bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Vitamin E Source and Dietary Supplementation Level on Production Performance of Sunshine Bass, Morone chrysops ♀ × Morone saxatilis ♂, Fillet Tocopherol Content, and Immunocompetency during Stress and Bacterial Challenge
Authors: Trushenski Jesse T. , Kohler Christopher C.
Published: July 2008

We evaluated the effects of dietary vitamin E concentration and source on production performance and immunocompetency of sunshine bass, Morone chrysops × Morone saxatilis, following stress and disease challenge. Four diets were formulated to contain requisite levels (1×) or five times (5×) the vitamin E requirement of sunshine bass as met by synthetic vitamin E (SYNE) or natural source vitamin E (NSVE). Each diet was fed to juvenile sunshine bass for 8 wk prior to experimental challenges. Replicate tanks within each dietary treatment were challenged with stressor exposure (chasing with dip net), incidental Flavobacterium columnare exposure, or both; control groups were not challenged. Pathogen and/or stressor exposure largely resulted in significant reductions in immunological performance. Although significant independent dietary effects were not observed among immunological parameters, suppression of complement and macrophage respiratory burst activities was numerically lower within the 5× NSVE treatment. Production performance was largely unaffected by dietary vitamin E source or level. Fillet α‐tocopherol concentration was significantly higher among fish fed the 5× diets (40.7/41.6 vs. 12.2/14.5 μg/g dry tissue for 1× diets); however, the dietary concentration required to achieve these levels was lower for NSVE. Although super‐requirement levels of either source of vitamin E were apparently beneficial, NSVE was effective at ∼50% lower supplementation levels.
Improvement of Water Quality by the Macroalga, Gracilaria lemaneiformis (Rhodophyta), near Aquaculture Effluent Outlets
Authors: Xu Yongjian , Fang Jianguang , Tang Qisheng , Lin Junda , Le Guanzong , Liao Lv
Published: July 2008

Raft culture of the seaweed, Gracilaria lemaneiformis (Bory) Dawson, was used as biofilter for purifying effluent and removing nutrients from the nearby animal aquaculture. The results showed that the cultivated seaweed grew well outside effluent discharge outlets for growout ponds and a hatchery plant. The biomass (fresh weight) of Gracilaria from the 0.5‐ha area outside the growout ponds increased about 60 times, from 80 to 4750 g/m during the 65 d of experiment (with the daily special growth rate [SGR] of 3.87%/d); the yield was 30.4 tons and 93.97 kg N and 12.81 kg P were removed; the seaweed biomass from the 0.2‐ha area outside the hatchery outlet increased 37.5 times, from <100 to 3600 g/m (with SGR of 3.4%/d); the yield was 10.4 tons and 31.7 kg N and 4.33 kg P were removed. Several water quality parameters such as dissolved oxygen, secchi disk depth, and pH value in the algal cultivation area were substantially higher than those in the noncultivation zone, whereas chemical oxygen demand, dissolved inorganic nitrogen, and dissolved inorganic phosphorous at both areas were similar.
Excess Runoff Contribution to Daily Discharge Frequency of Channel Catfish Farms in Alabama
Authors: Boyd Claude E , Pine Harvey , Boyd Christopher A , Hulcher Richard
Published: July 2008

Aquaculture facilities producing more than 45,454 kg/yr and discharging 30 d or more annually, excluding excess runoff, are designated concentrated aquatic animal production facilities by the United States Environmental Protection Agency (USEPA), and they require National Pollutant Discharge Elimination System permits. Three individual ponds and three of four channel catfish farms in Alabama discharged 30 d or more annually. USEPA did not define excess runoff or explain how to adjust for it. There is normally at least 7.6 cm storage depth in ponds when rainfall begins. Runoff that causes overflow should be considered excess runoff. The year in Alabama can be divided into three soil moisture epochs. The 24‐h rainfall amounts necessary to cause ponds to overflow under normal conditions for each epoch were estimated by water budgeting. For watershed ponds, daily rainfall greater than amounts given below could cause excess runoff:

Period
Blackland Prairie region (cm)
Other regions (cm)

December to April
2
3.3

May to August
3.8
5.8

September to November
5.6
7.5

Daily rainfall above 7.5 cm could cause overflow during any soil moisture epoch from embankment ponds in all regions. Ponds discharged for 2–5 d after some rainfall events, and discharge for up to 4 d after an excess rainfall day should be excess runoff.
Critical Thermal Minima of Penaeus semisulcatus (Decapoda: Penaeidae) Acclimated to Four Temperature Levels
Authors: Kır Mehmet , Kumlu Metin
Published: July 2008

Critical thermal minima (CTmin) and lower incipient lethal temperature (LILT) were determined for Penaeus semisulcatus juveniles at four different acclimation temperatures (14, 20, 26, and 32 
C). The effect of cooling rate on the CTmin was also investigated. The CTmin of shrimps at these respective acclimation temperatures were 7.1, 8.9, 10.5, 12.6 
C and 6.6, 8.0, 9.7, 11.4 
C and 6.1, 7.2, 8.3, 9.9 
C for the cooling rates of 0.25, 0.5, and 1.0 
C/h, respectively. The LILT value of P. semisulcatus were 5.23, 6.14, 7.36, 8.57 
C at 14, 20, 26, and 32 
C, respectively. The results indicated that both the cooling rate and the acclimation temperature significantly affected the CTmin (P < 0.05). Acclimation temperature had also significant effects on the LILT of P. 

semisulcatus

(P < 0.05). In acclimation temperatures between 14 and 32 
C, the acclimation response ratio values were 0.30, 0.26, and 0.21 at the cooling rates of 0.25, 0.5, and 1 
C/h, respectively. The cold tolerance zone in which P. 

semisulcatus

can survive for short period in this study ranged from 6.1 to 12.6 
C.
Evaluation of Brewer’s Waste as Partial Replacement of Fish Meal Protein in Nile Tilapia, Oreochromis niloticus, Diets
Authors: Zerai Desale B. , Fitzsimmons Kevin M. , Collier Robert J. , Duff Glenn C
Published: July 2008

Abstract.— Brewer’s waste is one of the promising protein source by‐products for fish diets. A 10‐wk feeding trial experiment involving five different diets with increasing levels of brewer’s waste (32% crude protein) was carried out to evaluate the use of brewer’s waste in tilapia diets in place of fish meal. Growth performance was compared against a control diet formulated to have similar composition to a typical commercial diet. Four experimental diets replaced successively 25, 50, 75, and 100% of the fish meal protein with brewer’s waste. The diets were isonitrogenous and isocaloric. Results indicated that weight gain did not differ significantly (P > 0.05) with up to 50% replacement. Feed intake and utilization were depressed at high levels of brewer’s waste. In addition, methionine of high replacement level diets was low. The results of the digestibility trial demonstrated that the brewer’s waste used in this study has an apparent digestibility coefficient for protein of 70%. It was concluded that 50% of the fish meal protein in a typical commercial diet could be replaced with brewer’s waste with no adverse effect on growth and feed utilization for tilapia.
The dense indumentum with its polyphenol content may replace the protective role of the epidermis in some young xeromorphic leaves
Authors: Karabourniotis George , Fasseas Costas
Published: July 2008

The bright, yellow-green, ammonia-induced fluorescence of polyphenol compounds contained in the nonglandular hairs and within the epidermis of Olea europaea and Quercus ilex leaves was age dependent. Epifluorescence microscopic examination of transverse sections of leaves from both species showed that abaxial and adaxial epidermal layers emitted the characteristic green-yellow bright fluorescence only in late developmental stages, when a considerable decrease of the trichome density had already occurred. At earlier developmental stages, only the dense and thick trichome layer emitted the bright green-yellow fluorescence. In addition, the trichomes of young leaves of Olea and Quercus resembled the glandular ones of other species morphologically and possibly functionally. These findings suggest that the protective role of the trichome against ultraviolet-B radiation damage and (or) other environmental factors is particularly significant during the early stages of leaf development and may be less important at later stages, when the protective role is taken over by the epidermis. Keywords: leaf hairs, phenolics, UV-B radiation damage, leaf development, Olea europaea L., Quercus ilex L.
Temporal scale and the accumulation of peat in a Sphagnum bog
Authors: Belyea Lisa R. , Warner Barry G.
Published: July 2008

We examined short-term (decadal) and long-term (millenial) processes of peat accumulation, and the links between them, in a Sphagnum bog in continental Canada. A previously published model of bog growth was fitted to age profiles of the oxic acrotelm (surface, < 60 cm thick) and the underlying, anoxic catotelm (210 cm thick). Approximately 5300 years of accumulation were represented in a radiocarbon-dated core that extended to the base of the deepest part of the peat deposit. The model estimated that the overall rate at which material entered long-term storage in the catotelm was 60–66 g∙m−2∙a−1. Although the decay rate coefficient was near zero, the bog stopped accumulating peat within the past 1500 years, resulting from either a decrease in the rate of transfer of material from the acrotelm or an increase in the rate of decay of material at the top of the catotelm. The model of bog growth estimated recent inputs to the acrotelm (90–930 g∙m−2∙a−1) that were twofold higher than published field measurements of aboveground productivity, and decay rate coefficients (0.005–0.040 a−1) that were 10-fold lower than published litter-bag measurements of mass loss. The pattern of mass loss over time, approximated from nitrogen concentration data, deviated from the pattern predicted by exponential models of decay. Calculations of the balance between additions to and losses from the acrotelm suggest that the amount of material transferred to the underlying catotelm differs among microhabitats. Such spatial variability in short-term processes is incompatible with long-term processes determining the position of the acrotelm–catotelm boundary. We discuss the applicability of the model to continental peatlands and suggest ways to improve modelling of short-term autogenic processes. Keywords: peatland, peat accumulation, organic matter, decomposition, age profiles, mathematical models.
The influence of light quality and carbon dioxide enrichment on the growth and physiology of seedlings of three conifer species. I. Growth responses
Authors: Hoddinott John , Scott Rickey
Published: July 2008

Plant growth responds to light quality, as evaluated by the red/far-red (R/FR) quantum flux ratio, and to the level of CO2. Pinus banksiana, Picea mariana and Picea glauca seedlings were raised at 350, 700, or 1050 μL∙L−1 CO2 and high or low R/FR ratios and growth was measured over a 16-week growth period. Far-red rich light enhanced the whole plant and height relative growth rates of Pinus banksiana. The three species showed species specific responses in plant organ relative growth rates and partitioning ratios. On the basis of their biomass partitioning the species would be ranked Pinus banksiana < Picea mariana < Picea glauca for shade tolerance. In commercial operations, seedlings grown for outplanting are selected, in part, on the basis of plant form as described by the stem height/diameter ratio. More desirable ratios were obtained at ambient CO2 concentrations for Pinus banksiana and Picea mariana in red rich light and for Picea glauca in far-red rich light. Keywords: seedling growth, light quality, CO2 enrichment.
Morphological and genetic variation in disjunct populations of the avalanche lilyErythronium montanum
Authors: Allen Geraldine A. , Antos Joseph A. , Worley Anne C. , Suttill Terri A. , Hebda Richard J.
Published: July 2008

The genetic structure and morphological variability of species are influenced by both life-history traits and historical factors. We studied morphological and genetic variability in 12 populations of the avalanche lily, Erythronium montanum, representing the four disjunct regions of its geographic range in Oregon, Washington, and British Columbia. Floral traits exhibited significant differences among regions and among populations within regions, but these differences showed no clear geographic pattern, and for all traits there was substantial overlap among populations. In contrast, analysis of isozyme variation indicated a marked north–south gradient in genetic variability. The northernmost populations (from the B.C. Coast Range) had an average of 13% polymorphic loci and 1.13 alleles per locus, whereas southern populations (from the Cascade Mountains) averaged 48% polymorphic loci and 1.67 alleles per locus. The northern populations possessed no unique alleles but contained a subset of the alleles found in regions further south. We conclude that disjunct populations of E. montanum in B.C. probably arose through long-distance dispersal from more southern populations following deglaciation. Keywords: Erythronium montanum, genetic variation, glacial refugia, isozymes, long-distance dispersal, phytogeography.
The presence and antifeedant function of toxin-producing secretory cells on hyphae of the lawn-inhabiting agaric Conocybe lactea
Authors: Hutchison Leonard J. , Madzia Susan E. , Barron George L.
Published: July 2008

On water agar, Conocybe lactea (Lange) Metrod produces droplets of toxin on conspicuous secretory cells. Both free-living rhabditoid nematodes and fungus-feeding nematodes (Aphelenchoides sp.) are immobilized when they contact the toxin droplets. Prolonged and (or) repeated exposure to the toxin results in death of the nematodes, which may take place at some distance from the contact point. Unlike Pleurotus ostreatus (Jacq.:Fr.) Kummer, the hyphae of C. lactea do not locate and colonize immobilized nematodes and (or) consume them as a nutrient source. It is considered that the toxin droplets are for protection of the hyphal system and function as antifeedants to repel or kill fungus-feeding nematodes and possibly other fungus-feeding soil microfauna. No differences were observed in nematode response between dikaryotic and monokaryotic cultures, although the latter produced a spermatial-like arthrosporic anamorph. Panaeolina foenisecii (Pers.:Fr.) R. Maire also produces secretory cells with fluid droplets. These droplets, however, are not as toxic to nematodes as those of C. lactea. Keywords: secretory cells, nematotoxin, antifeedants, lawn mushroom.
Genetics of Cronartium ribicola. I. Axenic culture of haploid clones
Authors: Kinloch Jr. Bohun B. , Dupper Gayle E.
Published: July 2008

Genetically pure lines of the mononucleate (haploid) stage of Cronartium ribicola can be grown by isolating mycelium from single spots on infected white pine needles or by culturing single basidiospores on defined media preconditioned by cell-free diffusates of massed germinating basidiospores. Although growth is initially slow, cultures can be increased rapidly by alternately subculturing from solid to liquid media and back again indefinitely. The ability to culture pure haploid clones has important implications for studying the genetic structure and sexual behavior of rust populations and the nature of virulence. Keywords: white pine blister rust, sugar pine, virulence.
New rusts from Pakistan
Authors: Khalid A. N. , Iqbal S. H.
Published: July 2008

Phakopsora anaphalidis-adnatae sp.nov. is described and illustrated. Phakopsora artemisiae, a rust on Artemisia montana, is also newly reported from Pakistan. Keywords: Uredinales, Phakopsora anaphalidis-adnatae, P. artemisiae, Anaphalis, Artemisia.
Growth hormone responses to 3 different exercise bouts in 18- to 25- and 40- to 50-year-old men
Authors: Gilbert Kate L. , Stokes Keith A. , Hall George M. , Thompson Dylan
Published: July 2008

Exercise is a potent stimulus for growth hormone (GH) release, although aging appears to attenuate this response. The aim of this study was to investigate GH responses to different exercise stimuli in young and early middle-aged men. Eight men aged 18–25 y and 8 men aged 40–50 y completed 3 trials, at least 7 days apart, in a random order: 30 s cycle-ergometer sprint (sprint), 30 min resistance exercise bout (resistance), 30 min cycle at 70% maximal oxygen consumption (endurance). Blood samples were taken pre-, during, and post-exercise, and area under the GH vs. time curve was calculated for a total of 120 min. Mean blood lactate concentrations and percentage heart rate maximum at which the participants were working were not different between groups in any of the trials. In both groups, blood lactate concentrations were significantly lower in the endurance trial than in the sprint and resistance trials. There were no significant differences in resting GH concentration between groups or trials. GH AUC was significantly greater in the young group than the early middle-aged group, in both sprint (531 (±347) vs. 81 (±54) µg·L–1 per 120 min, p = 0.003) and endurance trials (842 (±616) vs. 177 (±137) µg·L–1 per 120 min, p = 0.010). Endurance exercise elicits a greater GH response than sprint and resistance exercise; however, aging per se, factors associated with aging, or an inability to achieve a sufficient absolute exercise intensity results in a smaller GH response to an exercise stimulus in early middle-aged men.
About unsuspected potential determinants of obesity
Authors: Tremblay Angelo , Chaput Jean-Philippe
Published: July 2008

The positive energy balance underlying obesity is generally attributed to factors exerting a direct measurable impact on energy intake or expenditure. Thus, sedentariness and (or) excess caloric intake represent the “Big Two” factors on which almost all the attention of health professionals is devoted in preventive and therapeutic programs for obesity. However, recent research reveals that other more discrete factors can also promote a positive energy balance and body fat gain. Accordingly, this paper documents the effects of low micronutrient intake, short sleep duration, knowledge-based work, and organochlorine compounds on components of energy balance and body composition. These effects aid in the understanding as to why modernity accentuates the risk of obesity. Furthermore, they also suggest that body fat gain is not only a problem, but also a solution in maintaining body homeostasis, i.e., a state of optimal body functionality, in the context of modernity and globalization.
An obsession with CO2This paper is a summary from the John Sutton Memorial Lecture at the Canadian Society for Exercise Physiology Annual Meeting, held in London, Ont., 14–17 November 2007.
Authors: Jones Norman L.
Published: July 2008

The concept that underlies this paper is that carbon dioxide (CO2) removal is at least as important as the delivery of oxygen for maximum performance during exercise. Increases in CO2pressure and reductions in the pH of muscle influence muscle contractile properties and muscle metabolism (via effects on rate-limiting enzymes), and contribute to limiting symptoms. The approach of Barcroft exemplified the importance of integrative physiology, in describing the adaptive responses of the circulatory and respiratory systems to the demands of CO2production during exercise. The extent to which failure in the response of one system may be countered by adaptation in another is also explained by this approach. A key factor in these linked systems is the transport of CO2in the circulation. CO2is mainly (90%) transported as bicarbonate ions — as such, transport of CO2is critically related to acid–base homeostasis. Understanding in this field has been facilitated by the approach of Peter Stewart. Rooted in classical physico–chemical relationships, the approach identifies the independent variables contributing to homeostasis — the strong ion difference ([SID]), ionization of weak acids (buffers, Atot) and CO2pressure (PCO2). The independent variables may be reliably measured or estimated in muscle, plasma, and whole blood. Equilibrium conditions are calculated to derive the dependent variables — the most important being the concentrations of bicarbonate and hydrogen ions. During heavy exercise, muscle [H+] can exceed 300 nEq·L–1(pH 6.5), mainly due to a greatly elevated PCO2and fall in [SID] as a result of increased lactate (La–) production. As blood flows through active muscle, [La–] increase in plasma is reduced by uptake of La–and Cl–by red blood cells, with a resultant increase in plasma [HCO3–]. Inactive muscle contributes to homeostasis through transfer of La–and Cl–into the muscle from both plasma and red blood cells; this results in a large increase in [HCO3–]. In the lungs, oxygenation of hemoglobin increases red blood cell [A–] aiding rapid conversion of HCO3–into CO2in red cells (containing carbonic anhydrase), with diffusion of CO2into alveoli, but full equilibration of the CO2system in plasma may not occur during the short pulmonary capillary circulation time in heavy exercise. The ionization state of imidazole groups on protein histidine may provide integration between acid–base homeostasis, membrane anion transfer proteins, and activation of rate-limiting enzymes.
Association between non-responsiveness to plant sterol intervention and polymorphisms in cholesterol metabolism genes: a case-control study
Authors: Rudkowska Iwona , AbuMweis Suhad S. , Nicolle Catherine , Jones Peter J.H.
Published: July 2008

Plant sterol (PS) consumption decreases low-density lipoprotein cholesterol (LDL-C) levels; however, high variability of responsiveness of lipid levels to PS intervention has been observed. We hypothesized that common single-nucleotide polymorphisms (SNPs) in the genes for the ATP binding cassette proteins G5 (ABCG5) and G8 (ABCG8), Niemann-Pick C1-like 1 (NPC1L1), or other proteins of the cholesterol pathway, would underline inter-individual variations in response to PS. Twenty-six hyperlipidemic subjects completed a randomized trial of 3 PS phases and a control phase. Three non-responders were identified who failed on 3 consecutive occasions to decrease either total cholesterol or LDL-C level vs. control. It was observed that after 3 PS phases compared with a control phase, cholesterol absorption changed to a lesser degree (–7.7% ± 10.8%) in the non-responders than in the top 3 responders (–22.1% ± 8.8%); however, cholesterol synthesis rates did not differ between sub-groups. No common polymorphisms in ABCG8, ABCG5, or NPC1L1 were demonstrated between the 3 top responders and the non-responders. Yet, 1 non-responsive subject did demonstrate a rare SNP in NPC1L1. Results indicate PS intake did not decrease cholesterol absorption rates to the same degree in certain subjects, possibly clarifying the inter-individual variability in the cholesterol-lowering effect; hence, this work should be expanded.
Physical activity in youth from a subsistence agriculture community in the Valley of Oaxaca, southern Mexico
Authors: Malina Robert M. , Reyes Maria Eugenia Peña , Tan Swee Kheng , Little Bertis B.
Published: July 2008

Observations of activities of contemporary subsistence agricultural communities may provide insights into the lifestyle of youth of 2 to 3 generations ago. The purpose of this study was to document age- and sex-associated variation in household activities and daily steps walking to school of youth 9–17 years in an indigenous subsistence agricultural community in Oaxaca, southern Mexico. Activities during leisure were also considered. A cross-sectional survey of a rural Zapotec-speaking community was undertaken, and respondents included 118 boys and 152 girls, aged 8.7–17.9 years. Household and leisure activities were documented by questionnaire and subsequent interview. Household activities were classified by estimated intensity for before and after school and on the weekend, and an estimate of METS per day accumulated while doing chores was derived. Number of steps from home to school was estimated. Contingency table analysis and MANCOVA controlling for age was used to evaluate results. Household activities tended to cluster at light and moderate intensities in girls and at moderate to moderate-to-vigorous intensities in boys. Estimated METS per day in ~2 h of chores differed significantly by sex. Secondary school girls expended significantly more METS per day in chores than primary school girls, but there was no difference by school level in boys. The daily round trip from home to school was ~2400 steps for primary students and ~2700 and ~3100 steps for secondary boys and girls, respectively. Television viewing and participation in sports were major leisure activities for boys and girls. Daily household chores, walking, and leisure activities suggest moderately active and moderately-to-vigorously active lifestyles in girls and boys, respectively, in this indigenous subsistence agricultural community.
Moving forward by looking back: lessons learned from long-lost lifestyles
Authors: Tremblay Mark S. , Esliger Dale W. , Copeland Jennifer L. , Barnes Joel D. , Bassett David R.
Published: July 2008

The paper briefly reviews the status and trends in physical activity, physical inactivity, and overweight/obesity in Canada; discusses the consequences of these trends; examines evidence that our frame of reference with respect to physical activity and obesity is changing; promotes the importance of getting “back to the basics” as a strategy for enhancing childhood physical activity; and provides suggestions for future research in this area. In addressing these topics, the paper explores and contrasts the lifestyles and characteristics of Old Order Amish and Old Order Mennonite children with children exposed to contemporary modern living. This exploration is used as a model to learn from traditional lifestyles, which were comparatively active and resistant to obesity. The fitness characteristics and physical activity levels of traditional and contemporary groups are compared and demonstrate significant differences among groups. This evidence may provide important insight for informing future physical activity recommendations. Idiosyncrasies of performing research on these traditional-living groups are also provided.
Moving forward by looking back: children’s physical activity across the ages
Authors: Tremblay Mark S.
Published: July 2008

Some cultural groups provide a glimpse at the past because they preserve or adhere to traditional behaviours and (or) living conditions. This brief introduction outlines a series of papers presented at the Canadian Society for Exercise Physiology Conference that used this model to explore changes in the physical activity behaviour of children over time.
Monitoring muscle oxygenation after eccentric exercise-induced muscle damage using near-infrared spectroscopy
Authors: Ahmadi Sirous , Sinclair Peter J. , Foroughi Nasim , Davis Glen M.
Published: July 2008

Eccentric exercise (EE), a common type of muscular activity whereby muscles lengthen and contract simultaneously, is associated with higher levels of force but may also evoke muscle damage. We investigated the hypothesis that unaccustomed EE might impair muscle oxygenation and muscle blood flow in healthy adults. Ten healthy males performed a bout of 70 maximal eccentric contractions of the elbow flexors. Before and after EE on day 1 and over the next 6 days, maximum voluntary isometric torque (MVT), serum creatine kinase (CK), and the changes in muscle oxygen saturation, blood flow, and oxygen uptake (using near-infrared spectroscopy) within the biceps brachii were assessed. MVT decreased, whereas muscle soreness and CK increased after EE (p < 0.05). Mean resting oxygen saturation increased by 22% after acute EE, and remained elevated by 5%–9% for the following 6 days. During isometric contractions, significant decreases were observed in oxygen desaturation and re-saturation kinetics after EE and these declines were also significantly prevalent over the following 6 days. Both muscle blood flow and oxygen uptake increased significantly after acute EE, but recovered on the next day. This study revealed some prolonged alterations in muscle oxygenation at rest and during exercise after EE, which might be due to a decrease in muscle oxygen consumption, an increase in oxygen delivery, and (or) a combination of both. However, both oxygen consumption and blood flow recovered within 24 h after the eccentric exercise session, and therefore, the reason(s) for the changes in tissue oxygen saturation remain unknown.
The effect of inspiratory muscle training on high-intensity, intermittent running performance to exhaustion
Authors: Tong Tom Kwokkeung , Fu Frank Hokin , Chung Pak Kwong , Eston Roger , Lu Kui , Quach Binh , Nie Jinlei , So Raymond
Published: July 2008

The effects of inspiratory muscle (IM) training on maximal 20 m shuttle run performance (Ex) during Yo-Yo intermittent recovery test and on the physiological and perceptual responses to the running test were examined. Thirty men were randomly allocated to 1 of 3 groups. The experimental group underwent a 6 week pressure threshold IM training program by performing 30 inspiratory efforts twice daily, 6 d/week, against a load equivalent to 50% maximal static inspiratory pressure. The placebo group performed the same training procedure but with a minimal inspiratory load. The control group received no training. In post-intervention assessments, IM function was enhanced by >30% in the experimental group. The Ex was improved by 16.3% ± 3.9%, while the rate of increase in intensity of breathlessness (RPB/4i) was reduced by 11.0% ± 6.2%. Further, the whole-body metabolic stress reflected by the accumulations of plasma ammonia, uric acid, and blood lactate during the Yo-Yo test at the same absolute intensity was attenuated. For the control and placebo groups, no significant change in these variables was observed. In comparison with previous observations that the reduced RPB/4i resulting from IM warm-up was the major reason for improved Ex, the reduced RPB/4i resulting from the IM training program was lower despite the greater enhancement of IM function, whereas improvement in Ex was similar. Such findings suggest that although both IM training and warm-up improve the tolerance of intense intermittent exercise, the underlying mechanisms may be different.
Can supine recovery mitigate the exercise intensity dependent attenuation of post-exercise heat loss responses?
Authors: Kenny Glen P. , Gagnon Daniel , Jay Ollie , McInnis Natalie H. , Journeay W. Shane , Reardon Francis D.
Published: July 2008

Cutaneous vascular conductance (CVC) and sweat rate are subject to non-thermal baroreflex-mediated attenuation post-exercise. Various recovery modalities have been effective in attenuating these decreases in CVC and sweat rate post-exercise. However, the interaction of recovery posture and preceding exercise intensity on post-exercise thermoregulation remains unresolved. We evaluated the combined effect of supine recovery and exercise intensity on post-exercise cardiovascular and thermal responses relative to an upright seated posture. Seven females performed 15 min of cycling ergometry at low- (LIE, 55% maximal oxygen consumption) or high-(HIE, 85% maximal oxygen consumption) intensity followed by 60 min of recovery in either an upright seated or supine posture. Esophageal temperature, CVC, sweat rate, cardiac output, stroke volume, heart rate, total peripheral resistance, and mean arterial pressure (MAP) were measured at baseline, at end-exercise, and at 2, 5, 12, 20, and every 10 min thereafter until the end of recovery. MAP and stroke volume were maintained during supine recovery to a greater extent relative to an upright seated recovery following HIE (p ≤ 0.05) and were paralleled by an elevated CVC and sweat rate response (p ≤ 0.05). A significantly lower esophageal temperature was subsequently observed when supine throughout recovery (p ≤ 0.05). Although we observed a reflex bradycardia and increased stoke volume with supine recovery following LIE, no differences were observed for MAP, CVC, sweat rate or esophageal temperature. Supine recovery attenuates the post-exercise reductions in MAP, CVC, and sweat rate in a manner dependent directly on exercise intensity. This effect is likely attributable to a non-thermal baroreceptor mechanism.
An exploration of the association between frailty and muscle fatigue
Authors: Theou Olga , Jones Gareth R. , Overend Tom J. , Kloseck Marita , Vandervoort Anthony A.
Published: July 2008

Frailty is increasingly recognized as a geriatric syndrome that shares common biomedical determinants with rapid muscle fatigue: aging, disease, inflammation, physical inactivity, malnutrition, hormone deficiencies, subjective fatigue, and changes in neuromuscular function and structure. In addition, there is an established relationship between muscle fatigue and core elements of the cycle of frailty as proposed by Fried and colleagues (sarcopenia, neuroendocrine dysregulation and immunologic dysfunction, muscle weakness, subjective fatigue, reduced physical activity, low gait speed, and weight loss). These relationships suggest that frailty and muscle fatigue are closely related and that low tolerance for muscular work may be an indicator of frailty phenotype.
Oxygenation performance of a laboratory-scale Speece Cone hypolimnetic aerator: preliminary assessment
Authors: Ashley K. I. , Mavinic D. S. , Hall K. J.
Published: July 2008

A prototype laboratory-scale Speece Cone hypolimnetic aerator was used to examine the effect of oxygen input rate and outlet port water velocity on oxygen transfer, using four standard units of measure for quantifying oxygen transfer: (i) the oxygen transfer coefficient at 20 °C, KLa20 (h–1); (ii) the standard oxygen transfer rate (SOTR) (g O2·h–1); (iii) the standard aeration efficiency (SAE) (g O2 kW·h–1); and (iv) the standard oxygen transfer efficiency (SOTE) (%). The maximum inlet velocity (i.e., 70 cm·s–1) was only 23% of the recommended design velocity (i.e., 305 cm·s–1), and the two-phase bubble swarm did not properly develop inside the cone, but remained as a gas pocket at the top of the cone, resulting in a drastically reduced bubble surface area to water ratio. Therefore, all of the performance measures from this prototype Speece Cone were much lower than would be expected with the recommended design inlet velocity of 305 cm·s−1. Despite this difference, the system was still capable of oxygen transfer efficiencies of about 61%, under low gas flow rates, which is still higher than any full-lift design hypolimnetic aerator operating on air. Future research efforts are focused on building a pilot-scale Speece Cone, with as close to the correct inlet and outlet velocities, hydraulic residence time, and physical dimensions as possible, such that a two-phase bubble swarm could be generated. Once this experimental data is collected and analyzed, it can be properly compared with predictive models.
Concrete pavement surface textures and multivariables frictional performance analysis: a North American case study
Authors: Ahammed M. Alauddin , Tighe Susan L.
Published: July 2008

Concrete pavements are well known for long structural life. The major challenge, however, is to provide a durable surface with adequate skid resistance for economy and safety. This paper examines the long-term frictional performance of eight different surface textures on 197 sections of concrete pavements within the long-term pavement performance (LTPP) program database. Analysis shows that tined and (or) grooved textures maintain consistently higher skid resistance over time and the surface friction of concrete pavements is less sensitive to ambient temperature. Cumulative traffic passes are more sensitive to longevity of friction than the cumulative axle loads. Five alternative models have also been successfully developed for prediction of the long-term skid resistance of concrete pavements as a function of texture type, cumulative traffic passes, speed, and concrete compressive strength. These models were shown to be statistically significant at 95% confidence levels with reasonable prediction accuracy.
Formulation de fonctions de transfert de débit entre les aménagements hydroélectriques de la rivière Péribonka
Authors: Delage Pierre-Luc , Marche Claude , Larouche Bruno
Published: July 2008

Une méthode pour représenter les comportements dynamiques d’une rivière par des fonctions de transfert fiables est proposée. Elle est appliquée à la rivière Péribonka (Québec). L’article détaille la création de ces fonctions entre les centrales Chutes-des-Passes et Chute-du-Diable, incluant la centrale Péribonka en construction (lors de la rédaction de cet article). Le logiciel FLDWAV modélise les écoulements sous des conditions de production variées. Le modèle a été étalonné sur plusieurs saisons estivales grâce aux stations hydrométriques de la rivière Péribonka. Les multiples fonctions de transfert de débit (FTD) obtenues pour diverses conditions de débit et de niveau d’eau ont été simplifiées en vue de leur usage en optimisation de la production. Elles ont été validées sur chaque tronçon de la rivière. Les tests montrent qu’elles respectent bien la dynamique des écoulements en eau libre. Toutefois, l’utilisation des mêmes FTD n’est pas recommandable pour simuler l’écoulement de l’eau en période hivernale.
Specimen nonuniformities in water-pluviated and moist-tamped sands under undrained triaxial compression and extension
Authors: Thomson P. R. , Wong R. C.K.
Published: July 2008

X-ray computed tomography (CT) methods and specialized triaxial equipment were developed to quantify void ratio distribution within saturated sand specimens reconstituted by water pluviation and moist tamping methods during undrained triaxial compression and extension. The CT measurements were obtained at several points along the stress path of each specimen without significant removal of axial load. It was observed that two reconstitution methods yielded very different void ratio distributions within specimens. Significant void ratio redistribution occurred within each specimen during the undrained shearing tests. The influences of void ratio redistribution on globally observed specimen responses are discussed. The findings of this research investigation provide unique insight into fundamental aspects of saturated sand behaviour during undrained triaxial shearing.
Freezing-induced water migration in compacted base-course materials
Authors: Konrad J.-M.
Published: July 2008

Ramped-freezing tests were conducted on three base-course materials with fines contents of less than 7% and compacted at different initial states but always at degrees of saturation near or well below 60%. Three different quarries were studied. The natural fines from crushed gneiss with biotite, limestone, and monzonite were all frost susceptible. Frost heave was relatively small, but significant water intake occurred in all samples during freezing with access to an external water source, regardless of initial saturation level. The frost susceptibility of coarse-grained soils cannot be solely evaluated with respect to frost heave but needs also to consider the amount of water drawn to the freezing front during the freezing process and the consequences of this water during thaw. The normalized heave of the base-course layer of pavements is a practical and efficient indicator of the frost susceptibility of the base-course aggregates. If it is larger than 1%, the base-course material can be considered as frost susceptible leading to a significant increase in the degree of saturation once frozen. Current base-course material specifications based solely on grain-size distribution are not adequate to differentiate materials that are nonfrost susceptible from those that are frost susceptible. Hence, an additional criterion based on the fines frost susceptibility should be considered.
A practical iterative procedure to estimate seismic-induced deformations of shallow rectangular structures
Authors: Bobet Antonio , Fernandez Gabriel , Huo Hongbin , Ramirez Julio
Published: July 2008

An iterative procedure is proposed to estimate seismic-induced distortions of cut-and-cover rectangular structures. The procedure is based on an existing analytical solution for deep rectangular structures subjected to far-field shear stress which assumes elastic behavior of the soil and structure, tied contact at the soil–structure interface, and static loading. The new proposed procedure builds on the analytical solution and approximates dynamic response with a pseudo-static analysis and incorporates soil-stiffness degradation through an iterative scheme where the soil shear modulus is changed in each iteration based on the shear strain of the soil obtained in the previous iteration. The presence of the ground surface and slip at the soil–structure interface are neglected in the method proposed, but their effects are shown to be small and have compensating results when soil nonlinearity is introduced. Predictions obtained from the analytical solution have been verified by a series of numerical tests, which include the response of the Daikai subway station during the 1995 Kobe earthquake in Japan and the Los Angeles Civic Center subway station subjected to the 1994 Northridge earthquake in California. The relative errors in terms of deformation between analytical and numerical results are smaller than 15%. The procedure results in stresses on the structure that compare well with those obtained with the numerical method when there is no slip between soil and structure. If slip is allowed, the analytical solution overpredicts tensile normal stresses and underpredicts compressive normal stresses.
Analysis of instrumented sharp cone and pressuremeter tests in stiff sensitive clay
Authors: Silvestri V. , Abou-Samra G.
Published: July 2008

The objective of this paper is to compare field test results obtained in a stiff sensitive clay from Quebec using prebored, instrumented sharp cone tests (ISCTs) with those deduced from prebored and self-boring pressuremeter tests (PMTs and SBPMTs, respectively) and vane shear tests (VSTs). Comparisons are also made with triaxial test results. It is shown that undrained shear strengths Sudeduced from PMTs and ISCTs are greatly overestimated with respect to the values inferred from SBPMTs and VSTs. As for the shear modulus G, the opposite is true. These discrepancies are considered to arise from initial disturbance and unloading caused by drilling of pilot holes in the case of PMTs and ISCTs. Interpretation problems may be also related to the existence of very high lateral pressures at rest in the clay deposit.
Effect of cementation on the compressibility of Singapore upper marine clay
Authors: Low Han-Eng , Phoon Kok-Kwang
Published: July 2008

A series of one-dimensional consolidation tests were performed under varying pretreatments on high quality soil samples collected from a Singapore upper marine clay layer in an attempt to evaluate the effect of cementation by amorphous materials on its compressibility. The findings from this study seem to suggest that cementation by ethylene-diamine tetraacetic acid (EDTA) removable amorphous materials may only partially contribute to the development of soil microstructure and overconsolidation in Singapore upper marine clay.
Influence of tension cut-off on the stability of anchored concrete soldier-pile walls in clay
Authors: Antão Armando N. , Guerra Nuno M. da Costa , Matos Fernandes Manuel , Cardoso António S.
Published: July 2008

A previous paper studied the stability of soldier-pile walls in clay under vertical loading using upper bound analyses. A classical Tresca yield criterion was assumed in that analysis. This paper extends that study by considering a tension truncated Tresca yield criterion in an upper bound numerical analysis of the problem. It shows that assuming zero tension soil strength has a significant influence on the values of the minimum soldier-pile resistance required to ensure stability.
H3PW12O40 — A selective, environmentally benign, and reusable catalyst for the preparation of methoxymethyl and ethoxymethyl ethers and their deprotections under mild conditions
Authors: Mohammadpoor-Baltork Iraj , Moghadam Majid , Tangestaninejad Shahram , Mirkhani Valiollah , Mirjafari Arsalan
Published: July 2008

Different types of primary and secondary alcohols were efficiently transformed to their corresponding methoxymethyl (MOM) and ethoxymethyl (EOM) ethers in the presence of catalytic amounts of H3PW12O40 at room temperature under solvent-free conditions. Selective protection of primary and secondary alcohols in the presence of phenols and tertiary alcohols was achieved by this method. Deprotection of these ethers to their parent alcohols was also performed using this catalyst in ethanol under reflux conditions. We have also found that primary and secondary MOM- and EOM-ethers are selectively deprotected in the presence of phenolic and tertiary ones, methyl and benzyl ethers, esters, and trimethylsilyl ethers by this catalyst. The notable advantages of this protocol are high yields, short reaction times, easy work-up, non-toxicity, easy availability and handling, eco-friendly, and reusability of the catalyst.Key words: methoxymethylation, ethoxymethylation, protection, deprotection, heteropoly acid.
Palladium-catalyzed aerobic alcohol oxidation supported by a new type of α-diimine ligands
Authors: Zhou Jin , Li Xiaoyan , Sun Hongjian
Published: July 2008

A series of new ionic sulfonated α-diimine ligands were prepared and employed as supporting ligands for the palladium-catalyzed aerobic alcohol oxidation. The electronic properties, rigidity, and steric hindrance of ligands have remarkable influences upon the catalytic activity of the palladium complexes. The best catalytic result could be achieved using ligand 9 with an electron-withdrawing sulfonyl substituent together with bulky groups (iso-propyl in 2,6-positions). This diimine/palladium-catalyzed system is highly efficient for the oxidation of various benzylic alcohols, and showed moderate yields for the secondary aliphatic alcohols and cyclic alcohols.Key words: α-diimine, palladium, aerobic oxidation, alcohol.
Hydrolysis of dimethylphenyltin(IV) and triphenyltin(IV) chlorides in different aqueous ethanol solutions
Authors: Jabbari Morteza , Gharib Farrokh , Amini Mostafa Mohammadpour , Azadmehr Amirreza
Published: July 2008

The hydrolysis of [(Me)2(Ph)Sn(IV)]+ and [(Ph)3Sn(IV)]+ has been investigated at 25 °C and different aqueous solutions of ethanol, using a combination of spectrophotometric and potentiometric techniques. The species formed together with their formation constants have been determined using the computer program Squad over a wide pH range of 1 to 11. The hydrolysis constants in different media were analyzed in terms of Kamlet and Taft parameters. Single-parameter correlation of the formation constants, K11 and K12, versus α (hydrogen-bond donor acidity), β (hydrogen-bond acceptor basicity), and π* (dipolarity/polarizability) for both cases are relatively poor in all solutions, but multiparameter correlation represents significant improvement with regard to the single-parameter models. In this work, we have also used the normalized polarity parameter, ETN, alone and in combination with the Kamlet–Taft parameter to find a better correlation of the formation constants in different aqueous ethanol solutions.Key words: dimethylphenyltin(IV) chloride, triphenyltin(IV) chloride, hydrolysis constant, aqueous ethanol solutions, solvent effect.
Radical-mediated cyclization reaction — Regioselective synthesis of pyrimidine- and coumarin-annulated [6,6]-fused oxygen heterocycles
Authors: Majumdar Krishna C , Debnath Pradip , Maji Pradip K
Published: July 2008

The n-Bu3SnH-AIBN mediated aryl radical cyclization of various 8-[(2-bromophenoxy)methyl]-1,3-dimethyl-2,3,4,6-tetrahydro-1H-pyrano[3,2-d]pyrimidine-2,4-diones and 1-[(2-bromophenoxy)methyl]-3,5-dihydropyrano[2,3-c]coumarins was investigated with the formation of [6,6]-fused oxygen heterocycles as a single regioisomer.Key words: n-Bu3SnH-AIBN, aryl radical cyclization, 6-endo-trig, oxygen heterocycles, coumarin derivatives, pyrimidine derivatives.