212 research outputs found

    Effect of Saline and Non-Specific Insulin Binding on the Phase Behavior of Poly (Ethylene Glycol)-Grafted Phosphoethanolamine-Succinyl Model Membranes

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    Poly (ethylene glycol)-grafted membrane-mimetic surfaces bearing negatively charged phospholipid headgroups have gained significant attention due to their promising contributions in numerous biomedical applications. The conformational properties of PEG chains have been mainly studied at the air/water interface, which does not elucidate much about its behavior at the physiological pH ~ 7.4. In this contribution, binary mixtures of a phosphoethanolamine-Succinyl bearing C16 aliphatic chains, DPPE-Succinyl, and a PEG-phospholipid conjugate bearing a PEG chain of 2000 Da, DPPE-PEG2000, have been used as ideal models of bio-nonfouling membrane-mimetic surfaces. The effect of PBS with pH ~7.4 as well as each of its individual constituents including Na2HPO4, KCl, KH2PO4, and NaCl on the biophysical properties of model membrane was examined. Our findings suggest that saline and each of its individual constituents play a pivotal role in the phase and conformational behavior of PEG-grafted membrane models. Insulin as a model protein was then selected to further investigate the effect of phase and conformation behavior of PEG-grafted membrane models on protein/membrane interactions. The insulin/membrane interactions were quantified in terms of monolayer area expansion, ΔA, penetration area, Ap, as well as protein binding degree, χp. To the best of our knowledge, this study provides the first insight into mechanistic aspects of protein interactions with model negatively charged PEG-grafted membranes. This knowledge, may aid in understanding the in-vivo performance of advanced targeted therapeutic carriers

    Linear Sigma Models in QCD and S3 Symmetry for Neutrinos

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    This thesis has two parts with different topics in particle physics. In part I, we consider various linear sigma models and their applications to scalar mesons. It is shown that the tree amplitude for ππ scattering in the minimal linear sigma model has an exact expression which induces an infinite geometric series in which the pattern for both the I = 0 and I = 2 s-wave scattering lengths to orders p2p^2, p4p^4 and p6p^6 seems to agree with chiral perturbation theory predictions. The model is then gauged to study the mass differences between the vector meson and the axial vector meson as a possibly useful template for the role of a light scalar in QCD as well as for (at a different scale) an effective Higgs sector for some recently proposed walking technicolor models. The model is applied to the s-wave pion-pion scattering in QCD. Both the near threshold region and (with an assumed unitarization) the global region up to about 800 MeV are considered. It is noted that there is a little tension between the choice of bare sigma mass parameter for describing these two regions. By including the parity reversed partner we study a simple two Higgs dou-blet model which reflects, in a phenomenological way, the idea of compositeness for the Higgs sector. It is relatively predictive. In one scenario, it allows for a hidden usual Higgs particle in the 100 GeV region and a possible dark matter candidate. Poles in unitarized [pi pi] scattering amplitude are studied in a generalized linear sigma model which contains two scalar nonets (one of quark-antiquark type and the other of diquark-antidiquark type) and two corresponding pseu- doscalar nonets. It is shown that a reasonable agreement with experimental data is obtained up to about 1 GeV. Some comparison is made to the situation in the usual SU(3) linear sigma model with a single scalar nonet. We show that the mixing of two bare nonets, one of which is of quark- antiquark type and the other of two quark- two antiquark type is, before chiral symmetry breaking terms are included, only possible for three flavors. Specif ically, our criterion would lead one to believe that scalar and pseudoscalar states containing charm would not have four quark admixtures. We also discuss some aspects associated with the possibility of getting new experi- mental information about scalars from semileptonic decays of heavy charged mesons into an isosinglet scalar or pseudoscalar plus leptons. In part II we explore a predictive model based on permutation symmetry S3 for the masses and mixing matrix of three Majorana neutrinos. At zeroth order the model yielded degenerate neutrinos and a generalized tribimaximal mixing matrix. We first study the effects of the perturbation which violates S3 but preserves the well known (23) interchange symmetry. This is done in the presence of an arbitrary Majorana phase ψ which serves to insure the degeneracy of the three neutrinos at the unperturbed level. At this order the mass splitting was incorporated and the tribimaximal mixing matrix emerged with very small corrections but with a zero value for the parameter s13. Next a different, assumed weaker, perturbation is included which gives a non zero value for s13 and further corrections to other quantities. These corrections are worked out and their consequences discussed under the simplifying assumption that the conventional CP violation phase vanishes. It is shown that the existing measurements of the parameter s23 provide strong bounds on s13 in this model

    Calendar Anomalies in Stock Market: A Case of KSE 100 Index

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    This paper aims to investigate the calendar anomalies in Karachi Stock exchange by using KSE 100 index during the period of 2008 to 2012. The study examined the existence of week days, weekend and monthly seasonal anomalies. These calendar effects are examined by applying different statistical techniques. First of all series of daily and monthly returns were calculated. Then mean and standard deviation of daily and monthly returns were calculated. The values of mean and standard deviation have rejected the first two null hypothesis and accepted the third one. The results provide an evidence for the existence of calendar anomalies at KSE 100 index. The results showed that there is significant difference among the returns of days of the week, and Friday has highest mean average return which makes it confirm that weekend effect exists at KSE. Finally monthly anomaly in stock returns is also present because there is highest positive return in the month of March.     Keywords. Stock Market, Anomalies, weekday effect, weekend effect, monthly effect, Return

    Efficient energy management for the internet of things in smart cities

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    The drastic increase in urbanization over the past few years requires sustainable, efficient, and smart solutions for transportation, governance, environment, quality of life, and so on. The Internet of Things offers many sophisticated and ubiquitous applications for smart cities. The energy demand of IoT applications is increased, while IoT devices continue to grow in both numbers and requirements. Therefore, smart city solutions must have the ability to efficiently utilize energy and handle the associated challenges. Energy management is considered as a key paradigm for the realization of complex energy systems in smart cities. In this article, we present a brief overview of energy management and challenges in smart cities. We then provide a unifying framework for energy-efficient optimization and scheduling of IoT-based smart cities. We also discuss the energy harvesting in smart cities, which is a promising solution for extending the lifetime of low-power devices and its related challenges. We detail two case studies. The first one targets energy-efficient scheduling in smart homes, and the second covers wireless power transfer for IoT devices in smart cities. Simulation results for the case studies demonstrate the tremendous impact of energy-efficient scheduling optimization and wireless power transfer on the performance of IoT in smart cities

    Unhappy on the Job: An Unpleasent Experience Faced by Cashiers in the Banking Sector of Pakistan: Evidence from District Faisalabad

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    The study is aimed to depict the factors that affect the job satisfaction of cashiers in the banking sector of Pakistan and make them to feel unhappy on the job. For in-depth understanding of the concept under study, qualitative research strategy is applied. To achieve the objectives, MCB Bank Limited and Habib Bank Limited were selected as population of the study from city district Faisalabad, Pakistan. A semi structured interview technique is employed to collect the data from cashiers of study who provide the necessary information about their feelings at their jobs and its different facets. Nvivo-10 software is used to analyze the data. Different queries are run to explore the factors contributing towards unhappiness of employees. We find that cashiers feel unhappy on the job at banks due to low salary, limited benefits & opportunities for promotion, job insecurity, long working hours, imbalance in work & family life, lack of participation in decision making and nature of work itself. The findings are helpful to the HR departments of the banking sector as the findings reveal cashiers are unhappy on their jobs which may lead towards increased absenteeism/turnover. HR department of banks can make effective policies to change the feelings of cashiers to increase their performance and avoid turnover costs. A wide range of factors contributing to unhappy feelings of cashiers, but in the current study we explore not many factors. Furthermore the study is limited to only two banks of district Faisalabad with only 30 interviews

    Combined zinc and nitrogen applications at panicle initiation for zinc biofortification in rice

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    Background and purpose: Increasing zinc (Zn) concentration in rice grains can help improve Zn nutrition of people. The combinations of Zn and nitrogen (N) applications at panicle initiation were investigated for Zn biofortification in rice. Materials and methods: Rice (cv. Super Basmati) seedling were grown in pots having a calcareous soil. All possible combinations of four Zn (control, Soil 6 mg Zn kg–1, foliar 2 × 0.2% Zn and soil + foliar Zn) and three N (control, soil 20 mg N kg–1 and foliar 0.5% N) levels were imposed at panicle initiation. At maturity, grains were analysed for Zn and proteins. Results: Grain protein concentration was significantly increased with foliar Zn treatments, and with soil and foliar N. Maximum grain Zn concertation (30 mg kg–1) was achieved with application of soil Zn + foliar Zn + foliar N. At each N level, Zn application by either method significantly increased grain Zn concentration over control. This increase in grain Zn concertation at N levels was 36 to 54% with soil Zn + foliar Zn, 27 to 45% with foliar Zn and 9 to 15% with soil Zn over its control level. Conclusions: Grain Zn concentration was significantly increased with soil N when combined with soil Zn, and with foliar N when combined with foliar Zn treatments. Conclusively, foliar N combined with soil + foliar Zn is the best combination of late Zn and N application for agronomic Zn biofortification in rice.</p

    Combined zinc and nitrogen applications at panicle initiation for zinc biofortification in rice

    Get PDF
    Background and purpose: Increasing zinc (Zn) concentration in rice grains can help improve Zn nutrition of people. The combinations of Zn and nitrogen (N) applications at panicle initiation were investigated for Zn biofortification in rice. Materials and methods: Rice (cv. Super Basmati) seedling were grown in pots having a calcareous soil. All possible combinations of four Zn (control, Soil 6 mg Zn kg–1, foliar 2 × 0.2% Zn and soil + foliar Zn) and three N (control, soil 20 mg N kg–1 and foliar 0.5% N) levels were imposed at panicle initiation. At maturity, grains were analysed for Zn and proteins. Results: Grain protein concentration was significantly increased with foliar Zn treatments, and with soil and foliar N. Maximum grain Zn concertation (30 mg kg–1) was achieved with application of soil Zn + foliar Zn + foliar N. At each N level, Zn application by either method significantly increased grain Zn concentration over control. This increase in grain Zn concertation at N levels was 36 to 54% with soil Zn + foliar Zn, 27 to 45% with foliar Zn and 9 to 15% with soil Zn over its control level. Conclusions: Grain Zn concentration was significantly increased with soil N when combined with soil Zn, and with foliar N when combined with foliar Zn treatments. Conclusively, foliar N combined with soil + foliar Zn is the best combination of late Zn and N application for agronomic Zn biofortification in rice

    Combined zinc and nitrogen applications at panicle initiation for zinc biofortification in rice

    Get PDF
    Background and purpose: Increasing zinc (Zn) concentration in rice grains can help improve Zn nutrition of people. The combinations of Zn and nitrogen (N) applications at panicle initiation were investigated for Zn biofortification in rice. Materials and methods: Rice (cv. Super Basmati) seedling were grown in pots having a calcareous soil. All possible combinations of four Zn (control, Soil 6 mg Zn kg–1, foliar 2 × 0.2% Zn and soil + foliar Zn) and three N (control, soil 20 mg N kg–1 and foliar 0.5% N) levels were imposed at panicle initiation. At maturity, grains were analysed for Zn and proteins. Results: Grain protein concentration was significantly increased with foliar Zn treatments, and with soil and foliar N. Maximum grain Zn concertation (30 mg kg–1) was achieved with application of soil Zn + foliar Zn + foliar N. At each N level, Zn application by either method significantly increased grain Zn concentration over control. This increase in grain Zn concertation at N levels was 36 to 54% with soil Zn + foliar Zn, 27 to 45% with foliar Zn and 9 to 15% with soil Zn over its control level. Conclusions: Grain Zn concentration was significantly increased with soil N when combined with soil Zn, and with foliar N when combined with foliar Zn treatments. Conclusively, foliar N combined with soil + foliar Zn is the best combination of late Zn and N application for agronomic Zn biofortification in rice

    Impact of Corporate Governance on Firm Performance: Evidence from Sugar Mills of Pakistan

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    This paper examines the impact of corporate governance mechanisms (Board Size, Board Composition, and CEO/Chairman Duality) on firm performance (Return on Asset) in sugar industry of Pakistan. The data of corporate governance mechanisms (Board Size, Board Composition, and CEO/Chairman Duality) collected from 12 listed sugar mills of Pakistan from 2005 to 2010. Using panel data methodology as a method of estimation Arithmetic mean, ANOVA and t-test applied on data by using SPSS. The results raveled that there is a significant impact of corporate governance on firm performance. Results further reveal that there is a significant impact of board size, CEO/Chairman Duality on ROA, and there is insignificant impact of Board Composition on ROA. Keywords: Corporate governance, Board of director, firm performanc

    Performance Appraisal Purpose and Job Embeddedness: Examining the Interaction Effect of Multidimensional Locus of Control

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    Using Social exchange theory, this study aimed to examine whether the developmental and evaluative purpose of performance appraisal significantly predicts job embeddedness and the interaction effect of internal and external locus of control. Data were gathered from salespersons of the pharmaceutical industry working in Peshawar, Khyber Pakhtunkhwa. A sample of 304 respondents using a cross-sectional survey was drawn for final analysis using non-probability sampling technique. Measurement and structural model was tested using partial least squares structural equation modeling (PLS-SEM). Findings revealed that both developmental performance appraisal and evaluative performance appraisal significantly and positively influence job embeddedness. Results also indicate that internal and external locus of control significantly moderates the relationship between developmental and evaluative performance appraisal with job embeddedness. These findings provide important insights in understanding the dimensions of performance appraisal for predicting workplace outcome. The study has theoretically contributed to the existing literature by examining the boundary condition of internal and external locus of control. Finally, recommendations for managers and future research directions have been documented at the end of the study
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