104 research outputs found
Public attitudes towards different management scenarios for ‘surplus’ dairy calves
No full textAs awareness grows, some traditional management practices used by the dairy industry will be questioned by members of the public. Therefore, to maintain its social license to operate, the industry needs to account for public perspectives when developing future directions. Our aims were to assess attitudes of members of the public toward the management of surplus calves not needed for milk production on dairy farms, and to assess how specific calf management practices might influence these attitudes. A mixed-methods questionnaire was developed and distributed online in the United States and in Canada. After reading an introductory paragraph stating that surplus calves are generally used for meat production, participants were randomly allocated into groups and read 1 of 4 scenarios that described different surplus calf management practices in more detail. The scenarios followed a 2 × 2 factorial design, and the factors that differed were the calf's age at slaughter (≤2 wk vs. ≥12 mo), and whether the calf was separated from the cow at birth or sometime later. Data representative of key census demographics from 998 participants were analyzed. Quantitative data analysis included descriptive statistics, nonparametric tests, generalized partial credit models, and linear regression models. For qualitative data, we used reliability thematic analysis. Overall, participants were slightly positive in their attitudes toward the introductory paragraph, and participants in the groups in which the calf was slaughtered after 12 mo of age often specifically linked their acceptance of the practice to the fact that the calves' lives had a purpose (i.e., contributing meaningfully to the beef supply). In contrast, only 3% of the participants regarded a slaughter age of <1 mo as appropriate. Participants in the groups in which calves were slaughtered within 2 wk after birth had more negative attitudes, and these attitudes declined even further when the calf was separated from the cow soon after birth. Besides the 2 main factors (age at slaughter and cow-calf separation), information on pasture access, the healthiness of the meat from the calves, and the exact age of slaughter were also considered important by participants to make a more informed decision about their view on surplus calf management. Overall, our results indicate that failure by the dairy industry to provide assurances that excess dairy calves have a reasonable length of life and that this life has purpose (i.e., contributes to the beef supply chain) places the industry at odds with public values. Also, as awareness grows, the practice of early cow-calf separation will be increasingly questioned by the public; failure to begin discussions on this topic will increase the risk that future decisions about this topic will be made in the absence of the farmer.Hans Sigrist Research Prize (Hans Sigrist Foundation, Bern, Switzerland
A study of the vacuum pyrolysis of para-substituted diazoacetophenones with He(I) ultraviolet photoelectron spectroscopy
No full textAn ultraviolet photoelectron (PE) spectrometer apparatus that utilizes a tuneable 50 W CW CO2 laser as a directed heat source was used to study the vacuum pyrolysis of diazoacetophenone (la) and its p-methyl, p-methoxy, p-chloro, and p-nitro analogues Ib, Ic, Id, and le. Analysis of the pyrolysate with He(I) ultraviolet PE spectroscopy shows that at a laser power Level of 26 W (500 +/- 50 degrees C) la, Ib, Ic, and Id, cleanly yield the corresponding phenylketenes 2a, 2b, 2c, and 2d, respectively, the products of the Wolff rearrangement of the incipient ketocarbenes. Of this group of highly reactive ketenes, which cannot be isolated in the condensed phase at ambient temperature, only 2a has been the subject of a previous PE spectroscopic study. But our work indicates that the sample of 2a prepared in the earlier study was impure. The low volatility of p-nitrodiazoacetophenone (le) thwarted our attempts to generate 2e and obtain its spectrum. Calculations at semiempirical (AMI) and ab inito (WF/G-31G(d)) levels of theory established that the diazoacetophenones prefer to adopt twisted syn conformations. That the calculated ionization potentials (HAM/3 and Becke3LYP/6-31+G(d)//HF/G-31G(d)) of la-ld and the synthesized PE spectra of la, Ib, and Ic correlate well with the PE spectroscopic data supports this finding. Shifts observed in the three low-energy ionizations of ketenes 26, 2c, and 2d induced by the para-substitution can be related to the character of the corresponding occupied molecular orbitals of phenylketene (2a).PT: J; CR: *HYP INC, 1994, HYPERCHEM 4 0 ALLEN AD, 1987, CAN J CHEM, V65, P1719 ANDRAOS J, 1991, J PHOTOCH PHOTOBIO A, V57, P165 ARDUENGO AJ, 1994, J AM CHEM SOC, V116, P6641 ASBRINK L, 1981, QCPE, V13, P393 BACHMANN C, 1990, J AM CHEM SOC, V112, P7488 BECKE AD, 1993, J CHEM PHYS, V98, P5648 CHMIELEWSKI D, 1993, CAN J CHEM, V71, P1741 CHONG DP, 1984, J PHYS CHEM-US, V88, P1479 COLBOURNE D, 1980, J CHEM SOC CHEM COMM, P250 COLBOURNE D, 1985, J CHEM SOC P2, P2049 FRISCH MJ, 1995, GAUSSIAN 94 REVISION HEHRE WJ, AB INITIO MOL ORBITA HOPE H, 1972, ACTA CRYSTALLOGR B, V28, P3632 HOTZEL A, 1980, ANGEW CHEM INT EDIT, V19, P739 KAPLAN F, 1966, J AM CHEM SOC, V88, P950 KIMURA K, 1981, HDB HEI PHOTOELECTRO KIRMSE W, 1994, ADV CARBENE CHEM, V1 KOOPMANS T, 1933, PHYSICA, V1, P104 MCMAHON RJ, 1985, J AM CHEM SOC, V107, P597 MCMAHON RJ, 1987, J AM CHEM SOC, V109, P2456 MODELLI A, 1980, J ELECT SPECTROSC RE, V18, P359 MOHMAND S, 1981, CHEM BER, V114, P2595 MUCHALL HM, IN PRESS TETRAHEDRON MUCHALL HM, 1997, CAN J CHEM, V75, P1851 MUCHALL HM, 1997, J MOL STRUCT, V435, P157 MUCHALL HM, 1998, CAN J CHEM, V76, P221 MUCHALL HM, 1998, CAN J CHEM, V76, P238 PATAI S, 1978, CHEM DIAZONIUM D 1 2 REGITZ M, 1968, CHEM BER, V101, P2622 SAMMYNAIKEN R, 1989, J CHEM SOC P2, P1987 STEWART JJP, 1983, QCPE, P455 STEWART JJP, 1986, AUSTIN MODEL 1 PACKA, P506 TROST BM, 1975, J AM CHEM SOC, V97, P2438 VOROBEV AS, 1993, RUSS CHEM B, V42, P281 WERSTIUK NH, 1992, CAN J CHEM, V70, P1971 WERSTIUK NH, 1994, CAN J CHEM, V72, P2537 WERSTIUK NH, 1994, J CHEM SOC FARADAY T, V90, P3383 WERSTIUK NH, 1995, CAN J CHEM, V73, P146 WERSTIUK NH, 1995, CAN J CHEM, V73, P1738 WERSTIUK NH, 1996, CAN J CHEM, V74, P1903 WERSTIUK NH, 1996, CAN J CHEM, V74, P2536 WERSTIUK NH, 1998, CAN J CHEM, V76, P672 WOLFF L, 1912, LIEBIGS ANN CHEM, V394, P23; NR: 44; TC: 8; J9: CAN J CHEM; PG: 12; GA: 143VNSource type: Electronic(1
Chlamydien-bedingte Erkrankungen beim Menschen nach Kontakt zu infiziertem Nutzgeflügel : ein Fallbericht
No full textMolecular typing of German Mycobacterium avium subsp. paratuberculosis isolates from different hosts by MLSSR, RFLP and MIRU-VNTR analysis
No full textMolecular diversity among bovine Mycobacterium avium subsp. paratuberculosis strains from Germany detected by RFLP and MIRU-VNTR analysis
No full textA influência do ambiente físico e social no bem-estar de leitões desmamados
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em Agroecossistemas.Na suinocultura industrial, o desmame de leitões é realizado de forma brusca, geralmente às 3 semanas de vida e envolve, além da separação da mãe, a mudança de dieta, a remoção para um novo ambiente e a mistura de leitegadas visando lotes de pesos homogêneos. Estes elementos podem contribuir para agravar problemas relacionados ao desmame como a baixa ingestão de alimento e a conseqüente parada no crescimento e a alta incidência de diarréias e vocalizações que ocorrem nos primeiros dias pós-desmame. Isso interfere no comportamento, no bem-estar e na produtividade desses leitões. Um estudo foi desenvolvido no Centro Nacional de Pesquisa em Suínos e Aves - EMBRAPA, localizada no município de Concórdia - SC, com o objetivo de avaliar a influência da perda da mãe e concomitante mudança de dieta, a mudança no ambiente social e a transferência para um novo espaço físico, no desempenho e comportamento de leitões nos primeiros dias após o desmame. Vinte e quatro leitegadas foram desmamadas com 21 (± 1,4) dias e distribuídas aleatoriamente nos seguintes tratamentos: T1- retirou-se a porca e a leitegada permaneceu na baia de maternidade, T2- uma leitegada inteira foi levada para uma baia da creche, e T3- leitões - entre 9 e 12 - de duas leitegadas foram misturados e alojados na creche. As observações foram realizadas no dia do desmame e nos dias 2, 3, 4, 7 e 10 após o desmame. O ganho de peso, o consumo de ração e a conversão alimentar não diferiram significativamente entre os tratamentos. Houve efeito significativo do tratamento (P 0,5) nos comportamentos exploratório, deitado e interações agonísticas. O T1 apresentou menor freqüência do comportamento exploratório e maior tempo deitado e menor freqüência de interações agonísticas do que os dois outros tratamentos (P < 0,01). Os grupos do T3 apresentaram maior freqüência de interações agonísticas, maior freqüência do comportamento exploratório e menor freqüência do comportamento deitado do que os do T2 (P < 0,01). O tratamento (P < 0,01) e o dia (P < 0,001) influenciaram a freqüência de vocalizações, que foi semelhante entre T2 e T3 e menor (P < 0,01) no T1. Em relação às lesões de pele graves, houve uma interação entre tratamento e dia de avaliação. No dia 2 pós-desmame houve maior porcentagem de leitões com lesões graves no T3 (P < 0,1) do que nos outros dois tratamentos que não diferiram entre si. No dia 7, os três tratamentos diferiram entre si (P < 0,001), sendo maior a porcentagem no T3 e menor no T1. A remoção de dois estressores - a mudança de ambiente físico e a mistura social - favoreceu alguns indicadores de bem-estar nos leitões, de forma que este foi superior naqueles do tratamento que permaneceu na maternidade. A mistura de leitões foi o fator que mais afetou o bem-estar dos animais, a julgar por alguns comportamentos apresentados, como a alta freqüência de vocalizações e interações agonísticas acompanhadas de lesões graves de pele, indicando dor e sofrimento desses animais. A mudança de ambiente físico, um fator pouco estudado como estressor na suinocultura e prevalente em vários manejos da suinocultura industrial, teve uma contribuição relevante no empobrecimento do bem-estar desses animais. Os resultados deste estudo permitem inferir sobre possíveis alterações no manejo que podem contribuir para melhorar o bem-estar dos suínos, como por exemplo, a realização de sistemas que favoreçam a integração das leitegadas antes do desmame com desmame em etapas, com vistas a separar os estressores aos quais os leitões são submetidos por ocasião do desmame
Temperature dependence of surface state lifetimes, dephasing rates and binding energies on Cu(111) studied with time-resolved photoemission
No full textThe ultrafast electron dynamics of surface states on Cu(111) is investigated as a function of temperature between 25 K and 460 K employing time-resolved two-photon photoemission (2PPE) spectroscopy. Analysis of the thermally-induced energy shift of the unoccupiedn = 1 image potential state based on a multiple reflection model allows a precise determination of the position of the upper edge (L6+) of the sp-gap in the (111)-directin(EL6+ (T) − EF = 4.15eV− (0.26meV/K)T). We find that the lifetime of then = 1 image state decreases from22 ± 3 fs at 25 K to14 ± 3 fs at 350 K. This is attributed to the increasing penetration depth of the image state wave function into the bulk at higher temperatures, where the image state crosses the band edge. The phonon contribution to the electronic dephasing of then = 0 surface state and then = 1 image state on Cu(111) is determined from their temperature-dependent linewidths using three-level optical Bloch equations and is found to correlate with their wave function overlap with bulk states
The kinetic temperature of Barnard 68
No full textWe have observed
the nearby isolated globule Barnard 68 (B68) in the and
inversion lines of ammonia. The gas kinetic temperature derived
from these is
T=10\pm1.2~\ensuremath{{\rm K}}. The observed line-widths are almost
thermal: \ensuremath{\Delta V}=0.181\pm0.003~\ensuremath{{\rm km\,s^{-1}}}
(\ensuremath{\Delta V_{\rm therm}}=
0.164\pm0.010~\ensuremath{{\rm km\,s^{-1}}}),
supporting the earlier hypothesis that B68 is in hydrostatic
equilibrium.
The kinetic temperature is an input
parameter to the physical cloud model put forward recently, and we
discuss the impact of the new value in this context
Solar system objects in the ISOPHOT 170
No full textThe ISOPHOT Serendipity Survey (ISOSS) covered approximately 15%
of the sky at a wavelength of 170 μm while the ISO satellite
was slewing from one target to the next. By chance, ISOSS slews
went over many solar system objects (SSOs). We identified
the comets, asteroids and planets in the slews through a fast
and effective search procedure based on N-body ephemeris and
flux estimates. The detections were analysed from a calibration and
scientific point of view.
Through the measurements of the well-known asteroids Ceres, Pallas,
Juno and Vesta and the planets Uranus and Neptune it was possible to
improve the photometric calibration of ISOSS and to extend it to
higher flux regimes. We were also able to establish calibration
schemes for the important slew end data.
For the other asteroids we derived radiometric diameters and albedos
through a recent thermophysical model. The scientific results
are discussed in the context of our current knowledge of
size, shape and albedos, derived from IRAS observations,
occultation measurements and lightcurve inversion techniques.
In all cases where IRAS observations were available we confirm
the derived diameters and albedos. For the five asteroids without
IRAS detections only one was clearly detected and the radiometric
results agreed with sizes given by occultation and HST observations.
Four different comets have clearly been detected at 170 μm
and two have marginal detections. The observational results are
presented to be used by thermal comet models in the future.
The nine ISOSS slews over Hale-Bop
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