A Multi-hop Topology Control Based on Inter-node Range Measurement for Wireless Sensor Networks Node Localization

In centralized range-based localization techniques, sufficiency of inter-node range information received by the base station strongly affects node position estimation results. Successful data aggregation is influenced by link stability of each connection of routes, especially in a multi-hop topology model. In general, measuring the inter-node range is only performed for position determination purposes. This research introduces the use of inter-node range measurement information for link selection in a multi-hop route composition in order to increase the rate of data aggregation. Due to irregularity problems of wireless media, two areas of node communication have been considered. The regular communication area is the area in which other nodes are able to perform symmetrical communication to the node without failure. The irregular area is the area in which other nodes are seldom able to communicate. Due to its instability, some existing methods tried to avoid the irregular area completely. The proposed method, named Virtual Boundaries (VBs) prioritizes these areas. The regular communication area’s nodes have high priority to be selected as link vertices; however, when there is no link candidate inside this area, nodes within the irregular area will be selected with respect to their range to the parent node. This technique resulted in a more robust multi-hop topology that can reduce isolated node numbers and increase the percentage of data collected by the base station accordingly

Thermodynamic properties of ferromagnetic mixed-spin chain systems

Using a combination of high-temperature series expansion, exact diagonalization and quantum Monte Carlo, we perform a complementary analysis of the thermodynamic properties of quasi-one-dimensional mixed-spin systems with alternating magnetic moments. In addition to explicit series expansions for small spin quantum numbers, we present an expansion that allows a direct evaluation of the series coefficients as a function of spin quantum numbers. Due to the presence of excitations of both acoustic and optical nature, the specific heat of a mixed-spin chain displays a double-peak-like structure, which is more pronounced for ferromagnetic than for antiferromagnetic intra-chain exchange. We link these results to an analytically solvable half-classical limit. Finally, we extend our series expansion to incorporate the single-ion anisotropies relevant for the molecular mixed-spin ferromagnetic chain material MnNi(NO$_{2}$)$_{4}$(ethylenediamine)$_{2}$, with alternating spins of magnitude 5/2 and 1. Including a weak inter-chain coupling, we show that the observed susceptibility allows for an excellent fit, and the extraction of microscopic exchange parameters.Comment: 8 pages including 7 figures, submitted to Phys. Rev. B; series extended to 29th. QMC adde

The relationship between oxidised LDL, endothelial progenitor cells and coronary endothelial function in patients with CHD

Objective The balance between coronary endothelial dysfunction and repair is influenced by many protective and deleterious factors circulating in the blood. We studied the relationship between oxidised low-density lipoprotein (oxLDL), circulating endothelial progenitor cells (EPCs) and coronary endothelial function in patients with stable coronary heart disease (CHD). Methods 33 patients with stable CHD were studied. Plasma oxLDL was measured using ELISA, coronary endothelial function was assessed using intracoronary acetylcholine infusion and EPCs were quantified using flow cytometry for CD34+/KDR+ cells. Results Plasma oxLDL correlated positively with the number of EPCs in the blood (r=0.46, p=0.02). There was a positive correlation between the number of circulating EPCs and coronary endothelial function (r=0.42, p=0.04). There was no significant correlation between oxLDL and coronary endothelial function. Conclusions Plasma levels of oxLDL are associated with increased circulating EPCs in the blood of patients with CHD, which may reflect a host-repair response to endothelial injury. Patients with stable CHD had a high prevalence of coronary endothelial dysfunction, which was associated with lower numbers of circulating EPCs, suggesting a mechanistic link between endothelial dysfunction and the pathogenesis of atherosclerosis

Single-chain Fv phage display propensity exhibits strong positive correlation with overall expression levels

<p>Abstract</p> <p>Background</p> <p>Single chain Fvs (scFvs) are widely applied in research, diagnostics and therapeutic settings. Display and selection from combinatorial libraries is the main route to their discovery and many factors influence the success of this process. They exhibit low thermodynamic stability, resulting in low levels of premature cytosolic folding or aggregation which facilitates <it>sec </it>YEG-mediated translocation and phage in <it>E. coli</it>. However, there is little data analysing how this is related to and influenced by scFv protein expression.</p> <p>Results</p> <p>We characterised the relationship between overall scFv expression and display propensity for a panel of 15 anti-tetanus toxin scFvs and found a strong positive correlation (Rho = 0.88, p < 0.005) between the two parameters. Display propensity, overall expression and soluble localisation to the periplasm and extracellular fractions were clone specific characteristics which varied despite high levels of sequence homology. There was no correlation between display of scFv or its expression in non-fused (free) form with soluble scFv localisation to the periplasm or culture supernatant. This suggests that divergence in the fate of scFv-pIII and non-fused scFv after translocation to the periplasm accounts for the observed disparity. Differential degrees of periplasmic aggregation of non-fused scFv between clones may affect the partitioning of scFv in the periplasm and culture supernatant abrogating any correlation. We suggest that these factors do not apply to the scFv-pIII fusion since it remains anchored to the bacterial inner membrane as part of the innate phage packaging and budding process.</p> <p>Conclusion</p> <p>We conclude that in the absence of premature cytosolic aggregation or folding, the propensity of a scFv to be displayed on phage is directly related to its overall expression level and is thus indirectly influenced by factors such as codon bias, mRNA abundance or putative DNA motifs affecting expression. This suggests that scFvs capable of high overall expression and display levels may not produce high yields of non phage-fused soluble protein in either the periplasmic or extracellular fractions of <it>E. coli</it>. This should be considered when screening clones selected from combinatorial libraries for further study.</p> <p>The nucleotide and amino acid sequences of the anti-tetanus toxin scFvs have been deposited in the EMBL data base: accession numbers-C1: <ext-link ext-link-type="embl" ext-link-id="AM749134">AM749134</ext-link>, C2: <ext-link ext-link-type="embl" ext-link-id="AM749135">AM749135</ext-link>, C3: <ext-link ext-link-type="embl" ext-link-id="AM749136">AM749136</ext-link>, C4: <ext-link ext-link-type="embl" ext-link-id="AM749137">AM749137</ext-link>, C5: <ext-link ext-link-type="embl" ext-link-id="AM749138">AM749138</ext-link>, N1: <ext-link ext-link-type="embl" ext-link-id="AM749139">AM749139</ext-link>, N2: <ext-link ext-link-type="embl" ext-link-id="AM749140">AM749140</ext-link>, N3: <ext-link ext-link-type="embl" ext-link-id="AM749141">AM749141</ext-link>, N4: <ext-link ext-link-type="embl" ext-link-id="AM749142">AM749142</ext-link>, N5: <ext-link ext-link-type="embl" ext-link-id="AM749143">AM749143</ext-link> J1; <ext-link ext-link-type="embl" ext-link-id="AM749144">AM749144</ext-link>, J2: <ext-link ext-link-type="embl" ext-link-id="AM749145">AM749145</ext-link>, J3: <ext-link ext-link-type="embl" ext-link-id="AM749146">AM749146</ext-link>, J4: <ext-link ext-link-type="embl" ext-link-id="AM749147">AM749147</ext-link>, J5: <ext-link ext-link-type="embl" ext-link-id="AM749148">AM749148</ext-link>.</p

Properties of Healthcare Teaming Networks as a Function of Network Construction Algorithms

Network models of healthcare systems can be used to examine how providers collaborate, communicate, refer patients to each other. Most healthcare service network models have been constructed from patient claims data, using billing claims to link patients with providers. The data sets can be quite large, making standard methods for network construction computationally challenging and thus requiring the use of alternate construction algorithms. While these alternate methods have seen increasing use in generating healthcare networks, there is little to no literature comparing the differences in the structural properties of the generated networks. To address this issue, we compared the properties of healthcare networks constructed using different algorithms and the 2013 Medicare Part B outpatient claims data. Three different algorithms were compared: binning, sliding frame, and trace-route. Unipartite networks linking either providers or healthcare organizations by shared patients were built using each method. We found that each algorithm produced networks with substantially different topological properties. Provider networks adhered to a power law, and organization networks to a power law with exponential cutoff. Censoring networks to exclude edges with less than 11 shared patients, a common de-identification practice for healthcare network data, markedly reduced edge numbers and greatly altered measures of vertex prominence such as the betweenness centrality. We identified patterns in the distance patients travel between network providers, and most strikingly between providers in the Northeast United States and Florida. We conclude that the choice of network construction algorithm is critical for healthcare network analysis, and discuss the implications for selecting the algorithm best suited to the type of analysis to be performed.Comment: With links to comprehensive, high resolution figures and networks via figshare.co

Is having sex with other men a risk factor for transfusion-transmissible infections in male blood donors in Western countries?: a systematic review

Background : Although increased prevalence of transfusion transmissible infections (TTI) among “men who have sex with men” (MSM) has been well documented, the exclusion of MSM as blood donors is contested. The aim of this systematic review is to find studies that describe the risk of TTI in MSM blood donors. Methods : We searched MEDLINE, Embase, The Cochrane Central Register of Controlled Trials, Cinahl, and Web of Science, and used GRADE for determining evidence quality. We included studies comparing MSM and non-MSM blood donors (or people eligible to give blood), living in areas most relevant for our Blood Service. Results : Out of 18 987 articles, 14 observational studies were included. Two studies directly compared MSM with non-MSM donors showing that MSM donors have a statistically significant higher risk of HIV-1 infections. In one of these studies it was shown that this was related to recent (< 12 months) MSM contact. In two additional studies no evidence was shown in favour of a certain deferral period for MSM. Ten studies, applying permanent deferral for MSM, compared infected versus non-infected donors. One study found that MSM is a statistically significant risk factor for HIV-1 infection in blood donors. For other TTI such as HBV or HCV, an increased risk of infection could not be demonstrated, because the precision of the results was affected by the low numbers of donors with MSM as risk factor, or because of risk of bias in the included studies. All studies included low level evidence, because of risk of bias and imprecision of the results. Conclusions : High-quality studies investigating the risk of TTI in MSM who donate blood are scarce. The available evidence suggests a link between MSM blood donors and HIV-1 infection, but is too limited to be able to unambiguously/clearly recommend a certain deferral policy

High School and College Athletes Should Be Required to Undergo Pre-Participation Cardiac Screening Prior to Participation in Competitive Sports

Sudden Cardiac Arrest (SCA) is the leading cause of death in young athletes. Most of these athletes are unaware they have a condition that puts them at risk. In addition it is estimated that approximately 1 in 220,000 young athletes experience Sudden Cardiac Death (SCD) each year, although, these numbers are not truly reliable because there is no national mandatory reporting system in the United States. My paper argues that all high school and college athletes should be required to undergo pre-participation cardiac screening (i.e. an ECG and extensive family health history) as a part of a required physical exam to identify student-athletes at risk of SCD. Studies in Italy, where pre-participation screening is mandatory, and at some US universities in the US where collegiate athletes received cardiovascular screening prior to sports participation suggest that including ECG improved overall sensitivity, mass ECG screening is achievable and cost-effective, and that screening lowered the death rates in the population screened. Some critics believe that the cost of the screening is not cost-effective, but others believe the costs are reasonable; some hospitals in the US now provide student athletes with free ECG screening, or at reduced cost. ECG screening will save lives, and should not be discounted as being too costly. Every parent who has a child participating in school athletics should be informed of the risks, and be given the opportunity to have their child tested. Saving someone’s child is worth the cost of testing. My interest in this topic comes from my family’s personal experience with a student athlete who experienced a cardiac event characterized by shortness of breath and dizziness while playing in a collegiate baseball game. Our son, Neil, was a healthy 21-year-old student athlete who had participated in organized sports since he was seven years old. His event was initially diagnosed as a panic attack, but after he underwent a series of cardiac testing, including an ECG that showed an abnormality, he was diagnosed with Arrhythmogenic Right Ventricular Dysplasia (ARVD), a progressive heart disease. We have no family history to link to Neil’s disease, and we had no idea he was at risk. Today Neil lives with an implantable cardioverter defibrillator (ICD), takes anti-arrhythmic medication, and no longer participates in team sports. Neil is one of the lucky ones who survived, and his survival impelled me to get involved in my community to promote awareness about sudden cardiac arrest, and the importance of CPR training and the availability of automated external defibrillators (AEDs). Our experience also inspired me to research adding pre-participation cardiac screening for young athletes. If such a program had been instituted at his high school or college, Neil’s disease would have been diagnosed and treated, keeping him from being at risk during athletics

Functional Glycosylation of Dystroglycan Is Crucial for Thymocyte Development in the Mouse

BACKGROUND: Alpha-dystroglycan (alpha-DG) is a cell surface receptor providing a molecular link between the extracellular matrix (ECM) and the actin-based cytoskeleton. During its biosynthesis, alpha-DG undergoes specific and unusual O-glycosylation crucial for its function as a high-affinity cellular receptor for ECM proteins. METHODOLOGY/PRINCIPAL FINDINGS: We report that expression of functionally glycosylated alpha-DG during thymic development is tightly regulated in developing T cells and largely confined to CD4(-)CD8(-) double negative (DN) thymocytes. Ablation of DG in T cells had no effect on proliferation, migration or effector function but did reduce the size of the thymus due to a significant loss in absolute numbers of thymocytes. While numbers of DN thymocytes appeared normal, a marked reduction in CD4(+)CD8(+) double positive (DP) thymocytes occurred. In the periphery mature naïve T cells deficient in DG showed both normal proliferation in response to allogeneic cells and normal migration, effector and memory T cell function when tested in acute infection of mice with either lymphocytic choriomeningitis virus (LCMV) or influenza virus. CONCLUSIONS/SIGNIFICANCE: Our study demonstrates that DG function is modulated by glycosylation during T cell development in vivo and that DG is essential for normal development and differentiation of T cells

Neurological impact of emboli during adult cardiac surgery.

OBJECTIVES: This study draws on advances in Doppler ultrasound bubble sizing to investigate whether high volumes of macro-bubbles entering the brain during cardiac surgery increase the risk of new cerebral microbleeds (CMBs), ischemic MR lesions, or post-operative cognitive decline (POCD). METHODS: Transcranial Doppler (TCD) ultrasound recordings were analysed to estimate numbers of emboli and macrobubbles (>100 μm) entering the brain during cardiac surgery. Logistic regression was used to explore the hypothesis that emboli characteristics affect the incidence of new brain injuries identified through pre- and post-operative MRI and neuropsychological testing. RESULTS: TCD, MRI, and neuropsychological test data were compared between 28 valve and 18 CABG patients. Although valve patients received over twice as many emboli per procedure [median: 1995 vs. 859, p = .004], and seven times as many macro-bubbles [median: 218 vs. 28, p = .001], high volumes of macrobubbles were not found to be significantly associated with new CMBs, new ischaemic lesions, or POCD. The odds of acquiring new CMBs increased by approximately 5% [95% CI: 1 to 10%] for every embolus detected in the first minute after the release of the aortic cross-clamp (AxC). Logistic regression models also confirmed previous findings that cardiopulmonary bypass time and valve surgery were significant predictors for new CMBs (both p = .03). Logistic regression analysis estimated an increase in the odds of acquiring new CMBs of 6% [95% CI: 1 to 12%] for every minute of bypass time over 91 mins. CONCLUSIONS: This small study provides new information about the properties and numbers of bubbles entering the brain during surgery, but found no evidence to substantiate a direct link between large numbers of macrobubbles and adverse cognitive or MR outcome. Clinical Trial Registration URL - http://www.isrctn.com. Unique identifier: 66022965

Caries experience among publicly-funded dental patients in Australia, 1995-96: Type of care and geographic location

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Health card holders are a financially disadvantaged group and are the target population eligible for publicly-funded dental care. While their health status is generally worse compared with other Australians, there is also considerable variation among card holders. The aims of this study were to describe the oral health status of publicly-funded dental patients by type of care, geographic location and age, and to compare trends over time against other Australian studies. Patients were sampled randomly, based on date of birth, by State/Territory dental services in 1995-96. Dentists recorded oral health measures at the initial visit of a course of care using written instructions, but there was no formal calibration. The 6109 patients sampled were weighted in proportion to the numbers of publicly-funded dental patients for each State/Territory. Multiple linear regression analysis indicated that caries experience measured by the DMFT index increased across older age groups (p<0.05). For rural compared with urban patients, mean numbers of decayed and filled teeth tended to be higher. For emergency compared with non-emergency care, mean numbers of decayed and missing teeth were higher, and filled teeth lower. The findings of this monitoring survey document high levels of previous disease and treatment and indicate variation between subgroups of users of publicly-funded dental care. This included an uneven geographic distribution of oral health and disease, and variation in unmet treatment needs by type of course of care. Temporal comparisons indicate publicly-funded patients have experienced the population trend towards lower levels of tooth loss over time but have higher levels of untreated decayed teeth compared with the general population.D.S. Brennan, A.J. Spencer and G.D Slad