The electric field response to the growth phase and expansion phase onset of a small isolated substorm

International audienceWe capitalise on the very large field of view of the Halley HF radar to provide a comprehensive description of the electric field response to the substorm growth phase and expansion phase onset of a relatively simple isolated substorm ( |AL| 12 h) of magnetic quiescence, such that prior to the start of the growth phase, the apparent latitudinal motion of the radar backscatter returns is consistent with the variation in latitude of the quiet-time auroral oval with magnetic local time. The growth phase is characterised by an increasing, superimposed equatorward motion of the equatorward edge of the radar backscatter as the auroral oval expands. Within this backscatter region, there is a poleward gradient in the Doppler spectral width, which we believe to correspond to latitudinal structure in auroral emissions and magnetospheric precipitation. During the growth phase the ionospheric convection is dominated by a relatively smooth large-scale flow pattern consistent with the expanding DP2 (convection) auroral electrojets. Immediately prior to substorm onset the ionospheric convection observed by the radar in the midnight sector has a predominantly equatorward flow component. At substorm onset a dramatic change occurs and a poleward flow component prevails. The timing and location are quite remarkable. The timing of the flow change is within one minute of the dispersionless injection observed at geostationary orbit and the Pi2 magnetic signature on the ground. The location shows that this sudden change in flow is due to the effect of the upward field aligned current of the substorm current wedge imposed directly within the Halley radar field of view

Penentuan prosentase zakat profesi: studi komparatif antara pendapat Yusuf Qardawi dan Muhammad al Ghazali

Skripsi ini, merupakan hasil penelitian kepustakaan yang dilakukan penulis untuk menjawab pertanyaan : Bagaimana Tipologi berfikir, Metode Ijtihad dan Pendapat Yusuf Qardawi dan Muhammad Al-Gazali Tentang penentuan prosentase Zakat Profesi ? Data penelitian dihimpun melalui pembacaan teks (text reading) selanjutnya dianalisis dengan teknik deskriptif Analitis dengan pola pikir induktif. Hasil penelitian menyimpulkan bahwa dalam perbedaan tipologi berfikir kedua ulama diatas yaitu Yusuf Qardawi, Realistis dalam berijtihad, fiqih selalu didasarkan pada pertimbangan maslah}ah dan mafsadat. Sedangkan Muhammad al-Gazali, al-Quran melebihi dari permasalahan maslahah dan mafsadat, sebab tidak ada satupun ayat al-Quran yang bertentangan dengan maslahat. Pada metode ijtihad Yusuf Qardawi menggunakan qiyas dalam persoalan-persoalan ibadah yang tidak murni. Sedangkan Muhammad al-Gazali memandang qiyas sebagai alat yang digunakan pada waktu tidak ada nas, baik dari quran ataupun hadis. Pada waktu ada nas maka qiyas tidak boleh dipakai. Perbedaan antara Yusuf Qardawi dan Muhammad al-Gazali dalam penentuan prosentase penentuan zakat profesi adalah dari hasil qiyas mereka, Yusuf Qardawi menggunakan qiyas zakat profesi dengan zakat perniagaan atau usaha perdagangan, sehingga prosentase zakat profesi apapun jenisnya adalah 2,5 % dari keseluruhan hasil profesi, karena penghasilan profesi tidak selalu menentu, ada mingguan dan bulanan, karena itu beliau memukul rata profesi harus mengeluarkan 2,5% dari hasil keseluruhan setelah dikurangi kebutuhan-kebutuhan pokok lainnya. Sedangkan Muhammad al-Gazali menggunakan analogi zakat profesi dengan zakat pertanian yang menghasilkan prosentase pengeluaran pada zakat profesi menjadi 10 %, karena mendasarkan dari teks ayat dalam surat al-Baqarah ayat 267 yang menjelaskan bahwa hanya hasil yang dikeluarkan dari bumi yang harus dikeluarkan zakatnya, dalam hal ini lebih dekat dengan pertanian dan pertambangan. Sejalan dengan kesimpulan diatas, maka kepada para pejabat atau pemegang otoritas ketentuan masalah zakat, baik pengumpulannya ataupun distribusinya untuk segera merealisasikan ketentuan pada zakat profesi yang sesuai dengan aturan fiqh yang disepakati oleh para ulama dan secara bertanggung jawab baik kepada masyarakat ataupun kepada Tuhan Yang Maha Esa

Dynamics of ions in the selectivity filter of the KcsA channel

The statistical and dynamical properties of ions in the selectivity filter of the KcsA ion channel are considered on the basis of molecular dynamics (MD) simulations of the KcsA protein embedded in a lipid membrane surrounded by an ionic solution. A new approach to the derivation of a Brownian dynamics (BD) model of ion permeation through the filter is discussed, based on unbiased MD simulations. It is shown that depending on additional assumptions, ion’s dynamics can be described either by under-damped Langevin equation with constant damping and white noise or by Langevin equation with a fractional memory kernel. A comparison of the potential of the mean force derived from unbiased MD simulations with the potential produced by the umbrella sampling method demonstrates significant differences in these potentials. The origin of these differences is an open question that requires further clarifications

The institutional shaping of management: in the tracks of English individualism

Globalisation raises important questions about the shaping of economic action by cultural factors. This article explores the formation of what is seen by some as a prime influence on the formation of British management: individualism. Drawing on a range of historical sources, it argues for a comparative approach. In this case, the primary comparison drawn is between England and Scotland. The contention is that there is a systemic approach to authority in Scotland that can be contrasted to a personal approach in England. An examination of the careers of a number of Scottish pioneers of management suggests the roots of this systemic approach in practices of church governance. Ultimately this systemic approach was to take a secondary role to the personal approach engendered by institutions like the universities of Oxford and Cambridge, but it found more success in the different institutional context of the USA. The complexities of dealing with historical evidence are stressed, as is the value of taking a comparative approach. In this case this indicates a need to take religious practice as seriously as religious belief as a source of transferable practice. The article suggests that management should not be seen as a simple response to economic imperatives, but as shaped by the social and cultural context from which it emerges

An aggravated trajectory of depression and anxiety co-morbid with hepatitis C: : A 21 to 62 month follow-up study in 61 South Australian outpatients

BACKGROUND: This study aimed to explore the course of depression and anxiety in chronic hepatitis C patients. METHODS:   Data were combined from two studies: (1) Hospital Anxiety and Depression Scale (HADS) scores in 395 consecutive Australian outpatients from 2006 to 2010 formed the baseline measurement; and (2) Depression Anxiety Stress Scales (DASS) scores in a survey of a sub-sample of these patients in 2011 formed the follow-up measurement. After converting DASS to HADS scores, changes in symptom scores and rates of case-ness (≥8), and predictors of follow-up symptoms were assessed. RESULTS:   Follow-up data were available for 61 patients (70.5% male) whose age ranged from 24.5 to 74.6 years (M=45.6). The time to follow-up ranged from 20.7 to 61.9 months (M=43.8). Baseline rates of depression (32.8%) and anxiety (44.3%) increased to 62.3% and 67.2%, respectively. These findings were confirmed, independent of the conversion, by comparing baseline HADS and follow-up DASS scores with British community norms. Baseline anxiety and younger age predicted depression, while baseline anxiety, high school non-completion, and single relationship status predicted anxiety. CONCLUSION:  This study demonstrated a worsening trajectory of depression and anxiety. Further controlled and prospective research in a larger sample is required to confirm these findings

COVID-19: Rapid antigen detection for SARS-CoV-2 by lateral flow assay: A national systematic evaluation of sensitivity and specificity for mass-testing

Background Lateral flow device (LFD) viral antigen immunoassays have been developed around the world as diagnostic tests for SARS-CoV-2 infection. They have been proposed to deliver an infrastructure-light, cost-economical solution giving results within half an hour. Methods LFDs were initially reviewed by a Department of Health and Social Care team, part of the UK government, from which 64 were selected for further evaluation from 1st August to 15th December 2020. Standardised laboratory evaluations, and for those that met the published criteria, field testing in the Falcon-C19 research study and UK pilots were performed (UK COVID-19 testing centres, hospital, schools, armed forces). Findings 4/64 LFDs so far have desirable performance characteristics (orient Gene, Deepblue, Abbott and Innova SARS-CoV-2 Antigen Rapid Qualitative Test). All these LFDs have a viral antigen detection of >90% at 100,000 RNA copies/ml. 8951 Innova LFD tests were performed with a kit failure rate of 5.6% (502/8951, 95% CI: 5.1–6.1), false positive rate of 0.32% (22/6954, 95% CI: 0.20–0.48). Viral antigen detection/sensitivity across the sampling cohort when performed by laboratory scientists was 78.8% (156/198, 95% CI 72.4–84.3). Interpretation Our results suggest LFDs have promising performance characteristics for mass population testing and can be used to identify infectious positive individuals. The Innova LFD shows good viral antigen detection/sensitivity with excellent specificity, although kit failure rates and the impact of training are potential issues. These results support the expanded evaluation of LFDs, and assessment of greater access to testing on COVID-19 transmission. Funding Department of Health and Social Care. University of Oxford. Public Health England Porton Down, Manchester University NHS Foundation Trust, National Institute of Health Research