Electromagnetic properties of ice coated surfaces

The electromagnetic scattering from ice coated structures is examined. The influence of ice is shown from a measurement standpoint and related to a simple analytical model. A hardware system for the realistic measurement of ice coated structures is also being developed to use in an existing NASA Lewis icing tunnel. Presently, initial measurements have been performed with a simulated tunnel to aid in the development

Large collection of astrophysical S-factors and its compact representation

Numerous nuclear reactions in the crust of accreting neutron stars are strongly affected by dense plasma environment. Simulations of superbursts, deep crustal heating and other nuclear burning phenomena in neutron stars require astrophysical S-factors for these reactions (as a function of center-of-mass energy E of colliding nuclei). A large database of S-factors is created for about 5000 non-resonant fusion reactions involving stable and unstable isotopes of Be, B, C, N, O, F, Ne, Na, Mg, and Si. It extends the previous database of about 1000 reactions involving isotopes of C, O, Ne, and Mg. The calculations are performed using the Sao Paulo potential and the barrier penetration formalism. All calculated S-data are parameterized by an analytic model for S(E) proposed before [Phys. Rev. C 82, 044609 (2010)] and further elaborated here. For a given reaction, the present S(E)-model contains three parameters. These parameters are easily interpolated along reactions involving isotopes of the same elements with only seven input parameters, giving an ultracompact, accurate, simple, and uniform database. The S(E) approximation can also be used to estimate theoretical uncertainties of S(E) and nuclear reaction rates in dense matter, as illustrated for the case of the 34Ne+34Ne reaction in the inner crust of an accreting neutron star.Comment: 13 pages, 2 figures, Phys. Rev. C, accepte

Electromagnetic properties of material coated surfaces

The electromagnetic properties of material coated conducting surfaces were investigated. The coating geometries consist of uniform layers over a planar surface, irregularly shaped formations near edges and randomly positioned, electrically small, irregularly shaped formations over a surface. Techniques to measure the scattered field and constitutive parameters from these geometries were studied. The significance of the scattered field from these geometries warrants further study

Molecular Identification of Eimeria Species in Broiler Chickens in Trinidad, West Indies

Coccidiosis is an intestinal disease of chickens of major economic importance to broiler industries worldwide. Species of coccidia found in chickens include Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, and Eimeria tenella. In recent years, polymerase chain reaction (PCR) has been developed to provide accurate and rapid identification of the seven known Eimeria species of chickens. The aim of this study was to use species-specific real-time PCR (qPCR) to identify which of the seven Eimeria species are present in Trinidad poultry. Seventeen pooled fecal samples were collected from 6 broiler farms (2–5 pens per farm) across Trinidad. Feces were also collected from birds showing clinical signs of coccidiosis in two live bird markets (pluck shops). qPCR revealed the presence of five species of Eimeria (E. acervulina, E. maxima, E. mitis, E. necatrix, and E. tenella), but not E. brunetti or E. praecox. Mixed infections were detected on all broiler farms, and DNA of two highly pathogenic Eimeria species (E. tenella and E. necatrix) was detected in feces taken from clinically sick birds sampled from the two pluck shops

Crocodiles as dinosaurs: Behavioural thermoregulation in very large ectotherms leads to high and stable body temperatures

Empirical field data describing daily and seasonal cycles in body temperature (Tb) of free-ranging Crocodylus porosus (32-1010 kg) can be predicted by a mathematical analysis. The analysis provides a mechanistic explanation for the decreased amplitude of daily cycles in Tb and the increase in 'average' Tb with increasing mass. Assessments of 'average' daily Tb were made by dividing the integral of the difference between measured values of Tb and minimum operative temperature by the period of integration, to yield a thermal index expressing relative 'warmth' of crocodiles. The average daily Tb of a 1010 kg crocodile was 3.7 degrees C warmer than that of a 42 kg individual in summer and 1.9 degreesC warmer than that of a 32 kg individual in winter. The success of this mathematical approach confirms that crocodiles are simple ectotherms and that there is unlikely to be a significant contribution to their thermal biology from physiological mechanisms. Behaviour, however, is very important even in large individuals. Crocodiles in the field typically move daily between land and water in cycles that vary seasonally. We predicted Tb for the reverse of these behavioural cycles, which more than doubled seasonal fluctuations in Tb compared with the observed fluctuations. We were also able to predict the Tb of very large, dinosaur-sized crocodiles in a similar climate to that at our study site. A 10 000 kg 'crocodile', for example, would be expected to have a Tb of 31 degreesC in winter, varying by less than 0.1 degrees C during a day when operative temperatures varied by nearly 20 degrees C, from 20 to 38 degrees C. The study confirms that, in low latitudes at least, large dinosaurs must have had an essentially high and stable value of Tb, without any need for endothermy. Also, access to shade or water must have been crucial for the survival of large dinosaurs at low latitudes. Furthermore, the finding of increasing 'average' Tb as ectotherms grow larger may have implications for the metabolic rates of very large reptiles, because the Q10 effect could counteract the downscaling of metabolic rate with mass, an effect that seems not to have been recognised previously

Application of an Ultralight Aircraft to Aerial Surveys of Kangaroos on Grazing Properties

A Drifter ultralight aircraft was used as a platform for line-transect aerial surveys of three species of kangaroo in the sheep rangelands south-east of Blackall and north of Longreach in central-western Queensland in winter 1993 and 1994. Favourable comparisons between the results of ultralight surveys and those made from a helicopter flying the same transects and foot surveys along another set of transects, all within a few days of the ultralight survey, confirmed the expectation we had that an ultralight would be a satisfactory and much cheaper vehicle for conducting aerial surveys of kangaroos. The comparisons are even more favourable when data for the three species surveyed are combined, pointing to a problem in species identification and underlining the importance of using only experienced observers for aerial survey of kangaroos, whatever the platform. The use of an ultralight aircraft could have particular value where a comparatively small area, such as an individual sheep or cattle property, is under consideration. In this paper, we present the numerical comparisons, along with an evaluation of the practicability of using this type of aircraft. We also describe a possible future scenario in which an accreditation process could see approved kangaroo surveyors undertaking property assessments by ultralight, under contract to graziers or other interested parties

Training Observers

From a large data base on observer training gathered over 20 years of South Australian kangaroo survey (SAKS), it was estimated that approximately 40-48 hours in the air (including both survey and transport time) were required to train and calibrate a new observer. Training consisted of learning to see a consistent proportion of the popoulation and calibrating this proportion against a "standard" trained observer. On a first survey flight, an untrained observer, even with prior ground survey experience, always saw fewer kangaroos than a trained observer. Proper training of observers is mandatory if aerial surveys for kangaroos are to continue to improve and remain a respected method of estimating kangaroo populations

Maternal inflammation at 0.7 gestation in ewes leads to intrauterine growth restriction and impaired glucose metabolism in offspring at 30 d of age

Fetal programming associated with intrauterine growth restriction (IUGR) leads to lifelong deficits in growth and metabolic function (Hales and Barker, 2013). IUGR arises when fetuses respond to poor in utero conditions by developing adaptations that repartition nutrients to critical tissues and away from skeletal muscle (Yates et al., 2012, 2018). This fetal programming is beneficial in utero but leads to persistent reductions in muscle mass and glucose homeostasis in offspring (DeFronzo et al., 1981). Recent studies by our laboratory in sheep and rats demonstrate that maternal inflammation during gestation induces fetal inflammatory adaptations that impair growth and disrupt muscle glucose metabolism (Cadaret et al., 2017, 2018). IUGR fetal skeletal muscle exhibits indicators of enhanced inflammatory sensitivity, which could disrupt glucose uptake and oxidation (Yates et al., 2016; Cadaret et al., 2018). Enhanced inflammatory responsiveness would help explain growth and metabolic deficits observed in IUGR offspring. We hypothesize that fetal programming induced by maternal inflammation persists in offspring and contributes to impaired growth and glucose metabolism at 30 d. Therefore, the objective of this study was to determine whether sustained maternal inflammation induced by bacterial endotoxin at 0.7 gestation leads to fetal programming that contributes to deficits in growth and glucose metabolism in offspring

Changes in Cigarette Smoking and Vaping in Response to the COVID-19 Pandemic in the UK: Findings from Baseline and 12-Month Follow up of HEBECO Study

This study investigated UK adults’ changes in cigarette smoking and vaping during the COVID-19 pandemic and factors associated with any changes. Data were from an online longitudinal study. A self-selected sample (n = 332) of 228 smokers and 155 vapers (51 participants were both smokers and vapers) completed 5 surveys between April 2020 and June 2021. Participants self-reported data on sociodemographics, COVID-19-related, and smoking/vaping characteristics. During the 12 months of observations, among smokers, 45% self-reported a quit attempt (27.5% due to COVID-19-related reasons) since the onset of COVID-19 pandemic and the quit rate was 17.5%. At 12 months, 35.1% of continuing smokers (n = 174) reported smoking less and 37.9% the same, while 27.0% reported an increase in the number of cigarettes smoked/day. Among vapers, 25.0% self-reported a quit attempt (16.1% due to COVID-19-related reasons) and the quit rate was 18.1%. At 12 months, 47.7% of continuing vapers (n = 109) reported no change in the frequency of vaping/hour, while a similar proportion reported vaping less (27.5%) and more (24.8%). Motivation to quit smoking and being younger were associated with making a smoking quit attempt and smoking cessation. Being a cigarette smoker was associated with vaping cessation. Among a self-selected sample, COVID-19 stimulated more interest in reducing or quitting cigarette smoking than vaping