824 research outputs found
Diffusion Effects on the Breakdown of a Linear Amplifier Model Driven by the Square of a Gaussian Field
We investigate solutions to the equation , where is a Gaussian stochastic field
with covariance , and . It is shown that the
coupling at which the -th moment
diverges at time $t$, is always less or equal for ${\cal D}>0$ than for ${\cal
D}=0$. Equality holds under some reasonable assumptions on $C$ and, in this
case, $\lambda_{cN}(t)=N\lambda_c(t)$ where $\lambda_c(t)$ is the value of
$\lambda$ at which diverges.
The case is solved for a class of . The dependence of
on is analyzed. Similar behavior is conjectured when
diffusion is replaced by diffraction, , the case of
interest for backscattering instabilities in laser-plasma interaction.Comment: 19 pages, in LaTeX, e-mail addresses: [email protected],
[email protected], [email protected],
[email protected]
Effects of boundary conditions on irreversible dynamics
We present a simple one-dimensional Ising-type spin system on which we define
a completely asymmetric Markovian single spin-flip dynamics. We study the
system at a very low, yet non-zero, temperature and we show that for empty
boundary conditions the Gibbs measure is stationary for such dynamics, while
introducing in a single site a condition the stationary measure changes
drastically, with macroscopical effects. We achieve this result defining an
absolutely convergent series expansion of the stationary measure around the
zero temperature system. Interesting combinatorial identities are involved in
the proofs
Technology in Public Health Higher Education
© 2018 APJPH. Streamed and recorded lectures as well as audience response technology are increasingly used in public health tertiary education, to train practitioners to address Asia-Pacific region’s rapidly changing health needs. However, little is known about the impact on student performance, satisfaction, and understanding. This study aimed to assess postgraduate students’ perceptions and their use of technology in a large epidemiology subject at an Australian university in internal and external modes. The study used both routinely collected student data (n = 453) and survey data (n = 88). Results indicate that students accept and use technology-based learning tools, and perceive audience response technology as well as streamed and recorded lectures as useful for their learning (96.6%). Students have shown a preference to review recorded lectures rather than viewing streamed lectures. Analyses further suggest that the use of recorded and streamed lectures may be linked to better student performance for external students (passing, any use odds ratio = 3.32). However, these effects are not consistent across all student subgroups and externally enrolled students may profit more than those enrolled internally
A simple mean field model for social interactions: dynamics, fluctuations, criticality
We study the dynamics of a spin-flip model with a mean field interaction. The
system is non reversible, spacially inhomogeneous, and it is designed to model
social interactions. We obtain the limiting behavior of the empirical averages
in the limit of infinitely many interacting individuals, and show that phase
transition occurs. Then, after having obtained the dynamics of normal
fluctuations around this limit, we analize long time fluctuations for critical
values of the parameters. We show that random inhomogeneities produce critical
fluctuations at a shorter time scale compared to the homogeneous system.Comment: 37 pages, 2 figure
PROFITABILITAS BERBASIS PERPUTARAN MODAL KERJA
Tujuan penelitian ini adalah: (1) Untuk menganalisis realisasi pengelolaan sumber dan penggunaan dana dalam menjalankan operasional bisnis; (2) Untuk menganalisis tingkat stabilitas keuangan perusahaan dalam mencapai efektifitas pengelolaan keuangan perusahaan. Penelitian ini dilakukan di PT. Adhi Karya (Persero) Tbk, pada periode 2018-2019. Teknik pengumpulan data yang digunakan adalah studi pustaka dan dokumentasi. Teknik analisis data yang digunakan adalah (1) analisis rasio; (2) analisis sumber dan penggunaan dana. Hasil penelitian menunjukkan bahwa: (1) Penggunaan dana masih jauh lebih besar dari pada sumber dana; (2) Rasio yang digunakan dalam penelitian ini yaitu rasio Likuiditas dan rasio profiltabilitas menunjukkan penurunan dari tahun 2018 ke tahun 2019 (3) Tingkat stabilitas keuangan berlum tercapai.
Kata Kunci: Sumber dan Penggunaan Dana, Stabilitas Keuanga
From constrain to opportunity: win-win public-private partnership for financing sustainable poplar plantations and biodiversity conservation in Lombardy (northern Italy)
Financing the creation and maintenance of biodiversity conservation areas is a major challenge in times of constraints in public spending. In this context, Payment for Ecosystem Services are considered innovative and effective market approaches to conservation finance. We analyzed the objectives, the contents of the negotiated agreement, and the main outcomes of a Payment for Biodiversity Conservation Scheme (ECOPAY Connect) in the Lombardy Region in northern Italy, which brings together Regional Park authorities, timber industry, and private poplar growers as partners involved in complying with the requirements connected to an FSC\uae (Forest Stewardship Council) certification initiative. This scheme represents a win-win solution and transforms a certification compliance requirement, i.e. the set-aside of the 10% of the productive area for ecological restoration, into an opportunity, where a public-private partnership led to reduction of costs for both partners, and more functional restoration interventions within the park. The scheme now runs by its own, making ECOPAY Connect one of the few functioning PES schemes in Italy and in EU. The scheme was launched with a grant from the Bank Foundation and this partnership is now used as a best practice in many EU projects such as Gestire 2020, an integrated LIFE project by Lombardy Region, and Sincere, a Horizon 2020 project
The Structure of Turbulence and mixed-phase Cloud Microphysics in a Highly Supercooled Altocumulus Cloud
Observations of vertically resolved turbulence and cloud microphysics in a mixed-phase altocumulus cloud are presented using in situ measurements from an instrumented aircraft. The turbulence spectrum is observed to have an increasingly negative skewness with distance below cloud top, confirming that longwave radiative cooling from the liquid layer cloud is the source of turbulence kinetic energy. Turbulence data are presented from both the liquid cloud layer and ice virga below. Vertical profiles of both bulk and microphysical liquid and ice cloud properties indicate that ice is produced within the liquid cloud layer at a temperature of -30° C. These high resolution in situ measurements support previous remotely-sensed observations from both ground based and space borne instruments, and could be used to evaluate numerical model simulations of altocumulus clouds at all scales from eddy resolving to climate
Screening of Adhatoda vasica Nees as a Putative HIV-protease Inhibitor
SUMMARYAIDS remain as one of the greatest public health challenges in the current world’s health sector. Adhatoda vasica Nees, is widely used as a folk medicine and in Ayurvedic system of medicine in India. As a part of our prescreening program of anti-HIV agents from natural sources, various crude extracts of A. vasica were evaluated in-vitro. Pepsin Assay as a substitute of HIV-Protease was used for screening HIV-protease inhibitors in this experiment. The crude extract of A. vasica exhibited potent inhibitory activity of enzyme Pepsin in this assay system, so it might be a potent inhibitor of HIV-Protease which belongs to same aspartate family of enzyme and sharing same signature group at the active site.Key words: HIV-Protease, HAART, AIDS, Pepstatine A K.P. Singh et al.  Screening of Adhatoda vasica Nees as a Putative HIV-protease Inhibitor. J Phytol 2/4 (2010) 78-8
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