Abundance analysis of normal and mercury-manganase type late-B stars from optical spectra

The aim of this project was to perform an abundance analysis of a selection of mercury-manganese and normal A and B-type stars. Observations of thirteen stars were taken using the Hamilton Echelle Spectrograph and coude auxilliary telescope (CAT) situated at Lick Observatory. The high signal-to-noise optical spectra were reduced with the aid of the software packages FIGARO and VISTA. A technique for measuring the parasitic light parallel to the dispersion of the spectrum was devised; none was found (mean P = -1.0±0.8%), which implies that measured equivalent widths should be free of this important systematic error. Measurements were made of the wavelengths and equivalent widths of unblended spectral lines. The spectra were modelled using ATLAS-6 model atmospheres and the synthesis package UCLSYN. Effective temperatures and surface gravities for the programme stars were adopted from Smith and Dworetsky (1993). Abundances were generally determined by comparing synthetic equivalent widths to measured equivalent widths. Where line blends made this impossible, the observed spectra were compared to the synthetic spectra. The instrumental profile was determined from arc calibration lines and was found to be asymmetric; the profile was measured and was convolved with the synthetic spectra to allow a comparison with observations to be made. Microturbulence parameters for these stars were determined according to the method of Magain (1984); stars with effective temperatures below 11000K showed a positive value, but stars above this temperature yielded microturbulences consistent with zero. The abundances generally compare well with the literature and are in many cases an improvement on existing work. Phosphorus showed a positive correlation with effective temperature in HgMn stars and manganese also exhibits a strong correlation, in agreement with previous observations. The strong manganese line at λ4206.367 was found to exhibit a systematic discrepancy with respect to other manganese lines at high abundances; this is probably due to hyperfine structure and it is recommended that this line not be used for abundance analysis in the future unless its structure can be modelled explicitly

“Catch 22”: biosecurity awareness, interpretation and practice amongst poultry catchers

Campylobacter contamination of chicken on sale in the UK remains at high levels and has a substantial public health impact. This has prompted the application of many interventions in the supply chain, including enhanced biosecurity measures on-farm. Catching and thinning are acknowledged as threats to the maintenance of good biosecurity, yet the people employed to undertake this critical work (i.e. ‘catchers’) are a rarely studied group. This study uses a mixed methods approach to investigate catchers’ (n = 53) understanding of the biosecurity threats posed by the catching and thinning, and the barriers to good biosecurity practice. It interrogated the role of training in both the awareness and practice of good biosecurity. Awareness of lapses in biosecurity was assessed using a Watch-&-Click hazard awareness survey (n = 53). Qualitative interviews (n = 49 catchers, 5 farm managers) explored the understanding, experience and practice of catching and biosecurity. All of the catchers who took part in the Watch-&-Click study identified at least one of the biosecurity threats with 40% detecting all of the hazards. Those who had undergone training were significantly more likely to identify specific biosecurity threats and have a higher awareness score overall (48% compared to 9%, p = 0.03). Crucially, the individual and group interviews revealed the tensions between the high levels of biosecurity awareness evident from the survey and the reality of the routine practice of catching and thinning. Time pressures and a lack of equipment rather than a lack of knowledge appear a more fundamental cause of catcher-related biosecurity lapses. Our results reveal that catchers find themselves in a ‘catch-22′ situation in which mutually conflicting circumstances prevent simultaneous completion of their job and compliance with biosecurity standards

Effects of portion size on chronic energy intake

© 2007 Jeffery et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Seeing the way: visual sociology and the distance runner's perspective

Employing visual and autoethnographic data from a two‐year research project on distance runners, this article seeks to examine the activity of seeing in relation to the activity of distance running. One of its methodological aims is to develop the linkage between visual and autoethnographic data in combining an observation‐based narrative and sociological analysis with photographs. This combination aims to convey to the reader not only some of the specific subcultural knowledge and particular ways of seeing, but also something of the runner's embodied feelings and experience of momentum en route. Via the combination of narrative and photographs we seek a more effective way of communicating just how distance runners see and experience their training terrain. The importance of subjecting mundane everyday practices to detailed sociological analysis has been highlighted by many sociologists, including those of an ethnomethodological perspective. Indeed, without the competence of social actors in accomplishing these mundane, routine understandings and practices, it is argued, there would in fact be no social order

Spatiotemporal distribution of phycotoxins and their co-occurrence within nearshore waters

Harmful algal blooms (HABs), varying in intensity and causative species, have historically occurred throughout the Chesapeake Bay, U.S.; however, phycotoxin data are sparse. The spatiotemporal distribution of phycotoxins was investigated using solid-phase adsorption toxin tracking (SPATT) across 12 shallow, nearshore sites within the lower Chesapeake Bay and Virginia\u27s coastal bays over one year (2017-2018). Eight toxins, azaspiracid-1 (AZA1), azaspiracid-2 (AZA2), microcystin-LR (MC-LR), domoic acid (DA), okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-2 (PTX2), and goniodomin A (GDA) were detected in SPATT extracts. Temporally, phycotoxins were always present in the region, with at least one phycotoxin group (i.e., consisting of OA and DTX1) detected at every time point. Co-occurrence of phycotoxins was also common; two or more toxin groups were observed in 76% of the samples analyzed. Toxin maximums: 0.03 ng AZA2/g resin/day, 0.25 ng DA/g resin/day, 15 ng DTX1/g resin/day, 61 ng OA/g resin/day, 72 ng PTX2/g resin/day, and 102,050 ng GDA/g resin/day were seasonal, with peaks occurring in summer and fall. Spatially, the southern tributary and coastal bay regions harbored the highest amount of total phycotoxins on SPATT over the year, and the former contained the greatest diversity of phycotoxins. The novel detection of AZAs in the region, before a causative species has been identified, supports the use of SPATT as an explorative tool in respect to emerging threats. The lack of karlotoxin in SPATT extracts, but detection of Karlodinium veneficum by microscopy, however, emphasizes that this tool should be considered complementary to, but not a replacement for, more traditional HAB management and monitoring methods

The psychosocial impact of exercising with epilepsy: a narrative analysis

© 2016 Elsevier Inc.Research has presented the benefits of and barriers to exercise for people with epilepsy through quantitative means. However, individual experiences through qualitative investigations have been absent. This research will present the narratives of people with epilepsy exercising over time and, as a result, develop further understanding of the psychosocial impact of exercising with epilepsy. Four interviews were conducted over the course of one year (one every three to four months) with four participants (aged 23–38 years) who varied in seizure type and control (16 interviews in total). A narrative analysis was used to analyze their exercise experiences. Results showed that exercise creates a positive effect on psychological and physical well-being. However, prevention from exercise as a result of medical advice or recurrent seizures can create negative effects such as social isolation, anxiety, lack of confidence, frustration, and anger. Adaptations of decreasing exercise intensity level and partaking in different physical activities are techniques used to lessen the negative impact and maintain an exercise routine. Time was shown to be an important factor in this adaptation as well as portrayed the cyclical responses of negative and positive emotions in regard to their exercise life. These findings provide valuable insight into the psychosocial benefits of and barriers to exercising with epilepsy and draw attention to the individual differences in how a person with epilepsy copes with uncontrolled seizures and their impact on his/her exercise routine. This knowledge can lead to future research in exploring how a person with epilepsy can overcome these barriers to exercise and encourage more people with epilepsy to enjoy the benefits of exercise

The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics

Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h3 (~skewness) and h4 (~kurtosis) in galaxies to their cosmological assembly history. Here, we assess these results by measuring the stellar kinematics on a sample of 315 galaxies, without a morphological selection, using two-dimensional integral field data from the SAMI Galaxy Survey. Proxies for the spin parameter (${\lambda }_{{R}_{{\rm{e}}}}$) and ellipticity (${\epsilon }_{{\rm{e}}}$) are used to separate fast and slow rotators; there exists a good correspondence to regular and non-regular rotators, respectively, as also seen in earlier studies. We confirm that regular rotators show a strong h3 versus $V/\sigma$ anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h3 and $V/\sigma$. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h3 versus $V/\sigma$ signatures. Within the SAMI Galaxy Survey, we identify five classes of high-order stellar kinematic signatures using Gaussian mixture models. Class 1 corresponds to slow rotators, whereas Classes 2–5 correspond to fast rotators. We find that galaxies with similar {\lambda }_{{R}_{{\rm{e}}}}\mbox{--}{\epsilon }_{{\rm{e}}} values can show distinctly different {h}_{3}\mbox{--}V/\sigma signatures. Class 5 objects are previously unidentified fast rotators that show a weak h3 versus $V/\sigma$ anti-correlation. From simulations, these objects are predicted to be disk-less galaxies formed by gas-poor mergers. From morphological examination, however, there is evidence for large stellar disks. Instead, Class 5 objects are more likely disturbed galaxies, have counter-rotating bulges, or bars in edge-on galaxies. Finally, we interpret the strong anti-correlation in h3 versus $V/\sigma$ as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy