4,297 research outputs found
Atrial Fibrillation in Eight New World Camelids.
BackgroundThere is limited information on the incidence of clinical signs, concurrent illness and treatment options for atrial fibrillation (AF) in New World Camelids (NWC).ObjectiveDescribe clinical signs and outcome of AF in NWC.AnimalsEight New World Camelids admitted with AF.MethodsA retrospective observational study of camelids diagnosed with AF based on characteristic findings on electrocardiogram (ECG).ResultsAll animals had an irregularly irregular heart rhythm detected on physical examination and 4 cases had obtunded mentation on admission. Three camelids were diagnosed with AF secondary to oleander intoxication, 3 animals had underlying cardiovascular disease, 1 was diagnosed with lone AF and 1 had AF diagnosed on examination for a urethral obstruction. Five of eight animals survived to discharge and nonsurvivors consisted of animals which died or were euthanized as a result of cardiovascular disease (2/8) or extra-cardiac disease unrelated to the AF (1/8).Conclusions and clinical importanceAtrial fibrillation occurs in NWC in association with cardiovascular disease, extra-cardiac disease or as lone AF. Amiodarone and transthoracic cardioversion were attempted in one llama with lone AF, but were unsuccessful. Atrial fibrillation was recorded in 0.1% of admissions
Molecular data suggest long-term in Situ Antarctic persistence within Antarctica's most speciose plant genus, Schistidium
© 2018 Biersma, Jackson, Stech, Griffiths, Linse and Convey. From glacial reconstructions it is clear that Antarctic terrestrial life must have been extremely limited throughout Quaternary glacial periods. In contrast, recent biological studies provide clear evidence for long-term in situ persistence throughout glacial times within most extant Antarctic faunal and several microbial groups. However, even now, the evolutionary history of the Antarctic flora-despite playing major role in Antarctic ecosystems-remains poorly studied. We assessed the diversity, richness and relative age divergences within Schistidium (Grimmiaceae, Bryophyta), the most species-rich plant genus in the Antarctic, as well as the plant genus containing most Antarctic endemic species. We applied phylogenetic and molecular dating methods based on nuclear ribosomal Internal Transcribed Spacer sequences, including all known Antarctic Schistidium species with available sample material. We additionally investigated the continent-wide genetic diversity within the most common Antarctic representative of the genus-the endemic species Schistidium antarctici-and performed preliminary phylogeographic analyses of the bipolar species Schistidium rivulare. Most previously described Antarctic Schistidium species were genetically distinct, confirming their specific status. Interspecific divergences of all species took place at least ~1 Mya, suggesting a likely in situ persistence in Antarctica for (at least) all endemic Schistidium species. The widespread endemic species, Schistidium antarctici, diverged from other Antarctic congeners in the late Miocene, thereby revealing the oldest extant plant species currently known in Antarctica, and providing increasing support for the hypothesis of vegetation survival through multiple glacial periods. Within S. antarctici we identified several distinct clades dividing the eastern Antarctic Peninsula and Scotia Arc islands from the western Antarctic Peninsula and all continental locations. This suggests that the mountainous spine on the Antarctic Peninsula forms a strong barrier to gene flow in this species, while increased genetic diversity in the northern Maritime Antarctic indicates likely glacial refugia in this area. This study provides an important first step toward assessing the diversity and evolutionary history of the most speciose moss genus in the Antarctic. The multi-million year presence of several endemic species contributes to studies on their adaptive potential to survive climate change over both historical and contemporary timescales.NERC STUDENTSHIP
NE/K50094X/
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On the Changing Role of the Stratosphere on the Tropospheric Ozone Budget: 1979â2010
We study the evolution of tropospheric ozone over the period 1979-2010 using a chemistry-climate model employing a stratosphere-troposphere chemistry scheme. By running with specified dynamics, the key feedback of composition on meteorology is suppressed, isolating the chemical response. By using historical forcings and emissions, interactions between processes are realistically represented. We use the model to assess how the ozone responds over time and to investigate model responses and trends. We find that the CFC-driven decrease in stratospheric ozone plays a significant role in the tropospheric ozone burden. Over the period 1979-1994, the decline in transport of ozone from the stratosphere, partially offsets an emissions-driven increase in tropospheric ozone production. From 1994-2010, despite a levelling off in emissions increased stratosphere-to-troposphere transport of ozone drives a small increase in the tropospheric ozone burden. These results have implications for the impact of future stratospheric ozone recovery on air quality and radiative forcing.European Communityâs Seventh Framework Programme 10 (FP7/2007-2013) under grant agreement no. 603557 (StratoClim)
Low genetic variation between South American and Antarctic populations of the bank-forming moss Chorisodontium aciphyllum (Dicranaceae)
The AntarcticâSouth American bank-forming moss Chorisodontium aciphyllum is known for having the oldest sub-fossils of any extant plant in Antarctica as well as extreme survival abilities, making it a candidate species for possible long-term survival in Antarctica. Applying phylogeographic and population genetic methods using the plastid markers trnL-F and rps4 and the nuclear internal transcribed spacer, we investigated the genetic diversity within C. aciphyllum throughout its range. Low genetic variation was found in all loci, both between and within Antarctic and southern South American populations, suggesting a relatively recent (likely within the last million years) colonization of this moss to the Antarctic, as well as a likely severe bottleneck during Pleistocene glaciations in southern South America. We also performed a simple atmospheric transfer modeling approach to study potential colonization rates of small (microscopic/microbial) or spore-dispersed organisms (such as many mosses and lichens). These suggested that the northern Antarctic Peninsula shows potentially regular connectivity from southern South America, with air masses transferring, particularly southbound, between the two regions. We found elevated genetic variation of C. aciphyllum in Elephant Island, also the location of the oldest known moss banks (> 5500 years), suggesting this location to be a genetic hotspot for this species in the Antarctic.This research was funded by a Natural Environment Research Council (NERC) Ph.D. studentship (ref. NE/K50094X/1) to E.M.B. and supported by NERC core funding to the BAS Biodiversity, Evolution and Adaptation Team
Laryngeal Nerve Activity During Pulse Emission in the CF-FM Bat, Rhinolophus ferrumequinum. I. Superior Laryngeal Nerve (External Motor Branch)
The activity of the external (motor) branch of the superior laryngeal nerve (SLN), innervating the cricothyroid muscle, was recorded in the greater horseshoe bat,Rhinolophus ferrumequinum. The bats were induced to change the frequency of the constant frequency (CF) component of their echolocation signals by presenting artificial signals for which they Doppler shift compensated. The data show that the SLN discharge rate and the frequency of the emitted CF are correlated in a linear manner
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Barriers to Treatment for Female Problem Gamblers: A UK Perspective
There is a paucity of research in the UK which examines problem gambling and that which does exist is mainly quantitative, focuses on male samples and fails to look at treatment seeking populations or obstacles preventing problem gamblers from seeking treatment. This paper presents findings from part of a larger qualitative study that explored the experience of treatment for female problem gamblers. Data were collected using semi-structured interviews with eight women who had received individual cognitive-behavioural therapy in the National Health Service for their gambling problem. An interpretative phenomenological analysis approach was applied in the research process, identifying three main themes, of which the subtheme âBarriers to Treatmentâ is examined here. Internal and external barriers to treatment organically emerged in all female participantsâ accounts and appear to have an impact on service utilisation. Input directly from gamblers can be combined with findings from other studies to devise better ways of reaching female problem gamblers. A better understanding of barriers to treatment can also provide valuable direction for future research and suggest applications in clinical service provision and treatment planning
Combinatorial RNA Design: Designability and Structure-Approximating Algorithm
In this work, we consider the Combinatorial RNA Design problem, a minimal
instance of the RNA design problem which aims at finding a sequence that admits
a given target as its unique base pair maximizing structure. We provide
complete characterizations for the structures that can be designed using
restricted alphabets. Under a classic four-letter alphabet, we provide a
complete characterization of designable structures without unpaired bases. When
unpaired bases are allowed, we provide partial characterizations for classes of
designable/undesignable structures, and show that the class of designable
structures is closed under the stutter operation. Membership of a given
structure to any of the classes can be tested in linear time and, for positive
instances, a solution can be found in linear time. Finally, we consider a
structure-approximating version of the problem that allows to extend bands
(helices) and, assuming that the input structure avoids two motifs, we provide
a linear-time algorithm that produces a designable structure with at most twice
more base pairs than the input structure.Comment: CPM - 26th Annual Symposium on Combinatorial Pattern Matching, Jun
2015, Ischia Island, Italy. LNCS, 201
Area-level deprivation and adiposity in children: is the relationship linear?
OBJECTIVE: It has been suggested that childhood obesity is inversely associated with deprivation, such that the prevalence is higher in more deprived groups. However, comparatively few studies actually use an area-level measure of deprivation, limiting the scope to assess trends in the association with obesity for this indicator. Furthermore, most assume a linear relationship. Therefore, the aim of this study was to investigate associations between area-level deprivation and three measures of adiposity in children: body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR). DESIGN: This is a cross-sectional study in which data were collected on three occasions a year apart (2005-2007). SUBJECTS: Data were available for 13,333 children, typically aged 11-12 years, from 37 schools and 542 lower super-output areas (LSOAs). MEASURES: Stature, mass and WC. Obesity was defined as a BMI and WC exceeding the 95th centile according to British reference data. WHtR exceeding 0.5 defined obesity. The Index of Multiple Deprivation affecting children (IDACI) was used to determine area-level deprivation. RESULTS: Considerable differences in the prevalence of obesity exist between the three different measures. However, for all measures of adiposity the highest probability of being classified as obese is in the middle of the IDACI range. This relationship is more marked in girls, such that the probability of being obese for girls living in areas at the two extremes of deprivation is around half that at the peak, occurring in the middle. CONCLUSION: These data confirm the high prevalence of obesity in children and suggest that the relationship between obesity and residential area-level deprivation is not linear. This is contrary to the 'deprivation theory' and questions the current understanding and interpretation of the relationship between obesity and deprivation in children. These results could help make informed decisions at the local level
Assessing Internet addiction using the parsimonious Internet addiction components model - a preliminary study [forthcoming]
Internet usage has grown exponentially over the last decade. Research indicates that excessive Internet use can lead to symptoms associated with addiction. To date, assessment of potential Internet addiction has varied regarding populations studied and instruments used, making reliable prevalence estimations difficult. To overcome the present problems a preliminary study was conducted testing a parsimonious Internet addiction components model based on Griffithsâ addiction components (2005), including salience, mood modification, tolerance, withdrawal, conflict, and relapse. Two validated measures of Internet addiction were used (Compulsive Internet Use Scale [CIUS], Meerkerk et al., 2009, and Assessment for Internet and Computer Game Addiction Scale [AICA-S], Beutel et al., 2010) in two independent samples (ns = 3,105 and 2,257). The fit of the model was analysed using Confirmatory Factor Analysis. Results indicate that the Internet addiction components model fits the data in both samples well. The two sample/two instrument approach provides converging evidence concerning the degree to which the components model can organize the self-reported behavioural components of Internet addiction. Recommendations for future research include a more detailed assessment of tolerance as addiction component
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