CellTree: A New Paradigm for Distributed Data Repositories

We present CellTree, a new architecture for distributed data repositories. The repository allows data to be stored in largely independent, and highly programmable cells, which are “assimilated” into a tree structure. The data in the cells are allowed to change over time, subject to each cell’s own policies; a cell’s policies also govern how the policies themselves can evolve. A design goal of the architecture is to let a CellTree evolve organically over time, and adapt itself to multiple applications. Different parts of the tree may be maintained by different sets of parties interested in the respective parts, and the core mechanisms used for maintaining the tree can also vary across the tree and over time. We present provable guarantees of liveness, correctness and consistency (the last one being a generalization of the typical blockchain guarantee of “persistence,” when data is dynamic), when the CellTree architecture is instantiated using a simple set of modules. These properties can be guaranteed for individual cells that satisfy requisite trust assumptions, even if these trust assumptions do not hold for other cells in the tree. We also discuss several features of a CellTree that can be exploited by applications. We leave it for future work to develop full-fledged applications on top of this powerful architecture

A population-based study examining the emergence of community-associated methicillin-resistant Staphylococcus aureus USA300 in New York City

BACKGROUND: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is a serious pathogen in several regions in the United States. It is unclear which populations are at high risk for the emergence of these strains. METHODS: All unique patient isolates of S. aureus were collected from hospitals in Brooklyn, NY over a three-month period. Isolates of MRSA that were susceptible to clindamycin underwent SCCmec typing. Isolates with the SCCmec type IV (characteristic of CA-MRSA strains) underwent ribotyping. Demographic information involving the neighborhoods of Brooklyn was also gathered and correlated with the prevalence of CA-MRSA strains. RESULTS: Of 1316 isolates collected during the surveillance, 217 were MRSA susceptible to clindamycin. A total of 125 isolates possessed SCCmec type IV; 72 belonged to the USA300 strain and five belonged to the USA400 strain. Hospitals in the eastern part of the city had the highest prevalence of USA300 strain. Individuals in the eastern region, when compared to the western region, were more likely to be Black, Hispanic, female, and < 18 years of age, and to have households of ≥ 3 persons. In addition, the median household income was lower, and the proportion of individuals on public assistance was higher, for the population in the eastern region. CONCLUSION: The USA300 strain of CA-MRSA is emerging in New York City. In this population-based study, urban regions of lower socioeconomic status and with evidence of overcrowding appear to be at higher risk for the emergence of this pathogen

Gene expression signatures of peripheral CD4+ T cells clearly discriminate between patients with acute and chronic hepatitis B infection

CD4+ T and regulatory T cells (Tregs) seem to play a key role in persistence of hepatitis B virus (HBV) infection. However, the molecular events by which Tregs exert their modulatory activity are largely unknown. The transcriptional profiles of CD4+ T cells of healthy controls (HCs) and patients affected by acute hepatitis B (AVH-B) or chronic hepatitis B (CHB) infection were established using a custom expression array consisting of 350 genes relevant for CD4+ T cell and Treg function. These studies were complemented by real-time reverse-transcription polymerase chain reaction. Peripheral blood mononuclear cells (PBMCs) were also analyzed for the presence of Tregs, which were more abundant in the acute stage of the disease (7%) than in HCs and CHB infection (HCs versus AVH-B, P = 0.003; AVH-B versus CHB, P = 0.04). One hundred eighteen genes (34%) intrinsically differentiate HBV-infected patients from HCs. Using gene ontology, we identified T cell receptor signaling and clusterization, mitogen-activated protein kinase kinase signaling, cell adhesion, cytokines and inflammatory responses, cell cycle/cell proliferation, and apoptosis as the most prominent affected modules. A higher expression of CCR1, CCR3, CCR4, CCR5, and CCR8 was seen in AVH-B than in CHB-infected patients and HCs. Annotation of the interconnected functional network of genes provided a unique representation of global immune activation during acute infection. Almost all genes were down-regulated in patients with CHB infection. Conclusion: The fingerprints enable clear discrimination between patients suffering from AVH-B or CHB infection. The observed profiles suggest accumulation of effector T cells with a potential role in necro-inflammation during the acute stage. Subsequent down-regulated effector functions support the hypothesis of suppressed CD4+ effector T cells favoring viral persistence in the chronic infection stage

Methodology to map spatial variability of available nutrients in area of intensively growing potato (Solanum tuberosum) using remote sensing and GIS

A methodology is developed for mapping spatial variability of available nutrients of soils of a pocket growing potato (Solanum tuberosum L.) crop using GIS. For this purpose potato growing pockets of the Jalandhar district were demarcated based on the available information, ground truth and classification of the IRS P6 AWiFS image. The classified potato area in the image was taken as background to generate the sampling site map and representative soil samples of potato fields from these sites were collected along with geographical coordinates using GPS receiver(ETREX-VISTA, Garmin). Values of different parameters (like pH, OC, available P and K and micronutrients) were tagged with corresponding points and interpolation maps for each individual parameters were prepared using suitable semivariogram and kriging in remote sensing GIS software. These prepared maps were further classified giving suitable ranges of different soil parameters

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A case of meropenem-induced liver injury and jaundice

This report describes what we believe is the first reported case of clinically significant cholestasis and acute liver injury within three days of meropenem therapy. An 83-year-old Hispanic female was admitted for sepsis of unknown origin and was started on intravenous meropenem. Three days following initiation of the antibiotic, the patient developed mixed hepatocellular and cholestatic liver injury with jaundice and pruritus. Possible causes of cholestasis were excluded after extensive investigations. A drug-induced liver injury was suspected and meropenem was discontinued. Following discontinuation of meropenem, the patient demonstrated symptomatic and laboratory improvements, and her liver enzymes and bilirubin levels were normalized

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Not AvailableSoil samples of potato growing pockets of Hoshiarpur district of Punjab were collected and analysed for pH, OC and available NPK. The soil analysis data was fed into GIS software and spatial maps generated. The soils of the district in general, were slightly acidic to slightly alkaline in reaction. The pH of collected soil samples varied from 5.0 to 8.2 with a mean value of 6.8. About 90 per cent of the total area had pH less than 7.5, a situation considered much suitable for potato cultivation. The organic carbon ranged from low to medium (0.2 to 0.7%) with an average value of 0.4 per cent. Available nitrogen ranged from 186.3 to 355.6 kg/ ha with mean value of 242.5 kg/ ha and more than 88 per cent samples had available phosphorus greater than 20 ppm. None of the collected sample was deficient in available phosphorus, suggesting build-up of P fertilizers in these areas. In case of available soil potassium, 79, 19.2 and 2 per cent samples were found to be low, medium and high, respectively. After kriging, results showed that 30.5 and 18.8% area had high and very high phosphorus, respectively, but low in nitrogen and potassium. About 17.3 per cent area was medium in available nitrogen, very high in phosphorus but low in available potassium, while 12.8% area was medium in both available N and K but very high in P.Not Availabl