95 research outputs found

    Quasi 1D Bose-Einstein condensate flow past a nonlinear barrier

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    The problem of a quasi 1D {\it repulsive} BEC flow past through a nonlinear barrier is investigated. Two types of nonlinear barriers are considered, wide and short range ones. Steady state solutions for the BEC moving through a wide repulsive barrier and critical velocities have been found using hydrodynamical approach to the 1D Gross-Pitaevskii equation. It is shown that in contrast to the linear barrier case, for a wide {\it nonlinear} barrier an interval of velocities 0<v<v0 < v < v_- {\it always} exists, where the flow is superfluid regardless of the barrier potential strength. For the case of the δ\delta function-like barrier, below a critical velocity two steady solutions exist, stable and unstable one. An unstable solution is shown to decay into a gray soliton moving upstream and a stable solution. The decay is accompanied by a dispersive shock wave propagating downstream in front of the barrier.Comment: 6 pages, 7 figures, extended abstract, revised arguments in Sects 2,3 results unchanged, added reference

    Prevalensi dan Faktor Risiko Hipertensi di Kecamatan Ilir Timur II Palembang Tahun 2012

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    Hipertensi adalah suatu keadaan dimana tekanan darah melampaui tekanan darah normal. Tekanan darah disebut normal apabila tekanan sistolik <120 mmHg dan tekanan diastolik <80 mmHg. Hipertensi merupakan faktor risiko yang penting penyebab terjadinya penyakit jantung dan pembuluh darah, dan sering disebut sebagai “the silent diseaseâ€. Hipertensi timbul karena berbagai faktor risiko seperti umur lanjut, riwayat keluarga, berat badan berlebih, kebiasaan merokok, kurang aktifitas fisik, asupan natrium berlebih, dislipidemia, diabetes mellitus, dan stres. Penelitian ini bertujuan untuk mengetahui prevalensi dan faktor risiko hipertensi di Kecamatan Ilir Timur II Palembang tahun 2012. Penelitian ini dilakukan pada bulan November-Desember tahun 2012 di Kecamatan Ilir Timur II Palembang dengan metode analitik observasional. Rancangan penelitian yang digunakan adalah Cross Sectional. Populasi penelitian adalah penduduk yang berumur ≥15 tahun. Jumlah sampel adalah 512 unit. Data tekanan darah, berat badan, dan tinggi badan didapatkan dengan pengukuran langsung memakai alat dengan metode yang sudah ditentukan, dan data lainnya didapatkan dengan wawancara. Dari data di Kecamatan Ilir Timur II Palembang diperoleh jumlah total penderita hipertensi adalah sebanyak 182 (35.5%) penderita dari 512 total penduduk yang diambil sebagai sampel penelitian. Kesimpulan penelitian menunjukkan bahwa umur (p= 0,000), Indeks Massa Tubuh (p= 0,002), riwayat keluarga yang menderita hipertensi (p= 0,001), dan lama merokok (p= 0,000) merupakan faktor yang berpengaruh pada prevalensi hipertensi di Kecamatan Ilir Timur II Palembang tahun 2012

    Condensation of an ideal gas with intermediate statistics on the horizon

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    We consider a boson gas on the stretched horizon of the Schwartzschild and Kerr black holes. It is shown that the gas is in a Bose-Einstein condensed state with the Hawking temperature Tc=THT_c=T_H if the particle number of the system be equal to the number of quantum bits of space-time N \simeq {A}/{{\l_{p}}^{2}}. Entropy of the gas is proportional to the area of the horizon (A)(A) by construction. For a more realistic model of quantum degrees of freedom on the horizon, we should presumably consider interacting bosons (gravitons). An ideal gas with intermediate statistics could be considered as an effective theory for interacting bosons. This analysis shows that we may obtain a correct entropy just by a suitable choice of parameter in the intermediate statistics.Comment: 12 pages, added new sections related to an ideal gas with intermediate statistic

    Efficacy and Safety of Three Antiretroviral Regimens for Initial Treatment of HIV-1: A Randomized Clinical Trial in Diverse Multinational Settings

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    Background:Antiretroviral regimens with simplified dosing and better safety are needed to maximize the efficiency of antiretroviral delivery in resource-limited settings. We investigated the efficacy and safety of antiretroviral regimens with once-daily compared to twice-daily dosing in diverse areas of the world.Methods and Findings:1,571 HIV-1-infected persons (47% women) from nine countries in four continents were assigned with equal probability to open-label antiretroviral therapy with efavirenz plus lamivudine-zidovudine (EFV+3TC-ZDV), atazanavir plus didanosine-EC plus emtricitabine (ATV+DDI+FTC), or efavirenz plus emtricitabine-tenofovir-disoproxil fumarate (DF) (EFV+FTC-TDF). ATV+DDI+FTC and EFV+FTC-TDF were hypothesized to be non-inferior to EFV+3TC-ZDV if the upper one-sided 95% confidence bound for the hazard ratio (HR) was ≤1.35 when 30% of participants had treatment failure.An independent monitoring board recommended stopping study follow-up prior to accumulation of 472 treatment failures. Comparing EFV+FTC-TDF to EFV+3TC-ZDV, during a median 184 wk of follow-up there were 95 treatment failures (18%) among 526 participants versus 98 failures among 519 participants (19%; HR 0.95, 95% CI 0.72-1.27; p = 0.74). Safety endpoints occurred in 243 (46%) participants assigned to EFV+FTC-TDF versus 313 (60%) assigned to EFV+3TC-ZDV (HR 0.64, CI 0.54-0.76; p<0.001) and there was a significant interaction between sex and regimen safety (HR 0.50, CI 0.39-0.64 for women; HR 0.79, CI 0.62-1.00 for men; p = 0.01). Comparing ATV+DDI+FTC to EFV+3TC-ZDV, during a median follow-up of 81 wk there were 108 failures (21%) among 526 participants assigned to ATV+DDI+FTC and 76 (15%) among 519 participants assigned to EFV+3TC-ZDV (HR 1.51, CI 1.12-2.04; p = 0.007).Conclusion: EFV+FTC-TDF had similar high efficacy compared to EFV+3TC-ZDV in this trial population, recruited in diverse multinational settings. Superior safety, especially in HIV-1-infected women, and once-daily dosing of EFV+FTC-TDF are advantageous for use of this regimen for initial treatment of HIV-1 infection in resource-limited countries. ATV+DDI+FTC had inferior efficacy and is not recommended as an initial antiretroviral regimen.Trial Registration:http://www.ClinicalTrials.gov NCT00084136

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Crop-based irrigation operations in the North West Frontier Province of Pakistan. Vol.III: data collection procedures and data sets. Final report

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    Final report of the Technical Assistance Study TA-1481 PA
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