Finite Element Analysis of WWCB WALL Panel Flexural Behaviour

In the present work, the finite element method is applied to understand the load–deflection response of Wood Wool Cement Board (WWCB) wall panel. The WWCB wall panel was  modelled using ANSYS finite element software with 8-noded SOLID65 and SOLID45 Element. The same parameters as the experimental data were used to  model the wall panel in FEA. Characteristic points on the load-deflection response curve predicted using finite element analysis (FEA) were compared to experimental data. The comparison shows that the ANSYS finite element program is capable of modelling and predicting the actual deformation behaviour for wall panels. Conclusions were then made as to the accuracy of using finite element modelling for analysis of WWCB wall panel

Thin-film fixed-bed reactor (TFFBR) for solar photocatalytic inactivation of aquaculture pathogen Aeromonas hydrophila

Background: Outbreaks of infectious diseases by microbial pathogens can cause substantial losses of stock in aquaculture systems. There are several ways to eliminate these pathogens including the use of antibiotics, biocides and conventional disinfectants, but these leave undesirable chemical residues. Conversely, using sunlight for disinfection has the advantage of leaving no chemical residue and is particularly suited to countries with sunny climates. Titanium dioxide (TiO2) is a photocatalyst that increases the effectiveness of solar disinfection. In recent years, several different types of solar photocatalytic reactors coated with TiO2 have been developed for waste water and drinking water treatment. In this study a thin-film fixed-bed reactor (TFFBR), designed as a sloping flat plate reactor coated with P25 DEGUSSA TiO2, was used. Results: The level of inactivation of the aquaculture pathogen Aeromonas hydrophila ATCC 35654 was determined after travelling across the TFFBR under various natural sunlight conditions (300- 1200 W m-2), at 3 different flow rates (4.8, 8.4 and 16.8 L h-1). Bacterial numbers were determined by conventional plate counting using selective agar media, cultured (i) under conventional aerobic conditions to detect healthy cells and (ii) under conditions designed to neutralise reactive oxygen species (agar medium supplemented with the peroxide scavenger sodium pyruvate at 0.05% w/v, incubated under anaerobic conditions), to detect both healthy and sub-lethally injured (oxygen-sensitive) cells. The results clearly demonstrate that high sunlight intensities (≥600 W m-2) and low flow rates (4.8 L h-1) provided optimum conditions for inactivation of A. hydrophila ATCC 3564, with greater overall inactivation and fewer sub-lethally injured cells than at low sunlight intensities or high flow rates. Low sunlight intensities resulted in reduced overall inactivation and greater sub-lethal injury at all flow rates.Conclusions: This is the first demonstration of the effectiveness of the TFFBR in the inactivation of Aeromonas hydrophila at high sunlight intensities, providing proof-of-concept for the application of solar photocatalysis in aquaculture systems

Prevalence of obesity and overweight, its clinical markers and associated factors in a high risk South-Asian population

Background: Obesity is a global epidemic, which is a risk factor for cardiovascular diseases and metabolic abnormalities. It is measured by body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), body fat (BF) distribution and abdominal fat mass, each having its own merits and limitations. Variability in body composition between ethnic groups in South-Asians is significant and may not be truly reflected by BMI alone, which may result in misclassification. This study therefore, aims to determine the frequency of obesity, body fat composition and distribution, in a high risk population of an urban slum of Karachi, Pakistan. This survey included 451 participants selected by systematic sampling who were administered pre-tested questionnaires on socio-demographics, diet and physical activity. Chi-square was used to determine the association between categorical variables and multiple linear regression was used for quantitative variables. A P value of less than 0.05 was considered significant.Results: Classified by BMI, 29% study subjects were overweight and 21% obese (58.7% with central obesity). Body fat percent (BF%) classified 81% as overweight. Females were more obese (P 0.03) with higher prevalence of central obesity (P \u3c 0.001) and WHR (P 0.003) but with a lower muscle mass (P 0.001). Activity score and muscle mass showed inverse linear association with BF% whereas, WC, weight, BMI and WHR had a positive linear association with BF%. The relationship between BMI and BF% was quadratic with a weaker association at lower BMI. Adjusting for socio-demographic variables, BF%, weight, diastolic blood pressure (DBP), BMI and score on the diet questionnaire had a positive linear association with WC, while WC, WHR and BP had a positive linear association with BF%. BF%, muscle content and WC had a positive linear association with BMI.Conclusion: Considering lower cut-offs for South-Asians BMI and WC, this study showed a high prevalence of obesity among a sub-urban population of Karachi, which was even higher when BF% was measured. Considering the rising prevalence of non-communicable diseases, BF%, WC, WHR and BMI measurements are convenient and feasible means of identifying population at risk and hence addressing it through public awareness and early detection

Frequency and determinants of vaginal infection in postpartum period: a cross sectional survey from low socioeconomic settlements, Karachi, Pakistan

Objective: To determine the frequency and factors associated with perceived vaginal infections among married women in their postpartum period. Methods: A cross-sectional study was conducted from July 2000 to October 2000 in five squatter settlements of Karachi, Pakistan. These squatter settlements were selected on the basis of an existing surveillance system run by female community health workers for maternal and child healthcare which identified women who had delivered 42-56 days prior to the date of interview. Vaginal infection was considered present when a mother perceived foul smelling vaginal discharge during the postpartum period. Mothers were interviewed to gain insight into socioeconomic and demographic variables, materials used to staunch lochia, duration of labour, personal and perineal hygiene and past obstetric history. Results: A total of 525 women were interviewed. The estimated prevalence of perceived vaginal infection was 5.1%. Factors associated with perceived vaginal infections included, delivery conducted by a non-medical personnel (AOR 3.5, CI 1.3-9.5) and use of unhygienic cloth or cotton for staunch of lochia (AOR 2.7, CI 1.1-6.2). Conclusion: Among women who reported perceived vaginal infection, a higher proportion were delivered by non-medical personnel, and used unhygienic material (cloth or cotton) for staunch of lochia as compared to women who did not perceive vaginal infection. We recommend deliveries to be conducted by trained personnel and provision of health education for persons who conduct delivery and women to use hygienic material for staunch of lochia during post partum period (JPMA 56:99;2006)

Knowledge and practice of radiation safety among invasive cardiologists

OBJECTIVE: To assess the availability, practices and knowledge of radiation safety measures among invasive cardiologists in a tertiary care hospital. METHOD: A cross sectional survey of invasive cardiologists working in academic institutions was conducted using a questionnaire. RESULTS: A total of 28 cardiologists completed the questionnaire with a mean working experience of 10.5 + 7.6 years. All were of the opinion that radiation safety is extremely important and 93% always used lead aprons. Less than half of them used other radiation protective measures including thyroid collar, lead eyeglasses and lead shields. Only 7% regularly utilized a radiation dose badge to monitor the exposure. This may be related to the availability, as lead aprons are readily available but other devices i.e. lead glasses, lead shield and radiation dose badge is available to less than a third of them. On evaluating knowledge only one fourth knew more than 60% of the answers to questions testing the basic principles of radiation safety. When working experience of cardiologists was correlated with their knowledge and practice of radiation safety surprisingly a paradoxical relationship was noted. Mean number of correct answers in those with experience of \u3e 10 years vs \u3c 10 years was 45% vs 56%, p \u3c 0.03. All of the above findings are probably because less than 50% have received any formal education in this important field. CONCLUSIONS: There is a lack of standard radiation safety measures and equipments in cardiac catheterization laboratories. Significant lapses exist in practice and lack of knowledge of radiation safety among invasive cardiologists in this part of the world. With rapid growth in the number of cardiac catheterization laboratories in developing countries significant improvement in knowledge, practice and availability of radiation safety measures is needed

City tumour board Karachi: an innovative step in multidisciplinary consensus meeting and its two years audit.

Management of cancer patients is a team work which usually comprises of surgeons, oncologists, radiologists, pathologists, psychiatrist, nutritionist and a nurse. Any patient who is suffering from any tumour needs a multimodality meeting as cancer treatment is not a single persons job. Most of the time, it is difficult to get the whole team together for a plan discussion due to their busy schedule. This problem was overcome by starting a tumour board meeting early morning of Sunday in Karachi which was named City Tumour Board (CTB) Karachi . Its first meeting was held on Sunday March 28, 2010 and since then it takes place regularly fortnightly. Till March 2012, 44 sessions were conducted and total 264 cases were discussed. Here we present an audit of these two years. On average, in 60% of cases, tumour was up (36%) or down staged (12%) while in 52% of cases the stage remained unchanged. In 70% of cases (inclusive of above 60%), initial treatment plan was changed after discussion in the tumour board. This data signifies the importance of tumour board especially in a Pakistani setup where patient and even referring persons are not well aware of this disease and its outcome. It is advisable that every case should be discussed in tumour board before embarking on any treatment so that the best treatment plan can be given. It is also important that all relevant specialists should be present in the tumour board when planning for any treatment

Integrating Explainability into Graph Neural Network Models for the Prediction of X-ray Absorption Spectra

The use of sophisticated machine learning (ML) models, such as graph neural networks (GNNs), to predict complex molecular properties or all kinds of spectra has grown rapidly. However, ensuring the interpretability of these models’ predictions remains a challenge. For example, a rigorous understanding of the predicted X-ray absorption spectrum (XAS) generated by such ML models requires an in-depth investigation of the respective black-box ML model used. Here, this is done for different GNNs based on a comprehensive, custom-generated XAS data set for small organic molecules. We show that a thorough analysis of the different ML models with respect to the local and global environments considered in each ML model is essential for the selection of an appropriate ML model that allows a robust XAS prediction. Moreover, we employ feature attribution to determine the respective contributions of various atoms in the molecules to the peaks observed in the XAS spectrum. By comparing this peak assignment to the core and virtual orbitals from the quantum chemical calculations underlying our data set, we demonstrate that it is possible to relate the atomic contributions via these orbitals to the XAS spectrum

Integrating Explainability into Graph Neural Network Models for the Prediction of X-ray Absorption Spectra

The use of sophisticated machine learning (ML) models, such as graph neural networks (GNNs), to predict complex molecular properties or all kinds of spectra has grown rapidly. However, ensuring the interpretability of these models’ predictions remains a challenge. For example, a rigorous understanding of the predicted X-ray absorption spectrum (XAS) generated by such ML models requires an in-depth investigation of the respective black-box ML model used. Here, this is done for different GNNs based on a comprehensive, custom-generated XAS data set for small organic molecules. We show that a thorough analysis of the different ML models with respect to the local and global environments considered in each ML model is essential for the selection of an appropriate ML model that allows a robust XAS prediction. Moreover, we employ feature attribution to determine the respective contributions of various atoms in the molecules to the peaks observed in the XAS spectrum. By comparing this peak assignment to the core and virtual orbitals from the quantum chemical calculations underlying our data set, we demonstrate that it is possible to relate the atomic contributions via these orbitals to the XAS spectrum

Transition metal acetylsalicylates and their anti-inflammatory activity.

Mononuclear and binuclear transition metal [Co(II), Cu(II), Ni(II) and Zn(II)] acetylsalicylates of the type [M(L)2], [M(L)2Cl2] and [(M)2(L)4] have been prepared and characterized on the basis of their physical, spectral and analytical data. The complexes have been investigated in an in vivo animal model for anti-inflammatory activity and show a better effect and a more potent action than acetylsalicylic acid