A Self-Adaptive Regression-Based Multivariate Data Compression Scheme with Error Bound in Wireless Sensor Networks

Wireless sensor networks (WSNs) have limited energy and transmission capacity, so data compression techniques have extensive applications. A sensor node with multiple sensing units is called a multimodal or multivariate node. For multivariate stream on a sensor node, some data streams are elected as the base functions according to the correlation coefficient matrix, and the other streams from the same node can be expressed in relation to one of these base functions using linear regression. By designing an incremental algorithm for computing regression coefficients, a multivariate data compression scheme based on self-adaptive regression with infinite norm error bound for WSNs is proposed. According to error bounds and compression incomes, the self-adaption means that the proposed algorithms make decisions automatically to transmit raw data or regression coefficients, and to select the number of data involved in regression. The algorithms in the scheme can simultaneously explore the temporal and multivariate correlations among the sensory data. Theoretically and experimentally, it is concluded that the proposed algorithms can effectively exploit the correlations on the same sensor node and achieve significant reduction in data transmission. Furthermore, the algorithms perform consistently well even when multivariate stream data correlations are less obvious or non-stationary. </jats:p

A cardinal role for cathepsin D in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci

The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP) and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D-/- hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function

Stool Xpert MTB/RIF as a possible diagnostic alternative to sputum in Africa: a systematic review and meta-analysis

Introduction: Worldwide, COVID-19 pandemic lead to a large fall in the number of newly reported TB cases. In sub-Saharan Africa, microbiological diagnosis of TB is generally based on smear microscopy and Xpert MTB/RIF on sputum samples, but good quality sputum samples are often difficult to obtain, leading clinicians to rely on more invasive procedures for diagnosis. Aim of this study was to investigate pooled sensitivity and specificity of Xpert MTB/RIF on stool samples compared to respiratory microbiological reference standards in African countries. Methods: Four investigators independently searched PubMed, SCOPUS, and Web of Science until 12th October 2022, then screened titles and abstracts of all potentially eligible articles. The authors applied the eligibility criteria, considered the full texts. All the studies reported the data regarding true positive (TP), true negative (TN), false positive (FP) and false negative (FN). Risk of bias and applicability concerns were assessed with the Quadas-2 tool. Results: overall, among 130 papers initially screened, we evaluated 47 works, finally including 13 papers for a total of 2,352 participants, mainly children. The mean percentage of females was 49.6%, whilst the mean percentage of patients reporting HIV was 27.7%. Pooled sensitivity for Xpert MTB/RIF assay for detecting pulmonary tuberculosis was 68.2% (95%CI: 61.1–74.7%) even if characterized by a high heterogeneity (I2=53.7%). Specificity was almost 100% (99%, 95%CI: 97–100%; I2 = 45.7%). When divided for reference standard, in the six studies using sputum and nasogastric aspirate the accuracy was optimal (AUC = 0.99, SE = 0.02), whilst in the studies using only sputum for tuberculosis detection the AUC was 0.85 (with a SE = 0.16). The most common source of bias was exclusion of enrolled patients in the analysis. Conclusions: Our study confirms that, in Africa, stool Xpert MTB/RIF may be a useful rule-in test for children above and below 5 years of age under evaluation for pulmonary tuberculosis. Sensitivity increased substantially when using both sputum and nasogastric aspirate as reference samples

Local IL-17 Production Exerts a Protective Role in Murine Experimental Glomerulonephritis

IL-17 is a pro-inflammatory cytokine implicated in the pathogenesis of glomerulonephritis and IL-17 deficient mice are protected from nephrotoxic nephritis. However, a regulatory role for IL-17 has recently emerged. We describe a novel protective function for IL-17 in the kidney. Bone marrow chimeras were created using wild-type and IL-17 deficient mice and nephrotoxic nephritis was induced. IL-17 deficient hosts transplanted with wild-type bone marrow had worse disease by all indices compared to wild-type to wild-type bone marrow transplants (serum urea p<0.05; glomerular thrombosis p<0.05; tubular damage p<0.01), suggesting that in wild-type mice, IL-17 production by renal cells resistant to radiation is protective. IL-17 deficient mice transplanted with wild-type bone marrow also had a comparatively altered renal phenotype, with significant differences in renal cytokines (IL-10 p<0.01; IL-1β p<0.001; IL-23 p<0.01), and macrophage phenotype (expression of mannose receptor p<0.05; inducible nitric oxide synthase p<0.001). Finally we show that renal mast cells are resistant to radiation and produce IL-17, suggesting they are potential local mediators of disease protection. This is a novel role for intrinsic cells in the kidney that are radio-resistant and produce IL-17 to mediate protection in nephrotoxic nephritis. This has clinical significance as IL-17 blockade is being trialled as a therapeutic strategy in some autoimmune diseases

A Secure and Scalable Digital Time-stamping Service

We propose a distributed digital time--stamping service (TSS) based on absolute timestamps and resilient to Byzantine failures. In contrast with previous solutions based on linking schemes, our TSS provides \emph{high scalability}, \emph{better response time}, and \emph{fine granularity}. It works in asynchronous systems

Revising Quorum Systems for Energy Conservation in Sensor Networks

Quorum systems are well-known techniques designed to enhance the performance of distributed systems, such as to reduce the access cost per operation, to balance the load, and to improve the system scalability. All of these properties make quorum systems particularly attractive for largescale sensor applications involving coordinated tasks, such as rescue applications. In this paper we analyze quorum techniques in the specific context of sensor networks and energy conservation, and show why quorum systems designed for wired networks and their metrics fail to address the challenges introduced by sensor networks. We then redefine quorum metrics such as access cost, load balance, and capacity in a way that takes into account the limitations and the characteristics of sensor networks, and discuss some energy-efficient design strategies. In addition, we propose a family of energy-efficient quorum systems and a particular construction, called Regional Quorum system (RQ), which reduces the quorum access cost. Finally, we propose a data diffusion protocol built on top of the RQ system, which improves energy consumption by reducing message transmissions and collisions, and increases the available bandwidth. We apply our diffusion protocol to analyze the RQ system using our novel metrics