1,031 research outputs found
Insights into Adolescent Online Conflict through Qualitative Analysis of Online Messages
Given adolescents’ widespread use of online messaging and social media, as well as the prevalence of cyberbullying, analyzing adolescents’ online message-based communication topics and patterns is relevant to public health. To better describe conflict in adolescent online communication, this paper analyzes patterns of conflict in a dataset of adolescent online messages. We describe a qualitative methodology for analyzing these complex data, to expand understanding of adolescents’ online conversations, and to identify how best to categorize conflict within online media datasets. In this study, 14,239 messages from 20 adolescents in the Northeast United States (of which 1,911 were coded) were analyzed using thematic analysis. Several distinct kinds of conflict and responses were identified. Conflict was either direct or indirect, serious or non-serious; it most often was indirect and serious, referenced either insults or romantic contacts, and was frequently related to in-person fights. Coding relied on understanding both textual contexts and referents
The interaction of human and Epstein–Barr virus miRNAs with Multiple Sclerosis risk loci
Although the causes of Multiple Sclerosis (MS) still remain largely unknown, multiple lines of evidence suggest that Epstein–Barr virus (EBV) infection may contribute to the development of MS. Here, we aimed to identify the potential contribution of EBV-encoded and host cellular miRNAs to MS pathogenesis. We identified differentially expressed host miRNAs in EBV infected B cells (LCLs) and putative host/EBV miRNA interactions with MS risk loci. We estimated the genotype effect of MS risk loci on the identified putative miRNA:mRNA interactions in silico. We found that the protective allele of MS risk SNP rs4808760 reduces the expression of hsa-mir-3188-3p. In addition, our analysis suggests that hsa-let-7b-5p may interact with ZC3HAV1 differently in LCLs compared to B cells. In vitro assays indicated that the protective allele of MS risk SNP rs10271373 increases ZC3HAV1 expression in LCLs, but not in B cells. The higher expression for the protective allele in LCLs is consistent with increased IFN response via ZC3HAV1 and so decreased immune evasion by EBV. Taken together, this provides evidence that EBV infection dysregulates the B cell miRNA machinery, including MS risk miRNAs, which may contribute to MS pathogenesis via interaction with MS risk genes either directly or indirectly
Approaches for integrating heterogeneous RNA-seq data reveal cross-talk between microbes and genes in asthmatic patients.
Sputum induction is a non-invasive method to evaluate the airway environment, particularly for asthma. RNA sequencing (RNA-seq) of sputum samples can be challenging to interpret due to the complex and heterogeneous mixtures of human cells and exogenous (microbial) material. In this study, we develop a pipeline that integrates dimensionality reduction and statistical modeling to grapple with the heterogeneity. LDA(Latent Dirichlet allocation)-link connects microbes to genes using reduced-dimensionality LDA topics. We validate our method with single-cell RNA-seq and microscopy and then apply it to the sputum of asthmatic patients to find known and novel relationships between microbes and genes
The TcEG1 beetle (Tribolium castaneum) cellulase produced in transgenic switchgrass is active at alkaline pH and auto-hydrolyzes biomass for increased cellobiose release
Background
Genetically engineered biofuel crops, such as switchgrass (Panicum virgatum L.), that produce their own cell wall-digesting cellulase enzymes would reduce costs of cellulosic biofuel production. To date, non-bioenergy plant models have been used in nearly all studies assessing the synthesis and activity of plant-produced fungal and bacterial cellulases. One potential source for cellulolytic enzyme genes is herbivorous insects adapted to digest plant cell walls. Here we examine the potential of transgenic switchgrass-produced TcEG1 cellulase from Tribolium castaneum (red flour beetle). This enzyme, when overproduced in Escherichia coliand Saccharomyces cerevisiae, efficiently digests cellulose at optima of 50 °C and pH 12.0. Results TcEG1 that was produced in green transgenic switchgrass tissue had a range of endoglucanase activity of 0.16–0.05 units (µM glucose release/min/mg) at 50 °C and pH 12.0. TcEG1 activity from air-dried leaves was unchanged from that from green tissue, but when tissue was dried in a desiccant oven (46 °C), specific enzyme activity decreased by 60%. When transgenic biomass was “dropped-in” into an alkaline buffer (pH 12.0) and allowed to incubate at 50 °C, cellobiose release was increased up to 77% over non-transgenic biomass. Saccharification was increased in one transgenic event by 28%, which had a concurrent decrease in lignin content of 9%. Histological analysis revealed an increase in cell wall thickness with no change to cell area or perimeter. Transgenic plants produced more, albeit narrower, tillers with equivalent dry biomass as the control. Conclusions This work describes the first study in which an insect cellulase has been produced in transgenic plants; in this case, the dedicated bioenergy crop switchgrass. Switchgrass overexpressing the TcEG1 gene appeared to be morphologically similar to its non-transgenic control and produced equivalent dry biomass. Therefore, we propose TcEG1 transgenics could be bred with other transgenic germplasm (e.g., low-lignin lines) to yield new switchgrass with synergistically reduced recalcitrance to biofuel production. In addition, transgenes for other cell wall degrading enzymes may be stacked with TcEG1 in switchgrass to yield complementary cell wall digestion features and complete auto-hydrolysis
A database of microRNA expression patterns in Xenopus laevis
MicroRNAs (miRNAs) are short, non-coding RNAs around 22 nucleotides long. They inhibit gene expression either by translational repression or by causing the degradation of the mRNAs they bind to. Many are highly conserved amongst diverse organisms and have restricted spatio-temporal expression patterns during embryonic development where they are thought to be involved in generating accuracy of developmental timing and in supporting cell fate decisions and tissue identity. We determined the expression patterns of 180 miRNAs in Xenopus laevis embryos using LNA oligonucleotides. In addition we carried out small RNA-seq on different stages of early Xenopus development, identified 44 miRNAs belonging to 29 new families and characterized the expression of 5 of these. Our analyses identified miRNA expression in many organs of the developing embryo. In particular a large number were expressed in neural tissue and in the somites. Surprisingly none of the miRNAs we have looked at show expression in the heart. Our results have been made freely available as a resource in both XenMARK and Xenbase
A 2.3-Day Periodic Variability in the Apparently Single Wolf-Rayet Star WR 134: Collapsed Companion or Rotational Modulation?
We present the results of an intensive campaign of spectroscopic and
photometric monitoring of the peculiar Wolf-Rayet star WR 134 from 1989 to
1997.
This unprecedentedly large data set allows us to confirm unambiguously the
existence of a coherent 2.25 +/- 0.05 day periodicity in the line-profile
changes of He II 4686, although the global pattern of variability is different
from one epoch to another. This period is only marginally detected in the
photometric data set. Assuming the 2.25 day periodic variability to be induced
by orbital motion of a collapsed companion, we develop a simple model aiming at
investigating (i) the effect of this strongly ionizing, accreting companion on
the Wolf-Rayet wind structure, and (ii) the expected emergent X-ray luminosity.
We argue that the predicted and observed X-ray fluxes can only be matched if
the accretion on the collapsed star is significantly inhibited. Additionally,
we performed simulations of line-profile variations caused by the orbital
revolution of a localized, strongly ionized wind cavity surrounding the X-ray
source. A reasonable fit is achieved between the observed and modeled
phase-dependent line profiles of He II 4686. However, the derived size of the
photoionized zone substantially exceeds our expectations, given the observed
low-level X-ray flux. Alternatively, we explore rotational modulation of a
persistent, largely anisotropic outflow as the origin of the observed cyclical
variability. Although qualitative, this hypothesis leads to greater consistency
with the observations.Comment: 34 pages, 16 figures. Accepted by the Astrophysical Journa
Polymorphisms in Plasmodium falciparum chloroquine resistance transporter and multidrug resistance 1 genes: parasite risk factors that affect treatment outcomes for P. falciparum malaria after artemether-lumefantrine and artesunate-amodiaquine.
Adequate clinical and parasitologic cure by artemisinin combination therapies relies on the artemisinin component and the partner drug. Polymorphisms in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1) genes are associated with decreased sensitivity to amodiaquine and lumefantrine, but effects of these polymorphisms on therapeutic responses to artesunate-amodiaquine (ASAQ) and artemether-lumefantrine (AL) have not been clearly defined. Individual patient data from 31 clinical trials were harmonized and pooled by using standardized methods from the WorldWide Antimalarial Resistance Network. Data for more than 7,000 patients were analyzed to assess relationships between parasite polymorphisms in pfcrt and pfmdr1 and clinically relevant outcomes after treatment with AL or ASAQ. Presence of the pfmdr1 gene N86 (adjusted hazards ratio = 4.74, 95% confidence interval = 2.29 - 9.78, P < 0.001) and increased pfmdr1 copy number (adjusted hazards ratio = 6.52, 95% confidence interval = 2.36-17.97, P < 0.001 : were significant independent risk factors for recrudescence in patients treated with AL. AL and ASAQ exerted opposing selective effects on single-nucleotide polymorphisms in pfcrt and pfmdr1. Monitoring selection and responding to emerging signs of drug resistance are critical tools for preserving efficacy of artemisinin combination therapies; determination of the prevalence of at least pfcrt K76T and pfmdr1 N86Y should now be routine
Starvation and recovery in the deep-sea methanotroph Methyloprofundus sedimenti
In the deep ocean, the conversion of methane into derived carbon and energy drives the establishment of diverse faunal communities. Yet specific biological mechanisms underlying the introduction of methane-derived carbon into the food web remain poorly described, due to a lack of cultured representative deep-sea methanotrophic prokaryotes. Here, the response of the deep-sea aerobic methanotroph Methyloprofundus sedimenti to methane starvation and recovery was characterized. By combining lipid analysis, RNA analysis, and electron cryotomography, it was shown that M. sedimenti undergoes discrete cellular shifts in response to methane starvation, including changes in headgroup-specific fatty acid saturation levels, and reductions in cytoplasmic storage granules. Methane starvation is associated with a significant increase in the abundance of gene transcripts pertinent to methane oxidation. Methane reintroduction to starved cells stimulates a rapid, transient extracellular accumulation of methanol, revealing a way in which methane-derived carbon may be routed to community members. This study provides new understanding of methanotrophic responses to methane starvation and recovery, and lays the initial groundwork to develop Methyloprofundus as a model chemosynthesizing bacterium from the deep sea
Shared medical appointments and mindfulness for Type 2 diabetes : a mixed-methods feasibility study
Introduction: Type 2 diabetes (T2DM) is a major health concern with significant personal and healthcare system costs. There is growing interest in using shared medical appointments (SMAs) for management of T2DM. We hypothesize that adding mindfulness to SMAs may be beneficial. This study aimed to assess the feasibility and acceptability of SMAs with mindfulness for T2DM within primary care in Australia. Materials and Methods: We conducted a single-blind randomized controlled feasibility study of SMAs within primary care for people with T2DM living in Western Sydney, Australia. People with T2DM, age 21 years and over, with HbA1c > 6.5% or fasting glucose >7.00 mmol/L within the past 3 months were eligible to enroll. The intervention group attended six 2-h programmed SMAs (pSMAs) which were held fortnightly. pSMAs included a structured education program and mindfulness component. The control group received usual care from their healthcare providers. We collected quantitative and qualitative data on acceptability as well as glycemic control (glycated hemoglobin and continuous glucose monitoring), lipids, anthropometric measures, blood pressure, selfreported psychological outcomes, quality of life, diet, and physical activity using an ActiGraph accelerometer. Results: Over a 2-month period, we enrolled 18 participants (10 females, 8 males) with a mean age of 58 years (standard deviation 9.8). We had 94.4% retention. All participants in the intervention group completed at least four pSMAs. Participants reported that attending pSMAs had been a positive experience that allowed them to accept their diagnosis and empowered them to make changes, which led to beneficial effects including weight loss and better glycemic control. Four pSMA participants found the mindfulness component helpful while two did not. All of the seven participants who contributed to qualitative evaluation reported improved psychosocial wellbeing and found the group setting beneficial. There was a significant difference in total cholesterol levels at 12 weeks between groups (3.86 mmol/L in intervention group vs. 4.15 mmol/L in the control group; p = 0.025) as well as pain intensity levels as measured by the PROMIS-29 (2.11 vs. 2.38; p = 0.034). Conclusion: pSMAs are feasible and acceptable to people with T2DM and may result in clinical improvement. A follow-up fully-powered randomized controlled trial is warranted. Clinical Trial Registration: Australia and New Zealand Clinical Trial Registry, identifier ACTRN12619000892112
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