Experimental functional response and inter-individual variation in foraging rate of teal (Anas crecca)

The functional response, i.e. the change in per capita food intake rate per time unit with changed food availability, is a widely used tool for understanding the ecology and behaviour of animals. However, waterfowl remain poorly explored in this context. In an aviary experiment we derived a functional response curve for teal (Anascrecca) foraging on rice (Oryzasativa) seeds. We found a linear relationship between intake rate and seed density, as expected for a filter-feeder. At high seed densities we found a threshold, above which intake rate still increased linearly but with a lower slope, possibly reflecting a switch from filter-feeding to a scooping foraging mode. The present study shows that food intake rate in teal is linearly related to food availability within the range of naturally occurring seed densities, a finding with major implications for management and conservation of wetland habitats.</p

The effect of age and unilateral leg immobilisation for 2 weeks on substrate ulilisation during moderate-intensity exercise in human skeletal muscle

Age and inactivity have been associated with intramuscular triglyceride (IMTG) accumulation. Here, we attempt to disentangle these factors by studying the effect of 2 weeks of unilateral leg immobilization on substrate utilization across the legs during moderate-intensity exercise in young (n = 17; 23 ± 1 years old) and older men (n = 15; 68 ± 1 years old), while the contralateral leg served as the control. After immobilization, the participants performed two-legged isolated knee-extensor exercise at 20±1W(_50% maximalwork capacity) for 45 min with catheters inserted in the brachial artery and both femoral veins.Biopsy samples obtained from vastus lateralis muscles of both legs before and after exercise were used for analysis of substrates, protein content and enzyme activities. During exercise, leg substrate utilization (respiratoryquotient) did not differ between groups or legs. Leg fatty acid uptake was greater in older than in young men, and although young men demonstrated net leg glycerol release during exercise, older men showed net glycerol uptake. At baseline, IMTG, muscle pyruvate dehydrogenase complex activity and the protein content of adipose triglyceride lipase, acetyl-CoA carboxylase 2 and AMP-activated protein kinase (AMPK)γ3 were higher in young than in older men. Furthermore, adipose triglyceride lipase, plasma membrane-associated fatty acid binding protein and AMPKγ3 subunit protein contents were lower and IMTG was higher in the immobilized than the contralateral leg in young and older men. Thus, immobilization and age did not affect substrate choice (respiratory quotient) during moderate exercise, but the whole-leg and molecular differences in fatty acid mobilization could explain the age- and immobilization-induced IMTG accumulation

Acromioclavicular joint reconstruction with coracoacromial ligament transfer using the docking technique

<p>Abstract</p> <p>Background</p> <p>Symptomatic Acromioclavicular (AC) dislocations have historically been surgically treated with Coracoclavicular (CC) ligament reconstruction with transfer of the Coracoacromial (CA) ligament. Tensioning the CA ligament is the key to success.</p> <p>Methods</p> <p>Seventeen patients with chronic, symptomatic Type III AC joint or acute Type IV and V injuries were treated surgically. The distal clavicle was resected and stabilized with CC ligament reconstruction using the CA ligament. The CA ligament was passed into the medullary canal and tensioned, using a modified 'docking' technique. Average follow-up was 29 months (range 12–57).</p> <p>Results</p> <p>Postoperative ASES and pain significantly improved in all patients (p = 0.001). Radiographically, 16 (94%) maintained reduction, and only 1 (6%) had a recurrent dislocation when he returned to karate 3 months postoperatively. His ultimate clinical outcome was excellent.</p> <p>Conclusion</p> <p>The docking procedure allows for tensioning of the transferred CA ligament and healing of the ligament in an intramedullary bone tunnel. Excellent clinical results were achieved, decreasing the risk of recurrent distal clavicle instability.</p

No effect of glutamine supplementation and hyperoxia on oxidative metabolism and performance during high-intensity exercise.

addresses: Health and Biology, Liverpool Hope University, Liverpool, UK. [email protected]: Comparative Study; Journal ArticleThis is an Author's Accepted Manuscript of an article published in Journal of Sports Sciences, 2008, Vol. 26, Issue 10, pp. 1081 – 1090 © 2008 copyright Taylor & Francis, available online at: http://www.tandfonline.com/doi/abs/10.1080/02640410801930200Glutamine enhances the exercise-induced expansion of the tricarboxylic acid intermediate pool. The aim of the present study was to determine whether oral glutamine, alone or in combination with hyperoxia, influenced oxidative metabolism and cycle time-trial performance. Eight participants consumed either placebo or 0.125 g kg body mass(-1) of glutamine in 5 ml kg body mass(-1) placebo 1 h before exercise in normoxic (control and glutamine respectively) or hyperoxic (FiO(2) = 50%; hyperoxia and hyperoxia + glutamine respectively) conditions. Participants then cycled for 6 min at 70% maximal oxygen uptake (VO(2max)) immediately before completing a brief high-intensity time-trial (approximately 4 min) during which a pre-determined volume of work was completed as fast as possible. The increment in pulmonary oxygen uptake during the performance test (DeltaVO(2max), P = 0.02) and exercise performance (control: 243 s, s(x) = 7; glutamine: 242 s, s(x) = 3; hyperoxia: 231 s, s(x) = 3; hyperoxia + glutamine: 228 s, s(x) = 5; P < 0.01) were significantly improved in hyperoxic conditions. There was some evidence that glutamine ingestion increased DeltaVO(2max) in normoxia, but not hyperoxia (interaction drink/FiO(2), P = 0.04), but there was no main effect or impact on performance. Overall, the data show no effect of glutamine ingestion either alone or in combination with hyperoxia, and thus no limiting effect of the tricarboxylic acid intermediate pool size, on oxidative metabolism and performance during maximal exercise

Gender differentiated preferences for a community-based conservation initiative

Community-based conservation (CBC) aims to benefit local people as well as to achieve conservation goals, but has been criticised for taking a simplistic view of "community" and failing to recognise differences in the preferences and motivations of community members. We explore this heterogeneity in the context of Kenya's conservancies, focussing on the livelihood preferences of men and women living adjacent to the Maasai Mara National Reserve. Using a discrete choice experiment we quantify the preferences of local community members for key components of their livelihoods and conservancy design, differentiating between men and women and existing conservancy members and non-members. While Maasai preference for pastoralism remains strong, non-livestock-based livelihood activities are also highly valued and there was substantial differentiation in preferences between individuals. Involvement with conservancies was generally perceived to be positive, but only if households were able to retain some land for other purposes. Women placed greater value on conservancy membership, but substantially less value on wage income, while existing conservancy members valued both conservancy membership and livestock more highly than did non-members. Our findings suggest that conservancies can make a positive contribution to livelihoods, but care must be taken to ensure that they do not unintentionally disadvantage any groups. We argue that conservation should pay greater attention to individuallevel differences in preferences when designing interventions in order to achieve fairer and more sustainable outcomes for members of local communities

Subcellular distributions of calcium/calmodulin-stimulated and guanine nucleotide-regulated adenylate cyclase activities in the cerebral cortex

The subcellular distribution of Ca 2+ /calmodulin-stimulated adenylate cyclase activity was studied in comparison with that of guanine nucleotide-stimulated cyclase activity. The distributions of these activities were similar among the crude fractions but differed among the purified subsynaptosomal fractions. The specific activity of Ca 2+ /calmodulin-stimulated cyclase was highest in a light synaptic membrane fraction, which has few, if any, postsynaptic densities, whereas that of guanine nucleotide-stimulated cyclase was highest in a heavier synaptic membrane fraction rich in postsynaptic densities. These results suggest that the Ca 2+ /calmodulin-stimulated cyclase has, at least in part, a different cellular or subcellular location than the guanine nucleotide-stimulated cyclase.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45402/1/11064_2004_Article_BF00965018.pd