789 research outputs found

    An experimental study of ZigBee for body sensor networks

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    We present an experimental performance evaluation of ZigBee networks in the context of data-intensive body sensor networks (BSNs). IEEE 802.15.4/ZigBee devices were mainly developed for use in wireless sensors network (WSN) applications; however, due to characteristics such as low power and small form factor, they are also being widely used in BSN applications, making it necessary to evaluate their suitability in this context. The delivery ratio and end-to-end delay were evaluated, under contention, for both star and tree topologies. The reliability of the ZigBee network in a star topology without hidden nodes was very good (delivery ratio close to 100%), provided the acknowledgement mechanism was enabled. On the other hand, the performance in a tree topology was degraded due to router overload and the activation of the route maintenance protocol triggered by periods of high traffic load. The effect of the devices’ clock drift and hidden nodes on the reliability of the star network was modeled and validated through experimental tests. In these tests, the worst-case delivery ratio when the acknowledgment is used decreased to 90% with two sensor nodes, while for the non-acknowledged mode the result was of 13%. These results show that a mechanism for distributing the nodes’ traffic over the time is required to avoid BSN performance degradation caused by router overload, clock drift and hidden node issues.Fundação para a Ciência e Tecnologi

    Tissue losses and metabolic adaptations both contribute to the reduction in resting metabolic rate following weight loss

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    OBJECTIVE: To characterize the contributions of the loss of energy-expending tissues and metabolic adaptations to the reduction in resting metabolic rate (RMR) following weight loss. METHODS: A secondary analysis was conducted on data from the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy study. Changes in RMR, body composition, and metabolic hormones were examined over 12 months of calorie restriction in 109 individuals. The contribution of tissue losses to the decline in RMR was determined by weighing changes in the size of energy-expending tissues and organs (skeletal muscle, adipose tissue, bone, brain, inner organs, residual mass) assessed by dualenergy X-ray absorptiometry with their tissue-specific metabolic rates. Metabolic adaptations were quantified as the remaining reduction in RMR. RESULTS: RMR was reduced by 101 ± 12 kcal/d as participants lost 7.3 ± 0.2 kg (both p \u3c 0.001). On average, 60% of the total reduction in RMR were explained by energy-expending tissues losses, while 40% were attributed to metabolic adaptations. The loss of skeletal muscle mass (1.0 ± 0.7 kg) was not significantly related to RMR changes (r = 0.14, p = 0.16), whereas adipose tissue losses (7.2 ± 3.0 kg) were positively associated with the reduction in RMR (r = 0.42, p \u3c 0.001) and metabolic adaptations (r = 0.31, p \u3c 0.001). Metabolic adaptations were correlated with declines in leptin (r = 0.27, p \u3c 0.01), triiodothyronine (r = 0.19, p \u3c 0.05), and insulin (r = 0.25, p \u3c 0.05). CONCLUSIONS: During weight loss, tissue loss and metabolic adaptations both contribute to the reduction in RMR, albeit variably. Contrary to popularly belief, it is not skeletal muscle, but rather adipose tissue losses that seem to drive RMR reductions following weight loss. Future research should target personalized strategies addressing the predominant cause of RMR reduction for weight maintenance

    A DC-DC Step-Up mu-Power Converter for Energy Harvesting Applications, Using Maximum Power PointTracking, Based on Fractional Open Circuit Voltage

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    A DC-DC step-up micro power converter for solar energy harvesting applications is presented. The circuit is based on a switched-capacitorvoltage tripler architecture with MOSFET capacitors, which results in an, area approximately eight times smaller than using MiM capacitors for the 0.131mu m CMOS technology. In order to compensate for the loss of efficiency, due to the larger parasitic capacitances, a charge reutilization scheme is employed. The circuit is self-clocked, using a phase controller designed specifically to work with an amorphous silicon solar cell, in order to obtain themaximum available power from the cell. This will be done by tracking its maximum power point (MPPT) using the fractional open circuit voltage method. Electrical simulations of the circuit, together with an equivalent electrical model of an amorphous silicon solar cell, show that the circuit can deliver apower of 1132 mu W to the load, corresponding to a maximum efficiency of 66.81%

    Red Cell Distribution Width and Acute Complications of Diabetes

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    Context. Red cell distribution width (RDW) has been associated with type 2 diabetes (T2DM), however data in relation to diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar non-ketotic acidosis (HONK) remains unclear. Objective. The aim of this study was to evaluate the association between RDW, MCV, and RDW/MVC values and acute complications in T2DM. Patients and Methods. RDW was measured in 90 T2DM patients (30 DKA, 30 HONK and 30 T2DM without acute complications). Clinical variables were analyzed by One -Way ANOVA, Kruskal-Wallis and Pearson analysis with SPSS software. Diagnostic screening tests and ROC curve analysis determined the cut-off point of MCV,RDW and RDW/MCV values. Results. DKA patients had higher levels of plasma glucose (524.20 +/- 201.43mg/dL, p<0.001), HbA1c (10.73 +/- 2.29%, p<0.001), osmotic pressure (310.32 mosm/L, p<0.001), RDW (14.61 +/- 1.75g/L, p<0.01), and the RDW/MCV ratio (0.17 +/- 0.04%, p<0.01), compared to HONK patients. RDW/MCV cut-off value was 0.15 with 90% sensitivity 50% specifity these values for only MCV were 76.67%-70%, for only RDW were 76.67%-63.33% respectively. The area under curve values for the ability to reflect DKA for RDW and the RDW/MCV ratio were 0.708 and 0.766, respectively (p<0.001). Conclusions. RDW and RDW/MCV ratio were found associated with DKA and valuable in predicting DKA. However these parameters were not valuable in predicting HONK

    Introduction: World Fairs, Exhibitions and Anthropology

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    World fairs and exhibitions served as important venues for empires to showcase their industrial and technological achievements. Moreover, they also presented ‘civilisational models’ that portrayed Europeans as the most advanced and sophisticated and depicted the distant inhabitants as exotic and primitive. In portraying distant peoples, these contrasts were evident through their dress styles, dance, music, and performance of daily customs, but most noticeably, through their skin colours. With five articles focusing on world fairs and exhibitions in diverse locations and times, this special issue raises questions about the display and showcasing of humans that are still pertinent to the current contexts of anthropology. The articles call for ‘decolonising’ thoughts, discourses, and practices in political and public space in displaying contemporary cultures. While acknowledging the problematics and limits of ‘decolonisation’ itself, the articles reassess through a critical lens the connections between fairs and exhibitions in the early days of anthropology.info:eu-repo/semantics/publishedVersio

    ACENOCOUMAROL OR WARFARIN: WHICH IS THE CLINICIAN'S ALLY?

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    ABSTRACTWarfarin and acenocoumarol are commonly prescribed oral anticoagulant drugs that are used in the prevention and treatment of thromboembolicdisorders across the world. Although both these drugs act by a similar mechanism, there are significant differences between them, especially in termsof their half-lives, and more importantly, in their variability in response pharmacogenetically. This case report highlights an instance wherein warfarinproved to provide a much more stable anticoagulant cover, as compared to that provided by acenocoumarol.Keywords: Thrombosis, Bleeding, Antiphospholipid antibody syndrome, Anticoagulant, International normalized ratio

    Clinico-social parameters of diabetes among patientsutilizing emergency medical services

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    Background: Diabetes mellitus (DM) is increasing in its potential in developing countries. Rise in diabetic patients calling emergency medical services (EMS) is expected. It calls for thorough assessment of patients with DM utilizing EMS. In the present study, was to assess magnitude of DM among patients utilizing EMS and its clinico-social parameters.Methods: It was hospital record based observational study of patients calling EMS delivered by a tertiary care hospital in Pune, Maharashtra, India during 1st January 2013 to 31st December 2014. Patients with incomplete records were excluded. A person with medical background was trained to extract required information from hospital records. Patients with previously diagnosed DM were considered those who were on diet, oral hypoglycemic agents or taking insulin therapy and newly diagnosed patients with DM were considered those with the value of glycemia on admission >200 mg/dl in first 24 hours. Data analysis was done using SPSS 15.0 software.Results: 45.8% (894/1951) were Patients with DM out of that 78.19% (699/894) were known to have DM while 28.81% (195/1951) were new cases of DM. 5.1% (100/1951) patients had uncontrolled DM. DM was significantly more in >60 years age group and in urban residents (p<0.001). Patients with DM were significantly more to have breathlessness, altered sensorium and dyspnoea as major purpose to call EMS (p<0.001, <0.001 and 0.045 respectively). Other co-morbidities in the form of Hypertension, other cardiovascular abnormalities, COPD, CKD and history of CVA were significantly more among Patients with DM (p<0.001, except for COPD, p=0.027).Conclusions: There was a high burden of patients with DM on EMS. EMS teams should be well trained to diagnose and manage such emergencies. Mass awareness of screening for DM and its proper management will help to decrease such burden

    Validation of the modified Berlin questionnaire to identify patients at risk for the obstructive sleep apnoea syndrome

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    Background &amp; Objectives: Awareness regarding obstructive sleep apnoea (OSA) among general public as well as practicing physicians is low in India. The present study was undertaken to test the utility of modified Berlin questionnaire for risk categorization of OSA in Indian setting. Methods: The modified Berlin questionnaire was administered in 180 middle aged adults (of 320 screened), of whom, 104 underwent overnight polysomnograhy, in a cross-sectional study at a tertiary care, referral center in north India. Questionnaire addressed the presence of frequency of snoring, wake time sleepiness, fatigue, obesity and hypertension. Subjects with persistent and frequent symptoms in any two of these three domains were considered in high risk category for obstructive sleep apnoea. Overnight polysomnograhy was performed to measure apnoea and hypopnoea index (AHI). Results: Questions about the symptoms demonstrated internal consistency (Cronbach alpha correlations 0.92-0.96). Of the 180 respondents to the screening questions, 80 were in the high risk and the rest were in low risk group. For 104 subjects who underwent polysomnograhy, risk grouping was useful in prediction of AHI. High risk category predicted an AHI &#62; 5 with a sensitivity of 86 per cent, specificity of 95 per cent, positive and negative predictive values of 96 and 82 per cent respectively. These results were comparable to Berlin questionnaire study done in the western population for validation. Interpretation &amp; Conclusion: On the basis of the findings of present study it is concluded that administration of modified Berlin questionnaire prior to a polysomnography study can identify high risk subjects and can thus avoid unnecessary polysomnography studies especially in resource-limited settings. To identify subjects at risk for OSA syndrome in general population, this questionnaire can be applied. However, the findings of the present study need to be confirmed further in a large number of subjects in a community-based setting
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