176 research outputs found

    Anti-predator behaviour of the red-legged partridge Alectoris rufa (Galliformes: Phasianidae) to simulated terrestrial and aerial predators

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    This study is intended to investigate the differences in anti-predator behavioural and acoustic response to terrestrial and aerial predators as well as the behavioural differences between sexes in the red-legged partridge. To this aim we observed the response of 114 partridge (57 males and 57 females) to dummy terrestrial and aerial predators, a raptor and a fox. We divided behavioural responses to predators into four mutually exclusive categories: vigilance, freezing, escape and non-anti-predator behaviours. We also recorded and analysed the vocalizations emitted during tests. The animals reacted differently to aerial and terrestrial stimuli. The reactions elicited by the terrestrial predator were ranked as follows: vigilance, escape, non-anti-predator behaviours, and freezing. Those elicited by the aerial predator were ranked as follows: vigilance, freezing, escape and non-anti-predator behaviours. Vigilance and escape were elicited more frequently by the terrestrial predator than by the aerial predator (vigilance: p 0.001; escape: p 0.001). Freezing was the most frequent behaviour following the appearance of the aerial predator (p 0.001). In fact, freezing may represent an effective strategy in an open space, combining camouflage from and detection by the predator. On the other hand, vigilance is an effective behaviour to detect and avoid a terrestrial predator hunting by ambush. We did not find clear-cut differences between sexes. The analysis of vocalizations revealed that the fox and the raptor elicited significantly different calls (p = 0.003); the fox evoked significantly more vocalizations than the raptor (p 0.001), differing in addition in frequency parameters. Thus partridges not only discriminate between aerial and terrestrial predators and behave consequently, but are also able to tune alarm calls in relation to the context of predation

    Total coliform and Escherichia coli contamination in rural well water: Analysis for passive surveillance

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    With increasing stress on our water resources and recent waterborne disease outbreaks, understanding the epidemiology of waterborne pathogens is crucial to build surveillance systems. The purpose of this study was to explore techniques for describing microbial water quality in rural drinking water wells, based on spatiotemporal analysis, time series analysis and relative risk mapping. Tests results for Escherichia coli and coliforms from private and small public well water samples, collected between 2004 and 2012 in Alberta, Canada, were used for the analysis. Overall, 14.6 and 1.5% of the wells were total coliform and E. coli-positive, respectively. Private well samples were more often total coliform or E. coli-positive compared with untreated public well samples. Using relative risk mapping we were able to identify areas of higher risk for bacterial contamination of groundwater in the province not previously identified. Incorporation of time series analysis demonstrated peak contamination occurring for E. coli in July and a later peak for total coliforms in September, suggesting a temporal dissociation between these indicators in terms of groundwater quality, and highlighting the potential need to increase monitoring during certain periods of the year

    Dog-walking behaviours affect gastrointestinal parasitism in park-attending dogs

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    In urban parks, dogs, wildlife and humans can be sympatric, introducing the potential for inter- and intra-specific transmission of pathogens among hosts. This study was conducted to determine the prevalence of zoonotic and non-zoonotic gastrointestinal parasites in dogs in Calgary city parks, and assess if dog-walking behaviour, park management, history of veterinary care, and dog demographics were associated with parasitism in dog

    A difficult choice for tiny pests:host-seeking behaviour in Xenos vesparum triungulins

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    The first-instar larvae of strepsipteran parasites, commonly referred to as otriungulinso, are the host-seeking stage: they must locate, invade and successfully develop in the new host, in order to start their parasitic cycle. Little information is available about the behaviour of Xenos vesparum triungulins. They emerge in batches from the endoparasitic female infecting Polistes dominulus, the primary host, and reach the nest through a vector (a foraging wasp or the parasitised wasp itself). Once there, they have the possibility to penetrate into wasp immatures at different developmental stages. In this study, we performed preliminary analyses aimed to investigate which cues are important to direct triungulin movements during their brief stay in wasp nests. In laboratory conditions we selectively presented different stimuli to Xenos larvae: apparently, the host larva itself is attractive in an open arena, but not inside a confined space, nor are epicuticular compounds of wasp larvae able to control triungulin movements. These are more likely oriented by their gregarious behaviour, whereas light (positive phototaxy) may at a previous stage enhance their emergence via the brood canal opening in the female cephalothorax

    The clinical efficacy of a sublingual monomeric allergoid at different maintenance doses: a randomized controlled trial

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    Sublingual immunotherapy is widely recognized as a viable treatment for allergic rhinitis and asthma, but the optimal dosage is still under debate, expecially with modified allergens. We assessed the clinical effects of a monomeric allergoid across 3 different maintenance doses in mite-monosensitized patients with rhinitis and intermittent asthma. Eighty-nine patients allergic to HDM were randomized to 3 maintenance doses of monomeric allergoid (Lais®, Lofarma) or medications only. All the patients recorded their symptoms and rescue drug consumption in a diary card from November to February. Additionally, nasal eosinophil count, spirometry and methacholine bronchial challenge were performed at the beginning of the study and after 3 years. The symptom scores showed a clear improvement in all the three active arms versus baseline and versus the controls, irrespective of the dose. Likewise, a similar improvement versus baseline was seen for nasal inflammation and bronchial hyperreactivity. The SLIT with monomeric allergoids produces clinically significant results across a wide range of doses. The absence of significant side effects, even at high doses, is probably due to their low level of allergenicity

    Guest or pest? Spatio-temporal occurrence and effects on soil and vegetation of the wild boar on the Elba island

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    In areas where allochthonous large mammals, such as the wild boars (Sus scrofa), occur in high density, human-wildlife conflicts may arise. In these contexts, assessing spatio-temporal patterns of the introduced population is paramount to its management. Here, we studied wild boars in the Elba island, Italy, where they have been introduced and are perceived as pests. While crop-raiding has been documented, no studies addressed the spatio-temporal occurrence, nor the impact of foraging on natural habitat. We surveyed the Western part of the island with three camera trapping surveys within one year. We found that the species' estimated occupancy probability was higher in summer-autumn (0.75±0.14) and winter-early spring (0.70±0.10) than in late spring-summer (0.53±0.15), whereas detection probability did not vary. Occupancy was significantly associated with elevation and vegetation cover, with preference for lower elevation and woodland. The lower site use of wild boars during spring-summer might reflect lower food availability in this season, and/or movements towards landfarms outside the sampled area. Detectability increased with proximity to roads during spring-summer and decreased with humans' relative abundance in the other periods. Moreover, boars were mainly nocturnal, with an overlap with human activity that decreased when human presence was higher. Combined, these suggest behavioural avoidance of human disturbance by boars. We also evaluated the impact of boars' foraging on the soil and vegetation and found that it was higher in pine plantations than other covers, however, it was not associated with variation in boars' occupancy across habitats. Our results indicate that the spatio-temporal activity of wild boars on Elba island appears driven by seasonal preferences for food-rich cover and avoidance of human disturbance. The lowered site use in months with lower resources could partially reflect increased proximity to settled and farmed areas, which may, in turn, trigger crop-raiding and hence the negative perception by residents

    Search for proton radioactivity in <SUP>65</SUP>As, <SUP>69</SUP>Br and <SUP>77</SUP>Y

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    A search for proton radioactivity in 65As, 69Br and 77Y, produced as residues of fusion reactions, was carried out at the Orsay Tandem accelerator. The residues were collected at the image point of the spectrometer Soleno and implanted into the gaseous medium of an ionization chamber which was also used to detect the radioactivity protons. No such protons have been observed in the energy range of 250–600 keV and in the half-life interval of 10 μs-100 ms, within a production cross section sensitivity of 1 μb.Facultad de Ciencias Exacta

    2-Carboxythioester-1,3-dithiane: a functionalized masked carbonyl nucleophile for the organocatalytic enantioselective Michael addition to enones

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    An S-(2,2,2-trifluoroethyl) 1,3-dithiane-2-carbothioate has been successfully employed as acyl anion synthon in the organocatalytic enantioselective addition to enones promoted by quinine- and quinidine-derived tertiary/primary diamines. By proper selection of a co-catalyst and by optimization of the reaction parameters, convenient experimental conditions were found that allowed to obtain the highly functionalized products in up to 90% yield and 98% ee in short reaction times. These compounds, featuring selectively removable functionalities, proved to be versatile synthetic intermediates, which could be transformed into different derivatives without any erosion of the stereochemical integrity of the molecules
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