324 research outputs found
The cis-regulatory system of the tbrain gene: Alternative use of multiple modules to promote skeletogenic expression in the sea urchin embryo
The genomic cis-regulatory systems controlling regulatory gene expression usually include multiple modules. The regulatory output of such systems at any given time depends on which module is directing the function of the basal transcription apparatus, and ultimately on the transcription factor inputs into that module. Here we examine regulation of the Strongylocentrotus purpuratus tbrain gene, a required activator of the skeletogenic specification state in the lineage descendant from the embryo micromeres. Alternate cis-regulatory modules were found to convey skeletogenic expression in reporter constructs. To determine their relative developmental functions in context, we made use of recombineered BAC constructs containing a GFP reporter and of derivatives from which specific modules had been deleted. The outputs of the various constructs were observed spatially by GFP fluorescence and quantitatively over time by QPCR. In the context of the complete genomic locus, early skeletogenic expression is controlled by an intron enhancer plus a proximal region containing a HesC site as predicted from network analysis. From ingression onward, however, a dedicated distal module utilizing positive Ets1/2 inputs contributes to definitive expression in the skeletogenic mesenchyme. This module also mediates a newly discovered negative Erg input which excludes non-skeletogenic mesodermal expression
Detection of potentially toxic metals by SERS using salen complexes
Surfaced enhanced Raman scattering (SERS) can discriminate between metal complexes due to the characteristic âspectral fingerprintsâ obtained. As a result, SERS has the potential to develop relatively simple and sensitive methods of detecting and quantifying a range of metal ions in solution. This could be beneficial for the environmental monitoring of potentially toxic metals (PTMs). Here, salen (C16H16N2O2) was used as a ligand to form complexes of Ni(II), Cu(II), Mn(II) and Co(II) in solution. The SERS spectra showed characteristic spectral differences specific to each metal complex, thus allowing the identification of each of these metal ions. This method allows a number of metal ions to be detected using the same ligand and an identical preparation procedure. The limit of detection (LOD) was determined for each metal ion, and it was found that Ni(II), Cu(II) and Mn(II) could be detected below the WHOâs recommended limits in drinking water at 1, 2 and 2 ”g L-1, respectively. Co(II) was found to have an LOD of 20 ”g L-1, however no limit has been set for this ion by the WHO as the concentration of Co(II) in drinking water is generally <1-2 ÎŒg L-1. A contaminated water sample was also analysed where Mn(II) was detected at a level of 800 ”g L-1
Eff ectiveness of 4% chlorhexidine umbilical cord care on neonatal mortality in Southern Province, Zambia (ZamCAT): a cluster-randomised controlled trial
Background Chlorhexidine umbilical cord washes reduce neonatal mortality in south Asian populations with high
neonatal mortality rates and predominantly home-based deliveries. No data exist for sub-Saharan African populations
with lower neonatal mortality rates or mostly facility-based deliveries. We compared the eff ect of chlorhexidine with
dry cord care on neonatal mortality rates in Zambia.
Methods We undertook a cluster-randomised controlled trial in Southern Province, Zambia, with 90 health facilitybased
clusters. We enrolled women who were in their second or third trimester of pregnancy, aged at least 15 years,
and who would remain in the catchment area for follow-up of 28 days post-partum. Newborn babies received clean
dry cord care (control) or topical application of 10 mL of a 4% chlorhexidine solution once per day until 3 days after
cord drop (intervention), according to cluster assignment. We used stratifi ed, restricted randomisation to divide
clusters into urban or two rural groups (located <40 km or â„40 km to referral facility), and randomly assigned clusters
(1:1) to use intervention (n=45) or control treatment (n=45). Sites, participants, and fi eld monitors were aware of their
study assignment. The primary outcomes were all-cause neonatal mortality within 28 days post-partum and all-cause
neonatal mortality within 28 days post-partum among babies who survived the fi rst 24 h of life. Analysis was by
intention to treat. Neonatal mortality rate was compared with generalised estimating equations. This study is
registered at ClinicalTrials.gov (NCT01241318).
Findings From Feb 15, 2011, to Jan 30, 2013, we screened 42 356 pregnant women and enrolled 39 679 women (mean
436·2 per cluster [SD 65·3]), who had 37 856 livebirths and 723 stillbirths; 63·8% of deliveries were facility-based. Of
livebirths, 18 450 (99·7%) newborn babies in the chlorhexidine group and 19 308 (99·8%) newborn babies in the dry cord
care group were followed up to day 28 or death. 16 660 (90·0%) infants in the chlorhexidine group had chlorhexidine
applied within 24 h of birth. We found no signifi cant diff erence in neonatal mortality rate between the chlorhexidine
group (15·2 deaths per 1000 livebirths) and the dry cord care group (13·6 deaths per 1000 livebirths; risk ratio [RR] 1·12,
95% CI 0·88â1·44). Eliminating day 0 deaths yielded similar fi ndings (RR 1·12, 95% CI 0·86â1·47).
Interpretation Despite substantial reductions previously reported in south Asia, chlorhexidine cord applications did not
signifi cantly reduce neonatal mortality rates in Zambia. Chlorhexidine cord applications do not seem to provide clear
benefi ts for newborn babies in settings with predominantly facility-based deliveries and lower (<30 deaths per
1000 livebirths) neonatal mortality rates
An exploration of cognitive subgroups in Alzheimer's disease
Heterogeneity is observed in the patterns of cognition in Alzheimer's disease (AD). Such heterogeneity might suggest the involvement of different etiological pathways or different host responses to pathology. A total of 627 subjects with mild/moderate AD underwent cognitive assessment with the Mini-Mental State Examination (MMSE) and the Dementia Rating Scale-2 (DRS-2). Latent class analysis (LCA) was performed on cognition subscale data to identify and characterize cognitive subgroups. Clinical, demographic, and genetic factors were explored for association with class membership. LCA suggested the existence of four subgroups; one group with mild and another with severe global impairment across the cognitive domains, one group with primary impairments in attention and construction, and another group with primary deficits in memory and orientation. Education, disease duration, age, Apolipoprotein E-Δ4 (APOE Δ4) status, gender, presence of grasp reflex, white matter changes, and early or prominent visuospatial impairment were all associated with class membership. Our results support the existence of heterogeneity in patterns of cognitive impairment in AD. Our observation of classes characterized by predominant deficits in attention/construction and memory respectively deserves further exploration as does the association between membership in the attention/construction class and APOE Δ4 negative status. (JINS, 2010, 16, 233-243.
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The impact of mental health recovery narratives on recipients experiencing mental health problems: Qualitative analysis and change model.
BACKGROUND: Mental health recovery narratives are stories of recovery from mental health problems. Narratives may impact in helpful and harmful ways on those who receive them. The objective of this paper is to develop a change model identifying the range of possible impacts and how they occur. METHOD: Semi-structured interviews were conducted with adults with experience of mental health problems and recovery (n = 77). Participants were asked to share a mental health recovery narrative and to describe the impact of other people's recovery narratives on their own recovery. A change model was generated through iterative thematic analysis of transcripts. RESULTS: Change is initiated when a recipient develops a connection to a narrator or to the events descripted in their narrative. Change is mediated by the recipient recognising experiences shared with the narrator, noticing the achievements or difficulties of the narrator, learning how recovery happens, or experiencing emotional release. Helpful outcomes of receiving recovery narratives are connectedness, validation, hope, empowerment, appreciation, reference shift and stigma reduction. Harmful outcomes are a sense of inadequacy, disconnection, pessimism and burden. Impact is positively moderated by the perceived authenticity of the narrative, and can be reduced if the recipient is experiencing a crisis. CONCLUSIONS: Interventions that incorporate the use of recovery narratives, such as peer support, anti-stigma campaigns and bibliotherapy, can use the change model to maximise benefit and minimise harms from narratives. Interventions should incorporate a diverse range of narratives available through different mediums to enable a range of recipients to connect with and benefit from this material. Service providers using recovery narratives should preserve authenticity so as to maximise impact, for example by avoiding excessive editing
High In Situ Repeatability of Behaviour Indicates Animal Personality in the Beadlet Anemone Actinia equina (Cnidaria)
âAnimal personalityâ means that individuals differ from one another in either single behaviours or suites of related behaviours in a way that is consistent over time. It is usually assumed that such consistent individual differences in behaviour are driven by variation in how individuals respond to information about their environment, rather than by differences in external factors such as variation in microhabitat. Since behavioural variation is ubiquitous in nature we might expect âanimal personalityâ to be present in diverse taxa, including animals with relatively simple nervous systems. We investigated in situ startle responses in a sea anemone, Actinia equina, to determine whether personalities might be present in this example of an animal with a simple nervous system. We found very high levels of repeatability among individuals that were re-identified in the same locations over a three week sampling period. In a subset of the data, where we used tide-pool temperature measurements to control for a key element of variation in microhabitat, these high levels of repeatability remained. Although a range of other consistent differences in micro-habitat features could have contributed to consistent differences between the behaviour of individuals, these data suggest the presence of animal personality in A. equina. Rather than being restricted to certain groups, personality may be a general feature of animals and may be particularly pronounced in species with simple nervous systems
Evaluation of polygenic risk scores for breast and ovarian cancer risk prediction in BRCA1 and BRCA2 mutation carriers
Background: Genome-wide association studies (GWAS) have identified 94 common single-nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk and 18 associated with ovarian cancer (OC) risk. Several of these are also associated with risk of BC or OC for women who carry a pathogenic mutation in the high-risk BC and OC genes BRCA1 or BRCA2. The combined effects of these variants on BC or OC risk for BRCA1 and BRCA2 mutation carriers have not yet been assessed while their clinical management could benefit from improved personalized risk estimates.
Methods: We constructed polygenic risk scores (PRS) using BC and OC susceptibility SNPs identified through population-based GWAS: for BC (overall, estrogen receptor [ER]-positive, and ER-negative) and for OC. Using data from 15 252 female BRCA1 and 8211 BRCA2 carriers, the association of each PRS with BC or OC risk was evaluated using a weighted cohort approach, with time to diagnosis as the outcome and estimation of the hazard ratios (HRs) per standard deviation increase in the PRS.
Results: The PRS for ER-negative BC displayed the strongest association with BC risk in BRCA1 carriers (HR = 1.27, 95% confidence interval [CI] = 1.23 to 1.31, P = 8.2 x 10(53)). In BRCA2 carriers, the strongest association with BC risk was seen for the overall BC PRS (HR = 1.22, 95% CI = 1.17 to 1.28, P = 7.2 x 10(-20)). The OC PRS was strongly associated with OC risk for both BRCA1 and BRCA2 carriers. These translate to differences in absolute risks (more than 10% in each case) between the top and bottom deciles of the PRS distribution; for example, the OC risk was 6% by age 80 years for BRCA2 carriers at the 10th percentile of the OC PRS compared with 19% risk for those at the 90th percentile of PRS.
Conclusions: BC and OC PRS are predictive of cancer risk in BRCA1 and BRCA2 carriers. Incorporation of the PRS into risk prediction models has promise to better inform decisions on cancer risk management
Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR
New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and
NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a
quiescent state since at least early 2015, reactivated between 2017 March 19
and April 5. The radio flux density, while variable, is approximately 100x
larger than during its dormant state. The X-ray flux one month after
reactivation was at least 800x larger than during quiescence, and has been
decaying exponentially on a 111+/-19 day timescale. This high-flux state,
together with a radio-derived rotational ephemeris, enabled for the first time
the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV
pulsed fraction is comparable to the smallest observed for magnetars. The
overall pulsar geometry inferred from polarized radio emission appears to be
broadly consistent with that determined 6-8 years earlier. However, rotating
vector model fits suggest that we are now seeing radio emission from a
different location in the magnetosphere than previously. This indicates a novel
way in which radio emission from magnetars can differ from that of ordinary
pulsars. The torque on the neutron star is varying rapidly and unsteadily, as
is common for magnetars following outburst, having changed by a factor of 7
within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure
Broadly Neutralizing Alphavirus Antibodies Bind an Epitope on E2 and Inhibit Entry and Egress
SummaryWe screened a panel of mouse and human monoclonal antibodies (MAbs) against chikungunya virus and identified several with inhibitory activity against multiple alphaviruses. Passive transfer of broadly neutralizing MAbs protected mice against infection by chikungunya, Mayaro, and Oânyongânyong alphaviruses. Using alanine-scanning mutagenesis, loss-of-function recombinant proteins and viruses, and multiple functional assays, we determined that broadly neutralizing MAbs block multiple steps in the viral lifecycle, including entry and egress, and bind to a conserved epitope on the B domain of the E2 glycoprotein. A 16Â Ă
resolution cryo-electron microscopy structure of a Fab fragment bound to CHIKV E2 B domain provided an explanation for its neutralizing activity. Binding to the B domain was associated with repositioning of the A domain of E2 that enabled cross-linking of neighboring spikes. Our results suggest that B domain antigenic determinants could be targeted for vaccine or antibody therapeutic development against multiple alphaviruses of global concern
Maternal Feeding Practices Become More Controlling After and Not Before Excessive Rates of Weight Gain
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93708/1/oby.2009.54.pd
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