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

    PubMed

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

    2010-06-03

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

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

    PubMed Central

    2010-01-01

    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. PMID

  3. Intussusception in children seen at Muhimbili National Hospital, Dar es Salaam.

    PubMed

    Carneiro, P M R; Kisusi, D M

    2004-09-01

    -ray. All children were then managed by surgery, 11(39.3%) underwent bowel resection. Histopathology reports of those available did not show cause of intussusception. Seven patients died postoperatively, hospital mortality of 25%. The approximate incidence of intussusception in less than one-year olds is 1:7557 in Dar es Salaam. It is a concern in our environment causing considerable morbidity and mortality due to late presentation and efforts should be made to improve sanitation and hygiene, referring health facilities, socio-economic factors and probably look into ways of preventing the problem occurring. Seasonal variation was seen, most cases(78.6%) presenting in the dry season when there is shortage of water in the city.

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

    PubMed

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

    2009-09-19

    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). 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. 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. 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.

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

    PubMed Central

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

    2009-01-01

    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. PMID:19765312

  6. 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

    PubMed Central

    2011-01-01

    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 < 0.5 was statistically significant. 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

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

    PubMed

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

    2000-07-01

    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.

  8. Pattern of occurrence and treatment of impacted teeth at the Muhimbili National Hospital, Dar es Salaam, Tanzania

    PubMed Central

    2013-01-01

    Background Impacted teeth predispose to periodontal disease and dental caries of adjacent teeth resulting in pain, discomfort and loss of function. This study analyzed the pattern of occurrence of impacted teeth, associated symptoms, treatment and complications of treatment in patients who presented at the Muhimbili National Hospital, Tanzania. Method This was a crossectional descriptive study which utilized notes and x rays of patients who were treated for impacted teeth at the Oral and Maxillofacial firm in Muhimbili National Hospital over five years, from January 2005 to August 2010. These records were retrieved and examined for the major complaint of the patient at presentation to hospital, demography, impacted tooth, type of impaction (for third molars), treatment offered and complications after treatment. Similar information was collected from all patients with impacted teeth attended in the same centre from 1st September 2010 to 31st August 2011. Results A total of 896 patients (496 males and 400 females) treated for complaints related to impacted teeth were recorded. The male to female ratio was 1.2:1, age range of 16 to 85 years and a mean age of 28.9 years (SD = 9.5). Slightly more than 84% of the patients presented with mandibular third molar impactions. Most (44.7%) of these patients had an impacted lower right third molar followed by those presenting with a lower left third molar impaction (39.7%). In 1.3% of the patients all the four third molars were impacted. Sixty nine (7.7%) patients had impacted upper 3rd molars while 2% had impacted upper canines. Of the mandibular 3rd molar impactions 738 (76%) were mesio-angular type, 87 (8.9%) horizontal type and 69 (7.1%) disto-angular. Patients presented with a variety of complaints. About 85% of the patients presented to hospital due to varying degrees of pain. In 4.9% the detection of the impacted tooth/teeth was coincidental after presenting to hospital for other reasons not related to the impaction

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

    PubMed

    Mhada, Tumaini V; Fredrick, Francis; Matee, Mecky I; Massawe, Augustine

    2012-10-24

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

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

    PubMed

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

    2012-01-01

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

  11. Excreta disposal in Dar-es-Salaam.

    PubMed

    Chaggu, Esnati; Mashauri, Damas; van Buuren, Joost; Sanders, Wendy; Lettinga, Gatze

    2002-11-01

    The sociocultural and socioeconomic situation of sanitation in Dar-es-Salaam (Dsm), Tanzania, was studied with explicit emphasis on pit-latrines. Without considering the sociocultural conditions, the so-called best solution might not be the right one. Therefore, in order to achieve the intended goal, a literature review, a questionnaire survey, and personal visits to the chosen study areas were done. In total, 207 household questionnaires were filled in 16 areas of the city. Interviewers did house-to-house visits and questionnaires were filled out on the spot. Results indicated that the city population is about 3.8 million at present, with over 80% of the dwellers using pit-latrines; some 3% use septic tanks with soakage pits, about 6% are connected to the sewerage system, and 1% have no excreta disposal facility. Difficulties faced include dismal budget allocations, fragmentation of sanitation activities among subsectors, lack of or poor sanitation record keeping, unsatisfactory machinery for septic tank and pit-latrine emptying, lack of a clear policy on pit-latrine handling and, in competition for resources, low priority is accorded to an excreta disposal system among the people. City residents will continue to use the pit-latrines for a long time to come. Reusing the fecal sludge is not known by most city dwellers and is influenced by sociocultural habits. To prevent groundwater pollution and to recover useful products in human excreta and urine, ecological sanitation toilets and anaerobic digesters offer a good option.

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

    PubMed

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

    2017-04-17

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

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

    PubMed Central

    2013-01-01

    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

  14. 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

    PubMed Central

    Nagu, Tumaini J; Bakari, Muhammad; Matee, Mecky

    2008-01-01

    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. PMID:19099553

  15. Methicillin-resistant staphylococcus aureus (MRSA) colonization among Intensive Care Unit (ICU) patients and health care workers at Muhimbili national hospital, Dar Es Salaam, Tanzania, 2012.

    PubMed

    Geofrey, Alfred; Abade, Ahmed; Aboud, Said

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has been recognized as important nosocomial pathogens worldwide. S aureus may induce clinically manifested diseases, or the host may remain completely asymptomatic. A cross-sectional hospital-based study was conducted from October 2012 to March 2013 in two ICUs at MNH. Admitted patients and health care workers were enrolled in the study. Interviewer administered questionnaires; patient history forms, observation charts and case report forms were used to collect data. Swabs (nostrils, axillary or wounds) were collected. MRSA were screened and confirmed using cefoxitin, oxacillin discs and oxacillin screen agar. Antibiotic susceptibility was performed using Kirby-Bauer disk diffusion method. The risk factors for MRSA were determined using the logistic regression analysis and a p - value of <0.05 was considered as statistically significant. Of the 169 patients and 47 health workers who were recruited, the mean age was 43.4 years ± SD 15.3 and 37.7 years ± (SD) 11.44 respectively. Among the patients male contributed 108 (63.9%) while in health worker majority 39(83%) were females. The prevalence of MRSA colonization among patients and health care workers was 11.83% and 2.1% respectively. All (21) MRSA isolates were highly resistant to penicillin and erythromycin, and 17 (85.7%) were highly sensitive to vancomycin. Being male (AOR 6.74, 95% CI 1.31-34.76), history of sickness in past year (AOR 4.89, 95% CI 1.82- 13.12), being sick for more 3 times (AOR 8.91, 95% CI 2.32-34.20), being diabetic (AOR 4.87, 95% CI 1.55-15.36) and illicit drug use (AOR 10.18, 95%CI 1.36-76.52) were found to be independently associated with MRSA colonization. A study identified a high prevalence of MRSA colonization among patients admitted in the ICU. MRSA isolates were highly resistant to penicillin and erythromycin. History of illegal drug use was highly associated with MRSA colonization.

  16. Urban agriculture and Anopheles habitats in Dar es Salaam, Tanzania.

    PubMed

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

    2009-05-01

    A cross-sectional survey of agricultural areas, combined with routinely monitored mosquito larval information, was conducted in urban Dar es Salaam, Tanzania, to investigate how agricultural and geographical features may influence the presence of Anopheles larvae. Data were integrated into a geographical information systems framework, and predictors of the presence of Anopheles larvae in farming areas were assessed using multivariate logistic regression with independent random effects. It was found that more than 5% of the study area (total size 16.8 km2) was used for farming in backyard gardens and larger open spaces. The proportion of habitats containing Anopheles larvae was 1.7 times higher in agricultural areas compared to other areas (95% confidence interval = 1.56-1.92). Significant geographic predictors of the presence of Anopheles larvae in gardens included location in lowland areas, proximity to river, and relatively impermeable soils. Agriculture-related predictors comprised specific seedbed types, mid-sized gardens, irrigation by wells, as well as cultivation of sugar cane or leafy vegetables. Negative predictors included small garden size, irrigation by tap water, rainfed production and cultivation of leguminous crops or fruit trees. Although there was an increased chance of finding Anopheles larvae in agricultural sites, it was found that breeding sites originated by urban agriculture account for less than a fifth of all breeding sites of malaria vectors in Dar es Salaam. It is suggested that strategies comprising an integrated malaria control effort in malaria-endemic African cities include participatory involvement of farmers by planting shade trees near larval habitats.

  17. Homicide death in Dar es Salaam, Tanzania 2005.

    PubMed

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

    2008-12-01

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

  18. Management of neonatal sepsis at Muhimbili National Hospital in Dar es Salaam: diagnostic accuracy of C-reactive protein and newborn scale of sepsis and antimicrobial resistance pattern of etiological bacteria.

    PubMed

    Mkony, Martha Franklin; Mizinduko, Mucho Michael; Massawe, Augustine; Matee, Mecky

    2014-12-05

    We determined the accuracy of Rubarth's newborn scale of sepsis and C- reactive protein in diagnosing neonatal sepsis and assessed antimicrobial susceptibility pattern of etiological bacteria. This cross sectional study was conducted at Muhimbili National Hospital in Dar es Salaam, Tanzania between July 2012 and March 2013. Neonates suspected to have sepsis underwent physical examination using Rubarth's newborn scale of sepsis (RNSOS). Blood was taken for culture and antimicrobial sensitivity testing, full blood picture and C - reactive protein (CRP) performed 12 hours apart. The efficacy of RNSOS and serial CRP was assessed by calculating sensitivity, specificity, negative and positive predictive values, receiver operating characteristics (ROC) analysis as well as likelihood ratios (LHR) with blood culture result used as a gold standard. Out of 208 blood samples, 19.2% had a positive blood culture. Single CRP had sensitivity and specificity of 87.5% and 70.9% respectively, while RNSOS had sensitivity of 65% and specificity of 79.7%. Serial CRP had sensitivity of 69.0% and specificity of 92.9%. Combination of CRP and RNSOS increased sensitivity to 95.6% and specificity of 56.4%. Combination of two CRP and RNSOS decreased sensitivity to 89.1% but increased specificity to 74%. ROC for CRP was 0.86; and for RNSOS was 0.81. For CRP the LHR for positive test was 3 while for negative test was 0.18, while for RNSOS the corresponding values were 3.24 and for negative test was 0.43. Isolated bacteria were Klebsiella spp 14 (35%), Escherichia coli 12 (22.5%), Coagulase negative staphlococci 9 (30%), Staphylococcus aureus 4 (10%), and Pseudomonas spp 1 (2.5%). The overall resistance to the WHO recommended first line antibiotics was 100%, 92% and 42% for cloxacillin, ampicillin and gentamicin, respectively. For the second line drugs resistance was 45%, 40%, and 7% for ceftriaxone, vancomycin and amikacin respectively. Single CRP in combination with RNSOS can be used for rapid

  19. Homicide of children in Dar es Salaam, Tanzania, 2005

    PubMed Central

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

    2014-01-01

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

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

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

    ERIC Educational Resources Information Center

    Mtebe, Joel S.; Raphael, Christina

    2013-01-01

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

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

    ERIC Educational Resources Information Center

    Mlozi, Malongo R. S.

    1995-01-01

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

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

    ERIC Educational Resources Information Center

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

    2016-01-01

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

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

    ERIC Educational Resources Information Center

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

    2016-01-01

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

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  6. Clinical, Virologic, and Epidemiologic Characteristics of Dengue Outbreak, Dar es Salaam, Tanzania, 2014.

    PubMed

    Vairo, Francesco; Mboera, Leonard E G; De Nardo, Pasquale; Oriyo, Ndekya M; Meschi, Silvia; Rumisha, Susan F; Colavita, Francesca; Mhina, Athanas; Carletti, Fabrizio; Mwakapeje, Elibariki; Capobianchi, Maria Rosaria; Castilletti, Concetta; Di Caro, Antonino; Nicastri, Emanuele; Malecela, Mwelecele N; Ippolito, Giuseppe

    2016-05-01

    We investigated a dengue outbreak in Dar es Salaam, Tanzania, in 2014, that was caused by dengue virus (DENV) serotype 2. DENV infection was present in 101 (20.9%) of 483 patients. Patient age and location of residence were associated with infection. Seven (4.0%) of 176 patients were co-infected with malaria and DENV.

  7. Clinical, Virologic, and Epidemiologic Characteristics of Dengue Outbreak, Dar es Salaam, Tanzania, 2014

    PubMed Central

    Mboera, Leonard E.G.; De Nardo, Pasquale; Oriyo, Ndekya M.; Meschi, Silvia; Rumisha, Susan F.; Colavita, Francesca; Mhina, Athanas; Carletti, Fabrizio; Mwakapeje, Elibariki; Capobianchi, Maria Rosaria; Castilletti, Concetta; Di Caro, Antonino; Nicastri, Emanuele; Malecela, Mwelecele N.; Ippolito, Giuseppe

    2016-01-01

    We investigated a dengue outbreak in Dar es Salaam, Tanzania, in 2014, that was caused by dengue virus (DENV) serotype 2. DENV infection was present in 101 (20.9%) of 483 patients. Patient age and location of residence were associated with infection. Seven (4.0%) of 176 patients were co-infected with malaria and DENV. PMID:27088845

  8. Assessment of human thermal perception in the hot-humid climate of Dar es Salaam, Tanzania.

    PubMed

    Ndetto, Emmanuel L; Matzarakis, Andreas

    2017-01-01

    Dar es Salaam, Tanzania, is a typical African city along the Indian Ocean coast, and therefore an important urban area to examine human thermal perception in the hot-humid tropical climate. Earlier research on human bioclimate at Dar es Salaam indicated that heat stress prevails during the hot season from October to March, peaking between December and February, particularly the early afternoons. In order to assess the human thermal perception and adaptation, two popular places, one at an urban park and another at a beach environment, were selected and questionnaire surveys were conducted in August-September 2013 and January 2014, concurrently with local micro-meteorological measurements at survey locations. The thermal conditions were quantified in terms of the thermal index of the physiologically equivalent temperature (PET) using the micro-scale climate model RayMan. The thermal comfort range of human thermal comfort and the local thermal adaptive capacity were determined in respect to the thermal index by binning thermal sensation votes. The thermal comfort range was found to be well above that in temperate climates at about 23-31 °C of PET. The study could significantly contribute to urban planning in Dar es Salaam and other coastal cities in the tropics.

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

    PubMed

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

    2013-10-01

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

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

    PubMed Central

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

    2013-01-01

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

  11. Assessment of human thermal perception in the hot-humid climate of Dar es Salaam, Tanzania

    NASA Astrophysics Data System (ADS)

    Ndetto, Emmanuel L.; Matzarakis, Andreas

    2017-01-01

    Dar es Salaam, Tanzania, is a typical African city along the Indian Ocean coast, and therefore an important urban area to examine human thermal perception in the hot-humid tropical climate. Earlier research on human bioclimate at Dar es Salaam indicated that heat stress prevails during the hot season from October to March, peaking between December and February, particularly the early afternoons. In order to assess the human thermal perception and adaptation, two popular places, one at an urban park and another at a beach environment, were selected and questionnaire surveys were conducted in August-September 2013 and January 2014, concurrently with local micro-meteorological measurements at survey locations. The thermal conditions were quantified in terms of the thermal index of the physiologically equivalent temperature (PET) using the micro-scale climate model RayMan. The thermal comfort range of human thermal comfort and the local thermal adaptive capacity were determined in respect to the thermal index by binning thermal sensation votes. The thermal comfort range was found to be well above that in temperate climates at about 23-31 °C of PET. The study could significantly contribute to urban planning in Dar es Salaam and other coastal cities in the tropics.

  12. Pit Latrine Emptying Behavior and Demand for Sanitation Services in Dar Es Salaam, Tanzania

    PubMed Central

    Jenkins, Marion W.; Cumming, Oliver; Cairncross, Sandy

    2015-01-01

    Pit latrines are the main form of sanitation in unplanned areas in many rapidly growing developing cities. Understanding demand for pit latrine fecal sludge management (FSM) services in these communities is important for designing demand-responsive sanitation services and policies to improve public health. We examine latrine emptying knowledge, attitudes, behavior, trends and rates of safe/unsafe emptying, and measure demand for a new hygienic latrine emptying service in unplanned communities in Dar Es Salaam (Dar), Tanzania, using data from a cross-sectional survey at 662 residential properties in 35 unplanned sub-wards across Dar, where 97% had pit latrines. A picture emerges of expensive and poor FSM service options for latrine owners, resulting in widespread fecal sludge exposure that is likely to increase unless addressed. Households delay emptying as long as possible, use full pits beyond what is safe, face high costs even for unhygienic emptying, and resort to unsafe practices like ‘flooding out’. We measured strong interest in and willingness to pay (WTP) for the new pit emptying service at 96% of residences; 57% were WTP ≥U.S. $17 to remove ≥200 L of sludge. Emerging policy recommendations for safe FSM in unplanned urban communities in Dar and elsewhere are discussed. PMID:25734790

  13. Pit latrine emptying behavior and demand for sanitation services in Dar Es Salaam, Tanzania.

    PubMed

    Jenkins, Marion W; Cumming, Oliver; Cairncross, Sandy

    2015-02-27

    Pit latrines are the main form of sanitation in unplanned areas in many rapidly growing developing cities. Understanding demand for pit latrine fecal sludge management (FSM) services in these communities is important for designing demand-responsive sanitation services and policies to improve public health. We examine latrine emptying knowledge, attitudes, behavior, trends and rates of safe/unsafe emptying, and measure demand for a new hygienic latrine emptying service in unplanned communities in Dar Es Salaam (Dar), Tanzania, using data from a cross-sectional survey at 662 residential properties in 35 unplanned sub-wards across Dar, where 97% had pit latrines. A picture emerges of expensive and poor FSM service options for latrine owners, resulting in widespread fecal sludge exposure that is likely to increase unless addressed. Households delay emptying as long as possible, use full pits beyond what is safe, face high costs even for unhygienic emptying, and resort to unsafe practices like 'flooding out'. We measured strong interest in and willingness to pay (WTP) for the new pit emptying service at 96% of residences; 57% were WTP≥U.S. $17 to remove ≥200 L of sludge. Emerging policy recommendations for safe FSM in unplanned urban communities in Dar and elsewhere are discussed.

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

    PubMed

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

    2017-10-01

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

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

    NASA Astrophysics Data System (ADS)

    Luciani, Giulia; Sappa, Giuseppe; Cella, Antonella

    2016-04-01

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

  16. Residents’ perceptions of institutional performance in water supply in Dar es Salaam

    NASA Astrophysics Data System (ADS)

    Mwakalila, Shadrack

    This paper addresses the performance of institutions in water supply systems for improving social and economic benefits of people living in Dar es Salaam city. The methods employed in field data and information collection included interviews, questionnaire, focus group discussions and participatory observation. Kinondoni and Ilala Districts were used as case study. The study revealed that, the main water sources in the study areas are boreholes, shallow wells, rain water and water vendors. Other minor sources are piped water and natural water sources, such as rivers and streams. The supply of piped water by Dar es Salaam Water Sewerage and Sanitation Company (DAWASA/DAWASCO) meets only 45% of the total water demands. Individuals own and sell water from boreholes, shallow wells, piped water connected to their individual houses and natural wells located in their individual plots. The price of one 20 l bucket of water from a water vendor depends on the availability of water and the distance walked from the water source to the customer. Majority of the respondents (77.5%) indicated that individual water delivery systems provide sufficient water as compared to five years ago in the study areas. Few of the respondents (6.3%) said individual water delivery systems have no capacity to provide sufficient water while 16.3% indicate that individual water delivery systems provide moderate water supply but are important in supplementing other water providers in the study areas. The study reveals that a majority of the local population are satisfied with the capacity of individual water delivery systems in providing water for household uses. This paper recommends some improvements to be done to water supply systems in the Dar es Salaam city.

  17. HIV counselling and testing practices for children seen in an urban emergency department of a tertiary referral hospital in Dar es Salaam, Tanzania: a retrospective cross-sectional study

    PubMed Central

    Sawe, Hendry R; Mfinanga, Juma A; Ringo, Faith H; Mwafongo, Victor; Reynolds, Teri A; Runyon, Michael S

    2016-01-01

    Objectives To describe the HIV counselling and testing practices for children presenting to an emergency department (ED) in a low-income country. Setting The ED of a large east African national referral hospital. Participants This retrospective review of all paediatric (<18 years old) ED visits in 2012 enrolled patients who had an HIV test ordered and excluded those without testing. Files were available for 5540/5774 (96%) eligible patients and 1632 (30%) were tested for HIV, median age 1.3 years (IQR 9 months to 4 years), 58% <18 months old and 61% male. Primary and secondary outcome measures The primary outcome measure was documentation of pretest and post-test counselling, or deferral of counselling, for children tested for HIV in the ED. Secondary measures included the overall rate of HIV testing, rate of counselling documented in the inpatient record when deferred in the ED, rate of counselling documented when testing was initiated by the inpatient service, rate of counselling documented by test result (positive vs negative) and the rate of referral to follow-up HIV care among patients testing positive. Results Of 418 patients tested in the ED, counselling, or deferral of counselling, was documented for 70 (17%). When deferred to the ward, subsequent counselling was documented for 15/42 (36%). Counselling was documented in 33% of patients testing positive versus 1.1% patients testing negative (OR 43 (95% CI 23 to 83). Of 199 patients who tested positive and survived to hospital discharge, 76 (38%) were referred for follow-up at the HIV clinic on discharge. Conclusions Physicians documented the provision, or deferral, of counselling for <20% of children tested for HIV in the ED. Counselling was much more likely to be documented when the test result was positive. Less than 40% of those testing positive were referred for follow-up care. PMID:26880672

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

    PubMed Central

    2012-01-01

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

  19. Body-Art Practices Among Undergraduate Medical University Students in Dar Es Salaam, Tanzania, 2014

    PubMed Central

    Chacha, Chacha Emmanuel; Kazaura, Method R.

    2015-01-01

    Background: Body-art practices are increasing among adolescents and young adults. Although substantial data are available in developed countries, little has been documented about body-art practices in developing countries. Objective: To determine the magnitude, types and reasons for practicing body-art practices among undergraduate medical University students in Dar es Salaam, Tanzania. Materials and Methods: A cross-sectional descriptive study was conducteed among undergraduate University students in Dar es Salaam involving 536 respondents from two Universities. We used a self-administered questionnaire to collect data. Analyses were based on summary measures and bivariate analyses. Results: While 7.5% of undergraduate students reported having tattoos, 20% reported having body puncturing or piercing. Body piercing is reported more among female university undergraduate students than their male counterparts. Reported main reasons for undergoing body-art include “a mark of beauty,” 24%, “just wanted one,” 18% and “a mark of femininity or masculinity,” 17%. The majority (98%) of students were aware that unsafe body-art practices may lead to contracting HIV and more than half (52%) reported awareness of the risk of Hepatitis B infection. Conclusions: Despite high awareness of the potential risks involved in unsafe body arts that include tattoo and piercing, these practices are increasing among adolescents and young adults. There is need to have educational and counseling efforts so as to minimize associated health risks. PMID:25814729

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

    PubMed

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

    2014-05-01

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

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

    NASA Astrophysics Data System (ADS)

    Ndetto, Emmanuel L.; Matzarakis, Andreas

    2013-10-01

    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.

  2. HIV counselling and testing practices for children seen in an urban emergency department of a tertiary referral hospital in Dar es Salaam, Tanzania: a retrospective cross-sectional study.

    PubMed

    Sawe, Hendry R; Mfinanga, Juma A; Ringo, Faith H; Mwafongo, Victor; Reynolds, Teri A; Runyon, Michael S

    2016-02-15

    To describe the HIV counselling and testing practices for children presenting to an emergency department (ED) in a low-income country. The ED of a large east African national referral hospital. This retrospective review of all paediatric (<18 years old) ED visits in 2012 enrolled patients who had an HIV test ordered and excluded those without testing. Files were available for 5540/5774 (96%) eligible patients and 1632 (30%) were tested for HIV, median age 1.3 years (IQR 9 months to 4 years), 58% <18 months old and 61% male. The primary outcome measure was documentation of pretest and post-test counselling, or deferral of counselling, for children tested for HIV in the ED. Secondary measures included the overall rate of HIV testing, rate of counselling documented in the inpatient record when deferred in the ED, rate of counselling documented when testing was initiated by the inpatient service, rate of counselling documented by test result (positive vs negative) and the rate of referral to follow-up HIV care among patients testing positive. Of 418 patients tested in the ED, counselling, or deferral of counselling, was documented for 70 (17%). When deferred to the ward, subsequent counselling was documented for 15/42 (36%). Counselling was documented in 33% of patients testing positive versus 1.1% patients testing negative (OR 43 (95% CI 23 to 83). Of 199 patients who tested positive and survived to hospital discharge, 76 (38%) were referred for follow-up at the HIV clinic on discharge. Physicians documented the provision, or deferral, of counselling for <20% of children tested for HIV in the ED. Counselling was much more likely to be documented when the test result was positive. Less than 40% of those testing positive were referred for follow-up care. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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

  4. Sexual behaviour among youths at high risk for HIV-1 infection in Dar es Salaam, Tanzania

    PubMed Central

    Mwakagile, D; Mmari, E; Makwaya, C; Mbwana, J; Biberfeld, G; Mhalu, F; Sandstrom, E

    2001-01-01

    Objectives: To investigate sex specific sexual behaviour in youths visiting a youth clinic for sexual and reproductive health in Dar es Saalam. Methods: A questionnaire was administered to a random sample of youths between 10 and 24 years of age attending the youth health clinic in Dar es Saalam. The clinical investigation included testing for syphilis and HIV-1 antibodies Results: 1423 youths attended the clinic between September 1997 and August 1998. The study population comprised 213 (53.5%) males and 185 (46.5%) females. 97 (24.4%) were below 20 years. The mean age at coitarche was 16.5 and 17.0 years of age for males and females, respectively. The coitarche was involuntary in 15 females (8.6%). 49.5% males reported more than five lifetime partners compared with 14.1% for females (p<0.0001). Males reported recent partners to be 2.5 years younger, while females reported them to be 5.0 years older. No contraceptive use was reported by 29.7% of the males and 40.3% of females. 52.7% females had been pregnant and 26 (14.1%) reported induced abortions. Genital discharge was found in 69.5% and 73.9% and GUD in 36.6% and 27.1% of males and females respectively. 12 males (5.9%) and 43 females (24.6%) were found to be HIV-1 infected. 13.8% of the females with only one lifetime partner were HIV-1 infected compared with 40.9% with more than five partners (p = 0.028). Conclusions: Many youths in Dar es Salaam engage in sexual behaviours that put them at risk of unwanted pregnancies and STIs including HIV infection. Female youths were more likely to contract HIV infection than males. In African urban areas youth oriented clinics can have a pivotal role in HIV/STI prevention and control Key Words: youth; sexual behaviour; HIV PMID:11463924

  5. Understanding household behavioral risk factors for diarrheal disease in Dar es Salaam: a photovoice community assessment.

    PubMed

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

    2011-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    CLUVA (CLimate change and Urban Vulnerability in Africa; http://www.cluva.eu/) is a 3 years project, funded by the European Commission in 2010. The main objective of CLUVA is to develop context-centered methods and knowledge to be applied to African cities to assess vulnerabilities and increase knowledge on managing climate related risks. The project estimates the impacts of climate changes in the next 40 years at urban scale and downscales IPCC climate projections to evaluate specific threats to selected African test cities. These are mainly from floods, sea-level rise, droughts, heat waves, and desertification. The project evaluates and links: social vulnerability; urban green structures and ecosystem services; urban-rural interfaces; vulnerability of urban built environment and lifelines; and related institutional and governance dimensions of adaptation. The multi-scale and multi-disciplinary qualitative, quantitative and probabilistic approach of CLUVA is currently being applied to selected African test cities (Addis Ababa - Ethiopia; Dar es Salaam - Tanzania; Douala - Cameroun; Ouagadougou - Burkina Faso; St. Louis - Senegal). In particular, the poster will present preliminary findings for the Dar es Salaam case study. Dar es Salaam, which is Tanzania's largest coastal city, is exposed to floods, coastal erosion, droughts and heat waves, and highly vulnerable to impacts as a result of ineffective urban planning (about 70% unplanned settlements), poverty and lack of basic infrastructure (e.g. lack of or poor quality storm water drainage systems). Climate change could exacerbate the current situation increasing hazard-exposure alongside the impacts of development pressures which act to increase urban vulnerability for example because of informal (unregulated) urbanization. The CLUVA research team - composed of climate and environmental scientists, risk management experts, urban planners and social scientists from both European and African institutions - has

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

    PubMed Central

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

    2011-01-01

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

  8. Urban mosquitoes, situational publics, and the pursuit of interspecies separation in Dar es Salaam

    PubMed Central

    KELLY, ANN H.; LEZAUN, JAVIER

    2014-01-01

    Recent work in anthropology points to the recognition of multispecies entanglements as the grounds for a more ethical politics. In this article, we examine efforts to control mosquitoes in Dar es Salaam, Tanzania, as an example of the laborious tasks of disentanglement that characterize public health interventions. The mosquito surveillance and larval elimination practices of an urban malaria control program offer an opportunity to observe how efforts to create distance between species relate to the physical and civic textures of the city. Seen in the particular context of the contemporary African metropolis, the work of public health appears less a matter of control than a commitment to constant urban maintenance and political mobilization. PMID:25429167

  9. Determinants of high blood pressure and barriers to diagnosis and treatment in Dar es Salaam, Tanzania.

    PubMed

    Zack, Rachel M; Irema, Kahema; Kazonda, Patrick; Leyna, Germana H; Liu, Enju; Spiegelman, Donna; Fawzi, Wafaie; Njelekela, Marina; Killewo, Japhet; Danaei, Goodarz

    2016-12-01

    We assessed the prevalence and determinants of high blood pressure (BP), and barriers to diagnosis and treatment, in Dar es Salaam, Tanzania. We surveyed and screened 2174 community-dwelling adults aged at least 40 years in 2014 and conducted a follow-up after 1 year. Median BP was 131/81 mmHg, and hypertension prevalence was 37%. Mean adjusted difference in SBP was 4.0 mmHg for overweight, 6.3 mmHg for obese class I, and 10.5 mmHg for obese class II/III compared with normal weight participants. Those who were physically inactive had 4.8 mmHg higher SBP compared with those with more than 24 h of moderate or vigorous activity per week. Drinkers of at least 10 g of alcohol per day had 4.5 mmHg higher SBP than did nondrinkers. Among hypertensive participants, 48% were previously diagnosed, 22% were treated, and 10% were controlled. Hypertensive participants without health insurance were 12% less likely to have been previously diagnosed than insured hypertensive participants. Of referred participants, 68% sought care, but only 27% were on treatment and 8% had controlled BP at follow-up. Reasons for not seeking care included lack of symptoms, cost of visit, and lack of time. Reasons for not being on treatment included lack of symptoms, not being prescribed treatment, and having finished one course of treatment. Major risk factors for hypertension in Dar es Salaam are overweight, obesity, inadequate physical activity, and limited access to quality medical care. Increased insurance coverage and community-based screening, along with quality medical care and patient education, may help control this burgeoning epidemic.

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

    PubMed

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

    2006-04-04

    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. 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. 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. 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.

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

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

    ERIC Educational Resources Information Center

    Meli, Benjamin Mbeba

    2015-01-01

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

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

    ERIC Educational Resources Information Center

    Jamison, Amy J.

    2010-01-01

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

  14. Risk Factors of Loss to Follow up Among HIV Positive Pediatric Patients in Dar es Salaam, Tanzania

    PubMed Central

    MCCORMICK, Nora M.; LI, Nan; SANDO, David; MUYA, Aisa; MANJI, Karim P.; KISENGE, Rodrick; DUGGAN, Christopher; CHALAMILLA, Guerino; FAWZI, Wafaie W.; SPIEGELMAN, Donna

    2015-01-01

    Objective To identify risk factors for loss to follow up (LTFU) in an HIV-infected pediatric population in Dar es Salaam, Tanzania between 2004 and 2011. Design Longitudinal analysis of 6236 HIV-infected children. Methods We conducted a prospective cohort study of 6236 pediatric patients enrolled in care and treatment in Dar es Salaam from October 2004 to September 2011. LTFU was defined as missing a clinic visit for >90 days for patients on ART and for >180 days for patients in care and monitoring. The relationship of baseline and time-varying characteristics to risk of LTFU was examined using a Cox proportional hazards model. Results 2130 children (34%) were LTFU over a median follow up of 16.7 months (IQR, 3.4–36.9). Factors independently associated with a higher risk of LTFU were age 2 years (RR=1.59, 95% CI 1.40–1.80), diarrhea at enrollment (RR=1.20, 95% CI 1.03–1.41), a low mid-upper arm circumference for age (RR=1.20, CI 1.05–1.37), eating protein 3 times a week (RR=1.39, 95% CI 1.05–1.90), taking cotrimoxazole (RR=1.39, 95% CI 1.06–1.81), initiating onto antiretrovirals (RR=1.37, 95% CI 1.17–1.61), receiving treatment at a hospital instead of a local facility (RR=1.39, 95% CI 1.06–1.41), and starting treatment in 2006 or later (RR=1.10, 95% CI 1.04–1.16). Conclusions Health workers should be aware of pediatric patients who are at greatest risk of LTFU, such as younger and undernourished patients, so that they can proactively counsel families about the importance of visit adherence. Findings support decentralization of HIV care to local facilities as opposed to hospitals. PMID:26247894

  15. Urban lymphatic filariasis in the metropolis of Dar es Salaam, Tanzania

    PubMed Central

    2013-01-01

    Background The last decades have seen a considerable increase in urbanization in Sub-Saharan Africa, and it is estimated that over 50% of the population will live in urban areas by 2040. Rapid growth of cities combined with limited economic resources often result in informal settlements and slums with favorable conditions for proliferation of vectors of lymphatic filariasis (LF). In Dar es Salaam, which has grown more than 30 times in population during the past 55 years (4.4 million inhabitants in 2012), previous surveys have indicated high prevalences of LF. This study investigated epidemiological aspects of LF in Dar es Salaam, as a background for planning and implementation of control. Methods Six sites with varying distance from the city center (3–30 km) and covering different population densities, socioeconomic characteristics, and water, sewerage and sanitary facilities were selected for the study. Pupils from one public primary school at each site were screened for circulating filarial antigen (CFA; marker of adult worm infection) and antibodies to Bm14 (marker of exposure to transmission). Community members were examined for CFA, microfilariae and chronic manifestations. Structured questionnaires were administered to pupils and heads of community households, and vector surveys were carried out in selected households. Results The study indicated that a tremendous decrease in the burden of LF infection had occurred, despite haphazard urbanisation. Contributing factors may be urban malaria control targeting Anopheles vectors, short survival time of the numerous Culex quinquefasciatus vectors in the urban environment, widespread use of bed nets and other mosquito proofing measures, and mass drug administration (MDA) in 2006 and 2007. Although the level of ongoing transmission was low, the burden of chronic LF disease was still high. Conclusions The development has so far been promising, but continued efforts are necessary to ensure elimination of LF as a

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

    PubMed

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

    2010-03-16

    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. 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

  17. Hepatitis B virus markers in the population of Dar es Salaam, Tanzania.

    PubMed

    Haukenes, G; Shao, J F; Mbena, E; Rustad, S

    1987-09-01

    A total of 542 serum samples from healthy adults (medical students and medical staff, blood donors and pregnant women) residing in or near the city of Dar es Salaam, Tanzania were examined for markers of hepatitis B virus (HBV) infection. Of these samples, 95 (17.5%) were not found to contain any HBV marker when examined by enzyme-linked immunoassay for hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs) and antibody to hepatitis B core antigen (anti-HBc). HBsAg was demonstrated in 52 (9.6%) samples of which 7 (13.5%) were positive for hepatitis Be antigen (HBeAg) and 17 (32.7%) were positive for anti-HBc IgM. None of 9 HBsAg positive pregnant women were carriers of HBeAg. These results show that hepatitis B infection is very common in this country. The relatively low prevalence of HBeAg among HBsAg carriers may indicate that transmission of hepatitis B at birth is not of major importance.

  18. Immunity to tetanus in male adults in Dar es Salaam, Tanzania.

    PubMed

    Aboud, S; Lyamuya, E F; Kristoffersen, E K; Matre, R

    2002-02-01

    To determine immunity to tetanus in male blood donors with previous diphtheria-pertussis-tetanus (DPT)/tetanus toxoid (TT) vaccination. A cross sectional study, conducted in September 1999. Blood bank, Muhimbili Medical Centre, Dar es Salaam, Tanzania. Using an antigen competition ELISA technique, serum tetanus anti-toxin levels in two hundred male blood donors were determined. Vaccination history was absent in 43 (21.5%) blood donors, whereas 60 (30%) and 97 (48.5%) reported childhood DPT and TT vaccination, respectively. Tetanus anti-toxin was undetectable in 47 (23.5%) blood donors and the levels were below that considered protective (> or = 0.1 IU/ml) in 25 (12.5%). Among those with undetectable level, 43 (91.5%) had no vaccination history. Time after last DPT/TT vaccination correlated significantly with tetanus anti-toxin levels (r2=-0.331, p=0.001). In multivariate analysis, TT doses received and time after last vaccination explained 4.8% and 29.4%, respectively, of the variations in tetanus anti-toxin levels. Seventy two (36%) male blood donors were susceptible to tetanus and the susceptibility was highest from 48 years. A regular TT booster dose at 10 yearly intervals is recommended to provide adequate and long lasting immunity in male adults. Proper keeping of vaccination records is emphasised.

  19. Prevalence of helmet use among motorcycle users in Dar Es Salaam, Tanzania.

    PubMed

    Kauky, Cosmas George; Kishimba, Rogath Saika; Urio, Loveness John; Abade, Ahmed Mohammed; Mghamba, Janneth Maridadi

    2015-01-01

    The purpose of this study was to determine prevalence of helmet use among motorcyclists as one of the preventive measures for road traffic injuries. A cross sectional observational survey was conducted in the 3 Districts (Kinondoni, Ilala and Temeke) that make Dar es Salaam. Tanzania. A standardized line-listing form and checklist were used to record the drivers and passengers use of helmet as observed by study investigators. Data for helmet use was collected on one weekday and one weekend day. Time for observation was during the rush hour in the morning, noon and evening. Then data were entered into Epi Info 3.5.1 analysis. A total of 7,678 motorcycle drivers and 4,328 passengers observed in this study. Drivers were almost male (98.8%) and 73.2% of all passengers were males. The prevalence use of helmet use among motorcyclist's riders was 82.1% and among passengers was 22.5%. Proportion of helmet use in drivers and passengers observed were relatively similar during weekday and weekend day and time of observation. This study showed the relative high helmet use among motorcyclist riders though very low in passengers. This study recommends increased community awareness on helmet use among passengers and enforcement and revival of road safety laws of passengers and motorcyclists on helmet use.

  20. Urban health in daily practice: livelihood, vulnerability and resilience in Dar es Salaam, Tanzania.

    PubMed

    Obrist, Brigit

    2003-12-01

    Health is the core value and ultimate goal of health development, yet we know very little about health conceptions in everyday life. Inspired by investigations into lay health concepts in Europe, our study explores experiences and meanings of health in a strikingly different context, namely, in a low-income neighbourhood of an African city. Grounded in ethnographic research in Dar es Salaam, we introduce the concept of 'health practice' and examine health definitions, explanations, and activities of urban Swahili women. Our findings show that representations of health form a set of experiences, meanings and embodied practice centring on the links between body, mind, and living conditions. We suggest that 'livelihood', 'vulnerability' and 'resilience' best capture women's main concerns of health practice in such a setting. All women face an emotional burden of being exposed to urban afflictions and an intellectual and practical burden of overcoming them, but some meet this challenge more successfully than others do. This approach tips the balance towards a positive view of health that has been neglected in medical anthropology. It also opens new lines of inquiry in urban health research by consequently following a resource orientation that acknowledges women's struggle to stay healthy and directs attention to their agency.

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

    PubMed

    Obrist, Brigit

    2004-04-01

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

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

    PubMed

    Kassenga, Gabriel R

    2007-03-01

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

  3. Rape against women: the magnitude, perpetrators and patterns of disclosure of events in Dar es Salaam, Tanzania.

    PubMed

    Muganyizi, Projestine S; Kilewo, Charles; Moshiro, Candida

    2004-12-01

    This cross-sectional household survey was conducted in Dar es Salaam between July and August 2000. The objectives were to establish the magnitude of rape against women, the perpetrators, disclosure of events and other related factors. Among the 1004 women who completed their interviews, 20% said they were ever raped. The known perpetrators were responsible for 92% of the most recent events. Whereas 34% of events were disclosed for non-legal purposes, only 10% were disclosed to the police. Repeated rape and patterns of disclosure were significantly associated with existing social relationships with the perpetrator. The results indicate that rape against women is a serious public health problem in Dar es Salaam commonly involving people who are close to the victims.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  5. Nutritional status of HIV-infected women with tuberculosis in Dar es Salaam, Tanzania

    PubMed Central

    Wamsele, J.; MacKenzie, T.; Maro, I.; Kimario, J.; Ali, S.; Dowla, S.; Hendricks, K.; Lukmanji, Z.; Neke, N. M.; Waddell, R.; Matee, M.; Pallangyo, K.; von Reyn, C. F.

    2013-01-01

    Setting: Tuberculosis (TB) treatment clinics in Dar es Salaam, Tanzania. Objective: To quantify anthropometrics and intake of en-ergy and protein among human immunodeficiency virus (HIV) positive women with TB. Design: HIV-positive women with newly diagnosed TB were assessed on their anthropometric characteristics and dietary intake. Energy and protein intake were determined using Tanzania food composition tables and compared with standard recommendations. Patients were re-evaluated after 4–6 months of anti-tuberculosis treatment. Results: Among 43 women, the baseline median CD4 count was 209 cells/µl (range 8–721); 19 (44%) had a CD4 count of <200; 20 (47%) were on antiretroviral therapy. Body mass index was <18.5 kg/m2 in 25 (58%); the median food insecurity score was 6. The median level of kcal/day was 1693 (range 1290–2633) compared to an estimated need of 2658; the median deficit was 875 kcal (range −65–1278). The median level of protein/day was 42 g (range 27–67) compared to 77 g estimated need; the median protein deficit was 35 g (range 10–50). The median weight gain among 29 patients after 4–6 months was 6 kg. Conclusion: HIV-positive women with TB have substantial 24-h deficits in energy and protein intake, report significant food insecurity and gain minimal weight on anti-tuberculosis treatment. Enhanced dietary education together with daily supplementation of 1000 kcal with 40 g protein may be required. PMID:26393034

  6. Irrational antibiotic usage in boarding secondary school settings in Dar es Salaam.

    PubMed

    Mwambete, Kennedy D

    2009-08-01

    To assess the prevalence of antibiotic misuse among boarding secondary school students in Dares Salaam. This descriptive cross-sectional study was conducted over 3-month period amongst boarding secondary school students. A randomized sample of students was recruited from at least 3 secondary schools from each of the three municipalities of Dar es Salaam region. Questionnaire with both closed-and open-ended questions was used for data collection in which socio-demographic characteristics, knowledge of ATBs, sources of prescription, procurement of ATBs, infections for which ATBs were used, and antibiotic therapy compliance were assessed. The collected data were analyzed using SPSS/PC+ version 15.0 computer package. A total of 424 randomly selected students with a mean age of 20 years were interviewed, of those 150 were females and 274 were males. Majority of the respondents (74%) have had heard of ATBs, however only 105 (25%) respondent described them correctly. Prevalence of antibiotic usage among the students was high (69%). Of 293 students who have had used ATBs, 73% of them had procured the drugs on prescription; 170 (58%) respondents used the ATBs for non-microbial infections/diseases, only 183 (62%) were compliant to antibiotic therapies (ABT), while 226 (77%) admitted to have had shared ATBs with friends/relatives whenever deemed necessary. Of those who had procured ATBs without prescriptions, 66% of them obtained the drugs from pharmacies. The study revealed inadequate knowledge on ATBs among the respondents and that pharmacies played a major role on easy availability of ATBs as over-the-counter (OTC) drugs attributing to high rate of irrational use of ATBs. We recommended that health care providers should succinctly explain to patients the importance of ABT compliance and adverse effects of non-compliance. Regulatory authorities should re-enforce the laws on sales of ATBs by prohibiting their availability as OTC drugs.

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

    PubMed

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

    2007-09-01

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

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

    PubMed

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

    2016-10-01

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

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

    PubMed Central

    Vyas, Seema; Mbwambo, Jessie

    2017-01-01

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

  10. Gender differences in diet and nutrition among adults initiating antiretroviral therapy in Dar es Salaam, Tanzania.

    PubMed

    Abioye, Ajibola I; Isanaka, Sheila; Liu, Enju; Mwiru, Ramadhani S; Noor, Ramadhani A; Spiegelman, Donna; Mugusi, Ferdinand; Fawzi, Wafaie

    2015-01-01

    Human immunodeficiency virus (HIV)-infected males have poor treatment outcomes after initiation of antiretroviral therapy (ART) compared to HIV-infected women. Dietary factors might mediate the association between sex and disease progression. However, the gender difference in diet among HIV-infected individuals in sub-Saharan Africa is largely unknown. The objective of this study was to examine differences in dietary intake among HIV-infected men and women. We conducted a cross-sectional analysis of dietary questionnaire data from 2038 adults initiating ART in Dar es Salaam, Tanzania to assess whether nutrient adequacy differed by sex. We dichotomized participants' nutrient intakes by whether recommended dietary allowances (RDAs) were met and estimated the relative risk (RR) of meeting RDAs in males using binomial regression models. We also estimated the mean difference in intake of foods and food groups by gender. We found poorer dietary practices among men compared to women. Males were less likely to meet the RDAs for micronutrients critical for slowing disease progression among HIV patients: niacin (RR = 0.39, 95% confidence interval [CI]: 0.27 to 0.55), riboflavin (RR = 0.81, 95% CI: 0.73 to 0.91), vitamin C (RR = 0.94, 95% CI: 0.89 to 1.00), and zinc (RR = 0.06, 95% CI: 0.01 to 0.24). Intake of thiamine, pantothenate, vitamins B6, B12, and E did not vary by gender. Males were less likely to eat cereals (mean difference [servings per day] = -0.21, 95% CI: -0.44 to 0.001) and vegetables (mean difference = -0.47, 95% CI: -0.86 to -0.07) in their diet, but more likely to have meat (mean difference = 0.14, 95% CI: 0.06 to 0.21). We conclude that male HIV patients have poorer dietary practices than females, and this may contribute to faster progression of the disease in males.

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    ERIC Educational Resources Information Center

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

    2017-01-01

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

  14. High Prevalence of Faecal Carriage of ESBL-Producing Enterobacteriaceae among Children in Dar es Salaam, Tanzania.

    PubMed

    Tellevik, Marit G; Blomberg, Bjørn; Kommedal, Øyvind; Maselle, Samuel Y; Langeland, Nina; Moyo, Sabrina J

    2016-01-01

    Faecal carriage of ESBL-producing bacteria is a potential risk for transmission and infection. Little is known about faecal carriage of antibiotic resistance in Tanzania. This study aimed to investigate the prevalence of faecal carriage of ESBL-producing Enterobacteriaceae and to identify risk factors for carriage among young children in Tanzania. From August 2010 to July 2011, children below 2 years of age were recruited in Dar es Salaam, including healthy community children (n = 250) and children hospitalized due to diarrhoea (n = 250) or other diseases (n = 103). ChromID ESBL agar and ChromID CARBA SMART agar were used for screening. Antimicrobial susceptibility testing was performed by the disk diffusion method. ESBL genotypes were identified by Real-Time PCR and sequencing. The overall prevalence of ESBL carriage was 34.3% (207/ 603). The prevalence of ESBL carriage was significantly higher among hospitalized children (50.4%), compared to community children (11.6%; P < 0.001; OR = 7.75; 95% CI: 4.99-12.03). We found high prevalence of Multidrug-resistance (94%) among Escherichia coli and Klebsiella pneumoniae isolates. No resistance to carbapenems was detected. For the majority of isolates (94.7%) we detected a blaCTX-M-15-like gene. In addition, the plasmid mediated AmpC beta-lactamase CMY-2 was detected for the first time in Tanzania. ESBL prevalence was significantly higher among HIV positive (89.7%) than HIV negative (16.9%) children (P = 0.001; OR = 9.99; 95% CI: 2.52-39.57). Use of antibiotics during the past 14 days and age below 1 year was also associated with ESBL carriage. We report a high rate of faecal carriage of ESBL-producing Enterobacteriaceae among children below 2 years of age in Tanzania, particularly those with HIV-infection. Resistance to a majority of the available antimicrobials commonly used for children in Tanzania leaves few treatment options for infections when caused by these bacteria.

  15. High Prevalence of Faecal Carriage of ESBL-Producing Enterobacteriaceae among Children in Dar es Salaam, Tanzania

    PubMed Central

    Tellevik, Marit G.; Blomberg, Bjørn; Kommedal, Øyvind; Maselle, Samuel Y.; Langeland, Nina; Moyo, Sabrina J.

    2016-01-01

    Background Faecal carriage of ESBL-producing bacteria is a potential risk for transmission and infection. Little is known about faecal carriage of antibiotic resistance in Tanzania. This study aimed to investigate the prevalence of faecal carriage of ESBL-producing Enterobacteriaceae and to identify risk factors for carriage among young children in Tanzania. Methodology/Principal Findings From August 2010 to July 2011, children below 2 years of age were recruited in Dar es Salaam, including healthy community children (n = 250) and children hospitalized due to diarrhoea (n = 250) or other diseases (n = 103). ChromID ESBL agar and ChromID CARBA SMART agar were used for screening. Antimicrobial susceptibility testing was performed by the disk diffusion method. ESBL genotypes were identified by Real-Time PCR and sequencing. The overall prevalence of ESBL carriage was 34.3% (207/ 603). The prevalence of ESBL carriage was significantly higher among hospitalized children (50.4%), compared to community children (11.6%; P < 0.001; OR = 7.75; 95% CI: 4.99–12.03). We found high prevalence of Multidrug-resistance (94%) among Escherichia coli and Klebsiella pneumoniae isolates. No resistance to carbapenems was detected. For the majority of isolates (94.7%) we detected a blaCTX-M-15-like gene. In addition, the plasmid mediated AmpC beta-lactamase CMY-2 was detected for the first time in Tanzania. ESBL prevalence was significantly higher among HIV positive (89.7%) than HIV negative (16.9%) children (P = 0.001; OR = 9.99; 95% CI: 2.52–39.57). Use of antibiotics during the past 14 days and age below 1 year was also associated with ESBL carriage. Conclusions/Significance We report a high rate of faecal carriage of ESBL-producing Enterobacteriaceae among children below 2 years of age in Tanzania, particularly those with HIV-infection. Resistance to a majority of the available antimicrobials commonly used for children in Tanzania leaves few treatment options for infections when

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

    PubMed Central

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

    2009-01-01

    Background Malaria transmission in Africa occurs predominantly inside houses where the primary vectors prefer to feed. Human preference and investment in blocking of specific entry points for mosquitoes into houses was evaluated and compared with known entry point preferences of the mosquitoes themselves. Methods Cross-sectional household surveys were conducted in urban Dar es Salaam, Tanzania to estimate usage levels of available options for house proofing against mosquito entry, namely window screens, ceilings and blocking of eaves. These surveys also enabled evaluation of household expenditure on screens and ceilings and the motivation behind their installation. Results Over three quarters (82.8%) of the 579 houses surveyed in Dar es Salaam had window screens, while almost half (48.9%) had ceilings. Prevention of mosquito entry was cited as a reason for installation of window screens and ceilings by 91.4% (394/431) and 55.7% (127/228) of respondents, respectively, but prevention of malaria was rarely cited (4.3%, 22/508). The median cost of window screens was between US $ 21-30 while that of ceilings was between US $301-400. The market value of insecticide-treated nets, window screening and ceilings currently in use in the city was estimated as 2, 5 and 42 million US$. More than three quarters of the respondents that lacked them said it was too expensive to install ceilings (82.2%) or window screens (75.5%). Conclusion High coverage and spending on screens and ceilings implies that these techniques are highly acceptable and excellent uptake can be achieved in urban settings like Dar es Salaam. Effective models for promotion and subsidization should be developed and evaluated, particularly for installation of ceilings that prevent entry via the eaves, which are the most important entry point for mosquitoes that cause malaria, a variety of neglected tropical diseases and the nuisance which motivates uptake. PMID:19785779

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

    PubMed Central

    Maheu-Giroux, Mathieu; Castro, Marcia C.

    2013-01-01

    Background The use of larval source management is not prioritized by contemporary malaria control programs in sub-Saharan Africa despite historical success. Larviciding, in particular, could be effective in urban areas where transmission is focal and accessibility to Anopheles breeding habitats is generally easier than in rural settings. The objective of this study is to assess the effectiveness of a community-based microbial larviciding intervention to reduce the prevalence of malaria infection in Dar es Salaam, United Republic of Tanzania. Methods and Findings Larviciding was implemented in 3 out of 15 targeted wards of Dar es Salaam in 2006 after two years of baseline data collection. This intervention was subsequently scaled up to 9 wards a year later, and to all 15 targeted wards in 2008. Continuous randomized cluster sampling of malaria prevalence and socio-demographic characteristics was carried out during 6 survey rounds (2004–2008), which included both cross-sectional and longitudinal data (N = 64,537). Bayesian random effects logistic regression models were used to quantify the effect of the intervention on malaria prevalence at the individual level. Effect size estimates suggest a significant protective effect of the larviciding intervention. After adjustment for confounders, the odds of individuals living in areas treated with larviciding being infected with malaria were 21% lower (Odds Ratio = 0.79; 95% Credible Intervals: 0.66–0.93) than those who lived in areas not treated. The larviciding intervention was most effective during dry seasons and had synergistic effects with other protective measures such as use of insecticide-treated bed nets and house proofing (i.e., complete ceiling or window screens). Conclusion A large-scale community-based larviciding intervention significantly reduced the prevalence of malaria infection in urban Dar es Salaam. PMID:23977099

  18. Mapping intra-urban malaria risk using high resolution satellite imagery: a case study of Dar es Salaam.

    PubMed

    Kabaria, Caroline W; Molteni, Fabrizio; Mandike, Renata; Chacky, Frank; Noor, Abdisalan M; Snow, Robert W; Linard, Catherine

    2016-07-30

    With more than half of Africa's population expected to live in urban settlements by 2030, the burden of malaria among urban populations in Africa continues to rise with an increasing number of people at risk of infection. However, malaria intervention across Africa remains focused on rural, highly endemic communities with far fewer strategic policy directions for the control of malaria in rapidly growing African urban settlements. The complex and heterogeneous nature of urban malaria requires a better understanding of the spatial and temporal patterns of urban malaria risk in order to design effective urban malaria control programs. In this study, we use remotely sensed variables and other environmental covariates to examine the predictability of intra-urban variations of malaria infection risk across the rapidly growing city of Dar es Salaam, Tanzania between 2006 and 2014. High resolution SPOT satellite imagery was used to identify urban environmental factors associated malaria prevalence in Dar es Salaam. Supervised classification with a random forest classifier was used to develop high resolution land cover classes that were combined with malaria parasite prevalence data to identify environmental factors that influence localized heterogeneity of malaria transmission and develop a high resolution predictive malaria risk map of Dar es Salaam. Results indicate that the risk of malaria infection varied across the city. The risk of infection increased away from the city centre with lower parasite prevalence predicted in administrative units in the city centre compared to administrative units in the peri-urban suburbs. The variation in malaria risk within Dar es Salaam was shown to be influenced by varying environmental factors. Higher malaria risks were associated with proximity to dense vegetation, inland water and wet/swampy areas while lower risk of infection was predicted in densely built-up areas. The predictive maps produced can serve as valuable resources for

  19. Molecular epidemiology of HIV-associated tuberculosis in Dar es Salaam, Tanzania: strain predominance, clustering, and polyclonal disease.

    PubMed

    Adams, Lisa V; Kreiswirth, Barry N; Arbeit, Robert D; Soini, Hanna; Mtei, Lillian; Matee, Mecky; Bakari, Muhammad; Lahey, Timothy; Wieland-Alter, Wendy; Shashkina, Elena; Kurepina, Natalia; Driscoll, Jeffrey R; Pallangyo, Kisali; Horsburgh, C Robert; von Reyn, C Fordham

    2012-08-01

    Molecular typing of Mycobacterium tuberculosis can be used to elucidate the epidemiology of tuberculosis, including the rates of clustering, the frequency of polyclonal disease, and the distribution of genotypic families. We performed IS6110 typing and spoligotyping on M. tuberculosis strains isolated from HIV-infected subjects at baseline or during follow-up in the DarDar Trial in Tanzania and on selected community isolates. Clustering occurred in 203 (74%) of 275 subjects: 124 (80%) of 155 HIV-infected subjects with baseline isolates, 56 (69%) of 81 HIV-infected subjects with endpoint isolates, and 23 (59%) of 39 community controls. Overall, 113 (41%) subjects had an isolate representing the East Indian "GD" family. The rate of clustering was similar among vaccine and placebo recipients and among subjects with or without cellular immune responses to mycobacterial antigens. Polyclonal disease was detected in 6 (43%) of 14 patients with multiple specimens typed. Most cases of HIV-associated tuberculosis among subjects from this study in Dar es Salaam resulted from recently acquired infection. Polyclonal infection was detected and isolates representing the East Indian GD strain family were the most common.

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

    PubMed

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

    2015-12-01

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

  1. Prevalence of Overweight and Obesity among Primary School Children Aged 8-13 Years in Dar es Salaam City, Tanzania.

    PubMed

    Pangani, Ismail N; Kiplamai, Festus K; Kamau, Jane W; Onywera, Vincent O

    2016-01-01

    Background. The understanding of obesity as a growing health problem in Africa and Tanzania in particular is hampered by lack of data as well as sociocultural beliefs in which overweight and obesity are revered. This study sought to determine the prevalence of overweight and obesity among primary school children aged 8-13 years in Dar es Salaam, Tanzania. Method. A cross-sectional analytical research design was used to study overweight and obesity in primary schools in Dar es Salaam, Tanzania. The target population was 150,000 children aged 8-13 years. Stratified random sampling was used to select 1781 children. Weight and height were taken and WHO standards for children were used to determine weight status. Results. Findings showed that the prevalence of overweight and obesity was 15.9% and 6.7%, respectively (N = 1781). However, 6.2% of the children were underweight. There were significant differences in mean BMI between children in private and public schools (p = 0.021), between male and female (p < 0.001), and across age groups of 8-10 and 11-13 years (p < 0.001). Conclusion. The prevalence of overweight and obesity among primary school children is significant and requires management and prevention strategies.

  2. Improvements in Health-related Quality of Life among Methadone Maintenance Clients in Dar es Salaam, Tanzania

    PubMed Central

    Ubuguyu, Omary; Tran, Olivia C.; Bruce, R. Douglas; Masao, Frank; Nyandindi, Cassian; Sabuni, Norman; McCurdy, Sheryl; Mbwambo, Jessie

    2016-01-01

    Background Injection of heroin has become widespread in Dar es Salaam, Tanzania and is spreading throughout the country. To prevent potential bridging of HIV epidemics, the Tanzanian government established a methadone maintenance treatment (MMT) clinic in February 2011. We assess the effect of MMT on health-related quality of life (HRQOL) and examine factors, particularly HIV infection and methadone dose, associated with changes in HRQOL. Methods This study utilized routine data on clients enrolling in methadone from February 2011 to April 2012 at Muhimbili National Hospital. Change in physical (PCS) and mental health (MCS) composite scores, as measured by the SF-12 tool, were the primary outcomes. Backward stepwise linear regression, with a criterion of p<0.2 was used to identify baseline exposure variables for inclusion in multivariable models, while adjusting for baseline scores. Results A total of 288 MMT clients received baseline and follow-up assessments. Mean methadone dose administered was 45 mg (SD±25) and 76(27%) were confirmed HIV-positive. Significant improvements were observed in PCS and MCS, with mean increases of 15.7 and 3.3, respectively. In multivariable models, clients who had previous poly-substance use with cocaine [p=0.040] had a significantly higher mean change in PCS. Clients who were living with HIV [p=0.002]; satisfied with current marital situation [p=0.045]; had a history of suicidal thoughts [p=0.021]; and previously experienced cognitive difficulties [p=0.012] had significantly lower mean change in PCS. Clients with shorter history of heroin use [p=0.012] and who received higher methadone doses [p=0.028] had significantly higher mean change in MCS, compared to their counterparts. Discussion Aspects of mental and physical health, risk behaviors and quality of life among drug users are intertwined and complex. Our research revealed positive short-term effects of MMT on HRQOL and highlights the importance of sustained retention for

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

    PubMed

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

    2000-05-01

    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.

  4. Effect of urban design on microclimate and thermal comfort outdoors in warm-humid Dar es Salaam, Tanzania

    NASA Astrophysics Data System (ADS)

    Yahia, Moohammed Wasim; Johansson, Erik; Thorsson, Sofia; Lindberg, Fredrik; Rasmussen, Maria Isabel

    2017-06-01

    Due to the complexity of built environment, urban design patterns considerably affect the microclimate and outdoor thermal comfort in a given urban morphology. Variables such as building heights and orientations, spaces between buildings, plot coverage alter solar access, wind speed and direction at street level. To improve microclimate and comfort conditions urban design elements including vegetation and shading devices can be used. In warm-humid Dar es Salaam, the climate consideration in urban design has received little attention although the urban planning authorities try to develop the quality of planning and design. The main aim of this study is to investigate the relationship between urban design, urban microclimate, and outdoor comfort in four built-up areas with different morphologies including low-, medium-, and high-rise buildings. The study mainly concentrates on the warm season but a comparison with the thermal comfort conditions in the cool season is made for one of the areas. Air temperature, wind speed, mean radiant temperature (MRT), and the physiologically equivalent temperature (PET) are simulated using ENVI-met to highlight the strengths and weaknesses of the existing urban design. An analysis of the distribution of MRT in the areas showed that the area with low-rise buildings had the highest frequency of high MRTs and the lowest frequency of low MRTs. The study illustrates that areas with low-rise buildings lead to more stressful urban spaces than areas with high-rise buildings. It is also shown that the use of dense trees helps to enhance the thermal comfort conditions, i.e., reduce heat stress. However, vegetation might negatively affect the wind ventilation. Nevertheless, a sensitivity analysis shows that the provision of shade is a more efficient way to reduce PET than increases in wind speed, given the prevailing sun and wind conditions in Dar es Salaam. To mitigate heat stress in Dar es Salaam, a set of recommendations and guidelines on

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

    PubMed

    Shirima, Candida P; Kinabo, Joyce L

    2005-01-01

    Studies that link adolescence pregnancies, nutritional status, and birth outcomes in Tanzania are scarce. We examined the nutritional status and birth outcomes of pregnant adolescent girls from rural and urban areas of three regions in Tanzania. The study was carried out in the regions of Dar es Salaam (Chamazi and Gezaulole dispensaries and Round Table Maternity Home), Coast (Tumbi Regional Hospital and Mlandizi Health Center), and Morogoro (Regional Hospital, Uhuru Clinic, and Mlali Health Center). One hundred eighty pregnant adolescent girls ages 15 to 19 y were recruited and interviewed, and their nutritional status measurements were taken at the seven health facilities. Information concerning date of birth, marital status, educational status, sex education, and income status was collected with a structured questionnaire. Height, weight, and mid-upper arm circumference were measured according to standard techniques. Hemoglobin concentration was measured with a hemoglobinometer and the HemoCue technique. Nutritional status was assessed by body mass index, and hemoglobin concentration was determined by cutoff points of the World Health Organization. Suitable statistical analysis was done with SPSS 9.0. Weekly weight gain during pregnancy was measured in 123 subjects who kept their appointments and reported back after 2 wk. Fifty-seven subjects did not keep their appointments and were lost to follow-up. Records of infants' birth weights and mode of delivery were obtained from 50 subjects who delivered at the study sites. The height of about 54% of the subjects was shorter than 151 cm, suggestive of short maternal height. Severe wasting was observed in 27% of subjects. Mean weekly weight gain during pregnancy was 317 +/-110 g (-500 to 500 g). No significant differences were observed between rural and urban settings. Mean infant birth weight was 2600 +/- 480 g. About 48% of infants had low birth weight (<2500 g) and only 14% of infants had birth weight greater than

  6. The Risk of Dengue Virus Transmission in Dar es Salaam, Tanzania during an Epidemic Period of 2014

    PubMed Central

    Mboera, Leonard E. G.; Mweya, Clement N.; Rumisha, Susan F.; Tungu, Patrick K.; Stanley, Grades; Makange, Mariam R.; Misinzo, Gerald; De Nardo, Pasquale; Vairo, Francesco; Oriyo, Ndekya M.

    2016-01-01

    Background In 2010, 2012, 2013 and 2014 dengue outbreaks have been reported in Dar es Salaam, Tanzania. However, there is no comprehensive data on the risk of transmission of dengue in the country. The objective of this study was to assess the risk of transmission of dengue in Dar es Salaam during the 2014 epidemic. Methodology/Principal Findings This cross-sectional study was conducted in Dar es Salaam, Tanzania during the dengue outbreak of 2014. The study involved Ilala, Kinondoni and Temeke districts. Adult mosquitoes were collected using carbon dioxide-propane powered Mosquito Magnet Liberty Plus traps. In each household compound, water-holding containers were examined for mosquito larvae and pupae. Dengue virus infection of mosquitoes was determined using real-time reverse transcription polymerase chain reaction (qRT-PCR). Partial amplification and sequencing of dengue virus genome in infected mosquitoes was performed. A total of 1,000 adult mosquitoes were collected. Over half (59.9%) of the adult mosquitoes were collected in Kinondoni. Aedes aegypti accounted for 17.2% of the mosquitoes of which 90.6% were from Kinondoni. Of a total of 796 houses inspected, 38.3% had water-holding containers in their premises. Kinondoni had the largest proportion of water-holding containers (57.7%), followed by Temeke (31.4%) and Ilala (23.4%). The most common breeding containers for the Aedes mosquitoes were discarded plastic containers and tires. High Aedes infestation indices were observed for all districts and sites, with a house index of 18.1% in Ilala, 25.5% in Temeke and 35.3% in Kinondoni. The respective container indices were 77.4%, 65.2% and 80.2%. Of the reared larvae and pupae, 5,250 adult mosquitoes emerged, of which 61.9% were Ae. aegypti. Overall, 27 (8.18) of the 330 pools of Ae. aegypti were positive for dengue virus. On average, the overall maximum likelihood estimate (MLE) indicates pooled infection rate of 8.49 per 1,000 mosquitoes (95%CI = 5.72–12

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

    ERIC Educational Resources Information Center

    Kombo, Ibun

    2015-01-01

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

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

    ERIC Educational Resources Information Center

    Kafyulilo, Ayoub C.

    2010-01-01

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

  9. Implementation and Operational Research: Risk Factors of Loss to Follow-up Among HIV-Positive Pediatric Patients in Dar es Salaam, Tanzania.

    PubMed

    McCormick, Nora M; Li, Nan; Sando, David; Muya, Aisa; Manji, Karim P; Kisenge, Rodrick; Duggan, Christopher; Chalamilla, Guerino; Fawzi, Wafaie W; Spiegelman, Donna

    2015-11-01

    To identify risk factors for loss to follow-up (LTFU) in an HIV-infected pediatric population in Dar es Salaam, Tanzania, between 2004 and 2011. Longitudinal analysis of 6236 HIV-infected children. We conducted a prospective cohort study of 6236 pediatric patients enrolled in care and treatment in Dar es Salaam from October 2004 to September 2011. LTFU was defined as missing a clinic visit for >90 days for patients on ART and for >180 days for patients in care and monitoring. The relationship of baseline and time-varying characteristics to the risk of LTFU was examined using a Cox proportional hazards model. A total of 2130 children (34%) were LTFU over a median follow-up of 16.7 months (interquartile range, 3.4-36.9). Factors independently associated with a higher risk of LTFU were age ≤2 years (relative risk [RR] = 1.59, 95% CI: 1.40 to 1.80), diarrhea at enrollment (RR = 1.20, 95% CI: 1.03 to 1.41), a low mid-upper arm circumference for age (RR = 1.20, CI: 1.05 to 1.37), eating protein-rich foods ≤3 times a week (RR = 1.39, 95% CI: 1.05 to 1.90), taking cotrimoxazole (RR = 1.39, 95% CI: 1.06 to 1.81), initiating onto antiretrovirals (RR = 1.37, 95% CI: 1.17 to 1.61), receiving treatment at a hospital instead of a local facility (RR = 1.39, 95% CI: 1.06 to 1.41), and starting treatment in 2006 or later (RR = 1.10, 95% CI: 1.04 to 1.16). Health workers should be aware of pediatric patients who are at a greatest risk of LTFU, such as younger and undernourished patients, so that they can proactively counsel families about the importance of visit adherence. Findings support decentralization of HIV care to local facilities as opposed to hospitals.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    Urban green structure provides important regulating ecosystem services, such as temperature and flood regulation, and thus, has the potential to increase the resilience of African cities to climate change. Green structures within urban areas are not only limited to discrete units associated with recreational parks, agricultural areas and open spaces: they also exist within zones which have other primary functions, such as church yards, along transport routes, and within residential areas. Differing characteristics of urban areas can be conceptualised and subsequently mapped through the idea of urban morphology types. Urban morphology types are classifications which combine facets of urban form and function. When mapped, UMT units provide biophysically relevant meso-scale geographical zones which can be used as the basis for understanding climate-related impacts and adaptations. For example, they support the assessment of urban temperature patterns and the temperature regulating services provided by urban green structures. There are some examples of the use of UMTs for assessing regulating ecosystem services in European cities but little similar knowledge is available in an African context. This paper outlines the concept of urban morphology types (UMTs) and how they were applied to African case study cities (Cavan et al., 2012). It then presents the methods used to understand temperature regulating ecosystem services across an example African case study city, including (i) a GIS-based assessment of urban green structures, and (ii) applying an energy balance model to estimate current and future surface temperatures under climate change projections. The assessment is carried out for Dar es Salaam, Tanzania. Existing evidence suggests increases in both mean and extreme temperatures in the city. Historical analysis of the number of hot days per year suggests a rise from a maximum of 47 days per year in the period 1961-87 to 72 days per year in 2003-2011 (Giugni et al

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

    PubMed

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

    2011-11-16

    The prevalence of HIV/AIDS has exacerbated the impact of childhood undernutrition in many developing countries, including Tanzania. Even with the provision of antiretroviral therapy, undernutrition among HIV-positive children remains a serious problem. Most studies to examine risk factors for undernutrition have been limited to the general population and ART-naive HIV-positive children, making it difficult to generalize findings to ART-treated HIV-positive children. The objectives of this study were thus to compare the proportions of undernutrition among ART-treated HIV-positive and HIV-negative children and to examine factors associated with undernutrition among ART-treated HIV-positive children in Dar es Salaam, Tanzania. From September to October 2010, we conducted a cross-sectional survey among 213 ART-treated HIV-positive and 202 HIV-negative children in Dar es Salaam, Tanzania. We measured the children's anthropometrics, socio-demographic factors, food security, dietary habits, diarrhea episodes, economic status, and HIV clinical stage. Data were analyzed using both univariate and multivariate methods. ART-treated HIV-positive children had higher rates of undernutrition than their HIV-negative counterparts. Among the ART-treated HIV-positive children, 78 (36.6%) were stunted, 47 (22.1%) were underweight, and 29 (13.6%) were wasted. Households of ART-treated HIV-positive children exhibited lower economic status, lower levels of education, and higher percentages of unmarried caregivers with higher unemployment rates. Food insecurity was prevalent in over half of ART-treated HIV-positive children's households. Furthermore, ART-treated HIV-positive children were more likely to be orphaned, to be fed less frequently, and to have lower body weight at birth compared to HIV-negative children.In the multivariate analysis, child's HIV-positive status was associated with being underweight (AOR = 4.61, 95% CI 1.38-15.36 P = 0.013) and wasting (AOR = 9.62, 95% CI 1

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

    PubMed Central

    2011-01-01

    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

  13. Management and outcome of traumatic brain injury patients at Muhimbili Orthopaedic Institute Dar es Salaam, Tanzania.

    PubMed

    Boniface, Respicious; Lugazia, Edwin Rwebugisa; Ntungi, Abel Mussa; Kiloloma, Othman

    2017-01-01

    Traumatic brain Injuries represents a significant cause of morbidity and mortality worldwide and road traffic crashes accounts for a significant proportion of these injuries. However, access to neurosurgical care is poor in low income countries like Tanzania. The aim of this study was to assess the management and outcome of Traumatic brain injury patients at a tertiary level health facility in Tanzania. A retrospective observational study of Traumatic brain injury patients attended at Muhimbili Orthopedic Institute between January 2014 and June 2014. A total of 627 Traumatic brain injury (TBI) patients were seen, 86% were males. Majority (73%) were between 15 - 45 years age group. Road traffic crashes were the leading cause of injury (59.3%). Majority 401/627 (64%) sustained mild TBI, 114/627 (18.2%) moderate TBI and 112/627 (17.8%) severe TBI. All mild TBI patients had good recovery. Among patients with moderate and severe TBI; 19.1% had good recovery, 50.2% recovered with disabilities and 30.7% died. Independent factors associated with mortality were: Severe TBI (Odds Ratio (OR) 3.16. 95%CI 3.42-10.52) and Systolic blood pressure at referring hospital of more than 90mmHg (Odds Ratio (OR) 0.13, 95%CI 0.04-0.49). Traumatic brain injury is a public health problem in Tanzania, mostly due to road traffic crashes. It is therefore important to reinforce preventive measures for road traffic crashes. There is also a need to develop and implement protocols for pre-hospital as well as in-hospital management of brain trauma in Tanzania.

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

    PubMed Central

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  16. Motivations to participate in a Phase I/II HIV vaccine trial: A descriptive study from Dar es Salaam, Tanzania.

    PubMed

    Tarimo, E A M; Bakari, M; Kakoko, D C V; Kohi, T W; Mhalu, F; Sandstrom, E; Kulane, A

    2016-02-24

    The search for an efficacious HIV vaccine is a global priority. To date only one HIV vaccine trial (RV144) has shown modest efficacy in a phase III trial. With existing different HIV-1 subtypes and frequent mutations, multiple trials are needed from different geographical sites particularly in sub-Saharan Africa where most HIV infections occur. Thus, motivations to participate in HIV vaccine trials among Tanzanians need to be assessed. This paper describes the motives of Police Officers who showed great interest to volunteer in HIVIS-03 in Dar es Salaam, Tanzania. A descriptive cross-sectional study was conducted among Police Officers who showed interest to participate in the HIVIS-03, a phase I/II HIV vaccine trial in Dar es Salaam. Prior to detailed training sessions about HIV vaccine trials, the potential participants narrated their individual motives to participate in the trial on a piece of paper. Descriptive analysis using content approach and frequency distributions were performed. Of the 265 respondents, 242 (91.3%) provided their socio-demographic characteristics as well as reasons that would make them take part in the proposed trial. Majority, (39.7%), cited altruism as the main motive. Women were more likely to volunteer due to altruism compared to men (P < 0.01). Researchers' explanations about HIV/AIDS vaccine studies motivated 15.3%. More men (19.6%) than women (1.7%) were motivated to volunteer due to researchers' explanations (P < 0.001). Also, compared to other groups, those unmarried and educated up to secondary level of education were motivated to volunteer due to researchers' explanation (P < 0.05). Other reasons were: desire to become a role model (18.6%); to get knowledge for educating others (14.0%); to cooperate with researchers in developing an HIV vaccine (9.5%); to get protection against HIV infection (7.0%), and severity of the disease within families (6.2%). These results were supported by testimonies from both men and women

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

    PubMed

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

    2006-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

  19. Tetanus neonatorum--experience with intrathecal serotherapy at Muhimbili Medical Centre, Dar es Salaam, Tanzania.

    PubMed

    Mongi, P S; Mbise, R L; Msengi, A E; Do Amsi, D M

    1987-03-01

    In an attempt to lower the mortality rate of neonatal tetanus a study was undertaken to determine whether intrathecal serotherapy influences mortality from this disease. Sixty-six babies with tetanus neonatorum were studied. The mortality rate among babies who received intrathecal anti-tetanus serum (ATS) was 45% compared with 82% in the control group given intramuscular ATS (P congruent to 0.002). Infants who received intrathecal ATS also had fewer complications than controls (P less than 0.001) and the duration of hospital stay for the survivors was 19.3 days compared with 28.7 days for the control group (P less than 0.05). It is concluded that intrathecal ATS is superior to intramuscular ATS in the treatment of neonatal tetanus.

  20. Awareness of HIV/AIDS and its oral manifestations among people living with HIV in Dar es Salaam, Tanzania.

    PubMed

    Kahabuka, Febronia; Fabian, Flora; Petersen, Poul Erick; Nguvumali, Hubert

    2007-04-01

    The aim of this study was to investigate the awareness of the oral manifestations of HIV/AIDS and general issues about HIV and AIDS among people living with HIV (PLHIV) in Dar es Salaam, Tanzania. A structured questionnaire was used to collect information from 187 participants chosen by convenience sampling from NGOs supporting PLHIV. A total of 13.4% of the participants were completely unaware of the oral manifestations of HIV/AIDS whereas all participants were fully aware of general symptoms of AIDS. There were no significant associations between awareness of oral manifestations and general awareness of HIV/AIDS, or level of education. Participants were relatively well aware of the different types of oral manifestations (e.g. oral ulcers 87%, oral candidiasis 84%) while their knowledge of the management of specific oral manifestations and the problems associated with oral manifestations was more limited. It is recommended that health authorities in Tanzania establish population-oriented health education for improving knowledge about oral disease in HIV/AIDS and that oral health professionals provide sound information to PLHIV in community-outreach oral healthcare programmes.

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

    PubMed

    Silberschmidt, M; Rasch, V

    2001-06-01

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

  2. Sexual motivation, sexual transactions and sexual risk behaviors in men who have sex with men in Dar es Salaam, Tanzania

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2005-01-01

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

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

    PubMed Central

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

    2010-01-01

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

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

    PubMed

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

    2010-02-01

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

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

    PubMed

    Kivaria, F M; Noordhuizen, J P T M

    2010-05-01

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

  7. Predictors of AIDS knowledge, condom use and high-risk sexual behaviour among women in Dar-es-Salaam, Tanzania.

    PubMed

    Kapiga, S H; Lwihula, G K; Shao, J F; Hunter, D J

    1995-01-01

    Reducing the number of sex partners and using condoms are the major means for individuals to protect themselves from STDs and AIDS in sub-Saharan Africa. To identify predictors of having only one sex partner in the last year and to assess knowledge and use of condoms among women of reproductive age in Dar-es-Salaam, Tanzania, we interviewed 2285 women at 3 representative family planning clinics between February 1991 and June 1992. After interview, blood and genital specimens were collected for laboratory diagnosis of HIV and other sexually transmitted diseases (STDs). Although knowledge of sexual transmission of AIDS was very high, less than a half of the respondents (42.8%) mentioned use of condoms as an AIDS preventive measure. Younger and more educated women were more likely to mention use of condoms for AIDS prevention, however only 4.6% of women interviewed were regular users of condoms, while 19.8% were occasional users. The majority of women who had never used a condom (57.5%) reported not using condoms because 'men did not like them'. Condom use was positively associated with increasing level of education and increasing number of sexual partners. 14.8% of women reported having more than one sex partner in the last year; this behaviour was more likely among cohabiting women (increased by 210%); HIV-positives (increased by 120%); and among women with STDs (increased by 50%).(ABSTRACT TRUNCATED AT 250 WORDS)

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

    PubMed Central

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

    2015-01-01

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

  9. Current clinical efficacy of chloroquine for the treatment of Plasmodium falciparum infections in urban Dar es Salaam, United Republic of Tanzania.

    PubMed Central

    Premji, Z.; Makwaya, C.; Minjas, J. N.

    1999-01-01

    Reported is the use of a 14-day WHO protocol, which takes into account the clinical, parasitological and haematological responses to antimalarial drugs, to determine the efficacy of chloroquine in the treatment of uncomplicated malaria in young children (n = 200) in urban Dar es Salaam. Chloroquine failure was found in 43% of the children. Of these, 12.5% were considered to be early treatment failures and were given a single dose of sulfadoxine-pyrimethamine. Fever subsided in all children treated with sulfadoxine-pyrimethamine and there were no parasitological failures. In addition, children treated with sulfadoxine-pyrimethamine because of early treatment failure with chloroquine had better haematological recovery than the chloroquine-sensitive group. It is concluded that chloroquine can no longer be considered an effective therapy for P. falciparum malaria in young children in Dar es Salaam. PMID:10534897

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

    PubMed

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

    2015-02-01

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

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

    PubMed

    Senkoro, Mbazi; Mfinanga, Sayoki G; Mørkve, Odd

    2010-07-16

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    1995-01-01

    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) PMID:7704932

  14. Community Health Workers to Improve Antenatal Care and PMTCT Uptake in Dar es Salaam, Tanzania: A Quantitative Performance Evaluation

    PubMed Central

    Sando, David; Magesa, Lucy; Machumi, Lameck; Mungure, Esther; Mwanyika Sando, Mary; Geldsetzer, Pascal; Foster, Dawn; Kajoka, Deborah; Naburi, Helga; Ekström, Anna M.; Spiegelman, Donna; Li, Nan; Chalamilla, Guerino; Fawzi, Wafaie; Bärnighausen, Till

    2014-01-01

    Background: Home visits by community health workers (CHW) could be effective in identifying pregnant women in the community before they have presented to the health system. CHW could thus improve the uptake of antenatal care (ANC), HIV testing, and prevention of mother-to-child transmission (PMTCT) services. Methods: Over a 16-month period, we carried out a quantitative evaluation of the performance of CHW in reaching women early in pregnancy and before they have attended ANC in Dar es Salaam, Tanzania. Results: As part of the intervention, 213 CHW conducted more than 45,000 home visits to about 43,000 pregnant women. More than 75% of the pregnant women identified through home visits had not yet attended ANC at the time of the first contact with a CHW and about 40% of those who had not yet attended ANC were in the first trimester of pregnancy. Over time, the number of pregnant women the CHW identified each month increased, as did the proportion of women who had not yet attended ANC. The median gestational age of pregnant women contacted for the first time by a CHW decreased steadily and significantly over time (from 21/22 to 16 weeks, P-value for test of trend <0.0001). Conclusions: A large-scale CHW intervention was effective in identifying pregnant women in their homes early in pregnancy and before they had attended ANC. The intervention thus fulfills some of the conditions that are necessary for CHW to improve timely ANC uptake and early HIV testing and PMTCT enrollment in pregnancy. PMID:25436818

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

    PubMed

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

    2016-07-01

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

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

    PubMed

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

    2014-05-01

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

  17. Prevalence of extra-intestinal porcine helminth infections and assessment of sanitary conditions of pig slaughter slabs in Dar es Salaam city, Tanzania.

    PubMed

    Mkupasi, Ernatus M; Ngowi, Helena A; Nonga, Hezron Emmanuel

    2011-02-01

    A study was carried out to establish the prevalence of extra-intestinal porcine helminth infections and to assess the pig slaughter slab sanitary conditions in Dar es Salaam city, Tanzania. A total of 24 privately owned pig slaughter slabs were assessed. All slaughter slabs were sub-standard; wrongly located, poorly designed and constructed and lacked most basic requirements for a slaughter house. Because of inadequate slaughtering, disposal and cleaning facilities, the slaughter slabs were under unhygienic condition with questionable safety, soundness and wholesomeness of the pork produced. Routine meat inspection procedures were used to detect extra-intestinal porcine helminth infections. Of the 731 examined pigs; 8.1%, 5.9% and 0.4% were infected with ascariosis, porcine cysticercosis and hydatidosis, respectively. It was noted that almost all slaughter pigs in Dar es Salaam originated from different regions. Based on the region of origin, the status of porcine cysticercosis was 8.2% for Dodoma (n = 98), 8.2% for Manyara (n = 260) and 6.9% for Mbeya (n = 116). This study disclosed the unhygienic sanitary condition prevailing in Dar es Salaam pig slaughter slabs and recommends that strategies should be devised to improve the situation. Porcine ascariosis and cysticercosis were widely prevalent and caused economic losses due to condemnations. Because of their zoonotic nature, the observed extra-intestinal porcine helminth infections in pig pose a public health risk among consumers. Thus, there is a need to introduce appropriate control measures of parasitic infections in pigs.

  18. “Can’t you initiate me here?”: Challenges to timely initiation on antiretroviral therapy among methadone clients in Dar es Salaam, Tanzania

    PubMed Central

    Saleem, Haneefa T.; Mushi, Dorothy; Hassan, Saria; Bruce, R. Douglas; Cooke, Alexis; Mbwambo, Jessie; Lambdin, Barrot H.

    2016-01-01

    Background Despite dramatic improvement in antiretroviral therapy (ART) access globally, people living with HIV who inject drugs continue to face barriers that limit their access to treatment. This paper explores barriers and facilitators to ART initiation among clients attending a methadone clinic in Dar es Salaam, Tanzania. Methods We interviewed 12 providers and 20 clients living with HIV at the Muhimbili National Hospital methadone clinic between January and February 2015. We purposively sampled clients based on sex and ART status and providers based on job function. To analyze interview transcripts, we adopted a content analysis approach. Results Participants identified several factors that hindered timely ART initiation for clients at the methadone clinic. These included delays in CD4 testing and receiving CD4 test results; off-site HIV clinics; stigma operating at the individual, social and institutional levels; insufficient knowledge of the benefits of early ART initiation among clients; treatment breakdown at the clinic level possibly due to limited staff; and initiating ART only once one feels physically ill. Participants perceived social support as a buffer against stigma and facilitator of HIV treatment. Some clients also reported that persistent monitoring and follow-up on their HIV care and treatment by methadone clinic providers led them to initiate ART. Conclusion Health system factors, stigma and limited social support pose challenges for methadone clients living with HIV to initiate ART. Our findings suggest that on-site point-of-care CD4 testing, a peer support system, and trained HIV treatment specialists who are able to counsel HIV-positive clients and initiate them on ART at the methadone clinic could help reduce barriers to timely ART initiation for methadone clients. PMID:26831364

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

    PubMed Central

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

    2016-01-01

    women from Dar es Salaam, Tanzania. Environ Health Perspect 125:134–140; http://dx.doi.org/10.1289/EHP256 PMID:27286442

  20. Understanding resilience of female adolescents towards teenage pregnancy: a cross-sectional survey in Dar es Salaam, Tanzania.

    PubMed

    Pfeiffer, Constanze; Ahorlu, Collins K; Alba, Sandra; Obrist, Brigit

    2017-06-26

    In Tanzania, teenage pregnancy rates are still high despite the efforts being made to reduce them. Not enough is known about how adolescents experience and cope with sexuality and teenage pregnancy. Over the past few decades, most studies have focused on vulnerability and risk among youth. The concept of 'reproductive resilience' is a new way of looking at teenage pregnancy. It shifts the perspective from a deficit-based to a strength-based approach. The study presented here aimed to identify factors that could contribute to strengthening the reproductive resilience of girls in Dar es Salaam, Tanzania. Using a cross-sectional cluster sampling approach, 750 female adolescents aged 15-19 years were interviewed about how they mobilize resources to avoid or deal with teenage pregnancy. The main focus of the study was to examine how social capital (relations with significant others), economic capital (command over economic resources), cultural capital (personal dispositions and habits), and symbolic capital (recognition and prestige) contribute to the development of adolescent competencies for avoiding or dealing with teenage pregnancy and childbirth. A cumulative competence scale was developed to assess reproductive resilience. The cumulative score was computed based on 10 competence indicators that refer to the re- and pro-active mobilization of resources. About half of the women who had never been pregnant fell into the category, 'high competence' (50.9%), meaning they could get the information and support needed to avoid pregnancies. Among pregnant women and young mothers, most were categorized as 'high competence' (70.5%) and stated that they know how to avoid or deal with health problems that might affect them or their babies, and could get the information and support required to do so. Cultural capital, in particular, contributed to the competence of never-pregnant girls [OR = 1.80, 95% CI = 1.06 to 3.07, p = 0.029], pregnant adolescents and young mothers

  1. Generating trust: Programmatic strategies to reach women who inject drugs with harm reduction services in Dar es Salaam, Tanzania.

    PubMed

    Zamudio-Haas, Sophia; Mahenge, Bathsheba; Saleem, Haneefa; Mbwambo, Jessie; Lambdin, Barrot H

    2016-04-01

    Strong evidence supports the effectiveness of methadone-assisted therapy (MAT) to treat opioid dependence, reduce the risk of HIV transmission, and improve HIV related health outcomes among people who inject drugs (PWID). HIV prevalence reaches 71% in women who inject drugs (WWID) in Dar es Salaam, Tanzania; creating an urgent need for access to MAT. Despite the availability and potential benefits of treatment, few women have enrolled in services. This formative research sought to identify programmatic strategies to increase women's participation in outreach and their subsequent enrollment in MAT. We conducted twenty-five, in-depth interviews with patients and their providers at a MAT clinic. Open-ended interviews explored enrollment experiences, with a focus on contextual barriers and facilitators unique to women. Ethnographic observations of harm reduction education at outreach sites and the MAT clinic enriched interview data. Trust/mistrust emerged as an overarching theme cross cutting patient and provider accounts of the connective process to enroll PWID in the methadone program. We explore trust and mistrust in relationship to the interrelated themes of family loss, social isolation, vehement discrimination and motivation for treatment. Narratives delineated both the generation of mistrust against PWID and the generation of mistrust in PWID against outsiders and medical institutions. In order to enroll PWID in treatment, community base organizations engaged outreach strategies to overcome mistrust and connect eligible patients to care, which varied in their success at recruiting women and men. Greater discrimination against WWID pushed them into hiding, away from outreach teams that focus on outdoor areas where men who inject drugs congregate. Building trust through multiple encounters and making a personal connection facilitated entry into care for women. Only PWID were eligible for MAT, due to resource constraints and the higher risk associated with

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

    PubMed Central

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

    2009-01-01

    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 < 0.001). During the post-cleaning period, a higher risk of infection (OR = 1.7, 95% CI 1.1–2.4, p = 0.0069) was observed in neighbourhoods under no intervention compared to intervention ones. Eighteen months after the initial cleaning, one of the drains was still clean due to continued maintenance efforts (it contained no waste materials and the water was flowing at normal velocity). A three-month moving average of the percentage of water habitats in that drain containing pupae and/or Anopheles larvae indicated a decline in larval density. In the other drain, lack of proper resources and local commitment limited success. Conclusion Although

  3. Generating trust: Programmatic strategies to reach women who inject drugs with harm reduction services in Dar es Salaam, Tanzania

    PubMed Central

    Zamudio-Haas, Sophia; Mahenge, Bathsheba; Saleem, Haneefa; Mbwambo, Jessie; Lambdin, Barrot H.

    2016-01-01

    Background Strong evidence supports the effectiveness of methadone-assisted therapy (MAT) to treat opioid dependence, reduce the risk of HIV transmission, and improve HIV related health outcomes among people who inject drugs (PWID). HIV prevalence reaches 71% in women who inject drugs (WWID) in Dar es Salaam, Tanzania; creating an urgent need for access to MAT. Despite the availability and potential benefits of treatment, few women have enrolled in services. This formative research sought to identify programmatic strategies to increase women’s participation in outreach and their subsequent enrollment in MAT. Methods We conducted twenty-five, in-depth interviews with patients and their providers at a MAT clinic. Open-ended interviews explored enrollment experiences, with a focus on contextual barriers and facilitators unique to women. Ethnographic observations of harm reduction education at outreach sites and the MAT clinic enriched interview data. Trust/mistrust emerged as an overarching theme cross cutting patient and provider accounts of the connective process to enroll PWID in the methadone program. We explore trust and mistrust in relationship to the interrelated themes of family loss, social isolation, vehement discrimination and motivation for treatment. Results Narratives delineated both the generation of mistrust against PWID and the generation of mistrust in PWID against outsiders and medical institutions. In order to enroll PWID in treatment, community base organizations engaged outreach strategies to overcome mistrust and connect eligible patients to care, which varied in their success at recruiting women and men. Greater discrimination against WWID pushed them into hiding, away from outreach teams that focus on outdoor areas where men who inject drugs congregate. Building trust through multiple encounters and making a personal connection facilitated entry into care for women. Only PWID were eligible for MAT, due to resource constraints and the higher

  4. Why are primary school children overweight and obese? A cross sectional study undertaken in Kinondoni district, Dar-es-salaam.

    PubMed

    Mwaikambo, Sijenunu A; Leyna, Germana H; Killewo, Japhet; Simba, Azma; Puoane, Thandi

    2015-12-21

    The world is experiencing an alarming increase in prevalence of childhood obesity. Despite this trend little is known about determinants of childhood obesity in Tanzania. A cross sectional study determined the prevalence and factors associated with overweight and obesity in 1722 children aged 7-14 years (10.9 ± 1.74) attending primary schools in Dar es Salaam. Six public and four private schools were systemically selected from a total of 227 primary schools. Anthropometric measurements (weight and height) were collected using a standard protocol and Body Mass Index (BMI) was calculated. Interviews collected demographic characteristics and lifestyle factors. Multiple logistic regression test was used to assess the influence of independent variables on overweight and obesity while controlling for confounding factors. The level of significance was set at α = 5 %. Of 1, 722 children 10.2 % were overweight and 4.5 % were obese. Overweight and obesity was higher in boys (14.9 %) than girls (14.5 %), higher in children attending private schools (27.7 %) than public schools (5.9 %). Children who walked to and from school were less likely to be overweight or obese than those who used vehicles (AOR = 0.5; 95%CI: 0.3-0.6; p < 0.001). Those who used private cars or school buses were more likely to be overweight or obese than those who used public transport (AOR = 2.9; 95%CI: 0.2-0.7; p < 0.05). Computer/video game use were associated with increased risk of overweight and obesity (AOR = 1.6; 95%CI: 1.1-2.3; p = 0.03). Lunch provided by schools was associated with increased risk of overweight or obese (AOR = 6.4, 95 % CI = 4.2-9.6, p < 0.001). The findings of this study identified a number of behavioural and dietary factors that are related to overweight and obesity. Parents and teachers should encourage children to be physically active by limiting screen time and promoting active transport to and from school to promote

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

    PubMed

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

    2017-01-01

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

  6. The Doctor of Medicine curriculum review at the School of Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania: a tracer study report from 2009.

    PubMed

    Mwakigonja, Amos Rodger

    2016-08-25

    The School of Medicine (SoM) is one among five at Muhimbili University of Health and Allied Sciences (MUHAS). It currently houses eight undergraduate and many post-graduate programmes. The Doctor of Medicine (MD) programme reported herein is the oldest having ten semesters (5 years) followed by a 1 year compulsory rotatory internship at a hospital approved by the Medical Council of Tanganyika (MCT). However, this training was largely knowledge-based and thus the need to shift towards competency-based education (CBE) and full modularization necessitated this study. A cross-sectional tracer study of MUHAS MD graduates from SoM who completed training between 2006 and 2008 was conducted using quantitative (structured interviewer-administered questionnaires) as well as qualitative methods [In-depth questionnaire (IDI) and Focus group discussions (FGDs)]. A total of 147 MD graduates were traced and interviewed, representing 29 % of the 510 students who graduated from the SoM between 2006 and 2008. Majority (70.1 %, n = 103/147) were males. About 70 % graduated in 2008 and majority (68 %, n = 100/147) were doing internship. Majority (60.5 % n = 89/147) were based in/near Dar es Salaam at district, regional or referral hospitals. With reasonable concordance, most competencies ranked low except on four aspects. Teaching, System-based Practice and Good Practice had the lowest. Seminars/Tutorials, Laboratory Skills/Practicals, Theatre Skills, Outpatients clinics, Family Case Studies, Visits/Excursions and Self Reflection were rated less useful teaching methods compared to Lectures, Teaching Ward Rounds, Elective Studies, Field Work, Presentations, Continuous Assessments Tests, Final Examinations, Short Answers, Clinical/Practical Examinations. ICT and Library facilities were not considered to meet the students learning needs and Clinical Logbooks also ranked low. Teachers were generally ranked less favorably including in professional role-modelling and

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

    PubMed Central

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

    2010-01-01

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

  8. Physical, Sexual, Emotional and Economic Intimate Partner Violence and Controlling Behaviors during Pregnancy and Postpartum among Women in Dar es Salaam, Tanzania.

    PubMed

    Mahenge, Bathsheba; Stöckl, Heidi; Abubakari, Abdulai; Mbwambo, Jessie; Jahn, Albrecht

    2016-01-01

    Intimate partner violence (IPV) during pregnancy and postpartum is a serious global health problem affecting millions of women worldwide. This study sought to determine the prevalence of different forms of IPV during pregnancy and postpartum and associated factors among women in Dar es Salaam, Tanzania. We conducted a cross-sectional study among 500 women at one to nine months postpartum in three health facilities in the three districts of Dar es Salaam: Temeke, Kinondoni and Illala. Two trained research assistants administered the questionnaire, which aimed to examine sociodemographic characteristics and different forms of IPV. Of the 500 women who were interviewed, 18.8% experienced some physical and/or sexual violence during pregnancy. Forty-one women (9%) reported having experienced some physical and/or sexual violence at one to nine months postpartum. Physical and/or sexual IPV during pregnancy was associated with cohabiting (AOR 2.2, 95% CI 1.24-4.03) and having a partner who was 25 years old or younger (AOR 2.7, 95% CI 1.08-6.71). Postpartum, physical and/or sexual IPV was associated with having a partner who was 25 years old or younger (AOR 4.4, 95% CI 1.24-15.6). We found that IPV is more prevalent during pregnancy than during the postpartum phase. There is also continuity and maintenance of IPV during and after pregnancy. These results call for policy and interventions to be tailored for pregnant and postpartum women.

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

    PubMed

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

    2007-09-04

    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. 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). 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. 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.

  10. Methadone Treatment for HIV Prevention—Feasibility, Retention, and Predictors of Attrition in Dar es Salaam, Tanzania: A Retrospective Cohort Study

    PubMed Central

    Lambdin, Barrot H.; Masao, Frank; Chang, Olivia; Kaduri, Pamela; Mbwambo, Jessie; Magimba, Ayoub; Sabuni, Norman; Bruce, R. Douglas

    2014-01-01

    Background. People who inject drugs (PWID) in Dar es Salaam, Tanzania, have an estimated human immunodeficiency virus (HIV) prevalence of 42%–50% compared with 6.9% among the general population. Extensive evidence supports methadone maintenance to lower morbidity, mortality, and transmission of HIV and other infectious diseases among PWID. In 2011, the Tanzanian government launched the first publicly funded methadone clinic on the mainland of sub-Saharan Africa at Muhimbili National Hospital. Methods. We conducted a retrospective cohort study of methadone-naive patients enrolling into methadone maintenance treatment. Kaplan-Meier survival curves were constructed to assess retention probability. Proportional hazards regression models were used to evaluate the association of characteristics with attrition from the methadone program. Results. Overall, 629 PWID enrolled into methadone treatment during the study. At 12 months, the proportion of clients retained in care was 57% (95% confidence interval [CI], 53%–62%). Compared with those receiving a low dose (<40 mg), clients receiving a medium (40–85 mg) (adjusted hazard ratio [aHR], 0.50 [95% CI, .37–.68]) and high (>85 mg) (aHR, 0.41 [95% CI, .29–.59]) dose of methadone had a lower likelihood of attrition, adjusting for other characteristics. Older clients (aHR, 0.53 per 10 years [95% CI, .42–.69]) and female clients (aHR, 0.50 [95% CI, .28–.90]) had a significantly lower likelihood of attrition, whereas clients who reported a history of sexual abuse (aHR, 2.84 [95% CI, 1.24–6.51]) had a significantly higher likelihood of attrition. Conclusions. Patient retention in methadone maintenance is comparable to estimates from programs in North America, Europe, and Asia. Future implementation strategies should focus on higher doses and flexible dosing strategies to optimize program retention and strengthened efforts for clients at higher risk of attrition. PMID:24855149

  11. Evaluation of the hygienic quality and associated public health hazards of raw milk marketed by smallholder dairy producers in the Dar es Salaam region, Tanzania.

    PubMed

    Kivaria, F M; Noordhuizen, J P T M; Kapaga, A M

    2006-04-01

    A cross-sectional study was conducted to determine three parameters of the quality of the raw milk marketed by milk selling points (MSPs) in Dar es Salaam region. Total bacterial count (TBC) was used as an indicator of the microbial quality of the milk; antimicrobial residues were determined; and the California mastitis test (CMT) was used to screen for milk somatic cells as an indication of the mastitis level in the cows that provided the milk. Moreover, a water sample at each MSP was taken for bacteriological culturing. Finally, a questionnaire survey was conducted with the milk sellers at the MSPs to identify risk factors for poor milk hygiene. A total of 128 milk samples and corresponding water samples were collected from randomly selected milk selling points in Dar es Salaam region. The mean TBC was (8.2 +/- 1.9) x 10(6) cfu/ml, and major bacterial isolates from the milk samples were Escherichia coli (6.3%), Bacillus cereus (6.3%), Staphylococcus aureus (6.3%) and Streptococcus agalactiae (6.3%), Enterobacter aerogenes (5.6%) and Enterococcus faecalis (4.7%). In most cases, the organisms identified in milk corresponded to those isolated from the corresponding water samples. Of milk samples, 79.0% were positive to the CMT and 7.0% were positive for antimicrobial residues. TBC was normalized by log-transformation, and the possible predictors of TBC were identified by fitting two linear regression models. In a random effect model, water microbial quality, frequency of cleaning the milk containers, frequency of milk supply, milk storage time and the type of containers, and mixing of fresh and previous milk were significantly (p < 0.05) associated with the mean log TBC. In a fixed effect model, in addition to these indicators, water shortage, water source and the refrigerator condition were significantly (p < or = 0.01) associated with log TBC. It was concluded that the milk sold in Dar es Salaam region is of poor quality and is of public health significance.

  12. OSL dating of the Aterian levels at Dar es-Soltan I (Rabat, Morocco) and implications for the dispersal of modern Homo sapiens

    NASA Astrophysics Data System (ADS)

    Barton, R. N. E.; Bouzouggar, A.; Collcutt, S. N.; Schwenninger, J.-L.; Clark-Balzan, L.

    2009-09-01

    The Aterian is a distinctive Middle Palaeolithic industry which is very widely spread across North Africa. Its dating and significance have been debated for nearly a century. Renewed interest in the Aterian has arisen because of a recent proposal that its development and spread may be linked to the dispersal of anatomically modern humans. The industry contains technological innovations such as thin bifacially flaked lithic points and pedunculates as well as evidence for personal ornaments and use of red ochre. Such markers as shell beads are believed to be indicative of symbolic behaviour. Dar es-Soltan I on the Atlantic coast of Morocco contains a thick sequence of Aterian deposits that were thought to represent the later stages of development of this industry. New Optically Stimulated Luminescence dates and geomorphological study indicate a much older sequence and so far the earliest yet recorded ages for the Aterian. They suggest an appearance in the Maghreb region during MIS (Marine Isotope Stage) 5.

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

    PubMed

    Rumisha, Cyrus; Elskens, Marc; Leermakers, Martine; Kochzius, Marc

    2012-03-01

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

  14. "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.

    PubMed

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

    2010-05-04

    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.

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

    PubMed

    Gaspare, Lydia; Machiwa, John F; Mdachi, S J M; Streck, Georg; Brack, Werner

    2009-01-01

    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.

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

    PubMed

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

    2014-06-25

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

  17. Physical, Sexual, Emotional and Economic Intimate Partner Violence and Controlling Behaviors during Pregnancy and Postpartum among Women in Dar es Salaam, Tanzania

    PubMed Central

    Mahenge, Bathsheba; Stöckl, Heidi; Abubakari, Abdulai; Mbwambo, Jessie; Jahn, Albrecht

    2016-01-01

    Background Intimate partner violence (IPV) during pregnancy and postpartum is a serious global health problem affecting millions of women worldwide. This study sought to determine the prevalence of different forms of IPV during pregnancy and postpartum and associated factors among women in Dar es Salaam, Tanzania. Methods We conducted a cross-sectional study among 500 women at one to nine months postpartum in three health facilities in the three districts of Dar es Salaam: Temeke, Kinondoni and Illala. Two trained research assistants administered the questionnaire, which aimed to examine sociodemographic characteristics and different forms of IPV. Results Of the 500 women who were interviewed, 18.8% experienced some physical and/or sexual violence during pregnancy. Forty-one women (9%) reported having experienced some physical and/or sexual violence at one to nine months postpartum. Physical and/or sexual IPV during pregnancy was associated with cohabiting (AOR 2.2, 95% CI 1.24–4.03) and having a partner who was 25 years old or younger (AOR 2.7, 95% CI 1.08–6.71). Postpartum, physical and/or sexual IPV was associated with having a partner who was 25 years old or younger (AOR 4.4, 95% CI 1.24–15.6). Conclusion We found that IPV is more prevalent during pregnancy than during the postpartum phase. There is also continuity and maintenance of IPV during and after pregnancy. These results call for policy and interventions to be tailored for pregnant and postpartum women. PMID:27755559

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

    PubMed Central

    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

    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. PMID:17784963

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

    PubMed Central

    2014-01-01

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

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

    PubMed

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

    2012-08-29

    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. 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. 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). 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.

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

    PubMed Central

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

    2012-01-01

    Objective To assess feeding practices of infants born to HIV-positive women in Dar es Salaam, Tanzania. These data then served as a proxy to evaluate the adequacy of current infant feeding counselling. Design A cross-sectional survey of infant feeding behaviours. Setting Four clinics in greater Dar es Salaam in early 2008. Subjects A total of 196 HIV-positive mothers of children aged 6–10 months recruited from HIV clinics. Results Initiation of breastfeeding was reported by 95·4% of survey participants. In the entire sample, 80·1%, 34·2% and 13·3% of women reported exclusive breast-feeding (EBF) up to 2, 4 and 6 months, respectively. Median duration of EBF among women who ever breast-fed was 3 (interquartile range (IQR): 2·1, 4·0) months. Most non-breast-milk foods fed to infants were low in nutrient density. Complete cessation of breast-feeding occurred within 14 d of the introduction of non-breast-milk foods among 138 of the 187 children (73·8%) who had ever received any breast milk. Of the 187 infants in the study who ever received breast milk, 19·4% received neither human milk nor any replacement milks for 1 week or more (median duration of no milk was 14 (IQR: 7, 152) d). Conclusions Infant feeding practices among these HIV-positive mothers resulted in infants receiving far less breast milk and more mixed complementary feeds than recommended, thus placing them at greater risk of both malnutrition and HIV infection. An environment that better enables mothers to follow national guidelines is urgently needed. More intensive infant feeding counselling programmes would very likely increase rates of optimal infant feeding. PMID:20587116

  2. [Qualifications and morality requisite for the personnel to be employed in the Ottoman Hospitals (Dar-al-Shifas)].

    PubMed

    Sari, N

    1995-01-01

    Ottomans legislated various codes and founded several institutions to provide care and protection for the sick, disabled, orphans, widows, invalids and the aged. Sultans passed acts assigning a proportion of the tax income to the needs of the diseased and disabled people in hospitals (dar-al-shifas) and nursing; and created foundations of health with trusts of deeds (waqfiyyes). These deeds comprise interesting information on hospital management as well as the duties, responsibilities, qualities, and proficiency standards requisite for physicians and other employees of these institutions. This article deals with the trusts of deeds of the dar-al-shifas founded by the Sultans, Bayazid I. in 1400, Mehmed II. the Conqueror in 1470, Bayazid II. in 1488, Süleyman the Magnificent in 1556, Sultan Ahmet I in 1616; and the Sultans' wifes', Hafsa's in 1539, Haseki Sultan Hurrem's in 1550, and Nurbanu's in 1582, in view of the characteristics stated above. A Hospital which presumably had a capacity of 20 to 50 patients had a staff consisting of approximately 20 to 25 employees, covering primarily, physicians (tabib), ophtalmologists (kahhal), surgeons (djarrah) and assistant health personnel such as pharmacists (ashshab), cook-dieticians (tabbah), a drug-smasher (adviyekub), a cellar-keeper (kilardje), nurses (kayyum), an attendant of kitchen ware (qassa-kash), sweepers (farrash), a W.C. cleaner (ab-reze) and a doorkeeper (bevvab) etc. ...

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

    PubMed

    Jackson, Msafiri M

    2006-05-01

    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

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

    PubMed Central

    2014-01-01

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

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

    PubMed Central

    2014-01-01

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

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

    PubMed Central

    2012-01-01

    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. PMID:22931107

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

    PubMed

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

    2017-09-06

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

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

    PubMed

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

    2014-08-07

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

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

    PubMed Central

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

    2015-01-01

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

  10. Social cognitive determinants of HIV voluntary counselling and testing uptake among married individuals in Dar es Salaam Tanzania: Theory of Planned Behaviour (TPB).

    PubMed

    Mtenga, Sally M; Exavery, Amon; Kakoko, Deodatus; Geubbels, Eveline

    2015-03-04

    Cumulative evidence indicates increasing HIV infection among married individuals. Voluntary Counselling and Testing for HIV (HCT) is known to be an effective intervention to induce safer sex behaviour and access to early treatment, care and support among married individuals, which are important for HIV prevention. In this context, knowledge of factors associated with HCT uptake among married individuals is critical in promoting the use of the services. This study therefore intended to identify the social cognitive factors associated with acceptance of HCT among married individuals. In a cross-sectional analytical study face to face questionnaires were administered among 200 randomly selected married individuals in Kinondoni district, Dar es Salaam Tanzania. The questionnaire included self-reported HCT, socio-demographic variables and social cognitive variables (attitude, subjective norms, perceived control and perceived risk). Logistic regression was used to identify the independent association of social cognitive predictors of HCT among married individuals. Nearly half (42%) of the respondents had never had HCT. Of the social cognitive constructs, the strongest predictor of HCT uptake was attitude (OR per additional score point = 1.07, 95% CI 1.04-1.10) followed by perceived behavioural control (OR = 1.04, 95% CI 1.02-1.06). Subjective norm and perceived risk were not associated with HCT uptake. Public health interventions targeting married individuals should be designed to enhance their positive attitude towards HCT and empower them to overcome barriers to the use of the services.

  11. Pollution and self-cleansing of an urban river in a developing country: a case study in Dar es Salaam, Tanzania.

    PubMed

    Mbuligwe, Stephen E; Kaseva, Mengiseny E

    2005-08-01

    Pollution and self-purification trends of an urban river namely, Msimbazi River, in Dar es Salaam City, Tanzania, were investigated. Site investigations and water quality analyses were done. The river is polluted in terms of high organic and nutrient concentrations, low dissolved oxygen, and high counts of indicator organisms. Biochemical oxygen demand (BOD5) concentrations were 27-340 mg/L. Dissolved oxygen was found to be as low as 0.9 mg O2/L. Bacteriological pollution increased with distance downstream of the river, a trend attributable to an increase in the catchment of pollution sources, which are on-site sanitation systems. Although the river has an appreciable self-purification capacity, the capacity is strained by persistent pollution overloads. The pollution plight of the river is attributable to its being flanked by expanding human habitats and vibrant industrial, institutional, and socio-economic activities. Provision for pretreatment of discharges into the river is put forward as a remedial measure for the observed pollution. Matching non-technical and techno-social remedial measures are also recommended. These include sensitization of polluters on merits of environmental protection practices such as cleaner production and strict enforcement of environmental protection laws.

  12. First Report of Gender Based Violence as a Deterrent to Methadone Access Among Females Who Use Heroin in Dar es Salaam, Tanzania.

    PubMed

    Balaji, Divya; Mlunde, Linda B; Tran, Olivia C; Lambdin, Barrot; Mbwambo, Jessie; Nyandindi, Cassian; Matiko, Eva; Copenhaver, Michael; Douglas Bruce, R

    2017-07-01

    High prevalence of human immunodeficiency virus (HIV) among females who use drugs in Dar es Salaam, Tanzania, contrasts strikingly with their low enrollment in HIV risk reduction services such as methadone assisted therapy (MAT). We conducted a case-control study to examine factors associated with non-enrollment in MAT, with a focus on gender-based violence. We interviewed 202 female heroin users not enrolled in MAT as cases and 93 females enrolled in MAT. We fitted logistic regression models with MAT enrollment as the outcome of interest. The likelihood of MAT enrollment decreased upon being in a violent relationship [odds ratio (OR) 0.23; 95 % CI 0.11-0.40], with experience of discrimination by a healthcare provider (OR 0.11; 95 % CI 0.04-0.35), and having a partner who also uses drugs (OR 0.05; 95 % CI 0.01-0.26). The results indicate that violence and discrimination are major impediments to MAT enrollment, necessitating implementation of interventions to address them.

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

    PubMed

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

    2016-12-01

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

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

    PubMed

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

    2006-06-30

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2007-05-01

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

  17. A retrospective study of the aetiology and temporal distribution of bovine clinical mastitis in smallholder dairy herds in the Dar es Salaam region of Tanzania.

    PubMed

    Kivaria, F M; Noordhuizen, J P T M

    2007-05-01

    A 31-year record-based retrospective study was carried out to determine the aetiology and temporal distribution of bovine clinical mastitis in smallholder dairy herds in the Dar es Salaam region of Tanzania over the period November 1971-December 2002. Laboratory information on 1964 quarter samples from 1365 cows in 281 smallholder dairy herds were retrieved, compiled and studied. Eighty-eight percent of the quarter samples were culture-positive and the predominant mastitis pathogens isolated were Staphylococcus aureus (25.7%), Streptococcus agalactiae (15.4%), Klebsiella pneumoniae (14.3%) and Escherichia coli (14.1%). Other isolates included Pseudomonas aeruginosa (7.5%), Streptococcus dysgalactiae (5.2%) and Streptococcus uberis (4.2%). Contagious mastitis pathogens were isolated from 45.6% of the culture-positive samples, whereas environmental and miscellaneous pathogens were isolated from 48.2% and 5.7%, respectively. Thirty percent of the miscellaneous mastitis pathogens were Candida species. The results demonstrate a steady increase in clinical Candida albicans mastitis. The prevalence of Candida albicans has increased from 1% in 1971 to 17.0% in November 2002. Conversely, despite some fluctuations, the prevalence of Staphylococcus aureus, Streptococcus agalactiae, E. coli and K. pneumoniae remain above 10%. The possible risk factors for these observations are discussed.

  18. Does the use of modern family planning promote healthy timing and spacing of pregnancy in Dar es Salaam?

    PubMed Central

    2013-01-01

    Background Timing, spacing and limiting of pregnancy are key outcomes of family planning (FP) whose role in promoting health of mothers and babies is evidence based. Despite the evidence, recent studies in Tanzania have reported a trend towards child birth in older age, non-adherence to standard inter-pregnancy spacing, and preference of large families in the background of a rising national contraceptive prevalence rate. We explored if the use of modern FP promotes healthy timing and spacing of pregnancy among women seeking antenatal services. Design Analytical Cross-sectional study Methods Women seeking antenatal services at Muhimbili National Hospital, Tanzania (August-October, 2012) were enrolled. We used a semi-structured questionnaire to obtained information from the women. Data were analyzed using SPSS version 19. Outcomes of interest were adherence to timing of first pregnancy and to inter-pregnancy spacing after normal childbirth. Use of modern FP prior to index pregnancy was the independent variable of primary interest. Bivariate and multivariate logistic regression analyses were conducted to obtain odds ratios (OR) and 95% confidence intervals (CI) as estimates risk and clinical importance respectively. Ethical approval was obtained from the Research and Publications Committee at Muhimbili University of Health and Allied Sciences. Results In total 427 women were interviewed. Ages ranged 15–45 years, mean 29.2 (SD ± 5.1). Among all, 129 (30.2%) were primigravida, 298 (69. 8%) multigravida. Of these 298 women, 51 (17.1%) lost pregnancies preceding the index. Overall, 179 (41.9%) had ever used modern FP, 103 (24.1%) were on modern FP just prior to index pregnancy. Non-adherence to timing was increased for primigravida (AOR = 4.5, 95% CI: 2.1-9.6) and for women older than 29 years (AOR = 7.6 95% CI: 3.8-15.2). Non-adherence to spacing was increased with loss of the immediate past pregnancy (AOR = 2.5; 95% CI: 1.3-4.7). Use of modern FP

  19. Does the use of modern family planning promote healthy timing and spacing of pregnancy in Dar es Salaam?

    PubMed

    Muganyizi, Projestine S; Mageta, Debora

    2013-12-12

    Timing, spacing and limiting of pregnancy are key outcomes of family planning (FP) whose role in promoting health of mothers and babies is evidence based. Despite the evidence, recent studies in Tanzania have reported a trend towards child birth in older age, non-adherence to standard inter-pregnancy spacing, and preference of large families in the background of a rising national contraceptive prevalence rate. We explored if the use of modern FP promotes healthy timing and spacing of pregnancy among women seeking antenatal services. Analytical Cross-sectional study Women seeking antenatal services at Muhimbili National Hospital, Tanzania (August-October, 2012) were enrolled. We used a semi-structured questionnaire to obtained information from the women. Data were analyzed using SPSS version 19. Outcomes of interest were adherence to timing of first pregnancy and to inter-pregnancy spacing after normal childbirth. Use of modern FP prior to index pregnancy was the independent variable of primary interest. Bivariate and multivariate logistic regression analyses were conducted to obtain odds ratios (OR) and 95% confidence intervals (CI) as estimates risk and clinical importance respectively. Ethical approval was obtained from the Research and Publications Committee at Muhimbili University of Health and Allied Sciences. In total 427 women were interviewed. Ages ranged 15-45 years, mean 29.2 (SD ± 5.1). Among all, 129 (30.2%) were primigravida, 298 (69. 8%) multigravida. Of these 298 women, 51 (17.1%) lost pregnancies preceding the index. Overall, 179 (41.9%) had ever used modern FP, 103 (24.1%) were on modern FP just prior to index pregnancy.Non-adherence to timing was increased for primigravida (AOR = 4.5, 95% CI: 2.1-9.6) and for women older than 29 years (AOR = 7.6 95% CI: 3.8-15.2). Non-adherence to spacing was increased with loss of the immediate past pregnancy (AOR = 2.5; 95% CI: 1.3-4.7). Use of modern FP was neither associated with adherence to timing (AOR = 1

  20. Prevention of mother-to-child transmission of HIV-1 through breastfeeding by treating mothers with triple antiretroviral therapy in Dar es Salaam, Tanzania: the Mitra Plus study.

    PubMed

    Kilewo, Charles; Karlsson, Katarina; Ngarina, Matilda; Massawe, Augustine; Lyamuya, Eligius; Swai, Andrew; Lipyoga, Rosina; Mhalu, Fred; Biberfeld, Gunnel

    2009-11-01

    The main aim of this study was to reduce breast-milk transmission of HIV-1 by treating HIV-1-infected women with highly active antiretroviral therapy (HAART) during breastfeeding. Mitra Plus was an open-label, nonrandomized, prospective cohort study. HIV-1-infected pregnant women in Dar es Salaam were treated with zidovudine (ZDV) + lamivudine (3TC) + nevirapine (NVP). NVP was later replaced by nelfinavir for mothers with CD4 cell counts >200 cells per microliter or with adverse reaction to NVP. HAART was initiated at 34 weeks of gestation. For women with symptomatic HIV infection or CD4 cell counts below 200 cells per microliter, HAART was started earlier if possible. Treatment of the mothers was stopped at 6 months except for those mothers who needed HAART for their own health. The infants received ZDV + 3TC for 1 week after birth. Mothers were advised to exclusively breastfeed and to wean abruptly between 5 and 6 months. Transmission of HIV-1 was analyzed using the Kaplan-Meier survival technique. Cox regression was used for comparison with the breastfeeding population of the Petra trial arm A. There were 441 infants included in the analysis of HIV-1 transmission. The cumulative transmission of HIV-1 was 4.1 % [95% confidence interval (CI): 2.2 to 6.0] at 6 weeks, 5.0% (95% CI: 2.9 to 7.1) at 6 months, and 6.0% (95% CI: 3.7 to 8.3) at 18 months after delivery. The cumulative risk of HIV transmission between 6 weeks and 6 months was 1.0% and between 6 months and 18 months 1.1%. The cumulative HIV infection or death rate was 8.6% (95% CI: 6.0 to 11.2) at 6 months and 13.6% (95% CI: 10.3 to 16.9) at 18 months after delivery. Viral load at enrollment and duration of HAART before delivery were significantly associated with transmission but CD4 cell count at enrollment was not. The median time of breastfeeding was 24 weeks. The transmission in the Mitra Plus study was about half of the transmission in the breastfeeding population in the Petra trial arm A at 6 months

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

    PubMed Central

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

    2008-01-01

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

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

    PubMed

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

    1995-04-01

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

  3. Impregnating hessian strips with the volatile pyrethroid transfluthrin prevents outdoor exposure to vectors of malaria and lymphatic filariasis in urban Dar es Salaam, Tanzania.

    PubMed

    Govella, Nicodem J; Ogoma, Sheila B; Paliga, John; Chaki, Prosper P; Killeen, Gerry

    2015-06-12

    Semi-field trials using laboratory-reared Anopheles arabiensis have shown that, delivering the volatile pyrethroid transfluthrin by absorption into hessian strips, consistently provided > 99% human protective efficacy against bites for 6 months without retreating. Here the impact of this approach upon human exposure to wild populations of vectors for both malaria and filariasis under full field conditions is assessed for the first time. Transfluthrin-treated and untreated strips were placed around human volunteers conducting human landing catch in an outdoor environment in urban Dar es Salaam, where much human exposure to malaria and filariasis transmission occurs outdoors. The experiment was replicated 9 times at 16 outdoor catching stations in 4 distinct locations over 72 working nights between May and August 2012. Overall, the treated hessian strips conferred 99% protection against An. gambiae (1 bite versus 159) and 92% protection against Culex spp. (1478 bites versus 18,602). No decline in efficacy over the course of the study could be detected for the very sparse populations of An. gambiae (P = 0.32) and only a slow efficacy decline was observed for Culex spp. (P < 0.001), with protection remaining satisfactory over 3 months after strip treatment. Diversion of mosquitoes to unprotected humans in nearby houses was neither detected for An. gambiae (P = 0.152) nor for Culex spp. (Relative rate, [95% CI] = 1.03, [0.95, 1.11], P = 0.499). While this study raises more questions than it answers, the presented evidence of high protection over long periods suggest this technology may have potential for preventing outdoor transmission of malaria, lymphatic filariasis and other vector-borne pathogens.

  4. Prevalence of Hypertension and Its Associated Risk Factors among 34,111 HAART Naïve HIV-Infected Adults in Dar es Salaam, Tanzania

    PubMed Central

    Aveika, Akum; Spiegelman, Donna; Hawkins, Claudia; Armstrong, Catharina; Liu, Enju; Okuma, James; Chalamila, Guerino; Kaaya, Sylvia; Mugusi, Ferdinand; Fawzi, Wafaie

    2016-01-01

    Background. Elevated blood pressure has been reported among treatment naïve HIV-infected patients. We investigated prevalence of hypertension and its associated risk factors in a HAART naïve HIV-infected population in Dar es Salaam, Tanzania. Methods. A cross-sectional analysis was conducted among HAART naïve HIV-infected patients. Hypertension was defined as systolic blood pressure (SBP) ≥ 140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg. Overweight and obesity were defined as body mass index (BMI) between 25.0–29.9 kg/m2 and ≥30 kg/m2, respectively. We used relative risks to examine factors associated with hypertension. Results. Prevalence of hypertension was found to be 12.5%. After adjusting for possible confounders, risk of hypertension was 10% more in male than female patients. Patients aged ≥50 years had more than 2-fold increased risk for hypertension compared to 30–39-years-old patients. Overweight and obesity were associated with 51% and 94% increased risk for hypertension compared to normal weight patients. Low CD4+ T-cell count, advanced WHO clinical disease stage, and history of TB were associated with 10%, 42%, and 14% decreased risk for hypertension. Conclusions. Older age, male gender, and overweight/obesity were associated with hypertension. Immune suppression and history of TB were associated with lower risk for hypertension. HIV treatment programs should screen and manage hypertension even in HAART naïve individuals. PMID:27872756

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

    PubMed

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

    2011-09-28

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

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

    PubMed

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

    2008-12-16

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

  7. 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.

    PubMed

    Ritte, S A; Kessy, A T

    2012-03-01

    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. 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. 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. 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.

  8. Determination of Levels of Organochlorine, Organophosphorus, and Pyrethroid Pesticide Residues in Vegetables from Markets in Dar es Salaam by GC-MS

    PubMed Central

    Khamis, Farhat A.; Lugwisha, Esther H. J.

    2017-01-01

    This study investigated the levels of pesticides and metabolites in vegetables from major markets in Dar es Salaam city, Tanzania. Samples of fresh cabbage, spinach, and onions from the markets were analysed for pesticide residues. Extraction was performed using acetone followed by dichloromethane : cyclohexane mixture and the extracts were cleaned up using Florisil. The compounds were determined by gas chromatography-mass spectrometry (GC-MS). Pesticides and metabolites were detected in 72.2% of the samples. The detected pesticide residues and their highest mean concentrations were p,p′-DDT 4.00 × 10−3 mg/kg, p,p′-DDD 6.40 × 10−1 mg/kg, o,p′-DDD 1.00 × 10−2 mg/kg, α-endosulfan 6.00 × 10−1 mg/kg, β-endosulfan 2.10 × 10−1 mg/kg, chlorpyrifos 3.00 mg/kg, and cypermethrin 4.00 × 10−2 mg/kg. The most frequently detected compounds were p,p′-DDD and chlorpyrifos. The order of contamination was spinach > cabbage > onions. Generally, there were no significant variations in concentrations of pesticide residues among samples and sampling sites, which indicated similarities in contamination patterns. The concentrations of contaminants were above the maximum residue limits (MRLs) in 33.3–50% of the samples. The findings indicated risks and concerns for public health. PMID:28280510

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

    PubMed

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

    2014-10-01

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

  10. Microbial Larvicide Application by a Large-Scale, Community-Based Program Reduces Malaria Infection Prevalence in Urban Dar Es Salaam, Tanzania

    PubMed Central

    Geissbühler, Yvonne; Kannady, Khadija; Chaki, Prosper Pius; Emidi, Basiliana; Govella, Nicodem James; Mayagaya, Valeliana; Mtasiwa, Deo; Mshinda, Hassan; Lindsay, Steven William; Tanner, Marcel; Fillinger, Ulrike; de Castro, Marcia Caldas; Killeen, Gerry Francis

    2009-01-01

    Background Malaria control in Africa is most tractable in urban settlements yet most research has focused on rural settings. Elimination of malaria transmission from urban areas may require larval control strategies that complement adult mosquito control using insecticide-treated nets or houses, particularly where vectors feed outdoors. Methods and Findings Microbial larvicide (Bacillus thuringiensis var. israelensis (Bti)) was applied weekly through programmatic, non-randomized community-based, but vertically managed, delivery systems in urban Dar es Salaam, Tanzania. Continuous, randomized cluster sampling of malaria infection prevalence and non-random programmatic surveillance of entomological inoculation rate (EIR) respectively constituted the primary and secondary outcomes surveyed within a population of approximately 612,000 residents in 15 fully urban wards covering 55 km2. Bti application for one year in 3 of those wards (17 km2 with 128,000 residents) reduced crude annual transmission estimates (Relative EIR [95% Confidence Interval] = 0.683 [0.491–0.952], P = 0.024) but program effectiveness peaked between July and September (Relative EIR [CI] = 0.354 [0.193 to 0.650], P = 0.001) when 45% (9/20) of directly observed transmission events occurred. Larviciding reduced malaria infection risk among children ≤5 years of age (OR [CI] = 0.284 [0.101 to 0.801], P = 0.017) and provided protection at least as good as personal use of an insecticide treated net (OR [CI] = 0.764 [0.614–0.951], P = 0.016). Conclusions In this context, larviciding reduced malaria prevalence and complemented existing protection provided by insecticide-treated nets. Larviciding may represent a useful option for integrated vector management in Africa, particularly in its rapidly growing urban centres. PMID:19333402

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

    PubMed

    Mbonile, Lumuli; Kayombo, Edmund J

    2008-04-01

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

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

    PubMed Central

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

    2006-01-01

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

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

    PubMed

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

    2014-10-01

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

  14. Glycaemic control in type 1 diabetes mellitus among children and adolescents in a resource limited setting in Dar es Salaam - Tanzania.

    PubMed

    Noorani, Mariam; Ramaiya, Kaushik; Manji, Karim

    2016-05-31

    Type 1 Diabetes Mellitus is a rapidly growing problem in Tanzania. Children and adolescents with type 1 diabetes have previously been found to have poor glycaemic control and high prevalence of complications. Strict glycaemic control reduces the incidence and progression of chronic complications. The aim of this study was to identify the factors associated with glycaemic control among children and adolescents. A cross sectional study was done at the diabetes clinic for children and adolescents. Data on socioeconomic, demographic and diabetes specific variables including adherence, diabetes knowledge, caregivers knowledge and their involvement in the care of the child was obtained. Glycaemic control was assessed by measuring glycosylated hemoglobin. (HbA1C). Linear regression analysis was done to determine factors associated with glycaemic control Seventy-five participants were recruited into the study (51 % males). The mean HbA1c was 11.1 ± 2.1 %. Children aged <10 years were found to have a significantly better glycaemic control (9.8 %) as compared to 10-14 year olds (11.5 %) and >14 year olds (11.4 %) (P value = 0.022). Sixty-eight percent of patients had good adherence to insulin while adherence to blood glucose monitoring regimen was 48 % and to diet control was 28 %. Younger age, having the mother as the primary caregiver, better caregiver knowledge of diabetes, better adherence to blood glucose monitoring regimen and diabetes duration of less than 1 year were associated with better glycaemic control. In multivariate analysis, age, adherence to blood glucose monitoring regimen and the mother as the primary caregiver were found to independently predict glycaemic control (R(2) = 0.332, p value = 0.00). Children and adolescents with type 1 diabetes in Dar es Salaam have poor glycaemic control. In order to improve metabolic control, adherence to blood glucose monitoring should be encouraged and caregivers encouraged to participate in

  15. Predictors of Patient Dissatisfaction with Services for Prevention of Mother-To-Child Transmission of HIV in Dar es Salaam, Tanzania

    PubMed Central

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

    2016-01-01

    Background Mother-to-child transmission (MTCT) of HIV remains a major source of new HIV infections in children. Prevention of mother-to-child transmission of HIV (PMTCT) using lifelong antiretroviral treatment (ART) for all pregnant and breastfeeding women living with HIV (Option B+) is the major strategy for eliminating paediatric HIV. Ensuring that patients are satisfied with PMTCT services is important for optimizing uptake, adherence and retention in treatment. Methods We conducted a facility based quantitative cross-sectional survey in Dar-es-Salaam, Tanzania, between March and April 2014, when the country was transitioning to the implementation of PMTCT Option B+. We interviewed 595 pregnant and breastfeeding women living with HIV, who received PMTCT care in 36 public health facilities. Predictors of overall dissatisfaction with PMTCT services were identified using a multiple logistic regression. Results Overall 8% of the patients expressed dissatisfaction with PMTCT services. Patients who perceived health care workers (HCW) communication skills as poor, had a 5-fold (OR 4.9, 95% CI 1.8–13.4) increased risk of dissatisfaction and those who perceived HCW capacity to understand client concerns as poor, had a 6-fold (OR 5.7, 95% CI 2.3–14.0) increased risk. Having a total visit time longer than two hours was associated with a 2-fold increased risk of being dissatisfied (OR 2.3, 95% CI 1.1–4.7). Every 30-minute increment in total visit time was associated with a 10% higher (OR 1.1, 95% CI 1.0–1.2) risk of being dissatisfied. The probability of being dissatisfied ranged from 4% (95% CI 2% - 6%) in the presence of patient-perceived good communication, good understanding of patient concerns, and a total visit time below two hours, to 70% (95% CI 47% - 86%) if HCW failed in all of these aspects. Conclusion Patient dissatisfaction with PMTCT services was generally low; reflecting that quality of care was maintained during Tanzania’s transition to Option B

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

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

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

    PubMed Central

    2009-01-01

    Background Preventing malaria by controlling mosquitoes in their larval stages requires regular sensitive monitoring of vector populations and intervention coverage. The study assessed the effectiveness of operational, community-based larval habitat surveillance systems within the Urban Malaria Control Programme (UMCP) in urban Dar es Salaam, Tanzania. Methods Cross-sectional surveys were carried out to assess the ability of community-owned resource persons (CORPs) to detect mosquito breeding sites and larvae in areas with and without larviciding. Potential environmental and programmatic determinants of habitat detection coverage and detection sensitivity of mosquito larvae were recorded during guided walks with 64 different CORPs to assess the accuracy of data each had collected the previous day. Results CORPs reported the presence of 66.2% of all aquatic habitats (1,963/2,965), but only detected Anopheles larvae in 12.6% (29/230) of habitats that contained them. Detection sensitivity was particularly low for late-stage Anopheles (2.7%, 3/111), the most direct programmatic indicator of malaria vector productivity. Whether a CORP found a wet habitat or not was associated with his/her unfamiliarity with the area (Odds Ratio (OR) [95% confidence interval (CI)] = 0.16 [0.130, 0.203], P < 0.001), the habitat type (P < 0.001) or a fence around the compound (OR [95%CI] = 0.50 [0.386, 0.646], P < 0.001). The majority of mosquito larvae (Anophelines 57.8% (133/230) and Culicines 55.9% (461/825) were not reported because their habitats were not found. The only factor affecting detection of Anopheline larvae in habitats that were reported by CORPs was larviciding, which reduced sensitivity (OR [95%CI] = 0.37 [0.142, 0.965], P = 0.042). Conclusions Accessibility of habitats in urban settings presents a major challenge because the majority of compounds are fenced for security reasons. Furthermore, CORPs under-reported larvae especially where larvicides were applied. This UMCP

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

    PubMed Central

    2011-01-01

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

  19. "Experiences with disclosure of HIV-positive status to the infected child": Perspectives of healthcare providers in Dar es Salaam, Tanzania.

    PubMed

    Sariah, Adellah; Rugemalila, Joan; Somba, Magreat; Minja, Anna; Makuchilo, Margareth; Tarimo, Edith; Urassa, David; Siril, Helen

    2016-10-13

    The specific age to which an HIV infected child can be disclosed to is stipulated to begin between ages 4 and 6 years. It has also been documented that before disclosure of HIV positive status to the infected child. Health care providers should consider children's cognitive-developmental ability. However, observation and situation analysis show that, health care providers still feel uncomfortable disclosing the HIV positive status to the infected child. The aim of the study was to explore healthcare providers' experiences in disclosure of HIV-positive status to the infected child. A qualitative study involving 20 health care providers who attend HIV-positive children was conducted in September, 2014 in Dar es Salaam, Tanzania. Participants were selected from ten HIV care and treatment clinics (CTC) by purposive sampling. An interview guide, translated into participants' national language (Kiswahili) was used during in-depth interviews. Sampling followed the principle of data saturation. The interviews focused on perspectives of health-care providers regarding their experience with paediatric HIV disclosure. Data from in-depth interviews were transcribed into text; data analysis followed qualitative content analysis. The results show how complex the process of disclosure to children living with HIV can be to healthcare providers. Confusion was noted among healthcare providers about their role and responsibility in the process of disclosing to the HIV infected child. This was reported to be largely due to unclear guidelines and lack of standardized training in paediatric HIV disclosure. Furthermore, healthcare providers were concerned about parental hesitancy to disclose early to the child due to lack of disclosure skills and fear of stigma. In order to improve the disclosure process in HIV infected children, healthcare providers recommended further standardized training on paediatric HIV disclosure with more emphasis on practical skills and inclusion of disclosure

  20. Hospital acquired infections among surgical, gynaecology and obstetrics patients in Felege-Hiwot referral hospital, Bahir Dar, northwest Ethiopia.

    PubMed

    Melaku, Silabat; Gebre-Selassie, Solomon; Damtie, Meku; Alamrew, Kassahun

    2012-04-01

    Hospital-acquired infection is an important public health problem that contributes to significant morbidity and mortality worldwide. The aim of this study was to assess the prevalence and risk factors of hospital-acquired infections and the antibiotic susceptibility pattern of bacterial isolates in Felege-Hiwot referral hospital. The study was conducted during April-August 2009. A total of 1383 patients admitted to Surgical and Gynecology/Obstetrics wards were followed throughout their stay in the hospital for development of infections. Data on sociodemographic, underlying diseases and risk factors were collected and analysed Laboratory investigations including culture, biochemical tests, Gram staining and antibacterial sensitivity tests using disc diffusion methods were done. Of the 1383 patients assessed 961 surgical, 333 obstetrics and 89 gynaecology patients assessed, 17.1% 21.0% and 13.5% developed infections, respectively. The over all incidence of hospital acquired infections was 246 (17.8%) with 251 (18.1%) episodes of bacterial infections. Urinary tract and surgical site infections were detected in 118 (48%) and 112 (45.6%) of the cases, respectively. Of the bacterial isolates, 132 (52.6%) were gram negative and 119 (47.4%) gram positive. Escherichia coli, Klebsiella pneumoniae, Psuedomonas aeruginosa, were the dominant gram negative isolates accounting for 49 (19.5%), 36 (14.3%) and 26 (10.4%), respectively. On the other hand, Staphylococcus aureus, coagulase negative staphylococci, and Enteroccocus species were isolated in 91 (36.3%), 18 (7.2%) and 10 (4.0%), respectively. Surgery, catheterization, underlying diseases, antibiotics prophylaxis and length of hospital stay were risk factors for infection (P<0.0001). Most, >80% of isolates showed high rate of resistance to ampicillin, chloramphenicol, and amoxacillin-clavulanic acid The incidence of surgical site infection in surgical and UTI in obstetrics patients was high. Escherichia coli from urinary

  1. Prevalence of intestinal protozoan infections among individuals living with HIV/AIDS at Felegehiwot Referral Hospital, Bahir Dar, Ethiopia.

    PubMed

    Kiros, Habtom; Nibret, Endalkachew; Munshea, Abaineh; Kerisew, Bizuayehu; Adal, Melaku

    2015-06-01

    HIV infection continues to pose a serious challenge to global health by predisposing patients to opportunistic infections. A cross-sectional study was conducted from December 2012 to February 2013 to assess the enteric protozoan infection status among individuals living with HIV/AIDS in Felegehiwot Referral Hospital, Bahir Dar, northwest Ethiopia. Stool specimens from 399 HIV-positive individuals were examined for the presence of trophozoites, cysts, and oocysts using direct wet mount, formol-ether sedimentation and modified Ziehl-Neelsen techniques. In addition, CD4+ T-cell counts were measured to evaluate the immune status of the study subjects. An overall prevalence of 30.6% enteric protozoan infections was recorded. Pre-ART (antiretroviral treatment) individuals were more infected than patients on ART, although this was not statistically significant (p>0.05). The highest prevalence of enteric protozoan infection was due to Entamoeba histolytica/E. dispar (19.3%), followed by Cryptosporidium spp (5.8%), Giardia lamblia (4.3%), and Isospora belli (1.3%). A CD4+ T-cell count of <200 cells/μl and status of being diarrhoeic were significantly associated with the overall prevalence of enteric protozoan infection. A relatively high prevalence of enteric protozoan infection was observed among individuals living with HIV/AIDS. Routine stool and CD4+ T-cell examinations should be conducted to monitor the status of HIV/AIDS patients. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Prevalence of hepatitis B and C viruses infection among military personnel at Bahir Dar Armed Forces General Hospital, Ethiopia.

    PubMed

    Birku, Tigist; Gelaw, Baye; Moges, Feleke; Assefa, Abate

    2015-12-01

    Military personnel are high-risk people for parenteral and sexually transmitted diseases such as hepatitis B virus (HBV) and hepatitis C virus (HCV). Data regarding HBV and HCV prevalence among military personnel in Ethiopia is limited. Hence, the study aimed to determine sero-prevalence and associated risk factors of HBV and HCV among military personnel at Bahir Dar Armed Forces General Hospital, Ethiopia. A cross-sectional study was conducted in a total of 403 military personnel from February to May 2015. Socio-demographic characteristics and risk factors were collected through face to face interview using structured questionnaire. HBV and HCV infection was determined using HBsAg and anti-HCV antibody rapid tests. Logistic regression analysis was employed to assess possible risk factors for HBV and HCV infections. The sero-prevalence of HBV and HCV infection were 4.2 and 0.2%, respectively. None of the study subjects were co-infected with HBV and HCV. Higher prevalence of HBV infection (11.3%) was observed in the age group of 40 and above. Being at the age of 40 years and above (COR 7.6; 95% CI 2.0-29.0, p = 0.003), history of nose piercing (COA 5.9; 95% CI 1.2-29.9, p = 0.033) and sexually transmitted infection (COR 4.3; 95% CI 1.1-16.4, p = 0.03) were significantly associated with these viral hepatitis infections. Intermediate prevalence of HBV and low prevalence of HCV were observed among military personnel. Strengthening HBV screening strategies among military personal may further reduce these viral diseases.

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2016-02-03

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

  5. Knowledge, attitude, and practice towards blood donation among health care providers in hospitals at Bahir Dar City, Ethiopia.

    PubMed

    Abera, Bayeh; Mohammed, Beyan; Betela, Wendmagegn; Yimam, Reshid; Oljira, Adam; Ahmed, Merhab; Tsega, Wubet; Mulu, Wondemagegn; Yizengaw, Endalew

    2017-06-01

    Like other sub-Saharan Africa, in Ethiopia there is a shortage of adequate and safe blood supplies. Health care providers are potential resource and promoter of voluntary blood donation. This study was conducted to determine the knowledge, attitude and practice towards blood donation among health care providers in Bahir Dar City, Ethiopia. Paper based questionnaire was distributed to 276 health care providers from May 01 to June 30, 2016. Overall, 42.8% had donated blood at least once. Of these, males accounted for 60%. The median age of blood donors was 26 years. Voluntary-unpaid donation was 21.2%. Overall, 75.5% health care providers were knowledgeable. The levels of knowledge were significantly different among different disciplines (One-way ANOVA; F=69.7; P=0.004). Males were more knowledgeable than females (P<0.05). The overall favorable attitude was 78.6%. Previous practice of blood donation determined the odds of favorable attitude to be a future regular voluntary-unpaid blood donor (OR: 5.7, 95% CI: 3.2-10.4). Majority of health care providers had adequate knowledge and favorable attitude. However, voluntary-unpaid donation practice (21.1%) was lower compared to 100% target of voluntary-unpaid donation. There should be motivation packages to enhance voluntary-unpaid blood donation among health care professionals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. The natural course of disease following HIV-1 infection in dar es salaam, Tanzania: a study among hotel workers relating clinical events to CD4 T-lymphocyte counts.

    PubMed

    Bakari, Muhammad; Urassa, Willy; Pallangyo, Kisali; Swai, Andrew; Mhalu, Fred; Biberfeld, Gunnel; Sandström, Eric

    2004-01-01

    Current HIV management guidelines are based on natural history studies from the developed world. Data on the similarity of the natural course of HIV-1 infection conflict with studies in the developing world. A cohort of 1887 hotel workers with no access to antiretroviral therapy was followed between 1990 and 1998 in Dar es Salaam through annual clinical evaluations and CD4+ T-lymphocyte (CD4 cell) count determinations. 196 (10.4%) were HIV-1 sero-prevalents; 133 (7.9%) were HIV-1 sero-incidents; and 1558 (82.6%) remained HIV seronegative. Follow-up duration was 13,719 and 82,742 months for HIV-1 seropositives and HIV seronegatives respectively. Clinical events occurred at median CD4 cell counts similar to those previously reported from the developed world, but death occurred at higher counts. Off-duty last 6 months, chronic diarrhoea and a faster CD4 cell count decline were associated with faster disease progression and death. In Tanzania HIV natural history is similar to that from the developed world and similar management guidelines could be employed.

  7. 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.

    PubMed

    Bowring, Anna L; Luhmann, Niklas; Pont, Sandrine; Debaulieu, Céline; Derozier, Stéphanie; Asouab, Fatima; Toufik, Abdalla; van Gemert, Caroline; Dietze, Paul; Stoove, Mark

    2013-01-01

    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). 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. 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. 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. Copyright © 2012 Elsevier B.V. All rights reserved.

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

    PubMed

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

    2012-06-01

    Sanitary inspection of wells was performed according to World Health Organization (WHO) procedures using risk-of-contamination (ROC) scoring in the peri-urban tropical lowlands of Dar es Salaam, Tanzania. The ROC was assessed for its capacity to predict bacterial faecal pollution in the investigated well water. The analysis was based on a selection of wells representing environments with low to high presumptive faecal pollution risk and a multi-parametric data set of bacterial indicators, generating a comprehensive picture of the level and characteristics of faecal pollution (such as vegetative Escherichia coli cells, Clostridium perfringens spores and human-associated sorbitol fermenting Bifidobacteria). ROC scoring demonstrated a remarkable ability to predict bacterial faecal pollution levels in the investigated well water (e.g. 87% of E. coli concentration variations were predicted by ROC scoring). Physicochemical characteristics of the wells were not reflected by the ROC scores. Our results indicate that ROC scoring is a useful tool for supporting health-related well water management in urban and suburban areas of tropical, developing countries. The outcome of this study is discussed in the context of previously published results, and future directions are suggested.

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

    PubMed Central

    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

    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 (χ2 = 4.31; df = 1; p = 0.03) and parotid enlargement (χ2 = 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 < 200 cell/mm3 (χ2 = 52.4; df = 2; p = 0.006) and with WHO clinical stage (χ2 = 121; df = 3; p = 0.008). Oral lesions were also associated with tobacco smoking (χ2 = 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

  10. [The motives for hospitalization at Adauto Botelho Hospital (Cariacica, ES) in the second half of the twentieth century].

    PubMed

    Carrion, Carla Torres Pereira; Margotto, Lilian Rose; Aragão, Elizabeth Maria Andrade

    2014-01-01

    This paper discusses the procedures for referring patients to Adauto Botelho Hospital, in Cariacica, Espírito Santo state, Brazil. The research is based on the medical records since its inauguration in 1954 and statements by people who worked there in the second half of the twentieth century. One hundred and two records were analyzed and four people were interviewed. The records revealed the active involvement of the Chief of Police in hospitalizations. The interviews corroborate this, while also showing the long duration of the hospitalizations. The tone of the paper is set by the life stories of the people hospitalized there. The conclusion is that this hospital served not so much for treatment as for confinement.

  11. 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

    PubMed Central

    2012-01-01

    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

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

    PubMed

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

    2016-04-01

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

  13. 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.

    PubMed

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

    2012-07-19

    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. 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. 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. 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

  14. Prevalence and Predictors of Human Immunodeficiency Virus and Selected Sexually Transmitted Infections Among People Who Inject Drugs in Dar es Salaam, Tanzania: A New Focus to Get to Zero.

    PubMed

    Mmbaga, Elia John; Moen, Kåre; Makyao, Neema; Leshabari, Melkizedeck

    2017-02-01

    Previous studies in Tanzania indicated that human immunodeficiency virus (HIV) prevalence among people who inject drugs (PWIDs) could be as high as 40%. We aim to provide data on the prevalence of HIV and sexually transmitted infection among PWIDs to inform national plans to get to zero. Respondent-driven sampling was used to collect drug use, and sexual practices data among PWIDs aged 15 years and older. Blood samples were examined for HIV, herpes simplex virus type 2, syphilis, and hepatitis B. A total of 620 PWIDs with a median age of 32 (interquartile range, 17-52) participated in the study. Their use of drugs had typically started during adolescence. The prevalence of HIV was found to be 15.5%, whereas that of herpes simplex type 2 was 43.3%. Associated with an increased likelihood of HIV infection was being a female (adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.0-3.6), sharing of syringes (aOR, 2.4; 95% CI, 1.1-6.1), used syringes hidden in public places (aOR, 5.1; 95% CI, 1.3-10.2), and having had a genital ulcer during the last 12 months before this survey. On the other hand, being educated, use of noninjectable drugs, access (aOR, 0.5; 95% CI, 0.2-0.8), and use of clean syringes (aOR, 0.3; 95% CI, 0.1-0.6) were associated with decreased likelihood of HIV infection. The prevalence of HIV infection among PWIDs in Dar es Salaam is 3 times higher than that in the general population. Behavioral and biological risk factors contribute to HIV transmission and needs to be addressed to be able to get to zero.

  15. Women's Preferences Regarding Infant or Maternal Antiretroviral Prophylaxis for Prevention of Mother-To-Child Transmission of HIV during Breastfeeding and Their Views on Option B+ in Dar es Salaam, Tanzania

    PubMed Central

    Ngarina, Matilda; Tarimo, Edith A. M.; Naburi, Helga; Kilewo, Charles; Mwanyika-Sando, Mary; Chalamilla, Guerino; Biberfeld, Gunnel; Ekstrom, Anna Mia

    2014-01-01

    Background The WHO 2010 guidelines for prevention of mother-to-child transmission (PMTCT) of HIV recommended prophylactic antiretroviral treatment (ART) either for infants (Option A) or mothers (Option B) during breastfeeding for pregnant women with a CD4 count of >350 cell/µL in low-income countries. In 2012, WHO proposed that all HIV-infected pregnant women should receive triple ART for life (B+) irrespective of CD4 count. Tanzania has recently switched from Option A to B+, with a few centers practicing B. However, more information on the real-life feasibility of these options is needed. This qualitative study explored women's preferences for Option A vs B and their views on Option B+ in Dar es Salaam, Tanzania. Methods We conducted four focus group discussions with a total of 27 pregnant women with unknown HIV status, attending reproductive and child health clinics, and 31 in-depth interviews among HIV-infected pregnant and post-delivery women, 17 of whom were also asked about B+. Results Most participants were in favor of Option B compared to A. The main reasons for choosing Option B were: HIV-associated stigma, fear of drug side-effects on infants and difficult logistics for postnatal drug adherence. Some of the women asked about B+ favored it as they agreed that they would eventually need ART for their own survival. Some were against B+ anticipating loss of motivation after protecting the child, fearing drug side-effects and not feeling ready to embark on lifelong medication. Some were undecided. Conclusion Option B was preferred. Since Tanzania has recently adopted Option B+, women with CD4 counts of >350 cell/µL should be counseled about the possibility to “opt-out” from ART after cessation of breastfeeding. Drug safety and benefits, economic concerns and available resources for laboratory monitoring and evaluation should be addressed during B+ implementation to enhance long-term feasibility and effectiveness. PMID:24465532

  16. Louse-borne relapsing fever profile at Felegehiwot referral hospital, Bahir Dar city, Ethiopia: a retrospective study

    PubMed Central

    2014-01-01

    Background Louse- borne relapsing fever is an acute febrile illness caused by Borrelia recurrentis and is transmitted by body lice, Pediculus humanus corporis. The disease has occurred as epidemic in different parts of the country.Therefore, the aim of this retrospective study was conducted to assess the LBRF profile for the last four years. Methods A retrospective study was conducted on patients with LBRF admitted from 2009–2012 at Felegehiwot referral hospital. The diagnosis was based on both clinical and laboratory methods. Patients with strong clinical suspicion of LBRF and positive for Borrelia species in their blood was diagnosed as LBRF cases. Data was collected from all patients with LBRF- like symptoms in their registration book. Data was checked for completeness, coded and analysed using SPSS version 16. P < 0.05 was considered significant for comparison. Results Of the 4559 patients admitted with LBRF- like symptoms, 4178 (91.6%) were males and 381 (8.4%) were females. Most of the patients (74.2%) were within age groups 11–20 years. The majority of patients (94.4%) were from urban residence. The overall prevalence of LBRF was 225 (4.9%) and the highest prevalence 171 (5.1%) was observed in age groups of 11–20 years. The association between seasonal variation and prevalence of LBRF showed that more patients with positive for Borrelia species were recorded in dry 27 (9.7%) than wet 198 (4.6%) seasons (P < 0.001). Finally, a trend in prevalence of LBRF for the last four years showed that the highest numbers of cases were documented in 2010. Conclusion The overall prevalence of LBRF was high and the highest prevalence was observed in young age groups. Moreover, most of the patients with LBRF were from urban dwellers. Therefore, health education should be delivered towards LBRF prevention in the city. PMID:24742342

  17. [Practice in situations of legal abortion from the perspective of health professionals at Fernando Magalhães public hospital].

    PubMed

    Farias, Rejane Santos; Cavalcanti, Ludmila Fontenele

    2012-07-01

    The scope of this study was to analyze perceptions of health professionals at Fernando Magalhães Public Hospital regarding situations involving the practice of legal abortion. With this in mind, we sought to characterize the professionals interviewed, understand the qualifying process for assistance of women requiring abortion and identify the perceptions of the professionals regarding the practice of legal abortion. The quantitative and qualitative approach in terms of methodology was adopted. The instruments used were analysis of institutional documentation and semi-structured interviews based on a script with informed consent. The results of this research revealed: the inappropriate use of the right to conscientious objection by health professionals; the existence of difficulties faced by professionals in construction of a posture that ensures access to legally sanctioned abortion; and the interference of ethical and religious values as an important element in professional attitudes that discourage the practice of legal abortion. Measures for the ongoing education of professionals and the monitoring of actions applied to technical norms are recommended.

  18. Predictors of Hospitalization During the First Year of Life among 31999 Tanzanian Infants.

    PubMed

    Briegleb, Christina; Sudfeld, Christopher R; Smith, Emily R; Ruben, Julia; Muhihi, Alfa; Mshamu, Salum; Noor, Ramadhani Abdallah; Masanja, Honorati; Fawzi, Wafaie W

    2015-10-01

    This study explored the risk factors for infant hospitalization in urban and peri-urban/rural Tanzania. We conducted a prospective cohort study examining predictors of hospitalization during the first year of life among infants enrolled at birth in a large randomized controlled trial of neonatal vitamin A supplementation conducted in urban Dar es Salaam (n = 11,895) and peri-urban/rural Morogoro region (n = 20,104) in Tanzania. Demographic, socioeconomic, environmental and birth outcome predictors of hospitalization were assessed using proportional hazard models. The rate of hospitalization was highest during the neonatal period in both Dar es Salaam (102/10,000 neonatal-months) and Morogoro region (78/10,000 neonatal-months). Hospitalization declined with increased age and was lowest for infants 6-12 months of age in both Dar es Salaam (11/10,000 infant-months) and Morogoro region (16/10,000 infant-months). In both Dar es Salaam and Morogoro region, older maternal age, male sex, low birth weight and being small for gestational age were significant predictors of higher risk of hospitalization (p < 0.05). Increased wealth and having a flush toilet were significantly associated with an increased risk of hospitalization in Morogoro region only (p < 0.05). This study determined high rates of neonatal hospitalization in Tanzania. Interventions to increase birth size may decrease risk of hospitalization. Equity in access to hospitals for poor rural families in Tanzania requires attention. © The Author [2015]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. The costs of providing antiretroviral therapy services to HIV-infected individuals presenting with advanced HIV disease at public health centres in Dar es Salaam, Tanzania: Findings from a randomised trial evaluating different health care strategies

    PubMed Central

    Kimaro, Godfather Dickson; Mfinanga, Sayoki; Simms, Victoria; Kivuyo, Sokoine; Bottomley, Christian; Hawkins, Neil; Harrison, Thomas S.; Jaffar, Shabbar; Guinness, Lorna

    2017-01-01

    Background Understanding the costs associated with health care delivery strategies is essential for planning. There are few data on health service resources used by patients and their associated costs within antiretroviral (ART) programmes in Africa. Material and methods The study was nested within a large trial, which evaluated screening for cryptococcal meningitis and tuberculosis and a short initial period of home-based adherence support for patients initiating ART with advanced HIV disease in Tanzania and Zambia. The economic evaluation was done in Tanzania alone. We estimated costs of providing routine ART services from the health service provider's perspective using a micro-costing approach. Incremental costs for the different novel components of service delivery were also estimated. All costs were converted into US dollars (US$) and based on 2012 prices. Results Of 870 individuals enrolled in Tanzania, 434 were enrolled in the intervention arm and 436 in the standard care/control arm. Overall, the median (IQR) age and CD4 cell count at enrolment were 38 [31, 44] years and 52 [20, 89] cells/mm3, respectively. The mean per patient costs over the first three months and over a one year period of follow up following ART initiation in the standard care arm were US$ 107 (95%CI 101–112) and US$ 265 (95%CI 254–275) respectively. ART drugs, clinic visits and hospital admission constituted 50%, 19%, and 19% of the total cost per patient year, while diagnostic tests and non-ART drugs (co-trimoxazole) accounted for 10% and 2% of total per patient year costs. The incremental costs of the intervention to the health service over the first three months was US$ 59 (p<0.001; 95%CI 52–67) and over a one year period was US$ 67(p<0.001; 95%CI 50–83). This is equivalent to an increase of 55% (95%CI 51%–59%) in the mean cost of care over the first three months, and 25% (95%CI 20%–30%) increase over one year of follow up. PMID:28234969

  20. The costs of providing antiretroviral therapy services to HIV-infected individuals presenting with advanced HIV disease at public health centres in Dar es Salaam, Tanzania: Findings from a randomised trial evaluating different health care strategies.

    PubMed

    Kimaro, Godfather Dickson; Mfinanga, Sayoki; Simms, Victoria; Kivuyo, Sokoine; Bottomley, Christian; Hawkins, Neil; Harrison, Thomas S; Jaffar, Shabbar; Guinness, Lorna

    2017-01-01

    Understanding the costs associated with health care delivery strategies is essential for planning. There are few data on health service resources used by patients and their associated costs within antiretroviral (ART) programmes in Africa. The study was nested within a large trial, which evaluated screening for cryptococcal meningitis and tuberculosis and a short initial period of home-based adherence support for patients initiating ART with advanced HIV disease in Tanzania and Zambia. The economic evaluation was done in Tanzania alone. We estimated costs of providing routine ART services from the health service provider's perspective using a micro-costing approach. Incremental costs for the different novel components of service delivery were also estimated. All costs were converted into US dollars (US$) and based on 2012 prices. Of 870 individuals enrolled in Tanzania, 434 were enrolled in the intervention arm and 436 in the standard care/control arm. Overall, the median (IQR) age and CD4 cell count at enrolment were 38 [31, 44] years and 52 [20, 89] cells/mm3, respectively. The mean per patient costs over the first three months and over a one year period of follow up following ART initiation in the standard care arm were US$ 107 (95%CI 101-112) and US$ 265 (95%CI 254-275) respectively. ART drugs, clinic visits and hospital admission constituted 50%, 19%, and 19% of the total cost per patient year, while diagnostic tests and non-ART drugs (co-trimoxazole) accounted for 10% and 2% of total per patient year costs. The incremental costs of the intervention to the health service over the first three months was US$ 59 (p<0.001; 95%CI 52-67) and over a one year period was US$ 67(p<0.001; 95%CI 50-83). This is equivalent to an increase of 55% (95%CI 51%-59%) in the mean cost of care over the first three months, and 25% (95%CI 20%-30%) increase over one year of follow up.

  1. Adult Education and Development: International Conference in Dar Es Salaam

    ERIC Educational Resources Information Center

    Indian Journal of Adult Education, 1975

    1975-01-01

    A major international conference sponsored by the International Council for Adult Education will be held in Tanzania, focusing on the role of adult education in development with special emphasis on increasing the interaction between those concerned with planning in agriculture, workers education, health, community development, and communication.…

  2. CONHECIMENTO DA LEI GERAL DE SAÚDE – RESPEITO ÀS TRANSFUSÕES SANGUÍNEAS EM MÉDICOS E PACIENTES TESTEMUNHAS DE JEOVÁ DO HOSPITAL DR. DARÍO CONTRERAS DA REPÚBLICA DOMINICANA

    PubMed Central

    SANTANA, ELSA DÍAZ

    2010-01-01

    Este estudo avalia quanto o corpo médico do Hospital Dr. Darío Contreras de República Dominicana conhece, respeita, informa e aplica a Lei Geral de Saúde em relação aos direitos do paciente Testemunha de Jeová de negar-se a ser transfundido (respeito a sua autonomia); também se os Testemunhas de Jeová conhecem a Lei Geral de Saúde e até que ponto têm se beneficiado diante dessa proposição. O estudo revelou que nem médicos, nem Testemunhas de Jeová conhecem de fato essa lei. PMID:20689657

  3. LiDAR: Providing structure

    USGS Publications Warehouse

    Vierling, Lee A.; Martinuzzi, Sebastián; Asner, Gregory P.; Stoker, Jason M.; Johnson, Brian R.

    2011-01-01

    Since the days of MacArthur, three-dimensional (3-D) structural information on the environment has fundamentally transformed scientific understanding of ecological phenomena (MacArthur and MacArthur 1961). Early data on ecosystem structure were painstakingly laborious to collect. However, as reviewed and reported in recent volumes of Frontiers(eg Vierling et al. 2008; Asner et al.2011), advances in light detection and ranging (LiDAR) remote-sensing technology provide quantitative and repeatable measurements of 3-D ecosystem structure that enable novel ecological insights at scales ranging from the plot, to the landscape, to the globe. Indeed, annual publication of studies using LiDAR to interpret ecological phenomena increased 17-fold during the past decade, with over 180 new studies appearing in 2010 (ISI Web of Science search conducted on 23 Mar 2011: [{lidar AND ecol*} OR {lidar AND fores*} OR {lidar AND plant*}]).

  4. Recovery rate and associated factors of children age 6 to 59 months admitted with severe acute malnutrition at inpatient unit of Bahir Dar Felege Hiwot Referral hospital therapeutic feeding unite, northwest Ethiopia

    PubMed Central

    Desyibelew, Hanna Demelash; Fekadu, Abel; Woldie, Haile

    2017-01-01

    Background Despite numerous advances made in improving child health and the clinical management protocols for treating severe acute malnutrition at treatment centers, evidences concerning the treatment outcomes are scarce. Therefore, this study was conducted to assess the recovery rate and associated factors of severely acute malnourished children of age 6 to 59 months admitted to inpatient therapeutic feeding unit at Felege Hiwot Referral Hospital. Methods We conducted a hospital-based cross-sectional study including 401 severely malnourished children who were admitted from September 2012 to January 2016. Bivariable and a Multivariable logistic regression model were fitted to identify factors associated with recovery rate. Adjusted Odds ratio with its 95% CI was reported and P-value less than 0.05 was considered as significant. Results Fifty eight percent (58.4%) (95%CI: 53.1–64.1) of admitted children were recovered with a mean recovery time of 18 (±6.3) days. Being female, children who were fully and partially vaccinated, who had better MUAC measurement, who stayed longer in the hospital, and children who took routine vitamin-A supplementation had better recovery rate. However, children who had co-morbidity at admission, had human immune virus (HIV) and Tuberculosis (TB) infection, and who had edema were less likely to recover. Interpretation Recovery rate was low as compared to international SPHERE cutoff points (> 75% recovery rate). Interventions that could address the outlined factors would be helpful to improve treatment recovery rate of admitted children. PMID:28166247

  5. Management of Takotsubo cardiomyopathy in non-academic hospitals in France: The Observational French SyndromEs of TakoTsubo (OFSETT) study.

    PubMed

    Yayehd, Komlavi; N'da, N'kenon W; Belle, Loïc; Bataille, Vincent; Hanssen, Michel; Leddet, Pierre; Aupetit, Jean-François; Commeau, Philippe; Filippi, Emmanuelle; Georges, Jean-Louis; Albert, Franck; Rangé, Grégoire; Meimoun, Patrick; Marcaggi, Xavier; Baleynaud, Serge; Nallet, Olivier; Dibie, Alain; Barnay, Claude; Jouve, Bernard; Legrand, Maud; Cattan, Simon; Mulak, Geneviève; Simon, Tabassome; Danchin, Nicolas; Dujardin, Jean-Jacques

    2016-01-01

    Takotsubo cardiomyopathy (TTC) is a rare condition characterized by a sudden temporary weakening of the heart. TTC can mimic acute myocardial infarction and is associated with a minimal release of myocardial biomarkers in the absence of obstructive coronary artery disease. To provide an extensive description of patients admitted to hospital for TTC throughout France and to study the management and outcomes of these patients. In 14 non-academic hospitals, we collected clinical, electrocardiographic, biological, psychological and therapeutic data in patients with a diagnosis of TTC according to the Mayo Clinic criteria. Of 117 patients, 91.5% were women, mean ± SD age was 71.4 ± 12.1 years and the prevalence of risk factors was high (hypertension: 57.9%, dyslipidaemia: 33.0%, diabetes: 11.5%, obesity: 11.5%). The most common initial symptoms were chest pain (80.5%) and dyspnoea (24.1%). A triggering psychological event was detected in 64.3% of patients. ST-segment elevation was found in 41.7% of patients and T-wave inversion in 71.6%. Anterior leads were most frequently associated with ST-segment elevation, whereas T-wave inversion was more commonly associated with lateral leads, and Q-waves with septal leads. The ratio of peak B-type natriuretic peptide (BNP) or N-terminal prohormone BNP (NT-proBNP) level to peak troponin level was 1.01. No deaths occurred during the hospital phase. After 1 year of follow-up, 3 of 109 (2.8%) patients with available data died, including one cardiovascular death. Rehospitalizations occurred in 17.4% of patients: 2.8% due to acute heart failure and 14.7% due to non-cardiovascular causes. There was no recurrence of TTC. This observational study of TTC included primarily women with atherosclerotic risk factors and mental stress. T-wave inversion was more common than ST-segment elevation. There were few adverse cardiovascular outcomes in these patients after 1-year follow-up. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  6. LiDAR as an Exploration Tool

    DOE Data Explorer

    Boschmann, D.; Diles, J.; Clarno, J.; Meigs, A.; Walsh, P.

    2011-01-01

    Using LiDAR to identify structural and volcanic evolution of a Miocene-Pleistocene age bimodal volcanic complex and implications for geothermal potential. The file includes an updated geologic map, methods, and preliminary results.

  7. Urban Classification Techniques Using the Fusion of LiDAR and Spectral Data

    DTIC Science & Technology

    2012-09-01

    outlines . The analysis utilized pan- sharpened multi-spectral imagery from IKONOS in conjunction with LiDAR. Their study area was a subset of an...Photogrammetry and Remote Sensing, 62, 43–63. Stein, D., Beaven, S ., Hoff, L., Winter, E., Schaum , A., & Stocker, A. (2002). Anomaly detection from...FUNDING NUMBERS 6. AUTHOR Justin E. Mesina 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) Naval Postgraduate School Monterey, CA 93943–5000 8

  8. LiDAR utility for natural resource managers

    Treesearch

    Andrew Thomas Hudak; Jeffrey Scott Evans; Alistair Mattthew Stuart. Smith

    2009-01-01

    Applications of LiDAR remote sensing are exploding, while moving from the research to the operational realm. Increasingly, natural resource managers are recognizing the tremendous utility of LiDAR-derived information to make improved decisions. This review provides a cross-section of studies, many recent, that demonstrate the relevance of LiDAR across a suite of...

  9. Characterizing Lava Flows With LiDAR

    NASA Astrophysics Data System (ADS)

    Deligne, N. I.; Cashman, K. V.; Deardorff, N.; Dietterich, H. R.; House, P. K.; Soule, S.

    2009-12-01

    Digital elevation models (DEMs) have been used in volcanology in predictive modeling of lava flow paths, both for assessment of potential hazards and specific predictions of lava flow paths. Topographic analysis of a lava flow is potentially useful for mapping and quantifying flow surface morphologies, which in turn can be used to determine flow emplacement conditions, such as effusion rate, steadiness of flow, and interactions with pre-existing topography and surface water. However, this has been limited in application because of the coarse resolution of most DEMs. In recent years, use of Light Detection and Ranging (LiDAR) airborne laser altimetry, capable of producing high resolution (≤ 1 meter) DEMs, has become increasingly common in the geomorphic and mapping community. However, volcanologists have made little use of airborne LiDAR. Here we compare information obtained using field observations and standard (10 meter) DEMs against LiDAR high resolution DEMs to assess the usefulness, capabilities, and limitations of LiDAR as applicable to lava flows. We compare morphologic characteristics of five lava flows of different compositions, tectonic settings, flow extents, slopes, and eruption duration: (1) 1984 Mauna Loa lava flow, Hawaii; (2) December 1974 Kilauea lava flow, Hawaii; (3) c. 1600 ybp Collier Cone lava flow, central Oregon Cascades; (4) Holocene lava flows from the Sand Mountain volcanic chain, central Oregon Cascades; and (5) Pleistocene lava flows along the Owyhee River, eastern Oregon basin and range. These lava flows range in composition from basalt to andesite, and have eruption durations ranging from 6 hours (observed) to years (inferred). We measure channel width, levee and flow front heights, compression ridge amplitude, wavelength and tumuli dimensions, and surface roughness. For all but the smallest scale features, LiDAR is easily used to quantify these features, which often is impossible or technically challenging to do in the field, while

  10. ES Review, Fall 2006

    ERIC Educational Resources Information Center

    Education Sector, 2006

    2006-01-01

    "ES Review" brings together in one publication recent Education Sector work that reflects both the reach of its policy projects and its commitment to translating the complexities of education policymaking for a wide range of audiences. Articles in this first edition of "ES Review" are: (1) Community College Confidential…

  11. ES Review, Fall 2006

    ERIC Educational Resources Information Center

    Education Sector, 2006

    2006-01-01

    "ES Review" brings together in one publication recent Education Sector work that reflects both the reach of its policy projects and its commitment to translating the complexities of education policymaking for a wide range of audiences. Articles in this first edition of "ES Review" are: (1) Community College Confidential…

  12. Parenting practices and styles associated with adolescent sexual health in Dar es Salaam, Tanzania.

    PubMed

    Kajula, Lusajo J; Darling, Nancy; Kaaya, Sylvia F; De Vries, Hein

    2016-11-01

    Parenting styles and practices are suggested to be important predictors of adolescent sexual health, mostly in Europe and North America. Limited research has been conducted on these processes in Sub-Saharan Africa, which has different patterns of adolescent sexual behavior and family traditions. This study qualitatively explored parenting practices and styles associated with adolescent sexual health in Tanzania, with 12 adolescents and 12 parents of adolescents. The themes we identified from the data included parental monitoring, preventive, and punitive behaviors. Parents were reported to use mostly punitive behaviors to correct or prohibit sexual behavior; parents also set clear rules about appropriate sexual behavior (e.g., modesty and abstinence). Parents were also reported to closely monitor their adolescent children's friendships and sexual behavior to minimize sexual behavior. However, some parents also engaged in positive preventive practices aimed at protecting their adolescent children.

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

    PubMed Central

    Mwambete, K. D.; Lyombe, F.

    2011-01-01

    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. PMID:22131630

  14. Challenging HIV vulnerability discourse: the case of professional and entrepreneurial women in Dar Es Salaam, Tanzania.

    PubMed

    Jangu, Neema William; Tam, Ailie; Maticka-Tyndale, Eleanor

    2017-05-01

    A poverty-HIV narrative has dominated many HIV prevention strategies in Africa despite epidemiological data showing higher prevalence of infection among educated and wealthier women in several African countries. This paper examines the perspectives of professional and entrepreneurial women on HIV risk and vulnerability based on their knowledge and lived experiences, comparing this to the HIV discourse evident in five strategic documents that shape intervention in Tanzania. The purpose is to uncover the confluence and dissonance between the discourses of government and those of professional women themselves. Qualitative research methods included critical discourse analysis of five strategic documents and thematic analysis of 37 in-depth interviews with women. The findings challenge fixed representations of women and notions of vulnerability embedded in the poverty-HIV discourse. Women described using their sexuality and sexual agency as a means to elevate their position in ways that made them vulnerable to sexual harassment and coercion. This is explored through two intersecting themes: non-marital sexual exchanges to gain an education or employment, and marriage. The intersecting social positions and constructions of female sexuality and agency expressed by the women in this study provide insights into other avenues and forms of HIV vulnerability.

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

    PubMed

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

    2010-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    Groundwater is globally important for human consumption, and changes in quality can have serious consequences. The study area is within a coastal aquifer where groundwater quality is influenced by various potential sources of salinity that determine the composition of water extracted from wells. Groundwater chemistry data from the aquifer have been acquired to determine the geochemical conditions and processes that occur in this area and assess their implications for aquifer susceptibility. Analysis of groundwater samples shows that the dominant watertype is mostly NaCl with pH < 7 in both aquifers (i.e. upper and lower) except for the shallow wells where CaHCO3 prevails with pH ⩾ 7, and boreholes located near the Indian Ocean, where coral reef limestone deposits are located and the watertype evolves towards CaHCO3. In the lower aquifer, Cl- is higher than in the upper aquifer. The origin of salinity in the area is strongly influenced by groundwater ascending from deep marine Miocene Spatangid Shales through faults, seawater incursion on the border of the Indian Ocean, and throughout, there is some salinity within the Quaternary aquifer, especially in intercalated deltaic clays in the fluviatile deposits, showing some marine influences. The seawater intrusion is linked to the strongly increasing groundwater exploitation since 1997. Another process that plays a major role to the concentration of major ions in the groundwater is calcite dissolution. Next to geogenic salinity and seawater intrusion, anthropogenic pollution as well is affecting groundwater quality in the aquifer. An important result of this study is the observation of high nitrate concentrations, that call for improved sanitation in the area, where domestic sewage with on-site sanitation (mainly pit latrines) also threatens the groundwater resource.

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

    PubMed

    Mwambete, K D; Lyombe, F

    2011-01-01

    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.

  18. From Denis Burkitt to Dar es Salaam. What happened next in East Africa?--Tanzania's story.

    PubMed

    Scanlan, Trish; Kaijage, Jane

    2012-03-01

    East Africa was at the forefront of early achievements and discoveries in paediatric oncology thanks to Denis Burkitt's seminal work. Although these successes have been built upon and continued elsewhere, they were sadly not sustained in sub-Saharan Africa for a variety of reasons. In recent years however this situation is slowly changing in countries across the continent. Tanzania is one such African country. Until very recently, survival rates of 5-10% for all children's cancers were expected. However, change has been brought about thanks to the combined efforts and commitments of the Tanzanian Ministry of Health, non-governmental organizations--such as The International Network for Cancer Treatment and Research, and Children in Crossfire-- and the participation of the private sector. Services are rapidly developing and outcomes are continuing to improve with 1-year survival rates of approximately 60% achieved. Efforts to maintain this early progress are concentrated around providing high quality local subspecialty medical training and continued local ownership of the programme.

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

    ERIC Educational Resources Information Center

    Kokeyo, Carolyne Adhiambo; Oluoch, John

    2015-01-01

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

  20. DoD Architecture Registry System (DARS)

    DTIC Science & Technology

    2012-04-30

    Communications-Electronics Research, Development and Engineering Center (CERDEC), S ft E i i Di t t (SED) UNCLASSIFIED 5 o ware ng neer ng rec ora e...Army 1245 (1183, 5 %)  Air Force 960 (889, 8%)  OSD 358 (346, 3%) M i 223 ( %) ar nes 209, 7  Combatant Command 156 (155, 1%)  Joint Staff...Program • Deployed DARS Release 5 6 in April 29 2011 This releaseCompleted Support . . included: • Migrate Community Management and

  1. Recent development of hyperspectral LiDAR using supercontinuum laser

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Li, Chuanrong; Zhou, Mei; Zhang, Huijing; He, Wenjing; Li, Wei; Qiu, Yuanyuan

    2016-10-01

    Hyperspectral Light Detection And Ranging (Hyperspectral LiDAR), a recently developed technique, combines the advantages of the LiDAR and hyperspectral imaging and has been attractive for many applications. Supercontinuum laser (SC laser), a rapidly developing technique offers hyperspectral LiDAR a suitable broadband laser source and makes hyperspectral Lidar become an installation from a theory. In this paper, the recent research and progressing of the hyperspectral LiDAR are reviewed. The hyperspectral LiDAR has been researched in theory, prototype system, instrument, and application experiment. However, the pulse energy of the SC laser is low so that the range of the hyperspectral LiDAR is limited. Moreover, considering the characteristics of sensors and A/D converter, in order to obtain the full waveform of the echo, the repetition rate and the pulse width of the SC laser needs to be limited. Recently, improving the detection ability of hyperspectral LiDAR, especially improving the detection range, is a main research area. A higher energy pulse SC laser, a more sensitive sensor, or some algorithms are applied in hyperspectral LiDAR to improve the detection distance from 12 m to 1.5 km. At present, a lot of research has been focused on this novel technology which would be applied in more applications.

  2. LiDAR - An emerging tool for geological applications

    USGS Publications Warehouse

    Stoker, Jason M.

    2012-01-01

    Over the past five to ten years the use and applicability of light detection and ranging (LiDAR) technology has increased dramatically. As a result, more and more LiDAR data now are being collected across the country for a wide range of applications, and LiDAR currently is the technology of choice for high resolution terrain model creation, 3-D city and infrastructure modeling, forestry, and a wide range of scientific applications. LiDAR is a key technology for geological applications both within and outside the U.S. Geological Survey, and efforts are underway to try to collect high resolution LiDAR data for the entire United States (https://pubs.usgs.gov/fs/2012/3089/pdf/fs2012-3089.pdf).

  3. ES H action plan

    SciTech Connect

    Not Available

    1991-01-01

    This document contains planned actions to correct the deficiencies identified in the Pre-Tiger Team Self-Assessment (PTTSA), January 1991, of Sandia National Laboratories (SNL -- Albuquerque, New Mexico; Tonopah, Nevada; and Kauai, Hawaii). The Self-Assessment was conducted by a Self-Assessment Working Group consisting of 19 department managers, with support from Environment, Safety, and Health (ES H) professionals, from October through December 1990. Findings from other past audits, dating back to 1985, were reviewed and compared with the PTTSA findings to determine if additional findings, key findings, or root causes were warranted. The resulting ES H Action Plan and individual planned actions were prepared by the ES H Action Plan Project Group with assistance from the Program owners/authors during February and March 1991. The plan was reviewed by SNL Management in April 1991. This document serves as a planning instrument for the Laboratories to aid in the scoping and sizing of activities related to ES H compliance for the coming five years. It will be modified as required to ensure a workload/funding balance and to address the findings resulting from the Tiger Team assessment at SNL, Albuquerque. The process of producing this document has served well to prepare SNL, Albuquerque, for the coming task of producing the required post-Tiger Team action plan document. 8 tabs.

  4. The Effectiveness, cost-effectiveness and acceptability of Community versus Hospital Eye Service follow-up for patients with neovascular age-related macular degeneration with quiescent disease (ECHoES): a virtual randomised balanced incomplete block trial.

    PubMed Central

    Reeves, Barnaby C; Scott, Lauren J; Taylor, Jodi; Hogg, Ruth; Rogers, Chris A; Wordsworth, Sarah; Townsend, Daisy; Muldrew, Alyson; Peto, Tunde; Violato, Mara; Dakin, Helen; Cappel-Porter, Heike; Mills, Nicola; O'Reilly, Dermot; Harding, Simon P; Chakravarthy, Usha

    2016-01-01

    -effectiveness and acceptability of Community versus Hospital Eye Service follow-up for patients with neovascular age-related macular degeneration with quiescent disease (ECHoES) study web application was robust and could be used for future training or research. The benefit of reducing HES workload was not considered in the economic evaluation. A framework of programme budgeting and marginal analysis could explicitly explore the resource implications of shifting resources within a given health service area, as the benefit of reducing HES workload was not considered in the economic evaluation. Future qualitative research could investigate professional differences of opinion that were identified in multidisciplinary focus groups. TRIAL REGISTRATION Current Controlled Trials ISRCTN07479761. FUNDING This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 80. See the NIHR Journals Library website for further project information. PMID:27809956

  5. The Effectiveness, cost-effectiveness and acceptability of Community versus Hospital Eye Service follow-up for patients with neovascular age-related macular degeneration with quiescent disease (ECHoES): a virtual randomised balanced incomplete block trial.

    PubMed

    Reeves, Barnaby C; Scott, Lauren J; Taylor, Jodi; Hogg, Ruth; Rogers, Chris A; Wordsworth, Sarah; Townsend, Daisy; Muldrew, Alyson; Peto, Tunde; Violato, Mara; Dakin, Helen; Cappel-Porter, Heike; Mills, Nicola; O'Reilly, Dermot; Harding, Simon P; Chakravarthy, Usha

    2016-10-01

    Patients with neovascular age-related macular degeneration (nAMD) usually attend regular reviews, even when the disease is quiescent. Reviews are burdensome to health services, patients and carers. To compare the proportion of correct lesion classifications made by community-based optometrists and ophthalmologists from vignettes of patients; to estimate the cost-effectiveness of community follow-up by optometrists compared with follow-up by ophthalmologists in the Hospital Eye Service (HES); to ascertain views of patients, their representatives, optometrists, ophthalmologists and clinical commissioners on the proposed shared care model. Community-based optometrists and ophthalmologists in the HES classified lesions from vignettes comprising clinical information, colour fundus photographs and optical coherence tomography images. Participants' classifications were validated against experts' classifications (reference standard). Internet-based application. Ophthalmologists had to have ≥ 3 years post-registration experience in ophthalmology, have passed part 1 of the Royal College of Ophthalmologists, Diploma in Ophthalmology or equivalent examination, and have experience in the age-related macular degeneration service. Optometrists had to be fully qualified, be registered with the General Optical Council for ≥ 3 years and not be participating in nAMD shared care. The trial sought to emulate a conventional trial in comparing optometrists' and ophthalmologists' decision-making, but vignettes, not patients, were assessed; therefore, there were no interventions. Participants received training prior to assessing vignettes. Primary outcome - correct classification of the activity status of a lesion based on a vignette, compared with a reference standard. Secondary outcomes - frequencies of potentially sight-threatening errors, participants' judgements about specific lesion components, participant-rated confidence in their decisions and cost-effectiveness of follow

  6. Processing LiDAR Data to Predict Natural Hazards

    NASA Technical Reports Server (NTRS)

    Fairweather, Ian; Crabtree, Robert; Hager, Stacey

    2008-01-01

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

  7. Tensor Modeling Based for Airborne LiDAR Data Classification

    NASA Astrophysics Data System (ADS)

    Li, N.; Liu, C.; Pfeifer, N.; Yin, J. F.; Liao, Z. Y.; Zhou, Y.

    2016-06-01

    Feature selection and description is a key factor in classification of Earth observation data. In this paper a classification method based on tensor decomposition is proposed. First, multiple features are extracted from raw LiDAR point cloud, and raster LiDAR images are derived by accumulating features or the "raw" data attributes. Then, the feature rasters of LiDAR data are stored as a tensor, and tensor decomposition is used to select component features. This tensor representation could keep the initial spatial structure and insure the consideration of the neighborhood. Based on a small number of component features a k nearest neighborhood classification is applied.

  8. Automatic registration method for mobile LiDAR data

    NASA Astrophysics Data System (ADS)

    Wang, Ruisheng; Ferrie, Frank P.

    2015-01-01

    We present an automatic mutual information (MI) registration method for mobile LiDAR and panoramas collected from a driving vehicle. The suitability of MI for registration of aerial LiDAR and aerial oblique images has been demonstrated under an assumption that minimization of joint entropy (JE) is a sufficient approximation of maximization of MI. We show that this assumption is invalid for the ground-level data. The entropy of a LiDAR image cannot be regarded as approximately constant for small perturbations. Instead of minimizing the JE, we directly maximize MI to estimate corrections of camera poses. Our method automatically registers mobile LiDAR with spherical panoramas over an approximate 4-km drive, and is the first example we are aware of that tests MI registration in a large-scale context.

  9. Shipborne LiDAR system for coastal change monitoring

    NASA Astrophysics Data System (ADS)

    Kim, chang hwan; Park, chang hong; Kim, hyun wook; hyuck Kim, won; Lee, myoung hoon; Park, hyeon yeong

    2016-04-01

    Coastal areas, used as human utilization areas like leisure space, medical care, ports and power plants, etc., are regions that are continuously changing and interconnected with oceans and land and the sea level has risen by about 8cm (1.9mm / yr) due to global warming from 1964 year to 2006 year in Korea. Coastal erosion due to sea-level rise has caused the problem of marine ecosystems and loss of tourism resources, etc. Regular monitoring of coastal erosion is essential at key locations with such volatility. But the survey method of land mobile LiDAR (light detection and ranging) system has much time consuming and many restrictions. For effective monitoring beach erosion, KIOST (Korea Institute of Ocean Science & Technology) has constructed a shipborne mobile LiDAR system. The shipborne mobile LiDAR system comprised a land mobile LiDAR (RIEGL LMS-420i), an INS (inertial navigation system, MAGUS Inertial+), a RTKGPS (LEICA GS15 GS25), and a fixed platform. The shipborne mobile LiDAR system is much more effective than a land mobile LiDAR system in the measuring of fore shore areas without shadow zone. Because the vessel with the shipborne mobile LiDAR system is continuously moved along the shoreline, it is possible to efficiently survey a large area in a relatively short time. Effective monitoring of the changes using the constructed shipborne mobile LiDAR system for seriously eroded coastal areas will be able to contribute to coastal erosion management and response.

  10. Modelling rating curves using remotely sensed LiDAR data

    USGS Publications Warehouse

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

    2012-01-01

    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

  11. Georeferenced LiDAR 3D Vine Plantation Map Generation

    PubMed Central

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

    2011-01-01

    The use of electronic devices for canopy characterization has recently been widely discussed. Among such devices, LiDAR sensors appear to be the most accurate and precise. Information obtained with LiDAR sensors during reading while driving a tractor along a crop row can be managed and transformed into canopy density maps by evaluating the frequency of LiDAR returns. This paper describes a proposed methodology to obtain a georeferenced canopy map by combining the information obtained with LiDAR with that generated using a GPS receiver installed on top of a tractor. Data regarding the velocity of LiDAR measurements and UTM coordinates of each measured point on the canopy were obtained by applying the proposed transformation process. The process allows overlap of the canopy density map generated with the image of the intended measured area using Google Earth®, providing accurate information about the canopy distribution and/or location of damage along the rows. This methodology was applied and tested on different vine varieties and crop stages in two important vine production areas in Spain. The results indicate that the georeferenced information obtained with LiDAR sensors appears to be an interesting tool with the potential to improve crop management processes. PMID:22163952

  12. Georeferenced LiDAR 3D vine plantation map generation.

    PubMed

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

    2011-01-01

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

  13. Freezing human ES cells.

    PubMed

    Trish, Erin; Dimos, John; Eggan, Kevin

    2006-10-12

    Here we demonstrate how our lab freezes HuES human embryonic stem cell lines. A healthy, exponentially expanding culture is washed with PBS to remove residual media that could otherwise quench the Trypsin reaction. Warmed 0.05% Trypsin-EDTA is then added to cover the cells, and the plate allowed to incubate for up to 5 mins at room temperature. During this time cells can be observed rounding, and colonies lifting off the plate surface. Gentle repeated pipetting will remove cells and colonies from the plate surface. Trypsinized cells are placed in a standard conical tube containing pre-warmed hES cell media to quench remaining trypsin, and then spun. Cells are resuspended growth media at a concentration of approximately one million cells in one mL of media, a concentration such that one frozen aliquot is sufficient to resurrect a culture on a 10 cm plate. After cells are adequately resuspended, ice cold freezing media is added at equal volume. Cell suspensions are mixed thoroughly, aliquoted into freezing vials, and allowed to slowly freeze to -80 C over 24 hours. Frozen cells can then moved to the vapor phase of liquid nitrogen for long term storage, or remain at -80 for approximately six months.

  14. LiDAR Vegetation Investigation and Signature Analysis System (LVISA)

    NASA Astrophysics Data System (ADS)

    Höfle, Bernhard; Koenig, Kristina; Griesbaum, Luisa; Kiefer, Andreas; Hämmerle, Martin; Eitel, Jan; Koma, Zsófia

    2015-04-01

    Our physical environment undergoes constant changes in space and time with strongly varying triggers, frequencies, and magnitudes. Monitoring these environmental changes is crucial to improve our scientific understanding of complex human-environmental interactions and helps us to respond to environmental change by adaptation or mitigation. The three-dimensional (3D) description of the Earth surface features and the detailed monitoring of surface processes using 3D spatial data have gained increasing attention within the last decades, such as in climate change research (e.g., glacier retreat), carbon sequestration (e.g., forest biomass monitoring), precision agriculture and natural hazard management. In all those areas, 3D data have helped to improve our process understanding by allowing quantifying the structural properties of earth surface features and their changes over time. This advancement has been fostered by technological developments and increased availability of 3D sensing systems. In particular, LiDAR (light detection and ranging) technology, also referred to as laser scanning, has made significant progress and has evolved into an operational tool in environmental research and geosciences. The main result of LiDAR measurements is a highly spatially resolved 3D point cloud. Each point within the LiDAR point cloud has a XYZ coordinate associated with it and often additional information such as the strength of the returned backscatter. The point cloud provided by LiDAR contains rich geospatial, structural, and potentially biochemical information about the surveyed objects. To deal with the inherently unorganized datasets and the large data volume (frequently millions of XYZ coordinates) of LiDAR datasets, a multitude of algorithms for automatic 3D object detection (e.g., of single trees) and physical surface description (e.g., biomass) have been developed. However, so far the exchange of datasets and approaches (i.e., extraction algorithms) among LiDAR users

  15. Uas Topographic Mapping with Velodyne LiDAR Sensor

    NASA Astrophysics Data System (ADS)

    Jozkow, G.; Toth, C.; Grejner-Brzezinska, D.

    2016-06-01

    Unmanned Aerial System (UAS) technology is nowadays willingly used in small area topographic mapping due to low costs and good quality of derived products. Since cameras typically used with UAS have some limitations, e.g. cannot penetrate the vegetation, LiDAR sensors are increasingly getting attention in UAS mapping. Sensor developments reached the point when their costs and size suit the UAS platform, though, LiDAR UAS is still an emerging technology. One issue related to using LiDAR sensors on UAS is the limited performance of the navigation sensors used on UAS platforms. Therefore, various hardware and software solutions are investigated to increase the quality of UAS LiDAR point clouds. This work analyses several aspects of the UAS LiDAR point cloud generation performance based on UAS flights conducted with the Velodyne laser scanner and cameras. The attention was primarily paid to the trajectory reconstruction performance that is essential for accurate point cloud georeferencing. Since the navigation sensors, especially Inertial Measurement Units (IMUs), may not be of sufficient performance, the estimated camera poses could allow to increase the robustness of the estimated trajectory, and subsequently, the accuracy of the point cloud. The accuracy of the final UAS LiDAR point cloud was evaluated on the basis of the generated DSM, including comparison with point clouds obtained from dense image matching. The results showed the need for more investigation on MEMS IMU sensors used for UAS trajectory reconstruction. The accuracy of the UAS LiDAR point cloud, though lower than for point cloud obtained from images, may be still sufficient for certain mapping applications where the optical imagery is not useful.

  16. Cost-effectiveness of community versus hospital eye service follow-up for patients with quiescent treated age-related macular degeneration alongside the ECHoES randomised trial

    PubMed Central

    Violato, M; Dakin, H; Chakravarthy, U; Reeves, B C; Peto, T; Hogg, R E; Harding, S P; Scott, L J; Taylor, J; Cappel-Porter, H; Mills, N; O'Reilly, D; Rogers, C A; Wordsworth, S

    2016-01-01

    Objectives To assess the cost-effectiveness of optometrist-led follow-up monitoring reviews for patients with quiescent neovascular age-related macular degeneration (nAMD) in community settings (including high street opticians) compared with ophthalmologist-led reviews in hospitals. Design A model-based cost-effectiveness analysis with a 4-week time horizon, based on a ‘virtual’ non-inferiority randomised trial designed to emulate a parallel group design. Setting A virtual internet-based clinical assessment, conducted at community optometry practices, and hospital ophthalmology clinics. Participants Ophthalmologists with experience in the age-related macular degeneration service; fully qualified optometrists not participating in nAMD shared care schemes. Interventions The participating optometrists and ophthalmologists classified lesions from vignettes and were asked to judge whether any retreatment was required. Vignettes comprised clinical information, colour fundus photographs and optical coherence tomography images. Participants' classifications were validated against experts' classifications (reference standard). Resource use and cost information were attributed to these retreatment decisions. Main outcome measures Correct classification of whether further treatment is needed, compared with a reference standard. Results The mean cost per assessment, including the subsequent care pathway, was £411 for optometrists and £397 for ophthalmologists: a cost difference of £13 (95% CI −£18 to £45). Optometrists were non-inferior to ophthalmologists with respect to the overall percentage of lesions correctly assessed (difference −1.0%; 95% CI −4.5% to 2.5%). Conclusions In the base case analysis, the slightly larger number of incorrect retreatment decisions by optometrists led to marginally and non-significantly higher costs. Sensitivity analyses that reflected different practices across eye hospitals indicate that shared care pathways between

  17. LiDAR point classification based on sparse representation

    NASA Astrophysics Data System (ADS)

    Li, Nan; Pfeifer, Norbert; Liu, Chun

    2017-04-01

    In order to combine the initial spatial structure and features of LiDAR data for accurate classification. The LiDAR data is represented as a 4-order tensor. Sparse representation for classification(SRC) method is used for LiDAR tensor classification. It turns out SRC need only a few of training samples from each class, meanwhile can achieve good classification result. Multiple features are extracted from raw LiDAR points to generate a high-dimensional vector at each point. Then the LiDAR tensor is built by the spatial distribution and feature vectors of the point neighborhood. The entries of LiDAR tensor are accessed via four indexes. Each index is called mode: three spatial modes in direction X ,Y ,Z and one feature mode. Sparse representation for classification(SRC) method is proposed in this paper. The sparsity algorithm is to find the best represent the test sample by sparse linear combination of training samples from a dictionary. To explore the sparsity of LiDAR tensor, the tucker decomposition is used. It decomposes a tensor into a core tensor multiplied by a matrix along each mode. Those matrices could be considered as the principal components in each mode. The entries of core tensor show the level of interaction between the different components. Therefore, the LiDAR tensor can be approximately represented by a sparse tensor multiplied by a matrix selected from a dictionary along each mode. The matrices decomposed from training samples are arranged as initial elements in the dictionary. By dictionary learning, a reconstructive and discriminative structure dictionary along each mode is built. The overall structure dictionary composes of class-specified sub-dictionaries. Then the sparse core tensor is calculated by tensor OMP(Orthogonal Matching Pursuit) method based on dictionaries along each mode. It is expected that original tensor should be well recovered by sub-dictionary associated with relevant class, while entries in the sparse tensor associated with

  18. Waveform LiDAR across forest biomass gradients

    NASA Astrophysics Data System (ADS)

    Montesano, P. M.; Nelson, R. F.; Dubayah, R.; Sun, G.; Ranson, J.

    2011-12-01

    Detailed information on the quantity and distribution of aboveground biomass (AGB) is needed to understand how it varies across space and changes over time. Waveform LiDAR data is routinely used to derive the heights of scattering elements in each illuminated footprint, and the vertical structure of vegetation is related to AGB. Changes in LiDAR waveforms across vegetation structure gradients can demonstrate instrument sensitivity to land cover transitions. A close examination of LiDAR waveforms in footprints across a forest gradient can provide new insight into the relationship of vegetation structure and forest AGB. In this study we use field measurements of individual trees within Laser Vegetation Imaging Sensor (LVIS) footprints along transects crossing forest to non-forest gradients to examine changes in LVIS waveform characteristics at sites with low (< 50Mg/ha) AGB. We relate field AGB measurements to original and adjusted LVIS waveforms to detect the forest AGB interval along a forest - non-forest transition in which the LVIS waveform lose the ability to discern differences in AGB. Our results help identify the lower end the forest biomass range that a ~20m footprint waveform LiDAR can detect, which can help infer accumulation of biomass after disturbances and during forest expansion, and which can guide the use of LiDAR within a multi-sensor fusion biomass mapping approach.

  19. Wet Channel Network Extraction based on LiDAR Data

    NASA Astrophysics Data System (ADS)

    Hooshyar, M.; Kim, S.; Wang, D.; Medeiros, S. C.

    2015-12-01

    The temporal dynamics of stream network is vitally important for understanding hydrologic processes including groundwater interactions and hydrograph recessions. However, observations are limited on flowing channel heads, which are usually located in headwater catchments and under canopy. Near infrared LiDAR data provides an opportunity to map the flowing channel network owing to the fine spatial resolution, canopy penetration, and strong absorption of the light energy by the water surface. A systematic method is developed herein to map flowing channel networks based on the signal intensity of ground LiDAR return, which is lower on water surfaces than on dry surfaces. Based on the selected sample sites where the wetness conditions are known, the signal intensities of ground returns are extracted from the LiDAR point data. The frequency distributions of wet surface and dry surface returns are constructed. With the aid of LiDAR-based ground elevation, the signal intensity thresholds are identified for mapping flowing channels. The developed method is applied to Lake Tahoe area based on eight LiDAR snapshots during recession periods in five watersheds. A power-law relationship between streamflow and flowing channel length during the recession period is derived based on the result.

  20. Using LiDAR technology in forestry activities.

    PubMed

    Akay, Abdullah Emin; Oğuz, Hakan; Karas, Ismail Rakip; Aruga, Kazuhiro

    2009-04-01

    Managing natural resources in wide-scale areas can be highly time and resource consuming task which requires significant amount of data collection in the field and reduction of the data in the office to provide the necessary information. High performance LiDAR remote sensing technology has recently become an effective tool for use in applications of natural resources. In the field of forestry, the LiDAR measurements of the forested areas can provide high-quality data on three-dimensional characterizations of forest structures. Besides, LiDAR data can be used to provide very high quality and accurate Digital Elevation Model (DEM) for the forested areas. This study presents the progress and opportunities of using LiDAR remote sensing technology in various forestry applications. The results indicate that LiDAR based forest structure data and high-resolution DEMs can be used in wide-scale forestry activities such as stand characterizations, forest inventory and management, fire behaviour modeling, and forest operations.

  1. Automated Probabilistic LiDAR Swath Registration

    NASA Astrophysics Data System (ADS)

    Jalobeanu, A.; Gonçalves, G. R.

    2014-12-01

    We recently developed a new point cloud registration algorithm. Compared to Iterated Closest Point (ICP) techniques, it is robust to noise and outliers, and easier to use, as it is less sensitive to initial conditions. It minimizes the entropy of the joint point cloud (including intensity attributes to help register areas with poor relief), uses a voxel space and B-Spline interpolation to accelerate computation. A natural application of registration is swath alignment in airborne light detection and ranging (LiDAR). Indeed, due to uncertainty in the inertial navigation system (INS), attitude angles are subject to time-dependent errors. Such errors can be understood as a sum of three terms: 1) a global term, or boresight error, which can be addressed using several existing techniques; 2) a low-frequency term, which is modeled as a constant attitude error for regions several hundred meters along-track; 3) a high-frequency term, responsible for corduroy artifacts (not addressed here). We propose to use the new registration algorithm to correct the low-frequency attitude variations. Relative geometric errors are significantly reduced, as pairs of swaths are registered onto each other local corrections. Absolute geometric errors are reduced during a second step, by applying all the corrections together to the entire dataset. We used a test area of 200 km2 in Portugal, with a density of 3-4 pts/m2. The point clouds were derived from waveform data, and include predictive range uncertainties estimated within a Bayesian framework. The data collection was supported by FCT and FEDER as part of the AutoProbaDTM research project (2009-2012). Modeling and reducing geometric error helps build consistent uncertainty maps. After correction, residual errors are taken into account in the final 3D error budget. For gridded elevation models a vertical uncertainty map is computed. Finally, it is possible to use the inter-swath registration parameters to estimate the distribution of

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

    SciTech Connect

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

    1988-03-01

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

  3. Application of LiDAR's multiple attributes for wetland classification

    NASA Astrophysics Data System (ADS)

    Ding, Qiong; Ji, Shengyue; Chen, Wu

    2016-03-01

    Wetlands have received intensive interdisciplinary attention as a unique ecosystem and valuable resources. As a new technology, the airborne LiDAR system has been applied in wetland research these years. However, most of the studies used only one or two LiDAR observations to extract either terrain or vegetation in wetlands. This research aims at integrating LiDAR's multiple attributes (DSM, DTM, off-ground features, Slop map, multiple pulse returns, and normalized intensity) to improve mapping and classification of wetlands based on a multi-level object-oriented classification method. By using this method, we are able to classify the Yellow River Delta wetland into eight classes with overall classification accuracy of 92.5%

  4. Raster Vs. Point Cloud LiDAR Data Classification

    NASA Astrophysics Data System (ADS)

    El-Ashmawy, N.; Shaker, A.

    2014-09-01

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

  5. Spectral LiDAR analysis for terrain classification

    NASA Astrophysics Data System (ADS)

    McIver, Charles A.; Metcalf, Jeremy P.; Olsen, Richard C.

    2017-05-01

    Data from the Optech Titan airborne laser scanner were collected over Monterey, CA, in three wavelengths (532 nm, 1064 nm, and 1550 nm), in May 2016, by the National Center for Airborne LiDAR Mapping (NCALM). Analysis techniques have been developed using spectral technology largely derived from the analysis of spectral imagery. Data are analyzed as individual points, vs techniques that emphasize spatial binning. The primary tool which allows for this exploitation is the N-Dimensional Visualizer contained in the ENVI software package. The results allow for significant improvement in classification accuracy compared to results obtained from techniques derived from standard LiDAR analysis tools

  6. Effectiveness of Community versus Hospital Eye Service follow-up for patients with neovascular age-related macular degeneration with quiescent disease (ECHoES): a virtual non-inferiority trial

    PubMed Central

    Reeves, Barnaby C; Scott, Lauren J; Taylor, Jodi; Harding, Simon P; Peto, Tunde; Muldrew, Alyson; Hogg, Ruth E; Wordsworth, Sarah; Mills, Nicola; O'Reilly, Dermot; Rogers, Chris A; Chakravarthy, Usha

    2016-01-01

    Objectives To compare the ability of ophthalmologists versus optometrists to correctly classify retinal lesions due to neovascular age-related macular degeneration (nAMD). Design Randomised balanced incomplete block trial. Optometrists in the community and ophthalmologists in the Hospital Eye Service classified lesions from vignettes comprising clinical information, colour fundus photographs and optical coherence tomographic images. Participants' classifications were validated against experts' classifications (reference standard). Setting Internet-based application. Participants Ophthalmologists with experience in the age-related macular degeneration service; fully qualified optometrists not participating in nAMD shared care. Interventions The trial emulated a conventional trial comparing optometrists' and ophthalmologists' decision-making, but vignettes, not patients, were assessed. Therefore, there were no interventions and the trial was virtual. Participants received training before assessing vignettes. Main outcome measures Primary outcome—correct classification of the activity status of a lesion based on a vignette, compared with a reference standard. Secondary outcomes—potentially sight-threatening errors, judgements about specific lesion components and participants' confidence in their decisions. Results In total, 155 participants registered for the trial; 96 (48 in each group) completed all assessments and formed the analysis population. Optometrists and ophthalmologists achieved 1702/2016 (84.4%) and 1722/2016 (85.4%) correct classifications, respectively (OR 0.91, 95% CI 0.66 to 1.25; p=0.543). Optometrists' decision-making was non-inferior to ophthalmologists' with respect to the prespecified limit of 10% absolute difference (0.298 on the odds scale). Optometrists and ophthalmologists made similar numbers of sight-threatening errors (57/994 (5.7%) vs 62/994 (6.2%), OR 0.93, 95% CI 0.55 to 1.57; p=0.789). Ophthalmologists assessed lesion components as

  7. The Ubiquitin Receptors DA1, DAR1, and DAR2 Redundantly Regulate Endoreduplication by Modulating the Stability of TCP14/15 in Arabidopsis

    PubMed Central

    Peng, Yuancheng; Chen, Liangliang; Lu, Yaru; Wu, Yingbao; Dumenil, Jack; Zhu, Zhengge; Bevan, Michael W.; Li, Yunhai

    2015-01-01

    Organ growth involves the coordination of cell proliferation and cell growth with differentiation. Endoreduplication is correlated with the onset of cell differentiation and with cell and organ size, but little is known about the molecular mechanisms linking cell and organ growth with endoreduplication. We have previously demonstrated that the ubiquitin receptor DA1 influences organ growth by restricting cell proliferation. Here, we show that DA1 and its close family members DAR1 and DAR2 are redundantly required for endoreduplication during leaf development. DA1, DAR1, and DAR2 physically interact with the transcription factors TCP14 and TCP15, which repress endoreduplication by directly regulating the expression of cell-cycle genes. We also show that DA1, DAR1, and DAR2 modulate the stability of TCP14 and TCP15 proteins in Arabidopsis thaliana. Genetic analyses demonstrate that DA1, DAR1, and DAR2 function in a common pathway with TCP14/15 to regulate endoreduplication. Thus, our findings define an important genetic and molecular mechanism involving the ubiquitin receptors DA1, DAR1, and DAR2 and the transcription factors TCP14 and TCP15 that links endoreduplication with cell and organ growth. PMID:25757472

  8. The ubiquitin receptors DA1, DAR1, and DAR2 redundantly regulate endoreduplication by modulating the stability of TCP14/15 in Arabidopsis.

    PubMed

    Peng, Yuancheng; Chen, Liangliang; Lu, Yaru; Wu, Yingbao; Dumenil, Jack; Zhu, Zhengge; Bevan, Michael W; Li, Yunhai

    2015-03-01

    Organ growth involves the coordination of cell proliferation and cell growth with differentiation. Endoreduplication is correlated with the onset of cell differentiation and with cell and organ size, but little is known about the molecular mechanisms linking cell and organ growth with endoreduplication. We have previously demonstrated that the ubiquitin receptor DA1 influences organ growth by restricting cell proliferation. Here, we show that DA1 and its close family members DAR1 and DAR2 are redundantly required for endoreduplication during leaf development. DA1, DAR1, and DAR2 physically interact with the transcription factors TCP14 and TCP15, which repress endoreduplication by directly regulating the expression of cell-cycle genes. We also show that DA1, DAR1, and DAR2 modulate the stability of TCP14 and TCP15 proteins in Arabidopsis thaliana. Genetic analyses demonstrate that DA1, DAR1, and DAR2 function in a common pathway with TCP14/15 to regulate endoreduplication. Thus, our findings define an important genetic and molecular mechanism involving the ubiquitin receptors DA1, DAR1, and DAR2 and the transcription factors TCP14 and TCP15 that links endoreduplication with cell and organ growth. © 2015 American Society of Plant Biologists. All rights reserved.

  9. Microbial contamination of nonsterile pharmaceuticals in public hospital settings.

    PubMed

    Mugoyela, Veronica; Mwambete, Kennedy D

    2010-10-05

    Contamination of pharmaceuticals with microorganisms irrespective whether they are harmful or nonpathogenic can bring about changes in physicochemical characteristics of the medicines. Although sterility is not a requirement in official compendia for nonsterile pharmaceuticals, bioburdens need to be within acceptable limits. Therefore, this study investigated microbial contamination of 10 nonsterile pharmaceuticals frequently delivered to outpatients by identifying and quantifying microbial contaminants and susceptibility pattern testing on the microbes isolated. The study was carried out at Amana Municipal Hospital in Dar es Salaam, Tanzania. The protocol for the study involved structured selection of representative tablets, syrups, and capsules from the hospital's outpatient pharmacy. Constitutive microorganisms were elaborated and enumerated using standard microbiologic procedures. Results showed that 50% of all tested products were heavily contaminated, and the predominant contaminants comprised Klebsiella, Bacillus, and Candida species. Furthermore, the results showed that the isolated Bacillus and Klebsiella species were resistant to Augmentin ® and cloxacillin. The differences in means for cfu/mL and zones of inhibition among the microorganisms isolated were considered significant at P < 0.05. The nonsterile pharmaceuticals were presumably microbiologically contaminated due to poor handling during dispensing, repackaging, and/or nonadherence to good manufacturing practice. Therefore, training and educating the dispensers, as well as patients, on the proper handling and use of medicines cannot be overemphasized, because these are key aspects in controlling cross-contamination of medicines.

  10. Effect of Zinc Supplementation on Duration of Hospitalization in Tanzanian Children Presenting with Acute Pneumonia

    PubMed Central

    Fataki, Maulidi R.; Kisenge, Rodrick R.; Sudfeld, Christopher R.; Aboud, Said; Okuma, James; Mehta, Saurabh; Spiegelman, Donna

    2014-01-01

    Background: Zinc supplementation prevents incident pneumonia in children; however, the effect for pneumonia treatment remains unclear. Methods: A randomized, double-blind, placebo-controlled trial of zinc supplements (daily 25 mg) adjunct to antibiotic treatment of radiology-confirmed acute pneumonia was conducted among hospitalized children (6–36 months) in Dar es Salaam, Tanzania. Results: The trial was stopped early due to low enrollment, primarily owing to exclusion of children outside the age range and >3 days of prior illness. Among children enrolled (n = 94), zinc supplementation indicated no beneficial effect on the duration of hospitalization (IRR: 0.69; 95% CI 0.45–1.06; p = 0.09) or the proportion of children who were hospitalized for <3 days (RR: 0.85; 95% CI: 0.57–1.25; p = 0.40) or <5 days (RR: 1.01; 95% CI: 0.83–1.23; p = 0.92) (IRRs and RRs >1.0 favor zinc). Conclusions: Although underpowered, this randomized trial provided no evidence for a beneficial effect of zinc supplementation adjunct to antibiotics for hospitalized children. PMID:24194421

  11. Quantifying Ladder Fuels: A New Approach Using LiDAR

    Treesearch

    Heather Kramer; Brandon Collins; Maggi Kelly; Scott Stephens

    2014-01-01

    We investigated the relationship between LiDAR and ladder fuels in the northern Sierra Nevada, California USA. Ladder fuels are often targeted in hazardous fuel reduction treatments due to their role in propagating fire from the forest floor to tree crowns. Despite their importance, ladder fuels are difficult to quantify. One common approach is to calculate canopy base...

  12. Coastal monitoring with LiDAR: challenges, problems, and pitfalls

    NASA Astrophysics Data System (ADS)

    Kidner, David B.; Thomas, Malcolm C.; Leigh, Charlotte; Oliver, J. Robert; Morgan, Christopher G.

    2004-10-01

    The National Assembly for Wales (NAW) is responsible for monitoring the effects of dredging for fine aggregate from sandbanks off the coast of South Wales. A key monitoring objective is the analysis of changes to the sandbank bathymetry and the adjacent coastline. This paper reviews the monitoring strategy, with a particular emphasis on the use of laserscanning with LiDAR over the last six years for large-scale topographic beach mapping and analysis. The focus is on the methodologies that were implemented in order to make the data compatible, consistent and usable within a geographical information system (GIS). The issues that are addressed include data handling strategies; automatic error/blunder detection of spurious data; identifying sources of errors; projection and datum transformations; LiDAR artefacts; quality control; choice of digital terrain model and spatial resolution; choice of interpolation algorithm; the calibration of LiDAR surveys to ensure consistency; and LiDAR accuracy compared with land surveys. Some of these issues have proved problematic, which if not correctly resolved, can produce significant application errors, thus reducing confidence in this technology. The paper concludes with some examples of the analyses undertaken to date.

  13. Modeling low-height vegetation with airborne LiDAR

    USDA-ARS?s Scientific Manuscript database

    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...

  14. Airborne LiDAR based Mapping of Alpine Permafrost Distribution

    NASA Astrophysics Data System (ADS)

    Sailer, Rudolf; Bollmann, Erik; Briese, Christian; Fischer, Andrea; Krainer, Karl; Pfeifer, Norbert; Rieg, Lorenzo; Stötter, Johann

    2010-05-01

    Recent global climate change findings show an acceleration of melting of glaciers, ice-sheets and ice caps. Extended remote sensing and in-situ measurements demonstrate that glaciers are losing mass at an increasing rate. In contrast to glaciers with large mass losses (about 5 m per year at the lower parts of the glacier tongue of Hintereisferner, Ötztal Alps, Tyrol, Austria), moderate to small changing rates (centimetres to decimetres per year) characterize the surface variations caused by permafrost degradation in high mountain areas. For a reliable mapping of the spatial permafrost distribution advanced remote sensing techniques with a high degree of vertical accuracy have to be applied. Recent studies have shown that airborne LiDAR survey in mountainous regions provide high-resolution spatial data with a vertical accuracy range of centimetre to decimetre. This prediction is based on a world wide unique dataset of 18 airborne LiDAR campaigns covering the Hintereisferner region . Furthermore, the according multi-temporal dataset offers the opportunity to identify surface changes (altitudinal changes) outside glaciated areas, which have not been observed until now. Excluding gravitational induced processes these altitudinal changes have to be assigned to alpine permafrost degradations, although detailed information from prominent permafrost features like rock glaciers are missing. Beyond the detection of the climate induced permafrost degradation, based on the multi-temporal LiDAR data set, the method (point based and avoiding point to raster conversions) will be applied to identify altitudinal changes and displacement rates of prominent rock glaciers in the Stubai and Ötztal Alps (Tyrol, Austria). In contrast to the multi-temporal approach, with at least one LiDAR terrain model per ablation period (June to September), the analysis of the rock glacier features is based on a data set of only two LiDAR campaigns, which were carried out with a time shift of four

  15. ES '70 REPORT NUMBER 2.

    ERIC Educational Resources Information Center

    1967

    IN A JULY 1967 MEETING, THE EDUCATIONAL SYSTEM FOR THE SEVENTIES (ES '70) EXECUTIVE COMMITTEE (1) REVIEWED THE PLANS FOR THE SUMMER WORKSHOP FOR LOCAL ES '70 PROGRAM COORDINATORS TO BE HELD IN AUGUST 1967, (2) REVIEWED THE LIST OF 15 PARTICIPATING SCHOOL SYSTEMS--BLOOMFIELD HILLS, MICHIGAN, MINEOLA, NEW YORK, SAN MATEO, CALIFORNIA, MONROE,…

  16. 47 CFR 25.401 - Satellite DARS applications subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Satellite DARS applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for DARS § 25.401 Satellite DARS applications subject to competitive bidding. Mutually exclusive initial applications for...

  17. 47 CFR 25.401 - Satellite DARS applications subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Satellite DARS applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for DARS § 25.401 Satellite DARS applications subject to competitive bidding. Mutually exclusive initial applications for...

  18. 47 CFR 25.401 - Satellite DARS applications subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Satellite DARS applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for DARS § 25.401 Satellite DARS applications subject to competitive bidding. Mutually exclusive initial applications for...

  19. 47 CFR 25.401 - Satellite DARS applications subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Satellite DARS applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for DARS § 25.401 Satellite DARS applications subject to competitive bidding. Mutually exclusive initial applications for...

  20. A multiscale curvature algorithm for classifying discrete return LiDAR in forested environments

    Treesearch

    Jeffrey S. Evans; Andrew T. Hudak

    2007-01-01

    One prerequisite to the use of light detection and ranging (LiDAR) across disciplines is differentiating ground from nonground returns. The objective was to automatically and objectively classify points within unclassified LiDAR point clouds, with few model parameters and minimal postprocessing. Presented is an automated method for classifying LiDAR returns as ground...

  1. Temporal transferability of LiDAR-based imputation of forest structure attributes

    Treesearch

    Patrick A. Fekety; Michael J. Falkowski; Andrew T. Hudak

    2015-01-01

    Forest inventory and planning decisions are frequently informed by LiDAR data. Repeated LiDAR acquisitions offer an opportunity to update forest inventories and potentially improve forest inventory estimates through time. We leveraged repeated LiDAR and ground measures for a study area in northern Idaho, U.S.A., to predict (via imputation) - across both space and time-...

  2. Demystifying LiDAR technologies for temperate rainforest in the Pacific Northwest

    Treesearch

    Rhonda Mazza; Demetrios Gatziolis

    2013-01-01

    Light detection and ranging (LiDAR), also known as airborne laser scanning, is a rapidly emerging technology for remote sensing. Used to help map, monitor, and assess natural resources, LiDAR data were first embraced by forestry professionals in Scandinavia as a tool for conducting forest inventories in the mid to late 1990s. Thus early LiDAR theory and applications...

  3. 47 CFR 25.401 - Satellite DARS applications subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Satellite DARS applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for DARS § 25.401 Satellite DARS applications subject to competitive bidding. Mutually exclusive initial applications for...

  4. Relationship between LiDAR-derived forest canopy height and Landsat images

    Treesearch

    Cristina Pascual; Antonio Garcia-Abril; Warren B. Cohen; Susana. Martin-Fernandez

    2010-01-01

    The mean and standard deviation (SD) of light detection and ranging (LiDAR)-derived canopy height are related to forest structure. However, LiDAR data typically cover a limited area and have a high economic cost compared with satellite optical imagery. Optical images may be required to extrapolate LiDAR height measurements across a broad landscape. Different spectral...

  5. Three-dimensional canopy fuel loading predicted using upward and downward sensing LiDAR systems

    Treesearch

    Nicholas S. Skowronski; Kenneth L. Clark; Matthew Duveneck; John. Hom

    2011-01-01

    We calibrated upward sensing profiling and downward sensing scanning LiDAR systems to estimates of canopy fuel loading developed from field plots and allometric equations, and then used the LiDAR datasets to predict canopy bulk density (CBD) and crown fuel weight (CFW) in wildfire prone stands in the New Jersey Pinelands. LiDAR-derived height profiles were also...

  6. Social venues that protect against and promote HIV risk for young men in Dar es Salaam, Tanzania

    PubMed Central

    Yamanis, Thespina Jeanne; Maman, Suzanne; Mbwambo, Jessie K.; Earp, JoAnne; Kajula, Lusajo

    2010-01-01

    Developing effective place-based health interventions requires understanding of the dynamic between place and health. The therapeutic landscape framework explains how place-based social processes and physical geography interact and influence health behavior. This study applied this framework to examine how venues, or social gathering places, influenced HIV risk behavior among young, urban men in Tanzania. Eighty-three public venues where men ages 15–19 met new sexual partners were identified by community informants in one city ward. The majority (86%) of the venues were called ‘camps’, social gathering places that had formal leaders and members. Observations were conducted at 23 camps and in-depth interviews were conducted with 36 camp members and 10 camp leaders in 15 purposively selected camps. Geographic and social features of camps were examined to understand their contributions to men’s behaviors. Camps were characterized by a geographic space claimed by members, a unique name and a democratic system of leadership and governance. Members were mostly men and socialized daily at their camp. They reported strong social bonds and engaging in health-promoting activities such as playing sports and generating income. Members also engaged in HIV risk behaviors, such as meeting new sexual partners and having sex in or around the camp at night. Some members promoted concurrent sexual partnerships with their friends and resisted camp leaders’ efforts to change their sexual risk behavior. We conclude that camps are strategic venues for HIV prevention programs for young Tanzanian men. They served as both protective and risk landscapes, illustrating three domains of the therapeutic landscape framework: the built environment; identities of landscape occupants; and sites for collective efficacy. The framework and data suggest HIV intervention components that might augment the protective features of the camps, while changing environmental features to reduce risk. PMID:20846768

  7. Prevalence and risk factors of cervical squamous intraepithelial lesions among HIV-infected women in Dar es Salaam, Tanzania.

    PubMed

    Liu, Enju; McCree, Renicha; Mtisi, Expeditho; Fawzi, Wafaie W; Aris, Eric; Lema, Irene A; Hertzmark, Ellen; Chalamilla, Guerino; Li, Nan; Vermund, Sten H; Spiegelman, Donna

    2016-03-01

    To determine the prevalence and predictors of cervical squamous intraepithelial lesions (SIL) among HIV-infected women in Tanzania, a cross-sectional study was conducted among HIV-infected women at HIV care and treatment clinics. A Papanicolaou (Pap) smear was used as a screening tool for detection of cervical SIL. From December 2006 to August 2009, 1365 HIV-infected women received cervical screening. The median age was 35 (interquartile range [IQR]: 30-42) years, and the median CD4 + cell count was 164 (IQR: 80-257) cells/mm(3). The prevalence of cervical SIL was 8.7% (119/1365). In multivariate analysis, older age (≥50 versus 30-<40 years: prevalence ratio [PR], 2.36; 95% confidence interval [CI], 1.45-3.84, p for trend = 0.001), lower CD4 + cell counts (<100 versus ≥200 cells/mm(3): PR, 1.55; 95% CI, 1.01-2.36, p for trend = 0.03) and cervical inflammation (PR, 1.73; 95% CI, 1.16-2.60, p = 0.008) were associated with an increased risk of cervical SIL. Women with advanced WHO HIV disease stage (IV versus I/II: PR, 3.45; 95% CI, 1.35-8.85, p for trend = 0.01) had an increased risk for high-grade SIL. In resource-limited settings where it is not feasible to provide cervical cancer prevention services to all HIV-infected women, greater efforts should focus on scaling-up services among those who are older than 50 years, with lower CD4 cell counts and advanced HIV disease stage. © The Author(s) 2015.

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

    PubMed

    Urassa, J A E

    2012-03-01

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

  9. Experiences and Impact of Stigma and Discrimination among People on Antiretroviral Therapy in Dar es Salaam: A Qualitative Perspective

    PubMed Central

    Mhode, Maisara; Nyamhanga, Tumaini

    2016-01-01

    Background. The impact of stigma on adherence to antiretroviral therapy (ART) has been less studied in Tanzania. Recent studies indicate that people on ART still experience stigma. Qualitative information on the subject matter is especially insufficient. Objective. This paper reports on the dimensions of stigma and discrimination and their impact on adherence to ART as experienced by people living with HIV (PLHIV). Design. A phenomenological approach was used to gather information on the lived experiences of stigma and discrimination. The sample size was determined according to the saturation principle. Results. Respondents experienced different forms of HIV-related stigma such as verbal, social, and perceived stigma. Various forms of discrimination were experienced, including relational discrimination, mistreatment by health care workers, blame and rejection by spouses, and workplace discrimination. HIV-related stigma and discrimination compromised ART adherence by reinforcing concealment of HIV status and undermining social suppport. Conclusion. After nearly a decade of increasing the provision of ART in Tanzania, PLHIV still experience stigma and discrimination; these experiences still appear to have a negative impact on treatment adherence. Efforts to reduce stigma and discrimination remain relevant in the ART period and should be given more impetus in order to maximize positive treatment outcomes. PMID:27110395

  10. Smear positive pulmonary tuberculosis among HIV patients receiving highly active antiretroviral therapy in Dar es Salaam, Tanzania.

    PubMed

    Bwana, Veneranda; Tenu, Filemoni; Magesa, Stephen M; Mfinanga, Sayoki G

    2011-01-01

    Globally, tuberculosis-HIV co-infections are on the increase. In 2007, 15% (1.37 million) of the tuberculosis cases were HIV-positive tuberculosis (TB). This cross-sectional study was conducted in February 2009 to assess the effect of the level of CD4 lymphocyte counts on the development of smear positive pulmonary TB (PTB) among HIV patients before and after initiation of highly active antiretroviral therapy (HAART). A total of 155 HIV patients who were on HAART programme were enrolled and out of these 42 (27.1%) were smear positive PTB. Of the 42 PTB patients, 38 (90.5%) were also infected with HIV and were already at initiation of HAART. There was no association between the development of smear positive PTB and socio-demographic characteristics among HIV patients before and after HAART initiation (P>0.05). A larger proportion of HIV+PTB patients diagnosed before and after HAART initiation was found with CD4 lymphocyte count <200cells/microl. However, the difference was not statistically significant (P =0.092). Among HIV patients who were diagnosed to be smear positive PTB after HAART initiation, their CD4 lymphocyte counts at time of TB diagnosis was lower than their CD4 lymphocyte counts at time of HAART initiation. The four patients diagnosed with PTB after HAART initiation had mean CD4 lymphocyte counts at HAART initiation not statistically different from that at TB diagnosis (t=0.715, P=0.526). The median time period within which the diagnosis of smear positive PTB was made after HAART initiation was 22 weeks and the mean time was 66.75 weeks. These findings provide evidence that development of smear positive PTB after HAART initiation may occur at any level of CD4 lymphocyte count (P<0.05). This study was limited by the relatively small sample size, we therefore recommend more studies involving a larger sample size in order to estimate more accurately the effect of both level of CD4 lymphocyte count and HAART on the development of smear positive PTB among HIV patients on treatment.

  11. A community-based study on prevalence and correlates of erectile dysfunction among Kinondoni District Residents, Dar Es Salaam, Tanzania.

    PubMed

    Pallangyo, Pedro; Nicholaus, Paulina; Kisenge, Peter; Mayala, Henry; Swai, Noel; Janabi, Mohamed

    2016-11-29

    Globally, erectile dysfunction burden (ED) is rising appreciably and it is projected to affect about 332 million men by the year 2025. This rise is attributable to the rising incidence of conditions associated with ED including obesity, diabetes, hypertension, coronary artery disease and depression. We conducted this community-based screening to elucidate on the prevalence of ED and its associated factors among men residing in an urban community in Tanzania. We conducted a cross-sectional community-based study and interviewed 441 men aged at least 18 years. Diabetes and hypertension were defined as per the International Diabetes Federation (IDF) and the 7th Report of the Joint National Committee (JNC 7) respectively. The 5-item version of the International Index of Erectile Function (IIEF-5) Scale was used to assess for erectile dysfunction. Multivariate logistic regression analyses were performed to explore the factors associated with ED. The mean age was 47.1 years, 57.6 % had excess body weight, 8.2 % had diabetes and 61.5 % had high blood pressure. Overall, 24 % (106/441) of men in this study had some form of ED. Participants with age ≥55, positive smoking history, obesity, diabetes and hypertension displayed highest rates of ED in their respective subgroups. However, age ≥40 and diabetes were ultimately the strongest factors for ED after multivariate logistic regression analyses, (OR 5.0, 95 % CI 2.2-11.2, p < 0.001 and OR 5.3, 95 % CI 2.2-12.7, p < 0.001 respectively). Erectile dysfunction affects about a quarter of adult men living in Kinondoni district. Old age, obesity, smoking, hypertension and diabetes have the potential to increase the odds of ED up-to 5 times. In view of this, men with diabetes and hypertension should be offered screening services and treatment of ED as an integral component in their management.

  12. Deficiencies of macronutrient intake among HIV-positive breast-feeding women in Dar es Salaam, Tanzania

    PubMed Central

    Kim, Faith; Neke, Nyasule Majura; Hendricks, Kristy; Wamsele, Joyce; Lukmanji, Zohra; Waddell, Richard; Maro, Isaac; Connor, Ruth; Mackenzie, Todd; Matee, Mecky; Bakari, Muhammad; Pallangyo, Kisali; von Reyn, C. Fordham

    2014-01-01

    We compared macronutrient intake, food insecurity and anthropometrics in breast feeding women: 40 HIV-positive women not yet on antiretroviral therapy and 40 HIV-negative women. Calculated deficits at 2 weeks were 517 kcal/d for HIV-positive women vs 87 kcal/d surplus for HIV-negative women (p = 0.01) and 29g protein/d for HIV-positive women vs 16g protein/d for HIV-negative women (p = 0.04). Food insecurity scores were 11.3 for HIV-positive women vs 7.8 for HIV− negative women (p < 0.01). Enhanced dietary education together with macronutrient supplementation may be required to improve health outcomes in HIV-positive women and their infants. PMID:25230293

  13. Evaluation of HIV antigen /antibody combination ELISAs for diagnosis of HIV infection in Dar Es Salaam, Tanzania

    PubMed Central

    Urio, Loveness John; Mohamed, Mohamed Ally; Mghamba, Janneth; Abade, Ahmed; Aboud, Said

    2015-01-01

    Introduction The aim of this study was to evaluate the performance of Enzygnost HIV Integral II antigen/antibody combination ELISAs in order to formulate HIV ELISA testing algorithms for the Ministry of Health and Social Welfare, Tanzania. Methods This was a laboratory-based evaluation of Enzygnost HIV Integral II Antibody/ Antigen, Murex HIV antigen/antibody and Vironostika HIV Uniform II antigen/antibody conducted between October 2011 and May 2012. Results A total of 600 blood samples were included in the evaluation. A total of 209/596 (35.1%) serum samples were confirmed HIV positive. Of these, the prevalence of HIV infection was 2.3% (3/130), 2.3% (3/127), 2.2% (3/139) and 100% (200/200) for VCT clients, ANC attendees, blood donors and CTC patients, respectively. Three hundred and eighty seven (64.9%) were HIV negative samples. Sensitivity was 100% (95% CI; 98.3-100%) for all the three HIV ELISAs. The specificity for the Enzygnost HIV Integral II and Murex was 100% (95% CI; 99.1-100%). The final specificity at repeat testing was 99.5% (95% CI; 98.2-99.9%) for Vironostika. Enzygnost HIV Integral II detected HIV infection seven days since first bleed. Conclusion Initial testing using either Vironostika or Murex HIV antigen/antibody combination ELISA followed by testing of reactive samples on the Enzygnost HIV Integral II gave a sensitivity and specificity of 100% with reduced window period. Combination of two HIV antigen/antibody combination ELISAs can be used as an alternative confirmatory testing strategy for screening of donated blood at the National and Zonal blood transfusion centres and in lab diagnosis of HIV infection. PMID:26113927

  14. Social venues that protect against and promote HIV risk for young men in Dar es Salaam, Tanzania.

    PubMed

    Yamanis, Thespina J; Maman, Suzanne; Mbwambo, Jessie K; Earp, Jo Anne E; Kajula, Lusajo J

    2010-11-01

    Developing effective place-based health interventions requires understanding of the dynamic between place and health. The therapeutic landscape framework explains how place-based social processes and physical geography interact and influence health behavior. This study applied this framework to examine how venues, or social gathering places, influenced HIV risk behavior among young, urban men in Tanzania. Eighty-three public venues where men aged 15-19 met new sexual partners were identified by community informants in one city ward. The majority (86%) of the venues were called 'camps', social gathering places that had formal leaders and members. Observations were conducted at 23 camps and in-depth interviews were conducted with 36 camp members and 10 camp leaders in 15 purposively selected camps. Geographic and social features of camps were examined to understand their contributions to men's behaviors. Camps were characterized by a geographic space claimed by members, a unique name and a democratic system of leadership and governance. Members were mostly men and socialized daily at their camp. They reported strong social bonds and engaging in health-promoting activities such as playing sports and generating income. Members also engaged in HIV risk behaviors, such as meeting new sexual partners and having sex in or around the camp at night. Some members promoted concurrent sexual partnerships with their friends and resisted camp leaders' efforts to change their sexual risk behavior. We conclude that camps are strategic venues for HIV prevention programs for young Tanzanian men. They served as both protective and risk landscapes, illustrating three domains of the therapeutic landscape framework: the built environment; identities of landscape occupants; and sites for collective efficacy. The framework and data suggest HIV intervention components might augment the protective features of the camps, while changing environmental features to reduce risk. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Volume component analysis for classification of LiDAR data

    NASA Astrophysics Data System (ADS)

    Varney, Nina M.; Asari, Vijayan K.

    2015-03-01

    One of the most difficult challenges of working with LiDAR data is the large amount of data points that are produced. Analysing these large data sets is an extremely time consuming process. For this reason, automatic perception of LiDAR scenes is a growing area of research. Currently, most LiDAR feature extraction relies on geometrical features specific to the point cloud of interest. These geometrical features are scene-specific, and often rely on the scale and orientation of the object for classification. This paper proposes a robust method for reduced dimensionality feature extraction of 3D objects using a volume component analysis (VCA) approach.1 This VCA approach is based on principal component analysis (PCA). PCA is a method of reduced feature extraction that computes a covariance matrix from the original input vector. The eigenvectors corresponding to the largest eigenvalues of the covariance matrix are used to describe an image. Block-based PCA is an adapted method for feature extraction in facial images because PCA, when performed in local areas of the image, can extract more significant features than can be extracted when the entire image is considered. The image space is split into several of these blocks, and PCA is computed individually for each block. This VCA proposes that a LiDAR point cloud can be represented as a series of voxels whose values correspond to the point density within that relative location. From this voxelized space, block-based PCA is used to analyze sections of the space where the sections, when combined, will represent features of the entire 3-D object. These features are then used as the input to a support vector machine which is trained to identify four classes of objects, vegetation, vehicles, buildings and barriers with an overall accuracy of 93.8%

  16. Compact Adaptable Mobile LiDAR System Deployment

    NASA Astrophysics Data System (ADS)

    Glennie, C. L.; Brooks, B. A.; Ericksen, T. L.; Hudnut, K. W.; Foster, J. H.; Hauser, D.; Avery, J.

    2012-12-01

    Airborne LiDAR (LIght Detection And Ranging) systems have become a standard mechanism for acquiring dense high-precision topography, making it possible to perform large scale documentation (100's of km2) per day at spatial scales as fine as a few decimeters horizontally and a few centimeters vertically. However, current airborne and terrestrial LiDAR systems suffer from a number of drawbacks. They are expensive, bulky, require significant power supplies, and are often optimized for use in only one type of mobility platform. It would therefore be advantageous to design a lightweight, compact and relatively inexpensive multipurpose LiDAR and imagery system that could be used from a variety of mobility platforms - both terrestrial and airborne. The system should be quick and easy to deploy, and require a minimum amount of existing infrastructure for operational support. With these goals in mind, our research teams have developed a prototype field deployable compact dynamic laser scanning system that is configured for use on a variety of mobility platforms, including backpack wearable, as well as unmanned aerial vehicles (e.g. balloons & helicopters) and small off-road vehicles such as ATV's. The system is small, self-contained, relatively inexpensive, and easy to deploy. The first version of this multipurpose LiDAR system has been successfully tested in both backpack configuration and on a tethered flight attached to a helium balloon. We will present system design and development details, along with field experiences and a detailed accuracy analysis of the acquired point clouds which show that accuracy of 3-5 cm (1 sigma) vertical can be achieved in both backpack and balloon modalities.

  17. Rockfall hazard analysis using LiDAR and spatial modeling

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  18. Road Curb Extraction From Mobile LiDAR Point Clouds

    NASA Astrophysics Data System (ADS)

    Xu, Sheng; Wang, Ruisheng; Zheng, Han

    2017-02-01

    Automatic extraction of road curbs from uneven, unorganized, noisy and massive 3D point clouds is a challenging task. Existing methods often project 3D point clouds onto 2D planes to extract curbs. However, the projection causes loss of 3D information which degrades the performance of the detection. This paper presents a robust, accurate and efficient method to extract road curbs from 3D mobile LiDAR point clouds. Our method consists of two steps: 1) extracting the candidate points of curbs based on the proposed novel energy function and 2) refining the candidate points using the proposed least cost path model. We evaluated our method on a large-scale of residential area (16.7GB, 300 million points) and an urban area (1.07GB, 20 million points) mobile LiDAR point clouds. Results indicate that the proposed method is superior to the state-of-the-art methods in terms of robustness, accuracy and efficiency. The proposed curb extraction method achieved a completeness of 78.62% and a correctness of 83.29%. These experiments demonstrate that the proposed method is a promising solution to extract road curbs from mobile LiDAR point clouds.

  19. LiDAR observation of the flow structure in typhoons

    NASA Astrophysics Data System (ADS)

    Wu, Yu-Ting; Hsuan, Chung-Yao; Lin, Ta-Hui

    2015-04-01

    Taiwan is subject to 3.4 landfall typhoons each year in average, generally occurring in the third quarter of every year (July-September). Understanding of boundary-layer turbulence characteristics of a typhoon is needed to ensure the safety of both onshore and offshore wind turbines used for power generation. In this study, a floating LiDAR (Light Detection and Ranging) was deployed in a harbor to collect data of wind turbulence, atmospheric pressure, and temperature in three typhoon events (Matmo typhoon, Soulik typhoon, Trami typhoon). Data collected from the floating LiDAR and from meteorological stations located at Taipei, Taichung and Kaohsiung are adopted to analyse the wind turbulence characteristics in the three typhoon events. The measurement results show that the maximum 10-min average wind speed measured with the floating LiDAR is up to 24 m/s at a height of 200 m. Compared with other normal days, the turbulence intensity is lower in the three typhoon events where the wind speed has a rapid increase. Changes of wind direction take place clearly as the typhoons cross Taiwan from East to West. Within the crossing intervals, the vertical momentum flux is observed to have a significant pattern with both upward and downward propagating waves which are relevant to the flow structure of the typhoons.

  20. Characterizing Canopy Structure Using Waveform LiDAR

    NASA Astrophysics Data System (ADS)

    Wang, K.; Kumar, P.

    2016-12-01

    The structure of light penetration through the canopy plays an important role in water, carbon, and energy fluxes between the biosphere and the atmosphere. Canopy clumping, a description of foliage distribution, is one of the major aspects of canopy structure that significantly influence light and vegetation interaction. Airborne full-waveform LiDAR data contains large amounts of vegetation structural information, and is a powerful tool for providing detailed foliage distribution information for large areas of vegetation. In this study, we present a method for describing physical canopy clumping structure for individual trees that can resolve fine scale variations in foliage distribution. We first utilize the K-means clustering algorithm to extract structure from the large amounts of vegetation data provided by full-waveform LiDAR. Then we find representative traits for data clusters and use them to classify the clusters into three groups. Based on these traits, we draw conclusions about physical representations of each group, and identify two groups to contain structurally significant clusters. This study demonstrates that large amounts of canopy structural information can be extracted from waveform LiDAR data. The fine resolution canopy clumping structure found by the method described in this work can be used as valuable input for ecological models.

  1. Increasing the Efficiency of LiDAR Based Forest Inventories: A Novel Approach for Integrating Variable Radius Inventory Plots with LiDAR Data.

    NASA Astrophysics Data System (ADS)

    Falkowski, M. J.; Fekety, P.; Silva, C. A.; Hudak, A. T.

    2015-12-01

    LiDAR data are increasingly applied to support forest inventory and assessment across a variety of spatial scales. Typically this is achieved by integrating LiDAR data with forest inventory collected at fixed radius forest inventory plots. A well-designed forest inventory, one that covers the full range of structural and compositional variation across the forest of interest, is costly especially when collecting fixed radius plot data. Variable radius plots offer an alternative inventory protocol that is more efficient in terms of both time and money. However, integrating variable radius plot data with LiDAR data is problematic because the plots have unknown sizes that vary with variation in tree size. This leads to a spatial mismatch between LiDAR metrics (e.g., mean height, canopy cover, density, etc.) and plot data, which ultimately translates into errors in LiDAR derived forest inventory predictions. We propose and evaluate and novel approach for integrating variable radius plot data into a LiDAR based forest inventories in two different forest systems, one in the inland northwest and another in the northern lakes states of the USA. The novel approach calculates LiDAR metrics by weighting the point cloud proportional to return height, mimicking the way in which variable radius plot data weights tree measurements by tree size. This could increase inventory sampling efficiency, allowing for the collection of a greater number of inventory plots, and ultimately improve the performance of LiDAR based inventories.

  2. Immunogenicity and Protective Efficacy of the DAR-901 Booster Vaccine in a Murine Model of Tuberculosis

    PubMed Central

    Lahey, Timothy; Laddy, Dominick; Hill, Krystal; Schaeffer, Jacqueline; Hogg, Alison; Keeble, James; Dagg, Belinda; Ho, Mei Mei; Arbeit, Robert D.; von Reyn, C. Fordham

    2016-01-01

    Background The development of a novel tuberculosis vaccine is a leading global health priority. SRL172, an inactivated, whole-cell mycobacterial vaccine, was safe, immunogenic and reduced the incidence of culture-confirmed tuberculosis in a phase III trial in HIV-infected and BCG immunized adults in Tanzania. Here we describe the immunogenicity and protective efficacy of DAR-901, a booster vaccine against tuberculosis manufactured from the same seed strain using a new scalable method. Methods We evaluated IFN-γ responses by ELISpot and antibody responses by enzyme linked immunosorbent assay in C57BL/6 and BALB/c mice after three doses of DAR-901. In an aerosol challenge model, we evaluated the protective efficacy of the DAR-901 booster in C57BL/6 mice primed with BCG and boosted with two doses of DAR-901 at 4 dosage levels in comparison with homologous BCG boost. Results DAR-901 vaccination elicited IFN-γ responses to mycobacterial antigen preparations derived from both DAR-901 and Mycobacterium tuberculosis. DAR-901 immunization enhanced antibody responses to DAR-901 but not Mycobacterium tuberculosis lysate or purified protein derivative. Among animals primed with BCG, boosting with DAR-901 at 1 mg provided greater protection against aerosol challenge than a homologous BCG boost (lungs P = 0.036, spleen P = 0.028). Conclusions DAR-901 induces cellular and humoral immunity and boosts protection from M. tuberculosis compared to a homologous BCG boost. PMID:27997597

  3. Detecting and connecting agricultural ditches using LiDAR data

    NASA Astrophysics Data System (ADS)

    Roelens, Jennifer; Dondeyne, Stefaan; Van Orshoven, Jos; Diels, Jan

    2017-04-01

    High-resolution hydrological data are essential for spatially-targeted water resource management decisions and future modelling efforts. For Flanders, small water courses like agricultural ditches and their connection to the river network are incomplete in the official digital atlas. High-resolution LiDAR data offer the prospect for automated detection of ditches, but there is no established method or software to do so nor to predict how these are connected to each other and the wider hydrographic network. An aerial LiDAR database encompassing at least 16 points per square meter linked with simultaneously collected digital RGB aerial images, is available for Flanders. The potential of detecting agricultural ditches and their connectivity based on point LiDAR data was investigated in a 1.9 km2 study area located in the alluvial valley of the river Demer. The area consists of agricultural parcels and woodland with a ditch network of approximately 17 km. The entire network of open ditches, and the location of culverts were mapped during a field survey to test the effectiveness of the proposed method. In the first step of the proposed method, the LiDAR point data were transformed into a raster DEM with a 1-m resolution to reduce the amount of data to be analyzed. This was done by interpolating the bare earth points using the nearest neighborhood method. In a next step, a morphological approach was used for detecting a preliminary network as traditional flow algorithms are not suitable for detecting small water courses in low-lying areas. This resulted in a preliminary classified raster image with ditch and non-ditch cells. After eliminating small details that are the result of background noise, the resulting classified raster image was vectorized to match the format of the digital watercourse network. As the vectorisation does not always adequately represent the shape of linear features, the results did not meet the high-quality cartographic needs. The spatial accuracy

  4. ES Review: Selections from 2007

    ERIC Educational Resources Information Center

    Smiles, Robin, Ed.

    2008-01-01

    The second edition of the "ES Review" brings together, in one setting, abridged versions of research reports, outside articles and op-eds, book reviews, and other Education Sector publications. The 2007 edition features: (1) K-12 Accountability (Laboratories of Reform: Virtual High Schools and Innovation in Public Education (Bill…

  5. ES Review: Selections from 2007

    ERIC Educational Resources Information Center

    Smiles, Robin, Ed.

    2008-01-01

    The second edition of the "ES Review" brings together, in one setting, abridged versions of research reports, outside articles and op-eds, book reviews, and other Education Sector publications. The 2007 edition features: (1) K-12 Accountability (Laboratories of Reform: Virtual High Schools and Innovation in Public Education (Bill…

  6. Microbial contamination of nonsterile pharmaceuticals in public hospital settings

    PubMed Central

    Mugoyela, Veronica; Mwambete, Kennedy D

    2010-01-01

    Purpose Contamination of pharmaceuticals with microorganisms irrespective whether they are harmful or nonpathogenic can bring about changes in physicochemical characteristics of the medicines. Although sterility is not a requirement in official compendia for nonsterile pharmaceuticals, bioburdens need to be within acceptable limits. Therefore, this study investigated microbial contamination of 10 nonsterile pharmaceuticals frequently delivered to outpatients by identifying and quantifying microbial contaminants and susceptibility pattern testing on the microbes isolated. Methods The study was carried out at Amana Municipal Hospital in Dar es Salaam, Tanzania. The protocol for the study involved structured selection of representative tablets, syrups, and capsules from the hospital’s outpatient pharmacy. Constitutive microorganisms were elaborated and enumerated using standard microbiologic procedures. Results Results showed that 50% of all tested products were heavily contaminated, and the predominant contaminants comprised Klebsiella, Bacillus, and Candida species. Furthermore, the results showed that the isolated Bacillus and Klebsiella species were resistant to Augmentin ® and cloxacillin. The differences in means for cfu/mL and zones of inhibition among the microorganisms isolated were considered significant at P < 0.05. Conclusion The nonsterile pharmaceuticals were presumably microbiologically contaminated due to poor handling during dispensing, repackaging, and/or nonadherence to good manufacturing practice. Therefore, training and educating the dispensers, as well as patients, on the proper handling and use of medicines cannot be overemphasized, because these are key aspects in controlling cross-contamination of medicines. PMID:20957135

  7. Segmenting tree crowns from terrestrial and mobile LiDAR data by exploring ecological theories

    NASA Astrophysics Data System (ADS)

    Tao, Shengli; Wu, Fangfang; Guo, Qinghua; Wang, Yongcai; Li, Wenkai; Xue, Baolin; Hu, Xueyang; Li, Peng; Tian, Di; Li, Chao; Yao, Hui; Li, Yumei; Xu, Guangcai; Fang, Jingyun

    2015-12-01

    The rapid development of light detection and ranging (LiDAR) techniques is advancing ecological and forest research. During the last decade, numerous single tree segmentation techniques have been developed using airborne LiDAR data. However, accurate crown segmentation using terrestrial or mobile LiDAR data, which is an essential prerequisite for extracting branch level forest characteristics, is still challenging mainly because of the difficulties posed by tree crown intersection and irregular crown shape. In the current work, we developed a comparative shortest-path algorithm (CSP) for segmenting tree crowns scanned using terrestrial (T)-LiDAR and mobile LiDAR. The algorithm consists of two steps, namely trunk detection and subsequent crown segmentation, with the latter inspired by the well-proved metabolic ecology theory and the ecological fact that vascular plants tend to minimize the transferring distance to the root. We tested the algorithm on mobile-LiDAR-scanned roadside trees and T-LiDAR-scanned broadleaved and coniferous forests in China. Point-level quantitative assessments of the segmentation results showed that for mobile-LiDAR-scanned roadside trees, all the points were classified to their corresponding trees correctly, and for T-LiDAR-scanned broadleaved and coniferous forests, kappa coefficients ranging from 0.83 to 0.93 were obtained. We believe that our algorithm will make a contribution to solving the problem of crown segmentation in T-LiDAR scanned-forests, and might be of interest to researchers in LiDAR data processing and to forest ecologists. In addition, our research highlights the advantages of using ecological theories as guidelines for processing LiDAR data.

  8. Development of a regional LiDAR field plot strategy for Oregon and Washington

    Treesearch

    Arvind Bhuta; Leah. Rathbun

    2015-01-01

    The National Forest System (NFS) Pacific Northwest Region (R6) has been flying LiDAR on a per project basis. Additional field data was also collected in situ to many of these LiDAR projects to aid in the development of predictive models and estimate values which are unattainable through LiDAR data alone (e.g. species composition, tree volume, and downed woody material...

  9. Can we estimate precipitation rate during snowfall using a scanning terrestrial LiDAR?

    NASA Astrophysics Data System (ADS)

    LeWinter, A. L.; Bair, E. H.; Davis, R. E.; Finnegan, D. C.; Gutmann, E. D.; Dozier, J.

    2012-12-01

    Accurate snowfall measurements in windy areas have proven difficult. To examine a new approach, we have installed an automatic scanning terrestrial LiDAR at Mammoth Mountain, CA. With this LiDAR, we have demonstrated effective snow depth mapping over a small study area of several hundred m2. The LiDAR also produces dense point clouds by detecting falling and blowing hydrometeors during storms. Daily counts of airborne detections from the LiDAR show excellent agreement with automated and manual snow water equivalent measurements, suggesting that LiDAR observations have the potential to directly estimate precipitation rate. Thus, we suggest LiDAR scanners offer advantages over precipitation radars, which could lead to more accurate precipitation rate estimates. For instance, uncertainties in mass-diameter and mass-fall speed relationships used in precipitation radar, combined with low reflectivity of snow in the microwave spectrum, produce errors of up to 3X in snowfall rates measured by radar. Since snow has more backscatter in the near-infrared wavelengths used by LiDAR compared to the wavelengths used by radar, and the LiDAR detects individual hydrometeors, our approach has more potential for directly estimating precipitation rate. A key uncertainty is hydrometeor mass. At our study site, we have also installed a Multi Angle Snowflake Camera (MASC) to measure size, fallspeed, and mass of individual hydrometeors. By combining simultaneous MASC and LiDAR measurements, we can estimate precipitation density and rate.

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

    NASA Astrophysics Data System (ADS)

    Zhi, Xiaodong

    2008-10-01

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

  11. Weibull approximation of LiDAR waveforms for estimating the beam attenuation coefficient.

    PubMed

    Montes-Hugo, Martin A; Vuorenkoski, Anni K; Dalgleish, Fraser R; Ouyang, Bing

    2016-10-03

    Tank experiments were performed at different water turbidities to examine relationships between the beam attenuation coefficient (c) and Weibull shape parameters derived from LiDAR waveforms measured with the Fine Structure Underwater LiDAR (FSUIL). Optical inversions were made at 532 nm, within a c range of 0.045-1.52 m-1, and based on a LiDAR system having two field-of-view (15 and 75.7 mrad) and two linear polarizations. Consistently, the Weibull scale parameter or P2 showed the strongest covariation with c and was a more accurate proxy with respect to the LiDAR attenuation coefficient.

  12. LiDAR and Image Point Cloud Comparison

    DTIC Science & Technology

    2014-09-01

    2.5D 2.5-dimensional 3D 3-dimensional CC CloudCompare DEM digital elevation model DSM digital surface model ETS electronic total station GCP...The product website also indicates it can accept inputs of JPEG, PNG, and BMP. Quick Terrain Modeler (QTM) and CloudCompare (CC) are visualization...Topographic Map (Left, after “Digital Wisdom,” 2014), Nadir View (Bottom) D. COMPARISON WITH LIDAR Turning to the CloudCompare software, the LiDAR

  13. The Daily Activity Report (DAR) a Novel Measure of Functional Outcome for Serious Mental Illness

    PubMed Central

    Velligan, Dawn I.; Mintz, Jim; Sierra, Cynthia; Martin, Mona L.; Fredrick, Megan; Maglinte, Gregory A.; Corey-Lisle, Patricia K.

    2016-01-01

    The assessment of real-world functional outcomes in clinical trials for medications targeting negative symptoms and cognitive impairment is extremely important. We tested the psychometric properties of the Daily Activity Report (DAR), a novel assessment of productive daily activity. We administered the DAR and additional assessments of functional outcome, functional capacity, cognition and symptomatology to 50 individuals with schizophrenia at 2 time points, 1 month apart and to 25 healthy controls. The DAR records a person’s daily activity for 7 consecutive days based upon phone calls made 3 times a day. A total score and scores in 3 domains; instrumental activities (ie, independent living), social and work or school related activities are generated for the DAR. Inter-item consistency was high 0.89–0.94 for each domain and 0.88 overall. Test–retest reliability across 1 month for the total DAR score was 0.67, P < .0001. The total DAR score as well as scores for social activity and nondomestic work/school differed significantly between control and patient participants (P < .0001). DAR domain scores were associated with negative symptoms and functional outcomes, but the primary score related to these measures was the work/school dimension of the DAR. DAR scores were only weakly and nonsignificantly related to positive symptoms. This study provides preliminary support for the reliability and validity of the DAR using interviewer administration. The development of a patient reported version of the DAR using smart phone technology with automatic scoring is the next step. PMID:26712856

  14. Identifying Colluvial Slopes by Airborne LiDAR Analysis

    NASA Astrophysics Data System (ADS)

    Kasai, M.; Marutani, T.; Yoshida, H.

    2015-12-01

    Colluvial slopes are one of major sources of landslides. Identifying the locations of the slopes will help reduce the risk of disasters, by avoiding building infrastructure and properties nearby, or if they are already there, by applying appropriate counter measures before it suddenly moves. In this study, airborne LiDAR data was analyzed to find their geomorphic characteristics to use for extracting their locations. The study site was set in the suburb of Sapporo City, Hokkaido in Japan. The area is underlain by Andesite and Tuff and prone to landslides. Slope angle and surface roughness were calculated from 5 m resolution DEM. These filters were chosen because colluvial materials deposit at around the angle of repose and accumulation of loose materials was considered to form a peculiar surface texture differentiable from other slope types. Field survey conducted together suggested that colluvial slopes could be identified by the filters with a probability of 80 percent. Repeat LiDAR monitoring of the site by an unmanned helicopter indicated that those slopes detected as colluviums appeared to be moving at a slow rate. In comparison with a similar study from the crushed zone in Japan, the range of slope angle indicative of colluviums agreed with the Sapporo site, while the texture was rougher due to larger debris composing the slopes.

  15. Performance testing of LiDAR exploitation software

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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.

  16. Applying the Moment Distance Framework to LiDAR Waveforms

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  17. Peripheral Sensory Neuropathy and associated factors among adult diabetes mellitus patients in Bahr Dar, Ethiopia.

    PubMed

    Jember, Gashaw; Melsew, Yayehirad Alemu; Fisseha, Berihu; Sany, Kedir; Gelaw, Asmare Yitayeh; Janakiraman, Balamurugan

    2017-01-01

    Diabetic sensory neuropathy is a common form of microvascular complication among diabetic patients. The swiftly growing population of people living with diabetes in Ethiopia and lack of elaborated scientific data on peripheral sensory neuropathy among diabetic population in Ethiopia prompted this work. This study was set out to assess the enormity and associated factors of peripheral sensory neuropathy among diabetes patients attending chronic illness clinic of Felege Hiwot Regional Referral Hospital, Bahr Dar, Northwest Ethiopia. An institution based cross-sectional study was conducted at Felege Hiwot Referral Hospital chronic illness clinic using Michigan neuropathy screening instrument tool for diabetic peripheral sensory neuropathy on 408 diabetic patients during 2016. Data were collected using interview, patient record review, anthropometric measurements and physical examination. Both bivariate and multivariate binary logistic regression was employed to identify factors associated with peripheral sensory neuropathy. Odds ratios with their 95% CI and P value less than 0.05 used to determine statistically significant associations. A total of 368 patients were included with the mean age of 49 ± 14.3 years. The overall prevalence of Peripheral Sensory Neuropathy was found to be 52.2%. The major associated factors identified by multivariate analysis were age >50 years: AOR: 3.0 CI [1.11, 7.89]; overweight and obese: AOR: 7.3 CI [3.57, 14.99]; duration of DM: AOR: 3.4 CI [1.75, 6.60]; not involved in physical exercise: AOR: 4.8 CI [1.90, 7.89]; male gender: AOR: 2.4 CI [1.18, 5.05]. Almost half of the diabetic patients who attended Felege Hiwot regional referral hospital during study period were found to present with peripheral sensory neuropathy. Socio-demographic and bio characteristics like patients age, Body Mass Index, level of physical activity and marital status were significantly associated with diabetic peripheral sensory neuropathy.

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

    USGS Publications Warehouse

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

    2015-01-01

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

  19. Layer stacking: A novel algorithm for individual forest tree segmentation from LiDAR point clouds

    Treesearch

    Elias Ayrey; Shawn Fraver; John A. Kershaw; Laura S. Kenefic; Daniel Hayes; Aaron R. Weiskittel; Brian E. Roth

    2017-01-01

    As light detection and ranging (LiDAR) technology advances, it has become common for datasets to be acquired at a point density high enough to capture structural information from individual trees. To process these data, an automatic method of isolating individual trees from a LiDAR point cloud is required. Traditional methods for segmenting trees attempt to isolate...

  20. Utility of LiDAR for large area forest inventory applications

    Treesearch

    Nicholas S. Skowronski; Andrew J. Lister

    2012-01-01

    Multi-resource inventory data are used in conjunction with Light Detection and Ranging (LiDAR) data from the Pennsylvania Department of Natural Resource's PAMAP Program to assess the utility of extensive LiDAR acquisitions for large area forest assessments. Background, justification, and initial study designs are presented. The proposed study will involve three...

  1. Quantifying aboveground forest carbon pools and fluxes from repeat LiDAR surveys

    Treesearch

    Andrew T. Hudak; Eva K. Strand; Lee A. Vierling; John C. Byrne; Jan U. H. Eitel; Sebastian Martinuzzi; Michael J. Falkowski

    2012-01-01

    Sound forest policy and management decisions to mitigate rising atmospheric CO2 depend upon accurate methodologies to quantify forest carbon pools and fluxes over large tracts of land. LiDAR remote sensing is a rapidly evolving technology for quantifying aboveground biomass and thereby carbon pools; however, little work has evaluated the efficacy of repeat LiDAR...

  2. Nacelle LiDAR online wind field reconstruction applied to feedforward pitch control

    NASA Astrophysics Data System (ADS)

    GUILLEMIN, F.; DOMENICO, D. DI; NGUYEN, N.; SABIRON, G.; BOQUET, M.; GIRARD, N.; COUPIAC, O.

    2016-09-01

    This paper presents innovative filtering and reconstruction techniques of nacelle LiDAR data, and exploitation of obtained wind anticipation capabilities for wind turbine control strategy. The implemented algorithms are applied under industrial constraints, on a MAIA EOLIS wind turbine, equipped with a LEOSPHERE 5-beams pulsed LiDAR, during experimental campaigns of SMARTEOLE collaborative project.

  3. LiDAR, a great tool for archaeologists, but how do you interpret it?

    NASA Astrophysics Data System (ADS)

    Leisz, S.; Fisher, C.

    2013-05-01

    This paper focuses on the use of airborne LiDAR to identify archaeological features below forest canopies in Mesoamerica and the challenges faced in interpreting the data. To illustrate the issues involved in interpreting LiDAR point clouds and derived data sets for archaeological purposes, the case study of the use of airborne LiDAR at the archaeological site of Angamuco in West-Central Mexico is discussed. The case study details the reason LiDAR was collected, the challenges in interpreting it, methods and techniques that the authors are investigating to improve the interpretation of the LiDAR, and discoveries that have so far been made through the use of LiDAR. A key point discussed is the need to analyze the LiDAR point cloud in conjunction with products developed from the point cloud. Analyzing the various data sets jointly allows the user to better identify archaeological features of interest. New ways of utilizing hillshades of DEMs, such as creating 360 degree hillshades of the derived DEMs, are also presented. Last the authors discuss their experience in using object-based classification of the products derived from the LiDAR point cloud as an example of one possible technique for automating the delineation and classification of archaeological features.

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

    Treesearch

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

    2013-01-01

    Incorporating vertical vegetation structure into models of animal distributions can improve understanding of the patterns and processes governing habitat selection. LiDAR can provide such structural information, but these data are typically collected via aircraft and thus are limited in spatial extent. Our objective was to explore the utility of satellite-based LiDAR...

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

    ERIC Educational Resources Information Center

    Espinoza, Delia; Lopez, Santiago, III

    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…

  6. Comparisons between field- and LiDAR-based measures of stand structrual complexity

    Treesearch

    Van R. Kane; Robert J. McGaughey; Jonathan D. Bakker; Rolf F. Gersonde; James A. Lutz; Jerry F. Franklin

    2010-01-01

    Forest structure, as measured by the physical arrangement of trees and their crowns, is a fundamental attribute of forest ecosystems that changes as forests progress through successional stages. We examined whether LiDAR data could be used to directly assess the successional stage of forests by determining the degree to which the LiDAR data would show the same relative...

  7. Status and prospects for LiDAR remote sensing of forested ecosystems

    Treesearch

    M. A. Wulder; N. C. Coops; A. T. Hudak; F. Morsdorf; R. Nelson; G. Newnham; M. Vastaranta

    2013-01-01

    The science associated with the use of airborne and satellite Light Detection and Ranging (LiDAR) to remotely sense forest structure has rapidly progressed over the past decade. LiDAR has evolved from being a poorly understood, potentially useful tool to an operational technology in a little over a decade, and these instruments have become a major success story in...

  8. Using LiDAR surveys to document floods: A case study of the 2008 Iowa flood

    NASA Astrophysics Data System (ADS)

    Chen, Bo; Krajewski, Witold F.; Goska, Radek; Young, Nathan

    2017-10-01

    Can we use Light Detection and Ranging (LiDAR), an emergent remote sensing technology with wide applications, to document floods with high accuracy? To explore the feasibility of this application, we propose a method to extract distributed inundation depths from a LiDAR survey conducted during flooding. This method consists of three steps: (1) collecting LiDAR data during flooding; (2) classifying the LiDAR observational points as flooded water surface points and non-flooded points, and generating a floodwater surface elevation model; and (3) subtracting the bare earth Digital Terrain Model (DTM) from the flood surface elevation model to obtain a flood depth map. We applied this method to the 2008 Iowa flood in the United States and evaluated the results using the high-water mark measurements, flood extent extracted from SPOT (Small Programmable Object Technology) imagery, and the near-simultaneously acquired aerial photography. The root mean squared error of the LiDAR-derived floodwater surface profile to high-water marks was 30 cm, the consistency between the two flooded areas derived from LiDAR and SPOT imagery was 72% (81% if suspicious isolated ponds in the SPOT-derived extent were removed), and LiDAR-derived flood extent had a horizontal resolution of ∼3 m. This work demonstrates that LiDAR technology has the potential to provide calibration and validation reference data with appreciable accuracy for improved flood inundation modeling.

  9. Wetland inundation mapping and change monitoring using landsat and airborne LiDAR data

    USDA-ARS?s Scientific Manuscript database

    This paper presents a new approach for mapping wetland inundation change using Landsat and LiDAR intensity data. In this approach, LiDAR data were used to derive highly accurate reference subpixel inundation percentage (SIP) maps at the 30-m resolution. The reference SIP maps were then used to est...

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    In October 2012, aerial green LiDAR data were collected in the Snake River (within Idaho and Oregon) to test this emerging technology in a large river with poor water clarity. Six study areas (total of 30 river miles spread out over 250 river miles) were chosen to represent a variety of depths, channel types, and surface conditions to test the accuracy, depth penetration, data density of aerial green LiDAR. These characteristics along with cost and speed of acquisition were compared to other bathymetric survey techniques including rod surveys (total station and RTK-GPS), single-beam sonar, and multibeam echosounder (MBES). The green LiDAR system typically measured returns from the riverbed through 1-2 meters of water, which was less than one Secchi depth. However, in areas with steep banks or aquatic macrophytes, LiDAR returns from the riverbed were less frequent or non-existent. In areas of good return density, depths measured from green LiDAR data corresponded well with previously collected data sets from traditional bathymetric survey techniques. In such areas, the green LiDAR point density was much higher than both rod and single beam sonar surveys, yet lower than MBES. The green LiDAR survey was also collected more efficiently than all other methods. In the Snake River, green LiDAR does not provide a method to map the entire riverbed as it only receives bottom returns in shallow water, typically at the channel margins. However, green LiDAR does provide survey data that is an excellent complement to MBES, which is more effective at surveying the deeper portions of the channel. In some cases, the green LiDAR was able to provide data in areas that the MBES could not, often due to issues with navigating the survey boat in shallow water. Even where both MBES and green LiDAR mapped the river bottom, green LiDAR often provides more accurate data through a better angle of incidence and less shadowing than the MBES survey. For one MBES survey in 2013, the green LiDAR

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

    PubMed

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

    2012-10-30

    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.

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

    PubMed Central

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

    2012-01-01

    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

  13. Using a multiwavelength LiDAR for improved remote sensing of natural waters.

    PubMed

    Gray, Deric J; Anderson, John; Nelson, Jean; Edwards, Jarrod

    2015-11-01

    This paper describes research to characterize the benefits of a multiwavelength oceanographic LiDAR for various water types. Field measurements were conducted to establish endmembers representative of both typical and extremely challenging natural conditions. Laboratory tests were performed using a prototype multiwavelength LiDAR in water tanks with optical conditions simulating both sediment-laden and biologically rich water types. LiDAR models were used to simulate the LiDAR signal from both field and laboratory experiments. Our measurements and models show that using a laser wavelength of 470-490 nm in the open ocean leads to an improvement factor of 1.50-1.75 compared to a 532 nm system. In more turbid areas using a laser wavelength of 560-580 nm leads to an improvement factor of 1.25. We conclude by demonstrating how using multiple LiDAR wavelengths can help detect and characterize constituents in the water column.

  14. Modelling Sensor and Target effects on LiDAR Waveforms

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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

  15. A General-purpose Framework for Parallel Processing of Large-scale LiDAR Data

    NASA Astrophysics Data System (ADS)

    Li, Z.; Hodgson, M.; Li, W.

    2016-12-01

    Light detection and ranging (LiDAR) technologies have proven efficiency to quickly obtain very detailed Earth surface data for a large spatial extent. Such data is important for scientific discoveries such as Earth and ecological sciences and natural disasters and environmental applications. However, handling LiDAR data poses grand geoprocessing challenges due to data intensity and computational intensity. Previous studies received notable success on parallel processing of LiDAR data to these challenges. However, these studies either relied on high performance computers and specialized hardware (GPUs) or focused mostly on finding customized solutions for some specific algorithms. We developed a general-purpose scalable framework coupled with sophisticated data decomposition and parallelization strategy to efficiently handle big LiDAR data. Specifically, 1) a tile-based spatial index is proposed to manage big LiDAR data in the scalable and fault-tolerable Hadoop distributed file system, 2) two spatial decomposition techniques are developed to enable efficient parallelization of different types of LiDAR processing tasks, and 3) by coupling existing LiDAR processing tools with Hadoop, this framework is able to conduct a variety of LiDAR data processing tasks in parallel in a highly scalable distributed computing environment. The performance and scalability of the framework is evaluated with a series of experiments conducted on a real LiDAR dataset using a proof-of-concept prototype system. The results show that the proposed framework 1) is able to handle massive LiDAR data more efficiently than standalone tools; and 2) provides almost linear scalability in terms of either increased workload (data volume) or increased computing nodes with both spatial decomposition strategies. We believe that the proposed framework provides valuable references on developing a collaborative cyberinfrastructure for processing big earth science data in a highly scalable environment.

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

    NASA Astrophysics Data System (ADS)

    Korpela, Ilkka; Hovi, Aarne; Korhonen, Lauri

    2013-09-01

    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.

  17. Full waveform hyperspectral LiDAR for terrestrial laser scanning.

    PubMed

    Hakala, Teemu; Suomalainen, Juha; Kaasalainen, Sanna; Chen, Yuwei

    2012-03-26

    We present the design of a full waveform hyperspectral light detection and ranging (LiDAR) and the first demonstrations of its applications in remote sensing. The novel instrument produces a 3D point cloud with spectral backscattered reflectance data. This concept has a significant impact on remote sensing and other fields where target 3D detection and identification is crucial, such as civil engineering, cultural heritage, material processing, or geomorphological studies. As both the geometry and spectral information on the target are available from a single measurement, this technology will extend the scope of imaging spectroscopy into spectral 3D sensing. To demonstrate the potential of the instrument in the remote sensing of vegetation, 3D point clouds with backscattered reflectance and spectral indices are presented for a specimen of Norway spruce.

  18. Dynamic LiDAR-NDVI classification of fluvial landscape units

    NASA Astrophysics Data System (ADS)

    Ramírez-Núñez, Carolina; Parrot, Jean-François

    2015-04-01

    The lower basin of the Coatzacoalcos River is a wide floodplain in which, during the wet season, local and major flooding are distinguished. Both types of floods, intermittent and regional, are important in terms of resources; the regional flood sediments enrich the soils of the plains and intermittent floods allow obtaining aquatic resources for subsistence during the heatwave. In the floodplain different abandoned meanders and intermittent streams are quickly colonized by aquatic vegetation. However, from the 1990s, the Coatzacoalcos River floodplain has important topographic changes due to mining, road and bridges construction; erosion and sedimentation requires continuous parcel boundaries along with the increasing demand of channel reparation, embankments, levees and bridges associated to tributaries. NDVI data, LiDAR point cloud and various types of flood simulations taking into account the DTM are used to classify the dynamic landscape units. These units are associated to floods in relation with water resources, agriculture and livestock. In the study area, the first returns of the point cloud allow extracting vegetation strata. The last returns correspond to the bare earth surface, especially in this area with few human settlements. The surface that is not covered by trees or by aquatic vegetation, correspond to crops, pastures and bare soils. The classification is obtained by using the NDVI index coupled with vegetation strata and water bodies. The result shows that 47.96% of the area does not present active vegetation and it includes 31.53% of bare soils. Concerning the active vegetation, pastures, bushes and trees represent respectively 25.59%, 11.14% and 13.25%. The remaining 1.25% is distributed between water bodies with aquatic vegetation, trees and shrubs. Dynamic landscape units' classification represents a tool for monitoring water resources in a fluvial plain. This approach can be also applied to forest management, environmental services and

  19. Development of forest growth inputs from LiDAR

    NASA Astrophysics Data System (ADS)

    Tinkham, W. T.; Falkowski, M. J.; Smith, A. M.; Hudak, A. T.; Crookston, N. L.

    2012-12-01

    Investigating the potential impacts of climate change on forest dynamics is a critical area of science, especially given the vast amount of ecosystems services forests provide. Critical understanding of these impacts is lacking, most visibly, at regional to local scales where on-the-ground management activities are implemented. To plan ahead and mitigate the impacts of climate change, land managers need of decision support tools that can be used to evaluate the future impacts of climate change on forest conditions, so that sustainable management practices that enhance ecosystem resilience can be defensibly developed, evaluated, and implemented. However, to be applicable to both regional forest planning and local operational forest management decisions, approaches must be capable of simulating forest dynamics across large spatial extents (required for regional planning) while maintaining a high-level of spatial detail (required for operational management). Numerous studies have demonstrated that LiDAR remote sensing is an effective tool for accurately measuring forest structure at landscape scales, providing information with a level of detail appropriate for operational forest management. This study attempts to develop a system to spatially parameterize and supply critical initial conditions for Climate-FVS and other forest growth models across major ecoregions (in terms of forest structure and composition) in the Pacific Northwest (PNW) of the US, via an integration of airborne LiDAR, spatial measures of productivity, and local climate. Integrating these inputs into forest growth models would be a big step towards planning and optimizing landscape level alterations to forest structure and productivity from climate change.

  20. Advances in animal ecology from 3D ecosystem mapping with LiDAR

    NASA Astrophysics Data System (ADS)

    Davies, A.; Asner, G. P.

    2015-12-01

    The advent and recent advances of Light Detection and Ranging (LiDAR) have enabled accurate measurement of 3D ecosystem structure. Although the use of LiDAR data is widespread in vegetation science, it has only recently (< 14 years) been applied to animal ecology. Despite such recent application, LiDAR has enabled new insights in the field and revealed the fundamental importance of 3D ecosystem structure for animals. We reviewed the studies to date that have used LiDAR in animal ecology, synthesising the insights gained. Structural heterogeneity is most conducive to increased animal richness and abundance, and increased complexity of vertical vegetation structure is more positively influential than traditionally measured canopy cover, which produces mixed results. However, different taxonomic groups interact with a variety of 3D canopy traits and some groups with 3D topography. LiDAR technology can be applied to animal ecology studies in a wide variety of environments to answer an impressive array of questions. Drawing on case studies from vastly different groups, termites and lions, we further demonstrate the applicability of LiDAR and highlight new understanding, ranging from habitat preference to predator-prey interactions, that would not have been possible from studies restricted to field based methods. We conclude with discussion of how future studies will benefit by using LiDAR to consider 3D habitat effects in a wider variety of ecosystems and with more taxa to develop a better understanding of animal dynamics.

  1. DArT Markers Effectively Target Gene Space in the Rye Genome

    PubMed Central

    Gawroński, Piotr; Pawełkowicz, Magdalena; Tofil, Katarzyna; Uszyński, Grzegorz; Sharifova, Saida; Ahluwalia, Shivaksh; Tyrka, Mirosław; Wędzony, Maria; Kilian, Andrzej; Bolibok-Brągoszewska, Hanna

    2016-01-01

    Large genome size and complexity hamper considerably the genomics research in relevant species. Rye (Secale cereale L.) has one of the largest genomes among cereal crops and repetitive sequences account for over 90% of its length. Diversity Arrays Technology is a high-throughput genotyping method, in which a preferential sampling of gene-rich regions is achieved through the use of methylation sensitive restriction enzymes. We obtained sequences of 6,177 rye DArT markers and following a redundancy analysis assembled them into 3,737 non-redundant sequences, which were then used in homology searches against five Pooideae sequence sets. In total 515 DArT sequences could be incorporated into publicly available rye genome zippers providing a starting point for the integration of DArT- and transcript-based genomics resources in rye. Using Blast2Go pipeline we attributed putative gene functions to 1101 (29.4%) of the non-redundant DArT marker sequences, including 132 sequences with putative disease resistance-related functions, which were found to be preferentially located in the 4RL and 6RL chromosomes. Comparative analysis based on the DArT sequences revealed obvious inconsistencies between two recently published high density consensus maps of rye. Furthermore we demonstrated that DArT marker sequences can be a source of SSR polymorphisms. Obtained data demonstrate that DArT markers effectively target gene space in the large, complex, and repetitive rye genome. Through the annotation of putative gene functions and the alignment of DArT sequences relative to reference genomes we obtained information, that will complement the results of the studies, where DArT genotyping was deployed, by simplifying the gene ontology and microcolinearity based identification of candidate genes. PMID:27833625

  2. Automatic registration of UAV-borne sequent images and LiDAR data

    NASA Astrophysics Data System (ADS)

    Yang, Bisheng; Chen, Chi

    2015-03-01

    Use of direct geo-referencing data leads to registration failure between sequent images and LiDAR data captured by mini-UAV platforms because of low-cost sensors. This paper therefore proposes a novel automatic registration method for sequent images and LiDAR data captured by mini-UAVs. First, the proposed method extracts building outlines from LiDAR data and images and estimates the exterior orientation parameters (EoPs) of the images with building objects in the LiDAR data coordinate framework based on corresponding corner points derived indirectly by using linear features. Second, the EoPs of the sequent images in the image coordinate framework are recovered using a structure from motion (SfM) technique, and the transformation matrices between the LiDAR coordinate and image coordinate frameworks are calculated using corresponding EoPs, resulting in a coarse registration between the images and the LiDAR data. Finally, 3D points are generated from sequent images by multi-view stereo (MVS) algorithms. Then the EoPs of the sequent images are further refined by registering the LiDAR data and the 3D points using an iterative closest-point (ICP) algorithm with the initial results from coarse registration, resulting in a fine registration between sequent images and LiDAR data. Experiments were performed to check the validity and effectiveness of the proposed method. The results show that the proposed method achieves high-precision robust co-registration of sequent images and LiDAR data captured by mini-UAVs.

  3. 4D Near Real-Time Environmental Monitoring Using Highly Temporal LiDAR

    NASA Astrophysics Data System (ADS)

    Höfle, Bernhard; Canli, Ekrem; Schmitz, Evelyn; Crommelinck, Sophie; Hoffmeister, Dirk; Glade, Thomas

    2016-04-01

    The last decade has witnessed extensive applications of 3D environmental monitoring with the LiDAR technology, also referred to as laser scanning. Although several automatic methods were developed to extract environmental parameters from LiDAR point clouds, only little research has focused on highly multitemporal near real-time LiDAR (4D-LiDAR) for environmental monitoring. Large potential of applying 4D-LiDAR is given for landscape objects with high and varying rates of change (e.g. plant growth) and also for phenomena with sudden unpredictable changes (e.g. geomorphological processes). In this presentation we will report on the most recent findings of the research projects 4DEMON (http://uni-heidelberg.de/4demon) and NoeSLIDE (https://geomorph.univie.ac.at/forschung/projekte/aktuell/noeslide/). The method development in both projects is based on two real-world use cases: i) Surface parameter derivation of agricultural crops (e.g. crop height) and ii) change detection of landslides. Both projects exploit the "full history" contained in the LiDAR point cloud time series. One crucial initial step of 4D-LiDAR analysis is the co-registration over time, 3D-georeferencing and time-dependent quality assessment of the LiDAR point cloud time series. Due to the high amount of datasets (e.g. one full LiDAR scan per day), the procedure needs to be performed fully automatically. Furthermore, the online near real-time 4D monitoring system requires to set triggers that can detect removal or moving of tie reflectors (used for co-registration) or the scanner itself. This guarantees long-term data acquisition with high quality. We will present results from a georeferencing experiment for 4D-LiDAR monitoring, which performs benchmarking of co-registration, 3D-georeferencing and also fully automatic detection of events (e.g. removal/moving of reflectors or scanner). Secondly, we will show our empirical findings of an ongoing permanent LiDAR observation of a landslide (Gresten

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  5. Frontiers in Using LiDAR to Analyze Urban Landscape Heterogeneity

    NASA Astrophysics Data System (ADS)

    Singh, Kunwar Krishna Veer

    Light Detection and Ranging (LiDAR) technology has facilitated extraordinary advances in our ability to remotely sense precise details of both built and natural environments. The inherent complexity of urban landscapes and the massive data volumes produced by LiDAR require unique methodological considerations for big data remote sensing over large metropolitan regions. The heterogeneous landscapes of the rapidly urbanizing Charlotte Metropolitan Region of North Carolina provided an ideal testing ground for developing methods of analysis for urban ecosystems over large regional extents, including: (1) fusion of LiDAR digital surface models (DSMs) with Landsat TM imagery to balance spatial resolution, data volume, and mapping accuracy of urban land covers, (2) comparison of LiDAR-derived metrics to fine grain optical imagery -- and their integration -- for detecting forest understory plant invaders, and (3) data reduction techniques for computationally efficient estimation of aboveground woody biomass in urban forests. In Chapter 1, I examined tradeoffs between potential gains in mapping accuracy and computational costs by integrating DSMs (structural and intensity) extracted from LiDAR with TM imagery and evaluating the degree to which TM, LiDAR, and LiDAR-TM fusion data discriminated land covers. I used Maximum Likelihood and Classification Tree algorithms to classify TM data, LiDAR data, and LiDAR-TM fusions. I assessed the relative contributions of LiDAR DSMs to map classification accuracy and identified an optimal spatial resolution of LiDAR DSMs for large area assessments of urban land cover. In Chapter 2, I analyzed combinations of datasets developed from categorized LiDAR-derived variables (Overstory, Understory, Topography, and Overall Vegetation Characteristics) and IKONOS imagery ( Optical) to detect and map the understory plant invader, Ligustrum sinense, using Random Forest (RF) and logistic regression (LR) algorithms, and I assessed the relative

  6. Compression strategies for LiDAR waveform cube

    NASA Astrophysics Data System (ADS)

    Jóźków, Grzegorz; Toth, Charles; Quirk, Mihaela; Grejner-Brzezinska, Dorota

    2015-01-01

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

  7. Maternal near-miss and death and their association with caesarean section complications: a cross-sectional study at a university hospital and a regional hospital in Tanzania.

    PubMed

    Litorp, Helena; Kidanto, Hussein L; Rööst, Mattias; Abeid, Muzdalifat; Nyström, Lennarth; Essén, Birgitta

    2014-07-23

    The maternal near-miss (MNM) concept has been developed to assess life-threatening conditions during pregnancy, childhood, and puerperium. In recent years, caesarean section (CS) rates have increased rapidly in many low- and middle-income countries, a trend which might have serious effects on maternal health. Our aim was to describe the occurrence and panorama of maternal near-miss and death in two low-resource settings, and explore their association with CS complications. We performed a cross-sectional study, including all women who fulfilled the WHO criteria for MNM or death between February and June 2012 at a university hospital and a regional hospital in Dar es Salaam, Tanzania. Cases were assessed individually to determine their association with CS. Main outcome measures included MNM ratio; maternal mortality ratio; proportion of MNM and death associated with CS complications; and the risk for such outcomes per 1,000 operations. The risk ratio of life-threatening CS complications at the university hospital compared to the regional hospital was calculated. We identified 467 MNM events and 77 maternal deaths. The MNM ratio was 36 per 1,000 live births (95% CI 33-39) and the maternal mortality ratio was 587 per 100,000 live births (95% CI 460-730). Major causes were eclampsia and postpartum haemorrhage, but we also detected nine MNM events and five deaths from iatrogenic complications. CS complications accounted for 7.9% (95% CI 5.6-11) of the MNM events and 13% (95% CI 6.4-23) of the maternal deaths. The risk of experiencing a life-threatening CS complication was three times higher at the regional hospital (22/1,000 operations, 95% CI 12-37) compared to the university hospital (7.0/1,000 operations, 95% CI 3.8-12) (risk ratio 3.2, 95% CI 1.5-6.6). The occurrence of MNM and death at the two hospitals was high, and many cases were associated with CS complications. The maternal risks of CS in low-resource settings must not be overlooked, and measures should be

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

    PubMed

    Li, Xiaolu; Liang, Yu

    2015-05-20

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

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

    NASA Astrophysics Data System (ADS)

    Kwak, Eunju; Habib, Ayman

    2014-07-01

    Three-dimensional building models are important for various applications, such as disaster management and urban planning. The development of laser scanning sensor technologies has resulted in many different approaches for efficient building model generation using LiDAR data. Despite this effort, generation of these models lacks economical and reliable techniques that fully exploit the advantage of LiDAR data. Therefore, this research aims to develop a framework for fully-automated building model generation by integrating data-driven and model-driven methods using LiDAR datasets. The building model generation starts by employing LiDAR data for building detection and approximate boundary determination. The generated building boundaries are then integrated into a model-based processing strategy because LiDAR derived planes show irregular boundaries due to the nature of LiDAR point acquisition. The focus of the research is generating models for the buildings with right-angled-corners, which can be described with a collection of rectangles under the assumption that the majority of the buildings in urban areas belong to this category. Therefore, by applying the Minimum Bounding Rectangle (MBR) algorithm recursively, the LiDAR boundaries are decomposed into sets of rectangles for further processing. At the same time, the quality of the MBRs is examined to verify that the buildings, from which the boundaries are generated, are buildings with right-angled-corners. The parameters that define the model primitives are adjusted through a model-based boundary fitting procedure using LiDAR boundaries. The level of details in the final Digital Building Model is based on the number of recursions during the MBR processing, which in turn are determined by the LiDAR point density. The model-based boundary fitting improves the quality of the generated boundaries and as seen in experimental results, the quality depends on the average LiDAR point spacing. This research thus develops an

  10. Validation points generation for LiDAR-extracted hydrologic features

    NASA Astrophysics Data System (ADS)

    Felicen, M. M.; De La Cruz, R. M.; Olfindo, N. T.; Borlongan, N. J. B.; Ebreo, D. J. R.; Perez, A. M. C.

    2016-10-01

    This paper discusses a novel way of generating sampling points of hydrologic features, specifically streams, irrigation network and inland wetlands, that could provide a promising measure of accuracy using combinations of traditional statistical sampling methods. Traditional statistical sampling techniques such as simple random sampling, systematic sampling, stratified sampling and disproportionate random sampling were all designed to generate points in an area where all the cells are classified and subjected to actual field validation. However, these sampling techniques are not applicable when generating points along linear features. This paper presents the Weighted Disproportionate Stratified Systematic Random Sampling (WDSSRS), a tool that combines the systematic and disproportionate stratified random sampling methods in generating points for accuracy computation. This tool makes use of a map series boundary shapefile covering around 27 by 27 kilometers at a scale of 1:50000, and the LiDAR-extracted hydrologic features shapefiles (e.g. wetland polygons and linear features of stream and irrigation network). Using the map sheet shapefile, a 10 x 10 grid is generated, and grid cells with water and non-water features are tagged accordingly. Cells with water features are checked for the presence of intersecting linear features, and the intersections are given higher weights in the selection of validation points. The grid cells with non-intersecting linear features are then evaluated and the remaining points are generated randomly along these features. For grid cells with nonwater features, the sample points are generated randomly.

  11. Have I Been Here Before? A Method for Detecting Loop Closure With LiDAR

    DTIC Science & Technology

    2015-01-01

    JOHN G ROGERS III (1 HC, 1 PDF) JASON M GREGORY (1 HC, 1 PDF) STUART H YOUNG (1 PDF) 18 INTENTIONALLY LEFT BLANK. ...Have I Been Here Before? A Method for Detecting Loop Closure With LiDAR by John G Rogers III and Jason M Gregory ARL-TR-7165 January...TR-7165 January 2015 Have I Been Here Before? A Method for Detecting Loop Closure With LiDAR John G Rogers III and Jason M

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

    USGS Publications Warehouse

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

    2014-01-01

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

  13. Automated Aerial Refueling Position Estimation Using a Scanning LiDAR

    DTIC Science & Technology

    2012-03-22

    early analysis of algorithms that use LiDAR measurements [20]. Powell et al. [21] have shown LiDAR simulation with commercial ray tracing software is... tracing , where ray tracing is considered the true measurement. The speedup from using these two methods over the brute force methods is required to...as dark green arrows, are used to determine the green set of points. These points trace out the base of a cone created by all the slope lines

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  15. Aboveground Biomass Modeling from Field and LiDAR Data in Brazilian Amazon Tropical Rain Forest

    NASA Astrophysics Data System (ADS)

    Silva, C. A.; Hudak, A. T.; Vierling, L. A.; Keller, M. M.; Klauberg Silva, C. K.

    2015-12-01

    Tropical forests are an important component of global carbon stocks, but tropical forest responses to climate change are not sufficiently studied or understood. Among remote sensing technologies, airborne LiDAR (Light Detection and Ranging) may be best suited for quantifying tropical forest carbon stocks. Our objective was to estimate aboveground biomass (AGB) using airborne LiDAR and field plot data in Brazilian tropical rain forest. Forest attributes such as tree density, diameter at breast height, and heights were measured at a combination of square plots and linear transects (n=82) distributed across six different geographic zones in the Amazon. Using previously published allometric equations, tree AGB was computed and then summed to calculate total AGB at each sample plot. LiDAR-derived canopy structure metrics were also computed at each sample plot, and random forest regression modelling was applied to predict AGB from selected LiDAR metrics. The LiDAR-derived AGB model was assessed using the random forest explained variation, adjusted coefficient of determination (Adj. R²), root mean square error (RMSE, both absolute and relative) and BIAS (both absolute and relative). Our findings showed that the 99th percentile of height and height skewness were the best LiDAR metrics for AGB prediction. The AGB model using these two best predictors explained 59.59% of AGB variation, with an Adj. R² of 0.92, RMSE of 33.37 Mg/ha (20.28%), and bias of -0.69 (-0.42%). This study showed that LiDAR canopy structure metrics can be used to predict AGC stocks in Tropical Forest with acceptable precision and accuracy. Therefore, we conclude that there is good potential to monitor carbon sequestration in Brazilian Tropical Rain Forest using airborne LiDAR data, large field plots, and the random forest algorithm.

  16. Detecting understory plant invasion in urban forests using LiDAR

    NASA Astrophysics Data System (ADS)

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

    2015-06-01

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

  17. Synergy of VSWIR and LiDAR for Ecosystem Structure, Biomass, and Canopy Diversity

    NASA Technical Reports Server (NTRS)

    Cook, Bruce D.; Asner, Gregory P.

    2010-01-01

    This slide presentation reviews the use of Visible ShortWave InfraRed (VSWIR) Imaging Spectrometer and LiDAR to study ecosystem structure, biomass and canopy diversity. It is shown that the biophysical data from LiDAR and biochemical information from hyperspectral remote sensing provides complementary data for: (1) describing spatial patterns of vegetation and biodiversity, (2) characterizing relationships between ecosystem form and function, and (3) detecting natural and human induced change that affects the biogeochemical cycles.

  18. Development of LiDAR aware allometrics for Abies grandis: A Case Study

    NASA Astrophysics Data System (ADS)

    Stone, G. A.; Tinkham, W. T.; Smith, A. M.; Hudak, A. T.; Falkowski, M. J.; Keefe, R.

    2012-12-01

    Forest managers rely increasingly on accurate allometric relationships to inform decisions regarding stand rotations, silvilcultural treatments, timber harvesting, and biometric modeling. At the same time, advances in remote sensing techniques like LiDAR (light detection and ranging) have brought about opportunities to advance how we assess forest growth, and thus are contributing to the need for more accurate allometries. Past studies have attempted to relate LiDAR data to both plot and individual tree measures of forest biomass. However, many of these studies have been limited by the accuracy of their coincident observations. In this study, 24 Abies grandis were measured, felled, and dissected for the explicit objective of developing LiDAR aware allometrics. The analysis predicts spatial variables of competition, growth potential (e.g, trees per acre, aspect, elevation, etc.) and common statistical distributional metrics (e.g., mean, mode, percentiles, variance, skewness, kurtosis, etc.) derived from LiDAR point cloud returns to coincident in situ measures of Abies grandis stem biomass. The resulting allometries exemplify a new approach for predicting structural attributes of interest (biomass, basal area, volume, etc.) directly from LiDAR point cloud data, precluding the measurement errors that are propogated by indirectly predicting these structure attributes of interest from LiDAR data using traditional plot-based measurements.

  19. On the impact of a refined stochastic model for airborne LiDAR measurements

    NASA Astrophysics Data System (ADS)

    Bolkas, Dimitrios; Fotopoulos, Georgia; Glennie, Craig

    2016-09-01

    Accurate topographic information is critical for a number of applications in science and engineering. In recent years, airborne light detection and ranging (LiDAR) has become a standard tool for acquiring high quality topographic information. The assessment of airborne LiDAR derived DEMs is typically based on (i) independent ground control points and (ii) forward error propagation utilizing the LiDAR geo-referencing equation. The latter approach is dependent on the stochastic model information of the LiDAR observation components. In this paper, the well-known statistical tool of variance component estimation (VCE) is implemented for a dataset in Houston, Texas, in order to refine the initial stochastic information. Simulations demonstrate the impact of stochastic-model refinement for two practical applications, namely coastal inundation mapping and surface displacement estimation. Results highlight scenarios where erroneous stochastic information is detrimental. Furthermore, the refined stochastic information provides insights on the effect of each LiDAR measurement in the airborne LiDAR error budget. The latter is important for targeting future advancements in order to improve point cloud accuracy.

  20. Norovirus - hospital

    MedlinePlus

    Gastroenteritis - norovirus; Colitis - norovirus; Hospital acquired infection - norovirus ... fluids ( dehydration ). Anyone can become infected with norovirus. Hospital patients who are very old, very young, or ...

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

    PubMed Central

    Shubi, Farrid M; Hamza, Omar JM; Kalyanyama, Boniphace M; Simon, Elison NM

    2008-01-01

    Background Human bites in the maxillofacial region compromise function and aesthetics, resulting in social and psychological effects. There is paucity of information regarding human bite injuries in Tanzania. The aim of the study was to assess the occurrence, treatment modalities and prognosis of human bite injuries in the oro-facial region at the Muhimbili National Hospital Dar es Salaam, Tanzania. Methods In a prospective study the details of patients with human bite injuries in the oro-facial region who attended at the Department of Oral and Maxillofacial Surgery of the Muhimbili National Hospital between January 2001 and December 2005 were recorded. Data included information on age, sex, site, duration of the injury at the time of reporting to hospital, reasons, details of treatment offered and outcome after treatment. Results A total of 33 patients, 13 males and 20 females aged between 12 and 49 years with human bite injuries in the oro-facial region were treated. Thirty patients presented with clean uninfected wounds while 3 had infected wounds. The most (45.5%) frequently affected site was the lower lip. Treatment offered included thorough surgical cleansing with adequate surgical debridement and primary suturing. Tetanus prophylaxis and a course of broad-spectrum antibiotics were given to all the patients. In 90% of the 30 patients who were treated by suturing, the healing was uneventful with only 10% experiencing wound infection or necrosis. Three patients who presented with wounds that had signs of infection were treated by surgical cleansing with debridement, antibiotics and daily dressing followed by delayed primary suturing. Conclusion Most of the human bite injuries in the oro-facial region were due to social conflicts. Although generally considered to be dirty or contaminated they could be successfully treated by surgical cleansing and primary suture with a favourable outcome. Management of such injuries often need multidisciplinary approach. PMID

  2. Classification of LiDAR Data with Point Based Classification Methods

    NASA Astrophysics Data System (ADS)

    Yastikli, N.; Cetin, Z.

    2016-06-01

    LiDAR is one of the most effective systems for 3 dimensional (3D) data collection in wide areas. Nowadays, airborne LiDAR data is used frequently in various applications such as object extraction, 3D modelling, change detection and revision of maps with increasing point density and accuracy. The classification of the LiDAR points is the first step of LiDAR data processing chain and should be handled in proper way since the 3D city modelling, building extraction, DEM generation, etc. applications directly use the classified point clouds. The different classification methods can be seen in recent researches and most of researches work with the gridded LiDAR point cloud. In grid based data processing of the LiDAR data, the characteristic point loss in the LiDAR point cloud especially vegetation and buildings or losing height accuracy during the interpolation stage are inevitable. In this case, the possible solution is the use of the raw point cloud data for classification to avoid data and accuracy loss in gridding process. In this study, the point based classification possibilities of the LiDAR point cloud is investigated to obtain more accurate classes. The automatic point based approaches, which are based on hierarchical rules, have been proposed to achieve ground, building and vegetation classes using the raw LiDAR point cloud data. In proposed approaches, every single LiDAR point is analyzed according to their features such as height, multi-return, etc. then automatically assigned to the class which they belong to. The use of un-gridded point cloud in proposed point based classification process helped the determination of more realistic rule sets. The detailed parameter analyses have been performed to obtain the most appropriate parameters in the rule sets to achieve accurate classes. The hierarchical rule sets were created for proposed Approach 1 (using selected spatial-based and echo-based features) and Approach 2 (using only selected spatial-based features

  3. Quantifying Forest Carbon and Structure with Terrestrial LiDAR

    NASA Astrophysics Data System (ADS)

    Stovall, A. E.; Shugart, H. H., Jr.

    2014-12-01

    Current rising atmospheric CO2 concentrations are a major concern with significant global ramifications, however, of the carbon (C) fluxes that are known to occur on Earth, the terrestrial sink has the greatest amount of uncertainty. Improved monitoring of forest cover and change is required for reducing emissions from deforestation and forest degradation (REDD). We determine C storage from volume measurements with a high-precision Terrestrial Laser Scanner (TLS), substantially improving current standard ground validation techniques. This technology is utilized on several 30 m x 30 m plots in a Virginia temperate forest. Aboveground C is calculated on each of the study sites with commonly used allometric equations to offer a realistic comparison of field-based estimations to TLS-derived methods. The TLS and aerial LiDAR point cloud data are compared via the development of canopy height models at the plot scale. The novel method of point cloud voxelization is applied to our TLS data in order to produce detailed volumetric calculations in these complex forest ecosystems. Statistical output from the TLS data allows us to resolve and compare forest structure on scales from the individual plot to the entire forest landscape. The estimates produced from this research will be used to inform more widely available remote sensing datasets provided by NASA's Landsat satellites, significantly reducing the uncertainty of the terrestrial C cycle in temperate forests. Preliminary findings corroborate previous research, suggesting the potential for highly detailed monitoring of forest C storage as defined by the REDD initiative and analysis of complex ecosystem structure.

  4. Ionospheric irregularities over Bahir Dar, Ethiopia during selected geomagnetic storms

    NASA Astrophysics Data System (ADS)

    Kassa, Tsegaye; Damtie, Baylie

    2017-07-01

    We have analyzed the effect of geomagnetic storms on the occurrence of ionospheric irregularities by considering seven case studies in the period of 2013-2014 over Bahir Dar, Ethiopia (11° N , 38° E). We inferred the irregularity indices from GPS phase fluctuation by computing the median of 1-min rate of change of total electron content (fp) along the ray paths from all satellites observed. The Fp -index was calculated as an hourly average fp -index values along the ray paths from all satellites observed during each hour. Our results revealed that the irregularity level was inhibited during post sunset hours of the main phase of the storms we considered. On average, the irregularity index has dropped from 400 (0.4 TECU/min) during quiet time to 50 (0.05 TECU/min) on disturbed time with an amount of 350 (0.35 TECU/min). However, in some of the cases, immediately after the onset of the storm, we observed the enhancement of irregularities. We found that only the observations on 01 June 2013 and 19 February 2014 exhibited a correspondence of the time of occurrence of the minimum of the Dst-index with inhibition of irregularities noted by other researchers. Our observations of the enhancement of irregularities on 17 March 2013 and 19 February 2014 can partly be explained by the orientation of the IMF BZ . Other measurements such as neutral wind, electric field are required to explain the observations on 29 June 2013, 06 July 2013, 09 November 2013 and 27 February 2014.

  5. Association between anaemia and infections (HIV, malaria and hookworm) among children admitted at Muhimbili National Hospital.

    PubMed

    Magesa, A S; Magesa, P M

    2012-09-01

    Anaemia is the major cause of morbidity and mortality in paediatric age with much aetiology. The magnitude of childhood anaemia has been inadequately studied at Muhimbili National Hospital (MNH). The study was aimed at determining the frequency of anaemia and associated infections in patients admitted in general paediatric wards at MNH in Dar es Salaam. This was a descriptive cross-sectional study. This was conducted at MNH in general paediatric wards from 20th August, 2009 to 15th December, 2009. Patients, aged 1-84 months, consecutively admitted were recruited in the study. After informed verbal consent from the guardian or parent was obtained, information on demographic and clinical characteristics was collected from the parent or guardian. Physical examination and laboratory tests on blood ; stool samples for hookworm screening; blood slides for malaria parasites; Human Immunodeficiency Virus (HIV) screening; and blood peripheral smears were done on all subjects. Additional information was taken from medical files. Data management: The prevalence of anemia was determined as a percentage of all paediatric patients recruited during the time of data collection. All information was recorded using questionnaires and analysis was done using SPSS version 13.0. A p value of < 0.05 was considered statistically significant. A total of 315 children were assessed. The frequency of anaemia was 79.4%. This is much higher than the WHO prevalence of 67.6% in Africa for anaemia to be taken as a disease of public health importance. The proportion of malaria was 7.9%, HIV seropositive was 10.2% and hookworm was 1.0% of all admissions. There was an increased risk of anaemia in patients with HIV seropositive and or malaria although this was not statistically significant (RR > 1.0, p > 0.05). Anaemia in paediatric patients admitted at MNH is a disease of high public health importance in Dar es Salaam and may well carry a high burden in the rest of the country. Other risk factors of

  6. ES '70 NEWS. VOLUME 1, NO. 2.

    ERIC Educational Resources Information Center

    Shelly (E.F.) and Co., New York, NY.

    SPECIFICS OF IMPLEMENTING THE OBJECTIVES OF THE EDUCATIONAL SYSTEM FOR THE SEVENTIES (ES '70) PROGRAM TO RELATE EDUCATION TO THE NEEDS OF AMERICAN YOUTH, CLARIFYING THE STRUCTURE OF THE ES '70 NETWORK, AND CHARTING THE BROAD DIRECTION OF THE LONG-RANGE ACTIVITIES OF THE PARTICIPANTS WERE THE PRIMARY SUBJECTS FOR REVIEW AT THE SECOND ANNUAL MEETING…

  7. LiDAR Applications in Resource Geology and Benefits for Land Management

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

    Light Detection and Ranging (LiDAR) data is being increasingly used as an effective alternative to conventional optical remote sensing to accurately estimate aboveground forest biomass ranging from individual tree to stand levels. Recent advancements in LiDAR technology have resulted in higher point densities and improved data accuracies accompanied by challenges for procuring and processing voluminous LiDAR data for large-area assessments. Reducing point density lowers data acquisition costs and overcomes computational challenges for large-area forest assessments. However, how does lower point density impact the accuracy of biomass estimation in forests containing a great level of anthropogenic disturbance? We evaluate the effects of LiDAR point density on the biomass estimation of remnant forests in the rapidly urbanizing region of Charlotte, North Carolina, USA. We used multiple linear regression to establish a statistical relationship between field-measured biomass and predictor variables derived from LiDAR data with varying densities. We compared the estimation accuracies between a general Urban Forest type and three Forest Type models (evergreen, deciduous, and mixed) and quantified the degree to which landscape context influenced biomass estimation. The explained biomass variance of the Urban Forest model, using adjusted R2, was consistent across the reduced point densities, with the highest difference of 11.5% between the 100% and 1% point densities. The combined estimates of Forest Type biomass models outperformed the Urban Forest models at the representative point densities (100% and 40%). The Urban Forest biomass model with development density of 125 m radius produced the highest adjusted R2 (0.83 and 0.82 at 100% and 40% LiDAR point densities, respectively) and the lowest RMSE values, highlighting a distance impact of development on biomass estimation. Our evaluation suggests that reducing LiDAR point density is a viable solution to regional

  9. Elements of systemic sensitivity and propagated uncertainty in LiDAR-based forest attribute maps (Invited)

    NASA Astrophysics Data System (ADS)

    Hopkinson, C.; Chasmer, L.; Kljun, N.; van Gorsel, E.

    2013-12-01

    The application of airborne LiDAR to vegetation and forest attribute extraction and modeling is now common place. Direct estimates of tree-, plot- or stand-level height and canopy cover are frequently made as pre-cursors to more complex and indirect attribute derivations such as leaf area, biomass, basal area, fuel, even species. Frequently, the faith placed in LiDAR to produce these spatial variables appears so complete that raw data properties or the methods employed in the modeling of direct or indirect attributes are glossed over. The assumption being that if basic variables and derivatives can be easily predicted across a few studies, then it follows this will always be the case. Few studies address explicitly the range of sensitivity in direct and indirect forest attribute estimations: a) derived from LiDAR data of differing fundamental acquisition or point cloud properties; or b) produced using different data extraction, filtering or raster interpolation approaches. The paper will illustrate some of the critical acquisition and point cloud attributes (such as pulse power, flight line configuration, timing and point density) that strongly influence mapped and modeled forest attributes at a range of case study sites in North America and Australia. Further, the influence of multiple seemingly defensible canopy height model generation criteria will be compared to illustrate the high sensitivity in even the most basic of LiDAR-based forest attribute maps. We conclude that not all LiDAR are created equal and that both raw data properties and all data manipulation steps must be communicated when utilising such data. Finally, we believe that as with more standard products like LiDAR point cloud formats and digital terrain models (DTMs), an international committee is needed to provide guidance on airborne LiDAR vegetation products so that uncertainties can be mitigated when data are shared or compared across sites and through time.

  10. Estimation of effective plant area index for South Korean forests using LiDAR system.

    PubMed

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

    2010-07-01

    Light Detection and Ranging (LiDAR) systems can be used to estimate both vertical and horizontal forest structure. Woody components, the leaves of trees and the understory can be described with high precision, using geo-registered 3D-points. Based on this concept, the Effective Plant Area Indices (PAI(e)) for areas of Korean Pine (Pinus koraiensis), Japanese Larch (Larix leptolepis) and Oak (Quercus spp.) were estimated by calculating the ratio of intercepted and incident LIDAR laser rays for the canopies of the three forest types. Initially, the canopy gap fraction (G ( LiDAR )) was generated by extracting the LiDAR data reflected from the canopy surface, or inner canopy area, using k-means statistics. The LiDAR-derived PAI(e) was then estimated by using G ( LIDAR ) with the Beer-Lambert law. A comparison of the LiDAR-derived and field-derived PAI(e) revealed the coefficients of determination for Korean Pine, Japanese Larch and Oak to be 0.82, 0.64 and 0.59, respectively. These differences between field-based and LIDAR-based PAI(e) for the different forest types were attributed to the amount of leaves and branches in the forest stands. The absence of leaves, in the case of both Larch and Oak, meant that the LiDAR pulses were only reflected from branches. The probability that the LiDAR pulses are reflected from bare branches is low as compared to the reflection from branches with a high leaf density. This is because the size of the branch is smaller than the resolution across and along the 1 meter LIDAR laser track. Therefore, a better predictive accuracy would be expected for the model if the study would be repeated in late spring when the shoots and leaves of the deciduous trees begin to appear.

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

    PubMed

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

    2014-03-10

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

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

    PubMed

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

    2013-01-01

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

  13. Malaria in patients with sickle cell anemia: burden, risk factors, and outcome at the outpatient clinic and during hospitalization

    PubMed Central

    Makani, Julie; Komba, Albert N.; Cox, Sharon E.; Oruo, Julie; Mwamtemi, Khadija; Kitundu, Jesse; Magesa, Pius; Rwezaula, Stella; Meda, Elineema; Mgaya, Josephine; Pallangyo, Kisali; Okiro, Emelda; Muturi, David; Newton, Charles R.; Fegan, Gregory; Marsh, Kevin; Williams, Thomas N.

    2010-01-01

    Approximately 280 000 children are born with sickle cell anemia (SCA) in Africa annually, yet few survive beyond childhood. Falciparum malaria is considered a significant cause of this mortality. We conducted a 5-year prospective surveillance study for malaria parasitemia, clinical malaria, and severe malarial anemia (SMA) in Dar-es-Salaam, Tanzania, between 2004 and 2009. We recorded 10 491 visits to the outpatient clinic among 1808 patients with SCA and 773 visits among 679 patients without SCA. Similarly, we recorded 691 hospital admissions among 497 patients with SCA and 2017 in patients without SCA. Overall, the prevalence of parasitemia was lower in patients with SCA than in patients without SCA both at clinic (0.7% vs 1.6%; OR, 0.53; 95% CI, 0.32-0.86; P = .008) and during hospitalization (3.0% vs 5.6%; OR, 0.46; 95% CI, 0.25-0.94; P = .01). Furthermore, patients with SCA had higher rates of malaria during hospitalization than at clinic, the ORs being 4.29 (95% CI, 2.63-7.01; P < .001) for parasitemia, 17.66 (95% CI, 5.92-52.71; P < .001) for clinical malaria, and 21.11 (95% CI, 8.46-52.67; P < .001) for SMA. Although malaria was rare among patients with SCA, parasitemia during hospitalization was associated with both severe anemia and death. Effective treatment for malaria during severe illness episodes and further studies to determine the role chemoprophylaxis are required. PMID:19901265

  14. Demonstration of LiDAR and Orthophotography for Wide Area Assessment at Pueblo Precision Bombing Range #2, Colorado

    DTIC Science & Technology

    2008-01-01

    for classification of LiDAR points into vegetation, ground, and “other,” creating bare earth and surface model digital terrain models ( DTM ...for rectification of the photography to the DTM . 2.1.6 Data Analysis Once processed, the LiDAR /orthophotography datasets are analyzed to...creation: Triangulation results were loaded into ortho-processing software, along with a LiDAR -derived DTM and aerial photography. Aerial photographs

  15. Optimizing variable radius plot size and LiDAR resolution to model standing volume in conifer forests

    Treesearch

    Ram Kumar Deo; Robert E. Froese; Michael J. Falkowski; Andrew T. Hudak

    2016-01-01

    The conventional approach to LiDAR-based forest inventory modeling depends on field sample data from fixed-radius plots (FRP). Because FRP sampling is cost intensive, combining variable-radius plot (VRP) sampling and LiDAR data has the potential to improve inventory efficiency. The overarching goal of this study was to evaluate the integration of LiDAR and VRP data....

  16. In situ Oceanographic LiDAR as a Tool for Retrieving and Characterizing Particle Distributions in the Ocean

    NASA Astrophysics Data System (ADS)

    Flouros, A.; Zimmerman, R. C.; Collister, B.; Hill, V. J.

    2016-02-01

    An in situ LiDAR system (iLiDAR) was deployed from a surface vessel on a cruise in the Chesapeake Bay in June 2015, and the profiles retrieved were compared with other water column optical properties measured in situ. An iLiDAR offers several advantages when compared to airborne or satellite based LiDAR. Examples include the cost effectiveness of use on a cruise, the ability to make other measurements simultaneously, increased spatial coverage, and a shorter time frame of data collection. The system attenuation values (Ksys) retrieved from the iLiDAR profiles were compared to a variety of optical properties measured on station. A linear regression modeling the relationship between diffuse attenuation (Kd) and the iLiDAR system attenuation yielded a near 1:1 relationship (m=0.9903, R2=0.8144, p<0.05). The iLiDAR can provide a reasonable estimate of diffuse attenuation within the water column, which can be used to estimate chlorophyll and primary production. The depolarization ratio of the backscattered iLiDAR signal was compared to the backscatter ratio in an attempt to better understand the distribution of particles throughout the water column. The results of this analysis were not conclusive, but the potential for the iLiDAR to detect changes in types of particles in the water column is described.

  17. Fission barriers for /sup 255/Es, /sup 256/Es, and /sup 255/Fm

    SciTech Connect

    Britt, H.C.; Cheifetz, E.; Hoffman, D.C.; Wilhelmy, J.B.; Dupzyk, R.J.; Lougheed, R.W.

    1980-02-01

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

  18. Geotechnical applications of LiDAR pertaining to geomechanical evaluation and hazard identification

    NASA Astrophysics Data System (ADS)

    Lato, Matthew J.

    Natural hazards related to ground movement that directly affect the safety of motorists and highway infrastructure include, but are not limited to, rockfalls, rockslides, debris flows, and landslides. This thesis specifically deals with the evaluation of rockfall hazards through the evaluation of LiDAR data. Light Detection And Ranging (LiDAR) is an imaging technology that can be used to delineate and evaluate geomechanically-controlled hazards. LiDAR has been adopted to conduct hazard evaluations pertaining to rockfall, rock-avalanches, debris flows, and landslides. Characteristics of LiDAR surveying, such as rapid data acquisition rates, mobile data collection, and high data densities, pose problems to traditional CAD or GIS-based mapping methods. New analyses methods, including tools specifically oriented to geomechanical analyses, are needed. The research completed in this thesis supports development of new methods, including improved survey techniques, innovative software workflows, and processing algorithms to aid in the detection and evaluation of geomechanically controlled rockfall hazards. The scientific research conducted between the years of 2006-2010, as presented in this thesis, are divided into five chapters, each of which has been published by or is under review by an international journal. The five research foci are: (i) geomechanical feature extraction and analysis using LiDAR data in active mining environments; (ii) engineered monitoring of rockfall hazards along transportation corridors: using mobile terrestrial LiDAR; (iii) optimization of LiDAR scanning and processing for automated structural evaluation of discontinuities in rockmasses; (iv) location orientation bias when using static LiDAR data for geomechanical analysis; and (v) evaluating roadside rockmasses for rockfall hazards from LiDAR data: optimizing data collection and processing protocols. The research conducted pertaining to this thesis has direct and significant implications with

  19. Spinning a laser web: predicting spider distributions using LiDAR.

    PubMed

    Vierling, K T; Bässler, C; Brandl, R; Vierling, L A; Weiss, I; Müller, J

    2011-03-01

    LiDAR remote sensing has been used to examine relationships between vertebrate diversity and environmental characteristics, but its application to invertebrates has been limited. Our objectives were to determine whether LiDAR-derived variables could be used to accurately describe single-species distributions and community characteristics of spiders in remote forested and mountainous terrain. We collected over 5300 spiders across multiple transects in the Bavarian National Park (Germany) using pitfall traps. We examined spider community characteristics (species richness, the Shannon index, the Simpson index, community composition, mean body size, and abundance) and single-species distribution and abundance with LiDAR variables and ground-based measurements. We used the R2 and partial R2 provided by variance partitioning to evaluate the predictive power of LiDAR-derived variables compared to ground measurements for each of the community characteristics. The total adjusted R2 for species richness, the Shannon index, community species composition, and body size had a range of 25-57%. LiDAR variables and ground measurements both contributed >80% to the total predictive power. For species composition, the explained variance was approximately 32%, which was significantly greater than expected by chance. The predictive power of LiDAR-derived variables was comparable or superior to that of the ground-based variables for examinations of single-species distributions, and it explained up to 55% of the variance. The predictability of species distributions was higher for species that had strong associations with shade in open-forest habitats, and this niche position has been well documented across the European continent for spider species. The similar statistical performance between LiDAR and ground-based measures at our field sites indicated that deriving spider community and species distribution information using LiDAR data can provide not only high predictive power at

  20. Localized Segment Based Processing for Automatic Building Extraction from LiDAR Data

    NASA Astrophysics Data System (ADS)

    Parida, G.; Rajan, K. S.

    2017-05-01

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

  1. LiDAR, UAV or compass-clinometer? Accuracy, coverage and the effects on structural models

    NASA Astrophysics Data System (ADS)

    Cawood, Adam J.; Bond, Clare E.; Howell, John A.; Butler, Robert W. H.; Totake, Yukitsugu

    2017-05-01

    Light Detection and Ranging (LiDAR) and Structure from Motion (SfM) provide large amounts of digital data from which virtual outcrops can be created. The accuracy of these surface reconstructions is critical for quantitative structural analysis. Assessment of LiDAR and SfM methodologies suggest that SfM results are comparable to high data-density LiDAR on individual surfaces. The effect of chosen acquisition technique on the full outcrop and the efficacy on its virtual form for quantitative structural analysis and prediction beyond single bedding surfaces, however, is less certain. Here, we compare the accuracy of digital virtual outcrop analysis with traditional field data, for structural measurements and along-strike prediction of fold geometry from Stackpole syncline. In this case, the SfM virtual outcrop, derived from UAV imagery, yields better along-strike predictions and a more reliable geological model, in spite of lower accuracy surface reconstructions than LiDAR. This outcome is attributed to greater coverage by UAV and reliable reconstruction of a greater number of bedding planes than terrestrial LiDAR, which suffers from the effects of occlusion. Irrespective of the chosen acquisition technique, we find that workflows must incorporate careful survey planning, data processing and quality checking of derived data if virtual outcrops are to be used for robust structural analysis and along-strike prediction.

  2. Development of LiDAR measurements for the German offshore test site

    NASA Astrophysics Data System (ADS)

    Rettenmeier, A.; Kühn, M.; Wächter, M.; Rahm, S.; Mellinghoff, H.; Siegmeier, B.; Reeder, L.

    2008-05-01

    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.

  3. Building Roof Boundary Extraction from LiDAR and Image Data Based on Markov Random Field

    NASA Astrophysics Data System (ADS)

    Dal Poz, A. P.; Fernandes, V. J. M.

    2017-05-01

    In this paper a method for automatic extraction of building roof boundaries is proposed, which combines LiDAR data and highresolution aerial images. The proposed method is based on three steps. In the first step aboveground objects are extracted from LiDAR data. Initially a filtering algorithm is used to process the original LiDAR data for getting ground and non-ground points. Then, a region-growing procedure and the convex hull algorithm are sequentially used to extract polylines that represent aboveground objects from the non-ground point cloud. The second step consists in extracting corresponding LiDAR-derived aboveground objects from a high-resolution aerial image. In order to avoid searching for the interest objects over the whole image, the LiDAR-derived aboveground objects' polylines are photogrammetrically projected onto the image space and rectangular bounding boxes (sub-images) that enclose projected polylines are generated. Each sub-image is processed for extracting the polyline that represents the interest aboveground object within the selected sub-image. Last step consists in identifying polylines that represent building roof boundaries. We use the Markov Random Field (MRF) model for modelling building roof characteristics and spatial configurations. Polylines that represent building roof boundaries are found by optimizing the resulting MRF energy function using the Genetic Algorithm. Experimental results are presented and discussed in this paper.

  4. The IsoDAR high intensity H2+ transport and injection tests

    NASA Astrophysics Data System (ADS)

    Alonso, J.; Axani, S.; Calabretta, L.; Campo, D.; Celona, L.; Conrad, J. M.; Day, A.; Castro, G.; Labrecque, F.; Winklehner, D.

    2015-10-01

    This technical report reviews the tests performed at the Best Cyclotron Systems, Inc. facility in regards to developing a cost effective ion source, beam line transport system, and acceleration system capable of high H2+ current output for the IsoDAR (Isotope Decay At Rest) experiment. We begin by outlining the requirements for the IsoDAR experiment then provide overviews of the Versatile Ion Source (VIS), Low Energy Beam Transport (LEBT) system, spiral inflector, and cyclotron. The experimental measurements are then discussed and the results are compared with a thorough set of simulation studies. Of particular importance we note that the VIS proved to be a reliable ion source capable of generating a large amount of H2+ current. The results suggest that with further upgrades, the VIS could potentially be a suitable candidate for IsoDAR. The conclusion outlines the key results from our tests and introduces the forthcoming work this technical report has motivated.

  5. [Analysis of an Air Pollution Process Using LiDAR in Nanjing, Spring of 2014].

    PubMed

    Bao, Qing; He, Jun-liang; Zha, Yong; Cheng, Feng; Li, Qian-nan

    2015-04-01

    Based on environmental monitoring data, meteorological data and the results of numerical simulation, a typical air pollution process in Nanjing, from 26th May to 1st June, 2014 was deeply analyzed combining aerosol extinction coefficient derived from LiDAR system. Experimental results showed that the entire pollution process was affected by both local pollution and exogenous inputs including dust and smoke. Meteorological factors played a significant role in the generation and elimination of pollutants. Low pressure and temperature inversion also hindered the diffusion of pollutants, while strong rainfall terminated the pollution process. During the pollution, the height of atmospheric boundary layer was lower than normal situation and changed little during the pollution period, which provided a poor diffusion condition for pollutants. LiDAR could accurately detect aerosol vertical structure which was able to capture the temporal and spatial variation of pollutant distributions. Therefore, LiDAR can be of great significance for the atmospheric pollution monitoring.

  6. The role of terrestrial 3D LiDAR scan in bridge health monitoring

    NASA Astrophysics Data System (ADS)

    Liu, Wanqiu; Chen, Shen-En; Sajedi, Allen; Hauser, Edd

    2010-04-01

    This paper addresses the potential applications of terrestrial 3D LiDAR scanning technologies for bridge monitoring. High resolution ground-based optical-photonic images from LiDAR scans can provide detailed geometric information about a bridge. Applications of simple algorithms can retrieve damage information from the geometric point cloud data, which can be correlated to possible damage quantification including concrete mass loss due to vehicle collisions, large permanent steel deformations, and surface erosions. However, any proposed damage detection technologies should provide information that is relevant and useful to bridge managers for their decision making process. This paper summaries bridge issues that can be detected from the 3D LiDAR technologies, establishes the general approach in using 3D point clouds for damage evaluation and suggests possible bridge state ratings that can be used as supplements to existing bridge management systems (BMS).

  7. Octree-based segmentation for terrestrial LiDAR point cloud data in industrial applications

    NASA Astrophysics Data System (ADS)

    Su, Yun-Ting; Bethel, James; Hu, Shuowen

    2016-03-01

    Automated and efficient algorithms to perform segmentation of terrestrial LiDAR data is critical for exploitation of 3D point clouds, where the ultimate goal is CAD modeling of the segmented data. In this work, a novel segmentation technique is proposed, starting with octree decomposition to recursively divide the scene into octants or voxels, followed by a novel split and merge framework that uses graph theory and a series of connectivity analyses to intelligently merge components into larger connected components. The connectivity analysis, based on a combination of proximity, orientation, and curvature connectivity criteria, is designed for the segmentation of pipes, vessels, and walls from terrestrial LiDAR data of piping systems at industrial sites, such as oil refineries, chemical plants, and steel mills. The proposed segmentation method is exercised on two terrestrial LiDAR datasets of a steel mill and a chemical plant, demonstrating its ability to correctly reassemble and segregate features of interest.

  8. Understanding hospitality.

    PubMed

    Patten, C S

    1994-03-01

    Bridging patient/"customer" issues and business aspects can be aided through developing a specific nursing basis for hospitality. The ancient practice of hospitality has evolved into three distinct levels: public, personal and therapeutic. Understanding these levels is helpful in integrating various dimensions of guest relations programs in hospitals into a more comprehensive vision. Hospitality issues must become a greater part of today's nursing management.

  9. Reconstruction and analysis of a deciduous sapling using digital photographs or terrestrial-LiDAR technology

    PubMed Central

    Delagrange, Sylvain; Rochon, Pascal

    2011-01-01

    Background and Aims To meet the increasing need for rapid and non-destructive extraction of canopy traits, two methods were used and compared with regard to their accuracy in estimatating 2-D and 3-D parameters of a hybrid poplar sapling. Methods The first method consisted of the analysis of high definition photographs in Tree Analyser (TA) software (PIAF-INRA/Kasetsart University). TA allowed the extraction of individual traits using a space carving approach. The second method utilized 3-D point clouds acquired from terrestrial light detection and ranging (T-LiDAR) scans. T-LiDAR scans were performed on trees without leaves to reconstruct the lignified structure of the sapling. From this skeleton, foliage was added using simple modelling rules extrapolated from field measurements. Validation of the estimated dimension and the accuracy of reconstruction was then achieved by comparison with an empirical data set. Key Results TA was found to be slightly less precise than T-LiDAR for estimating tree height, canopy height and mean canopy diameter, but for 2-D traits both methods were, however, fully satisfactory. TA tended to over-estimate total leaf area (error up to 50 %), but better estimates were obtained by reducing the size of the voxels used for calculations. In contrast, T-LiDAR estimated total leaf area with an error of <6 %. Finally, both methods led to an over-estimation of canopy volume. With respect to this trait, T-LiDAR (14·5 % deviation) greatly surpassed the accuracy of TA (up to 50 % deviation), even if the voxels used were reduced in size. Conclusions Taking into account their magnitude of data acquisition and analysis and their accuracy in trait estimations, both methods showed contrasting potential future uses. Specifically, T-LiDAR is a particularly promising tool for investigating the development of large perennial plants, by itself or in association with plant modelling. PMID:21515607

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  12. Detailed Hydrographic Feature Extraction from High-Resolution LiDAR Data

    SciTech Connect

    Danny L. Anderson

    2012-05-01

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

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

    PubMed

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

    2010-07-01

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

  14. Fish ES cells and applications to biotechnology.

    PubMed

    Alvarez, M Carmen; Béjar, Julia; Chen, Songlin; Hong, Yunhan

    2007-01-01

    ES cells provide a promising tool for the generation of transgenic animals with site-directed mutations. When ES cells colonize germ cells in chimeras, transgenic animals with modified phenotypes are generated and used either for functional genomics studies or for improving productivity in commercial settings. Although the ES cell approach has been limited to mice, there is strong interest for developing the technology in fish. We describe the step-by-step procedure for developing ES cells in fish. Key aspects include avoiding cell differentiation, specific in vitro traits of pluripotency, and, most importantly, testing for production of chimeric animals as the main evidence of pluripotency. The entire process focuses on two model species, zebrafish and medaka, in which most work has been done. The achievements attained in these species, as well as their applicability to other commercial fish, are discussed. Because of the difficulties relating to germ line competence, mostly of long-term fish ES cells, alternative cell-based approaches such as primordial germ cells and nuclear transfer need to be considered. Although progress to date has been slow, there are promising achievements in homologous recombination and alternative avenues yet to be explored that can bring ES technology in fish to fruition.

  15. Modeling rating curves using remotely-sensed LiDAR data

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  16. Comparing LiDAR-Generated to ground- surveyed channel cross-sectional profiles in a forested mountain stream

    Treesearch

    Brian C. Dietterick; Russell White; Ryan. Hilburn

    2012-01-01

    Airborne Light Detection and Ranging (LiDAR) holds promise to provide an alternative to traditional ground-based survey methods for stream channel characterization and some change detection purposes, even under challenging landscape conditions. This study compared channel characteristics measured at 53 ground-surveyed and LiDAR-derived crosssectional profiles located...

  17. Computer-based synthetic data to assess the tree delineation algorithm from airborne LiDAR survey

    Treesearch

    Lei Wang; Andrew G. Birt; Charles W. Lafon; David M. Cairns; Robert N. Coulson; Maria D. Tchakerian; Weimin Xi; Sorin C. Popescu; James M. Guldin

    2013-01-01

    Small Footprint LiDAR (Light Detection And Ranging) has been proposed as an effective tool for measuring detailed biophysical characteristics of forests over broad spatial scales. However, by itself LiDAR yields only a sample of the true 3D structure of a forest. In order to extract useful forestry relevant information, this data must be interpreted using mathematical...

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

    Treesearch

    James E. Garabedian; Robert J. McGaughey; Stephen E. Reutebuch; Bernard R. Parresol; John C. Kilgo; Christopher E. Moorman; M. Nils. Peterson

    2014-01-01

    Light detection and ranging (LiDAR) technology has the potential to radically alter the way researchers and managers collect data on wildlife–habitat relationships. To date, the technology has fostered several novel approaches to characterizing avian habitat, but has been limited by the lack of detailed LiDAR-habitat attributes relevant to species across a continuum of...

  19. Investigating the influence of LiDAR ground surface errors on the utility of derived forest inventories

    Treesearch

    Wade T. Tinkham; Alistair M. S. Smith; Chad Hoffman; Andrew T. Hudak; Michael J. Falkowski; Mark E. Swanson; Paul E. Gessler

    2012-01-01

    Light detection and ranging, or LiDAR, effectively produces products spatially characterizing both terrain and vegetation structure; however, development and use of those products has outpaced our understanding of the errors within them. LiDAR's ability to capture three-dimensional structure has led to interest in conducting or augmenting forest inventories with...

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

    Treesearch

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    The 16 October 1999 Hector Mine earthquake (Mw7.1) generated significant surface rupture along the Lavic Lake Fault through almost 60 kilometers of sparsely vegetated, relatively barren desert terrain. It was the first large earthquake for which post-earthquake airborne LiDAR, collected to image the fault surface rupture, exists. Despite the lack of pre-earthquake high-resolution topographic data, we were able to make both horizontal and vertical displacement measurements, which complement published field investigation results that include ~254 data points (164 of which are within LiDAR coverage area). We made 255 new horizontal and 83 vertical displacement measurements using a 0.5 m DEM generated from the LiDAR dataset. The maximum horizontal offset value is 6.6 ± 1.1 m, and is located approximately ~700 m south of the maximum horizontal offset observed during the field work. The average horizontal offset value from LiDAR measurements is ~2.27 m, whereas the average calculated from field data is ~2.5 m. The maximum vertical displacement is ~1.2 m, and the average vertical offset value is less than 1 m. No consistent trends are apparent in the sense of the vertical component, except in the north of the mountainous section, which is predominated by east-side-down measurements. Compared to field data, LiDAR-based measurements (a) have larger measurement uncertainties, (b) have slightly higher values, (c) do not include many measurements of offsets <1 m due to the DEM resolution, and (d) are spatially denser. The field investigation produced measurements of higher quality in alluvial deposits (e.g. tire tracks, offset rock or pebble lineaments) which are not typically visible with 0.5 m resolution DEMs unless a piercing feature has a very large or clear offset. LiDAR measurements included more geomorphic features with larger measurement uncertainties, which may not have been measured in the field due to their proximity to higher quality measurements. However, along

  2. Visualization of High-Resolution LiDAR Topography in Google Earth

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    The growing availability of high-resolution LiDAR (Light Detection And Ranging) topographic data has proven to be revolutionary for Earth science research. These data allow scientists to study the processes acting on the Earth’s surfaces at resolutions not previously possible yet essential for their appropriate representation. In addition to their utility for research, the data have also been recognized as powerful tools for communicating earth science concepts for education and outreach purposes. Unfortunately, the massive volume of data produced by LiDAR mapping technology can be a barrier to their use. To facilitate access to these powerful data for research and educational purposes, we have been exploring the use of Keyhole Markup Language (KML) and Google Earth to deliver LiDAR-derived visualizations. The OpenTopography Portal (http://www.opentopography.org/) is a National Science Foundation-funded facility designed to provide access to Earth science-oriented LiDAR data. OpenTopography hosts a growing collection of LiDAR data for a variety of geologic domains, including many of the active faults in the western United States. We have found that the wide spectrum of LiDAR users have variable scientific applications, computing resources, and technical experience and thus require a data distribution system that provides various levels of access to the data. For users seeking a synoptic view of the data, and for education and outreach purposes, delivering full-resolution images derived from LiDAR topography into the Google Earth virtual globe is powerful. The virtual globe environment provides a freely available and easily navigated viewer and enables quick integration of the LiDAR visualizations with imagery, geographic layers, and other relevant data available in KML format. Through region-dependant network linked KML, OpenTopography currently delivers over 20 GB of LiDAR-derived imagery to users via simple, easily downloaded KMZ files hosted at the Portal

  3. Sporadic Layer es and Siesmic Activity

    NASA Astrophysics Data System (ADS)

    Alimov, Obid; Blokhin, Alexandr; Kalashnikova, Tatyana

    2016-07-01

    To determine the influence of seismogenic disturbances on the calm state of the iono-sphere and assess the impact of turbulence development in sporadic-E during earthquake prepa-ration period we calculated the variation in the range of semitransparency ∆fES = f0ES - fbES. The study was based primarily on the ionograms obtained by vertical sounding of the ionosphere at Dushanbe at nighttime station from 15 to 29 August 1986. In this time period four successive earthquakes took place, which serves the purpose of this study of the impact of seis-mogenic processes on the intensity of the continuous generation of ionospheric turbulence. Analysis of the results obtained for seismic-ionospheric effects of 1986 earthquakes at station Dushanbe has shown that disturbance of ionospheric parameters during earthquake prepa-ration period displays a pronounced maximum with a duration of t = 1-6 hours. Ionospheric effects associated with the processes of earthquake preparation emerge quite predictably, which verifies seismogenic disturbances in the ionosphere. During the preparation of strong earthquakes, ionograms of vertical sounding produced at station Dushanbe - near the epicenter area - often shown the phenomenon of spreading traces of sporadic Es. It is assumed that the duration of manifestation of seismic ionospheric precursors in Du-shanbe τ = 1 - 6 hours may be associated with deformation processes in the Earth's crust and var-ious faults, as well as dissimilar properties of the environment of the epicentral area. It has been shown that for earthquakes with 4.5 ≤ M ≤ 5.5 1-2 days prior to the event iono-spheric perturbations in the parameters of the sporadic layer Es and an increase in the value of the range of semitransparency Es - ΔfEs were observed, which could lead to turbulence at altitudes of 100-130 km.

  4. Differential regulation of dendritic and axonal development by the novel Krüppel-like factor Dar1

    PubMed Central

    Ye, Bing; Kim, Jung Hwan; Yang, Limin; McLachlan, Ian; Younger, Susan; Jan, Lily Yeh; Jan, Yuh Nung

    2011-01-01

    Dendrites and axons are two major neuronal compartments with differences that are critical for neuronal functions. To learn about the differential regulation of dendritic and axonal development, we conducted a genetic screen in Drosophila and isolated the dendritic arbor reduction 1 (dar1) mutants, which display defects in dendritic but not axonal growth. The dar1 gene encodes a novel transcription regulator in the Krüppel-like factor family. Neurons lacking dar1 function have severely reduced growth of microtubule- but not F-actin-based dendritic branches. In contrast, overexpression of Dar1 dramatically increased the growth of microtubule-based dendritic branches. Our results suggest that Dar1 promotes dendrite growth in part by suppressing the expression of the microtubule severing protein Spastin. Our study thus uncovers a novel transcriptional program for microtubule regulation that preferentially controls dendrite growth. PMID:21368042

  5. The Earth System (ES-DOC) Project

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  6. Line-Based Registration of Panoramic Images and LiDAR Point Clouds for Mobile Mapping

    PubMed Central

    Cui, Tingting; Ji, Shunping; Shan, Jie; Gong, Jianya; Liu, Kejian

    2016-01-01

    For multi-sensor integrated systems, such as the mobile mapping system (MMS), data fusion at sensor-level, i.e., the 2D-3D registration between an optical camera and LiDAR, is a prerequisite for higher level fusion and further applications. This paper proposes a line-based registration method for panoramic images and a LiDAR point cloud collected by a MMS. We first introduce the system configuration and specification, including the coordinate systems of the MMS, the 3D LiDAR scanners, and the two panoramic camera models. We then establish the line-based transformation model for the panoramic camera. Finally, the proposed registration method is evaluated for two types of camera models by visual inspection and quantitative comparison. The results demonstrate that the line-based registration method can significantly improve the alignment of the panoramic image and the LiDAR datasets under either the ideal spherical or the rigorous panoramic camera model, with the latter being more reliable. PMID:28042855

  7. Linking rainforest ecophysiology and microclimate through fusion of airborne LiDAR and hyperspectral imagery

    Treesearch

    Eben N. Broadbent; Angélica M. Almeyda Zambrano; Gregory P. Asner; Christopher B. Field; Brad E. Rosenheim; Ty Kennedy-Bowdoin; David E. Knapp; David Burke; Christian Giardina; Susan Cordell

    2014-01-01

    We develop and validate a high-resolution three-dimensional model of light and air temperature for a tropical forest interior in Hawaii along an elevation gradient varying greatly in structure but maintaining a consistent species composition. Our microclimate models integrate high-resolution airborne waveform light detection and ranging data (LiDAR) and hyperspectral...

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

    ERIC Educational Resources Information Center

    Haslam, Nick

    2011-01-01

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

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

    PubMed

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

    2013-03-21

    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.

  10. Use of LiDAR to Assist in Delineating Waters of the United States, Including Wetlands

    DTIC Science & Technology

    2014-03-01

    Bathymetry Technical Center of Expertise KML Keyhole Markup Language LAS Log ASCII Standard LCT Land Cover Type LiDAR Light Detection and Ranging MLS...field investigation. ERDC/CRREL TR-14-3 48 References Anderson, K., J. Bennie, E. Milton , P. Hughes, R. Lindsay, and R. Meade. 2010

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

    ERIC Educational Resources Information Center

    Turkheimer, Eric

    2011-01-01

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

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

    PubMed Central

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

    2013-01-01

    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. PMID:23516227

  13. Mapping of post-event earthquake induced landslides in Sg. Mesilou using LiDAR

    NASA Astrophysics Data System (ADS)

    Hanan Mat Yusoff, Habibah; Azahari Razak, Khamarrul; Yuen, Florence; Harun, Afifi; Talib, Jasmi; Mohamad, Zakaria; Ramli, Zamri; Abd Razab, Razain

    2016-06-01

    Earthquake is a common natural disaster in active tectonic regions. The disaster can induce cascading disasters such as debris flow, mudflow and reactivated old landslides. M 6.0 Ranau earthquake dated on June 05, 2015 coupling with intense and prolonged rainfall caused several mass movements such as debris flow, deep-seated and shallow landslides in Mesilou, Sabah. This study aims at providing a better insight into the use of advanced LiDAR mapping technology for recognizing landslide induced by earthquakes particularly in a vegetated terrain, assessing post event hazard and analyzing its distribution for hazard zonation. We developed the landslide inventory using LiDAR-derived visual analysis method and validated in the field. A landslide inventory map improved with the support of LiDAR derivative data. Finally, landslide inventory was analysed by emphasizing its distribution and density in such a way that it provides clues of risky zone as a result of debris flow. We recommend that mitigation action and risk reduction should be taken place at a transport zone of the channel compared to other zones. This study indicates that modern airborne LiDAR can be a good complementary tool for improving landslide inventory in a complex environment, and an effective tool for rapid regional hazard and risk assessment in the tropics.

  14. Total canopy transmittance estimated from small-footprint, full-waveform airborne LiDAR

    NASA Astrophysics Data System (ADS)

    Milenković, Milutin; Wagner, Wolfgang; Quast, Raphael; Hollaus, Markus; Ressl, Camillo; Pfeifer, Norbert

    2017-06-01

    Canopy transmittance is a directional and wavelength-specific physical parameter that quantifies the amount of radiation attenuated when passing through a vegetation layer. The parameter has been estimated from LiDAR data in many different ways over the years. While early LiDAR methods treated each returned echo equally or weighted the echoes according to their return order, recent methods have focused more on the echo energy. In this study, we suggest a new method of estimating the total canopy transmittance considering only the energy of ground echoes. Therefore, this method does not require assumptions for the reflectance or absorption behavior of vegetation. As the oblique looking geometry of LiDAR is explicitly considered, canopy transmittance can be derived for individual laser beams and can be mapped spatially. The method was applied on a contemporary full-waveform LiDAR data set collected under leaf-off conditions and over a study site that contains two sub regions: one with a mixed (coniferous and deciduous) forest and another that is predominantly a deciduous forest in an alluvial plain. The resulting canopy transmittance map was analyzed for both sub regions and compared to aerial photos and the well-known fractional cover method. A visual comparison with aerial photos showed that even single trees and small canopy openings are visible in the canopy transmittance map. In comparison with the fractional cover method, the canopy transmittance map showed no saturation, i.e., there was better separability between patches with different vegetation structure.

  15. An Algorithm to Identify and Localize Suitable Dock Locations from 3-D LiDAR Scans

    DTIC Science & Technology

    2013-05-10

    3-D) LiDARs have proved themselves very useful on many autonomous ground vehicles, such as the Google Driverless Car Project, the DARPA, Defense...appear in a typical point cloud data set, relative to other clusters such as cars , trees, boulders, etc. In this algorithm, these values were

  16. Airborne hyperspectral and LiDAR data integration for weed detection

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  17. Comparison of LiDAR- and photointerpretation-based estimates of canopy cover

    Treesearch

    Demetrios Gatziolis

    2012-01-01

    An evaluation of the agreement between photointerpretation- and LiDARbased estimates of canopy cover was performed using 397 90 x 90 m reference areas in Oregon. It was determined that at low canopy cover levels LiDAR estimates tend to exceed those from photointerpretation and that this tendency reverses at high canopy cover levels. Characteristics of the airborne...

  18. Modeling and mapping basal area of Pinus taeda L. plantation using airborne LiDAR data.

    PubMed

    Silva, Carlos A; Klauberg, Carine; Hudak, Andrew T; Vierling, Lee A; Fennema, Scott J; Corte, Ana Paula D

    2017-01-01

    Basal area (BA) is a good predictor of timber stand volume and forest growth. This study developed predictive models using field and airborne LiDAR (Light Detection and Ranging) data for estimation of basal area in Pinus taeda plantation in south Brazil. In the field, BA was collected from conventional forest inventory plots. Multiple linear regression models for predicting BA from LiDAR-derived metrics were developed and evaluated for predictive power and parsimony. The best model to predict BA from a family of six models was selected based on corrected Akaike Information Criterion (AICc) and assessed by the adjusted coefficient of determination (adj. R²) and root mean square error (RMSE). The best model revealed an adj. R²=0.93 and RMSE=7.74%. Leave one out cross-validation of the best regression model was also computed, and revealed an adj. R² and RMSE of 0.92 and 8.31%, respectively. This study showed that LiDAR-derived metrics can be used to predict BA in Pinus taeda plantations in south Brazil with high precision. We conclude that there is good potential to monitor growth in this type of plantations using airborne LiDAR. We hope that the promising results for BA modeling presented herein will stimulate to operate this technology in Brazil.

  19. Multispectral LiDAR Data for Land Cover Classification of Urban Areas.

    PubMed

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

    2017-04-26

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

  20. Multispectral LiDAR Data for Land Cover Classification of Urban Areas

    PubMed Central

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

    2017-01-01

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

  1. Modeling forest biomass and growth: Coupling long-term inventory and LiDAR data

    Treesearch

    Chad Babcock; Andrew O. Finley; Bruce D. Cook; Aaron Weiskittel; Christopher W. Woodall

    2016-01-01

    Combining spatially-explicit long-term forest inventory and remotely sensed information from Light Detection and Ranging (LiDAR) datasets through statistical models can be a powerful tool for predicting and mapping above-ground biomass (AGB) at a range of geographic scales. We present and examine a novel modeling approach to improve prediction of AGB and estimate AGB...

  2. Spatial Patterns of Trees from Airborne LiDAR Using a Simple Tree Segmentation Algorithm

    NASA Astrophysics Data System (ADS)

    Jeronimo, S.; Kane, V. R.; McGaughey, R. J.; Franklin, J. F.

    2015-12-01

    Objectives for management of forest ecosystems on public land incorporate a focus on maintenance and restoration of ecological functions through silvicultural manipulation of forest structure. The spatial pattern of residual trees - the horizontal element of structure - is a key component of ecological restoration prescriptions. We tested the ability of a simple LiDAR individual tree segmentation method - the watershed transform - to generate spatial pattern metrics similar to those obtained by the traditional method - ground-based stem mapping - on forested plots representing the structural diversity of a large wilderness area (Yosemite NP) and a large managed area (Sierra NF) in the Sierra Nevada, Calif. Most understory and intermediate-canopy trees were not detected by the LiDAR segmentation; however, LiDAR- and field-based assessments of spatial pattern in terms of tree clump size distributions largely agreed. This suggests that (1) even when individual tree segmentation is not effective for tree density estimates, it can provide a good measurement of tree spatial pattern, and (2) a simple segmentation method is adequate to measure spatial pattern of large areas with a diversity of structural characteristics. These results lay the groundwork for a LiDAR tool to assess clumping patterns across forest landscapes in support of restoration silviculture. This tool could describe spatial patterns of functionally intact reference ecosystems, measure departure from reference targets in treatment areas, and, with successive acquisitions, monitor treatment efficacy.

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

    USDA-ARS?s Scientific Manuscript database

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

  4. The Effect of Lava Texture on LiDAR Attributes and Full Waveform

    NASA Astrophysics Data System (ADS)

    Anderson, S. W.; Finnegan, D. C.; LeWinter, A.

    2013-12-01

    The distribution of glassy, vesicular, and crystalline textures on lava flow and dome surfaces provides insights regarding the physical and chemical processes occurring during emplacement. For silicic flows, these textures may reflect variations in the volatile content of lava upon eruption. To assess the efficacy of texture detection with our terrestrial full waveform LiDAR system capable of measuring ~125,000 topographic points/second, we analyzed attribute and full waveform data from a variety of lava textures displayed on recent rhyolitic obsidian flows of the Inyo Dome chain (California) and pahoehoe and aa flows at Kilauea volcano (Hawaii). We find that attributes such as intensity, amplitude and deviation of the returned 1550nm laser pulse fall into discrete ranges associated with glassy, pumiceous and crystalline textures on both the rhyolitic and basaltic surfaces. This enables detection of vesicularity at ranges in excess of 500 m, making LiDAR a useful tool for remotely determining lava texture. Scan times using our Riegl VZ1000 and VZ400 systems require only minutes, allowing for repeated scans over a short time period, and processing times are <1 hour. We have also analyzed the full digitized waveforms of LiDAR pulses returned from these surfaces, and find that they also have unique signatures related to texture. We therefore suggest that LiDAR can provide reliable information on lava texture during eruption, aiding in the interpretation of eruption hazards from increasing volatile contents.

  5. Biomass estimation of Douglas fir stands using airborne LiDAR data

    USDA-ARS?s Scientific Manuscript database

    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...

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

    ERIC Educational Resources Information Center

    Turkheimer, Eric

    2011-01-01

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

  7. Mapping snags and understory shrubs for LiDAR based assessment of wildlife habitat suitability

    Treesearch

    Sebastian Martinuzzi; Lee A. Vierling; William A. Gould; Michael J. Falkowski; Jeffrey S. Evans; Andrew T. Hudak; Kerri T. Vierling

    2009-01-01

    The lack of maps depicting forest three-dimensional structure, particularly as pertaining to snags and understory shrub species distribution, is a major limitation for managing wildlife habitat in forests. Developing new techniques to remotely map snags and understory shrubs is therefore an important need. To address this, we first evaluated the use of LiDAR data for...

  8. LiDAR based prediction of forest biomass using hierarchical models with spatially varying coefficients

    Treesearch

    Chad Babcock; Andrew O. Finley; John B. Bradford; Randy Kolka; Richard Birdsey; Michael G. Ryan

    2015-01-01

    Many studies and production inventory systems have shown the utility of coupling covariates derived from Light Detection and Ranging (LiDAR) data with forest variables measured on georeferenced inventory plots through regression models. The objective of this study was to propose and assess the use of a Bayesian hierarchical modeling framework that accommodates both...

  9. An Analysis of Student Reading as Measured on the Diagnostic Assessment of Reading (DAR)

    ERIC Educational Resources Information Center

    Baca, Jo-Ann M.; Shepperson, Barbara A.

    2006-01-01

    As part of the reporting of Delaware's State Improvement Grant (DelaSIG), the Delaware Education Research and Development Center (R&D Center) completed a study on the Diagnostic Assessment of Reading (DAR) scores of students whose teachers attended a professional development program designed to help focus teacher instruction of struggling …

  10. A comparison of two open source LiDAR surface classification algorithms

    Treesearch

    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

    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....

  11. Into the third dimension: Benefits of incorporating LiDAR data in wildlife habitat models

    Treesearch

    Melissa J. Merrick; John L. Koprowski; Craig Wilcox

    2013-01-01

    LiDAR (Light detection and ranging) is a tool with potential for characterizing wildlife habitat by providing detailed, three-dimensional landscape information not available from other remote sensing applications. The ability to accurately map structural components such as canopy height, canopy cover, woody debris, tree density, and ground surface has potential to...

  12. Registration of optical imagery and LiDAR data using an inherent geometrical constraint.

    PubMed

    Zhang, Wuming; Zhao, Jing; Chen, Mei; Chen, Yiming; Yan, Kai; Li, Linyuan; Qi, Jianbo; Wang, Xiaoyan; Luo, Jinghui; Chu, Qing

    2015-03-23

    A novel method for registering imagery with Light Detection And Ranging (LiDAR) data is proposed. It is based on the phenomenon that the back-projection of LiDAR point cloud of an object should be located within the object boundary in the image. Using this inherent geometrical constraint, the registration parameters computation of both data sets only requires LiDAR point clouds of several objects and their corresponding boundaries in the image. The proposed registration method comprises of four steps: point clouds extraction, boundary extraction, back-projection computation and registration parameters computation. There are not any limitations on the geometrical and spectral properties of the object. So it is suitable not only for structured scenes with man-made objects but also for natural scenes. Moreover, the proposed method based on the inherent geometrical constraint can register two data sets derived from different parts of an object. It can be used to co-register TLS (Terrestrial Laser Scanning) LiDAR point cloud and UAV (Unmanned aerial vehicle) image, which are obtaining more attention in the forest survey application. Using initial registration parameters comparable to POS (position and orientation system) accuracy, the performed experiments validated the feasibility of the proposed registration method.

  13. Prioritizing treatment of second-growth forests using LiDAR

    Treesearch

    Lathrop P. Leonard; Daryl Van Dyke

    2012-01-01

    We used multi-return light detecting and ranging (LiDAR) to develop a costeffective method for describing forest conditions and prioritizing stands for treatment in over 14,000 ha of second-growth forests (11 to 85 years old) in Del Norte Coast Redwoods State Park (DNCRSP). DNCRSP consists primarily of redwood and Douglas-fir dominated forests with scattered tanoak...

  14. Using LiDAR data to define stream flow rating curves

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    In remote locations, it is difficult to obtain stream flow information because of the difficulty making sufficient discharge measurements. In this study we investigate the feasibility to constrain a fluid mechanics-based flow model for defining stream flow rating curves with remotely sensed topographic data from airborne LiDAR scanning. A near infrared (NIR) LiDAR scan was carried out for an 8-m wide channel in northern Sweden. The topographic information from this NIR LiDAR scan along the 90-m surveyed reach was used to define channel geometry above the water surface. To fill in the channel bed topography below the water surface we used a detailed ground survey to create a hybrid model for comparison to a simple assumption of a flat bottom channel. Based on the boundaries of confidence intervals calculated from the direct measurements, we show that for the channel considered the simple flat bottom assumption performs just as well as the hybrid model with regards to estimating direct discharge measurements. The mismatch between the two models was greatest at low flows and may be associated with unresolved submerged bed topography. This deficiency, while rather small, could potentially be remedied by scanning during periods of low flow, or use other techniques such as multi-frequency bathymetric LiDAR or passive optical remote sensing that offer alternative ways for generating the necessary topographic information.

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

    ERIC Educational Resources Information Center

    Haslam, Nick

    2011-01-01

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

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

    USDA-ARS?s Scientific Manuscript database

    Implementation of molecular methods in hop breeding is dependent on the availability of sizeable numbers of polymorphic markers and a comprehensive understanding of genetic variation. Diversity Arrays Technology (DArT) is a high-throughput cost-effective method for the discovery of large numbers of...

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

    PubMed

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

    2011-05-01

    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.

  18. Impact of a refined airborne LiDAR stochastic model for natural hazard applications

    NASA Astrophysics Data System (ADS)

    Glennie, C. L.; Bolkas, D.; Fotopoulos, G.

    2016-12-01

    Airborne Light Detection and Ranging (LiDAR) is often employed to derive multi-temporal Digital Elevation Models (DEMs), that are used to estimate vertical displacement resulting from natural hazards such as landslides, rockfalls and erosion. Vertical displacements are estimated by computing the difference between two DEMs separated by a specified time period and applying a threshold to remove the inherent noise. Thus, reliable information about the accuracy of DEMs is essential. The assessment of airborne LiDAR errors is typically based on (i) independent ground control points (ii) forward error propagation utilizing the LiDAR geo-referencing equation. The latter approach is dependent on the stochastic model information of the LiDAR measurements. Furthermore, it provides the user with point-by-point accuracy estimation. In this study, a refined stochastic model is obtained through variance component estimation (VCE) for a dataset in Houston, Texas. Results show that initial stochastic information was optimistic by 35% for both horizontal coordinates and ellipsoidal heights. To assess the impact of a refined stochastic model, surface displacement simulations are evaluated. The simulations include scenarios with topographic slopes that vary from 10º to 60º, and vertical displacement of ±1 to ±5 m. Results highlight the cases where a reliable stochastic model is important. A refined stochastic model can be used in practical applications for determining appropriate noise thresholds in vertical displacement, improve quantitative analysis, and enhance relevant decision-making.

  19. Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology

    PubMed Central

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

    2012-01-01

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

  20. Statistical rigor in LiDAR-assisted estimation of aboveground forest biomass

    Treesearch

    Timothy G. Gregoire; Erik Næsset; Ronald E. McRoberts; Göran Ståhl; Hans Andersen; Terje Gobakken; Liviu Ene; Ross Nelson

    2016-01-01

    For many decades remotely sensed data have been used as a source of auxiliary information when conducting regional or national surveys of forest resources. In the past decade, airborne scanning LiDAR (Light Detection and Ranging) has emerged as a promising tool for sample surveys aimed at improving estimation of aboveground forest biomass. This technology is now...

  1. Interpersonal Conflicts and Styles of Managing Conflicts among Students at Bahir Dar University, Ethiopia

    ERIC Educational Resources Information Center

    Bazezew, Arega; Neka, Mulugeta

    2017-01-01

    Interpersonal conflict happens everywhere and at any time and is inherent in all societies. However, the methods of managing such conflict are quite different from one organisation to the other. The general objective of the study was to assess interpersonal conflicts and styles of managing conflicts among students at Bahir Dar University.…

  2. Examining conifer canopy structural complexity across forest ages and elevations with LiDAR data

    Treesearch

    Van R. Kane; Jonathan D. Bakker; Robert J. McGaughey; James A. Lutz; Rolf F. Gersonde; Jerry F. Franklin

    2010-01-01

    LiDAR measurements of canopy structure can be used to classify forest stands into structural stages to study spatial patterns of canopy structure, identify habitat, or plan management actions. A key assumption in this process is that differences in canopy structure based on forest age and elevation are consistent with predictions from models of stand development. Three...

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

    Treesearch

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

    2010-01-01

    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...

  4. Multitemporal Error Analysis of LiDAR Data for Geomorphological Feature Detection

    NASA Astrophysics Data System (ADS)

    Sailer, R.; Höfle, B.; Bollmann, E.; Vetter, M.; Stötter, J.; Pfeifer, N.; Rutzinger, M.; Geist, T.

    2009-04-01

    Since 2001 airborne LiDAR measurements have been carried out regularly at the Hintereisferner region (Ötztal, Tyrol, Austria). This results in a worldwide unique data set, which is primarily used for multitemporal glacial and periglacial analyses. Several methods and tools i) to delineate the glacier boundary, ii) to derive standard glaciological mass balance parameters (e.g. volume changes), iii) to excerpt crevasse zones or iv) to classify glacier surface features (e.g. snow, firn, glacier ice, debris covered glacier ice) have been developed as yet. Furthermore, the available multitemporal LiDAR data set offers the opportunity to identify surface changes occurring outside the glacier boundary, which have not been recognized until now. The respective areas are characterized by small variations of the surface topography from year to year. These changes of the surface topography are primarily caused by periglacial processes further initiating secondary gravitative mass movements. The present study aims at quantifying the error range of LiDAR measurements. The error analysis, which is based on (at least) 66 cross-combinations of the single LiDAR measurement campaigns, excluding areas which are obviously related to glacial surface changes, results in statistically derived error margins. Hence, surface changes which exceed these error margins have to be assigned to periglacial or gravitative process activities. The study further aims at identifying areas which are explicitly related to those periglacial and gravitative processes.

  5. Hyperspectral and LiDAR remote sensing of fire fuels in Hawaii Volcanoes National Park.

    PubMed

    Varga, Timothy A; Asner, Gregory P

    2008-04-01

    Alien invasive grasses threaten to transform Hawaiian ecosystems through the alteration of ecosystem dynamics, especially the creation or intensification of a fire cycle. Across sub-montane ecosystems of Hawaii Volcanoes National Park on Hawaii Island, we quantified fine fuels and fire spread potential of invasive grasses using a combination of airborne hyperspectral and light detection and ranging (LiDAR) measurements. Across a gradient from forest to savanna to shrubland, automated mixture analysis of hyperspectral data provided spatially explicit fractional cover estimates of photosynthetic vegetation, non-photosynthetic vegetation, and bare substrate and shade. Small-footprint LiDAR provided measurements of vegetation height along this gradient of ecosystems. Through the fusion of hyperspectral and LiDAR data, a new fire fuel index (FFI) was developed to model the three-dimensional volume of grass fuels. Regionally, savanna ecosystems had the highest volumes of fire fuels, averaging 20% across the ecosystem and frequently filling all of the three-dimensional space represented by each image pixel. The forest and shrubland ecosystems had lower FFI values, averaging 4.4% and 8.4%, respectively. The results indicate that the fusion of hyperspectral and LiDAR remote sensing can provide unique information on the three-dimensional properties of ecosystems, their flammability, and the potential for fire spread.

  6. Dynamic displacement estimation by fusing LDV and LiDAR measurements via smoothing based Kalman filtering

    NASA Astrophysics Data System (ADS)

    Kim, Kiyoung; Sohn, Hoon

    2017-01-01

    This paper presents a smoothing based Kalman filter to estimate dynamic displacement in real-time by fusing the velocity measured from a laser Doppler vibrometer (LDV) and the displacement from a light detection and ranging (LiDAR). LiDAR can measure displacement based on the time-of-flight information or the phase-shift of the laser beam reflected off form a target surface, but it typically has a high noise level and a low sampling rate. On the other hand, LDV primarily measures out-of-plane velocity of a moving target, and displacement is estimated by numerical integration of the measured velocity. Here, the displacement estimated by LDV suffers from integration error although LDV can achieve a lower noise level and a much higher sampling rate than LiDAR. The proposed data fusion technique estimates high-precision and high-sampling rate displacement by taking advantage of both LiDAR and LDV measurements and overcomes their limitations by adopting a real-time smoothing based Kalman filter. To verify the performance of the proposed dynamic displacement estimation technique, a series of lab-scale tests are conducted under various loading conditions.

  7. a Data Driven Method for Building Reconstruction from LiDAR Point Clouds

    NASA Astrophysics Data System (ADS)

    Sajadian, M.; Arefi, H.

    2014-10-01

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

  8. A comparison of two open source LiDAR surface classification algorithms

    USDA-ARS?s Scientific Manuscript database

    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 op...

  9. Line-Based Registration of Panoramic Images and LiDAR Point Clouds for Mobile Mapping.

    PubMed

    Cui, Tingting; Ji, Shunping; Shan, Jie; Gong, Jianya; Liu, Kejian

    2016-12-31

    For multi-sensor integrated systems, such as the mobile mapping system (MMS), data fusion at sensor-level, i.e., the 2D-3D registration between an optical camera and LiDAR, is a prerequisite for higher level fusion and further applications. This paper proposes a line-based registration method for panoramic images and a LiDAR point cloud collected by a MMS. We first introduce the system configuration and specification, including the coordinate systems of the MMS, the 3D LiDAR scanners, and the two panoramic camera models. We then establish the line-based transformation model for the panoramic camera. Finally, the proposed registration method is evaluated for two types of camera models by visual inspection and quantitative comparison. The results demonstrate that the line-based registration method can significantly improve the alignment of the panoramic image and the LiDAR datasets under either the ideal spherical or the rigorous panoramic camera model, with the latter being more reliable.

  10. Errors in LiDAR-derived shrub height and crown area on sloped terrain

    USDA-ARS?s Scientific Manuscript database

    This study developed and tested four methodologies for determining shrub height measurements with LiDAR data in a semiarid shrub-steppe in southwestern Idaho, USA. Unique to this study was the focus of sagebrush height measurements on sloped terrain. The study also developed one of the first metho...

  11. Shape Detection from Raw LiDAR Data with Subspace Modeling.

    PubMed

    Wang, Jun; Xu, Kevin Kai

    2016-08-31

    LiDAR scanning has become a prevalent technique for digitalizing large-scale outdoor scenes. However, the raw LiDAR data often contain imperfections, e.g., missing large regions, anisotropy of sampling density, and contamination of noise and outliers, which are the major obstacles that hinder its more ambitious and higher level applications in digital city modeling. Observing that 3D urban scenes can be locally described with several low dimensional subspaces, we propose to locally classify the neighborhoods of the scans to model the substructures of the scenes. The key enabler is the adaptive kernel-scale scoring, filtering and clustering of substructures, making it possible to recover the local structures at all points simultaneously, even in the presence of severe data imperfections. Integrating the local analyses leads to robust shape detection from raw LiDAR data. On this basis, we develop several urban scene applications and verify them on a number of LiDAR scans with various complexities and styles, which demonstrates the effectiveness and robustness of our methods.

  12. Geospatial revolution and remote sensing LiDAR in Mesoamerican archaeology.

    PubMed

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

    2012-08-07

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

  13. Automatic extraction of pavement markings on streets from point cloud data of mobile LiDAR

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Zhong, Ruofei; Tang, Tao; Wang, Liuzhao; Liu, Xianlin

    2017-08-01

    Pavement markings provide an important foundation as they help to keep roads users safe. Accurate and comprehensive information about pavement markings assists the road regulators and is useful in developing driverless technology. Mobile light detection and ranging (LiDAR) systems offer new opportunities to collect and process accurate pavement markings’ information. Mobile LiDAR systems can directly obtain the three-dimensional (3D) coordinates of an object, thus defining spatial data and the intensity of (3D) objects in a fast and efficient way. The RGB attribute information of data points can be obtained based on the panoramic camera in the system. In this paper, we present a novel method process to automatically extract pavement markings using multiple attribute information of the laser scanning point cloud from the mobile LiDAR data. This method process utilizes a differential grayscale of RGB color, laser pulse reflection intensity, and the differential intensity to identify and extract pavement markings. We utilized point cloud density to remove the noise and used morphological operations to eliminate the errors. In the application, we tested our method process on different sections of roads in Beijing, China, and Buffalo, NY, USA. The results indicated that both correctness (p) and completeness (r) were higher than 90%. The method process of this research can be applied to extract pavement markings from huge point cloud data produced by mobile LiDAR.

  14. Using Satellite and Airborne LiDAR to Model Woodpecker Habitat Occupancy at the Landscape Scale

    PubMed Central

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Valerio Iungo, Giacomo; Porté-Agel, Fernando

    2014-05-01

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

  16. Field and LiDAR observations of the Hector Mine California 1999 surface rupture

    NASA Astrophysics Data System (ADS)

    Sousa, F.; Akciz, S. O.; Harvey, J. C.; Hudnut, K. W.; Lynch, D. K.; Scharer, K. M.; Stock, J. M.; Witkosky, R.; Kendrick, K. J.; Wespestad, C.

    2014-12-01

    We report new field- and computer-based investigations of the surface rupture of the October 16, 1999 Hector Mine Earthquake. Since May 2012, in cooperation with the United States Marine Corps Air Ground Combat Center (MCAGCC) at Twentynine Palms, CA, our team has been allowed ground and aerial access to the entire surface rupture. We have focused our new field-based research and imagery analysis along the ~10 kilometer-long maximum slip zone (MSZ) which roughly corresponds to the zone of >4 meter dextral horizontal offset. New data include: 1) a 1 km wide aerial LiDAR survey along the entire surface rupture (@ 10 shots/m2, May 2012, www.opentopography.org); 2) terrestrial LiDAR surveys at 5 sites within the MSZ (@ >1000 shots/m2, April 2014); 3) low altitude aerial photography and ground based photography of the entire MSZ; 4) a ground-truthed database of 87 out of the 94 imagery-based offset measurements made within the MSZ; and 5) a database of 50 new field-based offset measurements made within the MSZ by our team on the ground, 31 of which have also been made on the computer (Ladicaoz) with both the 2000 LiDAR data (@ 0.5 m DEM resolution; Chen et al, in review) and 2012 LiDAR data (@ 35 cm DEM resolution; our team). New results to date include 1) significant variability (> 2 m) in horizontal offsets measured along short distances of the surface rupture (~100 m) within segments of the surface rupture that are localized to a single fault strand; 2) strong dependence of decadal scale fault scarp preservation on local lithology (bedrock vs. alluvial fan vs. fine sediment) and geomorphology (uphill vs. downhill facing scarp); 3) newly observed offset features which were never measured during the post-event field response; 4) newly observed offset features too small to be resolved in airborne LiDAR data (< 1 m); 5) nearly 25% of LiDAR imagery-based measurements that were later ground-truthed were judged by our team to warrant removal from the database due to

  17. Distinguishing grass from ground using LiDAR: Techniques and applications

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    Standard protocols exist for extracting bare-earth Digital Elevation Models (DEMs) from LiDAR point clouds that include trees and other large woody vegetation. Grasses and other herbaceous plants can also obscure the ground surface, yet methods for optimally distinguishing grass from ground to generate accurate LiDAR-based raster products for geomorphic and ecological applications are still under development. Developing such methods is important because LiDAR-based difference products (e.g. snow thickness) require accurate representations of the ground surface and because raster data for grass height and density have important applications in ecology. In this study, we developed and tested methods for constructing optimal bare-earth and grass height raster layers from LiDAR point clouds and compared the results to high-quality field-based measurements of grass height, density, and species type for nearly 1000 precisely geo-referenced locations collected during the acquisition of a >200 km^2 airborne LiDAR flight of the Valles Caldera National Preserve (New Mexico). In cases of partially bare ground (where the skewness of return heights above a plane fit to the lowest first returns is sufficiently large), a planar fit to the lowest first returns provides a good method of producing an accurate bare-earth DEM and the statistics of the first returns above that planar fit provide good estimates of the mean and variance of grass height. In areas of relatively thick grass cover, however, a fit to the lowest first returns yields a bare-earth DEM that may be a meter or more above the actual ground surface. Here we propose a method to solve this problem using field-measured correlations among the mean, variance, and skewness of grass heights. In this method, the variance and skewness of the differences between LiDAR first returns and a 10m^2 planar fit to the lowest first returns is used, together with field-based correlations of grass height statistics, to estimate the mean

  18. Hospital diversification.

    PubMed

    Eastaugh, Steven R

    2005-01-01

    Hospital diversification and its impact on the operating ratio are studied for 168 hospitals during the period from 1999 to 2004. Diversification and the operating ratio are modeled in a two-stage least squares (TSLS) framework as being jointly dependent. Institutional diversification is found to yield a better financial position, and the better operating ratio allows the institution the wherewithal to diversify. The impact of external government planning and hospital competition are also measured. An institution lifecycle hypothesis is advanced to explain hospital behavior: boom and bust, diversification and divestiture, occasionally leading to closure or merger. Management's attitude concerning risk and reward is considered.

  19. Response categories and anger measurement: do fewer categories result in poorer measurement?: development of the DAR5.

    PubMed

    Hawthorne, Graeme; Mouthaan, Joanne; Forbes, David; Novaco, Raymond W

    2006-02-01

    Anger is a key long-term outcome from trauma exposure, regardless of trauma type, and it is implicated as a moderator of response to treatment. It therefore seems important that anger is assessed in both epidemiological studies of trauma sequelae and in intervention evaluation research. This study explored the measurement properties of a recently investigated anger scale, the Dimensions of Anger Reactions (DAR) Scale. In our previous study, the DAR was found to be a measure of trait anger, but although brief, the nine response categories per item may have confused respondents, suggesting fewer response categories may work equally well. Additionally, our previous analysis suggested there were two redundant items within the DAR. Three samples of Australian veterans were used to investigate the psychometric properties associated with alterations to the response categories of the DAR; veterans who participated in the DAR validation study, those participating in group therapy programmes for post-traumatic stress disorder, and veterans participating in lifestyle programmes. Item response theory analysis was used to explore the internal properties of competing DAR models, and models were assessed against external criteria. The results showed that the number of item responses in the DAR exceeded channel capacity, and that response bias occurred in the second half of the instrument. We hypothesized that this was due to respondents not discriminating among the many response categories. Based on a modelling exercise in which we reduced the number of DAR items from 7 to 5 and the number of response categories from 9 to 5, validation tests showed that there was no loss of sensitivity, reliability or validity. To avoid confusion with the DAR, we have referred to the revised version of the DAR as the DAR5. We conclude that the DAR5, which abbreviates the original DAR to half its original length, has similar psychometric properties and is therefore to be preferred especially for

  20. Mapping the Risk of Forest Wind Damage Using Airborne Scanning LiDAR

    NASA Astrophysics Data System (ADS)

    Saarinen, N.; Vastaranta, M.; Honkavaara, E.; Wulder, M. A.; White, J. C.; Litkey, P.; Holopainen, M.; Hyyppä, J.

    2015-03-01

    Wind damage is known for causing threats to sustainable forest management and yield value in boreal forests. Information about wind damage risk can aid forest managers in understanding and possibly mitigating damage impacts. The objective of this research was to better understand and quantify drivers of wind damage, and to map the probability of wind damage. To accomplish this, we used open-access airborne scanning light detection and ranging (LiDAR) data. The probability of wind-induced forest damage (PDAM) in southern Finland (61°N, 23°E) was modelled for a 173 km2 study area of mainly managed boreal forests (dominated by Norway spruce and Scots pine) and agricultural fields. Wind damage occurred in the study area in December 2011. LiDAR data were acquired prior to the damage in 2008. High spatial resolution aerial imagery, acquired after the damage event (January, 2012) provided a source of model calibration via expert interpretation. A systematic grid (16 m x 16 m) was established and 430 sample grid cells were identified systematically and classified as damaged or undamaged based on visual interpretation using the aerial images. Potential drivers associated with PDAM were examined using a multivariate logistic regression model. Risk model predictors were extracted from the LiDAR-derived surface models. Geographic information systems (GIS) supported spatial mapping and identification of areas of high PDAM across the study area. The risk model based on LiDAR data provided good agreement with detected risk areas (73 % with kappa-value 0,47). The strongest predictors in the risk model were mean canopy height and mean elevation. Our results indicate that open-access LiDAR data sets can be used to map the probability of wind damage risk without field data, providing valuable information for forest management planning.

  1. A universal airborne LiDAR approach for tropical forest carbon mapping.

    PubMed

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

    2012-04-01

    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.

  2. Applying a weighted random forests method to extract karst sinkholes from LiDAR data

    NASA Astrophysics Data System (ADS)

    Zhu, Junfeng; Pierskalla, William P.

    2016-02-01

    Detailed mapping of sinkholes provides critical information for mitigating sinkhole hazards and understanding groundwater and surface water interactions in karst terrains. LiDAR (Light Detection and Ranging) measures the earth's surface in high-resolution and high-density and has shown great potentials to drastically improve locating and delineating sinkholes. However, processing LiDAR data to extract sinkholes requires separating sinkholes from other depressions, which can be laborious because of the sheer number of the depressions commonly generated from LiDAR data. In this study, we applied the random forests, a machine learning method, to automatically separate sinkholes from other depressions in a karst region in central Kentucky. The sinkhole-extraction random forest was grown on a training dataset built from an area where LiDAR-derived depressions were manually classified through a visual inspection and field verification process. Based on the geometry of depressions, as well as natural and human factors related to sinkholes, 11 parameters were selected as predictive variables to form the dataset. Because the training dataset was imbalanced with the majority of depressions being non-sinkholes, a weighted random forests method was used to improve the accuracy of predicting sinkholes. The weighted random forest achieved an average accuracy of 89.95% for the training dataset, demonstrating that the random forest can be an effective sinkhole classifier. Testing of the random forest in another area, however, resulted in moderate success with an average accuracy rate of 73.96%. This study suggests that an automatic sinkhole extraction procedure like the random forest classifier can significantly reduce time and labor costs and makes its more tractable to map sinkholes using LiDAR data for large areas. However, the random forests method cannot totally replace manual procedures, such as visual inspection and field verification.

  3. Estimating Above Ground Biomass using LiDAR in the Northcoast Redwood Forests

    NASA Astrophysics Data System (ADS)

    Rao, M.; Stewart, E.

    2010-12-01

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

  4. Building Damage Assessment after Earthquake Using Post-Event LiDAR Data

    NASA Astrophysics Data System (ADS)

    Rastiveis, H.; Eslamizade, F.; Hosseini-Zirdoo, E.

    2015-12-01

    After an earthquake, damage assessment plays an important role in leading rescue team to help people and decrease the number of mortality. Damage map is a map that demonstrates collapsed buildings with their degree of damage. With this map, finding destructive buildings can be quickly possible. In this paper, we propose an algorithm for automatic damage map generation after an earthquake using post-event LiDAR Data and pre-event vector map. The framework of the proposed approach has four main steps. To find the location of all buildings on LiDAR data, in the first step, LiDAR data and vector map are registered by using a few number of ground control points. Then, building layer, selected from vector map, are mapped on the LiDAR data and all pixels which belong to the buildings are extracted. After that, through a powerful classifier all the extracted pixels are classified into three classes of "debris", "intact building" and "unclassified". Since textural information make better difference between "debris" and "intact building" classes, different textural features are applied during the classification. After that, damage degree for each candidate building is estimated based on the relation between the numbers of pixels labelled as "debris" class to the whole building area. Calculating the damage degree for each candidate building, finally, building damage map is generated. To evaluate the ability proposed method in generating damage map, a data set from Port-au-Prince, Haiti's capital after the 2010 Haiti earthquake was used. In this case, after calculating of all buildings in the test area using the proposed method, the results were compared to the damage degree which estimated through visual interpretation of post-event satellite image. Obtained results were proved the reliability of the proposed method in damage map generation using LiDAR data.

  5. Characterizing Wildlife Habitat With LiDAR Data: Distribution Mapping Of Snags And Understory Shrubs

    NASA Astrophysics Data System (ADS)

    Martinuzzi, S.; Vierling, L.; Gould, W.; Falkowski, M.; Evans, J.; Hudak, A.; Vierling, K.

    2008-12-01

    Spatial data about the distribution of snags and understory shrubs is a major need for managing wildlife habitat in forests. We are evaluating the use of discrete return LiDAR data for predicting the distribution (presence/absence) of understory shrubs and different classes (i.e. diameters) of snags, in a managed, mixed-conifer forest in Northern Idaho, US. We are using a variety of ground and vegetation metrics derived from LiDAR data and the Random Forest algorithm to build our distribution models, and have obtained overall accuracies >80%. These preliminary results indicate that LiDAR data are valuable for predicting the distribution of understory shrubs and common snag diameter classes in the study area. In particular, LiDAR-derived metrics allow us to 1) quantify a variety of ecological factors (e.g. canopy structure, topography) that are known to influence the distribution and abundance of understory vegetation and snags in temperate, mountainous forests, and 2) quantify structural characteristics that are known to directly or indirectly indicate the presence of our classes of interest, such as the percent of vegetation returns in the lower strata of the canopy (for the shrubs), and the structural heterogeneity of the forest canopy (for the snags). Finally, and in order to further evaluate the use of LiDAR data for characterizing wildlife habitat, we integrate our maps of snags and shrubs distribution into models of habitat suitability, using four avian species (i.e. three woodpeckers and a flycatcher) as a case study.

  6. Water turbidity estimation from airborne hyperspectral imagery and full waveform bathymetric LiDAR

    NASA Astrophysics Data System (ADS)

    Pan, Z.; Glennie, C. L.; Fernandez-Diaz, J. C.

    2015-12-01

    The spatial and temporal variations in water turbidity are of great interest for the study of fluvial and coastal environments; and for predicting the performance of remote sensing systems that are used to map these. Conventional water turbidity estimates from remote sensing observations have normally been derived using near infrared reflectance. We have investigated the potential of determining water turbidity from additional remote sensing sources, namely airborne hyperspectral imagery and single wavelength bathymetric LiDAR (Light Detection and Ranging). The confluence area of the Blue and Colorado River, CO was utilized as a study area to investigate the capabilities of both airborne bathymetric LiDAR and hyperspectral imagery for water turbidity estimation. Discrete and full waveform bathymetric data were collected using Optech's Gemini (1064 nm) and Aquarius (532 nm) LiDAR sensors. Hyperspectral imagery (1.2 m pixel resolution and 72 spectral bands) was acquired using an ITRES CASI-1500 imaging system. As an independent reference, measurements of turbidity were collected concurrent with the airborne remote sensing acquisitions, using a WET Labs EcoTriplet deployed from a kayak and turbidity was then derived from the measured backscatter. The bathymetric full waveform dataset contains a discretized sample of the full backscatter of water column and benthic layer. Therefore, the full waveform records encapsulate the water column characteristics of turbidity. A nonparametric support vector regression method is utilized to estimate water turbidity from both hyperspectral imagery and voxelized full waveform LiDAR returns, both individually and as a fused dataset. Results of all the evaluations will be presented, showing an initial turbidity prediction accuracy of approximately 1.0 NTU. We will also discuss our future strategy for enhanced fusion of the full waveform LiDAR and hyperspectral imagery for improved turbidity estimation.

  7. Combined use of LiDAR data and multispectral earth observation imagery for wetland habitat mapping

    NASA Astrophysics Data System (ADS)

    Rapinel, Sébastien; Hubert-Moy, Laurence; Clément, Bernard

    2015-05-01

    Although wetlands play a key role in controlling flooding and nonpoint source pollution, sequestering carbon and providing an abundance of ecological services, the inventory and characterization of wetland habitats are most often limited to small areas. This explains why the understanding of their ecological functioning is still insufficient for a reliable functional assessment on areas larger than a few hectares. While LiDAR data and multispectral Earth Observation (EO) images are often used separately to map wetland habitats, their combined use is currently being assessed for different habitat types. The aim of this study is to evaluate the combination of multispectral and multiseasonal imagery and LiDAR data to precisely map the distribution of wetland habitats. The image classification was performed combining an object-based approach and decision-tree modeling. Four multispectral images with high (SPOT-5) and very high spatial resolution (Quickbird, KOMPSAT-2, aerial photographs) were classified separately. Another classification was then applied integrating summer and winter multispectral image data and three layers derived from LiDAR data: vegetation height, microtopography and intensity return. The comparison of classification results shows that some habitats are better identified on the winter image and others on the summer image (overall accuracies = 58.5 and 57.6%). They also point out that classification accuracy is highly improved (overall accuracy = 86.5%) when combining LiDAR data and multispectral images. Moreover, this study highlights the advantage of integrating vegetation height, microtopography and intensity parameters in the classification process. This article demonstrates that information provided by the synergetic use of multispectral images and LiDAR data can help in wetland functional assessment

  8. Object-Based Land Use Classification using Airborne LiDAR

    NASA Astrophysics Data System (ADS)

    Antonarakis, A. S.; Richards, K. S.; Brasington, J.

    2007-12-01

    Better information on roughness of various types of vegetation is needed for use in resistance equations and eventually in flood modelling. These types include woody riparian species with different structural characteristics. Remote Sensing information such as 3D point cloud data from LiDAR can be used as a tool for extracting simple roughness information relevant for the condition of below canopy flow, as well as roughness relevant for more complex tree morphology that affects the flow when it enters the canopy levels. A strategy for extracting roughness parameters from remote sensing techniques is to use a data fusion object classification model. This means that multiple datasets such as LiDAR, digital aerial photography, ground data and satellite data can be combined to produce roughness parameters estimated for different vegetative patches, which can subsequently be mapped spatially using a classification methodology. Airborne LiDAR is used in this study in order to classify forest and ground types quickly and efficiently without the need for manipulating multispectral image files. LiDAR has the advantage of being able to create elevation surfaces that are in 3D, while also having information on LiDAR intensity values, thus it is a spatial and spectral segmentation tool. This classification method also uses point distribution frequency criteria to differentiate between land cover types. The classification of three meanders of the Garonne and Allier rivers in France has demonstrated overall classification accuracies of 95%. Five types of riparian forest were classified with accuracies between 66-98%. These forest types included planted and natural forest stands of different ages. Classifications of short vegetation and bare earth also produced high accuracies averaging above 90%.

  9. Effects of LiDAR Derived DEM Resolution on Hydrographic Feature Extraction

    NASA Astrophysics Data System (ADS)

    Yang, P.; Ames, D. P.; Glenn, N. F.; Anderson, D.

    2010-12-01

    This paper examines the effect of LiDAR-derived digital elevation model (DEM) resolution on digitally extracted stream networks with respect to known stream channel locations. Two study sites, Reynolds Creek Experimental Watershed (RCEW) and Dry Creek Experimental Watershed (DCEW), which represent terrain characteristics for lower and intermediate elevation mountainous watersheds in the Intermountain West, were selected as study areas for this research. DEMs reflecting bare earth ground were created from the LiDAR observations at a series of raster cell sizes (from 1 m to 60 m) using spatial interpolation techniques. The effect of DEM resolution on resulting hydrographic feature (specifically stream channel) derivation was studied. Stream length, watershed area, and sinuosity were explored at each of the raster cell sizes. Also, variation from known channel location as estimated by root mean square error (RMSE) between surveyed channel location and extracted channel was computed for each of the DEMs and extracted stream networks. As expected, the results indicate that the DEM based hydrographic extraction process provides more detailed hydrographic features at a finer resolution. RMSE between the known channel location and modeled locations generally increased with larger cell size DEM with a greater effect in the larger RCEW. Sensitivity analyses on sinuosity demonstrated that the resulting shape of streams obtained from LiDAR data matched best with the reference data at an intermediate cell size instead of highest resolution, which is at a range of cell size from 5 to 10 m likely due to original point spacing, terrain characteristics, and LiDAR noise influence. More importantly, the absolute sinuosity deviation displayed a smallest value at the cell size of 10 m in both experimental watersheds, which suggests that optimal cell size for LiDAR-derived DEMs used for hydrographic feature extraction is 10 m.

  10. Conference on Resource Sharing in Southern and Central Africa (Dar-es-Salaam, Tanzania, December 16-19, 1985). Final Report.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific and Cultural Organization, Paris (France). General Information Programme.

    This document summarizes the activities of a conference held at the Institute of Finance Management in Tanzania on information resource sharing in Southern and Central Africa. Delegates and observers from Lesotho, Swaziland, Mozambique, Botswana, Zimbabwe, Malawi, Zambia, and Tanzania attended the conference. The 15 participants, 8 sponsored by…

  11. Social reactions to rape: experiences and perceptions of women rape survivors and their potential support providers in Dar es Salaam, Tanzania.

    PubMed

    Muganyizi, Projestine S; Hogan, Nora; Emmelin, Maria; Lindmark, Gunilla; Massawe, Siriel; Nystrom, Lennarth; Axemo, Pia

    2009-01-01

    Social reactions to rape are socioculturally determined and have a strong influence on the coping and recovery of the survivor. The existing knowledge on social reactions emanates from Western countries with limited research attention on non-Western populations, particularly sub-Saharan Africa. We aimed to establish the types and perceptions of social reactions that are expressed to rape survivors and people's intentions to express them to survivors of varied social backgrounds in Tanzania. Using triangulation of research methods, experiences of social reactions among rape survivors (n = 50) and nurses (n = 44) from a community in Tanzania were explored, and the intentions to express typical social reactions to rape survivors of different social backgrounds were established from a representative community sample (n = 1,505). Twelve typical social reactions were identified with the positive reactions more commonly mentioned than the negative reactions. Nondisclosure of rape events and distracting the survivor from the event were perceived as both positive and negative. A commercial sex worker was most vulnerable to negative reactions. The cultural influences of social reactions and implications for practical applicability of the results are discussed.

  12. Conference on Resource Sharing in Southern and Central Africa (Dar-es-Salaam, Tanzania, December 16-19, 1985). Final Report.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific and Cultural Organization, Paris (France). General Information Programme.

    This document summarizes the activities of a conference held at the Institute of Finance Management in Tanzania on information resource sharing in Southern and Central Africa. Delegates and observers from Lesotho, Swaziland, Mozambique, Botswana, Zimbabwe, Malawi, Zambia, and Tanzania attended the conference. The 15 participants, 8 sponsored by…

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

    ERIC Educational Resources Information Center

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

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

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

    ERIC Educational Resources Information Center

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

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

  15. ES Review: Selections from 2009 and 2010

    ERIC Educational Resources Information Center

    Smiles, Robin, Ed.

    2010-01-01

    This fourth edition of the "ES Review" brings together, in one setting, some of the best work from 2009-10. It features: (1) Teacher Quality (Teachers at Work: Improving Teacher Quality Through School Design (Elena Silva); Understanding Teachers Contracts (Andrew J. Rotherham); How Teachers Unions Lost the Media (Richard Whitmire and…

  16. ES Review: Selections from 2008 & 2009

    ERIC Educational Resources Information Center

    Smiles, Robin, Ed.

    2009-01-01

    This third edition of the "ES Review" brings together, in one setting, some of the best work from 2008-09. It features: (1) K-12 Accountability (Measuring Skills for the 21st Century (Elena Silva); Beyond the Bubble: Technology and the Future of Student Assessment (Bill Tucker); Testing the Limits (Bill Tucker); Changing the Game: The…

  17. ES Review: Selections from 2009 and 2010

    ERIC Educational Resources Information Center

    Smiles, Robin, Ed.

    2010-01-01

    This fourth edition of the "ES Review" brings together, in one setting, some of the best work from 2009-10. It features: (1) Teacher Quality (Teachers at Work: Improving Teacher Quality Through School Design (Elena Silva); Understanding Teachers Contracts (Andrew J. Rotherham); How Teachers Unions Lost the Media (Richard Whitmire and…

  18. ES Review: Selections from 2008 & 2009

    ERIC Educational Resources Information Center

    Smiles, Robin, Ed.

    2009-01-01

    This third edition of the "ES Review" brings together, in one setting, some of the best work from 2008-09. It features: (1) K-12 Accountability (Measuring Skills for the 21st Century (Elena Silva); Beyond the Bubble: Technology and the Future of Student Assessment (Bill Tucker); Testing the Limits (Bill Tucker); Changing the Game: The…

  19. Documenting CMIP6 with ES-DOC

    NASA Astrophysics Data System (ADS)

    Greenslade, Mark

    2017-04-01

    The Earth System Documentation (ES-DOC) project is an international effort aiming to deliver a robust earth system model inter-comparison project documentation infrastructure. Such infrastructure both simplifies & standardizes the process of documenting (in detail) projects, experiments, models, forcings & simulations. In support of CMIP6, ES-DOC has upgraded its eco-system of tools, web-services & web-sites. The upgrade consolidates the existing infrastructure (built for CMIP5) and extends it with the introduction of new capabilities. The strategic focus of the upgrade is improvements in the documentation experience and broadening the range of scientific use-cases that the archived documentation may help deliver. Whether it is highlighting dataset errors, exploring experimental protocols, comparing forcings across ensemble runs, understanding sub-mip objectives, reviewing citations, exploring component properties of configured models, visualizing inter-model relationships, scientists involved in CMIP6 will find the ES-DOC infrastructure helpful. During this PICO session scientists will be walked through demonstrations of various aspcects of the ES-DOC eco-system. Documentation will be created & published, viewed and compared. Following the walk-throughs scientitists will realize that documenting their work has been greatly simplified and provides concrete benefits.

  20. Object-based habitat mapping using very high spatial resolution multispectral and hyperspectral imagery with LiDAR data

    NASA Astrophysics Data System (ADS)

    Onojeghuo, Alex Okiemute; Onojeghuo, Ajoke Ruth

    2017-07-01

    This study investigated the combined use of multispectral/hyperspectral imagery and LiDAR data for habitat mapping across parts of south Cumbria, North West England. The methodology adopted in this study integrated spectral information contained in pansharp QuickBird multispectral/AISA Eagle hyperspectral imagery and LiDAR-derived measures with object-based machine learning classifiers and ensemble analysis techniques. Using the LiDAR point cloud data, elevation models (such as the Digital Surface Model and Digital Terrain Model raster) and intensity features were extracted directly. The LiDAR-derived measures exploited in this study included Canopy Height Model, intensity and topographic information (i.e. mean, maximum and standard deviation). These three LiDAR measures were combined with spectral information contained in the pansharp QuickBird and Eagle MNF transformed imagery for image classification experiments. A fusion of pansharp QuickBird multispectral and Eagle MNF hyperspectral imagery with all LiDAR-derived measures generated the best classification accuracies, 89.8 and 92.6% respectively. These results were generated with the Support Vector Machine and Random Forest machine learning algorithms respectively. The ensemble analysis of all three learning machine classifiers for the pansharp QuickBird and Eagle MNF fused data outputs did not significantly increase the overall classification accuracy. Results of the study demonstrate the potential of combining either very high spatial resolution multispectral or hyperspectral imagery with LiDAR data for habitat mapping.

  1. LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter

    PubMed Central

    Liu, Wanli

    2017-01-01

    The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated. PMID:28282897

  2. LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter.

    PubMed

    Liu, Wanli

    2017-03-08

    The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated.

  3. Development and validation of the Dimensional Anhedonia Rating Scale (DARS) in a community sample and individuals with major depression.

    PubMed

    Rizvi, Sakina J; Quilty, Lena C; Sproule, Beth A; Cyriac, Anna; Michael Bagby, R; Kennedy, Sidney H

    2015-09-30

    Anhedonia, a core symptom of Major Depressive Disorder (MDD), is predictive of antidepressant non-response. In contrast to the definition of anhedonia as a "loss of pleasure", neuropsychological studies provide evidence for multiple facets of hedonic function. The aim of the current study was to develop and validate the Dimensional Anhedonia Rating Scale (DARS), a dynamic scale that measures desire, motivation, effort and consummatory pleasure across hedonic domains. Following item selection procedures and reliability testing using data from community participants (N=229) (Study 1), the 17-item scale was validated in an online study with community participants (N=150) (Study 2). The DARS was also validated in unipolar or bipolar depressed patients (n=52) and controls (n=50) (Study 3). Principal components analysis of the 17-item DARS revealed a 4-component structure mapping onto the domains of anhedonia: hobbies, food/drink, social activities, and sensory experience. Reliability of the DARS subscales was high across studies (Cronbach's α=0.75-0.92). The DARS also demonstrated good convergent and divergent validity. Hierarchical regression analysis revealed the DARS showed additional utility over the Snaith-Hamilton Pleasure Scale (SHAPS) in predicting reward function and distinguishing MDD subgroups. These studies provide support for the reliability and validity of the DARS.

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

    NASA Astrophysics Data System (ADS)

    Bailey, Brian N.; Mahaffee, Walter F.

    2017-06-01

    The rapid evolution of high performance computing technology has allowed for the development of extremely detailed models of the urban and natural environment. Although models can now represent sub-meter-scale variability in environmental geometry, model users are often unable to specify the geometry of real domains at this scale given available measurements. An emerging technology in this field has been the use of terrestrial LiDAR scanning data to rapidly measure the three-dimensional geometry of trees, such as the distribution of leaf area. However, current LiDAR methods suffer from the limitation that they require detailed knowledge of leaf orientation in order to translate projected leaf area into actual leaf area. Common methods for measuring leaf orientation are often tedious or inaccurate, which places constraints on the LiDAR measurement technique. This work presents a new method to simultaneously measure leaf orientation and leaf area within an arbitrarily defined volume using terrestrial LiDAR data. The novelty of the method lies in the direct measurement of the fraction of projected leaf area G from the LiDAR data which is required to relate projected leaf area to total leaf area, and in the new way in which radiation transfer theory is used to calculate leaf area from the LiDAR data. The method was validated by comparing LiDAR-measured leaf area to (1) ‘synthetic’ or computer-generated LiDAR data where the exact area was known, and (2) direct measurements of leaf area in the field using destructive sampling. Overall, agreement between the LiDAR and reference measurements was very good, showing a normalized root-mean-squared-error of about 15% for the synthetic tests, and 13% in the field.

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

    PubMed Central

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

    2009-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

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

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

    USGS Publications Warehouse

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

    2011-01-01

    Airborne light detection and ranging (LiDAR) data were used to map water level (WL) and hydraulic gradients (??H/??x) in the Mackenzie Delta. The LiDAR WL data were validated against eight independent hydrometric gauge measurements and demonstrated mean offsets from - 0??22 to + 0??04 m (??< 0??11). LiDAR-based WL gradients could be estimated with confidence over channel lengths exceeding 5-10 km where the WL change exceeded local noise levels in the LiDAR data. For the entire Delta, the LiDAR sample coverage indicated a rate of change in longitudinal gradient (??2H/??x) of 5??5 ?? 10-10 m m-2; therefore offering a potential means to estimate average flood stage hydraulic gradient for areas of the Delta not sampled or monitored. In the Outer Delta, within-channel and terrain gradient measurements all returned a consistent estimate of - 1 ?? 10-5 m m-1, suggesting that this is a typical hydraulic gradient for the downstream end of the Delta. For short reaches (<10 km) of the Peel and Middle Channels in the middle of the Delta, significant and consistent hydraulic gradient estimates of - 5 ?? 10-5 m m-1 were observed. Evidence that hydraulic gradients can vary over short distances, however, was observed in the Peel Channel immediately upstream of Aklavik. A positive elevation anomaly (bulge) of > 0??1 m was observed at a channel constriction entering a meander bend, suggesting a localized modification of the channel hydraulics. Furthermore, water levels in the anabranch channels of the Peel River were almost 1 m higher than in Middle Channel of the Mackenzie River. This suggests: (i) the channels are elevated and have shallower bank heights in this part of the delta, leading to increased cross-delta and along-channel hydraulic gradients; and/or (ii) a proportion of the Peel River flow is lost to Middle Channel due to drainage across the delta through anastamosing channels. This study has demonstrated that airborne LiDAR data contain valuable information describing

  8. Importance of Hig