Exercising the Pregnant Mare from Day 16 to Day 80 of Gestation

Our previous research has demonstrated moderate exercise can be detrimental to early pregnancy in the mare, but little work has examined exercise after pregnancy has been detected. We exercised mares (n = 8) 6 days a week for 45 min from Day 16 until Day 80 of gestation. Color Doppler ultrasonography was used to evaluate embryonic vesicle size, fetal length, and uterine blood flow. Blood was sampled every other day to analyze cortisol and progesterone concentrations. Results indicated that exercising pregnant mares (n = 4) led to greater (P < .01) cortisol concentrations 30 min after the exercise period. No overall treatment effect could be detected in progesterone concentrations; however, following Day 60 of gestation, progesterone concentrations were lower (P < .05) in exercised mares. Additionally, progesterone concentrations peaked earlier in exercised mares at Day 52 of gestation compared to peak levels at Day 68 of gestation for control mares. No significant effects were detected in embryonic vesicle size. Fetal length tended (P = .06) to be longer in the conceptus of exercised mares. Uterine blood flow did not differ between groups but increased as pregnancy progressed (P < .001) in both groups. All mares in this study went on to deliver healthy foals and suffered no difficulties during parturition. These results indicated that moderate exercise was not detrimental to mare pregnancy.     

Tank culture of yellowfin tuna, Thunnus albacares: developing a spawning population for research purposes

A land-based culture facility for research on yellowfin tuna, Thunnus albacares, was developed at the Achotines Laboratory in the Republic of Panama. Six concrete tanks, and seawater and life support systems were built to maintain a yellowfin broodstock. On average, 50% of the yellowfin caught survived capture and handling, and approximately 30% became broodstock in Tank 1 (17 m diameter, 6 m depth) or Tank 2 (8.5 m diameter, 3 m depth). Each fish was tagged with a microchip implant tag, then weighed, measured, and injected with oxytetracycline (OTC) prior to stocking. Daily rations of primarily market squid, Loligo opalescens, and Pacific thread herring, Opisthonema spp., were regulated based on the feeding activity and energy requirements of the fish. Feeding activity of the broodstock decreased when the water temperatures decreased, and the fish ate decreasing daily rations and increasing calories with increasing size. Spawning occurred in both tanks within 6–8 months of capture. Spawning first occurred in Tank 1 when 24 females ranged in size from 6 to 16 kg and 65 to 93 cm fork length (FL). Spawning was intermittent during the first 2 months and occurred near daily thereafter. Tank size appeared to affect survival rates, the types of mortalities that occurred, and the growth of the fish. Survival rates after 1 year in captivity were higher, and the fish were larger, on average, in Tank 1 than in Tank 2. Most of the mortalities in Tank 1 were the result of wall strikes, which occurred more frequently after the fish reached their highest density of 0.64 kg m⁻³ and sizes greater than 96 cm FL and 19 kg. Non-linear growth models were fitted to the initial stocking sizes and final sizes of fish that died or were removed from Tank 1 during 1996–1999. Estimated growth rates in length (11–48 cm year⁻¹) for fish between 51 and 150 cm FL decreased with increasing length. Estimated growth rates in weight ranged from 9 to 19 kg year⁻¹ for fish less than 19 kg and 20–23 kg year⁻¹ for fish greater than 19 kg. The results of this work demonstrate that the stable environment of a land-based culture facility may be the preferred system for long-term maintenance of a yellowfin broodstock.     

Catch efficiency and retentive ability of commercial crawfish traps

The catch efficiency and retentive ability of 10 commercial crawfish traps were evaluated in commercial ponds. Trap designs with three entrance funnels caught significantly more crawfish than did trap designs with one or two funnels. Conversely, the retentive ability of the trap designs was inversely related to the number of entrance funnels.Traps constructed from PVC plastic-coated wire caught significantly more crawfish than identical trap designs made from galvanized wire; however, retentive ability of traps was not related to construction material. The posture (horizontal versus vertical) of identically designed traps when set in the pond did not affect the catch efficiency nor retentive ability of the traps. Traps with exposed bait caught 40–47% more crawfish than did traps with protected bait. An average of 84, 80 and 64% of marked crawfish were retained by traps after 12, 24 and 48 h, respectively.     

Ecosystem experiments

Experimental manipulations of entire ecosystems have been conducted in lakes, catchments, streams, and open terrestrial and marine environments. Experiments have addressed applied problems of ecosystem management and complex responses of communities and ecosystems to perturbations. In the course of some experiments, environmental indicators and models have been developed and tested. Surprising results with implications for ecological understanding and management are common.     

Recapitulation of IVIG anti-inflammatory activity with a recombinant IgG Fc

It is well established that high doses of monomeric immunoglobulin G (IgG) purified from pooled human plasma [intravenous immunoglobulin (IVIG)] confer anti-inflammatory activity in a variety of autoimmune settings. However, exactly how those effects are mediated is not clear because of the heterogeneity of IVIG. Recent studies have demonstrated that the anti-inflammatory activity of IgG is completely dependent on sialylation of the N-linked glycan of the IgG Fc fragment. Here we determine the precise glycan requirements for this anti-inflammatory activity, allowing us to engineer an appropriate IgG1 Fc fragment, and thus generate a fully recombinant, sialylated IgG1 Fc with greatly enhanced potency. This therapeutic molecule precisely defines the biologically active component of IVIG and helps guide development of an IVIG replacement with improved activity and availability.     

Plant conservation: old problems, new perspectives

Nature conservation has changed from an idealistic philosophy to a serious technology(J. Harper, 1992)A review is given of the major conceptual changes that have taken place during the last 50 years in our understanding of the nature of plant conservation and of the principal methodological advances in undertaking conservation assessments and actions, largely through the incorporation of tools and techniques from other disciplines. The interrelationships between conservation and sustainable use are considered as well as the impact of the development of the discipline of conservation biology, the effects of the general acceptance of the concept of biodiversity and the practical implications of the implementation of the Convention on Biological diversity. The effect on conservation policy and management of the accelerating loss or conversion of habitats throughout the world and approaches for combating this are discussed.