Circuit Design for Thermal Compensation of Avalanche Photodiode

It has been observed that the breakdown voltage of the avalanche photodiode (APD) changes with the change in the ambient temperature. This situation may result in a poorer signal to noise ratio and sometimes to permanent damage to the APD. In order to overcome these problems, various considerations may be taken into account, including maintaining the temperature of the APD permanently or the design of a bias system, which would be self-adjusting according to any changes in the temperature. The latter technique was adopted and the design of a bias supply is presented in this article

The biochemical composition of body fluids, their osmolalities and ultrafiltrates

The serum osmolality has been determined in 101 cases of hypochloraemia. The cause of the chloride depletion was duo to vomiting, less often to continuous gastric suction, and rarely to diarrhoea or fistulae, associated with various clinical disorders. Patients were divided into three groups according to whether the serum osmolality was normal, decreased or increased. The patients in group I succeeded in maintaining the osmotic pressure within normal limits in spite of chloride depletion by the compensatory retention of bicarbonate and urea. This compensatory mechanism failed to operate in the group II patients where the loss of chloride eventually resulted in lowering the osmotic pressure. In group III patients, the serum osmolality was elevated in spite of low chloride, partly due to bicarbonate retention but mainly due to urea retention. There was a relationship between the increased serum osmolslity and urea concentration. Although the chloride ions contribute 35% of the total osmotic pressure, there was no relationship between the serum chloride concentration and the osmotic pressure in any of the three groups. The patients in group III may simply be the extension of group I cases. The transition of one group to the other probably coincides with the onset of renal dysfunction. This kidney involvement is a reversible process and, therefore, must be distinguished from renal disease. The patients in group II were quite distinct from the oases in the other two groups and wore not in the early stages of biochemical upset, end had not passed through the stages corresponding to other groups. Failure to retain urea and to maintain the osmotic pressure of extracellular fluids may be due to a defect in come mechanism presumably related to osmoregulatory centres, abnormal secretion of antidiuretic hormone or to renal tubular damage. PART 2. A new simple ultrafiltration technique has been described and the procedure outlined for ultrafiltration of blood serum. The importance of the method of sample collection, duration of ultrafiltration and pH was investigated. The ultrafiltration results were affected considerably by large changes in pH, while duration of ultrafiltration had no effect. For 20 healthy human subjects, the range for ultrafilterable celcium was found to be 55-61% of the total serum calcium. Ultrafiltration data on sera from patients with hyperparathyroidism before and after removal of parathyroid adenomas, hypoparathyroidism, vitamin D therapy, multiple myeloma, hyperealcaemia due to other causes, and renal disease has been presented. The serum ultrafilterable calcium was raised before operation in ever patient with a functioning parathyroid adenoma even though the serum total calcium was within the normal limits. After removal of the adenema, the serum ultrafilterable celcium always fell below normal. This fall was proportionately greater then the fall in the protein hound fraction. It was inferred that parathyroid hormone reduces the capacity of serum protein to hind calcium. This was supported by the observation of the effect of intravenous calcium on a human subject where the suppression of parathyroid glande resulted in an increase in the binding capacity. The ultrafilterable calcium was reduced in oases of hypercalcaemia due to causes other then hyperparathyroidium. This was also associated with reduced ultrafiltorability of inorgenic phosphate, possibly due to the formation of non-filterable calcium-phosphate-protein complex. Hence difficult cases such as these with functioning parathyroid adenoma associated with normal serum calcium values end cases with hypercalcaemia without parathyroid adenoma, the ultrafiltration results may be of some aid in the differiential diagnosis. The serum ultrafilterable calcium was found to be diminished in hypoparathyroidism, but poor correlation of the extent of tetany with either total serum calcium or the ultrafiltorable calcium was found to exist. Hypoprotenaemia was generally associated with hypocalcaemia, which was accompanied by normal or, more frequently, a high percentage ultrafiltorability of calcium. The hypoosicaemia present was due to the loss in the hound fraction. In renal disease although the total serum calcium was low the percentage of ultrafilterable calcium was almost invariably high, regardless of the concentration of serum proteins. The absence of tetany in those cases was not duo to acidosis alone. Other factors e.g. hypoalbuminaemia and the specific alteration in binding capacity of serum protein by the excess secretion of parathyroid hormone also contribute in maintaining the ultrafilterable calcium. Normal values for both serum and ultrefiltarable magnesium were found in hyperparathyroidism and in hypoparathyroidism. It was concluded that parathyroid glands play no part in magnesium metabolism

Cross-sectional survey of changes in knowledge, attitudes and practice of mask use in Sydney and Melbourne during the 2020 COVID-19 pandemic

Objectives Since mask uptake and the timing of mask use has the potential to influence the control of the COVID-19 pandemic, this study aimed to assess the changes in knowledge toward mask use in Sydney and Melbourne, Australia, during the 2020 COVID-19 pandemic. Design An observational study, using a cross-sectional survey, was distributed to adults in Sydney and Melbourne, Australia, during July-August 2020 (survey 1) and September 2020 (survey 2), during the COVID-19 pandemic in Australia. Setting and participants Participants aged 18 years or older and living in either Sydney or Melbourne. Primary and secondary outcome measures Demographics, risk measures, COVID-19 severity and perception, mask attitude and uptake were determined in this study. Results A total of 700 participants completed the survey. In both Sydney and Melbourne, a consistent decrease was reported in almost all risk-mitigation behaviours between March 2020 and July 2020 and again between March 2020 and September 2020. However, mask use and personal protective equipment use increased in both Sydney and Melbourne from March 2020 to September 2020. There was no significant difference in mask use during the pandemic between the two cities across both timepoints (1.24 (95% CI 0.99 to 1.22; p=0.072)). Perceived severity and perceived susceptibility of COVID-19 infection were significantly associated with mask uptake. Trust in information on COVID-19 from both national (1.77 (95% CI 1.29 to 2.44); p<0.000)) and state (1.62 (95% CI 1.19 to 2.22); p=0.003)) government was a predictor of mask use across both surveys. Conclusion Sydney and Melbourne both had high levels of reported mask wearing during July 2020 and September 2020, consistent with the second wave and mask mandates in Victoria, and cluster outbreaks in Sydney at the time. High rates of mask compliance may be explained by high trust levels in information from national and state government, mask mandates, risk perceptions, current outbreaks and the perceived level of risk of COVID-19 infection at the time

Integrated condition assessment models for sustainable sewer pipelines

The Federation of Canadian Municipalities (FCM) reported that approximately 55% of sewer infrastructure in Canada did not meet current standards. Therefore, burden on Canadian municipalities to maintain and prioritize sewers is increasing. One of the major challenges is to develop a framework to standardize the condition assessment procedures for sewer pipelines. Lack of detailed knowledge on the condition of sewer networks escalates vulnerability to catastrophic failures. This research presents a proactive methodology of assessing the existing condition of sewers by considering various physical, environmental, and operational influence factors. Based on historic data collected from two municipalities in Canada, structural and operational condition assessment models for sewers are developed using multiple regression technique. These models are utilized to generate deterioration curves for Concrete, Asbestos Cement, and Polyvinyl Chloride (PVC) sewers. A combined condition index (CCI) for sewers is developed, which integrates the combined effect of structural and operational conditions. The CCI is divided into 5 condition categories, ranging from "Acceptable" to "Critical". It is developed based on integrating the two major sewer condition assessment protocols adapted in Canada: WRc (Water Research Centre, UK) and CERIU (Centre for Expertise and Research on Infrastructures in Urban Areas, Canada). Unsupervised, self-organizing, neural network approach is used in order to develop the CCI and the integrated protocol. The developed regression models show 82% to 86% accuracy when they are applied to the validation data set. The CCI and integrated protocol are verified by municipal practitioners and experts of the CERIU sub-committee for developing a unified sewer condition assessment system. Based on the developed models, a web-based sewer condition assessment tool, coded in Java (version 5.0), is developed to predict structural and hydraulic conditions as well as the CCI. The developed models will assist municipal engineers in identifying critical sewers, prioritizing sewer inspections, and developing a unified sewer condition assessment system

An Internet of Things based bed-egress alerting paradigm using wearable sensors in elderly care environment

The lack of healthcare staff and increasing proportions of elderly population is alarming. The traditional means to look after elderly has resulted in 255,000 reported falls (only within UK). This not only resulted in extensive aftercare needs and surgeries (summing up to £4.4 billion) but also in added suffering and increased mortality. In such circumstances, the technology can greatly assist by offering automated solutions for the problem at hand. The proposed work offers an Internet of things (IoT) based patient bed-exit monitoring system in clinical settings, capable of generating a timely response to alert the healthcare workers and elderly by analyzing the wireless data streams, acquired through wearable sensors. This work analyzes two different datasets obtained from divergent families of sensing technologies, i.e., smartphone-based accelerometer and radio frequency identification (RFID) based accelerometer. The findings of the proposed system show good efficacy in monitoring the bed-exit and discriminate other ambulating activities. Furthermore, the proposed work manages to keep the average end-to-end system delay (i.e., communications of sensed data to Data Sink (DS)/Control Center (CC) + machine-based feature extraction and class identification + feedback communications to a relevant healthcare worker/elderly) below 1 10 th of a second

The REDS score: a new scoring system to risk-stratify emergency department suspected sepsis: a derivation and validation study.

OBJECTIVE: To derive and validate a new clinical prediction rule to risk-stratify emergency department (ED) patients admitted with suspected sepsis. DESIGN: Retrospective prognostic study of prospectively collected data. SETTING: ED. PARTICIPANTS: Patients aged ≥18 years who met two Systemic Inflammatory Response Syndrome criteria or one Red Flag sepsis criteria on arrival, received intravenous antibiotics for a suspected infection and admitted. PRIMARY OUTCOME MEASURE: In-hospital all-cause mortality. METHOD: The data were divided into derivation and validation cohorts. The simplified-Mortality in Severe Sepsis in the ED score and quick-SOFA scores, refractory hypotension and lactate were collectively termed 'component scores' and cumulatively termed the 'Risk-stratification of ED suspected Sepsis (REDS) score'. Each patient in the derivation cohort received a score (0-3) for each component score. The REDS score ranged from 0 to 12. The component scores were subject to univariate and multivariate logistic regression analyses. The receiver operator characteristic (ROC) curves for the REDS and the components scores were constructed and their cut-off points identified. Scores above the cut-off points were deemed high-risk. The area under the ROC (AUROC) curves and sensitivity for mortality of the high-risk category of the REDS score and component scores were compared. The REDS score was internally validated. RESULTS: 2115 patients of whom 282 (13.3%) died in hospital. Derivation cohort: 1078 patients with 140 deaths (13%). The AUROC curve with 95% CI, cut-off point and sensitivity for mortality (95% CI) of the high-risk category of the REDS score were: derivation: 0.78 (0.75 to 0.80); ≥3; 85.0 (78 to 90.5). VALIDATION: 0.74 (0.71 to 0.76); ≥3; 84.5 (77.5 to 90.0). The AUROC curve and the sensitivity for mortality of the REDS score was better than that of the component scores. Specificity and mortality rates for REDS scores of ≥3, ≥5 and ≥7 were 54.8%, 88.8% and 96.9% and 21.8%, 36.0% and 49.1%, respectively. CONCLUSION: The REDS score is a simple and objective score to risk-stratify ED patients with suspected sepsis

The Phylogeography of MERS-CoV in Hospital Outbreak-Associated Cases Compared to Sporadic Cases in Saudi Arabia.

This study compared the phylogeography of MERS-CoV between hospital outbreak-associated cases and sporadic cases in Saudi Arabia. We collected complete genome sequences from human samples in Saudi Arabia and data on the multiple risk factors of human MERS-CoV in Saudi Arabia reported from 2012 to 2018. By matching each sequence to human cases, we identified isolates as hospital outbreak-associated cases or sporadic cases. We used Bayesian phylogenetic methods including temporal, discrete trait analysis and phylogeography to uncover transmission routes of MERS-CoV isolates between hospital outbreaks and sporadic cases. Of the 120 sequences collected between 19 June 2012 and 23 January 2017, there were 64 isolates from hospital outbreak-associated cases and 56 from sporadic cases. Overall, MERS-CoV is fast evolving at 7.43 × 10-4 substitutions per site per year. Isolates from hospital outbreaks showed unusually fast evolutionary speed in a shorter time-frame than sporadic cases. Multiple introductions of different MERS-CoV strains occurred in three separate hospital outbreaks. MERS-CoV appears to be mutating in humans. The impact of mutations on viruses transmissibility in humans is unknown

Factors Associated with SARS-CoV-2 Attack Rates in Aged Care-A Meta-Analysis

Background: The coronavirus disease 2019 (COVID-19) pandemic has resulted in significant morbidity and mortality in aged-care facilities worldwide. The attention of infection control in aged care needs to shift towards the built environment, especially in relation to using the existing space to allow social distancing and isolation. Physical infrastructure of aged care facilities has been shown to present challenges to the implementation of isolation procedures. To explore the relationship of the physical layout of aged care facilities with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) attack rates among residents, a meta-Analysis was conducted. Methods: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocol (PRISMA-P), studies were identified from 5 databases using a registered search strategy with PROSPERO. Meta-Analysis for pooled attack rates of SARS-CoV-2 in residents and staff was conducted, with subgroup analysis for physical layout variables such as total number of beds, single rooms, number of floors, number of buildings in the facility, and staff per 100 beds. Results: We included 41 articles across 11 countries, reporting on 90 657 residents and 6521 staff in 757 facilities. The overall pooled attack rate was 42.0% among residents (95% CI, 38.0%-47.0%) and 21.7% in staff (95% CI, 15.0%-28.4%). Attack rates in residents were significantly higher in single-site facilities with standalone buildings than facilities with smaller, detached buildings. Staff-To-bed ratio significantly explains some of the heterogeneity of the attack rate between studies. Conclusions: The design of aged care facilities should be smaller in size, with adequate space for social distancing

Association of influenza infection and vaccination with cardiac biomarkers and left ventricular ejection fraction in patients with acute myocardial infarction

Aims: The aim of this study was to examine the association of influenza infection and vaccination with extent of cardiac damage during acute myocardial infarctions (AMIs) as measured by serum biomarkers and left ventricular ejection function (LVEF) in patients. Methods: Post-hoc analysis was performed on data from a prospective case-control study of influenza and AMI, conducted in a tertiary care hospital in Sydney, Australia. We included 275 cases of AMI, aged ≥ 40 years admitted to the cardiology during the study period. Results: Mean and median CK-MB levels were significantly higher among unvaccinated group compared to vaccinated group (p value < 0.05). Troponin levels were also higher among unvaccinated group compared to vaccinated group; although not statistically significant. Troponin and CKMB values were not statistically different among influenza positive cases and influenza negative cases. Large size infarcts were less frequent among vaccinated cases compared to unvaccinated cases (25% vs 35.5%) and were more frequent among influenza positive cases compared to influenza negative cases (35.3% vs 31.5%), however differences were not statistically significant. LVEF was lower among vaccinated cases compared to unvaccinated cases (62.5% vs. 52.8%) and influenza positive cases compared to influenza negative cases (58.8% vs 55.4), however differences were not significant. Conclusion: Lower CKMB levels among vaccinated groups showed that influenza vaccine may have a protective effect against large infarcts, therefore influenza vaccination should be recommended for high risk groups. The study suggests an association of larger infarcts with influenza infection, but larger studies are required to confirm this

Automated iterative neutrosophic lung segmentation for image analysis in thoracic computed tomography

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134994/1/mp2679.pd