143 research outputs found
Detailed Abundances for a Large Sample of Giant Stars in the Globular Cluster 47 Tucanae (NGC 104)
47 Tuc is an ideal target to study chemical evolution and GC formation in
massive more metal-rich GCs since is the closest, massive GC. We present
chemical abundances for O, Na, Al, Si, Ca, Ti, Fe, Ni, La, and Eu in 164 red
giant branch (RGB) stars in the massive globular cluster 47 Tuc using spectra
obtained with both the Hydra multi-fiber spectrograph at the Blanco 4-m
telescope and the FLAMES multi-object spectrograph at the Very Large Telescope.
We find an average [Fe/H]=--0.790.09 dex, consistent with literature
values, as well as over-abundances of alpha-elements
([\alpha/\mbox{Fe}]\sim0.3 dex). The n-capture process elements indicate that
47 Tuc is r-process dominated ([Eu/La]=+0.24), and the light elements O, Na,
and Al exhibit star-to-star variations. The Na-O anti-correlation, a signature
typically seen in Galactic globular clusters, is present in 47 Tuc, and extends
to include a small number of stars with [O/Fe] \,--0.5. Additionally, the
[O/Na] ratios of our sample reveal that the cluster stars can be separated into
three distinct populations. A KS-test demonstrates that the O-poor/Na-rich
stars are more centrally concentrated than the O-rich/Na-poor stars. The
observed number and radial distribution of 47 Tuc's stellar populations, as
distinguished by their light element composition, agrees closely with the
results obtained from photometric data. We do not find evidence supporting a
strong Na-Al correlation in 47 Tuc, which is consistent with current models of
AGB nucleosynthesis yields.Comment: Accepted for publication in The Astrophysical Journa
AGB Sodium Abundances in the Globular Cluster 47 Tucanae (NGC 104)
A recent analysis comparing the [Na/Fe] distributions of red giant branch
(RGB) and asymptotic giant branch (AGB) stars in the Galactic globular cluster
NGC 6752 found that the ratio of Na-poor to Na-rich stars changes from 30:70 on
the RGB to 100:0 on the AGB. The surprising paucity of Na-rich stars on the AGB
in NGC 6752 warrants additional investigations to determine if the failure of a
significant fraction of stars to ascend the AGB is an attribute common to all
globular clusters. Therefore, we present radial velocities, [Fe/H], and [Na/Fe]
abundances for 35 AGB stars in the Galactic globular cluster 47 Tucanae (47
Tuc; NGC 104), and compare the AGB [Na/Fe] distribution with a similar RGB
sample published previously. The abundances and velocities were derived from
high resolution spectra obtained with the Michigan/Magellan Fiber System (M2FS)
and MSpec spectrograph on the Magellan-Clay 6.5m telescope. We find the average
heliocentric radial velocity and [Fe/H] values to be =-18.56 km s^-1
(sigma=10.21 km s^-1) and =-0.68 (sigma=0.08), respectively, in
agreement with previous literature estimates. The average [Na/Fe] abundance is
0.12 dex lower in the 47 Tuc AGB sample compared to the RGB sample, and the
ratio of Na-poor to Na-rich stars is 63:37 on the AGB and 45:55 on the RGB.
However, in contrast to NGC 6752, the two 47 Tuc populations have nearly
identical [Na/Fe] dispersion and interquartile range values. The data presented
here suggest that only a small fraction <20% of Na-rich stars in 47 Tuc may
fail to ascend the AGB. Regardless of the cause for the lower average [Na/Fe]
abundance in AGB stars, we find that Na-poor stars and at least some Na-rich
stars in 47 Tuc evolve through the early AGB phase. [abridged]Comment: Accepted for publication in the Astronomical Journal; 15 pages; 8
figures; 4 table
Creació d'un nou projecte d'inserció a Manlleu : TAC Empresa d'Inserció
El projecte parteix d'una necessitat real del territori. A Manlleu i a la Comarca d'Osona hi ha un alt índex de persones en situació d'atur, que presenta dificultats per accedir al mercat laboral.El proyecto parte de una necesidad real del territorio. En Manlleu y en la Comarca de Osona hay un alto índice de personas en situación de paro, que presenta dificultades para acceder al mercado laboral.The project is based on a real necessity for the territory. In Manlleu and Osona there are a high level of unemployment, which has difficulties to access the labor market
Anti-vascular endothelial growth factor for proliferative diabetic retinopathy.
BACKGROUND: Proliferative diabetic retinopathy (PDR) is a complication of diabetic retinopathy that can cause blindness. Although panretinal photocoagulation (PRP) is the treatment of choice for PDR, it has secondary effects that can affect vision. An alternative treatment such as anti-vascular endothelial growth factor (anti-VEGF), which produces an inhibition of vascular proliferation, could improve the vision of people with PDR. OBJECTIVES: To assess the effectiveness and safety of anti-VEGFs for PDR. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to April 2014), EMBASE (January 1980 to April 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 28 April 2014. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing anti-VEGFs to another active treatment, sham treatment or no treatment for people with PDR. We also included studies that assessed the combination of anti-VEGFs with other treatments. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies for inclusion, extracted data and assessed risk of bias for all included trials. We calculated the risk ratio (RR) or the mean difference (MD), and 95% confidence intervals (CI). MAIN RESULTS: We included 18 RCTs with 1005 participants (1131 eyes) of whom 57% were men. The median number of participants per RCT was 40 (range 15 to 261). The studies took place in Asia (three studies), Europe (two studies), the Middle East (seven studies), North America (three studies) and South America (three studies). Eight RCTs recruited people eligible for PRP, nine RCTs enrolled people with diabetes requiring vitrectomy and one RCT recruited people undergoing cataract surgery. The median follow-up was six months (range one to 12 months). Seven studies were at high risk of bias and the remainder were unclear risk of bias in one or more domains.Very low quality evidence from one study of 61 people showed that people treated with bevacizumab and PRP were less likely to lose 3 or more lines of visual acuity at 12 months compared with people treated with PRP alone (RR 0.19, 95% CI 0.05 to 0.81). People treated with anti-VEGF had an increased chance of gaining 3 or more lines of visual acuity but the effect was imprecise and compatible with no effect or being less likely to gain vision (RR 6.78, 95% CI 0.37 to 125.95). No other study reported these two outcomes. On average, people treated with anti-VEGF (bevacizumab, pegaptanib or ranibizumab) had better visual acuity at 12 months compared with people not receiving anti-VEGF (MD -0.07 logMAR, 95% CI -0.12 to -0.02; 5 RCTs, 373 participants, low quality evidence). There was some evidence to suggest a regression of PDR with smaller leakage on fluorescein angiography but it was difficult to estimate a pooled result from the two trials reporting this outcome. People receiving anti-VEGF were less likely to have vitreous or pre-retinal haemorrhage at 12 months (RR 0.32, 95% CI 0.16 to 0.65; 3 RCTs, 342 participants, low quality evidence). No study reported on fluorescein leakage or quality of life.All of the nine trials of anti-VEGF before or during vitrectomy investigated bevacizumab; most studies investigated bevacizumab before vitrectomy, one study investigated bevacizumab during surgery.People treated with bevacizumab and vitrectomy were less likely to lose 3 or more lines of visual acuity at 12 months compared with people given vitrectomy alone but the effect was imprecise and compatible with no effect or being more likely to lose vision (RR 0.49, 95% CI 0.08 to 3.14; 3 RCTs, 94 participants, low quality evidence). People treated with bevacizumab were more likely to gain 3 or more lines of visual acuity (RR 1.62, 95% CI 1.20 to 2.17; 3 RCTs, 94 participants, low quality evidence). On average, people treated with bevacizumab had better visual acuity at 12 months compared with people not receiving bevacizumab but there was uncertainty in the estimate (the CIs included 0; i.e. were compatible with no effect, and there was considerable inconsistency between studies; MD -0.24 logMAR, 95% CI -0.50 to 0.01; 6 RCTs, 335 participants, I(2) = 67%; low quality evidence). People receiving bevacizumab were less likely to have vitreous or pre-retinal haemorrhage at 12 months (RR 0.30, 95% CI 0.18 to 0.52; 7 RCTs, 393 participants, low quality evidence). No study reported on quality of life.Reasons for downgrading the quality of the evidence included risk of bias in included studies, imprecision of the estimates, inconsistency of effect estimates and indirectness (few studies reported at 12 months).Adverse effects were rarely reported and there was no evidence for any increased risk with anti-VEGF but given the relatively few studies that reported these, and the low event rate, the power of the analysis to detect any differences was low. AUTHORS' CONCLUSIONS: There was very low or low quality evidence from RCTs for the efficacy and safety of anti-VEGF agents when used to treat PDR over and above current standard treatments. However, the results suggest that anti-VEGFs can reduce the risk of intraocular bleeding in people with PDR. Further carefully designed clinical trials should be able to improve this evidence
b-Initiated processes at the LHC: a reappraisal
Several key processes at the LHC in the standard model and beyond that
involve quarks, such as single-top, Higgs, and weak vector boson associated
production, can be described in QCD either in a 4-flavor or 5-flavor scheme. In
the former, quarks appear only in the final state and are typically
considered massive. In 5-flavor schemes, calculations include quarks in the
initial state, are simpler and allow the resummation of possibly large initial
state logarithms of the type into the
parton distribution function (PDF), being the typical scale of the
hard process. In this work we critically reconsider the rationale for using
5-flavor improved schemes at the LHC. Our motivation stems from the observation
that the effects of initial state logs are rarely very large in hadron
collisions: 4-flavor computations are pertubatively well behaved and a
substantial agreement between predictions in the two schemes is found. We
identify two distinct reasons that explain this behaviour, i.e., the
resummation of the initial state logarithms into the -PDF is relevant only
at large Bjorken and the possibly large ratios 's are
always accompanied by universal phase space suppression factors. Our study
paves the way to using both schemes for the same process so to exploit their
complementary advantages for different observables, such as employing a
5-flavor scheme to accurately predict the total cross section at NNLO and the
corresponding 4-flavor computation at NLO for fully exclusive studies.Comment: Fixed typo in Eq. (A.10) and few typos in Eq. (C.2) and (C.3
UK women smokers' experiences of an age-progression smoking cessation intervention: Thematic analysis of accounts
Objectives Appearance-related interventions to promote healthy behaviour have been found effective to communicate health risks. The current study aimed to explore women smokers' experiences of age-progression software showing the effects of smoking on the face. Methods A qualitative design was implemented, utilizing both individual interviews and focus groups within a critical realist framework. Fifteen, 19–52 year-old women smokers were administered an age-progression intervention. All participants responded to the intervention, engaged in semi-structured interviews, and were invited back to attend one of three focus groups. Data were analysed using inductive thematic analysis. Results Four main themes were identified: Health versus Appearance, Shock Reaction, Perceived Susceptibility, and Intention to Quit. Participants found the intervention useful, voicing need for a comprehensive approach that includes both appearance and health. Despite increases in appearance-based apps which could diminish impact, women's accounts of shock induced by the aged smoking-morphed images were similar to previous work conducted more than ten years previously. Conclusions The study provides novel insights in how women smokers currently perceive, and react to, an age-progression intervention for smoking cessation. Innovation Findings emphasise the implementation of this intervention type accompanied by health information in a range of patient settings
Violence-related PTSD and neural activation when seeing emotionally charged male-female interactions.
Post-traumatic stress disorder (PTSD) is a disorder that involves impaired regulation of the fear response to traumatic reminders. This study tested how women with male-perpetrated interpersonal violence-related PTSD (IPV-PTSD) differed in their brain activation from healthy controls (HC) when exposed to scenes of male-female interaction of differing emotional content. Sixteen women with symptoms of IPV-PTSD and 19 HC participated in this study. During magnetic resonance imaging, participants watched a stimulus protocol of 23 different 20 s silent epochs of male-female interactions taken from feature films, which were neutral, menacing or prosocial. IPV-PTSD participants compared with HC showed (i) greater dorsomedial prefrontal cortex (dmPFC) and dorsolateral prefrontal cortex (dlPFC) activation in response to menacing vs prosocial scenes and (ii) greater anterior cingulate cortex (ACC), right hippocampus activation and lower ventromedial prefrontal cortex (vmPFC) activty in response to emotional vs neutral scenes. The fact that IPV-PTSD participants compared with HC showed lower activity of the ventral ACC during emotionally charged scenes regardless of the valence of the scenes suggests that impaired social perception among IPV-PTSD patients transcends menacing contexts and generalizes to a wider variety of emotionally charged male-female interactions
Hold me or stroke me? Individual differences in static and dynamic affective touch
Low-threshold mechanosensory C-fibres, C-tactile afferents (CTs), respond optimally to sensations associated with a human caress. Additionally, CT-stimulation activates brain regions associated with processing affective states. This evidence has led to the social touch hypothesis, that CTs have a key role in encoding the affective properties of social touch. Thus, to date, the affective touch literature has focussed on gentle stroking touch. However, social touch interactions involve many touch types, including static, higher force touch such as hugging and holding. This study aimed to broaden our understanding of the social touch hypothesis by investigating relative preference for static vs dynamic touch and the influence of force on these preferences. Additionally, as recent literature has highlighted individual differences in CT-touch sensitivity, this study investigated the influence of affective touch experiences and attitudes, autistic traits, depressive symptomology and perceived stress on CT-touch sensitivity. Directly experienced, robotic touch responses were obtained through a lab-based study and vicarious touch responses through an online study where participants rated affective touch videos. Individual differences were determined by self-report questionnaire measures. In general, static touch was preferred over CT-non-optimal stroking touch, however, consistent with previous reports, CT-optimal stroking (velocity 1–10 cm/s) was rated most pleasant. However, static and CT-optimal vicarious touch were rated comparably for dorsal hand touch. For all velocities, 0.4N was preferred over 0.05N and 1.5N robotic touch. Participant dynamic touch quadratic terms were calculated for robotic and vicarious touch as a proxy CT-sensitivity measure. Attitudes to intimate touch significantly predict robotic and vicarious quadratic terms, as well as vicarious static dorsal hand touch ratings. Perceived stress negatively predicted robotic static touch ratings. This study has identified individual difference predictors of CT-touch sensitivity. Additionally, it has highlighted the context dependence of affective touch responses and the need to consider static, as well as dynamic affective touch.</jats:p
Impacts of Use and Abuse of Nature in Catalonia with Proposals for Sustainable Management
This paper provides an overview of the last 40 years of use, and in many cases abuse, of the natural resources in Catalonia, a country that is representative of European countries in general, and especially those in the Mediterranean region. It analyses the use of natural resources made by mining, agriculture, livestock, logging, fishing, nature tourism, and energy production and consumption. This use results in an ecological footprint, i.e., the productive land and sea surface required to generate the consumed resources and absorb the resulting waste, which is about seven times the amount available, a very high number but very similar to other European countries. This overexploitation of natural resources has a huge impact on land and its different forms of cover, air, and water. For the last 25 years, forests and urban areas have each gained almost 3% more of the territory at the expense of agricultural land; those municipalities bordering the sea have increased their number of inhabitants and activity, and although they only occupy 6.7% of the total surface area, they account for 43.3% of the population; air quality has stabilized since the turn of the century, and there has been some improvement in the state of aquatic ecosystems, but still only 36% are in good condition, while the remainder have suffered morphological changes and different forms of nonpoint source pollution; meanwhile the biodiversity of flora and fauna remains still under threat. Environmental policies do not go far enough so there is a need for revision of the legislation related to environmental impact and the protection of natural areas, flora, and fauna. The promotion of environmental research must be accompanied by environmental education to foster a society which is more knowledgeable, has more control and influence over the decisions that deeply affect it. Indeed, nature conservation goes hand in hand with other social and economic challenges that require a more sustainable vision. Today's problems with nature derive from the current economic model, which is environmentally unsustainable in that it does not take into account environmental impacts. Lastly, we propose a series of reasonable and feasible priority measures and actions related to each use made of the country's natural resources, to the impacts they have had, and to their management, in the hope that these can contribute to improving the conservation and management of the environment and biodiversity and move towards sustainability
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