Optimal microscale water cooled heat sinks for targeted alleviation of hotspot in microprocessors

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Hotspots in microprocessors arise due to non-uniform utilization of the underlying integrated circuits during chip operation. Conventional liquid cooling using microchannels leads to undercooling of the hotspot areas and overcooling of the background area of the chip resulting in excessive temperature gradients across the chip. These in turn adversely affect the chip performance and reliability. This problem becomes even more acute in multi-core processors where most of the processing power is concentrated in specific regions of the chip called as cores. We present a 1-dimensional model for quick design of a microchannel heat sink for targeted, single-phase liquid cooling of hotspots in microprocessors. The method utilizes simplifying assumptions and analytical equations to arrive at the first estimate of a microchannel heat sink design that distributes the cooling capacity of the heat sink by adapting the coolant flow and microchannel size distributions to the microprocessor power map. This distributed cooling in turn minimizes the chip temperature gradient. The method is formulated to generate a heat sink design for an arbitrary chip power map and hence can be readily utilized for different chip architectures. It involves optimization of microchannel widths for various zones of the chip power map under the operational constraints of maximum pressure drop limit for the heat sink. Additionally, it ensures that the coolant flows uninterrupted through its entire travel length consisting of microchannels of varying widths. The resulting first design estimate significantly reduces the computational effort involved in any subsequent CFD analysis required to fine tune the design for more complex flow situations arising, for example, in manifold microchannel heat sinks

Validation of the perceived stress scale (Pss-10) in medical and health sciences students in Hong Kong

INTRODUCTION: The demanding nature of medical and health sciences studies can cause stress among students in these disciplines affecting their wellbeing and academic performance. The Perceived Stress Scale (PSS-10) is a widely used measure of perceived stress among medical students and healthcare professionals that has not yet been validated among medical and health sciences students in Hong Kong. The aim of this study is to establish the construct validity and reliability of the PSS-10 in this context. METHODS: 267 final year medical and health sciences students were surveyed using the PSS-10. The data were analysed using exploratory factor analysis for construct validity and Cronbach’s alpha coefficient and corrected item-total correlations for reliability. RESULTS: Exploratory factor analysis revealed a two-factor structure for PSS-10, with Cronbach’s alpha of 0.865 and 0.796, indicating good internal consistency. Corrected item-total correlations showed satisfactory correlation ranged from 0.539 to 0.748 for all items and their respective subscale. Both tests supported PSS-10 as a two-factor scale. CONCLUSIONS: The PSS-10 is a valid measure for assessing perceived stress in Hong Kong medical and health sciences students

Assessment of anti-inflammatory tumor treatment efficacy by longitudinal monitoring employing sonographic micro morphology in a preclinical mouse model

<p>Abstract</p> <p>Background</p> <p>With the development of increasingly sophisticated three-dimensional volumetric imaging methods, tumor volume can serve as a robust and reproducible measurement of drug efficacy. Since the use of molecularly targeted agents in the clinic will almost certainly involve combinations with other therapeutic modalities, the use of volumetric determination can help to identify a dosing schedule of sequential combinations of cytostatic drugs resulting in long term control of tumor growth with minimal toxicity. The aim of this study is to assess high resolution sonography imaging for the in vivo monitoring of efficacy of Infliximab in pancreatic tumor.</p> <p>Methods</p> <p>In the first experiment, primary orthotopic pancreatic tumor growth was measured with Infliximab treatment. In the second experiment, orthotopic tumors were resected ten days after inoculation of tumor cells and tumor recurrence was measured following Infliximab treatment. Tumor progression was evaluated using 3D high resolution sonography.</p> <p>Results</p> <p>Sonography measurement of tumor volume in vivo showed inhibitory effect of Infliximab on primary tumor growth in both non-resected and resected models. Measurement of the dynamics of tumor growth by sonography revealed that in the primary tumor Infliximab is effective against established tumors while in the resection model, Infliximab is more effective at an early stage following tumor resection. Infliximab treatment is also effective in inhibiting tumor growth growth as a result of tumor cell contamination of the surgical field.</p> <p>Conclusions</p> <p>Clinical application of Infliximab is feasible in both the neoadjuvant and adjuvant setting. Infliximab is also effective in slowing the growth of tumor growth under the peritoneum and may have application in treating peritoneal carcinomatosis. Finally the study demonstrates that high resolution sonography is a sensitive imaging modality for the measurement of pancreatic tumor growth.</p

Manual de procedimentos de referência e pesquisa dos serviços de atendimento da Biblioteca Acadêmico Luiz Viana Filho, do Senado Federal

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Faculdade de Ciência da Informação, Curso de Graduação em Biblioteconomia, 2018.O objetivo deste trabalho é elaborar/atualizar o Manual dos processos realizados pela área de Atendimento ao Usuário, pertencente a Biblioteca Acadêmico Luiz Viana Filho do Senado Federal, que engloba os setores de Serviço de Empréstimo e Devolução de Material Bibliográfico (SEEMP), Serviço de Pesquisa e Recuperação de Informações Bibliográficas (SEPRIB), Serviço de Manutenção e Conservação de Acervo (SEMACO) e o Serviço de Pesquisa Parlamentar (SEPESP). O manual proporciona o registro das atividades realizadas diariamente, pelos setores mencionados, direcionadas para senadores, servidores do senado e usuários externos que são seu público alvo. Fez-se necessário a descrição de rotinas, para a orientação de como funcionam os processos, tanto para os servidores que os realizam, quanto para os futuros funcionários da instituição, além de servir como base para melhorias nos serviços prestados pelo setor. Para a coleta de dados foram utilizados a pesquisa participante, a análise documental e entrevista com profissionais dos setores. Utiliza como procedimentos metodológicos a abordagem qualitativa descritiva e a pesquisa participante.The objective of this work is to prepare a Manual of the processes performed by the Customer Service area, belonging to the Luiz Viana Filho Academic Library of the Federal Senate, which encompasses the Service of Loan and Return of Bibliographic Material (SEEMP), Research and Recovery of Bibliographic Information (SEPRIB), Service of Maintenance and Preservation of the Collection (SEMACO) and the Service of Parliamentary Research (SEPESP). The purpose of the manual is to provide a record of activities performed daily by the sectors mentioned above, directed at senators, senate servers and external users who are your target audience. It was necessary to describe routines, to guide how the processes work, both for the servers that perform them and for the future employees of the institution, as well as serve as a basis for improvements in the services provided by the sector. To collect data were used the participant research, the documentary analysis and interview with professionals of the sectors. It uses as methodological procedures the qualitative descriptive approach and the participant research

Genome-wide identification and expression profiling of auxin response factor (ARF) gene family in maize

<p>Abstract</p> <p>Background</p> <p>Auxin signaling is vital for plant growth and development, and plays important role in apical dominance, tropic response, lateral root formation, vascular differentiation, embryo patterning and shoot elongation. Auxin Response Factors (ARFs) are the transcription factors that regulate the expression of auxin responsive genes. The <it>ARF </it>genes are represented by a large multigene family in plants. The first draft of full maize genome assembly has recently been released, however, to our knowledge, the <it>ARF </it>gene family from maize (<it>ZmARF </it>genes) has not been characterized in detail.</p> <p>Results</p> <p>In this study, 31 maize (<it>Zea mays </it>L.) genes that encode ARF proteins were identified in maize genome. It was shown that maize <it>ARF </it>genes fall into related sister pairs and chromosomal mapping revealed that duplication of <it>ZmARFs </it>was associated with the chromosomal block duplications. As expected, duplication of some <it>ZmARFs </it>showed a conserved intron/exon structure, whereas some others were more divergent, suggesting the possibility of functional diversification for these genes. Out of these 31 <it>ZmARF </it>genes, 14 possess auxin-responsive element in their promoter region, among which 7 appear to show small or negligible response to exogenous auxin. The 18 <it>ZmARF </it>genes were predicted to be the potential targets of small RNAs. Transgenic analysis revealed that increased miR167 level could cause degradation of transcripts of six potential targets (<it>ZmARF3</it>, <it>9</it>, <it>16</it>, <it>18</it>, <it>22 </it>and <it>30</it>). The expressions of maize <it>ARF </it>genes are responsive to exogenous auxin treatment. Dynamic expression patterns of <it>ZmARF </it>genes were observed in different stages of embryo development.</p> <p>Conclusions</p> <p>Maize <it>ARF </it>gene family is expanded (31 genes) as compared to <it>Arabidopsis </it>(23 genes) and rice (25 genes). The expression of these genes in maize is regulated by auxin and small RNAs. Dynamic expression patterns of <it>ZmARF </it>genes in embryo at different stages were detected which suggest that maize <it>ARF </it>genes may be involved in seed development and germination.</p

A lightweight, flow-based toolkit for parallel and distributed bioinformatics pipelines

<p>Abstract</p> <p>Background</p> <p>Bioinformatic analyses typically proceed as chains of data-processing tasks. A pipeline, or 'workflow', is a well-defined protocol, with a specific structure defined by the topology of data-flow interdependencies, and a particular functionality arising from the data transformations applied at each step. In computer science, the dataflow programming (DFP) paradigm defines software systems constructed in this manner, as networks of message-passing components. Thus, bioinformatic workflows can be naturally mapped onto DFP concepts.</p> <p>Results</p> <p>To enable the flexible creation and execution of bioinformatics dataflows, we have written a modular framework for parallel pipelines in Python ('PaPy'). A PaPy workflow is created from re-usable components connected by data-pipes into a directed acyclic graph, which together define nested higher-order map functions. The successive functional transformations of input data are evaluated on flexibly pooled compute resources, either local or remote. Input items are processed in batches of adjustable size, all flowing one to tune the trade-off between parallelism and lazy-evaluation (memory consumption). An add-on module ('NuBio') facilitates the creation of bioinformatics workflows by providing domain specific data-containers (<it>e.g</it>., for biomolecular sequences, alignments, structures) and functionality (<it>e.g</it>., to parse/write standard file formats).</p> <p>Conclusions</p> <p>PaPy offers a modular framework for the creation and deployment of parallel and distributed data-processing workflows. Pipelines derive their functionality from user-written, data-coupled components, so PaPy also can be viewed as a lightweight toolkit for extensible, flow-based bioinformatics data-processing. The simplicity and flexibility of distributed PaPy pipelines may help users bridge the gap between traditional desktop/workstation and grid computing. PaPy is freely distributed as open-source Python code at <url>http://muralab.org/PaPy</url>, and includes extensive documentation and annotated usage examples.</p

Measurement of Lifetime and Decay-Width Difference in B0s -> J/psi phi Decays

We measure the mean lifetime, tau=2/(Gamma_L+Gamma_H), and the width difference, DeltaGamma=Gamma_L-Gamma_H, of the light and heavy mass eigenstates of the B0s meson, B0sL and B0sH, in B0s -> J/psi phi decays using 1.7 fb^-1 of data collected with the CDF II detector at the Fermilab Tevatron ppbar collider. Assuming CP conservation, a good approximation for the B0s system in the Standard Model, we obtain DeltaGamma = 0.076^+0.059_-0.063 (stat.) +- 0.006 (syst.) ps^-1 and tau = 1.52 +- 0.04 (stat.) +- 0.02 (syst.) ps, the most precise measurements to date. Our constraints on the weak phase and DeltaGamma are consistent with CP conservation. Dedicated to the memory of our dear friend and colleague, Michael P. Schmid

Limits on Anomalous Triple Gauge Couplings in ppbar Collisions at sqrt{s}=1.96 TeV

We present a search for anomalous triple gauge couplings (ATGC) in WW and WZ boson production. The boson pairs are produced in ppbar collisions at sqrt{s}=1.96 TeV, and the data sample corresponds to 350 pb-1 of integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. In this search one W decays to leptons, and the other boson (W or Z) decays hadronically. Combining with a previously published CDF measurement of Wgamma boson production yields ATGC limits of -0.18 < lambda < 0.17 and -0.46 < Delta kappa < 0.39 at the 95% confidence level, using a cut-off scale Lambda=1.5 TeV.Comment: 7 pages, 3 figures. Submitted to Phys. Rev.

Measurement of the Dipion Mass Spectrum in X(3872) -> J/Psi Pi+ Pi- Decays

We measure the dipion mass spectrum in X(3872)--> J/Psi Pi+ Pi- decays using 360 pb-1 of pbar-p collisions at 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity (3S1, 1P1, and 3DJ) charmonia decaying to J/Psi Pi+ Pi-, as well as even C-parity states in which the pions are from Rho0 decay. The latter case also encompasses exotic interpretations, such as a D0-D*0Bar molecule. Only the 3S1 and J/Psi Rho hypotheses are compatible with our data. Since 3S1 is untenable on other grounds, decay via J/Psi Rho is favored, which implies C=+1 for the X(3872). Models for different J/Psi-Rho angular momenta L are considered. Flexibility in the models, especially the introduction of Rho-Omega interference, enable good descriptions of our data for both L=0 and 1.Comment: 7 pages, 4 figures -- Submitted to Phys. Rev. Let

Forward-Backward Asymmetry in Top Quark Production in ppbar Collisions at sqrt{s}=1.96 TeV

Reconstructable final state kinematics and charge assignment in the reaction ppbar->ttbar allows tests of discrete strong interaction symmetries at high energy. We define frame dependent forward-backward asymmetries for the outgoing top quark in both the ppbar and ttbar rest frames, correct for experimental distortions, and derive values at the parton-level. Using 1.9/fb of ppbar collisions at sqrt{s}=1.96 TeV recorded with the CDF II detector at the Fermilab Tevatron, we measure forward-backward top quark production asymmetries in the ppbar and ttbar rest frames of A_{FB,pp} = 0.17 +- 0.08 and A_{FB,tt} = 0.24 +- 0.14.Comment: 7 pages, 2 figures, submitted to Phys.Rev.Lett, corrected references and change of tex