225 research outputs found

    THE URUGUAY ROUND NEGOTIATIONS AND AGRICULTURAL TRADE

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    International Relations/Trade,

    Smut in Small Grains

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    Smut Is one or the most common and widespread diseases of cereals and causes an annual loss on Iowa farms or many thousands and often millions or dollars. Smut not only cuts down yield, but it often seriously Impairs the quality or grain and lowers the price per bushel. It Is fortunate that smut Is unlike many or the other fungus and bacterial diseases of farm crops, in that It can be destroyed easily and at very little expense

    Experimental chronic noise is related to elevated fecal corticosteroid metabolites in lekking male greater Sage-Grouse (Centrocercus urophasianus).

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    There is increasing evidence that individuals in many species avoid areas exposed to chronic anthropogenic noise, but the impact of noise on those who remain in these habitats is unclear. One potential impact is chronic physiological stress, which can affect disease resistance, survival and reproductive success. Previous studies have found evidence of elevated stress-related hormones (glucocorticoids) in wildlife exposed to human activities, but the impacts of noise alone are difficult to separate from confounding factors. Here we used an experimental playback study to isolate the impacts of noise from industrial activity (natural gas drilling and road noise) on glucocorticoid levels in greater sage-grouse (Centrocercus urophasianus), a species of conservation concern. We non-invasively measured immunoreactive corticosterone metabolites from fecal samples (FCMs) of males on both noise-treated and control leks (display grounds) in two breeding seasons. We found strong support for an impact of noise playback on stress levels, with 16.7% higher mean FCM levels in samples from noise leks compared with samples from paired control leks. Taken together with results from a previous study finding declines in male lek attendance in response to noise playbacks, these results suggest that chronic noise pollution can cause greater sage-grouse to avoid otherwise suitable habitat, and can cause elevated stress levels in the birds who remain in noisy areas

    Large-Scale Release of Campylobacter Draft Genomes: Resources for Food Safety and Public Health from the 100K Pathogen Genome Project.

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    Campylobacter is a food-associated bacterium and a leading cause of foodborne illness worldwide, being associated with poultry in the food supply. This is the initial public release of 202 Campylobacter genome sequences as part of the 100K Pathogen Genome Project. These isolates represent global genomic diversity in the Campylobacter genus

    Understanding park visitors’ soundscape perception using subjective and objective measurement

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    Environmental noise knows no boundaries, affecting even protected areas. Noise pollution, originating from both external and internal sources, imposes costs on these areas. It is associated with adverse health effects, while natural sounds contribute to cognitive and emotional improvements as ecosystem services. When it comes to parks, individual visitors hold unique perceptions of soundscapes, which can be shaped by various factors such as their motivations for visiting, personal norms, attitudes towards specific sounds, and expectations. In this study, we utilized linear models and geospatial data to evaluate how visitors’ personal norms and attitudes, the park’s acoustic environment, visitor counts, and the acoustic environment of visitors’ neighborhoods influenced their perception of soundscapes at Muir Woods National Monument. Our findings indicate that visitors’ subjective experiences had a greater impact on their perception of the park’s soundscape compared to purely acoustic factors like sound level of the park itself. Specifically, we found that motivations to hear natural sounds, interference caused by noise, sensitivity to noise, and the sound levels of visitors’ home neighborhoods influenced visitors’ perception of the park’s soundscape. Understanding how personal factors shape visitors’ soundscape perception can assist urban and non-urban park planners in effectively managing visitor experiences and expectations

    Standing Variation and the Capacity for Change: Are Endocrine Phenotypes More Variable That Other Traits?

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    Circulating steroid hormone levels exhibit high variation both within and between individuals, leading some to hypothesize that these phenotypes are more variable than other morphological, physiological, and behavioral traits. This should have profound implications for the evolution of steroid signaling systems, but few studies have examined how endocrine variation compares to that of other traits or differs among populations. Here we provide such an analysis by first exploring how variation in three measures of corticosterone (CORT)—baseline, stress-induced, and post-dexamethasone injection—compares to variation in key traits characterizing morphology (wing length, mass), physiology (reactive oxygen metabolite concentration [d-ROMs] and antioxidant capacity), and behavior (provisioning rate) in two populations of tree swallow (Tachycineta bicolor). After controlling for measurement precision and within-individual variation, we found that only post-dex CORT was more variable than all other traits. Both baseline and stress-induced CORT exhibit higher variation than antioxidant capacity and provisioning rate, but not oxidative metabolite levels or wing length. Variation in post-dex CORT and d-ROMs was also elevated in the higher-latitude population in that inhabits a less predictable environment. We next studied how these patterns might play out on a macroevolutionary scale, assessing patterns of variation in baseline testosterone (T) and multiple non-endocrine traits (body length, mass, social display rate, and locomotion rate) across 17 species of Anolis lizards. At the macroevolutionary level, we found that circulating T levels and the rate of social display output are higher than other behavioral and morphological traits. Altogether, our results support the idea that within-population variability in steroid levels is substantial, but not exceptionally higher than many other traits that define animal phenotypes. As such, circulating steroid levels in free-living animals should be considered traits that exhibit similar levels of variability from individual to individual in a population

    The Large Quasar Reference Frame (LQRF) - an optical representation of the ICRS

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    The large number and all-sky distribution of quasars from different surveys, along with their presence in large, deep astrometric catalogs,enables the building of an optical materialization of the ICRS following its defining principles. Namely: that it is kinematically non-rotating with respect to the ensemble of distant extragalactic objects; aligned with the mean equator and dynamical equinox of J2000; and realized by a list of adopted coordinates of extragalatic sources. Starting from the updated and presumably complete LQAC list of QSOs, the initial optical positions of those quasars are found in the USNO B1.0 and GSC2.3 catalogs, and from the SDSS DR5. The initial positions are next placed onto UCAC2-based reference frames, following by an alignment with the ICRF, to which were added the most precise sources from the VLBA calibrator list and the VLA calibrator list - when reliable optical counterparts exist. Finally, the LQRF axes are inspected through spherical harmonics, contemplating to define right ascension, declination and magnitude terms. The LQRF contains J2000 referred equatorial coordinates for 100,165 quasars, well represented across the sky, from -83.5 to +88.5 degrees in declination, and with 10 arcmin being the average distance between adjacent elements. The global alignment with the ICRF is 1.5 mas, and the individual position accuracies are represented by a Poisson distribution that peaks at 139 mas in right ascension and 130 mas in declination. It is complemented by redshift and photometry information from the LQAC. The LQRF is designed to be an astrometric frame, but it is also the basis for the GAIA mission initial quasars' list, and can be used as a test bench for quasars' space distribution and luminosity function studies.Comment: 23 pages, 23 figures, 6 tables Accepted for publication by Astronomy & Astrophysics, on 25 May 200

    Simulations of spiral galaxies with an active potential: molecular cloud formation and gas dynamics

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    We describe simulations of the response of a gaseous disc to an active spiral potential. The potential is derived from an N-body calculation and leads to a multi-armed time-evolving pattern. The gas forms long spiral arms typical of grand design galaxies, although the spiral pattern is asymmetric. The primary difference from a grand-design spiral galaxy, which has a consistent 2/4-armed pattern, is that instead of passing through the spiral arms, gas generally falls into a developing potential minimum and is released only when the local minimum dissolves. In this case, the densest gas is coincident with the spiral potential, rather than offset as in the grand-design spirals. We would there fore expect no offset between the spiral shock and star formation, and no obvious co-rotation radius. Spurs which occur in grand-design spirals when large clumps are sheared off leaving the spiral arms, are rare in the active, time-evolving spiral reported here. Instead, large branches are formed from spiral arms when the underlying spiral potential is dissolving due to the N-body dynamics. We find that the molecular cloud mass spectrum for the active potential is similar to that for clouds in grand design calculations, depending primarily on the ambient pressure rather than the nature of the potential. The largest molecular clouds occur when spiral arms collide, rather than by agglomeration within a spiral arm.Comment: 11 pages, 7 figures, accepted for publication in MNRA

    Optical Observations of SAX J1808.4-3658 During Quiescence

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    We observed the accreting millisecond pulsar SAX J1808.4-3658 with Gemini-South in g' and i' bands, nearly simultaneous with XMM-Newton observations. A clear periodic flux modulation on the system's orbital period is present, consistent with the varying aspect of the donor star's heated face. We model the contributions of a disk and donor star to these optical bands. To produce the observed modulation amplitudes, we conclude that the donor must be irradiated by an external flux 2 orders of magnitude greater than provided by the measured X-ray luminosity. A possible explanation for this irradiation is that the radio pulsar mechanism becomes active during the quiescent state as suggested by Burderi et al., with relativistic particles heating the donor's day-side face. Our modelling constrains the binary inclination to be between 36 and 67 degrees. We obtain estimates for the pulsar mass of >2.2 solar masses (although this limit is sensitive to the source's distance), consistent with the accelerated NS cooling in this system indicated by X-ray observations. We also estimate the donor mass to be in the range of 0.07-0.11 solar masses, providing further indications that the system underwent non-standard binary evolution to reach its current state.Comment: 11 pages, 10 figures, accepted for publication in MNRA

    Albarella future – zero carbon emission

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    Climate warming is setting requirements on research also in the agronomic and forest fields. The soil and vegetation are available as carbon sinks. Ecosystems under high exploitation lost part of their carbon. It is possible to recover this carbon from the air with natural processes and to return it to the land. Besides, global warming requires a change in mentality that moves into the replacement of fossil fuels with other energy sources. In this perspective, the island of Albarella, with its environment and economic activities, represents an attractive miniature model of the planet Earth. For this design, we estimated (Vensim simulation) the emissions and storage of CO2 equivalent of the whole island. Then, with the idea of acting on natural ecosystems to make them more active in carbon storage, we analyzed two vegetation series from the forest to the sea, one located in the nearby natural reserve of Porto Caleri, and one on the island of Albarella. The investigation concerns the soil carbon storage and the quality and quantity of populations of arthropods, bacteria, and fungi as well. The biodiversity of artificial environments resulted in higher than that of natural habitats, opening a debate. Acting in different ways on the substitution of fuels, we obtained scenarios with decreasing emissions, from consumerist without substitution of fuels, realistic with 15% of replacement by solar energy, and sustainable with zero use of fossil energy and all the island electricity produced through photovoltaic panels
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