 
 
 
321

3D modeling of light interception in heterogeneous forest canopies using ground-based LiDAR data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A methodology is presented that describes the direct interaction of a forest canopy with incoming radiation using terrestrial LiDAR based vegetation structure in a radiative transfer model. The proposed ‘Voxel-based Light Interception Model’ (VLIM) is designed to estimate the Percentage of Above Canopy Light (PACL) at any given point of the forest scene. First a voxel-based representation of trees is derived from terrestrial LiDAR data as structural input to model and analyze the light in...

Zande, Dimitry; Stuckens, Jan; Verstraeten, Willem W.; Mereu, Simone; Muys, Bart; Coppin, Pol

2011-01-01

322

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...

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

2011-01-01

323

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

Science.gov (United States)

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

324

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

325

¿Es redundante la prueba de selectividad?.  

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Full Text Available Como consecuencia de la futura reforma en las pruebas de acceso a la universidad española, en donde la principal novedad será la eliminación de la prueba de conjunto o selectividad, cabe reflexionar sobre tan controvertida prueba y preguntarnos si realmente dicha prueba ha servido para algo y su aplicación ha sido efectiva en el rendimiento del alumno una vez dentro de la universidad o, por el contrario, si se trata de una prueba redundante. A partir del expediente académico y de las notas de selectividad de una muestra de 2.500 alumnos durante siete años, se llevará a cabo un análisis econométrico del grado de explicación que estas notas tienen sobre la prueba de conjunto y se constatará si dicha prueba es efectiva o redundante.

Rúa Vieytes, Antonio.

2003-01-01

326

Study of TrES-3 Exoplanet  

Science.gov (United States)

The first amateur observation of an exoplanet was made from the Nyrola Observatory in September 16, 2000. (Marko Moilanen, Jalo Ojanperä, Jouni Sorvari, Aki Id and Arto Oksanen). The jovian-type planet orbits a star that is 153 light years far away, and was called HD209458b in Pegasus [1]. The equipment used by this Observatory was a 16 inches MEADE LX200, a ST7E CCD SBIG camera with a V photometric filter and an f/6.3 focal distance reducer. At the University of Nariño Observatory we have a similar equipment. The equipment we employed is: 14"LX200 GPS MEADE telescope and STL-1001 SBIG. The camera we used in our search is much more sensible than the one used by the Nyrola Observatory [2]. From the Astronomical Observatory at the University of Nariño-COLOMBIA, we begun a systematic search for exoplanets. We have already confirmed the transit of the exoplanet TrES-3. This exoplanet was discovered by O'Donovan and other investigators, and turns around the GSC 03089- 00929, with an orbital period of 1.30619 days (31.34856 hours) and inclination of 82.15 deg [3]. The TrES-3 is quite interesting because it has one of the smallest periods found on exoplanets. Jessie L. Christiansen, et.al. observed seven transits and they found that the duration of transit is 81.9+/-1.1 minutes and inclination of 81.99+/-0.30 deg [4], [5]. We have captured a lot of data to elaborate the lightcurves so we can estimate the physical parameters of the exoplanet.

Vodniza, A. Q.; Rojas, M.; Reyes, K.

2011-10-01

327

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

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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

328

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

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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

329

La avenida sexta de día es una y de noche es otra, Cali  

Digital Repository Infrastructure Vision for European Research (DRIVER)

En el pie de foto dice lo siguiente: La avenida sexta de día es una y de noche otra. Y bien distinta. Entre las diez de la mañana y las seis de la tarde, ofrece el más variado comercio. Hasta los hippies tienen asiento para sus chucherías que suelen comprar las sardinas y sardinos.- El Archivo del Patrimonio Fotográfico y Fílmico del Valle del Cauca es responsabilidad de la Biblioteca Departamental del Valle Jorge Garcés Borrero, por convenio de cooperación suscrito con la Secretaria ...

Go?mez, Gustavo

1984-01-01

330

Monitoring Depth of Shallow Atmospheric Boundary Layer to Complement LiDAR Measurements Affected by Partial Overlap  

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Full Text Available There is compelling evidence that the incomplete laser beam receiver field-of-view overlap (i.e., partial overlap of ground-based vertically-pointing aerosol LiDAR restricts the observational range for detecting aerosol layer boundaries to a certain height above the LiDAR. This height varies from one to few hundreds of meters, depending on the transceiver geometry. The range, or height of full overlap, is defined as the minimum distance at which the laser beam is completely imaged onto the detector through the field stop in the receiver optics. Thus, the LiDAR signal below the height of full overlap remains erroneous. In effect, it is not possible to derive the atmospheric boundary layer (ABL top (zi below the height of full overlap using lidar measurements alone. This problem makes determination of the nocturnal zi almost impossible, as the nocturnal zi is often lower than the minimum possible retrieved height due to incomplete overlap of lidar. Detailed studies of the nocturnal boundary layer or of variability of low zi would require changes in the LiDAR configuration such that a complete transceiver overlap could be achieved at a much lower height. Otherwise, improvements in the system configuration or deployment (e.g., scanning LiDAR are needed. However, these improvements are challenging due to the instrument configuration and the need for Raman channel signal, eye-safe laser transmitter for scanning deployment, etc. This paper presents a brief review of some of the challenges and opportunities in overcoming the partial overlap of the LiDAR transceiver to determine zi below the height of full-overlap using complementary approaches to derive low zi. A comprehensive discussion focusing on four different techniques is presented. These are based on the combined (1 ceilometer and LiDAR; (2 tower-based trace gas (e.g., CO2 concentration profiles and LiDAR measurements; (3 222Rn budget approach and LiDAR-derived results; and (4 encroachment model and LiDAR observations.

Sandip Pal

2014-09-01

331

¿Qué tan verde es tu mercado?  

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Full Text Available El mercado de lo verde y lo ecológico es una tendencia indiscutible en nuestro mundo globalizado, que busca de alguna manera resarcir el daño infringido sobre el medio ambiente. Más allá de simple altruismo, la ecología se ha convertido en una moda, de la cual unos y otros toman ventaja a su mejor acomodo, haciendo del mercado de productos y servicios su tribuna; eco-diseño, planes de responsabilidad social y ambiental, campañas por el reciclaje y consumo de productos "más amigables" con el medio ambiente hacen parte del panorama que se intenta describir en esta reseña. Por medio de un estudio de caso, se hará énfasis en cómo la comunicación asume un papel crucial en la verdadera apropiación del concepto de "consumidor verde" y "consumidor responsable", de manera que la propuesta transversal de las tic se convierta en una herramienta no solo tecnológica, sino también de empoderamiento del papel que la sociedad puede representar en el cuidado de los recursos naturales.

Wilmar R. Olaya-Gonz\\u00E1lez

2011-01-01

332

The photometric period in ES Ceti  

CERN Document Server

We present ULTRACAM photometry of ES Cet, an ultracompact binary with a 620s orbital period. The mass transfer in systems such as this one is thought to be driven by gravitational radiation, which causes the binary to evolve to longer periods since the semi-degenerate donor star expands in size as it loses mass. We supplement these ULTRACAM+WHT data with observations made with smaller telescopes around the world over a nine year baseline. All of the observations show variation on the orbital period, and by timing this variation we track the period evolution of this system. We do not detect any significant departure from a linear ephemeris, implying a donor star that is of small mass and close to a fully degenerate state. This finding favours the double white dwarf formation channel for this AM CVn star. An alternative explanation is that the system is in the relatively short-lived phase in which the mass transfer rate climbs towards its long-term value.

Copperwheat, C M; Dhillon, V S; Littlefair, S P; Woudt, P A; Warner, B; Patterson, J; Steeghs, D; Kemp, J; Armstrong, E; Rea, R

2011-01-01

333

Enfermedad de Alzheimer: ¿Es posible la prevención?  

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Full Text Available La enfermedad de Alzheimer, junto con la depresión, está considerada como una de las epidemias del siglo. Según los estudios de la organización Alzheimer’s DiseaseInternational (ADI, alrededor de 25 millones de personas en el mundo padecen de demencia, siendo la más frecuente el Alzheimer. El impacto económico de este trastorno también tiene serias implicancias para los países, dado el alto costo que implica su tratamiento. En Estados Unidos, el Alzheimer es la tercera enfermedad más cara en tratarse después de las enfermedades cardiovasculares y el cáncer.La expansión de esta enfermedad supone revisar y ampliar los conocimientos sobre las posibles causas que están detrás de su aparición y los métodos de prevención que se deben impulsar o promover. En este contexto, el presente artículo nos da luces sobre estos aspectos poco estudiados y que constituye la prevención primaria, la cual está dirigida a evitar que se desarrolle la enfermedad o retrasar su aparición. Mariella Guerra repasa y explica cada uno de los factores ambientales, genéticos y los propios del envejecimiento que intervienen en el desarrollo del alzheimer.

Mariella Guerra

2009-06-01

334

Accuracy of Forest Road and Stream Channel Characteristics Derived from LiDAR Terrain Data in Forested Mountain Conditions  

Science.gov (United States)

Airborne LiDAR data is now commonly used to create digital elevation models with a vertical accuracy and grid resolution that surpasses traditional sources of topographic data. The improved topographic detail of LiDAR-derived DEMs allows for identification and measurement of important topographic features including forest roads, historic landslides and potentially unstable areas. When used conjunction with GIS-based flow accumulation algorithms, high-resolution DEMs can also provide improvements to the positional accuracy, longitudinal profile, stream lengths of topographically-derived stream channels. LiDAR data collected over forested and steep terrain however, requires careful evaluation. The reduced density and variable spacing of LiDAR ground returns, which is often encountered in these settings, reduces the effective resolution of LiDAR DEMs and may limit fine-scale topographic mapping. This study tested the completeness and accuracy forest road and stream channel features mapped using a 1.5 m LiDAR-derived DEM for a 526-hectare watershed in the Santa Cruz mountains in California. Positional accuracy, longitudinal slope and length of LiDAR-derived features were compared to field-survey measurements obtained using total station. LiDAR-derived measurements were also compared to measurements from traditional data sources such as a USGS 10 m DEM and a 1 m orthophoto. The LiDAR- derived road was manually digitized from the LiDAR hillshade and slope layers, with a positional accuracy of 2.2 m normal to the field-surveyed centerline. LiDAR-derived road slope was accurate to within 0.59% of field-surveyed slope at a 95% confidence interval. The entire 4 km road length could be mapped using the LiDAR data. Due to the dense overstory canopy only 18% of that road length could be identified from the orthophoto. Stream channel features derived using Arc Hydro were compared to field-surveyed data at six 100 m study reaches. The average positional accuracy of the derived channel locations was 2.7 m normal to the field- surveyed thalweg. Longitudinal channel slope was measured to within 0.49% compared to the field- surveyed slope while channel length was underestimated by an average of 6 percent. These measurements provided an improvement over the features derived from the USGS 10 m DEM, where channel features had a positional accuracy of 8.7 m, channel length was underestimated by 11% and had a longitudinal slope error was one order of magnitude greater than the LiDAR-derived measurement. These findings indicate that even in densely forested areas, LiDAR has the potential to support accurate, watershed-wide inventories of forest road and stream channel features, which can contribute to our understanding road erosion, sediment transport, and their effects on the stream channel network.

White, R. A.; Dietterick, B. C.

2008-12-01

335

Assessment of potential catastrophic landslides in Taiwan by airborne LiDAR-derived DEM  

Science.gov (United States)

The heavy rainfall of Typhoon Morakot caused severe damage to infrastructures, property and human lives in southern Taiwan in 2009. The most atrocious incident was the Hsiaolin landslide, which buried more than 400 victims. After this catastrophic event, the recognition of localities of deep-seated landslides becomes a critical issue in landslide hazard mitigation induced from extreme climate events. Consequently the airborne LiDAR survey was carried out in first phase from 2010 to 2012 by Central Geological Survey, MOEA in Taiwan in order to assess the potential catastrophic deep-seated landslides in the steep and rocky terrain in south-central Taiwan. The second phase of LiDAR survey is ongoing from 2013 to 2015 for the recognition and the assessment of possible impact area induced by deep-seated landslide in the mountainous area of whole Taiwan. Transitionally, the recognition of potential deep-seated landslide sites is adopted in term of landslide inventories from space-borne images, aerial photographs and field investigation. However, it is difficult to produce robust landslide inventories due to the poor spatial resolution of ground elevation and highly dense vegetation in mountainous area in Taiwan. In this study, the 1 m LiDAR-derived DEM is used to extract key geomorphological features such as crown cracks, minor scarps, toe of surface rupture at meter to sub-meter scale hidden under forests with high degree of accuracy. Preliminary result shows that about 400 potential landslide sites have been recognized to improve the quality of landslide inventories. In addition, detailed contour maps and visualized images are reproduced to outline the shape of potential deep-seated landslides. Further geomorphometric analyses based on hillshade, aspect, slope, eigenvalue ratio (ER) and openness will be integrated to easily create landslide inventories to mitigate landslide disasters in Taiwan mountainous area.

Hou, Chin-Shyong; Hsieh, Yu-Chung; Hu, Jyr-Ching; Chiu, Cheng-Lung; Chen, Hung-Jen; Fei, Li-Yuan

2013-04-01

336

Quantifying vertical and horizontal stand structure using terrestrial LiDAR in Pacific Northwest forests  

Science.gov (United States)

Stand level spatial distribution is a fundamental part of forest structure that influences many ecological processes and ecosystem functions. Vertical and horizontal spatial structure provides key information for forest management. Although horizontal stand complexity can be measured through stem mapping and spatial analysis, vertical complexity within the stand remains a mostly visual and highly subjective process. Tools and techniques in remote sensing, specifically LiDAR, provide three dimensional datasets that can help get at three dimensional forest stand structure. Although aerial LiDAR (ALS) is the most widespread form of remote sensing for measuring forest structure, it has a high omission rate in dense and structurally complex forests. In this study we used terrestrial LiDAR (TLS) to obtain high resolution three dimensional point clouds of plots from stands that vary by density and composition in the second-growth Pacific Northwest forest ecosystem. We used point cloud slicing techniques and object-based image analysis (OBIA) to produce canopy profiles at multiple points of vertical gradient. At each height point we produced segments that represented canopies or parts of canopies for each tree within the dataset. The resulting canopy segments were further analyzed using landscape metrics to quantify vertical canopy complexity within a single stand. Based on the developed method, we have successfully created a tool that utilizes three dimensional spatial information to accurately quantify the vertical structure of forest stands. Results show significant differences in the number and the total area of the canopy segments and gap fraction between each vertical slice within and between individual forest management plots. We found a significant relationship between the stand density and composition and the vertical canopy complexity. The methods described in this research make it possible to create horizontal stand profiles at any point along the vertical gradient of forest stands with high frequency, therefore providing ecologists with measures of horizontal and vertical stand structure. Key Words: Terrestrial laser scanning, canopy structure, landscape metrics, aerial laser scanning, lidar, calibration, Pacific Northwest.

Kazakova, Alexandra N.

337

Comparison of remotely sensed water stages from LiDAR, topographic contours and SRTM  

Science.gov (United States)

Digital elevation models (DEMs) are at the core of most environmental process modelling and disaster management. In flood inundation modelling, surface elevation constitutes one of the most important model boundary conditions. With the availability of high-precision DEMs (e.g. LiDAR) and globally available DEMs (e.g. SRTM InSAR) a big step seems to have been taken in terms of hydraulic modelling application or hydraulic information retrieval from such DEMs, with high potential in particular for ungauged basins. Comparative studies exist that report on both the validation of different remotely sensed elevation sources and their use for both hydrologic and hydraulic studies. To contribute to the existing literature on DEMs and hydraulic information, this study aims at comparing water stages derived from LiDAR, topographic contours and SRTM. A flood inundation model calibrated with distributed ground-surveyed high water marks is used to evaluate the remotely sensed water stages. The results show that, as expected, LiDAR derived water stages exhibit the lowest RMSE (0.35 m), followed by the contour DEM (0.7 m). A relatively good performance of the SRTM (1.07 m), which is possibly linked to the low-lying floodplain, suggests that the SRTM is a valuable source for initial vital flood information extraction in large, homogeneous floodplains. Subsequent 3D flood mapping from remotely sensed water stages confirms this but also indicates that flood mapping with low-resolution, low-precision surface elevation data is hardly possible on the small scale, as the accuracy of the resulting map depends too much on DEM uncertainties and errors both in the horizontal and vertical directions.

Schumann, G.; Matgen, P.; Cutler, M. E. J.; Black, A.; Hoffmann, L.; Pfister, L.

338

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

Directory of Open Access Journals (Sweden)

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

339

Investigation on the contribution of LiDAR data in 3D cadastre  

Science.gov (United States)

The existing 2D cadastral systems worldwide cannot provide a proper registration and representation of the land ownership rights, restrictions and responsibilities in a 3D context, which appear in our complex urban environment. ?n such instances, it may be necessary to consider the development of a 3D Cadastre in which proprietary rights acquire appropriate three-dimensional space both above and below conventional ground level. Such a system should contain the topology and the coordinates of the buildings' outlines and infrastructure. The augmented model can be formed as a full 3D Cadastre, a hybrid Cadastre or a 2D Cadastre with 3D tags. Each country has to contemplate which alternative is appropriate, depending on the specific situation, the legal framework and the available technical means. In order to generate a 3D model for cadastral purposes, a system is required which should be able to exploit and represent 3D data such as LiDAR, a remote sensing technology which acquires three-dimensional point clouds that describe the earth's surface and the objects on it. LiDAR gives a direct representation of objects on the ground surface and measures their coordinates by analyzing the reflecting light. Moreover, it provides very accurate position and height information, although direct information about the objects' geometrical shape is not conveyed. In this study, an experimental implementation of 3D Cadastre using LiDAR data is developed, in order to investigate if this information can satisfy the specifications that are set for the purposes of the Hellenic Cadastre. GIS tools have been used for analyzing DSM and true orthophotos of the study area. The results of this study are presented and evaluated in terms of usability and efficiency.

Giannaka, Olga; Dimopoulou, Efi; Georgopoulos, Andreas

2014-08-01

340

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

Science.gov (United States)

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

 
 
 
 
341

Relevance of IsoDAR and DAEdALUS to Medical Radioisotope Production  

CERN Document Server

The very-high current cyclotrons being designed for the IsoDAR and DAEdALUS experiments are of value to fields outside of neutrino physics. In particular, the medical isotopes industry can benefit from these cyclotron developments to produce a new generation of machines with capabilities far in excess of today's technology. This paper provides a tutorial on the field of medical isotopes: from properties of isotopes desired for clinical applications, to production considerations and available technology, concluding with discussion of the impact of the new cyclotrons on the field.

Alonso, Jose R

2012-01-01

342

Using High-Resolution Airborne LiDAR-Data for Landslide Mapping in the Eastern Alps  

Science.gov (United States)

Due to the increasing frequency of natural disasters like floods and landslides, the active remote sensing technique LiDAR (Light Detection and Ranging), has become a topic of great interest to the Federal State Government of Styria, Federal Republic of Austria. In a perennial project from 2008 to 2012 high-resolution 3D Airborne LiDAR Data of the Province of Styria, an area about 16.000km2 in south-eastern Austria were collected. These data were processed to create Digital Terrain Models (DTM) and Digital Surface Models (DSM) at 1m resolution with a vertical accuracy of 15 [cm] and a positional accuracy of 40 [cm]. High resolution DTMs can be used in different geo-related applications like geomorphological mapping or natural hazard mapping. DTMs show because of its high accuracy various natural and anthropogenic terrain features such as erosion scarps, alluvial fans, landslides, old creeks, topographic edges and karstforms, as well as walking paths and roads and in addition to that LiDAR data allows the detection and outlining of these different geomorphological and anthropogenic features with the help of ArcGIS 10 geoprocessing and analysing techniques, mathematical, statistical and image processing methods and the open source scripting language Python. As a result complex workflows and new geoprocessing tools can be implemented in an ArcGIS 10 workspace and are provided as easy to use toolbox contents. The landslide phenomena take in centre stage of the research work of the author. Thereby the main focus is targeted on sliding movements out of soils and bedrock. Factors like gravity take effect on slope stability directly and cause complex mass movements with a downslope directed, gliding movement of bed- and/or loose-rock as well as soil material. In this paper the author presents the result of her master thesis, an automatic ArcGIS 10 landslide mapping tool using high-resolution LiDAR data in the rock masses of the Eastern Alps (Province of Styria, Austria). This tool based on analyzing and modeling different land surface parameters such as slope, variance of slope, curvature or roughness. The ArcGIS 10 Landslide Mapping Tool points out endangered regions in the Province of Styria and shows the quantity of landslides in a specific area.

Kamp, N.

2012-04-01

343

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

344

Skeleton-based botanic tree diameter estimation from dense LiDAR data:  

Digital Repository Infrastructure Vision for European Research (DRIVER)

New airborne LiDAR (Light Detection and Ranging) measurement systems, like the FLI-MAP 400 System, make it possible to obtain high density data containing far more information about single objects, like trees, than traditional airborne laser systems. Therefore, it becomes feasible to analyze geometric properties of trees on the individual object level. In this paper a new 3-step strategy is presented to calculate the stem diameter of individual natural trees at 1.3m height, the so-called brea...

Bucksch, A.; Lindenbergh, R.; Mementi, M.; Raman, M. Z.

2009-01-01

345

LiDAR measurements of full scale wind turbine wake characteristics  

DEFF Research Database (Denmark)

Full scale wind speed measurements, recorded inside the wake of an operating 2MW/80m wind turbine,has been performed during the spring 2009, as part of the EU-TOPFARM project. Longitudinal wind speeds in wake cross sections are measured with a LiDAR system mounted in the rear of the nacelle. The experimental setup, the amount of data, preliminary analysis and limitations of using LIDAR measurements to identify the wake dynamics will be presented. Resolving the wake in the meandering frame of reference further allows for identification of the wake characteristics both in terms of wake deficit and wake turbulence.

Hansen, Kurt Schaldemose; Larsen, Gunner Chr.

2009-01-01

346

Unsupervised building detection from irregularly spaced LiDAR and aerial imagery  

Science.gov (United States)

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

Shorter, Nicholas Sven

347

Financial sustainability in municipal solid waste management--costs and revenues in Bahir Dar, Ethiopia.  

Science.gov (United States)

Providing good solid waste management (SWM) services while also ensuring financial sustainability of the system continues to be a major challenge in cities of developing countries. Bahir Dar in northwestern Ethiopia outsourced municipal waste services to a private waste company in 2008. While this institutional change has led to substantial improvement in the cleanliness of the city, its financial sustainability remains unclear. Is the private company able to generate sufficient revenues from their activities to offset the costs and generate some profit? This paper presents a cost-revenue analysis, based on data from July 2009 to June 2011. The analysis reveals that overall costs in Bahir Dar's SWM system increased significantly during this period, mainly due to rising costs related to waste transportation. On the other hand, there is only one major revenue stream in place: the waste collection fee from households, commercial enterprises and institutions. As the efficiency of fee collection from households is only around 50%, the total amount of revenues are not sufficient to cover the running costs. This results in a substantial yearly deficit. The results of the research therefore show that a more detailed cost structure and cost-revenue analysis of this waste management service is important with appropriate measures, either by the privates sector itself or with the support of the local authorities, in order to enhance cost efficiency and balance the cost-revenues towards cost recovery. Delays in mitigating the evident financial deficit could else endanger the public-private partnership (PPP) and lead to failure of this setup in the medium to long term, thus also endangering the now existing improved and currently reliable service. We present four options on how financial sustainability of the SWM system in Bahir Dar might be enhanced: (i) improved fee collection efficiency by linking the fees of solid waste collection to water supply; (ii) increasing the value chain by sales of organic waste recycling products; (iii) diversifying revenue streams and financing mechanisms (polluter-pays-, cross-subsidy- and business-principles); and (iv) cost reduction and improved cost-effectiveness. We argue that in a PPP setup such as in Bahir Dar, a strong alliance between the municipality and private enterprise is important so that appropriate solutions for improved financial sustainability of a SWM system can be sought and implemented. PMID:24246579

Lohri, Christian Riuji; Camenzind, Ephraim Joseph; Zurbrügg, Christian

2014-02-01

348

Temporal Analysis and Automatic Calibration of the Velodyne HDL-32E LiDAR System  

Science.gov (United States)

At the end of the first quarter of 2012, more than 600 Velodyne LiDAR systems had been sold worldwide for various robotic and high-accuracy survey applications. The ultra-compact Velodyne HDL-32E LiDAR has become a predominant sensor for many applications that require lower sensor size/weight and cost. For high accuracy applications, cost-effective calibration methods with minimal manual intervention are always desired by users. However, the calibrations are complicated by the Velodyne LiDAR's narrow vertical field of view and the very highly time-variant nature of its measurements. In the paper, the temporal stability of the HDL-32E is first analysed as the motivation for developing a new, automated calibration method. This is followed by a detailed description of the calibration method that is driven by a novel segmentation method for extracting vertical cylindrical features from the Velodyne point clouds. The proposed segmentation method utilizes the Velodyne point cloud's slice-like nature and first decomposes the point clouds into 2D layers. Then the layers are treated as 2D images and are processed with the Generalized Hough Transform which extracts the points distributed in circular patterns from the point cloud layers. Subsequently, the vertical cylindrical features can be readily extracted from the whole point clouds based on the previously extracted points. The points are passed to the calibration that estimates the cylinder parameters and the LiDAR's additional parameters simultaneously by constraining the segmented points to fit to the cylindrical geometric model in such a way the weighted sum of the adjustment residuals are minimized. The proposed calibration is highly automatic and this allows end users to obtain the time-variant additional parameters instantly and frequently whenever there are vertical cylindrical features presenting in scenes. The methods were verified with two different real datasets, and the results suggest that up to 78.43% accuracy improvement for the HDL-32E can be achieved using the proposed calibration method.

Chan, T. O.; Lichti, D. D.; Belton, D.

2013-10-01

349

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.

350

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.

2014-06-01

351

Belleza, sí, pero ¿qué es eso?  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish El concepto de belleza es relativo al imaginario colectivo y los dictados culturales de las diversas épocas, si bien admite casi tantas miradas como individuos. Un contrapeso a tal relativismo: aun hoy suele hablarse de la supuesta "belleza eterna" del arte griego. En épocas de cambio y al amparo de [...] rupturas estéticas-filosóficas, artistas y pensadores se han rebelado contra los modelos canónicos. Así, la revolución romántica proclamó que lo bello no sólo podría no depender de la equidad y armonía pregonadas desde Aristóteles, sino que consistiría en la total subversión de dicha armonía. En lo que va del placer al goce lacaniano, irrumpe la belleza de lo feo, o de su representación. La revolución copernicana y el yo escindido de Freud trastornaron las ideas de eje único y de verdad. ¿El arte ya no existe? Las visiones estéticas enfrentadas dan paso a emergentes capaces de cuestionar los dogmas pre-establecidos Abstract in english The concept of beauty is related to the collective imaginary and the cultural dictates of diverse eras, as well as admitting almost as many visions as individuals. A counterweight to such relativism: even today we often hear of the supposed "eternal beauty" of Greek art. In periods of change and und [...] er the shelter of aesthetic-philosophical ruptures, artists and thinkers have rebelled against those canonical models. The romantic revolution proclaimed that the beautiful could not only not depend on the equality and harmony proffered since Aristotle, but that it would consist of the total subversion of that harmony. In respect to the pleasure of Lacanian joy, it is the beauty of ugliness that emerges, or its representation. The Copernican Revolution and Freud’s divided ego upset the ideas of one axis and of truth. Does art no longer exist? The confrontation of aesthetic visions gives way to emergent ones that are capable of questioning pre-established dogmas

Jorge Ariel, Madrazo.

352

¿Es posible ser moralmente responsable? Notas para una nueva definición del concepto de sujeto  

Directory of Open Access Journals (Sweden)

Full Text Available The Strawson´s Basic Argument is the stronger against moral responsibility in Philosophy of action. One should be responsible of his identity to be moral responsible of his actions, but then nobody could be never responsible. In this article I criticize orthodox solutions to Strawson´s sceptical challenge and show how they share with the Argument the same theological notion of monadical agent. A new solution needs a new conception of agent..Una de las objeciones más fuertes contra la responsabilidad moral en filosofía de la acción sería el Argumento Básico de Galen Strawson, que plantea la necesidad de que uno sea responsable de ser quien es para poder ser responsable moralmente de sus acciones, exigencia ésta harto difícil o imposible de cumplir por lo que, en consecuencia, nadie sería nunca responsable. Los diversas respuestas ortodoxas al reto escéptico de Strawson comparten con el Argumento Básico una misma noción teológica heredada de agente-mónada y, según trato de mostrar en mi artículo, sería necesaria una nueva concepción del sujeto para dar cuenta correctamente de este Argumento.

Raga Rosaleny, Vicente

2006-04-01

353

A LiDAR-based approach for a multi-purpose characterization of Alpine forests: an Italian case study  

Directory of Open Access Journals (Sweden)

Full Text Available Several studies have verified the suitability of LiDAR for the estimation of forest metrics over large areas. In the present study we used LiDAR as support for the characterization of structure, volume, biomass and naturalistic value in mixed-coniferous forests of the Alpine region. Stem density, height and structure in the test plots were derived using a mathematical morphology function applied directly on the LiDAR point cloud. From these data, digital maps describing the horizontal and vertical forest structure were derived. Volume and biomass were then computed using regression models. A strong agreement (accuracy of the map = 97%, Kappa Cohen = 94% between LiDAR land cover map (i.e., bare soil, forest, shrubs and ground data was found, while a moderate agreement between coniferous/broadleaf map derived from LiDAR data and ground surveys was detected (accuracy = 73%, Kappa Cohen = 60%. An analysis of the forest structure map derived from LiDAR data revealed a prevalence of even-age stands (66% in comparison to the multilayered and uneven-aged forests (20%. In particular, the even-age stands, whether adult or mature, were overwhelming (33%. A moderate agreement was then detected between this map and ground data (accuracy = 68%, Kappa Cohen = 58%. Moreover, strong correlations between LiDAR-estimated and ground-measured volume and aboveground carbon stocks were detected. Related observations also showed that stem density can be rightly estimated for adult and mature forests, but not for younger categories, because of the low LiDAR posting density (2.8 points m-2. Regarding environmental issues, this study allowed us to discriminate the different contribution of LiDAR-derived forest structure to biodiversity and ecological stability. In fact, a significant difference in floristic diversity indexes (species richness - R, Shannon index - H’ was found among structural classes, particularly between pole wood (R=15 and H’=2.8; P <0.01 and multilayer forest (R=31 and H’=3.4 or thicket (R=28 and H’=3.4 where both indexes reached their maximum values.

Alberti G

2013-04-01

354

¿ES FACTIBLE EL PROGRESO SOCIAL CUANDO DIEZ MENOS UNO ES IGUAL A CERO?  

Directory of Open Access Journals (Sweden)

Full Text Available Este artículo analiza las opiniones de dieciséis académicos caribeños sobre el progreso social y concluye que tal cosa es en realidad inalcanzable en el Caribe, donde las metanarrativas diezman las masas y mantienen las posiciones de poder de unas pocas elites. Een vista de esto, un paso importante hacia el avance social en Eel Caribe sería la evisceración de las metanarrativas europeas atrincheradas.

Alexander Miller

2009-01-01

355

The use of 1572 nm Mie LiDAR for observation of the optical properties of aerosols over Wuhan, China  

Science.gov (United States)

CO2 is a major component of greenhouse gases. When CO2 concentration is measured by satellites, calibration of the lower atmosphere becomes an essential procedure. Since the 1572 nm infrared region is widely used in remote sensing of CO2, we constructed a Mie LiDAR system, designed to work at 1572 nm, for measuring the optical properties of aerosols in the lower troposphere. Based on the particle size distribution measured by the heliograph, the LiDAR ratio is independently determined for Wuhan, China. The LiDAR echo signal is then processed by the Fernald method to calculate the extinction coefficient on both clear and cloudy days. The maximum detection height is restricted by the low laser energy and quantum efficiency of the Photomultiplier Tube (PMT) used. Moreover, a simplified method for detecting the position of clouds is presented and this method is verified using a variety of passive radiation instruments that offer partial support for calibrating and verifying LiDAR data. The observed results indicate that this LiDAR system could be a reliable source of data support for the spaceborne remote sensing of CO2.

Gong, Wei; Ma, Xin; Dong, Yanni; Lin, Hong; Li, Jun

2014-03-01

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