365 research outputs found
Considering the impact of situation-specific motivations and constraints in the design of naturally ventilated and hybrid buildings
A simple logical model of the interaction between a building and its occupants is presented based on the principle that if free to do so, people will adjust their posture, clothing or available building controls (windows, blinds, doors, fans, and thermostats) with the aim of achieving or restoring comfort and reducing discomfort. These adjustments are related to building design in two ways: first the freedom to adjust depends on the availability and ease-of-use of control options; second the use of controls affects building comfort and energy performance. Hence it is essential that these interactions are considered in the design process. The model captures occupant use of controls in response to thermal stimuli (too warm, too cold etc.) and non-thermal stimuli (e.g. desire for fresh air). The situation-specific motivations and constraints on control use are represented through trigger temperatures at which control actions occur, motivations are included as negative constraints and incorporated into a single constraint value describing the specifics of each situation. The values of constraints are quantified for a range of existing buildings in Europe and Pakistan. The integration of the model within a design flow is proposed and the impact of different levels of constraints demonstrated. It is proposed that to minimise energy use and maximise comfort in naturally ventilated and hybrid buildings the designer should take the following steps: 1. Provide unconstrained low energy adaptive control options where possible, 2. Avoid problems with indoor air quality which provide motivations for excessive ventilation rates, 3. Incorporate situation-specific adaptive behaviour of occupants in design simulations, 4. Analyse the robustness of designs against variations in patterns of use and climate, and 5. Incorporate appropriate comfort standards into the operational building controls (e.g. BEMS)
Comfort driven adaptive window opening behaviour and the influence of building design
It is important to understand and model the behaviour of occupants in buildings and how this behaviour impacts energy use and comfort. It is similarly important to understand how a buildings design affects occupant comfort, occupant behaviour and ultimately the energy used in the operation of the building. In this work a behavioural algorithm for window opening developed from field survey data has been implemented in a dynamic simulation tool. The algorithm is in alignment with the proposed CEN standard for adaptive thermal comfort. The algorithm is first compared to the field study data then used to illustrate the impact of adaptive behaviour on summer indoor temperatures and heating energy. The simulation model is also used to illustrate the sensitivity of the occupant adaptive behaviour to building design parameters such as solar shading and thermal mass and the resulting impact on energy use and comfort. The results are compared to those from other approaches to model window opening behaviour. The adaptive algorithm is shown to provide insights not available using non adaptive simulation methods and can assist in achieving more comfortable and lower energy buildings
Development of an adaptive window-opening algorithm to predict the thermal comfort, energy use and overheating in buildings
This investigation of the window opening data from extensive field surveys in UK office buildings demonstrates: 1) how people control the indoor environment by opening windows; 2) the cooling potential of opening windows; and 3) the use of an ‘adaptive algorithm’ for predicting window opening behaviour for thermal simulation in ESP-r. It was found that when the window was open the mean indoor and outdoor temperatures were higher than when closed, but show that nonetheless there was a useful cooling effect from opening a window. The adaptive algorithm for window opening behaviour was then used in thermal simulation studies for some typical office designs. The thermal simulation results were in general agreement with the findings of the field surveys. The adaptive algorithm is shown to provide insights not available using non adaptive simulation methods and can assist in achieving more comfortable, lower energy buildings while avoiding overheating
First Panel Testing In SAARC Regional Networks of TB Reference Laboratories
Setting: South Asian Association for Regional Co-operation (SAARC) region with disproportionately high burden of TB
in comparison of regional population.
Objective: To establish a quality assurance on sputum smear microcopy in SAARC regional network of TB reference
laboratories.
Methods: Panel of slides were prepared and sent to national TB reference laboratories. The laboratory technician
read the slides and sent report to SAARC TB center and report were analyzed.
Results: Seven laboratories had no error of any type and one laboratory got two minor types of errors.
Conclusion: Mot of the laboratories had excellent performance in panel testing
Molecular mechanisms of drug resistance in natural Leishmania populations vary with genetic background
The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L.) donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread applicability
Glucose-6-phosphate dehydrogenase deficiency in people living in malaria endemic districts of Nepal
Background Glucose-6-phosphate dehydrogenase (G6PD) is a rate limiting enzyme of the pentose phosphate pathway and is closely associated with the haemolytic disorders among patients receiving anti-malarial drugs, such as primaquine. G6PD deficiency (G6PDd) is an impending factor for radical treatment of malaria which affects the clearance of gametocytes from the blood and subsequent delay in the achievement of malaria elimination. The main objective of this study was to assess the prevalence of G6PD deficiency in six malaria endemic districts in Southern Nepal. Methods A cross-sectional population based prevalence survey was conducted in six malaria endemic districts of Nepal, during April–Dec 2013. A total of 1341 blood samples were tested for G6PDd using two different rapid diagnostic test kits (Binax-Now® and Care Start™). Equal proportions of participants from each district (n ≥ 200) were enrolled considering ethnic and demographic representation of the population groups. Results Out of total 1341 blood specimens collected from six districts, the overall prevalence of G6PDd was 97/1341; 7.23% on Binax Now and 81/1341; 6.0% on Care Start test. Higher prevalence was observed in male than females [Binax Now: male 10.2%; 53/521 versus female 5.4%; 44/820 (p = 0.003) and Care Start: male 8.4%; 44/521 versus female 4.5%; 37/820 (p = 0.003)]. G6PDd was higher in ethnic groups Rajbanshi (11.7%; 19/162) and Tharu (5.6%; 56/1005) (p = 0.006), major inhabitant of the endemic districts. Higher prevalence of G6PDd was found in Jhapa (22/224; 9.8%) and Morang districts (18/225; 8%) (p = 0.031). In a multivariate analysis, male were found at more risk for G6PDd than females, on Binax test (aOR = 1.97; CI 1.28–3.03; p = 0.002) and Care Start test (aOR = 1.86; CI 1.16–2.97; p = 0.009). Conclusions The higher prevalence of G6PDd in certain ethnic group, gender and geographical region clearly demonstrates clustering of the cases and ascertained the risk groups within the population. This is the first study in Nepal which identified the vulnerable population groups for G6PDd in malaria endemic districts. The finding of this study warrants the need for G6PDd testing in vulnerable population groups in endemic districts, and also facilitates use of primaquine in mass supporting timely progress for malaria elimination
Results of Autogenous Trephine Biopsy Needle Bone Grafting in Fractures of Radius and Ulna
Cortico-Cancellous bone graft harvested from the anterior iliac crest by the conventional open method is
associated with more morbidity and is more time consuming as compared to the percutaneous method using
trephine biopsy needle. The aim of the study was to determine whether cancellous bone graft harvested from
anterior iliac crest using trephine biopsy needle consistently achieved bone union in comminuted fractures
and fractures of more than 3 weeks duration of radius and ulna and also to determine the morbidity at the
donor site.
Autogenous cancellous bone graft was harvested percutaneously from 28 iliac crests in 16 patients and
applied at fracture sites of 30 forearm bones using a 4mm trephine biopsy needle after the fratures had been
fixed with plate and screws. The patients were followed up regularly upto 6 to 9 months post - operatively in
the OPD to determine the union status of the fractured bones and the morbidity at the donor site.
29 of the 30 fractures of the forearm bones united without any problems. The shaft of a trephine got bent
during the harvesting procedure at the beginning of the study due to improper technique.
Cancellous bone graft harvested from the anterior iliac crest results in predictable good union results in
comminuted fractures of forearm bones and also fractures presenting after 3 weeks of injury. It is also an
easier and quicker way of harvesting bone graft and is associated with lesser morbidity and earlier recovery
as compared to conventional open method.
Key Words: Bone graft, trephine, fracture of radius and ulna morbidit
Analysis of erroneous data entries in paper based and electronic data collection
Objective Electronic data collection (EDC) has become a suitable alternative to paper based data collection (PBDC) in biomedical research even in resource poor settings. During a survey in Nepal, data were collected using both systems and data entry errors compared between both methods. Collected data were checked for completeness, values outside of realistic ranges, internal logic and date variables for reasonable time frames. Variables were grouped into 5 categories and the number of discordant entries were compared between both systems, overall and per variable category Results Data from 52 variables collected from 358 participants were available. Discrepancies between both data sets were found in 12.6% of all entries (2352/18,616). Differences between data points were identified in 18.0% (643/3580) of continuous variables, 15.8% of time variables (113/716), 13.0% of date variables (140/1074), 12.0% of text variables (86/716), and 10.9% of categorical variables (1370/12,530). Overall 64% (1499/2352) of all discrepancies were due to data omissions, 76.6% (1148/1499) of missing entries were among categorical data. Omissions in PBDC (n = 1002) were twice as frequent as in EDC (n = 497, p < 0.001). Data omissions, specifically among categorical variables were identified as the greatest source of error. If designed accordingly, EDC can address this short fall effectively
Assessment of deficits in specific cognitive domains in older adults living with HIV.
A significant proportion of people living with HIV (PLWH) have cognitive impairment. Moreover, approximately 70% of PLWH in the United States will be ≥50 years old by 2030, raising concerns of a higher incidence of dementia as they age. Accordingly, there is a clinical need to monitor their cognitive status. The aim of this study was to delineate specific cognition areas impacted in OALWH with a clinical diagnosis of neurocognitive impairment. We used a comprehensive set of tests (paper and NIH Toolbox Cognition Battery), to assess different cognitive domains in a total of 25 OALWH ≥ 50 years. 64% were diagnosed with neurocognitive impairment and 36% were non-impaired. T-scores were compared using t-tests of means. Differences in means and 95% confidence intervals (CI) were reported. Impaired patients scored on average 18.35 T-score points lower on Hopkins Verbal Learning Test (HVLT) retention trial (p 0.016, CI:6.74-29.97) and 9.19 T-score points lower on the NIH Picture Vocabulary Test (PVT) (p 0.033, CI:1.12-17.26). Stroop color word, NIH Card Sort and NIH Picture sequence memory test were trending to be significantly lower in impaired patients (p\u3c 0.07). In impaired OALWH, the HVLT data demonstrated a decreased capacity to learn and an early memory loss, suggesting frontal executive and attention type deficits. Moreover, the decreased PVT scores demonstrated an impact on crystallized intelligence, indicating decline in verbal skills, semantic knowledge, or retrieval. Overall, the observed deficits in different cognitive domains support early neurocognitive screening even when OALWH do not show overt signs of neurocognitive impairment
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