1,116 research outputs found
Vectorcardiographic changes during extended space flight
To assess the effects of space flight on cardiac electrical properties, vectorcardiograms were taken on the 9 Skylab astronauts during the flights of 28, 59, and 84 days. The Frank lead system was used and observations were made at rest; during 25%, 50% and 75% of maximum exercise; during a short pulse of exercise (150 watts, 2 minutes); and after exercise. Data from 131 in-flight tests were analyzed by computer and compared to preflight and postflight values. Statistically significant increase in QRS vector magnitude (six of nine crewmen); T vector magnitude (five of nine crewmen); and resting PR interval duration (six of nine crewmen) occurred. During exercise the PR interval did not differ from preflight. Exercise heart rates inflight were the same as preflight, but increased in the immediate postflight period. With the exception of the arrhythmias, no deleterious vectorcardiographic changes were observed during the Skylab missions
A generalization of the van-der-Pol oscillator underlies active signal amplification in Drosophila hearing
The antennal hearing organs of the fruit fly Drosophila melanogaster boost their sensitivity by an active mechanical process that, analogous to the cochlear amplifier of vertebrates, resides in the motility of mechanosensory cells. This process nonlinearly improves the sensitivity of hearing and occasionally gives rise to self-sustained oscillations in the absence of sound. Time series analysis of self-sustained oscillations now unveils that the underlying dynamical system is well described by a generalization of the van-der-Pol oscillator. From the dynamic equations, the underlying amplification dynamics can explicitly be derived. According to the model, oscillations emerge from a combination of negative damping, which reflects active amplification, and a nonlinear restoring force that dictates the amplitude of the oscillations. Hence, active amplification in fly hearing seems to rely on the negative damping mechanism initially proposed for the cochlear amplifier of vertebrate
Psychology students’ perception of and engagement with feedback as a function of year of study
Undergraduate students’ perception of feedback and level of engagement with the feedback they receive have gained increasing attention in the educational literature recently to identify areas which require educators’ attention. However, research in this area has generally been based on limited self-selecting samples, and has not considered how students’ relationship with feedback may alter depending on their year of study. To address this, a survey measuring students’ views and practices regarding feedback was completed at a higher education institution by 447 first-, second- and third-year psychology students, representing 77% of the cohort. Findings revealed that third years responded more negatively in both areas than their first- and second-year counterparts, whose ratings on these aspects themselves were far from optimal. These findings highlight the need for early interventions to improve students’ perception of and engagement with feedback in the earlier years, and to prevent the recorded deterioration later on in the degree course
Gamma oscillatory activity in vitro: a model system to assess pathophysiological mechanisms of comorbidity between autism and epilepsy.
Autism spectrum disorder (ASD) and temporal lobe epilepsy exhibit remarkable comorbidity, but for reasons not clearly understood. To reveal a common pathophysiological mechanism, we here describe and characterize an in vitro epileptiform activity in the rat hippocampus that exhibits common features with in vivo activity in rodent ASD models. We discovered the development of this activity in the CA1 region of horizontal slices after prolonged interictal-like epileptiform activity in the CA3 region that was provoked by incubation in high potassium artificial cerebrospinal fluid. The CA1 epileptiform bursts were insensitive to blockers of glutamatergic transmission, and were carried by synaptic as well as extrasynaptic, tonically activated gamma-aminobutyric acid type A (GABA(A)) receptors. The bursts bear resemblance to in vivo gamma-oscillatory activity found in rat ASD models with respect to their gamma frequency spectrum, their origin (in the CA1), and their sensitivity to blockers of cation-chloride pumps (NKCC1 and KCC2), as well as to oxytocin. Considering this bursting activity as an in vitro model for studying comorbidity between epilepsy and ASD may help to disentangle the intricate interactions that underlie the comorbidity between both diseases and suggests that extrasynaptic tonic GABAergic transmission could represent a potential target for ASD
'20 days protected learning' - students' experiences of an Overseas Nurses Programme - 4 years on: A retrospective survey
Background
From September 2005 the Nursing and Midwifery Council (NMC) introduced new arrangements for the registration of non-EU overseas nurses which requires all applicants to undertake '20 days of protected learning' time in the UK and for some, a period of supervised practice. A survey was undertaken at Bournemouth University, which offers a '20 days protected learning only' programme, to elicit overseas nurses' demographic details, experiences in completing the programme and their 'final destinations' once registered.
Methods
An online survey was devised which contained a mixture of tick box and open ended questions which covered demographic details, views on the programme and final destinations This was uploaded to www.SurveyMonkey.com and sent out to nurses who had completed the Overseas Nurses Programme (ONP) with Bournemouth University (n=1050). Quantiative data were analysed using descriptive statistics and the qualitative data were coded and analysed using content analysis .
Results
There were 251 respondents (27.7% response rate). The typical 'profile' of a nurse who responded to the survey was female, aged 25-40 years and had been qualified for more than 5 years with a bachelors degree. The majority came from Australia on a 2 year working holiday visa and the key final destination in the UK, on registration with the NMC, was working for an agency. There were five key findings regarding experience of the programe. Of those surveyed 61.2% did not feel it necessary to undergo an ONP; 71.6% felt that they should be able to complete the programme on-line in their own country; 64.2% that the ONP should only contain information about delivery of healthcare in UK and Legal and professional (NMC) issues; 57% that European nurses should also undergo the same programme and sit an IELTS test; and 68.2% that the programme was too theory orientated; and should have links to practice (21%).
Conclusions
The NMC set the admissions criteria for entry to the register and Standards for an ONP. The findings of this survey raise issues regarding the percieved value and use of this approach for overseas nurses, and it may be helpful to take this into account when considering future policy
A multi-exon deletion within WWOX is associated with a 46,XY disorder of sex development
Disorders of sex development (DSD) are congenital conditions where chromosomal, gonad or genital development is atypical. In a significant proportion of 46,XY DSD cases it is not possible to identify a causative mutation, making genetic counseling difficult and potentially hindering optimal treatment. Here, we describe the analysis of a 46,XY DSD patient that presented at birth with ambiguous genitalia. Histological analysis of the surgically removed gonads showed bilateral undifferentiated gonadal tissue and immature testis, both containing malignant germ cells. We screened genomic DNA from this patient for deletions and duplications using an Illumina whole-genome SNP microarray. This analysis revealed a heterozygous deletion within the WWOX gene on chromosome 16, removing exons 6-8. Analysis of parental DNA showed that the deletion was inherited from the mother. cDNA analysis confirmed that the deletion maintained the reading frame, with exon 5 being spliced directly onto exon 9. This deletion is the first description of a germline rearrangement affecting the coding sequence of WWOX in humans. Previously described Wwox knockout mouse models showed gonadal abnormalities, supporting a role for WWOX in human gonad development
Loss of LMOD1 impairs smooth muscle cytocontractility and causes megacystis microcolon intestinal hypoperistalsis syndrome in humans and mice
Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a congenital visceral myopathy characterized by severe dilation of the urinary bladder and defective intestinal motility. The genetic basis of MMIHS has been ascribed to spontaneous and autosomal dominant mutations in actin gamma 2 (ACTG2), a smooth muscle contractile gene. However, evidence suggesting a recessive origin of the disease also exists. Using combined homozygosity mapping and whole exome sequencing, a genetically isolated family was found to carry a premature termination codon in Leiomodin1 (LMOD1), a gene preferentially expressed in vascular and visceral smooth muscle cells. Parents heterozygous for the mutation exhibited no abnormalities, but a child homozygous for the premature termination codon displayed symptoms consistent with MMIHS. We used CRISPR-Cas9 (CRISPR-associated protein) genome editing of Lmod1 to generate a similar premature termination codon. Mice homozygous for the mutation showed loss of LMOD1 protein and pathology consistent with MMIHS, including late gestation expansion of the bladder, hydronephrosis, and rapid demise after parturition. Loss of LMOD1 resulted in a reduction of filamentous actin, elongated cytoskeletal dense bodies, and impaired intestinal smooth muscle contractility. These results define LMOD1 as a disease gene for MMIHS and suggest its role in establishing normal smooth muscle cytoskeletal-contractile coupling
Acquisition of pneumococci specific effector and regulatory Cd4+ T cells localising within human upper respiratory-tract mucosal lymphoid tissue
The upper respiratory tract mucosa is the location for commensal Streptococcus (S.) pneumoniae colonization and therefore represents a major site of contact between host and bacteria. The CD4(+) T cell response to pneumococcus is increasingly recognised as an important mediator of immunity that protects against invasive disease, with data suggesting a critical role for Th17 cells in mucosal clearance. By assessing CD4 T cell proliferative responses we demonstrate age-related sequestration of Th1 and Th17 CD4(+) T cells reactive to pneumococcal protein antigens within mucosal lymphoid tissue. CD25(hi) T cell depletion and utilisation of pneumococcal specific MHCII tetramers revealed the presence of antigen specific Tregs that utilised CTLA-4 and PDL-1 surface molecules to suppress these responses. The balance between mucosal effector and regulatory CD4(+) T cell immunity is likely to be critical to pneumococcal commensalism and the prevention of unwanted pathology associated with carriage. However, if dysregulated, such responses may render the host more susceptible to invasive pneumococcal infection and adversely affect the successful implementation of both polysaccharide-conjugate and novel protein-based pneumococcal vaccines
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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