Comparison of two different centrifugation extenders for preservation of frozen equine semen

This study compares a commercial semen extender (control group) to ultra high temperature (UHT) skimmed milk (treatment group) used during centrifugation for subsequent cryopreservation of equine semen. Following post‐thawing of semen samples parameters measured included motility, sperm motion kinetics (using computerised assisted semen analysis) as well as acrosome and plasmatic membrane integrity (using fluorescent dyes). After collection and analysis, the sperm‐rich fraction was divided and diluted with either: control (1:1 dilution in a skimmed milk‐glucose extender) or treatment (1:1 dilution in UHT skimmed milk). The milk used in this experiment was of the same source, commercial brand, of only one lot. After dilution, samples were subjected to centrifugation at 600 g for 10 min and sperm pellets were resuspended in a freezing extender to a concentration of 200 × 10⁶ cells/ml. Aliquots were packed into 0.5 ml straws placed in a stainless steel support and kept inside the refrigerator (5°C) for 20 min. Subsequently, these straws were placed at a height of 6 cm over liquid nitrogen for 20 min in an isotherm box. No significant differences were observed in total sperm motility (42.71 vs. 38.29%), progressive sperm motility (12.29 vs. 7.86%), plasma membrane integrity (53.43 vs. 60.14%) or acrosomal membrane integrity (93.29 vs. 93.71%) with a P>0.05 calculated between the control and the treatment groups, respectively. Considering that UHT skimmed milk has a lower cost than the commercial semen extender, this could be an option used during the centrifugation protocol to decrease the expense of the equine semen cryopreservation process and increase shelf life.     

Analysis of the effect of ozone on soybean in the Mediterranean region: I. The consequences on crop-water status

This study was carried out over three successive years (2003–2004–2005) in the southern Mediterranean region of Europe. Soybean plants were subjected to well-watered and water-stress conditions, and three levels of ozone (zero, low and high) in open top chambers (OTC) during the growing seasons.

The paper has four objectives: (i) to reproduce in OTCs the ozone concentrations actually observed in the field; (ii) to analyze the effect of ozone on well-watered crops by comparing a “control” (OTC ozone filtered treatment) with two ozone levels (at the end of the soybean growing seasons accumulated AOT40 values were 3400 and 9000 ppb h for low and high ozone treatments, respectively); observations were carried out both at leaf scale (stomatal conductance) and at canopy scale (determination of daily evapotranspiration, AET); (iii) to take into consideration the effect of drought, where the leaf and canopy scale observations were also implemented on water-stressed crops; and (iv) to analyze and verify the reliability of the ozone exposure–plant response relationship.

In well-watered conditions, an increase in ozone concentration levels reduced stomatal conductance and AET. Reductions in AET were 14% and 28% at low and high ozone levels, respectively, as compared to the control treatment. Hence, the results of daily AET were consistent with stomatal conductance results.

In water stress conditions, on the contrary, an increase in ozone had no effect on stomatal conductance and AET.

During the 3-year study, significant relationships were found between AOT40 and relative (low or high to control ozone treatment) values of stomatal conductance and AET in well-watered conditions. The reliability observed for these relationships suggest that they will be useful in soybean growth and yield-prediction models.     

Golden Grey Mullet (Liza aurata) Alkaline Proteases: Biochemical Characterization,Application in the Shrimp Wastes Deproteinization,Laundry Commercial Detergents,and Preparation of Antioxidant Protein Hydrolysate

Digestive alkaline proteinases from golden grey mullet (Liza aurata) were extracted and characterized. The crude alkaline protease showed optimum activity at pH 8.0 and 60°C, and it was highly stable over a wide range of pH from 4.0 to 10.0, retaining more than 80% activity after incubation for 1 h at 4°C. The alkaline proteases showed extreme stability toward nonionic and anionic surfactants after preincubation for 1 h at 25°C and relative stability toward oxidizing agents. Additionally, the crude enzyme showed excellent stability and compatibility with various solid and liquid detergents. Further, proteases from golden grey mullet viscera were found to be effective in the deproteinization of shrimp wastes. The protein removal after 3 h at 45°C with an enzyme/substrate (E/S) ratio of 10 U/mg protein was about 76%. The golden grey mullet proteases were also shown to be efficient in the production of antioxidant protein hydrolysate.     

Suitability of Marine- and Porcine-Derived Collagen Type I Hydrogels for Bioprinting and Tissue Engineering Scaffolds

Collagens from a wide array of animals have been explored for use in tissue engineering in an effort to replicate the native extracellular environment of the body. Marine-derived biomaterials offer promise over their conventional mammalian counterparts due to lower risk of disease transfer as well as being compatible with more religious and ethical groups within society. Here, collagen type I derived from a marine source (Macruronus novaezelandiae, Blue Grenadier) is compared with the more established porcine collagen type I and its potential in tissue engineering examined. Both collagens were methacrylated, to allow for UV crosslinking during extrusion 3D printing. The materials were shown to be highly cytocompatible with L929 fibroblasts. The mechanical properties of the marine-derived collagen were generally lower than those of the porcine-derived collagen; however, the Young’s modulus for both collagens was shown to be tunable over a wide range. The marine-derived collagen was seen to be a potential biomaterial in tissue engineering; however, this may be limited due to its lower thermal stability at which point it degrades to gelatin.     

Identification of volatile compounds in soybean at various developmental stages using solid phase microextraction

Soybean (Glycine max) seed volatiles were analyzed using a solid phase microextraction (SPME) method combined with gas chromatography-mass spectrometry (GC-MS). Thirty volatile compounds already reported for soybean were recovered, and an additional 19 compounds not previously reported were identified or tentatively identified. The SPME method was utilized to compare the volatile profile of soybean seed at three distinct stages of development. Most of the newly reported compounds in soybean seed were aldehydes and ketones. During early periods of development at maturity stage R6, several volatiles were present at relatively high concentrations, including 3-hexanone, (E)-2-hexenal, 1-hexanol, and 3-octanone. At maturity stage R7 and R8, decreased amounts of 3-hexanone, (E)-2-hexenal, 1-hexanol, and 3-octanone were observed. At maturity stage R8 hexanal, (E)-2-heptenal, (E)-2-octenal, ethanol, 1-hexanol, and 1-octen-3-ol were detected at relatively high concentrations. SPME offers the ability to differentiate between the three soybean developmental stages that yield both fundamental and practical information.     

热处理对腺瘤豆木材天然耐久性的影响

用4种热处理方法处理腺瘤豆心材,可有效去除异味,替代珍贵绿柄桑木材使用.处理后的木材经白腐菌侵染 12星期,平均质量损失率与未经处理的试材相比变化不大,天然耐久性等级保持不变,而且其中2种处理方法还能够明显提高木材的耐腐性能,木材的天然耐久性等级因此也由Ⅱ类提高到Ⅰ类.