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11.
KS Johnson JH Thywissen NH Dekker KK Berggren AP Chu R Younkin M Prentiss 《Science (New York, N.Y.)》1998,280(5369):1583-1586
The spatially dependent de-excitation of a beam of metastable argon atoms, traveling through an optical standing wave, produced a periodic array of localized metastable atoms with position and momentum spreads approaching the limit stated by the Heisenberg uncertainty principle. Silicon and silicon dioxide substrates placed in the path of the atom beam were patterned by the metastable atoms. The de-excitation of metastable atoms upon collision with the surface promoted the deposition of a carbonaceous film from a vapor-phase hydrocarbon precursor. The resulting patterns were imaged both directly and after chemical etching. Thus, quantum-mechanical steady-state atom distributions can be used for sub-0.1-micrometer lithography. 相似文献
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AP Del Carro E Rosset A Josson‐Schramme V Lambert S Buff 《Reproduction in domestic animals》2014,49(5):E48-E52
An eight‐month‐old female dog presented with ambiguous external genitalia. A thorough clinical examination together with various imaging techniques and a histology examination showed the presence of two testicles linked to both the Mullerian and Wolffian ducts. The discovery of the 78,XX SRY‐negative karyotype led to the diagnosis of incoherence between the chromosomal and gonadal sex, which is typical for a 78,XX testicular disorder of sex development. Our case was unique because the testicles were still located in their normal scrotal position, whereas the literature contains reports of the presence of cryptorchid testicles in this karyotype setting. To our knowledge, this is the first case that describes an SRY‐negative 78,XX testicular disorder of sex development with bilateral scrotal testicles. 相似文献
15.
前言目前畜牧生产的高效率是以下几方面因素综合作用的结果:1.畜牧生产者能迅速地接受新的饲养管理技术;2.遗传、营养和饲养管理方面的研究取得了非常有价值的成果,能够以尽可能低的成本生产优质的畜产品;3.政府鼓励科研的发展,为畜牧工作提出合理建议并制订必要的法规。在科学计算的基础上,应用配合饲料,特别是全价饲料(粉料或顺粒料)喂猪和禽能够迅速有效地将营养研究成果和革新技术应用到实际中去。全价饲料可以节省劳力,提高饲料 相似文献
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AP Herman T Misztal A Herman Dorota Tomaszewska – Zaremba 《Reproduction in domestic animals》2010,45(6):e426-e433
This study was designed to determine the effect of intravenous lipopolysaccharide (LPS) administration on the secretion of interleukin (IL)‐1β and IL‐1 receptors (IL‐1Rs) gene expression in the hypothalamus of anoestrous ewes. Gene expression of IL‐1β and its receptors was assayed by the real‐time polymerase chain reaction. The expression of IL‐1β in the hypothalamus was detected using Western blot. Our results showed that IL‐1β mRNA is transcribed in the ovine hypothalamus. Lipopolysaccharide increased (p ≤ 0.01) the IL‐1β gene expression in the pre‐optic area 2.4‐fold, the anterior hypothalamus (AHA) 3.4‐fold, the medial basal hypothalamus 3.7‐fold and the medial eminence 3.9‐fold. The pro‐form and mature form of IL‐1β protein were found in the hypothalamus after endotoxin injection. In general, the endotoxin also increased more than two times (p ≤ 0.01) the expression of IL‐1 receptor type I (IL‐1R1) and type II (IL‐1R2) genes in the hypothalamus, except the AHA, where the number of IL‐1R2 mRNA was extremely low and not sufficient to the quantitative analysis. These results demonstrate that the peripheral immune/inflammatory challenge increases the IL‐1β expression in the hypothalamus. This endogenous IL‐1β seems to be involved in the modulation of processes which are regulated at the hypothalamic level. One of these processes could be a reproduction. 相似文献
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Epidemiology of an avian influenza outbreak in Victoria in 1985 总被引:1,自引:0,他引:1
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Thomson GR Perry BD Catley A Leyland TJ Penrith ML Donaldson AI 《The Veterinary record》2006,159(2):53-57
The current system for the certification of internationally traded animal commodities can act as a barrier to developing countries accessing high-value international markets. In this Viewpoint article, Gavin Thomson and colleagues discuss the situation as it stands and identify inconsistencies with respect to the certification process. They suggest ways to address the lack of capacity for credible certification in some developing countries that will encourage market access for livestock commodities. They emphasise the role of mechanisms other than demonstrating that an area of production is free from a range of animal diseases, arguing that this could be of significant benefit to developing regions and countries, but that a reliable and independent system of certification based on international standards is essential. 相似文献
19.
Mochabo KO Kitala PM Gathura PB Ogara WO Catley A Eregae EM Kaitho TD 《Tropical animal health and production》2005,37(3):187-204
This paper presents the results of a study conducted in Lapur Division of Turkana District, Kenya, to estimate the incidence and mortality of camel trypanosomosis using participatory methods. Four livestock camps ('adakars') were conveniently selected for the study. Four informant groups comprising 6 8 key persons were used for the participatory exercises. The camel diseases identified by the pastoralists in their order of importance according to annual incidence were: trypanosomosis (11.4%); mange (10.8%); tick infestation (7.9%); haemorrhagic septicaemia (7.7%); and non-specific diarrhoea (7.6%). Almost half (49.3%) of the camel population suffered from at least one disease over the previous year. The annual incidence and mortality rates of trypanosomosis were estimated at 15%, and 9.9%, in adult camels and 6.9% and 5.2%, in young camels, respectively. There was a seasonal occurrence of trypanosomosis, with most cases reported in the dry season. The prevalence levels of the disease reportedly declined from about 100%, in 1978 to an almost stable state of about 15% in 2002. This study revealed that camel trypanosomosis is still an important disease in Turkana District, exacting a heavy toll in terms of morbidity and mortality. The economic losses due to the disease were likely to have been great owing to the central role the camel plays in this arid district of Kenya. 相似文献
20.
Thomson GR Tambi EN Hargreaves SK Leyland TJ Catley AP van 't Klooster GG Penrith ML 《The Veterinary record》2004,155(14):429-433
International animal health standards designed to facilitate safe trade in livestock and livestock products are set by the Office International des Epizooties (OIE) under the Sanitary and Phytosanitary Agreement of the World Trade Organization (WTO) and documented in the OIE's Terrestrial Animal Health Code. A core principle of the Code is the need for countries to eradicate important transboundary animal diseases (TADs) to reduce the risk of exporting disease to trading partners. International food safety standards are set by the Codex Alimentarius Commission, administered jointly by the World Health Organization and the Food and Agriculture Organization of the United Nations. The goal of global eradication of most TADs is unachievable for the foreseeable future, other than in the case of rinderpest, and this prevents many countries, especially developing nations, from engaging in international trade under WTO rules. This paper proposes an alternative, commodity-based approach to the formulation of international animal health and food safety standards, based on the fact that different commodities pose very different risks when it comes to the spread of human and animal pathogens. Therefore, the risk mitigation strategies required are equally commodity-dependent. The authors conclude that more focused commodity standards would improve access to international markets for all countries, especially those in the developing world. For this objective to be realised, credible and independent certification is required. 相似文献