Approximate performance analysis of generalized join the shortest queue routing

In this paper we propose a highly accurate approximate performance analysis of a heterogeneous server system with a processor sharing service discipline and a general job-size distribution under a generalized join the shortest queue (GJSQ) routing protocol. The GJSQ routing protocol is a natural extension of the well-known join the shortest queue routing policy that takes into account the non-identical service rates in addition to the number of jobs at each server. The performance metrics that are of interest here are the equilibrium distribution and the mean and standard deviation of the number of jobs at each server. We show that the latter metrics are near-insensitive to the job-size distribution using simulation experiments. By applying a single queue approximation we model each server as a single server queue with a state-dependent arrival process, independent of other servers in the system, and derive the distribution of the number of jobs at the server. These state-dependent arrival rates are intended to capture the inherent correlation between servers in the original system and behave in a rather atypical way.Comment: 16 pages, 5 figures -- version 2 incorporates minor textual change

Steady-state analysis of shortest expected delay routing

We consider a queueing system consisting of two non-identical exponential servers, where each server has its own dedicated queue and serves the customers in that queue FCFS. Customers arrive according to a Poisson process and join the queue promising the shortest expected delay, which is a natural and near-optimal policy for systems with non-identical servers. This system can be modeled as an inhomogeneous random walk in the quadrant. By stretching the boundaries of the compensation approach we prove that the equilibrium distribution of this random walk can be expressed as a series of product-forms that can be determined recursively. The resulting series expression is directly amenable for numerical calculations and it also provides insight in the asymptotic behavior of the equilibrium probabilities as one of the state coordinates tends to infinity.Comment: 41 pages, 13 figure

Métodos de captura, contenção e fixação de transmissores VHF em caititus (Tayassu tajacu).

O objetivo do trabalho foi descrever metodologias para a captura, contenção e marcação de caititus. A captura foi realizada de duas formas: com laço e com armadilhas; os métodos de contenção considerados foram: físico e químico; transmissores de VHF foram afixados aos animais para monitoramento após captura utilizando colar de couro, colar de aço revestido ou brinco. As armadilhas medindo 1,5m x 0,8m x 0,6m, foram instaladas em locais com indícios da presença da espécie, durante a estação seca no Pantanal da Nhecolândia. Água em reservatórios plásticos nivelados à superfície do solo (25 litros) e pequenas quantidades de mandioca foram utilizadas como atrativo. As armadilhas instaladas nas condições descritas mostraram-se eficientes para atração e captura de animais da espécie. Embora o método do laço tenha se mostrado eficiente, seu uso certamente compromete o bem estar dos animais manejados, devido à presença de cães. Quando houve apenas a contenção física dos animais a mortalidade pós-captura foi menor. Dentre as opções testadas para anexar transmissores aos animais, o colar confeccionado manualmente utilizando sola de couro foi a mais viável

Towards 3D Magnetic Force Microscopy

Magnetic force microscopy (MFM) is long established as a powerful tool for probing the local manifestation of magnetic nanostructures across a range of temperatures and applied stimuli. A major drawback of the technique, however, is that the detection of stray fields emanating from a samples surface rely on a uniaxial vertical cantilever oscillation, and thus are only sensitive to vertically oriented stray field components. The last two decades have shown an ever-increasing literature fascination for exotic topological windings where particular attention to in-plane magnetic moment rotation is highly valuable when identifying and understanding such systems. Here we present a new method of detecting in-plane magnetic stray field components, by utilizing a home made split-electrode excitation piezo that allows the simultaneous excitation of a cantilever at its fundamental flexural and torsional modes. This allows for the joint acquisition of traditional vertical mode (V-MFM) images and a lateral MFM (L-MFM) where the tip-cantilever system is only sensitive to stray fields acting perpendicular to the torsional axis of the cantilever

Middle Level Teacher Recruitment: Challenging Deficit Narratives

Perceptions of middle level learners vary, and unfortunately, some are deficit-oriented, labeling young adolescents as “hormonal” and “erratic” without a deep understanding of their emotional and physical development or the knowledge and skills that they bring to a classroom. In this paper, we provide empirical evidence for this deficit narrative—including the marginalization of middle level learners—from interviews conducted with teacher candidates in elementary, middle, secondary, and K-12 programs in two different states. Three themes around perceptions of teaching middle grades students are shared: adult needs and interests, resistance to student agency, and challenging the deficit narrative. We posit that developing a broader understanding of young adolescents might inform and inspire teacher candidates to choose to become middle school teachers. Thus, we encourage an asset approach to recruitment of middle level teacher candidates entering teacher preparation programs, and we offer recommendations for middle level recruitment into teacher education programs with an explicitly asset lens

Transmission of Foot-and-Mouth Disease SAT2 Viruses at the Wildlife-Livestock Interface of Two Major Transfrontier Conservation Areas in Southern Africa.

Over a decade ago, foot-and-mouth disease (FMD) re-emerged in Southern Africa specifically in beef exporting countries that had successfully maintained disease-free areas in the past. FMD virus (FMDV) serotype SAT2 has been responsible for a majority of these outbreaks. Epidemiological studies have revealed the importance of the African buffalo as the major wildlife FMD reservoir in the region. We used phylogeographic analysis to study dynamics of FMD transmission between buffalo and domestic cattle at the interface of the major wildlife protected areas in the region currently encompassing two largest Transfrontier conservation areas: Kavango-Zambezi (KAZA) and Great Limpopo (GL). Results of this study showed restricted local occurrence of each FMDV SAT2 topotypes I, II, and III, with occasional virus migration from KAZA to GL. Origins of outbreaks in livestock are frequently attributed to wild buffalo, but our results suggest that transmission from cattle to buffalo also occurs. We used coalescent Bayesian skyline analysis to study the genetic variation of the virus in cattle and buffalo, and discussed the association of these genetic changes in the virus and relevant epidemiological events that occurred in this area. Our results show that the genetic diversity of FMDV SAT2 has decreased in buffalo and cattle population during the last decade. This study contributes to understand the major dynamics of transmission and genetic variation of FMDV SAT2 in Southern Africa, which will could ultimately help in designing efficient strategies for the control of FMD at a local and regional level

Equity “On the Sideline”: A Mixed Methods Study of New England Evaluation Practice in 2020

Background: Centering equity in evaluations is increasingly recognized as an important professional responsibility of evaluators. While some theoretical and practical guidance exists, the evaluation field has limited empirical research on equity within evaluation practice. Purpose: This paper explores whether and how evaluators address inequities and advance equity throughout evaluation phases drawing on select findings from a larger study. Setting: The study focuses on American Evaluation Association-affiliated evaluators in the New England region of the United States who work in a variety of areas (e.g., health, education).   Intervention: Not applicable Research Design: The study uses a complementarity, sequential mixed methods design comprised of a researcher-developed online questionnaire administered to a census and snowball sample of practicing evaluators (n=82) and individual, semi-structured interviews with a subset of this sample selected to maximize variation (n=21). Quantitative data were analyzed using descriptive statistics (i.e., means and standard deviations, frequencies). Qualitative data were analyzed using a collaborative process of deductive and inductive coding followed by thematic analysis. Findings: Eight overarching findings suggest that despite evaluators’ attempts to center equity, it remains largely “on the sideline.” This is due to evaluators’ need to work against some conventional professional and methodological norms, within contractual and contextual constraints, and with limited professional preparation. &nbsp

Cochlear implantation of a Hungarian deaf and blind patient with discharging ears suffering from Behçet's disease

A case is reported in which a Nucleus 22 channel intracochlear device was implanted a deaf/blind Hungarian adult with discharging ears suffering from Behçet's disease. Preconditioning surgery was employed three months prior to the implantation procedure to ensure a sterile, dry protected environment for the electrodes. One month after implantation, the patient exhibited excellent auditory discrimination capability at the time of the first switch on. We suggest that some deaf/blind individuals may serve as very good candidates for intracochlear implantatio

Route of Administration of the TLR9 Agonist CpG Critically Determines the Efficacy of Cancer Immunotherapy in Mice

Contains fulltext : 81648.pdf (publisher's version ) (Open Access)BACKGROUND: The TLR9 agonist CpG is increasingly applied in preclinical and clinical studies as a therapeutic modality to enhance tumor immunity. The clinical application of CpG appears, however, less successful than would be predicted from animal studies. One reason might be the different administration routes applied in most mouse studies and clinical trials. We studied whether the efficacy of CpG as an adjuvant in cancer immunotherapy is dependent on the route of CpG administration, in particular when the tumor is destructed in situ. METHODOLOGY/PRINCIPAL FINDINGS: In situ tumor destruction techniques are minimally invasive therapeutic alternatives for the treatment of (nonresectable) solid tumors. In contrast to surgical resection, tumor destruction leads to the induction of weak but tumor-specific immunity that can be enhanced by coapplication of CpG. As in situ tumor destruction by cryosurgery creates an instant local release of antigens, we applied this model to study the efficacy of CpG to enhance antitumor immunity when administrated via different routes: peritumoral, intravenous, and subcutaneous but distant from the tumor. We show that peritumoral administration is superior in the activation of dendritic cells, induction of tumor-specific CTL, and long-lasting tumor protection. Although the intravenous and subcutaneous (at distant site) exposures are commonly used in clinical trials, they only provided partial protection or even failed to enhance antitumor responses as induced by cryosurgery alone. CONCLUSIONS/SIGNIFICANCE: CpG administration greatly enhances the efficacy of in situ tumor destruction techniques, provided that CpG is administered in close proximity of the released antigens. Hence, this study helps to provide directions to fully benefit from CpG as immune stimulant in a clinical setting