Author Keywords: Shivering; electromyography; electrodes; EMG activity; heat production; data acquisition; spectral analysis; thermoregulation; bantam hens 相似文献
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991.
1. 1.|Simple electronics for measurement of shivering, which include direct and mean rectified EMG (Umrv), are suggested.
2. 2.|A software system (LabGraph) for measurement and analysis is described.
3. 3.|Three different electrode designs were tested with the system by recording electromyography (EMG) from m. iliotibialis with subdermal, intramuscular and safety pin electrodes in bantam hens exposed to cold eggs. The signal characteristics of EMG are discussed in relation to electrode design and signal processing.
4. 4.|A method for normalizing EMG activity within an experiment to units of heat production is presented and was tested successfully in bantam hens.
992.
Biosynthesis and Genetic Engineering of Lignin 总被引:1,自引:0,他引:1
Lignin, a complex heteropolymer of cinnamyl alcohols, is, second to cellulose, the most abundant biopolymer on Earth. Lignification has played a determining role in the adaptation of plants to terrestrial life. As all extracellular polymers, lignin confers rheological properties to plant tissues and participates probably in many other functions in cell and tissue physiology orin cell-to-cell communication. Economically, lignin is very important because it determines wood quality and it affects the pulp and paper-making processes as well as the digestibility of forage crops. For all these reasons the lignin biosynthesis pathway has been the subject of many studies. At present, most genes encoding the enzymes involved in the biosynthesis of lignin have been cloned and characterized. Various recent studies report on the alteration of the expression of these genes by genetic engineering, yielding plants with modified lignin. In addition, several mutants have been analyzed with changes in lignin content or lignin composition resulting in altered properties. Thanks to these studies, progress in the knowledge of the lignin biosynthesis pathway has been obtained. It is now clear that the pathway is more complex than initially thought and there is evidence for alternative pathways. A fine manipulation of the lignin content and/or composition in plants is now achievable and could have important economical and environmental benefits. 相似文献
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996.
《Animal : an international journal of animal bioscience》2014,8(12):2016-2026
The sustainability of breeding activities in 15 pig farming systems in five European countries was evaluated. One conventional and two differentiated systems per country were studied. The Conventional systems were the standard systems in their countries. The differentiated systems were of three categories: Adapted Conventional with focus on animal welfare, meat quality or environment (five systems); Traditional with local breeds in small-scale production (three systems) and Organic (two systems). Data were collected with a questionnaire from nine breeding organisations providing animals and semen to the studied farming systems and from, on average, five farmers per farming system. The sustainability assessment of breeding activities was performed in four dimensions. The first dimension described whether the market for the product was well defined, and whether the breeding goal reflected the farming system and the farmers’ demands. The second dimension described recording and selection procedures, together with genetic change in traits that were important in the system. The third dimension described genetic variation, both within and between pig breeds. The fourth dimension described the management of the breeding organisation, including communication, transparency, and technical and human resources. The results show substantial differences in the sustainability of breeding activities, both between farming systems within the same category and between different categories of farming systems. The breeding activities are assessed to be more sustainable for conventional systems than for differentiated systems in three of the four dimensions. In most differentiated farming systems, breeding goals are not related to the system, as these systems use the same genetic material as conventional systems. The breeds used in Traditional farming systems are important for genetic biodiversity, but the small scale of these systems renders them vulnerable. It is hoped that, by reflecting on different aspects of sustainability, this study will encourage sustainable developments in pig production. 相似文献
997.
《Process Biochemistry》2014,49(3):474-489
In the world, the evolution of biodiesel demand influences the global market of edible feedstocks, affecting their commercial prices and availability and consequently food security. Colombia as a tropical country has the potential of producing multiple oleochemical feedstocks including both edible and non-edible vegetable oils and animal fats. However, the oleochemical industry in the country is based on a small range of feedstocks. In this paper, five oleochemical feedstocks were selected according to comparative criteria of national availability, potential oleochemical derivatives, projected expansion, impact on food security and land requirements. This analysis allowed obtaining oil palm, maize, jatropha, castorbean, and microalgae as promissory feedstocks. Then, multiproduct biorefineries were developed and economically and environmentally assessed, according to their production features. Thus, it was stated that the proposed configurations were able to support the development of the oleochemical industry in Colombia providing sustainable alternatives, which supply a growing demand of biodiesel and other oleochemical derivatives. 相似文献
998.
《Critical reviews in biotechnology》2013,33(1):32-52
The exponentially growing human population and the emergence of new diseases are clear indications that the world can no longer depend solely on conventional vaccine technologies and production schemes. The race to find a new vaccine technology is crucial to help speed up and complement the World Health Organization (WHO) disease elimination program. The ultimate goal is to uncover fast and efficient production schemes in the event of a pandemic, and also to effectively fight deadly diseases such as malaria, bird flu, hepatitis, and human immunodeficiency virus (HIV). Plasmid DNA vaccines, if properly formulated, offer specific priming of the immune system and similar or even better prophylactic effects than conventional vaccines. This article discusses many of the critical issues that need to be considered when developing fast, effective, and reliable plasmid DNA vaccine manufacturing processes. Different modes of plasmid production via bacterial fermentation are compared. Plasmid purification by chromatography is specifically discussed as it is the most commercially viable bioprocess engineering technique for continuous purification of supercoiled plasmid DNA. Current techniques and progress covering the area of plasmid DNA vaccine design, formulation, and delivery are also put forward. 相似文献
999.
Structure and transcription of genes within the β-hbd-adh1 region of Clostridium acetobutylicum P262
Jonathan S. Youngleson Fu-Pang Lin Sharon J. Reid David R. Woods 《FEMS microbiology letters》1995,125(2-3):185-191
Abstract The 1.2-kb DNA fragment upstream of the linked β- hbd (3-hydroxybutyryl-CoA dehydrogenase) and adh1 (NADPH-dependent alcohol dehydrogenase) genes from Clostridium acetobutylicum P262 was sequenced. The upstream region contained an open reading frame (ORFB) which was found to have 44% amino acid identity to the fixB gene products of yRhizobium and Azorhizobium . The β- hbd and ORFB genes were expressed during the acidogenic and solventogenic phases. The β- hbd gene was transcribed on a single mRNA species of 2.0 kb, whereas the ORFB gene was transcribed on two species of mRNA of 2.0 and 3.5 kb, respectively. The adh1 gene was induced or derepressed at the pH breakpoint before the onset of solventogenesis and was transcribed on a single species of mRNA of 2.4 kb. 相似文献
1000.
An Improved CARV Process for Bioethanol Production from a Mixture of Sugar Beet Mash and Potato Mash
《Bioscience, biotechnology, and biochemistry》2013,77(3):602-604
A mixed mash of sugar beet roots and potato tubers with a sugar concentration of 23.7% w/v was used as a feedstock for bioethanol production. Enzymatic digestion successfully reduced the viscosity of the mixture, enabling subsequent heat pretreatment for liquefaction/sterilization. An energy-consuming thick juice preparation from sugar beet for concentration and sterilization was omitted in this new process. 相似文献