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1

Challenges in diagnosing paediatric malaria in Dar es Salaam, Tanzania.  

UK PubMed Central (United Kingdom)

BACKGROUND: Malaria is a major cause of paediatric morbidity and mortality. As no clinical features clearly differentiate malaria from other febrile illnesses, and malaria diagnosis is challenged by often lacking laboratory equipment and expertise, overdiagnosis and overtreatment is common. METHODS: Children admitted with fever at the general paediatric wards at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania from January to June 2009 were recruited consecutively and prospectively. Demographic and clinical features were registered. Routine thick blood smear microscopy at MNH was compared to results of subsequent thin blood smear microscopy, and rapid diagnostics tests (RDTs). Genus-specific PCR of Plasmodium mitochondrial DNA was performed on DNA extracted from whole blood and species-specific PCR was done on positive samples. RESULTS: Among 304 included children, 62.6% had received anti-malarials during the last four weeks prior to admission and 65.1% during the hospital stay. Routine thick blood smears, research blood smears, PCR and RDT detected malaria in 13.2%, 6.6%, 25.0% and 13.5%, respectively. Positive routine microscopy was confirmed in only 43% (17/40), 45% (18/40) and 53% (21/40), by research microscopy, RDTs and PCR, respectively. Eighteen percent (56/304) had positive PCR but negative research microscopy. Reported low parasitaemia on routine microscopy was associated with negative research blood slide and PCR. RDT-positive cases were associated with signs of severe malaria. Palmar pallor, low haemoglobin and low platelet count were significantly associated with positive PCR, research microscopy and RDT. CONCLUSIONS: The true morbidity attributable to malaria in the study population remains uncertain due to the discrepancies in results among the diagnostic methods. The current routine microscopy appears to result in overdiagnosis of malaria and, consequently, overuse of anti-malarials. Conversely, children with a false positive malaria diagnosis may die because they do not receive treatment for the true cause of their illness. RDTs appear to have the potential to improve routine diagnostics, but the clinical implication of the many RDT-negative, PCR-positive samples needs to be elucidated.

Strøm GE; Haanshuus CG; Fataki M; Langeland N; Blomberg B

2013-01-01

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Elemental contents in hair of children from two regions in dar es salaam.  

UK PubMed Central (United Kingdom)

The work presented in this paper is part of the study which aims at determining the levels of elements in hair of children in Tanzania as a bioindicator of their nutrition and health. In this paper, the levels of trace elements in hair from children living in Dar es Salaam have been analysed. The analysis was carried out by long and short irradiation INAA at the reactor centre of the Institute of Nuclear Physics, Rez Czech Republic. 22 samples were collected from children living at Kiwalani about 12 km from Dar es Salaam city and 16 samples from children living at Mlimani, the main campus of University of Dar es Salaam. A total of 34 elements were found in the hair of the children. There were no big differences between the concentration levels of the essential elements in hair samples collected from the children which might indicate the same food consumption habits.

Mohammed NK

2012-01-01

3

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Robert B. Kiunsi

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ind...

Rasch, Vibeke; Massawe, Siriel; Yambesi, Fortunata; Bergstrom, Staffan

5

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

International Nuclear Information System (INIS)

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

2005-01-01

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Clinical and bacteriological studies in otitis externa in Dar es Salaam, Tanzania.  

UK PubMed Central (United Kingdom)

The symptoms and signs as well as the bacterial flora from the auditory canals of 54 Tanzanian patients (74 ears) living in Dar es Salaam and suffering from otitis externa were studied. Itching and pain were the most common symptoms and erythema and secretion were the prevalent clinical findings. Pseudomonas aeruginosa was found in 38%, Aspergillus in 24%, Staphylococcus aureus in 18% and Candida albicans in 14%. Bacterial cultures from the auditory canals of 21 healthy subjects revealed only normal skin flora.

Manni JJ; Kuylen K

1984-12-01

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SWOT ANALYSIS OF GROWTH OF WOMEN ENTREPRENEURS IN DAR ES SALAAM  

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Full Text Available With limited data and information, this paper aims to examine the growth of women entrepreneurs in Dar es Salaam city Tanzania on strengths, weakness, opportunities and threats. Well-functioning business sectors are crucial driving forces for economic growth. In developing countries, entrepreneurship can function as a tool to fight poverty as well as to strengthen the growth of women entrepreneurs in Tanzania. This study used the sample size of 130 women entrepreneurs from the three districts in Dar es Salaam city; Simple random sampling was used in sampling the women entrepreneurs in Dar es Salaam city in Tanzania. A descriptive statistics analysis was made, comprising the generation of mean and standard deviation. SPSSv16.0 software was used to generate the mean and standard deviation. The findings however reflected as, a major strength was the need for financial independence is an attractive feature to women entrepreneurs. The major opportunity was the desire to own boss leads to women entrepreneurship. The weakness was most women lack entrepreneurs fail because they lack of education and the major threat was most women entrepreneurs have pressure of child care in the family.

Masese Chuma Benard; Kebande Rigworo Victor

2013-01-01

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

Science.gov (United States)

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

Ndetto, Emmanuel L.; Matzarakis, Andreas

2013-01-01

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

Science.gov (United States)

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

Ndetto, Emmanuel L.; Matzarakis, Andreas

2013-10-01

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

Science.gov (United States)

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

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

2013-04-01

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 soci...

Rasch, V; Silberschmidt, Margrethe; Mchumvu, Y; Mmary, V

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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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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 w...

Lutale, Janet Joy Kachuchuru; Thordarson, Hrafnkell; Abbas, Zulfiqarali Gulam; Vetvik, Kåre

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 feature...

Lutale, Janet Joy Kachuchuru; Thordarson, Hrafnkell; Abbas, Zulfiqarali Gulam; Vetvik, Kåre

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Urban household perceptions and energy use, dar es Salaam, Tanzania. Memorandum report  

Energy Technology Data Exchange (ETDEWEB)

The report contains the results of a three-week survey of household energy behavior and energy perception in Dar es Salaam, Tanzania, conducted from 12 March to 2 April, 1991, with the objective of identifying the main variables in household energy behavior (defined broadly to include cooking stoves and fuel choices, cooking habits, food preparation, cooking space, etc.) and household attributes that are relevant to understanding energy behavior (e.g. household budgeting and gender roles). The purpose was to look specifically at household-level decisions on energy use, that is, to put energy use in a specific cultural context and to understand both what these households are (how they are constituted and organized) and the social context in which all resource-related decisions including energy are taken.

Campbell, J.R.

1992-01-01

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

DEFF Research Database (Denmark)

In many developing countries, the market is still the most important source of commerce for traders and provisions for the general public. The transmission of disease in the market place involves factors relating to the host, the agent and the environment. This study examines the quality of solid waste management in Kariakoo market, Dar es Salaam. The main problems identified were poor market design and lack of a well organized waste storage, collection and disposal systems. Two-thirds of the waste consists of vegetable matter. Proposals for improved design of storage and collection facilities are described. Experiments revealed wastes from the market are readily decomposable by composting. A change in the design of covered markets and improvements in waste handling are essential to reduce the potential health hazards in developing countries.

Yhdego, Michael

1992-01-01

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

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

Wang Shr-Jie; Lengeler Christian; Mtasiwa Deodatus; Mshana Thomas; Manane Lusinge; Maro Godson; Tanner Marcel

2006-01-01

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Informal urban settlements and cholera risk in Dar es Salaam, Tanzania.  

UK PubMed Central (United Kingdom)

BACKGROUND: As a result of poor economic opportunities and an increasing shortage of affordable housing, much of the spatial growth in many of the world's fastest-growing cities is a result of the expansion of informal settlements where residents live without security of tenure and with limited access to basic infrastructure. Although inadequate water and sanitation facilities, crowding and other poor living conditions can have a significant impact on the spread of infectious diseases, analyses relating these diseases to ongoing global urbanization, especially at the neighborhood and household level in informal settlements, have been infrequent. To begin to address this deficiency, we analyzed urban environmental data and the burden of cholera in Dar es Salaam, Tanzania. METHODOLOGY/PRINCIPAL FINDINGS: Cholera incidence was examined in relation to the percentage of a ward's residents who were informal, the percentage of a ward's informal residents without an improved water source, the percentage of a ward's informal residents without improved sanitation, distance to the nearest cholera treatment facility, population density, median asset index score in informal areas, and presence or absence of major roads. We found that cholera incidence was most closely associated with informal housing, population density, and the income level of informal residents. Using data available in this study, our model would suggest nearly a one percent increase in cholera incidence for every percentage point increase in informal residents, approximately a two percent increase in cholera incidence for every increase in population density of 1000 people per km(2) in Dar es Salaam in 2006, and close to a fifty percent decrease in cholera incidence in wards where informal residents had minimally improved income levels, as measured by ownership of a radio or CD player on average, in comparison to wards where informal residents did not own any items about which they were asked. In this study, the range of access to improved sanitation and improved water sources was quite narrow at the ward level, limiting our ability to discern relationships between these variables and cholera incidence. Analysis at the individual household level for these variables would be of interest. CONCLUSIONS/SIGNIFICANCE: Our results suggest that ongoing global urbanization coupled with urban poverty will be associated with increased risks for certain infectious diseases, such as cholera, underscoring the need for improved infrastructure and planning as the world's urban population continues to expand.

Penrose K; de Castro MC; Werema J; Ryan ET

2010-01-01

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Environmental Burden of Charcoal Production and Use in Dar es Salaam, Tanzania  

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Full Text Available Tanzanian forests are excessively threatened by increased charcoal production fuelled by increased demand crucially in Dar es Salaam city which consumes nearly 70% of all the charcoal produced in the country. Through use of ecological modeling software STELLA® the environmental burden of charcoal production and use in Tanzania has been established. The study has revealed that the country losses 150,433 ha of forest per year. Due to increase in population by year 2030 almost 2.8 million ha of forests will have been lost. This is equivalent to 8.5% of the total forest cover the country had in 2009. The environmental burden includes air pollution characterized by a total emission of 49, 1.0, and 9.0, 12 million tonnes of CO2, SO2, NOx, and CH4, respectively by 2030. Other adverse impacts include loss of forest cover which ultimately causes degradation of soil quality by increased soil erosion, degradation of water sources and disruption of rainfall pattern including inducing draught. Taking into account that the agriculture in Tanzania is primarily rain fed, this has an adverse impact in agricultural production. In the current exploitation of this important natural resource, its sustainability is severely challenged and the whole concept of the forest being renewable is put into question. From these findings, it is recommended that concrete and deliberate efforts be made to reduce and eventually prohibit the use of charcoal in cities and towns.

Neema Msuya; Enock Masanja; Abrahamu Kimangano Temu

2011-01-01

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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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Determinants of anemia in postpartum HIV-negative women in Dar es Salaam, Tanzania.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The determinants of anemia during both pregnancy and postpartum recovery remain incompletely understood in sub-Saharan African women. SUBJECTS/METHODS: In a prospective cohort study among pregnant women, we assessed dietary, biochemical, anthropometric, infectious and sociodemographic factors at baseline. In multivariate Cox proportional hazards models, we examined predictors of incident anemia (hemoglobin <11?g/dl) and iron deficiency anemia (anemia plus mean corpuscular volume <80fL), and recovery from anemia and iron deficiency anemia through 18 months postpartum at antenatal clinics in Dar es Salaam, Tanzania between 2001 and 2005. A total of 2364 non-anemic pregnant women and 4884 anemic women were enrolled between 12 and 27 weeks of gestation. RESULTS: In total, 292 women developed anemia during the postpartum period and 165 developed iron deficiency anemia, whereas 2982 recovered from baseline anemia and 2044 from iron deficiency anemia. Risk factors for postpartum anemia were delivery complications (RR 1.6, 95% confidence interval (CI) 1.13, 2.22) and low postpartum CD4 cell count (RR 1.73, 95% CI 0.96, 3.17). Iron/folate supplementation during pregnancy had a protective relationship with the incidence of iron deficiency anemia. Absence of delivery complications, education status and iron/folate supplementation were positively associated with time to recovery from iron deficiency. CONCLUSION: Maternal nutritional status during pregnancy, prenatal iron/folate supplementation, perinatal care, and prevention and management of infections, such as malaria, are modifiable risk factors for the occurrence of, and recovery from, anemia.

Petraro P; Duggan C; Urassa W; Msamanga G; Makubi A; Spiegelman D; Fawzi WW

2013-07-01

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

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

Nyamtema Angelo S; Urassa David P; Pembe Andrea B; Kisanga Felix; van Roosmalen Jos

2010-01-01

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

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

Panya Millembe F; Mgonda Yassin M; Massawe Augustine W

2009-01-01

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

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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.

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

2007-01-01

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Capillary haemangioma successfully treated with oral beta-blocker in Dar es Salaam, Tanzania: a case report.  

UK PubMed Central (United Kingdom)

Capillary haemangiomas are the most common orbital and periocular tumors in children, typically presenting in infancy. Propranolol has recently been introduced as a novel pharmacologic treatment for infantile haemangiomas, after Leaute-Labreze and colleagues observed that two patients being treated for cardiac indications had rapid regression of their haemangiomas. We report a case of haemangioma, successfully treated with oral beta-blocker, in the context of a public eye clinic in Dar es Salaam, Tanzania. To the best of our knowledge, this is the first recorded instance of a capillary haemangioma being successfully treated with a systemic beta-blocker in Tanzania.

Cloke A; Lim LT; Blaikie A

2013-01-01

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

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

Kahesa Crispin; Kjaer Susanne; Ngoma Twalib; Mwaiselage Julius; Dartell Myassa; Iftner Thomas; Rasch Vibeke

2012-01-01

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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.

Urassa Willy; Mugusi Ferdinand; Villamor Eduardo; Msamanga Gernard; Moshiro Candida; Bosch Ronald; Saathoff Elmar; Fawzi Wafaie

2008-01-01

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Neuropathology of human immunodeficiency virus 1 infection. Significance of studying in forensic autopsy cases at Dar es Salaam, Tanzania.  

UK PubMed Central (United Kingdom)

OBJECTIVE: In sub-Saharan Africa, only a few studies of neurologic complications of human immunodeficiency virus 1 (HIV-1) infection have been done. The authors studied neuropathology of HIV-1 infection in Tanzania. DESIGN: Forensic autopsy study at Dar es Salaam, Tanzania. SETTING: A joint research project between Dar es Salaam, Tanzania, and Kumamoto, Japan. PATIENTS: Thirty patients with risk factors for HIV-1 infection. MAIN OUTCOME MEASURES: Human immunodeficiency virus 1 infection was evaluated by HIV-1 antibody test on postmortem serum samples. The brains of HIV-1-infected persons were studied histopathologically. RESULTS: Infection with HIV-1 was identified on postmortem serum samples in 10 of 30 forensic autopsy cases. Neuropathologic changes of the brain were observed in 8 of the 10 HIV-1-infected persons; these changes consisted of lymphocytic meningitis, bacterial meningoencephalitis, cryptococcal meningoencephalitis, tuberculous meningitis with brain abscesses, and intracerebral hemorrhage. CONCLUSIONS: Because none of the persons studied was suspected to have had brain diseases before autopsy, the results suggest that brain diseases of HIV-1-infected patients are likely to go unrecognized in Tanzania. In addition, the high incidence of neuropathologic findings in HIV-1-infected persons indicates that HIV-1-related brain diseases are common in Tanzania, as they are in developed countries. Further forensic autopsy study will determine the range and prevalence of brain complications and have immediate impact on the management of HIV-1-infected patients in Tanzania and other developing countries.

Kibayashi K; Ng'walali PM; Mbonde MP; Makata AM; Mwakagile D; Harada S; Kitinya JN; Tsunenari S

1999-06-01

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

UK PubMed Central (United Kingdom)

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

Kahama-Maro J; D'Acremont V; Mtasiwa D; Genton B; Lengeler C

2011-01-01

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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; Poudel Krishna C; Sunguya Bruno F; Mbwambo Jessie K K; Yasuoka Junko; Otsuka Keiko; Ubuguyu Omary; Jimba Masamine

2012-01-01

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Living in a peri-urban area as part of a livelihood strategy : The case of Mbezi Luisi, Dar es Salaam  

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The aim of this study is to analyze the choice of living in a peri-urban area as part of a livelihood strategy. The method used for collection of primary data for the study was in-depth interviews and questionnaires, undertaken with residents of Mbezi Luisi, a peri-urban area in Dar es Salaam. In or...

Fagerlund, Alexander

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Heavy metal levels in the sediments of four Dar es Salaam mangroves: accumulation in, and effect on the morphology of the periwinkle, Littoraria scabra (Mollusca: Gastropoda)  

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Heavy metals were determined in the soft tissue and shells of the littorinid, Littoraria scabra, and in the sediments of four mangrove areas along the Dar es Salaam coastline where L. scabra was collected. Several metals accumulate, preferentially in the animals' soft body parts, but d...

De Wolf, H.; Ulomi, S.A.; Backeljau, T.; Pratap, H.B.; Blust, R.

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

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The aim of the present study was to assess the occurrence of glutamic acid decarboxylase autoantibodies (GADA) and insulinoma antigen 2 autoantibodies (IA2A) among patients of African origin in Dar es Salaam, Tanzania and to compare the occurrence of autoimmune mediated Type 1 diabetes w...

Lutale, Janet Joy Kachuchuru; Thordarson, Hrafnkell; Holm, Pål Ivar; Eide, Geir Egil; Vetvik, Kåre

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

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Background: The aim of the present study was to assess the occurrence of glutamic acid decarboxylase autoantibodies (GADA) and insulinoma antigen 2 autoantibodies (IA2A) among patients of African origin in Dar es Salaam, Tanzania and to compare the occurrence of autoimmune mediated Type 1 diabetes w...

Lutale, Janet Joy Kachuchuru; Thordarson, Hrafnkell; Holm, Pål Ivar; Eide, Geir Egil; Vetvik, Kåre

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

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

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

2011-01-01

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

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

Kahama-Maro Judith; D'Acremont Valerie; Mtasiwa Deo; Genton Blaise; Lengeler Christian

2011-01-01

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

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

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

2013-04-01

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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; Silumbe R

2013-01-01

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

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

Moyo Sabrina J; Gro Njolstad; Kirsti Vainio; Matee Mecky I; Kitundu Jesse; Maselle Samwel Y; Langeland Nina; Myrmel Helge

2007-01-01

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

UK PubMed Central (United Kingdom)

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

Tarimo EA; Kohi TW; Bakari M; Kulane A

2013-08-01

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

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

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

2013-04-01

 
 
 
 
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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.

Moyo Sabrina J; Gro Njolstad; Matee Mecky I; Kitundu Jesse; Myrmel Helge; Mylvaganam Haima; Maselle Samuel Y; Langeland Nina

2011-01-01

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

UK PubMed Central (United Kingdom)

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 < 0.001, among respondents with high socio-economic status (29.2%) as compared to those with medium (14.3%) and low socio-economic status (11.3%), p value for trend < 0.001, and among respondents with light intensity activities (26.0%), p value for trend < 0.001. 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.

Shayo GA; Mugusi FM

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.

Shayo Grace A; Mugusi Ferdinand M

2011-01-01

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Not at all so hard-to-reach: same-sex attracted men in Dar es Salaam.  

UK PubMed Central (United Kingdom)

Based on research in Tanzania, this paper critically examines the widely circulating notion that African same-sex attracted men are hard-to-reach individuals and populations. Despite expectations to the contrary, it was neither time consuming nor difficult to identify and get to know same-sex attracted men in Dar es Salaam. On the contrary, a large and diverse group of such men could readily be encountered, befriended and involved in HIV-related research. The fieldwork was characterised by communicative openness and the researcher was treated with immense kindliness, hospitality and inclusivity. While we may not be in a position to say that the situation is identical everywhere else, we find reason to caution against accepting and propagating unexplained, unexamined and unverified claims to the effect that same-sex attracted men in Africa cannot be reached. We argue that such claims contribute to stigmatise same-sex attracted men and to hinder much-needed HIV-related research and programming.

Moen K; Aggleton P; Leshabari MT; Middelthon AL

2012-01-01

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Organochlorine pesticide residues in sediments and biota from the coastal area of Dar es Salaam city, Tanzania.  

UK PubMed Central (United Kingdom)

Sediment and biota samples were collected from Msimbazi and Kizinga rivers and from the coastal marine environment of Dar es Salaam during both dry and wet seasons. The samples were analyzed for various organochlorine pesticide residues using GC-ECD and GC-MS. Dieldrin, p,p'-DDT, p,p'-DDE, p,p'-DDD, o,p'-DDT and y-HCH were detected at significantly greater concentrations above the method detection limits. Recoveries of pesticide residues ranged 86.5-120% in sediments and 62-102% in biota. The average concentrations of total DDT in sediments for the two seasons were almost the same. Biota samples showed significant difference in levels of residues depending on mode of feeding and age of analyzed biota. p,p'-DDT to total DDT ratios in all matrices indicated recent use of DDT. The levels of residues in sediments suggest possible adverse effects to humans consuming biota that are directly exposed to the sediments. This effect, which is associated with bio-concentration of residues in the tissues of edible aquatic biota, should not affect wildlife. In spite of concern on the adverse effect to humans posed by pesticide residues in sediments, edible biota from the examined water bodies were found to be safe for human consumption.

Mwevura H; Othman OC; Mhehe GL

2002-01-01

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Intimate partner violence and the association with HIV risk behaviors among young men in Dar es Salaam, Tanzania.  

UK PubMed Central (United Kingdom)

There is growing evidence of the association between gender-based violence and HIV from the perspective and experiences of women. The purpose of this study is to examine these associations from the perspective of young men living in Dar es Salaam, Tanzania. A community-based sample of 951 men were interviewed, of whom 360 had sex in the past 6 months and were included in these analyses. Almost a third of the men (29.2%) reported that they had been physically violent at least once with an intimate partner. Men who reported more lifetime sexual partners (OR = 8.75; 95% CI = 2.65, 28.92), experienced physical violence as a child at home (OR = 1.73; 95% CI = 1.09, 2.76), and were more educated (OR = 1.91; 95% CI = 1.18, 3.11) were significantly more likely to report perpetrating violence. These associations persisted after adjusting for other variables. These data from the perspective of young men reinforce earlier findings from women that HIV risk and violence are occurring together in relationships of young adults. Interventions are needed to identify men at high risk for HIV and engage them in interventions that are designed to change norms and behaviors related to power and control with their sexual partners.

Maman S; Yamanis T; Kouyoumdjian F; Watt M; Mbwambo J

2010-10-01

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

UK PubMed Central (United Kingdom)

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

Pickering AJ; Boehm AB; Mwanjali M; Davis J

2010-02-01

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

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

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

2009-01-01

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

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

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

2009-01-01

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

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Full Text Available 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 results 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 bacte (more) ria 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.

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

2010-12-01

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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; John Lupala; Shaaban Sheuya

2012-01-01

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

UK PubMed Central (United Kingdom)

A study of community awareness of mosquitos and related subjects in the residential areas of two Tanzanian cities (Dar es Salaam and Tanga) showed that residents were well aware of mosquitos. Almost all claimed to use some form of domestic mosquito control product for their personal protection, and many spend a significant portion of the household income on this. The problems of nuisance-biting and malaria transmission are usually not separated and are considered to be the result of poor environmental hygiene, for which both residents and local authorities are responsible. Although Culex mosquitos are not a primary target of the Urban Malaria Control Project (UMCP), the persistence of nuisance-biting has made residents sceptical and dissatisfied with insecticide spraying. The residents' priorities are evidently not the same as those of the health authorities, yet mutual cooperation is essential. In order to maintain community support, campaigns aimed at malaria vectors should consider the need for additional measures to control Culex mosquitos, such as those now being tried by the UMCP. Mosquito breeding sites are non-specifically associated with rubbish and standing water of all kinds, and so the actions that the community considers necessary for mosquito source reduction tend to be poorly targeted. Residents do not recognize that some sources produce malaria mosquitos while others produce nuisance mosquitos. The environmental anti-mosquito measures currently promoted by health education and other forms of propaganda are also poorly targeted. While some of them are directed at important Culex breeding sites, others are aimed at sites of little importance for mosquitos of any kind.(ABSTRACT TRUNCATED AT 250 WORDS)

Stephens C; Masamu ET; Kiama MG; Keto AJ; Kinenekejo M; Ichimori K; Lines J

1995-01-01

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

UK PubMed Central (United Kingdom)

BACKGROUND: 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.

Kamuhabwa AA; Silumbe R

2013-01-01

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Elemental and ionic components of atmospheric aerosols and associated gaseous pollutants in and near Dar es Salaam, Tanzania  

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Elemental and water-soluble ionic compounds (WSICs) of atmospheric aerosols (total suspended particulate – TSP) and some gaseous pollutants (SO2, NO2 and O3) from a coastal, semi-urban and rural site in and near Dar es Salaam, Tanzania were investigated during dry and wet seasons of January 2005–November 2007. Na+, Ca2+, SO42?, NO3? and Cl? made up the dominant fraction of WSICs during the dry season with average concentrations ranging from non-detectable (n.d.)–5.4, 0.26–2.6, 0.74–14.7, 0.4–1.5 and 1.1–3.4 ?g m?3, respectively, while in the wet season, from n.d. up to 1.7, 1.2, 4.4, 2.1 and 3.0 ?g m?3, respectively. The total air concentrations of the detected elements (Al, Si, S, Cl, K, Ca, Fe and Zn) showed seasonal and site-specific variation in the range of 7.5–26.6 with an average of 14.5 ?g m?3. Most of the air concentrations of pollutants were observed to decrease with increasing distance from the coastal site, which is under urban and industrial pollutant emissions. Sulphur and nitrogen oxidation ratios during the dry season ranged from 0.08 to 0.91 and 0.013 to 0.049, respectively, while they were between 0.09–0.65 and 0.002–0.095, respectively, in the wet season. These values indicate the photochemical oxidation of SO2 and a high extent of NO3?formation in the atmosphere. Neutralization ratios revealed the presence of acidic SO42? and NO3? aerosols. Principal component analysis identified sea spray, local combustion, vehicular traffic, biomass burning and re-suspended road dust as dominant sources of aerosols at the studied coastal and semi-urban sites. However, at the rural site, besides sea spray, crustal sources, soil dust re-suspension and long-range transport are the possible origins of suspended particulates.

Mmari, Albert G.; Potgieter-Vermaak, Sanja S.; Bencs, László; McCrindle, Robert I.; Van Grieken, René

2013-10-01

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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.

Lutale Janet; Thordarson Hrafnkell; Abbas Zulfiqarali; Vetvik Kåre

2007-01-01

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The magnitude and factors associated with delays in management of smear positive tuberculosis in Dar es Salaam, Tanzania  

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Full Text Available Abstract Objective To assess the magnitude and factors responsible for delay in TB management. Design A cross sectional hospital based survey in Dar es Salaam region, May 2006. Results We interviewed 639 TB patients. A total of 78.4% of patients had good knowledge on TB transmission. Only 35.9% had good knowledge on the symptoms. Patient delay was observed in 35.1% of the patients, with significantly (X2 = 5.49, d.f. = 1, P = 0.019) high proportion in females (41.0%) than in males (31.5%). Diagnosis delay was observed in 52.9% of the patients, with significantly (X2 = 10.1, d.f. = 1, P = 0.001) high proportion in females (62.1%) than in males (47.0%). Treatment delay was observed in 34.4% of patients with no significant differences among males and females. Several risk factors were significantly associated with patient's delays in females but not in males. The factors included not recognizing the following as TB symptoms: night sweat (OR = 1.92, 95% CI 1.20, 3.05), chest pain (OR = 1.62, 95% CI 1.1, 2.37), weight loss (OR = 1.55, 95% CI 1.03, 2.32), and coughing blood (OR = 1.47, 95% CI 1.01, 2.16). Other factors included: living more than 5 Km from a health facility (OR = 2.24, 95% CI 1.41, 3.55), no primary education (OR = 1.74, 95% CI 1.01, 3.05) and no employment (OR = 1.77, 95% CI 1.20, 2.60). In multiple logistic regression, five factors were more significant in females (OR = 2.22, 95% CI 1.14, 4.31) than in males (OR = 0.70, 95% CI 0.44, 1.11). These factors included not knowing that night sweat and chest pain are TB symptoms, a belief that TB is always associated with HIV infection, no employment and living far from a health facility. Conclusion There were significant delays in the management of TB patients which were contributed by both patients and health facilities. However, delays in most of patients were due to delay of diagnosis and treatment in health facilities. The delays at all levels were more common in females than males. This indicates the need for education targeting health seeking behaviour and improvement in health system.

Mfinanga Sayoki G; Mutayoba Beatrice K; Kahwa Amos; Kimaro Godfather; Mtandu Rugola; Ngadaya Esther; Egwaga Said; Kitua Andrew Y

2008-01-01

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STUDENT’S MOTIVES FOR UTILIZING SOCIAL NETWORKING SITES IN PRIVATE UNIVERSITIES IN DAR ES SALAAM, TANZANIA  

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Full Text Available This study explored the student motives for utilizing SNSs in Dar Salaam Tanzania. The Research design used in this study was cross-sectional Descriptive research design. The target population was 7337 students and a sample of 356 was selected through Proportionate Random sampling. The Quantitative data collected was analyzed using descriptive statistics such as mean, tables, frequency, percentages and standard deviation. Connecting to classmates, Sending messages, opinions and updates, socializing, chatting and updating profile were some of most students’ motives for using SNSs. Student should use SNSs with motives which can raise their academic achievement. Despite of using SNSs, students can still manage to be efficient enough in maintaining class achievement by meeting studies’ targets andcovering syllabus with little time devoted to studies. University students are recommended to make use of education based SNSs to enhance their academic achievement therefore they should restrict themselves from non-academic purposes, since it might have adverse impact in their academic achievement.

PRIVATE UNIVERSITIES IN DAR ES SALAAM, TANZANIA Michael Kariuki Muriithi; Irene Wanjiru Muriithi

2013-01-01

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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.

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

2011-01-01

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Determinants of Previous HIV Testing and Knowledge of Partner's HIV Status Among Men Attending a Voluntary Counseling and Testing Clinic in Dar es Salaam, Tanzania.  

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

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

2012-12-04

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

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

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

2007-01-01

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

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

UK PubMed Central (United Kingdom)

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

Jackson MM

2006-05-01

63

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

Science.gov (United States)

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

Jackson, Msafiri M

2006-05-01

64

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

Science.gov (United States)

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

2013-01-01

65

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

UK PubMed Central (United Kingdom)

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

Munseri PJ; Bakari M; Janabi M; Aris E; Aboud S; Hejdeman B; Sandstrom E

2013-08-01

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; Wangwe Peter; Kilewo Charles D; Nystrom Lennarth; Lindmark Gunnila

2012-01-01

67

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

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

Mgonda Yassin M; Chale Pauline NF

2011-01-01

68

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

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

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

2012-01-01

69

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

UK PubMed Central (United Kingdom)

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

Sunguya BF; Poudel KC; Mlunde LB; Otsuka K; Yasuoka J; Urassa DP; Mkopi NP; Jimba M

2012-01-01

70

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

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

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

2009-01-01

71

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.  

UK PubMed Central (United Kingdom)

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.

Mbwambo HA; Magwisha HB; Mfinanga JM

2006-06-01

72

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

73

Slow progression of HIV-1 infection in a cohort of antiretroviral naive hotel workers in Dar es Salaam, Tanzania as defined by their CD4 cell slopes.  

UK PubMed Central (United Kingdom)

Data on slow progression following HIV-1 infection in Africa are sparse. From a study on the natural history of HIV-1 infection in Dar es Salaam, Tanzania, an analysis of immunological and clinical data from 237 HIV-1 seropositive individuals was performed. Annual CD4 cell determinations were carried out by flow cytometry. None was on antiretroviral treatment. CD4+ cell slopes were obtained by fitting a linear regression model. A study population of 50 individuals with >3 CD4 cell determinations and followed for >5 y had a mean follow-up of 72.7 months, and mean 5.7 CD4+ cell determinations. With a criterion of maintaining a CD4 cell count >or=500 cells/ml, 8 of the 50 (16.0%) were long-term non-progressors (LTNP). With a definition of maintaining a CD4+ cell slope

Bakari M; Urassa W; Mhalu F; Biberfeld G; Pallangyo K; Sandström E

2008-01-01

74

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

2009-01-01

75

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

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

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

2009-01-15

76

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

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

RRJ Akarro

2011-01-01

77

Social factors and lifestyle attributes associated with nutritional status of people living with HIV/AIDS attending care and treatment clinics in Ilala District, Dar Es Salaam.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Tanzania is one of the countries that suffer huge burden of malnutrition and food poverty with over two million people living with HIV/AIDS. Despite ongoing nutritional interventions in care and treatment clinics for people living with HIV/AIDS (PLWHA), a high proportion of them still face nutritional problems, with about 29% being underweight. This study therefore aimed assessing social factors and lifestyle attributes associated with nutritional status among adults living with HIV/AIDS and attending care and treatment clinics (CTCs) in an urban district in Tanzania. METHODS: An interview schedule was administered to 412 randomly selected adult male and female clients attending different CTCs in Ilala district. Their anthropometric measurements i.e. body weights and heights were also taken. RESULTS: Findings revealed that 18.4% of males and females were underweight according to their body mass indices. The risk of being underweight was higher among respondents who were young; who had never married; had no formal education as well as those who reported to be living with their families or friends, although these associations were not statistically significant. On the other hand, factors which had statistically significant association with nutritional status included the type of persons the client was living with and the habit of drinking alcohol. CONCLUSION: From the findings we conclude that PLWHA attending Care and Treatment Clinics in Ilala district, Dar es Salaam have problems with their nutrition with underweight being common among them. This suggests that the existing care and treatment clinics that provide nutritional support to PLWHA do not appear to address these issues in their totality. There is therefore, need to ensure that more efforts are geared towards providing nutritional counseling, support and encouragement of these clients within social contexts of their lives so in order for the current efforts to give best results.

Ritte SA; Kessy AT

2012-03-01

78

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

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

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

2006-01-01

79

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

UK PubMed Central (United Kingdom)

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

Young S; Leshabari S; Arkfeld C; Singler J; Dantzer E; Israel-Ballard K; Mashio C; Maternowska C; Chantry C

2013-06-01

80

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.

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

2008-01-01

 
 
 
 
81

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.

Joachim Agricola; Matee Mecky I; Massawe Furaha A; Lyamuya Eligius F

2009-01-01

82

Oral lesions associated with HIV/AIDS in HIV-seropositive patients attending a counselling and treatment centre in Dar es Salaam.  

UK PubMed Central (United Kingdom)

OBJECTIVE: ?To assess the prevalences and patterns of oral lesions occurring in human immunodeficiency virus (HIV) and acquired immune deficiency syndrome (AIDS). METHODS: ?A cross-sectional study was conducted among 200 people living with HIV/AIDS (PlwHA) who regularly attended a counselling and treatment centre in Dar es Salaam, Tanzania. A questionnaire-guided interview and clinical oral assessment were used. Strict confidentiality and adherence to ethical codes were observed. RESULTS: The mean age of participants was 38.91 years (standard deviation: 10.424; mode: 35 years; median: 37.0 years; range: 15-76 years). Most participants (58.5%) were aware of predispositions towards the occurrence of oral lesions such as oral candidiasis (60.0%) in HIV/AIDS and most of these (72.0%) were aware that the lesions are treatable. Some participants reported occurrences of oral thrush (22.5%) and lip ulcerations (28.5%), although only 47.0% of these had sought medical advice. Examinations revealed that 29.0% of participants had at least one oral lesion associated with HIV/AIDS. Prevalences of the various types of lesion were: 11.5% for herpes simplex; 7.5% for oral candidiasis; 4.0% for oral hairy leukoplakia; 3.5% for Kaposi's sarcoma; 1.5% for dry mouth; 0.5% for angular cheilitis, and 0.5% for acute necrotising ulcerative gingivitis. Herpes simplex and Kaposi's sarcoma were more frequently observed in males (56.5% and 71.4%, respectively), whereas oral candidiasis and dry mouth were observed more often in females (86.7% and 66.7%, respectively) (?(2) = 16.692, P =?0.016). CONCLUSIONS: ? Prevalences of oral lesions associated with HIV/AIDS in PlwHA and using antiretroviral therapy are persistent, of moderate intensity and vary according to individual immune status. These patients' level of awareness about oral lesions was satisfactory, but formal medicodental lines of management were not prioritised. Contemporary protocol for the management of oral lesions should be understood and disseminated to the general public by dentists.

Mwangosi IE; Tillya J

2012-08-01

83

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

UK PubMed Central (United Kingdom)

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 < 0.05. Other risk factors such as prolonged rupture of membrane, intrapartum fever, low birth weight and HIV infection did not correlate with GBS colonisation. All isolates were sensitive to vancomycin and ampicillin. Resistance to clindamycin, erythromycin and penicillin G was found to 17.6%, 13% and 9.4%, respectively. 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.

Joachim A; Matee MI; Massawe FA; Lyamuya EF

2009-01-01

84

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.

Matee Mecky IN; Magesa Pius M; Lyamuya Eligius F

2006-01-01

85

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; Germana H Leyna; Elia J Mmbaga

2013-01-01

86

Adherence to antiretroviral therapy among HIV infected children measured by caretaker report, medication return, and drug level in Dar Es Salaam, Tanzania.  

UK PubMed Central (United Kingdom)

BACKGROUND: 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 concentration. In addition, the association between level of adherence and patient's immune status was compared across the three methods of measuring adherence. METHODS: This was a descriptive cross-sectional study involving HIV infected children aged 2-14 years, on nevirapine- based antiretroviral treatment for at least six months, attending care and treatment clinic in three municipal hospitals in Dar- Es- Salaam City. Eligible patients and their accompanying caretakers were consecutively enrolled after obtaining written informed consent. Structured questionnaires were administered to caretakers to assess patient's adherence by caretaker report and medication return whereas a single blood sample for CD4 cell count/percent and determination of nevirapine plasma concentration was taken from patients on the day of assessment. RESULTS: A total of 300 patients and accompanying caretakers were enrolled and the mean patient age (SD) was 8 (3) years. Caretakers' report and medication return showed good adherence (98% and 97%) respectively. However, the level of adherence assessed by nevirapine plasma concentration (85%) was significantly lower than caretaker report and medication return (p?5% of prescribed doses) and caretaker reported missing more than one dose within 72 hours prior to interview were not associated with immunosuppression (p?=?0. 474), (p?=?0. 569) respectively. CONCLUSION: Lower adherence level observed using nevirapine plasma concentration and its association with immunological response supports the validity of the method and indicates that adherence data obtained from caretaker report and medication return may overestimate the true adherence in paediatric antiretroviral therapy.

Mghamba FW; Minzi OM; Massawe A; Sasi P

2013-01-01

87

"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.

Kolling Marie; Winkley Kirsty; von Deden Mette

2010-01-01

88

An urgent need to scale-up injecting drug harm reduction services in Tanzania: prevalence of blood-borne viruses among drug users in Temeke District, Dar-es-Salaam, 2011.  

UK PubMed Central (United Kingdom)

BACKGROUND: Injecting drug use (IDU) is a growing concern in Tanzania compounded by reports of high-risk injecting and sexual risk behaviours among people who inject drugs (PWID). These behaviours have implications for transmission of blood-borne viruses, including HIV and hepatitis C (HCV). METHODS: We recruited 267 PWID (87% male) from Temeke District, Dar-es-Salaam through snowball and targeted sampling. A behavioural survey was administered alongside repeated rapid HIV and HCV antibody testing. HIV and HCV prevalence estimates with 95% confidence intervals (CIs) were calculated. RESULTS: Among PWID, 34.8% (95%CI 29.1-40.9) tested HIV positive (29.9% of males and 66.7% of females); 27.7% (95%CI 22.0-34.0) tested HCV antibody positive. Almost all (97%) participants were aware of HIV and 34% of HCV. 45% of male and 64% of female PWID reported a previous HIV test; only five (2%) PWID reported a previous HCV test. Of HIV and HCV positive tests, 73% and 99%, respectively, represented newly diagnosed infections. CONCLUSION: High prevalence of HIV and HCV were detected in this population of PWID. Rapid scale-up of targeted primary prevention and testing and treatment services for PWID in Tanzania is needed to prevent further transmission and consequent morbidities.

Bowring AL; Luhmann N; Pont S; Debaulieu C; Derozier S; Asouab F; Toufik A; van Gemert C; Dietze P; Stoove M

2013-01-01

89

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

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

Telatela Safila P; Matee Mecky I; Munubhi Emmanuel K

2007-01-01

90

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

DEFF Research Database (Denmark)

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

Kolling, Marie; Winkley, Kirsty

2010-01-01

91

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

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

Tarimo Edith AM; Francis Joel M; Kakoko Deodatus; Munseri Patricia; Bakari Muhammad; Sandstrom Eric

2012-01-01

92

Bacteriologic studies in external otitis in Dar es Salaam, Tanzania.  

UK PubMed Central (United Kingdom)

The bacterial flora from the auditory canals of 54 patients (74 ears) with external otitis was studied. Pseudomonas aeruginosa was found in 38%. Aspergillus in 24%, Staphylococcus aureus in 18% and Candida albicans in 14%. Bacterial cultures from the auditory canals of 21 healthy subjects produced only the normal skin flora.

Manni JJ; Kuylen K

1984-09-01

93

Pattern of drug use among elderly patients in public and private hospitals in Dar-as Salaam.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The aim of this study was to assess the use of potentially inappropriate medications in the elderly patients (> or = 65 years of age) according to the 2002 Beers criteria. METHOD: This was a retrospective and prospective study that was carried between December 2006 and June 2007. During this period, a total of 514 prescriptions of elderly patients were collected and examined for the pattern of drug use. The study involved reviewing prescriptions of patients who are 65 years old and above. Patients were those who were attending the clinics in the selected hospitals during the period of the study. In addition, files of patients who had attended the hospitals for not longer than the past 12 months were reviewed. The hospitals included two public hospitals (Mwananyamala municipal hospital and Muhimbili National Hospital) and two privately-owned hospitals (Aga Khan and Hindu Mandal hospitals) in Dar es Salaam. RESULTS: The study revealed that 11.4% of medicines prescribed were drugs of concern i.e. medications that should be avoided in elderly patients or which are inappropriate for use in elderly patients according to Beers list. Among these drugs those with high frequency of use were Nifedipine (3.5%), Iron sulphate (2.2%), Chlorpropamide (2%) and Digoxin (1.8%). These drugs were more prescribed in the public hospitals than in private ones. It was also observed that more women (62.3%) are suffering from a number of diseases than males (37.7%). In addition, women received more inappropriate medications (60.7%) than their male counterparts (393%). The common most prevalent diseases were hypertension (22.5%), diabetes mellitus (17.9%), malaria (13.5%), urinary tract infection (4.2%) and anemia (3.7%). CONCLUSION: Based on the findings, there is a need for both the public and health care professionals to be aware of the harmful drugs in the old age so as to minimize occurrence of side effects.

Kamuhabwa AR; Lugina R

2010-03-01

94

Risk factors for HIV infection in gynaecological inpatients in Dar es Salaam, Tanzania, 1988-1990.  

Science.gov (United States)

A prevalence of 12.8% for anti-HIV-1 and a prevalence of 16.8% for anti-syphilis antibodies was found in 359 gynaecological inpatients admitted in the Department of Gynaecology and Obstetrics, Muhimbili University College of Health Sciences from 1988 to 1990. The highest HIV prevalence (17.3%) was observed in the youngest age group (14-20 years), whereas the highest syphilis prevalence (22.2%) was found in the oldest age group (> 45 years). Infections with HIV and syphilis were both significantly associated with variables related to sexual behaviour, such as marital status, age at first intercourse and number of sexual partners in the past ten years. After adjustment for these common risk variables linked to sexual behaviour, syphilis infection was still associated with a more than twofold higher risk of HIV infection (odds ratio (OR) = 2.60, p = 0.02) and trichomonas vaginalis infection with a nearly threefold higher risk (OR = 2.96, p < 0.001). These data characterize patients at risk for HIV infection among inpatients of a gynaecological department in East Africa, and indicate that effective measures to prevent sexually transmitted disease may reduce HIV transmission. PMID:1298634

ter Meulen, J; Mgaya, H N; Chang-Claude, J; Luande, J; Mtiro, H; Mhina, M; Kashaija, P; Pawlita, M

1992-12-01

95

Risk factors for HIV infection in gynaecological inpatients in Dar es Salaam, Tanzania, 1988-1990.  

UK PubMed Central (United Kingdom)

A prevalence of 12.8% for anti-HIV-1 and a prevalence of 16.8% for anti-syphilis antibodies was found in 359 gynaecological inpatients admitted in the Department of Gynaecology and Obstetrics, Muhimbili University College of Health Sciences from 1988 to 1990. The highest HIV prevalence (17.3%) was observed in the youngest age group (14-20 years), whereas the highest syphilis prevalence (22.2%) was found in the oldest age group (> 45 years). Infections with HIV and syphilis were both significantly associated with variables related to sexual behaviour, such as marital status, age at first intercourse and number of sexual partners in the past ten years. After adjustment for these common risk variables linked to sexual behaviour, syphilis infection was still associated with a more than twofold higher risk of HIV infection (odds ratio (OR) = 2.60, p = 0.02) and trichomonas vaginalis infection with a nearly threefold higher risk (OR = 2.96, p < 0.001). These data characterize patients at risk for HIV infection among inpatients of a gynaecological department in East Africa, and indicate that effective measures to prevent sexually transmitted disease may reduce HIV transmission.

ter Meulen J; Mgaya HN; Chang-Claude J; Luande J; Mtiro H; Mhina M; Kashaija P; Pawlita M

1992-12-01

96

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

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

Urassa W; Moshiro C; Chalamilla G; Mhalu F; Sandstrom E

2008-01-01

97

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

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

Lasse Møller-Jensen; Juma R Kiduanga; Phillip K. Mwanukuzi

2012-01-01

98

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; P<0.01) between zones of inhibition and soaps' 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 (P<0.01) against S. aureus. In conclusion, majority of the assayed medicated soaps 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.

Mwambete KD; Lyombe F

2011-01-01

99

Mortality and Treatment Failure among HIV-Infected Adults in Dar Es Salaam, Tanzania.  

UK PubMed Central (United Kingdom)

UNLABELLED: Objectives: Monitoring antiretroviral treatment (ART) outcomes is essential for assessing the success of HIV care and treatment programs in resource-limited settings (RLS). METHODS: Longitudinal analyses of clinical and immunologic parameters in HIV-infected adults initiated on ART between November 2004 and June 2008 at Management and Development for Health (MDH)-Presidents Emergency Plan For AIDS Relief PEPFAR supported HIV care and treatment clinics in Tanzania. RESULTS: A total of 12 842 patients were analyzed (65.9% female, median baseline CD4 count, 106 cells/mm(3)). Significant improvements in immunologic status were observed with an increase in CD4 count to 298 (interquartile range [IQR] 199-416), 372 (256-490) and 427 (314-580) cells/mm(3), at 1, 2, and 3 years, respectively. Overall mortality was 13.1% (1682 of 12 842). Male sex, World Health Organization (WHO) stage III/IV, CD4 <200 cells/mm(3), hemoglobin (Hgb) <8.5 g/dL, and stavudine (d4T)-containing regimens were independently associated with early and overall mortality. Conclusions: Closer monitoring of males and patients with advanced HIV disease following ART initiation may improve clinical and immunologic outcomes in these individuals.

Chalamilla G; Hawkins C; Okuma J; Spiegelman D; Aveika A; Christian B; Koda H; Kaaya S; Mtasiwa D; Fawzi W

2012-09-01

100

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

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Abstract Background Effective maternal and perinatal audits are associated with improved quality of care and reduction of severe adverse outcome. Although audits at the level of care were formally introduced in Tanzania around 25 years ago, little information is available about thei...

Nyamtema Angelo S; Urassa David P; Pembe Andrea B; Kisanga Felix; van Roosmalen Jos

 
 
 
 
101

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.

Kidanto Hussein L; Mogren Ingrid; van Roosmalen Jos; Thomas Angela N; Massawe Siriel N; Nystrom Lennarth; Lindmark Gunilla

2009-01-01

102

Informal urban settlements and cholera risk in Dar es Salaam, Tanzania  

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Background: As a result of poor economic opportunities and an increasing shortage of affordable housing, much of the spatial growth in many of the world's fastest-growing cities is a result of the expansion of informal settlements where residents live without security of tenure and with limited acce...

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

103

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

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Adolescent girls' early sexual activity, early pregnancy, induced abortions and the increase in HIV infections have become major concerns in Sub-Saharan Africa. Efforts, though, to understand their sexual behaviour and to prevent reproductive health problems are almost non-existent. Adolescent girls...

Silberschmidt, Margrethe; Rasch, V

104

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

UK PubMed Central (United Kingdom)

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

Kakoko DC

2013-01-01

105

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

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

Kamat Vinay R; Nyato Daniel J

2010-01-01

106

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

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

Rasch Vibeke; Yambesi Fortunata; Massawe Siriel

2008-01-01

107

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; Outwater Anne

2012-01-01

108

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

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

Hamza Omar JM; Matee Mecky IN; Simon Elison NM; Kikwilu Emil; Moshi Mainen J; Mugusi Ferdinand; Mikx Frans HM; Verweij Paul E; van der Ven André JAM

2006-01-01

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

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

Daniel Linus Naila

2013-01-01

110

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

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Illegal abortion is known to be a major contributor to maternal mortality. The objective of the study was firstly to identify women with illegally induced abortion, (IA) and to compare them with women admitted with a spontaneous abortion (SA) or receiving antenatal care (AC), and secondly to describ...

Rasch, V; Muhammad, H; Urassa, E; Bergström, S

111

Hepatitis A, B and C viral co-infections among HIV-infected adults presenting for care and treatment at Muhimbili National Hospital in Dar es Salaam, Tanzania  

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Full Text Available Abstract Background Tanzania is currently scaling-up access to anti-retro viral therapy (ART) to reach as many eligible persons as possible. Hepatitis viral co-infections are known to influence progression, management as well as outcome of HIV infection. However, information is scarce regarding the prevalence and predictors of viral hepatitis co-infection among HIV-infected individuals presenting at the HIV care and treatment clinics in the country. Methods A cross-sectional study conducted between April and September 2006 enrolled 260 HIV-1 infected, HAART naïve patients aged ?18 years presenting at the HIV care and treatment clinic (CTC) of the Muhimbili National Hospital (MNH). The evaluation included clinical assessment and determination of CD4+ T-lymphocyte count, serum transaminases and serology for Hepatitis A, B and C markers by ELISA. Results The prevalence of anti HAV IgM, HBsAg, anti-HBc IgM and anti-HCV IgG antibodies were 3.1%, 17.3%, 2.3% and 18.1%, respectively. Dual co-infection with HBV and HCV occurred in 10 individuals (3.9%), while that of HAV and HBV was detected in two subjects (0.8%). None of the patients had all the three hepatitis viruses. Most patients (81.1%) with hepatitis co-infection neither had specific clinical features nor raised serum transaminases. History of blood transfusion and jaundice were independent predictors for HBsAg and anti-HBc IgM positivity, respectively. Conclusion There is high prevalence of markers for hepatitis B and C infections among HIV infected patients seeking care and treatment at MNH. Clinical features and a raise in serum alanine aminotransferase were of limited predictive values for the viral co-infections. Efforts to scale up HAART should also address co-infections with Hepatitis B and C viruses.

Nagu Tumaini J; Bakari Muhammad; Matee Mecky

2008-01-01

112

"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 litt...

Kolling, Marie; Winkley, Kirsty; von Deden, Mette

113

High rate of fatal cases of pediatric septicemia caused by gram-negative bacteria with extended-spectrum beta-lactamases in Dar es Salaam, Tanzania.  

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Extended-spectrum beta-lactamases (ESBLs) were present in high proportions of Escherichia coli (25% [9 of 36]) and Klebsiella pneumoniae isolates (17% [9 of 52]) causing pediatric septicemia at a tertiary hospital in Tanzania. Patients with septicemia due to ESBL-producing organisms had a significantly higher fatality rate than those with non-ESBL isolates (71% versus 39%, P = 0.039). This is the first report of the CTX-M-15 genotype of ESBLs on the African continent and the first observation of SHV-12 genotype in an isolate of Salmonella enterica serotype Newport. PMID:15695674

Blomberg, Bjørn; Jureen, Roland; Manji, Karim P; Tamim, Bushir S; Mwakagile, Davis S M; Urassa, Willy K; Fataki, Maulidi; Msangi, Viola; Tellevik, Marit G; Maselle, Samwel Y; Langeland, Nina

2005-02-01

114

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

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Abstract Background HIV/AIDS is associated with an increased burden of undernutrition among children even under antiretroviral therapy (ART). To treat undernutrition, WHO endorsed the use of Ready to Use Therapeutic Foods (RUTF) that can reduce case fatality and undernutrition among...

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

115

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

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Abstract Background In recent randomized controlled trials, male circumcision has been proven to complement the available biomedical interventions in decreasing HIV transmission from infected women to uninfected men. Consequently, Tanzania is striving to scale-up safe medical male c...

Tarimo Edith AM; Francis Joel M; Kakoko Deodatus; Munseri Patricia; Bakari Muhammad; Sandstrom Eric

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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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.

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

2009-01-01

117

Urbanisation and its discontents: urban refugees in Tanzania  

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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

1999-01-01

118

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?  

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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

2000-01-01

119

Acute haemorrhagic conjunctivitis epidemics and outbreaks of Paederus spp. keratoconjunctivitis ('Nairobi red eyes') and dermatitis  

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Full Text Available Abstract in english An epidemic of acute conjunctivitis in Dar es Salaam in 2010 demonstrated the importance of a strong infectious diseases epidemiological surveillance network to minimise disease outbreaks. Misunderstanding of the causes and management of diseases explains the repetitive nature of acute haemorrhagic conjunctivitis (AHC) in Dar es Salaam. This paper discusses AHC and Paederus spp. keratoconjunctivitis and periorbital oedema ('Nairobi red eyes') that are confused as being associated with recurrent epidemics of conjunctivitis in Dar es Salaam.

Mbonile, L

2011-08-01

120

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

Scientific Electronic Library Online (English)

Full Text Available 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 diferentes beneficiários desse projecto. Conclui que são factores positivos a duração do pedido nas edições do jornal e o número de dependentes a cargo dos ben (more) eficiários. 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 diferentes 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 e (more) l 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 each 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 positive (more) ly 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.

Reis Mourão, Paulo

2013-07-01

 
 
 
 
121

Agrotóxico: que nome dar?  

Directory of Open Access Journals (Sweden)

Full Text Available Os trabalhadores, de um modo geral, estão sempre expostos a maiores ou menores intensidades de risco. Os agricultores, em particular, também estão expostos e de forma bastante estabelecida. Contudo, trabalhos têm mostrado que existe um código coletivo de proteção para lhes permitir dar continuidade às suas atividades, uma vez que, em sua maioria, os próprios donos do cultivo fazem parte do processo produtivo e, portanto, precisam garantir a sua safra aplicando os agrotóxicos. Este trabalho apresenta uma pesquisa desenvolvida com agricultores de dois municípios do sudeste do Piauí, utilizando uma abordagem qualitativa, com o intuito de compreender os mecanismos de proteção destes agricultores com a sua atividade. Os resultados apontaram para práticas defensivas tais como consumo de bebida alcoólica, a sublocação do serviço aos mais jovens e a existência de um certo grau de compreensão do risco à saúde com a utilização dos agrotóxicos. A partir daí, se discute a importância da denominação dada ao agrotóxico, como um fator de proteção que deveria ser mais valorizado para maximizar a proteção do agricultor, em vez de se manter a estratégia de aumento de informação e controle de EPI (Equipamento de Proteção Individual).

Gomide Márcia

2005-01-01

122

Dar sem (se) perder  

Scientific Electronic Library Online (English)

Full Text Available 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 generalizada da utilização do analgésico epidural em partos eutócicos, pretendemos dar um contributo para a compreensão psicólogica do pedido ou da adesão à sugestão dos t (more) écnicos 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.

Gil, Maria José

1998-09-01

123

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

2012-01-01

124

Orienteerumiskaart vs. LiDAR / Marek Karm  

Index Scriptorium Estoniae

Bakalaureusetööst, mille eesmärk oli võrrelda orienteerumiskaardi reljeefi LiDAR-i andmete põhjal saadava reljeefimudeliga ning leida vastus küsimusele, kas o-kaart võib olla kasulik kooste- või kontrollmaterjal mistahes reljeefimudelile

Karm, Marek

2012-01-01

125

Qué es la ética económica  

Directory of Open Access Journals (Sweden)

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

Georges Enderle

1993-01-01

126

Direct Georeferencing of Stationary LiDAR  

Directory of Open Access Journals (Sweden)

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

Ahmed Mohamed; Benjamin Wilkinson

2009-01-01

127

DOMESTIC AQUAPONIC RECREATION SYSTEM DARS2007  

UK PubMed Central (United Kingdom)

The construct of DARS described by (FIG-A) which incorporates by reference all assemblies and sub assembly drawings outlined in the DARS master drawing list (FIG-1) will result in a portable recirculating aquaculture system or fish farm that will provide the user with the following capabilities; A means by which to raise or store edible varieties of fish to a market-size. A means by which to raise or store live ornamental or bait fish. A means by which to raise or store live fish specimens used in research. A means by which to deliver live fish to local markets. A means by which to produce up to 200 liters of nutrient rich water to nourish hydroponic, aquaponic and terrestrial farm-plants.

ORSILLO THOMAS EDWARD

128

Decay of 248Es  

International Nuclear Information System (INIS)

[en] The electron capture and alpha decays of 248Es was studied. Previous experiments have identified 248Es by means of the 6.87 MeV alpha particles from its 0.25% alpha decay branch, but because of a lack of target material or an inappropriate choice of reaction, detailed studies of the decay properties of 248Es were not possible. In the present experiments, a much larger and cleaner source of 248Es was made available. Many gamma rays have been found to accompany the electron capture decay of 248Es. The gamma ray and alpha decay data from the present experiments support the existence of two isomers of 248Es

1985-01-01

129

LiDAR Utility for Natural Resource Managers  

Directory of Open Access Journals (Sweden)

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

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

2009-01-01

130

¿Es la ocratoxina a una micotoxina mutagénica?  

Directory of Open Access Journals (Sweden)

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

L. Arbillaga; O. Ezpeleta; A. López de Cerain

2004-01-01

131

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

2006-01-01

132

Eleanor Roosevelt Resigns from the DAR: A Study in Conscience.  

Science.gov (United States)

Because the Daughters of the American Revolution's (DAR) Black exclusion rule prevented Black singer Marion Anderson from performing in the DAR auditorium in 1939, Eleanor Roosevelt resigned from the organization. Primary source materials regarding this incident and learning activities for secondary level students are presented. (RM)

Freeman, Elsie T.; And Others

1984-01-01

133

Asesorar es acompañar  

Directory of Open Access Journals (Sweden)

Full Text Available El asesoramiento busca construir nuevos conocimientos y afrontar las necesidades de cambio de los equipos docentes a partir del estudio de las prácticas, de los sujetos y de las instituciones. Es una oportunidad para repensar la docencia a partir de sus propias experiencias y dejarse interrogar por las repercusiones la complejidad del mundo actual en la escuela. Desde esta mirada el asesoramiento abre la posibilidad de reflexionar las repercusiones de sus cambios como una forma de mejorar la escuela. Un trabajo de resignificación que permite pensar en prácticas docentes que integren nuevas culturas y narrativas.

Montse Ventura

2008-01-01

134

¿Qué es el neozapatismo?  

Directory of Open Access Journals (Sweden)

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

Xóchitl Leyva Solano; Willibald Sonnleitner

2000-01-01

135

Modelling rating curves using remotely sensed LiDAR data  

Science.gov (United States)

Accurate stream discharge measurements are important for many hydrological studies. In remote locations, however, it is often difficult to obtain stream flow information because of the difficulty in making the discharge measurements necessary to define stage-discharge relationships (rating curves). This study investigates the feasibility of defining rating curves by using a fluid mechanics-based model constrained with topographic data from an airborne LiDAR scanning. The study was carried out for an 8m-wide channel in the boreal landscape of northern Sweden. LiDAR data were used to define channel geometry above a low flow water surface along the 90-m surveyed reach. The channel topography below the water surface was estimated using the simple assumption of a flat streambed. The roughness for the modelled reach was back calculated from a single measurment of discharge. The topographic and roughness information was then used to model a rating curve. To isolate the potential influence of the flat bed assumption, a 'hybrid model' rating curve was developed on the basis of data combined from the LiDAR scan and a detailed ground survey. Whereas this hybrid model rating curve was in agreement with the direct measurements of discharge, the LiDAR model rating curve was equally in agreement with the medium and high flow measurements based on confidence intervals calculated from the direct measurements. The discrepancy between the LiDAR model rating curve and the low flow measurements was likely due to reduced roughness associated with unresolved submerged bed topography. Scanning during periods of low flow can help minimize this deficiency. These results suggest that combined ground surveys and LiDAR scans or multifrequency LiDAR scans that see 'below' the water surface (bathymetric LiDAR) could be useful in generating data needed to run such a fluid mechanics-based model. This opens a realm of possibility to remotely sense and monitor stream flows in channels in remote locations.

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

2012-01-01

136

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 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 (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 (more) 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 (more) 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.

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

2012-01-01

137

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; Tarmo K Remmel; Gunho Sohn

2012-01-01

138

Georeferenced LiDAR 3D Vine Plantation Map Generation  

Science.gov (United States)

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

Llorens, Jordi; Gil, Emilio; Llop, Jordi; Queralto, Meritxell

2011-01-01

139

Georeferenced LiDAR 3D Vine Plantation Map Generation  

Directory of Open Access Journals (Sweden)

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

Jordi Llorens; Emilio Gil; Jordi Llop; Meritxell Queraltó

2011-01-01

140

Gobernar es educar  

Directory of Open Access Journals (Sweden)

Full Text Available Resumen. La educación juega un papel fundamental en la reducción del enemigo más formidable de la paz, la democracia y el desarrollo humano: la pobreza. Es el instrumento catalizador de la participación constructiva en los procesos sociales y políticos de los sectores silenciados y marginados del desarrollo. La educación es particularmente importante en un mundo cada vez más globalizado, convirtiéndose en punto de partida y elemento clave para comprender el pluralismo de los estados y sus diferentes manifestaciones culturales, contribuyendo de esta manera, a la integración nacional y regional. La educación como responsabilidad de todos debe no solo fijarse como objetivo la capacitación y adiestramiento de las personas, sino también, educarlas, más con el ejemplo que con la prédica, en una serie de principios y valores. Concluye el autor puntualizando la importancia de que se asuma el hacer política como práctica pedagógica. El político debe ser un maestro capaz de generar conocimiento en sí mismo y en los pueblos y modelar en sus acciones los principios que defiende con sus palabras. Hacer política y gobernar es educar y educarse.   Abstract. Education plays a critical role in the reduction of the most prominent enemy of peace, democracy, and human development: poverty. It is the catalyst of the constructive participation in the social and political processes of those groups traditionally silenced and excluded from development. Education is particularly important in a global society. It is a fundamental factor to understand the pluralism of the nations and their cultural diversity. It contributes to the national and regional integration. Education, viewed as everyone's responsibility, should not only be aimed at instructing and training individuals for the labor market, but also at educating them in a series of principles and values. In so doing, educating by the example should play a major role. The author concludes stressing the importance that participation in politics becomes a pedagogical practice. Politicians should become educators capable of generating knowledge for themselves and the people they represent. They should model with their example the principles the preach. To do politics and govern is to educate.

Oscar Arias Sánchez

2001-01-01

 
 
 
 
141

¿Qué es una emoción?  

Directory of Open Access Journals (Sweden)

Full Text Available Gregorio Marañón wrote relatively little about emotion. Nevertheless, he considered emotion to be “one of the most interesting problems of human life.” This article describes the basic brain processes of emotion that motivates living beings to follow patterns of behaviour whose ultimate meaning is the survival of the individual and the species. A description is given here of the emotional processing of sensory information. It is noted that any process of conscious learning and memory is always emotionally coloured. Finally, one of the main conclusions of this article is that there is no rational thought without a previous emotional process in the brain. There is no reason without emotion. This is a conclusion that would probably have amazed Professor Marañón.El Dr. Gregorio Marañón no escribió mucho sobre la emoción. Pero sí es cierto que consideró que se trataba de “uno de los problemas más interesantes de la vida humana”. En este artículo se describen los procesos cerebrales básicos de la emoción que nos alertan y motivan hacia la realización de conductas en cuyo significado último se encuentra la supervivencia del individuo y de la especie. Se describe el procesamiento emocional de la información sensorial. Se señala que todo proceso de aprendizaje y memoria consciente siempre viene coloreado emocionalmente. Y se destaca que el profesor Marañón posiblemente mostraría asombro ante una de las principales conclusiones de este artículo en las que se indica que no hay pensamiento sin una emoción previa que lo alimente. Que no hay razón sin emoción.

Mora Teruel, Francisco

2013-01-01

142

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.

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

2013-01-01

143

LiDAR error estimation with WAsP engineering  

International Nuclear Information System (INIS)

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

2008-05-01

144

Alternative Methodologies for LiDAR System Calibration  

Directory of Open Access Journals (Sweden)

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

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

2010-01-01

145

Modeling low-height vegetation with airborne LiDAR  

Science.gov (United States)

Low-height vegetation, common in semiarid regions, is difficult to characterize with LiDAR (Light Detection and Ranging) due to similarities, in time and space, of the point returns of vegetation and ground. Other complications may occur due to the low-height vegetation structural characteristics a...

146

DAR: A Modern Institutional Repository with a Scalability Twist  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Digital Assets Repository (DAR) is an Institutional Repository developed at the Bibliotheca Alexandrina to manage the full lifecycle of a digital asset: its creation and ingestion, its metadata management, storage and archival in addition to the necessary mechanisms for publishing and disseminat...

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

147

Forest Structural Parameter Extraction Using Terrestrial LiDAR  

Science.gov (United States)

Accurate forest structural parameters are crucial to forest inventory, carbon cycling and wildlife habit modeling. LiDAR (Light Detection and Ranging) is a novel technique to measure forest structural parameters. In this paper we describe a pilot research to extract forest structural parameters, such as tree height, DBH (diameter at breast height), and the position of each individual tree using a terrestrial LiDAR. The raw data were acquired using a terrestrial LiDAR (Riegel, LMS-Z360i), and vertical and horizontal scanning were done to obtain point cloud of the whole scene. An ICP (Iterative Closet Point) algorithm was introduced to get the transformation matrix of each range image and to mosaic multiple range images together. Based on the whole data sets, a variable scale and threshold filtering method was used to classify ground from forest. Meanwhile, a DEM (Digital Elevation Model) and a CHM (Canopy Height Model) were generated from the classified point cloud. A stem detection algorithm was used to extract the location of individual trees. A slice above 1.3 m from the ground was extracted and rasterized. A circle fitting algorithm was used to retrieve the DBH based on the rasterized grid. Tree heights were calculated using the height difference between the vertex and nadir. Our methods and results confirm that terrestrial LiDAR can provide nondestructive, high- resolution and automatic determination of parameters required in forest inventory.

Huang, H.; Gong, P.; Cheng, X.; Wang, J.

2008-12-01

148

Forest structures retrieval from LiDAR onboard ULA  

Science.gov (United States)

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

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

2013-04-01

149

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 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 fenôme (more) no, 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 enfermedad arterial coronaria o con alto riesgo de desarrollarla. En insuficiencia cardíaca crónica (ICC), bajos niveles de colesterol están asociados con aumento de la mortalidad. (more) 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 increased risk to develop coronary artery disease. However, in patients with chronic heart failure (CHF), low levels of cholesterol are related to increased mortality. This phenomeno (more) n 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 specifically in CHF models and patien

León, Carlos Andrés; Moro, Silvia

2007-12-01

150

Technology Transfer and Technological Capability Building in Informal Firms in Tanzania  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Technology transfer is important to understand how knowledge is transformed to economic value. Applying a case study approach, this thesis investigates the technology transfer efforts from the University of Dar Es Salaam to indigenous informal SMEs in Tanzania and examines the impact of one of their...

Szogs, Astrid

151

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

Science.gov (United States)

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

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

2010-01-01

152

National Policies towards Broadcasting in Tanzania.  

Science.gov (United States)

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

Samwilu-Mwaffisi, M.

153

Quality and comparison of antenatal care in public and private providers in the United Republic of Tanzania.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

OBJECTIVE: To compare the quality of public and private first-tier antenatal care services in Dar es Salaam, United Republic of Tanzania, using defined criteria. METHODS: Structural attributes of quality were assessed through a checklist, and process attributes, including interpersonal and technical...

Boller, Christoph; Wyss, Kaspar; Mtasiwa, Deo; Tanner, Marcel

154

Artisan Training and Employment Outcomes in Tanzania  

Science.gov (United States)

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

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

2006-01-01

155

'Es' war einmal ein Subjekt  

Directory of Open Access Journals (Sweden)

Full Text Available This article deals with the occurrence of 'es' in the subject position in German. It explores the functions of 'es' as the subject of impersonal verbs, impersonal copula constructions and impersonal passive constructions. Explanations are offered to its obligatory and facultative functions in different construction types. The final part of the paper explores through a pilot study the acceptability of 'es' as an expletive element in sentences with two predicates and one subject. Two rules are given to explain the findings.

Hentschel, Elke

2003-01-01

156

¡Dos es mejor que uno!  

Science.gov (United States)

Text Version... Es posible que los síntomas tarden algunos días o incluso semanas en aparecer, y pueden incluir fiebre, escalofríos, dolores musculares, náuseas ... More results from www.fda.gov/downloads/food/resourcesforyou

157

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

Directory of Open Access Journals (Sweden)

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

Michael G. Wing; Michael Craven; John Sessions; Jeff Wimer

2013-01-01

158

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

Scientific Electronic Library Online (English)

Full Text Available 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 (more) 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 personas significativas, sobre todo considerando el estigma que está asociado a él. El contacto con estos sujetos permitió que entendiéramos que mismo cuando estos son inte (more) rnados 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 stigma 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 (more) 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.

Gandra, Sofia Santanna; Teixeira, Zélia

2010-01-01

159

Performance testing of LiDAR exploitation software  

Science.gov (United States)

Mobile LiDAR systems are being used widely in recent years for many applications in the field of geoscience. One of most important limitations of this technology is the large computational requirements involved in data processing. Several software solutions for data processing are available in the market, but users are often unknown about the methodologies to verify their performance accurately. In this work a methodology for LiDAR software performance testing is presented and six different suites are studied: QT Modeler, AutoCAD Civil 3D, Mars 7, Fledermaus, Carlson and TopoDOT (all of them in x64). Results depict as QTModeler, TopoDOT and AutoCAD Civil 3D allow the loading of large datasets, while Fledermaus, Mars7 and Carlson do not achieve these powerful performance. AutoCAD Civil 3D needs large loading time in comparison with the most powerful softwares such as QTModeler and TopoDOT. Carlson suite depicts the poorest results among all the softwares under study, where point clouds larger than 5 million points cannot be loaded and loading time is very large in comparison with the other suites even for the smaller datasets. AutoCAD Civil 3D, Carlson and TopoDOT show more threads than other softwares like QTModeler, Mars7 and Fledermaus.

Varela-González, M.; González-Jorge, H.; Riveiro, B.; Arias, P.

2013-04-01

160

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

Directory of Open Access Journals (Sweden)

Full Text Available One of the first areas investigated for commercial applications of LiDAR was for forest applications. Topography and forest coverage are of extreme importance for forest resources managers. Accurate information on trees height and density, besides being fundamental for planning, are hard to obtain by conventional methods. Laser scanning technology, as opposed to satellite images and aerial photographs, can concurrently map the ground and obtain estimates of trees height. The use of modeling associated with LiDAR data allows to obtain estimates of several other forest variables such as basal area, diameter, volume,�  biomass and fuel material. Besides these applications, LiDAR technology presents a great potential for planning forest harvesting activities, road construction and maintenance. However, there are great challenges to be overcome in developing technologies and computational applications more robust and reliable for modeling data from this type of sensor.doi: 10.4336/2010.pfb.30.63.231 Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 Uma das primeiras �¡reas investigadas para o uso comercial do sistema de varredura a laser LiDAR (Light Detection and Ranging) foram as aplica�§�µes florestais. As informa�§�µes da topografia e da cobertura florestal s�£o extremamente importantes para os gestores de recursos florestais e naturais. Informa�§�µes precisas sobre altura das �¡rvores e densidade, al�©m de serem fundamentais, s�£o de dif�­cil obten�§�£o, com a utiliza�§�£o das t�©cnicas convencionais. A tecnologia de varredura a laser, ao contr�¡rio das imagens de sat�©lite e de fotografias a�©reas, pode simultaneamente mapear o terreno embaixo das �¡rvores, bem como obter a estimativa da altura destas. A utiliza�§�£o da modelagem integrada aos dados LiDAR possibilita, tamb�©m, estimativas de diversas vari�¡veis florestais, como: �¡rea basal, di�¢metro, volume, biomassa, carbono e quantidade de material combust�­vel. Apresenta, igualmente, grande potencial nas atividades de�  planejamento da explora�§�£o florestal e constru�§�£o de estradas. Entretanto, existem ainda muitos desafios a serem superados no desenvolvimento de metodologias e aplica�§�µes computacionais mais confi�¡veis e robustas�  para a modelagem de dados provenientes deste sensor.doi: 10.4336/2010.pfb.30.63.231

Marcos Giongo; Henrique Soares Koehler; Sebastião do Amaral Machado; Flavio Felipe Kirchner; Marco Marchetti

2010-01-01

 
 
 
 
161

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

162

Update 2012 der ESC-Guidelines zum Management von Vorhofflimmern - Was gibt es Neues?  

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Full Text Available Kurzfassung: Das Guideline-Update der ESC zum Management von Vorhofflimmern betrifft vor allem die Bereiche Antikoagulation, medikamentöse Rhythmuskontrolle und Katheterablation. Im Bereich der Antikoagulation stellen die Etablierung des CHADSVASc- und des HAS-BLEDScores zur Risikostratifizierung sowie die Einführung der neuen Antikoagulantien die wichtigsten Neuerungen dar. Hinsichtlich der medikamentösen Therapie kommt es in den Guidelines zu einer Erst- bzw. Neubewertung von Vernakalant zur medikamentösen Kardioversion und von Dronedaron zur rhythmuserhaltenden Therapie. Der Stellenwert der Katheterablation von VHF wird durch die Guidelines weiter gesteigert.

Scherr D; Lercher P; Manninger-Wünscher M; Bisping E; Heinzel F; Rotman B; Pieske B

2013-01-01

163

Flood Modeling Using a Synthesis of Multi-Platform LiDAR Data  

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

Ashleigh B. Turner; Jeffrey D. Colby; Ryan M. Csontos; Michael Batten

2013-01-01

164

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

Science.gov (United States)

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

Espinoza, Delia; Lopez, Santiago, III

165

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

Science.gov (United States)

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 ...

J. R. Weidner P. R. Stoots

1990-01-01

166

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

2012-10-30

167

Multipath estimation in urban environments from joint GNSS receivers and LiDAR sensors.  

UK PubMed Central (United Kingdom)

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.

Ali K; Chen X; Dovis F; De Castro D; Fernández AJ

2012-01-01

168

Backscattering of individual LiDAR pulses from forest canopies explained by photogrammetrically derived vegetation structure  

Science.gov (United States)

In recent years, airborne LiDAR sensors have shown remarkable performance in the mapping of forest vegetation. This experimental study looks at LiDAR data at the scale of individual pulses to elucidate the sources behind interpulse variation in backscattering. Close-range photogrammetry was used for obtaining the canopy reference measurements at the ratio scale. The experiments illustrated different orientation techniques in the field, LiDAR acquisitions and photogrammetry in both leaf-on and leaf-off conditions, and two-waveform recording LiDAR sensors. The intrafootprint branch silhouettes in zenith-looking images, in which the camera, footprint, and LiDAR sensor were collinear, were extracted and contrasted with LiDAR backscattering. An enhanced planimetric match (refinement of strip matching) was achieved by shifting the pulses in a strip and searching for the maximal correlation between the silhouette and LiDAR intensity. The relative silhouette explained up to 80–90% of the interpulse variation. We tested whether accounting for the Gaussian spread of intrafootprint irradiance would improve the correlations, but the effect was blurred by small-scale geometric noise. Accounting for receiver gain variations in the Leica ALS60 sensor data strengthened the dependences. The size of the vegetation objects required for triggering a LiDAR observation was analyzed. We demonstrated the use of LiDAR pulses adjacent to canopy vegetation, which did not trigger a canopy echo, for canopy mapping. Pulses not triggering an echo constitute the complement to the actual canopy. We conclude that field photogrammetry is a useful tool for mapping forest canopies from below and that quantitative analysis is feasible even at the scale of single pulses for enhanced understanding of LiDAR observations from vegetation.

Korpela, Ilkka; Hovi, Aarne; Korhonen, Lauri

2013-09-01

169

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

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

Philippe Perrenoud

2011-01-01

170

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

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

Robert C. Parker; David L. Evans

2009-01-01

171

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

International Nuclear Information System (INIS)

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

2009-01-01

172

Transmission of intestinal schistosomiasis in Bahir Dar, northwest Ethiopia.  

UK PubMed Central (United Kingdom)

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

Erko B; Tedla S; Petros B

1991-10-01

173

Transmission of intestinal schistosomiasis in Bahir Dar, northwest Ethiopia.  

Science.gov (United States)

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

Erko, B; Tedla, S; Petros, B

1991-10-01

174

Dar razón de la libertad en Kant y en Hegel  

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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

175

Forest Roads Mapped Using LiDAR in Steep Forested Terrain  

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Full Text Available LiDAR-derived digital elevation models can reveal road networks located beneath dense forest canopy. This study tests the accuracy of forest road characteristics mapped using LiDAR in the Santa Cruz Mountains, CA. The position, gradient, and total length of a forest haul road were accurately extracted using a 1 m DEM. In comparison to a field-surveyed centerline, the LiDAR-derived road exhibited a positional accuracy of 1.5 m, road grade measurements within 0.53% mean absolute difference, and total road length within 0.2% of the field-surveyed length. Airborne LiDAR can provide thorough and accurate road inventory data to support forest management and watershed assessment activities.

Russell A. White; Brian C. Dietterick; Thomas Mastin; Rollin Strohman

2010-01-01

176

UTILITY OF THE DIMENSIONS OF ANGER REACTIONS-5 (DAR-5) SCALE AS A BRIEF ANGER MEASURE.  

UK PubMed Central (United Kingdom)

BACKGROUND: Anger is a common emotional sequel in the aftermath of traumatic experience. As it is associated with significant distress and influences recovery, anger requires routine screening and assessment. Most validated measures of anger are too lengthy for inclusion in self-report batteries or as screening tools. This study examines the psychometric properties of a shortened 5-item version of the Dimensions of Anger Reactions (DAR), an existing screening tool. METHODS: Responses to the DAR-5 were analysed from a sample of 486 college students with and without a history of trauma exposure. RESULTS: The DAR-5 demonstrated strong internal reliability and concurrent validity with the State Trait Anger Expression Inventory-2 (STAXI-2). Confirmatory factor analysis supported a single factor model of the DAR-5 for the trauma-exposed and nontrauma subsamples. A screening cut-off point of 12 on the DAR-5 successfully differentiated high and low scorers on STAXI-2 Trait Anger and PCL posttraumatic stress scores. Further discriminant validity was found with depression symptom scores. CONCLUSIONS: The results support use of the DAR-5 for screening for anger when a short scale is required.

Forbes D; Alkemade N; Mitchell D; Elhai JD; McHugh T; Bates G; Novaco RW; Bryant R; Lewis V

2013-06-01

177

Potential and limit of LiDAR data for earthquake recurrence characterization  

Science.gov (United States)

The characterization of earthquake (EQ) recurrence --assessing timing and size of past EQs along a given fault (section)-- has proven difficult, largely due the relatively short time span that is covered by instrumental seismic observations. While major EQs along a given fault are inferred to occur roughly on centennial to millennial time scales, seismographs to record them emerged little more than 100 years ago. Thus, recurrence of major EQs has essentially not yet been observed instrumentally. Stratigraphic and geomorphic evidence is used instead to describe and constrain recurrence of surface rupturing EQs. In the 1980s, analysis of such data sets culminated in the formulation of now classical EQ recurrence models. The debate about the correctness and thus applicability of these in part contradicting models is still ongoing. Over the last 10 years or so Light Detection and Ranging (LiDAR) technology became available to paleoseismic and tectono-geomorphic investigations. High spatial resolution, precision, and accuracy --the key features of LiDAR data-- revealed details in the tectono-geomorphic record that could not be resolved previously by field investigation or air photo analysis. As a result LiDAR data sets contributed and continues to contribute to improvements in the recurrence characterization of (surface rupturing) EQs. Here, I will present an overview on LiDAR data implementation in paleoseismic and tectono-geomorphic studies, including trench-based LiDAR, terrestrial LiDAR, and airborne LiDAR and I will discuss the impact of LiDAR data on constraining EQ recurrence characteristics as well as their relation to the classical EQ recurrence models. Additionally, I will discuss the intrinsic limits (that even LiDAR data cannot overcome) that arise when investigating geomorphic and stratigraphic evidence for EQ recurrence characterization. The natural complexity of the rupture process itself and its imprint on the analyzed data sets puts an unavoidable limit on the respective model fidelity. It is important to identify this limit to avoid over-interpretation of the otherwise very rich LiDAR data sets.

Zielke, Olaf

2013-04-01

178

Agrotóxico: que nome dar? Pesticide: how can it named?  

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Full Text Available Os trabalhadores, de um modo geral, estão sempre expostos a maiores ou menores intensidades de risco. Os agricultores, em particular, também estão expostos e de forma bastante estabelecida. Contudo, trabalhos têm mostrado que existe um código coletivo de proteção para lhes permitir dar continuidade às suas atividades, uma vez que, em sua maioria, os próprios donos do cultivo fazem parte do processo produtivo e, portanto, precisam garantir a sua safra aplicando os agrotóxicos. Este trabalho apresenta uma pesquisa desenvolvida com agricultores de dois municípios do sudeste do Piauí, utilizando uma abordagem qualitativa, com o intuito de compreender os mecanismos de proteção destes agricultores com a sua atividade. Os resultados apontaram para práticas defensivas tais como consumo de bebida alcoólica, a sublocação do serviço aos mais jovens e a existência de um certo grau de compreensão do risco à saúde com a utilização dos agrotóxicos. A partir daí, se discute a importância da denominação dada ao agrotóxico, como um fator de proteção que deveria ser mais valorizado para maximizar a proteção do agricultor, em vez de se manter a estratégia de aumento de informação e controle de EPI (Equipamento de Proteção Individual).Workers, generally speaking, are always exposed to higher or lower risk degrees. Farmers are particularly exposed, which is demonstrated in the specialized literature. Nevertheless, papers have stated that there are, in fact, some sort of common protection law that permit them carry on their activities. This is because the majority of the employers take part in the production process to guarantee their harvests using pesticide. This paper presents a research carried out in two cities in the Southwest Piauí State using a qualitative approach in order to understand the protection mechanisms farmers perform against their occupational hazards. The outcomes reveal defensive strategies such as alcohol consumption and subletting work to younger workers. There is also the existence of some level of awareness about the risks of pesticide use to health. Considering that, the importance of the designation given to pesticides as a protection factor must be discussed and that should be more valorized in order to maximize farmers self-protection instead of insisting on the information increase or the personal protection equipaments control strategies.

Márcia Gomide

2005-01-01

179

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

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

Worku Awoke; Kenie Seleshi

2013-01-01

180

Improved estimates of forest vegetation structure and biomass with a LiDAR-optimized sampling design  

Science.gov (United States)

LiDAR data are increasingly available from both airborne and spaceborne missions to map elevation and vegetation structure. Additionally, global coverage may soon become available with NASA's planned DESDynI sensor. However, substantial challenges remain to using the growing body of LiDAR data. First, the large volumes of data generated by LiDAR sensors require efficient processing methods. Second, efficient sampling methods are needed to collect the field data used to relate LiDAR data with vegetation structure. In this paper, we used low-density LiDAR data, summarized within pixels of a regular grid, to estimate forest structure and biomass across a 53,600 ha study area in northeastern Wisconsin. Additionally, we compared the predictive ability of models constructed from a random sample to a sample stratified using mean and standard deviation of LiDAR heights. Our models explained between 65 to 88% of the variability in DBH, basal area, tree height, and biomass. Prediction errors from models constructed using a random sample were up to 68% larger than those from the models built with a stratified sample. The stratified sample included a greater range of variability than the random sample. Thus, applying the random sample model to the entire population violated a tenet of regression analysis; namely, that models should not be used to extrapolate beyond the range of data from which they were constructed. Our results highlight that LiDAR data integrated with field data sampling designs can provide broad-scale assessments of vegetation structure and biomass, i.e., information crucial for carbon and biodiversity science.

Hawbaker, Todd J.; Keuler, Nicholas S.; Lesak, Adrian A.; Gobakken, Terje; Contrucci, Kirk; Radeloff, Volker C.

2009-06-01

 
 
 
 
181

Preliminary application and evaluation of loop-mediated isothermal amplification (LAMP) for detection of bovine theileriosis and trypanosomosis in Tanzania : research communication  

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Full Text Available The sensitivity of LAMP, PCR and microscopy to detect Theileria spp. and Trypanosoma congolense in field-derived bovine blood samples from Tanzania was evaluated and compared. No parasites were detected by microscopy. Furthermore, no bovine Theileria spp. were detected by LAMP and PCR from all the 24 samples collected from Arusha. Four and one out of 24 samples were positive for Theileria congolense infection by LAMP and PCR respectively while, 18 and nine out of 40 samples from Dar es Salaam were positive by LAMP and PCR for Theileria spp. Infection, respectively. Although all samples from Dar es Salaam were negative for Trypanosoma congolense infections by PCR, 12 out of 40 samples were LAMP positive. Whilst PCR is an established gene amplification method for the detection of Theileria and trypanosome parasites, this study introduces LAMP as an alternative molecular diagnostic tool that could be used in large-scale epidemiological surveys.

O.M.M. Thekisoe; J.D. Omolo; E.S. Swai; K. Hayashida; J. Zhang; C. Sugimoto; N. Inoue

2010-01-01

182

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

183

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

Science.gov (United States)

The wake flow produced from an Enercon E-70 wind turbine is investigated through three scanning Doppler wind LiDARs. One LiDAR is deployed upwind to characterize the incoming wind, while the other two LiDARs are located downstream to carry out wake measurements. The main challenge in performing measurements of wind turbine wakes is represented by the varying wind conditions, and by the consequent adjustments of the turbine yaw angle needed to maximize power production. Consequently, taking into account possible variations of the relative position between the LiDAR measurement volume and wake location, different measuring techniques were carried out in order to perform 2-D and 3-D characterizations of the mean wake velocity field. However, larger measurement volumes and higher spatial resolution require longer sampling periods; thus, to investigate wake turbulence tests were also performed by staring the LiDAR laser beam over fixed directions and with the maximum sampling frequency. The characterization of the wake recovery along the downwind direction is performed. Moreover, wake turbulence peaks are detected at turbine top-tip height, which can represent increased fatigue loads for downstream wind turbines within a wind farm.

Iungo, G. V.; Porté-Agel, F.

2013-05-01

184

Development of LiDAR measurements for the German offshore test site  

International Nuclear Information System (INIS)

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

2008-05-01

185

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

DEFF Research Database (Denmark)

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

Tomaszewski, Céline; Byrne, Stephen

2012-01-01

186

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

Directory of Open Access Journals (Sweden)

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

Redazione GEOmedia

2013-01-01

187

Robust 3D reconstruction using LiDAR and N - visual image  

Science.gov (United States)

3D image reconstruction is desirable in many applications such as city planning, cartography and many vision applications. The accuracy of the 3D reconstruction plays a vital role in many real world applications. We introduce a method which uses one LiDAR image and N conventional visual images to reduce the error and to build a robust registration for 3D reconstruction. In this method we used lines as features in both the LiDAR and visual images. Our proposed system consists of two steps. In the first step, we extract lines from the LiDAR and visual images using Hough transform. In the second step, we estimate the camera matrices using a search algorithm combined with the fundamental matrices for the visual cameras. We demonstrate our method on a synthetic model which is an idealized representation of an urban environment.

Duraisamy, Prakash; Jackson, Stephen; Namuduri, Kamesh; Alam, Mohammed S.; Buckles, Bill

2013-03-01

188

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

Science.gov (United States)

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 powerful high-throughput method for obtaining accurate and reproducible marker data, despite the low cost per data point. This method appears to be suitable for aligning the genetic maps of different segregating populations. The standard complexity reduction method, based on the methylation-sensitive PstI restriction enzyme, resulted in a high frequency of markers, although there was 52-54% redundancy due to the repeated sampling of highly similar sequences. Sequencing of the marker clones showed that they are significantly enriched for low-copy, genic regions. The genome coverage using the standard method was 55-76%. For improved genome coverage, an alternative complexity reduction method was examined, which resulted in less redundancy and additional segregating markers. The DArT markers proved to be of high quality and were very suitable for genetic mapping at low cost for the apple, providing moderate genome coverage. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11032-011-9579-5) contains supplementary material, which is available to authorized users. PMID:22408382

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

2011-05-15

189

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

UK PubMed Central (United Kingdom)

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 powerful high-throughput method for obtaining accurate and reproducible marker data, despite the low cost per data point. This method appears to be suitable for aligning the genetic maps of different segregating populations. The standard complexity reduction method, based on the methylation-sensitive PstI restriction enzyme, resulted in a high frequency of markers, although there was 52-54% redundancy due to the repeated sampling of highly similar sequences. Sequencing of the marker clones showed that they are significantly enriched for low-copy, genic regions. The genome coverage using the standard method was 55-76%. For improved genome coverage, an alternative complexity reduction method was examined, which resulted in less redundancy and additional segregating markers. The DArT markers proved to be of high quality and were very suitable for genetic mapping at low cost for the apple, providing moderate genome coverage. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11032-011-9579-5) contains supplementary material, which is available to authorized users.

Schouten HJ; van de Weg WE; Carling J; Khan SA; McKay SJ; van Kaauwen MP; Wittenberg AH; Koehorst-van Putten HJ; Noordijk Y; Gao Z; Rees DJ; Van Dyk MM; Jaccoud D; Considine MJ; Kilian A

2012-03-01

190

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; C. Hauer; B. Höfle; H. Habersack; N. Pfeifer

2008-01-01

191

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; C. Hauer; B. Höfle; H. Habersack; N. Pfeifer

2009-01-01

192

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

Directory of Open Access Journals (Sweden)

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

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

2011-01-01

193

Was bedeutet es, Rechte zu haben?  

Directory of Open Access Journals (Sweden)

Full Text Available Dieser Artikel bietet eine Einführung in die Sprache der Rechte und in die Rolle, die Rechte in Ethik und Recht spielen, unter besondererBezugnahme auf die Rechte von Kindern. Es zeichnet sich ab, dass es eine ganze Reihe von Funktionen gibt, die für die Sprache der Rechtecharakteristisch sind, sowohl in der Ethik als auch in der Rechtswissenschaft. Viele davon bieten die Möglichkeit, den Appell an moralische und juridische Prinzipien zu stärken, während andere Fallen stellen, die es zu vermeiden gilt. Zum Schluss werden zwei theoretische Fragen, die Rechte aufwerfen, behandelt: Zum einen, ob das Konzept der Rechte ohne Verlust durch das Konzept der Pflichten ersetzt werden kann; zum anderen, ob Rechte als soziale Konstrukte, die von Verpflichtungen abgeleitet sind, gesehen werden sollten, oder ob es plausibler ist, die Prioritätenfolge umzudrehen.

Birnbacher, Dieter

2012-01-01

194

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.

Mace Emma S; Xia Ling; Jordan David R; Halloran Kirsten; Parh Dipal K; Huttner Eric; Wenzl Peter; Kilian Andrzej

2008-01-01

195

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).

1984-01-01

196

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

Directory of Open Access Journals (Sweden)

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

Xuelian Meng; Nate Currit; Kaiguang Zhao

2010-01-01

197

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

Science.gov (United States)

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

Janke, Jason R.

2013-08-01

198

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; M. Cavalli; L. Marchi

2009-01-01

199

Monitoring Automotive Particulate Matter Emissions with LiDAR: A Review  

Directory of Open Access Journals (Sweden)

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

Claudio Mazzoleni; Hampden D. Kuhns; Hans Moosmüller

2010-01-01

200

Numerical study of ES-SAGD process  

Energy Technology Data Exchange (ETDEWEB)

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

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

2006-07-01

 
 
 
 
201

Draft genome sequence of Bacillus thuringiensis strain DAR 81934, which exhibits molluscicidal activity.  

UK PubMed Central (United Kingdom)

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 A; Pattemore J; Ash G; Williams A; Hane J

2013-03-01

202

Biomass estimation of Douglas fir stands using airborne LiDAR data  

Science.gov (United States)

Biomass is an important parameter not only for carbon cycle modeling, but also for supporting land management operations (e.g. land use policy, forest fire management). Various remote sensing data have been utilized for biomass estimation, especially in forested areas. LiDAR (Light Detection And Ran...

203

The impact of ethnicity on student relations in Bahir Dar University, Ethiopia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study was designed to assess the impacts of ethnicity on the relation of students from different ethnic background and to suggest possible strategies for managing student conflicts in Bahir-Dar University. Particularly, the study aims to examine inter-ethnic relations among Amhara, Oromo and Ti...

Asmamaw, Anteneh Tadesse

204

Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology.  

UK PubMed Central (United Kingdom)

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

Chase AF; Chase DZ; Fisher CT; Leisz SJ; Weishampel JF

2012-08-01

205

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

UK PubMed Central (United Kingdom)

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

Howard EL; Whittock SP; Jakše J; Carling J; Matthews PD; Probasco G; Henning JA; Darby P; Cerenak A; Javornik B; Kilian A; Koutoulis A

2011-05-01

206

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

207

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

Directory of Open Access Journals (Sweden)

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

Tuszynska Irina; Bujnicki Janusz M

2011-01-01

208

Drug-to-antibody ratio (DAR) by UV/Vis spectroscopy.  

UK PubMed Central (United Kingdom)

UV/Vis spectroscopy is a simple and convenient method to determine protein concentrations as well as the average number of drugs that are conjugated to the antibody in an antibody-drug conjugate (ADC). Using the measured absorbances of the ADC and the extinction coefficients of the antibody and the drug, the average drug-to-antibody ratio (DAR) can be determined.

Chen Y

2013-01-01

209

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

Directory of Open Access Journals (Sweden)

Full Text Available Our objective is to identify and map individuals of nine tree species in a Hawaiian lowland tropical forest by comparing the performance of a variety of semi-supervised classifiers. A method was adapted to process hyperspectral imagery, LiDAR intensity variables, and LiDAR-derived canopy height and use them to assess the identification accuracy. We found that semi-supervised Support Vector Machine classification using tensor summation kernel was superior to supervised classification, with demonstrable accuracy for at least eight out of nine species, and for all combinations of data types tested. We also found that the combination of hyperspectral imagery and LiDAR data usually improved species classification. Both LiDAR intensity and LiDAR canopy height proved useful for classification of certain species, but the improvements varied depending upon the species in question. Our results pave the way for target-species identification in tropical forests and other ecosystems.

Jean-Baptiste Féret; Gregory P. Asner

2012-01-01

210

Sensitivity analysis of simulated bathymetric LiDAR waveforms according to sensor and river parameters variability  

Science.gov (United States)

LiDAR (Light Detection and Ranging) can be used as a ranging system using electromagnetic waves in the optical domain. LiDAR airborne or satellite sensors are promising techniques for river bathymetry and water surface altimetry considering its potential accuracy, its high spatial density and resolution. When considering physics of LiDAR, many factors coming from sensor characteristics and optical phenomena interacting during the signal transfer at media interfaces are conditioning LiDAR signals, i.e. waveforms. Waveforms are the registered signals in LiDAR from which, hydrological variables, as surface water altimetry, bathymetry, are retrieved. To move forward in the LIDAR airborne and satellite sensors capabilities for river monitoring, a modelling tool extending different existing radiative transfer models has been developed. This model allows the simulation of LiDAR data from a set of instrumental parameters and a representative collection of fluvial target for laser beam (water turbidity, river bottom reflectivity, etc). Due to the large numbers of parameters in the modelling and their natural range of variation, one of the questions is which of those parameters have the most impact, and those who have a negligible effect on returned waveform? And consequently, which of them most impact the accuracy of the retrieved hydrological variables from waveforms? In order to assess the robustness of the proposed model, to look for parsimony and to identify the key sensor parameters, a study of the model sensitivity to different media characteristics (surface reflection, absorption, scattering, bottom Albedo, etc) and sensor parameters (wavelength, pulse width, transmitted power, etc) is performed. Due to the complexity of the LiDAR waveform modelling, we used a sensitivity analysis method based on variance decomposition (Sobol) and Latin hypercube random sampling design in factor variation domains. As output model are waveforms, i.e. temporal signal, we used the specific Sobol framework proposed by Lamboni (2010). Results are the synthetic Sobol indices showing which factors are highly conditioning waveforms and others that can be neglected in the modelling. By pursuing the sensitivity analysis up to the waveform inversion (Gaussian fitting) to retrieve bathymetry, sensor and river parameters which are the more impacting bathymetry accuracy can also been hierarchically identified in this framework.

Bailly, J.; Abdallah, H.; Baghdadi, N.; Saint-Geours, N.

2010-12-01

211

A universal airborne LiDAR approach for tropical forest carbon mapping.  

UK PubMed Central (United Kingdom)

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.

Asner GP; Mascaro J; Muller-Landau HC; Vieilledent G; Vaudry R; Rasamoelina M; Hall JS; van Breugel M

2012-04-01

212

Habitat assessment for forest dwelling species using LiDAR remote sensing: Capercaillie in the Alps  

UK PubMed Central (United Kingdom)

Large-scale information on habitat suitability is indispensable for planning management actions to further endangered species with large-spatial requirements. So far, remote sensing based habitat variables mostly included environmental and land cover data derived from passive sensors, but lacked information on vegetation structure. This is a serious constraint for the management of endangered species with specific structural requirements. Light detection and ranging (LiDAR), in contrast to passive remote sensing techniques, may bridge this gap in structural information at the landscape scale. We investigated the potential of LiDAR data to quantify habitat suitability for capercaillie (Tetrao urogallus), an endangered forest grouse in Central Europe, in a forest reserve of 17.7km². We used continuous variables of horizontal and vertical stand structure from first and last pulse LiDAR data and presence-absence information from field work to model habitat suitability with generalized linear models (GLM). The two final habitat suitability models explained the observed presence-absence pattern moderately well (AUC of 0.71 and 0.77) with horizontal structure explaining better than vertical structure. Relative tree canopy cover was the most important variable with intermediate values indicating highest habitat suitability. As such, LiDAR allowed us to translate the results from habitat modeling at the landscape scale to effective management recommendations at the local scale at a level of detail that hitherto was unavailable for large areas. LiDAR thus enabled us to integrate individual habitat preferences at the scale of entire populations and thus offers great potential for effective habitat monitoring and management of endangered species.

Graf RolandF; Mathys Lukas; Bollmann Kurt

2009-01-01

213

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

Directory of Open Access Journals (Sweden)

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.

Kopecký David; Bartoš Jan; Lukaszewski Adam J; Baird James H; ?ernoch Vladimír; Kölliker Roland; Rognli Odd; Blois Helene; Caig Vanessa; Lübberstedt Thomas; Studer Bruno; Shaw Paul; Doležel Jaroslav; Kilian Andrzej

2009-01-01

214

A fine-scale architectural model of trees to enhance LiDAR-derived measurements of forest canopy structure  

UK PubMed Central (United Kingdom)

Forest canopy structure consists of the complex spatial arrangement of the foliage, branches, and boles of trees. Measuring forest canopy structure is an active research question because of its influence on a wide range of biophysical and ecological processes. Light detection and ranging technology (LiDAR), both with airborne and terrestrial instruments, has been used to assess canopy structure and estimate vegetation attributes. Although LiDAR has proven to be an effective tool for mapping the forest canopy, its ability to probe all canopy elements is limited by the signal occlusion that occurs when multiple objects lie between the sensor and target area. This limitation can be alleviated by comparing realistic fine-scale 3D canopy architectural models with terrestrial and airborne LiDAR point-cloud data sets. We propose a method that mitigates the limitations of object occlusion and allows detailed description of 3D canopy structure from small-footprint airborne LiDAR (ALiDAR). Our approach involved reconstructing stem-mapped forest stands with catalogs of terrestrial LiDAR (TLiDAR) scans of individual trees, using an architectural model called L-Architect (LiDAR data to vegetation Architecture). L-Architect has been developed to link TLiDAR scans to tree-level structural attributes that reproduce the branching structure and foliage spatial distribution of a tree according to information gathered from detailed mensurational data. This study has further developed the potential of L-Architect to reconstruct individual trees to model the structure of a stand. The method was evaluated by comparing vertical profiles of material density for a forest stand calculated from TLiDAR scans and L-Architect's canopy model, resulting in a Pearson's correlation coefficient of 0.95. Most individual tree structures were reproduced with high accuracy, with a relative deviation of <10% on tree diameter at breast height (DBH) and total leaf area. The use of the ALiDAR data together with L-Architect allowed quantifying how significant object occlusion affects untreated data. We obtained mean correlations between ALiDAR data sets and L-Architect derived profiles of 0.84 and 0.43 for the vertical and horizontal material distribution, respectively. We demonstrate how L-Architect can be used to make accurate 3D maps of stand components from LiDAR data.

Côté Jean-François; Fournier RichardA; Frazer GordonW; Olaf Niemann K

2012-12-01

215

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.

1989-05-00

216

Differentiation of ES cells into cerebellar neurons.  

Science.gov (United States)

The neuronal circuits of the cerebellar cortex are essential for motor and sensory learning, associative memory formation, and the vestibular ocular reflex. In children and young adults, tumors of the granule cell, the medulloblastomas, represent 40% of brain tumors. We report the differentiation of E14 ES cells into mature granule neurons by sequential treatment with secreted factors (WNT1, FGF8, and RA) that initiate patterning in the cerebellar region of the neural tube, bone morphogenic proteins (BMP6/7 and GDF7) that induce early granule cell progenitor markers (MATH1, MEIS1, ZIC1), mitogens (SHH, JAG1) that control proliferation and induce additional granule cell markers (Cyclin D2, PAX2/6), and culture in glial-conditioned medium to induce markers of mature granule neurons (GABAalpha(6)r), including ZIC2, a unique marker for granule neurons. Differentiated ES cells formed classic "T-shaped" granule cell axons in vitro, and implantation of differentiated Pde1c-Egfp-BAC transgenic ES cells into the external granule cell layer of neonatal mice resulted in the extension of parallel fibers, migration across the molecular layer, incorporation into the internal granule cell layer, and extension of short dendrites, typical of young granule cells forming synaptic connections with afferent mossy fibers. These results underscore the utility of treating ES cells with local, inductive signals that regulate CNS neuronal development in vivo as a strategy for cell replacement therapy of defined neuronal populations. PMID:17293457

Salero, Enrique; Hatten, Mary E

2007-02-09

217

A DArT marker genetic map of perennial ryegrass (Lolium perenne L.) integrated with detailed comparative mapping information; comparison with existing DArT marker genetic maps of Lolium perenne, L. multiflorum and Festuca pratensis.  

UK PubMed Central (United Kingdom)

BACKGROUND: Ryegrasses and fescues (genera, Lolium and Festuca) are species of forage and turf grasses which are used widely in agricultural and amenity situations. They are classified within the sub-family Pooideae and so are closely related to Brachypodium distachyon, wheat, barley, rye and oats. Recently, a DArT array has been developed which can be used in generating marker and mapping information for ryegrasses and fescues. This represents a potential common marker set for ryegrass and fescue researchers which can be linked through to comparative genomic information for the grasses. RESULTS: A F2 perennial ryegrass genetic map was developed consisting of 7 linkage groups defined by 1316 markers and deriving a total map length of 683 cM. The marker set included 866 DArT and 315 gene sequence-based markers. Comparison with previous DArT mapping studies in perennial and Italian ryegrass (L. multiflorum) identified 87 and 105 DArT markers in common, respectively, of which 94% and 87% mapped to homoeologous linkage groups. A similar comparison with meadow fescue (F. pratensis) identified only 28 DArT markers in common, of which c. 50% mapped to non-homoelogous linkage groups. In L. perenne, the genetic distance spanned by the DArT markers encompassed the majority of the regions that could be described in terms of comparative genomic relationships with rice, Brachypodium distachyon, and Sorghum bicolor. CONCLUSIONS: DArT markers are likely to be a useful common marker resource for ryegrasses and fescues, though the success in aligning different populations through the mapping of common markers will be influenced by degrees of population interrelatedness. The detailed mapping of DArT and gene-based markers in this study potentially allows comparative relationships to be derived in future mapping populations characterised using solely DArT markers.

King J; Thomas A; James C; King I; Armstead I

2013-07-01

218

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

Science.gov (United States)

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

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

2012-04-01

219

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

Directory of Open Access Journals (Sweden)

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

Michael Leslar; Jian-guo Wang; Baoxin Hu

2011-01-01

220

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

UK PubMed Central (United Kingdom)

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.

Jing HC; Bayon C; Kanyuka K; Berry S; Wenzl P; Huttner E; Kilian A; Hammond-Kosack KE

2009-01-01

 
 
 
 
221

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.

Jing Hai-Chun; Bayon Carlos; Kanyuka Kostya; Berry Simon; Wenzl Peter; Huttner Eric; Kilian Andrzej; E Hammond-Kosack Kim

2009-01-01

222

¿El terrorismo global es amorfo o polimorfo?  

Directory of Open Access Journals (Sweden)

Full Text Available La urdimbre del terrorismo global incluye, siete años después de los atentados del 11 de septiembre, tanto a una al–Qaeda reconstituida y a las extensiones territoriales que ha conseguido establecer, como al heterogéneo conjunto de grupos y organizaciones afines a la misma, al igual que a células locales independientes e informales constituidas de manera espontánea. Sería un error tomar esta última parte por el todo y afirmar que el terrorismo global es un fenómeno amorfo, cuando en realidad es polimorfo. Los riesgos y amenazas que el terrorismo global plantea para un determinado país o región del mundo dependen precisamente del modo en que se combinan sus distintos componentes. Para las sociedades occidentales, esos riesgos y amenazas no son ahora menores, aunque sí más complejos. Los atentados del 11 de marzo en Madrid constituyeron un ejemplo.

Fernando Reinares

2009-01-01

223

Software for the ES-1010 intercomputer connection  

International Nuclear Information System (INIS)

Software for the ES-1010 intercomputer connection, realized in the framework of NODAL interpretation system, used in on-line control system for the ITEP proton synchrotron is described. A description is given of command organization principles and respective logs of intercompUter information exchange. The described software enables to combine up to 16 computers into one system. The development of intercomputer information exchange procedure is the first stage for the creation of mutiprocessing control system of the ITEP accelerator complex.

1983-01-01

224

[The activity of the "Hygrobac DAR 352" filter in resuscitation patients  

UK PubMed Central (United Kingdom)

The Authors clinically evaluated the efficacy of the "Hygrobac DAR 352" filter as an antibacterial barrier in a group of patients during mechanical ventilation. After 24 hours of IPVV, a cultural sample has been taken on both sides of the filter introduced in the breathing circuit (patient's side; ventilator's side). While bacteria has been isolated on "the patient's side" of the filter, they were not present on the surface of the "ventilator's side" of the filter. Therefore, the Authors emphasize that the Hygrobac DAR 352 filter represents a good barrier against the passage of bacteria, as it avoids the contamination of the mechanical ventilator by keeping pathogenic organisms coming from patient's airways inside the filter itself.

Grondona G; Morando L; Piccardo GC; D'Angelo MT

1990-04-01

225

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

Science.gov (United States)

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

Trickey, Evan; Church, Philip; Cao, Xiaoying

2013-05-01

226

Point-based rendering optimization with textured meshes for fast LiDAR visualization  

Science.gov (United States)

In this paper a new method for high quality rendering of large LiDAR-based terrain data is presented. The visualization system upgrades previous methods of point-based rendering by detecting continuous surfaces and replacing them with decimated triangle meshes. High-quality visualization is retained by using render-to-texture methods to generate color textures and bump maps from original LiDAR data and applying them to the newly generated triangle meshes. This hybrid approach is able to decrease rendering times of surfaces to less than 50% with little to no difference in rendering quality. The described optimizations can be executed at run-time without interfering with user interaction.

Kuder, Marko; Šterk, Marjan; Žalik, Borut

2013-09-01

227

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

Directory of Open Access Journals (Sweden)

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

Sandra Englhart; Juilson Jubanski; Florian Siegert

2013-01-01

228

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

Directory of Open Access Journals (Sweden)

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

Asghar Montazerol Ghaem; Bahman Zeinali; Seyed Asghar Mahmoud Abadi

2013-01-01

229

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

Science.gov (United States)

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

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

2013-01-01

230

Combining LiDAR and IKONOS data for eco-hydrological classification of an ombrotrophic peatland.  

UK PubMed Central (United Kingdom)

Remote sensing techniques have potential for peatland monitoring, but most previous work has focused on spectral approaches that often result in poor discrimination of cover types and neglect structural information. Peatlands contain structural "microtopes" (e.g., hummocks and hollows) which are linked to hydrology, biodiversity and carbon sequestration, and information on surface structure is thus a useful proxy for peatland condition. The objective of this work was to develop and test a new eco-hydrological mapping technique for ombrotrophic (rain-fed) peatlands using a combined spectral-structural remote sensing approach. The study site was Wedholme Flow, Cumbria, UK. Airborne light dectection and ranging (LiDAR) data were used with IKONOS data in a combined multispectral-structural approach for mapping peatland condition classes. LiDAR data were preprocessed so that spatial estimates of minimum and maximum land surface height, variance and semi-variance (from semi-variogram analysis) were extracted. These were assimilated alongside IKONOS data into a maximum likelihood classification procedure, and thematic outputs were compared. Ecological survey data were used to validate the results. Considerable improvements in thematic separation of peatland classes were achieved when spatially-distributed measurements of LiDAR variance or semi-variance were included. Specifically, the classification accuracy improved from 71.8% (IKONOS data only) to 88.0% when a LiDAR semi-variance product was used. Of note was the improved delineation of management classes (including Eriophorum bog, active raised bog and degraded raised bog). The application of a combined textural-optical approach can improve land cover mapping in areas where reliance on purely spectral discrimination approaches would otherwise result in considerable thematic uncertainty.

Anderson K; Bennie JJ; Milton EJ; Hughes PD; Lindsay R; Meade R

2010-01-01

231

Combining LiDAR and IKONOS data for eco-hydrological classification of an ombrotrophic peatland.  

Science.gov (United States)

Remote sensing techniques have potential for peatland monitoring, but most previous work has focused on spectral approaches that often result in poor discrimination of cover types and neglect structural information. Peatlands contain structural "microtopes" (e.g., hummocks and hollows) which are linked to hydrology, biodiversity and carbon sequestration, and information on surface structure is thus a useful proxy for peatland condition. The objective of this work was to develop and test a new eco-hydrological mapping technique for ombrotrophic (rain-fed) peatlands using a combined spectral-structural remote sensing approach. The study site was Wedholme Flow, Cumbria, UK. Airborne light dectection and ranging (LiDAR) data were used with IKONOS data in a combined multispectral-structural approach for mapping peatland condition classes. LiDAR data were preprocessed so that spatial estimates of minimum and maximum land surface height, variance and semi-variance (from semi-variogram analysis) were extracted. These were assimilated alongside IKONOS data into a maximum likelihood classification procedure, and thematic outputs were compared. Ecological survey data were used to validate the results. Considerable improvements in thematic separation of peatland classes were achieved when spatially-distributed measurements of LiDAR variance or semi-variance were included. Specifically, the classification accuracy improved from 71.8% (IKONOS data only) to 88.0% when a LiDAR semi-variance product was used. Of note was the improved delineation of management classes (including Eriophorum bog, active raised bog and degraded raised bog). The application of a combined textural-optical approach can improve land cover mapping in areas where reliance on purely spectral discrimination approaches would otherwise result in considerable thematic uncertainty. PMID:20048314

Anderson, K; Bennie, J J; Milton, E J; Hughes, P D M; Lindsay, R; Meade, R

2009-12-30

232

Analysis of airborne LiDAR surveys to quantify the characteristic morphologies of northern forested wetlands  

Science.gov (United States)

A new technique for quantifying the geomorphic form of northern forested wetlands from airborne LiDAR surveys is introduced, demonstrating the unprecedented ability to characterize the geomorphic form of northern forested wetlands using high-resolution digital topography. Two quantitative indices are presented, including the lagg width index (LWI) which objectively quantifies the lagg width, and the lateral slope index (LSI) which is a proxy measurement for the dome shape or convexity of the wetland ground surface. For 14 forested wetlands in central Ontario, Canada, northwestern Ontario, Canada, and northern Minnesota, United States, these indices were systematically correlated to metrics of topographic setting computed from LiDAR digital elevation models. In particular, these indices were strongly correlated with a Peatland Topographic Index (PTI, r2 = 0.58 and r2 = 0.64, respectively, p < = 0.001) describing the relative influence of upslope contributing area on the hydrology and biogeochemistry of individual wetlands. The relationship between PTI and the LWI and LSI indices was interpreted as geomorphic evolution in response to the spatially varying influence of upslope runoff on subsurface hydrochemistry. Spatial patterns of near-surface pore water chemistry were consistent with this interpretation. Specifically, at four wetland sites sampled extensively for pore water chemistry, the mean and variance of near-surface pore water methylmercury (MeHg) concentrations were higher within the zone of enhanced upland-wetland interactions, as inferred from the LiDAR-derived LWI estimates. Use of LiDAR surveys to measure subtle topographic gradients within wetlands may therefore help quantify the influence of upland-wetland interactions on biogeochemical cycling and export in northern forested landscapes.

Richardson, Murray C.; Mitchell, Carl P. J.; Branfireun, Brian A.; Kolka, Randall K.

2010-09-01

233

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

234

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

235

Shift work and sleep disorder among textile mill workers in Bahir Dar, northwest Ethiopia.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To assess the length and quality of sleep among shift workers at Bahir Dar textile mill. DESIGN: A cross sectional study using structured questionnaire that contained sociodemographic variables, duration of work, work schedule, number of sleeping hours, sleep disorders, and associated reasons for such disorders. SETTING: A textile mill in Bahir Dar, northwest Ethiopia. SUBJECTS: Three-hundred ninety four random sample of production workers of the mill. OUTCOME MEASURES: Sleep disorders, and the impact of external and home environment on sleep. RESULTS: The mean duration of work in the factory was 25.4 +/- 7.1 years. Ninety-seven per cent of the study population work in a rotating eight hourly shift system. The mean number of hours a worker sleeps after a worked shift was 5.1 +/- 2.3. Two hundred thirty (58.4%) claimed to experience a sleep disorder. Sleep disturbance was significantly associated with rotating shift work, external environmental noise, and working in the spinning department. CONCLUSION: The majority of the workers in Bahir Dar textile mill experienced sleep disturbances as detailed in the study methodology.

Abebe Y; Fantahun M

1999-07-01

236

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

UK PubMed Central (United Kingdom)

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.

Taft RJ; Vanderver A; Leventer RJ; Damiani SA; Simons C; Grimmond SM; Miller D; Schmidt J; Lockhart PJ; Pope K; Ru K; Crawford J; Rosser T; de Coo IF; Juneja M; Verma IC; Prabhakar P; Blaser S; Raiman J; Pouwels PJ; Bevova MR; Abbink TE; van der Knaap MS; Wolf NI

2013-05-01

237

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

Science.gov (United States)

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

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

2006-06-01

238

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.

Wade T. Tinkham; Hongyu Huang; Alistair M. S. Smith; Rupesh Shrestha; Michael J. Falkowski; Andrew T. Hudak; Timothy E. Link; Nancy F. Glenn; Danny G Marks

2011-01-01

239

Range determination for generating point clouds from airborne small footprint LiDAR waveforms.  

Science.gov (United States)

This paper presents a range determination approach for generating point clouds from small footprint LiDAR waveforms. Waveform deformation over complex terrain area is simulated using convolution. Drift of the peak center position is analyzed to identify the first echo returned by the illuminated objects in the LiDAR footprint. An approximate start point of peak in the waveform is estimated and adopted as the indicator of range calculation; range correction method is proposed to correct pulse widening over complex terrain surface. The experiment was carried out on small footprint LiDAR waveform data acquired by RIEGL LMS-Q560. The results suggest that the proposed approach generates more points than standard commercial products; based on field measurements, a comparative analysis between the point clouds generated by the proposed approach and the commercial software GeocodeWF indicates that: 1). the proposed approach obtained more accurate tree heights; 2). smooth surface can be achieved with low standard deviation. In summary, the proposed approach provides a satisfactory solution for range determination in estimating 3D coordinate values of point clouds, especially for correcting range information of waveforms containing deformed peaks. PMID:23187409

Qin, Yuchu; Vu, Tuong Thuy; Ban, Yifang; Niu, Zheng

2012-11-01

240

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

UK PubMed Central (United Kingdom)

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 CL; Carter WE; Shrestha RL; Dietrich WE

2013-08-01

 
 
 
 
241

ASTER GDEM validation using LiDAR data over coastal regions of Greenland  

DEFF Research Database (Denmark)

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

Hvidegaard, Sine Munk; SØrensen, Louise Sandberg

2011-01-01

242

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

Science.gov (United States)

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

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

2013-09-01

243

Exercise 8: Using LiDAR and GPS data to model the water table in ArcScene  

Science.gov (United States)

Barbara and David Tewksbury, Hamilton College Summary In this exercise, students process LiDAR data for the Hamilton College campus area to determine accurate elevations of wellheads of sampling wells on campus. ...

Tewksbury, Barb

244

First test of a nacelle-based '2-beam' wind LiDAR system under offshore conditions  

Energy Technology Data Exchange (ETDEWEB)

First results of the intercomparison between a nacelle-based LiDAR and FINO1 mast measurements based on 10-min mean values have been presented in this article. The results from the LiDAR campaign are promising, especially for the comparison of mean wind speeds and the high data availability of the two beams LIDAR WIND IRIS prototype. However some open questions like the increasing wind speeds with distance to the rotor plane and the role of the blocking effect on the LiDAR wind speed should be clarified in further studies. It is evident, that the '2-beams' LiDAR has a high potential in providing wind speeds for the purpose of power curve measurements once these deviations from a mast measurement are understood and corrected, as they have a significant influence on the shape of the power curve. (orig.)

Canadillas, B.; Neumann, T. [Deutsches Windenergie-Institut GmbH (DEWI), Wilhelmshaven (Germany)

2011-08-15

245

La disputa por el cuerpo de la mujer, la/s sexualidad/es y la/s familia/s en Estados Unidos y México  

Directory of Open Access Journals (Sweden)

Full Text Available La intención del presente artículo es iniciar una revisión de la disputa cultural contemporánea por dar sentido a la realidad social entre dos propuestas societales que se expresan tanto en Estados Unidos como en México y que han situado al cuerpo de la mujer, la sexualidad, la pareja y la familia en el centro de la contienda. En un primer acercamiento a la problemática, propongo identificar el contexto histórico que definió la fisonomía contemporánea de los agentes confrontados, describir los procesos de consolidación de dichas actoras/es colectivas/os y la maduración de sus planteamientos en Estados Unidos y México, examinar su lógica articuladora y el avance político de sus propuestas a partir de la sinergia nacional-internacional y, finalmente, ejemplificar su mecánica a través del proceso de la despenalización del aborto en México, D. F., en julio de 2007, donde se definieron nítidamente las fronteras imaginarias de feministas, laicas/os, liberales y progresistas, por un lado, y las/os neoconservadoras/es y fundamentalistas religiosas/os, por el otro. El artículo pretende ejemplificar las diferencias y tensiones entre dichas lecturas societales en el estira y afloja de la disputa por dar sentido a la realidad social y lograr la hegemonía de la interpretación cultural

Elizabeth Maier

2008-01-01

246

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

247

DArT markers for the rye genome - genetic diversity and mapping  

Directory of Open Access Journals (Sweden)

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

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

2009-01-01

248

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

Science.gov (United States)

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

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

2013-04-01

249

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.

Paul Treitz; Kevin Lim; Murray Woods; Doug Pitt; Dave Nesbitt; Dave Etheridge

2012-01-01

250

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

2010-01-01

251

EMI Execution Service (EMI-ES) Specification  

CERN Multimedia

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

Schuller, B

2010-01-01

252

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

253

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

254

Comparison of genetic and cytogenetic maps of hexaploid wheat (Triticum aestivum L.) using SSR and DArT markers.  

UK PubMed Central (United Kingdom)

A number of technologies are available to increase the abundance of DNA markers and contribute to developing high resolution genetic maps suitable for genetic analysis. The aim of this study was to expand the number of Diversity Array Technology (DArT) markers on the wheat array that can be mapped in the wheat genome, and to determine their chromosomal location with respect to simple sequence repeat (SSR) markers and their position on the cytogenetic map. A total of 749 and 512 individual DArT and SSR markers, respectively, were identified on at least one of four genetic maps derived from recombinant inbred line (RIL) or doubled haploid (DH) populations. A number of clustered DArT markers were observed in each genetic map, in which 20-34% of markers were redundant. Segregation distortion of DArT and SSR markers was also observed in each mapping population. Only 14% of markers on the Version 2.0 wheat array were assigned to chromosomal bins by deletion mapping using aneuploid lines. In this regard, methylation effects need to be considered when applying DArT marker in genetic mapping. However, deletion mapping of DArT markers provides a reference to align genetic and cytogenetic maps and estimate the coverage of DNA markers across the wheat genome.

Francki MG; Walker E; Crawford AC; Broughton S; Ohm HW; Barclay I; Wilson RE; McLean R

2009-02-01

255

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

Directory of Open Access Journals (Sweden)

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

Pirotti F

2011-01-01

256

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

Scientific Electronic Library Online (English)

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

Uzar, Melis; Yastikli, Naci

2013-06-01

257

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

CERN Multimedia

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

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

2009-01-01

258

El Pseudo-Hiepes es Bernardo Polo  

Directory of Open Access Journals (Sweden)

Full Text Available Nearly fifteen years ago, the author proposed the name Pseudo-Hiepes to refer to a then anonymous painter whom certain Italian art historians had called the Master of the Lombard Fruit Bowl. At the time, he argued for an Aragonese origin in the later part of the century. A signed work has finally been discovered and is published here. The artist was indeed from Zaragoza, and his name is Bernardo Polo.Hace unos quince años, el autor propuso el apodo Pseudo-Hiepes para identificar al pintor anónimo a quien algunos entendidos italianos habían bautizado como Maestro del Frutero lombardo. En aquel entonces, argumentó que debía tratarse de un artista aragonés, de la segunda mitad de siglo. Por fin ha aparecido una obra firmada que se presenta aquí. Efectivamente, el artista era zaragozano y su nombre es Bernardo Polo.

Jordan, William B.

2009-01-01

259

Contratación Electrónica: ¿Es necesaria una convención internacional ?  

Directory of Open Access Journals (Sweden)

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

Daniel Peña Valenzuela

2002-01-01

260

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.

Thomas Adams; Peter Beets; Christopher Parrish

2012-01-01

 
 
 
 
261

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.

Luke Wallace; Arko Lucieer; Christopher Watson; Darren Turner

2012-01-01

262

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

Science.gov (United States)

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

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

2013-04-01

263

LiDAR measurements of full scale wind turbine wake characteristics  

DEFF Research Database (Denmark)

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

Hansen, Kurt Schaldemose; Larsen, Gunner Chr.

2009-01-01

264

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

Directory of Open Access Journals (Sweden)

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

Alberti G; Boscutti F; Pirotti F; Bertacco C; De Simon G; Sigura M; Cazorzi F; Bonfanti P

2013-01-01

265

LA TASA DE CAMBIO: ¿ES GERENCIABLE?  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El estudio "La tasa de cambio: ¿Es gerenciable?" define el tipo de cambio como el precio de una moneda en función de otra, señalando su influencia en los mercados, al formar los precios. Son los regímenes cambiarios fijo, flotante y administrado, los empleados para orientar la política cambiaria, pudiéndose predecir el tipo de cambio mediante la observación analítica de diez factores esenciales, herramienta que le permite al administrador, pronosticar la tasa de cambio y decidir sus operaciones comerciales con visión gerencial. Abstract in english Exchange rate: is it manageable? The paper titled "Exchange rate: is it manageable?" defines exchange rate as the price of a currency in function of another, thereby noting the influence it has on setting prices in the markets. Fixed, variable and managed exchange systems are used for guiding the exchange policies and forecasting exchange rates based on an analytical review of 10 determining factors. This tool enables administrators to forecast exchange rates and make decisions about their business operations with a management vision.

RAMÍREZ, ELBAR; CAJIGAS ROMERO, MARGOT; LOZANO REYES, FANOR

2007-09-01

266

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

Science.gov (United States)

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

Aktaruzzaman, Md.; Schmitt, Theo G.

2011-10-01

267

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

Directory of Open Access Journals (Sweden)

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

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

2011-01-01

268

A new method for building roof segmentation from airborne LiDAR point cloud data  

Science.gov (United States)

A new method based on the combination of two kinds of clustering algorithms for building roof segmentation from airborne LiDAR (light detection and ranging) point cloud data is proposed. The K-plane algorithm is introduced to classify the laser footprints that cannot be correctly classified by the traditional K-means algorithm. High-precision classification can be obtained by combining the two aforementioned clustering algorithms. Furthermore, to improve the performance of the new segmentation method, a new initialization method is proposed to acquire the number and coordinates of the initial cluster centers for the K-means algorithm. In the proposed initialization method, the geometrical planes of a building roof are estimated from the elevation image of the building roof by using the mathematical morphology and Hough transform techniques. By calculating the number and normal vectors of the estimated geometrical planes, the number and coordinates of the initial cluster centers for the K-means algorithm are obtained. With the aid of the proposed initialization and segmentation methods, the point cloud of the building roof can be rapidly and appropriately classified. The proposed methods are validated by using both simulated and real LiDAR data.

Kong, Deming; Xu, Lijun; Li, Xiaolu

2013-09-01

269

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

DEFF Research Database (Denmark)

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

Boudreault, Louis-Etienne; Dellwik, Ebba

270

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

Science.gov (United States)

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

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

2013-05-01

271

Evaluation of Automatic Building Detection Approaches Combining High Resolution Images and LiDAR Data  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, two main approaches for automatic building detection and localization using high spatial resolution imagery and LiDAR data are compared and evaluated: thresholding-based and object-based classification. The thresholding-based approach is founded on the establishment of two threshold values: one refers to the minimum height to be considered as building, defined using the LiDAR data, and the other refers to the presence of vegetation, which is defined according to the spectral response. The other approach follows the standard scheme of object-based image classification: segmentation, feature extraction and selection, and classification, here performed using decision trees. In addition, the effect of the inclusion in the building detection process of contextual relations with the shadows is evaluated. Quality assessment is performed at two different levels: area and object. Area-level evaluates the building delineation performance, whereas object-level assesses the accuracy in the spatial location of individual buildings. The results obtained show a high efficiency of the evaluated methods for building detection techniques, in particular the thresholding-based approach, when the parameters are properly adjusted and adapted to the type of urban landscape considered.

Txomin Hermosilla; Luis A. Ruiz; Jorge A. Recio; Javier Estornell

2011-01-01

272

LiDAR-Assisted identification of an active fault near Truckee, California  

Science.gov (United States)

We use high-resolution (1.5-2.4 points/m2) bare-earth airborne Light Detection and Ranging (LiDAR) imagery to identify, map, constrain, and visualize fault-related geomorphology in densely vegetated terrain surrounding Martis Creek Dam near Truckee, California. Bare-earth LiDAR imagery reveals a previously unrecognized and apparently youthful right-lateral strike-slip fault that exhibits laterally continuous tectonic geomorphic features over a 35-km-long zone. If these interpretations are correct, the fault, herein named the Polaris fault, may represent a significant seismic hazard to the greater Truckee-Lake Tahoe and Reno-Carson City regions. Three-dimensional modeling of an offset late Quaternary terrace riser indicates a minimum tectonic slip rate of 0.4 ?? 0.1 mm/yr.Mapped fault patterns are fairly typical of regional patterns elsewhere in the northern Walker Lane and are in strong coherence with moderate magnitude historical seismicity of the immediate area, as well as the current regional stress regime. Based on a range of surface-rupture lengths and depths to the base of the seismogenic zone, we estimate a maximum earthquake magnitude (M) for the Polaris fault to be between 6.4 and 6.9.

Hunter, L. E.; Howle, J. F.; Rose, R. S.; Bawden, G. W.

2011-01-01

273

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

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Full Text Available Object-based point cloud analysis (OBPA) is useful for information extraction from airborne LiDAR point clouds. An object-based classification method is proposed for classifying the airborne LiDAR point clouds in urban areas herein. In the process of classification, the surface growing algorithm is employed to make clustering of the point clouds without outliers, thirteen features of the geometry, radiometry, topology and echo characteristics are calculated, a support vector machine (SVM) is utilized to classify the segments, and connected component analysis for 3D point clouds is proposed to optimize the original classification results. Three datasets with different point densities and complexities are employed to test our method. Experiments suggest that the proposed method is capable of making a classification of the urban point clouds with the overall classification accuracy larger than 92.34% and the Kappa coefficient larger than 0.8638, and the classification accuracy is promoted with the increasing of the point density, which is meaningful for various types of applications.

Jixian Zhang; Xiangguo Lin; Xiaogang Ning

2013-01-01

274

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

Scientific Electronic Library Online (English)

Full Text Available 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 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 µ (more) g.g-1 for the triploid Nanica (Cavendish group) to 19.24 µg.g-1 for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 µg.g-1). The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00). DArT analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank.

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

2009-01-01

275

Belleza, sí, pero ¿qué es eso?  

Scientific Electronic Library Online (English)

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

Madrazo, Jorge Ariel

2006-01-01

276

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

2010-01-01

277

Arrangements for enhanced measurements of a large turbine near-wake using LiDAR from the nacelle  

International Nuclear Information System (INIS)

New LiDAR techniques are being tested and developed to support the development of large offshore wind turbines. Our interest in this paper is concentrated in wake measurements; therefore, a pulsed standard LiDAR is adapted for fullscale wind field measurements from the nacelle of a large wind turbine. We show the conceptual framework for planned adaptations to a Windcube (registered) LiDAR for operation at the nacelle of a 5 MW wind turbine. The standard scanning mode is to be modified to properly obtain downstream and also upstream wind speeds. The wind field measurements are intended for verification of models for near-wake wind speed, wake meandering and new predictive control estrategies.

2008-05-01

278

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

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

Alexander Miller

2009-01-01

279

Durante el embarazo - ¿Qué es una enfermedad transmitida ...  

Science.gov (United States)

... Durante el embarazo - ¿Qué es una enfermedad transmitida por los alimentos? ... Qué es una enfermedad transmitida por los alimentos? ... More results from www.fda.gov/food/foodborneillnesscontaminants/peopleatrisk

280

Polyethylene glycol-electrolyte solution (PEG-ES)  

Science.gov (United States)

Polyethylene glycol-electrolyte solution (PEG-ES) is used to empty the colon (large intestine, bowel) before a ... Polyethylene glycol-electrolyte solution (PEG-ES) comes as a powder to mix with water and take by ...

 
 
 
 
281

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

Directory of Open Access Journals (Sweden)

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

Curtis Edson; Michael G. Wing

2011-01-01

282

¿Quién es el dueño de la pantalla?  

Directory of Open Access Journals (Sweden)

Full Text Available A partir de 1990 la legislación colombiana ha tenido significativos avances para permitir que todas las personas puedan acceder a los servicios de telecomunicaciones, tal como corresponde en ejercicio del derecho fundamental del acceso a la información. Gracias al desarrollo de la tecnología, la limitación que generaba la necesidad de utilizar frecuencias radioeléctricas ya no es una razón válida desde el punto de vista constitucional para restringir el establecimiento de nuevos servicios y la difusión de información. Esta realidad técnica debe ser reconocida por el ordenamiento jurídico respecto de todos los servicios de telecomunicaciones. Dentro del actual marco constitucional no existe ningún fundamento para que los servicios que no utilicen frecuencias radioeléctricas sean objeto de reserva estatal. Este reconocimiento ya lo hizo el legislador al establecer que el servicio de telefonía pública básica conmutada local no sea objeto de concesión. En el mismo sentido, los medios masivos de comunicación, incluida la televisión, que no requieran el uso de frecuencias radioeléctricas y que puedan ser trasmitidos a través de redes de cable, gozan del derecho constitucional de establecerse libremente, aunque deben someterse a los reglamentos del servicio que establezca la autoridad competente. Las disposiciones legales que actualmente no permiten el ejercicio de tal derecho, son inconstitucionales. / Since 1990 Colombian telecommunication law has had significant advances allowing everybody access to telecommunication services in exercise of the fundamental right of information. Technology development permit that the limitation which generated the need of use frequencies, know days is not a valid reason -from a constitutional point of view- to restrict the operation of new telecommunication services and the information diffusion. This technical reality, have to be recognize in the legal order among all the telecommunication services. Colombian constitutional framework, does not has any rule that allow the restriction of telecom services which do not use frequencies under a "state reserve regime". Legal recognition in this sense, has been made by the legislator, when he established that the local telephony service does not required concession for its operation. In the same sense, massive media operators -including television operators- which do not use frequencies and which can be transmitted by wires, can be freely established observing only the specific service regulation dictated by the telecommunication authority. Legal dispositions that today do not allow the exercise of this constitutional right are illegal.

Juan Carlos Gómez Jaramillo

2006-01-01

283

Object-Based Integration of Photogrammetric and LiDAR Data for Automated Generation of Complex Polyhedral Building Models  

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Full Text Available This research is concerned with a methodology for automated generation of polyhedral building models for complex structures, whose rooftops are bounded by straight lines. The process starts by utilizing LiDAR data for building hypothesis generation and derivation of individual planar patches constituting building rooftops. Initial boundaries of these patches are then refined through the integration of LiDAR and photogrammetric data and hierarchical processing of the planar patches. Building models for complex structures are finally produced using the refined boundaries. The performance of the developed methodology is evaluated through qualitative and quantitative analysis of the generated building models from real data.

Changjae Kim; Ayman Habib

2009-01-01

284

Direct georeferencing of airborne LiDAR data in national coordinates  

Science.gov (United States)

The topographic mapping products of airborne light detection and ranging (LiDAR) are usually required in the national coordinates (i.e., using the national datum and a conformal map projection). Since the spatial scale of the national datum is usually slightly different from the World Geodetic System 1984 (WGS 84) datum, and the map projection frame is not Cartesian, the georeferencing process in the national coordinates is inevitably affected by various geometric distortions. In this paper, all the major direct georeferencing distortion factors in the national coordinates, including one 3D scale distortion (the datum scale factor distortion), one height distortion (the earth curvature distortion), two length distortions (the horizontal-to-geodesic length distortion and the geodesic-to-projected length distortion), and three angle distortions (the skew-normal distortion, the normal-section-to-geodesic distortion, and the arc-to-chord distortion) are identified and demonstrated in detail; and high-precision map projection correction formulas are provided for the direct georeferencing of the airborne LiDAR data. Given the high computational complexity of the high-precision map projection correction approach, some more approximate correction formulas are also derived for the practical calculations. The simulated experiments show that the magnitude of the datum scale distortion can reach several centimeters to decimeters for the low (e.g., 500 m) and high (e.g., 8000 m) flying heights, and therefore it always needs to be corrected. Our proposed practical map projection correction approach has better accuracy than Legat's approach,Legat (2006).1 but it needs 25% more computational cost. As the correction accuracy of Legat's approach can meet the requirements of airborne LiDAR data with low and medium flight height (up to 3000 m above ground), our practical correction approach is more suitable to the high-altitude aerial imagery. The residuals of our proposed high-precision map projection correction approach are trivial even for the high flight height of 8000 m. It can be used for the theoretical applications such as the accurate evaluation of different GPS/INS attitude transformation methods to the national coordinates.

Zhang, Yongjun; Shen, Xiang

2013-10-01

285

Beyond Cross Sections; LiDAR in Support of Sprague River geomorphology Studies, Klamath Basin, Oregon  

Science.gov (United States)

LiDAR terrain data was collected in November 2004 for 750 square kilometers of the Sprague River valley, Oregon, by Watershed Sciences, Inc., under contract with the Klamath Tribes. This coverage, obtained to support multiple ecologic analysis and restoration activities in the Klamath Basin, encompasses about 90 km of valley- bottom corridor for the main Sprague River as well as downstream alluvial sections of principal tributaries, including 15 km of the Sycan River, 15 km of the South Fork Sprague River, and 10 km of the North Fork Sprague River. Acquisition conditions were leaf-off at normal fall low flow. Assessment of the vertical divergence between 967 surveyed points and the laser points gave a RMSE of 0.052 m with a standard deviation of 0.051 m. The resulting bare-earth 1-m grid has been used for geomorphic mapping, paleo- and historical-channel mapping, qualitative and quantitative analysis of floodplain morphology, and assessment of channel incision over various timescales.4 Using the high resolution topography in combination with floodplain stratigraphy, we delineated the late Holocene (post 7.7 ka Mazama eruption) active floodplain. The morphology of this floodplain reveals processes locally important in forming the Sprague and Sycan river floodplains, including avulsion, meander abandonment and filling, lateral bar building, deposition by crevasses, and lateral migration. Mapping present and paleo-channel positions determined from historic photos and maps onto the LiDAR digital terrain model, coupled with augering to determine channel gravel depths, has allowed local assessment of long term channel incision and aggradation over the last several thousand years. Reaches of possible historic incision have also been delineated by comparing floodplain elevation to channel elevation in an essentially continuous manner along the valley corridor. This analysis reveals multiple reaches where the 1940 channel, as depicted on aerial photographs, is apparently higher than the 2004 channel, and these incised reaches generally correspond to reaches of lower sinuosity (locally imposed by channelization) and rates of channel migration. The continuous and high-resolution elevation data provided by LiDAR terrain models provides a means for continuous mapping of floodplain and channel features at scales relevant to geomorphic and ecologic processes on many river systems, thus providing a means to obtain significantly more information on state and process than can typically be accomplished by the sparse sampling of river systems afforded by a cross-section based approach.

O'Connor, J. E.; McDowell, P. F.; Lind, P.; Haluska, T.; Jackson, K.

2007-12-01

286

No todo es dermatitis atópica/ Not all is atopic dermatitis  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish La dermatitis atópica (DA) comparte características comunes con otras enfermedades cutáneas inflamatorias, que, aunque menos prevalentes, pueden dar lugar a confusión diagnóstica y a excesos o déficits terapéuticos. Intentaremos aportar una sencilla guía de las claves más intuitivas y necesarias para salir airosos de este trance. Abstract in english Atopic dermatitis (AD) shares some common features with other inflammatory skin conditions, that although less prevalent, they can produce misdiagnosis and over or under treatment. We will try to produce a simple guideline on the most intuitive and necessary clues to get out successfully in this business.

de Lucas Laguna, R.; Sendagorta Cudós, E.

2009-06-01

287

Estimation of canopy base height using airborne laser scanning data (LiDAR)  

Directory of Open Access Journals (Sweden)

Full Text Available Lately, data acquisition using Airborne Laser Scanning (ALS) with LiDAR technology (Light Detection andRanging) is becoming promising in the forest field, especially for estimation of dendrometric variables and toevaluate vertical and horizontal structure of the forest. Topographic and forest coverage information are extremelyimportant to forest and natural resources managers. Accurate information on trees height and density arefundamental for planning, but also hard to obtain by conventional methods. The use of modeling associated withLIDAR data allows the researcher to obtain estimates of several other forest variables, such as basal area,diameter, volume, biomass and combustible material. The estimation of the trees base heights with plots of differentsizes (10, 15 and 20 meters) showed an standard error of 1.42, 0.95 and 0.82 m, which correspond to 23.62, 15.70and 13.84%, respectively.

Marcos Giongo; Henrique Soares Koehler; Marcelo Ribeiro Viola; Patrick dos Santos Bastos; André Ferreira dos Santos; Giovanni Santopuoli

2012-01-01

288

A multiresolution hierarchical classification algorithm for filtering airborne LiDAR data  

Science.gov (United States)

We presented a multiresolution hierarchical classification (MHC) algorithm for differentiating ground from non-ground LiDAR point cloud based on point residuals from the interpolated raster surface. MHC includes three levels of hierarchy, with the simultaneous increase of cell resolution and residual threshold from the low to the high level of the hierarchy. At each level, the surface is iteratively interpolated towards the ground using thin plate spline (TPS) until no ground points are classified, and the classified ground points are used to update the surface in the next iteration. 15 groups of benchmark dataset, provided by the International Society for Photogrammetry and Remote Sensing (ISPRS) commission, were used to compare the performance of MHC with those of the 17 other publicized filtering methods. Results indicated that MHC with the average total error and average Cohen's kappa coefficient of 4.11% and 86.27% performs better than all other filtering methods.

Chen, Chuanfa; Li, Yanyan; Li, Wei; Dai, Honglei

2013-08-01

289

¿Qué es leer? ¿Qué es la lectura? What is to read? What is reading?  

Directory of Open Access Journals (Sweden)

Full Text Available El artículo se propone explorar lo que sostienen algunos pensadores de los campos de las humanidades y las ciencias sociales de la segunda mitad del siglo XX, en torno a interrogantes referentes a qué es leer y qué es la lectura. Paulo Freire, Roland Barthes, Michel de Certeau, Robert Escarpit, Noé Jitrik, Roger Chartier y Jorge Larrosa son autores en los que encontramos propuestas innovadoras fundadas en aparatos teóricos interdisciplinarios. Las coincidencias y divergencias, que sobre tan complejo tema encontramos en los autores citados, nos llevan a formular una propuesta conceptual desde la perspectiva bibliotecológica separada del discurso pedagógico, y se orienta a formar al ciudadano de la sociedad de la información y al de la industria editorial, ambos inmersos en nuevos modelos de consumo de la cultura escrita, e involucrados en la tecnología digital. En el contexto actual, la bibliotecología debe renovar su función social y uno de los aspectos fundamentales de dicha función es la problemática de la lectura, por lo que es indispensable abrir y explorar las teorías y métodos sobre ésta, en los que se basa el discurso y la práctica de la bibliotecología.The paper explores what is held by some authors of the second half of the 20th Century in the fields of humanities and social sciences, such as Paulo Freire, Roland Barthes, Michel de Certeau, Robert Escarpit, Noé Jitrik, Roger Chartier and Jorge Larrosa, among which we find innovative proposals based in theoretical interdisciplinary apparatuses. Coincidences and disagreements of these authors on such a complex matter lead us to formulate a conceptual answer from the library science perspective, which differs from the pedagogical discourse and points towards the education of the citizen of the information society and that of the publishing industry, both involved in digital technology. In today's context, library science must renew its social function and one of the fundamental aspects of this are the problematics of reading. Thus, reading methods and theories in which the discourse and practice of library science have been based up to now, must be opened and explored.

Elsa M. Ramírez Leyva

2009-01-01

290

¿Qué es leer? ¿Qué es la lectura?/ What is to read? What is reading?  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El artículo se propone explorar lo que sostienen algunos pensadores de los campos de las humanidades y las ciencias sociales de la segunda mitad del siglo XX, en torno a interrogantes referentes a qué es leer y qué es la lectura. Paulo Freire, Roland Barthes, Michel de Certeau, Robert Escarpit, Noé Jitrik, Roger Chartier y Jorge Larrosa son autores en los que encontramos propuestas innovadoras fundadas en aparatos teóricos interdisciplinarios. Las coincidencias y div (more) ergencias, que sobre tan complejo tema encontramos en los autores citados, nos llevan a formular una propuesta conceptual desde la perspectiva bibliotecológica separada del discurso pedagógico, y se orienta a formar al ciudadano de la sociedad de la información y al de la industria editorial, ambos inmersos en nuevos modelos de consumo de la cultura escrita, e involucrados en la tecnología digital. En el contexto actual, la bibliotecología debe renovar su función social y uno de los aspectos fundamentales de dicha función es la problemática de la lectura, por lo que es indispensable abrir y explorar las teorías y métodos sobre ésta, en los que se basa el discurso y la práctica de la bibliotecología. Abstract in english The paper explores what is held by some authors of the second half of the 20th Century in the fields of humanities and social sciences, such as Paulo Freire, Roland Barthes, Michel de Certeau, Robert Escarpit, Noé Jitrik, Roger Chartier and Jorge Larrosa, among which we find innovative proposals based in theoretical interdisciplinary apparatuses. Coincidences and disagreements of these authors on such a complex matter lead us to formulate a conceptual answer from the lib (more) rary science perspective, which differs from the pedagogical discourse and points towards the education of the citizen of the information society and that of the publishing industry, both involved in digital technology. In today's context, library science must renew its social function and one of the fundamental aspects of this are the problematics of reading. Thus, reading methods and theories in which the discourse and practice of library science have been based up to now, must be opened and explored.

Ramírez Leyva, Elsa M.

2009-04-01

291

Fusion of LiDAR and aerial imagery for the estimation of downed tree volume using Support Vector Machines classification and region based object fitting  

Science.gov (United States)

The study classifies 3D small footprint full waveform digitized LiDAR fused with aerial imagery to downed trees using Support Vector Machines (SVM) algorithm. Using small footprint waveform LiDAR, airborne LiDAR systems can provide better canopy penetration and very high spatial resolution. The small footprint waveform scanner system Riegl LMS-Q680 is addition with an UltraCamX aerial camera are used to measure and map downed trees in a forest. The various data preprocessing steps helped in the identification of ground points from the dense LiDAR dataset and segment the LiDAR data to help reduce the complexity of the algorithm. The haze filtering process helped to differentiate the spectral signatures of the various classes within the aerial image. Such processes, helped to better select the features from both sensor data. The six features: LiDAR height, LiDAR intensity, LiDAR echo, and three image intensities are utilized. To do so, LiDAR derived, aerial image derived and fused LiDAR-aerial image derived features are used to organize the data for the SVM hypothesis formulation. Several variations of the SVM algorithm with different kernels and soft margin parameter C are experimented. The algorithm is implemented to classify downed trees over a pine trees zone. The LiDAR derived features provided an overall accuracy of 98% of downed trees but with no classification error of 86%. The image derived features provided an overall accuracy of 65% and fusion derived features resulted in an overall accuracy of 88%. The results are observed to be stable and robust. The SVM accuracies were accompanied by high false alarm rates, with the LiDAR classification producing 58.45%, image classification producing 95.74% and finally the fused classification producing 93% false alarm rates The Canny edge correction filter helped control the LiDAR false alarm to 35.99%, image false alarm to 48.56% and fused false alarm to 37.69% The implemented classifiers provided a powerful tool for downed tree classification with fused LiDAR and aerial image. The classified tree pixels are utilized in the object based region fitting technique to compute the diameter and height of the downed trees and the volume of the trees are estimated. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html)

Selvarajan, Sowmya

292

Calculating the ecosystem service of water storage in isolated wetlands using LiDAR in north central Florida, USA (presentation)  

Science.gov (United States)

This study used remotely-sensed Light Detection and Ranging (LiDAR) data to estimate potential water storage capacity of isolated wetlands in north central Florida. The data were used to calculate the water storage potential of >8500 polygons identified as isolated wetlands. We f...

293

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents algorithmic components and corresponding software routines for extracting shoreline features from remote sensing imagery and LiDAR data. Conceptually, shoreline features are treated as boundary lines between land objects and water objects. Numerical algorithms have been identifie...

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

294

Diversity arrays technology (DArT) for studying the genetic polymorphism of flue-cured tobacco (Nicotiana tabacum).  

UK PubMed Central (United Kingdom)

Diversity arrays technology (DArT) is a microarray-based marker system that achieves high throughput by reducing the complexity of the genome. A DArT chip has recently been developed for tobacco. In this study, we genotyped 267 flue-cured cultivars/landraces, including 121 Chinese accessions over five decades from widespread geographic regions in China, 103 from the Americas, and 43 other foreign cultivars, using the newly developed chip. Three hundred and thirty polymorphic DArT makers were selected and used for a phylogenetic analysis, which suggested that the 267 accessions could be classified into two subgroups, which could each be further divided into 2?4 sections. Eight elite cultivars, which account for 83% of the area of Chinese tobacco production, were all found in one subgroup. Two high-quality cultivars, HHDJY and Cuibi1, were grouped together in one section, while six other high-yield cultivars were grouped into another section. The 330 DArT marker clones were sequenced and close to 95% of them are within non-repetitive regions. Finally, the implications of this study for Chinese flue-cured tobacco breeding and production programs were discussed.

Lu XP; Xiao BG; Li YP; Gui YJ; Wang Y; Fan LJ

2013-07-01

295

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

Science.gov (United States)

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 were used to scan the genomes of the 81 accessions. Out of 7500 markers (5500 wheat and 2000 Ae. tauschii), 4449 were polymorphic (3776 wheat and 673 Ae. tauschii). Phylogenetic and population structure studies revealed that the accessions could be divided into three groups. The two Ae. tauschii subspecies could also be separately clustered, suggesting that the current taxonomy might be valid. DArT markers are effective to detect very small polymorphisms. The information obtained about Ae. tauschii in the current study could be useful for wheat breeding. In addition, the new DArT array from this Ae. tauschii population is expected to be an effective tool for hexaploid wheat studies.

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

2012-01-01

296

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

UK PubMed Central (United Kingdom)

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 were used to scan the genomes of the 81 accessions. Out of 7500 markers (5500 wheat and 2000 Ae. tauschii), 4449 were polymorphic (3776 wheat and 673 Ae. tauschii). Phylogenetic and population structure studies revealed that the accessions could be divided into three groups. The two Ae. tauschii subspecies could also be separately clustered, suggesting that the current taxonomy might be valid. DArT markers are effective to detect very small polymorphisms. The information obtained about Ae. tauschii in the current study could be useful for wheat breeding. In addition, the new DArT array from this Ae. tauschii population is expected to be an effective tool for hexaploid wheat studies.

Sohail Q; Shehzad T; Kilian A; Eltayeb AE; Tanaka H; Tsujimoto H

2012-03-01

297

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

Directory of Open Access Journals (Sweden)

Full Text Available 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.

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

2011-01-01

298

Expanding carbon stock and flux modeling capabilities through the improvement of LiDAR-derived forest age estimates  

Science.gov (United States)

Understanding the terrestrial carbon cycle is integral to modeling and mitigating global climatic change as well as generating accurate carbon inventory maps. Understanding the relationships between forest function, structure and carbon sequestration is therefore of the utmost importance. Ecosystem models have been developed that estimate future carbon fluxes in forested ecosystems based on forest structural and functional properties. The Ecosystem Demography (ED) model, in particular, has capitalized on the recent availability of LiDAR data over large areas. LiDAR can be used to estimate forest height, and ED is initialized with the distribution of LiDAR heights to estimate carbon flux, assuming a relationship between forest age and height. However, forest height alone is not always an appropriate proxy for age, as forest height can be stunted by environmental constraints. This research attempts to explore how forest age is related to other forest structural attributes, including stand density, canopy gap frequency and vertical structure. LVIS data are used to model and map forest structure along a 2 km wide transect running from Maryland to southern Mississippi. A validated forest disturbance product derived from ~25 years of LANDSAT imagery is used as forest age data. Empirical relationships are developed between forest age and structural metrics. These relationships are also constrained with known allometric scaling relationships that aim to improve model efficacy. If LiDAR data can be used as a suitable proxy for forest age, global LiDAR datasets may be able to provide unprecedented capabilities for modeling global forest carbon stocks and fluxes at present, and into the future.

Duncanson, L.; Dubayah, R.; Hurtt, G. C.; Huang, C.; Fisk, J. P.; Dolan, K.

2011-12-01

299

LAS TRES G: GOBERNAR ES GRAVAR PARA GASTAR* Gobernar eficientemente es gravar y gastar eficientemente  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Los gobiernos deben recaudar los recursos necesarios para cumplir con sus funciones, independientemente de la intensidad con que intervengan en la vida de la sociedad. Al fin de cuentas, gobernar debe ser gravar para gastar. Lo debatible es todo lo demás: las intenciones de los gobiernos, la composición de sus gastos, la legitimidad de sus intervenciones y otros asuntos igualmente difíciles de resolver, pero gravar y gastar son las funciones decisivas de los gobiernos. (more) Siglos de progreso en el difícil arte de gobernar no han, sin embargo, dado una solución definitiva al problema de la tributación eficiente. Los economistas no pueden estar satisfechos con las soluciones propuestas. Todas ellas son imperfectas ... y las imperfecciones crecen exponencialmente a medida que los gobiernos amplían sus ámbitos de acción. El IVA, a pesar de sus imperfecciones, es el que mejor cumple con el pro-pósito recaudador de la tributación. El impuesto al ingreso tiene un propósito redistributivo que, a fin de cuentas, fracasa en alcanzar y, por lo tanto, permanece como un impuesto a la deriva, en búsqueda de un objetivo que pueda efectivamente satisfacer. La corrección de externalidades a través de impuestos es otra tarea que tampoco ha sido satisfactoriamente cumplida en la práctica. Esto podría parecer, quizás, desalentador y pesimista. Por el contrario, esta situación debe ser considerada un fascinante desafío que muestra la importancia de la tarea que los economistas aún deben realizar para contribuir a la labor insigne de gobernar la sociedad Abstract in english Governments must collect the resources necessary to carry out their duties, regardless of the intensity with which governments intervene in society. Ultimately, to govern must be to tax in order to spent. Everything else, such as the intentions of governments, the composition of their expenditure, the legitimacy of their intervention, and other thorny issues, can be debatable but taxing and spending are doubtless the defining functions of governments. Centuries of progres (more) s in the difficult art of governing society did not yield a definite solution to the problem of efficient taxation. Economists cannot be satisfied with the proposed solutions. The alternative proposals are poor and imperfect ? and such imperfections grow exponencially as governments widen the scope of their actions. The VAT, despite its imperfections, can best fulfill the revenue yielding purpose of taxation. The income tax has a redistributive purpose that, ultimately, fails to achieve and, therefore, remains a tax instrument in search of a duty it can effectively perform. Externality corrections by selective taxes is another task that has not been satisfactorily fulfilled in practice. These conclusions might, perhaps, be considered crestfallen and gloomy. Nothing of the sort; they must be considered a fascinating challenge showing the importance of the work that economists have yet to accomplish to contribute to the superior task of governing society

Schenone, Osvaldo H.

2003-04-01

300

Approach to ES and H Assurance Programs for institutions. Volume 1. Institutional and ES and H staff functions  

Energy Technology Data Exchange (ETDEWEB)

The approach taken toward the development of environmental, safety, and health (ES and H) management systems that provide assurance of performance has involved four overlapping phases: planning, testing, implementation studies, and information dissemination. In order to promote better understanding of ES and H Assurance Program concepts as a part of the final information dissemination phase of the development program, 13 of the 15 guidance documents used in successful implementation tests of ES and H Assurance management concepts and a discussion of the ES and H Assurance Program Standard have been combined in two volumes. This is the first of this 2-volume set. Chapter titles include: introduction; a discussion of the ES and H Assurance Program Standard; characteristics of ES and H Assurance Programs; a model plan for institutional ES and H Assurance Programs; a model plan for ES and H staff review activities; a model plan for ES and H staff audits and appraisals; a model plan for institutional emergency response programs; and a model plan for institutional accident investigations. Nine appendixes are included. (JGB)

Ellingson, A.C.; Trauth, C.A. Jr. (eds.)

1982-09-01

 
 
 
 
301

Solar Energy Grid Integration Systems Energy Storage (SEGIS-ES).  

Science.gov (United States)

This paper describes the concept for augmenting the SEGIS Program (an industry-led effort to greatly enhance the utility of distributed PV systems) with energy storage in residential and small commercial applications (SEGIS-ES). The goal of SEGIS-ES is to...

C. J. Hanley D. T. Ton G. H. Peek J. D. Boyes

2008-01-01

302

El yoco del cielo es cultivado: perspectivas sobre Paullinia yoco en el chamanismo airo-pai (secoya-tucano occidental)  

Directory of Open Access Journals (Sweden)

Full Text Available Este artículo asocia la cosmovisón chamánica y onírica de los airo-pai (secoya) con su manejo silvicultural del yoco (Paullinia yoco), una liana silvestre rica en cafeína, endémica del refugio del pleistocénico del Napo. Según las nociones etnobotánicas airo-pai,el yoco tiene la propiedad de «dar consejo» a quienes lo consumen. A partir del análisis de un canto chamánico de yajé (Banisteriopsis caapi), mitos e interpretación de sueños, mostramos cómo el manejo de esta especiees concebido según perspectivas contrastantes: para los espíritus celestiales el yoco es una planta cultivada, que crece en las chagras del cielo; para cuacuiyó («el dueño» del yoco), ave dispersora de su semilla, el yoco es su propio cultivo; y para los seres humanos terrestres, la recolección de yoco silvestre es parecida a la cacería (asociada oníricamente con el paujil (Nothocrax urumutum). De esta manera, este estudio ilustra la relevancia de un abordaje perspectivistapara comprender los conocimientos etnobotánicos subyacentesal manejo y extracción de especies silvestres de importancia ritual y práctica. -- This article associates Airo-pai shamanistic vision and interpretation of dreams with their silvicultural management of yoco (Paullinia yoco), a wild vine rich in caffeine, endemic to the pleistocene refuge of Napo. According to Airo-pai ethnobotanic notions, yoco is a plantthat «gives advice» to those who intake it. From the analysis of a shamanic chant of yajé (Banisteriopsis caapi), myths and interpretation of dreams, we show how the management of this species is conceived from contrasting perspectives: for celestial beings, yoco is a domesticated plant that grows in the celestial gardens; for cuacuiyó (yoco’s «Master»), a seed-dispersing bird, yoco is its own plantation; and for terrestrial human beings, the collection of wild yoco is like hunting, associated in dreams with the nocturnal curassow (Nothocrax urumutum). This study thus illustrates the relevance of a perspectivist approach to understand the ethnobotanic lore underlying the management and extraction of a wild species of ritual and practical importance.

Luisa Elvira Belaunde; Juan Alvaro Echeverri

2008-01-01

303

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

Scientific Electronic Library Online (English)

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

Calame, Claude

2004-12-01

304

Recovery of Forest Canopy Parameters by Inversion of Multispectral LiDAR Data  

Directory of Open Access Journals (Sweden)

Full Text Available We describe the use of Bayesian inference techniques, notably Markov chain Monte Carlo (MCMC) and reversible jump MCMC (RJMCMC) methods, to recover forest structural and biochemical parameters from multispectral LiDAR (Light Detection and Ranging) data. We use a variable dimension, multi-layered model to represent a forest canopy or tree, and discuss the recovery of structure and depth profiles that relate to photochemical properties. We first demonstrate how simple vegetation indices such as the Normalized Differential Vegetation Index (NDVI), which relates to canopy biomass and light absorption, and Photochemical Reflectance Index (PRI) which is a measure of vegetation light use efficiency, can be measured from multispectral data. We further describe and demonstrate our layered approach on single wavelength real data, and on simulated multispectral data derived from real, rather than simulated, data sets. This evaluation shows successful recovery of a subset of parameters, as the complete recovery problem is ill-posed with the available data. We conclude that the approach has promise, and suggest future developments to address the current difficulties in parameter inversion.

Andrew Wallace; Caroline Nichol; Iain Woodhouse

2012-01-01

305

Filtering airborne LiDAR data by embedding smoothness-constrained segmentation in progressive TIN densification  

Science.gov (United States)

Progressive TIN densification (PTD) is one of the classic methods for filtering airborne LiDAR point clouds. However, it may fail to preserve ground measurements in areas with steep terrain. A method is proposed to improve the PTD using a point cloud segmentation method, namely segmentation using smoothness constraint (SUSC). The classic PTD has two core steps. The first is selecting seed points and constructing the initial TIN. The second is an iterative densification of the TIN. Our main improvement is embedding the SUSC between these two steps. Specifically, after selecting the lowest points in each grid cell as initial ground seed points, SUSC is employed to expand the set of ground seed points as many as possible, as this can identify more ground seed points for the subsequent densification of the TIN-based terrain model. Seven datasets of ISPRS Working Group III/3 are utilized to test our proposed algorithm and the classic PTD. Experimental results suggest that, compared with the PTD, the proposed method is capable of preserving discontinuities of landscapes and reducing the omission errors and total errors by approximately 10% and 6% respectively, which would significantly decrease the cost of the manual operation required for correcting the result in post-processing.

Zhang, Jixian; Lin, Xiangguo

2013-07-01

306

Development of solar driers for pyrethrum in Tanzania  

Energy Technology Data Exchange (ETDEWEB)

Research work to develop a solar crop drier suitable for use in rural areas by small and large scale farmers started in November, 1980. The research team was based at Morogoro Campus - Department of Agricultural Engineering and Land Planning of the University of Dar es Salaam. Initially, a solar crop drier, a direct/indirect type was designed and fabricated. The drier suitable for a small scale farmer had a capacity of drying 50kg of pyrethrum flowers per day. With this prototype, it was possible to reach drying temperatures of 53{sup o}C inside the drier with a collection efficiency of 32.8% (Tarimo,1982). (author).

Simalenga, T.E.; Mrema, G.C. (Sokoine Univ., of Agriculture, Morogoro (TZ))

1991-02-01

307

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

Scientific Electronic Library Online (English)

Full Text Available 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 period 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. (more) Equatorial Africa has high levels of UV radiation, and because ozone shields UV radiation from reaching the Earth's surface, there is a need to monitor TOCAs and EUV doses. In this paper we investigated the trend of TOCAs and EUV doses, the effects of annual and solar cycles on TOCAs, as well as the link between lightning and ozone production in the equatorial African belt. We also compared clear-sky simulated EUV doses with the corresponding EUV doses derived from TOMS measurements. The TOCAs were found to vary in the ranges 243 DU - 289 DU, 231 DU - 286 DU, and 236 DU - 296 DU, with mean values of 266.9 DU, 260.9 DU, and 267.8 DU for Dar-es-Salaam, Kampala and Serrekunda, respectively. Daily TOCA time series indicated that Kampala had the lowest TOCA values, which we attributed to the altitude effect. There were two annual ozone peaks in Dar-es-Salaam and Kampala, and one annual ozone peak in Serrekunda. The yearly TOCA averages showed an oscillation within a five-year period. We also found that the EUV doses were stable at all three locations for the period 1979-2000, and that Kampala and Dar-es-Salaam were mostly cloudy throughout the year, whereas Serrekunda was mostly free from clouds. It was also found that clouds were among the major factors determining the level of EUV reaching the Earth´s surface. Finally, we noted that during rainy seasons, horizontal advection effects augmented by lightning activity may be responsible for enhanced ozone production in the tropics.

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

2010-02-01

308

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  

Directory of Open Access Journals (Sweden)

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.

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

2011-01-01

309

Seroepidemiology of Rickettsia typhi, spotted fever group rickettsiae, and Coxiella burnetti infection in pregnant women from urban Tanzania.  

UK PubMed Central (United Kingdom)

Immunofluorescent antibody (IFA) testing was performed on sera drawn from 150 pregnant women in the port city of Dar es Salaam, Tanzania. Prevalence of antibodies to Rickettsia typhi was 28%, higher than in any of the 12 other African countries in which serosurveys using IFA testing have been performed. Seroprevalence of antibodies to spotted fever group rickettsiae antigens was 25.3%, comparable with that found in other sub-Saharan countries endemic for Amblyomma ticks. Only 4.7% of women were seropositive for Coxiella burnetii.

Anstey NM; Tissot Dupont H; Hahn CG; Mwaikambo ED; McDonald MI; Raoult D; Sexton DJ

1997-08-01

310

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

UK PubMed Central (United Kingdom)

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

Messo IN

2013-05-01

311

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.  

UK PubMed Central (United Kingdom)

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.

Mbawalla HS; Mtaya M; Masalu JR; Brudvik P; Astrom AN

2011-01-01

312

Adaptive Slope Filtering of Airborne LiDAR Data in Urban Areas for Digital Terrain Model (DTM) Generation  

Directory of Open Access Journals (Sweden)

Full Text Available A filtering algorithm is proposed that accurately extracts ground data from airborne light detection and ranging (LiDAR) measurements and generates an estimated digital terrain model (DTM). The proposed algorithm utilizes planar surface features and connectivity with locally lowest points to improve the extraction of ground points (GPs). A slope parameter used in the proposed algorithm is updated after an initial estimation of the DTM, and thus local terrain information can be included. As a result, the proposed algorithm can extract GPs from areas where different degrees of slope variation are interspersed. Specifically, along roads and streets, GPs were extracted from urban areas, from hilly areas such as forests, and from flat area such as riverbanks. Validation using reference data showed that, compared with commercial filtering software, the proposed algorithm extracts GPs with higher accuracy. Therefore, the proposed filtering algorithm effectively generates DTMs, even for dense urban areas, from airborne LiDAR data.

Junichi Susaki

2012-01-01

313

Urban Vegetation Mapping from Fused Hyperspectral Image and LiDAR Data with Application to Monitor Urban Tree Heights  

Directory of Open Access Journals (Sweden)

Full Text Available Urban vegetations have infinite proven benefits for urban inhabitants including providing shade, improving air quality, and enhancing the look and feel of communities. But creating a complete inventory is a time consuming and resource intensive process. The extraction of urban vegetation is a challenging task, especially to monitor the urban tree heights. In this study we present an efficient extraction method for mapping and monitoring urban tree heights using fused hyperspectral image and LiDAR data. Endmember distribution mapping using the spectral angle mapper technique is employed in this study. High convenience results achieved using fused hyperspectral and LiDAR data from this semiautomatics technique. This method could enable urban community organizations or local governments to map and monitor urban’s tree height and its spatial distribution.

Fatwa Ramdani

2013-01-01

314

La pobreza es multidimensional: un ensayo de clasificación  

Directory of Open Access Journals (Sweden)

Full Text Available En este ensayo clasificatorio presentamos cinco tipos básicos de multidimensionalidad en la literatura reciente sobre desarrollo y pobreza. El primer tipo básico es intra- económico pues incluye dos o más variables económicas. El segundo añade indicadores no económicos al ingreso. Podemos distinguir dos variantes en ese caso. Una de ellas es la que introduce la multidimensionalidad en el campo de los factores de la pobreza, usualmente de ingreso. Algunos de esos factores son definidos como (capital),. Otra es la que incorpora elementos no económicos en la definición de pobreza. El tercer tipo de multidimensionalidad elimina el ingreso y las variables económicas de la definición de pobreza, lo que coloca a la dimensión económica meramente como un factor. Es el caso del planteamiento de Sen que define el problema como uno de libertad, en última instancia. Dentro de ese enfoque nos interesa destacar una de las maneras menos comprendidas de hacerlo cual es la que sirve para construir el Índice de Desarrollo Humano en los Informes sobre Desarrollo Humano del PNUD. La cuarta manera de establecer la multidimensionalidad de la pobreza es la que introduce la clasificación “económica”, “política”, “social” “cultural” u otras, y que se deriva de la modalidad de separación de esferas de la vida propia del mundo liberal. La última que exponemos es la que se apoya directamente en las ideas de lo valioso en la vida y su relación con el desarrollo que tienen diversas corrientes filosóficas.

Javier María Iguiniz Echeverria

2001-01-01

315

IMMUNE REGULATING ES-PRODUCTS IN PARASITIC NEMATODES  

DEFF Research Database (Denmark)

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

Bahlool, Qusay Zuhair Mohammad; Buchmann, Kurt

316

The Exceptionally Luminous Type II-L SN 2008es  

CERN Document Server

We report on our early photometric and spectroscopic observations of the extremely luminous Type II supernova (SN) 2008es. With an observed peak optical magnitude of m_V = 17.6 mag and at a redshift z = 0.213, SN 2008es had a peak absolute magnitude of M_V = -22.5 mag, making it the second most luminous SN ever observed. The photometric evolution of SN 2008es exhibits a fast decline rate (~0.042 mag day^-1), similar to the extremely luminous Type II-L SN 2005ap. We show that SN 2008es spectroscopically resembles the luminous Type II-L SN 1979C. Although the spectra of SN 2008es lack the narrow and intermediate-width line emission typically associated with the interaction of a SN with the circumstellar medium (CSM) of its progenitor star, we argue that the extreme luminosity of SN 2008es is powered via strong interaction with a dense, optically-thick CSM. The integrated bolometric luminosity of SN 2008es yields a total radiated energy at ultraviolet (UV) and optical wavelengths of > 10^51 ergs. Finally, we exa...

Miller, A A; Perley, D A; Ganeshalingam, M; Butler, N R; Bloom, J S; Smith, N; Modjaz, M; Poznanski, D; Filippenko, A V; Shiode, J H; Silverman, J M

2008-01-01

317

La pobreza es multidimensional: un ensayo de clasificación  

Directory of Open Access Journals (Sweden)

Full Text Available En este ensayo clasificatorio presentamos cinco tipos básicos de multidimensionalidad en la literatura reciente sobre desarrollo y pobreza. El primer tipo básico es intra- económico pues incluye dos o más variables económicas. El segundo añade indicadores no económicos al ingreso. Podemos distinguir dos variantes en ese caso. Una de ellas es la que introduce la multidimensionalidad en el campo de los factores de la pobreza, usualmente de ingreso. Algunos de esos factores son definidos como (capital),. Otra es la que incorpora elementos no económicos en la definición de pobreza. El tercer tipo de multidimensionalidad elimina el ingreso y las variables económicas de la definición de pobreza, lo que coloca a la dimensión económica meramente como un factor. Es el caso del planteamiento de Sen que define el problema como uno de libertad, en última instancia. Dentro de ese enfoque nos interesa destacar una de las maneras menos comprendidas de hacerlo cual es la que sirve para construir el Índice de Desarrollo Humano en los Informes sobre Desarrollo Humano del PNUD. La cuarta manera de establecer la multidimensionalidad de la pobreza es la que introduce la clasificación “económica”, “política”, “social” “cultural” u otras, y que se deriva de la modalidad de separación de esferas de la vida propia del mundo liberal. La última que exponemos es la que se apoya directamente en las ideas de lo valioso en la vida y su relación con el desarrollo que tienen diversas corrientes filosóficas.

Javier María Iguiniz Echeverria

2012-01-01

318

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

Directory of Open Access Journals (Sweden)

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

Marco González T.; Salim Mattar V.

2011-01-01

319

Comparative analysis of genetic diversity in Canadian barley assessed by SSR, DarT, and pedigree data.  

Science.gov (United States)

The aim of this study was to measure genetic diversity and population structure among 92 Canadian barley cultivars using two types of molecular markers (SSRs and DArTs) and pedigree data. A total of 368 alleles were identified at 50 SSR loci. The number of alleles per locus ranged between 2 and 13 ([Formula: see text] = 7.36) and PIC values ranged from 0.34 to 0.86 ([Formula: see text] = 0.69). For the biallelic DArT markers, the genetic distance matrix was based on 971 markers whose PIC values ranged between 0.06 and 0.50 ([Formula: see text] = 0.39). A third distance matrix was computed based on the kinship coefficient. Clustering of genotypes was performed based on the genetic distance matrix and the three dendrograms obtained showed the genetic relationships among barley cultivars. The topological similarity of the three dendrograms was estimated using a congruence index and showed the three dendrograms to be in very good agreement. Statistical analysis also showed a highly significant correlation between the SSR and DArT matrices (r = 0.80, p 0.5 was 3.8 cM. Information obtained from comparing results of different genetic diversity estimation methods should be useful for the improvement and conservation of barley genetic resources. PMID:23957675

Lamara, Mebarek; Zhang, Li Yi; Marchand, Suzanne; Tinker, Nicholas A; Belzile, François

2013-06-18

320

Hydrography change detection: the usefulness of surface channels derived From LiDAR DEMs for updating mapped hydrography  

Science.gov (United States)

The 1:24,000-scale high-resolution National Hydrography Dataset (NHD) mapped hydrography flow lines require regular updating because land surface conditions that affect surface channel drainage change over time. Historically, NHD flow lines were created by digitizing surface water information from aerial photography and paper maps. Using these same methods to update nationwide NHD flow lines is costly and inefficient; furthermore, these methods result in hydrography that lacks the horizontal and vertical accuracy needed for fully integrated datasets useful for mapping and scientific investigations. Effective methods for improving mapped hydrography employ change detection analysis of surface channels derived from light detection and ranging (LiDAR) digital elevation models (DEMs) and NHD flow lines. In this article, we describe the usefulness of surface channels derived from LiDAR DEMs for hydrography change detection to derive spatially accurate and time-relevant mapped hydrography. The methods employ analyses of horizontal and vertical differences between LiDAR-derived surface channels and NHD flow lines to define candidate locations of hydrography change. These methods alleviate the need to analyze and update the nationwide NHD for time relevant hydrography, and provide an avenue for updating the dataset where change has occurred.

Poppenga, Sandra K.; Gesch, Dean B.; Worstell, Bruce B.

2013-01-01

 
 
 
 
321

Formulario 1-B - Descripción: El título de este formulario es ...  

Science.gov (United States)

Text VersionPage 1. Formulario 1-B - Descripción: El título de este formulario es: Acuerdo de informe de empleados condicionales y empleados que manipulan ... More results from www.fda.gov/downloads/food/guidanceregulation

322

On spread-Es effects in the ionosphere before earthquakes  

Directory of Open Access Journals (Sweden)

Full Text Available The spread-Es phenomenon which appears as diffusivity of the traces of sporadic E-layers on the ionogrammes of vertical sounding stations and which reflects the turbulization of the sporadic layers -Es is studied in connection with earthquake preparation processes. Spread-Es data obtained at night every 15 min by the midlatitudinal vertical sounding station of the ionosphere in Dushanbe (?=38.5° N, ?=68.8° E) are analysed. Groups of earthquakes with different magnitudes and different distances between the epicenter and the sounding station are considered. A statistical analysis of the obtained results is performed. It is shown that during the three nights before an earthquake, spread-Es phenomena are observed more often than during the forth, fifth and sixth nights before the event. This effect is found to depend on both the magnitude of the earthquake and the distance between the epicenter and the sounding station.

V. A. Liperovsky; C.-V. Meister; E. V. Liperovskaya; N. E. Vasil'eva; O. Alimov

2005-01-01

323

Efficient, Off-Grid LiDAR Scanning of Remote Field Sites  

Science.gov (United States)

As terrestrial LiDAR scanning systems become increasingly available, strategies for executing efficient field surveys in settings without access to the power grid are increasingly needed. To evaluate scan methods and develop an off-grid power system, we used a tripod-mounted laser scanner to create high resolution (?40 mm point spacing) topographic maps for use in neotectonic studies of active faulting in arid, high elevation settings. We required 1-2 cm internal precision within point clouds spanning field sites that were ~300 x 300 m. Main components of our survey system included a Trimble GX DR200+ terrestrial laser scanner, a Leica TCR407power total station, a ruggedized laptop (2 GB RAM, 2.33 GHz dual-processor, and an Intel GMA 950 graphics card), batteries, and a portable photovoltaic array. Our first goal was to develop an efficient field-survey workflow. We started each survey project by using the total station for 1-2 days to locate an average of 8 ground control locations per site and to measure key geomorphic features within the project area. We then used the laser scanner to capture overlapping scans of the site, which required an average of six, 5-hour scanning sessions and an average of ten station setups. At each station, the scanner located itself on a particular point by measuring the relative positions of an average of four backsights, each of which is a ~17 x 17cm reflective target mounted on a tripod over the ground control point. To locate the scanner at a particular station prior to scanning, we experimented with both setting up over known points as measured using the total station, and resectioning, by positioning the scanner over an unmeasured location and backsighting on previously scanned points. We found that resectioning provided the smallest errors in scan registration. We then framed and queued a series of scans from each station that optimized point density and minimized data repetition. We also increased the accuracy of the scanner location by adding backsight measurements between scans. During scanning, incoming data were displayed in real-time by the scanner software, allowing the user to check scan area, shadowing, and resolution by interactively visualizing the project point cloud individually or in the context of previously scanned point clouds. Because individual scans must be stitched to build the total point cloud, we are currently testing different scan registration techniques to better quantify which minimizes registration errors in the final point cloud. A second goal of our study was to develop a low-cost, off-grid method for powering the survey equipment. To this end, we used two sets of three, 65Ah, 12V sealed lead acid batteries, which we charged using two 55W and one 25W, 12V photovoltaic arrays. We found that key elements for maximizing efficiency included real-time data visualization for planning future scans, use of polygons to delimit scan area as tightly as possible, distance-limited scanning to minimize unnecessary measurements, target tear-down and set-up synchronous with scanning. Using these strategies, we completed two survey projects, each of which covered a field site of approximately 300 x 300 m with ~31 million data points at an average point spacing of ~37 mm. Our experience demonstrates the feasibility of executing terrestrial LiDAR scanning with an average of ~5.2 million points per scan day in remote, off-grid field areas.

Gold, P.; Gold, R.; Cowgill, E.; Kreylos, O.; Hamann, B.

2007-12-01

324

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

UK PubMed Central (United Kingdom)

Diversity Arrays Technology (DArT) provides a robust, high throughput, cost-effective method to query thousands of sequence polymorphisms in a single assay. Despite the extensive use of this genotyping platform for numerous plant species, little is known regarding the sequence attributes and genome-wide distribution of DArT markers. We investigated the genomic properties of the 7,680 DArT marker probes of a Eucalyptus array, by sequencing them, constructing a high density linkage map and carrying out detailed physical mapping analyses to the Eucalyptus grandis reference genome. A consensus linkage map with 2,274 DArT markers anchored to 210 microsatellites and a framework map, with improved support for ordering, displayed extensive collinearity with the genome sequence. Only 1.4 Mbp of the 75 Mbp of still unplaced scaffold sequence was captured by 45 linkage mapped but physically unaligned markers to the 11 main Eucalyptus pseudochromosomes, providing compelling evidence for the quality and completeness of the current Eucalyptus genome assembly. A highly significant correspondence was found between the locations of DArT markers and predicted gene models, while most of the 89 DArT probes unaligned to the genome correspond to sequences likely absent in E. grandis, consistent with the pan-genomic feature of this multi-Eucalyptus species DArT array. These comprehensive linkage-to-physical mapping analyses provide novel data regarding the genomic attributes of DArT markers in plant genomes in general and for Eucalyptus in particular. DArT markers preferentially target the gene space and display a largely homogeneous distribution across the genome, thereby providing superb coverage for mapping and genome-wide applications in breeding and diversity studies. Data reported on these ubiquitous properties of DArT markers will be particularly valuable to researchers working on less-studied crop species who already count on DArT genotyping arrays but for which no reference genome is yet available to allow such detailed characterization.

Petroli CD; Sansaloni CP; Carling J; Steane DA; Vaillancourt RE; Myburg AA; da Silva OB Jr; Pappas GJ Jr; Kilian A; Grattapaglia D

2012-01-01

325

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

Science.gov (United States)

Diversity Arrays Technology (DArT) provides a robust, high throughput, cost-effective method to query thousands of sequence polymorphisms in a single assay. Despite the extensive use of this genotyping platform for numerous plant species, little is known regarding the sequence attributes and genome-wide distribution of DArT markers. We investigated the genomic properties of the 7,680 DArT marker probes of a Eucalyptus array, by sequencing them, constructing a high density linkage map and carrying out detailed physical mapping analyses to the Eucalyptus grandis reference genome. A consensus linkage map with 2,274 DArT markers anchored to 210 microsatellites and a framework map, with improved support for ordering, displayed extensive collinearity with the genome sequence. Only 1.4 Mbp of the 75 Mbp of still unplaced scaffold sequence was captured by 45 linkage mapped but physically unaligned markers to the 11 main Eucalyptus pseudochromosomes, providing compelling evidence for the quality and completeness of the current Eucalyptus genome assembly. A highly significant correspondence was found between the locations of DArT markers and predicted gene models, while most of the 89 DArT probes unaligned to the genome correspond to sequences likely absent in E. grandis, consistent with the pan-genomic feature of this multi-Eucalyptus species DArT array. These comprehensive linkage-to-physical mapping analyses provide novel data regarding the genomic attributes of DArT markers in plant genomes in general and for Eucalyptus in particular. DArT markers preferentially target the gene space and display a largely homogeneous distribution across the genome, thereby providing superb coverage for mapping and genome-wide applications in breeding and diversity studies. Data reported on these ubiquitous properties of DArT markers will be particularly valuable to researchers working on less-studied crop species who already count on DArT genotyping arrays but for which no reference genome is yet available to allow such detailed characterization. PMID:22984541

Petroli, César D; Sansaloni, Carolina P; Carling, Jason; Steane, Dorothy A; Vaillancourt, René E; Myburg, Alexander A; da Silva, Orzenil Bonfim; Pappas, Georgios Joannis; Kilian, Andrzej; Grattapaglia, Dario

2012-09-11

326

ROTATION CURVES IN (E+S) ISOLATED GALAXY PAIRS  

Directory of Open Access Journals (Sweden)

Full Text Available As part of a broad investigation to quantify the effects of interaction in the evolution of disk galaxies, we measured rotation curves of 102 spirals in mixed morphology pairs (E+S), drawn from the Karachantsev catalogue of isolated pairs of galaxies. In this summary we simply present characteristic rotation curves of spirals in isolated (E+S) pairs, in preparation for a future comparison with isolated spirals in a Tully-Fisher diagram.

E. M. Huerta; J. J. Gonzu00E1lez

2009-01-01

327

Lord of the Rings: GroES Structure  

Science.gov (United States)

Access to the article is free, however registration and sign-in are required. The crystal structure of the chaparonin GroES, which together with GroEL assists in the folding of many proteins in Escherichia coli, is reported in this issue of Science by Mande et al. (p. 203). In this perspective, M. Mayhew and F. U. Hartl discuss the implications of the new structure for the function of the GroEL:GroES complex.

Mark Mayhew (Memorial Sloan Kettering Cancer Center;Howard Hughes Medical Institute and Cellular Biochemistry and Biophysics Program); F. Ulrich Hartl (Memorial Sloan Kettering Cancer Center;Howard Hughes Medical Institute and Cellular Biochemistry and Biophysics Program)

1996-01-12

328

Efficient FLP recombination in mouse ES cells and oocytes.  

UK PubMed Central (United Kingdom)

We report an improved vector, pCAGGS-FLPe, for transient expression of the enhanced FLP recombinase in mouse ES cells and oocytes. In standard transfection experiments, about 6% of total ES colonies showed FLP recombination, albeit with mosaicism within each colony. After microinjection of pCAGGS-FLPe into oocytes, about one-third of heterozygotic mice born showed complete FLP recombination. Thus pCAGGS-FLPe presents two practical options for removal of FRT cassettes in mice.

Schaft J; Ashery-Padan R; van der Hoeven F; Gruss P; Stewart AF

2001-09-01

329

Efficient FLP recombination in mouse ES cells and oocytes.  

Science.gov (United States)

We report an improved vector, pCAGGS-FLPe, for transient expression of the enhanced FLP recombinase in mouse ES cells and oocytes. In standard transfection experiments, about 6% of total ES colonies showed FLP recombination, albeit with mosaicism within each colony. After microinjection of pCAGGS-FLPe into oocytes, about one-third of heterozygotic mice born showed complete FLP recombination. Thus pCAGGS-FLPe presents two practical options for removal of FRT cassettes in mice. PMID:11668672

Schaft, J; Ashery-Padan, R; van der Hoeven, F; Gruss, P; Stewart, A F

2001-09-01

330

Effect of Terrestrial LiDAR Point Sampling Density in Ephemeral Gully Characterization  

Directory of Open Access Journals (Sweden)

Full Text Available Gully erosion can account for significant volumes of sediment exiting agricultural landscapes, but is difficult to monitor and quantify its evolution with traditional surveying technology. Scientific investigations of gullies depend on accurate and detailed topographic information to understand and evaluate the complex interactions between field topography and gully evolution. Detailed terrain representations can be produced by new technologies such as terrestrial LiDAR systems. These systems are capable of collecting information with a wide range of ground point sampling densities as a result of operator controlled factors. Increasing point density results in richer datasets at a cost of increased time needed to complete field surveys. In large research watersheds, with hundreds of sites being monitored, data collection can become costly and time consuming. In this study, the effect of point sampling density on the capability to collect topographic information was investigated at individual gully scale. This was performed through the utilization of semi-variograms to produce overall guiding principles for multi-temporal gully surveys based on various levels of laser sampling points and relief variation (low, moderate, and high). Results indicated the existence of a point sampling density threshold that produces little or no additional topographic information when exceeded. A reduced dataset was created using the density thresholds and compared to the original dataset with no major discrepancy. Although variations in relief and soil roughness can lead to different point sampling density requirements, the outcome of this study serves as practical guidance for future field surveys of gully evolution and erosion.

Henrique G. Momm; Ronald L. Bingner; Robert R. Wells; Seth M. Dabney; Lyle D. Frees

2013-01-01

331

Characterization of an Alpine Treeline using Airborne LiDAR Data and Physiological Modeling.  

UK PubMed Central (United Kingdom)

Understanding what environmental drivers control the position of the alpine treeline is important for both refining our understanding of plant stress and tree development, as well as for climate change studies. However, monitoring the location of the treeline position and potential movement is difficult due to cost and technical challenges, as well as a lack of a clear boundary. Advanced remote sensing technologies such as Light Detection and Ranging (LIDAR) offer significant potential to map short individual tree crowns within the transition zone despite the lack of predictive capacity. Process based forest growth models offer a complementary approach by quantifying the environmental stresses trees experience at the treeline, allowing transition zones to be defined and ultimately mapped. In this paper we investigate the role remote sensing and physiological, ecosystem based, modeling can play in the delineation of the alpine treeline. To do so we utilize airborne LiDAR data to map tree height and stand density across a series of altitudinal gradients from below to above the treeline within the Swiss National Park (SNP), Switzerland. We then utilize a simple process based model to assess the importance of seasonal variations on four climatically-related variables that impose non-linear constraints on photosynthesis. Our results indicate that all methods predict the treeline to within a 50m altitudinal zone and indicate that aspect is not a driver of significant variations in treeline position in the region. Tree cover, rather than tree height is the main discriminator of the treeline at higher elevations. Temperatures in fall and spring are responsible for the major differences along altitudinal zones, however changes in evaporative demand also control plant growth at lower altitudes. Our results indicate that the two methods provide complementary information on treeline location and, when combined, provide additional insights into potentially endangered forest / grassland transition zones. This article is protected by copyright. All rights reserved.

Coops NC; Morsdorf F; Schaepman ME; Zimmermann NE

2013-07-01

332

Mapping tropical forest biomass with radar and spaceborne LiDAR: overcoming problems of high biomass and persistent cloud  

Directory of Open Access Journals (Sweden)

Full Text Available Spatially-explicit maps of aboveground biomass are essential for calculating the losses and gains in forest carbon at a regional to national level. The production of such maps across wide areas will become increasingly necessary as international efforts to protect primary forests, such as the REDD+ (Reducing Emissions from Deforestation and forest Degradation) mechanism, come into effect, alongside their use for management and research more generally. However, mapping biomass over high-biomass tropical forest is challenging as (1) direct regressions with optical and radar data saturate, (2) much of the tropics is persistently cloud-covered, reducing the availability of optical data, (3) many regions include steep topography, making the use of radar data complex, (4) while LiDAR data does not suffer from saturation, expensive aircraft-derived data are necessary for complete coverage. We present a solution to the problems, using a combination of terrain-corrected L-band radar data (ALOS PALSAR), spaceborne LiDAR data (ICESat GLAS) and ground-based data. We map Gabon's Lopé National Park (5000 km2) because it includes a range of vegetation types from savanna to closed-canopy tropical forest, is topographically complex, has no recent cloud-free high-resolution optical data, and the dense forest is above the saturation point for radar. Our 100 m resolution biomass map is derived from fusing spaceborne LiDAR (7142 ICESat GLAS footprints), 96 ground-based plots (average size 0.8 ha) and an unsupervised classification of terrain-corrected ALOS PALSAR radar data, from which we derive the aboveground biomass stocks of the park to be 78 Tg C (173 Mg C ha?1). This value is consistent with our field data average of 181 Mg C ha?1, from the field plots measured in 2009 covering a total of 78 ha, and which are independent as they were not used for the GLAS-biomass estimation. We estimate an uncertainty of ± 25 % on our carbon stock value for the park. This error term includes uncertainties resulting from the use of a generic tropical allometric equation, the use of GLAS data to estimate Lorey's height, and the necessity of separating the landscape into distinct classes. As there is currently no spaceborne LiDAR satellite in operation (GLAS data is available for 2003–2007 only), this methodology is not suitable for change-detection. This research underlines the need for new satellite LiDAR data to provide the potential for biomass-change estimates, although this need will not be met before 2015.

E. T. A. Mitchard; S. S. Saatchi; L. J. T. White; K. A. Abernethy; K. J. Jeffery; S. L. Lewis; M. Collins; M. A. Lefsky; M. E. Leal; I. H. Woodhouse; P. Meir

2011-01-01

333

Nanos3 gene targeting in medaka ES cells.  

Science.gov (United States)

Gene targeting (GT) by homologous recombination offers the best precision for genome editing in mice. nanos3 is a highly conserved gene and encodes a zinc-finger RNA binding protein essential for germ stem cell maintenance in Drosophila, zebrafish and mouse. Here we report nanos3 GT in embryonic stem (ES) cells of the fish medaka as a lower vertebrate model organism. A vector was designed for GT via homologous recombination on the basis of positive-negative selection (PNS). The ES cell line MES1 after gene transfer and PNS produced 56 colonies that were expanded into ES cell sublines. Nine sublines were GT-positive by PCR genotyping, 4 of which were homologous recombinants as revealed by Southern blot. We show that one of the 4, A15, contains a precisely targeted nanos3 allele without any random events, demonstrating the GT feasibility in medaka ES cells. Importantly, A15 retained all features of undifferentiated ES cells, including stable self-renewal, an undifferentiated phenotype, pluripotency gene expression and differentiation during chimeric embryogenesis. These results provide first evidence that the GT procedure and genuine GT on a chromosomal locus such as nanos3 do not compromise pluripotency in ES cells of a lower vertebrate. PMID:23678294

Guan, Guijun; Yan, Yan; Chen, Tiansheng; Yi, Meisheng; Ni, Hong; Naruse, Kiyoshi; Nagahama, Yoshitaka; Hong, Yunhan

2013-05-09

334

Nanos3 gene targeting in medaka ES cells.  

UK PubMed Central (United Kingdom)

Gene targeting (GT) by homologous recombination offers the best precision for genome editing in mice. nanos3 is a highly conserved gene and encodes a zinc-finger RNA binding protein essential for germ stem cell maintenance in Drosophila, zebrafish and mouse. Here we report nanos3 GT in embryonic stem (ES) cells of the fish medaka as a lower vertebrate model organism. A vector was designed for GT via homologous recombination on the basis of positive-negative selection (PNS). The ES cell line MES1 after gene transfer and PNS produced 56 colonies that were expanded into ES cell sublines. Nine sublines were GT-positive by PCR genotyping, 4 of which were homologous recombinants as revealed by Southern blot. We show that one of the 4, A15, contains a precisely targeted nanos3 allele without any random events, demonstrating the GT feasibility in medaka ES cells. Importantly, A15 retained all features of undifferentiated ES cells, including stable self-renewal, an undifferentiated phenotype, pluripotency gene expression and differentiation during chimeric embryogenesis. These results provide first evidence that the GT procedure and genuine GT on a chromosomal locus such as nanos3 do not compromise pluripotency in ES cells of a lower vertebrate.

Guan G; Yan Y; Chen T; Yi M; Ni H; Naruse K; Nagahama Y; Hong Y

2013-01-01

335

Nanos3 Gene Targeting in Medaka ES Cells  

Science.gov (United States)

Gene targeting (GT) by homologous recombination offers the best precision for genome editing in mice. nanos3 is a highly conserved gene and encodes a zinc-finger RNA binding protein essential for germ stem cell maintenance in Drosophila, zebrafish and mouse. Here we report nanos3 GT in embryonic stem (ES) cells of the fish medaka as a lower vertebrate model organism. A vector was designed for GT via homologous recombination on the basis of positive-negative selection (PNS). The ES cell line MES1 after gene transfer and PNS produced 56 colonies that were expanded into ES cell sublines. Nine sublines were GT-positive by PCR genotyping, 4 of which were homologous recombinants as revealed by Southern blot. We show that one of the 4, A15, contains a precisely targeted nanos3 allele without any random events, demonstrating the GT feasibility in medaka ES cells. Importantly, A15 retained all features of undifferentiated ES cells, including stable self-renewal, an undifferentiated phenotype, pluripotency gene expression and differentiation during chimeric embryogenesis. These results provide first evidence that the GT procedure and genuine GT on a chromosomal locus such as nanos3 do not compromise pluripotency in ES cells of a lower vertebrate.

Guan, Guijun; Yan, Yan; Chen, Tiansheng; Yi, Meisheng; Ni, Hong; Naruse, Kiyoshi; Nagahama, Yoshitaka; Hong, Yunhan

2013-01-01

336

Improved Step Size Adaptation for the MO-CMA-ES  

DEFF Research Database (Denmark)

The multi-objective covariance matrix adaptation evolution strategy (MO-CMA-ES) is an evolutionary algorithm for continuous vector-valued optimization. It combines indicator-based selection based on the contributing hypervolume with the efficient strategy parameter adaptation of the elitist covariance matrix adaptation evolution strategy (CMA-ES). Step sizes (i.e., mutation strengths) are adapted on individual-level using an improved implementation of the 1/5-th success rule. In the original MO-CMA-ES, a mutation is regarded as successful if the offspring ranks better than its parent in the elitist, rank-based selection procedure. In contrast, we propose to regard a mutation as successful if the offspring is selected into the next parental population. This criterion is easier to implement and reduces the computational complexity of the MO-CMA-ES, in particular of its steady-state variant. The new step size adaptation improves the performance of the MO-CMA-ES as shown empirically using a large set of benchmarkfunctions. The new update scheme in general leads to larger step sizes and thereby counteracts premature convergence. The experiments comprise the first evaluation of the MO-CMA-ES for problems with more than two objectives.

Voß, T.; Hansen, N.

2010-01-01

337

Impact of Business Flexibility Capabilities on Firm Performance: Es Perspective  

Directory of Open Access Journals (Sweden)

Full Text Available Enterprise Resource Planning (ERP) systems have become transaction backbone of organizations in the private, governmental and non-governmental non-profit sector, seeking growth. According to research firm Gartner, fully 85% of the fortune 500 firms have implemented ERP and increasingly small to medium enterprises (SMEs) are finding ways to incorporate ERP systems. While on one hand when organizations are going for large scale ERP implementations, often a debate is raised whether ERP deployment contributes towards the business flexibility capabilities of firms or not. Using a conceptual model firmly grounded in the resource- based view as a frame of reference was developed, hypotheses generated and tested for 53 large Indian manufacturing firms, with respondents being senior most business and IT executives to investigate the potential link between ES resources and its contribution to business flexibility capabilities and contribution of business flexibility capabilities on performance. For this, three important relationships are posited between: ES resources and business flexibility capabilities, business flexibility capabilities and firm performance and ES resources and firm performance Findings of this study highlights that ES resources was not positively associated with business flexibility capabilities, also association between business flexibility capabilities with firm performance was low. Based on the strong empirical evidence, the study suggested that ES resources are not contributing towards business flexibility capabilities and managers going for such systems should tread with caution.

Anupam Saxena; M.P. Jaiswal

2012-01-01

338

Prevenir la enfermedad es la mejor estrategia para mejorar la salud/ Prevention: The Most Effective Strategy to Improve Health  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish La salud es el bien más preciado para el ser humano, de lo cual toma consciencia sobre todo al perderla, o cuando la pérdida ocurre a un ser querido. Por tal motivo, una de las tareas fundamentales del Estado es garantizar la mejor salud posible a los ciudadanos, y esto en Costa Rica se ha hecho en forma muy eficiente, tanto que los indicadores de salud son de los mejores del mundo. Esto no es casual, sino el producto de decisiones políticas del pasado de costarricense (more) s asertivos. Hoy el país enfrenta un gran reto con el crecimiento en la demanda de servicios públicos y el incremento en su costo. Para mantener el legado es preciso tomar decisiones igual de visionarias. Se señala como un alto riesgo de desmejorar estos indicadores, el concentrar los esfuerzos y presupuestos en tratar las enfermedades en sus etapas finales y, por el contrario, se propone dar prioridad a la prevención, con base en el hecho de que las principales causas de mortalidad prematura en los costarricenses, se asocian con factores de riesgo prevenibles. Se recomienda la educación como el camino para prevenir la enfermedad, y se debe involucrar a profesionales en impartir la “educación para la salud”, dirigida primero y formalmente a niños y adolescentes. Abstract in english Good health is the most prized possession a human being can have, only recognized when one or a dear one losses it. In a well-functioning society it is the responsibility of the State to provide its citizens with tools that guarantee the best possible state of health for themselves and their relatives. In Costa Rica, this issue has been approached very effectively, and health indicators are comparable to the best in the world. This success is the product of wise political (more) decisions made in the past by assertive leaders. Nowadays, the nation is challenged by an increasing demand of services and by a raise in their cost. In order to keep this legacy, equally visionary decisions need to be taken. Devoting the majority of resources and efforts to treat disease in its final stages is detrimental to the said health indicators, those resources, instead, should be directed towards prevention, since causes of premature mortality and illness are the result of societal practices and are associated with risk factors that are preventable. Education is recommended to prevent disease and professionals should teach “heatlh education”, primarily directed to children and adolescents.

Mainieri-Hidalgo, José Alberto

2011-01-01

339

LiDAR snow cover studies on glacier surface: significance of snow- and ice dynamical processes  

Directory of Open Access Journals (Sweden)

Full Text Available The storage of water within the seasonal snow cover is a substantial source for runoff in high mountain catchments. Information about the spatial distribution of snow accumulation is necessary for calibration and validation of hydro-meteorological models. Generally only a small number of precipitation measurements deliver precipitation input for modeling in remote mountain areas. The spatial interpolation and extrapolation of measurements of precipitation is still difficult. Multi-temporal application of Light Detecting And Ranging (LiDAR) techniques from aircraft, so-called airborne laser scanning (ALS), enables to derive surface elevations changes even in inaccessible terrain. Within one snow accumulation season these surface elevation changes can be interpreted as snow depths as a first assumption for snow hydrological studies. However, dynamical processes in snow, firn and ice are contributing to surface elevation changes on glaciers. To evaluate the magnitude and significance of these processes on alpine glaciers in the present state, ALS derived surface elevation changes were compared to converted snow depths from 35.4 km of ground penetrating radar (GPR) profiles on four glaciers in the high alpine region of Ötztal Alps. LANDSAT data were used to distinguish between firn and ice areas of the glaciers. In firn areas submerging ice flow and densification of firn and snow are contributing to a mean relative deviation of ALS surface elevation changes from actually observed snow depths of ?20.0% with a mean standard deviation of 17.1%. Deviations between ALS surface elevation changes and GPR snow depth are small along the profiles on the glacier tongues. At these areas mean absolute deviation of ALS surface elevation changes and GPR snow depth is 0.004 m with a mean standard deviation of 0.27 m. Emergence flow leads to distinct positive deviations only at the very front of the glacier tongues. Snow depths derived from ALS deviate less from actually measured snow depths than expected errors of in-situ measurements of solid precipitation. Hence, ALS derived snow depths are an important data source for both, spatial distribution and total sum of the snow cover volume stored on the investigated glaciers and in the corresponding high mountain catchments at the end of an accumulation season.

K. Helfricht; M. Kuhn; M. Keuschnig; A. Heilig

2013-01-01

340

Risky Sexual Behaviour among Big Construction Enterprise Workers; Bahir Dar City, Amhara Regional State, Northwest Ethiopia  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Risky sexual behaviors are the major factors in rising sexually transmitted infections among adolescents and young adults. In Ethiopia construction industry is on increasing and deriving young people from rural area to the cities. Therefore, the aim of this study was to determine the prevalence of risky sexual behaviour and factors associated with among construction workers. Methods: A cross sectional study was conducted in March 2012 among construction workers in Bahir Dar city. The analysis was carried out using SPSS version 16. The data were analyzed in bivariate and multivariate logistic regression. Result: The prevalence of risky sexual behavior among construction workers was 44.9%. Female workers were about four times more likely to have had risky sexual practices than males (AOR = 3.86, 95% CI: 2.34 - 6.37). Respondents whose educational level less than fourth grade were 12 times more likely to be engaged in risky sex than whose educational level tenth grade or more (AOR = 12.13, 95% CI: 1.84 - 79.78). Divorced individuals were about five times more likely to have had risky sexual activities than married individuals (AOR = 4.63, 95% CI: 1.32 - 16.12). Respondents whose first sexual commencement from 15 - 19 years were about three times more likely to have had risky sexual behavior than from 20 - 24 years (AOR = 2.89, 95% CI: 1.70 - 4.91). Besides, the odds of having risky sexual behaviour among construction workers who had sexual partner at the time of the study were about 0.6 times less likely to have had risky sexual behaviours than workers who did not have (AOR = 0.6, 95% CI: 0.38, 0.96). Conclusion: The prevalence of risky sexual behavior among construction workers was 44.9%. Variables such as sex, educational level, marital status, age at first sexual intercourse, presence of current sexual partner and casual sex were found to be independent predictors of risky sexual behaviour. Therefore, interventions targeting on these factors were recommended.

Mekibib Kassa; Eleni Tesfaye; Zelalem Alamrew

2013-01-01

 
 
 
 
341

La controversial Ritalina: ¿Cómo es su consumo en Costa Rica?  

Directory of Open Access Journals (Sweden)

Full Text Available El déficit atencional y déficit atencional con hiperactividad son trastornos que se diagnostican cada vez con mayor frecuencia en la población infantil en edad escolar. Este fenómeno ha generado un aumento en el consumo de Ritalina. Con el objetivo de determinar la prevalencia de estos trastornos en Costa Rica, y la magnitud del consumo de Ritalina, se utilizó información proporcionada por el Ministerio de Salud sobre la venta del medicamento durante un período de 30 meses entre el 2000 y el 2003. Se encontró que a pesar de que la prevalencia es baja en términos globales, su distribución geográfica es muy heterogénea. En la Región Central Norte el consumo es 11 veces mayor que en la Brunca. Se recomienda impulsar la homogenización de criterios para el diagnóstico de estos trastornos, con el fin de mejorar la atención y tratamiento de los niños que así lo requieran.

Santamaría Ulloa, Carolina

2007-01-01

342

STACEE Observations of 1ES 1218+304  

CERN Document Server

We present the analysis and results of recent high-energy gamma-ray observations of the high energy-peaked BL Lac (HBL) object 1ES 1218+304 with the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE). 1ES 1218+304 is an X-ray bright HBL at a redshift z=0.182. It has been predicted to be a gamma-ray emitter above 100 GeV, detectable by ground-based Cherenkov telescopes. Recently this source has been detected by MAGIC and VERITAS, confirming these predictions. STACEE's sensitivity to astrophysical sources at energies above 100 GeV allows it to explore high energy sources such as X-ray bright active galaxies and gamma-ray bursts. We present results from STACEE observations of 1ES 1218+304 in the 2006 and 2007 observing seasons.

Mukherjee, R; Ball, J; Carson, J E; Covault, C E; Driscoll, D D; Fortin, P; Gingrich, D M; Hanna, D S; Jarvis, A; Kildea, J; Lindner, T; Müller, C; Ong, R A; Ragan, K; Williams, D A; Zweerink, J

2007-01-01

343

Certification testing for the ES-2 shipping package  

International Nuclear Information System (INIS)

[en] The ES-2 is a multiconfiguration, Type B fissile material shipping package, designed by the Y-12 Nuclear Packaging Systems. It is unique in that a castable refractory material performs primary impact absorption and thermal insulation duties. This material, unlike the insulation often used in fissile material packages, such as Celotex and various foams, is fireproof at temperatures associated with Type B package testing (800 C). The ES-2 is designed to permit the use of three different containment vessels which can result in as many as six different configurations. Eight prototype units were manufactured and successfully tested to US Federal Regulatory Requirements

1998-01-01

344

Dynamics of the TrES-2 system  

CERN Document Server

The TrES-2 system harbors one planet which was discovered with the transit technique. In this work we investigate the dynamical behavior of possible additional, lower-mass planets. We identify the regions where such planets can move on stable orbits and show how they depend on the initial eccentricity and inclination. We find, that there are stable regions inside and outside the orbit of TrES-2b where additional, smaller planets can move. We also show that those planets can have a large orbital inclination which makes a detection with the transit technique very difficult.

Freistetter, Florian; Funk, Barbara

2009-01-01

345

Blasentumornachsorge - EAU-Guidelines: Was gibt es Neues?  

Directory of Open Access Journals (Sweden)

Full Text Available Das obligate 3-monatliche Intervall von Kontrollzystoskopien nach jedem oberflächlichen Blasentumor gilt nach dem aktuellen Stand der Wissenschaft nicht mehr. Die EAU-Guidelines geben hier ein risikoadaptiertes Vorgehen vor, das auch praktisch sinnvoll erscheint. Die Nachsorge bei muskelinvasiven und fortgeschrittenen Urothelkarzinomen nach Zystektomie zielt auf eine möglichst frühe Erkennung eines Tumorrezidivs ab, um weitere palliative Maßnahmen rechtzeitig einleiten zu können. Hierfür wird ein Intervall von 3?4 Monaten empfohlen. Eine spezielle Nachsorgeempfehlung für Harnableitung mit Verwendung von Darmsegmenten gibt es von der EAU nicht, hier gibt es Empfehlungen der Deutschen Gesellschaft für Urologie.

Lazica DA; Brandt AS; Rundstedt FC; Roth S

2008-01-01

346