Electrophysiological studies on the effect of sesamex upon the action of dieldrin in Blaberus discoidalis

Treatment of the metathoracic ganglion of the cockroach, Blaberus discoidalis, with dieldrin (HEOD) at a concentration of 10^?5M produced changes in spontaneous efferent activity and afterdischarge in efferent pathways. Pretreatment with sesamex markedly reduced the spontaneous activity caused by dieldrin and also reduced the latency of appearance of symptoms from 60 min to nearly 30 min. However, pretreatment with sesamex did not alter the intensity and duration of the dieldrin-induced synaptic afterdischarge. Pretreatment of cockroaches with sesamex did not measurably change the toxicity of dieldrin in vivo.     

Wavelength Selection for Classifying Paddy Rice by Near‐Infrared Spectroscopy

Using five paddy rice cultivars grown in Central, Eastern, and Southern Taiwan and harvested in the summers of 1997, 1998, and 1999, eight calibrated models were established by discriminant analysis and back‐propagation neural network with four wavelength selection methods. Randomly adding 80 samples of the 2000 year crop in the three‐crop‐year calibrated models for annual recalibration, eight models were used to classify paddy rice harvested in the summer of 2000. With 351 wavelengths of models 1 and 2, the average classification rates by discriminant analysis and backpropagation neural network were 98.1 and 92.5%, respectively. With 69 wavelengths selected by stepwise discrimination of models 3 and 4, the average classification rates by discriminant analysis and backpropagation neural network were 98.5 and 85.5%, respectively. With 69 wavelengths selected by correlation matrix of models 5 and 6, the average classification rates by discriminant analysis and neural network were 72.0 and 72.2%, respectively. With 69 wavelengths from loading values in the first and second principal components of models 7 and 8, the average classification rates by discriminant analysis and neural network were 69.1 and 60.6%, respectively. Model 3 would be recommended for classifying paddy rice to set trading prices because of its highest classification rate (98.5%).     

Aboveground Characteristics, Yield Potential and Drought Tolerance in “Konyu” Potato Cultivars with Large Root Mass

To improve drought tolerance of potato, we bred four cultivars with large root mass and registered them as Konyu-1 to Konyu-4 in 2007. In this paper, we present the yield performance and the related aboveground characteristics of three Konyu cultivars and cv. Konafubuki (small root mass, one of the parents of these Konyu cultivars) in irrigated and droughted fields for 3 years. Consistent with our previous reports, we observed that the yield reduction in droughted fields relative to irrigated fields was less in Konyu cultivars than in Konafubuki. Konyu-2 showed the highest yield in both fields in all three experimental years. Konyu-2 and Konafubuki had a relatively high harvest index (HI) as a result of lower dry weight partitioning to the shoot regardless of water treatment. This characteristic contributed to the higher yield in the irrigated field in both cultivars compared with the other cultivars. In addition, Konyu-2 had a higher leaf/stem ratio coupled with a lower number of branches than the other cultivars. In the year of the most severe drought, the leaf area index remained below 3 (optimum value for intercept radiation) in Konafubuki, but not in Konyu-2 because of its high leaf/stem ratio. The present results suggest that in addition to large root mass, high HI coupled with high leaf/stem ratio with low number of branches may contribute to achieve high and stable yields in drought prone environments.     

Effect of various levels of dissolved oxygen on reactive oxygen species and cryocapacitation‐like changes in bull sperm

The present investigation was carried out to study the effect of various levels of dissolved oxygen (DO) on reactive oxygen species (ROS) and cryocapacitation‐like changes in bull sperm. Egg yolk–Tris–glycerol (EYTG) extender was split into four subextenders; viz., Extender I (control; no flushing with liquid nitrogen (LN₂)), Extender II, Extender III and Extender IV were flushed with LN₂ for 40, 16 and 8 min, respectively. The DO levels were standardized to 11.7, 2, 4 and 8 ppm, respectively, in control (Extender I), Extender II, Extender III and Extender IV. Ejaculates with mass motility of ≥ 3+ were divided into group I (diluted with Extender I), group II (diluted with Extender II), group III (diluted with Extender III) and group IV (diluted with Extender IV) up to 80 × 10⁶ sperm/ml. Extended semen samples were packed in French mini straws (0.25 ml), equilibrated and cryopreserved. Semen samples were evaluated at prefreeze and post‐thaw stage for various parameters (DO, progressive motility (PM), viability (VIB), acrosomal integrity (AI), hypo‐osmotic swelling (HOS) test, ROS, cholesterol (C) and phospholipid (P). The percentage of PM, VIB, AI, HOS test, cholesterol (C) and phospholipid (P) levels, and capacitated sperm were significantly (p < 0.05) higher in groups III and IV as compared to groups I and II. However, the acrosome‐reacted sperm (%; pattern AR) were significantly (p < 0.05) decreased in group III as compared to all other groups. Besides the proportion of sperm displaying tyrosine‐phosphorylated pattern, EA (fluorescence at both equatorial and anterior acrosomal regions, i.e. high capacitation level) was significantly (p < 0.05) reduced in group III compared to all other groups. In conclusion, varying DO levels in the extender significantly affect sperm quality, ROS production and capacitation‐like changes in bulls.     

Exogenous cholesterol prevents cryocapacitation-like changes,membrane fluidity,and enhances in vitro fertility in bubaline spermatozoa

A study was conducted to determine the optimum dosage of the exogenous cholesterol-loaded cyclodextrins (CLC) to get maximum cryoprotection for bubaline spermatozoa. In the present study, 120 × 10⁶ spermatozoa were incubated in 2, 3 and 4 mg of CLC as grouped as Gr II, III and IV, respectively, and sperm progressive motility, intracellular Ca²⁺, capacitation status by protein tyrosine phosphorylation (PTP) assay and zona binding per cent (ZBP) and cleavage rate (CR) of the cryopreserved buffalo spermatozoa by in vitro fertility assay were assessed in comparison with an untreated control group (Gr I). Results revealed that there was a significant (p < .05) linear decrease in percentage of sperm population with higher intracellular Ca²⁺ and percentage of sperm population with medium or high capacitated by PTP in CLC treated from 2 to 3 mg and then increased to 4 mg/120 × 10⁶ spermatozoa whereas sperm progressive motility, percentage of sperm population with low capacitated, ZBP and CR were increased significantly (p < .05) in sperm population treated from 2 to 3 mg CLC and then decreased to 4 mg/120 × 10⁶ spermatozoa. The study has clearly indicated that CLC at 3 mg/120 × 10⁶ spermatozoa has maximum beneficial effects in protection of sperm progressive motility, membrane fluidity (low intracellular Ca²⁺); prevention of cryocapacitation (low capacitation pattern in immunolocalization) and enhancement of in vitro ZBP and CR. Post-thaw motility of the CLC-treated sperm has shown positively significant (p < .05) correlation with sperm population with low intracellular Ca²⁺, low capacitated sperm population, ZBP and CR, whereas it was negatively (p < .05) correlated with sperm population with high intracellular Ca²⁺, medium or high capacitated sperm. The present study has revealed for the first time that incubation of spermatozoa with CLC of higher dose (>3 mg/120 × 10⁶ spermatozoa) had adverse effects on sperm cryopreservation, although incubation of sperm with 3 mg/120 million prior to processing had minimised the freezing–thawing-associated damages in bubaline species.     

Strong fisheries management and governance positively impact ecosystem status

Fisheries have had major negative impacts on marine ecosystems, and effective fisheries management and governance are needed to achieve sustainable fisheries, biodiversity conservation goals and thus good ecosystem status. To date, the IndiSeas programme (Indicators for the Seas) has focussed on assessing the ecological impacts of fishing at the ecosystem scale using ecological indicators. Here, we explore fisheries ‘Management Effectiveness’ and ‘Governance Quality’ and relate this to ecosystem health and status. We developed a dedicated expert survey, focused at the ecosystem level, with a series of questions addressing aspects of management and governance, from an ecosystem‐based perspective, using objective and evidence‐based criteria. The survey was completed by ecosystem experts (managers and scientists) and results analysed using ranking and multivariate methods. Results were further examined for selected ecosystems, using expert knowledge, to explore the overall findings in greater depth. Higher scores for ‘Management Effectiveness’ and ‘Governance Quality’ were significantly and positively related to ecosystems with better ecological status. Key factors that point to success in delivering fisheries and conservation objectives were as follows: the use of reference points for management, frequent review of stock assessments, whether Illegal, Unreported and Unregulated (IUU) catches were being accounted for and addressed, and the inclusion of stakeholders. Additionally, we found that the implementation of a long‐term management plan, including economic and social dimensions of fisheries in exploited ecosystems, was a key factor in successful, sustainable fisheries management. Our results support the thesis that good ecosystem‐based management and governance, sustainable fisheries and healthy ecosystems go together.     

Effect of l-arginine methyl ester (l-NAME) on hormonal profile and estrous cycle length in buffaloes (Bubalus bubalis)

The present study was undertaken to evaluate the effect of L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor on serum nitric oxide, progesterone, estradiol profiles and estrous cycle length in buffaloes. Murrah buffaloes (n?=?16) exhibiting regular estrous cycles were randomly allocated to two groups of eight animals. In the treatment group, buffaloes were administered 400?mg/h?L-NAME over 2?h (total dose?=?800?mg) via the coccygeal artery and the aorta abdominalis on day 15 of the estrous cycle. In the control group, normal saline was infused on the same day of the cycle by the same route. Blood samples were collected every 4?h on days 15 and 16, and once daily from days 17 to 21 of the estrous cycle for the assay of progesterone, estradiol and nitric oxide. L-NAME treatment significantly (p?相似文献