A comparison of methods to spatially represent pelagic longline fishing effort in catch and bycatch studies

Bycatch in fisheries has been recognized as a threat to many endangered populations of sea turtles, sea birds and marine mammals. Interactions between pelagic longline fisheries and critically endangered populations of leatherback sea turtles (Dermochelys coriacea) have led to temporary closures of the Hawaiian pelagic longline swordfish fishery and severe bycatch quotas. The negative impact of these events on both the populations of certain endangered species and the economic livelihood of the fishermen has resulted in a strong push from all sides to better understand bycatch events. Typically, analyses of longline catch and bycatch have examined fishing effort summarized over large areas (≥1°). Although aggregation of effort to this level may be necessary to account for uncertainty, confidentiality concerns, or to make comparisons across regions, it specifically limits the researcher's ability to characterize the local oceanographic factors that may drive individual bycatch events. Higher resolution analyses must be undertaken to identify such features. However, for these higher resolution analyses, the methods currently used to spatially represent pelagic longline fishing effort may significantly affect researcher's results. Here, we look at different methods to represent this fishing effort (i.e., points, centroids, polylines and polygons) at various resolutions (2 km to 5°) to better understand which method and spatial resolution are most appropriate. Our results validate the use of point features to represent fishing effort in previous low resolution studies of the Hawaiian pelagic longline fishery by showing that the set point method is suitable for studies with resolutions lower than 15 km. However, at higher resolutions (≤15 km) and in areas with more sparsely distributed fishing, aggregated effort values differed significantly between spatial representation methods. We demonstrate that the use of polygons to describe pelagic longline fishing effort is more representative and necessary for such high resolution analyses.     

Effects of residues of deltamethrin in cattle faeces on the development and survival of three species of dungbreeding insect

Objective To assess the toxicity to insects of drug residues excreted in cattle faeces following treatment with deltamethrin.
Design Bioassays were performed on one species of dung-breeding fly ( Musca vetustissima ) and two species of dung beetle ( Onthophagus binodis and Euoniticellus fulvus ).
Animals Cattle on properties near Kangaroo Valley, Canberra and Gundagai were treated with pour-on formulations of deltamethrin. Untreated animals acted as controls.
Procedures Faeces from treated and untreated cattle were inoculated with newly emerged fly larvae or fed to adults of two species of dung beetle. Percentage survival and duration of development provided measures of the toxicity of deltamethrin residues in faeces.
Results Residues of deltamethrin were excreted in concentrations sufficient to inhibit survival of larvae of M vetustissima for 1 to 2 weeks after treatment. Peak concentrations of 0.4mg deltamethrin/kg dry weight of faeces occurred 3 days after treatment and were sufficient to kill adult beetles for at least twice this period. With one of two formulations tested, there was evidence of a reduction in dung beetle fecundity and an increase in the duration of juvenile development. A model of the effect of deltamethrin on the breeding success of dung beetles in the field suggests that a single treatment, applied when most of the population is in a non-parous condition, may cause up to 75% reduction in beetle acitivity by the end of the season. Multiple treatments at 10 or 21 day intervals may drive local populations towards extinction.
Conclusion Depending on the time and frequency of treatment, the effect of deltamethrin on insects in cattle faeces may range from negligible to catastrophic.     

Assessment of System of Rice Intensification(SRI) and Conventional Practices under Organic and Inorganic Management in Japan

The system of rice intensification(SRI) is a production system that involves the adoption of certain changes in management practices for rice cultivation that create a better growing environment for the crop.This system was compared with conventional practices and assessed under organic and inorganic management.SRI practices showed significant response in root number,number of effective tillers per hill,days to flowering and harvest index.In addition,SRI was found effective in minimizing pest and disease in...     

Plasma Concentrations of 13, 14‐Dihydro‐15‐keto‐Prostaglandin F2α, Progesterone and Cortisol During Periparturient Period in Yaks (Poephagus grunniens L.)

An attempt was made to determine plasma concentrations of, 13, 14‐dihydro‐15‐keto‐prostaglandin F_2α (PGFM), cortisol and progesterone during periparturient period in yak. Plasma PGFM level showed an increasing trend beginning day 5 prior to parturition (0.48 ± 0.14 ng/ml) and increased steeply thereafter to reach a peak level (17.16 ± 1.31 ng/ml) on the day of parturition. The levels, then, declined sharply on day 1 postpartum to reach 1.20 ± 0.40 ng/ml and thereafter declined gradually over the days to reach 0.28 ± 0.09 ng/ml on day 20 postpartum and this level was maintained with fluctuation within narrow limits thereafter till conclusion of the blood sampling on day 90 post‐calving. The plasma progesterone concentration on days 7 and 6 before parturition was high (2.10 ± 0.10 and 2.12 ± 0.10 ng/ml, respectively). The level then decreased gradually and abrupt fall was observed 1–2 days before parturition and became basal on day of parturition (0.24 ± 0.04 ng/ml). This basal level was maintained till the end of the blood sampling on day 90 postpartum. Plasma cortisol level showed an increasing trend beginning day 2 prior to parturition (2.36 ± 0.65 ng/ml) and increased steeply thereafter to reach a peak level (26.65 ± 5.28 ng/ml) on the day of parturition. The levels, then, declined gradually over the days and touched 2.36 ± 0.25 ng/ml on day 3 postpartum and this level was maintained with fluctuation within narrow limits thereafter till day 7 post‐calving.     

Optimizing Electrical Activation of Porcine Oocytes by Adjusting Pre‐ and Post‐Activation Mannitol Exposure Times

Modifying electrical activation conditions have been used to improve in vitro embryo production and development in pigs. However, there is insufficient information about correlations of porcine embryo development with oocyte pre‐ and post‐activation conditions. The purpose of this study was to compare the developmental rates of porcine oocytes subjected to different mannitol exposure times, either pre‐ or post‐electrical activation, and to elucidate the reason for the optimal mannitol exposure time. Mannitol exposure times around activation were adjusted as 0, 1, 2 or 3 min. Blastocyst development were checked on day 7. Exposure of oocytes to mannitol for 1 or 2 min before electrical activation produced significantly higher blastocyst rates than exposure for 0 or 3 min. There was no significant difference in blastocyst rates when activated oocytes were exposed to mannitol for 0, 1, 2 or 3 min after electrical activation. While exposure of oocytes to mannitol for 1 min pre‐ and 3 min post‐activation showed significantly higher blastocyst development than 0 min pre‐ and 0 min post‐activation. It also showed higher maintenance of normal oocyte morphology than exposure for 0 min pre‐ and 0 min post‐activation. In conclusion, exposure of oocytes to mannitol for 1 min pre‐ and 3 min post‐activation seems to be optimal for producing higher in vitro blastocyst development of porcine parthenogenetic embryos. The higher blastocyst development is correlated with higher maintenance of normal morphology in oocytes exposed to mannitol for 1 min pre‐ and 3 min post‐activation.     

Comparison of Conventional Freezing and Vitrification with Dimethylformamide and Ethylene Glycol for Cryopreservation of Ovine Embryos

The aim of this work was to evaluate the efficiency of the cryoprotectants dimethylformamide and ethylene glycol for cryopreservation of ovine embryos using vitrification and conventional freezing. The recovered embryos were distributed randomly in three treatment groups: Gr. 1: conventional freezing (n = 44), Gr. 2: vitrification with ethylene glycol (n = 39) and Gr. 3: vitrification with dimethylformamide (n = 38). Quality of fresh embryos in control group as well as of frozen and vitrified embryos was examined by three methodologies: staining with propidium iodide and Hoechst 33258 and evaluation under fluorescent microscopy, evaluation of re‐expansion and hatching rates after culture, and determination of apoptotic index with TUNEL technique. It was established that re‐expansion rate in all treatment groups was similar. In the same time, hatching rates were higher in Gr. 1 (40.5%) and Gr. 2 (35.3%) in comparison with Gr. 3 (15.5%, p < 0.05). The number of dead cells in vitrified embryos of Gr. 2 and Gr. 3 was higher (42.6 ± 26.2 and 63.2 ± 34.65, respectively) in comparison with Gr. 1 (conventional freezing, 10.1 ± 8.5, p < 0.05). Embryos vitrified with dimethylformamide included the same quality of apoptotic cells that Gr. 1 (conventional freezing) and fresh embryos. In conclusion, the dimethylformamide and ethylene glycol used as cryoprotectant to vitrify ovine embryos, in the concentrations and exposition time tested in this work, were not as efficient as the conventional freezing for cryopreservation of ovine embryos Thus, the conventional freezing with ethylene glycol was the most efficient method to cryopreserve ovine embryos in comparison with vitrification.     

Identification of lactoferrin and glutamate receptor‐interacting protein 1 in bovine cervical mucus: A putative marker for oestrous detection

Accurate detection of oestrus is important for artificial insemination. The aim of this study was to identify oestrous‐specific bovine cervical mucus proteins that could be used to determine the optimal time for artificial insemination. Non‐oestrous and controlled internal drug release (CIDR)‐induced oestrous‐stage mucus proteins were purified and subjected to surface‐enhanced laser desorption/ionization time‐of‐flight mass spectrometry, sodium dodecyl sulphate polyacrylamide gel electrophoresis and MALDI‐TOF/TOF. Among differentially expressed proteins, lactoferrin (LF) and glutamate receptor‐interacting protein 1 (GRIP1) showed a twofold increase during the CIDR‐induced oestrous stage compared to the levels in non‐oestrous stage in bovine cervical mucus. The RT‐PCR, Western blotting and immunohistochemistry results showed that LF and GRIP1 expression was significantly increased during the oestrous stage in the uterus. This study demonstrated that bovine LF and GRIP1 exist during the oestrous stage, but not during the non‐oestrous stage, suggesting that cervical mucus LF and GRIP1 are useful oestrous detection markers in cattle.     

Aquaporin 9 is expressed in the epididymis of immature and mature pigs

Aquaporins (AQPs) are channel proteins that facilitate the transepithelial and bidirectional movement of water. AQP9 is an aquaporin that is expressed in the mammalian epididymis. This water transport contributes to epididymal sperm concentration. This study aimed to examine the morphology of epididymal epithelium in piglets and boars, as well as the expression and immunolocalization of AQP9. The piglets presented an epididymal epithelium in differentiation with principal, basal and apical cells. The cellular population of the epididymal epithelium in boars consisted of principal, basal, apical, clear and narrow cells. The migratory cells known as halo cells were observed in the epididymis of both piglets and boars. AQP9 expression presented differences between piglets and boars. Moderate intensity of AQP9 immunoreaction was observed in the apical border of the epididymal epithelium of the caput and cauda regions in the piglet epididymis. A moderate‐to‐intense reaction for AQP9 was observed in the nuclei of epithelial cells of the three epididymal regions in the boar epididymis. The region of the cauda epididymis showed reactivity for AQP9 also in the apical border of the epithelium. It is believed that the AQP9 is already functional in piglets at only 1 week of age and is more active, playing a pivotal role in the caput and cauda regions of the epididymis. Moreover, the intense AQP9 expression in the apical border of epithelial cells in the cauda region of the boar epididymis suggests a higher performance of AQP9 in this region, where sperm complete their maturation process, stored and concentrated.