Muscle glycogen recovery after exercise measured by13C-magnetic resonance spectroscopy in humans: effect of nutritional solutions

The rate of glycogen resynthesis in human skeletal muscle after glycogen-depleting exercise is known to depend on carbohydrate intake and is reported to reach a platean after an adequate amount of carbohydrate (CHO) consumption. Efforts to maximize the rate of glycogen storage by changing the type and form of CHO, as well as by adding proteins or lipids have yielded inconsistent results. The objective of this study was to assess whether isocaloric addition of proteins and arginine to a CHO diet in the first 4 h after an endurance exercise would increase the rate of glycogen synthesis. The CHO solution, given twice at a 2 h interval according to earlier optimized protocols, contained 1.7 g CHO kgbody weight. The effects of this solution were compared to those of an isocaloric solution containing 1.2 g CHO/kgbody weight plus 0.5 g protein/kgbody weight (including 5 g arginine). Glycogen was measured in quadriceps muscle in vivo with natural abundance13C-magnetic resonance spectroscopy before exercise and twice after exercise, before and at the end of a 4-h period following the intake of one of the solutions. Eight subjects took part in a randomized cross-over trial separated by at least 1 week. Glycogen synthesis was found to be significantly increased with both regimes compared to a zero-caloric placebo diet, but no significant difference in glycogen resynthesis was found between the CHO-only diet and the one supplemented by proteins and arginine. It is estimated that significance would have been reached for an increase of 34%, while the effectively measured synthesis rates only differed by 5

Forest chimpanzees (Pan troglodytes verus) remember the location of numerous fruit trees

It is assumed that spatial memory contributes crucially to animal cognition since animals’ habitats entail a large number of dispersed and unpredictable food sources. Spatial memory has been investigated under controlled conditions, with different species showing and different conditions leading to varying performance levels. However, the number of food sources investigated is very low compared to what exists under natural conditions, where food resources are so abundant that it is difficult to precisely identify what is available. By using a detailed botanical map containing over 12,499 trees known to be used by the Taï chimpanzees, we created virtual maps of all productive fruit trees to simulate potential strategies used by wild chimpanzees to reach resources without spatial memory. First, we simulated different assumptions concerning the chimpanzees’ preference for a particular tree species, and, second, we varied the detection field to control for the possible use of smell to detect fruiting trees. For all these assumptions, we compared simulated distance travelled, frequencies of trees visited, and revisit rates with what we actually observed in wild chimpanzees. Our results show that chimpanzees visit rare tree species more frequently, travel shorter distances to reach them, and revisit the same trees more often than if they had no spatial memory. In addition, we demonstrate that chimpanzees travel longer distances to reach resources where they will eat for longer periods of time, and revisit resources more frequently where they ate for a long period of time during their first visit. Therefore, this study shows that forest chimpanzees possess a precise spatial memory which allows them to remember the location of numerous resources and use this information to select the most attractive resources

Environmental effects of James River sewage treatment plant outfall construction

In the spring of 1975 the Institute began a program to determine whether significant environmental changes would occur in the area of the new James River Plant outfall that might be related to its construction and/or initial operation. Parameters measured in the study were benthic animal and oyster populations, coliform levels and chlorine residuals. The primary emphasis of the study centered on the estimation of the impact of the construction activity on shellfish beds in the area. The results of the investigation are presented in three segments, the first dealing with shellfish populations, the second with other benthic animals and the third with coliforms and chlorine. Section I. Environmental Effects of James River Sewage Treatment Plant Outfall Construction on Oyster Beds in the James River by Dexter S. Haven and Paul C . Kendall Section II. Environmental Effects of the James River Sewage Treatment Plant Outfall Construction: Soft Bottom Macrobenthos by Robert J. Diaz and Donald F. Boesch Section III. Water Quality in the Vicinity of James River Sewage Treatment Plant Outfall by Michael E. Bende

How Scheduling Fits in the Irrigation Program in the Grand Valley of Colorado

The Grand Valley is an irrigated area of about 26,000 hectares (65,000 acres) adjacent to the Colorado River near Grand Junction, Colorado (Soil Conservation Service 1977). Grand Junction is near the Colorado-Utah border due west of Denver, Colorado. Implementation of the on-farm Grand Valley Salinity Control Program was initiated in January 1979. The program is authorized under Title II of Public Law 93-320. The purpose of this law is "to authorize certain works in the Colorado River Basin to control the salinity of water delivered to users in the United States and Mexico." Title I of Public Law 93-320 authorized certain works of improvement below Imperial Dam in southwestern Arizona. Some of these works of improvement have been completed or are under construction (Strand et al 1981). Title II of Public Law 93-320 authorized construction of four upstream projects on the Colorado River and studies on twelve additional projects. The Grand Valley Program is one of the four authorized projects. About 1.7 million dollars per year of U.S. Government funds have been used since 1979 to cost-share the installation of on-farm irrigation systems

Fuel metabolism during exercise in euglycaemia and hyperglycaemia in patients with type 1 diabetes mellitus—a prospective single-blinded randomised crossover trial

Aims/hypothesis: We assessed systemic and local muscle fuel metabolism during aerobic exercise in patients with type 1 diabetes at euglycaemia and hyperglycaemia with identical insulin levels. Methods: This was a single-blinded randomised crossover study at a university diabetes unit in Switzerland. We studied seven physically active men with type 1 diabetes (mean ± SEM age 33.5 ± 2.4years, diabetes duration 20.1 ± 3.6years, HbA1c 6.7 ± 0.2% and peak oxygen uptake [ $$\mathop {\text{V}}\limits^{\text{.}} {\text{O}}_{2{\text{peak}}}$$ ] 50.3 ± 4.5ml min−1 kg−1). Men were studied twice while cycling for 120min at 55 to 60% of $$\mathop {\text{V}}\limits^{\text{.}} {\text{O}}_{{\text{2peak}}}$$ , with a blood glucose level randomly set either at 5 or 11mmol/l and identical insulinaemia. The participants were blinded to the glycaemic level; allocation concealment was by opaque, sealed envelopes. Magnetic resonance spectroscopy was used to quantify intramyocellular glycogen and lipids before and after exercise. Indirect calorimetry and measurement of stable isotopes and counter-regulatory hormones complemented the assessment of local and systemic fuel metabolism. Results: The contribution of lipid oxidation to overall energy metabolism was higher in euglycaemia than in hyperglycaemia (49.4 ± 4.8 vs 30.6 ± 4.2%; p < 0.05). Carbohydrate oxidation accounted for 48.2 ± 4.7 and 66.6 ± 4.2% of total energy expenditure in euglycaemia and hyperglycaemia, respectively (p < 0.05). The level of intramyocellular glycogen before exercise was higher in hyperglycaemia than in euglycaemia (3.4 ± 0.3 vs 2.7 ± 0.2 arbitrary units [AU]; p < 0.05). Absolute glycogen consumption tended to be higher in hyperglycaemia than in euglycaemia (1.3 ± 0.3 vs 0.9 ± 0.1 AU). Cortisol and growth hormone increased more strongly in euglycaemia than in hyperglycaemia (levels at the end of exercise 634 ± 52 vs 501 ± 32nmol/l and 15.5 ± 4.5 vs 7.4 ± 2.0ng/ml, respectively; p < 0.05). Conclusions/interpretation: Substrate oxidation in type 1 diabetic patients performing aerobic exercise in euglycaemia is similar to that in healthy individuals revealing a shift towards lipid oxidation during exercise. In hyperglycaemia fuel metabolism in these patients is dominated by carbohydrate oxidation. Intramyocellular glycogen was not spared in hyperglycaemia. Trial registration: ClinicalTrials.Gov NCT00325559 Funding: This study was supported by unrestricted grants from the Oetliker-Stiftung für Physiologie, from the Swiss Diabetes Foundation, from NovoNordisk, Switzerland, and from the Swiss National Science Foundatio

Precision requirements for space-based X_(CO_2) data

Precision requirements are determined for space-based column-averaged CO_2 dry air mole fraction (X_(CO)_2) data. These requirements result from an assessment of spatial and temporal gradients in (X_(CO)_2) the relationship between (X_(CO)_2) precision and surface CO_2 flux uncertainties inferred from inversions of the (X_(CO)_2) data, and the effects of (X_(CO)_2) biases on the fidelity of CO_2 flux inversions. Observational system simulation experiments and synthesis inversion modeling demonstrate that the Orbiting Carbon Observatory mission design and sampling strategy provide the means to achieve these (X_(CO)_2) data precision requirements

Spinocerebellar ataxia types 1, 2, 3, and 6: disease severity and nonataxia symptoms.

OBJECTIVE: To identify factors that determine disease severity and clinical phenotype of the most common spinocerebellar ataxias (SCAs), we studied 526 patients with SCA1, SCA2, SCA3. or SCA6. METHODS: To measure the severity of ataxia we used the Scale for the Assessment and Rating of Ataxia (SARA). In addition, nonataxia symptoms were assessed with the Inventory of Non-Ataxia Symptoms (INAS). The INAS count denotes the number of nonataxia symptoms in each patient. RESULTS: An analysis of covariance with SARA score as dependent variable and repeat lengths of the expanded and normal allele, age at onset, and disease duration as independent variables led to multivariate models that explained 60.4% of the SARA score variance in SCA1, 45.4% in SCA2, 46.8% in SCA3, and 33.7% in SCA6. In SCA1, SCA2, and SCA3, SARA was mainly determined by repeat length of the expanded allele, age at onset, and disease duration. The only factors determining the SARA score in SCA6 were age at onset and disease duration. The INAS count was 5.0 +/- 2.3 in SCA1, 4.6 +/- 2.2 in SCA2, 5.2 +/- 2.5 in SCA3, and 2.0 +/- 1.7 in SCA6. In SCA1, SCA2, and SCA3, SARA score and disease duration were the strongest predictors of the INAS count. In SCA6, only age at onset and disease duration had an effect on the INAS count. CONCLUSIONS: Our study suggests that spinocerebellar ataxia (SCA) 1, SCA2, and SCA3 share a number of common biologic properties, whereas SCA6 is distinct in that its phenotype is more determined by age than by disease-related factors

Interplay of disorder and nonlinearity in Klein-Gordon models: Immobile kinks

We consider Klein-Gordon models with a $\delta$-correlated spatial disorder. We show that the properties of immobile kinks exhibit strong dependence on the assumptions as to their statistical distribution over the minima of the effective random potential. Namely, there exists a crossover from monotonically increasing (when a kink occupies the deepest potential well) to the non-monotonic (at equiprobable distribution of kinks over the potential minima) dependence of the average kink width as a function of the disorder intensity. We show also that the same crossover may take place with changing size of the system.Comment: 7 pages, 4 figure

On the existence of internal modes of sine-Gordon kinks

We study whether or not sine-Gordon kinks exhibit internal modes or ``quasimodes.'' By considering the response of the kinks to ac forces and initial distortions, we show that neither intrinsic internal modes nor ``quasimodes'' exist in contrast to previous reports. However, we do identify a different kind of internal mode bifurcating from the bottom edge of the phonon band which arises from the discretization of the system in the numerical simulations, thus confirming recent predictions.Comment: 4 pages, 2 figures, REVTeX, to appear as a Rapid Communication in Phys Rev E (July 1st

The plight of the sense-making ape

This is a selective review of the published literature on object-choice tasks, where participants use directional cues to find hidden objects. This literature comprises the efforts of researchers to make sense of the sense-making capacities of our nearest living relatives. This chapter is written to highlight some nonsensical conclusions that frequently emerge from this research. The data suggest that when apes are given approximately the same sense-making opportunities as we provide our children, then they will easily make sense of our social signals. The ubiquity of nonsensical contemporary scientific claims to the effect that humans are essentially--or inherently--more capable than other great apes in the understanding of simple directional cues is, itself, a testament to the power of preconceived ideas on human perception