Developmental competence of in vitro matured ovine oocytes vitrified in solutions with different concentrations of trehalose

This study aimed to determine the optimum concentration of trehalose in solutions used for vitrification of in vitro matured (IVM) ovine oocytes. IVM oocytes were randomly divided into four experimental (vitrified) and one control (fresh) groups. Experimental groups were treated with different concentrations (0.0, 0.25, 0.5 and 1.0 M) of trehalose. After warming, some viable oocytes were exposed to 0.25% pronase to test zona pellucida hardening, whereas the others were fertilized and cultured in vitro for 8 days to evaluate their developmental competence. Blastocysts quality was assessed by differential staining and TUNEL test. Survival and developmental rates of oocytes vitrified in the presence of 0.5 M trehalose were significantly higher than those of the other vitrified groups. Furthermore, there was a significant difference between fresh and vitrified groups in total blastocyst rate. Analysis of blastocysts quality also revealed a significant difference between the group treated with 0.5 M trehalose and other groups in terms of apoptotic index. Furthermore,zona pellucida digestion time period was longer in trehalose‐free (0.0 M) group compared to other groups. In conclusion, we found that IVM ovine oocytes vitrified in solutions containing 0.5 M trehalose are fertilization‐competent and are able to produce good‐quality blastocysts with an apoptotic index comparable to that of the fresh oocytes. Therefore, 0.5 M may be considered the optimum concentration of trehalose to be used in solutions prepared for vitrification of oocytes.     

Selective predation and prey class behaviour as possible mechanisms explaining cheetah impacts on kudu demographics

A number of predator–prey studies show that certain prey demographic classes are targeted over others. The possible mechanisms driving these effects can be two-fold. Firstly, a preference for a certain demographic class results in selective predation by a predator. Secondly, different demographic classes exhibit varied behaviour and thus susceptibility to predation risk. To test these mechanisms, a study was conducted on Samara Private Game Reserve to investigate the potential impact cheetah (Acinonyx jubatus) predation has had on the kudu (Tragelaphus strepciseros) population. Kudu age and sex data were collected across both predator-present and predator-absent sections using a spotlight-count method. Results suggest that juvenile kudu and subadult male kudu are selectively hunted by cheetah. This was reflected in significantly lower proportions of these two demographic classes within the predator-present section (both 6.0%, respectively) compared with the predator-absent section (16.8% and 17.4%, respectively). These findings indicate that the shift in the demographics of the kudu population within Samara could be explained by a combination of these two mechanisms.     

The distribution of the cardiac veins in angora rabbits (Oryctolagus cuniculus)

This study was carried out to describe the ramifications of the cardiac veins of Angora rabbit. For this purpose, a total of 16 adult healthy Angora rabbits of both sexes, 1.5-2 years of age, were used. The great, middle, right cardiac veins ran in a subepicardial course and opened into the left cranial vena cava, but some tributaries of the right cardiac veins sometimes also joined various portions of the right atrium. The smallest cardiac veins followed subendocardially and terminated in the right chambers of the heart. Based on their origin, course and frequency, it was concluded that the smallest cardiac veins are primarily responsible for the drainage of the interventricular septum. Results from this study are thought to shed light on further heart-related medical studies, and to contribute considerably to the present anatomical knowledge of the cardiac veins in this species.     

The distribution of the coronary arteries in the Angora rabbit

The aim of this study was to determine the origin, course, termination and anastomosing of the coronary arteries in Angora rabbits. Eight adult healthy male Angora rabbits were used. Coloured latex was injected into the ascending aorta. A. coronaria sinistra of the Angora rabbit had larger diameter than a. coronaria dextra. It was divided into r. proximalis atrii sinistri, r. interventricularis paraconalis and r. circumflexus sinister in six Angora rabbits as well as r. septi interventricularis in two. R. septi interventricularis that stem directly from a. coronaria sinistra in two animals and from r. interventricularis paraconalis in six was a principal vessel responsible for the septum interventriculare. R. marginis ventricularis sinistri originating from r. circumflexus sinister was the most prominent artery on the auricular surface of the heart. R. interventricularis subsinuosus was not detected in Angora rabbits examined. A. coronaria dextra, crossing the sulcus coronarius immediately after its origin, ran obliquely in direction of the sulcus interventricularis subsinuosus to supply the right portion of the heart. The ventricular and septal branches of a. coronaria sinistra and a. coronaria dextra ran subepicardially at the beginning then intramyocardially and mostly parallel to the muscle fibres as surrounded by a thin adipose tissue. Their atrial branches were seen continuously to run subepicardially.     

Prediction of the Weight of Aquacultured Rainbow Trout (Oncorhynchus mykiss) by Image Analysis

Prediction relationships between weight and image features were established with a high correlation for whole aquacultured rainbow trout. Three hundred fish from three different farms were used. The fish were temporarily removed from the raceway, anesthetized, and their picture was taken by a digital camera. A reference square of known surface area and color was placed beside the fish. The fish were then returned to the raceway alive. The image was analyzed, and the view area of the fish was calculated using the area of the reference square. The average color of the fish was also determined (L*, a*, and b* values). The following equations were used to fit the view area (X) vs. weight (Y) data: linear, power, and second order polynomial. The R² values for the used equations were: linear = 0.98; power = 0.99; polynomial = 0.98. Image analysis can be used reliably to predict the weight of whole aquacultured rainbow trout. In addition, color and other visual attributes can be objectively determined by image analysis to sort by visual quality.     

Optimization of Antioxidant Activity and Phenolic Compound Extraction Conditions from Red Seaweed (Laurencia obtuse)

ABSTRACT

Response surface methodology was used to investigate the effect of ultrasound-assisted extraction conditions including solvent:seaweed ratio (10:1–30:1), extraction temperature (30–50°C), and extraction time (30–60 min) on the total phenolic compounds and antioxidant activity of red seaweed (Laurencia obtuse) extracts. The optimum extraction parameters for maximum phenolic content were as follows: solvent:seaweed ratio, 30:1; extraction temperature, 50°C; and extraction time, 42.8 min. The experiment results showed that the solvent:seaweed ratio was the most significant parameter for the extraction. The optimum extraction conditions for maximum antioxidant activity were as follows: solvent:seaweed ratio, 24.3:1; extraction temperature, 45.3°C; and extraction time, 58 min. Under the above-mentioned conditions, the experimental total phenolic content and antioxidant activity value were 26.23 ± 0.75 mg GAE/g seaweed and 120.89 ± 0.81 TEAC, respectively, of seaweed tested, which are well compatible with the predicted contents.     

崖柏群落优势乔木种群生态位

采用定量分析方法,对崖柏群落中15个优势乔木种群的重要值、生态位宽度和生态位重叠进行分析.结果表明:崖柏种群的重要值和水平生态位宽度都显著高于其他种群,川陕鹅耳枥、高山栎和华千金榆等种群的水平生态位宽度值较大,虎皮楠、铁杉、中华槭和川鄂山茱萸种群的水平生态位宽度值较小;各种群的水平生态位宽度值与重要值呈显著正相关;崖柏种群对其他种群的水平生态位重叠值高于其他种群对崖柏种群的生态位重叠值,反映出崖柏种群具有较强的竞争能力;崖柏群落优势乔木种群间水平生态位重叠值较小,说明现存崖柏群落结构具有一定的稳定性;高山栎、乌岗栎和青榨槭的垂直生态位宽度值大于崖柏,原因在于崖柏结实母树少,林下更新幼苗、幼树少;崖柏对小叶青冈、城口青冈、乌岗栎和铁杉等种群的垂直生态位重叠值较大,说明它们之间在利用随着高度变化的以光因子为主导的生态资源方面存在较强的竞争.     

Alteration of oceanic volcanic glass: textural evidence of microbial activity

The subsurface biosphere may constitute as much as 50 percent of Earth's biomass. Direct and indirect evidence suggests that an extensive biosphere exists in the rocks below the sea floor. This survey of basalts of the Atlantic, Pacific, and Indian Oceans supports the hypothesis that bacteria have colonized much of the upper oceanic crust, which has a volume estimated at 10(18) cubic meters. Although this is the largest habitat on Earth, its low abundance of bacteria constitutes much less than 1 percent of Earth's biomass.     

Pollution attenuation by roadside greenbelt in and around urban areas

Greenbelts are effective tools for mitigation of traffic induced air and noise pollution. In this study, the potential role of greenbelts along the roadside for the reduction of air pollution and noise levels has been assessed by using seasonally monitored data in a megacity of Bangladesh. Correlation analysis was performed between the vegetation status, measured by canopy density and shelterbelt porosity, and the total suspended particles (TSP) removal percentage. Further, the reduction of noise level was also analyzed. The results showed that the greenbelts greatly contributed to reduce TSP pollution and it was as much as 65%. Noise level reduction was also achieved up to 17 dB when compared to the open area. Moreover, TSP removal percentage was correlated to the crown density. Area having higher crown density demonstrated less air pollution and lower level of noise compared to the area having lower crown density. Greenbelt showed better performance in summer time than winter.