Lactic acid bacteria Holzapfel, Wilhelm H; Wood, Brian J.B
2014., 2014, 2014-04-29
eBook
Lactic Acid Bacteria Biodiversity and Taxonomy Lactic Acid Bacteria Biodiversity and Taxonomy Edited by Wilhelm H. Holzapfel and Brian J.B. Wood The lactic acid bacteria (LAB) are a group of related ...microorganisms that are enormously important in the food and beverage industries. Generally regarded as safe for human consumption (and, in the case of probiotics, positively beneficial to human health), the LAB have been used for centuries, and continue to be used worldwide on an industrial scale, in food fermentation processes, including yoghurt, cheeses, fermented meats and vegetables, where they ferment carbohydrates in the foods, producing lactic acid and creating an environment unsuitable for the survival of food spoilage organisms and pathogens. The shelf life of the product is thereby extended, but of course these foods are also enjoyed around the world for their organoleptic qualities. They are also important to the brewing and winemaking industries, where they are often undesirable intruders but can in specific cases have desirable benefits. The LAB are also used in producing silage and other agricultural animal feeds. Clinically, they can improve the digestive health of young animals, and also have human medical applications. This book provides a much-needed and comprehensive account of the current knowledge of the LAB, covering the taxonomy and relevant biochemistry, physiology and molecular biology of these scientifically and commercially important microorganisms. It is directed to bringing together the current understanding concerning the organisms' remarkable diversity within a seemingly rather constrained compass. The genera now identified as proper members of the LAB are treated in dedicated chapters, and the species properly recognized as members of each genus are listed with detailed descriptions of their principal characteristics. Each genus and species is described using a standardized format, and the relative importance of each species in food, agricultural and medical applications is assessed. In addition, certain other bacterial groups (such as Bifidobacterium) often associated with the LAB are given in-depth coverage. The book will also contribute to a better understanding and appreciation of the role of LA B in the various ecosystems and ecological niches that they occupy. In summary, this volume gathers together information designed to enable the organisms' fullest industrial, nutritional and medical applications. Lactic Acid Bacteria: Biodiversity and Taxonomy is an essential reference for research scientists, biochemists and microbiologists working in the food and fermentation industries and in research institutions. Advanced students of food science and technology will also find it an indispensable guide to the subject. Also available from Wiley Blackwell The Chemistry of Food Jan Velisek ISBN 978-1-118-38384-1 Progress in Food Preservation Edited by Rajeev Bhat, Abd Karim Alias and Gopinadham Paliyath ISBN 978-0-470-65585-6
Our species exhibits spectacular success due to cumulative culture. While cognitive evolution of social learning mechanisms may be partially responsible for adaptive human culture, features of early ...human social structure may also play a role by increasing the number potential models from which to learn innovations. We present interview data on interactions between same-sex adult dyads of Ache and Hadza hunter-gatherers living in multiple distinct residential bands (20 Ache bands; 42 Hadza bands; 1201 dyads) throughout a tribal home range. Results show high probabilities (5%-29% per year) of cultural and cooperative interactions between randomly chosen adults. Multiple regression suggests that ritual relationships increase interaction rates more than kinship, and that affinal kin interact more often than dyads with no relationship. These may be important features of human sociality. Finally, yearly interaction rates along with survival data allow us to estimate expected lifetime partners for a variety of social activities, and compare those to chimpanzees. Hadza and Ache men are estimated to observe over 300 men making tools in a lifetime, whereas male chimpanzees interact with only about 20 other males in a lifetime. High intergroup interaction rates in ancestral humans may have promoted the evolution of cumulative culture.
Modeling Turbulent Flows in Porous Media Wood, Brian D; He, Xiaoliang; Apte, Sourabh V
Annual review of fluid mechanics,
01/2020, Letnik:
52, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Turbulent flows in porous media occur in a wide variety of applications, from catalysis in packed beds to heat exchange in nuclear reactor vessels. In this review, we summarize the current state of ...the literature on methods to model such flows. We focus on a range of Reynolds numbers, covering the inertial regime through the asymptotic turbulent regime. The review emphasizes both numerical modeling and the development of averaged (spatially filtered) balances over representative volumes of media. For modeling the pore scale, we examine the recent literature on Reynolds-averaged Navier-Stokes (RANS) models, large-eddy simulation (LES) models, and direct numerical simulations (DNS). We focus on the role of DNS and discuss how spatially averaged models might be closed using data computed from DNS simulations. A Darcy-Forchheimer-type law is derived, and a prior computation of the permeability and Forchheimer coefficient is presented and compared with existing data.
Western lifestyles differ markedly from those of our hunter-gatherer ancestors, and these differences in diet and activity level are often implicated in the global obesity pandemic. However, few ...physiological data for hunter-gatherer populations are available to test these models of obesity. In this study, we used the doubly-labeled water method to measure total daily energy expenditure (kCal/day) in Hadza hunter-gatherers to test whether foragers expend more energy each day than their Western counterparts. As expected, physical activity level, PAL, was greater among Hadza foragers than among Westerners. Nonetheless, average daily energy expenditure of traditional Hadza foragers was no different than that of Westerners after controlling for body size. The metabolic cost of walking (kcal kg(-1) m(-1)) and resting (kcal kg(-1) s(-1)) were also similar among Hadza and Western groups. The similarity in metabolic rates across a broad range of cultures challenges current models of obesity suggesting that Western lifestyles lead to decreased energy expenditure. We hypothesize that human daily energy expenditure may be an evolved physiological trait largely independent of cultural differences.
We review the evolutionary origins of the human diet and the effects of ecology economy on the dietary proportion of plants and animals. Humans eat more meat than other apes, a consequence of hunting ...and gathering, which arose ∼2.5 Mya with the genus
Homo
. Paleolithic diets likely included a balance of plant and animal foods and would have been remarkably variable across time and space. A plant animal food balance of 50 50% prevails among contemporary warm-climate hunter-gatherers, but these proportions vary widely. Societies in cold climates, and those that depend more on fishing or pastoralism, tend to eat more meat. Warm-climate foragers, and groups that engage in some farming, tend to eat more plants. We present a case study of the wild food diet of the Hadza, a community of hunter-gatherers in northern Tanzania, whose diet is high in fiber, adequate in protein, and remarkably variable over monthly timescales.
Purpose of Review
This review summarizes novel interventions that employ technology to improve HIV pre-exposure prophylaxis (PrEP) availability, uptake, and adherence.
Recent Findings
Several notable ...technology-based programs are increasing access to PrEP in unique ways. We identified multiple models for using telehealth to bolster PrEP dissemination and adherence, such as mobile applications that offer PrEP prescribing without an in-person visit, longitudinal distance telementoring for community provider PrEP education and clinical guidance, and electronic consults for PrEP specialist support in the primary care setting. Outcomes data for all of these modalities are limited but show promise.
Summary
Technology-based interventions can address gaps in the PrEP care continuum. Future research should assess and compare outcomes, scalability
,
cost-effectiveness, and sustainability. Costs associated with the creation of new technological tools slow innovation and the field would benefit from a platform for technology sharing.
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