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Prospective study of incidence of juvenile diabetes mellitus over 10 years in Dar es Salaam, Tanzania.  

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OBJECTIVE--To ascertain the annual incidence of diabetes requiring treatment with insulin in children and adolescents aged 0-19 years in Dar es Salaam, Tanzania, during a 10 year period from 1 January 1982 to 31 December 1991. DESIGN--Prospective registration at a major urban hospital of all patients with newly diagnosed diabetes who were resident in Dar es Salaam. SETTING--Muhimbili Medical Centre, Dar es Salaam, Tanzania. PATIENTS--86 patients: 45 male, 41 female. RESULTS--The annual incide...

Swai, A. B.; Lutale, J. L.; Mclarty, D. G.

1993-01-01

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Gays, guys, and mchicha mwiba: same-sex relations and subjectivities in Dar es Salaam.  

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Drawing on 15 months of fieldwork, this article explores ways in which same-sex relations are perceived and performed in Dar es Salaam, Tanzania. While several different constructions of same-sex sexuality coexist in Dar es Salaam, it is common to conceive of same-sex practicing men as falling into two main categories. Men belonging to each of these differ with respect to the corporeal, gendered, and social positions that are open to them, and typically form dyads across the conceptual boundary of difference that runs between them. The article speaks to the importance of examining sexuality and gender in particular sociocultural settings. PMID:24313863

Moen, Kåre; Aggleton, Peter; Leshabari, Melkizedeck T; Middelthon, Anne-Lise

2014-01-01

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

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

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

Yhdego, Michael

2011-01-01

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Medicines Wastage at a Tertiary Hospital in Dar Es Salaam Tanzania  

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Medicines wastage is a problem in health care delivery systems, however the extent of this wastage and associated factors in many health care settings is less known. The objective of this study was to assess medicines wastage and its associated factors in a hospital setting in Dar es Salaam city Tanzania. Specifically to determine major types of medicines wasted and to identify factors contributing towards the wastage. A cross sectional study was carried out at a tertiary hospital, where pati...

Kagashe, Godeliver Anatory; Makenya, Florah Boniface; Buma, Deus

2014-01-01

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IINFORMAL LABOUR MARKET IN TANZANIA : A case of Kinondoni district in Dar es Salaam  

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ABSTRACT Juliet Manzala Setebe. Informal Labor Market in Tanzania: A case of Kinondoni District in Dar es Salaam. Jarvenpaa Autumn 2011, 48p., 2 appendices . Diaconia University of Applied Sciences, Diak South, Jarvenpaa Unit, Degree Program in Social Services (DSS). Informal Labor Market is a concept that has been researched for more than twenty years, but no one has come up with a concrete definition. Many researchers referred to it as activities which are done outside the governm...

Setebe, Juliet

2011-01-01

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Governance challenges and coalition building among urban environmental stakeholders in Dar es Salaam, Tanzania.  

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Rapid urbanization is arguably one of the most complex and important socioeconomic phenomena of the new millennium. It represents major and irreversible changes in production and consumption patterns and the way people interact with nature. The impact of urbanization will continue to bring about major changes especially in many countries in the developing world that are experiencing rapid urbanization. The serious environmental and development challenges facing Dar es Salaam, the largest commercial center of Tanzania, are highlighted in this report. PMID:15253912

Mtani, Anna

2004-06-01

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

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

Robert B. Kiunsi

2013-01-01

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

DEFF Research Database (Denmark)

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

Kahesa, Crispin; Kjaer, Susanne

2012-01-01

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Urban Lymphatic Filariasis in the Metropolis of Dar es Salaam, Tanzania  

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The last decades have seen a considerable increase in urbanization in Sub-Saharan Africa, and it is estimated that over 50% of the population will live in urban areas by 2040. Rapid growth of cities combined with limited economic resources often result in informal settlements and slums with favorable conditions for proliferation of vectors of lymphatic filariasis (LF). In Dar es Salaam, which has grown more than 30 times in population during the past 55 years (4.4 million inhabitants in 2012)...

Mwakitalu, Mbutolwe E.; Malecela, Mwelecele N.; Pedersen, Erling M.; Mosha, Franklin W.; Simonsen, Paul E.

2013-01-01

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

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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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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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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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The quality of sputum smear microscopy diagnosis of pulmonary tuberculosis in Dar es Salaam, Tanzania.  

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This study was carried out to determine the rate of agreement or disagreement of microscopy reading and culture positivity rate among smear positixe and negative specimens between peripheral tuberculosis diagnostic centres (PDCs) and Central Reference luberculosis laboratory (CTRL). In this study 13 PDCs in Dar es Salaam, Tanzania were involved. Lot Quality Assurance Sampling (LQAS) method was used to collect 222 sputum smear slides. A total of 190 morning sputum specimens with corresponding slides were selected for culture. First readings were done by technicians at PDCs and thereafter selected slides and specimens were sent to CTRL for re-examination and culture. Culture results were used as a gold standard. Of 222 slides selected, 214 were suitable for re-examination. Percentage of agreement of smear reading between PDCs and CTRL was 42.9% and 100% for positive and negative slides, respectively. Measure of agreement (Kappa statistic) was 0.5, indicating moderate agreement. Of 190 samples cultured, percentage of agreement between smear reading from PDCs and CTRL was 37% and 88.9% for smear positive and negative slides, respectively. Kappa statistic was 0.3 indicating poor-fair agreements. Comparison of smear reading from PDCs with culture showed sensitivity of 36.9% and specificity of 88.9%. Comparison of smear readings from CTRL with culture results showed sensitivity of 95.6% and specificity of 98.6%. In conclusion there was inadequate performance in diagnosis of TB using smear microscopy among peripheral diagnostic centres in Dar es Salaam. This calls for immediate and rigorous measures to improve the quality of smear microscopy. It is therefore important to strengthen the capacity of laboratory personnel in smear microscopy techniques through supportive supervision and training. PMID:18087893

Mfinanga, G S; Ngadaya, E; Mtandu, R; Mutayoba, B; Basra, D; Kimaro, G; Chonde, T M; Ngowi, P; Mfaume, S; Kilale, A M; Egwaga, S; Kitua, A Y

2007-09-01

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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 b...

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

2010-01-01

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

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

Matee Mecky I; Maselle Samwel Y; Moyo Sabrina J; Langeland Nina; Mylvaganam Haima

2007-01-01

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Uptake of Measles Vaccination Services and Associated Factors Among under Fives in Temeke district, Dar es salaam Region, Tanzania  

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Measles outbreaks have been recurring in Tanzania despite ongoing efforts in immunization. In May 2011, there was a large Measles outbreak in the Temeke district, Dar es salaam where a total 588 cases were reported. The investigation found that a large percentage of underfives had not received measles vaccination. Although measles vaccination coverage figures are easily available, information about factors affecting uptake of measles vaccination services is not easily available. In order to p...

Lyimo, Joyce

2012-01-01

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

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

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

2009-01-01

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The Pattern of Oral and Maxillofacial Injuries Among Patients Attending Muhimbili National Hospital, Dar es salaam, Tanzania  

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To determine the pattern of oral and maxillofacial injuries among patients attended at the Muhimbili National Hospital, Dar es Salaam, Tanzania. Descriptive cross-sectional hospital based study. The study was done at oral and maxillofacial surgery firm and emergency medicine department of Muhimbili National Hospital (MNH). All patients who attended the Oral and Maxillofacial Surgery firm and Emergency Medicine departments of MNH for treatment of oral and maxillofacial injuries during the peri...

Kileo, Baraka Fredrick

2012-01-01

 
 
 
 
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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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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....

Thordarson Hrafnkell; Lutale Janet; Abbas Zulfiqarali; Vetvik Kåre

2007-01-01

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

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

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

2007-01-01

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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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Financing of sanitation services in the slums of Kampala and Dar es Salaam  

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Full Text Available This paper presents an assessment of the extent and conditions under which private financing can be a realistic approach for sanitation in slums. It is based on a cross-sectional study comparing two slum communities in East Africa, where 250 households from Bwaise III in Kampala, Uganda and 379 households from Temeke in Dar es Salaam, Tanzania were interviewed in 2010. Also, 10 key-informant interviews and 8 focus group discussions were conducted in addition to field observations. Findings show that majority (85% of households used unimproved, private-shared pit latrines. These privately owned latrines had many structural shortfalls besides poor operation and maintenance while the public latrines provided by third-party were structurally sound but were under-utilized in residential slum neighorhoods. This is attributed to the presence free or at least cheaper alternatives which the community members preferred instead of paying per-visit user-fees. For the few who were willing to pay, willingness to pay was positively associated with the presence of a facility User committee and having been sensitized. In this context, a combination of these factors made cost recovery as well as operation and maintenance very minimal. The poor status of privately owned shared pit latrines matched the limited income levels of households. Similarly, cost recovery for public facilities was dependent on the number of users who were willing to pay: the more the users, the more the cost recovery. A combination of private and public financing is thus necessary to fund different but complementary aspects of sanitation in slums.

John Bosco Isunju

2013-04-01

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

Science.gov (United States)

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

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

2008-12-01

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

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Health system responsiveness (HSR) measures quality of care from the patient's perspective, an important component of ensuring adherence to medication and care among HIV patients. We examined HSR in private clinics serving HIV patients in Dar es Salaam, Tanzania. We surveyed 640 patients, 18 or older receiving care at one of 10 participating clinics, examining socioeconomic factors, HIV regimen, and self-reported experience with access and care at the clinic. Ordered logistic regression, adjusted for clustering of the clinic sites, was used to measure the relationships between age, gender, education, site size, and overall quality of care rating, as well as between the different HSR domains and overall rating. Overall, patients reported high levels of satisfaction with care received. Confidentiality, communication, and respect were particularly highly rated, while timeliness received lower ratings despite relatively short wait times, perhaps indicating high expectations when receiving care at a private clinic. Respect, confidentiality, and promptness were significantly associated with overall rating of health care, while provider skills and communication were not significantly associated. Patients reported that quality of service and confidentiality, rather than convenience of location, were the most important factors in their choice of a clinic. Site size (patient volume) was also positively correlated with patient satisfaction. Our findings suggest that, in the setting of urban private-sector clinics, flexible clinics hours, prompt services, and efforts to improve respect, privacy and confidentiality may prove more helpful in increasing visit adherence than geographic accessibility. While a responsive health system is valuable in its own right, more work is needed to confirm that improvements in HSR in fact lead to improved adherence to care. PMID:24499337

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

2014-01-01

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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)

The ionic composition of coarse, fine and total PM10 was investigated in aerosol samples collected from a kerbside in Dar es Salaam during the 2005 dry season and 2006 wet season. A 'Gent' PM10 stacked filter unit sampler with sequential Nuclepore polycarbonate filters, providing coarse (8 ?m) and fine (0.4 ?m) size fractions, was deployed. The mean concentrations and associated standard deviation of fine, coarse and PM10 were, respectively, 17 ± 4, 52 ± 27, and 69 ± 29 ?g/m3 during the 2005 dry season campaign and 13 ± 5, 34 ± 23 and 47 ± 25 ?g/m3 for the 2006 wet season campaign. The higher PM mass concentrations during the dry season campaign are essentially due to soil dust dispersal, much biomass burning and temperature inversions. Chloride, Na+ and Mg2+ were the dominant ions in coarse fraction, indicating a significant influence of sea-salt aerosols. In the fine fraction, SO42- and NH4+ and K+ were the most important ions. The mean equivalent PM2 NO3- concentration in the 2005 dry season campaign was two times higher than in the 2006 wet season campaign, probably due to reaction of NaCl (sea-salt) with HNO3 as a result of higher levels of NOx during the dry season and/or reduced volatilization of NH4NO3 due to lower temperature in the dry season. The results from our water-soluble ions stu 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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Window screening, ceilings and closed eaves as sustainable ways to control malaria in Dar es Salaam, Tanzania  

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

Chaki Prosper P

2009-09-01

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

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

Mshinda Hassan

2007-09-01

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

DEFF Research Database (Denmark)

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; Kjaer, Susanne Kruger

2012-01-01

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Green infrastructure for flood risk management in Dar es Salaam and Copenhagn: exploring the potential for transition towards sustainable urban water management  

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The risk of flooding in urban areas could be better approached by complementing conventional sewer systems with sustainable urban drainage systems (SUDS) for stormwater management. This may be the case for developing world cities like Dar es Salaam with incomplete sewer services, as well as cities like Copenhagen with fully developed sewer systems. This paper explores some theories relevant to understanding how the implementation of SUDS may be one option for supporting a transition towards sustainable urban water management (SUWM). Using interviews, document analysis and observation, a comparison of the opportunities and barriers for the implementation of SUDS in Dar es Salaam and Copenhagen is presented. The results indicate that a bottom-up approach in Dar es Salaam is important, with the community level taking the lead, while in Copenhagen the top-down approach currently employed is promising. The ability of the institutional frameworks of both cities to support the implementation of SUDS is also discussed.

Mguni, Patience; Herslund, Lise Byskov

2014-01-01

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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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Urbanization and Its Impacts to Food Systems and Environmental Sustainability in Urban Space: Evidence from Urban Agriculture Livelihoods in Dar es Salaam, Tanzania  

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Urbanisation is the key factor underpinning and catalysing changes in food systems, environmental quality, climate change and agriculture livelihoods in the overall urban ecosystem setting and its sustainability. The paper explores Dar es Salaam, a rapidly expanding city in Sub-Saharan Africa, and shows that urban agriculture provides urban ecosystem services and contributes to environmental sustainabilit...

Wakuru Magigi

2013-01-01

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

International Nuclear Information System (INIS)

The aim of this study was to review air pollution problems in the Southern Africa region and establish the quality of ambient air in Dar Es Salaam city in Tanzania with respect to three vehicular pollutants which are sulphur dioxide (SO2), nitrogen dioxide (NO2) and suspended particulate matters (SPM). These pollutants were measured in eight different locations in Dar-Es Salaam city which are Fire, Morocco, Tazara, Kariakoo, Ubungo, Posta, UCLAS, and Akiba. With the exception of South Africa and Botswana, other countries in the Southern Africa Region which include Tanzania, Mozambique, Malawi. Zambia, Zimbabwe. Angola and Namibia do not have air pollution standards, and regular air pollution monitoring is not carried out in these countries. Diesel fueled vehicles in South Africa are responsible for one third of all smog-forming nitrogen dioxides and almost two-thirds of all particulate pollution emitted by all vehicles. The measurement methods used in Dar Es Salaam study were pararosaniline method for SO2, Saltzman for measuring nitrogen dioxide, and filtration method for suspended particulate matters. The following was observed from the analysis: Hourly sulphur dioxide concentration ranged from 558 -1385 ?g/m3. These measured values were above the recommended WHO guidelines with an hourly objective value of 350 ?g/m3. Hourly nitrogen dioxide concentration was found to range from 18 to 53 ?g/m3. The ge 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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Does Personalized Water and Hand Quality Information Affect Attitudes, Behavior, and Health in Dar es Salaam, Tanzania?  

Science.gov (United States)

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

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

2008-12-01

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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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Exploring the Association Between HIV/and Violence:Young People's Experiences with Infidelity,Violence and Forced Sex in Dar es Salaam,Tanzania  

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Prior research has shown a strong correlation between HIV infection and a history of intimate partner violence, particularly among young women. However, the role violence plays in the sexual relationships of young people in Sub-Saharan Africa is not well understood. Locally trained interviewers conducted semi-structured interviews with 40 young men and 20 young women aged 16-24 who were recruited from public venues in Dar es Salaam, Tanzania. The participants described complex interactions ...

Lary, Heidi; Maman, Suzane; Katebalila, Malingo; Mccauley, Ann; Mbwambo, Jessie

2004-01-01

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

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Abstract Background Skin diseases are underestimated and overlooked by most clinicians despite being common in clinical practice. Many patients are hospitalized with co-existing dermatological conditions which may not be detected and managed by the attending physicians. The objective of this study was to determine the burden of co-existing and overlooked dermatological disorders among patients admitted to medical wards of Muhimbili National hospital in Dar es Salaam. S...

Nf, Chale Pauline; Mgonda Yassin M

2011-01-01

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

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Orphans are an increasing problem in developing countries particularly in Africa; due to the HIV/AIDS pandemic; and needs collective effort in intervention processes by including all stakeholders right from the grass roots level. This paper attempts to present the role of traditional healers in psychosocial support for orphan children in Dar-es-Salaam City with special focus on those whose parents have died because of HIV/AIDS. Six traditional healers who were in...

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

2005-01-01

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Monitoring Mosquitoes in Urban Dar es Salaam: Evaluation of Resting Boxes, Window Exit Traps, CDC Light Traps, Ifakara Tent Traps and Human Landing Catches.  

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

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

2011-01-01

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Diabetes in tropical Africa: a prospective study, 1981-7. I. Characteristics of newly presenting patients in Dar es Salaam, Tanzania, 1981-7.  

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OBJECTIVE--To study the clinical characteristics of newly diagnosed diabetic patients in tropical Africa. DESIGN--Prospective study of all newly diagnosed diabetic patients registered at a major urban hospital between 1 June 1981 and 31 May 1987. SETTING--Muhimbili Medical Centre, Dar es Salaam, Tanzania. PATIENTS--1250 Patients: 874 men, 376 women. RESULTS--272 (21.8%) Patients had diabetes requiring insulin, 825 (66.0%) had diabetes not requiring insulin, and 153 (12.2%) had diabetes of unc...

Swai, A. B.; Lutale, J.; Mclarty, D. G.

1990-01-01

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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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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 (approximate to 6%) with the majority of cases arriving after start of convulsions. In 2004-2005 the case-fat...

Kidanto, Hussein Lesio; Wangwe, Peter; Kilewo, Charles D.; Nystro?m, Lennarth; Lindmark, Gunnila

2012-01-01

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HIV risk behaviors, perceived severity of drug use problems, and prior treatment experience in a sample of young heroin injectors in Dar es Salaam, Tanzania  

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Interviews were conducted with 203 male and 95 female heroin injectors aged 17 to 25 in Dar es Salaam, Tanzania. Nearly one-quarter of participants reported injecting with needles used by someone else. Few reported cleaning needles with bleach. Multiple sexual partnerships, unprotected sex, and trading sex for money were especially present among women, the majority (55%) of whom was HIV seropositive. Self reports suggest the presence of heroin dependence among users. While most participants e...

Atkinson, John; Mccurdy, Sheryl; Williams, Mark; Mbwambo, Jessie; Kilonzo, Gad

2011-01-01

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

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Background: As the population of Africa rapidly urbanizes, large populations could be protected from malaria by controlling aquatic stages of mosquitoes if cost-effective and scalable implementation systems can be designed. Methods: A recently initiated Urban Malaria Control Programme in Dar es Salaam delegates responsibility for routine mosquito control and surveillance to modestly-paid community members, known as Community-Owned Resource Persons (CORPs). New vector surveillance, ...

Fillinger, U.; Kannady, K.; William, G.; Vanek, M. J.; Dongus, S.; Nyika, D.; Geissbuehler, Y.; Chaki, P. P.; Govella, N. J.; Mathenge, E. M.; Singer, B. H.; Mshinda, H.; Lindsay, S. W.; Tanner, M.; Mtasiwa, D.

2008-01-01

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

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Abstract Background As the population of Africa rapidly urbanizes, large populations could be protected from malaria by controlling aquatic stages of mosquitoes if cost-effective and scalable implementation systems can be designed. Methods A recently initiated Urban Malaria Control Programme in Dar es Salaam delegates responsibility for routine mosquito control and surveillance to modestly-paid community members, known as Community-Owned Resource Persons (CORPs)...

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

2008-01-01

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

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

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

2009-01-01

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

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Abstract Background Community participation in vector control and health services in general is of great interest to public health practitioners in developing countries, but remains complex and poorly understood. The Urban Malaria Control Program (UMCP) in Dar es Salaam, United Republic of Tanzania, implements larval control of malaria vector mosquitoes. The UMCP delegates responsibility for routine mosquito control and surveillance to community-owned resource persons (CORPs)...

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

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

DEFF Research Database (Denmark)

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

Silberschmidt, Margrethe; Rasch, V

2001-01-01

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

DEFF Research Database (Denmark)

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

Mwakitalu, Mbutolwe E; Malecela, Mwele N

2014-01-01

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Predictors of poor glycemic control in type 2 diabetic patients attending public hospitals in Dar es Salaam  

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Full Text Available Appolinary R Kamuhabwa, Emmanuel CharlesUnit of Pharmacology and Therapeutics, School of Pharmacy, Muhimbili University of Health and Allied Sciences, Dar es Salaam, TanzaniaBackground: Tanzania has recently experienced a significant rise in the burden of diabetes, and it is estimated that more than 400,000 people are living with diabetes. A major concern in the management of diabetes is the occurrence of diabetic complications that occur as a result of poor glycemic control. Identification of the factors associated with poor glycemic control is important in order to institute appropriate interventions for the purpose of improving glycemic control and prevention of chronic complications.Aim: The aim of this study was to determine the level of glycemic control and explore the factors associated with poor glycemic control among patients with type 2 diabetes mellitus (T2DM.Methodology: A cross-sectional study was carried out at the diabetic clinics for T2DM patients at the national and municipal hospitals in Dar es Salaam. A total of 469 patients were enrolled over a period of 8 weeks from March 2013 to May 2013. Patients' information such as sociodemographic characteristics, self-care management behaviors, and medication adherence were obtained through interviews. Blood pressure, weight, and height were measured during the day of the interview. All available last readings for fasting blood glucose (FBG measurements, lipid profile, and other clinical characteristics were obtained from patients' records.Results: The mean age of patients was 54.93 years. The majority (63.5% of patients were females and only eight patients had records of lipid profile measurements. Out of 469 patients, 69.7% had FBG of ?7.2 mmol/L, indicating poor glycemic control. Females aged between 40 years and 59 years had significantly higher poor glycemic control (76.1% as compared with their male counterparts. Thirty-eight percent of patients had poor medication adherence, which was associated with poor glycemic control. The proportion of poor glycemic control increased with age. A significantly high proportion of poor glycemic control was observed in patients who had had the disease for more than 20 years since diagnosis. Factors associated with poor glycemic control included lack of health insurance, using more than one oral hypoglycemic agent, normal body mass index, obesity, and nonadherence to diabetic medications.Conclusion: Patients in this study had generally poor glycemic control. From these findings it is recommended that diabetic patients should be routinely screened for lipid profile to determine levels of cholesterol, triglycerides, and low-density lipoproteins, which are risk factors for cardiovascular events. An education program should be developed to educate patients on the importance of medication adherence and weight management for better glycemic control.Keywords: type 2 diabetes, lipid profile, self-management behaviors

Kamuhabwa AR

2014-10-01

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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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Urban biowaste for solid fuel production: Waste suitability assessment and experimental carbonization in Dar es Salaam, Tanzania.  

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The poor state of solid waste management in Dar es Salaam (DSM), Tanzania, the large fraction of organic waste generated and a high charcoal consumption by city residents has triggered this research on carbonization of municipal biowaste. Char produced by the thermochemical conversion method of slow pyrolysis can be briquetted and used as cooking fuel alternative to wood-based charcoal. To explore the potential of biowaste carbonization in DSM, the most suitable organic wastes were selected and pyrolyzed in a simple, externally heated carbonization system developed as part of this study. A Multi-Criteria Analysis framework allowed to assess prevailing biowaste types regarding availability and accessibility, and respective suitability in terms of physical-chemical properties. The assessment, using data from a survey and lab analysis, revealed the following biowaste types with highest overall potential for char production in DSM: packaging grass/leaves (PG) used for transportation of fruit and vegetables to the markets, wood waste (WW) from wood workshops, and cardboard (CB) waste. Best practice carbonization of these biowastes in the pyrolyzer showed satisfactory char yields (PG: 38.7%; WW: 36.2%; CB: 35.7% on dry basis). Proximate composition (including volatile, fixed carbon and ash content) and heating value (PG: 20.1 MJ kg(-1); WW: 29.4 MJ kg(-1); CB: 26.7 MJ kg(-1)) of the produced char also compare well with literature data. The energy and emission-related aspects of the system still require further research and optimizations to allow financially viable and safe operation. PMID:25649406

Lohri, Christian Riuji; Faraji, Adam; Ephata, Elia; Rajabu, Hassan Mtoro; Zurbrügg, Christian

2015-02-01

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

Scientific Electronic Library Online (English)

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

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

2010-12-01

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Identifying Programmatic Gaps: Inequities in Harm Reduction Service Utilization among Male and Female Drug Users in Dar es Salaam, Tanzania  

Science.gov (United States)

Introduction Current estimates suggest an HIV prevalence of 42% among people who inject drugs (PWIDs) in Dar es Salaam, while HIV prevalence is estimated to be 8.8% among the general population in the city. To address the HIV epidemic in this population, the government of Tanzania began establishing HIV prevention, treatment and care services including outreach and medication assisted treatment (MAT) for PWIDs in 2010. We assessed gender inequities in utilization of outreach and MAT services and evaluated differences in HIV risk behaviors between female and male PWIDs. Materials and Methods Routine outreach data between December 2010 to mid-August 2012 and baseline data on clients enrolling in methadone from February 2011 to August 2012 were utilized. Binomial regression was used to estimate adjusted relative risk estimates comparing females to males. Results From December 2010 to August 2012, 8,578 contacts were made to drug users; among them 1,898 were injectors. A total of 453 injectors were eligible and referred to MAT, of which, 443 enrolled in treatment. However, regarding total outreach contacts, outreach to PWID, referral to MAT and enrollment in MAT, 8% or less of drug users accessing services were women. In contrast, weighted estimations from surveys suggest that 34% of PWIDs are female, and this approximation is similar to recent population size estimations. Overall, 43% of traditional outreach workers conducting outreach with drug users were female. Though reporting higher levels of condom usage, female PWID were more likely to report multiple sex partners, anal sex, commercial sex work and struggle under a higher burden of addiction, mental disorders and abuse. Conclusions Services have not been mobilized adequately to address the clear needs of females who inject drugs. A clear and urgent need exists for women-centered strategies that effectively engage female PWID into HIV prevention services. PMID:23825620

Lambdin, Barrot H.; Bruce, R. Douglas; Chang, Olivia; Nyandindi, Cassian; Sabuni, Norman; Zamudio-Haas, Sophia; McCurdy, Sheryl; Masao, Frank; Ivo, Yovin; Msami, Amani; Ubuguy, Omar; Mbwambo, Jessie

2013-01-01

 
 
 
 
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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

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

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

DEFF Research Database (Denmark)

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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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  

Science.gov (United States)

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

66

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

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

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

2014-01-01

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

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Evaluation trials of the efficacy of buparvaquone (BUTA-kel KELA Laboratoria, N.V. Belgium), as a treatment of field cases of Theileria parva infection (East Coast fever - ECF) were carried out on 63 cattle in the peri-urban of Dar Es Salaam city, Tanzania, during the period November 2004 to August 2005. Thirty-two cattle (56%) received single-dose treatment (2.5 mg buparvaquone per kg body weight), while two and three-dose treatment with interval(s) of 48 h was given to 33% and 11% of total treated cattle, respectively; 38 cattle (60.3%) were treated at an early stage of the disease, while 25 cattle (39.7%) were treated at an advanced stage of the disease. The rectal body temperature of 90.5% of buparvaquone-treated cattle dropped to normal values (37.5-39.5 degrees C) by day 7 of treatment, and by day 15 of treatment 96.8% of treated cattle showed normal values. Pulmonary signs were observed in 8/68 (11.8%) of total ECF diagnosed cattle and were successfully treated, albeit with parvaquone plus frusemide (Fruvexon); were not included in final evaluation of the efficacy of BUTA-kel. The present evaluation trials record a recovery rate of 95.2%. Buparvaquone (BUTA-kel KELA Laboratoria, N.V. Belgium), therefore, records another efficacious and valuable alternative treatment against East Coast fever in Tanzania. PMID:16567050

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

2006-06-30

70

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

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

Massila Mariam

2005-07-01

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

DEFF Research Database (Denmark)

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

Rasch, V; Muhammad, H

2000-01-01

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Maternal and neonatal colonisation of group B streptococcus at Muhimbili National Hospital in Dar es Salaam, Tanzania: prevalence, risk factors and antimicrobial resistance  

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Full Text Available Abstract Background Group B streptococcus (GBS, which asymptomatically colonises the vaginal and rectal areas of women, is the leading cause of septicemia, meningitis and pneumonia in neonates. In Tanzania no studies have been done on GBS colonisation of pregnant women and neonates. This study was conducted in Dar es Salaam, Tanzania to determine the prevalence of GBS colonisation among pregnant women, the neonatal colonisation rate and the antimicrobial susceptibility, thus providing essential information to formulate a policy for treatment and prevention regarding perinatal GBS diseases. Methods This cross sectional study involved 300 pregnant women attending antenatal clinic and their newborns delivered at Muhimbili National Hospital (MNH between October 2008 and March 2009. High vaginal, rectal, nasal, ear and umbilical swabs were cultured on Todd Hewitt Broth and in 5% sheep blood agar followed by identification of isolates using conventional methods and testing for their susceptibility to antimicrobial agents using the Kirby-Bauer method. Results GBS colonisation was confirmed in 23% of pregnant women and 8.9% of neonates. A higher proportion of GBS were isolated from the vagina (12.3% as compared to the rectum (5%. Prolonged duration of labour (>12 hrs was significantly shown to influence GBS colonisation in neonates P Conclusion Our findings seem to suggest that a quarter of pregnant women attending ANC clinic at MNH and approximately 10% of their newborns are colonised with GBS. All isolates were found to be sensitive to vancomycin and ampicillin which seem to be the most effective antibiotics for the time being. However there is a need for continuous antibiotics surveillance of GBS to monitor trend of resistance. The high isolation frequency of GBS among pregnant women suggests routine antenatal screening at 35 to 37 weeks of gestation in order to provide antibiotic prophylaxis to GBS carrier.

Lyamuya Eligius F

2009-12-01

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

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

Govella Nico J

2008-01-01

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

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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

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

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

Lyamuya Eligius F

2006-01-01

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

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

Lengeler Christian

2008-12-01

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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

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

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

Mbekenga Columba K

2011-11-01

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

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

Fillinger Ulrike

2011-09-01

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Reduction of anti-malarial consumption after rapid diagnostic tests implementation in Dar es Salaam: a before-after and cluster randomized controlled study  

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Full Text Available Abstract Background Presumptive treatment of all febrile patients with anti-malarials leads to massive over-treatment. The aim was to assess the effect of implementing malaria rapid diagnostic tests (mRDTs on prescription of anti-malarials in urban Tanzania. Methods The design was a prospective collection of routine statistics from ledger books and cross-sectional surveys before and after intervention in randomly selected health facilities (HF in Dar es Salaam, Tanzania. The participants were all clinicians and their patients in the above health facilities. The intervention consisted of training and introduction of mRDTs in all three hospitals and in six HF. Three HF without mRDTs were selected as matched controls. The use of routine mRDT and treatment upon result was advised for all patients complaining of fever, including children under five years of age. The main outcome measures were: (1 anti-malarial consumption recorded from routine statistics in ledger books of all HF before and after intervention; (2 anti-malarial prescription recorded during observed consultations in cross-sectional surveys conducted in all HF before and 18 months after mRDT implementation. Results Based on routine statistics, the amount of artemether-lumefantrine blisters used post-intervention was reduced by 68% (95%CI 57-80 in intervention and 32% (9-54 in control HF. For quinine vials, the reduction was 63% (54-72 in intervention and an increase of 2.49 times (1.62-3.35 in control HF. Before-and-after cross-sectional surveys showed a similar decrease from 75% to 20% in the proportion of patients receiving anti-malarial treatment (Risk ratio 0.23, 95%CI 0.20-0.26. The cluster randomized analysis showed a considerable difference of anti-malarial prescription between intervention HF (22% and control HF (60% (Risk ratio 0.30, 95%CI 0.14-0.70. Adherence to test result was excellent since only 7% of negative patients received an anti-malarial. However, antibiotic prescription increased from 49% before to 72% after intervention (Risk ratio 1.47, 95%CI 1.37-1.59. Conclusions Programmatic implementation of mRDTs in a moderately endemic area reduced drastically over-treatment with anti-malarials. Properly trained clinicians with adequate support complied with the recommendation of not treating patients with negative results. Implementation of mRDT should be integrated hand-in-hand with training on the management of other causes of fever to prevent irrational use of antibiotics.

Swai Ndeniria

2011-04-01

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

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

Winkley Kirsty

2010-05-01

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

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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

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

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

Kavishe, Angela

2011-01-01

84

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

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

Kavishe, Angela

2011-01-01

85

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

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

Isaksson, Raine

2012-01-01

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Obstetric Outcome among Adolescent Primigravidae Delivering at Muhimbili National Hospital Dar es Salaam, Tanzania  

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The number of adolescent pregnancies has increased throughout the world, and these pregnancies are reported in association with a higher rate of maternal and fetal complications. Objectives: The aim of this study was to compare obstetric outcome among adolescents and none- adolescents primigravidae. Methods: A prospective study was carried out during mid September to mid December 2001 at Muhimbili National Hospital to compare obstetric outcome of the first pregnancies of 190 adolescents with ...

Lyamuya, R. E.

2002-01-01

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Factors Affecting Treatment Compliance Among Hypertension Patients in three District Hospitals - Dar es Salaam  

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Hypertension is one of the most important cardiovascular risk factor but its control is still a challenge all around the world. Control of blood pressure can reduce cardiovascular morbidity and mortality, so the compliance to antihypertensive drugs and life style modification play an important role for the control of hypertension. With the guide of the Health Belief Model (HBM) conceptual framework, the study investigated factors affecting treatment compliance with antihypertensive therapy am...

Joho, Angelina Alphonce

2012-01-01

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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

89

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

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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, ...

Wegerif, Marc C. A.

2014-01-01

90

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

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Genetic diversity of norovirus in hospitalised diarrhoeic children and asymptomatic controls in Dar es Salaam, Tanzania.  

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This study investigated and reports norovirus diarrhoea, genetic diversity and associated clinical symptoms, HIV status and seasonality in a paediatric population of Tanzania. Stool specimens and demographic/clinical information, were prospectively collected from 705 hospitalised children with diarrhoea (cases) and 561 children without diarrhoea (controls) between 2010 and 2011. Norovirus detection was done by real-time RT-PCR. Genotype was determined using Gel-based and real time RT-PCR methods and sequencing targeting the polymerase and the capsid region respectively. Norovirus was detected in 14.3%, 181/1266 children. The prevalence of norovirus was significantly higher in cases (18.3%, 129/705) than in controls, (9.2%, 52/561), P<0.05. Except for one child who had double infection with GI and GII all 129 cases had GII. Among controls, 23.1% had GI and 76.9% had GII. Norovirus GII.4 was significantly more prevalent in cases 87.9% than in controls 56.5%. Other genotypes detected in both cases and controls were GII.21, GII.16 and GII.g. The highest numbers of norovirus were detected in April 2011. The number of norovirus detected was significantly higher during the first than second year of life (109/540, 20.2% vs. 20/165, 12.1%). The prevalence of norovirus in HIV-positive and negative children was (21.2%, 7/33) and (10.3%, 40/390, P=0.05) respectively, regardless of diarrhoea symptoms. No significant difference in gender, parent's level of education or nutritional status with norovirus infection was observed within cases or controls. This study confirms the significant role of norovirus infection, especially GII.4 in diarrhoeic children who need hospitalisation and adds knowledge on norovirus epidemiology in the African region. PMID:24960396

Moyo, Sabrina; Hanevik, Kurt; Blomberg, Bjørn; Kommedal, Oyvind; Vainio, Kirsti; Maselle, Samuel; Langeland, Nina

2014-08-01

92

Sources of salinity and urban pollution in the Quaternary sand aquifers of Dar es Salaam, Tanzania  

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Groundwater is globally important for human consumption, and changes in quality can have serious consequences. The study area is within a coastal aquifer where groundwater quality is influenced by various potential sources of salinity that determine the composition of water extracted from wells. Groundwater chemistry data from the aquifer have been acquired to determine the geochemical conditions and processes that occur in this area and assess their implications for aquifer susceptibility. Analysis of groundwater samples shows that the dominant watertype is mostly NaCl with pH Quaternary aquifer, especially in intercalated deltaic clays in the fluviatile deposits, showing some marine influences. The seawater intrusion is linked to the strongly increasing groundwater exploitation since 1997. Another process that plays a major role to the concentration of major ions in the groundwater is calcite dissolution. Next to geogenic salinity and seawater intrusion, anthropogenic pollution as well is affecting groundwater quality in the aquifer. An important result of this study is the observation of high nitrate concentrations, that call for improved sanitation in the area, where domestic sewage with on-site sanitation (mainly pit latrines) also threatens the groundwater resource.

Walraevens, Kristine; Mjemah, Ibrahimu Chikira; Mtoni, Yohana; Van Camp, Marc

2015-02-01

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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

94

Travel behaviour in Cape Town, Dar Es Salaam and Nairobi cities.  

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Public and non-motorised transport facilities in urban centres in Africa are less than what is justified by the demand. This may be due to the way the urban transportation problem has been formulated and travel surveys carried out with a focus on establishing demand for travel by car. The aim of this study was to document travel behaviour in the three cities without bias to any of the modes so that Issues hindering the sustainable modes may be identifies and investigated. Household interviews...

Masaoe, Estomihi N.; Del Mistro, Romano F.; Makajuma, George

2011-01-01

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Geochemistry of shallow groundwater at Kigamboni peninsula along Dar Es Salaam coastal strip Tanzania  

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The paper presents types of groundwater, hydrochemical facies, and chemical genesis of shallow groundwater at Kigamboni peninsula. Five types of groundwater have been identified as sodium bicarbonate, sodium sulphate, sodium chloride, calcium bicarbonate and magnesium bicarbonate type of waters. Hydrochemical facies change from calcium-sodium facies near the shore to sodium-calcium facies landward for cations, and from chloride-sulphate-bicarbonate to bicarbonate-chloride-sulphate facies respectively for anions. Calcium and Magnesium in high concentrations near the shore are attributed to dissolution of dolomitic limestone, being indicated by higher ratio of Ca 2+/Mg 2+ than one for samples K 6, K 7 and K 9. The rest of the samples show low ratios indicating dolomite dissolution with probable calcite precipitation. Whereas the higher alkali metal concentrations than alkaline earths, observed landward, may probably be due to cation exchange process, similar pattern seen for chloride and sulphate concentrations also suggest mixing of fresh recharge water with interstitial marine water and or dissolution of airbone salts by recharging rainwater resulting into oceanic salt recycling. However, the water is observed to be suitable for general domestic and irrigation purposes. It has been concluded that the chemical character of shallow groundwater in the studied area, is a result of the interaction between recharge water with lithology and mixing with probable trapped marine water.

Nkotagu, H. H.

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

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

Mwambete, K D; Lyombe, F

2011-01-01

97

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

98

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

99

Pharmaceutical Management and Prescribing Pattern of Antimalarial Drugs in the Public Health Facilities in Dar-es-salaam, Tanzania  

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Despite the efforts of minimizing utilization of limited financial resources in Tanzania, there are still some factors that affect the whole system of supply chain of antimalarial medicines. The goals of Integrated Logistic System (ILS) have not been realized since still there is drug shortage and poor stock recording system in the health facilities. Inadequate knowledge of the pharmaceutical management and inappropriate use of antimalarial drugs always contribute to the poor quality and avai...

Silumbe, Richard S.

2011-01-01

100

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

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

Tarimo, Edith Andrew Mroso

2011-01-01

 
 
 
 
101

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

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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 haphaza...

Samson Elisha Kasala

2014-01-01

102

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

103

HIV Serostatus, Hepatitis C and Depression Among Injection Drug Users in Kinondoni Municipality, Dar es Salaam, Tanzania.  

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Injection drug use in Sub Saharan Africa plays a big role in HIV and HCV transmission. This has brought a great interest with regard to control of the HIV pandemic and spread of HCV infections. In addition to that, Injection drug use is associated with mental conditions like depression. Situational analyses reveal that injection drug use is significantly increasing in different parts of Africa. Unfortunately, there are very few published studies available locally in Tanzania to assess the ext...

Nyandindi, Cassian L.

2011-01-01

104

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

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

Nyato Daniel J; Kamat Vinay R

2010-01-01

105

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

106

Knowledge and Practice of Intensive Care Nurses on Prevention of Ventilator Associated Pneumonia at Muhimbili National Hospital, Dar es Salaam, Tanzania  

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A cross-sectional and observational study was conducted among Intensive care (ICU) nurses at Muhimbili National Hospital (MNH), to identify knowledge and practice of ICU nurses on prevention of Ventilator Associated Pneumonia (VAP). Knowledge of 118 nurses working in ICU such as Main , Cardiac , Acute pediatric ICUs , emergency medicine department and highly dependent unit at MNH were tested by using a close ended questionnaire, 30 nurses among 118 were tested for knowledge and practice by us...

Said, Ally Tatu

2012-01-01

107

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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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 ...

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

2006-01-01

108

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

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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 D...

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

2011-01-01

109

Awareness of Food Labelling and Use of the Information in Purchasing Pre Packaged Food Products Among Consumers in Ilala Municipality Dar es Salaam  

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Liberalization of trade, globalization and development in food science and technology has resulted in an increase in trade and consumption of pre-packaged foods. Reading food labelling information is important to assist in making informed choices of food. This study determined level of awareness on pre-packaged food labelling information among consumers in Ilala Municipality, their perception on the importance of such information and difficulties encountered in reading and using pre- packaged...

Samson, G.

2012-01-01

110

Gender differences in HIV disease progression and treatment outcomes among HIV patients one year after starting antiretroviral treatment (ART) in Dar es Salaam, Tanzania  

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We investigated gender differences in treatment outcome during first line antiretroviral treatment (ART) in a hospital setting in Tanzania, assessing clinical, social demographic, virological and immunological factors. We conducted a cohort study involving HIV infected patients scheduled to start ART and followed up to 1 year on ART. Structured questionnaires and patients file review were used to collect information and blood was collected for CD4 and viral load testing. Gender differences we...

Mosha, Fausta; Muchunguzi, Victor; Matee, Mecey; Sangeda, Raphael Z.; Vercauteren, Jurgen; Nsubuga, Peter; Lyamuya, Eligius; Vandamme, Anne-mieke

2013-01-01

111

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

Directory of Open Access Journals (Sweden)

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

Mwakigonja Amos R

2012-02-01

112

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

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

Ambikile Joel

2012-07-01

113

Prevalence of Respiratory Symptoms and Chronic Obstructive Pulmonary Disease, and Reference Values for Lung Function Testing in Kinondoni District, Dar Es Salaam, Tanzania  

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In the wake of socioeconomic development, changing demographics towards ageing populations and the expatiation of non-communicable diseases put additional strains and new challenges unto health services and disease management in low-income countries. Chronic Obstructive Pulmonary Disease (COPD) is by the WHO Global Burden of Disease Study projected to rank as third leading cause of death worldwide in 2020, though studies concerning prevalence of COPD and presence of risk factors in low-i...

Knudsen, Gerd Toril Mørkve

2010-01-01

114

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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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. Meth...

Wandwalo Eliud R; Mfinanga Godfrey S; Ngadaya Esther S; Morkve Odd

2009-01-01

115

Adherence to Antiretroviral Therapy among HIV Infected Children Measured by Caretaker Report, Medication Return, and Drug Level in Dar Es Salaam, Tanzania.  

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Adherence to antiretroviral drugs in the treatment of paediatric HIV infection is complicated because of many factors including stigma and drug intake logistics. It is therefore important to identify children with non-adherence in order to intervene before they become at risk of developing treatment failure or drug resistance. The aim of this study was to determine the level of adherence to antiretroviral therapy (ART), measured by caretaker report, medication return and nevirapine plasma con...

Mghamba, Frida William; Minzi, Omary M. S.; Massawe, Augustine; Sasi, Philip

2013-01-01

116

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

117

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

118

Urbanisation and its discontents: urban refugees in Tanzania  

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This article explores the different labels under which refugees in Dar es Salaam may be categorised. It identifies and profiles differentgroups of urban refugee in Dar es Salaam and considers some common assumptions about urban refugees.

Marc Sommers

1999-01-01

119

Urbanisation and its discontents: urban refugees in Tanzania  

Directory of Open Access Journals (Sweden)

Full Text Available This article explores the different labels under which refugees in Dar es Salaam may be categorised. It identifies and profiles differentgroups of urban refugee in Dar es Salaam and considers some common assumptions about urban refugees.

Marc Sommers

1999-04-01

120

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

 
 
 
 
121

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

122

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.

1998-09-01

123

La alternancia dar/hacer en construcciones con verbo de apoyo y nombre de comunicación  

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Full Text Available En este artículo defendemos que la selección de un verbo de apoyo por parte del nombre que lo acompaña, dentro del contexto de una construcción con verbo de apoyo, se basa en criterios semánticos. En concreto, el objetivo del estudio será el de descubrir qué componente(s del significado del nombre determina(n la selección de dar y cuál(es, la de hacer, dos de los verbos de apoyo más frecuentes en español. Para llevar a cabo esta tarea, analizamos nombres pertenecientes al campo semántico de la comunicación verbal que pueden coocurrir con ambos verbos, dar y hacer (dar/hacer una sugerencia, y los contrastamos con otros dos grupos de nombres de comunicación: 1 los que se combinan con dar, pero rechazan *hacer (dar/*hacer una respuesta y 2 los coocurren con hacer, pero no con *dar (*dar/hacer una pregunta. En la comparación de los grupos trataremos de probar dos hipótesis: una que opera a nivel paradigmático, describiendo los vínculos semánticos entre los verbos de apoyo y los correspondientes verbos plenos y otra, a nivel sintagmático, analizando qué otros verbos, aparte de dar y/o hacer, constituyen la coocurrencia léxica restringida de los nombres de comunicación objeto de estudio.

Begoña Sanromán Vilas

2014-11-01

124

Fytoremediering av tungmetall förorenade jordar genom användning av lokala växter i Msimbazi flodens avrinningsområde, Tanzania.  

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This master thesis is a study of the feasibility of in situ soil remediation techniques in Dar es Salaam, Tanzania. It first looks at the existing on site remediation techniques and assesses how feasible they appear in the conditions of Dar es Salaam. Two methods were interpreted as more feasible than others, namely reactive zone remediation and phytoremediation. The feasibility of phytoremediation was assessed by sampling locally occurring plants and comparing their content of Cu, Pb and Zn ...

O?sterling, Eskil

2011-01-01

125

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

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

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

2008-01-01

126

Oral health behavior patterns among Tanzanian university students:a repeat cross-sectional survey  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purpose: This study examines oral health behavioral trends and the development of sociodemographic differences in oral health behaviors among Tanzanian students between 1999 and 2000. Methods: The population targeted was students attending the Muhimbili University College of Health Sciences (MUCHS) at the University of Dar es Salaam (UDSM), Dar es Salaam, Tanzania. Cross-sectional surveys were conducted and a total of 635 and 981 students, respectively, completed questionnai...

Astrom Nordrehaug, Anne; Masalu Rose, Joyce

2001-01-01

127

Oral health behavior patterns among Tanzanian university students: a repeat cross-sectional survey  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Purpose This study examines oral health behavioral trends and the development of sociodemographic differences in oral health behaviors among Tanzanian students between 1999 and 2000. Methods The population targeted was students attending the Muhimbili University College of Health Sciences (MUCHS) at the University of Dar es Salaam (UDSM), Dar es Salaam, Tanzania. Cross-sectional surveys were conducted and a total of 635 and 981 students, respectively, c...

Åstrøm Anne; Masalu Joyce

2001-01-01

128

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

129

Diseño e implementación de componentes software para dar soporte a la plataforma MEWiN en el sistema operativo Contiki  

Digital Repository Infrastructure Vision for European Research (DRIVER)

El presente proyecto final de carrera que tiene como título: "Diseño e Implementación de componentes software para dar soporte a la plataforma MEWiN en el sistema operativo Contiki" pretende dar soporte software al dispositivo MEWiN desarrollado. En la actualidad el sistema operativo Contiki es uno de los más utilizados en el ámbito de las redes inalámbricas de sensores, dada su característica de código libre y su alta escalabilidad. La mayoría de fabricantes de dispositivos elect...

Navarro Helli?n, Honorio

2011-01-01

130

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

131

¿Cuál 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

132

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

Scientific Electronic Library Online (English)

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

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

2013-01-01

133

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

134

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

135

Model-based inference for biomass estimation in a LiDAR sample survey in Hedmark County, Norway  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In forest inventories, regression models are often applied to predict quantities such as biomass at the level of sampling units. In this paper, we propose a model-based inference framework for combining sampling and model errors in the variance estimation. It was applied to airborne laser (LiDAR) data sets from Hedmark County, Norway, where the model error proportion of the total variance was found to be large for both scanning (airborne laser scanning) and profiling LiDAR when biomass was es...

Sta?hl, Go?ran; Holm, So?ren; Gregoire, Timothy G.; Gobakken, Terje; Næsset, Erik; Nelson, Ross

2011-01-01

136

Extraction of Mangrove Biophysical Parameters Using Airborne LiDAR  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 scal...

Poonsak Miphokasap; Phisan Santitamnont; Kiyoshi Honda; Wasinee Wannasiri; Masahiko Nagai

2013-01-01

137

LiDAR Elevation and DEM Errors in Forested Settings  

Directory of Open Access Journals (Sweden)

Full Text Available igital elevation models (DEMs form the basis of LiDAR derived tree height measurements and other topographic modeling needs within natural resource applications. We compared 2873 digital total station elevations to the closest discrete LiDAR elevation point and DEM raster cell across several forest and topographic settings. We also examined limiting comparisons to points within 0.5 m and within one meter. Using all nearest LiDAR points, average total station plot elevation differences ranged from -0.06 m (SD 0.40 to -0.59 m (SD 0.23 indicating that LiDAR elevations are higher than actual elevations. LiDAR DEM differences ranged from -0.09 (SD 0.41 to -0.56 m (SD 0.70. We also compared mapping-grade GPS receiver measurements to LiDAR point elevation and DEMs. Average plot GPS elevation differences ranged from 0.24 (SD 1.55 to 2.82 m (SD 4.58 for the nearest LiDAR point, and from 0.27 (SD 2.33 to 2.69 m (SD 5.06 for LiDAR DEMs. We believe that our efforts represent one of the most robust studies of LiDAR measurement errors available in published literature. The relatively small measurement differences that we found between LiDAR elevations and our most reliable field-based method of elevations, the digital total station, demonstrate the potential for LiDAR in forestry and natural resource applications.

Curtis Edson

2014-11-01

138

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

139

An Interactive Segmentation Method of LiDAR Data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In order to alleviate the problems inherent of automatic segmentation of LiDAR data, an interactive graph-cut segmentation method of LiDAR data is proposed. Firstly, the research background and the basic conceptions of the interactive graph-cut algorithm are introduced. Secondly, by analyzing the characteristics of LiDAR data, four-dimensional feature vectors are extracted, which as the graph-cut algorithm's input. Thirdly, the optimal parameter is estimated according to a new Sample-fitti...

Wen-Hui Li; Hong-Yin Ni; Hui-Ying Li; Ying Wang; Bo Fu; Yi-Feng Lin; Pei-Xun Liu

2013-01-01

140

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.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 (ROW 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.

Connie Ko

2012-01-01

 
 
 
 
141

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.

142

A DArT platform for quantitative bulked segregant analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2007-01-01

143

Electroporation of ES cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Author: Nagy Lab Cells are routinely passaged two days prior to electroporating. Usually one 10 cm plate at approximately 80% confluency will provide enough cells for 1-2 electroporations. ### Procedure 1. Change medium on ES cells 3-4 hours prior to electroporation - Gelatinize 10 cm plates, then add 10 ml medium to each. - Place them in a 37 0C incubator until they are required. - Switch on the electroporation apparatus. - Harvest ES cells by trypsinization. - Res...

sprotocols

2014-01-01

144

Gerenciar es crear  

Directory of Open Access Journals (Sweden)

Full Text Available Desde hace veinte años, los principios y el vocabulario de la gestión han invadido todas las esferasde la actividad humana. Ahora hay que administrar su vida, sus relaciones amorosas ¡y aún susemociones! La gestión ha adquirido tal estatus que numerosos individuos se ven impregnados deteorías y modelos a la moda sin que tengan realmente conciencia de ello. Se adoptan fórmulas lapidarias o eslóganes jurando que el cliente es el rey, que el beneficio es el único objetivo posible, quehay que crecer o morir, que la competencia debe ser necesariamente mundial, o que no se puede mejorar lo que es imposible medir. Cada día, los gerentes se ven particularmente bombardeados de“mensajes” que determinan sus actos y enfoques. Aún sin haber seguido programas específicosde formación, su práctica está modelada, prefabricada o condicionada por las tendencias delmomento.

Laurent Lapierre

2006-06-01

145

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

146

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

147

Cost-effective Design Options for IsoDAR  

CERN Document Server

This whitepaper reviews design options for the IsoDAR electron antineutrino source. IsoDAR is designed to produce $2.6 \\times 10^{22}$ electron antineutrinos per year with an average energy of 6.4 MeV, using isotope decay-at-rest. Aspects which must be balanced for cost-effectiveness include: overall cost; rate and energy distribution of the electron antineutrino flux and backgrounds; low technical risk; compactness; simplicity of underground construction and operation; reliability; value to future neutrino physics programs; and value to industry. We show that the baseline design outlined here is the most cost effective.

Adelmann, A; Barletta, W; Barlow, R; Bartoszek, L; Bungau, A; Calabretta, L; Calanna, A; Campo, D; Conrad, J M; Djurcic, Z; Kamyshkov, Y; Owen, H; Shaevitz, M H; Shimizu, I; Smidt, T; Spitz, J; Toups, M; Wascko, M; Winslow, L A; Yang, J J

2012-01-01

148

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Mosquito sampling methods are essential for monitoring and evaluating malaria vector control interventions. In urban Dar es Salaam, human landing catch (HLC) is the only method sufficiently sensitive for monitoring malaria-transmitting Anopheles. HLC is labour intensive, cumbersome, hazardous, and requires such intense supervision that is difficulty to sustain on large scales. Methods Novel tent traps were developed as alternatives t...

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

2009-01-01

149

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

150

¿Qué es conducta?  

Directory of Open Access Journals (Sweden)

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

Esteve Freixa i Baqu\\u00E9

2003-01-01

151

Freezing Human ES Cells  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Trish, Erin; Dimos, John; Eggan, Kevin

2006-01-01

152

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

153

¿Es la filosofía una ciencia?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Para tratar la cuestión de la cientificidad de la filosofía hay que preguntarse primero por la naturaleza de la filosofía. Constatamos primero que filosofar es una forma de pensar recursiva, y en ello es análoga a la matemática: la filosofía contiene la metafilosofía. Lo segundo es que el esquema general de las preguntas filosóficas es: “¿Qué es X?”. Ello, sin embargo, no nos dice gran cosa, pues la historia de la filosofía nos muestra que la variable X puede ser...

Moulines, C. Ulises

2011-01-01

154

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.

2007-12-01

155

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Schouten, H. J.; Weg, W. E.; Carling, J.; Khan, S. A.; Mckay, S. J.; Kaauwen, M. P. W.

2012-01-01

156

Texture-based landform segmentation of LiDAR imagery  

Science.gov (United States)

In this study, we implement and apply a region growing segmentation procedure based on texture to extract spatial landform objects from a light detection and ranging (LiDAR) digital surface model (DSM). The local binary pattern (LBP) operator, modeling texture, is integrated into a region growing segmentation algorithm to identify landform objects. We apply a multi-scale LBP operator to describe texture at different scales. The paper is illustrated with a case study that involves segmentation of coastal landform objects using a LiDAR DSM of a coastal area in the UK. Landform objects can be identified with the combination of a multi-scale texture measure and a region growing segmentation. We show that meaningful coastal landform objects can be extracted with this algorithm. Uncertainty values provide useful information on transition zones or fuzzy boundaries between objects.

Lucieer, Arko; Stein, Alfred

2005-03-01

157

Texture-based landform segmentation of LiDAR Imagery  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, we implement and apply a region growing segmentation procedure based on texture to extract spatial landform objects from a light detection and ranging (LiDAR) digital surface model (DSM). The local binary pattern (LBP) operator, modeling texture, is integrated into a region growing segmentation algorithm to identify landform objects. We apply a multi-scale LBP operator to describe texture at different scales. The paper is illustrated with a case study that involves segmentation...

Lucieer, A.; Stein, A.

2005-01-01

158

Quantifying Ladder Fuels: A New Approach Using LiDAR  

Directory of Open Access Journals (Sweden)

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

Heather A. Kramer

2014-06-01

159

Rapid topographic and bathymetric reconnaissance using airborne LiDAR  

Science.gov (United States)

Today airborne LiDAR (Light Detection And Ranging) systems has gained acceptance as a powerful tool to rapidly collect invaluable information to assess the impact from either natural disasters, such as hurricanes, earthquakes and flooding, or human inflicted disasters such as terrorist/enemy activities. Where satellite based imagery provides an excellent tool to remotely detect changes in the environment, the LiDAR systems, being active remote sensors, provide an unsurpassed method to quantify these changes. The strength of the active laser based systems is especially evident in areas covered by occluding vegetation or in the shallow coastal zone as the laser can penetrate the vegetation or water body to unveil what is below. The purpose of this paper is to address the task to survey complex areas with help of the state-of-the-art airborne LiDAR systems and also discuss scenarios where the method is used today and where it may be used tomorrow. Regardless if it is a post-hurricane survey or a preparation stage for a landing operation in unchartered waters, it is today possible to collect, process and present a dense 3D model of the area of interest within just a few hours from deployment. By utilizing the advancement in processing power and wireless network capabilities real-time presentation would be feasible.

Axelsson, Andreas

2010-10-01

160

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

Scientific Electronic Library Online (English)

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

Sofia Santanna, Gandra; Zélia, Teixeira.

 
 
 
 
161

LA DIETA MEDITERRÁNEA: ES CARDIOPROTECTIVA?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 e...

Alfredo Arredondo Bruce; Jacqueline Amores Carrate

2007-01-01

162

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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. Co...

Iungo, G. V.; Porte?-agel, F.

2013-01-01

163

Data management based on geocoding index and adaptive visualization for airborne LiDAR  

Science.gov (United States)

With more surveying practice and deeper application, data post-process for airborne LiDAR system has been extracted lots of attention in data accuracy, post-process, fusion, modeling, automation and visualization. However, post-process and flexible visualization were found to be the bottle-neck which limits the LiDAR data usage for industrial applications. The cause of above bottle-neck problems is great capacity for LiDAR system. Thus in article a geocoding index based multivariate data management and adaptive visualization will be studied for based on the feature of airborne LiDAR's data to improve automatization of post-process and surveying efficiency.

Zhi, Xiaodong

2008-10-01

164

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

165

Sampling Error Characteristics Of Cloud Observations From LiDAR  

Science.gov (United States)

Height profiles of cloud fraction is an important parameter that is not well represented in GCMs and in smaller scale models. Improvements should come from new and existing remote sensing technologies that will increasingly provide the science community with direct observations of such profiles. However, an inherent error or uncertainty is associated with any cloud fraction estimate from remote sensing data due to instrument and atmospheric noise, sensor resolution and the sampling scheme. While all sources of uncertainties need to be investigated further, this project focuses on the characteristics of the errors originating from the sampling scheme. Space-borne LiDAR data from the 1994 NASA LITE campaign is used to study and quantify the characteristics of such sampling errors in cloud fraction estimates from along transect measurements. This is done within a general model for sampling along a transect, which has been developed based on an approach from queuing theory, without making prior assumptions on the type of cloud distribution (Astin and Di Girolamo, 1999). Results will be presented giving estimates of the cloud fraction and its distributions over a range of altitudes as evaluated from cloudy and clear interval lengths as observed along the transects of the LITE observations. The estimates themselves are refined to account for missing data due to attenuation of the LiDAR signal by dense cloud. Further, the distribution of cloud cover fraction over the earth is also presented, which allows for climatological interpretation of the results. In this, estimates of the mean cloud cover fraction and distributions and confidence intervals are provided for pressure levels from the boundary layer to the tropopause. Estimates are also inferred from transects over the whole globe, but separated into climatological regions based on mean precipitation-evapotranspiration, as well as separated by surface type such as clouds over land versus those above sea. The above results allow examination of the error characteristics of the cover fraction estimates in relation with the underlying process and the LiDAR sampling scheme.

van de Poll, M.

2001-12-01

166

Towards a LiDAR based geomorphological database of Sweden  

Science.gov (United States)

Geomorphological maps can be important for both societal development and scientific research especially with the use of new technology and consideration for the end user's needs. Since 2009, the Swedish mapping agency (Lantmäteriet) has been using airborne light detection and ranging (LiDAR) to create a detailed "bare earth" digital elevation model (DEM) of Sweden. Presently, a LiDAR derived DEM with 2 m horizontal and 0.25 m vertical resolution exist for about half of the country. This data set enables viewing of the landscape in a new more detailed way; landforms never before seen can now be delineated easily in a desktop environment. We are using this DEM to map the geomorphology, bringing into existence a highly detailed, digitial, geomorphologic database and map. While prior geomorphological maps exist for Sweden, the new map being compiled by the Geological Survey of Sweden (SGU) will be the first one to be derived from and presented in an entirely digital format. With the use of GIS technology, it is possible to present a map with different layers and symbology depending on the scale of the area of interest. For example, when looking at a map at a small scale, every moraine within a moraine complex is visible, but when viewed at a larger scale the moraine complex is presented as a single object. The digital presentation allows users to select scale-appropriate geomorphological data to their needs. By coupling other SGU or external databases with the geomorphological database it is possible to produce a wide range of products suitable for a wide range of uses. For example, by adding bedrock or geochemical data to landforms indicative of ice flow direction, a product useful for mineral prospecting is created. Other derivative applications may include groundwater studies or evaluation of geoheritage areas. Regarding scientific applications, the new LiDAR data have enabled mapping of geomorphic landforms in greater detail than previous Swedish maps. In addition to refining the locations and dimensions of previously mapped landforms, features never described before have been brought to light. These features include terminal moraines and cross-cutting glacial lineations. At small scales, these newly mapped landforms show signs of a complex glacial history. On a larger scale, landforms indicative of ice flow direction can be used to create a gridded map of ice flow directions useful for glaciological modelling.

Peterson, Gustaf; Smith, Colby A.

2013-04-01

167

Modelling Sensor and Target effects on LiDAR Waveforms  

Science.gov (United States)

The aim of this research is to explore the influence of sensor characteristics and interactions with vegetation and terrain properties on the estimation of vegetation parameters from LiDAR waveforms. This is carried out using waveform simulations produced by the FLIGHT radiative transfer model which is based on Monte Carlo simulation of photon transport (North, 1996; North et al., 2010). The opportunities for vegetation analysis that are offered by LiDAR modelling are also demonstrated by other authors e.g. Sun and Ranson, 2000; Ni-Meister et al., 2001. Simulations from the FLIGHT model were driven using reflectance and transmittance properties collected from the Howland Research Forest, Maine, USA in 2003 together with a tree list for a 200m x 150m area. This was generated using field measurements of location, species and diameter at breast height. Tree height and crown dimensions of individual trees were calculated using relationships established with a competition index determined for this site. Waveforms obtained by the Laser Vegetation Imaging Sensor (LVIS) were used as validation of simulations. This provided a base from which factors such as slope, laser incidence angle and pulse width could be varied. This has enabled the effect of instrument design and laser interactions with different surface characteristics to be tested. As such, waveform simulation is relevant for the development of future satellite LiDAR sensors, such as NASA’s forthcoming DESDynI mission (NASA, 2010), which aim to improve capabilities of vegetation parameter estimation. ACKNOWLEDGMENTS We would like to thank scientists at the Biospheric Sciences Branch of NASA Goddard Space Flight Center, in particular to Jon Ranson and Bryan Blair. This work forms part of research funded by the NASA DESDynI project and the UK Natural Environment Research Council (NE/F021437/1). REFERENCES NASA, 2010, DESDynI: Deformation, Ecosystem Structure and Dynamics of Ice. http://desdyni.jpl.nasa.gov/ (accessed May 2010). NI-MEISTER, W., JUPP, D. L. B. and DUBAYAH, R., 2001, Modeling Lidar Waveforms in Heterogeneous and Discrete Canopies. IEEE Transactions on Geoscience and Remote Sensing, 39 (9): 1943-1958. NORTH, P. R. J., 1996, Three-Dimensional Forest Light Interaction Model Using a Monte Carlo Method. IEEE Transactions on Geoscience and Remote Sensing, 34 (4): 946-956. NORTH, P. R. J., ROSETTE, J. A. B., SUÁREZ, J. C. and LOS, S. O., 2010, A Monte Carlo radiative transfer model of satellite waveform lidar. International Journal of Remote Sensing, 31 (5): 1343-1358. SUN, G. and RANSON, K. J., 2000, Modeling lidar returns from forest canopies. IEEE Transactions on Geoscience and Remote Sensing, 38 (6): 2617-2626.

Rosette, J.; North, P. R.; Rubio, J.; Cook, B. D.; Suárez, J.

2010-12-01

168

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Connie Ko; Remmel, Tarmo K.; Gunho Sohn

2012-01-01

169

Remote sensing of Sonoran Desert vegetation structure and phenology with ground-based LiDAR  

Science.gov (United States)

Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of LiDAR to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat LiDAR scans of perennial plant canopies over the course of one year had high precision. LiDAR measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of LiDAR vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by LiDAR was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using LiDAR over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat LiDAR measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.

Sankey, Joel B.; Munson, Seth M.; Webb, Robert H.; Wallace, Cynthia S.A.; Duran, Cesar M.

2015-01-01

170

Applications and benefits of airborne LiDAR technology for transmission line asset management  

Energy Technology Data Exchange (ETDEWEB)

This presentation discussed applications and benefits of airborne LiDAR technology for transmission line asset management. There are many challenges to satisfy the growing energy demands, such as acquiring rights-of-way for new power lines; maximizing capacity and up-rating of existing lines; and changing detection and monitoring. One option is to use airborne LiDAR technology for power line asset management. Optech's airborne laser terrain mapper (ALTM) is a solution for power line corridor surveys. LiDAR technology for surveying applications include ground-based or airborne laser scanning. The specific topics that were discussed in this presentation were ALTM applications; airborne LiDAR for corridor surveys; advantages of airborne LiDAR; LiDAR workflow; engineering and profile sheets; sag analysis; clearance analysis; vegetation encroachment; and LiDAR data accuracy. The benefits of ALTM for power line surveys were also presented, with particular reference to compactness; installation flexibility; data collection efficiency; and high density of points. Field data for ALTM-Orion was illustrated. It was concluded that Optech's ALTM airborne LiDAR system provides the best solution for power line survey applications. tabs., figs.

Ussyshkin, R.V.; Sitar, M. [Optech, Inc., Downsview, ON (Canada)

2009-07-01

171

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

172

Soft seabed classification using Airborne LiDAR Bathymetry data  

Science.gov (United States)

Coastal seabed mapping is essential for a variety of environmental management activities. Recently-introduced Airborne LiDAR Bathymetry (ALB) sensors allow, under favourable conditions, time and cost-efficient collection of shallow coastal seabed data in comparison to acoustics. One important application here, given seabed footprint size on the order to several meters in diameter for shallow waters, is the development of classification maps. The coastal seabed is typically a complex environment consisting of diversity and thus necessitates classification accounting for heterogeneity. Recent ALB classification studies have used techniques that assign each ALB shot to a single seabed class (i.e. hard classification) instead of assignment to multiple classes (i.e. soft classification). In this study, a Soft Seabed Classification (SSC) algorithm is developed with fuzzy clustering accounting for diversity. Both simulation and an ALB dataset of area approximately 20,000 m2 were used. Cross validation of the SSC approach yield favourable soft and hard classification accuracies.

Narayanan, Ramasamy

2011-12-01

173

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; Fernández, Antonio J

2012-01-01

174

ES-2 Dummy Biomechanical Responses.  

Science.gov (United States)

This technical paper presents the results of biomechanical testing conducted on the ES-2 dummy by the Occupant Safety Research Partnership and Transport Canada. The ES-2 is a production dummy, based on the EuroSID-1 dummy, that was modified to further improve testing capabilities as recommended by users of the EuroSID-1 dummy. Biomechanical response data were obtained by completing a series of drop, pendulum, and sled tests that are outlined in the International Organization of Standardization Technical Report 9790 that describes biofidelity requirements for the midsize adult male side impact dummy. A few of the biofidelity tests were conducted on both sides of the dummy to evaluate the symmetry of its responses. Full vehicle crash tests were conducted to verify if the changes in the EuroSID-1, resulting in the ES-2 design, did improve the dummy's testing capability. In addition to the biofidelity testing, the ES-2 dummy repeatability, reproducibility and durability are discussed. Finally, this technical paper will compare the biofidelity ratings of the current adult side impact dummies with the ES-2 dummy, which received an overall dummy biofidelity rating of 4.6. PMID:17096233

Byrnes, Katie; Abramczyk, Joseph; Berliner, Jeff; Irwin, Annette; Jensen, Jack; Kowsika, Murthy; Mertz, Harold J; Rouhana, Stephen W; Scherer, Risa; Shi, Yibing; Sutterfield, Aleta; Xu, Lan; Tylko, Suzanne; Dalmotas, Dainius

2002-11-01

175

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

176

Surface-Based Registration of Airborne and Terrestrial Mobile LiDAR Point Clouds  

Directory of Open Access Journals (Sweden)

Full Text Available Light Detection and Ranging (LiDAR is an active sensor that can effectively acquire a large number of three-dimensional (3-D points. LiDAR systems can be equipped on different platforms for different applications, but to integrate the data, point cloud registration is needed to improve geometric consistency. The registration of airborne and terrestrial mobile LiDAR is a challenging task because the point densities and scanning directions differ. We proposed a scheme for the registration of airborne and terrestrial mobile LiDAR using the least squares 3-D surface registration technique to minimize the surfaces between two datasets. To analyze the effect of point density in registration, the simulation data simulated different conditions and estimated the theoretical errors. The test data were the point clouds of the airborne LiDAR system (ALS and the mobile LiDAR system (MLS, which were acquired by Optech ALTM 3070 and Lynx, respectively. The resulting simulation analysis indicated that the accuracy of registration improved as the density increased. For the test dataset, the registration error of mobile LiDAR between different trajectories improved from 40 cm to 4 cm, and the registration error between ALS and MLS improved from 84 cm to 4 cm. These results indicate that the proposed methods can obtain 5 cm accuracy between ALS and MLS.

Tee-Ann Teo

2014-12-01

177

Compression strategies for LiDAR waveform cube  

Science.gov (United States)

Full-waveform LiDAR data (FWD) provide a wealth of information about the shape and materials of the surveyed areas. Unlike discrete data that retains only a few strong returns, FWD generally keeps the whole signal, at all times, regardless of the signal intensity. Hence, FWD will have an increasingly well-deserved role in mapping and beyond, in the much desired classification in the raw data format. Full-waveform systems currently perform only the recording of the waveform data at the acquisition stage; the return extraction is mostly deferred to post-processing. Although the full waveform preserves most of the details of the real data, it presents a serious practical challenge for a wide use: much larger datasets compared to those from the classical discrete return systems. Atop the need for more storage space, the acquisition speed of the FWD may also limit the pulse rate on most systems that cannot store data fast enough, and thus, reduces the perceived system performance. This work introduces a waveform cube model to compress waveforms in selected subsets of the cube, aimed at achieving decreased storage while maintaining the maximum pulse rate of FWD systems. In our experiments, the waveform cube is compressed using classical methods for 2D imagery that are further tested to assess the feasibility of the proposed solution. The spatial distribution of airborne waveform data is irregular; however, the manner of the FWD acquisition allows the organization of the waveforms in a regular 3D structure similar to familiar multi-component imagery, as those of hyper-spectral cubes or 3D volumetric tomography scans. This study presents the performance analysis of several lossy compression methods applied to the LiDAR waveform cube, including JPEG-1, JPEG-2000, and PCA-based techniques. Wide ranges of tests performed on real airborne datasets have demonstrated the benefits of the JPEG-2000 Standard where high compression rates incur fairly small data degradation. In addition, the JPEG-2000 Standard-compliant compression implementation can be fast and, thus, used in real-time systems, as compressed data sequences can be formed progressively during the waveform data collection. We conclude from our experiments that 2D image compression strategies are feasible and efficient approaches, thus they might be applied during the acquisition of the FWD sensors.

Jó?ków, Grzegorz; Toth, Charles; Quirk, Mihaela; Grejner-Brzezinska, Dorota

2015-01-01

178

Petrogenesis of lunar highlands meteorites: Dhofar 025, Dhofar 081 Dar al Gani 262, and Dar al Gani 400  

Science.gov (United States)

The petrogenesis of four lunar highlands meteorites, Dhofar 025 (Dho 025), Dhofar 081 (Dho 081), Dar al Gani 262 (DaG 262), and Dar al Gani 400 (DaG 400) were studied. For Dho 025, measured oxygen isotopic values and Fe-Mn ratios for mafic minerals provide corroboratory evidence that it originated on the Moon. Similarly, Fe-Mn ratios in the mafic minerals of Dho 081 indicate lunar origin. Lithologies in Dho 025 and Dho 081 include lithic clasts, granulites, and mineral fragments. A large number of lithic clasts have plagioclase AN# and coexisting mafic mineral Mg# that plot within the "gap" separating ferroan anorthosite suite (FAN) and high-magnesium suite (HMS) rocks. This is consistent with whole rock Ti-Sm ratios for Dho 025, Dho 081, and DaG 262, which are also intermediate compared to FAN and HMS lithologies. Although ion microprobe analyses performed on Dho 025, Dho 081, DaG 262, and DaG 400 clasts and minerals show far stronger FAN affinities than whole rock data suggest, most clasts indicate admixture of £12% HMS component based on geochemical modeling. In addition, coexisting plagioclase-pyroxene REE concentration ratios in several clasts were compared to experimentally determined plagioclase-pyroxene REE distribution coefficient ratios. Two Dho 025 clasts have concordant plagioclase-pyroxene profiles, indicating that equilibrium between these minerals has been sustained despite shock metamorphism. One clast has an intermediate FAN-HMS composition. These lunar meteorites appear to represent a type of highland terrain that differs substantially from the KREEP-signatured impact breccias that dominate the lunar database. From remote sensing data, it is inferred that the lunar far side appears to have appropriate geochemical signatures and lithologies to be the source regions for these rocks; although, the near side cannot be completely excluded as a possibility. If these rocks are, indeed, from the far side, their geochemical characteristics may have far-reaching implications for our current scientific understanding of the Moon.

Cahill, J. T.; Floss, C.; Anand, M.; Taylor, L. A.; Nazarov, M. A.; Cohen, B. A.

2004-04-01

179

The pleiotropic mutation dar1 affects plant architecture in Arabidopsis thaliana.  

Science.gov (United States)

Shoot architecture is shaped upon the organogenic activity of the shoot apical meristem (SAM). Such an activity relies on the balance between the maintenance of a population of undifferentiated cells in the centre of the SAM and the recruitment of organ founder cells at the periphery. A novel mutation in Arabidopsis thaliana, distorted architecture1 (dar1), is characterised by disturbed phyllotaxy of the inflorescence and consumption of the apical meristem late in development. SEM and light microscopy analyses of the dar1 SAM reveal an abnormal partitioning of meristematic domains, and mutations known to affect the SAM structure and function were found to interact with dar1. Moreover, the mutant shows an alteration of the root apical meristem (RAM) structure. Those observations support the hypothesis that DAR1 has a role in meristem maintenance and it is required for the normal development of Arabidopsis inflorescence during plant life. PMID:12591242

Para, Alessia; Sundås-Larsson, Annika

2003-02-15

180

¿Es posible el capitalismo sostenible?  

Directory of Open Access Journals (Sweden)

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

James O\\u00B4Connor

2000-01-01

 
 
 
 
181

Does participatory forest management promote sustainable forest utilisation in Tanzania?  

DEFF Research Database (Denmark)

Over the past 20 years, Participatory Forest Management (PFM) has become a dominant forest management strategy in Tanzania, covering more than 4.1 million hectares. Sustainable forest use and supply of wood products to local people are major aims of PFM. This paper assesses the sustainability of forest utilisation under PFM, using estimates of forest condition and extraction rates based on forest inventories and 480 household surveys from 12 forests; seven under Community Based Forest Management (CBFM), three under Joint Forest Management (JFM) and two under government management (non-PFM). Extraction of products is intense in forests close to Dar es Salaam, regardless of management regime. Further from Dar es Salaam, harvesting levels in forests under PFM are, with one prominent exception, broadly sustainable. Using GIS data from 116 wards, it is shown that half of the PFM forests in Tanzania are likely to be too small to satisfy current local wood demand.

Treue, Thorsten; Ngaga, Y.M.

2014-01-01

182

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Airborne scanning LiDAR is a promising technique for efficient and accuratebiomass mapping due to its capacity for direct measurement of the three-dimensionalstructure of vegetation. A combination of individual tree detection (ITD) and an area-basedapproach (ABA) introduced in Vastaranta et al. [1] to map forest aboveground biomass(AGB) and stem volume (VOL) was investigated. The main objective of this study was totest the usability and accuracy of LiDAR in biomass mapping. The nearest neighb...

Petteri Alho; Hannu Hyyppä; Juha Hyyppä; Xiaowei Yu; Minna Räty; Markus Holopainen; Mikko Vastaranta; Ville Kankare; Risto Viitala

2013-01-01

183

Investigating assumptions of crown archetypes for modelling LiDAR returns  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2013-01-01

184

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Herein, an aerial LiDAR topographic dataset is analysed and interpolated by means of geostatistical techniques in order to examine the morphology of a scree slope area in the Eastern Italian Alps. The LiDAR-derived digital terrain model (DTM) is analysed using variogram maps as spatial continuity indexes. This allowed for evaluation of the reproduction of spatial variability of topography and for the characterization and comparison of different morphological features occurring in the study si...

Trevisani, S.; Cavalli, M.; Marchi, L.

2009-01-01

185

Change Detection from differential airborne LiDAR using a weighted Anisotropic Iterative Closest Point Algorithm  

Science.gov (United States)

Differential LiDAR (Light Detection and Ranging) from repeated surveys has recently emerged as an effective tool to measure three-dimensional (3D) change for applications such as quantifying slip and spatially distributed warping associated with earthquake ruptures, and examining the spatial distribution of beach erosion after hurricane impact. Currently, the primary method for determining 3D change is through the use of the iterative closest point (ICP) algorithm and its variants. However, all current studies using ICP have assumed that all LiDAR points in the compared point clouds have uniform accuracy. This assumption is simplistic given that the error for each LiDAR point is variable, and dependent upon highly variable factors such as target range, angle of incidence, and aircraft trajectory accuracy. Therefore, to rigorously determine spatial change, it would be ideal to model the random error for every LiDAR observation in the differential point cloud, and use these error estimates as apriori weights in the ICP algorithm. To test this approach, we implemented a rigorous LiDAR observation error propagation method to generate estimated random error for each point in a LiDAR point cloud, and then determine 3D displacements between two point clouds using an anistropic weighted ICP algorithm. The algorithm was evaluated by qualitatively and quantitatively comparing post earthquake slip estimates from the 2010 El Mayor-Cucapah Earthquake between a uniform weight and anistropically weighted ICP algorithm, using pre-event LiDAR collected in 2006 by Instituto Nacional de Estadística y Geografía (INEGI), and post-event LiDAR collected by The National Center for Airborne Laser Mapping (NCALM).

Zhang, X.; Kusari, A.; Glennie, C. L.; Oskin, M. E.; Hinojosa-Corona, A.; Borsa, A. A.; Arrowsmith, R.

2013-12-01

186

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2004-01-01

187

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Quantification of tropical forest Above Ground Biomass (AGB) over large areas as input for Reduced Emissions from Deforestation and forest Degradation (REDD+) projects and climate change models is challenging. This is the first study which attempts to estimate AGB and its variability across large areas of tropical lowland forests in Central Kalimantan (Indonesia) through correlating airborne Light Detection and Ranging (LiDAR) to forest inventory data. Two LiDAR height metrics were ana...

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

2012-01-01

188

High-Density LiDAR Mapping of the Ancient City of Mayapán  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Timothy Hare; Marilyn Masson; Bradley Russell

2014-01-01

189

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

190

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

191

Modeling and simulation return waveforms from forest canopy of large footprint LiDAR  

Science.gov (United States)

LiDAR (Light Detection and Ranging) can provide accurate remote sensing data for extracting surface information, and large footprint LiDAR has demonstrated great potential for accurately measuring forest canopy characteristics, which are important for regional and global climate change studies. In this study the Geometric Optical Model, Radiative Transfer Model and hotspot condition are used to explore the relationship between canopy structure and large footprint LiDAR return waveforms. A simplified model was simulated, and detailed analysis was made. The model was improved by adding an extinction coefficient and a scatter coefficient, and then some simplified parameters are introduced to the model. The new 3D model is simulated by considering the characteristics of large footprint LiDAR and forest stand. The experiment results show that terrain slop can influence LiDAR return waveform shapes greatly, while tree height just affects the starting position of waveforms, and the effects of terrain slop and extinction is reduced obviously. The new model was validated with field data of Changbai Mountain, and the results have good agreement with GLAS data, and relatively, the improved model and simulation of waveform fit the actual return waveform of large footprint LiDAR system.

Liu, Zhaoyan; Li, Ran; Xi, Xiaohuan; Tang, Lingli; Li, Chuanrong

2009-10-01

192

Hyperspectral imagery and LiDAR for geological analysis of Cuprite, Nevada  

Science.gov (United States)

Fusion of Light Detection and Ranging (LiDAR) and Hyperspectral Imagery (HSI) products is useful for geological analysis, particularly for visualization of geomorphology and hydrology. In early 2007, coincident hyperspectral imagery and LiDAR were acquired over Cuprite, Nevada. The data were analyzed with ENVI and the ENVI LiDAR Toolkit. Results of the analysis of these data suggest, for some surfaces, a correlation between mineral content and surface roughness. However, the LiDAR resolution (~1 meter ground sampling distance) is likely too coarse to extract surface texture properties of clay minerals in some of the alluvial fans captured in the imagery. Though not demonstrated in this particular experiment (but a goal of the research), the relation between surface roughness and mineral composition may provide valuable information about the mechanical properties of the surface cover-in addition to generating another variable useful for material characterization, image classification, and scene segmentation. Future mission planning should include consideration of determining optimal ground sampling to be used by LiDAR and HSI systems. The fusion of LiDAR elevation data and multi- and hyperspectral classification results is, in and of itself, a valuable tool for imagery analysis and should be explored further.

West, Michael S.; Resmini, Ronald G.

2009-05-01

193

Adaptive Covariance Estimation Method for LiDAR-Aided Multi-Sensor Integrated Navigation Systems  

Directory of Open Access Journals (Sweden)

Full Text Available The accurate estimation of measurements covariance is a fundamental problem in sensors fusion algorithms and is crucial for the proper operation of filtering algorithms. This paper provides an innovative solution for this problem and realizes the proposed solution on a 2D indoor navigation system for unmanned ground vehicles (UGVs that fuses measurements from a MEMS-grade gyroscope, speed measurements and a light detection and ranging (LiDAR sensor. A computationally efficient weighted line extraction method is introduced, where the LiDAR intensity measurements are used, such that the random range errors and systematic errors due to surface reflectivity in LiDAR measurements are considered. The vehicle pose change is obtained from LiDAR line feature matching, and the corresponding pose change covariance is also estimated by a weighted least squares-based technique. The estimated LiDAR-based pose changes are applied as periodic updates to the Inertial Navigation System (INS in an innovative extended Kalman filter (EKF design. Besides, the influences of the environment geometry layout and line estimation error are discussed. Real experiments in indoor environment are performed to evaluate the proposed algorithm. The results showed the great consistency between the LiDAR-estimated pose change covariance and the true accuracy. Therefore, this leads to a significant improvement in the vehicle’s integrated navigation accuracy.

Shifei Liu

2015-01-01

194

Dar razón de la libertad en Kant y en Hegel  

Directory of Open Access Journals (Sweden)

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

Félix Duque

2004-01-01

195

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

196

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

197

A Trial of the Effect of Micronutrient Supplementation on Treatment Outcome, T Cell Counts, Morbidity, and Mortality in Adults with Pulmonary Tuberculosis.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tuberculosis (TB) often coincides with nutritional deficiencies. The effects of micronutrient supplementation on TB treatment outcomes, clinical complications, and mortality are uncertain. We conducted a randomized, double-blind, placebo-controlled trial of micronutrients (vitamins A, B complex, C, and E, as well as selenium) in Dar es Salaam, Tanzania. We enrolled 471 human immunodeficiency virus (HIV)-infected and 416 HIV-negative adults with pulmonary TB at the time of initiating chemother...

Villamor, Eduardo; Mugusi, Ferdinand; Urassa, Willy; Bosch, Ronald J.; Saathoff, Elmar; Matsumoto, Kenji; Meydani, Simin N.; Fawzi, Wafaie W.

2008-01-01

198

Perceived University Students’ Attributions of Their Academic Success and Failure  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study examined the applicability of the attribution theory in understanding how students attribute their academic success and failure. Participants involved a sample of 260 undergraduate students at the University of Dar es Salaam, Tanzania. They completed an attitude questionnaire scale with items on locus of control, stability and controllability dimensions. The results show that the majority of students attributed their academic performance to internal, stable and controllable factors...

Mkumbo, Kitila A. K.; Jacqueline Amani

2012-01-01

199

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

200

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Temel, T.

2004-01-01

 
 
 
 
201

Urban-rural contrasts in explanatory models and treatment-seeking behaviours for stroke in Tanzania.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Stroke is an emerging problem in sub-Saharan Africa, about which little is known since most research to date has been based on retrospective, hospital-based studies. This anthropological work, designed to complement a large community-based project on stroke incidence, focuses on local understandings and treatment-seeking behaviours in urban (Dar-es-Salaam) and rural (Hai) areas of Tanzania. Semi-structured interviews (n=80) were conducted with 20 stroke patients, 20 relatives of stroke patien...

Mshana, G.; Hampshire, K.; Panter-Brick, C; Walker, R.

2008-01-01

202

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

BACKGROUND Mosquito sampling methods are essential for monitoring and evaluating malaria vector control interventions. In urban Dar es Salaam, human landing catch (HLC) is the only method sufficiently sensitive for monitoring malaria-transmitting Anopheles. HLC is labour intensive, cumbersome, hazardous, and requires such intense supervision that is difficulty to sustain on large scales. METHODS Novel tent traps were developed as alternatives to HLC. The Furvela tent, designed in ...

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

2009-01-01

203

Use and integration of vocabularies in digital repositories  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Free Webinar on the use of controlled vocabularies offered to people from Sokoine Agricultural University (SUA), University of Dar es Salaam (UDSM), Ardhi University (ARU) and Tanzania Meteorological Institute (TMA) working on the project "Strengthening documentation, communication and dissemination of information related to climate change impacts, adaptation and mitigation in Tanzania". The objective is to build the Tanzania Climate Change Repository, TaCCIRe, a subject repository based on D...

Subirats-coll, Imma

2013-01-01

204

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Smide, Bibbi

2000-01-01

205

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

206

Some remarks on one old Swahili manuscript  

Digital Repository Infrastructure Vision for European Research (DRIVER)

As is well-known, there are presently several archives of old Swahili manuscripts: in Dar es Salaam, Halle and Hamburg, London etc. These collections and separate manuscripts are being studied from various points of view by both European and African scholars. Beside the vast collection of old Swahili manuscripts kept in SOAS, there is another collection of Swahili works at the British Library in London, which has been considerably expanded recently by acquisitions from Jan Knappert. There, on...

Zhukov, Andrei

2012-01-01

207

TUKI 2004. Kamusi ya Kiswahili Sanifu. Toleo la Pili. [A standard Swahili dictionary. Second edition]. Nairobi: Oxford University Press. xviii, 477 pp. ISBN 0195732227. (ca. 15000 ThS/ 15.- €)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Book review: In 2004 the long awaited second edition of the Standard Swahili - Swahili Dictionary, edited by the Insitute of Kiswahili Research (TUKI) at the University of Dar es Salaam, appeared. With this publication TUKI has once again confirmed its leading role in the field of Swahili lexicography in East Africa. it is up to date, containing new words and phrases which are in use in East Africa in order to cope with the development in science and technology, society, economics and globali...

Herms, Irmtraud

2012-01-01

208

Increasing caesarean section rates among low-risk groups: a panel study classifying deliveries according to Robson at a university hospital in Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rising caesarean section (CS) rates have been observed worldwide in recent decades. This study sought to analyse trends in CS rates and outcomes among a variety of obstetric groups at a university hospital in a low-income country. We conducted a hospital-based panel study at Muhimbili National Hospital, Dar es Salaam, Tanzania. All deliveries between 2000 and 2011 with gestational age???28 weeks were included in the study. The 12 years were divided into four periods: 2000 to 2002, 2003 ...

Litorp, Helena; Kidanto, Hussein L.; Nystrom, Lennarth; Darj, Elisabeth; Esse?n, Birgitta

2013-01-01

209

Optimal Blood Mononuclear Cell Isolation Procedures for Gamma Interferon Enzyme-Linked Immunospot Testing of Healthy Swedish and Tanzanian Subjects?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Determination of antigen-specific T-cell responses is an important part of vaccine assessment. High levels of recovery, viability, and functionality of peripheral blood mononuclear cells (PBMCs) are essential for reliable assessment of cell-mediated immune responses. Here, we sought to find the cell preparation technique best suited for two clinical vaccine trial sites: Stockholm, Sweden, and Dar es Salaam, Tanzania. Standard Ficoll-Paque gradient centrifugation, BD Vacutainer cell preparatio...

Nilsson, C.; Aboud, S.; Karle?n, K.; Hejdeman, B.; Urassa, W.; Biberfeld, G.

2008-01-01

210

DO TANZANIAN COMPANIES PRACTICE PECKING ORDER THEORY, AGENCY COST THEORY OR TRADE-OFF THEORY? AN EMPIRICAL STUDY IN TANZANIAN LISTED COMPANIES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The empirical study was focused predominantly on validity tests of the three theories on capital structures, the static trade-off theory, the pecking order theory (information asymmetry theory), and agency cost theory in the Tanzanian context. The study used secondary data from eight of the non-financial companies listed in Dar Es Salaam Stock Exchange (DSE) from 2006-2012. The study used descriptive (quantitative) approach to test the practicality of the theories in Tanzania. The multiple re...

Ntogwa Ng'habi Bundala

2012-01-01

211

In the way of clean and safe drinking water : exploring limitations to improvement of the water supply in Bagamoyo District, Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bagamoyo District, in the Pwani region in Tanzania, supplies a large part of Tanzania'sbiggest city, Dar es Salaam, with water. At the same time many people in rural villages in thedistrict do not have access to clean and safe water. This thesis aims to explore what limitationsthere are to improvement of the rural water supply in Bagamoyo District. Specific attention ispaid to the organizational structure of the water sector and how roles and responsibilities aredivided, defined and communica...

Bemspa?ng, Josefina; Segerstro?m, Rebecka

2009-01-01

212

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2012-01-01

213

Discriminative ability of the generic and conditionspecific Child-Oral Impacts on Daily Performances (Child-OIDP) by the Limpopo-Arusha School Health (LASH) Project:A cross-sectional study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Generic and condition-specific (CS) oral-health-related quality-of-life (OHRQoL) instruments assess the impacts of general oral conditions and specific oral diseases. Focusing schoolchildren from Arusha and Dar es Salaam, in Tanzania, this study compared the discriminative ability of the generic Child OIDP with respect to dental caries and periodontal problems across the study sites. Secondly, the discriminative ability of the generic-and the CS Child OIDP...

Masalu Joyce R; Mtaya Matilda; Mbawalla Hawa S; Brudvik Pongsri; Astrom Anne N

2011-01-01

214

Clinical and socio-behavioral correlates of tooth loss: a study of older adults in Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Focusing 50 year olds and above, this study assessed the frequency, extent and correlates of tooth loss due to various reasons. Frequency and correlates of posterior occluding support was also investigated. Method A cross-sectional household survey was conducted in Pwani region and in Dar es Salaam in 2004/2005. One thousand and thirty-one subjects, mean age 62.9 years participated in a clinical examination and completed interviews. Re...

Åstrøm Anne N; Kida Irene A; Strand Gunhild V; Masalu Joyce R

2006-01-01

215

Price Discovery and Memory Effects in Infant African Stock Markets: Evidence from Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper examines the price discovery mechanism at the Dar es Salaam Stock Exchange (DSE) in Tanzania. The objective is to explain the efficiency of price discovery in relation to its dynamics and deterministic market features, using the All Sector Index (ASI). Our results provide evidence of inefficient price discovery at the Exchange, associated with some moments of structural shifts. Moreover, the inefficient price discovery is corroborated by the fact that the Index does not follow a...

Benedicto Kulwizira Lukanima

2014-01-01

216

¿Qué es el vídeo educativo?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

El artículo aborda la definición de vídeo educativo desde la doble perspectiva de su realización y de su utilización en el aula. Parte de la consideración de que cualquier vídeo que se emplee en la docencia puede ser considerado como educativo, con independencia de la forma narrativa que se haya empleado en su realización, para llegar a la conclusión de que el vídeo será o no educativo en la medida en que es aceptado por los alumnos como tal y el profesor lo utiliza en un contexto ...

Bravo Ramos, Luis

1996-01-01

217

Medikamentöse Therapie des Pankreaskarzinoms: Was gibt es Neues?  

Directory of Open Access Journals (Sweden)

Full Text Available Seit vielen Jahren stellt Gemcitabin die wichtigste Substanz in der Behandlung des Pankreaskarzinoms dar. Dieser Antimetabolit aus der Gruppe der Pyrimidinanaloga war 10 Jahre als Monosubstanz die Standardtherapie des metastasierten Pankreaskarzinoms. Im vergangenen Jahrzehnt wurden alle verfügbaren neuen Substanzen in Kombination mit Gemcitabin getestet, wobei jedoch die in Phase-II-Studien teilweise beobachteten vielversprechenden Daten in randomisierten Studien zumeist nicht bestätigt werden konnten. Neben der Kombination von Gemcitabin mit Platinen oder Capecitabin bei Patienten mit gutem Allgemeinzustand konnte nur für die Kombination von Gemcitabin mit Erlotinib, einem Tyrosinkinasehemmer gegen den EGFR (?epidermal growth factor receptor? eine Überlegenheit demonstriert werden. Die adjuvante Chemotherapie ist, basierend auf den Ergebnissen von ? 3 randomisierten Studien, als Standard anzusehen (Level Ia. Weiterhin offen sind die Frage nach dem Stellenwert einer neoadjuvanten Chemotherapie sowie der einer adjuvanten Radiochemotherapie. Trotz zahlreicher negativer Studien ist es insgesamt in den vergangenen Jahren zu einer spürbaren Verbesserung der Behandlungsmöglichkeiten der ursprünglich fast ausnahmslos fatalen und weitgehend Chemotherapie-refraktären Malignomerkrankung gekommen. Weiterhin gilt, dass möglichst alle Patienten im Rahmen von klinischen Studien behandelt werden sollten.

Kornek G

2010-01-01

218

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

219

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

220

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

 
 
 
 
221

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

Science.gov (United States)

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

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

2014-02-01

222

Correlation analysis between Patlack plot and DAR using 11C-methionine PET  

International Nuclear Information System (INIS)

Seven patients were studied with positron emission tomography (PET) using 11C-methionine. All had non-Hodgkin's lymphoma but one, who had Hodgkin's disease. By assuming a simple three-compartment model for dynamic data analysis, we used the graphic method proposed by Patlak et al., where Ki (K2K3/(K1+K3)) was compared with DAR (differential absorption ratio). Trichloroacetate was added to each plasma sample, and the activity of the acid-soluble fraction was counted to eliminate the influence of the protein-bound fraction of injected activity. Patlak data plots, using this acid-soluble fraction as an input factor, showed good linearity over the time of data collection. All tumors showed clear 11C-methionine accumulation. Tumor activity reached almost a plateau within 10 min and was kept at the same level for at least 30 min. Ki and DAR were 0.070±0.035 and 4.64±1.85 (mean±SD), respectively. There was no apparent correlation between histological type and Ki or DAR, while the correlation efficient between Ki and DAR was 0.875. Our conclusion is that DAR will give almost the same result as dynamic data in the analysis of methionine metabolism using PET. (author)

223

High-precision DEM reconstruction based on airborne LiDAR point clouds  

Science.gov (United States)

Airborne LiDAR point clouds have become important data sources for DEM generation recently; however the problem of low precision and low efficiency in DEM production still exists. This paper proposes a new technical scheme for high-precision DEM production based on airborne LiDAR point clouds systematically. Firstly, an elevation and density analysis method is applied to filter out outliers. Secondly, ground points are detected by an improved filter algorithm based on the hierarchical smoothing method. Finally, feature lines are extracted by the planar surface fitting and intersecting method, and a simple data structure of feature lines preserved DEM is proposed to achieve reconstructing high accuracy DEM, combing feature lines with ground points. Experimental results show that the proposed scheme is able to compensate for deficiencies of existing DEM reconstruction techniques and can meet the needs of high precision DEM production based on LiDAR data.

Xu, Jingzhong; Kou, Yuan; Wang, Jun

2014-05-01

224

In Situ Vitrification Engineering-Scale Test ES-INEL-4, ES-INEL-5, ES-INEL-6, and ES-INEL-7 Test Plan  

International Nuclear Information System (INIS)

The In Situ Vitrification Engineering-Scale Tests ES-4, ES-5, ES-6, and ES-7 Product Characterization Test Plan describes the methods and procedures to be used or the physical and chemical characterization of the solid product(s) resulting from the Idaho National Engineering Laboratory engineering scale in situ vitrification tests ES-4, ES-5, ES-6, and ES-7. The goals of this Test Plan are to insure that the product characterization results are sufficient to meet the data needs of the In Situ Vitrification Program and are technically and legally defensible. Important issues addressed by the test plan include sampling and analysis strategy, sampling procedures, laboratory analysis, sample control and document management, equipment, data reporting and validation, quality assurance, specific routine procedures to assess data representativeness, safety and training program, and data management. 9 refs., 1 fig., 3 tabs

225

Optimisation of LiDAR derived terrain models for river flow modelling  

Directory of Open Access Journals (Sweden)

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

G. Mandlburger

2008-12-01

226

Optimisation of LiDAR derived terrain models for river flow modelling  

Directory of Open Access Journals (Sweden)

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

G. Mandlburger

2009-08-01

227

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

Directory of Open Access Journals (Sweden)

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

S. Trevisani

2009-02-01

228

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

Science.gov (United States)

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

Trevisani, S.; Cavalli, M.; Marchi, L.

2009-02-01

229

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

230

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)

231

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

232

Investigation of the Hector Mine Earthquake Surface Rupture with Airborne LiDAR data  

Science.gov (United States)

The 16 October 1999 Hector Mine earthquake (Mw7.1) generated significant surface rupture along the Lavic Lake Fault through almost 60 kilometers of sparsely vegetated, relatively barren desert terrain. It was the first large earthquake for which post-earthquake airborne LiDAR, collected to image the fault surface rupture, exists. Despite the lack of pre-earthquake high-resolution topographic data, we were able to make both horizontal and vertical displacement measurements, which complement published field investigation results that include ~254 data points (164 of which are within LiDAR coverage area). We made 255 new horizontal and 83 vertical displacement measurements using a 0.5 m DEM generated from the LiDAR dataset. The maximum horizontal offset value is 6.6 ± 1.1 m, and is located approximately ~700 m south of the maximum horizontal offset observed during the field work. The average horizontal offset value from LiDAR measurements is ~2.27 m, whereas the average calculated from field data is ~2.5 m. The maximum vertical displacement is ~1.2 m, and the average vertical offset value is less than 1 m. No consistent trends are apparent in the sense of the vertical component, except in the north of the mountainous section, which is predominated by east-side-down measurements. Compared to field data, LiDAR-based measurements (a) have larger measurement uncertainties, (b) have slightly higher values, (c) do not include many measurements of offsets tire tracks, offset rock or pebble lineaments) which are not typically visible with 0.5 m resolution DEMs unless a piercing feature has a very large or clear offset. LiDAR measurements included more geomorphic features with larger measurement uncertainties, which may not have been measured in the field due to their proximity to higher quality measurements. However, along the section of the fault that traverses exposed rhyolite bedrock, LiDAR data provided additional measurements because it is possible to visualize the data from different angles to better identify possible offset features. Most of the overestimations of slip from LiDAR analysis might be caused by sinuous initial geometry of the piercing feature or by prior activity (probably pre-Holocene). Overall, the LiDAR measurements compare well within a reasonable level of expectation with the field observations. The objective of attempting to attain a greater number of observations was achieved, but the measurements had more uncertainty than did the field observations. The lack of pre-earthquake LiDAR or other well geo-referenced, high-resolution imagery limited our ability to uniquely resolve offset features from the post-event imagery alone. Nevertheless, the post-earthquake LiDAR proved to be very useful for quantifying the offset features and pattern of surface faulting, even in the absence of pre-earthquake data.

Chen, T.; Zhang, D.; Akciz, S. O.; Hudnut, K. W.

2011-12-01

233

Remote Sensing of Sonoran Desert Vegetation Structure and Phenology with Ground-Based LiDAR  

Directory of Open Access Journals (Sweden)

Full Text Available Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of LiDAR to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat LiDAR scans of perennial plant canopies over the course of one year had high precision. LiDAR measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of LiDAR vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by LiDAR was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using LiDAR over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat LiDAR measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.

Joel B. Sankey

2014-12-01

234

The use of airborne LiDAR data for the analysis of debris flow events in Switzerland  

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Full Text Available A methodology of magnitude estimates for debris flow events is described using airborne LiDAR data. Light Detection And Ranging (LiDAR is a widely used technology to generate digital elevation information. LiDAR data in alpine regions can be obtained by several commercial companies where the automated filtering process is proprietary and varies from companies to companies. This study describes the analysis of geomorphologic changes using digital terrain models derived from commercial LiDAR data. The estimation of the deposition volumes is based on two digital terrain models covering the same area but differing in their time of survey. In this study two surveyed deposition areas of debris flows, located in the canton of Berne, Switzerland, were chosen as test cases. We discuss different grid interpolating techniques, other preliminary work and the accuracy of the used LiDAR data and volume estimates.

C. Scheidl

2008-10-01

235

Diversity Arrays Technology (DArT) platform for genotyping and mapping in carrot (Daucus carota L.)  

Science.gov (United States)

Carrot is one of the most important root vegetable crops grown worldwide on more than one million hectares. Its progenitor, wild Daucus carota, is a weed commonly occurring across continents in the temperate climatic zone. Diversity Array Technology (DArT) is a microarray-based molecular marker syst...

236

Genetics and Human Agency: Comment on Dar-Nimrod and Heine (2011)  

Science.gov (United States)

Dar-Nimrod and Heine (2011) decried genetic essentialism without denying the importance of genetics in the genesis of human behavior, and although I agree on both counts, a deeper issue remains unaddressed: how should we adjust our cognitions about our own behavior in light of genetic influence, or is it perhaps not necessary to take genetics into…

Turkheimer, Eric

2011-01-01

237

Engineering monitoring of rockfall hazards along transportation corridors: using mobile terrestrial LiDAR  

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Full Text Available Geotechnical hazards along linear transportation corridors are challenging to identify and often require constant monitoring. Inspecting corridors using traditional, manual methods requires the engineer to be unnecessarily exposed to the hazard. It also requires closure of the corridor to ensure safety of the worker from passing vehicles. This paper identifies the use of mobile terrestrial LiDAR data as a compliment to traditional field methods. Mobile terrestrial LiDAR is an emerging remote data collection technique capable of generating accurate fully three-dimensional virtual models while driving at speeds up to 100 km/h. Data is collected from a truck that causes no delays to active traffic nor does it impede corridor use. These resultant georeferenced data can be used for geomechanical structural feature identification and kinematic analysis, rockfall path identification and differential monitoring of rock movement or failure over time. Comparisons between mobile terrestrial and static LiDAR data collection and analysis are presented. As well, detailed discussions on workflow procedures for possible implementation are discussed. Future use of mobile terrestrial LiDAR data for corridor analysis will focus on repeated surveys and developing dynamic four-dimensional models, higher resolution data collection. As well, computationally advanced, spatially accurate, geomechanically controlled three-dimensional rockfall simulations should be investigated.

M. Lato

2009-06-01

238

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

239

Draft Genome Sequence of Bacillus thuringiensis Strain DAR 81934, Which Exhibits Molluscicidal Activity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bacillus thuringiensis has been widely used as a biopesticide for a long time. Its molluscicidal activity, however, is rarely realized. Here, we report the genome sequence of B. thuringiensis strain DAR 81934, a strain with molluscicidal activity against the pest snail Cernuella virgata.

Wang, Aisuo; Pattemore, Julie; Ash, Gavin; Williams, Angela; Hane, James

2013-01-01

240

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

 
 
 
 
241

Verification of a 3-D LiDAR Viewer for Discontinuity Orientations  

Science.gov (United States)

Light detection and ranging (LiDAR) scanners are increasingly being used to measure discontinuity orientations on rock cuts to eliminate the bias and hazards of manual measurements which are also time consuming and somewhat subjective. Typically LiDAR data sets (point clouds) are analyzed by sophisticated algorithms that break down when conditions are not ideal, for example when some of the discontinuities are obscured by vegetation, or when significant portions of the rock face are composed of fractured facets, weathering generated surfaces, or anything that should not be identified as a discontinuity for the purposes of slope stability analysis. This paper presents a simple LiDAR point cloud viewer that allows the user to view the point cloud, identify discontinuities, pick three points on the surface (plane) of each discontinuity, and generate discontinuity orientations using the three-point method. Additionally, a test of our 3-D LiDAR viewer for discontinuity orientations on rock cuts in the United States of America and Canada is presented.

Otoo, James N.; Maerz, Norbert H.; Li, Xialing; Duan, Ye

2013-05-01

242

Habitat Classification of Temperate Marine Macroalgal Communities Using Bathymetric LiDAR  

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Full Text Available Here, we evaluated the potential of using bathymetric Light Detection and Ranging (LiDAR to characterise shallow water (<30 m benthic habitats of high energy subtidal coastal environments. Habitat classification, quantifying benthic substrata and macroalgal communities, was achieved in this study with the application of LiDAR and underwater video groundtruth data using automated classification techniques. Bathymetry and reflectance datasets were used to produce secondary terrain derivative surfaces (e.g., rugosity, aspect that were assumed to influence benthic patterns observed. An automated decision tree classification approach using the Quick Unbiased Efficient Statistical Tree (QUEST was applied to produce substrata, biological and canopy structure habitat maps of the study area. Error assessment indicated that habitat maps produced were primarily accurate (>70%, with varying results for the classification of individual habitat classes; for instance, producer accuracy for mixed brown algae and sediment substrata, was 74% and 93%, respectively. LiDAR was also successful for differentiating canopy structure of macroalgae communities (i.e., canopy structure classification, such as canopy forming kelp versus erect fine branching algae. In conclusion, habitat characterisation using bathymetric LiDAR provides a unique potential to collect baseline information about biological assemblages and, hence, potential reef connectivity over large areas beyond the range of direct observation. This research contributes a new perspective for assessing the structure of subtidal coastal ecosystems, providing a novel tool for the research and management of such highly dynamic marine environments.

Richard Zavalas

2014-03-01

243

¿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.

2007-11-01

244

Using satellite and airborne LiDAR to model woodpecker habitat occupancy at the landscape scale.  

Science.gov (United States)

Incorporating vertical vegetation structure into models of animal distributions can improve understanding of the patterns and processes governing habitat selection. LiDAR can provide such structural information, but these data are typically collected via aircraft and thus are limited in spatial extent. Our objective was to explore the utility of satellite-based LiDAR data from the Geoscience Laser Altimeter System (GLAS) relative to airborne-based LiDAR to model the north Idaho breeding distribution of a forest-dependent ecosystem engineer, the Red-naped sapsucker (Sphyrapicus nuchalis). GLAS data occurred within ca. 64 m diameter ellipses spaced a minimum of 172 m apart, and all occupancy analyses were confined to this grain scale. Using a hierarchical approach, we modeled Red-naped sapsucker occupancy as a function of LiDAR metrics derived from both platforms. Occupancy models based on satellite data were weak, possibly because the data within the GLAS ellipse did not fully represent habitat characteristics important for this species. The most important structural variables influencing Red-naped Sapsucker breeding site selection based on airborne LiDAR data included foliage height diversity, the distance between major strata in the canopy vertical profile, and the vegetation density near the ground. These characteristics are consistent with the diversity of foraging activities exhibited by this species. To our knowledge, this study represents the first to examine the utility of satellite-based LiDAR to model animal distributions. The large area of each GLAS ellipse and the non-contiguous nature of GLAS data may pose significant challenges for wildlife distribution modeling; nevertheless these data can provide useful information on ecosystem vertical structure, particularly in areas of gentle terrain. Additional work is thus warranted to utilize LiDAR datasets collected from both airborne and past and future satellite platforms (e.g. GLAS, and the planned IceSAT2 mission) with the goal of improving wildlife modeling for more locations across the globe. PMID:24324655

Vierling, Lee A; Vierling, Kerri T; Adam, Patrick; Hudak, Andrew T

2013-01-01

245

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

246

LDL-Cholesterin: Wie stark soll es gesenkt werden?  

Directory of Open Access Journals (Sweden)

Full Text Available Der klinische Nutzen einer LDL-C-Senkung mittels Statinen wurde in zahlreichen Studien zweifelsfrei nachgewiesen. Die im letzten Jahr veröffentlichten ATP III-Richtlinien stellen eine gute und praxisnahe Hilfestellung für die Entscheidung dar, ob eine Statintherapie eingeleitet und welche Zielwerte angestrebt werden sollen. Die wichtige Frage, ob eine noch aggressivere LDL-C-Senkung zu niedrigeren Zielwerten, als sie in diesen Richtlinien empfohlen werden (unter 80 mg/dl, einen zusätzlichen Nutzen bringt, ist noch nicht beantwortet. Wenn ein solcher Zusatznutzen erzielbar ist, so muß er jedenfalls gegen das möglicherweise erhöhte Nebenwirkungsrisiko einer dazu erforderlichen hochdosierten Statintherapie abgewogen werden. Es ist zu erwarten, daß die Ergebnisse laufender randomisierter Doppelblindstudien zur Klärung dieser Frage in den nächsten Jahren wesentlich beitragen werden. Die kürzlich veröffentlichten Ergebnisse der Heart Protection Study legen den Schluß nahe, daß bei Hochrisikopatienten eine LDL-Senkung im Ausmaß von 30-40 % in jedem Fall erfolgen sollte, auch wenn ein niedriger Ausgangswert des LDL-C vorliegt. Aufgrund von Daten der SAPHIR-Studie (Salzburger Atherosklerose-Präventionsprogramm bei Personen mit hohem Infarkt-Risiko kann abgeschätzt werden, daß gemäß ATP III etwa 20 % der Männer zwischen 40 und 55 Jahren und etwa 8 % der Frauen zwischen 50 und 65 Jahren mit einem Statin behandelt werden sollten. Ein neues hochpotentes Statin (Rosuvastatin, mit dem die empfohlenen Zielwerte noch besser als mit bisher verfügbaren Statinen erreicht werden können, steht kurz vor der Markteinführung. Ezetimibe ist ein Vertreter einer neuen Medikamentenklasse, der selektiven Cholesterinresorptionshemmer. Die Kombination einer niedrigen Statindosis mit Ezetimibe führt zu einer sehr effektiven LDL-C-Senkung, die in derselben Größenordnung liegt, wie sie durch Maximaldosen hochpotenter Statine erzielt werden kann.

Paulweber B

2002-01-01

247

A universal airborne LiDAR approach for tropical forest carbon mapping.  

Science.gov (United States)

Airborne light detection and ranging (LiDAR) is fast turning the corner from demonstration technology to a key tool for assessing carbon stocks in tropical forests. With its ability to penetrate tropical forest canopies and detect three-dimensional forest structure, LiDAR may prove to be a major component of international strategies to measure and account for carbon emissions from and uptake by tropical forests. To date, however, basic ecological information such as height-diameter allometry and stand-level wood density have not been mechanistically incorporated into methods for mapping forest carbon at regional and global scales. A better incorporation of these structural patterns in forests may reduce the considerable time needed to calibrate airborne data with ground-based forest inventory plots, which presently necessitate exhaustive measurements of tree diameters and heights, as well as tree identifications for wood density estimation. Here, we develop a new approach that can facilitate rapid LiDAR calibration with minimal field data. Throughout four tropical regions (Panama, Peru, Madagascar, and Hawaii), we were able to predict aboveground carbon density estimated in field inventory plots using a single universal LiDAR model (r ( 2 ) = 0.80, RMSE = 27.6 Mg C ha(-1)). This model is comparable in predictive power to locally calibrated models, but relies on limited inputs of basal area and wood density information for a given region, rather than on traditional plot inventories. With this approach, we propose to radically decrease the time required to calibrate airborne LiDAR data and thus increase the output of high-resolution carbon maps, supporting tropical forest conservation and climate mitigation policy. PMID:22033763

Asner, Gregory P; Mascaro, Joseph; Muller-Landau, Helene C; Vieilledent, Ghislain; Vaudry, Romuald; Rasamoelina, Maminiaina; Hall, Jefferson S; van Breugel, Michiel

2012-04-01

248

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

249

LiDAR Segmentation using Suitable Seed Points for 3D Building Extraction  

Science.gov (United States)

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

250

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

251

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

Directory of Open Access Journals (Sweden)

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

252

Exclusive DD¯${m{Dar D}}$ meson pair production in peripheral ultrarelativistic heavy ion collisions  

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Full Text Available The cross sections for exclusive D+D- and DD¯${D^0ar D^0}$ meson pair production in peripheral nucleus - nucleus collisions are calculated and several differential distributions are presented. The calculation of the elementary ?? ? DD¯${m{Dar D}}$ cross section is done within the heavy-quark approximation and in the Brodsky- Lapage formalism with distribution amplitudes describing recent CLEO data on leptonic D+ decay. Absorption effects are discussed and quantified. The cross sections of a few nb are predicted for RHIC and of a few hundreds of nb for LHC with details depending on the approximation made in calculating elementary ?? ? DD¯${m{Dar D}}$ cross sections.

Luszczak Marta

2012-12-01

253

Advances in animal ecology from 3D-LiDAR ecosystem mapping.  

Science.gov (United States)

The advent and recent advances of Light Detection and Ranging (LiDAR) have enabled accurate measurement of 3D ecosystem structure. Here, we review insights gained through the application of LiDAR to animal ecology studies, revealing the fundamental importance of structure for animals. Structural heterogeneity is most conducive to increased animal richness and abundance, and increased complexity of vertical vegetation structure is more positively influential compared with traditionally measured canopy cover, which produces mixed results. However, different taxonomic groups interact with a variety of 3D canopy traits and some groups with 3D topography. To develop a better understanding of animal dynamics, future studies will benefit from considering 3D habitat effects in a wider variety of ecosystems and with more taxa. PMID:25457158

Davies, Andrew B; Asner, Gregory P

2014-12-01

254

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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, present...

Ruopu Li; Zhenghong Tang; Xu Li; Jessie Winter

2013-01-01

255

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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, seg...

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

2014-01-01

256

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

257

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

258

Rockfall detection from terrestrial LiDAR point clouds: A clustering approach using R  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study we analyzed a series of terrestrial LiDAR point clouds acquired over a cliff in Puigcercos (Catalonia, Spain). The objective was to detect and extract individual rockfall events that occurred during a time span of six months and to investigate their spatial distribution. To this end local and global cluster algorithms were applied. First we used the nearest neighbor clutter removal (NNCR) method in combination with the expectation-maximization (EM) algorithm to separate feature ...

Marj Tonini; Antonio Abellan

2014-01-01

259

A Comparative Study between Frequency-Modulated Continous Wave LADAR and Linear LiDAR  

Science.gov (United States)

Topographic Light Detection and Ranging (LiDAR) technology has advanced greatly in the past decade. Pulse repetition rates of terrestrial and airborne systems havemultiplied thus vastly increasing data acquisition rates. Geiger-mode and FLASH LiDAR have also become far more mature technologies. However, a new and relatively unknown technology is maturing rapidly: Frequency-Modulated Continuous Wave Laser Detection and Ranging (FMCW-LADAR). Possessing attributes more akin to modern radar systems, FMCWLADAR has the ability to more finely resolve objects separated by very small ranges. For tactical military applications (as described here), this can be a real advantage over single frequency, direct-detect systems. In fact, FMCW-LADAR can range resolve objects at 10-7 to 10-6 meter scales. FMCW-LADAR can also detect objects at greater range with less power. In this study, a FMCWLADAR instrument and traditional LiDAR instrument are compared. The co-located terrestrial scanning instruments were set up to perform simultaneous 3-D measurements of the given scene. Several targets were placed in the scene to expose the difference in the range resolution capabilities of the two instruments. The scans were performed at or nearly the same horizontal and vertical angular resolutions. It is demonstrated that the FMCW-LADAR surpasses the perfomance of the linear mode LiDAR scanner in terms of range resolution. Some results showing the maximum range acquisition are discussed but this was not studied in detail as the scanners' laser powers differed by a small amount. Applications and implications of this technology are also discussed.

Massaro, R. D.; Anderson, J. E.; Nelson, J. D.; Edwards, J. D.

2014-11-01

260

New DArT Markers for Oat Provide Enhanced Map Coverage and Global Germplasm Characterization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Ohm Herbert W; Carson Marty L; Federizzi Luiz; Olsson Olof; Kolb Frederic L; Tuvesson Stine; Jackson Eric W; Sorrells Mark E; Stuthman Deon D; Rossnagel Brian G; Anderson Joseph M; Jannink Jean-Luc; Howarth Catherine J; Bjørnstad Åsmund; Rines Howard W

2009-01-01

 
 
 
 
261

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

262

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

263

Tree crown detection in high resolution optical and LiDAR images of tropical forest  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Tropical forests are complex ecosystems where the potential of remote sensing has not yet been fully realized. The increasing availability of satellite metric imagery along with canopy altimetry from airborne LiDAR open new prospects to detect individual trees. For this objective, we optimized, calibrated and applied a model based on marked point processes to detect trees in high biomass mangroves of French Guiana by considering a set of 1m pixel images including 1) panchromatic images from t...

Zhou, Jia; Proisy, Christophe; Descombes, Xavier; Hedhli, Ihssen; Barbier, Nicolas; Zerubia, Josiane; Gastellu-etchegorry, Jean-philippe; Couteron, Pierre

2010-01-01

264

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

265

Automatic large-volume object region segmentation in LiDAR point clouds  

Science.gov (United States)

LiDAR is a remote sensing method which produces precise point clouds consisting of millions of geo-spatially located 3D data points. Because of the nature of LiDAR point clouds, it can often be difficult for analysts to accurately and efficiently recognize and categorize objects. The goal of this paper is automatic large-volume object region segmentation in LiDAR point clouds. This efficient segmentation technique is intended to be a pre- processing step for the eventual classification of objects within the point cloud. The data is initially segmented into local histogram bins. This local histogram bin representation allows for the efficient consolidation of the point cloud data into voxels without the loss of location information. Additionally, by binning the points, important feature information can be extracted, such as the distribution of points, the density of points and a local ground. From these local histograms, a 3D automatic seeded region growing technique is applied. This technique performs seed selection based on two criteria, similarity and Euclidean distance to nearest neighbors. The neighbors of selected seeds are then examined and assigned labels based on location and Euclidean distance to a region mean. After the initial segmentation step, region integration is performed to rejoin over-segmented regions. The large amount of points in LiDAR data can make other segmentation techniques extremely time consuming. In addition to producing accurate object segmentation results, the proposed local histogram binning process allows for efficient segmentation, covering a point cloud of over 9,000 points in 10 seconds.

Varney, Nina M.; Asari, Vijayan K.

2014-10-01

266

GRASS GIS for the distinction of vegetation from buildings using LiDAR altimetric data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The LiDAR (Light Detection and Ranging) technology, based on the scanning of the territory by airborne laser telemeters, allows the construction of Digital Surface Models (DSM) by a simple data interpolation, and Digital Terrain Models (DTM) by the identification and removal of attached and detached object (such as buildings, bridges, power lines or trees). For this purpose, the Laboratory of Geomatica of the Politecnico di Milano - Campus of Como – developed a filter algorithm based on ...

Antoli?n Sa?nchez, Roberto; Brovelli, Maria A.

2008-01-01

267

LiDAR mapping of tidal marshes for ecogeomorphological modelling in the TIDE project  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The European research project TIDE (Tidal Inlets Dynamics and Environment) is developing and validating coupled models describing the morphological, biological and ecological evolution of tidal environments. The interactions between the physical and biological processes occurring in these regions requires that the system be studied as a whole rather than as separate parts. Extensive use of remote sensing including LiDAR is being made to provide validation data for the modelling. This pape...

Mason, David Cecil; Marani, M.; Belluco, E.; Feola, A.; Ferrari, S.; Katzenbeisser, R.; Lohani, B.; Menenti, M.; Paterson, D. M.; Scott, T. R.; Vardy, S.; Wang, C.; Wang, H-j

2005-01-01

268

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

269

A Comparison of Two Open Source LiDAR Surface Classification Algorithms  

Directory of Open Access Journals (Sweden)

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

Danny G Marks

2011-03-01

270

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

271

Accuracy and Precision of Terrestrial LiDAR for Ground Deformation Monitoring  

Science.gov (United States)

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

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

2007-12-01

272

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

273

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 (?? 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

274

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.

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

2013-08-01

275

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

276

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)

277

Mutations in DARS cause hypomyelination with brain stem and spinal cord involvement and leg spasticity.  

Science.gov (United States)

Inherited white-matter disorders are a broad class of diseases for which treatment and classification are both challenging. Indeed, nearly half of the children presenting with a leukoencephalopathy remain without a specific diagnosis. Here, we report on the application of high-throughput genome and exome sequencing to a cohort of ten individuals with a leukoencephalopathy of unknown etiology and clinically characterized by hypomyelination with brain stem and spinal cord involvement and leg spasticity (HBSL), as well as the identification of compound-heterozygous and homozygous mutations in cytoplasmic aspartyl-tRNA synthetase (DARS). These mutations cause nonsynonymous changes to seven highly conserved amino acids, five of which are unchanged between yeast and man, in the DARS C-terminal lobe adjacent to, or within, the active-site pocket. Intriguingly, HBSL bears a striking resemblance to leukoencephalopathy with brain stem and spinal cord involvement and elevated lactate (LBSL), which is caused by mutations in the mitochondria-specific DARS2, suggesting that these two diseases might share a common underlying molecular pathology. These findings add to the growing body of evidence that mutations in tRNA synthetases can cause a broad range of neurologic disorders. PMID:23643384

Taft, Ryan J; Vanderver, Adeline; Leventer, Richard J; Damiani, Stephen A; Simons, Cas; Grimmond, Sean M; Miller, David; Schmidt, Johanna; Lockhart, Paul J; Pope, Kate; Ru, Kelin; Crawford, Joanna; Rosser, Tena; de Coo, Irenaeus F M; Juneja, Monica; Verma, Ishwar C; Prabhakar, Prab; Blaser, Susan; Raiman, Julian; Pouwels, Petra J W; Bevova, Marianna R; Abbink, Truus E M; van der Knaap, Marjo S; Wolf, Nicole I

2013-05-01

278

Measuring and mapping forest wildlife habitat characteristics using LiDAR remote sensing and multi-sensor function  

Science.gov (United States)

Managing forests for multiple, often competing uses is challenging; managing Sierra National Forest's fire regime and California spotted owl habitat is difficult and compounded by lack of information about habitat quality. Consistent and accurate measurements of forest structure will reduce uncertainties regarding the amount of habitat reduction or alteration that spotted owls can tolerate. Current methods of measuring spotted owl habitat are mostly field-based and emphasize the important of canopy cover. However, this is more because of convenience than because canopy cover is a definitive predictor of owl presence or fecundity. Canopy cover is consistently and accurately measured in the field using a moosehorn densitometer; comparable measurements can be made using airphoto interpretation or from examining satellite imagery, but the results are not consistent. LiDAR remote sensing can produce consistent and accurate measurements of canopy cover, as well as other aspects of forest structure (such as canopy height and biomass) that are known or thought to be at least as predictive as canopy cover. Moreover, LiDAR can be used to produce maps of forest structure rather than the point samples available from field measurements. However, LiDAR data sets are expensive and not available everywhere. Combining LiDAR with other, remote sensing data sets with less expensive, wall-to-wall coverage will result in broader scale maps of forest structure than have heretofore been possible; these maps can then be used to analyze spotted owl habitat. My work consists of three parts: comparison of LiDAR estimates of forest structure with field measurements, statistical fusion of LiDAR and other remote sensing data sets to produce broad scale maps of forest structure, and analysis of California spotted owl presence and fecundity as a function of LiDAR-derived canopy structure. I found that LiDAR was able to replicate field measurements accurately. Additionally, I was able to statistically combine LiDAR with passive optical and RaDAR (SAR backscatter and InSAR range) data to produce broad scale maps of forest structure that are consistent and accurate relative to field data and LiDAR data alone. Finally, I was able to demonstrate that these forest structural attributes predict spotted owl presence and absence as well as productivity.

Hyde, Peter

279

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2013-01-01

280

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2012-01-01

 
 
 
 
281

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

282

Estimation of biomass and volume of shrub vegetation using LiDAR and spectral data in a Mediterranean environment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Several studies have addressed the biomass and volume of trees using Airborne Light Detection and Ranging (LiDAR) data. However, little research has been conducted into shrub vegetation, which covers a high percentage of Mediterranean forest. We used LiDAR data and an airborne image to estimate biomass and volume of shrub vegetation. Field data were collected in 29 square plots of 100 m2. In each plot, the percentage of the surface covered was measured in the field. Shrub veget...

Estornell Cremades, Javier; Ruiz Ferna?ndez, Luis A?ngel; Vela?zquez Marti?, Borja; Hermosilla, T.

2012-01-01

283

Analysis of urban land use and land cover changes: a case of study in Bahir Dar, Ethiopia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The high rate of urbanization coupled with population growth has caused changes in land use and land cover in Bahir Dar, Ethiopia. Therefore, understanding and quantifying the spatio- temporal dynamics of urban land use and land cover changes and its driving factors is essential to put forward the right policies and monitoring mechanisms on urban growth for decision making. Thus, the objective of this study was to analyze land use and land cover changes in Bahir Dar area, Ethiopia by applying...

Sahalu, Atalel Getu

2014-01-01

284

Financial sustainability in municipal solid waste management – Costs and revenues in Bahir Dar, Ethiopia  

Energy Technology Data Exchange (ETDEWEB)

Highlights: • Cost-revenue analysis over 2 years revealed insufficient cost-recovery. • Expenses for motorized secondary collection increased by 82% over two years. • Low fee collection rate and reliance on only one revenue stream are problematic. • Different options for cost reduction and enhanced revenue streams are recommended. • Good public–private alliance is crucial to plan and implement improvement measures. - Abstract: 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.

Lohri, Christian Riuji, E-mail: christian.lohri@eawag.ch; Camenzind, Ephraim Joseph, E-mail: ephraimcamenzind@hotmail.com; Zurbrügg, Christian, E-mail: christian.zurbruegg@eawag.ch

2014-02-15

285

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

286

Financial sustainability in municipal solid waste management – Costs and revenues in Bahir Dar, Ethiopia  

International Nuclear Information System (INIS)

Highlights: • Cost-revenue analysis over 2 years revealed insufficient cost-recovery. • Expenses for motorized secondary collection increased by 82% over two years. • Low fee collection rate and reliance on only one revenue stream are problematic. • Different options for cost reduction and enhanced revenue streams are recommended. • Good public–private alliance is crucial to plan and implement improvement measures. - Abstract: 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

287

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

288

LiDAR Sampling Density for Forest Resource Inventories in Ontario, Canada  

Directory of Open Access Journals (Sweden)

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

289

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

Directory of Open Access Journals (Sweden)

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

290

Timely binding of IHF and Fis to DARS2 regulates ATP-DnaA production and replication initiation.  

Science.gov (United States)

In Escherichia coli, the ATP-bound form of DnaA (ATP-DnaA) promotes replication initiation. During replication, the bound ATP is hydrolyzed to ADP to yield the ADP-bound form (ADP-DnaA), which is inactive for initiation. The chromosomal site DARS2 facilitates the regeneration of ATP-DnaA by catalyzing nucleotide exchange between free ATP and ADP bound to DnaA. However, the regulatory mechanisms governing this exchange reaction are unclear. Here, using in vitro reconstituted experiments, we show that two nucleoid-associated proteins, IHF and Fis, bind site-specifically to DARS2 to activate coordinately the exchange reaction. The regenerated ATP-DnaA was fully active in replication initiation and underwent DnaA-ATP hydrolysis. ADP-DnaA formed heteromultimeric complexes with IHF and Fis on DARS2, and underwent nucleotide dissociation more efficiently than ATP-DnaA. Consistently, mutant analyses demonstrated that specific binding of IHF and Fis to DARS2 stimulates the formation of ATP-DnaA production, thereby promoting timely initiation. Moreover, we show that IHF-DARS2 binding is temporally regulated during the cell cycle, whereas Fis only binds to DARS2 in exponentially growing cells. These results elucidate the regulation of ATP-DnaA and replication initiation in coordination with the cell cycle and growth phase. PMID:25378325

Kasho, Kazutoshi; Fujimitsu, Kazuyuki; Matoba, Toshihiro; Oshima, Taku; Katayama, Tsutomu

2014-12-01

291

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

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

2013-12-01

292

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

293

A Geoinformatics Approach to LiDAR / ALSM Data Distribution, Interpolation, and Analysis  

Science.gov (United States)

Distribution, interpolation and analysis of large LiDAR (Light Distance And Ranging, also known as ALSM (Airborne Laser Swath Mapping)) datasets pushes the computational limits of typical data distribution and processing systems. The high point-density of LiDAR datasets makes grid interpolation difficult for geoscience users who lack the computing and software resources necessary to handle these massive data volumes. We are using a geoinformatics approach to the distribution, interpolation and analysis of LiDAR data that capitalizes on cyberinfrastructure being developed as part of the GEON project (http://www.geongrid.org). Our approach utilizes a comprehensive workflow-based solution that begins with user-defined selection of a subset of raw data and ends with download and visualization of interpolated surfaces and derived products. The workflow environment allows us to modularize and generalize the procedure. It provides the freedom to easily plug-in new processes, to utilize existing sub workflows within an analysis, and easily extend or modify the analysis using drag-and-drop functionality through the Kepler workflow management system. In this GEON-based workflow, the billions of points within a LiDAR dataset point cloud are hosted in an IBM DB2 spatial database running on the DataStar terascale computer at San Diego Supercomputer Center; a machine designed specifically for data intensive computations. Data selection is performed via an ArcIMS-based interface that allows users to execute spatial and attribute subset queries on the larger dataset. The subset of data is then passed to a GRASS Open Source GIS-based web service, "lservice", that handles interpolation to grid and analysis of the data. Lservice was developed entirely within the open source domain and offers spline and inverse distance weighted (IDW) interpolation to grid with user-defined resolution and parameters. We also compute geomorphic metrics such as slope, curvature, and aspect. Users may choose to download their results in ESRI or ascii grid formats as well as geo tiff. Additionally, our workflow feeds into GEON web services in development that will allow visualization of Lservice outputs in either a web browser window or in 3D through Fledermaus' free viewer iView3D (or our own OpenGL-based tools). This geoinformatics-based system will allow GEON to host LiDAR point cloud data for the greater geoscience community, including data collected by the National Center for Airborne Laser Mapping (NCALM). In addition, most of the functions within this workflow are not limited to LiDAR data and may be used for distributing, interpolating and visualizing any computationally intensive point dataset (such as gravity). By utilizing the computational infrastructure developed by GEON, this system can democratize LiDAR data access for the geoscience community.

Crosby, C. J.; Conner, J.; Frank, E.; Arrowsmith, J. R.; Memon, A.; Nandigam, V.; Wurman, G.; Baru, C.

2005-12-01

294

An application of vessel-based LiDAR to quantify coastal retreat in Southern Monterey Bay, CA  

Science.gov (United States)

Coastal erosion has become a prominent issue in Monterey Bay, California. Areas at high risk include native coastal dunes, private and public beachfront properties, municipal sewage lines, and areas of the highway 1 corridor. Traditional airborne LiDAR has been an effective method in measuring coastal topography by providing high resolution and great coverage, but it remains costly. In 1997 and 1998, NASA, USGS, and NOAA collaborated to conduct pre- and post- El Niño airborne LiDAR surveys of the California coastline. Since then, there have been no further, publically available LiDAR surveys of the Monterey Bay shoreline. The goal of this project is to apply a vessel-based LiDAR system to measure coastal geomorphology, determine the efficiency of vessel-based topographic LiDAR for mapping coastal geomorphology, and quantify the spatial distribution of coastal retreat for Monterey Bay, California. The area of study was the Monterey Bay coastline from the Monterey Bay Commercial Wharf II to Marina State Beach at Reservation Rd. Sea cliff morphology data were measured on Dec 9th and 10th, 2008 through the use of a terrestrial LiDAR system mounted atop the CSUMB Seafloor Mapping Lab’s R/V VenTresca. These vessel based LiDAR data were compared with 1998 NOAA Airborne Topographic Mapper LiDAR data using mapping, modeling and spatial analysis tools in ArcGIS to quantify the spatial distribution of coastal retreat and calculate annualized rates of erosion for the Monterey Bay shoreline over the past decade. Preliminary results show a slight correlation between volumetric change and distance along the coast from Wharf II, in keeping with previous published results. On the other hand, average sand dune apron retreat rate is 0.92 m/yr with a significant relationship between sand dune apron retreat rate and distance along the coast. The utilization of vessel based LiDAR is an effective and cost efficient method to frequently measure sea cliff geomorphology with very high resolution. Annual LiDAR surveys should be completed to identify short and long term changes for coastal planning in the future.

Quan, S.; Kvitek, R.; Smith, D. P.

2009-12-01

295

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

296

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

Directory of Open Access Journals (Sweden)

Full Text Available We present the development of a low-cost Unmanned Aerial Vehicle-Light Detecting and Ranging (UAV-LiDAR system and an accompanying workflow to produce 3D point clouds. UAV systems provide an unrivalled combination of high temporal and spatial resolution datasets. The TerraLuma UAV-LiDAR system has been developed to take advantage of these properties and in doing so overcome some of the current limitations of the use of this technology within the forestry industry. A modified processing workflow including a novel trajectory determination algorithm fusing observations from a GPS receiver, an Inertial Measurement Unit (IMU and a High Definition (HD video camera is presented. The advantages of this workflow are demonstrated using a rigorous assessment of the spatial accuracy of the final point clouds. It is shown that due to the inclusion of video the horizontal accuracy of the final point cloud improves from 0.61 m to 0.34 m (RMS error assessed against ground control. The effect of the very high density point clouds (up to 62 points per m2 produced by the UAV-LiDAR system on the measurement of tree location, height and crown width are also assessed by performing repeat surveys over individual isolated trees. The standard deviation of tree height is shown to reduce from 0.26 m, when using data with a density of 8 points perm2, to 0.15mwhen the higher density data was used. Improvements in the uncertainty of the measurement of tree location, 0.80 m to 0.53 m, and crown width, 0.69 m to 0.61 m are also shown.

Darren Turner

2012-05-01

297

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

298

Comparison of DEMs generated from terrestrial LiDAR and Unmaned Aerial Vehicle data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this presentation we compare DEMs generated using terrestrial LIDAR and UAV data. The study site is a small agricultural watershed located near the region of Gembloux in Belgium. Terresttrial LiDAR data was collected using Trimble GX trought 14 scans. After correcting errors by using statistical approach, scans are meshed to generate a DEM of 1 m x 1 m resolution. UAV data was collected using the X100 UAV commercialized by gatewing. Data was processed in the open source MICMAC software to...

Ouedraogo, Mohamar

2012-01-01

299

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

300

Etude sanitaire de la zone 17.42 du Fiers d'Ars. Charente-Maritime  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Suite à la demande d'exploitation de la zone du Fier d’Ars par le Comité Régional de la Conchyliculture du Poitou-Charentes (CRCPC), la Direction Départementale du Territoire et de la Mer (DDTM) a demandé la réalisation d'une étude sanitaire en vue du classement de cette zone de production pour les bivalves fouisseurs (groupe 2). Cette étude réalisée par le Laboratoire Environnement Ressources des Pertuis Charentais bénéficie d'un financement de la Direction Générale de l 'Ali...

Derrien, Annick; Piquet, Jean-come; Fillon, Alain

2013-01-01

 
 
 
 
301

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

302

Wallace Creek Virtual Field Trip: Teaching Geoscience Concepts with LiDAR  

Science.gov (United States)

Recently available data such as LiDAR (Light Detection and Ranging) high-resolution topography can assist students to better visualize and understand geosciences concepts. It is important to bring these data into geosciences curricula as teaching aids while ensuring that the visualization tools, virtual environments, etc. do not serve as barriers to student learning. As a Southern California Earthquake Center ACCESS-G intern, I am creating a “virtual field trip” to Wallace Creek along the San Andreas Fault (SAF) using Google Earth as a platform and the B4 project LiDAR data. Wallace Creek is an excellent site for understanding the centennial-to-millennial record of SAF slip because of its dramatic stream offsets. Using the LiDAR data instead of, or alongside, traditional visualizations and teaching methods enhances a student’s ability to understand plate tectonics, the earthquake cycle, strike-slip faults, and geomorphology. Viewing a high-resolution representation of the topography in Google Earth allows students to analyze the landscape and answer questions about the behavior of the San Andreas Fault. The activity guides students along the fault allowing them to measure channel offsets using the Google Earth measuring tool. Knowing the ages of channels, they calculate slip rate. They look for the smallest channel offsets around Wallace Creek in order to determine the slip per event. At both a “LiDAR and Education” workshop and the Cyberinfrastructure Summer Institute for Geoscientists (CSIG), I presented the Wallace Creek activity to high school and college earth science teachers. The teachers were positive in their responses and had numerous important suggestions including the need for a teacher’s manual for instruction and scientific background, and that the student goals and science topics should be specific and well-articulated for the sake of both the teacher and the student. The teachers also noted that the technology in classrooms varies significantly. Some do not have computers available for students or do not have access to the internet or certain software licenses. For this reason, I am also creating a paper-based version of the same exercise. After a usable activity is developed I plan to make it available online through the OpenTopography portal (www.opentopography.com) using a format similar to the online teaching boxes seen at DLESE (www.dlese.org). The final version will facilitate visual student learning through the popular Google Earth platform along with student guides and a teacher’s manual.

Robinson, S. E.; Arrowsmith, R.; Crosby, C. J.

2009-12-01

303

REDESIGN OF LOGISTICAL INFORMATIONAL SYSTEM IN THE COMPANY DARS D.D.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

V nalogi smo v analizi stanja sistema predstavili obstoje?e logisti?ne procese s poudarkom na ABC in XYZ analizi z namenom zmanjšanja prevelikega stanja zalog na DARS d.d.. Rešitev problemskega stanja smo predstavili v obliki krovne funkcionalne specifikacije za prenovljeni logisti?ni informacijski sistem. Za u?inkovito zmanjšanje zalog smo najprej postavili sistem naro?anja za artikle razreda A, to so artikli, ki povzro?ajo 80 % vrednosti vse zaloge. Na podlagi ugotovitev iz ABC in ...

Bojc, Mihec

2011-01-01

304

Particle physics database system on ES computer  

International Nuclear Information System (INIS)

Main features, data definition language, query and output facilities of the BDMS database management system are presented. Adaptation of the BDMS system and processors for the DOCUMENTS, EXPERIMENTS and REACTIONS databases makes the particle physics data system available for specialists of the centres equipped with the ES series computers. 8 refs.; 1 fig

305

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

Directory of Open Access Journals (Sweden)

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

Wang DaoWen

2011-05-01

306

Evaluation of the dimensions of anger reactions-5 (DAR-5) scale in combat veterans with posttraumatic stress disorder.  

Science.gov (United States)

After a traumatic event many people experience problems with anger which not only results in significant distress, but can also impede recovery. As such, there is value to include the assessment of anger in routine post-trauma screening procedures. The Dimensions of Anger Reactions-5 (DAR-5), as a concise measure of anger, was designed to meet such a need, its brevity minimizing the burden on client and practitioner. This study examined the psychometric properties of the DAR-5 with a sample of 163 male veterans diagnosed with Posttraumatic Stress Disorder. The DAR-5 demonstrated internal reliability (?=.86), along with convergent, concurrent and discriminant validity against a variety of established measures (e.g., HADS, PCL, STAXI). Support for the clinical cut-point score of 12 suggested by Forbes et al. (2014, Utility of the dimensions of anger reactions-5 (DAR-5) scale as a brief anger measure. Depression and Anxiety, 31, 166-173) was observed. The results support considering the DAR-5 as a preferred screening and assessment measure of problematic anger. PMID:25445072

Forbes, David; Alkemade, Nathan; Hopcraft, Dale; Hawthorne, Graeme; O'Halloran, Paul; Elhai, Jon D; McHugh, Tony; Bates, Glen; Novaco, Raymond W; Bryant, Richard; Lewis, Virginia

2014-12-01

307

Quantifying and relating land-surface and subsurface variability in permafrost environments using LiDAR and surface geophysical datasets  

Science.gov (United States)

The value of remote sensing and surface geophysical data for characterizing the spatial variability and relationships between land-surface and subsurface properties was explored in an Alaska (USA) coastal plain ecosystem. At this site, a nested suite of measurements was collected within a region where the land surface was dominated by polygons, including: LiDAR data; ground-penetrating radar, electromagnetic, and electrical-resistance tomography data; active-layer depth, soil temperature, soil-moisture content, soil texture, soil carbon and nitrogen content; and pore-fluid cations. LiDAR data were used to extract geomorphic metrics, which potentially indicate drainage potential. Geophysical data were used to characterize active-layer depth, soil-moisture content, and permafrost variability. Cluster analysis of the LiDAR and geophysical attributes revealed the presence of three spatial zones, which had unique distributions of geomorphic, hydrological, thermal, and geochemical properties. The correspondence between the LiDAR-based geomorphic zonation and the geophysics-based active-layer and permafrost zonation highlights the significant linkage between these ecosystem compartments. This study suggests the potential of combining LiDAR and surface geophysical measurements for providing high-resolution information about land-surface and subsurface properties as well as their spatial variations and linkages, all of which are important for quantifying terrestrial-ecosystem evolution and feedbacks to climate.

Hubbard, S. S.; Gangodagamage, C.; Dafflon, B.; Wainwright, H.; Peterson, J.; Gusmeroli, A.; Ulrich, C.; Wu, Y.; Wilson, C.; Rowland, J.; Tweedie, C.; Wullschleger, S. D.

2013-02-01

308

Development of wild barley (Hordeum chilense)-derived DArT markers and their use into genetic and physical mapping.  

Science.gov (United States)

Diversity arrays technology (DArT) genomic libraries were developed from H. chilense accessions to support robust genotyping of this species and a novel crop comprising H. chilense genome (e.g., tritordeums). Over 11,000 DArT clones were obtained using two complexity reduction methods. A subset of 2,209 DArT markers was identified on the arrays containing these clones as polymorphic between parents and segregating in a population of 92 recombinant inbred lines (RIL) developed from the cross between H. chilense accessions H1 and H7. Using the segregation data a high-density map of 1,503 cM was constructed with average inter-bin density of 2.33 cM. A subset of DArT markers was also mapped physically using a set of wheat-H. chilense chromosome addition lines. It allowed the unambiguous assignment of linkage groups to chromosomes. Four segregation distortion regions (SDRs) were found on the chromosomes 2H(ch), 3H(ch) and 5H(ch) in agreement with previous findings in barley. The new map improves the genome coverage of previous H. chilense maps. H. chilense-derived DArT markers will enable further genetic studies in ongoing projects on hybrid wheat, seed carotenoid content improvement or tritordeum breeding program. Besides, the genetic map reported here will be very useful as the basis to develop comparative genomics studies with barley and model species. PMID:22048641

Rodríguez-Suárez, C; Giménez, M J; Gutiérrez, N; Avila, C M; Machado, A; Huttner, E; Ramírez, M C; Martín, A C; Castillo, A; Kilian, A; Martín, A; Atienza, S G

2012-03-01

309

Using a new GUI tool to leverage LiDAR data to aid in hyperspectral image material detection in the radiance domain on RIT SHARE LiDAR/HSI data  

Science.gov (United States)

This paper looks at a data set, called the SHARE 2010 collect, that has been designed to analyze the various impacts of illumination change on materials. Similar fabric materials were placed on different backgrounds where spectral signatures were analyzed to determined impacts of background adjacency. Hyperspectral, multispectral, and LiDAR modalities were used to image the panels in the above mentioned scenarios. Applications such as material detection with results are used to assess difficulties with finding such panels. The incorporation of point LiDAR data sets and physical models will aid in approximating the correct per-pixel signature to be used in the above mentioned detection scheme. This technique can help mitigate issues related to varying illumination across a scene. All of the processing (i.e., LiDAR, MODTRAN, HSI and detection) is performed in a new GUI tool which runs in the ENVI software.

Ientilucci, Emmett J.

2013-09-01

310

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

Directory of Open Access Journals (Sweden)

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

Petteri Alho

2013-05-01

311

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

Directory of Open Access Journals (Sweden)

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

Edson P. Amorim

2009-01-01

312

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

Scientific Electronic Library Online (English)

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

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

313

Airborne LiDAR for the Detection of Archaeological Vegetation Marks Using Biomass as a Proxy  

Directory of Open Access Journals (Sweden)

Full Text Available In arable landscapes, the airborne detection of archaeological features is often reliant on using the properties of the vegetation cover as a proxy for sub-surface features in the soil. Under the right conditions, the formation of vegetation marks allows archaeologists to identify and interpret archaeological features. Using airborne Laser Scanning, based on the principles of Light Detection and Ranging (LiDAR to detect these marks is challenging, particularly given the difficulties of resolving subtle changes in a low and homogeneous crop with these sensors. In this paper, an experimental approach is adopted to explore how these marks could be detected as variations in canopy biomass using both range and full waveform LiDAR data. Although some detection was achieved using metrics of the full waveform data, it is the novel multi-temporal method of using discrete return data to detect and characterise archaeological vegetation marks that is offered for further consideration. This method was demonstrated to be applicable over a range of capture conditions, including soils deemed as difficult (i.e., clays and other heavy soils, and should increase the certainty of detection when employed in the increasingly multi-sensor approaches to heritage prospection and management.

David Stott

2015-02-01

314

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

Science.gov (United States)

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

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

2014-04-01

315

3D modeling of pylon from airborne LiDAR data  

Science.gov (United States)

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

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

2014-05-01

316

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

Directory of Open Access Journals (Sweden)

Full Text Available Quantification of tropical forest above-ground biomass (AGB over large areas as input for Reduced Emissions from Deforestation and forest Degradation (REDD+ projects and climate change models is challenging. This is the first study which attempts to estimate AGB and its variability across large areas of tropical lowland forests in Central Kalimantan (Indonesia through correlating airborne light detection and ranging (LiDAR to forest inventory data. Two LiDAR height metrics were analysed, and regression models could be improved through the use of LiDAR point densities as input (R2 = 0.88; n = 52. Surveying with a LiDAR point density per square metre of about 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 43%, 102%, and 137%, respectively. The results show that AGB overestimation may lead to wrong greenhouse gas (GHG emission estimates due to deforestation in climate models. For REDD+ projects this leads to inaccurate carbon stock estimates and consequently to significantly wrong REDD+ based compensation payments.

J. Jubanski

2013-06-01

317

Knowledge-Based Modeling of Buildings in Dense Urban Areas by Combining Airborne LiDAR Data and Aerial Images  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, a knowledge-based algorithm is proposed for automatically generating three-dimensional (3D) building models in dense urban areas by using airborne light detection and ranging (LiDAR) data and aerial images. Automatic 3D building modeling using LiDAR is challenging in dense urban areas, in which houses are typically located close to each other and their heights are similar. This makes it difficult to separate point clouds into individual buildings. A combination of airborne LiDA...

Junichi Susaki

2013-01-01

318

Low-Density LiDAR and Optical Imagery for Biomass Estimation over Boreal Forest in Sweden  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Knowledge of the forest biomass and its change in time is crucial to understanding the carbon cycle and its interactions with climate change. LiDAR (Light Detection and Ranging) technology, in this respect, has proven to be a valuable tool, providing reliable estimates of aboveground biomass (AGB). The overall goal of this study was to develop a method for assessing AGB using a synergy of low point density LiDAR-derived point cloud data and multi-spectral imagery in conifer-dominated forest ...

Iurii Shendryk; Margareta Hellström; Leif Klemedtsson; Natascha Kljun

2014-01-01

319

Enhanced Access to High-Resolution LiDAR Topography through Cyberinfrastructure- Based Data Distribution and Processing  

Science.gov (United States)

The emergence of new digital data acquisition technologies in the geosciences has important implications for the types and quality of data that are now available to researchers. However, along with these datasets comes an increase in the volume and complexity of scientific data that must be efficiently managed, archived, distributed, processed and integrated in order for it to be of use to the scientific community. The rapid growth of LiDAR (Light Distance And Ranging, a.k.a. ALSM (Airborne Laser Swath Mapping)) for geoscience applications is an excellent example of the opportunities and challenges presented by these types of datasets. Capable of generating digital elevation models (DEMs) more than an order of magnitude more accurate than those currently available, LiDAR data offer geomorphologists and earthquake geologists the opportunity to study the tectonic and surficial processes that contribute to landscape evolution and measure deformation at resolutions not previously possible yet essential for their appropriate representation. Unfortunately, access to these datasets for the average geoscience user is difficult because of the massive volumes of data generated by LiDAR. The distribution and processing (DEM and derived product generation) of large LiDAR datasets, which frequently exceed billions of data-points, challenge internet-based data distribution systems and readily available desktop software. We use a geoinformatics approach to the distribution and processing of LiDAR data that capitalizes on cyberinfrastructure developed by the GEON project (http://www.geongrid.org). Our approach utilizes a comprehensive workflow-based solution, the GEON LiDAR Workflow (GLW), which begins with user-defined selection of a subset of point data and ends with download and visualization of DEMs and derived products. In this workflow, users perform point cloud data selection, interactive DEM generation and analysis, and product visualization all from an internet-based portal. Users are able to experiment with DEM resolution and DEM generation algorithms so as to optimize the terrain model for their science application. By using cyberinfrastructure resources, this approach allows users to carry out computationally intensive LiDAR data processing without having appropriate resources locally. Access to massive high-resolution LiDAR topography datasets via the GLW represents an excellent example of utilization of cyberinfrastructure to facilitate the user community's ability to incorporate these cutting edge and computationally challenging datasets into their research.

Crosby, C. J.; Arrowsmith, J. R.; Frank, E.; Nandigam, V.; Kim, H. S.; Conner, J.; Memon, A.; Baru, C.

2006-12-01

320

Un guijarro no es un canto rodado  

Directory of Open Access Journals (Sweden)

Full Text Available The sense or meaning of a word resides in thought and only manifests itself when the word is used. Yet the sense conveyed can be equivocal if the word is taken out of its context, spatial as well as temporal. Considering the present time then, we are dealing with the determination of a space, with exploring around the contextual area. The study that resulted in this paper involves geography, but is no geographical research; at most research on human geography. Although it involves speech, its direct object is not language. Neither it is, in strictness, ethnography nor cultural anthropology. But it concerns all of these fields and, therefore, cannot stay away from any of them. Only one concept, perhaps, overrides the whole undertaking and meets the double condition of being simple and complex at the same time: the concept of elementary area. This concept rests upon the seminal idea of taking the sense and meaning of something (in this case, a name or a noun as the use given to such something (such name or noun in a particular space: a here and a now. One word or signifier, one single meaning; that is all there is. Yet it is this extreme simplification that which allows freedom of speculation, clear and refined.

El sentido de una palabra está en el pensamiento y sólo se hace manifiesto a través de dicha palabra. Pero la información que conlleva la misma es equívoca si hacemos abstracción de un lugar y de un tiempo. Sea el tiempo actual. Se trata, pues, de la determinación de un lugar, de indagar acerca del territorio. El estudio propuesto trata, pues, de geografía, pero no es geografía; acaso geografía humana. Concierne al habla, pero su objeto directo no es la lengua. No es tampoco, en sentido estricto, etnografía ni antropología cultural. Pero siendo un poco todo ello, no puede prescindir de nada. Sólo uno de sus conceptos, quizá, presida todo el conjunto y reúna la doble condición de ser complejo y a la vez simple: área elemental. El concepto de área elemental descansa en la idea fecunda de considerar el sentido de algo (en este caso, de un nombre como el uso que se hace de dicho «algo», de dicho nombre, en algún lugar. Un aquí. Un ahora. Una palabra o significante. Un significado. Eso es todo. Y esta simplificación extrema permite a su vez una clara y depurada libertad especulativa.

Coronado Castillo, Ángel

2006-06-01

 
 
 
 
321

Building a LiDAR point cloud simulator: Testing algorithms for high resolution topographic change  

Science.gov (United States)

Terrestrial laser technique (TLS) is becoming a common tool in Geosciences, with clear applications ranging from the generation of a high resolution 3D models to the monitoring of unstable slopes and the quantification of morphological changes. Nevertheless, like every measurement techniques, TLS still has some limitations that are not clearly understood and affect the accuracy of the dataset (point cloud). A challenge in LiDAR research is to understand the influence of instrumental parameters on measurement errors during LiDAR acquisition. Indeed, different critical parameters interact with the scans quality at different ranges: the existence of shadow areas, the spatial resolution (point density), and the diameter of the laser beam, the incidence angle and the single point accuracy. The objective of this study is to test the main limitations of different algorithms usually applied on point cloud data treatment, from alignment to monitoring. To this end, we built in MATLAB(c) environment a LiDAR point cloud simulator able to recreate the multiple sources of errors related to instrumental settings that we normally observe in real datasets. In a first step we characterized the error from single laser pulse by modelling the influence of range and incidence angle on single point data accuracy. In a second step, we simulated the scanning part of the system in order to analyze the shifting and angular error effects. Other parameters have been added to the point cloud simulator, such as point spacing, acquisition window, etc., in order to create point clouds of simple and/or complex geometries. We tested the influence of point density and vitiating point of view on the Iterative Closest Point (ICP) alignment and also in some deformation tracking algorithm with same point cloud geometry, in order to determine alignment and deformation detection threshold. We also generated a series of high resolution point clouds in order to model small changes on different environments (erosion, landslide monitoring, etc) and we then tested the use of filtering techniques using 3D moving windows along the space and time, which considerably reduces data scattering due to the benefits of data redundancy. In conclusion, the simulator allowed us to improve our different algorithms and to understand how instrumental error affects final results. And also, improve the methodology of scans acquisition to find the best compromise between point density, positioning and acquisition time with the best accuracy possible to characterize the topographic change.

Carrea, Dario; Abellán, Antonio; Derron, Marc-Henri; Jaboyedoff, Michel

2014-05-01

322

How integrating 3D LiDAR data in the dike surveillance protocol: The French case  

Science.gov (United States)

The recent and dramatic floods of the last years in Europe (e.g. Rhône river major flood, December 2003, Windstorm Xynthia, February 2010, in France) and in the United-States (Hurricane Katrina, August 2005) showed the vulnerability of flood or coastal defence systems. The first key point for avoiding these dramatic damages and the high cost of a failure and its consequences lies in the appropriate conception and construction of the dikes, but above all in the relevance of the surveillance protocol. Many factors introduce weaknesses in the fluvial or maritime dikes. Most of them are old embankment structures. For instance, some of the French Loire River dikes were built several centuries ago. They may have been rebuilt, modified, heightened several times, with some materials that do not necessarily match the original conception of the structure. In other respects, tree roots or animal burrows could modify the structure of the dike and reduce the watertightness or mechanical properties. The French government has built a national database, "BarDigues", since 1999 to inventory and characterize dikes. Today, there are approx. 9000 km of dikes protecting 1.5 to 2 millions of people. In the meantime, a GIS application, called « Dike SIRS » [Maurel P., 2004] , provides an operational and accurate tool to several great stakeholders in charge of managing more than 100 km of dikes. Today, the dike surveillance and diagnosis protocol consists in identifying the weaknesses of the structure and providing the degree of safety by making a preliminary study (historical research, geological and morphodynamic study, topography), geophysical study (e.g. electromagnetic methods and electrical resistivity tomography) and at last geotechnical study (e.g. drillings and stability modelling) at the very local scale when necessary [Mériaux P. & Royet P, 2007] . Considering the stretch of hundreds of kilometres, rapid, cost-effective and reliable techniques for surveying the dike must be carried out. A LiDAR system is able to acquire data on a dike structure of up to 80 km per day, which makes the use of this technique also valuable in case of emergency situations. It provides additional valuable products like precious information on dike slopes and crest or their near environment (river banks, etc.). Moreover, in case of vegetation, LiDAR data makes possible to study hidden structures or defaults from images like the erosion of riverbanks under forestry vegetation. The possibility of studying the vegetation is also of high importance: the development of woody vegetation near or onto the dike is a major risk factor. Surface singularities are often signs of disorder or suspected disorder in the dike itself: for example a subsidence or a sinkhole on a ridge may result from internal erosion collapse. Finally, high resolution topographic data contribute to build specific geomechanical model of the dike that, after incorporating data provided by geophysical and geotechnical surveys, are integrated in the calculations of the structure stability. Integrating the regular use of LiDAR data in the dike surveillance protocol is not yet operational in France. However, the high number of French stakeholders at the national level (on average, there is one stakeholder for only 8-9km of dike !) and the real added value of LiDAR data makes a spatial data infrastructure valuable (webservices for processing the data, consulting and filling the database on the field when performing the local diagnosis)

Bretar, F.; Mériaux, P.; Fauchard, C.

2012-04-01

323

A LiDAR method of canopy structure retrieval for wind modeling of heterogeneous forests  

DEFF Research Database (Denmark)

The difficulty of obtaining accurate information about the canopy structure is a current limitation towards higher accuracy in numerical predictions of the wind field in forested terrain. The canopy structure in computational fluid dynamics is specified through the frontal area density and this information is required for each grid point in the three-dimensional computational domain. By using raw data from aerial LiDAR scans together with the Beer-Lambert law, we propose and test a method to calculate and grid highly variable and realistic frontal area density input. An extensive comparison with ground-based measurements of the vertically summed frontal area density (or plant area index) and tree height was used to optimize the method, both in terms of plant area index magnitude and spatial variability. The resolution of the scans was in general low (

Boudreault, Louis-Etienne; Bechmann, Andreas

2015-01-01

324

Fine-scale ignimbrite morphology revealed in LiDAR at Crater Lake, OR  

Science.gov (United States)

Mount Mazama erupted ~7,700 years ago resulting in the collapse of Crater Lake caldera, ash fall across the Pacific Northwest, and emplacement of compositionally zoned ignimbrite. Early climactic ignimbrite contains uniform rhyodacitic pumice and traveled far from the vent, whereas late, less mobile ignimbrite is dominated by crystal-rich andesitic scoria and mafic crystal mush. Funded by the USGS, NPS, and FHWA, the DOGAMI-led Oregon LiDAR Consortium contracted with Watershed Services to collect ~800 km2 of LiDAR over Crater Lake National Park from Aug 2010 to Sept 2010. Ground laser returns have an average density of 1.63 returns/m2 over the heavily forested area of interest. The data have a lateral RMSE and vertical accuracy of 0.05 m. A bare earth terrain model allows a virtual removal of the forest, revealing fine-scale surface morphology, notably in the climactic ignimbrite. Secondary pyroclastic flows, explosion craters, erosion by water, and compaction-related deformation modified the originally smooth ignimbrite surface. Distinct pyroclastic flow fronts are evident in the LiDAR in Annie Creek valley. Leveed flows stand approximately 5 m above the lower ignimbrite surface, and individual toes are about 1-2 m high. Preliminary field checking indicates that rhyodacitic pumice dominates the lower ignimbrite surface, but the leveed flows are a subequal mix of locally oxidized rhyodacitic pumice and andesitic scoria. We hypothesize that these deposits were secondary pyroclastic flows formed by gravitational failure of late ignimbrite. In the Castle Creek valley, is a 2-meter collapse scarp that may have spawned a small secondary pyroclastic flow; several such headwall scarps are present in Sand Creek valley. Differential compaction features are common in many thick ignimbrites. We suggest this caused the deformation of the ignimbrite apparent in the LiDAR. In Annie Creek valley are a series of flow parallel asymmetric ridges, with shallower slopes toward the valley center, in the surface of the rhyodacitic ignimbrite. The ridges are 1-2 m high, and have a variable wavelength averaging 60 m. We hypothesize that this terrain is a series of antithetic faults due to downbending towards the thickest part of the ignimbrite. The ignimbrite near the Pumice Desert is likely over 100 m thick. Here, cracks positioned on topographic highs or at breaks in slope are 50 m to 800 m long and up to 30 m wide. The cracks open towards the thickest part of the ignimbrite in the downslope direction. They appear to be tension fractures that opened because of differential compaction of the ignimbrite. Breakaway fractures mark where ignimbrite thickness abruptly decreases laterally, such as north-northeast of the caldera and at valley margins. Some fractures show evidence of water erosion during formation of fractures. On the lee side of Timber Crater, north of Crater Lake, is a series of N-S trending ribs composed of pumice fall from the climactic eruption deposited on glaciated andesite lava. Timber Crater lies on the main dispersal axis of the pumice fall. We suggest that high-energy pyroclastic flows encountered topographic bumps on the flanks of Timber Crater. This affected flow turbulence causing linear troughs to erode into the fall deposit and leaving pumice-fall ribs.

Robinson, J. E.; Bacon, C. R.; Wright, H. M.

2011-12-01

325

Automatic generation of digital terrain models from LiDAR and hyperspectral data using Bayesian networks  

Science.gov (United States)

Various tasks such as urban development, terrain mapping or waterway and drainage modeling depend on digital terrain models (DTM) from large scale remote sensing data. Usually, DTM generation is a task requiring extensive manual interference. Previous attempts for automation are mostly based on determining the non- ground regions via fixed thresholds followed by smoothing operations. Thus, we propose a novel approach to automatically deduce a DTM from a digital surface model (DSM) with the aid of hyperspectral data. For this, advantages of a line scanning LiDAR system and a pushbroom hyperspectral sensor are combined to improve the result. We construct a hybrid Bayesian network (HBN), where modeled nodes can be discrete or continuous, and incorporate our already determined features. Using this network we determine probability estimates whether each point is part of terrain obstructions. While using two different sensor types supplies robust features, Bayesian networks can be automatically trained and adapted to specific scenarios such as mountainous or urban regions.

Perpeet, Dominik; Gross, Wolfgang; Middelmann, Wolfgang

2012-11-01

326

On the use of airborne LiDAR for braided river monitoring and water surface delineation  

Science.gov (United States)

Airborne LiDAR is an established technology for Earth surface surveying. With LiDAR data sets it is possible to derive maps with different land use classes, which are important for hydraulic simulations. We present a 3D point cloud based method for automatic water surface delineation using single as well as multitemporal LiDAR data sets. With the developed method it is possible to detect the location of the water surface with high planimetric accuracy. The multitemporal analysis of different LiDAR data sets makes it possible to visualize, monitor and quantify the changes of the flow path of braided rivers as well as derived water surface land use classes. The reflection properties from laser beams (1064 nm wavelength) on water surfaces are characterized by strong absorption or specular reflection resulting in a dominance of low signal amplitude values and a high number of laser shot dropouts (i.e. non-recorded laser echoes). The occurrence of dropouts is driven by (i) the incidence angle, (ii) the surface reflectance and (iii) the roughness of the water body. The input data of the presented delineation method are the modeled dropouts and the point cloud attributes of geometry and signal amplitude. A terrestrial orthophoto is used to explore the point cloud in order to find proper information about the geometry and amplitude attributes that are characteristic for water surfaces. The delineation method is divided into five major steps. (a) We compute calibrated amplitude values by reducing the atmospheric, topographic influences and the scan geometry for each laser echo. (b) Then, the dropouts are modeled by using the information from the time stamps, the pulse repetition frequency, the inertial measurement unit and the GPS information of the laser shots and the airplane. The next step is to calculate the standard deviation of the heights for all reflections and all modeled dropouts (c) in a specific radius around the points. (d) We compute the amplitude ratio density for all shots. The amplitude density ratio is the relation between the number of laser echoes having an amplitude within a specific interval (i.e. very low amplitudes) plus the dropouts (i.e. with amplitude of zero) divided by the number of all laser shots in a fixed search distance of a point. (e) We classify each point in water or a non-water by using the attributes of (i) the standard deviation of the height and (ii) the amplitude density ratio. For validation, a terrestrial orthophoto is used, which was taken at the same time as the laser campaign. A major advantage of this new approach is the ability of a point cloud based delineation of water and non-water areas. We demonstrate the results at the glacier forefield of the Hintereisferner (Ötztal, Tyrol, Austria) with multitemporal data sets. The multitemporal analysis demonstrates the strength of the delineation method for mapping the watercourse and monitoring the changes in the flow path of the braided river between the different epochs.

Vetter, M.; Höfle, B.; Pfeifer, N.; Rutzinger, M.; Stötter, J.

2009-04-01

327

Fusion of terrestrial LiDAR and tomographic mapping data for 3D karst landform investigation  

Science.gov (United States)

Highly detailed topographic information has gained in importance for studying Earth surface landforms and processes. LiDAR has evolved into the state-of-the-art technology for 3D data acquisition on various scales. This multi-sensor system can be operated on several platforms such as airborne LS (ALS), mobile LS (MLS) from moving vehicles or stationary on ground (terrestrial LS, TLS). In karst research the integral investigation of surface and subsurface components of solution depressions (e.g. sediment-filled dolines) is required to gather and quantify the linked geomorphic processes such as sediment flux and limestone dissolution. To acquire the depth of the different subsurface layers, a combination of seismic refraction tomography (SRT) and electrical resistivity tomography (ERT) is increasingly applied. This multi-method approach allows modeling the extension of different subsurface media (i.e. colluvial fill, epikarst zone and underlying basal bedrock). Subsequent fusion of the complementary techniques - LiDAR surface and tomographic subsurface data - first-time enables 3D prospection and visualization as well as quantification of geomorphometric parameters (e.g. depth, volume, slope and aspect). This study introduces a novel GIS-based method for semi-automated fusion of TLS and geophysical data. The study area is located in the Dikti Mountains of East Crete and covers two adjacent dolines. The TLS data was acquired with a Riegl VZ-400 scanner from 12 scan positions located mainly at the doline divide. The scan positions were co-registered using the iterative closest point (ICP) algorithm of RiSCAN PRO. For the digital elevation rasters a resolution of 0.5 m was defined. The digital surface model (DSM) of the study was derived by moving plane interpolation of all laser points (including objects) using the OPALS software. The digital terrain model (DTM) was generated by iteratively "eroding" objects in the DSM by minimum filter, which additionally accounts for thresholds on slope and object size in order to avoid erosion of the doline slopes. Three SRT cross-sections (Geometrics, 48 channels) and three ERT profiles (Geotom, 100 electrodes) were measured. After post processing with RAYFRACT and RES2DINV software packages, subsurface media were identified taking advantage of different sensitivities of each geophysical technique by cross-checking and matching all outcomes. To join the LiDAR DTM and the subsurface profiles, symmetry of the subsurface bedrock zone is assumed. This allows extrapolation from seismic and resistivity data to the entire doline bottom. The extrapolated point cloud data is then joined with the surface LiDAR data by spline interpolation of the transition zone between surface and subsurface bedrock. The entire fusion procedure of the DTM and the tomographic cross-sections is implemented in the GRASS GIS environment. Finally, the derived digital terrain and subsurface model (DTSM) is used to extract the geomorphological parameters of the landforms (e.g. total volume, sediment volume). Tests using different input datasets (e.g. DSM, DTM, DTSM) for parameter derivation at varying cell resolutions clearly indicate the need for high-resolution terrain and subsurface data for obtaining the geometry and function of karst landforms.

Höfle, B.; Forbriger, M.; Siart, C.; Nowaczinski, E.

2012-04-01

328

¿Es la consciencia un tema de ciencia?  

Directory of Open Access Journals (Sweden)

Full Text Available La percepción que tenemos de nosotros mismos, la consciencia, parece vinculada esencialmente a la posibilidad de hacer preguntas y buscar las respuestas. En décadas recientes su caracterización y comprensión empiezan a ser objeto del esfuerzo científico, la estrategia más exitosa que hemos encontrado para hacer comprensible nuestro entorno, a partir de la evidencia, y en contraposición con la revelación o la especulación. Todo sugiere que la consciencia es resultado de la actividad extendida y armónica de distintas áreas del cerebro, aunque estamos lejos de sucomprensión.

Ram\\u00F3n Peralta-Fabi

2013-01-01

329

Martha senn: cuando la vida es creación  

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

Carlos Hernando Dueñas Montaño

2012-04-01

330

Tracking geomorphic signatures of watershed suburbanization with multitemporal LiDAR  

Science.gov (United States)

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

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

2014-08-01

331

LiDAR detection of paleolandslides in the vicinity of the Suasselkä postglacial fault, Finnish Lapland  

Science.gov (United States)

Spatial distribution of paleolandslides coincides with postglacial faults (PGFs) in northern Fennoscandia, yet the timing of the seismic events and associated paleoslides is insufficiently known. We applied airborne LiDAR (Light Detection And Ranging) to record distribution of paleolandslides possibly associated with the known Suasselkä postglacial fault in Kittilä, western Finnish Lapland. Landslide-buried organic material was radiocarbon dated to bring insight if the landslides were generated by single high-magnitude (Mw > 7) earthquake or if seismic activity has continued through the Holocene. We found a total of four sets of previously unrecognized paleolandslides to indicate fault-activity in the Kittilä area. The size of the landslide scarps exceeded up to 250-300 m in width, up to 600 m in length and 10 m in the height of the back-wall. A previously unrecognized (tentatively PGF) scarp, 6 m in height and in conjunction with paleolandslides, was found in granite rock west of the Kittilä village. The slide debris was similar to local tills, yet the maximum electrical conductivity (?a) anisotropy was incoherent to any of the ice-flow (morphological) stages recognized through LiDAR or known fabric-sedimentary stratigraphy. We found peat/gyttja beneath 6 m of slide debris which yielded radiocarbon (14C) age of 4400 ± 35 BP (cal. 5055 yr BP). Our previous finding of landslide-buried woody remnants of birch (Betula ssp.) yielded cal. 9730 yr BP in Kittilä. These ages suggest that seismic activity has continued at least 5 ky after deglaciation.

Sutinen, Raimo; Hyvönen, Eija; Kukkonen, Ilmo

2014-04-01

332

Multispectral, hyperspectral, and LiDAR remote sensing and geographic information fusion for improved earthquake response  

Science.gov (United States)

The Naval Postgraduate School (NPS) Remote Sensing Center (RSC) and research partners have completed a remote sensing pilot project in support of California post-earthquake-event emergency response. The project goals were to dovetail emergency management requirements with remote sensing capabilities to develop prototype map products for improved earthquake response. NPS coordinated with emergency management services and first responders to compile information about essential elements of information (EEI) requirements. A wide variety of remote sensing datasets including multispectral imagery (MSI), hyperspectral imagery (HSI), and LiDAR were assembled by NPS for the purpose of building imagery baseline data; and to demonstrate the use of remote sensing to derive ground surface information for use in planning, conducting, and monitoring post-earthquake emergency response. Worldview-2 data were converted to reflectance, orthorectified, and mosaicked for most of Monterey County; CA. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data acquired at two spatial resolutions were atmospherically corrected and analyzed in conjunction with the MSI data. LiDAR data at point densities from 1.4 pts/m2 to over 40 points/ m2 were analyzed to determine digital surface models. The multimodal data were then used to develop change detection approaches and products and other supporting information. Analysis results from these data along with other geographic information were used to identify and generate multi-tiered products tied to the level of post-event communications infrastructure (internet access + cell, cell only, no internet/cell). Technology transfer of these capabilities to local and state emergency response organizations gives emergency responders new tools in support of post-disaster operational scenarios.

Kruse, F. A.; Kim, A. M.; Runyon, S. C.; Carlisle, Sarah C.; Clasen, C. C.; Esterline, C. H.; Jalobeanu, A.; Metcalf, J. P.; Basgall, P. L.; Trask, D. M.; Olsen, R. C.

2014-06-01

333

Funciones del profesional de enfermería en salas de hospitalización de adultos: tratando de dar cuidado directo Funções do profissional de enfermagem em salas de hospitalização de adultos: tratando de dar cuidado direto Nursing professionals duties in adult hospitalization floors: trying to give direct care  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivo: describir las funciones y el quehacer del profesional de enfermería que labora en salas de hospitalización de adultos. Metodología: estudio etnográfico en el que fueron entrevistadas 17 enfermeras que laboraban en salas de hospitalización de adultos en instituciones de salud de la ciudad de Medellín y del área Metropolitana del Valle de Aburrá (Colombia, en 2007. Se hicieron diez observaciones del fenómeno estudiado en las salas en que trabajaban las participantes. Los resultados fueron socializados con las participantes de estudio para verificar si se reconocían en el análisis realizado. Resultados: se identificaron cuatro categorías de análisis: administrar la sala, tratando de dar cuidado directo, criterios para la clasificación del cuidado y el cuidado delegado. Las participantes en el estudio están principalmente ocupadas en funciones administrativas; su quehacer está centrado especialmente en actividades médico delegadas y de administración de la sala. Establecen la necesidad de brindar cuidado según criterios biológicos o procesos técnicos, y el cuidado es delegado en el personal auxiliar de enfermería. El contacto directo con los pacientes se reduce a un saludo protocolario y de cortesía la mayoría de las veces. En las enfermeras existe un sentimiento de culpabilidad por no dar el cuidado directo. Conclusión: el cuidado directo está en segundo lugar, después de las funciones médico delegadas y administrativas del servicio.Objetivo: descrever as funções e o afazer do profissional de enfermagem que labora em salas de hospitalização de adultos. Metodologia: estudo etnográfico no que se entrevistaram a 17 enfermeiras que laboravam em salas de hospitalização de adultos em instituições de saúde da cidade de Medellín e da área Metropolitana do Vale de Aburrá (Colômbia em 2007. Fizeramse dez observações do fenômeno estudado nas salas em que trabalhavam as participantes. Os resultados foram socializados com as participantes de estudo para verificar se reconheciam na análise realizada. Resultados: identificaramse quatro categorias análises: administrar a sala, tratando de dar cuidado direto, critérios para a classificação do cuidado e o cuidado delegado. As participantes do estudo estão principalmente ocupadas em funções administrativas; seu afazer está centrado especialmente em atividades médico delegado e de administração da sala. Estabelecem a necessidade de brindar cuidado segundo critérios biológicos ou processos técnicos, e o cuidado é delegado ao pessoal auxiliar de enfermagem. O contato direto com os pacientes se reduz a uma saudação protocolares e de cortesia, a maioria das vezes. Nas enfermeiras existe um sentimento de culpabilidade por não dar o cuidado direto. Conclusão: o cuidado direto está em segundo lugar, depois das funções médico delegado e administrativas do serviço.Objective: to describe the duties and work of nursing professionals who work in the adult hospitalization floors. Methodology: ethnographic study where 17 nurses who worked in the adult hospitalization floors in health care institutions located in the metropolitan area of the Aburra valley in Medellin (Colombia were interviewed during the year of 2007. Ten observations about the studied phenomenon were made in the floors where the participants worked. The results were socialized with the study participants to verify if they recognized the performed analysis. Results: four analysis categories were identified: Floor management, trying to give direct care, criteria for the classification of care and delegated care. The study participants are mainly engaged in management duties. Their work is centered specially in medical delegated activities and floor management. They establish the necessity to give care according to technical and biological criteria, and the care is delegated to the nurses’ aide personnel. The direct contact with the patients is reduced most of the times to a courtesy and protocol greeting. Between the nurses exists a guilt fee

Gloria Alcaraz López

2010-03-01

334

Funciones del profesional de enfermería en salas de hospitalización de adultos: tratando de dar cuidado directo / Nursing professionals duties in adult hospitalization floors: trying to give direct care / Funções do profissional de enfermagem em salas de hospitalização de adultos: tratando de dar cuidado direto  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in portuguese Objetivo: descrever as funções e o afazer do profissional de enfermagem que labora em salas de hospitalização de adultos. Metodologia: estudo etnográfico no que se entrevistaram a 17 enfermeiras que laboravam em salas de hospitalização de adultos em instituições de saúde da cidade de Medellín e da á [...] rea Metropolitana do Vale de Aburrá (Colômbia) em 2007. Fizeramse dez observações do fenômeno estudado nas salas em que trabalhavam as participantes. Os resultados foram socializados com as participantes de estudo para verificar se reconheciam na análise realizada. Resultados: identificaramse quatro categorias análises: administrar a sala, tratando de dar cuidado direto, critérios para a classificação do cuidado e o cuidado delegado. As participantes do estudo estão principalmente ocupadas em funções administrativas; seu afazer está centrado especialmente em atividades médico delegado e de administração da sala. Estabelecem a necessidade de brindar cuidado segundo critérios biológicos ou processos técnicos, e o cuidado é delegado ao pessoal auxiliar de enfermagem. O contato direto com os pacientes se reduz a uma saudação protocolares e de cortesia, a maioria das vezes. Nas enfermeiras existe um sentimento de culpabilidade por não dar o cuidado direto. Conclusão: o cuidado direto está em segundo lugar, depois das funções médico delegado e administrativas do serviço. Abstract in spanish Objetivo: describir las funciones y el quehacer del profesional de enfermería que labora en salas de hospitalización de adultos. Metodología: estudio etnográfico en el que fueron entrevistadas 17 enfermeras que laboraban en salas de hospitalización de adultos en instituciones de salud de la ciudad d [...] e Medellín y del área Metropolitana del Valle de Aburrá (Colombia), en 2007. Se hicieron diez observaciones del fenómeno estudiado en las salas en que trabajaban las participantes. Los resultados fueron socializados con las participantes de estudio para verificar si se reconocían en el análisis realizado. Resultados: se identificaron cuatro categorías de análisis: administrar la sala, tratando de dar cuidado directo, criterios para la clasificación del cuidado y el cuidado delegado. Las participantes en el estudio están principalmente ocupadas en funciones administrativas; su quehacer está centrado especialmente en actividades médico delegadas y de administración de la sala. Establecen la necesidad de brindar cuidado según criterios biológicos o procesos técnicos, y el cuidado es delegado en el personal auxiliar de enfermería. El contacto directo con los pacientes se reduce a un saludo protocolario y de cortesía la mayoría de las veces. En las enfermeras existe un sentimiento de culpabilidad por no dar el cuidado directo. Conclusión: el cuidado directo está en segundo lugar, después de las funciones médico delegadas y administrativas del servicio. Abstract in english Objective: to describe the duties and work of nursing professionals who work in the adult hospitalization floors. Methodology: ethnographic study where 17 nurses who worked in the adult hospitalization floors in health care institutions located in the metropolitan area of the Aburra valley in Medell [...] in (Colombia) were interviewed during the year of 2007. Ten observations about the studied phenomenon were made in the floors where the participants worked. The results were socialized with the study participants to verify if they recognized the performed analysis. Results: four analysis categories were identified: Floor management, trying to give direct care, criteria for the classification of care and delegated care. The study participants are mainly engaged in management duties. Their work is centered specially in medical delegated activities and floor management. They establish the necessity to give care according to technical and biological criteria, and the care is delegated to the nurses’ aide personnel. The direct cont

Gloria, Alcaraz López; Marleny, Zapata Herrera; Margarita, Gómez Gómez; Edison, Tavera Agudelo.

2010-03-01

335

Geometric calibration and radiometric correction of LiDAR data and their impact on the quality of derived products.  

Science.gov (United States)

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 systems and radiometric correction of collected intensity data while investigating their impact on the quality of the derived products. The proposed approach includes the use of a quasi-rigorous geometric calibration and the radar equation for the radiometric correction of intensity data. The proposed quasi-rigorous calibration procedure requires time-tagged point cloud and trajectory position data, which are available to most of the data users. The paper presents a methodology for evaluating the impact of the geometric calibration on the relative and absolute accuracy of the LiDAR point cloud. Furthermore, the impact of the geometric calibration and radiometric correction on land cover classification accuracy is investigated. The feasibility of the proposed methods and their impact on the derived products are demonstrated through experimental results using real data. PMID:22164121

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

2011-01-01

336

DEM Development from Ground-Based LiDAR Data: A Method to Remove Non-Surface Objects  

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Full Text Available Topography and land cover characteristics can have significant effects on infiltration, runoff, and erosion processes on watersheds. The ability to model the timing and routing of surface water and erosion is affected by the resolution of the digital elevation model (DEM. High resolution ground-based Light Detecting and Ranging (LiDAR technology can be used to collect detailed topographic and land cover characteristic data. In this study, a method was developed to remove vegetation from ground-based LiDAR data to create high resolution DEMs. Research was conducted on intensively studied rainfall–runoff plots on the USDA-ARS Walnut Gulch Experimental Watershed in Southeast Arizona. LiDAR data were used to generate 1 cm resolution digital surface models (DSM for 5 plots. DSMs created directly from LiDAR data contain non-surface objects such as vegetation cover. A vegetation removal method was developed which used a slope threshold and a focal mean filter method to remove vegetation and create bare earth DEMs. The method was validated on a synthetic plot, where rocks and vegetation were added incrementally. Results of the validation showed a vertical error of ±7.5 mm in the final DEM.

Maneesh Sharma

2010-11-01

337

Assessing Surface Fuel Hazard in Coastal Conifer Forests through the Use of LiDAR Remote Sensing  

Science.gov (United States)

The research problem that this thesis seeks to examine is a method of predicting conventional fire hazards using data drawn from specific regions, namely the Sooke and Goldstream watershed regions in coastal British Columbia. This thesis investigates whether LiDAR data can be used to describe conventional forest stand fire hazard classes. Three objectives guided this thesis: to discuss the variables associated with fire hazard, specifically the distribution and makeup of fuel; to examine the relationship between derived LiDAR biometrics and forest attributes related to hazard assessment factors defined by the Capitol Regional District (CRD); and to assess the viability of the LiDAR biometric decision tree in the CRD based on current frameworks for use. The research method uses quantitative datasets to assess the optimal generalization of these types of fire hazard data through discriminant analysis. Findings illustrate significant LiDAR-derived data limitations, and reflect the literature in that flawed field application of data modelling techniques has led to a disconnect between the ways in which fire hazard models have been intended to be used by scholars and the ways in which they are used by those tasked with prevention of forest fires. It can be concluded that a significant trade-off exists between computational requirements for wildfire simulation models and the algorithms commonly used by field teams to apply these models with remote sensing data, and that CRD forest management practices would need to change to incorporate a decision tree model in order to decrease risk.

Koulas, Christos

338

Urban flood modelling combining top-view LiDAR data with ground-view SfM observations  

Science.gov (United States)

Remote Sensing technologies are capable of providing high-resolution spatial data needed to set up advanced flood simulation models. Amongst them, aerial Light Detection and Ranging (LiDAR) surveys or Airborne Laser Scanner (ALS) systems have long been used to provide digital topographic maps. Nowadays, Remote Sensing data are commonly used to create Digital Terrain Models (DTMs) for detailed urban-flood modelling. However, the difficulty of relying on top-view LiDAR data only is that it cannot detect whether passages for floodwaters are hidden underneath vegetated areas or beneath overarching structures such as roads, railroads, and bridges. Such (hidden) small urban features can play an important role in urban flood propagation. In this paper, a complex urban area of Kuala Lumpur, Malaysia was chosen as a study area to simulate the extreme flooding event that occurred in 2003. Three different DTMs were generated and used as input for a two-dimensional (2D) urban flood model. A top-view LiDAR approach was used to create two DTMs: (i) a standard LiDAR-DTM and (ii) a Filtered LiDAR-DTM taking into account specific ground-view features. In addition, a Structure from Motion (SfM) approach was used to detect hidden urban features from a sequence of ground-view images; these ground-view SfM data were then combined with top-view Filtered LiDAR data to create (iii) a novel Multidimensional Fusion of Views-Digital Terrain Model (MFV-DTM). These DTMs were then used as a basis for the 2D urban flood model. The resulting dynamic flood maps are compared with observations at six measurement locations. It was found that when applying only top-view DTMs as input data, the flood simulation results appear to have mismatches in both floodwater depths and flood propagation patterns. In contrast, when employing the top-ground-view fusion approach (MFV-DTM), the results not only show a good agreement in floodwater depth, but also simulate more correctly the floodwater dynamics around small urban feature. Overall, the new multi-view approach of combining top-view LiDAR data with ground-view SfM observations shows a good potential for creating an accurate digital terrain map which can be then used as an input for a numerical urban flood model.

Meesuk, Vorawit; Vojinovic, Zoran; Mynett, Arthur E.; Abdullah, Ahmad F.

2015-01-01

339

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

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

Marcelo Ricardo Pereira

2010-03-01

340

Low-Density LiDAR and Optical Imagery for Biomass Estimation over Boreal Forest in Sweden  

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Full Text Available Knowledge of the forest biomass and its change in time is crucial to understanding the carbon cycle and its interactions with climate change. LiDAR (Light Detection and Ranging technology, in this respect, has proven to be a valuable tool, providing reliable estimates of aboveground biomass (AGB. The overall goal of this study was to develop a method for assessing AGB using a synergy of low point density LiDAR-derived point cloud data and multi-spectral imagery in conifer-dominated forest in the southwest of Sweden. Different treetop detection algorithms were applied for forest inventory parameter extraction from a LiDAR-derived canopy height model. Estimation of AGB was based on the power functions derived from tree parameters measured in the field, while vegetation classification of a multi-spectral image (SPOT-5 was performed in order to account for dependences of AGB estimates on vegetation types. Linear regression confirmed good performance of a newly developed grid-based approach for biomass estimation (R2 = 0.80. Results showed AGB to vary from below 1 kg/m2 in very young forests to 94 kg/m2 in mature spruce forests, with RMSE of 4.7 kg/m2. These AGB estimates build a basis for further studies on carbon stocks as well as for monitoring this forest ecosystem in respect of disturbance and change in time. The methodology developed in this study can be easily adopted for assessing biomass of other conifer-dominated forests on the basis of low-density LiDAR and multispectral imagery. This methodology is hence of much wider applicability than biomass derivation based on expensive and currently still scarce high-density LiDAR data.

Iurii Shendryk

2014-05-01

 
 
 
 
341

Discriminative ability of the generic and condition-specific Child-Oral Impacts on Daily Performances (Child-OIDP by the Limpopo-Arusha School Health (LASH Project: A cross-sectional study  

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Full Text Available Abstract Background Generic and condition-specific (CS oral-health-related quality-of-life (OHRQoL instruments assess the impacts of general oral conditions and specific oral diseases. Focusing schoolchildren from Arusha and Dar es Salaam, in Tanzania, this study compared the discriminative ability of the generic Child OIDP with respect to dental caries and periodontal problems across the study sites. Secondly, the discriminative ability of the generic-and the CS Child OIDP attributed to dental caries, periodontal problems and malocclusion was compared with respect to various oral conditions as part of a construct validation. Methods In Arusha, 1077 school children (mean age 14.9 years, range 12-17 years and 1601 school children in Dar es Salaam (mean age 13.0 years, range 12-14 years underwent oral clinical examinations and completed the Kiswahili version of the generic and CS Child-OIDP inventories. The discriminative ability was assessed as differences in overall mean and prevalence scores between groups, corresponding effect sizes and odd ratios, OR. Results The differences in the prevalence scores and the overall mean generic Child-OIDP scores were significant between the groups with (DMFT > 0 and without (DMFT = 0 caries experience and with (simplified oral hygiene index [OHI-S] > 1 and without periodontal problems (OHI-S ? 1 in Arusha and Dar es Salaam. In Dar es Salaam, differences in the generic and CS Child-OIDP scores were observed between the groups with and without dental caries, differences in the generic Child-OIDP scores were observed between the groups with and without periodontal problems, and differences in the CS Child-OIDP scores were observed between malocclusion groups. The adjusted OR for the association between dental caries and the CS Child-OIDP score attributed to dental caries was 5.4. The adjusted OR for the association between malocclusion and CS Child-OIDP attributed to malocclusion varied from 8.8 to 2.5. Conclusion The generic Child-OIDP discriminated equally well between children with and without dental caries and periodontal problems across socio-culturally different study sites. Compared with its generic form, the CS Child-OIDP discriminated most strongly between children with and without dental caries and malocclusion. The CS Child OIDP attributed to dental caries and malocclusion seems to be better suited to support clinical indicators when estimating oral health needs among school children in Tanzania.

Masalu Joyce R

2011-05-01

342

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

Scientific Electronic Library Online (English)

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

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

2010-02-01

343

Identification of VIM-2-Producing Pseudomonas aeruginosa from Tanzania Is Associated with Sequence Types 244 and 640 and the Location of blaVIM-2 in a TniC Integron.  

Science.gov (United States)

Epidemiological data on carbapenemase-producing Gram-negative bacteria on the African continent are limited. Here, we report the identification of VIM-2-producing Pseudomonas aeruginosa isolates in Tanzania. Eight out of 90 clinical isolates of P. aeruginosa from a tertiary care hospital in Dar es Salaam were shown to harbor blaVIM-2. The blaVIM-2-positive isolates belonged to two different sequence types (ST), ST244 and ST640, with blaVIM-2 located in an unusual integron structure lacking the 3' conserved region of qac?E1-sul1. PMID:25331700

Moyo, Sabrina; Haldorsen, Bjørg; Aboud, Said; Blomberg, Bjørn; Maselle, Samuel Y; Sundsfjord, Arnfinn; Langeland, Nina; Samuelsen, Ørjan

2015-01-01

344

Social context of disclosing HIV test results in Tanzania.  

Science.gov (United States)

This study sought to understand how individuals reveal their HIV test results to others and the ways in which social relations affect the disclosure process. The data were collected through open-ended interviews administered in Swahili to informants who had just been tested for HIV and to those who were living with HIV in Dar es Salaam and Iringa regions. Analysis shows that social relations influence the decisions individuals make about disclosure. Most people preferred to reveal their HIV status to close family members. Most also mentioned the fear of being rejected and discriminated against as major reasons for not disclosing their test results to others. PMID:21936654

Lugalla, Joe; Yoder, Stanley; Sigalla, Huruma; Madihi, Charles

2012-01-01

345

New late gene, dar, involved in the replication of bacteriophage T4 DNA. II. Overproduction of DNA binding protein (gene 32 protein) and further characterization  

International Nuclear Information System (INIS)

We have previously shown that the arrested DNA synthesis of mutants defective in T4 phage gene 59 can be reversed by a mutation in dar. In this paper, we have examined the effect of the dar mutation on the kinetics of gene 32 protein (DNA binding protein) synthesis, DNA packaging, progeny formation, and several other processes. Several lines of evidence are presented showing that the regulation of synthesis of gene 32 protein is abnormal in dar1-infected cells. In these cells, gene 32 protein, an early protein, is also expressed late in the infectious cycle. Our data also indicate that the packaging of DNA into T4 phase heads is delayed in dar mutant-infected cells, and this in turn results in a 6- to 8-min delay in intracellular progeny formation, although the synthesis of late proteins appears to be normal, as shown by gel electrophoresis. We have also studied the phenotypes of the double mutant dar-amC5 (gene 59). The increased sensitivity to hydroxyurea caused by a mutation in the dar gene can be alleviated by a second mutation in gene 59, but an increased sensitivity to uv irradiation caused by a mutation in gene 59 cannot be alleviated by a second mutation in the dar gene. Therefore, the double mutant still exhibits abnormalities in the repair of uv lesions

346

Probabilistic change mapping from airborne LiDAR for post-disaster damage assessment  

Science.gov (United States)

When both pre- and post-event LiDAR point clouds are available, change detection can be performed to identify areas that were most affected by a disaster event, and to obtain a map of quantitative changes in terms of height differences. In the case of earthquakes in built-up areas for instance, first responders can use a LiDAR change map to help prioritize search and recovery efforts. The main challenge consists of producing reliable change maps, robust to collection conditions, free of processing artifacts (due for instance to triangulation or gridding), and taking into account the various sources of uncertainty. Indeed, datasets acquired within a few years interval are often of different point density (sometimes an order of magnitude higher for recent data), different acquisition geometries, and very likely suffer from georeferencing errors and geometric discrepancies. All these differences might not be important for producing maps from each dataset separately, but they are crucial when performing change detection. We have developed a novel technique for the estimation of uncertainty maps from the LiDAR point clouds, using Bayesian inference, treating all variables as random. The main principle is to grid all points on a common grid before attempting any comparison, as working directly with point clouds is cumbersome and time consuming. A non-parametric approach based on local linear regression was implemented, assuming a locally linear model for the surface. This enabled us to derive error bars on gridded elevations, and then elevation differences. In this way, a map of statistically significant changes could be computed - whereas a deterministic approach would not allow testing of the significance of differences between the two datasets. This approach allowed us to take into account not only the observation noise (due to ranging, position and attitude errors) but also the intrinsic roughness of the observed surfaces occurring when scanning vegetation. As only elevation differences above a predefined noise level are accounted for (according to a specified confidence interval related to the allowable false alarm rate) the change detection is robust to all these sources of noise. To first validate the approach, we built small-scale models and scanned them using a terrestrial laser scanner to establish 'ground truth'. Changes were manually applied to the models then new scans were performed and analyzed. Additionally, two airborne datasets of the Monterey Peninsula, California, were processed and analyzed. The first one was acquired during 2010 (with relatively low point density, 1-3 pts/m2), and the second one was acquired during 2012 (with up to 30 pts/m2). To perform the comparison, a new point cloud registration technique was developed and the data were registered to a common 1 m grid. The goal was to correct systematic shifts due to GPS and INS errors, and focus on the actual height differences regardless of the absolute planimetric accuracy of the datasets. Though no major disaster event occurred between the two acquisition dates, sparse changes were detected and interpreted mostly as construction and natural landscape evolution.

Jalobeanu, A.; Runyon, S. C.; Kruse, F. A.

2013-12-01

347

Do we need a voxel-based approach for LiDAR data in geomorphology?  

Science.gov (United States)

Generations of geomorphologists have developed a multi-faceted approach to model the Earth's (and planetary) surface and the corresponding processes. This set of models is based on data, more specifically on conspicuously increasing amount of data. Obviously, all geomorphologists wish themselves more accurate and increasingly high resolution data on, or related to the Earth surface. This evolution also means that the studied boundary is not anymore a single surface; instead it is considered mostly a 2.5D object, sometimes a real 3D object. LiDAR technology can cope with this challenge: the data accuracy and resolution requirements can be fulfilled by applying this method. Although it is yet somewhat still expensive, more and more areas will be scanned, and in some regions the topographic point clouds are already multitemporal (causing of course other types of processing and evaluation problems). It is rather obvious that for certain, geomorphologically very interesting areas very dense and severalfold multitemporal LiDAR data will be available in the near future. These data sets will have various differences concerning the data density, accuracy, data acquisition technique (conventional or full-waveform), and perhaps most importantly, concerning the actual state of the surface. Similar to the satellite imagery integration problems, soon we all have to face with the LiDAR data integration problem. What type of surface or surfaces can be derived from this multitude of data sources with acceptable ambiguity? What conclusions can be drawn from these data that were originally acquired for various other purposes using various acquisition concepts? Will it be advantageous for geomorphic use to have a coverage of the surface with 100-200 points/m² density? Clearly, these data are, if they are once collected, still too expensive not to be integrated for further analyses. Consequently, we need a data reduction concept that effectively decreases the computer capacity needed to store, process and visualize the results. To reduce the amount of originally collected data for further applications, in general, continuous model surfaces are derived from the point clouds using interpolation approaches. Commonly, grid-based or triangulation models are used for that purpose. Typical models are Digital Surface Models (DSM) representing the whole topography including all natural (e.g. vegetation) and artificial (e.g. buildings) objects and Digital Terrain Models (DTM) representing the topography only. In the visual computing industry the voxel-based approach is quite common for various purposes. Although this technology is quite straightforward concerning the data reduction, it is hardly applied in the geomorphic context. An argument can be against its application that mostly we are interested in a surface, not a volume. Of course in the strict sense it is true, however, if we consider the technology itself how the data, especially the ground data are derived, it turns out that actually it is a volume with a certain accuracy that we are sampling of. The position of this "relatively thin" volume also varies, especially in mountainous areas. Here, depending on the slope angles, the accuracy also varies, especially for the integrated data set consisting of a multitude of sources, e.g. mixing conventional (first echo/last echo) and full-waveform data. These point clouds also contain attributes that otherwise could be very valuable, but during the integration, their meaning may be lost, or it cannot be integrated to the data set. A large scale application of such approaches is mainly prevented by the problems introduced by the high amount of data, making on-the-fly processing a challenging task. To overcome these restrictions and to enable taking advantage of the new possibilities provided by the waveform analysis, we propose a voxel-based data representation approach. The multichannel/multilayer design with an a priori unlimited number of layers enables storing an unlimited number of additional parameter per point. We expect that such a

Székely, Balázs; Dorninger, Peter; Faber, Robert; Nothegger, Clemens

2010-05-01

348

Using LiDAR Metrics to Characterize Forest Structural Complexity at Multiple Scales  

Science.gov (United States)

Forest structure - the size and arrangement of trees and foliage - reflects a stand's history of initiation, growth, disturbance, and mortality. Because of this, studying the structure of forests can provide key insights into ecological processes, guides to silvicultural prescriptions to improve habitat, and assessments of forested landscapes. This study tested LiDAR metrics to characterize stands based on canopy structure. The study site was the 34,591 ha of forests in the Cedar River Watershed in western Washington State, USA. Stands ranged in age from 350 years old (including old-growth). Study sites spanned the western hemlock- Douglas fir (Tsuga heterophylla-Pseudotsuga menziesii), Pacific silver fir (Abies amabilis), and mountain hemlock (Tsuga mertansiana) forest zones. Eighty sample plots were used to ground truth the LiDAR data. A variety of structural indices were used to study canopy structural variations at the plot, stand, and landscape scales. The two most successful indices used the exposed geometry of the canopy surface: (1) the ratio of the canopy surface area to ground surface area (rumple index), and (2) the ratio of the volume beneath the canopy surface to maximum volume beneath the 95th percentile height (modified canopy volume method). These two indices integrated the spatial effects of tree heights, foliage distribution, and tree arrangement within 15m pixels. Variation between pixels revealed structural complexity at larger scales. Results: At the plot scale (~4 pixels), correlations with standard plot metrics (e.g., diameter at breast height) were similar to those reported by other studies. Comparison of structural complexity with age and height revealed a diversity of development pathways. The relationship between height and complexity allowed stands to be classified by the degree to which they have achieved their potential structural complexity, a new way to examine forest development. At the stand scale, the indices allowed spatial analysis of the patterns of structural variance. Analyzing these patterns would assist managers in designing forest management regimes based on natural stand complexity patterns. At the landscape scale, the indices allowed classification of stands based on structural complexity, which better differentiated stands than using only age or simpler structural element classifications. Old-growth stands, for example, were classified into four distinct groups based on their canopy structural complexity.

Kane, V. R.; McGaughey, R. J.; Gersonde, R.; Franklin, J. F.

2007-12-01

349

Geomorphic mapping of the southern Maacama fault based on LiDAR data  

Science.gov (United States)

The Maacama fault is an active strike slip fault, and a potentially significant seismic source, within the San Andreas transform system. The fault is located east of and parallel to the San Andreas fault in Sonoma and Mendocino counties, California and is divided into a northern and southern section based on a NW to NNW change in strike. The southern segment comprises 54 km of the fault's 144 km total length and is primarily located in an upland area traversing mountainous terrain. Strain is thought to transfer northward from the East Bay fault zone along the Rodgers Creek fault and, through a right step, to the Maacama fault. LiDAR data collected in a 1-km-wide swath along the southern Maacama fault, as part of the GeoEarthscope project, were used to produce a bare-earth digital elevation model, from which hillshade, topographic contour, slope, and curvature maps with 0.5- to 1-m-resolution were derived. Mapping was primarily conducted digitally in a GIS environment, and interpretation of LiDAR data was supplemented with aerial photograph interpretation and field inspection. Primary, Holocene-age fault-related geomorphic features, consisting of scarps and dextrally offset drainages, define the southern Maacama. These features are sparsely distributed and comprise less than 20% of the fault length. The fault scarps define a sequence of left-stepping, en echelon fault segments with an average segment length of 230 m. By contrast, the northern Maacama fault is better defined geomorphically. The poor expression of the southern Maacama is likely due to the presence of active hillslope processes and low levels of seismicity. Seismicity along the southern segment is lower than that of the northern segment. The Coast Range uplands, primarily composed of Franciscan Complex, is characterized by numerous landslides and experiences annual precipitation of 75 to 180 cm. There is approximately 30 km of overlap between the northern end of the Rodgers Creek fault and the southern extent of the Maacama fault, and in this region the Rodgers Creek fault is better expressed geomorphically. Because climate and lithology are similar across this region, we attribute the stark differences in geomorphic appearance to tectonic activity. This difference suggests that over Holocene and late Pleistocene timescales, strain has been preferentially accommodated along the Rodgers Creek fault and is gradually transferred northward to the Maacama fault.

Hoeft, J. S.; Sowers, J. M.; Kelsey, H. M.; Prentice, C. S.; Frankel, K. L.

2008-12-01

350

A Decade Remote Sensing River Bathymetry with the Experimental Advanced Airborne Research LiDAR  

Science.gov (United States)

Since 2002, the first generation of the Experimental Advanced Airborne Research LiDAR (EAARL-A) sensor has been deployed for mapping rivers and streams. We present and summarize the results of comparisons between ground truth surveys and bathymetry collected by the EAARL-A sensor in a suite of rivers across the United States. These comparisons include reaches on the Platte River (NE), Boise and Deadwood Rivers (ID), Blue and Colorado Rivers (CO), Klamath and Trinity Rivers (CA), and the Shenandoah River (VA). In addition to diverse channel morphologies (braided, single thread, and meandering) these rivers possess a variety of substrates (sand, gravel, and bedrock) and a wide range of optical characteristics which influence the attenuation and scattering of laser energy through the water column. Root mean square errors between ground truth elevations and those measured by the EAARL-A ranged from 0.15-m in rivers with relatively low turbidity and highly reflective sandy bottoms to over 0.5-m in turbid rivers with less reflective substrates. Mapping accuracy with the EAARL-A has proved challenging in pools where bottom returns are either absent in waveforms or are of such low intensity that they are treated as noise by waveform processing algorithms. Resolving bathymetry in shallow depths where near surface and bottom returns are typically convolved also presents difficulties for waveform processing routines. The results of these evaluations provide an empirical framework to discuss the capabilities and limitations of the EAARL-A sensor as well as previous generations of post-processing software for extracting bathymetry from complex waveforms. These experiences and field studies not only provide benchmarks for the evaluation of the next generation of bathymetric LiDARs for use in river mapping, but also highlight the importance of developing and standardizing more rigorous methods to characterize substrate reflectance and in-situ optical properties at study sites. They also point out the continued necessity of ground truth data for algorithm refinement and survey verification.

Kinzel, P. J.; Legleiter, C. J.; Nelson, J. M.; Skinner, K.

2012-12-01

351

LiDAR-based characterization of the Mt Shasta debris avalanche deposit  

Science.gov (United States)

The failure of destabilized volcano flanks, due either to tectonic activity on basement structures underlying the volcanic edifice, magmatic intrusion or external forcing (e.g. weather events), is a likely occurrence during the lifetime of a stratovolcano. Flank failure can generate large debris avalanches, and the significant hazards associated with volcanic debris avalanches in the Cascade range were demonstrated by the collapse of Mt St Helens (WA, USA), which triggered its devastating explosive eruption in May 1980. Mt Shasta is a 4,317 m high, snow-capped, steep-sloped stratovolcano located in Northern California. The most voluminous of the Cascade volcanoes, the current edifice began forming on the remnants of an ancestral Mt Shasta that collapsed approximately 300,000 to 380,000 years ago producing one of the largest debris avalanches known on Earth. The debris avalanche deposit (DAD) covers a surface of 450 km2 across the Shasta valley, for a total volume of approximately 26 km3. A LiDAR point cloud and orthophoto of the Shasta DAD surveyed by the NCALM consortium provides a new topographic dataset of the area with unprecedented resolution. This will permit the identification of subtle topographic features of the Shasta DAD not apparent in the field or in coarser resolution datasets. Statistical measures of the LiDAR-derived digital elevation model, such as surface texture, will be used to detect and characterize the hummock topography, differentiate between various DAD facies and geomorphic units, and extract the morphological parameters for subsequent analogue and numerical modeling of the debris avalanche. This work aims to improve our understanding of the Mt Shasta DAD morphology and its dynamics, and provide insight into the cause, timing of events and mode of emplacement of the DAD. The Cascade range includes numerous large extinct, dormant or active stratovolcanoes, and knowledge of the link between basement structures and the Mt Shasta DAD will elucidate the causes of edifice instability and may be used to target priority areas for volcanic hazard mapping.

Tortini, R.; Carn, S. A.; van Wyk de Vries, B.

2013-12-01

352

2011 Japan tsunami survivor video based hydrograph and flow velocity measurements using LiDAR  

Science.gov (United States)

On March 11, 2011, a magnitude Mw 9.0 earthquake occurred off the coast of Japan's Tohoku region causing catastrophic damage and loss of life. Numerous tsunami reconnaissance trips were conducted in Japan (Tohoku Earthquake and Tsunami Joint Survey Group). This report focuses on the surveys at 9 tsunami eyewitness video recording locations in Yoriisohama, Kesennuma, Kamaishi and Miyako along Japan's Sanriku coast and the subsequent video image calibration, processing, tsunami hydrograph and flow velocity analysis. Selected tsunami video recording sites were visited, eyewitnesses interviewed and some ground control points recorded during the initial tsunami reconnaissance from April 9 to 25. A follow-up survey from June 9 to 15, 2011 focused on terrestrial laser scanning (TLS) at locations with previously identified high quality eyewitness videos. We acquired precise topographic data using TLS at nine video sites with multiple scans acquired from different instrument positions at each site. These ground-based LiDAR measurements produce a 3-dimensional "point cloud" dataset. Digital photography from a scanner-mounted camera yields photorealistic 3D images. Integrated GPS measurements allow accurate georeferencing of the TLS data in an absolute reference frame such as WGS84. We deployed a Riegl VZ-400 scanner (1550 nm wavelength laser, 42,000 measurements/second, visually identifiable ground control points measured in the LiDAR point cloud data. In a second step the video image motion induced by the panning of the video camera was determined from subsequent raw color images by means of planar particle image velocimetry (PIV) applied to fixed objects in the field of view. The third step involves the transformation of the raw tsunami video images from image coordinates to world coordinates. The mapping from video frame to real world coordinates follows the direct linear transformation (DLT) procedure (Holland et al., 1997). Finally, the tsunami surface current and flooding velocity vector maps are determined by applying the digital PIV analysis method to the rectified tsunami video images with floating debris clusters resulting in instantaneous tsunami velocity vector fields. Tsunami currents up to 10 m/s per second were measured in Kesennuma Bay making navigation impossible.

Fritz, H. M.; Phillips, D. A.; Okayasu, A.; Shimozono, T.; Liu, H.; Mohammed, F.; Skanavis, V.; Synolakis, C. E.; Takahashi, T.

2012-04-01

353

2011 Japan tsunami current and flow velocity measurements from survivor videos using LiDAR  

Science.gov (United States)

On March 11, 2011, a magnitude Mw 9.0 earthquake occurred off the coast of Japan's Tohoku region causing catastrophic damage and loss of life. Numerous tsunami reconnaissance trips were conducted in Japan (Tohoku Earthquake and Tsunami Joint Survey Group). This report focuses on the surveys at 9 tsunami eyewitness video recording locations in Yoriisohama, Kesennuma, Kamaishi and Miyako along Japan's Sanriku coast and the subsequent video image calibration, processing and tsunami flow velocity analysis. Selected tsunami video recording sites were visited, eyewitnesses interviewed and some ground control points recorded during the initial tsunami reconnaissance from April 9 to 25. A follow-up survey from June 9 to 15, 2011 focused on terrestrial laser scanning (TLS) at locations with previously identified high quality eyewitness videos. We acquired precise topographic data using TLS at nine video sites with multiple scans acquired from different instrument positions at each site. These ground-based LiDAR measurements produce a 3-dimensional "point cloud" dataset. Digital photography from a scanner-mounted camera yields photorealistic 3D images. Integrated GPS measurements allow accurate georeferencing of the TLS data in an absolute reference frame such as WGS84. We deployed a Riegl VZ-400 scanner (1550 nm wavelength laser, 42,000 measurements/second, visually identifiable ground control points measured in the LiDAR point cloud data. In a second step the video image motion induced by the panning of the video camera was determined from subsequent raw color images by means of planar particle image velocimetry (PIV) applied to fixed objects in the field of view. The third step involves the transformation of the raw tsunami video images from image coordinates to world coordinates. The mapping from video frame to real world coordinates follows the direct linear transformation (DLT) procedure (Holland et al., 1997). Finally, the tsunami surface current and flooding velocity vector maps are determined by applying the digital PIV analysis method to the rectified tsunami video images with floating debris clusters resulting in instantaneous tsunami velocity vector fields. Tsunami currents up to 10 m/s per second were measured in Kesennuma Bay making navigation impossible.

Fritz, H. M.; Phillips, D. A.; Okayasu, A.; Shimozono, T.; Liu, H.; Mohammed, F.; Skanavis, V.; Synolakis, C.; Takahashi, T.

2011-12-01

354

Object-Based Crop Species Classification Based on the Combination of Airborne Hyperspectral Images and LiDAR Data  

Directory of Open Access Journals (Sweden)

Full Text Available Identification of crop species is an important issue in agricultural management. In recent years, many studies have explored this topic using multi-spectral and hyperspectral remote sensing data. In this study, we perform dedicated research to propose a framework for mapping crop species by combining hyperspectral and Light Detection and Ranging (LiDAR data in an object-based image analysis (OBIA paradigm. The aims of this work were the following: (i to understand the performances of different spectral dimension-reduced features from hyperspectral data and their combination with LiDAR derived height information in image segmentation; (ii to understand what classification accuracies of crop species can be achieved by combining hyperspectral and LiDAR data in an OBIA paradigm, especially in regions that have fragmented agricultural landscape and complicated crop planting structure; and (iii to understand the contributions of the crop height that is derived from LiDAR data, as well as the geometric and textural features of image objects, to the crop species’ separabilities. The study region was an irrigated agricultural area in the central Heihe river basin, which is characterized by many crop species, complicated crop planting structures, and fragmented landscape. The airborne hyperspectral data acquired by the Compact Airborne Spectrographic Imager (CASI with a 1 m spatial resolution and the Canopy Height Model (CHM data derived from the LiDAR data acquired by the airborne Leica ALS70 LiDAR system were used for this study. The image segmentation accuracies of different feature combination schemes (very high-resolution imagery (VHR, VHR/CHM, and minimum noise fractional transformed data (MNF/CHM were evaluated and analyzed. The results showed that VHR/CHM outperformed the other two combination schemes with a segmentation accuracy of 84.8%. The object-based crop species classification results of different feature integrations indicated that incorporating the crop height information into the hyperspectral extracted features provided a substantial increase in the classification accuracy. The combination of MNF and CHM produced higher classification accuracy than the combination of VHR and CHM, and the solely MNF-based classification results. The textural and geometric features in the object-based classification could significantly improve the accuracy of the crop species classification. By using the proposed object-based classification framework, a crop species classification result with an overall accuracy of 90.33% and a kappa of 0.89 was achieved in our study area.

Xiaolong Liu

2015-01-01

355

Modelling Forest ?-Diversity and Floristic Composition — On the Added Value of LiDAR plus Hyperspectral Remote Sensing  

Directory of Open Access Journals (Sweden)

Full Text Available The decline of biodiversity is one of the major current global issues. Still, there is a widespread lack of information about the spatial distribution of individual species and biodiversity as a whole. Remote sensing techniques are increasingly used for biodiversity monitoring and especially the combination of LiDAR and hyperspectral data is expected to deliver valuable information. In this study spatial patterns of vascular plant community composition and alpha-diversity of a temperate montane forest in Germany were analysed for different forest strata. The predictive power of LiDAR (LiD and hyperspectral (MNF datasets alone and combined (MNF+LiD was compared using random forest regression in a ten-fold cross-validation scheme that included feature selection and model tuning. The final models were used for spatial predictions. Species richness could be predicted with varying accuracy (R2 = 0.26 to 0.55 depending on the forest layer. In contrast, community composition of the different layers, obtained by multivariate ordination, could in part be modelled with high accuracies for the first ordination axis (R2 = 0.39 to 0.78, but poor accuracies for the second axis (R2 ? 0.3. LiDAR variables were the best predictors for total species richness across all forest layers (R2 LiD = 0.3, R2 MNF = 0.08, R2 MNF+LiD = 0.2, while for community composition across all forest layers both hyperspectral and LiDAR predictors achieved similar performances (R2 LiD = 0.75, R2 MNF = 0.76, R2 MNF+LiD = 0.78. The improvement in R2 was small (?0.07—if any—when using both LiDAR and hyperspectral data as compared to using only the best single predictor set. This study shows the high potential of LiDAR and hyperspectral data for plant biodiversity modelling, but also calls for a critical evaluation of the added value of combining both with respect to acquisition costs.

Martin Wegmann

2012-09-01

356

Effects of the D1 Dopamine Receptor Agonist Dihydrexidine (DAR-0100A) on Working Memory in Schizotypal Personality Disorder.  

Science.gov (United States)

Pharmacological enhancement of prefrontal D1 dopamine receptor function remains a promising therapeutic approach to ameliorate schizophrenia-spectrum working memory deficits, but has yet to be rigorously evaluated clinically. This proof-of-principle study sought to determine whether the active enantiomer of the selective and full D1 receptor agonist dihydrexidine (DAR-0100A) could attenuate working memory impairments in unmedicated patients with schizotypal personality disorder (SPD). We performed a randomized, double-blind, placebo-controlled trial of DAR-0100A (15?mg/150?ml of normal saline administered intravenously over 30?min) in medication-free patients with SPD (n=16) who met the criteria for cognitive impairment (ie, scoring below the 25th percentile on tests of working memory). We employed two measures of verbal working memory that are salient to schizophrenia-spectrum cognitive deficits, and that clinical data implicate as being associated with prefrontal D1 availability: (1) the Paced Auditory Serial Addition Test (PASAT); and (2) the N-back test (ratio of 2-back:0-back scores). Study procedures occurred over four consecutive days, with working memory testing on Days 1 and 4, and DAR-0100A/placebo administration on Days 2-4. Treatment with DAR-0100A was associated with significantly improved PASAT performance relative to placebo, with a very large effect size (Cohen's d=1.14). Performance on the N-back ratio was also significantly improved; however, this effect rested on both a non-significant enhancement and diminution of 2-back and 0-back performance, respectively; therefore interpretation of this finding is more complicated. DAR-0100A was generally well tolerated, with no serious medical or psychiatric adverse events; common side effects were mild to moderate and transient, consisting mainly of sedation, lightheadedness, tachycardia, and hypotension; however, we were able to minimize these effects, without altering the dose, with supportive measures, eg, co-administered normal saline. Although preliminary, these findings lend further clinical support to the potential of D1 receptor agonists to treat schizophrenia-spectrum working memory impairments. These data suggest a need for further studies with larger group sizes, serum DAR-0100A levels, and a more comprehensive neuropsychological battery. PMID:25074637

Rosell, Daniel R; Zaluda, Lauren C; McClure, Margaret M; Perez-Rodriguez, M Mercedes; Strike, K Sloan; Barch, Deanna M; Harvey, Philip D; Girgis, Ragy R; Hazlett, Erin A; Mailman, Richard B; Abi-Dargham, Anissa; Lieberman, Jeffrey A; Siever, Larry J

2015-01-01

357

Contrasting Patterns of Damage and Recovery in Logged Amazon Forests From Small Footprint LiDAR Data  

Science.gov (United States)

Tropical forests ecosystems respond dynamically to climate variability and disturbances on time scales of minutes to millennia. To date, our knowledge of disturbance and recovery processes in tropical forests is derived almost exclusively from networks of forest inventory plots. These plots typically sample small areas (less than or equal to 1 ha) in conservation units that are protected from logging and fire. Amazon forests with frequent disturbances from human activity remain under-studied. Ongoing negotiations on REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus enhancing forest carbon stocks) have placed additional emphasis on identifying degraded forests and quantifying changing carbon stocks in both degraded and intact tropical forests. We evaluated patterns of forest disturbance and recovery at four -1000 ha sites in the Brazilian Amazon using small footprint LiDAR data and coincident field measurements. Large area coverage with airborne LiDAR data in 2011-2012 included logged and unmanaged areas in Cotriguacu (Mato Grosso), Fiona do Jamari (Rondonia), and Floresta Estadual do Antimary (Acre), and unmanaged forest within Reserva Ducke (Amazonas). Logging infrastructure (skid trails, log decks, and roads) was identified using LiDAR returns from understory vegetation and validated based on field data. At each logged site, canopy gaps from logging activity and LiDAR metrics of canopy heights were used to quantify differences in forest structure between logged and unlogged areas. Contrasting patterns of harvesting operations and canopy damages at the three logged sites reflect different levels of pre-harvest planning (i.e., informal logging compared to state or national logging concessions), harvest intensity, and site conditions. Finally, we used multi-temporal LiDAR data from two sites, Reserva Ducke (2009, 2012) and Antimary (2010, 2011), to evaluate gap phase dynamics in unmanaged forest areas. The rates and patterns of canopy gap formation at these sites illustrate potential issues for separating logging damages from natural forest disturbances over longer time scales. Multi-temporal airborne LiDAR data and coincident field measurements provide complementary perspectives on disturbance and recovery processes in intact and degraded Amazon forests. Compared to forest inventory plots, the large size of each individual site permitted analyses of landscape-scale processes that would require extremely high investments to study using traditional forest inventory methods.

Morton, D. C.; Keller, M.; Cook, B. D.; Hunter, Maria; Sales, Marcio; Spinelli, L.; Victoria, D.; Andersen, H.-E.; Saleska, S.

2012-01-01

358

Genomic characterization of DArT markers based on high-density linkage analysis and physical mapping to the Eucalyptus genome  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Diversity Arrays Technology (DArT) provides a robust, high throughput, cost-effective method to query thousands of sequence polymorphisms in a single assay. Despite the extensive use of this genotyping platform for numerous plant species, little is known regarding the sequence attributes and genome-wide distribution of DArT markers. We investigated the genomic properties of the 7,680 DArT marker probes of a Eucalyptus array, by sequencing them, constructing a high density linkage map and carr...

Petroli, Cesar D.; Sansaloni, Carolina P.; Carling, Jason; Steane, Dorothy A.; Vaillancourt, Rene E.; Myburg, Alexander Andrew; Da Silva Jr, Orzenil Bonfim; Pappas Jr, Georgios Joannis; Kilian, Andrzej; Grattapaglia, Dario

2012-01-01

359

Achieving Accuracy Requirements for Forest Biomass Mapping: A Data Fusion Method for Estimating Forest Biomass and LiDAR Sampling Error with Spaceborne Data  

Science.gov (United States)

The synergistic use of active and passive remote sensing (i.e., data fusion) demonstrates the ability of spaceborne light detection and ranging (LiDAR), synthetic aperture radar (SAR) and multispectral imagery for achieving the accuracy requirements of a global forest biomass mapping mission. This data fusion approach also provides a means to extend 3D information from discrete spaceborne LiDAR measurements of forest structure across scales much larger than that of the LiDAR footprint. For estimating biomass, these measurements mix a number of errors including those associated with LiDAR footprint sampling over regional - global extents. A general framework for mapping above ground live forest biomass (AGB) with a data fusion approach is presented and verified using data from NASA field campaigns near Howland, ME, USA, to assess AGB and LiDAR sampling errors across a regionally representative landscape. We combined SAR and Landsat-derived optical (passive optical) image data to identify forest patches, and used image and simulated spaceborne LiDAR data to compute AGB and estimate LiDAR sampling error for forest patches and 100m, 250m, 500m, and 1km grid cells. Forest patches were delineated with Landsat-derived data and airborne SAR imagery, and simulated spaceborne LiDAR (SSL) data were derived from orbit and cloud cover simulations and airborne data from NASA's Laser Vegetation Imaging Sensor (L VIS). At both the patch and grid scales, we evaluated differences in AGB estimation and sampling error from the combined use of LiDAR with both SAR and passive optical and with either SAR or passive optical alone. This data fusion approach demonstrates that incorporating forest patches into the AGB mapping framework can provide sub-grid forest information for coarser grid-level AGB reporting, and that combining simulated spaceborne LiDAR with SAR and passive optical data are most useful for estimating AGB when measurements from LiDAR are limited because they minimized forest AGB sampling errors by 15 - 38%. Furthermore, spaceborne global scale accuracy requirements were achieved. At least 80% of the grid cells at 100m, 250m, 500m, and 1km grid levels met AGB density accuracy requirements using a combination of passive optical and SAR along with machine learning methods to predict vegetation structure metrics for forested areas without LiDAR samples. Finally, using either passive optical or SAR, accuracy requirements were met at the 500m and 250m grid level, respectively.

Montesano, P. M.; Cook, B. D.; Sun, G.; Simard, M.; Zhang, Z.; Nelson, R. F.; Ranson, K. J.; Lutchke, S.; Blair, J. B.

2012-01-01

360

Enfermedad de Alzheimer: ¿Es posible la prevención?  

Directory of Open Access Journals (Sweden)

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

 
 
 
 
361

ES FUNDAMENTAL LA HERMENÉUTICA / Is Hermeneutics Fundamental  

Scientific Electronic Library Online (English)

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

EMMANUEL, FALQUE.

2013-08-01

362

Investigating sediment budgets and pathways using LiDAR DEMs of difference and a geomorphological map  

Science.gov (United States)

In alpine catchments sediment is moved from one landform to another as long as they are coupled by the activity of geomorphic processes. The spatial and functional interaction of these processes forms sediment cascades reaching from sediment sources or stores to sediment sinks, and ultimately to the catchment outlet. In study presented here, multitemporal high-resolution LiDAR datasets are used to establish morphological sediment budgets. These can be calculated on the raster cell scale, i.e. by differencing digital elevation models (DEM), and on the landform scale, by establishing the net balance of eroded and accumulated material; in the latter case, the spatial unit is a polygon identifying a particular landform on a detailed geomorphological map. The flow of mobilised sediment can be estimated on a DEM using a variety of flow routing algorithms, and the net balance (sediment eroded - sediment deposited) is accumulated along specific pathways. The results of landform-based sediment budgets can be used to validate the flow routing algorithms and to assess functional connectivity between landforms that are arranged along a toposequence. Graph theory is used to store and investigate resulting sediment pathways on different aggregation levels. The incorporation of the geomorphological map highlights potential advantages of object-based over pixel-based approaches to generating graph nodes and analysing sediment cascades.

Hilger, Ludwig; Becht, Michael; Heckmann, Tobias

2014-05-01

363

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

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Genomic discovery in oat and its application to oat improvement have been hindered by a lack of genetic markers common to different genetic maps, and by the difficulty of conducting whole-genome analysis using high-throughput markers. This study was intended to develop, characterize, and apply a large set of oat genetic markers based on Diversity Array Technology (DArT. Results Approximately 19,000 genomic clones were isolated from complexity-reduced genomic representations of pooled DNA samples from 60 oat varieties of global origin. These were screened on three discovery arrays, with more than 2000 polymorphic markers being identified for use in this study, and approximately 2700 potentially polymorphic markers being identified for use in future studies. DNA sequence was obtained for 2573 clones and assembled into a non-redundant set of 1770 contigs and singletons. Of these, 705 showed highly significant (Expectation vs. winter type, and to the presence of major breeding programs within geographical regions. Secondary clusters revealed groups that were often related to known pedigree structure. Conclusion These markers will provide a solid basis for future efforts in genomic discovery, comparative mapping, and the generation of an oat consensus map. They will also provide new opportunities for directed breeding of superior oat varieties, and guidance in the maintenance of oat genetic diversity.

Ohm Herbert W

2009-01-01

364

Taking Stock of Circumboreal Forest Carbon With Ground Measurements, Airborne and Spaceborne LiDAR  

Science.gov (United States)

The boreal forest accounts for one-third of global forests, but remains largely inaccessible to ground-based measurements and monitoring. It contains large quantities of carbon in its vegetation and soils, and research suggests that it will be subject to increasingly severe climate-driven disturbance. We employ a suite of ground-, airborne- and space-based measurement techniques to derive the first satellite LiDAR-based estimates of aboveground carbon for the entire circumboreal forest biome. Incorporating these inventory techniques with uncertainty analysis, we estimate total aboveground carbon of 38 +/- 3.1 Pg. This boreal forest carbon is mostly concentrated from 50 to 55degN in eastern Canada and from 55 to 60degN in eastern Eurasia. Both of these regions are expected to warm >3 C by 2100, and monitoring the effects of warming on these stocks is important to understanding its future carbon balance. Our maps establish a baseline for future quantification of ci