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Feed- and feed additives-related aspects of gut health and development in weanling pigs

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Journal of Animal Science and Biotechnology 2013年第2期4卷 83-89页

作者： john r Pluske Division of research and Development Murdoch University

The development of new/different management and feeding strategies to stimulate gut development and health in newly-weaned pigs, in order to improve growth performance while minimizing the use of antimicrobial compounds such as antibiotic growth promotants （AGP） and heavy mineral compounds, is essential for the long-term sustainability of the pig industry. Factors including the sub-optimal intake of nutrients and energy, inappropriate microbiota biomass and （or） balance, immature and compromised immune function, and psychosomatic factors caused by weaning can compromise both the efficiency of digestion and absorption and intestinal barrier function through mucosal damage and alteration of tight junction integrity. As a consequence, pigs at weaning are highly susceptible to pathogenic enteric conditions such as post-weaning diarrhea that may be caused by serotypes of enterotoxigenic Escherichia coil Many dietary components, e.g., protein, fiber, feed additives and minerals, are known to influence microbial growth in the gastrointestinal tract that in turn can impact upon pig growth and health, although the relationships between these are sometimes not necessarily apparent or obvious. In a world climate of increased scrutiny over the use of antibiotics per se in pig production, certain feed additives are seen as alternatives/replacements to antibiotics, and have evolved in some cases to have important roles in everyday commercial pig nutrition. Nevertheless and in general, there remains inconsistency and variability in the efficacy of some feed additives and in cases of severe disease outbreaks, for example, therapeutic antibiotics and/or heavy minerals such as zinc oxide （ZnO） are generally relied upon. If feed ingredients and （or） feed additives are to be used with greater regularity and reliability, then it is necessary to better understand the mechanisms whereby antibiotics and minerals such as ZnO influence animal physiology, in conjunction with the use of approp

关键词： Antibiotics Antimicrobials Nutrition Pigs Post-weaning diarrhoea Weaning

Deterministic epidemic models overestimate the basic reproduction number of observed outbreaks

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Infectious Disease Modelling 2024年第3期9卷 680-688页

作者： Wajid Ali Christopher E.Overton robert r.Wilkinson Kieran J.Sharkey Department of Mathematical Sciences University of LiverpoolPeach StreetLiverpoolL697ZXEnglandUnited Kingdom Department of Applied Mathematics Liverpool John Moores UniversityByrom StreetLiverpoolL35UXEnglandUnited Kingdom

The basic reproduction number,r_(0),is a well-known quantifier of epidemic ***,a class of existing methods for estimating r_(0)from incidence data early in the epidemic can lead to an over-estimation of this *** particular,when fitting deterministic models to estimate the rate of spread,we do not account for the stochastic nature of epidemics and that,given the same system,some outbreaks may lead to epidemics and some may ***,an observed epidemic that we wish to control is a major *** amounts to implicit selection for major outbreaks which leads to the over-estimation *** formally characterised the split between major and minor outbreaks by using Otsu's method which provides us with a working *** show that by conditioning a‘deterministic’model on major outbreaks,we can more reliably estimate the basic reproduction number from an observed epidemic trajectory.

关键词： Estimating r_(0) Simple birth-death process Major outbreak Conditioned epidemic Stochastic fade-out

Complementarity of CFD,experimentation and reactor models for solving challenging fluidization problems

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Particuology 2010年第6期8卷 498-500页

作者： john r. Grace Tingwen Li Department of Chemical and Biological Engineering University of British Columbia Vancouver V6T 1Z3 Canada National Energy Technology Laboratory 3610 Collins Ferry Rd Morgantown WV26507 USA

Experimentalists, numerical modellers and reactor modellers need to work together, not only just for validation of numerical codes, but also to shed fundamental light on each other＇s problems and underlying assumptions. Several examples are given, Experimental gas axial dispersion data provide a means of choosing the most appropriate boundary condition （no slip, partial slip or full slip） for particles at the wall of fluidized beds. CFD simulations help to identify how close ＂two-dimensional＂ experimental columns are to being truly two-dimensional and to representing three-dimensional columns. CFD also can be used to provide a more rational means of establishing assumptions needed in the modelling of two-phase fluidized bed reactors, for example how to deal with cases where there is a change in molar flow （and hence volumetric flow） as a result of chemical reactions.

关键词： Fluidization Mixing Computational Fluid dynamics Wall slip reactor modelling Volume change

Falling sperm counts twenty years on： where are we now？

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Asian Journal of Andrology 2013年第2期15卷 204-207,I0006页

作者： r john Aitken Priority research Centre in reproductive Science Discipline of Biological sciences University of Newcastle NSW 2308 Australia

Poor semen quality is an attribute of the human condition that we sharewith our closest primate ancestors and may be part of our evolutionary inheritance. This characteristic may also reflect the lack of selection pressure on male fertility in advanced societies that have gone through the demographic transition. In the future, such trends may be further exacerbated by the widespread use of ArT, which will impair the elimination of low fecundity genotypes from the human gene pool. Environmental pollutants may also be influencing male fertility, however, neither the chemical identity of these factors nor their mechanism-of-action are fully understood.

关键词： TESTICULAr DYSGENESIS SYNDrOME MALE-INFErTILITY rEPrODUCTIVE HEALTH PHTHALATE EXPOSUrE OXIDATIVE STrESS MALE-FErTILITY Y-CHrOMOSOME DNA-DAMAGE DIETHYLSTILBESTrOL COMPETITION

Palm oil biodiesel:An assessment of PAH emissions,oxidative potential and ecotoxicity of particulate matter

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Journal of Environmental Sciences 2021年第3期33卷 326-338页

作者： Silvana Arias Francisco Molina john r.Agudelo Grupo de Investigación en Gestión y Modelación Ambiental-GAIA Escuela AmbientalFacultad de IngenieríaUniversidad de Antioquia UdeACalle 70 No.52-21MedellínColombia Departamento de Ingeniería Mecánica Universidad de Antioquia UdeA

This work assessed the impact of fuelling an automotive engine with palm biodiesel(pure,and two blends of 10%and 20%with diesel,B100,B10 and B20,respectively)operating under representative urban driving conditions on 17 priority polycyclic aromatic hydrocarbon(PAH)compounds,oxidative potential of ascorbic acid(OP^(AA)),and ecotoxicity through D aphnia pulex mortality *** diluted with filtered fresh air(WD)gathered in a minitunel,and particulate matter(PM)collected directly from the exhaust gas stream(W/oD)were used for *** showed that PM collecting method significantly impact PAH *** all PAH appeared in both,WD and W/oD,higher concentrations were obtained in the last *** biodiesel concentration in the fuel blend decreased all PAH compounds,and those with 3 and 5 aromatic rings were the most *** biodiesel affected both OP^(AA)and *** B10 and B20 exhibited the same rate of ascorbic acid(AA)depletion,B100 showed significant faster oxidation rate during the first four minutes and oxidized 10%more AA at the end of the test.B100 and B20 were significantly more ecotoxic than *** lethal concentration LC50 for B10 was 6.13 mg/*** was concluded that palm biodiesel decreased PAH compounds,but increased the oxidative potential and ecotoxicity.

关键词： Biodiesel Particulate matter P emissions Oxidative stress Ecotoxicity Daphnia pulex

role of simple biomarkers in predicting fibrosis progression in HCV infection

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World Journal of Gastroenterology 2010年第45期16卷 5710-5715页

作者： rajasekhara r Mummadi john r Petersen Ned Snyder Division of Gastroenterology and Hepatology Department of Internal MedicineUniversity of Texas Medical BranchHoustonTX 77025United States Department of Pathology University of Texas Medical BranchHoustonTX 77025United States Department of Gastroenterology and Hepatology Kelsey Seybold Clinic2727 W. HolcombeHoustonTX 77025United States

AIM: To examine the accuracy of the aspartate aminotransferase (AST)/Platelet ratio Index (APrI) and FIB-4, in predicting longitudinal changes in liver histology in hepatitis C virus (HCV) ***: Patients that underwent repeat liver biopsies at least 1 year apart from 1999 to 2007 were identified. Liver fibrosis was staged on needle core biopsies evaluated by a single expert liver pathologist. Only laboratory values within 3 mo of the liver biopsies were ***: Thirty-six patients met the inclusion criteria with 50% stage 1 on initial biopsy, 25% stage 2, and 22% stage 3. Nineteen of 36 (53%) had progression of fibrosis on repeat biopsies, while 16 (44%) showed no change in stage, and one (3%) showed improvement. Patients that showed progression of fibrosis had significantly higher alanine aminotransferase and aspartate aminotransferase levels than the group that did not show progression. A significant correlation was seen between change in stage of fibrosis and change in APrI (r2 = 0.39, P = 0.00001) and a change in FIB-4 (r2 = 0.31, P = 0.00004). A change in APrI (ΔAPrI) of 0.18 had 80% positive predictive value (PPV) and 67% nega- tive predictive value (NPV) for progression of fibrosis. A change in FIB-4 (ΔFIB-4) of 0.39 had 75% PPV and 75% NPV for predicting progression of fibrosis. CONCLUSION: ΔAPrI and ΔFIB-4 parallel changes in fibrosis progression, and could be useful tools for clinicians in following patients with active chronic HCV infection.

关键词： Hepatitis C Liver fibrosis Liver biopsy Biomarkers

Carbon dioxide enrichment affected flower numbers transiently and increased successful post-pollination development stably but without altering final acorn production in mature pedunculate oak (Quercus robur L.)

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Journal of Forestry research 2024年第4期35卷 1-12页

作者： ryan McClory richard H.Ellis Martin Lukac Jo Clark Carolina Mayoral Kris M.Hart Andrew r.G.Plackett A.rob MacKenzie School of Agriculture Policy and DevelopmentUniversity of ReadingAgricultureEarley GateWhiteknights RoadPO Box 237Reading RG66EUUK Faculty of Forestry and Wood Sciences Czech University of Life Sciences PraguePrague 165000Czechia Future Trees Trust Harwell Innovation CentreBuilding 173Curie AvenueHarwellOxford OX110QGUK Birmingham Institute of Forest research University of BirminghamEdgbastonBirmingham B152TTUK School of Biosciences University of BirminghamEdgbastonBirmingham B152TTUK School of Geography Earth and Environmental SciencesUniversity of BirminghamEdgbastonBirmingham B152TTUK

Acorn production in oak(Quercus spp.)shows considerable inter-annual variation,known as masting,which provides a natural defence against seed predators but a highly-variable supply of acorns for uses such as in commercial tree planting each *** emissions of greenhouse gases have been very widely reported to influence plant growth and seed or fruit size and quantity via the‘fertilisation effect’that leads to enhanced *** examine if acorn production in mature woodland communities will be affected by further increase in CO_(2),the contents of litter traps from a Free Air Carbon Enrichment(FACE)experiment in deciduous woodland in central England were analysed for numbers of flowers and acorns of pedunculate oak(Quercus robur L.)at different stages of development and their predation levels under ambient and elevated CO_(2) ***-annual variation in acorn numbers was considerable and cyclical between 2015 and 2021,with the greatest numbers of mature acorns in 2015,2017 and 2020 but almost none in *** numbers of flowers,enlarged cups,immature acorns,empty acorn cups,and galls in the litter traps also varied amongst years;comparatively high numbers of enlarged cups were recorded in 2018,suggesting *** at this site is a fruit maturation masting species(i.e.,the extent of abortion of pollinated flowers during acorn development affects mature acorn numbers greatly).raising the atmospheric CO_(2) concentration by 150μL L^(−1),from early 2017,increased the numbers of immature acorns,and all acorn evidence(empty cups+immature acorns+mature acorns)detected in the litter traps compared to ambient controls by 2021,but did not consistently affect the numbers of flowers,enlarged cups,empty cups,or mature *** number of flowers in the elevated CO_(2) plots’litter traps was greater in 2018 than 2017,one year after CO_(2) enrichment began,whereas numbers declined in ambient *** with CO_(2) also increased the number o

关键词： Quercus robur L. Acorns Masting Pedunculate oak Carbon dioxide

Apoptosis and DNA damage in human spermatozoa

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Asian Journal of Andrology 2011年第1期13卷 36-42页

作者： r john Aitken Adam J Koppers ArC Centre of Excellence in Biotechnology and Development Priority Research Centre in Reproductive Science Discipline of Biological Sciences School of Environmental and Life Sciences University of Newcastle Callaghan NSW 2308 Australia Department of Anatomy and Developmental Biology School of Biomedical Sciences Monash University Clayton VIC 3800 Australia

DNA damage is frequently encountered in spermatozoa of subfertile males and is correlated with a range of adverse clinical outcomes including impaired fertilization, disrupted preimplantation embryonic development, increased rates of miscarriage and an enhanced risk of disease in the progeny. The etiology of DNA fragmentation in human spermatozoa is closely correlated with the appearance of oxidative base adducts and evidence of impaired spermiogenesis. We hypothesize that oxidative stress impedes spermiogenesis, resulting in the generation of spermatozoa with poorly remodelled chromatin. These defective cells have a tendency to default to an apeptotic pathway associated with motility loss, caspase activation, phosphatidylserine exteriorization and the activation of free radical generation by the mitochondria. The latter induces lipid peroxidation and oxidative DNA damage, which then leads to DNA fragmentation and cell death. The physical architecture of spermatozoa prevents any nucleases activated as a result of this apoptotic process from gaining access to the nuclear DNA and inducing its fragmentation. It is for this reason that a majority of the DNA damage encountered in human spermatozoa seems to be oxidative. Given the important role that oxidative stress seems to have in the etiology of DNA damage, there should be an important role for antioxidants in the treatment of this condition. If oxidative DNA damage in spermatozoa is providing a sensitive readout of systemic oxidative stress, the implications of these findings could stretch beyond our immediate goal of trying to minimize DNA damage in spermatozoa as a prelude to assisted conception therapy.

关键词： apoptosis DNA damage oxidative stress spermatozoa

Populating digital earth: improving access to Chinese remote sensing data for terrestrial applications

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International Journal of Digital Earth 2014年第12期7卷 952-968页

作者： Mengxue Li john r.Townshend Department of Geographical Sciences University of MarylandCollege ParkMD 20742MarylandUSA

Global change has a significant impact on the lives of *** observation can help to better understand our earth and cope with global *** the availability of more reliable environmental data sets,digital earth is becoming a popular way to monitor the Earth and provide information to researchers and decision makers on environment protection,disaster mitigation,and social ***,accessing data with lowering costs is essential for digital ***,there are big challenges in ensuring the feasibility of access to Chinese remote sensing *** paper outlines some of the main challenges in realizing data sharing,provides an analysis of the core reasons leading to these challenges,and proposes recommendations to overcome the *** the main challenges are differences in data policy to gain access to satellite data,diverse data formats,and delivery *** major challenge for the decision makers is to define a more open policy and for the scientist the challenge is to implement these polices for the benefit of *** paper proposes that governments should adopt policies encouraging more open distribution and access to their data,in order to generate an improved digital earth with increased benefits to human society.

关键词： date policy remote sensing data sharing China