Protease activity and the ultrastructure of broiler chicken PSE (pale,soft, exudative) meat

The biological cause of broiler PSE meat seems to be an excessive release of Ca²⁺, promoted by a genetic mutation of ryanodine receptors located in the sarcoplasmic reticulum of skeletal muscle cells. Excessive Ca²⁺, associated with protein denaturation in meat, enhances protease activity and influences the functional properties of PSE meat. Twenty-four-hour post-mortemPectoralis major m. samples exhibited lower values for pH, water-holding capacity, and shear force than did control samples, in contrast to colour (L∗) and cooking loss values. Protease activity, measured as myofibril fragmentation index, presented higher values in PSE meat than in control samples. Ultrastructural examination revealed shrinking and depolymerisation of myofilaments and Z-lines disorganisation within the sarcomere in PSE meat. Intense calpain activity was also observed, indicating that the process may initiate at the filaments, because of protein denaturation, and spread through Z-lines, resulting in the collapse of the sarcomere structure.     

Global gene expression profiling in larval zebrafish exposed to microcystin-LR and microcystis reveals endocrine disrupting effects of Cyanobacteria

Microcystis blooms occur worldwide and threaten aquatic ecosystems and human health. Sublethal effects on early developmental stages of fish are largely unknown, and research has mainly focused on microcystin toxins (such as MC-LR) rather than Microcystis cells. We exposed (96 h) zebrafish larvae to purified MC-LR (0-1000 μg/L) or lyophilized Microcystis aeruginosa containing 4.5 μg/L MC-LR and evaluated changes in global gene expression (Affymetrix GeneChip zebrafish genome arrays). Significant changes in gene expression (≥ 1.7-fold change, p < 0.0001) were determined with Rosetta Resolver 7.0, and ontology analysis was conducted with the DAVID bioinformatics tool. The number of differentially expressed genes relative to control increased with MC-LR concentration and included genes related to known mechanisms of action for MC-LR in mammals and older life stages of fish, as well as genes unique to larval zebrafish. Up-regulation of vitellogenin genes (vtg) (19.2-fold to >100-fold on arrays; 619.3-fold confirmed by quantitative PCR) was observed in Microcystis-exposed larvae but not in larvae exposed to MC-LR. Up-regulation of vtg indicates exposure to estrogenic substance(s) and suggests that Microcystis may be a natural source of environmental estrogens. Concerns about effects of Microcystis blooms may extend beyond those associated with the microcystin toxin.     

Methods for producing high-purity calcium

The techniques used in the United States for producing calcium metal are described. The methods and attempts to produce high-purity calcium from the crude calcium prepared by the current processes are discussed. A vaporization technique for the distillation of crude calcium is described in detail, and a fractional distillation technique for preparing special high-purity calcium is reported.     

Perspectives on pasture versus indoor feeding of dairy cows

The dairy industry in many regions of the world has moved towards a high‐input/high‐output system maximising annual milk production per cow, primarily through increasing concentrate‐based total mixed rations fed indoors year round, as opposed to allowing cows to feed on pasture. Pasture‐based dairy systems in regions like New Zealand and Ireland are oriented towards maximum milk yield per unit of pasture, which has led to Holstein strains that are 50 to 100 kg lighter, exhibit a higher body condition score, and produce roughly half the annual amount of milk as compared to their Holstein counterparts kept in confinement in North America and Europe. Freedom from hunger might not be guaranteed when high‐yielding dairy cows are kept on pasture without any supplemental feed, but at the same time no access to pasture can be considered an animal welfare concern, because pasturing is generally beneficial to the animals' health. On pasture, lighter‐weight dairy cows with a medium milk production potential have proven to be superior with regard to feed efficiency and fertility. The year‐round indoor feeding of high‐yielding dairy cows with total mixed rations containing substantial amounts of human‐edible crops from arable land puts global food security at risk and fails to utilise the evolutionary advantages of ruminants. © 2015 Society of Chemical Industry     

The social return on investment in the energy efficiency of buildings in Germany

The German government has developed a variety of policy instruments intended to reduce national CO₂ emissions. These instruments include a programme administered by KfW bank, which aims at improving the energy efficiency of buildings. It provides attractive credit conditions or subsidies to finance refurbishment measures which improve the energy efficiency of buildings significantly.     

现代织机系统的能效开发

尽管机织工厂生产织物时的能源需求仅占整个生产能源需求的20％,但合理地利用先进技术可进一步优化现代织机系统的能效,     

Lactobacillus spp. with in vitro probiotic properties from human faeces and traditional fermented products

Lactobacillus strains from traditional African fermented milk products, as well as human intestinal isolates were identified and investigated in vitro for their technological and functional characteristics as potential new probiotic strains. To test survival under gastrointestinal conditions, first the protective effect of milk and the effects of medium composition, lysozyme, pepsin, and pH of the medium on bacterial viability were assessed in vitro using the Plackett-Burman statistical model and the commercially used L. johnsonii LA1 probiotic strain. The use of either an artificial gastric electrolyte solution or MRS did not play a significant role in the viability of the cultures, while lysozyme, acidic conditions (pH 2.5), pepsin and the presence of milk significantly influenced the survival of the strain. Therefore, these parameters were selected as important test variables in a model stomach passage survival trial. Five strains identified as L. plantarum and two identified as L. johnsonii showed good survival under simulated gastrointestinal conditions. These selected strains also showed antimicrobial activity, probably due to production of organic acids. All strains exhibited bile salt hydrolase activity, while only the L. plantarum strains showed beta-galactosidase activity.