Contamination of Kallar Kahar Lake by Inorganic Elements and Heavy Metals and their Temporal Variations

The present study was conducted to find out the contamination of Kallar Kahar Lake by inorganic elements and heavy metals and the temporal variation of these chemicals in the lake water. Water samples were collected on monthly basis during December 2001 to November 2002. Concentration of 10 inorganic elements and heavy metals (sodium, potassium, magnesium, iron, nickel, cobalt, copper, cadmium, lead and zinc) was analyzed in the lake water by atomic absorption spectroscopy. Mean monthly concentration of the inorganic elements and heavy metals in the lake water was: nickel 0.117 mg. L-1, iron 1.456 mg. L-1, cobalt 0.061 mg. L-1, copper 0.258 mg. L-1 , cadmium 0.024 mg. L-1, lead 0.118 mg. L-1 sodium 397.970 mg. L-1, magnesium 115.710 mg. L-1, potassium 28.290 mg. L-1 and zinc 1.412 mg. L-1. Analysis of variance showed temporal variations (P < 0.001) in concentration of inorganic elements and heavy metals in Kallar Kahar Lake water. The present study indicates that the concentrations of inorganic elements and heavy metals were not within the safe limit at the sampling site throughout the period of study and water of Kallar Kahar Lake is not suitablefor drinking, farming and aquaculture. @JASE

Theoretical study of isolated dangling bonds, dangling bond wires and dangling bond clusters on H:Si(100)-(2×\times1) surface

We theoretically study the electronic band structure of isolated unpaired and paired dangling bonds (DB), DB wires and DB clusters on H:Si(100)-(2$\times$1) surface using Extended H\"uckel Theory (EHT) and report their effect on the Si band gap. An isolated unpaired DB introduces a near-midgap state, whereas a paired DB leads to $\pi$ and $\pi^*$ states, similar to those introduced by an unpassivated asymmetric dimer (AD) Si(100)-(2$\times$1) surface. Such induced states have very small dispersion due to their isolation from the other states, which reside in conduction and valence band. On the other hand, the surface state induced due to an unpaired DB wire in the direction along the dimer row (referred to as $[\bar{1}10]$), has large dispersion due to the strong coupling between the adjacent DBs, being 3.84$\AA$ apart. However, in the direction perpendicular to the dimer row (referred to as [110]), due to the reduced coupling between the DBs being 7.68$\AA$ apart, the dispersion in the surface state is similar to that of an isolated unpaired DB. Apart from this, a paired DB wire in $[\bar{1}10]$ direction introduces $\pi$ and $\pi^*$ states similar to those of an AD surface and a paired DB wire in [110] direction exhibits surface states similar to those of an isolated paired DB, as expected. Besides this, we report the electronic structure of different DB clusters, which exhibit states inside the band gap that can be interpreted as superpositions of states due to unpaired and paired DBs.Comment: 7 pages, 10 figure, 1 tabl

Incoherent Transport through Molecules on Silicon in the vicinity of a Dangling Bond

We theoretically study the effect of a localized unpaired dangling bond (DB) on occupied molecular orbital conduction through a styrene molecule bonded to a n++ H:Si(001)-(2x1) surface. For molecules relatively far from the DB, we find good agreement with the reported experiment using a model that accounts for the electrostatic contribution of the DB, provided we include some dephasing due to low lying phonon modes. However, for molecules within 10 angstrom to the DB, we have to include electronic contribution as well along with higher dephasing to explain the transport features.Comment: 9 pages, 5 figure

Pattern of panic-buying and its psychosocial correlates among Pakistani adults during COVID-19 pandemic

Background: As the COVID-19 pandemic rages on, one bizarre yet ubiquitous human behavior has resurfaced. Globally, people have engaged in panic buying and hoarding (PBH). This irrational practice of panic buying is driven by deficient, manipulated news amid COVID-19 crisis.Methods: A cross-sectional study was conducted with Pakistani adults (≤18 years). Data was collected through an anonymous self-reported online survey from 17th April 2020 (0800 hours) through 20th April 2020 (2200 hours) via social media platforms. The survey consisted of sociodemographic characteristics, questions regarding food/essential supplies PBH and its psychosocial correlates- attitudes about COVID-19 severity (CA), values related to social responsibility (SR), social trust (ST), and self-interest (SI). Data was entered and analyzed using IBM Statistical package for social sciences (SPSS) version 20.Results: There were 786 participants in the survey; 59% were females. Mean age was 26.6±7.6 years. Mean PBH score was 2.31±0.85 (range: 1-5). Overall, 28.4% hoarded supplies a few times or more and 47% agreed to have bought more food/essential supplies due to COVID-19. Correlation analysis showed a 12.3% positive correlation of PBH with ST and 8.5% positive correlation with SI (p<0.05). In the multivariate regression model, PBH showed a statistically significant (p<0.05) positive impact on ST and SI.Conclusions: More than one-fourth of the individuals indulged in panic buying and hoarding during the COVID-19 in Pakistan. Fear of contracting the virus and uncertainty about the duration of lockdown was the common reasons behind PBH. Social trust and self-interest were significant psychosocial contributors to hoarding behavior.

Clinical spectrum of systemic lupus erythematosus at the Aga Khan University Hospital.

BACKGROUND: Systemic lupus erythematosus is a disease of unknown etiology, which at onest may involve only one organ system or be multisystemic. The aim of our study is to determine the clinical presentation of SLE patients presenting to AKUH to establish whether guidelines laid down about this disease are in agreement with our experience. METHODS: A retrospective log review was carried out at AKUH, based on data obtained from 165 files of individuals admitted to the hospital over a period of 12 years with a confirmed diagnosis of SLE. RESULTS: From the sample size of 165, 143 (86.7%) were females and 22 (13.3%) males. The mean age of diagnosis was 30.9 years. Frequency of symptomatology was observed to be in the following order: systemic 78.8%, musculoskeletal 63% and hematological 60.6%. Oninvestigation ANA levels were positive in 112 patients. CONCLUSION: Our result lead us to conclude that the classification set forth by the American Rheumatological Association is applicable to patients presenting with SLE in our setting

Typhoid and Paratyphoid Cost of Illness in Pakistan: Patient and Health Facility Costs from the Surveillance for Enteric Fever in Asia Project II

Background: The objective of this study was to estimate the cost of illness from enteric fever (typhoid and paratyphoid) at selected sites in Pakistan. Methods: We implemented a cost-of-illness study in 4 hospitals as part of the Surveillance for Enteric Fever in Asia Project (SEAP) II in Pakistan. From the patient and caregiver perspective, we collected direct medical, nonmedical, and indirect costs per case of enteric fever incurred since illness onset by phone after enrollment and 6 weeks later. From the health care provider perspective, we collected data on quantities and prices of resources used at 3 of the hospitals, to estimate the direct medical economic costs to treat a case of enteric fever. We collected costs in Pakistani rupees and converted them into 2018 US dollars. We multiplied the unit cost per procedure by the frequency of procedures in the surveillance case cohort to calculate the average cost per case. Results: We collected patient and caregiver information for 1029 patients with blood culture-confirmed enteric fever or with a nontraumatic terminal ileal perforation, with a median cost of illness per case of US $196.37 (IQR, US$72.89-496.40). The median direct medical and nonmedical costs represented 8.2% of the annual labor income. From the health care provider perspective, the estimated average direct medical cost per case was US $50.88 at Hospital A, US$52.24 at Hospital B, and US $11.73 at Hospital C. Conclusions: Enteric fever can impose a considerable economic burden in Pakistan. These new estimates of the cost of illness of enteric fever can improve evaluation and modeling of the costs and benefits of enteric fever prevention and control measures, including typhoid conjugate vaccines

Refractive-index sensing with ultra-thin plasmonic nanotubes

We study the refractive-index sensing properties of plasmonic nanotubes with a dielectric core and ultra-thin metal shell. The few-nm thin metal shell is described by both the usual Drude model and the nonlocal hydrodynamic model to investigate the effects of nonlocality. We derive an analytical expression for the extinction cross section and show how sensing of the refractive index of the surrounding medium and the figure-of-merit are affected by the shape and size of the nanotubes. Comparison with other localized surface plasmon resonance sensors reveals that the nanotube exhibits superior sensitivity and comparable figure-of-merit