The crocodile project in Papua New Guinea

Crocodilians throughout the world are under very heavy pressure from habitat destruction, human displacement and deliberate hunting for skins. In Papua New Guinea crocodiles of two species are still relatively plentiful and play an important part in the economy of many remote settlements. An attempt is being made by the national government to implement a policy intended to bring about the harvesting of wild crocodiles on a sustained yield basis and provide an economic incentive for conserving wild stocks in their natural habitat. Low human population density and the existence of vast swamplands make this a possibility. In recognition of the policy and the exceptional circumstances, Papua New Guinea has been exempted from trade restrictions imposed by a number of countries under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).     

Season of the year influences testosterone secretion in bulls administered luteinizing honrmone

The objective of the present study was to evaluate the secretion of testosterone (T) in bulls in response to the administration of varying doses of bovine LH (bLH) during the four seasons of the year. Five adult bulls (4 yr of age) were treated with an amount of bLH that was estimated to induce a 5 ng/mL amplitude pulse of LH in blood serum on five consecutive days around the spring equinox, summer solstice, fall equinox, and winter solstice. Five hours after this dose, bulls were treated with bLH in amounts that were estimated to induce a 0.25, 0.5, 1, 2, or 4 ng/mL amplitude LH pulse in blood serum in a Latin square design. Blood samples were collected for 5 h after administration of a dose of bLH that was estimated to induce the 5-ng amplitude LH pulse, and for 3 h after administration of the variable doses of bLH, and were then assayed for concentrations of T. Average concentrations and amplitude of T release after doses of bLH that were estimated to induce the 5-ng amplitude LH pulses were greater during the spring and summer than during the winter (P < 0.05). The area under the release curve (AUC) was greater during the spring than during the winter (P < 0.05). During the 3 h after treatment with the variable doses of bLH, T response was affected by dose (P < 0.001) and season (P < 0.001), but there was no dose x season interaction. Testosterone response increased in a dose-dependent fashion for all variables studied. The greatest average concentrations of T and AUC were observed in the spring compared with the fall and winter (P < 0.05). These data support our working hypothesis that testes of bulls are more responsive in releasing T in response to bLH stimulation in the spring and summer compared with the winter; however, there were no changes in sensitivity of the testes to LH during different seasons of the year as indicated by the lack of a dose of bLH x season interaction.     

Effects of the calcium channel antagonist amlodipine in cats with surgically induced hypertensive renal insufficiency

OBJECTIVE: To determine whether amlodipine besylate decreases systemic arterial blood pressure (BP) and reduces the prevalence of complications in cats with induced hypertensive renal insufficiency. ANIMALS: 20 cats with partial nephrectomy. PROCEDURE: Following reduction in renal mass, 10 cats were administered 0.25 mg of amlodipine/kg, PO, q 24 h (group A). Ten cats served as a control group (group C). Systolic BP (SBP), diastolic BP (DBP), and mean BP (MBP), physical activity, and pulse rate were measured continuously for 36 days by use of radiotelemetric devices. RESULTS: Compared with values for clinically normal cats, SBP, DBP, and MBP were significantly increased in cats of group C. Cats in group A had significant reductions in SBP, DBP, and MBP, compared with values for cats in group C. Albuminuria but not urine protein-to-creatinine ratio was significantly correlated (R2 = 0.317) with SBP in hypertensive cats. Prevalence of ocular lesions attributable to systemic hypertension in group C (7 cats) was greater than that observed in group A (2). Two cats in group C were euthanatized on day 16 because of nuerologic complications attributed to systemic hypertension. One normotensive cat in group A was euthanatized because of purulent enteritis of unknown cause on day 27. CONCLUSIONS AND CLINICAL RELEVANCE: Amlodipine had an antihypertensive effect in cats with coexistent systemic hypertension and renal insufficiency. Its use may improve the prognosis for cats with systemic hypertension by decreasing the risk of ocular injury or neurologic complications induced by high BP.     

Freshwater mussel assemblage structure in a regulated river in the Lower Mississippi River Alluvial Basin,USA

• 1. This paper documents a diverse, reproducing freshwater mussel community (20 species) in Lower Lake — an impounded, regulated portion of the Little Tallahatchie River below Sardis Dam in Panola Co., Mississippi, USA.
• 2. Despite being regulated and impounded, the lake has a heterogeneous array of habitats that differ markedly in mussel community attributes. Four distinct habitat types were identified based on current velocity and substrate characteristics, representing a gradient from habitats having lotic characteristics to lentic habitats. All four habitat types supported mussels, but habitats most resembling unimpounded, lotic situations (relatively higher current velocity and coarser substrate) had the highest mussel abundance and species density (10.1 mussels m^?2, 1.8 species m^?2, respectively). Lentic habitats (no flow, fine substrate) were characterized by lower abundance and species density (2.0 mussels m^?2, 0.8 species m^?2, respectively), but supported mussel assemblages distinctive from lotic habitats.
• 3. Evidence of strong recent recruitment was observed for most species in the lake and was observed in all four habitat types.
• 4. Although impounded and regulated, Lower Lake represents one of the few areas of stable large‐stream habitat in the region. The presence of a diverse, healthy mussel community in this highly modified habitat suggests that a large component of the regional mussel fauna is relatively resilient and adaptable and is limited primarily by the absence of stable river reaches. Management actions that increase stream stability are likely to result in expansion of the mussel fauna and restoration of a valuable component of ecosystem function in this region.

Published in 2006 by John Wiley & Sons, Ltd.     

Mitochondrial reduction of metmyoglobin: dependence on the electron transport chain

Reduction of ferric myoglobin (metmyoglobin, MetMb) to its ferrous form is important for maintaining fresh meat color because only reduced myoglobin can bind oxygen to form the consumer-preferred cherry red color in fresh meat. The objective of this study was to characterize an apparent mitochondria electron transport chain (ETC)-linked pathway for MetMb reduction in vitro. MetMb was reduced in the presence of mitochondria and succinate (p < 0.05); mitochondria or succinate alone did not facilitate MetMb reduction relative to controls (p > 0.05). Flushing samples with oxygen greatly decreased MetMb reduction, while flushing with argon increased MetMb reduction when compared with controls (p < 0.05). ETC inhibitors were used to localize the site where electrons became available for MetMb reduction. MetMb reduction was increased by rotenone addition and decreased by malonic acid (p < 0.05); the reduction was completely abolished by additions of antimycin A or myxothiazol when compared with controls (p < 0.05). These results suggest that electrons become available for MetMb reduction at a site(s) between complex III and IV. Mitochondrial ETC-linked MetMb reduction increased with increased mitochondrial density and succinate concentration (p < 0.05); the greatest MetMb reduction was observed at pH 7.2 and 37 degrees C, and ETC-linked MetMb reducing activity decreased with time postmortem (p < 0.05). These results indicate that ETC-linked MetMb reduction exists but would be minimally active in postmortem muscles.     

Optothermistor as a breakthrough in the quantification of lycopene content of thermally processed tomato-based foods: verification versus absorption spectrophotometry and high-performance liquid chromatography

This study reports on the first use of the "optothermistor" as a novel, precise, fast, and low-cost detector of lycopene in a wide range of commercially available processed-tomato products. The quantitative performance of the new device was evaluated by comparing data obtained to that acquired by conventional methods, namely, absorption spectrophotometry and high-performance liquid chromatography (HPLC); the linear correlation was high (R = 0.98). The variation of data obtained with the optothermistor in a series of consecutive measurements performed with the same loading of the sample was better than 1%. However, the repeatability (RSD 0.5-9.0%, n = 3-5) achieved with the optothermistor by independent analyses (multiple loading) is comparable to that of HPLC and spectrophotometry. Results of the studies performed on the 19 products derived from tomatoes demonstrated that the optothermistor is suitable for selective, accurate, precise, and simple determination of lycopene (range = 7-75 mg/100 g of product weight) without the need for a sample pretreatment step. The estimated sensitivity of the present optothermistor is 2 mg of lycopene/100 g of product.     

Interactions between mitochondrial lipid oxidation and oxymyoglobin oxidation and the effects of vitamin E

Off-flavor and discoloration of meat products result from lipid oxidation and myoglobin (Mb) oxidation, respectively, and these two processes appear to be interrelated. The objective of this study was to investigate their potential interaction in mitochondria and the effects of mitochondrial alpha-tocopherol concentrations on lipid oxidation and metmyoglobin (MetMb) formation in vitro. The addition of ascorbic acid and ferric chloride (AA-Fe(3+)) increased ovine and bovine mitochondrial lipid oxidation when compared with their controls (p < 0.05); MetMb formation also increased with increased lipid oxidation relative to controls (p < 0.05). Reactions containing Mb and mitochondria with greater alpha-tocopherol concentrations demonstrated less lipid oxidation and MetMb formation than mitochondria with lower alpha-tocopherol concentrations. Greater mitochondrial alpha-tocopherol concentration was also correlated with increased mitochondrial oxygen consumption in vitro and with a more pronounced effect at pH 7.2 than at pH 5.6. Relative to controls, succinate addition to bovine mitochondria resulted in increased concentrations of ubiquinol 10 and alpha-tocopherol and decreased lipid and Mb oxidation (p < 0.05). Mitochondrial lipid oxidation was closely related to MetMb formation; both processes were inhibited by alpha-tocopherol in a concentration-dependent manner.     

Increased Growth and Production of Striped Bass × White Bass Hybrids in Earthen Ponds

Four 0.1 hectare earthen ponds were stocked with 16,500 hybrid striped bass (female Morone saxatilis × male M. chrysops ) per hectare on 22 June 1982. Mean weight at stocking was 5.2 g ± 0.10 SE. Fish were fed to satiation two or three times daily with a dry commercial salmonid diet, and the ponds were aerated mechanically during periods of low dissolved oxygen during warm weather. Survival at harvest on 6 March 1983 averaged 84.7%, and mean weight of the fish was 170.2 g ± 2.66 SE. Average weights of fish from individual ponds ranged from 149.0 to 189.7 g. The ponds were restocked on 1 April 1983 with 10,000 fish per hectare averaging 193.6 g. Ten months later, average survival in 3 ponds was 83.9% (range, 81.3–87.0%) and mean weight was 656.3 g ± 5.51 SE. Average weights of fish from individual ponds ranged from 632.5 to 690.7 g. All fish in one pond died in June as a result of an aerator failure. Standing crop at harvest in the three remaining ponds averaged 5, 504 kg/ha (range, 5,247–5,765 kg/ha). Improvements in culture techniques resulted in approximately a 138% increase in production per hectare over that reported in a prior study. Results demonstrated that hybrid striped bass offer considerable potential for commercial aquaculture in warm temperate latitudes of the United States.