Efficient hydrogen production from the lignocellulosic energy crop Miscanthus by the extreme thermophilic bacteria Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana

Background  

The production of hydrogen from biomass by fermentation is one of the routes that can contribute to a future sustainable hydrogen economy. Lignocellulosic biomass is an attractive feedstock because of its abundance, low production costs and high polysaccharide content.     

Twin peaks: the draft human genome sequence

Once thought to be impossible or a waste of resources, the initial high-volume stages of sequencing the human genome have been completed.     

Aversion learning techniques to evaluate dairy cattle handling practices

Fear of humans is a source of stress for Holstein dairy cattle and can result when animals are handled aversively. We used aversion learning techniques to determine which handling practices cattle find most aversive. In an aversion race, the cows are repeatedly walked down a race and treatments applied when they reached the end; the time and force required for cows to walk down the race are measured. The animal learns to associate walking down the race with the treatment received; if the treatment is aversive, the animal will take more time and require more force to reach the end of the race than if the treatment is positive. In experiment 1, 54 cows were assigned to four treatments (hit/shout, brushing, control, and food). Treatments of 2-min duration were applied three times a day for 4 days. Cows on the hit/shout treatment took more time and required more force to walk through the race than cows on other treatments, while brushed cows took longer to move through the race than cows given food. In experiment 2, 60 cows were assigned to five treatments (electric prod, shouting, hitting, tail twist, and control). Treatments of 1-min duration were applied three times a day for 3 days. Cows on the shout and electric prod treatments took more time and required more force to walk down the race than cows on the control treatment. In experiment 3, thirty-six 1-1.5-year-old heifers were assigned to three treatments (hand feeding, gentling, or control) applied as in experiment 2. Treatments did not affect the time or force required to walk down the race. The aversion race successfully discriminated between handling treatments that differ greatly in aversiveness but lacked sensitivity to distinguish between treatments that were similar. Although many procedural factors must be considered, aversion learning techniques are an effective method to determine which handling practices cattle find aversive or rewarding.     

A genome-wide scan for signatures of directional selection in domesticated pigs

Background

Animal domestication involved drastic phenotypic changes driven by strong artificial selection and also resulted in new populations of breeds, established by humans. This study aims to identify genes that show evidence of recent artificial selection during pig domestication.

Results

Whole-genome resequencing of 30 individual pigs from domesticated breeds, Landrace and Yorkshire, and 10 Asian wild boars at ~16-fold coverage was performed resulting in over 4.3 million SNPs for 19,990 genes. We constructed a comprehensive genome map of directional selection by detecting selective sweeps using an F_ST-based approach that detects directional selection in lineages leading to the domesticated breeds and using a haplotype-based test that detects ongoing selective sweeps within the breeds. We show that candidate genes under selection are significantly enriched for loci implicated in quantitative traits important to pig reproduction and production. The candidate gene with the strongest signals of directional selection belongs to group III of the metabolomics glutamate receptors, known to affect brain functions associated with eating behavior, suggesting that loci under strong selection include loci involved in behaviorial traits in domesticated pigs including tameness.

Conclusions

We show that a significant proportion of selection signatures coincide with loci that were previously inferred to affect phenotypic variation in pigs. We further identify functional enrichment related to behavior, such as signal transduction and neuronal activities, for those targets of selection during domestication in pigs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1330-x) contains supplementary material, which is available to authorized users.     

Heat stress in grapevine: the pros and cons of acclimation

Heat stress is a major limiting factor of grapevine production and quality. Acclimation and recovery are essential to ensure plant survival, and the recovery mechanisms can be independent of the heat response mechanisms. An experimental set up with and without acclimation to heat followed by recovery [stepwise acclimation and recovery (SAR) and stepwise recovery (SR), respectively] was applied to two grapevine varieties, Touriga Nacional (TN), and Trincadeira (TR), with different tolerance to abiotic stress. Major differences were found between leaves of SAR and SR, especially after recovery; in SAR, almost all parameters returned to basal levels while in SR they remained altered. Acclimation led to a swifter and short‐term antioxidative response, affecting the plant to a lesser extent than SR. Significant differences were found among varieties: upon stress, TN significantly increased ascorbate and glutathione reduction levels, boosting the cell's redox‐buffering capacity, while TR needed to synthesize both metabolites, its response being insufficient to keep the redox state at working levels. TR was affected by stress for a longer period and the up‐regulation pattern of antioxidative stress genes was more obvious. In TN, heat shock proteins were significantly induced, but the canonical heat‐stress gene signature was not evident probably because no shutdown of the housekeeping metabolism was needed.     

Aflatoxin contamination of rice in the United Arab Emirates

Many people in the United Arab Emirates store rice in large quantities for long periods of time before use. Five hundred samples of rice were collected from households in Al-Ain city during the summers of 1992-1994. Aflatoxin B₁ was detected in 160 samples (64%) of long grain rice and 81 Samples (32%) of short grain rice at levels ranging from 1.2 to 16.5 μg/kg. The moisture content of samples varied between 5.7% and 15.3%. Species ofAspergillus andPenicillium (includingA. flavus andA. parasiticus) were isolated from discoloured, broken and insect damaged grain and it was confirmed that at least two of the isolates ofA. flavus were aflatoxigenic. These findings demonstrate that rice may contribute to dietary exposure to aflatoxins which are known to be carcinogenic and immunosuppressive.