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Concentrating solar power central-receiver plants use thousands of sun-tracking mirrors, i.e., heliostats, to reflect sunlight to a central receiver, which collects and uses the heat to generate electricity. Over time, soiling reduces the reflectivity of the heliostats and, therefore, the efficiency of the system. Current industry practice sends vehicles to wash heliostats in an ad hoc fashion. We present a mixed-integer nonlinear program that determines wash vehicle fleet size, mix, and assignment of wash crews to heliostats to minimize the sum of (i) the revenues lost due to heliostat soiling, (ii) the costs of hiring wash crews and operating the vehicles, and (iii) the costs of purchasing wash vehicles. We establish conditions for convexity of the objective function, and then propose a decomposition method that enables near-optimal solutions to the wash vehicle fleet sizing and assignment problem on the order of a couple of minutes. These solutions yield hundreds of thousands of dollars in savings per year over current industry practices. [ABSTRACT FROM AUTHOR]

SBA-15 mesoporous materials modified by sulfonic acid and sulfamic acid functionalities, abbreviated as SBA-15/SO3H and SBA-15/NHSO3H, were synthesized and applied for the removal–separation of Eu(III), Th(IV), and U(VI). SBA-15/NHSO3H showed an excellent selectivity toward U(VI), while SBA-15/SO3H was more efficient adsorbent for Eu(III) and Th(IV). It was found that in the presence of KNO3 (1 mol L−1), the separation of Eu(III)/Th(IV) from their mixtures is possible. The results of the sorption behavior indicated a high adsorption capacity toward U(VI) and Th(IV) ions (140.5 and 106.7 mg g−1, respectively) and ultrafast kinetics (15 min) in Eu(III) adsorption. [ABSTRACT FROM AUTHOR]

In this work, pure MCM-41 mesoporous silica with active mesoporous sites has been successfully applied, as a highly efficient and recoverable catalyst, for the rapid and convenient synthesis of α-aminonitriles and imines. Various imines, as the intermediate of the Strecker reaction, were simply prepared from condensation of a wide range of aldehydes and amines in the presence of low loading of MCM-41 mesoporous silica under solvent-free conditions at room temperature in high to quantitative yields. Furthermore, the corresponding α-aminonitrile derivatives were prepared through the three-component Strecker reaction using trimethylsilylcyanide catalyzed by MCM-41 as a bifunctional heterogeneous mesoporous solid catalyst. [ABSTRACT FROM AUTHOR]

Capsule: Although survival of nests was similar between forest fragments and continuous forest, the range of predators differed. Artificial nests provide an under-estimate of nest predation by snakes. Aims: To estimate the natural nest predation rate in continuous primary forest, compare it with predation rates in forest fragments. To assess the reliability of nest survival rates determined by the use of artificial nests with clay eggs and identify the main nest predators. Methods: We observed survival of natural nests during the incubation period in continuous primary forest in Papua New Guinea. Some nests were monitored with infrared cameras. We also used artificial nests deployed with clay eggs to identify predators. Results: There was a predation rate of 50% for natural nests and snakes were major predators of nest contents. Clutch daily survival rates (DSRs) differed among nest types. The DSR of artificial nests (0.977) was not significantly different to that of natural cup nests (0.969). Survival rates of artificial nests were similar in forest fragments and continuous forest. Forest fragments had, however, a higher proportion of avian predators than continuous forest. Conclusion: Although, we observed similar survival rates in artificial and natural nests, the composition of nest predators was different between natural and artificial nests. Artificial nests were not suitable for estimating the real predation caused by reptiles. Nevertheless, we find that participation of avian nest predators can be estimated correctly with the use of artificial nests. [ABSTRACT FROM AUTHOR]

An efficient, mild catalyst was employed for the synthesis of dihydropyrimidinones via condensation of aldehyde, ethyl acetoacetate, and urea/thiourea in the presence of silica polymer nanocomposite functionalized with polyphosphoric acid. The present methodology offers an advantage of being mild and highly selective wherein a three-component reaction proceeds proficiently because of the synergistic role of the hydrophobic polymer and the acidic sites functionalized on silica, which allows easy removal of water molecule formed during the reaction. [ABSTRACT FROM AUTHOR]

Oceans are considered one of the richest sources of bioactive compounds. The extraction and utilization of marine peptides have attracted attention owing to their potential health benefits. They can be used in different functional and nutraceutical foods due to their antihypertensive, antioxidant, and antimicrobial properties. These bioactive peptides can be extracted from sponges, ascidians, seaweeds, and mollusks and reportedly have pharmacological properties. The objectives of this article are to provide an overview on the sources of marine bioactive peptides, a brief description of their extraction methods, and their biological activities and potential applications in functional foods and pharmaceuticals. [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoate (PHA) is a promising polymer for various biomedical applications. There is a high need to improve the production rate to achieve end use. When a cost-effective production was carried out with cheaper agricultural residues like molasses, traces of toxins were incorporated into the polymer, which makes it unfit for biomedical applications. On the other hand, there is an increase in the popularity of using chemically defined media for the production of compounds with biomedical applications. However, these media do not exhibit favorable characteristics such as efficient utilization at large scale compared to complex media. This article aims to determine the specific nutritional requirement of Pseudomonas sp. MNNG-S for efficient production of polyhydroxyalkanoate. Response surface methodology (RSM) was used in this study to statistically design for PHA production based on the interactive effect of five significant variables (sucrose; potassium dihydrogen phosphate; ammonium sulfate; magnesium sulfate; trace elements). The interactive effects of sucrose with ammonium sulfate, ammonium sulfate with combined potassium phosphate, and trace element with magnesium sulfate were found to be significant (p < .001). The optimization approach adapted in this study increased the PHA production more than fourfold (from 0.85 g L−1to 4.56 g L−1). [ABSTRACT FROM PUBLISHER]

Copyright of Social & Cultural Geography is the property of Routledge and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Prostate cancer is the most commonly diagnosed cancer among men and the second most common cause of cancer mortality among men in America. African-American men have a mortality rate from prostate cancer twice that of Caucasian men. Although prostate screening remains controversial, it provides an opportunity for the cancer to be detected early when treatment is most effective. Limited research has been conducted regarding prostate cancer awareness and knowledge among African-American men under 50. This article highlights a pilot study assessing the knowledge, attitudes, risk perceptions, and reasons for participating in prostate cancer screening among African-American males between the ages of 30–45. Study findings suggest these participants recognized an awareness of risk factors associated with the disease, yet underestimated their risk of developing the disease. Additionally they present uneven knowledge of the prostate and its function and possess positive perceptions of their general health beliefs and practices. Practice implications and directions for future research regarding prostate cancer among this population are highlighted. [ABSTRACT FROM AUTHOR]

This article presents the design and evaluation of a linear 3.3 V SiGe power amplifier for 3 G and 4 G femtocells with 18 dBm modulated output power at 2140 MHz. Different biasing schemes to achieve high linearity with low standby current were studied. The adjacent channel power ratio linearity performance with wide-band code division multiple access (3 G) and long term evolution (4 G) downlink signals were compared and differences analysed and explained. [ABSTRACT FROM PUBLISHER]

In the absence of any food or fluid intake during the hours of daylight during the month of Ramadan, a progressive loss of body water will occur over the course of each day, though these losses can be completely replaced each night. Large body water deficits will impair both physical and cognitive performance. The point at which water loss will begin to affect performance is not well defined, but it may be as little as 1–2% of body mass. For resting individuals in a temperate environment, the water loss that occurs during a day without food or fluid will typically amount to about 1% of body mass by the time of sunset. This small loss of body water is unlikely to have a major adverse effect on any aspect of physical or cognitive performance. Larger body water losses will occur, however, in hot weather or if exercise is undertaken. Performance in events lasting about 1 hour or longer may be impaired in the absence of fluid intake during the event. In weight-category sports, there may be difficulties due to the impossibility of restoring body water content between the weigh-in and competition, and athletes will require alternative strategies. Where more than one competition or training session takes place in a single day and where substantial fluid losses are incurred, recovery will be impaired by the absence of fluid intake. [ABSTRACT FROM PUBLISHER]

This paper aims to contribute to the discussion on increasing retention rates in higher degree students. It presents evidence from the literature on the value of increasing counselling and mentoring care for higher degree research students. The creation of, and rationale for, a designated higher degree student counsellor–mentor role is described. The role of a counselling-trained mentor is one that combines elements of counselling, mentoring, organisational and social support for both higher degree research students and supervisors. The creation of this role is proposed as a means of increasing student satisfaction and retention. [ABSTRACT FROM PUBLISHER]

Capsule Mammalian and avian predators respond differently to decoys. Aims To investigate if parental attendance, which is often not accounted for in artificial nest studies, could alter predator guilds and predation rates. Methods To analyze the effects of simulated parental attendance on nest predation trends we implemented decoys of mounted American Robin Turdus migratorius specimens. We set up 22 nest-sites in an Illinois (USA) forest with control (no decoy) and experimental (with decoy) nests, the latter of which simulated parental attendance. Motion-sensitive cameras and bite-mark impressions on plasticine eggs and quail eggs identified predators. Results We found that simulated parental attendance significantly reduced nest predation rates: 61% of the 22 paired treatments were totally depredated, and more control nests (77.3%) were depredated in comparison with nests with decoys (9.1%). Mammalian predators predominantly attacked nests with decoys and avian predators predominantly attacked control nests. Conclusions Using taxidermic decoys in artificial nest experiments may improve the emulation of predation trends of natural nests, while revealing that parental attendance differentially affects predators. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the effects of fluid ingestion on pacing strategies and performance during intermittent-sprint exercise in the heat. Nine male rugby players performed a habituation session and 2 × 50-min intermittent-sprint protocols at a temperature of 31°C, either with or without fluid. Participants were informed of a third session (not performed) to ensure that they remained blind to all respective conditions. The protocol consisted of a 15-m sprint every minute separated by self-paced bouts of hard running, jogging, and walking for the remainder of the minute. Sprint time, distance covered during self-paced exercise, and vertical jump height before and after exercise were recorded. Heart rate, core temperature, nude mass, capillary blood haematocrit, pH, lactate concentration, perceptual ratings of perceived exertion, thermal stress, and thirst were also recorded. Sprint times (fluid vs. no-fluid: 2.82 ± 0.11 vs. 2.82 ± 0.14) and distance covered during self-paced exercise (fluid vs. no-fluid: 4168 ± 419 vs. 3981 ± 263 m) were not different between conditions (P = 0.10-0.98) but were progressively reduced to a greater extent in the no-fluid trial (7 ± 13%) (d = 0.56-0.58). There were no differences (P = 0.22-1.00; d = <0.20-0.84) between conditions in any physiological measures. Perceptual ratings of perceived exertion and thermal stress did not differ between conditions (P = 0.34-0.91; d ≤0.20-0.48). Rating of thirst after exercise was lower in the fluid trial (P = 0.02; d = 0.62-0.73). The present results suggest that fluid availability did not improve intermittent-sprint performance, however did affect pacing stategies with a greater reduction in distance covered of self-paced exercise during the no-fluid trial. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine whether rates of total fat and carbohydrate oxidation and endurance capacity during running conducted in the fasted state are influenced by the glycaemic index (GI) of high carbohydrate diets consumed over 5 days. Nine healthy males performed three treadmill runs to exhaustion at 65% of maximum oxygen uptake ([Vdot]O2max): after a habitual diet (control trial), after 5 days on a high carbohydrate/high glycaemic index diet, and after 5 days on a high carbohydrate/low glycaemic index diet in randomized counterbalanced order. No significant differences in rates of fat and carbohydrate oxidation, concentrations of plasma insulin, glucose, non-esterified fatty acids and glycerol, or time to exhaustion were observed between the high carbohydrate/high glycaemic index and high carbohydrate/low glycaemic index trials. Compared with the control trial, the concentration of plasma glycerol and rate of fat oxidation were lower (P < 0.05) and the rate of carbohydrate oxidation higher (P < 0.05) in both the high carbohydrate/high glycaemic index diet and high carbohydrate/low glycaemic index trials during the run to exhaustion. In conclusion, the extent by which a high carbohydrate diet consumed over 5 days reduces rate of fat oxidation during subsequent running exercise in the fasted state is not influenced by the glycaemic index of the diet. [ABSTRACT FROM AUTHOR]

Capsule Avian predators are principally responsible. Aims To document the fate of Spotted Flycatcher nests and to identify the species responsible for nest predation. Methods During 2005-06, purpose-built, remote, digital nest-cameras were deployed at 65 out of 141 Spotted Flycatcher nests monitored in two study areas, one in south Devon and the second on the border of Bedfordshire and Cambridgeshire. Results Of the 141 nests monitored, 90 were successful (non-camera nests, 49 out of 76 successful, camera nests, 41 out of 65). Fate was determined for 63 of the 65 nests monitored by camera, with 20 predation events documented, all of which occurred during daylight hours. Avian predators carried out 1 7 of the 20 predations, with the principal nest predator identified as Eurasian Jay Garrulus glandarius. The only mammal recorded predating nests was the Domestic Cat Felis cafus, the study therefore providing no evidence that Grey Squirrels Sciurus carolinensis are an important predator of Spotted Flycatcher nests. There was no evidence of differences in nest survival rates at nests with and without cameras. Nest remains following predation events gave little clue as to the identity of the predator species responsible. Conclusions Nest-cameras can be useful tools in the identification of nest predators, and may be deployed with no subsequent effect on nest survival. The majority of predation of Spotted Flycatcher nests in this study was by avian predators, principally the Jay. There was little evidence of predation by mammalian predators. Identification of specific nest predators enhances studies of breeding productivity and predation risk. [ABSTRACT FROM AUTHOR]

Dinghy sailing is a physically challenging sport with competitors on water for several hours. Regulations and space in the boat limit the amount of food and fluid competitors can carry. Consequently, it is possible that the hydration and nutritional status of dinghy sailors may be compromised while racing. Despite this, the food and fluid intake of sailors while racing are unknown. The aim of this study was to assess the dietary intake of a group of club sailors while racing and compare this with current sports nutrition guidelines. Thirty-five sailors (9 females, 26 males) were monitored during a club regatta. Body mass changes were measured before and after racing, as were food and fluid intake. Results showed that most participants were in negative fluid balance after racing (males: mean -2.1%[95% confidence limits -1.7 to -2.5%]; females: -0.9%[0 to -1.8%]), most likely due to low voluntary fluid intake (males: 1215 ml [734 to 1695 ml]; females: 792 ml [468 to 1117 m]). Carbohydrate intake (males: 59 g [21 to 97 g]; females: 30 g [0 to 61 g]) was below recommendations for normal sports activity. Results revealed that the nutritional practices of club sailors do not comply with current sports nutrition guidelines. However, the performance implications of a compromise in nutrient intake remain to be investigated. Practical advice on methods of overcoming space limitations for the carriage of adequate fluid and food is offered. [ABSTRACT FROM AUTHOR]

The most recent (1996) drinking guidelines of the American College of Sports Medicine (ACSM) propose that athletes should drink "as much as tolerable" during exercise. Since some individuals can tolerate rates of free water ingestion that exceed their rates of free water loss during exercise, this advice has caused some to overdrink leading to water retention, weight gain and, in a few, death from exercise-associated hyponatraemic encephalopathy. The new drinking guidelines of the International Olympic Committee (IOC), recently re-published in this Journal, continue to argue that athletes must drink enough to replace all their weight lost during exercise and to ingest sodium chloride since sodium is "the electrolyte most critical to performance and health". In this rebuttal to that Consensus Document, I argue that these new guidelines, like their predecessors, lack an adequate, scientifically proven evidence base. Nor have they been properly evaluated in appropriately controlled, randomized, prospective clinical trials. In particular, these new guidelines provide erroneous recommendations on five topics. If novel universal guidelines for fluid ingestion during exercise are to be promulgated by important international bodies including the IOC, they should first be properly evaluated in appropriately controlled, randomized, prospective clinical trials conducted under environmental and other conditions that match those found in "out-of-doors" exercise. This, and the potential influence of commercial interests on scientific independence and objectivity, are the two most important lessons to be learned from the premature adoption of those 1996 ACSM drinking guidelines that are not evidence-based. These concerns need to be addressed before the novel IOC guidelines are accepted uncritically. Otherwise the predictable consequences of the premature adoption of the 1996 ACSM guidelines will be repeated. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the effects of exercise type, field dimensions, and coach encouragement on the intensity and reproducibility of small-sided games. Data were collected on 20 amateur soccer players (body mass 73.1 ± 8.6 kg, stature 1.79 ± 0.05 m, age 24.5 ± 4.1 years, V˙O2max 56.3 ± 4.8 ml · kg-1 · min-1). Aerobic interval training was performed during three-, four-, five- and six-a-side games on three differently sized pitches, with and without coach encouragement. Heart rate, rating of perceived exertion (RPE) on the CR10-scale, and blood lactate concentration were measured. Main effects were found for exercise type, field dimensions, and coach encouragement (P < 0.05), but there were no interactions between any of the variables (P > 0.15). During a six-a-side game on a small pitch without coach encouragement, exercise intensity was 84 ± 5% of maximal heart rate, blood lactate concentration was 3.4 ± 1.0 mmol · l-1, and the RPE was 4.8. During a three-a-side game on a larger pitch with coach encouragement, exercise intensity was 91 ± 2% of maximal heart rate, blood lactate concentration was 6.5 ± 1.5 mmol · l-1, and the RPE was 7.2. Typical error expressed as a coefficient of variation ranged from 2.0 to 5.4% for percent maximal heart rate, from 10.4 to 43.7% for blood lactate concentration, and from 5.5 to 31.9% for RPE. The results demonstrate that exercise intensity during small-sided soccer games can be manipulated by varying the exercise type, the field dimensions, and whether there is any coach encouragement. By using different combinations of these factors, coaches can modulate exercise intensity within the high-intensity zone and control the aerobic training stimulus. [ABSTRACT FROM AUTHOR]

Focuses on the development of clinician faculty using evidence-based medicine as an organizing theme. Task management approach; Critical appraisal of clinical research.

Capsule Nest predation in Linnets in Denmark was caused mainly by Hooded Crows Corvus corone cornix and Magpies Pica pica with no experimental evidence of antipredator aggression. Aims To investigate the influence of nest clumping on the risk of nest predation in Linnets, a species that often breeds semi-colonially. Methods The predation rates on clumped and randomly distributed nests were compared by the use of artificial nest experiments. Additionally, the behaviour of Linnets towards a potential nest predator was studied by presenting a mounted Magpie near the nest of breeding Linnets. Results The artificial nest experiments showed that semi-colonial breeding was not likely to increase the risk of nest predation, and an experiment with the mounted Magpie showed that Linnets did not exhibit anti-predator aggression. Conclusion Semi-colonial breeding, resulting in increased local nest density, did not appear to influence the risk of nest predation in Linnets. We suggest that semi-colonial breeding in Linnets is a means of pooling information on food sources. [ABSTRACT FROM AUTHOR]

Health status has been proposed as an important factor affecting individual variation in reproductive performance in birds. We studied individual variation in haematological variables indicating health status (haematocrit, white blood cell count (WBC), heterophil/lymphocyte ratio) in breeding Magellanic penguins Spheniscus magellanicus and their association with reproductive variables like egg size and fledging success. Haematological measures were taken for both males and females shortly after the hatching of their young, while the parents' condition was measured at laying. Sex had a significant effect on WBC, with males showing lower values. Females with more leucocytes in peripheral blood, and assumed, therefore, to be in poorer health, layed smaller eggs and raised fewer chicks to fledging. Both effects were linked to variation in lymphocyte but not heterophil number. Haematological measures together with condition may be used to predict the reproductive output of breeders without resorting to long-term population studies. [ABSTRACT FROM PUBLISHER]

The proportion of older adults in the U.S. population is growing. By the year 2050, 21% of all Americans aged 65+ years will be members of minority groups, with African Americans comprising the largest subgroup. Disparities in health status and mortality exist between older African American and Caucasian adults. The charge to gerontological social work in the new millennium is to develop effective means of reducing racial disparities in health status. This paper presents some of the key health issues facing older African American adults and describes approaches that could be used by gerontological social work practitioners and researchers in helping to close the widening racial gap in health status. [ABSTRACT FROM AUTHOR]

A fluorometric method was developed to quantify glyphosate loss from glass surfaces after exposure to the natural forest environment. The method was based on the principle of converting glyphosate into glycine, followed by the fluorogenic labeling with o‐phthalaldehyde. A fluorometer (with λ Ex = 360 nm / λEm =430 nm) was used to quantify the derivatized fluorogenic compound. Response was linear over the concentration range of 143, 286, 572, 858 and 1144 μg of glyphosate (acid equivalent, AE) per mL of the diluted Vision® formulation. Three end‐use mixtures of Vision® were prepared, each at a concentration of 28.6 g AE/L, without and with two adjuvants, Ethomeen® T/25 at 4.5 mL/L and Silwet® L‐77 at 1.5 mL/L. Several dilutions of the end‐use mixtures were applied on glass slides without and with the coating of cuticular wax extracted from trembling aspen foliage. The slides were left for 5 days in a forest opening to determine rainfastness, volatilization and photostability of glyphosate. The residues were quantified using the method developed. Three calibration curves were required because Silwet decreased the fluorometric response of glyphosate, whereas Ethomeen increased it. The minimum detection limit was 143 μg of glyphosate/mL. Glyphosate was resistant to volatilization and sunlight‐mediated degradation, regardless of the presence of wax coating or the adjuvants. About 64% of the applied glyphosate was washed off after a 9.6 mm rainfall when no adjuvant was present. Both adjuvants provided some amount of rain‐protection to glyphosate, but Silwet reduced the washoff to a greater extent (46%) than Ethomeen (55%). [ABSTRACT FROM PUBLISHER]

This study was conducted to determine the degradation rates in turfgrass soil over a 12‐month period after a single field application of propoxur and to isolate microorganisms from the soil capable of degrading the insecticide. Soil samples were collected from a turfgrass experimental site near Fort Lauderdale, FL one week before the field application of propoxur, and over a 12‐month period after the field application. Mineralization rates in surface (0 ‐ 15 cm depth) and subsurface (15 ‐ 30 cm depth) soil samples collected before the field application were low. Mineralization in surface and subsurface samples collected 1, 6 and 8 months after the field application was much higher than for corresponding samples collected before the field application. Mineralization in the subsurface samples collected 12 months after the field application had reverted back to the similar rate for the corresponding sample collected before field application. Half‐life values (t1/2) for propoxur showed similar trends to the results of mineralization. After a single application of propoxur, degradation in turfgrass soil was enhanced. Such enhancement lasted less than 12 months for the subsurface, but more than 12 months for the surface. A strain of Arthrobacter sp. capable of degrading propoxur was isolated from the soil. [ABSTRACT FROM PUBLISHER]

The article presents a study that examines the predation on artificial and natural nests. It states that artificial nests predation are higher than natural nests due to several factors including colour, size, nest appearance, and nest type. It tells that the absence of parental behaviour results for an increase in the predation rates. It notes that the passerine bird species called Red-backed Shrike or Lanius collurio was used for the experimental study. It also lays that the experiment on the bird shows a positive result for it to survive in artificial nests.

Fluids and electrolytes (sodium) are consumed by athletes, or recommended to athletes, for a number of reasons, before, during, and after exercise. These reasons are generally to sustain total body water, as deficits (hypohydration) will increase cardiovascular and thermal strain and degrade aerobic performance. Vigorous exercise and warm/hot weather induce sweat production, which contains both water and electrolytes. Daily water (4–10 L) and sodium (3500–7000 mg) losses in active athletes during hot weather exposure can induce water and electrolyte deficits. Both water and sodium need to be replaced to re-establish “normal” total body water (euhydration). This replacement can be by normal eating and drinking practices if there is no urgency for recovery. But if rapid recovery (<24 h) is desired or severe hypohydration (>5% body mass) is encountered, aggressive drinking of fluids and consuming electrolytes should be encouraged to facilitate recovery for subsequent competition. [ABSTRACT FROM PUBLISHER]