2,213 research outputs found
The utility of relative environmental suitability (RES) modelling for predicting distributions of seabirds in the North Atlantic
Pulsar Results with the Fermi Large Area Telescope
The launch of the Fermi Gamma-ray Space Telescope has heralded a new era in
the study of gamma-ray pulsars. The population of confirmed gamma-ray pulsars
has gone from 6-7 to more than 60, and the superb sensitivity of the Large Area
Telescope (LAT) on Fermi has allowed the detailed study of their spectra and
light curves. Twenty-four of these pulsars were discovered in blind searches of
the gamma-ray data, and twenty-one of these are, at present, radio quiet,
despite deep radio follow-up observations. In addition, millisecond pulsars
have been confirmed as a class of gamma-ray emitters, both individually and
collectively in globular clusters. Recently, radio searches in the direction of
LAT sources with no likely counterparts have been highly productive, leading to
the discovery of a large number of new millisecond pulsars. Taken together,
these discoveries promise a great improvement in the understanding of the
gamma-ray emission properties and Galactic population of pulsars. We summarize
some of the results stemming from these newly-detected pulsars and their timing
and multi-wavelength follow-up observations.Comment: 21 pages, 9 figures, to appear in Proceedings of ICREA Workshop on
The High-Energy Emission from Pulsars and their Systems, Sant Cugat, Spain,
2010 April 12-16 (Springer
Identification of patients with atrial fibrillation in UK community pharmacy: an evaluation of a new service
Background: Many patients with atrial fibrillation (AF) are asymptomatic and diagnosed via opportunistic screening. Community pharmacy has been advocated as a potential resource for opportunistic screening and lifestyle interventions. Objective: The objective of this evaluation is to describe the outcomes from an AF service, in terms of referrals and interventions provided to patients identified as not at risk. Method: Eligibility was assessed from pharmacy records and the completion of a short questionnaire. Once consented, patients were screened for AF and their blood pressure was measured. Results: Of 594 patients screened, nine were identified as at risk of having AF and were referred to their GP. The service also identified 109 patients with undiagnosed hypertension, 176 patients with a Body Mass Index (BMI) > 30, 131 with an Audit-C score > 5 and 59 smokers. Pharmacists provided 413 interventions in 326 patients aimed at weight reduction (239), alcohol consumption (123) and smoking cessation (51). Conclusion: This evaluation characterises the interventions provided to, not only those identified with the target condition - in this case AF - but also those without it. The true outcome of these additional interventions, along with appropriate follow-up, should be the focus of future studies.Impact of findings on patients or practice •Patients are willing to be screened for AF through community pharmacies•Screening can provide opportunities to identify other healthcare problems such a hypertension or poor lifestyle •Community pharmacists are able to provide brief advice to patients as a result of this opportunistic screenin
A prospective study to assess the value of MMP-9 in improving the appropriateness of urgent referrals for colorectal cancer
Background
Bowel cancer is common and is a major cause of death. Most people with bowel symptoms who meet the criteria for urgent referral to secondary care will not be found to have bowel cancer, and some people who are found to have cancer will have been referred routinely rather than urgently. If general practitioners could better identify people who were likely to have bowel cancer or conditions that may lead to bowel cancer, the pressure on hospital clinics may be reduced, enabling these patients to be seen more quickly. Increased levels of an enzyme called matrix metalloproteinase 9 (MMP-9) have been found to be associated with such conditions, and this can be measured from a blood sample. This study aims to find out whether measuring MMP-9 levels could improve the appropriateness of urgent referrals for patients with bowel symptoms.
Methods
People aged 18 years or older referred to a colorectal clinic will be asked to complete a questionnaire about symptoms, recent injuries or chronic illnesses (these can increase the level of matrix metalloproteinases) and family history of bowel cancer. A blood sample will be taken from people who consent to take part to assess MMP-9 levels, and the results of examination at the clinic and/or investigations arising from the clinic visit will be collected from hospital records. The accuracy of MMP-9 will be assessed by comparing the MMP-9 level with the resulting diagnosis. The combination of factors (e.g. symptoms and MMP-9 level) that best predict a diagnosis of malignancy (invasive disease or polyps) will be determined.
Discussion
Although guidelines are in place to facilitate referrals to colorectal clinics, symptoms alone do not adequately distinguish people with malignancy from people with benign conditions. This study will establish whether MMP-9 could assist this process. If this were the case, measurement of MMP-9 levels could be used by general practitioners to assist in the identification of people who were most likely to have bowel cancer or conditions that may lead to bowel cancer, and who should, therefore, be referred most urgently to secondary car
A perspective on using experiment and theory to identify design principles in dye-sensitized solar cells
Dye-sensitized solar cells (DSCs) have been the subject of wide-ranging studies for many
years because of their potential for large-scale manufacturing using roll-to-roll processing
allied to their use of earth abundant raw materials. Two main challenges exist for DSC
devices to achieve this goal; uplifting device efficiency from the 12 to 14% currently
achieved for laboratory-scale ‘hero’ cells and replacement of the widely-used liquid
electrolytes which can limit device lifetimes. To increase device efficiency requires optimized
dye injection and regeneration, most likely from multiple dyes while replacement
of liquid electrolytes requires solid charge transporters (most likely hole transport materials
– HTMs). While theoretical and experimental work have both been widely applied to
different aspects of DSC research, these approaches are most effective when working in
tandem. In this context, this perspective paper considers the key parameters which
influence electron transfer processes in DSC devices using one or more dye molecules
and how modelling and experimental approaches can work together to optimize electron
injection and dye regeneration.
This paper provides a perspective that theory and experiment are best used in tandem to study
DSC device
Movement profiles of soccer substitutes
Modifying a soccer substitute’s pre-pitch-entry activities may represent an opportunity to
maximise physical performance and minimise injury-risk following match-introduction.
Using a professional team that has previously participated in substitute profiling research,
this follow-up case study investigated the effects of a modified match-day protocol that
included substitutes; 1) performing a new pre-match warm-up alongside members of the
starting team (as opposed to a separate substitute-only warm-up), 2) participating in a staffled
half-time rewarm-up (as opposed to player-led half-time activities), and 3) receiving
ongoing education focusing on the efficacy of (re)warm-up activities. English Championship
substitutes (n = 15) were monitored using Micro-electromechanical Systems during 13
matches incorporating the modified practices (35 observations). On an individual player
basis, data were organised into bouts of warm-up activity (pre-pitch-entry) and five min
epochs of match-play (post-pitch-entry). Linear mixed modelling assessed the influence of
‘bout’ and ‘epoch’, position, and scoreline. Substitutes performed 3±1 rewarm-up bouts�-
player-1�match-1 between kick-off and pitch-entry, which were shorter (-17.2 to -27.1 min)
and elicited less distance (-696 to -1257 m) than the pre-match warm-up (p�0.001). Compared
with previous data, heightened absolute movement responses were observed during
the pre-match and staff-led half-time (re)warm-ups, alongside greater relative distances
covered during player-led activities performed between kick-off and pitch-entry. Whilst less
distance (-10%) was covered during the second versus first five min period following matchintroduction,
values remained higher than previously reported. Between pitch-entry and the
end of the match, the scoreline improved and worsened following 26% and 11% of substitutions,
respectively; a favourable record compared with existing observations. Acknowledging
the likely contribution from external factors, this case study reports heightened
movement profiles and improved match scorelines when pre-pitch-entry practices were
modified. Practitioners should note the potential influence of match-day activities on the physical responses of soccer substitutes and, if deemed necessary, consider adapting their
pre-pitch-entry routines accordingly
Psychological processes mediating the association between developmental trauma and specific psychotic symptoms in adults: a systematic review and meta-analysis
Experiencing psychological trauma during childhood and/or adolescence is associated with an increased risk of psychosis in adulthood. However, we lack a clear knowledge of how developmental trauma induces vulnerability to psychotic symptoms. Understanding the psychological processes involved in this association is crucial to the development of preventive interventions and improved treatments. We sought to systematically review the literature and combine findings using meta‐analytic techniques to establish the potential roles of psychological processes in the associations between developmental trauma and specific psychotic experiences (i.e., hallucinations, delusions and paranoia). Twenty‐two studies met our inclusion criteria. We found mediating roles of dissociation, emotional dysregulation and post‐traumatic stress disorder (PTSD) symptoms (avoidance, numbing and hyperarousal) between developmental trauma and hallucinations. There was also evidence of a mediating role of negative schemata, i.e. mental constructs of meanings, between developmental trauma and delusions as well as paranoia. Many studies to date have been of poor quality, and the field is limited by mostly cross‐sectional research. Our findings suggest that there may be distinct psychological pathways from developmental trauma to psychotic phenomena in adulthood. Clinicians should carefully ask people with psychosis about their history of developmental trauma, and screen patients with such a history for dissociation, emotional dysregulation and PTSD symptoms. Well conducted research with prospective designs, including neurocognitive assessment, is required in order to fully understand the biopsychosocial mechanisms underlying the association between developmental trauma and psychosis
SALL4 Expression in Gonocytes and Spermatogonial Clones of Postnatal Mouse Testes
The spermatogenic lineage is established after birth when gonocytes migrate to the basement membrane of seminiferous tubules and give rise to spermatogonial stem cells (SSC). In adults, SSCs reside within the population of undifferentiated spermatogonia (Aundiff) that expands clonally from single cells (Asingle) to form pairs (Apaired) and chains of 4, 8 and 16 Aaligned spermatogonia. Although stem cell activity is thought to reside in the population of Asingle spermatogonia, new research suggests that clone size alone does not define the stem cell pool. The mechanisms that regulate self-renewal and differentiation fate decisions are poorly understood due to limited availability of experimental tools that distinguish the products of those fate decisions. The pluripotency factor SALL4 (sal-like protein 4) is implicated in stem cell maintenance and patterning in many organs during embryonic development, but expression becomes restricted to the gonads after birth. We analyzed the expression of SALL4 in the mouse testis during the first weeks after birth and in adult seminiferous tubules. In newborn mice, the isoform SALL4B is expressed in quiescent gonocytes at postnatal day 0 (PND0) and SALL4A is upregulated at PND7 when gonocytes have colonized the basement membrane and given rise to spermatogonia. During steady-state spermatogenesis in adult testes, SALL4 expression overlapped substantially with PLZF and LIN28 in Asingle, Apaired and Aaligned spermatogonia and therefore appears to be a marker of undifferentiated spermatogonia in mice. In contrast, co-expression of SALL4 with GFRα1 and cKIT identified distinct subpopulations of Aundiff in all clone sizes that might provide clues about SSC regulation. Collectively, these results indicate that 1) SALL4 isoforms are differentially expressed at the initiation of spermatogenesis, 2) SALL4 is expressed in undifferentiated spermatogonia in adult testes and 3) SALL4 co-staining with GFRα1 and cKIT reveals distinct subpopulations of Aundiff spermatogonia that merit further investigation. © 2013 Gassei, Orwig
Clusters of health behaviours in Queensland adults are associated with different socio-demographic characteristics.
Background: The co-occurrence of unhealthy lifestyles, calls for interventions that target multiple health behaviours. This study investigates the clustering of health behaviours and examines demographic differences between each cluster. Methods: In total, 934 adults from Queensland, Australia completed a cross-sectional survey assessing multiple health behaviours. A two-step hierarchical cluster analysis using multiple iterations identified the optimal number of clusters and the subset of distinguishing health behaviour variables. Univariate analyses of variance and chi-squared tests assessed difference in health behaviours by socio-demographic factors and clusters. Results: Three clusters were identified: the 'lower risk' cluster (n = 436) reported the healthiest profile and met all public health guidelines. The 'elevated risk' cluster (n = 105) reported a range of unhealthy behaviours such as excessive alcohol consumption, sitting time, fast-food consumption, smoking, inactivity and a lack of fruit and vegetables. The 'moderate risk behaviour' cluster (n = 393) demonstrated some unhealthy behaviours with low physical activity levels and poor dietary outcomes. The 'elevated risk' cluster were significantly younger and more socio-economically disadvantaged than both the 'lower and moderate risk' clusters. Discussion: Younger people who live in more deprived areas were largely within the 'elevated risk' cluster and represent an important population for MHBC interventions given their wide range of unhealthy behaviours
Frequent burning promotes invasions of alien plants into a mesic African savanna
Fire is both inevitable and necessary for maintaining the structure and functioning of mesic savannas. Without disturbances such as fire and herbivory, tree cover can increase at the expense of grass cover and over time dominate mesic savannas. Consequently, repeated burning is widely used to suppress tree recruitment and control bush encroachment. However, the effect of regular burning on invasion by alien plant species is little understood. Here, vegetation data from a long-term fire experiment, which began in 1953 in a mesic Zimbabwean savanna, were used to test whether the frequency of burning promoted alien plant invasion. The fire treatments consisted of late season fires, lit at 1-, 2-, 3-, and 4-year intervals, and these regularly burnt plots were compared with unburnt plots. Results show that over half a century of frequent burning promoted the invasion by alien plants relative to areas where fire was excluded. More alien plant species became established in plots that had a higher frequency of burning. The proportion of alien species in the species assemblage was highest in the annually burnt plots followed by plots burnt biennially. Alien plant invasion was lowest in plots protected from fire but did not differ significantly between plots burnt triennially and quadrennially. Further, the abundance of five alien forbs increased significantly as the interval (in years) between fires became shorter. On average, the density of these alien forbs in annually burnt plots was at least ten times as high as the density of unburnt plots. Plant diversity was also altered by long-term burning. Total plant species richness was significantly lower in the unburnt plots compared to regularly burnt plots. These findings suggest that frequent burning of mesic savannas enhances invasion by alien plants, with short intervals between fires favouring alien forbs. Therefore, reducing the frequency of burning may be a key to minimising the risk of alien plant spread into mesic savannas, which is important because invasive plants pose a threat to native biodiversity and may alter savanna functioning
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