128 research outputs found

    Livestock as Sources of Greenhouse Gases and Its Significance to Climate Change

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    This chapter outlines the role of livestock in the production of greenhouse gases (GHGs) that contributes to climate change. Livestock contribute both directly and indirectly to climate change through the emissions of GHGs such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). As animal production systems are vulnerable to climate change and are large contributors to potential global warming, it is vital to understand in detail enteric CH4 emission and manure management in different livestock species. Methane emissions from livestock are estimated to be approximately 2.2 billion tonnes of CO2 equivalents, accounting for about 80% of agricultural CH4 and 35% of the total anthropogenic CH4 emissions. Furthermore, the global livestock sector contributes about 75% of the agricultural N2O emissions. Other sources of GHG emission from livestock and related activities are fossil fuels used for associated farm activities, N2O emissions from fertilizer use, CH4 release from the breakdown of fertilizers and from animal manure, and land-use changes for feed production. There are several techniques available to quantify CH4 emission, and simulation models offer a scope to predict accurately the GHG emission from a livestock enterprise as a whole. Quantifying GHG emission from livestock may pave the way for understanding the role of livestock to climate change and this will help in designing appropriate mitigation strategies to reduce livestock-related GHGs

    The Impact of Heat Load on Cattle

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    Heat stress and cold stress have a negative influence on cattle welfare and productivity. There have been some studies investigating the influence of cold stress on cattle, however the emphasis within this review is the influence of heat stress on cattle. The impact of hot weather on cattle is of increasing importance due to the changing global environment. Heat stress is a worldwide phenomenon that is associated with reduced animal productivity and welfare, particularly during the summer months. Animal responses to their thermal environment are extremely varied, however, it is clear that the thermal environment influences the health, productivity, and welfare of cattle. Whilst knowledge continues to be developed, managing livestock to reduce the negative impact of hot climatic conditions remains somewhat challenging. This review provides an overview of the impact of heat stress on production and reproduction in bovines

    Effect of multiple environmental stressors on the adaptive capability of Malpura rams based on physiological responses in a semi-arid tropical environment

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    A 45-day study was conducted where the primary objective was to evaluate the effect of simultaneously imposed multiple stressors (thermal, nutritional, and walking) on the adaptive capability of Malpura rams based on changes in ingestive behavior, physiological, blood biochemical, and endocrine responses. Twenty adult Malpura rams (average body weight 44.9\ua0kg) were used in the study. The rams were divided into 2 groups, CON (n\ua0= 10; control) and multiple stressors (MS; n\ua0= 10; multiple stressors). All of the rams were stall fed with a diet consisting of 70% roughage and 30% concentrate. The CON rams were maintained in a shed under ambient conditions with ad libitum feeding without walking, whereas MS rams were subjected to multiple stressors (thermal, nutritional, and walking). The feed intake (P < 0.01) was lower and water intake (P < 0.01) was higher in MS compared to CON rams. Among the physiological measurements, respiration rate afternoon (P < 0.01), pulse rate morning (P < 0.01), rectal temperature afternoon (P < 0.01), skin temperature afternoon (P < 0.05), and both morning and afternoon scrotum temperature (P < 0.01) increased significantly in MS rams. Both hemoglobin (P < 0.05), packed cell volume (P < 0.01), increased and plasma glucose (P < 0.01) reduced significantly (P < 0.01) in MS as compared to CON rams. Among the endocrine parameters, the plasma cortisol increased and plasma thyroxin reduced significantly (P < 0.05) in MS rams. The study indicates that Malpura rams have the capability to adjust their physio-biochemical and endocrine responses to cope with multiple stressors in a hot semi-arid environment. Furthermore, the study also indicated that respiration rate, rectal temperature, scrotal temperature, hemoglobin, packed cell volume, and cortisol may act as ideal biological markers for quantifying the impact of multiple stressors in Malpura rams

    Is the contemporary care of the older persons with acute coronary syndrome evidence-based?

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    Globally, ischaemic heart disease is the leading cause of death, with a higher mortality burden amongst older adults. Although advancing age is associated with a higher risk of adverse outcomes following acute coronary syndrome (ACS), older patients are less likely to receive evidence-based medications and coronary angiography. Guideline recommendations for managing ACS are often based on studies that exclude older patients, and more contemporary trials have been underpowered and produced inconsistent findings. There is also limited evidence for how frailty and comorbidity should influence management decisions. This review focuses on the current evidence base for the medical and percutaneous management of ACS in older patients and highlights the distinct need to enrol older patients with ACS into well-powered, large-scale randomized trials

    The effect of hydrogen dilution on the structure of a-C : H

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    Two a-C:H samples were prepared using a fast-atom deposition system from acetylene and an acetylene/hydrogen gas mixture. Their structure was investigated using neutron and x-ny diffraction and infrared spectroscopy measurements. Compositional analysis shows that a 1:1 C2H2:H-2 mixture results in a change from a-C-77:H-23 to a-C-79:H-21, i.e. has a very small effect on the composition. The diffraction data also show that the addition of hydrogen to the precursor gas has no significant effect on the average bond distances and angles but shows a small change in the H-C-H and C-C-H correlations between the two samples. However, the infrared data show that there are significant changes in the bonding of hydrogen within the sample-changes which do not affect the average network structure. We observe a decrease in the amount of sp(3) CH2 and CH3 groups, and an increase in the fraction of sp(2) and sp(3) CH groups, with the formation of a second sp(2) CH bonding environment in the hydrogen-diluted sample. Therefore, in addition to providing useful structural information on these a-C:H samples, this set of experiments illustrates very well the complementary nature of the data from diffraction and spectroscopic techniques

    Nucleon-Nucleon Interaction: A Typical/Concise Review

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    Nearly a recent century of work is divided to Nucleon-Nucleon (NN) interaction issue. We review some overall perspectives of NN interaction with a brief discussion about deuteron, general structure and symmetries of NN Lagrangian as well as equations of motion and solutions. Meanwhile, the main NN interaction models, as frameworks to build NN potentials, are reviewed concisely. We try to include and study almost all well-known potentials in a similar way, discuss more on various commonly used plain forms for two-nucleon interaction with an emphasis on the phenomenological and meson-exchange potentials as well as the constituent-quark potentials and new ones based on chiral effective field theory and working in coordinate-space mostly. The potentials are constructed in a way that fit NN scattering data, phase shifts, and are also compared in this way usually. An extra goal of this study is to start comparing various potentials forms in a unified manner. So, we also comment on the advantages and disadvantages of the models and potentials partly with reference to some relevant works and probable future studies.Comment: 85 pages, 5 figures, than the previous v3 edition, minor changes, and typos fixe

    A spectroscopic study of the structure of amorphous hydrogenated carbon

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    A range of amorphous hydrogenated carbon (a-C:H) samples have been studied using inelastic neutron spectroscopy (INS) and Fourier transform infrared (FTIR) spectroscopy. Using these complementary techniques, the bonding environments of both carbon and hydrogen can be probed in some detail, with the INS data providing not only qualitative but also quantitative information. By comparing the data from each of the samples we have been able to examine the effects of different deposition conditions, i.e. precursor gas, deposition energy and deposition method, on the atomic-scale structure of a-C:H

    Identification of hypertensive patients with dominant affective temperaments might improve the psychopathological and cardiovascular risk stratification: a pilot, case-control study.

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    BACKGROUND: Although mood disorders and cardiovascular diseases have widely studied psychosomatic connections, data concerning the influence of the psychopathologically important affective temperaments in hypertension are scarce. To define a possibly higher cardiovascular risk subpopulation we investigated in well-treated hypertensive patients with dominant affective temperaments (DOM) and in well-treated hypertensive patients without dominant temperaments the level of depression and anxiety, arterial stiffness and serum Brain-derived Neurotrophic Factor (seBDNF). METHODS: 175 hypertensive patients, free of the history of psychiatric diseases, completed the TEMPS-A, Beck Depression Inventory and Hamilton Anxiety Scale questionnaires in two primary care practices. Of those 175 patients, 24 DOM patients and 24 hypertensive controls (matched in age, sex and the presence of diabetes) were selected for measurements of arterial stiffness and seBDNF level. RESULTS: Beck and Hamilton scores in DOM patients were higher compared with controls. Pulse wave velocity and augmentation index did not differ between the groups while in the DOM patients decreased brachial systolic and diastolic and central diastolic blood pressures were found compared with controls. SeBDNF was lower in the DOM group than in the controls (22.4 +/- 7.2 vs. 27.3 +/- 7.8 ng/mL, p < 0.05). CONCLUSIONS: Although similar arterial stiffness parameters were found in DOM patients, their increased depression and anxiety scores, the decreased brachial and central diastolic blood pressures as well as the decreased seBDNF might refer to their higher vulnerability regarding the development not only of major mood disorders, but also of cardiovascular complications. These data suggest that the evaluation of affective temperaments should get more attention both with regard to psychopathology and cardiovascular health management

    Species Discrimination, Population Structure and Linkage Disequilibrium in Eucalyptus camaldulensis and Eucalyptus tereticornis Using SSR Markers

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    Eucalyptus camaldulensis and E. tereticornis are closely related species commonly cultivated for pulp wood in many tropical countries including India. Understanding the genetic structure and linkage disequilibrium (LD) existing in these species is essential for the improvement of industrially important traits. Our goal was to evaluate the use of simple sequence repeat (SSR) loci for species discrimination, population structure and LD analysis in these species. Investigations were carried out with the most common alleles in 93 accessions belonging to these two species using 62 SSR markers through cross amplification. The polymorphic information content (PIC) ranged from 0.44 to 0.93 and 0.36 to 0.93 in E. camaldulensis and E. tereticornis respectively. A clear delineation between the two species was evident based on the analysis of population structure and species-specific alleles. Significant genotypic LD was found in E. camaldulensis, wherein out of 135 significant pairs, 17 pairs showed r2≥0.1. Similarly, in E. tereticornis, out of 136 significant pairs, 18 pairs showed r2≥0.1. The extent of LD decayed rapidly showing the significance of association analyses in eucalypts with higher resolution markers. The availability of whole genome sequence for E. grandis and the synteny and co-linearity in the genome of eucalypts, will allow genome-wide genotyping using microsatellites or single nucleotide polymorphims
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