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Medical-education is associated with high overall stress and it is important to identify relevant factors.
The study was aimed to discern the differences in perceived stress among the students of public and private medical colleges of Pakistan and to identify factors subservient to any hypothesized difference.
This cross-sectional study was conducted at different private and public medical colleges of Pakistan using validated tools: PSS-14 (Perceived Stress Scale) to find out the levels of stress faced by each sector and MSSQ (Medical Student Stressor Questionnaire) to determine the factors associated with increased stress.
Total of 424 medical students from various public and private medical colleges of Pakistan (212 each) filled the questionnaires. The mean score +/- SD of PSS-14 was 36.17 ± 6.096 for the public sector and 36.29 ±5.732 for the private sector. Hence, there was no difference between the two comparative means of PSS score, t(422)=-0.213,p=0.831.The results for both sectors were classified as high perceived stress (27-40 score is high perceived stress). Out of 40 individual stress-causing factors in MSSQ, the students from private-sector scored higher as compared to public-sector: Quota System in examination t(422)=-3.951,p=0.000, stress caused by lack of time for friends and family t(422)=-3.225,p=0.001, stress caused by Tests/Examination t(422)=-2.131,p=0.034, stress caused by the parental wish for them to study medicine t(422)=-2.346,p=0.019 and stress caused by fear of getting poor marks t(422)=-2.183,p=0.030.
There exists no overall difference in the perceived-stress among the medical students of public and private medical colleges despite private-sectors having significantly more operational financial resources.
Intensity-modulated radiation therapy (IMRT) treatment delivery requires pre-treatment patient-specific quality assurance (QA) for the dosimetry verification due to its complex multileaf-collimator movement. The prostate target close position between the bladder and rectum requires a tight margin during planning, and mistreatment would have a huge impact on the patient. A commercially available QA tool consists of a homogeneous medium and does not represent an exact photon interaction on the tumour and also on the nearby healthy organ.
A heterogeneous male pelvis phantom was developed and investigated the efficiency of the treatment planning system (TPS) calculation on the off-axis region.
Polymethyl methacrylate was used for the phantom housing, and the material closed to the bladder, rectum and prostate density was chosen to construct the organ models. The phantom was scanned and validated by the computed tomography number and density. An IMRT treatment was planned in the Monaco TPS, and a thermoluminescent dosimeter (TLD-100) was used to validate the point dosimetry. In addition, an EGSnrc Monte Carlo simulation was carried out to validate the phantom dosimetry.
Results & Discussion:
The dose measurement between TLD-100, TPS, and EGSnrc was compared and validated in the pelvis phantom. In the prostate region, the dose difference was within ± 5%, and the maximum dose difference outside-the-irradiated field was up to 20·07 % and 47·31 % in TPS and TLD-100, respectively. Meanwhile, the measured dose was lower than the calculated dose, and it was apparent for the dose outside-the-irradiated field.
The developed heterogeneity male pelvis phantom was validated and verified to be an important QA device for validating radiation dosimetry in the pelvis region. The dose outside-the-irradiated field was underestimated by both TPS and TLD, respectively.
Background: MOG-IgG is associated with non-MS demyelinating disease of the optic nerves, spinal cord and brain. Specificity has been issue so we validated the live and fixed MOG-IgG CBAs against the Oxford Autoimmune Neurology Diagnostic Laboratory (OANG) live CBA as a comparator with high specificity. Methods: At BC Neuroimmunology lab (BCNI), 54 MOG-IgG serum samples previously positive by live-CBA at OANG and BCNI were blindly tested by commercial fixed CBA. All 54 MOG IgG positives came from MOG-IgG positive patients. In addition, 256 samples from healthy people and other neurolgic disease were tested. Results: The live MOG-IgG CBA performed at BCNI was 100% concordant (54/54) with OANG live CBA. In contrast, only 49/54 samples were found seropositive by the commercial fixed CBA. The BCNI live-CBA identified 3/256 control samples as positive while 6/256 controls were positive on the fixed commercial CBA. On this cohort the live CBA is 100% sensitive, 98.8% specific and has PPV of 95%. The commercial fixed MOG test is 91% sensitive, 97.6% specific and has PPV of 87.5%. Conclusions: BCNI live MOG-IgG CBAs are in 100% agreement with MOG-IgG. Three positive results in non-MOGAD associated clinical phenotype require further investigation. These data confirm the superiority of the live MOG CBA.
Mental disorder is common among individuals with neurological illness. We aimed to characterise the patient population referred for psychiatry assessment at a tertiary neurology service in terms of neurological and psychiatric diagnoses and interventions provided.
We studied all individuals referred for psychiatry assessment at a tertiary neurology service over a 2-year period (n= 82).
The most common neurological diagnoses among those referred were epilepsy (16%), Parkinson’s disease (15%) and multiple sclerosis (8%). The most common reasons for psychiatric assessment were low mood or anxiety (48%) and medically unexplained symptoms or apparent functional or psychogenic disease (21%). The most common diagnoses among those with mental disorder were mood disorders (62%), and neurotic, stress-related and somatoform disorders, including dissociative (conversion) disorders (28%). Psychiatric diagnosis was not related to gender, neurological diagnosis or psychiatric history.
Individuals with neurological illness demonstrate significant symptoms of a range of mental disorders. There is a need for further research into the characteristics and distribution of mental disorder in individuals with neurological illness, and for the enhancement of integrated psychiatric and neurological services to address the comorbidities demonstrated in this population.
This study aimed to describe the transmission dynamics, the serological and virus excretion patterns of Nipah virus (NiV) in Pteropus vampyrus bats. Bats in captivity were sampled every 7–21 days over a 1-year period. The data revealed five NiV serological patterns categorized as high and low positives, waning, decreasing and increasing, and negative in these individuals. The findings strongly suggest that NiV circulates in wild bat populations and that antibody could be maintained for long periods. The study also found that pup and juvenile bats from seropositive dams tested seropositive, indicating that maternal antibodies against NiV are transmitted passively, and in this study population may last up to 14 months. NiV was isolated from the urine of one bat, and within a few weeks, two other seronegative bats seroconverted. Based on the temporal cluster of seroconversion, we strongly believe that the NiV isolated was recrudesced and then transmitted horizontally between bats during the study period.
We report an experimental study of photocarrier lifetime, transport, and excitation spectra in silicon-on-insulator doped with sulfur far above thermodynamic saturation. The spectral dependence of photocurrent in coplanar structures is consistent with photocarrier generation throughout the hyperdoped and undoped sub-layers, limited by collection of holes transported along the undoped layer. Holes photoexcited in the hyperdoped layer are able to diffuse to the undoped layer, implying (μτ)h ∼ 5 × 10−9 cm2/V. Although high absorptance of hyperdoped silicon is observed from 1200 to 2000 nm in transmission experiments, the number of collected electrons per absorbed photon is 10−4 of the above-bandgap response of the device, consistent with (μτ)e < 1 × 10−7cm2/V.
Alzheimer's disease (AD) manifests clinically with an insidious onset and slow but progressive cognitive impairment. The clinical picture of AD can be classified into cognitive and behavioral changes. The initial deficit usually manifests as an amnesic syndrome which may progress very gradually for several years before impairment in other cognitive domains, such as language, semantic memory and visuospatial function, becomes apparent (Hodges and Patterson, 1995).
This study examined the role of food and water contamination in a health impact evaluation of a water and sanitation intervention project. Although lower diarrhoea rates were found in the improved area no consistent difference in food and water contamination was observed between areas. Furthermore, no relationship was found between contamination and diarrhoea in either area, even after controlling for the nutritional status of children. These results imply that other vehicles of transmission might be more important than food and water in diarrhoeal transmission. The focus of interventions should therefore be on changing behaviours to improve overall hygiene.
The aim of this study was to determine what weaning foods and food preparation practices expose children to a high risk of diarrhoeal disease through exposure to a contaminated diet. Bacterial contamination of 897 food and 896 drinking water samples was assessed in a water and santitation intervention project.
The geometric mean of faecal coliforms per g or ml was 7·5 x 103 in left-over rice, 1·4 x 102 in other types of boiled rice, 2·5 x 102 in milk, 4·8 in household drinking water, and 3·5 in bread. Multiplication of faecal coliforms occurred when there was a delay of more than 4 h between preparation and consumption of food. All samples were more contaminated in the rainy than in the dry season. Strategies to reduce contamination should therefore focus on ‘wet’ foods, early consumption after preparation, and re–heating of left–over foods. Understanding the reasons for the faulty practices is also essential to the formulation of effective measures.
Many vapor-deposited metal-on-insulator films exhibit a morphological progression with increasing thickness consisting of several distinct stages: (1) nucleation of 3-dimensional na-nocrystalline islands; (2) elongation of the islands; (3) film percolation. Here we report a study of this progression during Pulsed Laser Deposition (PLD), a technique for film deposition that differs from thermal deposition in that the depositing species arrive in short energetic bursts, leading to instantaneous deposition fluxes orders of magnitude higher than can be achieved in thermal growth. Atomic Force Microscopy reveals that advancement through this same morphological progression occurs at lower thickness in PLD films relative to films grown under comparable conditions by thermal deposition, with PLD films having lower RMS roughness at a given thickness. We also observe that for a constant amount deposited per pulse, films deposited at higher laser pulse frequency are further advanced in morphological state. Kinetic Monte Carlo simulations reveal that PLD nucleation behavior differs from that of thermally deposited films, and this can account for the observed differences. Simulations also reveal a scaling of the percolation thickness with pulse frequency that is consistent with experiment.
The tuffaceous sandstones and siltstones of the Ola Bula Formation in central Flores. east Indonesia, contain many fossil sites. Here, excavations at Boa Lesa and Dozu Dhalu and the results of regional site surveys are described. Stone artefacts indicate that hominids had arrived on the island by 840,000 years ago, post-dating a major change in the Lower Pleistocene fauna. Since water crossings were required to reach Flores from mainland Southeast Asia, this evidence has implications for the intellectual, technological and linguistic capabilities of early hominids.
We have studied the pressure-dependence of the interdiffusion rate in amorphous Si/Ge multilayers. Samples were annealed in an externally-heated diamond anvil cell at 693 K at pressures ranging from 0 to 3.1 GPa. Interdiffusion rates were determined by ex situ x-ray diffraction measurements of the decay of the artificial Bragg peaks associated with the multilayer periodicity. Scaling experiments were performed to factor out the effects of concentration and time dependence in the diffusivity. All samples showed a consistent increase in diffusivity with applied pressure, characterized by a negative activation volume ranging from −44±3 to −37±2 percent of the atomic volume of Si for films ranging in average Si composition from 25 to 71 percent, respectively. These results are consistent with a model for diffusion in amorphous Si and Ge based on dangling bond migration.
The stability of laser processed GeSi heteroepitaxial alloys on Si to partitioning driven interface instabilities is examined. Existing stability models are extended to include nonequi-librium solidification effects for nondilute alloys and are examined under typical conditions of laser induced solidification. Ge diffusion and partitioning were measured for quantitative input to the models. The Ge liquid-phase diffusivity was determined to be 2.5 x 10-4 cm2/s. The measured velocity-dependent partition coefficients k(v) were fit to the Continuous Growth Model using an equilibrium k of 0.45 and a diffusive speed of 2.7 m/s. Stability calculations based on these values and our extended stability model are presented. Although instabilities at compositions comparable to those experimentally observed to give defective films are predicted, the growth rates of these instabilities appear too slow to destabilize an interface on laser processing time scales. These results suggest that strain or other effects play an important role in the observed defective microstructures.
At the high growth rates accessible during pulsed-laser induced melting and
solidification and explosive crystallization, crystal growth kinetics are
dominated not by equilibrium thermodynamics, but by the atomistic mechanisms
by which crystallization proceeds. These Mechanisms can be probed by testing
the predictions of solute trapping models based on various crystal/Melt
interface structures against Measurements. We have measured the dependence
of solute trapping of several group III, IV, and V elements in silicon on
both interface orientation and crystallization speed. The Aperiodic Stepwise
Growth Model of Goldman and Aziz accurately fits both the velocity and
orientation dependence of the solute trapping observed in these systems. The
success of the model implies a ledge structure for the crystal/Melt
interface and a step-flow mechanism for crystal growth. In addition, we have
observed an empirical inverse correlation between the two free parameters
(“diffusive speeds”) in this model and the equilibrium solute partition
coefficient of a system. This correlation may be used to estimate values of
the diffusive speeds for other systems in which solute trapping has not been
or cannot be Measured.
We report initial results of an x-ray diffraction study of the
pressure-dependence of the interdiffusion rate in amorphous Si/Ge
Multilayers. Anneals were performed in a diamond anvil cell at 700 K for
various pressures and durations. Interdiffusion was measured by Monitoring
the rate of decay of the artificial Bragg peaks associated with the
multilayer periodicity. A consistent increase in diffusivity was seen with
pressure, characterized by an activation volume of -25±11 percent of the
atomic volume of Si. An atomistic mechanism that Might account for such
behavior is discussed.
We report preliminary results of a study of the activation volume for diffusion of arsenic in germanium. High-temperature high-pressure anneals were performed in a liquid argon pressure medium in a diamond anvil cell capable of reaching 5 GPa and 7500 C, which is externally heated for uniform and repeatable temperature profiles. The broadening of an ion-implanted arsenic profile was measured by Secondary Ion Mass Spectrometry. Hydrostatic pressure retards the diffusivity at 575°C, characterized by an activation volume that is +15% of the atomic volume of Ge. Implications for diffusion mechanisms are discussed.