559 research outputs found
Differences in transcription between free-living and CO_2-activated third-stage larvae of Haemonchus contortus
Background:
The disease caused by Haemonchus contortus, a blood-feeding nematode of small ruminants, is of major economic importance worldwide. The infective third-stage larva (L3) of this gastric nematode is enclosed in a cuticle (sheath) and, once ingested with herbage by the host, undergoes an exsheathment process that marks the transition from the free-living (L3) to the parasitic (xL3) stage. This study explored changes in gene transcription associated with this transition and predicted, based on comparative analysis, functional roles for key transcripts in the metabolic pathways linked to larval development.
Results:
Totals of 101,305 (L3) and 105,553 (xL3) expressed sequence tags (ESTs) were determined using 454 sequencing technology, and then assembled and annotated; the most abundant transcripts encoded transthyretin-like, calcium-binding EF-hand, NAD(P)-binding and nucleotide-binding proteins as well as homologues of Ancylostoma-secreted proteins (ASPs). Using an in silico-subtractive analysis, 560 and 685 sequences were shown to be uniquely represented in the L3 and xL3 stages, respectively; the transcripts encoded ribosomal proteins, collagens and elongation factors (in L3), and mainly peptidases and other enzymes of amino acid catabolism (in xL3). Caenorhabditis elegans orthologues of transcripts that were uniquely transcribed in each L3 and xL3 were predicted to interact with a total of 535 other genes, all of which were involved in embryonic development.
Conclusion:
The present study indicated that some key transcriptional alterations taking place during the transition from the L3 to the xL3 stage of H. contortus involve genes predicted to be linked to the development of neuronal tissue (L3 and xL3), formation of the cuticle (L3) and digestion of host haemoglobin (xL3). Future efforts using next-generation sequencing and bioinformatic technologies should provide the efficiency and depth of coverage required for the determination of the complete transcriptomes of different developmental stages and/or tissues of H. contortus as well as the genome of this important parasitic nematode. Such advances should lead to a significantly improved understanding of the molecular biology of H. contortus and, from an applied perspective, to novel methods of intervention
Combining genomics and epidemiology to track mumps virus transmission in the United States.
Unusually large outbreaks of mumps across the United States in 2016 and 2017 raised questions about the extent of mumps circulation and the relationship between these and prior outbreaks. We paired epidemiological data from public health investigations with analysis of mumps virus whole genome sequences from 201 infected individuals, focusing on Massachusetts university communities. Our analysis suggests continuous, undetected circulation of mumps locally and nationally, including multiple independent introductions into Massachusetts and into individual communities. Despite the presence of these multiple mumps virus lineages, the genomic data show that one lineage has dominated in the US since at least 2006. Widespread transmission was surprising given high vaccination rates, but we found no genetic evidence that variants arising during this outbreak contributed to vaccine escape. Viral genomic data allowed us to reconstruct mumps transmission links not evident from epidemiological data or standard single-gene surveillance efforts and also revealed connections between apparently unrelated mumps outbreaks
A study of patent thickets
Report analysing whether entry of UK enterprises into patenting in a technology area is affected by patent thickets in the technology area
DUVET Survey: Mapping Outflows in the Metal-Poor Starburst Mrk 1486
We present a method to characterize star-formation driven outflows from
edge-on galaxies and apply this method to the metal-poor starburst galaxy, Mrk
1486. Our method uses the distribution of emission line flux (from H and
[OIII] 5007) to identify the location of the outflow and measure the extent
above the disk, the opening angle, and the transverse kinematics. We show that
this simple technique recovers a similar distribution of the outflow without
requiring complex modelling of line-splitting or multi-Gaussian components, and
is therefore applicable to lower spectral resolution data. In Mrk 1486 we
observe an asymmetric outflow in both the location of the peak flux and total
flux from each lobe. We estimate an opening angle of depending
on the method and assumptions adopted. Within the minor axis outflows, we
estimate a total mass outflow rate of M yr, which
corresponds to a mass loading factor of . We observe a non-negligible
amount of flux from ionized gas outflowing along the edge of the disk
(perpendicular to the biconical components), with a mass outflow rate
M yr. Our results are intended to demonstrate a method that
can be applied to high-throughput, low spectral resolution observations, such
as narrow band filters or low spectral resolution IFS that may be more able to
recover the faint emission from outflows.Comment: 12 Pages, 6 Figure
Correlates of substance abuse treatment completion among disadvantaged communities in Cape Town, South Africa
BACKGROUND: Completion of substance abuse treatment is a proximal indicator of positive treatment outcomes. To design interventions to improve outcomes, it is therefore important to unpack the factors contributing to treatment completion. To date, substance abuse research has not examined the factors associated with treatment completion among poor, disadvantaged communities in developing countries. This study aimed to address this gap by exploring client-level factors associated with treatment completion among poor communities in South Africa. METHODS: Secondary data analysis was conducted on cross-sectional survey data collected from 434 persons residing in poor communities in Cape Town, South Africa who had accessed substance abuse treatment in 2006. RESULTS: Multiple regression analyses revealed that therapeutic alliance, treatment perceptions, abstinence-specific social support, and depression were significant partial predictors of treatment completion. CONCLUSIONS: Findings suggest that treatment completion rates of individuals from poor South African communities can be enhanced by i) improving perceptions of substance abuse treatment through introducing quality improvement initiatives into substance abuse services, ii) strengthening clients' abstinence-oriented social networks and, iii) strengthening the counselor-client therapeutic alliance
Effects of polygenic risk for suicide attempt and risky behavior on brain structure in young people with familial risk of bipolar disorder
Bipolar disorder (BD) is associated with a 20–30-fold increased suicide risk compared to the general population. First-degree relatives of BD patients show inflated rates of psychopathology including suicidal behaviors. As reliable biomarkers of suicide attempts (SA) are lacking, we examined associations between suicide-related polygenic risk scores (PRSs)—a quantitative index of genomic risk—and variability in brain structures implicated in SA. Participants (n = 206; aged 12–30 years) were unrelated individuals of European ancestry and comprised three groups: 41 BD cases, 96 BD relatives (“high risk”), and 69 controls. Genotyping employed PsychArray, followed by imputation. Three PRSs were computed using genome-wide association data for SA in BD (SA-in-BD), SA in major depressive disorder (SA-in-MDD) (Mullins et al., 2019, The American Journal of Psychiatry, 176(8), 651–660), and risky behavior (Karlsson Linnér et al., 2019, Nature Genetics, 51(2), 245–257). Structural magnetic resonance imaging processing employed FreeSurfer v5.3.0. General linear models were constructed using 32 regions-of-interest identified from suicide neuroimaging literature, with false-discovery-rate correction. SA-in-MDD and SA-in-BD PRSs negatively predicted parahippocampal thickness, with the latter association modified by group membership. SA-in-BD and Risky Behavior PRSs inversely predicted rostral and caudal anterior cingulate structure, respectively, with the latter effect driven by the “high risk” group. SA-in-MDD and SA-in-BD PRSs positively predicted cuneus structure, irrespective of group. This study demonstrated associations between PRSs for suicide-related phenotypes and structural variability in brain regions implicated in SA. Future exploration of extended PRSs, in conjunction with a range of biological, phenotypic, environmental, and experiential data in high risk populations, may inform predictive models for suicidal behaviors.Australian National Health and Medical Research Council (NHMRC); Lansdowne Foundation, Paul and Jenny Reid, Good Talk, and the Keith Pettigrew Family Bequest. DNA extraction was undertaken by Genetic Repositories Australia (GRA; www.neura.edu.au/GRA), Claudio Toma is a recipient of a “Ramón y Cajal” fellowship (RYC2018-024106-I) from the Spanish MINECO. This research was undertaken with the assistance of resources from the National Computational Infrastructure (NCI), which is supported by the Australian Governmen
Evolution of non-kin cooperation:social assortment by cooperative phenotype in guppies
© 2019 The Authors. Cooperation among non-kin constitutes a conundrum for evolutionary biology. Theory suggests that non-kin cooperation can evolve if individuals differ consistently in their cooperative phenotypes and assort socially by these, such that cooperative individuals interact predominantly with one another. However, our knowledge of the role of cooperative phenotypes in the social structuring of real-world animal populations is minimal. In this study, we investigated cooperative phenotypes and their link to social structure in wild Trinidadian guppies (Poecilia reticulata). We first investigated whether wild guppies are repeatable in their individual levels of cooperativeness (i.e. have cooperative phenotypes) and found evidence for this in seven out of eight populations, a result which was mostly driven by females. We then examined the social network structure of one of these populations where the expected fitness impact of cooperative contexts is relatively high, and found assortment by cooperativeness, but not by genetic relatedness. By contrast, and in accordance with our expectations, we did not find assortment by cooperativeness in a population where the expected fitness impact of cooperative contexts is lower. Our results provide empirical support for current theory and suggest that assortment by cooperativeness is important for the evolution and persistence of non-kin cooperation in real-world populations
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