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1.
J Phys Condens Matter ; 31(12): 124002, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30625433

RESUMO

We demonstrate a novel method for the excitation of sizable magneto-optical effects in Au by means of the laser-induced injection of hot spin-polarized electrons in Au/Fe/MgO(0 0 1) heterostructures. It is based on the energy- and spin-dependent electron transmittance of Fe/Au interface which acts as a spin filter for non-thermalized electrons optically excited in Fe. We show that after crossing the interface, majority electrons propagate through the Au layer with the velocity on the order of 1 nm fs-1 (close to the Fermi velocity) and the decay length on the order of 100 nm. Featuring ultrafast functionality and requiring no strong external magnetic fields, spin injection results in a distinct magneto-optical response of Au. We develop a formalism based on the phase of the transient complex MOKE response and demonstrate its robustness in a plethora of experimental and theoretical MOKE studies on Au, including our ab initio calculations. Our work introduces a flexible tool to manipulate magneto-optical properties of metals on the femtosecond timescale that holds high potential for active magneto-photonics, plasmonics, and spintronics.

2.
J Phys Condens Matter ; 29(17): 174002, 2017 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-28349899

RESUMO

We discuss fundamental aspects of laser-induced ultrafast demagnetization probed by the time-resolved magneto-optical Kerr effect (MOKE). Studying thin Fe films on MgO substrate in the absence of electronic transport, we demonstrate how to disentangle pump-induced variations of magnetization and magneto-optical coefficients. We provide a mathematical formalism for retrieving genuine laser-induced magnetization dynamics and discuss its applicability in real experimental situations. We further stress the importance of temporal resolution achieved in the experiments and argue that measurements of both time-resolved MOKE rotation and ellipticity are needed for the correct assessment of magnetization dynamics on sub-picosecond timescales. The framework developed here sheds light onto the details of the time-resolved MOKE technique and contributes to the understanding of the interplay between ultrafast laser-induced optical and magnetic effects.

3.
Artigo em Alemão | MEDLINE | ID: mdl-23242149

RESUMO

The second part of the recommendations deals with the healthcare and the regulatory framework for the husbandry of sheep and goats. The suggested concept for healthcare aims to develop an individual health plan for every flock. This health plan focuses not only on the prevention of notifiable diseases, but also on chronic and slow infections as well as on parasite monitoring. The emphasis is on early detection of diseases and prophylaxis. In conjunction with this, the handling of lameness, shearing, animal trade and quarantine as well as cleaning and disinfection in sheep and goat flocks are intensively discussed. There are detailed federal and European legal regulations concerning the transport and the physical well-being of animals. These laws are clearly presented and advice for their practical implementation is provided.


Assuntos
Criação de Animais Domésticos/métodos , Criação de Animais Domésticos/normas , Bem-Estar do Animal/normas , Cabras , Carneiro Doméstico , Criação de Animais Domésticos/legislação & jurisprudência , Bem-Estar do Animal/legislação & jurisprudência , Animais , Alemanha , Doenças das Cabras/diagnóstico , Doenças das Cabras/prevenção & controle , Ovinos , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/prevenção & controle
4.
Tierarztl Prax Ausg G Grosstiere Nutztiere ; 40(5): 314-25, 2012 Oct 17.
Artigo em Alemão | MEDLINE | ID: mdl-23076761

RESUMO

Recommendations for the different forms of sheep and goat husbandry based on the legal regulations are summarized. These are given in particular respect to transhumance, tending, alpine farming, and indoor housing. The requirements for pasture, housing, supply of water and food, lambing, rearing of lambs, and health management are intensively discussed. The general requirements of the extensive as well as of the intensive husbandry of sheep and goats are defined. Examples of species-specific capabilities for adaption, the limits of adaption, and signs of decompensation are provided. Compliance with these recommendations should accord the animals entrusted to our care the "five freedoms (13)": 1. Freedom from hunger and thirst, 2. freedom from discomfort, 3. freedom from pain, injury, or disease, 4. freedom to express normal behaviour, and 5. freedom from fear and distress.


Assuntos
Criação de Animais Domésticos/normas , Bem-Estar do Animal/normas , Cabras , Carneiro Doméstico , Animais , Guias como Assunto , Ovinos , Medicina Veterinária
5.
Sex Dev ; 1(1): 59-65, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18391516

RESUMO

The diploid/triploid (60,XX/90,XXY) condition in Bos taurus is very rare and only three cases have been published previously. The present animal exhibited an aplastic vulva, penis and clitoris agenesis, a male-like urethra located in a pseudoprepuce opening between the mammary complexes and a well developed M. rectipeninus. A normal (60,XX) female karyotype was detected in lymphocyte cultures whereas uterus and tendon cells revealed a 60,XX/90,XXY mixoploidy. Quantification of X and Y chromosome-specific sequences using RT-PCR revealed extraordinary high Y chromosome equivalents in the sample recovered from the male-like transformed vestibulum vaginae suggesting a causative relationship. The pathogenesis of the missing clitoris and penis, which is contrasted by the concomitant presence of a well developed M. rectipeninus, remains difficult to explain. A chimeric origin is suggested despite the fact that microsatellite analysis of the animal's blood cells displayed no un- usual allele accumulation.


Assuntos
Bovinos/genética , Cromossomos de Mamíferos/genética , Diploide , Transtornos do Desenvolvimento Sexual/genética , Poliploidia , Cromossomos Sexuais/genética , Animais , Feminino , Fibroblastos/citologia , Genitália Feminina/patologia , Linfócitos/citologia , Masculino , Metáfase
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