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To sustainably contribute to food security of a growing and richer world population, livestock production systems are challenged to increase production levels while reducing environmental impact, being economically viable, and socially responsible. Knowledge about the sustainability performance of current livestock production systems may help to formulate strategies for future systems. Our study provides a systematic overview of differences between conventional and organic livestock production systems on a broad range of sustainability aspects and animal species available in peer-reviewed literature. Systems were compared on economy, productivity, environmental impact, animal welfare and public health. The review was limited to dairy cattle, beef cattle, pigs, broilers and laying hens, and to Europe, North America and New Zealand. Results per indicators are presented as in the articles without performing additional calculations. Out of 4171 initial search hits, 179 articles were analysed. Studies varied widely in indicators, research design, sample size and location and context. Quite some studies used small samples. No study analysed all aspects of sustainability simultaneously. Conventional systems had lower labour requirements per unit product, lower income risk per animal, higher production per animal per time unit, higher reproduction numbers, lower feed conversion ratio, lower land use, generally lower acidification and eutrophication potential per unit product, equal or better udder health for cows and equal or lower microbiological contamination. Organic systems had higher income per animal or full time employee, lower impact on biodiversity, lower eutrophication and acidification potential per unit land, equal or lower likelihood of antibiotic resistance in bacteria and higher beneficial fatty acid levels in cow milk. For most sustainability aspects, sometimes conventional and sometimes organic systems performed better, except for productivity, which was consistently higher in conventional systems. For many aspects and animal species, more data are needed to conclude on a difference between organic and conventional livestock production systems.
Climate change is a growing international concern, and it is well established that the release of greenhouse gases (GHG) is a contributing factor. So far, within animal production, there is little or no concerted effort on long-term breeding strategies to mitigate against GHG from ruminants. In recent years, several consortia have been formed to collect and combine data for genetic evaluation. The discussion areas of these consortia focus on (1) What are methane-determining factors, (2) What are genetic parameters for methane emissions, (3) What proxies can be used, and what is their association with methane emission, and (4) How to move on with breeding for lower emitting animals? The methane-determining factors can be divided into four groups: (1) rumen microbial population, (2) feed intake and diet composition, (3) host physiology and (4) host genetics. The genetic parameters show that enteric methane is a heritable trait, and that it is highly genetically correlated with dry matter intake. So far, the most useful proxies relate to feed intake, milk mid IR spectral data and fatty acids in the milk. To be able to move on with a genetic evaluation and ranking of animals for methane emission, it is crucial to make measurements on commercial farms. In order to make that possible, it will be necessary to develop phenotypes that can be used by the farmer to optimise the production on farm level. Also, it is crucial to develop equipment that makes it possible to make measurements without interfering with everyday routines or identify proxies that are highly related to methane and which could easily be measured on a large scale. International collaboration is essential to make progress in this area. This is both in terms of sharing ideas, experiences and phenotypes, but also in terms of coming to a consensus regarding what phenotype to collect and to select for.
This study compares vanadium oxide catalysts from three different sources: Noakes (N), Harshaw Chemical (H) and Kh. Arslanov at the St. Petersburg State University, Russia (R). The catalysts are used to convert acetylene to benzene in the last step of benzene synthesis. The organic purity of benzene in all three catalysts is high; 99.91–99.93% for (N) and (H) and 99.87% for (R). The benzene yields range from 90.0 to 94.3%. (N) averaged 92.6%, (H) averaged 91.1% and (R) averaged 92.0%. A conversion residue in the catalysts was analyzed for δ13C and found to be isotopically lighter relative to acetylene by −2.2% for (N) and (H) and −3.9% for (R). Benzene yields were studied on different reconditioning methods applied to all catalysts: heating to 400° in air averaged 92.3%; the same temperature with a half and half mixture of O2 and Ar averaged 91.9%, adding a half and half mixture of H2 and Ar at 200° to the end of this treatment averaged 91.8%. Based on this research, the obvious difference seen between the catalysts is in their trace by-products.
From 1966 to 1979, the University of Missouri, the University of Arizona, and the Illinois State Museum conducted extensive interdisciplinary investigations of Late Pleistocene peat deposits associated with springs, some extinct, in the Pomme de Terre River Valley of the Ozark Highland, Missouri (fig 1). Most of the sites are now beneath the waters of the Harry S Truman reservoir. Archaeologic investigations in the area produced a remarkably long sequence of cultural change and development during the Holocene but produced no evidence of human presence in the area prior to 11,000 years ago despite diligent excavation of favorable bone-bearing deposits.
In August 2013, a nationwide vaccination campaign with bivalent oral polio vaccine (bOPV) was initiated after isolation of wild-type poliovirus type 1 (WPV-1) in routine sewage surveillance in Israel. The campaign started in the Southern district and later extended to the entire country. This study examined the association between socioeconomic status (SES), and compliance with bOPV vaccine during the campaign. Nationwide data relating to SES by geographical cluster were correlated with vaccine coverage rates in the same areas. All analyses were conducted separately for Jews and Arabs. Coverage with the bOPV vaccination campaign in the Arab population (92·4%) was higher than in the Jewish population (59·2%). This difference was consistently present in all SES clusters. In the Jewish population there was an inverse correlation between SES and vaccination coverage rates (R = −0·93, P < 0·001). Lower vaccination coverage with supplemental vaccine activities in higher SES groups is a challenge that needs to be addressed in future public health events and emergencies in order to achieve satisfactory protection rates for the public.
Measuring and mitigating methane (CH4) emissions from livestock is of increasing importance for the environment and for policy making. Potentially, the most sustainable way of reducing enteric CH4 emission from ruminants is through the estimation of genomic breeding values to facilitate genetic selection. There is potential for adopting genetic selection and in the future genomic selection, for reduced CH4 emissions from ruminants. From this review it has been observed that both CH4 emissions and production (g/day) are a heritable and repeatable trait. CH4 emissions are strongly related to feed intake both in the short term (minutes to several hours) and over the medium term (days). When measured over the medium term, CH4 yield (MY, g CH4/kg dry matter intake) is a heritable and repeatable trait albeit with less genetic variation than for CH4 emissions. CH4 emissions of individual animals are moderately repeatable across diets, and across feeding levels, when measured in respiration chambers. Repeatability is lower when short term measurements are used, possibly due to variation in time and amount of feed ingested prior to the measurement. However, while repeated measurements add value; it is preferable the measures be separated by at least 3 to 14 days. This temporal separation of measurements needs to be investigated further. Given the above issue can be resolved, short term (over minutes to hours) measurements of CH4 emissions show promise, especially on systems where animals are fed ad libitum and frequency of meals is high. However, we believe that for short-term measurements to be useful for genetic evaluation, a number (between 3 and 20) of measurements will be required over an extended period of time (weeks to months). There are opportunities for using short-term measurements in standardised feeding situations such as breath ‘sniffers’ attached to milking parlours or total mixed ration feeding bins, to measure CH4. Genomic selection has the potential to reduce both CH4 emissions and MY, but measurements on thousands of individuals will be required. This includes the need for combined resources across countries in an international effort, emphasising the need to acknowledge the impact of animal and production systems on measurement of the CH4 trait during design of experiments.
We developed two dose–response algorithms for P. aeruginosa pool folliculitis using bacterial and lesion density estimates, associated with undetectable, significant, and almost certain folliculitis. Literature data were fitted to Furumoto & Mickey's equations, developed for plant epidermis-invading pathogens: Nl = A ln(1 + BC) (log-linear model); Pinf = 1−e(−rcC) (exponential model), where A and B are 2.51644 × 107 lesions/m2 and 2.28011 × 10−11 c.f.u./ml P. aeruginosa, respectively; C = pathogen density (c.f.u./ml), Nl = folliculitis lesions/m2, Pinf = probability of infection, and rC = 4·3 × 10−7 c.f.u./ml P. aeruginosa. Outbreak data indicates these algorithms apply to exposure durations of 41 ± 25 min. Typical water quality benchmarks (≈10−2 c.f.u./ml) appear conservative but still useful as the literature indicated repeated detection likely implies unstable control barriers and bacterial bloom potential. In future, culture-based outbreak testing should be supplemented with quantitative polymerase chain reaction and organic carbon assays, and quantification of folliculitis aetiology to better understand P. aeruginosa risks.
The future evolution of energy supply technologies strongly depends on (and affects) the
economic and environmental systems, due to the high dependency of this sector on the
availability and cost of fossil fuels, especially on the small regional scale. This paper
aims at presenting the modeling system and preliminary results of a research project
conducted on the scale of Luxembourg to assess the environmental impact of future energy
scenarios for the country, integrating outputs from partial and computable general
equilibrium models within hybrid Life Cycle Assessment (LCA) frameworks. The general
equilibrium model for Luxembourg, LUXGEM, is used to evaluate the economic impacts of
policy decisions and other economic shocks over the time horizon 2006−2030. A techno-economic (partial
equilibrium) model for Luxembourg, ETEM, is used instead to compute operation levels of
various technologies to meet the demand for energy services at the least cost along the
same timeline. The future energy demand and supply are made consistent by coupling ETEM
with LUXGEM so as to have the same macro-economic variables and energy shares driving both
models. The coupling results are then implemented within a set of Environmentally-Extended
Input-Output (EE-IO) models in historical time series to test the feasibility of the
integrated framework and then to assess the environmental impacts of the country.
Accordingly, a disaggregated energy sector was built with the different ETEM technologies
in the EE-IO to allow hybridization with Life Cycle Inventory (LCI) and enrich the process
detail. The results show that the environmental impact slightly decreased overall from
2006 to 2009. Most of the impacts come from some imported commodities (natural gas, used
to produce electricity, and metalliferous ores and metal scrap). The main energy
production technology is the combined-cycle gas turbine plant “Twinerg”, representing
almost 80% of the domestic electricity production in Luxembourg. In the hybrid EE-IO
model, this technology contributes to around 7% of the total impact of the country’s net
consumption. The causes of divergence between ETEM and LUXGEM are also thoroughly
investigated to outline possible strategies of modeling improvements for future assessment
of environmental impacts using EE-IO. Further analyses focus first on the completion of
the models’ coupling and its application to the defined scenarios. Once the coupling is
consistently accomplished, LUXGEM can compute the IO flows from 2010 to 2030, while the
LCI processes in the hybrid system are harmonized with ETEM to represent the future
domestic and imported energy technologies.
Pseudomonas aeruginosa is the opportunistic pathogen mostly implicated in folliculitis and acute otitis externa in pools and hot tubs. Nevertheless, infection risks remain poorly quantified. This paper reviews disease aetiologies and bacterial skin colonization science to advance dose-response theory development. Three model forms are identified for predicting disease likelihood from pathogen density. Two are based on Furumoto & Mickey's exponential ‘single-hit’ model and predict infection likelihood and severity (lesions/m2), respectively. ‘Third-generation’, mechanistic, dose-response algorithm development is additionally scoped. The proposed formulation integrates dispersion, epidermal interaction, and follicle invasion. The review also details uncertainties needing consideration which pertain to water quality, outbreaks, exposure time, infection sites, biofilms, cerumen, environmental factors (e.g. skin saturation, hydrodynamics), and whether P. aeruginosa is endogenous or exogenous. The review's findings are used to propose a conceptual infection model and identify research priorities including pool dose-response modelling, epidermis ecology and infection likelihood-based hygiene management.
Feed is a major component of variable costs associated with dairy systems and is therefore an important consideration for breeding objectives. As a result, measures of feed efficiency are becoming popular traits for genetic analyses. Already, several countries account for feed efficiency in their breeding objectives by approximating the amount of energy required for milk production, maintenance, etc. However, variation in actual feed intake is currently not captured in dairy selection objectives, although this could be possible by evaluating traits such as residual feed intake (RFI), defined as the difference between actual and predicted feed (or energy) intake. As feed intake is expensive to accurately measure on large numbers of cows, phenotypes derived from it are obvious candidates for genomic selection provided that: (1) the trait is heritable; (2) the reliability of genomic predictions are acceptable to those using the breeding values; and (3) if breeding values are estimated for heifers, rather than cows then the heifer and cow traits need to be correlated. The accuracy of genomic prediction of dry matter intake (DMI) and RFI has been estimated to be around 0.4 in beef and dairy cattle studies. There are opportunities to increase the accuracy of prediction, for example, pooling data from three research herds (in Australia and Europe) has been shown to increase the accuracy of genomic prediction of DMI from 0.33 within country to 0.35 using a three-country reference population. Before including RFI as a selection objective, genetic correlations with other traits need to be estimated. Weak unfavourable genetic correlations between RFI and fertility have been published. This could be because RFI is mathematically similar to the calculation of energy balance and failure to account for mobilisation of body reserves correctly may result in selection for a trait that is similar to selecting for reduced (or negative) energy balance. So, if RFI is to become a selection objective, then including it in an overall multi-trait selection index where the breeding objective is net profit is sensible, as this would allow genetic correlations with other traits to be properly accounted for. If genetic parameters are accurately estimated then RFI is a logical breeding objective. If there is uncertainty in these, then DMI may be preferable.
Our previous work suggests that stressors that impact placental vascular growth result in a deformed chorionic surface shape, which reflects an abnormal placental three-dimensional shape. We propose to use variability of placental disk thickness as a reflector of deviations in placental vascular growth at the finer level of the fetal stems. We hypothesize that increased variability of thickness is associated with abnormal chorionic surface shape, but will be a predictor of reduced placental functional efficiency (smaller baby for a given placental weight) independent of shape. These measures may shed light on the mechanisms linking placental growth to risk of adult disease. The sample was drawn from the Pregnancy, Infection and Nutrition Study. In all, 94.6% of the cohort consented to placental examination. Of the 1023 delivered at term, those previously sectioned by the Pathology Department were excluded, leaving 587 (57%) cases with intact placentas that were sliced and photographed. The chorionic surface shape and the shape of a central randomly oriented placental slice were analyzed and measures were compared using correlation. Lower mean placental disk thickness and more variable disk thickness were each strongly and significantly correlated with deformed chorionic plate shapes. More variable disk thickness was strongly correlated with reduced placental efficiency independent of abnormal chorionic surface shape. Variability of placental disk thickness, simple to measure in a single randomly oriented central slice, may be an easily acquired measure that is an independent indicator of lowered placental efficiency, which may in turn program the infant and result in increased risk for development of adult diseases.
Thin films of indium oxide, In2O3 (4000 Å), deposited on commercially available In2O3: Sn (ITO)/glass by rf sputtering, have been examined for potential application as a counter-electrode material in an electrochromic device, based on their chemical, structural, and optical properties. Cyclic voltammetry experiments showed that mobile lithium ions can be inserted (chemical reduction) and removed (chemical oxidation) from the host structure of indium oxide. Coulometric titrations showed that the films exhibited a hysteresis behavior for the injection and removal of lithium ions in LixIn2O3 (x=0-0.23). Structural investigation of the indium oxide films, utilizing electron diffraction techniques, indicated that they were crystalline with a crystallite size of 175 Å, in agreement with x-ray diffraction results. Differences in optical transmission between the lithiated and delithiated thin films were no more than 5% in the visible/near-infrared regions of the spectrum.