bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of wing–wake interactions on the production of aerodynamic forces in flapping flight
Authors: Birch James M. , Dickinson Michael H. 
Published: May 2003

SUMMARYWe used two-dimensional digital particle image velocimetry (DPIV) to visualize flow patterns around the flapping wing of a dynamically scaled robot for a series of reciprocating strokes starting from rest. The base of the wing was equipped with strain gauges so that the pattern of fluid motion could be directly compared with the time history of force production. The results show that the development and shedding of vortices throughout each stroke are highly stereotyped and influence force generation in subsequent strokes. When a wing starts from rest, it generates a transient force as the leading edge vortex (LEV) grows. This early peak, previously attributed to added-mass acceleration, is not amenable to quasi-steady models but corresponds well to calculations based on the time derivative of the first moment of vorticity within a sectional slice of fluid. Forces decay to a stable level as the LEV reaches a constant size and remains attached throughout most of the stroke. The LEV grows as the wing supinates prior to stroke reversal, accompanied by an increase in total force. At stroke reversal, both the LEV and a rotational starting vortex (RSV) are shed into the wake, forming a counter-rotating pair that directs a jet of fluid towards the underside of the wing at the start of the next stroke. We isolated the aerodynamic influence of the wake by subtracting forces and flow fields generated in the first stroke, when the wake is just developing, from those produced during the fourth stroke, when the pattern of both the forces and wake dynamics has reached a limit cycle. This technique identified two effects of the wake on force production by the wing: an early augmentation followed by a small attenuation. The later decrease in force is consistent with the influence of a decreased aerodynamic angle of attack on translational forces caused by downwash within the wake and is well explained by a quasi-steady model. The early effect of the wake is not well approximated by a quasi-steady model, even when the magnitude and orientation of the instantaneous velocity field are taken into account. Thus,the wake capture force represents a truly unsteady phenomenon dependent on temporal changes in the distribution and magnitude of vorticity during stroke reversal.
The tremble dance of honey bees can be caused by hive-external foraging experience
Authors: Thom Corinna 
Published: May 2003

SUMMARY
The tremble dance of honey bee nectar foragers is part of the communication system that regulates a colony's foraging efficiency. A forager that returns to the hive with nectar, but then experiences a long unloading delay because she has difficulty finding a nectar receiver bee, will perform a tremble dance to recruit additional nectar receiver bees. A forager that experiences a short unloading delay will perform a waggle dance to recruit more nectar foragers. A long unloading delay was until now the only known cause of tremble dancing. However, several studies suggested that factors at the food source may also cause tremble dancing. Here I test whether one of these factors, crowding of nectar foragers at the food source, stimulates tremble dancing because it causes long unloading delays. To do so, I increased the density of nectar foragers at a food source by suddenly reducing the size of an artificial feeder, and recorded the unloading delay experienced by each forager, as well as the dance she performed, if any. A forager's unloading delay was measured as the time interval between entering the hive and either (1) the first unloading contact with a nectar receiver bee, or (2) the start of the first dance, if dancing began before the first unloading contact. I also recorded the unloading delays and dances of nectar foragers that returned from natural food sources. The results show that crowding of nectar foragers at the food source increases the probability of tremble dancing, but does not cause long unloading delays, and that tremble dancers that foraged at natural food sources also often have short unloading delays. When the cause of the tremble dance is not a low supply of nectar receiver bees, the tremble dance may have a function in addition to the recruitment of nectar receiver bees.
Repeated bouts of high-intensity exercise and muscle glycogen sparing in the rat
Authors: Raja Ghazala , Bräu Lambert , Palmer T. Norman , Fournier Paul A. 
Published: May 2003

SUMMARY
Even in the absence of food intake, several animal species recovering from physical activity of high intensity can replenish completely their muscle glycogen stores. In some species of mammals, such as in rats and humans,glycogen repletion is only partial, thus suggesting that a few consecutive bouts of high-intensity exercise might eventually lead to the sustained depletion of their muscle glycogen. In order to test this prediction, groups of rats with a lead weight of 10% body mass attached to their tails were subjected to either one, two or three bouts of high-intensity swimming, each bout being separated from the next by a 1 h re covery period. Although glycogen repletion after the first bout of exercise was only partial, all the glycogen mobilised in subsequent bouts was completely replenished during the corresponding recovery periods and irrespective of muscle fibre compositions. The impact of repeated bouts of high-intensity exercise on plasma levels of fatty acids, acetoacetate and β-hydroxybutyrate suggests that the metabolic state of the rat prior to the second and third bouts of exercise was different from that before the first bout. In conclusion, rats resemble other vertebrate species in that without food intake there are conditions under which they can replenish completely their muscle glycogen stores from endogenous carbon sources when recovering from high-intensity exercise. It remains to be established, however, whether this capacity is typical of mammals in general.
Permeation and toxicity of ethylene glycol and methanol in larvae of Anopheles gambiae
Authors: Liu Xiang-Hong , Pan Hongjun , Mazur Peter 
Published: May 2003

SUMMARY
In this study, we applied proton NMR to measure the permeation of two cryoprotective agents (CPAs), ethylene glycol (EG) and methanol, into 1st instar Anopheles larvae. Calibration with standard solutions of EG or methanol (0–10 mol l-1) confirmed the reliability of the NMR measurements for determining the concentration of these solutes. To assess permeation, larvae were immersed in 1.5 mol l-1 EG or 1.5 mol l-1 methanol for different periods of time at 22°C. The concentration of both CPAs in the larvae was then measured as a function of exposure time using 1H-NMR spectroscopy. Results show that after a 6 h exposure to 1.5 mol l-1 EG, the larval concentration of EG reaches a maximum value of 1.44 mol l-1, which is 96% of the theoretical maximum. By contrast, after just 1 h exposure to 1.5 mol l-1 methanol, the larval methanol concentration reaches its maximum, which, however, is only 75% of the theoretical maximum. Toxicity data show that larval survival remains 91% and 95% after 4 h and 1 h exposure to 1.5 mol l-1 EG and 1.5 mol l-1 methanol, respectively,at which time the larval concentration of EG and methanol has risen to 1.21 mol l -1 and 1.13 mol l-1, respectively. These results suggest that CPAs such as EG and methanol do permeate Anopheleslarvae to up to 81% and 75% of equilibrium, respectively, before the exposure becomes toxic.
Regulation of branchial Na+/K+-ATPase in common carpCyprinus carpioL. acclimated to different temperatures
Authors: Metz Juriaan R. , van den Burg Erwin H. , Bonga Sjoerd E. Wendelaar , Flik Gert 
Published: May 2003

SUMMARYIsogenic carp Cyprinus carpio L. were acclimated to water temperatures of 15, 22 and 29°C for at least 8 weeks. The acclimations consistently resulted in slightly, but significantly, different plasma osmolality, sodium, potassium and chloride concentrations between the groups studied. Plasma total and ionic calcium levels were unaffected, indicating successful adaptation. The apparent changes in set point for plasma ion levels are explained by altered sodium pump activity and hormonal control of branchial permeability to water and ions. It appears that in 15°C-acclimated fish, a lower apparent Na+/K+-ATPase activity is compensated by strongly enhanced Na+/K+-ATPase expression (determined biochemically and immunohistochemically). In 29°C-acclimated fish, the higher ambient temperature activates the enzyme. Arrhenius plots for branchial Na+/K+-ATPase preparations of the three groups of fish suggest the occurrence of different enzyme isoforms or protein (in)stability as explanations for differences in apparent enzyme activities, rather than temperature-dependent changes in membrane fluidity. As for hormonal control over permeability, prolactin mRNA expression (and anticipated production and release) is lower in fish kept at 29°C, suggesting that control over branchial permeability to water and ions needs to be downregulated at higher temperatures. In so doing, enhanced sodium pump activity is balanced by a controlled passive ion loss to fine-tune plasma sodium levels. Basal plasma cortisol levels did not correlate positively with Na+/K+-ATPase expression, but doubling plasma cortisol levels in control fish by administering exogenous cortisol (for 7 days, using implanted minipumps and thus stress-free) enhanced Na+/K+-ATPase expression. This effect must be the result of a glucocorticoid action of the steroid: in fish, mineralocorticoid receptors have higher affinity for cortisol than glucocorticoid receptors. At a lower ambient temperature, branchial Na+/K+-ATPase expression is upregulated to counteract the temperature-inhibited activity of the sodium pump, perhaps via a mineralocorticoid receptor.
Nitronyl Nitroxide Substituted Aniline o-APNN with a Three-dimensional Hydrogen Bond Network Showing Ferromagnetic Interaction
Authors: Doi Kentaro , Ishida Takayuki , Nogami Takashi 
Published: May 2003

Abstract
o-Aminophenyl nitronyl nitroxide (o-APNN) was prepared as the first aniline-substituted nitronyl nitroxide. X-Ray crystallographic analysis reveals a 3-D hydrogen bonded network due to the branching nature of –NH2. Magnetic measurements indicate the presence of ferromagnetic interaction.
Sensitivity of microscopy for the rapid diagnosis of gonorrhoea in men and women and the role of gonorrhoea serovars
Authors: Manavi Kaveh , Young Hugh , Clutterbuck Dan 
Published: May 2003

Auditing the sensitivity of microscopic diagnosis of gonorrhoea is recommended by the current guidelines. A retrospective study was performed of 596 cases of positive cultures for Neisseria gonorrhoeae in modified New York City culture (MNYC) media diagnosed from 1995 to 1999. The sensitivity of the cervical slides in women was 51% while in men who have sex with men (MSM) the sensitivity of urethral and rectal slides were 89% and 54% respectively. The sensitivity of urethral slides in heterosexual men was 84%. Neisseria serovar 1B02 among MSM and serovar 1B31 among women were mostly undiagnosed with microscopy. Serovars 1A05, 1A21, B08 among heterosexual men were exclusively associated with negative microscopy. Microscopy is important in the rapid detection and treatment of gonorrhoea. Infections with certain serovars are less likely to be detected by microscopy; making them more likely to spread within the community. Culture from different ano-genital sites is essential to maximize detection of gonorrhoea in all patients.
‘Levelling the playing field, activating the players’: New Labour and ‘the cycle of disadvantage’
Authors: Deacon Alan 
Published: May 2003

English
New Labour’s ‘third way’ on welfare has been much debated. It is argued here that there is substance to the claim that third way thinking integrates elements of hitherto conflicting perspectives.This is illustrated by New Labour’s interpretation of new evidence on the extent of intergenerational continuities in disadvantage. New Labour’s understanding of the cycle of disadvantage draws on five conflicting explanations of such continuities.The commitment to end child poverty was due in part to the impact of this evidence, and New Labour’s eclectic approach has led it to revisit issues neglected for much of the post-war period.
Education as industrial policy: New Labour’s marriage of the social and the economic
Authors: Stedward Gail 
Published: May 2003

English
Education has been repositioned in the Labour policy hierarchy – no longer a straightforward social policy item, it now straddles the social and economic agendas to an extent that makes it possible to talk about education as industrial policy.This article begins by charting the trajectory of ideas and trends which coalesced in the marriage of economic and social policy, the prioritising of education and its role as a key component in the New Labour analysis of Britain’s renewal. It then looks at the role of education in New Labour’s ‘new industrial policy’ and examines some of the problems arising from its approach.
Process research in healthcare: towards three-dimensional learning
Authors: Langley Ann , Denis Jean-Louis , Lamothe Lise 
Published: May 2003

English
This article argues that process research provides a way of adding depth and perspective to our understanding of organisational change in healthcare and in other fields. We present a three-dimensional model of the research process and argue for the importance of all three dimensions in building useful process knowledge that will have relevance beyond specific settings. We use the model to illustrate our own research process, providing examples of our work on the implementation of hospital mergers. We conclude by discussing some of the dilemmas we have faced and continue to face in conducting this type of research.
Process evaluation of health promotion interventions
Authors: Parry-Langdon Nina , Bloor Michael , Audrey Suzanne , Holliday Joanne 
Published: May 2003

English
This article uses two extended illustrations of current process evaluations to address areas of difficulty in health promotion design. There are no clear solutions to methodological problems that are rooted in competition between paradigms. Further,any design adopted must adapt to constraints of resources and time. Nevertheless, a multi-method approach can provide a pragmatic and realistic way forward, with the precise mix of methods selected being adapted to the particular requirements and constraints of the intervention project being evaluated.
Modification of leather properties by grafting. I. Effect of monomer chain on the physico‐mechanical properties of grafted leather
Authors: Abd El‐Ghaffar M. A. , El‐Sayed N. H. , Masoud R. A. 
Published: May 2003

AbstractAlthough leather has a number of desirable properties such as thermal stability and fire retardancey, in addition to high toughness, it has a few drawbacks such as weight, high water absorption, poor soil and rot resistance, and nonuniformity. If these defects are overcome, leather's usefulness would be further enhanced and its competitive position with respect to synthetics would increase. This study reports the physical and mechanical properties of buffalo leather after chemical graft copolymerization with ethyl acrylate, butyl acrylate, and 2‐ethyl hexyl acrylate using benzoyl peroxide as an initiator. The optimum conditions for grafting (e.g., monomer and initiator concentrations, temperature and time of grafting, and solvent leather ratio) were extensively investigated. The study achieved outstanding properties for buffalo leather in reduction of water uptake after grafting, especially on using 2‐ethyl hexyl acrylate and butyl acrylate monomers. FT‐IR and solid13C‐NMR for leather before and after grafting confirmed the grafting process.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1478–1483, 2003
Effect of molecular weight and degree of deacetylation of chitosan on urea adsorption properties of copper chitosan
Authors: Zhou Yong‐Guo , Yang Yue‐Dong , Guo Xue‐Min , Chen Gui‐Ru 
Published: May 2003

AbstractCopper chitosan complexes prepared by different specifications of chitosan and copper sulfate were used as urea sorbents. Experimental results showed that the adsorption capacity for urea of copper chitosan increased with an increasing degree of deacetylation and decreasing molecular weight of chitosan. The urea adsorption capacity of copper chitosan was 120.0 mg/g, when 1.0 g of copper chitosan was admitted to 100 mL of a 1300 mg/mL (pH 6.0) urea solution, with chitosan degree of deacetylation of 84.3% and viscosity molecular weight of 6.5 × 105, at 37°C for 8 h. No elution of the copper from the copper chitosan could be detected under the optimal conditions. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1520–1523, 2003
Thermal degradation of poly(3‐hydroxybutyrate) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) as studied by TG, TG–FTIR, and Py–GC/MS
Authors: Li Si‐Dong , He Ji‐Dong , Yu Peter H. , Cheung Man Ken 
Published: May 2003

AbstractThe thermal degradation kinetics of poly(3‐hydroxybutyrate) (PHB) and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) [poly(HB–HV)] under nitrogen was studied by thermogravimetry (TG). The results show that the thermal degradation temperatures (To, Tp, and Tf) increased with an increasing heating rate (B). Poly(HB–HV) was thermally more stable than PHB because its thermal degradation temperatures, To(0), Tp(0), and Tf(0)—determined by extrapolation to B = 0°C/min—increased by 13°C–15°C over those of PHB. The thermal degradation mechanism of PHB and poly(HB–HV) under nitrogen were investigated with TG–FTIR and Py–GC/MS. The results show that the degradation products of PHB are mainly propene, 2‐butenoic acid, propenyl‐2‐butenoate and butyric‐2‐butenoate; whereas, those of poly(HB–HV) are mainly propene, 2‐butenoic acid, 2‐pentenoic acid, propenyl‐2‐butenoate, propenyl‐2‐pentenoate, butyric‐2‐butenoate, pentanoic‐2‐pentenoate, and CO2. The degradation is probably initiated from the chain scission of the ester linkage. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1530–1536, 2003
Properties of poly(n‐butyl methacrylate) prepared by reverse atom transfer radical polymerization in an aqueous dispersed system
Authors: Peng Hui , Cheng Shiyuan , Feng Linxian 
Published: May 2003

AbstractReverse atom transfer radical polymerization (ATRP) of n‐butyl methacrylate (BMA) in waterborne media using Cu(II) complexes with azo initiators (i.e., reverse ATRP) was conducted. The influence of several factors, such as surfactant, catalyst, and reaction time, on the stability of the emulsion, the particle size, the morphology of the emulsion particles, and the control of the polymerization was investigated. The results showed great differences between ATRP and conventional emulsion polymerization, especially the nucleation mechanism and the kinetics. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1542–1547, 2003
Temperature dependence of effective thermal conductivity and thermal diffusivity of treated and untreated polymer composites
Authors: Agarwal Rajni , Saxena N. S. , Sharma Kanan Bala , Thomas S. , Sreekala M. S. 
Published: May 2003

AbstractThermal properties, such as thermal conductivity, thermal diffusivity, and specific heat, of treated and untreated oil palm fiber–reinforced PF composites were measured simultaneously at room temperature and normal pressure using the transient plane source (TPS) technique. An increase in thermal conductivity was observed in the fiber‐treated and resin‐treated composites. Surface modifications of fibers by prealkali, potassium permanganate, and peroxide treatments increased the fiber–matrix adhesion by increasing porosity and pore size of the fiber surfaces. The increase in crosslinking enhanced the thermal conductivity of a composite of resin treated with peroxide compared to other composites. Also an attempt was made to explain the temperature dependence of thermal conductivity and thermal diffusivity of amorphous polymer samples using the same technique. It was observed that at the glass‐transition peak of the polymer, thermal conductivity and diffusivity were maximum. Below and above this temperature their values decreased. This has been explained on the basis of predominant scattering processes. An empirical relationship was established for the theoretical prediction of thermal conductivity and diffusivity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1708–1714, 2003
Kinetics of the thermal degradation and thermal stability of conductive silicone rubber filled with conductive carbon black
Authors: Zhang Jie , Feng Shengyu , Ma Qingyu 
Published: May 2003

AbstractThe kinetics of the thermal degradation and thermal stability of conductive silicone rubber filled with conductive carbon black was investigated by thermogravimetric analysis in a flowing nitrogen atmosphere at a heating rate of 5°C/min. The rate parameters were evaluated by the method of Freeman–Carroll. The results show that the thermal degradation of conductive silicone rubber begins at about 350°C and ends at about 600°C. The thermal degradation is multistage, in which zero‐order reactions are principal. The kinetics of the thermal degradation of conductive silicone rubber has relevance to its loading of conductive carbon black. The activation energies are temperature‐sensitive and their sensitivity to temperature becomes weak as temperature increases. In addition, the conductive silicone rubber filled with conductive carbon black has better thermal stability than that of silicone rubber without any fillers. Also, conductive silicone rubber filled with conductive carbon black has better thermal stability than that of silicone rubber filled with the same amount of silica. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1548–1554, 2003
Effect of glass transition on the concentration dependence of self‐diffusion coefficients
Authors: Vrentas J. S. , Vrentas C. M. 
Published: May 2003

AbstractThe free‐volume theory of diffusion is used to predict the effect of the glass transition on the concentration dependence of the solvent self‐diffusion coefficient at constant temperature. The theoretical prediction is in agreement with experimental data. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1682–1684, 2003
Blends of poly(propylene) and polyacetal compatibilized by ethylene vinyl alcohol copolymers
Authors: Huang Jieh‐Ming , Cheng Hua‐Jen , Wu Jiann‐Shing , Chang Feng‐Chih 
Published: May 2003

AbstractPolymer blends of poly(propylene) (PP) and polyacetal (polyoxymethylene, POM) with ethylene vinyl alcohol (EVOH) copolymers were investigated by differential scanning calorimetry (DSC), rheological, tensile, and impact measurements, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The PP–POM–EVOH blends were extruded with a co‐rotating twin‐screw extruder. The ethylene group in the EVOH is partially miscible with PP, whereas the hydroxyl group in the EVOH can form hydrogen bonding with POM. The EVOH tends to reside along the interface, acting as a surfactant to reduce the interfacial tension and to increase the interfacial adhesion between the blends. Results from SEM and mechanical tests indicate that a small quantity of the EVOH copolymer or a smaller vinyl alcohol content in the EVOH copolymer results in a better compatibilized blend in terms of finer phase domains and better mechanical properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1471–1477, 2003