1,364 research outputs found

    Drinking behavior in nursery pigs: Determining the accuracy between an automatic water meter versus human observers

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    Assimilating accurate behavioral events over a long period can be labor-intensive and relatively expensive. If an automatic device could accurately record the duration and frequency for a given behavioral event, it would be a valuable alternative to the traditional use of human observers for behavioral studies. Therefore, the objective of this study was to determine the accuracy in the time spent at the waterer and the number of visits to the waterer by individually housed nursery pigs between human observers scoring video files using Observer software (OBS) and an automatic water meter Hobo (WM, control) affixed onto the waterline. Eleven PIC USA genotype gilts (22 ± 2 d of age; 6.5 ± 1.4 kg of BW) were housed individually in pens with ad libitum access to a corn-based starter ration and one nipple waterer. Behavior was collected on d 0 (day of weaning), 7, and 14 of the trial using 1 color camera positioned over 4 attached pens and a RECO-204 DVR at 1 frame per second. For the OBS method, 2 experienced observers recorded drinking behavior from the video files, which was defined as when the gilt placed her mouth over the nipple waterer. Data were analyzed using nonparametric methods and the general linear model and regression procedures in SAS. The experimental unit was the individual pen housing 1 gilt. The GLM model included the method of observation (WM vs. OBS) and time (24 h) as variables, and the gilt nested within method was used as the error term. Gilts consumed more water (P = 0.04) on d 14 than on d 0. The time of day affected (P \u3c 0.001) the number of visits and the time spent at the waterer regardless of the method. However, the OBS method underestimated (P \u3c 0.001) the number of visits to the waterer (3.48 ± 0.33 visits/h for OBS vs. 4.94 ± 0.33 for WM) and overestimated (P \u3c 0.001) the time spent at the waterer (22.6 ± 1.46 s/h for OBS vs. 13.9 ± 1.43 for WM) compared with WM. The relationship between the 2 methods for prediction of time spent at the waterer and number of visits made by the gilts was weak (R2 = 0.56 and 0.69, respectively). Collectively, these data indicate that the use of the traditional OBS method for quantifying drinking behavior in pigs can be misleading. Quantifying drinking behavior and perhaps other behavioral events via the OBS method must be more accurately validated

    Nesting Common Eider (Somateria mollissima) Population Quintuples in Northwest Greenland

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    Common eider (Somateria mollissima) populations in Greenland severely declined throughout the 20th century. As a result, in 2001, harvest regulations were changed and the length of the hunting season was reduced. Recent data suggest that these changes have been successful, and population regrowth is occurring. In the Avanersuaq District, northwest Greenland, only one systematic survey quantifying the number of nesting eiders had previously been conducted, in 1997 and 1998. Although this district had historically been identified as having the largest number of breeding eiders in Greenland, the 1997–98 survey results showed a relatively small estimated population of 5000 pairs. However, it is not known to what extent changes in hunting regulations have affected nesting abundance in this area. Therefore, the Avanersuaq District was systematically resurveyed during the 2009 breeding season, approximately 11 years after the previous survey. These results showed that the population had increased to 5.4 times its 1997–98 size, with an annual compounded growth rate of 15.3%. On a single island, nearly 4500 active nests were observed. Five islands had more than 2600 nests each and comprised 75% of the total nests counted. Along with historical information to account for additional nesting habitat not surveyed, the observed population growth rate from this study suggests that the overall Avanersuaq common eider breeding population size ranges from 25 000 to 30 000 pairs, or roughly half of the total estimated West Greenland breeding population. Despite the significance of the Avanersuaq District as a breeding area for common eiders, we have only limited information about this population. The effects of recent extensions of the hunting season on this population are also unknown, and the only wintering location information is based on a few individuals banded in the 1920s and 1940s. Additional research on migratory movements is suggested before any further changes are made to hunting regulations.Au cours du XXe siècle, les populations d’eiders à duvet (Somateria mollissima) ont connu un déclin considérable au Groenland. C’est pourquoi en 2001, le règlement relatif à la chasse a été modifié et la saison de chasse a été raccourcie. Selon des données récentes, ces changements ont porté fruits en ce sens que la population s’est accrue. Dans le district d’Avanersuaq, dans le nord-ouest du Groenland, seulement un relevé systématique ayant pour but de quantifier le nombre d’eiders nicheurs a été fait, et c’était en 1997-1998. Bien qu’au fil des ans, ce district a compté le plus grand nombre d’eiders reproducteurs du Groenland, le relevé de 1997-1998 avait établi que la population était relativement petite, avec une estimation de 5 000 paires. On ne sait toutefois pas dans quelle mesure la modification du règlement sur la chasse a eu des effets sur l’abondance d’eiders nichant dans la région. Par conséquent, le district d’Avarsuaq a systématiquement fait l’objet d’un autre relevé pendant la saison de reproduction de 2009, soit environ 11 ans après le relevé d’origine. Les résultats ont permis de constater que la population s’était accrue dans une mesure de 5,4 fois par rapport à sa taille de 1997-1998, ce qui correspondait à un taux d’accroissement annuel composé de 15,3 %. Sur une seule île, près de 4 500 nids actifs ont été observés. Cinq îles comptaient plus de 2 600 nids par île, ce qui représentait 75 % du nombre total de nids répertoriés. Jumelé aux données historiques tenant compte de l’habitat de nidification supplémentaire et non relevé, le taux d’accroissement de la population observé à partir de cette étude suggère que la taille de la population globale d’eiders à duvet nicheurs d’Avanersuaq varie de 25 000 à 30 000 paires, ce qui correspond à environ la moitié du total estimé de la population nicheuse de l’ouest du Groenland. Malgré l’importance que revêt le district d’Avanersuaq comme aire de reproduction de l’eider à duvet, nous ne possédons que des renseignements restreints au sujet de cette population. Les effets qu’aura le prolongement récent de la saison de chasse sur cette population sont également inconnus, et la seule information concernant la localisation de l’aire d’hivernage dont nous disposons a trait à quelques individus qui avaient été bagués dans les années 1920 et 1940. Par conséquent, il est suggéré de pousser les recherches relatives aux mouvements migratoires plus loin avant d’apporter d’autres changements au règlement de chasse

    M2K: I. A Jovian mass planet around the M3V star HIP79431

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    Doppler observations from Keck Observatory reveal the presence of a planet with Msini of 2.1 Mjup orbiting the M3V star HIP79431. This is the sixth giant planet to be detected in Doppler surveys of M dwarfs and it is one of the most massive planets discovered around an M dwarf star. The planet has an orbital period of 111.7 days and an orbital eccentricity of 0.29. The host star is metal rich, with an estimated [Fe/H] = +0.4. This is the first planet to emerge from our new survey of 1600 M-to-K dwarf stars.Comment: 5 figure

    Comparison of pre- and post-vaccination ovine Johne's disease prevalence using a Bayesian approach

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    postprintThis study was conducted to evaluate the effectiveness of GudairTM vaccine in decreasing the prevalence of shedding of Mycobacterium avium subsp. paratuberculosis (MAP) in flocks of varying initial prevalence. Thirty seven self-replacing Merino flocks from New South Wales and Victoria (Australia) that had been vaccinating lambs with GudairTM for at least five years were enrolled in the study. These flocks had been tested prior to or at commencement of vaccination using pooled faecal culture, agar gel immunodiffusion or both tests. These pre-vaccination test results were used to estimate pre-vaccination prevalence. Post-vaccination prevalence was estimated from culture of usually 7 pools of 50 sheep collected from the enrolled flocks in 2008-2009, approximately five or more years after commencement of vaccination. A Bayesian model was developed to estimate and compare the pre- and post-vaccination prevalences for the enrolled flocks. Apparent pre- and post-vaccination prevalences for flocks were modelled as functions of the true pre- and post-vaccination prevalences, respectively, and the sensitivities and specificities of the respective diagnostic tests. Logit-normal models were specified on pre- and post-vaccination true prevalences and were then used to make inferences about the median and 90th percentile of the prevalence distributions and their differences. Priors were mostly specified based on published literature or analysis of abattoir surveillance data for this population of flocks. The analysis found a significant decline in ovine Johne’s disease prevalence from a pre-vaccination median prevalence of 2.72% [95% probability interval (PI): 1.40; 6.86%] to a post-vaccination median prevalence of 0.72% (0.39; 1.27%). However 30 of the 37 flocks still contained sheep that were shedding MAP in their faeces. The results suggest that vaccination with Gudair™ is usually effective in reducing the prevalence of faecal shedding but the response to vaccination is variable among flocks. This approach could be implemented in similar situations to compare prevalences where information from multiple diagnostic tests with varied sensitivities and specificities is available. Keywords: Ovine Johne’s disease; Gudair; Vaccination; Abattoir surveillance; Faecal culture; Agar gel immune-diffusion test

    Comparison of pre- and post-vaccination ovine Johne's disease prevalence using a Bayesian approach

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    This study was conducted to evaluate the effectiveness of GudairTM vaccine in decreasing the prevalence of shedding of Mycobacterium avium subsp. paratuberculosis (MAP) in flocks of varying initial prevalence. Thirty seven self-replacing Merino flocks from New South Wales and Victoria (Australia) that had been vaccinating lambs with GudairTM for at least five years were enrolled in the study. These flocks had been tested prior to or at commencement of vaccination using pooled faecal culture, agar gel immunodiffusion or both tests. These pre-vaccination test results were used to estimate pre-vaccination prevalence. Post-vaccination prevalence was estimated from culture of usually 7 pools of 50 sheep collected from the enrolled flocks in 2008-2009, approximately five or more years after commencement of vaccination. A Bayesian model was developed to estimate and compare the pre- and post-vaccination prevalences for the enrolled flocks. Apparent pre- and post-vaccination prevalences for flocks were modelled as functions of the true pre- and post-vaccination prevalences, respectively, and the sensitivities and specificities of the respective diagnostic tests. Logit-normal models were specified on pre- and post-vaccination true prevalences and were then used to make inferences about the median and 90th percentile of the prevalence distributions and their differences. Priors were mostly specified based on published literature or analysis of abattoir surveillance data for this population of flocks. The analysis found a significant decline in ovine Johne’s disease prevalence from a pre-vaccination median prevalence of 2.72% [95% probability interval (PI): 1.40; 6.86%] to a post-vaccination median prevalence of 0.72% (0.39; 1.27%). However 30 of the 37 flocks still contained sheep that were shedding MAP in their faeces. The results suggest that vaccination with Gudair™ is usually effective in reducing the prevalence of faecal shedding but the response to vaccination is variable among flocks. This approach could be implemented in similar situations to compare prevalences where information from multiple diagnostic tests with varied sensitivities and specificities is available. Keywords: Ovine Johne’s disease; Gudair; Vaccination; Abattoir surveillance; Faecal culture; Agar gel immune-diffusion test

    Two Exoplanets Discovered at Keck Observatory

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    We present two exoplanets detected at Keck Observatory. HD 179079 is a G5 subgiant that hosts a hot Neptune planet with Msini = 27.5 M_earth in a 14.48 d, low-eccentricity orbit. The stellar reflex velocity induced by this planet has a semiamplitude of K = 6.6 m/s. HD 73534 is a G5 subgiant with a Jupiter-like planet of Msini = 1.1 M_jup and K = 16 m/s in a nearly circular 4.85 yr orbit. Both stars are chromospherically inactive and metal-rich. We discuss a known, classical bias in measuring eccentricities for orbits with velocity semiamplitudes, K, comparable to the radial velocity uncertainties. For exoplanets with periods longer than 10 days, the observed exoplanet eccentricity distribution is nearly flat for large amplitude systems (K > 80 m/s), but rises linearly toward low eccentricity for lower amplitude systems (K > 20 m/s).Comment: 8 figures, 6 tables, accepted, Ap
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