158 research outputs found
Aboveground forest biomass estimation with Landsat and LiDAR data and uncertainty analysis of the estimates.
Landsat Thematic mapper (TM) image has long been the dominate data source, and recently LiDAR has offered an important new structural data stream for forest biomass estimations. On the other hand, forest biomass uncertainty analysis research has only recently obtained sufficient attention due to the difficulty in collecting reference data. This paper provides a brief overview of current forest biomass estimation methods using both TM and LiDAR data. A case study is then presented that demonstrates the forest biomass estimation methods and uncertainty analysis. Results indicate that Landsat TM data can provide adequate biomass estimates for secondary succession but are not suitable for mature forest biomass estimates due to data saturation problems. LiDAR can overcome TM?s shortcoming providing better biomass estimation performance but has not been extensively applied in practice due to data availability constraints. The uncertainty analysis indicates that various sources affect the performance of forest biomass/carbon estimation. With that said, the clear dominate sources of uncertainty are the variation of input sample plot data and data saturation problem related to optical sensors. A possible solution to increasing the confidence in forest biomass estimates is to integrate the strengths of multisensor data
The use of emergency contraception among female senior high students in the Ho municipality of the Volta Region, Ghana
Background: Emergency contraception (EC) is one option for preventing unplanned pregnancy when it is available and properly used. Unsafe abortions are responsible for nearly one third of maternal deaths in sub-Saharan Africa and about quarter of unsafe abortions are among teenagers.Methods: A quantitative descriptive cross-sectional study. Data was collected using a pretested questionnaire. 260 senior high students were selected using a systematic sampling method in the Volta Region, Ghana. Data were cleaned and entered into SPSS version 22 and analysed into descriptive statistics.Results: Respondents acquired awareness about EC from friends (36.9%), family members (5.6%) and the mass media (41.6%). The required time for EC to be taken were stated as immediately after sex (57.9%), 24 hours after sex (1.2%) and (30.6%) did not know. 28.4% of participants indicated they would not use EC in the future as their faith was against it, 18.0% believed EC is ineffective and 24.9% consider it dangerous to their health. Reasons for use of EC included condom slipped (35.7%), inability to be on daily pill (33.7%), forced unprotected sex (8.2%) and miscalculation of the safe menstrual period (22.4%). There was a significant relationship between age and history of use of EC (p=0.000, c2=8.128, n=260).Conclusions: Strengthening education in Senior High Schools on sexual and reproductive health, with special emphasis on emergency contraceptives as a pregnancy preventive procedure will remain imperative to reducing the canker of maternal mortality attributed to adolescent abortions while improving understanding of the appropriate use of EC
Knowledge of pregnant women on the factors that influence anaemia in pregnancy in a rural farming district of the Western Region of Ghana
Background: The presence of anaemia in pregnancy is one of the serious public health concerns across the globe especially in developing countries like Ghana. This study assessed pregnant women's knowledge on factors influencing aneamia in pregnancy in a low-income district of Ghana.Methods: A quantitative descriptive cross-sectional study. Data was collected using a pretested questionnaire. 112 pregnant women seeking antenatal care were recruited using systematic sampling technique in the Wassa East district of Ghana. Data were cleaned and entered into SPSS version 22 and analysed into descriptive statistics.Results: Majority of participants; 72.3% did not know the causes of anaemia in pregnancy. Pregnant women (27.7%) indicated nutritional deficiency as a common cause of anaemia; 18.7% of them could identify appropriately at least one sign of anaemia in pregnancy with 28% asserting that pregnancy-related anaemia can affect labour, despite 72% indicating that anaemia could cause maternal mortality. The reasons for irregular ANC attendance included; perceived non importance of ANC (18.8%), financial difficulties (17.9%), health facility inaccessibility (18.8%) and time constraints (44.5%). There was a strong association between knowledge level on the cause of anaemia in pregnancy and the educational level of pregnant women (p=0.005 chi square = 50.289).Conclusions: Lack of knowledge on the importance of antenatal care and financial constraints were among the reasons leading to a surge in anaemia amongst pregnant women in the district. Health providers should incorporate services which enable pregnant women to access valuable information on anaemia prevention in pregnancy
A potential new tool for the toolbox: assessing gene drives for eradicating invasive rodent populations
Invasive rodents have significant negative impacts on island biodiversity. All but the smallest of rodent eradications currently rely on island-wide rodenticide applications. Although significant advances have been made in mitigating unintended impacts, rodent eradication on inhabited islands remains extremely challenging. Current tools restrict eradication eff orts to fewer than 15% of islands with critically endangered or endangered species threatened by invasive rodents. The Genetic Biocontrol of Invasive Rodents partnership is an interdisciplinary collaboration to develop and evaluate gene drive technology for eradicating invasive rodent populations on islands. Technological approaches currently being investigated include the production of multiple strains of Mus musculus with a modifi ed form of the native t-complex, or a CRISPR gene drive, carrying genes or mechanisms that determine sex. These systems have the potential to skew the sex ratio of off spring to approach 100% single-sex, which could result in population collapse. One goal proposed is to test the ability of constructs to spread and increase in frequency in M. musculus populations in biosecure, captive settings and undertake modelling to inform development and potential deployment of these systems. Structured ecologically-based risk assessments are proposed, along with social and cultural engagement to assess the acceptability of releasing a gene drive system. Work will be guided by an external ethics advisory board. Partners are from three countries with significant regulatory capacity (USA, Australia, New Zealand). Thus, we will seek data sharing agreements so that results from experiments may be used within all three countries and treat regulatory requirements as a minimum. Species-specific, scalable, and socially acceptable new eradication tools could produce substantial biodiversity benefits not possible with current technologies. Gene drive innovation may provide such a tool for invasive species management and be potentially transformative and worthy of exploring in an inclusive, responsible, and ethical manner
Clinical significance of hypoalbuminemia in outcome of patients with scrub typhus
<p>Abstract</p> <p>Background</p> <p>This study was designed to investigate the clinical significance of hypoalbuminemia as a marker of severity and mortality in patients with Scrub typhus.</p> <p>Methods</p> <p>The patients with scrub typhus were divided into two groups based on the serum albumin levels; Group I (serum albumin <3.0 g/dL) and Group II (serum albumin ≥3.0 g/dL). The outcome of patients with hypoalbuminemia was compared with that of normoalbuminemia.</p> <p>Results</p> <p>Of the total 246 patients who underwent the study, 84 patients (34.1%) were categorized as Group I and 162 patients were (65.9%) as Group II. Group I showed significantly higher incidence of confusion (24.6% vs. 5.3%, <it>p </it>< 0.001), pulmonary edema (15.8% vs. 3.2%, <it>p </it>= 0.002), pleural effusion (22.8% vs. 11.1%, <it>p </it>= 0.03), arrhythmia (12.3% vs. 2.6%, <it>p </it>= 0.008) and non-oliguric acute renal failure (40.4% vs. 11.1%, <it>p </it>< 0.001) compared to group II. Hypoalbuminemic group had a higher APACHE II score (11.37 ± 5.0 vs. 6.94 ± 4.2, <it>p </it>< 0.001), longer hospital stay (19.9 ± 42.1 days vs 7.5 ± 13.8 days, <it>p </it>= 0.012), and higher hospital cost compared to Group II.</p> <p>Conclusions</p> <p>This study showed hypoalbuminemia in scrub typhus was closely related to the frequency of various complication, longer hospital stay, consequently the higher medical cost, necessitating more efficient management of patients, including medical resources.</p
On Spatially Distributed Hydrological Ecosystem Services: Bridging the Quantitative Information Gap using Remote Sensing and Hydrological Models
One of the ways in which the CGIAR Research Program on Water, Land and Ecosystems (WLE) addresses the challenge of achieving sustainable growth is by improving our understanding of tradeoffs and synergies related to water, food, environment and energy. Essential to the success
of these efforts is the availability of quantitative data on these tradeoffs and synergies, and how
they vary across space and time.
Specifically for the countries sharing the Mekong River, WLE Greater Mekong seeks to drive and inform research and dialogue around the rivers of the region. Hydrological EcoSystem Services (HESS) are heavily affected by intensive development across the region, such as the construction of hydropower dams and land use changes - in particular deforestation, urbanization and agricultural intensification. The full extent of such changes in the agro-ecological system is often unknown, and it is a challenge to account for tradeoffs in HESS in policy processes. As in many other areas of the world, improving governance and management of water resources and associated land and ecosystems in the Greater Mekong region is not only a matter of generating more data. Sharing of knowledge and practices is a key focus of WLE Greater Mekong, which we strive to promote by enhancing the accessibility of valuable information to a wide diversity of regional stakeholders, and promoting dialogue by facilitating the creation of communities of practice. This white paper demonstrates state-of-the-art methods for assessing different HESS and their tradeoffs under different development scenarios. It explores opportunities for spatial monitoring of HESS and predicting changes under different future scenarios, information that is essential for achieving a balanced and healthy agro-ecological system. By relying on tools in the public domain and leveraging the resulting HESS data through online information platforms, this white paper is an excellent example of current efforts supported by WLE Greater Mekong to stimulate uptake of ecosystem services assessments in decision-making processes
End-of-study safety, immunogenicity, and efficacy of quadrivalent HPV (types 6, 11, 16, 18) recombinant vaccine in adult women 24–45 years of age
No short-cut in assessing trial quality: a case study
Assessing the quality of included trials is a central part of a systematic review. Many check-list type of instruments for doing this exist. Using a trial of antibiotic treatment for acute otitis media, Burke et al., BMJ, 1991, as the case study, this paper illustrates some limitations of the check-list approach to trial quality assessment. The general verdict from the check list type evaluations in nine relevant systematic reviews was that Burke et al. (1991) is a good quality trial. All relevant meta-analyses extensively used its data to formulate therapeutic evidence. My comprehensive evaluation, on the other hand, brought to the surface a series of serious problems in the design, conduct, analysis and report of this trial that were missed by the earlier evaluations. A check-list or instrument based approach, if used as a short-cut, may at times rate deeply flawed trials as good quality trials. Check lists are crucial but they need to be augmented with an in-depth review, and where possible, a scrutiny of the protocol, trial records, and original data. The extent and severity of the problems I uncovered for this particular trial warrant an independent audit before it is included in a systematic review
Larger and More Prominent Graphic Health Warnings on Plain-Packaged Tobacco Products and Avoidant Responses in Current Smokers: a Qualitative Study
Background: The introduction of tobacco plain packaging legislation in Australia meant that all tobacco products were to be sold in plain dark-brown packaging with 75 % front-of-pack graphic health warnings and standardised font type and size for brand name and product variant. The change in the size and prominence of the warnings has been proposed as a reason for behaviour change in smokers in terms of increased intentions to quit and quit attempts. Purpose: The current research examined attitudes and beliefs of cigarette smokers toward the increased size and prominence of the warnings and effects on their behaviour. Method: Participants (N = 160) completed open-ended responses to questions on beliefs, attitudes and responses to plain packaging. Responses were subjected to inductive thematic content analysis for key themes. Results: Four themes emerged from the analysis: emotional response to packaging, scepticism of health warnings, warnings and cessation behaviour, and avoidant coping behaviours. Participants reported increased negative emotional responses to the packaging and made specific reference to the graphic health warnings. Some participants attempted to discredit the messages. Others reported increased intentions to quit or quitting attempts. There were pervasive reports of avoidant responses including covering or hiding the warnings. Conclusion: Consistent with theories of illness perceptions and coping, current findings indicate that the larger, prominent graphic health warnings on plain-packaged tobacco products had pervasive effects on threat perceptions and subsequent behavioural responses. While some of the reported responses were adaptive (e.g. attempts to quit), others were maladaptive (e.g. avoiding the warnings)
Impact of housing on the survival of persons with AIDS
<p>Abstract</p> <p>Background</p> <p>Homeless persons with HIV/AIDS have greater morbidity and mortality, more hospitalizations, less use of antiretroviral therapy, and worse medication adherence than HIV-infected persons who are stably housed. We examined the effect of homelessness on the mortality of persons with AIDS and measured the effect of supportive housing on AIDS survival.</p> <p>Methods</p> <p>The San Francisco AIDS registry was used to identify homeless and housed persons who were diagnosed with AIDS between 1996 and 2006. The registry was computer-matched with a housing database of homeless persons who received housing after their AIDS diagnosis. The Kaplan-Meier product limit method was used to compare survival between persons who were homeless at AIDS diagnosis and those who were housed. Proportional hazards models were used to estimate the independent effects of homelessness and supportive housing on survival after AIDS diagnosis.</p> <p>Results</p> <p>Of the 6,558 AIDS cases, 9.8% were homeless at diagnosis. Sixty-seven percent of the persons who were homeless survived five years compared with 81% of those who were housed (p < 0.0001). Homelessness increased the risk of death (adjusted relative hazard [RH] 1.20; 95% confidence limits [CL] 1.03, 1.41). Homeless persons with AIDS who obtained supportive housing had a lower risk of death than those who did not (adjusted RH 0.20; 95% CL 0.05, 0.81).</p> <p>Conclusion</p> <p>Supportive housing ameliorates the negative effect of homelessness on survival with AIDS.</p
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