A Simple Simulator for Multicomputer Routing Networks

This report describes a concise program for simulating multicomputer routing networks [1]. The simulator is written in less than 200 lines of C code, and a complete listing is provided. Despite being terse, the simulator is exact, fast, and requires little memory

Mesh Distance Formulae

A table of useful summation formulae are derived, together with a Mathematica package for producing them. The distance distribution in mesh routing networks is derived. The mean and variance of the distance distribution are computed. A program for computing the distance distribution of any mesh is presented

Vpx rescues HIV-1 transduction of dendritic cells from the antiviral state established by type 1 interferon

<p>Abstract</p> <p>Background</p> <p>Vpx is a virion-associated protein encoded by SIV_SM, a lentivirus endemic to the West African sooty mangabey (<it>Cercocebus atys</it>). HIV-2 and SIV_MAC, zoonoses resulting from SIV_SMtransmission to humans or Asian rhesus macaques (<it>Macaca mulatta</it>), also encode Vpx. In myeloid cells, Vpx promotes reverse transcription and transduction by these viruses. This activity correlates with Vpx binding to DCAF1 (VPRBP) and association with the DDB1/RBX1/CUL4A E3 ubiquitin ligase complex. When delivered experimentally to myeloid cells using VSV G-pseudotyped virus-like particles (VLPs), Vpx promotes reverse transcription of retroviruses that do not normally encode Vpx.</p> <p>Results</p> <p>Here we show that Vpx has the extraordinary ability to completely rescue HIV-1 transduction of human monocyte-derived dendritic cells (MDDCs) from the potent antiviral state established by prior treatment with exogenous type 1 interferon (IFN). The magnitude of rescue was up to 1,000-fold, depending on the blood donor, and was also observed after induction of endogenous IFN and IFN-stimulated genes (ISGs) by LPS, poly(I:C), or poly(dA:dT). The effect was relatively specific in that Vpx-associated suppression of soluble IFN-β production, of mRNA levels for ISGs, or of cell surface markers for MDDC differentiation, was not detected. Vpx did not rescue HIV-2 or SIV_MACtransduction from the antiviral state, even in the presence of SIV_MACor HIV-2 VLPs bearing additional Vpx, or in the presence of HIV-1 VLPs bearing all accessory genes. In contrast to the effect of Vpx on transduction of untreated MDDCs, HIV-1 rescue from the antiviral state was not dependent upon Vpx interaction with DCAF1 or on the presence of DCAF1 within the MDDC target cells. Additionally, although Vpx increased the level of HIV-1 reverse transcripts in MDDCs to the same extent whether or not MDDCs were treated with IFN or LPS, Vpx rescued a block specific to the antiviral state that occurred after HIV-1 cDNA penetrated the nucleus.</p> <p>Conclusion</p> <p>Vpx provides a tool for the characterization of a potent, new HIV-1 restriction activity, which acts in the nucleus of type 1 IFN-treated dendritic cells.</p

Extensions of true skewness for unimodal distributions

A 2022 paper arXiv:2009.10305v4 introduced the notion of true positive and negative skewness for continuous random variables via Fr\'echet $p$-means. In this work, we find novel criteria for true skewness, establish true skewness for the Weibull, L\'evy, skew-normal, and chi-squared distributions, and discuss the extension of true skewness to discrete and multivariate settings. Furthermore, some relevant properties of the $p$-means of random variables are established

Caracterização do uso da água e da energia associada à água em uma edificação residencial convencional e uma dotada de um sistema de reuso de águas cinza.

A busca pela sustentabilidade no meio urbano compreende o uso das mais variadas práticas possíveis de conservação dos recursos como água e energia. Nesse sentido, a parcela referente ao consumo de água e energia nas residências é estratégica para a concepção de programas de conservação desses recursos em áreas urbanas, visto que o consumo residencial é responsável por uma grande parcela do consumo urbano, chegando a cerca de 80% em Minas Gerais. Visando avaliar um método de conservação de água, esse trabalho avaliou quantitativamente a economia gerada em uma edificação dotada de um sistema de reúso de águas cinza quando comparada a uma edificação com sistema hidrossanitário convencional. O monitoramento foi realizado de fevereiro a setembro de 2007 no edifício convencional e de fevereiro a setembro de 2008 naquele com sistema reúso de águas cinza, por meio de leituras diárias, sempre às 8h, de todos os hidrômetros e medidores de energia, além do levantamento de perfis de consumo de 24h. O consumo energético das bombas de recalque foi medido por meio eletrônico com a instalação de um analisador de energia. O consumo de água, avaliado através de perfis horários e dos indicadores per capita, por área e por dormitório, foi consistentemente mais elevado no edifício convencional, havendo um maior consumo nos meses de inverno nas duas edificações. Cerca de 32% da água cinza produzida são aproveitados como água de reúso na edificação, sendo que o volume de água de reúso utilizado é cerca de 22% do consumo total na edificação. Em termos energéticos, no edifício convencional o consumo das bombas de recalque foi de cerca de 8% do total de energia consumida. No dotado de reúso o consumo foi de 7% do total de energia consumida, sendo que 3% das bombas de água potável e 4% das bombas de reúso. Os valores altos de consumo energético das bombas sugerem uma maior atenção aos projetos de bombeamento. Foi observad

Human Herpesvirus-8 Glycoprotein B Interacts with Epstein–Barr Virus (EBV) Glycoprotein 110 but Fails to Complement the Infectivity of EBV Mutants

AbstractTo characterize human herpesvirus 8 (HHV-8) gB, the open reading frame was PCR amplified from the HHV-8-infected cell line BCBL-1 and cloned into an expression vector. To facilitate detection of expressed HHV-8 gB, the cytoplasmic tail of the glycoprotein was tagged with the influenza hemagglutinin (HA) epitope. Expression of tagged HHV-8 gB (gB-HA), as well as the untagged form, was readily detected in CHO-K1 cells and several lymphoblastoid cell lines (LCLs). HHV-8 gB-HA was sensitive to endoglycosidase H treatment, and immunofluorescence revealed that HHV-8 gB-HA was detectable in the perinuclear region of CHO-K1 cells. These observations suggest that HHV-8 gB is not processed in the Golgi and localizes to the endoplasmic reticulum or nuclear membrane. Because both HHV-8 and EBV are γ-herpesviruses, the ability of HHV-8 gB to interact with and functionally complement EBV gp110 was examined. HHV-8 gB-HA and EBV gp110 co-immunoprecipitated, indicating formation of hetero-oligomers. However, HHV-8 gB-HA and HHV-8 gB failed to restore the infectivity of gp110-negative EBV mutants. These findings indicate that although HHV-8 gB and EBV gp110 have similar patterns of intracellular localization and can interact, there is not sufficient functional homology to allow efficient complementation

A Critique of Adaptive Routing

This report refutes claims that adaptive routing performs better than dimension-order routing. Simulation results are presented that show dimension-order routing achieves both higher throughput and lower latency than adaptive routing. Specious claims for the advantages of adaptive routing are critiqued

Polarization of Migrating Monocytic Cells Is Independent of PI 3-Kinase Activity

BACKGROUND: Migration of mammalian cells is a complex cell type and environment specific process. Migrating hematopoietic cells assume a rapid amoeboid like movement when exposed to gradients of chemoattractants. The underlying signaling mechanisms remain controversial with respect to localization and distribution of chemotactic receptors within the plasma membrane and the role of PI 3-kinase activity in cell polarization. METHODOLOGY/PRINCIPAL FINDINGS: We present a novel model for the investigation of human leukocyte migration. Monocytic THP-1 cells transfected with the alpha(2A)-adrenoceptor (alpha(2A)AR) display comparable signal transduction responses, such as calcium mobilization, MAP-kinase activation and chemotaxis, to the noradrenaline homologue UK 14'304 as when stimulated with CCL2, which binds to the endogenous chemokine receptor CCR2. Time-lapse video microscopy reveals that chemotactic receptors remain evenly distributed over the plasma membrane and that their internalization is not required for migration. Measurements of intramolecular fluorescence resonance energy transfer (FRET) of alpha(2A)AR-YFP/CFP suggest a uniform activation of the receptors over the entire plasma membrane. Nevertheless, PI 3-kinase activation is confined to the leading edge. When reverting the gradient of chemoattractant by moving the dispensing micropipette, polarized monocytes--in contrast to neutrophils--rapidly flip their polarization axis by developing a new leading edge at the previous posterior side. Flipping of the polarization axis is accompanied by re-localization of PI-3-kinase activity to the new leading edge. However, reversal of the polarization axis occurs in the absence of PI 3-kinase activation. CONCLUSIONS/SIGNIFICANCE: Accumulation and internalization of chemotactic receptors at the leading edge is dispensable for cell migration. Furthermore, uniformly distributed receptors allow the cells to rapidly reorient and adapt to changes in the attractant cue. Polarized monocytes, which display typical amoeboid like motility, can rapidly develop a new leading edge facing the highest chemoattractant concentration at any site of the plasma membrane, including the uropod. The process appears to be independent of PI 3-kinase activity