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Selected AbstractsEffects of atmospheric CO2 concentration and defoliation on the growth of Themeda triandraGRASS & FORAGE SCIENCE, Issue 3 2004S. J. E. Wand Abstract The effects of elevated atmospheric carbon dioxide (CO2) concentration (700 ,mol mol,1) on defoliated (three clippings at 3-week intervals) and undefoliated plants were determined for the C4 grass Themeda triandra, Forsk. The elevated CO2 concentration significantly increased leaf regrowth following defoliation, and total leaf production was greatest in this treatment. Shoot biomass of undefoliated plants was also increased under the elevated CO2 concentration treatment. The primary effect of the elevated CO2 concentration in both defoliated and undefoliated plants was an increase in individual leaf length and mass of dry matter, linked to a higher leaf water content and increased photosynthetic rates at the canopy level. Photosynthetic down-regulation at the leaf level occurred, but this was compensated for by increased assimilation rates and greater canopy leaf area at the elevated CO2 concentration. Increases in leaf and sheath growth of defoliated plants in the elevated CO2 concentration treatment were lost following a final 3-week reversion to ambient CO2 concentration, but occurred in plants exposed to the elevated CO2 concentration for the final 3-week period only. In conclusion, elevated atmospheric CO2 concentration increases shoot growth via increased leaf extension, which is directly dependent on stimulation of concurrent photosynthesis. CO2 responsiveness is sustained following moderate defoliation but is reduced when plants experience reduced vigour as a result of maturation or high frequency of defoliation. [source] Comparing strategies for controlling an African pest rodent: an empirically based theoretical studyJOURNAL OF APPLIED ECOLOGY, Issue 5 2001Nils Chr. Summary 1Small rodents in general and the multimammate rat Mastomys natalensis in particular cause major economic losses in Africa through damage to crops. Attempts to develop dynamic population models for this and other pest rodents are ongoing. 2Demographic estimates from a capture,mark,recapture (CMR) study in Tanzania were used to parameterize a population model for this species. This model incorporated three functional age categories (juveniles, subadults and adults) of both sexes and used density-dependent and density-independent factors, the latter represented by rainfall. 3The model was used to analyse the effect of rodent control on the population dynamics and resulting number of rats. Control measures affecting survival as well as reproduction were considered. 4The model showed that control measures reducing survival will only have long-term effects on population size if they are also applied when rodent densities are low. Control measures applied only when rodent densities are high will not have persistent effects, even at high mortality rates. 5The model demonstrated that control measures reducing reproduction are likely to prevent Mastomys outbreaks, but will keep densities low over a long period only when the contraceptive effect is strong (> 75% reduction). 6Provided that CMR data are available, we recommend developing Leslie-type population models for rodent pests on the basis of CMR-estimated demographic schedules. Such models have great potential in rodent management and allow the evaluation of different strategies. 7Besides improving the ecological basis of the population modelling, economic considerations need to be incorporated into decisions about rodent control. We suggest that appropriate population models will provide important input into such decision making. [source] Dehydration kinetics of red pepper (Capsicum annuum L var Jaranda)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2003N Sanjuán Abstract Shredded and whole red pepper samples were dehydrated in a laboratory drier with a through-flow air velocity of 0.5,m,s,1 at 50, 55, 60 and 70,°C. Shredded peppers dried faster than whole peppers. The drying behaviour of whole samples was characterised by a constant- and a falling-rate drying period, whilst that of shredded samples was characterised by a falling-rate drying period only. The mass transfer coefficient for whole samples during the constant-rate period was computed experimentally. The effect of temperature on the mass transfer coefficient was described by the Arrhenius model. The activation energy was 58,kJ,mol,1. In the falling-rate period the mass transfer was described by a diffusional model, and the effective diffusion coefficient at each temperature was determined. Diffusion coefficients were estimated to lie between 4.38,×,10,11 and 10.99,×,10,11,m2,s,1 for whole peppers and between 37.23,×,10,11 and 99.61,×,10,11,m2,s,1 for shredded peppers. The effect of temperature on the effective diffusion coefficient was described by the Arrhenius equation, with an activation energy of 44,kJ,mol,1 for whole peppers and 56,kJ,mol,1 for shredded peppers. © 2003 Society of Chemical Industry [source] MULTIDISCIPLINARY PAIN ABSTRACTS: 47PAIN PRACTICE, Issue 1 2004Article first published online: 15 MAR 200 The purpose of this multicenter, randomized, controlled trial was to compare the effect of manual therapy to exercise therapy in sick-listed patients with chronic low back pain. The effects of exercise therapy and manual therapy on chronic low back pain with respect to pain, function, and sick leave have been investigated in a number of studies. The results are, however, conflicting. Patients with chronic low back pain or radicular pain sick-listed for more than 8 weeks and less than 6 months were included. A total of 49 patients were randomized to either manual therapy (n=27) or to exercise therapy (n=22). Sixteen treatments were given over the course of 2 months. Pain intensity, functional disability (Oswestry disability index), general health (Dartmouth Care Cooperative function charts), and return to work were recorded before, immediately after, at 4 weeks, 6 months, and 12 months after the treatment period. Spinal range of motion (Schober test) was measured before and immediately after the treatment period only. Although significant improvements were observed in both groups, the manual therapy group showed significantly larger improvements than the exercise therapy group on all outcome variables throughout the entire experimental period. Immediately after the 2-month treatment period, 67% in the manual therapy and 27% in the exercise therapy group had returned to work. It was concluded that improvements were found in both intervention groups, but manual therapy showed significantly greater improvement than exercise therapy in patients with chronic low back pain. The effects were reflected on all outcome measures, both on short- and long-term follow-up. [source] Brief communication: Puncture and crushing resistance scores of Tana river mangabey (Cercocebus galeritus) diet itemsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Julie Wieczkowski Abstract Cercocebus mangabeys are characterized by dental traits that have been interpreted as adaptations to eat hard diet items. Although there are data that mangabeys include a large proportion of fruit and especially seeds in their diets, no hardness measurements have been done on mangabeys' food items. This study measured puncture and crushing resistance of food items in the diet of the Tana River mangabey (C. galeritus). Feeding data were collected by the use of scan samples from one mangabey group from August 2000 to July 2001 and from July 2005 to June 2006. Food items were collected during the latter period only, and from the same tree in or under which mangabeys had been observed eating. A portable agricultural fruit tester was used to measure the puncture resistance of fruit and a valve spring tester was used to measure the crushing resistance of seeds. The average puncture resistance of fruit was 1.7 kg/mm2, and the average crushing resistance of seeds was 12.8 kg. There were no correlations between puncture resistance, crushing resistance, or all resistance scores and frequency contribution to the diet. Resistance scores measured in this study were within the range of hardness scores of fruit and exceeded hardness scores of seeds eaten by other hard object feeders. Although this study supports the interpretation that Cercocebus dental traits are adaptations to hard object feeding, future research should investigate other material properties of food, as well as the role hard diet items play in niche separation and as fallback foods. Am J Phys Anthropol 2009. © 2009 Wiley-Liss, Inc. [source] Oxidative stress parameters during starvation and refeeding periods in Adriatic sturgeon (Acipenser naccarii) and rainbow trout (Oncorhynchus mykiss)AQUACULTURE NUTRITION, Issue 6 2009M. FURNÉ Abstract This work analyses the changes in the redox balance in two fish species: Adriatic sturgeon (Acipenser naccarii) and rainbow trout (Oncorhynchus mykiss) during starvation and refeeding period. The starvation period raised the lipid peroxidation (thiobarbituric-acid-reacting substances) levels in liver and blood, while a decline occurred in the antioxidant enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione reductase (GR) in both fish species. In liver, after the refeeding period, SOD activity recovered in both species, whereas CAT activity recovered only in trout. Furthermore, in both tissues of the two species, the lipid peroxidation levels remained high after 2 months of refeeding. In white muscle and heart, the lipid peroxidation levels indicate that these tissues did not undergo oxidative stress during the 72-day period. During starvation, in the muscle of both fish the fall in the lipid peroxidation level coincided with a rise in CAT, GPX and GR. The refeeding period in this tissue raised the lipid peroxidation level, and the enzymatic activities reached the values of the first point of starvation. In heart, no oxidative damage was detected during starvation in either species. The CAT and SOD activities increased during the starvation period only in trout. [source] On the Role of Baseline Measurements for Crossover Designs under the Self and Mixed Carryover Effects ModelBIOMETRICS, Issue 1 2010Yuanyuan Liang Summary It is well known that optimal designs are strongly model dependent. In this article, we apply the Lagrange multiplier approach to the optimal design problem, using a recently proposed model for carryover effects. Generally, crossover designs are not recommended when carryover effects are present and when the primary goal is to obtain an unbiased estimate of the treatment effect. In some cases, baseline measurements are believed to improve design efficiency. This article examines the impact of baselines on optimal designs using two different assumptions about carryover effects during baseline periods and employing a nontraditional crossover design model. As anticipated, baseline observations improve design efficiency considerably for two-period designs, which use the data in the first period only to obtain unbiased estimates of treatment effects, while the improvement is rather modest for three- or four-period designs. Further, we find little additional benefits for measuring baselines at each treatment period as compared to measuring baselines only in the first period. Although our study of baselines did not change the results on optimal designs that are reported in the literature, the problem of strong model dependency problem is generally recognized. The advantage of using multiperiod designs is rather evident, as we found that extending two-period designs to three- or four-period designs significantly reduced variability in estimating the direct treatment effect contrast. [source] Alteration of inflammatory response following small-volume resuscitationBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 7 2000F. Gebhard Background Small-volume resuscitation is rather effective in the primary volume treatment of major trauma. Blood pressure stabilizing effects occur immediately but last for a limited period only. Influences on inflammatory reactions in humans have not been reported so far. This prospective randomized study therefore analysed the inflammatory response in the very early (pre)clinical period after administration of crystalloids plus starch, hyperosmolar/hyperoncotic starch and lyophilized plasma solutions. Methods Upon approval of the ethics committee, 41 patients were enrolled with multiple injuries (injury severity score (ISS) mean 34 (range 9,75)). The patients received randomly either standard solutions, i.e. starch plus crystalloids (group C (control); n = 14), hyperosmolar/hyperoncotic starch (group S (small volume); n = 14) or lyophilized plasma (group L (lyoplasma); n = 13). Subsets were performed according to the different solutions as well as to the severity of trauma (ISS below 17, 18,31, 32 or more) and survivors/non-survivors. The first blood sample was obtained at the scene of the accident before cardiopulmonary resuscitation, when appropriate. Subsequently, blood samples were collected hourly. All samples were spun immediately at 4°C and stored at ,70°C. Interleukin (IL) 6 as well as several different prostaglandins (PGI2, thromboxane A2, PGE2) were determined to characterize the overall inflammatory response. Results Eleven casualties (seven men and four women, mean age 31 years) died because of major trauma within 24 h after the incident. In all patients IL-6 levels promptly increased within the first 2 h, most pronounced in patients with the severest trauma (ISS greater than 32) and non-survivors. Patients in groups C and S had a comparable time course of IL-6 plasma levels with a slightly higher release in minor injuries (ISS less than 30). The same was true for prostaglandins. In contrast, patients in group L had clearly higher IL-6 concentrations during the first 2,12 h, again most pronounced in those with the severest trauma (ISS greater than 32). Conclusion These results demonstrate that the early systemic inflammatory response after small-volume resuscitation is rather similar to that of patients infused with standard-volume therapy after trauma. In contrast, lyoplasma seems to increase the inflammatory response regardless of the injury severity. © 2000 British Journal of Surgery Society Ltd [source] Effect of a 4-week treatment with theophylline on sputum eosinophilia and sputum eosinophil chemotactic activity in steroid-naive asthmaticsCLINICAL & EXPERIMENTAL ALLERGY, Issue 8 2000Louis Background The precise mechanism of action of theophylline in asthma is not fully understood but recent data have drawn attention to its potential anti-inflammatory effect. Objective The purpose of this study was to assess the effect of theophylline on sputum eosinophilia and sputum eosinophil chemotactic activity in steroid-naive asthmatics. Method We performed a 4-week randomized double-blind, placebo-controlled, parallel group study in 21 mild to moderate steroid-naive asthmatics whose sputum eosinophilia was found twice > 5% during the run in period. Eleven subjects received 600 mg/24 h theophylline for the first 2 weeks and 900 mg/24 h for the last 2 weeks while 10 subjects took a placebo for 4 weeks. Sputum was induced after 2 and 4 weeks of treatment and 1 week after stopping the treatment. The sputum samples were compared for their cell counts, eosinophil cationic protein (ECP) levels and eosinophil chemotactic activity using micro-Boyden chambers. Results Serum theophylline concentrations reached 7 and 11 ,g/mL at V3 and V4, respectively. Intragroup comparisons showed that theophylline, but not placebo, caused a significant reduction in sputum eosinophil counts at V3 (62 ± 10% from baseline, P < 0.01) and a strong trend at V4 (67 ± 16% from baseline, P = 0.07) when compared to baseline. The intergroup difference obtained after comparing the area under the curve over the 4 week treatment period only approached the statistical significance (P = 0.08). At baseline the fluid phase of the sputum contained a significant eosinophil chemotactic activity which was inhibited after a 4-week treatment by theophylline (P < 0.01) but not by placebo. The mean sputum theophylline levels after 4 weeks of treament (1.7 ,g/mL) was lower than that required to cause significant inhibition of eosinophil chemotaxis in vitro. Conclusion Theophylline decreases the natural sputum eosinophil chemotactic activity present in asthmatics. However, when using a small sample size, the 35% reduction in sputum eosinophilia achieved by theophylline failed to reach statistical significance when compared to that seen after placebo. [source] Comparative effects of resistance training on peak isometric torque, muscle hypertrophy, voluntary activation and surface EMG between young and elderly womenCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 2 2007Jack Cannon Summary We compared the effect of a 10-week resistance training program on peak isometric torque, muscle hypertrophy, voluntary activation and electromyogram signal amplitude (EMG) of the knee extensors between young and elderly women. Nine young women (YW; range 20,30 years) and eight elderly women (EW; 64,78 years) performed three sets of ten repetitions at 75% 1 repetition maximum for the bilateral leg extension and bilateral leg curl 3 days per week for 10 weeks. Peak isometric torque, EMG and voluntary activation were assessed before, during, and after the training period, while knee extensor lean muscle cross-sectional area (LCSA) and lean muscle volume (LMV) were assessed before and after the training period only. Similar increases in peak isometric torque (16% and 18%), LCSA (13% and 12%), LMV (10% and 9%) and EMG (19% and 21%) were observed between YW and EW, respectively, at the completion of training (P<0·05), while the increase in voluntary activation in YW (1·9%) and EW (2·1%) was not significant (P>0·05). These findings provide evidence to indicate that participation in regular resistance exercise can have significant neuromuscular benefits in women independent of age. The lack of change in voluntary activation following resistance training in both age groups despite the increase in EMG may be related to differences between measurements in their ability to detect resistance training-induced changes in motor unit activity. However, it is possible that neural adaptation did not occur and that the increase in EMG was due to peripheral adaptations. [source] Palivizumab efficacy in preterm infants with gestational age ,30 weeks without bronchopulmonary dysplasiaPEDIATRIC PULMONOLOGY, Issue 3 2007Marianne Grimaldi MD Abstract The present study was designed to determine the efficacy of administration of palivizumab to preterm infants with gestational age (GA) ,30 weeks without bronchopulmonary dysplasia (BPD). All patients born with GA ,30 weeks without BPD on Day 28 and hospitalized for RSV bronchiolitis in Burgundy (12 hospitals) from December 1 to April 30 of the next year were included in this prospective observational study during five successive RSV seasons (1999,2000, 2000,2001, 2001,2002, 2002,2003, and 2003,2004). Palivizumab was given to premature infants with a gestational age ,30 weeks without BPD in the 2002,2003 and 2003,2004 periods only. In the cohort of premature infants with GA ,30 weeks without BPD, the respiratory syncytial virus (RSV) bronchiolitis hospitalization rate was reduced significantly (P,<,0.01) in the two seasons with palivizumab prophylaxis (2002,2003: 0% and 2003,2004: 2%) versus the three previous RSV seasons (1999,2000: 14.3%; 2000,2001: 16.7%; 2001,2002: 10.2%). The number needed to treat to prevent one hospitalization for RSV bronchiolitis was 6 (95%CI: 4,11). Such favorable results have not been always found in the few available postmarketing epidemiological studies on hospitalization rate after palivizumab prophylaxis. Differences in health care organization could explain those discrepancies. Pediatr Pulmonol. 2007; 42:189,192. © 2007 Wiley-Liss, Inc. [source] | ||||||||||||||||