111 research outputs found
A five-stage treatment train for water recovery from urine and shower water for long-term human Space missions
Long-term human Space missions will rely on regenerative life support as resupply of water, oxygen and food comes with constraints. The International Space Station (ISS) relies on an evaporation/condensation system to recover 74-85% of the water in urine, yet suffers from repetitive scaling and biofouling while employing hazardous chemicals. In this study, an alternative non-sanitary five-stage treatment train for one "astronaut" was integrated through a sophisticated monitoring and control system. This so-called Water Treatment Unit Breadboard (WTUB) successfully treated urine (1.2-L-d with crystallisation, COD-removal, ammonification, nitrification and electrodialysis, before it was mixed with shower water (3.4-L-d(-1)). Subsequently, ceramic nanofiltration and single-pass flat-sheet RO were used. A four-months proof-of-concept period yielded: (i) chemical water quality meeting the hygienic standards of the European Space Agency, (ii) a 87- +/- -5% permeate recovery with an estimated theoretical primary energy requirement of 0.2-kWh p -L-1, (iii) reduced scaling potential without anti-scalant addition and (iv) and a significant biological reduction in biofouling potential resulted in stable but biofouling-limited RO permeability of 0.5 L-m(-2)-h(-1)-bar(-1). Estimated mass breakeven dates and a comparison with the ISS Water Recovery System for a hypothetical Mars transit mission show that WTUB is a promising biological membrane-based alternative to heat-based systems for manned Space missions
Detailed dimethylacetal and fatty acid composition of rumen content from lambs fed lucerne or concentrate supplemented with soybean oil
Articles in International JournalsLipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary
fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and
fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or
concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/
acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal,
oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid
composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain
dimethylacetals were mostly affected by basal diet. The presence of 18:1 dimethylacetals indicates that biohydrogenation
intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were
identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing
18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being
biohydrogenation intermediates of 18:2n26 and 18:3n23. Additionally, three oxo- fatty acids were identified in rumen
samples, and 16-O-18:0 might be produced during biohydrogenation of the 18:3n23
Early alterations in the MCH system link aberrant neuronal activity and sleep disturbances in a mouse model of Alzheimer’s disease
Early Alzheimer’s disease (AD) is associated with hippocampal hyperactivity and decreased sleep quality. Here we show that homeostatic mechanisms transiently counteract the increased excitatory drive to CA1 neurons in App NL-G-F mice, but that this mechanism fails in older mice. Spatial transcriptomics analysis identifies Pmch as part of the adaptive response in App NL-G-F mice. Pmch encodes melanin-concentrating hormone (MCH), which is produced in sleep–active lateral hypothalamic neurons that project to CA1 and modulate memory. We show that MCH downregulates synaptic transmission, modulates firing rate homeostasis in hippocampal neurons and reverses the increased excitatory drive to CA1 neurons in App NL-G-F mice. App NL-G-F mice spend less time in rapid eye movement (REM) sleep. App NL-G-F mice and individuals with AD show progressive changes in morphology of CA1-projecting MCH axons. Our findings identify the MCH system as vulnerable in early AD and suggest that impaired MCH-system function contributes to aberrant excitatory drive and sleep defects, which can compromise hippocampus-dependent functions
Open Access to Research Data: Strategic Delay and the Ambiguous Welfare Effects of Mandatory Data Disclosure
Purple non‐sulphur bacteria and plant production: benefits for fertilization, stress resistance and the environment
Purple non-sulphur bacteria (PNSB) are phototrophic microorganisms, which increasingly gain attention in plant production due to their ability to produce and accumulate high-value compounds that are benefi- cial for plant growth. Remarkable features of PNSB include the accumulation of polyphosphate, the pro- duction of pigments and vitamins and the production of plant growth-promoting substances (PGPSs). Scattered case studies on the application of PNSB for plant cultivation have been reported for decades, yet a comprehensive overview is lacking. This review highlights the potential of using PNSB in plant pro- duction, with emphasis on three key performanceindicators (KPIs): fertilization, resistance to stress (biotic and abiotic) and environmental benefits. PNSB have the potential to enhance plant growth performance, increase the yield and quality of edible plant biomass, boost the resistance to environmental stresses, bioremediate heavy metals and mitigate greenhouse gas emissions. Here, the mechanisms responsible for these attributes are discussed. A dis- tinction is made between the use of living and dead PNSB cells, where critical interpretation of existing literature revealed the better performance of living cells. Finally, this review presents research gaps that remain yet to be elucidated and proposes a roadmap for future research and implementation paving the way for a more sustainable crop production
Composição do leite de vacas alimentadas com diferentes fontes de compostos nitrogenados
Adding palm oil to the diet of sheep alters fatty acids profile on yogurt: Benefits to consumers
Invited review: Large-scale indirect measurements for enteric methane emissions in dairy cattle: A review of proxies and their potential for use in management and breeding decisions
Publication history: Accepted - 7 December 2016; Published online - 1 February 2017.Efforts to reduce the carbon footprint of milk production through selection and management of low-emitting
cows require accurate and large-scale measurements of
methane (CH4) emissions from individual cows. Several
techniques have been developed to measure CH4 in a research setting but most are not suitable for large-scale
recording on farm. Several groups have explored proxies (i.e., indicators or indirect traits) for CH4; ideally
these should be accurate, inexpensive, and amenable
to being recorded individually on a large scale. This
review (1) systematically describes the biological basis
of current potential CH4 proxies for dairy cattle; (2)
assesses the accuracy and predictive power of single
proxies and determines the added value of combining
proxies; (3) provides a critical evaluation of the relative
merit of the main proxies in terms of their simplicity,
cost, accuracy, invasiveness, and throughput; and (4)
discusses their suitability as selection traits. The proxies range from simple and low-cost measurements such
as body weight and high-throughput milk mid-infrared
spectroscopy (MIR) to more challenging measures such
as rumen morphology, rumen metabolites, or microbiome profiling. Proxies based on rumen samples are generally poor to moderately accurate predictors of CH4,
and are costly and difficult to measure routinely onfarm. Proxies related to body weight or milk yield and
composition, on the other hand, are relatively simple,
inexpensive, and high throughput, and are easier to
implement in practice. In particular, milk MIR, along
with covariates such as lactation stage, are a promising
option for prediction of CH4 emission in dairy cows.
No single proxy was found to accurately predict CH4,
and combinations of 2 or more proxies are likely to be
a better solution. Combining proxies can increase the
accuracy of predictions by 15 to 35%, mainly because
different proxies describe independent sources of variation in CH4 and one proxy can correct for shortcomings
in the other(s). The most important applications of
CH4 proxies are in dairy cattle management and breeding for lower environmental impact. When breeding for
traits of lower environmental impact, single or multiple
proxies can be used as indirect criteria for the breeding
objective, but care should be taken to avoid unfavorable correlated responses. Finally, although combinations of proxies appear to provide the most accurate
estimates of CH4, the greatest limitation today is the
lack of robustness in their general applicability. Future
efforts should therefore be directed toward developing
combinations of proxies that are robust and applicable
across diverse production systems and environments.Technical and financial support from the COST Action FA1302 of the European Union
- …