Packet Transactions: High-level Programming for Line-Rate Switches

Many algorithms for congestion control, scheduling, network measurement, active queue management, security, and load balancing require custom processing of packets as they traverse the data plane of a network switch. To run at line rate, these data-plane algorithms must be in hardware. With today's switch hardware, algorithms cannot be changed, nor new algorithms installed, after a switch has been built. This paper shows how to program data-plane algorithms in a high-level language and compile those programs into low-level microcode that can run on emerging programmable line-rate switching chipsets. The key challenge is that these algorithms create and modify algorithmic state. The key idea to achieve line-rate programmability for stateful algorithms is the notion of a packet transaction : a sequential code block that is atomic and isolated from other such code blocks. We have developed this idea in Domino, a C-like imperative language to express data-plane algorithms. We show with many examples that Domino provides a convenient and natural way to express sophisticated data-plane algorithms, and show that these algorithms can be run at line rate with modest estimated die-area overhead.Comment: 16 page

Characterization of bone marrow derived mesenchymal stem cells in suspension

INTRODUCTION: Bone marrow mesenchymal stem cells (BMMSCs) are a heterogeneous population of postnatal precursor cells with the capacity of adhering to culture dishes generating colony-forming unit-fibroblasts (CFU-F). Here we identify a new subset of BMMSCs that fail to adhere to plastic culture dishes and remain in culture suspension (S-BMMSCs). METHODS: To catch S-BMMSCs, we used BMMSCs-produced extracellular cell matrix (ECM)-coated dishes. Isolated S-BMMSCs were analyzed by in vitro stem cell analysis approaches, including flow cytometry, inductive multiple differentiation, western blot and in vivo implantation to assess the bone regeneration ability of S-BMMSCs. Furthermore, we performed systemic S-BMMSCs transplantation to treat systemic lupus erythematosus (SLE)-like MRL/lpr mice. RESULTS: S-BMMSCs are capable of adhering to ECM-coated dishes and showing mesenchymal stem cell characteristics with distinction from hematopoietic cells as evidenced by co-expression of CD73 or Oct-4 with CD34, forming a single colony cluster on ECM, and failure to differentiate into hematopoietic cell lineage. Moreover, we found that culture-expanded S-BMMSCs exhibited significantly increased immunomodulatory capacities in vitro and an efficacious treatment for SLE-like MRL/lpr mice by rebalancing regulatory T cells (Tregs) and T helper 17 cells (Th17) through high NO production. CONCLUSIONS: These data suggest that it is feasible to improve immunotherapy by identifying a new subset BMMSCs

A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

Impact of Duffy Antigen Receptor for Chemokines (DARC)-null linked Neutropenia on Neutrophil and Natural Killer cell Function in HIV-1 Infection.

Doctoral Degree. University of KwaZulu-Natal, Durban.Sub-Saharan Africa carries a disproportionate burden of the HIV-1 epidemic. The Duffy Antigen Receptor for Chemokines (DARC)-null polymorphism is a predictor of ethnic neutropenia which commonly occurs in persons of African ethnicity and is thought to account for up to 11% of HIV-1 infections on the African continent. Neutrophils are recognised for their killing mechanisms and have been noted for their regulatory mechanisms in recent years. For example, a role for neutrophils in natural killer (NK) cell priming in the periphery has been suggested, and neutrophil deficiency has been implicated in contributing to NK cell immaturity and dysfunction. While the DARC-null genotype is well associated with lower absolute neutrophil counts (ANCs), studies that assess the effects of the polymorphism on neutrophil functionality are lacking and the impact of DARC-null linked neutropenia on HIV disease progression is debatable. Furthermore, the influence of DARC-null neutropenia on the NK cell compartment is unknown. In this cross sectional pilot study, we assessed the impact of the DARC-null trait on neutrophil effector functions and also characterised NK cell profiles in Zulu/Xhosa African individuals from a high incidence HIV setting in Durban, South Africa. We hypothesised that in the context of the DARC-null genotype and lower ANCs in our cohort participants, neutrophils would have impaired functionality and would be unable to efficiently prime NK cells; thus affecting NK cell maturation and function, and altering NK cell homeostatic activities such as survival and proliferation. We further hypothesised that the impaired cellular responses in DARC-null individuals would be more prominent in HIV-1 infected individuals compared to HIV negative individuals. Neutrophil killing mechanisms were measured in HIV-1 chronically infected (n=22) individuals and HIV negative (uninfected) controls (n=20). For assessment of key neutrophil effector functions, isolated neutrophils were evaluated for Fc receptor-mediated phagocytosis following uptake of IgG opsonised beads using flow cytometry; reactive oxygen species (ROS) emission was measured by chemi-luminesce after activation of neutrophils with phorbol 12-myristate 13-acetate (PMA). Activated neutrophils were also visualised by fluorescent microscopy for neutrophil extracellular trap (NET) quantification. Assessment of the NK cell compartment in chronically HIV-1 infected (n=18) and uninfected (n=20) individuals using multi-parametric flow cytometry determined NK cell subsets, maturation profiles, cytokine production and degranulation. Annexin V and propidium iodide assays were used to determine NK cell survival, whilst CFSE staining was used to examine cytokine-activated NK cell proliferation. Study subjects were genotyped for the DARC trait using TaqMan allelic discrimination assays and ANCs were measured by full blood count. Our findings confirmed a high prevalence of the DARC-null allele in the African population and the polymorphism was significantly associated with lower ANCs. Neutrophil functional analysis detected rapid and higher phagocytic activity in the absence of DARC at 10 minutes (p=0.05 and p=0.009) and 60 minutes (p=0.05 and p=0.07) in HIV negative and HIV-1 infected subjects respectively. ROS and NET production in neutrophils were mostly unaffected by DARC negativity irrespective of HIV status. The only exception to this was a reduction in NET production in neutrophils from DARC-null HIV infected subjects (p=0.04) following prolonged in vitro stimulation. In the NK cell compartment, individuals showed similar NK cell counts irrespective of HIV status. In HIV negative individuals, a marked reduction of total NK cell counts was noted in the absence of DARC (p=0.006) and this correlated with lower ANCs (p=0.002) and a weak trend towards higher CD56 bright subset proportions was noted in DARC-null individuals (p=0.08). HIV negative DARC-null subjects also displayed a less mature NK cell phenotype with higher proportions of hypo-responsive KIR-NKG2A- NK cells (p=0.06) and lower frequencies of terminally differentiated CD57 (p=0.02) expressing NK cells. However, this immature phenotype did not translate to differences in expression of NK cell activation markers CD69 or HLA-DR and exhaustion marker PD-1 by DARC state. Furthermore, no differences in relation to NK cell degranulation and cytokine production were detected in the absence of DARC in HIV negative subjects. In contrast to HIV negative individuals, HIV-1 infected subjects displayed NK cell subset redistribution marked by higher CD56 negative NK cells, marginally higher frequencies of less mature NK cells, accompanied by higher expression of activation and exhaustion markers and lower cytolytic potential. However, these observed phenotypic and functional differences were lost upon DARC stratification in HIV-1 infected persons. Lastly, examination of NK cell survival capacity demonstrated only marginal differences during HIV infection in the absence of DARC (p=0.09); no changes were detected in NK cell proliferation by DARC state in HIV negative or infected individuals. Together our data suggests that the DARC-null polymorphism and lower ANCs does not adversely affect neutrophil activity irrespective of HIV status. We also show that while HIV negative individuals with the DARC-null genotype displayed reduced NK cell counts with a less mature phenotype, the condition did not compromise NK cell functionality or homeostatic activities. Furthermore, no significant differences were exhibited in the context of DARC during HIV infection, suggesting that any advantage that the DARC-positive trait may offer pre-infection is lost in chronic infection. DARC-null associated neutropenia is considered a mild condition and thus our findings support reports that the effect of ethnic neutropenia is not as pronounced as exhibited in severe neutropenia. Overall the data presented here provides mechanistic evidence behind the asymptomatic clinical characteristics associated with benign ethnic neutropenia.markers

Case Law On American Indians

An update on American Indian case law from September 2021-October 2022

Search for high-energy neutrinos from gravitational wave event GW151226 and candidate LVT151012 with ANTARES and IceCube

The Advanced LIGO observatories detected gravitational waves from two binary black hole mergers during their first observation run (O1). We present a high-energy neutrino follow-up search for the second gravitational wave event, GW151226, as well as for gravitational wave candidate LVT151012. We find two and four neutrino candidates detected by IceCube, and one and zero detected by Antares, within ±500 s around the respective gravitational wave signals, consistent with the expected background rate. None of these neutrino candidates are found to be directionally coincident with GW151226 or LVT151012. We use nondetection to constrain isotropic-equivalent high-energy neutrino emission from GW151226, adopting the GW event\u27s 3D localization, to less than 2×1051-2×1054 erg