Evolution of YidC/Oxa1/Alb3 insertases: three independent gene duplications followed by functional specialization in bacteria, mitochondria and chloroplasts

Members of the YidC/Oxa1/Alb3 protein family facilitate the insertion, folding and assembly of proteins of the inner membranes of bacteria and mitochondria and the thylakoid membrane of plastids. All homologs share a conserved hydrophobic core region comprising five transmembrane domains. On the basis of phylogenetic analyses, six subgroups of the family can be distinguished which presumably arose from three independent gene duplications followed by functional specialization. During evolution of bacteria, mitochondria and chloroplasts, subgroup-specific regions were added to the core domain to facilitate the association with ribosomes or other components contributing to the substrate spectrum of YidC/Oxa1/Alb3 proteins

Orphan GRB radio afterglows: Candidates and constraints on beaming

The number of orphan radio afterglows associated with gamma-ray bursts (GRBs) that should be detected by a flux limited radio survey, is calculated. It is shown that for jetted GRBs this number is smaller for smaller jet opening angle (theta), contrary to naive expectation. For a beaming factor f_b^{-1}=(theta^2/2)^{-1} = 500, roughly the value inferred by Frail et al. (2001) from analysis of afterglow light curves, we predict that between several hundreds to several thousands orphan radio afterglows should be detectable (over all sky) above 1 mJy at GHz frequencies at any given time. This orphan population is dominated by sources lying at distances of a few hundred Mpc, and having an age of ~1 yr. A search for point-like radio transients with flux densities greater than 6 mJy was conducted using the FIRST and NVSS surveys, yielding a list of 25 orphan candidates. We argue that most of the candidates are unlikely to be radio supernovae. However, the possibility that they are radio loud AGNs cannot be ruled out without further observations. Our analysis sets an upper limit for the all sky number of radio orphans, which corresponds to a lower limit f_b^{-1}>10 on the beaming factor. Rejection of all candidates found in our search would imply f_b^{-1}>100. This, and the fact that some candidates may indeed be radio afterglows, strongly motivate further observations of these transients.Comment: 18 pages, including 2 figure

Damage-induced phosphorylation of Sld3 is important to block late origin firing.

Origins of replication are activated throughout the S phase of the cell cycle such that some origins fire early and others fire late to ensure that each chromosome is completely replicated in a timely fashion. However, in response to DNA damage or replication fork stalling, eukaryotic cells block activation of unfired origins. Human cells derived from patients with ataxia telangiectasia are deficient in this process due to the lack of a functional ataxia telangiectasia mutated (ATM) kinase and elicit radioresistant DNA synthesis after γ-irradiation(2). This effect is conserved in budding yeast, as yeast cells lacking the related kinase Mec1 (ATM and Rad3-related (ATR in humans)) also fail to inhibit DNA synthesis in the presence of DNA damage. This intra-S-phase checkpoint actively regulates DNA synthesis by inhibiting the firing of late replicating origins, and this inhibition requires both Mec1 and the downstream checkpoint kinase Rad53 (Chk2 in humans). However, the Rad53 substrate(s) whose phosphorylation is required to mediate this function has remained unknown. Here we show that the replication initiation protein Sld3 is phosphorylated by Rad53, and that this phosphorylation, along with phosphorylation of the Cdc7 kinase regulatory subunit Dbf4, blocks late origin firing in Saccharomyces cerevisiae. Upon exposure to DNA-damaging agents, cells expressing non-phosphorylatable alleles of SLD3 and DBF4 (SLD3-m25 and dbf4-m25, respectively) proceed through the S phase faster than wild-type cells by inappropriately firing late origins of replication. SLD3-m25 dbf4-m25 cells grow poorly in the presence of the replication inhibitor hydroxyurea and accumulate multiple Rad52 foci. Moreover, SLD3-m25 dbf4-m25 cells are delayed in recovering from transient blocks to replication and subsequently arrest at the DNA damage checkpoint. These data indicate that the intra-S-phase checkpoint functions to block late origin firing in adverse conditions to prevent genomic instability and maximize cell survival

Effects of heating temperature and time on some mechanical properties of Balanites Aegyptiaca nut

Balanites aegyptiaca nuts were pretreated by heating at different temperatures in the range of 30 – 90oC for time durations in the range of 30 – 120 mins. Moisture content of the nuts prior to pretreatment was 4.7 % (d.b.). Some strength properties of the pretreated nuts namely, bioyield, yield and rupture points; bioyield, compressive and rupture strengths; and moduli of elasticity, resilience, stiffness and toughness were determined at lateral and longitudinal axial loading, using a Universal Testing Machine (UTM). Results showed that all the strength properties of the nut decreased with increase in temperature and varied significantly with heating time at different loading orientations. Temperature and heating time range existed within which the nuts exhibited the typical behavior of biomaterials when heated and subjected to compression. After these ranges were exceeded, the nuts’ behavior deviated.         The study suggests that in addition to conditioning balanites aegyptiaca nuts to a moisture level at which they could easily be cracked, further treatment by exposure to heat at a level and for a duration that would not compromise product quality, could be used to enhance energy efficiency. Loading along the longitudinal axis should be applied if the cracking of nut is to be carried out using uniaxial compression

Pemanfaatan Alginat dari Alga Laut untuk Meningkatkan Stabilitas Kompon Lateks Bahan Baku Souvenir Karet

This study aimed to determine the effect of adding sodium alginate as a stabilizer agent for latex goods preparation, such as rubber compound latex rubber raw material for souvenirs. Best alginate extraction temperature is obtained at a temperature of 60 °C with alginate to yield test results were 8.20%, ash content of 24.5%, the water content of 7.855% and 1.615 cps viscosity. Quality of the best liquid latex compound found in treatment 4 with the addition of 0.20 phr alginate as indicated by the test results of 119 cp viscosity money and time for testing mechanical stabilizer 597 Sec. The results showed that the compound latex mooney viscosity resulting in treatment 5 for 37, mooney scorch average of 0.27, the average hardness 38.5, tensile strength 38 kg/cm2, 20 kg/cm2 modulus 300%, elongation at break is 508%, tear resistance treatment 5 is 62 kg/cm2

Minimal Clinically Important Difference (MCID) in Allergic Rhinitis: Agency for Healthcare Research and Quality or Anchor-Based Thresholds?

BackgroundIn 2013, the Agency for Healthcare Research and Quality (AHRQ) recommended that allergic rhinitis (AR) studies calculate a minimal clinically important difference (MCID) based on an estimated threshold equal to 30% of the maximum total nasal symptom score. Applying this threshold, their data showed no differences between well-established treatments, and a subsequent analysis using prescribing information found no differences between active treatments and placebo controls.ObjectiveThe objective of this study was to demonstrate the application of an evidence-based model to determine MCIDs for AR studies, with an absolute value for an anchor-based threshold and validated methods for calculating distribution-based thresholds.MethodsUsing the same studies as the AHRQ report, anchor- and distribution-based MCID thresholds were determined for 3 clinical comparisons identified by the AHRQ: (1) oral antihistamine+intranasal corticosteroid (INCS) versus INCS, (2) montelukast versus INCS, and (3) intranasal antihistamine+INCS in a single device versus the monotherapies. The outcomes were compared with those reported using the AHRQ threshold.ResultsNo treatment comparison met the AHRQ-defined MCID threshold; all treatments were determined to be equivalent for all 3 queries. In contrast, the evidence-based model revealed some differences between treatments: INCS > montelukast; intranasal antihistamine+INCS > either monotherapy. No clinically relevant benefit was observed for adding an oral antihistamine to INCS, but some studies were not optimal choices for quantitative determination of MCIDs. Updating the literature search revealed no additional studies that met the AHRQ inclusion criteria.ConclusionsThe evidence-based threshold for MCID determination for AR studies should supersede the threshold recommended in the AHRQ report

Molecular systematics of the Middle American genus Hypopachus (Anura: Microhylidae)

We present the first phylogenetic study on the widespread Middle American microhylid frog genus Hypopachus. Partial sequences of mitochondrial (12S and 16S ribosomal RNA) and nuclear (rhodopsin) genes (1275 bp total) were analyzed from 43 samples of Hypopachus, three currently recognized species of Gastrophryne, and seven arthroleptid, brevicipitid and microhylid outgroup taxa. Maximum parsimony (PAUP), maximum likelihood (RAxML) and Bayesian inference (MrBayes) optimality criteria were used for phylogenetic analyses, and BEAST was used to estimate divergence dates of major clades. Population-level analyses were conducted with the programs NETWORK and Arlequin. Results confirm the placement of Hypopachus and Gastrophryne as sister taxa, but the latter genus was strongly supported as paraphyletic. The African phrynomerine genus Phrynomantis was recovered as the sister taxon to a monophyletic Chiasmocleis, rendering our well-supported clade of gastrophrynines paraphyletic. Hypopachus barberi was supported as a disjunctly distributed highland species, and we recovered a basal split in lowland populations of Hypopachus variolosus from the Pacific versant of Mexico and elsewhere in the Mesoamerican lowlands. Dating analyses from BEAST estimate speciation within the genus Hypopachusoccurred in the late Miocene/early Pliocene for most clades. Previous studies have not found bioacoustic or morphological differences among these lowland clades, and our molecular data support the continued recognition of two species in the genus Hypopachus

Valuation of Closely-Held Stock for Federal Tax Purposes: Approach to an Objective Method

The present double-standard approach to the valuation problem discriminates against owners of closely-held stock, that is, corporate shares which have no public market. The disparity of treatment is traceable to the unfortunate fact that, whereas actual sales or bona fide bid and asked prices govern the valuation for federal tax purposes of listed stocks and of unlisted stocks which are dealt in through brokers or have a market, the criteria employed in valuing closely-held stock are predominantly subjective. This makes a paradise for experts but they seldom agree and few, if any, of their assumptions and conclusions are anything more than unverified, and not always wholly disinterested, hunches. As a consequence, disagreement between taxpayer and revenue agent is frequent and the process of resolving disagreement is long and costly and the event uncertain. In short, the whole merry-go-round of valuing closely-held stock is wasteful and unfair. This paper and the study it reports are addressed to the possibility of improving the situation by making a fresh approach to the valuation of closely-held stock

Measuring Population Transmission Potential for HIV: An Alternative Metric of Transmission Risk in Men who have Sex with Men (MSM) in the US

Background Various metrics for HIV burden and treatment success [e.g. HIV prevalence, community viral load (CVL), population viral load (PVL), percent of HIV-positive persons with undetectable viral load] have important public health limitations for understanding disparities. Methods and Findings Using data from an ongoing HIV incidence cohort of black and white men who have sex with men (MSM), we propose a new metric to measure the prevalence of those at risk of transmitting HIV and illustrate its value. …See full text for complete abstract