927 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
Pre- and post-selected ensembles and time-symmetry in quantum mechanics
An expression is proposed for the quantum mechanical state of a pre- and
post-selected ensemble, which is an ensemble determined by the final as well as
the initial state of the quantum systems involved. It is shown that the
probabilities calculated from the proposed state agree with previous
expressions, for cases where they both apply. The same probabilities are found
when they are calculated in the forward- or reverse-time directions. This work
was prompted by several problems raised by Shimony recently in relation to the
state, and time symmetry, of pre- and post-selected ensembles.Comment: RevTex4, 17 pages, no fig
Blood flow rates to leg bones of extinct birds indicate high levels of cursorial locomotion
OnlinePublForamina of bones are beginning to yield more information about metabolic rates and activity levels of living and extinct species. This study investigates the relationship between estimated blood flow rate to the femur and body mass among cursorial birds extending back to the Late Cretaceous. Data from fossil foramina are compared with those of extant species, revealing similar scaling relationships for all cursorial birds and supporting crown birdâlike terrestrial locomotor activity. Because the perfusion rate in long bones of birds is related to the metabolic cost of microfracture repair due to stresses applied during locomotion, as it is in mammals, this study estimates absolute blood flow rates from sizes of nutrient foramina located on the femur shafts. After differences in body mass and locomotor behaviors are accounted for, femoral bone blood flow rates in extinct species are similar to those of extant cursorial birds. Femoral robustness is generally greater in aquatic flightless birds than in terrestrial flightless and ground-dwelling flighted birds, suggesting that the morphology is shaped by life-history demands. Femoral robustness also increases in larger cursorial bird taxa, probably associated with their weight redistribution following evolutionary loss of the tail, which purportedly constrains femur length, aligns it more horizontally, and necessitates increased robustness in larger species.Qiaohui Hu, Case Vincent Miller, Edward P. Snelling, and Roger S. Seymou
The identification of poultry processing in archaeological ceramic vessels using in-situ isotope references for organic residue analysis.
Poultry products are rarely considered when reconstructing pottery use through organic residue analysis, impinging upon our understanding of the changing role of these animals in the past. Here we evaluate an isotopic approach for distinguishing chicken fats from other animal products. We compare the carbon isotopes of fatty acids extracted from modern tissues and archaeological bones and demonstrate that archaeological bones from contexts associated with pottery provide suitable reference ranges for distinguishing omnivorous animal products (e.g. pigs vs. chickens) in pots. When applied to pottery from the Anglo-Saxon site of Flixborough, England, we succeeded in identifying residues derived from chicken fats that otherwise could not be distinguished from other monogastric and ruminant animals using modern reference values only. This provides the first direct evidence for the processing of poultry or their products in pottery. The results highlight the utility of âin-situâ archaeological bone lipids to identify omnivorous animal-derived lipids in archaeological ceramic vessels
Evaporation and Condensation of Clusters
Influence of surrounding matter on the properties of clusters is considered
by an approach combining the methods of statistical and quantum mechanics. A
cluster is treated as a bound N-particle system and surrounding matter as
thermostat. It is shown that, despite arbitrary strong interactions between
particles, cluster energy can be calculated by using the controlled
perturbation theory. The accuracy of the latter is found to be much higher than
that of the quasiclassical approximation. Spectral distribution is obtained by
minimizing conditional entropy. Increasing the thermostat temperature leads to
the depletion of bound states. The characteristic temperature when bound states
become essentially depleated defines the temperature of cluster evaporation.
The inverse process of lowering the thermostate temperature, yielding the
filling of bound states, corresponds to cluster condensation.Comment: 1 file, 15 pages, RevTex, 4 table
Exact and Asymptotic Degeneracies of Small Black Holes
We examine the recently proposed relations between black hole entropy and the
topological string in the context of type II/heterotic string dual models. We
consider the degeneracies of perturbative heterotic BPS states. In several
examples with N=4 and N=2 supersymmetry, we show that the macroscopic
degeneracy of small black holes agrees to all orders with the microscopic
degeneracy, but misses non-perturbative corrections which are computable on the
heterotic side. Using these examples we refine the previous proposals and
comment on their domain of validity as well as on the relevance of helicity
supertraces.Comment: 35pp. harvmac b-mode; v2 is substantially rewritten and includes new
results; v3 contains further clarifications, and some new results; v3: final
version to match published versio
The future problem solving program international: an intervention to promote creative skills in portuguese adolescents
The Future Problem Solving Program International (FPSPI) is an internationally applied educational
program that involves young people. Its theoretical foundation is both the Creative Problem Solving
Model and the Futurist Thinking. It aims to promote creative and critical thinking through a futurist
approach to problems. This study intended to analyze the effects of the program on creative skills evaluated
by the Torrance Tests of Creative Thinking (Figural Version). The participantsâ perceptions of the
efficacy of the program were also assessed. This intervention was carried out with 131 adolescents over
a period of 7 months in an extra-curricular context. The evaluation of the program takes into account
periods both before and after interventions, using similar experimental and control groups. The results
showed significant statistical differences for the all skills studied and very positive perceptions of the
efficacy of FPSPI. Two significant gender differences in creative performance were also found. The
results are described and discussed in order to promote awareness for future research concerning this program(undefined)info:eu-repo/semantics/publishedVersio
High-statistics measurement of the pion form factor in the rho-meson energy range with the CMD-2 detector
We present a measurement of the pion form factor based on e+e- annihilation
data from the CMD-2 detector in the energy range 0.6<sqrt(s)<1.0 GeV with a
systematic uncertainty of 0.8%. A data sample is five times larger than that
used in our previous measurement.Comment: 18 pages, 10 figures. Added comparison with KLOE measurement, minor
updates. Accepted by PL
Recent Advances in Understanding Particle Acceleration Processes in Solar Flares
We review basic theoretical concepts in particle acceleration, with
particular emphasis on processes likely to occur in regions of magnetic
reconnection. Several new developments are discussed, including detailed
studies of reconnection in three-dimensional magnetic field configurations
(e.g., current sheets, collapsing traps, separatrix regions) and stochastic
acceleration in a turbulent environment. Fluid, test-particle, and
particle-in-cell approaches are used and results compared. While these studies
show considerable promise in accounting for the various observational
manifestations of solar flares, they are limited by a number of factors, mostly
relating to available computational power. Not the least of these issues is the
need to explicitly incorporate the electrodynamic feedback of the accelerated
particles themselves on the environment in which they are accelerated. A brief
prognosis for future advancement is offered.Comment: This is a chapter in a monograph on the physics of solar flares,
inspired by RHESSI observations. The individual articles are to appear in
Space Science Reviews (2011
Late Winter Biogeochemical Conditions Under Sea Ice in the Canadian High Arctic
With the Arctic summer sea-ice extent in decline, questions are arising as to how changes in sea-ice dynamics might affect biogeochemical cycling and phenomena such as carbon dioxide (CO2) uptake and ocean acidification. Recent field research in these areas has concentrated on biogeochemical and CO2 measurements during spring, summer or autumn, but there are few data for the winter or winterâspring transition, particularly in the High Arctic. Here, we present carbon and nutrient data within and under sea ice measured during the Catlin Arctic Survey, over 40 days in March and April 2010, off Ellef Ringnes Island (78° 43.11âČ N, 104° 47.44âČ W) in the Canadian High Arctic. Results show relatively low surface water (1â10 m) nitrate (<1.3 ”M) and total inorganic carbon concentrations (mean±SD=2015±5.83 ”mol kgâ1), total alkalinity (mean±SD=2134±11.09 ”mol kgâ1) and under-ice pCO2sw (mean±SD=286±17 ”atm). These surprisingly low wintertime carbon and nutrient conditions suggest that the outer Canadian Arctic Archipelago region is nitrate-limited on account of sluggish mixing among the multi-year ice regions of the High Arctic, which could temper the potential of widespread under-ice and open-water phytoplankton blooms later in the season
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