527 research outputs found
Remote identification of sheep with flystrike using behavioural observations
Flystrike is a major problem affecting sheep in Australia. Identification of &lsquo;flystruck&rsquo; individuals is crucial for treatment; but requires labour-intensive physical examination. As the industry moves toward more low-input systems; there is a need for remote methods to identify flystruck individuals. The aim of this study was to investigate the behaviour of sheep with breech flystrike within a paddock setting. Video footage of sixteen Merino sheep; eight later confirmed with flystrike and eight without; was collected as they moved freely within the paddock with conspecifics. Quantitative behavioural measurements and a qualitative behavioural assessment (QBA) were conducted and compared to their breech conditions (i.e., faecal/urine staining; flystrike severity). Both qualitative and quantitative assessments indicated behavioural differences between flystruck and non-flystruck animals. Flystruck sheep had a behavioural profile characterised by restless behaviour; abnormal postures and reduced grazing time (<i>p</i> &lt; 0.05). Furthermore; flystruck sheep were scored to have a more &lsquo;exhausted/irritated&rsquo; demeanour using QBA (<i>p</i> &lt; 0.05). The behavioural responses also corresponded to the flystrike severity scores and condition of the breech area. We conclude that remotely assessed behaviour of flystruck sheep diverges markedly from non-flystruck sheep; and thus could be a low-input method for identifying and treating affected animals
Changes in epidemiological patterns of sea lice infestation on farmed Atlantic salmon, Salmo salar L., in Scotland between 1996 and 2006
Analyses of a unique database containing sea lice records over an 11 year period provide evidence of changing infestation patterns in Scotland. The data, collected from more than 50 commercial Atlantic salmon farms, indicate that both species of sea lice commonly found in Scotland, Lepeophtheirus salmonis and Caligus elongatus, have declined on farms over the past decade. Reductions for both species have been particularly marked since 2001 when more effective veterinary medicines became available. Treatment data were also available in the database and these show a growing trend towards the use of the in feed medication emamectin benzoate (Slice), particularly in the first year of the salmon production cycle. However, this trend to wards single product use has not been sustained in 2006, the latest year for which data are available. There is some evidence of region to region variation within Scotland with the Western Isles experiencing higher levels of infestation. However, compared to the levels observed between 1996 and 2000, all regions have benefited from reduced lice infestation, with the overall pattern showing a particular reduction in the second and third quarters of the second year of production
Cardiac magnetic resonance assessment of diastolic dysfunction in acute coronary syndrome
Chest pain is an important presenting symptom. However, few cases of chest pain are diagnosed as
acute coronary syndrome (ACS) in the acute setting. This results in frequent inappropriate
discharge and major delay in treatment for patients with underlying ACS. The conventional
methods of assessing ACS, which include electrocardiography and serological markers of infarct,
can take time to manifest. Recent studies have investigated more sensitive and specific imaging
modalities that can be used. Diastolic dysfunction occurs early following coronary artery occlusion
and its detection is useful in confirming the diagnosis, risk stratification, and prognosis post-ACS.
Cardiac magnetic resonance provides a single imaging modality for comprehensive evaluation of
chest pain in the acute setting. In particular, cardiac magnetic resonance has many imaging
techniques that assess diastolic dysfunction post-coronary artery occlusion. Techniques such as
measurement of left atrial size, mitral inflow, and mitral annular and pulmonary vein flow velocities
with phase-contrast imaging enable general assessment of ventricular diastolic function. More
novel imaging techniques, such as T2-weighted imaging for oedema, T1 mapping, and myocardial
tagging, allow early determination of regional diastolic dysfunction and oedema. These findings may
correspond to specific infarcted arteries that may be used to tailor eventual percutaneous
coronary artery intervention
The <i>M<sup>.</sup>–M</i><sub>disk</sub> Relationship for Herbig Ae/Be Stars: A lifetime problem for disks with low masses?
The accretion of material from protoplanetary disks onto their central stars is a fundamental process in the evolution of these systems and a key diagnostic in constraining the disk lifetime. We analyze the relationship between the stellar accretion rate and the disk mass in 32 intermediate-mass Herbig Ae/Be systems and compare them to their lower-mass counterparts, T Tauri stars. We find that the M ̇-Mdisk relationship for Herbig Ae/Be stars is largely flat at ∼10−7 M☉ yr−1 over 3 orders of magnitude in dust mass. While most of the sample follows the T Tauri trend, a subset of objects with high accretion rates and low dust masses are identified. These outliers (12 out of 32 sources) have an inferred disk lifetime of less than 0.01 Myr and are dominated by objects with low infrared excess. This outlier sample is likely identified in part by the bias in classifying Herbig Ae/Be stars, which requires evidence of accretion that can only be reliably measured above a rate of ∼10−9M☉ yr−1 for these spectral types. If the disk masses are not underestimated and the accretion rates are not overestimated, this implies that these disks may be on the verge of dispersal, which may be due to efficient radial drift of material or outer disk depletion by photoevaporation and/or truncation by companions. This outlier sample likely represents a small subset of the larger young, intermediate-mass stellar population, the majority of which would have already stopped accreting and cleared their disks
Comparison of Three CIDR Based Fixed-time AI Protocols for Beef Heifers
Several effective fixed-time AI (FTAI) protocols have been developed to facilitate AI while eliminating the need for estrus detection. Among these are the 5-d CO-Synch+CIDR (5d), PG 6-d CIDR (PG-CIDR), and 14-d CIDR-PG (CIDR-PG) protocols. While each of these protocols varies in duration and approach to synchronizing estrus and ovulation, each has been reported as an effective method to facilitate FTAI in beef heifers. Therefore, the objective of this study was to compare FTAI pregnancy rates in beef heifers synchronized with these three CIDR based protocols. Virgin beef heifers (n = 801) at four locations were synchronized with one of three protocols: 1) (5-day CO-Synch + CIDR) an injection of GnRH (100 μg; i.m.) and insertion of a CIDR on d -5, PG (25 mg; i.m.) and CIDR removal on d 0 with a second injection of PG (\u3e4 h after CIDR removal) on d 0 and FTAI at 72 h after CIDR removal, 2) (PG 6-day CIDR) PG (25 mg; i.m.) on d -9, GnRH (100 μg; i.m.) and insertion of a CIDR on d -6, PG and CIDR removal on d 0, and FTAI at 66 h after CIDR removal, or 3) (14-day CIDR-PG) a 14-day CIDR insert from d -30 to -16, PG (25 mg; i.m.) on d 0, and FTAI at 66 h after PG. All heifers received an injection of GnRH (100 μg; i.m.) concurrent with FTAI. Timing of treatment initiation was offset to allow all heifers to receive FTAI concomitantly and at random. Pregnancy success was determined between 35 and 40 d after FTAI by transrectal ultrasonography. Blood samples were collected approximately 12 d before the beginning of each protocol and at the initiation of each protocol to determine estrous cycling status (77%). Data were analyzed using the GLIMMIX procedures of SAS. Fixed-time AI pregnancy success did not differ between treatments (P = 0.13; 62.5%, 56.9%, and 53.3%, for 5-day CO-Synch + CIDR, PG 6-day CIDR, and 14-day CIDR-PG; respectively) or location (P = 0.16; 51.5%, 62.7%, 56.1%, and 58.6% for location 1, 2, 3, and 4; respectively). However, heifers that had reached puberty by initiation of synchronization had greater (P \u3c 0.01) pregnancy success compared to heifers that were prepubertal (60.7% and 47.3%; respectively). In summary, all three protocols had similar FTAI pregnancy success, and puberty status had the greatest impact on pregnancy success
Are they ‘worth their weight in gold’? Sport for older adults: benefits and barriers of their participation for sporting organisations
The ageing global population has led to an increased focus on health for older adults. However, older adults have not been a specific priority for some sporting organisations (SOs). Thus, there is an emerging opportunity for this age group to be considered within international sport policy. The aim of this study was to understand the benefits and barriers that SOs encounter when engaging older adults. Eight focus group interviews (n = 49) were held with representatives of Australian national sporting organisations (NSOs), and older adults who were either sport club or non-sport club members. The socioecological model domains, interpersonal, organisational and policy, were used as a framework for thematic analysis, and organisational capacity building concepts were utilised to explain the findings. Common perceived benefits included interpersonal benefits (intergenerational opportunities and role models) and organisational benefits (volunteering, financial contributions and maximised facility usage) for engaging older adults. Common perceived barriers included interpersonal barriers (competing priorities and perceived societal expectations), organisational barriers (lack of appropriate playing opportunities, lack of facility access and lack of club capacity) and policy barriers (strategic organisational focus on children and elite sport and risk management). Whilst participation in sport is not common for older adults, their involvement can be invaluable for sport clubs. It is not anticipated that any policy focus on older adults will significantly increase active participation for this age group. However, any increase in older adults’ sport participation either through actively playing, supporting family and friends and/or volunteering will contribute to the positive health of individuals, sport clubs and the community.Peer reviewedFinal Accepted Versio
New directions in island biogeography
Aim: Much of our current understanding of ecological and evolutionary processes comes from island research. With the increasing availability of data on distributions and phylogenetic relationships and new analytical approaches to understanding the processes that shape species distributions and interactions, a re-evaluation of this ever-interesting topic is timely.
Location: Islands globally.
Methods: We start by arguing that the reasons why island research has achieved so much in the past also apply to the future. We then critically assess the current state of island biogeography, focusing on recent changes in emphasis, including research featured in this special issue of Global Ecology and Biogeography. Finally, we suggest promising themes for the future. We cover both ecological and evolutionary topics, although the greater emphasis on island ecology reflects our own backgrounds and interests.
Results: Much ecological theory has been directly or indirectly influenced by research on island biotas. Currently, island biogeography is renascent, with research focusing on, among other things, patterns and processes underlying species interaction networks, species coexistence and the assembly of island communities through ecological and evolutionary time. Continuing island research should provide additional insight into biological invasions and other impacts of human activities, functional diversity and ecosystem functioning, extinction and diversification, species pools and more. Deeper understanding of the similarities and differences between island and mainland systems will aid transferability of island theory to continental regions.
Main conclusions: As research in biogeography and related fields expands in new directions, islands continue to provide opportunities for developing insights, both as natural laboratories for ecology and evolution and because of the exceptions islands often present to the usual ‘rules’ of ecology. New data collection initiatives are needed on islands world-wide and should be directed towards filling gaps in our knowledge of within-island distributions of species, as well as the functional traits and phylogenetic relationships of island species
Enhancement of the upper critical field by nonmagnetic impurities in dirty two-gap superconductors
Quasiclassic Uzadel equations for two-band superconductors in the dirty limit
with the account of both intraband and interband scattering by nonmagnetic
impurities are derived for any anisotropic Fermi surface. From these equations
the Ginzburg-Landau equations, and the critical temperature are obtained.
An equation for the upper critical field, which determines both the temperature
dependence of and the orientational dependence of
as a function of the angle between and the c-axis is
obtained. It is shown that the shape of the curve essentially
depends on the ratio of the intraband electron diffusivities and ,
and can be very different from the standard one-gap dirty limit theory. In
particular, the value can considerably exceed ,
which can have important consequences for applications of . A scaling
relation is proposed which enables one to obtain the angular dependence of
from the equation for at . It is shown
that, depending on the relation between and , the ratio of the upper
critical field for and can both increase and decrease as the temperature decreases. Implications
of the obtained results for are discussed
Interplay of structural and electronic phase separation in single crystalline La(2)CuO(4.05) studied by neutron and Raman scattering
We report a neutron and Raman scattering study of a single-crystal of
La(2)CuO(4.05) prepared by high temperature electrochemical oxidation. Elastic
neutron scattering measurements show the presence of two phases, corresponding
to the two edges of the first miscibility gap, all the way up to 300 K. An
additional oxygen redistribution, driven by electronic energies, is identified
at 250 K in Raman scattering (RS) experiments by the simultaneous onset of
two-phonon and two-magnon scattering, which are fingerprints of the insulating
phase. Elastic neutron scattering measurements show directly an
antiferromagnetic ordering below a N\'eel temperature of T_N =210K. The opening
of the superconducting gap manifests itself as a redistribution of electronic
Raman scattering below the superconducting transition temperature, T_c = 24K. A
pronounced temperature-dependent suppression of the intensity of the (100)
magnetic Bragg peak has been detected below T_c. We ascribe this phenomenon to
a change of relative volume fraction of superconducting and antiferromagnetic
phases with decreasing temperature caused by a form of a superconducting
proximity effect.Comment: 9 pages, including 9 eps figures, submitted to PR
Insights into the function of silver as an oxidation catalyst by ab initio, atomistic thermodynamics
To help understand the high activity of silver as an oxidation catalyst,
e.g., for the oxidation of ethylene to epoxide and the dehydrogenation of
methanol to formaldehyde, the interaction and stability of oxygen species at
the Ag(111) surface has been studied for a wide range of coverages. Through
calculation of the free energy, as obtained from density-functional theory and
taking into account the temperature and pressure via the oxygen chemical
potential, we obtain the phase diagram of O/Ag(111). Our results reveal that a
thin surface-oxide structure is most stable for the temperature and pressure
range of ethylene epoxidation and we propose it (and possibly other similar
structures) contains the species actuating the catalysis. For higher
temperatures, low coverages of chemisorbed oxygen are most stable, which could
also play a role in oxidation reactions. For temperatures greater than about
775 K there are no stable oxygen species, except for the possibility of O atoms
adsorbed at under-coordinated surface sites Our calculations rule out thicker
oxide-like structures, as well as bulk dissolved oxygen and molecular
ozone-like species, as playing a role in the oxidation reactions.Comment: 15 pages including 9 figures, Related publications can be found at
http://www.fhi-berlin.mpg.de/th/paper.htm
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