511 research outputs found

    The impact of physical conditions on network connectivity in wireless sensor network

    Get PDF
    In Wireless Sensor Networks, end-to-end routing paths need to be established when nodes want to communicate with the desired destination. For nodes assumed to be static, many routing protocols such as Directed Diffusion have been proposed to meet this requirement efficiently. The performance of such routing protocols is relative to the given network connectivity. This paper addresses mobile sensor nodes taking into account the diversity of scattered node density and investigates how physical conditions impact on network connectivity which in turn influences routing performance. Three analysis metrics: path availability, path duration, and interavailable path time are proposed to quantify the impact of different physical conditions on network connectivity. Simulation results show that the network connectivity varies significantly as a function of different physical conditions

    Ratcheting effect of reinforced graphite sheet with stainless steel insert (RGSWSSI) under cyclic compression at elevated temperature

    Get PDF
    Ratcheting and creep of RGSWSSI are tested under cyclic stress-controlled compression by a self-designed clamp from 500ÂșC to 600ÂșC. The effects of insert type, temperature, stress amplitude, stress rate, creep and loading sequence are considered. Results present that ratcheting deformations for RGSWSSI with 316L stainless steel tanged and bonded insert approach to each other and show little rate-dependence, while they slightly increase with the increment of stress amplitude and temperature. Moreover, obvious ratcheting effect takes place under cyclic pulsating loads with the peak stress of 32MPa at 500ÂșC or higher. The accumulated deformations of RGSWSSI under small stress amplitude only increase during about the first 25 cycles, and then always turn to shakedown. It can also be estimated by the corresponding static creep strain in practical engineering with good accuracy at high temperature. This work provides important data and understanding of RGSWSSI under harsh fluctuating loads

    Nutrigenomic and nutritional analyses reveal the effects of pelleted feeds on Asian Seabass (Lates calcarifer)

    Get PDF
    As nutrition-related expenses constitute the majority of the costs for aquaculture farms, it is essential for them to use feeds that provide an ideal combination of nutrients for the species of choice. In this study, the relative effect of consuming three different pelleted feeds (B, C and D) in comparison to frozen baitfish (A; control) were compared on juvenile Asian seabass (77.3 ± 22.4g) that were selected for increased growth rate over two generations. Our objectives were: 1) to evaluate the effects of different pelleted feeds based on overall physiological changes and nutritional quality of fillets; 2) improve our understanding of the underlying mechanisms with transcriptomic analysis; 3) if possible, identify the feed type that supports the growth of these fishes without substantially reducing the nutritional quality of fillet. The growth performance, fatty acid composition of fillet, hepatic histology and transcriptome of the fishes (Groups A-D) were analyzed. The majority of fatty acids of the fillets, except Îł-linolenic acid (GLA, C18:3n6), correlated significantly with the respective diets. Asian seabass fed Feed C showed highest specific growth rate (SGR) and feed conversion efficiency (FCE) with closest histology and transcriptomic profile to control, but their fillet contained the highest n6/n3 ratio. When the liver-based transcriptomes were analyzed, a complex set of differentially expressed genes were detected between groups fed pelleted feeds and controls as well as among the pellet-fed groups themselves. Significant enrichment of genes with growth-related function tallied with the morphological data measured. When compared with control (Group A), ‘Biosynthesis of unsaturated fatty acids’ and ‘Steroid biosynthesis’ pathways were significantly enriched in pellet-fed groups. Reduced goblet cell numbers were observed in the gut of pellet-fed fish compared to controls and fads6 was found to be a suitable candidate gene to separate wild-caught Asian seabass, from pellet-fed ones. These results provide insights for researchers on the various effects of feeds on the biochemistry and global gene expression of the fish and potentially for seabass farms to make more informed feed choices

    PARP1 gene variation and microglial activity on [11C]PBR28 PET in older adults at risk for Alzheimer's disease

    Get PDF
    Increasing evidence suggests that inflammation is one pathophysio-logical mechanism in Alzheimer's disease (AD). Recent studies have identified an association between the poly (ADP-ribose) polymerase 1 (PARP1) gene and AD. This gene encodes a protein that is involved in many biological functions, including DNA repair and chromatin remodeling, and is a mediator of inflammation. Therefore, we performed a targeted genetic association analysis to investigate the relationship between the PARP1 polymorphisms and brain micro-glial activity as indexed by [11C]PBR28 positron emission tomography (PET). Participants were 26 non-Hispanic Caucasians in the Indiana Memory and Aging Study (IMAS). PET data were intensity-normalized by injected dose/total body weight. Average PBR standardized uptake values (SUV) from 6 bilateral regions of interest (thalamus, frontal, parietal, temporal, and cingulate cortices, and whole brain gray matter) were used as endophenotypes. Single nucleotide polymorphisms (SNPs) with 20% minor allele frequency that were within +/− 20 kb of the PARP1 gene were included in the analyses. Gene-level association analyses were performed using a dominant genetic model with translocator protein (18-kDa) (TSPO) genotype, age at PET scan, and gender as covariates. Analyses were performed with and without APOE Δ4 status as a covariate. Associations with PBR SUVs from thalamus and cingulate were significant at corrected p<0.014 and <0.065, respectively. Subsequent multi-marker analysis with cingulate PBR SUV showed that individuals with the “C” allele at rs6677172 and “A” allele at rs61835377 had higher PBR SUV than individuals without these alleles (corrected P<0.03), and individuals with the “G” allele at rs6677172 and “G” allele at rs61835377 displayed the opposite trend (corrected P<0.065). A previous study with the same cohort showed an inverse relationship between PBR SUV and brain atrophy at a follow-up visit, suggesting possible protective effect of microglial activity against cortical atrophy. Interestingly, all 6 AD and 2 of 3 LMCI participants in the current analysis had one or more copies of the “GG” allele combination, associated with lower cingulate PBR SUV, suggesting that this gene variant warrants further investigation

    D2 Dopamine Receptor G Protein-Biased Partial Agonists Based on Cariprazine

    Get PDF
    Functionally selective G protein-coupled receptor ligands are valuable tools for deciphering the roles of downstream signaling pathways that potentially contribute to therapeutic effects versus side effects. Recently, we discovered both Gi/o-biased and ÎČ-arrestin2-biased D2 receptor agonists based on the Food and Drug Administration (FDA)-approved drug aripiprazole. In this work, based on another FDA-approved drug, cariprazine, we conducted a structure-functional selectivity relationship study and discovered compound 38 (MS1768) as a potent partial agonist that selectively activates the Gi/o pathway over ÎČ-arrestin2. Unlike the dual D2R/D3R partial agonist cariprazine, compound 38 showed selective agonist activity for D2R over D3R. In fact, compound 38 exhibited potent antagonism of dopamine-stimulated ÎČ-arrestin2 recruitment. In our docking studies, compound 38 directly interacts with S1935.42 on TM5 but has no interactions with extracellular loop 2, which appears to be in contrast to the binding poses of D2R ÎČ-arrestin2-biased ligands. In in vivo studies, compound 38 showed high D2R receptor occupancy in mice and effectively inhibited phencyclidine-induced hyperlocomotion. © 2019 American Chemical Society

    The Fueling and Evolution of AGN: Internal and External Triggers

    Full text link
    In this chapter, I review the fueling and evolution of active galactic nuclei (AGN) under the influence of internal and external triggers, namely intrinsic properties of host galaxies (morphological or Hubble type, color, presence of bars and other non-axisymmetric features, etc) and external factors such as environment and interactions. The most daunting challenge in fueling AGN is arguably the angular momentum problem as even matter located at a radius of a few hundred pc must lose more than 99.99 % of its specific angular momentum before it is fit for consumption by a BH. I review mass accretion rates, angular momentum requirements, the effectiveness of different fueling mechanisms, and the growth and mass density of black BHs at different epochs. I discuss connections between the nuclear and larger-scale properties of AGN, both locally and at intermediate redshifts, outlining some recent results from the GEMS and GOODS HST surveys.Comment: Invited Review Chapter to appear in LNP Volume on "AGN Physics on All Scales", Chapter 6, in press. 40 pages, 12 figures. Typo in Eq 5 correcte

    Quadratic-nonlinear Landau-Zener transition for association of an atomic Bose-Einstein condensate with inter-particle elastic interactions included

    Full text link
    We study the strong coupling limit of a quadratic-nonlinear Landau-Zener problem for coherent photo- and magneto-association of cold atoms taking into account the atom-atom, atom-molecule, and molecule-molecule elastic scattering. Using an exact third-order nonlinear differential equation for the molecular state probability, we develop a variational approach which enables us to construct a highly accurate and simple analytic approximation describing the time dynamics of the coupled atom-molecule system. We show that the approximation describing time evolution of the molecular state probability can be written as a sum of two distinct terms; the first one, being a solution to a limit first-order nonlinear equation, effectively describes the process of the molecule formation while the second one, being a scaled solution to the linear Landau-Zener problem (but now with negative effective Landau-Zener parameter as long as the strong coupling regime is considered), corresponds to the remaining oscillations which come up when the process of molecule formation is over.Comment: 19 pages, 7 figures, accepted for publication in Eur. Phys. J.

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

    Get PDF
    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    EGFR L858R Mutation and Polymorphisms of Genes Related to Estrogen Biosynthesis and Metabolism in Never-Smoking Female Lung Adenocarcinoma Patients

    Get PDF
    Purpose: To assess whether polymorphisms of genes related to estrogen biosynthesis and metabolism are associated with EGFR mutations. Experimental Design: We studied 617 patients with lung adenocarcinoma, including 302 never-smoking women. On the basis of multiple candidate genes approach, the effects of polymorphisms of CYP17, CYP19A1, ER alpha, and COMT in association with the occurrence of EGFR mutations were evaluated using logistic regression analysis. Results: In female never-smokers, significant associations with EGFR L858R mutation were found for the tetranucleotide (TTTA)(n) repeats in CYP19A1 (odds ratio, 2.6; 95%CI, 1.2-5.7 for 1 or 2 alleles with (TTTA)(n) repeats > 7 compared with both alleles with (TTTA) n repeats <= 7), and the rs2234693 in ERa (OR, 2.1; 95% CI, 1.1-4.0 for C/T and C/C genotypes compared with T/T genotype). The C/C genotype (vs. T/T genotype) of ERa was significantly associated with EGFR L858R mutation (OR, 3.0; 95% CI, 1.1-8.1), in-frame deletion (OR, 2.9; 95% CI, 1.1-7.6) and other mutations (OR, 4.3; 95% CI, 1.3-14.0). The genotype of COMT rs4680 was significantly associated with EGFR L858R mutation in female and male never-smokers showing OR's (95% CI) of 1.8 (1.0-3.2) and 3.6 (1.1-11.3), respectively, for genotypes G/A and G/G compared with genotype A/A. The number of risk alleles of CYP17, CYP19A1, ERa, and COMT was associated with an increasing OR of EGFR L858R mutation in female never-smokers (P = 0.0002 for trend). Conclusions: The L858R mutation of EGFR is associated with polymorphisms of genes related to estrogen biosynthesis and metabolism in never-smoking female lung adenocarcinoma patients. Clin Cancer Res; 17(8); 2149-58. (C) 2011 AACR
    • 

    corecore