3,271 research outputs found
Training-induced inversion of spontaneous exchange bias field on La1.5Ca0.5CoMnO6
In this work we report the synthesis and structural, electronic and magnetic
properties of La1.5Ca0.5CoMnO6 double-perovskite. This is a re-entrant spin
cluster material which exhibits a non-negligible negative exchange bias effect
when it is cooled in zero magnetic field from an unmagnetized state down to low
temperature. X-ray powder diffraction, X-ray photoelectron spectroscopy and
magnetometry results indicate mixed valence state at Co site, leading to
competing magnetic phases and uncompensated spins at the magnetic interfaces.
We compare the results for this Ca-doped material with those reported for the
resemblant compound La1.5Sr0.5CoMnO6, and discuss the much smaller spontaneous
exchange bias effect observed for the former in terms of its structural and
magnetic particularities. For La1.5Ca0.5CoMnO6, when successive magnetization
loops are carried, the spontaneous exchange bias field inverts its sign from
negative to positive from the first to the second measurement. We discuss this
behavior based on the disorder at the magnetic interfaces, related to the
presence of a glassy phase. This compound also exhibits a large conventional
exchange bias, for which there is no sign inversion of the exchange bias field
for consecutive cycles
Measures taken to reduce the risk of West Nile virus transmission by transplantation in Italy.
Effect of a high forage: Concentrate ratio on milk yield, blood parameters and oxidative status in lactating cows
A feeding strategy that requires a forage: concentrate ratio equal to 70: 30, with at least five different herbs in the forage and the use of silages prohibited, has recently been introduced in Italy. Despite the benefits in terms of human health (lower ω6: ω3 ratio, higher conjugated linoleic acid level) of the obtained milk, little information regarding the possible effects on cows' health is available. The aim of this study was to evaluate the effects of such a feeding strategy in dairy cows (90 days in milk at the beginning of the trial) on milk yield and composition, and blood metabolic profile, including the evaluation of oxidative stress. The proposed feeding strategy, compared with a semi-intensive strategy, resulted in an improvement of animal oxidative status (lower levels of reactive oxygen metabolites, higher levels of antioxidant potential and anti-reactive oxygen metabolites) and a significant increase of milk urea only in the first part of the trial. No differences in milk yield and composition were detected throughout the trial
Total orthotopic small bowel transplantation in swine under FK 506
Previous experimental studies in rodents and in dogs have established the efficacy of FK 506 in controlling the immunologic events following small bowel or multivisceral transplantation.1–5 To complete the assessment of FK 506 in experimental small bowel transplantation, we present here our experience with the frequently used swine model
Impact of delivery mode on the colostrum microbiota composition.
BACKGROUND: Breast milk is a rich nutrient with a temporally dynamic nature. In
particular, numerous alterations in the nutritional, immunological and
microbiological content occur during the transition from colostrum to mature
milk. The objective of our study was to evaluate the potential impact of delivery
mode on the microbiota of colostrum, at both the quantitative and qualitative
levels (bacterial abundance and microbiota network).
METHODS: Twenty-nine Italian mothers (15 vaginal deliveries vs 14 Cesarean
sections) were enrolled in the study. The microbiota of colostrum samples was
analyzed by next generation sequencing (Ion Torrent Personal Genome Machine). The
colostrum microbiota network associated with Cesarean section and vaginal
delivery was evaluated by means of the Auto Contractive Map (AutoCM), a
mathematical methodology based on Artificial Neural Network (ANN) architecture.
RESULTS: Numerous differences between Cesarean section and vaginal delivery
colostrum were observed. Vaginal delivery colostrum had a significant lower
abundance of Pseudomonas spp., Staphylococcus spp. and Prevotella spp. when
compared to Cesarean section colostrum samples. Furthermore, the mode of delivery
had a strong influence on the microbiota network, as Cesarean section colostrum
showed a higher number of bacterial hubs if compared to vaginal delivery, sharing
only 5 hubs. Interestingly, the colostrum of mothers who had a Cesarean section
was richer in environmental bacteria than mothers who underwent vaginal delivery.
Finally, both Cesarean section and vaginal delivery colostrum contained a greater
number of anaerobic bacteria genera.
CONCLUSIONS: The mode of delivery had a large impact on the microbiota
composition of colostrum. Further studies are needed to better define the meaning
of the differences we observed between Cesarean section and vaginal delivery
colostrum microbiota
Electronic fetal monitoring during labor: comparison of abdominal fetal electrocardiography and doppler cardiotocography
A blind HI survey of the M81 group
Results are presented of the first blind HI survey of the M81 group of
galaxies. The data were taken as part of the HI Jodrell All Sky Survey
(HIJASS). The survey reveals several new aspects to the complex morphology of
the HI distribution in the group. All four of the known dwarf irregular (dIrr)
galaxies close to M81 can be unambiguously seen in the HIJASS data. Each forms
part of the complex tidal structure in the area. We suggest that at least three
of these galaxies may have formed recently from the tidal debris in which they
are embedded. The structure connecting M81 to NGC2976 is revealed as a single
tidal bridge of mass approx. 2.1 x 10^8 Msol and projected spatial extent
approx. 80 kpc. Two `spurs' of HI projecting from the M81 complex to lower
declinations are traced over a considerably larger spatial and velocity extent
than by previous surveys. The dwarf elliptical (dE) galaxies BK5N and Kar 64
lie at the spatial extremity of one of these features and appear to be
associated with it. We suggest that these may be the remnants of dIrrs which
has been stripped of gas and transmuted into dEs by close gravitational
encounters with NGC3077. The nucleated dE galaxy Kar 61 is unambiguously
detected in HI for the first time and has an HI mass of approx.10^8 Msol,
further confirming it as a dE/dIrr transitional object. HIJASS has revealed one
new possible group member, HIJASS J1021+6842. This object contains approx. 2 x
10^7 Msol of HI and lies approx.105arcmin from IC2574. It has no optical
counterpart on the Digital Sky Survey.Comment: To be published in Astrophysical Journal Letters 9 pages, including 3
figure
Estimativas de parâmetros genĂ©ticos para caracterĂsticas reprodutivas e de crescimento em bovinos Canchim por mĂ©todo Bayesiano.
Obtiveram-se, neste estudo, parâmetros genĂ©ticos para as caracteristicas de permanĂŞncia de remeas no rebanho aos 76 meses de idade (PR76), idade ao primeiro parto (IPP), perĂmetro escrotal aos 420 dias de idade (PE420) e peso aos 420 dias de idade de machos e fĂŞmeas (P420) de animais da raça Canchim. No modelo animal, foram incluĂdos o grupo de contemporâneos e os efeitos aleatĂłrios aditivos diretos e residuais. Os dados foram analisados por meio de inferĂŞncia Bayesiana, em análise uni¬caracterĂstica. As mĂ©dias de PR76, IPP, PE420 e P420 foram iguais a 1,57±0,73 bezerros, 39,47±7,20 meses, 24,63±3,84 cm e 260,37±46,5l kg, respectivamente. As herdabilidades foram iguais a 0,0299±0,008, 0,0236±0,009, 0,2357±0,060 e 0,2235±0,048 para PR76, IPP, PE420 e P420, respectivamente. As estimativas de herdabilidade para PE420 e P420 indicam que a seleção direta para estas caracterĂsticas pode resultar em progresso genĂ©tico do rebanho da raça Canchim. As estimativas para as caracterĂsticas reprodutivas PR76 e IPP indicam que a seleção destas pouco contribuirá para o melhoramento genĂ©tico da raça
Estimativas de parâmetros genĂ©ticos para caracterĂsticas reprodutivas e de crescimento em bovinos da raça Canchim.
Estudou-se neste trabalho dados referentes Ă s caracterĂsticas de idade ao segundo parto (ISP), perĂmetro escrotal aos 420 dias de idade (PE420) e peso aos 420 dias de idade de machos e fĂŞmeas (P420) de animais da raça Canchim, para as quais foram obtidas estimativas de herdabilidade e correlações genĂ©ticas. No modelo animal, foram incluĂdos os efeitos fixos de grupo de contemporâneos e os efeitos aleatĂłrios aditivos diretos e residuais. Utilizou-se o mĂ©todo da máxima verossimilhança restrita em análise bi-caracterĂstica. As mĂ©dias de ISP, PE420 e P420 foram iguais a 57,07±8,69 meses, 24,63±3,84 cm e 260,37±46,5l kg, respectivamente. As estimativas de herdabilidade foram 0,07±0,01, 0,2l±0,05 e 0,24±0,03, respectivamente para ISP, PE420 e P420. As correlações genĂ©ticas foram iguais a -0,47 (ISPXPE420) e 0,10 (ISPxP420). A seleção direta para perĂmetro escrotal aos 420 dias de idade poderá resultar em progresso genĂ©tico favoráveis na assiduidade reprodutiva de fĂŞmeas da raça Canchim, considerando que o PE420 apresentou correlação genĂ©tica aditiva com idade ao segundo parto
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