Reduction in the mRNA expression of sVEGFR1 and sVEGFR2 is associated with the selection of dominant follicle in cows

The vascular endothelial growth factor (VEGF) is essential for follicular development by promoting follicular angiogenesis, as well as for the proliferation and survival of granulosa cells. The biological effects of VEGF are regulated by two membrane receptors, VEGFR1 and VEGFR2, and two soluble receptors, sVEGFR1 and sVEGFR2, which play an antagonistic role. Thus, the objective of this study was to identify the mRNA expression pattern of total VEGF, VEGFR1, VEGFR2, sVEGFR1 and sVEGFR2 in bovine preselected follicles (PRF) and post‐selected follicles (POF). The mRNA expression of these five genes in both granulosa cells (GC) and theca cells (TC) was compared between follicles classified as PRF and POF based on their diameter and on their ratio of estradiol/progesterone (E2/P4). Results showed a lower expression of mRNA of sVEGFR1 and sVEGFR2 in POF than in PRF (p < .05). Regarding the mRNA expression of total VEGF, VEGFR1 and VEGFR2, there was no difference between POF and PRF follicles (p > .05). Our results showed that the mRNA expression of VEGFR2 and sVEGFR1 was more abundant than the expression of VEGFR1 and sVEGFR2, while GC was the main source of mRNA for total VEGF. On the other hand, TC was the follicular compartment where the receptors were most expressed. Our results suggest that non‐dominant follicles maintain a greater concentration of the mRNA expression of both membrane and soluble VEGF receptors. On the other hand, follicular dominance is related to a reduction in the mRNA expression of sVEGFR1 and sVEGFR2, which may favour VEGF binding with VEGFR2 and, hence, improve the follicular health and development.     

Effects of dissolved organic matter on the mobility of copper in a contaminated sandy soil

Changes in land use can result in increased soil organic matter content, and decreases in Ca and pH which will affect the mobility of Cu in soil. We studied how the mobility and coagulation of dissolved organic matter and pH affected the mobility of Cu in contaminated sandy soil by batch and column experiments in the laboratory. The soil, with pH ranging from 3.8 to 5.7, had been polluted with Cu in the range 0.13–1.9 mmol kg^?1 more than a decade ago. Calcium and Cu bound by dissolved organic matter (purified humic acid) was determined in the pH range 4–8; Cu²⁺ concentration ranged from 10^?4 to 10^?12M and Ca²⁺ concentration from 10^?3 to 10^?6M. Binding of Cu by dissolved organic matter as affected by Ca and pH could be predicted well with the non-ideal competitive adsorption (NICA) model. Coagulation of dissolved organic matter was affected by the amount of trivalent (Al³⁺) and divalent (Ca²⁺ and Cu²⁺) cations in solution. There was little effect of pH on coagulation between pH 4 and 6. The concentration of the divalent cations, Ca²⁺ and Cu²⁺, at which coagulation of dissolved organic matter appeared could be explained by differences in the binding of Ca and Cu by dissolved organic matter. Binding of Cu by dissolved organic matter as well as by solid organic matter, both affected by Ca and pH, could be described well with the NICA model. We investigated the coagulation and mobility of dissolved organic matter in column experiments and found that they enhanced Cu mobility. Three processes, Cu desorption by soil, dissolved organic matter coagulation and Cu complexation by dissolved organic matter, act simultaneously in the soil columns. All three with counteracting effects on Cu mobility are influenced by Ca and pH and could be adequately represented by the multicomponent NICA model.     

Balance trials with African catfish Clarias gariepinus fed phytase-treated soybean meal-based diets

Balance trials were conducted with African catfish Clarias gariepinus to assess the effect of phytase treatment of soybean meal-based diets on growth, feed utilization and nutrient budgets. Isocaloric (20–22 kJ g⁻¹) and isonitrogenous (47–50% protein) diets were tested. In a first experiment the control diet (58% fish meal and 18% soybean meal) was compared with two diets containing 6% fish meal and 69% soybean meal, and two diets containing 29% fish meal and 41% soybean meal. One of each of these two diets had been pretreated with phytase (1000 units per kg dry diet). In the second experiment, the control diet (6% fish meal and 69% soybean meal, pretreated with 1000 units phytase kg⁻¹ dry diet) was compared with four diets that were similar in composition but supplemented with increasing amounts of phytase (15, 380, 750, 1000 units kg⁻¹ dry diet). Replacement of fish meal by soybean meal in the first experiment led to a depression in growth rate and feed utilization parameters. Results of both experiments clearly indicated a positive effect of phytase treatment, particularly on phosphorus digestibility and retention, and consequently the phosphorus conversion efficiency and the phosphorus budget. No differences in these parameters were found between addition of equal amounts of phytase by pretreatment or supplementation.     

Review of morphological and behavioural differences between reared and wild individuals: Implications for sea-ranching of Atlantic salmon, Salmo salar L., Atlantic cod, Gadus morhua L., and European lobster, Homarus gammarus L.

Abstract The main question which must be raised when planning to enhance natural populations through sea ranching is whether reared organisms are fit for a life in the wild, or more specifically, whether there are differences between reared and naturally resident individuals. The causes and effects of these differences are reviewed, and results from the Norwegian enhancement programme, which compared reared and wild individuals of Atlantic salmon, Salmo salar L., Atlantic cod, Gadus morhua L., and European lobster, Homarus gammarus L., are discussed with emphasis on morphological and behavioural differences. It was concluded that exposure to an artificial rearing environment during ontogeny can affect both the phenotype and the behaviour of the reared individuals, and thereby, their potential for survival after release into the wild as well. Suggestions are made as to how to diminish observed differences, and thereby, improve the survival potential.     

Stock structure of blue threadfin Eleutheronema tetradactylum across northern Australia as inferred from stable isotopes in sagittal otolith carbonate

Abstract Stable isotopes of δ¹⁸O and δ¹³C in sagittal otolith carbonates were used to determine the stock structure of the polynemid Eleutheronema tetradactylum (Shaw) across tropical northern Australia, where this species is an important component of inshore commercial and recreational fisheries. Stable isotopes from the sagittal otolith carbonate of 470 fish from 11 discrete locations across western, northern and eastern Australia were sampled between 2007 and 2009. Analysis of these stable isotopes revealed different location‐specific signatures, indicating strong population subdivision. The significant differences in the isotopic signatures of E. tetradactylum demonstrated that there is unlikely to be substantial movement of fish between these locations. The spatial separation of these populations indicates a complex fine spatial scale stock structure across northern Australia, with at least 11 stocks or management units present. The population subdivision of E. tetradactylum was evident along expansive stretches of open beach systems and within coastal embayments with no physical barriers such as headlands. These results indicate that optimal fisheries management will require a review of the current spatial arrangements, particularly the potential for localised depletion of stocks on small spatial scales.     

INDIGENOUS SOIL AND WATER CONSERVATION BY TERAS IN EASTERN SUDAN

Recent remotely sensed and socio-economic data of the Border Area in eastern Sudan indicate that indigenous soil and water conservation (ISWC) is expanding. The most elaborate technique is teras (bunded landholding) which uses earth bunds to harvest rainwater from small catchments. Most factors suggested in the literature to account for ISWC expansion do not apply to the Border Area. On the contrary, the region is characterised by precisely those factors which are commonly held to be responsible for a declining incidence of ISWC. Given the low level of ISWC returns when compared with incomes from other economic sectors and crop production techniques in the Border Area, the importance of ISWC must be understood from other merits. These include its role in livelihood diversification and risk-reduction strategies at household level. © 1997 John Wiley & Sons, Ltd.     

Seizures during medetomindine sedation and local anaesthesia in two dogs undergoing skin biopsy

Each of two dogs presented for multiple skin biopsies were sedated with intravenous medetomidine and lignocaine was injected subcutaneously to provide local anaesthesia for skin biopsy. One dog had a seizure during skin biopsy and again immediately following reversal of medetomidine with atipamezole. The other dog developed seizures 2 h following skin biopsy at which time the medetomidine was reversed with atipamezole. Both dogs were neurologically normal with no history of seizures prior to the procedure and remained neurologically normal for 14 weeks and 9 months, respectively, following the procedure. A drug interaction between the α₂-adrenergic agonist medetomidine and lignocaine is suspected and highlights the potential for seizures following the subcutaneous administration of relatively large doses of lignocaine under medetomidine sedation.     

THE EFFECT OF POSITIONING ON THE RADIOGRAPHIC APPEARANCE OF CAUDODORSAL MEDIASTINAL MASSES IN THE DOG

In this prospective study, the effect of thoracic positioning on the visibility and size of caudal esophageal masses caused by spirocercosis was investigated. Dorsoventral (DV), ventrodorsal (VD) as well as left lateral recumbent (LLR) and right lateral recumbent (RLR) thoracic radiographs of 28 dogs, diagnosed endoscopically with spirocercosis, were evaluated. The radiographic findings were compared with those of esophageal endoscopy. Masses were seen equally well in left vs. right recumbency as well as in DV vs. VD positions but in DV/VD views 86% of masses were detected whereas in lateral views only 50% of masses were identified. In spirocercosis-endemic areas DV and RLR views are advised as they also allow for better visualization of descending aorta aneurysms and to avoid interpreting the potentially normally visible esophagus in LLR in large dogs as a mass.