4,429 research outputs found

    Coalescent-based genome analyses resolve the early branches of the euarchontoglires

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    Despite numerous large-scale phylogenomic studies, certain parts of the mammalian tree are extraordinarily difficult to resolve. We used the coding regions from 19 completely sequenced genomes to study the relationships within the super-clade Euarchontoglires (Primates, Rodentia, Lagomorpha, Dermoptera and Scandentia) because the placement of Scandentia within this clade is controversial. The difficulty in resolving this issue is due to the short time spans between the early divergences of Euarchontoglires, which may cause incongruent gene trees. The conflict in the data can be depicted by network analyses and the contentious relationships are best reconstructed by coalescent-based analyses. This method is expected to be superior to analyses of concatenated data in reconstructing a species tree from numerous gene trees. The total concatenated dataset used to study the relationships in this group comprises 5,875 protein-coding genes (9,799,170 nucleotides) from all orders except Dermoptera (flying lemurs). Reconstruction of the species tree from 1,006 gene trees using coalescent models placed Scandentia as sister group to the primates, which is in agreement with maximum likelihood analyses of concatenated nucleotide sequence data. Additionally, both analytical approaches favoured the Tarsier to be sister taxon to Anthropoidea, thus belonging to the Haplorrhine clade. When divergence times are short such as in radiations over periods of a few million years, even genome scale analyses struggle to resolve phylogenetic relationships. On these short branches processes such as incomplete lineage sorting and possibly hybridization occur and make it preferable to base phylogenomic analyses on coalescent methods

    Chitosan Microspheres as Potential Vaccine Delivery Systems

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    The recent advances in controlled delivery systems for protein pharmaceuticals such as microspheres, liposomes, pumps and implants, have provided a new avenue for delivery of vaccine antigens. Adjuvants aimed at increasing the immunogenicity of recombinant antigens remain a focus in vaccine development worldwide, there is currently considerable care for the development of chitosan microspheres as controlled release of vaccines, since the major disadvantage of several currently available vaccines is the need for repeated administration. Microspheres prepared from the biodegradable and biocompatible polymers, chitosan have been shown to be effective adjuvants for a number of antigens. This review mainly focuses on chitosan microspheres adjuvant as vaccine delivery systems by summarizing our and other research groups’ investigation on properties of microspheres formulation encapsulating several kinds of antigens. The results indicate that compared with commonly used PLA and PLGA, chitosan biomaterial has several potentials in vaccine delivery systems. Chitosan microspheres can control the rate of release of entrapped antigens and therefore, offer generation adjuvant to replace or complement existing aluminium salts for vaccine potential. The review mainly aims to promote the investigation of chitosan microspheres adjuvant for antigens for world wide researcher.Keywords: Tetanus toxoid; Chitosan microspheres; Vaccine delivery system; Biodegradable polymers

    Chitosan Microspheres as Potential Vaccine Delivery Systems

    Get PDF
    The recent advances in controlled delivery systems for protein pharmaceuticals such as microspheres, liposomes, pumps and implants, have provided a new avenue for delivery of vaccine antigens. Adjuvants aimed at increasing the immunogenicity of recombinant antigens remain a focus in vaccine development worldwide, there is currently considerable care for the development of chitosan microspheres as controlled release of vaccines, since the major disadvantage of several currently available vaccines is the need for repeated administration. Microspheres prepared from the biodegradable and biocompatible polymers, chitosan have been shown to be effective adjuvants for a number of antigens. This review mainly focuses on chitosan microspheres adjuvant as vaccine delivery systems by summarizing our and other research groups’ investigation on properties of microspheres formulation encapsulating several kinds of antigens. The results indicate that compared with commonly used PLA and PLGA, chitosan biomaterial has several potentials in vaccine delivery systems. Chitosan microspheres can control the rate of release of entrapped antigens and therefore, offer generation adjuvant to replace or complement existing aluminium salts for vaccine potential. The review mainly aims to promote the investigation of chitosan microspheres adjuvant for antigens for world wide researcher.Keywords: Tetanus toxoid; Chitosan microspheres; Vaccine delivery system; Biodegradable polymers

    IACT observations of gamma-ray bursts: prospects for the Cherenkov Telescope Array

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    Gamma rays at rest frame energies as high as 90 GeV have been reported from gamma-ray bursts (GRBs) by the Fermi Large Area Telescope (LAT). There is considerable hope that a confirmed GRB detection will be possible with the upcoming Cherenkov Telescope Array (CTA), which will have a larger effective area and better low-energy sensitivity than current-generation imaging atmospheric Cherenkov telescopes (IACTs). To estimate the likelihood of such a detection, we have developed a phenomenological model for GRB emission between 1 GeV and 1 TeV that is motivated by the high-energy GRB detections of Fermi-LAT, and allows us to extrapolate the statistics of GRBs seen by lower energy instruments such as the Swift-BAT and BATSE on the Compton Gamma-ray Observatory. We show a number of statistics for detected GRBs, and describe how the detectability of GRBs with CTA could vary based on a number of parameters, such as the typical observation delay between the burst onset and the start of ground observations. We also consider the possibility of using GBM on Fermi as a finder of GRBs for rapid ground follow-up. While the uncertainty of GBM localization is problematic, the small field-of-view for IACTs can potentially be overcome by scanning over the GBM error region. Overall, our results indicate that CTA should be able to detect one GRB every 20 to 30 months with our baseline instrument model, assuming consistently rapid pursuit of GRB alerts, and provided that spectral breaks below 100 GeV are not a common feature of the bright GRB population. With a more optimistic instrument model, the detection rate can be as high as 1 to 2 GRBs per year.Comment: 28 pages, 24 figures, 4 tables, submitted to Experimental Astronom

    Can Reproductive Health Voucher Programs Improve Quality of Postnatal Care? A Quasi-Experimental Evaluation of Kenya’s Safe Motherhood Voucher Scheme

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    This study tests the group-level causal relationship between the expansion of Kenya’s Safe Motherhood voucher program and changes in quality of postnatal care (PNC) provided at voucher-contracted facilities. We compare facilities accredited since program inception in 2006 (phase I) and facilities accredited since 2010-2011 (phase II) relative to comparable non-voucher facilities. PNC quality is assessed using observed clinical content processes, as well as client-reported outcome measures. Two-tailed unpaired t-tests are used to identify differences in mean process quality scores and client-reported outcome measures, comparing changes between intervention and comparison groups at the 2010 and 2012 data collection periods. Difference-in-differences analysis is used to estimate the reproductive health (RH) voucher program’s causal effect on quality of care by exploiting group-level differences between voucher-accredited and non-accredited facilities in 2010 and 2012. Participation in the voucher scheme since 2006 significantly improves overall quality of postnatal care by 39% (p=0.02), where quality is defined as the observable processes or components of service provision that occur during a PNC consultation. Program participation since phase I is estimated to improve the quality of observed maternal postnatal care by 86% (p=0.02), with the largest quality improvements in counselling on family planning methods (IRR 5.0; p=0.01) and return to fertility (IRR 2.6; p=0.01). Despite improvements in maternal aspects of PNC, we find a high proportion of mothers who seek PNC are not being checked by any provider after delivery. Additional strategies will be necessary to standardize provision of packaged postnatal interventions to both mother and new-born. This study addresses an important gap in the existing RH literature by using a strong evaluation design to assess RH voucher program effectiveness on quality improvement

    Isolation and identification of microsatellite repeat motifs from the Epinephelus fuscoguttatus genome

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    Epinephelus fuscoguttatus belongs to one of the largest serranidae fish family. Genetic information regarding existing fish populations in the wild is crucial for the conservation, particularly since the species is listed under the IUCD Red List due to intense fishing. Microsatellites of E. fuscoguttatus were isolated using streptavidin-biotin enrichment method. In total, 378 microsatellites were identified and characterized. Of these 378 total microsatellites, 46 (12.2%) were mononucleotides, 175 (46.3%) were dinucleotides, 109 (28.8%) were trinucleotides, 36 (9.5%) were tetranucloetides, 7 (1.9%) were pentanucleotides, 4 (1.1%) were hexanucleotides and 1 (0.3%) was a heptanucleotide. The most abundant microsatellite present in E. fuscoguttatus was the dinucleotide motif, (AC)n.Key words: Enrichment, Epinephelus fuscoguttatus, microsatellite, diversity

    Chromosomal-level assembly of the Asian Seabass genome using long sequence reads and multi-layered scaffolding

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    We report here the ~670 Mb genome assembly of the Asian seabass (Lates calcarifer), a tropical marine teleost. We used long-read sequencing augmented by transcriptomics, optical and genetic mapping along with shared synteny from closely related fish species to derive a chromosome-level assembly with a contig N50 size over 1 Mb and scaffold N50 size over 25 Mb that span ~90% of the genome. The population structure of L. calcarifer species complex was analyzed by re-sequencing 61 individuals representing various regions across the species' native range. SNP analyses identified high levels of genetic diversity and confirmed earlier indications of a population stratification comprising three clades with signs of admixture apparent in the South-East Asian population. The quality of the Asian seabass genome assembly far exceeds that of any other fish species, and will serve as a new standard for fish genomics

    Leave entitlements, time off work and the household financial impacts of quarantine compliance during an H1N1 outbreak

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    The Australian state of Victoria, with 5.2 million residents, enforced home quarantine during a H1N1 pandemic in 2009. The strategy was targeted at school children. The objective of this study was to investigate the extent to which parents’ access to paid sick leave or paid carer’s leave was associated with (a) time taken off work to care for quarantined children, (b) household finances, and (c) compliance with quarantine recommendations.This project was funded by two NHMRC Strategic Awards: “Call for research on H1N1 influenza 09 to inform public policy” (#628962) and “Changing patterns of work: Impacts on physical and mental health and the mediating role of resilience and social capital” (#375196). JM is supported by a NHMRC Career Development Award; DS is funded by an ARC Federation Fellowship

    Isolated terawatt attosecond hard X-ray pulse generated from single current spike

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    Isolated terawatt (TW) attosecond (as) hard X-ray pulse is greatly desired for four-dimensional investigations of natural phenomena with picometer spatial and attosecond temporal resolutions. Since the demand for such sources is continuously increasing, the possibility of generating such pulse by a single current spike without the use of optical or electron delay units in an undulator line is addressed. The conditions of a current spike (width and height) and a modulation laser pulse (wavelength and power) is also discussed. We demonstrate that an isolated TW-level as a hard X-ray can be produced by a properly chosen single current spike in an electron bunch with simulation results. By using realistic specifications of an electron bunch of the Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL), we show that an isolated, >1.0 TW and similar to 36 as X-ray pulse at 12.4 keV can be generated in an optimized-tapered undulator line. This result opens a new vista for current XFEL operation: the attosecond XFEL

    An overview of the utilisation of microalgae biomass derived from nutrient recycling of wet market wastewater and slaughterhouse wastewater

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    Microalgae have high nutritional values for aquatic organisms compared to fish meal, because microalgae cells are rich in proteins, lipids, and carbohydrates. However, the high cost for the commercial production of microalgae biomass using fresh water or artificial media limits its use as fish feed. Few studies have investigated the potential of wet market wastewater and slaughterhouse wastewater for the production of microalgae biomass. Hence, this study aims to highlight the potential of these types of wastewater as an alternative superior medium for microalgae biomass as they contain high levels of nutrients required for microalgae growth. This paper focuses on the benefits of microalgae biomass produced during the phycore-mediation of wet market wastewater and slaughterhouse wastewater as fish feed. The extraction techniques for lipids and proteins as well as the studies conducted on the use of microalgae biomass as fish feed were reviewed. The results showed that microalgae biomass can be used as fish feed due to feed utilisation efficiency, physiological activity, increased resistance for several diseases, improved stress response, and improved protein retention
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