bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanosensory-induced behavioural gregarization in the desert locustSchistocerca gregaria
Authors: Rogers Stephen M. , Matheson Thomas , Despland Emma , Dodgson Timothy , Burrows Malcolm , Simpson Stephen J. 
Published: October 2003

SUMMARYDesert locusts show an extreme form of phenotypic plasticity, changing between a cryptic solitarious phase and a swarming gregarious phase that differ in many aspects of behaviour, physiology and appearance. Solitarious locusts show rapid behavioural phase change in response to tactile stimulation directed to the hind femora. Repeatedly touching as little as one quarter of the anterior (outer) surface area of a hind femur produced full behavioural gregarization within 4 h. Solitarious locusts have approximately 30% more mechanosensory trichoid sensilla on the hind femora than do gregarious locusts but have similar or fewer numbers of sensilla elsewhere on the legs. Tactile stimulation of a hind femur in solitarious locusts that had been restrained so that they could not move their legs failed to induce any behavioural gregarization. Patterned electrical stimulation of metathoracic nerve 5, which innervates the hind leg, however, produced full gregarization in restrained locusts. Our data show for the first time that the gregarizing signal combines both exteroceptive and proprioceptive components, which travel in both nerves 5B1 and 5B2, and provides us with a powerful experimental method with which to elicit and study neuronal plasticity in this system. Acetic acid odour, a strong chemosensory stimulus that activates the same local processing pathways as exteroceptive stimuli, failed to elicit behavioural gregarization,suggesting an early segregation in the central nervous system of the mechanosensory signals that leads to gregarization.
The ontogenetic scaling of hydrodynamics and swimming performance in jellyfish (Aurelia aurita)
Authors: McHenry Matthew J. , Jed Jason 
Published: October 2003

SUMMARYIt is not well understood how ontogenetic changes in the motion and morphology of aquatic animals influence the performance of swimming. The goals of the present study were to understand how changes in size, shape and behavior affect the hydrodynamics of jet propulsion in the jellyfish Aurelia aurita and to explore how such changes affect the ontogenetic scaling of swimming speed and cost of transport. We measured the kinematics of jellyfish swimming from video recordings and simulated the hydrodynamics of swimming with two computational models that calculated thrust generation by paddle and jet mechanisms. Our results suggest that thrust is generated primarily by jetting and that there is negligible thrust generation by paddling. We examined how fluid forces scaled with body mass using the jet model. Despite an ontogenetic increase in the range of motion by the bell diameter and a decrease in the height-to-diameter ratio, we found that thrust and acceleration reaction scaled with body mass as predicted by kinematic similarity. However, jellyfish decreased their pulse frequency with growth,and speed consequently scaled at a lower exponential rate than predicted by kinematic similarity. Model simulations suggest that the allometric growth in Aurelia results in swimming that is slower, but more energetically economical, than isometric growth with a prolate bell shape. The decrease in pulse frequency over ontogeny allows large Aurelia medusae to avoid a high cost of transport but generates slower swimming than if they maintained a high pulse frequency. Our findings suggest that ontogenetic change in the height-to-diameter ratio and pulse frequency of Aurelia results in swimming that is relatively moderate in speed but is energetically economical.
Justice in higher education
Authors: Kupfer Antonia 
Published: October 2003

English
Normative philosophical theories of justice can provide valuable solutions for problems of justice in higher education. In this article the author presents three categories of explanation for the under-representation of women students in sciences, mathematics and engineering, and of female professorships in every subject. Against the background of philosophical theories of justice, the arguments of natural difference, discrimination and selection process will be evaluated. This analysis leads to a practical model, which might serve to end injustice in higher education.
Health and employment: towards a New Deal
Authors: Easterlow Donna , Smith Susan J. 
Published: October 2003

English
This article draws on lay perspectives to question some assumptions underpinning the government’s New Deal for people with long-term illness or disability in Britain. Tracing out the interaction between health and employment trajectories, interviewees challenge the idea that over-generous benefits pave the route to non-employment. They also question the emphasis on matching skills to jobs as a pathway back to work. People experiencing ill-health do not lack the incentive to work and they are likely to be forced, rather than lured, into pensions and onto benefits. The New Deal aims to enhance labour supply, but the problems people experience are more about the organisation of work and the limited demand for their skills.
Preventing disease or helping the struggle for emancipation: does professional public health have a future?
Authors: Connelly Jim , Emmel Nick 
Published: October 2003

English
The professional practice of public health can be understood to derive from two contrasting models – one which emphasises epidemiology and evidence from randomised trials and sees effective preventive treatments and interventions as its major purpose, the other which derives its methods from critical social science and sees empowerment, materialist analysis, and emancipatory action as its main purpose. These two models are compared and contrasted, and a case for their synthesis is argued in the face of a misconceived redefinition of public health made recently by the UK Secretary of State for Health.
Tezosentan in the Treatment of Acute Heart Failure
Authors: Tovar John M , Gums John G 
Published: October 2003

OBJECTIVE: To evaluate the pharmacology, pharmacokinetics, clinical efficacy, and tolerability of tezosentan, a new intravenous endothelin (ET)-1 receptor antagonist. DATA SOURCES: Literature was identified through a MEDLINE search (1990–June 2003) using the search terms endothelin-1, heart failure, RITZ, and tezosentan. References listed in articles and abstracts from scientific meetings were also used. STUDY SELECTION AND DATA EXTRACTION: English-language literature reporting controlled animal and human clinical studies was reviewed to evaluate the pharmacology, pharmacokinetics, therapeutic use, and adverse effects of tezosentan. Clinical trials selected for inclusion were limited to those with human subjects and included data from animal studies if human data were not available. DATA SYNTHESIS: Tezosentan is a dual ET-1 receptor antagonist that has demonstrated efficacy in improving cardiac index and reducing pulmonary capillary wedge pressure in patients with acute, decompensated heart failure. Following infusion, tezosentan's plasma concentration approaches steady-state within the first 6 hours, with a relatively small volume of distribution (17 L) and clearance (39 L/h) that are dose independent. Tezosentan is excreted almost entirely unchanged via the bile (>95%), with the rest (<5%) excreted in the urine. Elimination can be explained by a biphasic profile that has a rapid elimination phase (half-life 6 min) followed by a slow phase (half-life 3 h) that accounts for distribution from tissues. The adverse event profile is significant for a higher incidence of headaches, nausea, and hypotension compared with placebo. CONCLUSIONS: Phase II and III clinical trials have rendered mixed results for the efficacy and tolerability of tezosentan. A dose optimization trial yet to be published and an ongoing Phase III registration study will provide valuable data regarding the efficacy and tolerability benefits, as well as the morbidity and mortality, of tezosentan. Until then, tezosentan's role in the treatment of patients with acute heart failure will remain unclear.
Mycophenolate Pharmacokinetics in Early Period Following Lung or Heart Transplantation
Authors: Ensom Mary HH , Partovi Nilufar , Decarie Diane , Ignaszewski Andrew P , Fradet Guy J , Levy Robert D 
Published: October 2003

BACKGROUND: The available pharmacokinetic and pharmacodynamic data on mycophenolic acid (MPA), the pharmacologically active metabolite of mycophenolate mofetil (MMF), are derived largely from renal transplant patients, not thoracic transplant recipients. OBJECTIVE: To evaluate, in a pilot study, the pharmacokinetics of MPA at 3 different times in the early period (up to the first 9 mo) following lung or heart transplantation. METHODS: Nine patients were entered into this open-label study. Upon administration of a steady-state morning MMF dose, blood samples were collected at 0, 20, 40, 60, and 90 minutes and at 2, 4, 6, 8, 10, and 12 hours after the dose at 3 times (denoted as sampling periods 1, 2, and 3) in the early posttransplant period. Total MPA concentrations were measured by a validated HPLC method with ultraviolet detection and followed by ultrafiltration of pooled samples for unbound MPA concentrations. Pharmacokinetic parameters (maximal concentration [Cmax], dose-normalized Cmax, time to Cmax, minimum concentration, predose concentration, AUC, dose-normalized AUC, free fraction, free AUC) were calculated by traditional noncompartmental methods. RESULTS: Patient characteristics included 7 men and 2 women, 5 lung and 4 heart transplant recipients, mean ± SD age 53 ± 11 years, and weight 77 ± 14 kg. All patients were receiving prednisone and cyclosporine (with the exception of 2 pts. on tacrolimus during sampling periods 2 and 3). Sampling periods 1, 2, and 3 occurred on posttransplant days 15 ± 13, 56 ± 33, and 125 ± 73, respectively. No significant differences were found between sampling periods in any pharmacokinetic parameter. Drug exposure as evaluated by AUC was 39.95 ± 44.86, 25.24 ± 25.68, and 43.96 ± 38.67 μg•h/mL during sampling periods 1, 2, and 3, respectively, (p > 0.05). CONCLUSIONS: As of September 26, 2003, this is the first study to systematically evaluate MPA pharmacokinetics in thoracic transplant recipients at 3 different time points during the early posttransplant period. Wide interpatient variability in MPA pharmacokinetics was observed, thus emphasizing the need to individualize dosing of MMF and to further evaluate important pharmacokinetic/pharmacodynamic parameters and endpoints that impact on clinical outcomes. Further studies involving more patients and pharmacodynamic outcomes are underway to help identify optimal MMF strategies.
Captive supplies and the spot market price of fed cattle: The plant‐level relationship
Authors: Schroeter John R. , Azzam Azzeddine 
Published: October 2003

AbstractNumerous articles in the agricultural economics literature investigate the empirical relationship between the spot market price of fed cattle and the volume of packers' precommitted, or “captive,” supplies of cattle. In this article, we use an extensive data set on the cattle procurement activities of four large packing plants in the Texas Panhandle from early 1995 through mid‐1996 to examine this relationship at the plant‐level. We find evidence to support the hypothesis that plants that anticipate near‐term future deliveries of captive supply cattle that are high relative to their regional‐market rivals' degrees of reliance on captive supplies tend to pay spot market prices that are below average. The effect, while statistically significant, is relatively small in magnitude, however. [EconLit citations: Q130, L200] © 2003 Wiley Periodicals, Inc. Agribusiness 19: 489–504, 2003.
Mean spillover effects in agricultural prices: The case of Greece
Authors: Apergis Nicholas , Rezitis Anthony 
Published: October 2003

AbstractThis article investigates the behavior of agricultural input prices, agricultural output prices, and retail food prices using the cointegration/error–correction methodology. The findings support “cost push” and “demand pull” theories, because disequilibrium at the input level is transmitted to the retail level, and vice versa, through the output level. The estimated error–correction coefficients and price responses indicate, first, imperfect price transmission among agricultural input, output, and retail food prices, and second, that agricultural output prices are more flexible than agricultural input and retail food prices. [EconLit citations: Q110; Q130]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 425–437, 2003.
Ocean liner shipping: Organizational and contractual response by agribusiness shippers to regulatory change
Authors: Stewart Hayden G. , Inaba Fred S. 
Published: October 2003

AbstractThe Ocean Shipping Reform Act of 1998 (OSRA) promotes changes in international ocean liner shipping. An important policy issue attendant to the passage of OSRA is the Act's likely impact on the international competitiveness of the sectors that depend upon ocean shipping. Thus, to establish how freight rates and other logistical costs of using ocean liner services are now determined, this study examines emerging methods of organization and contracting among exporters of food and forest products. We find that, although many shippers negotiate private contracts with carriers, many others utilize a third‐party agent to negotiate a rate with a carrier on their behalf. This article also identifies differences between two key types of third‐party agents. Finally, given that a shipper in this trade does not contract directly with a carrier, this article explains the shipper's conditional choice about which type of agent to use. [EconLit citations: L140, L980, Q130]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 459–472, 2003.
The reconfiguration of post‐Soviet food industries: Evidence from Ukraine and Moldova
Authors: Gorton Matthew , White John , Chernyshova Svetlana , Skripnik Alexander , Vinichenko Tatiana , Dumitrasco Mikhail , Soltan Galina 
Published: October 2003

AbstractThe 1990s witnessed widespread changes in the nature of food supply chain actors, government policies, and markets in the successor states of the Soviet Union. These changes have resulted in a more differentiated set of actors, but there is relatively little empirical knowledge on the reconfiguration of food processors and their relationships with agricultural processors. This article attempts to deal with this gap by researching structures and procurement relationships in the Ukraine and Moldova. Enterprise level survey data on the food‐processing sector in Moldova and the Ukraine reveals a diverse set of actors. Cluster analysis is employed to better characterize these different groups of processors. A three‐cluster solution is adopted, and the main characteristics, supply patterns, and dynamics of each cluster are further analyzed. [EconLit citations: L660, L100]. © 2003 Wiley Periodicals, Inc. Agribusiness 19: 409–424, 2003.
Neuzeitlicher Schadstofftrend: Polycylische aromatische Kohlenwasserstoffe (PAK) in aquatischen und terrestrischen Sedimenten
Authors: Hellmann Hubert 
Published: October 2003

AbstractDie in aquatischen Sedimenten Deutschlands, Englands, Finnlands und der USA in kleineren, mittleren und sehr großen Binnenseen, in Ästuarien und in terrestrischen Sedimenten ermittelten Konzentrationen polycyclischer aromatischer Kohlenwasserstoffe (PAK) wurden in Form von 10 Trendkurven über den Zeitraum 1800 bis 1990 dargestellt. Die Segmente der Bohrkerne waren hinsichtlich der Deposition datiert. Zur Vereinheitlichung der Ergebnisse wird der Trend überwiegend des Leitparameters Fluoranthen abgebildet. Es zeigt sich bis ins 19. Jahrhundert ein überregional konstanter Background in Höhe von CFluo = 10…50 μg/kg. Danach folgt ein starker Konzentrationsanstieg, der bei den aquatischen Sedimenten im Zeitintervall 1940 bis 1965, bei im einzelnen sehr unterschiedlichen Fluoranthen‐Werten zwischen 90 μg/kg und 2400 μg/kg, ein Maximum erreicht. In mehreren Regionen folgte dem Maximum ein mehr oder weniger deutlicher Rückgang, der bei den untersuchten terrestrischen Sedimenten und einem Ästuar sowie in abgelegenen Waldseen Finnlands zu fehlen scheint. Die Trendkurven enthalten den atmosphärischen Eintrag der PAK über den Luftstaub und fallweise den Runoff über die Flüsse. Die Sedimentprofile spiegeln daher die Entwicklung der Luftverschmutzung mit pyrogenen Schadstoffen über mehr als ein Jahrhundert wider. In Flüssen können Sedimentprofile wegen unregelmäßiger und wenig repräsentativer Sedimentation nur sehr eingeschränkt genutzt werden.
Simultaneous and Sensitive HPLC Determination of Mono‐ and Disaccharides, Uronic Acids, and Amino Sugars after Derivatization by Reductive Amination
Authors: Fischer Klaus , Wacht Marion , Meyer Axel 
Published: October 2003

AbstractThe reductive amination of low‐molecular‐weight saccharides, uronic acids, and amino sugars, followed by a separation of the derivates by means of ion‐pair chromatography or RP‐HPLC, offers an interesting alternative to HPAEC‐PAD for the environmental analysis of these compounds. Under this aspect various potential amination reagents, i.e., p‐amino‐benzoic acid (p‐AMBA), p‐AMBA propyl ester, 1‐aminopyrene, 2‐(2‐aminophenyl)indole, and 4‐aminoazobenzene, were tested with regard to the formation of derivates and to the chromatographic properties of the formed derivates.p‐AMBA, p‐AMBA propyl ester and 4‐aminoazobenzene proved to be especially suited, because they facilitate the amination of all carbohydrate reference components together with a complete separation and sensible detection (detection limits < 0.5 mg/L) of the derivates. Mainly the following elution sequence was ascertained: amino sugars (hexosamines) / disaccharide(s) / monosaccharides (hexoses) / hexuronic acid(s) / N‐acetyl‐D‐glucosamine. Detection limits down to 0.1 μmol/L were realized using p‐AMBA as reagent, facilitating the determination of the target compounds in landfill leachates and lysimeter percolates. Applying the p‐AMBA propyl ester for derivatization, chromatographic interferences with weakly retained derivates and the coelution of the reagent with its galactosamine derivate can be avoided, since the ester elutes after its derivates unlike p‐AMBA itself.
Schwefel und Selen: Bedeutung der Oxidationsstufe für Struktur und Funktion von Proteinen
Authors: Jacob Claus , Giles Gregory I. , Giles Niroshini M. , Sies Helmut 
Published: October 2003

AbstractSchwefel und Selen kommen in Proteinen als Bestandteile der Aminosäuren Cystein, Methionin, Selenocystein und Selenomethionin vor, deren Ausnahmestellung in neueren Arbeiten unterstrichen wird. Ihre Redoxeigenschaften unter physiologischen Bedingungen ermöglichen eine erstaunliche Vielfalt posttranslationaler Proteinmodifikationen, metallfreier Redoxreaktionen und ungewöhnlicher Chalkogenredoxzustände. Wie keine andere Aminosäure kann das “Redox‐Chamäleon” Cystein an so unterschiedlichen Redoxreaktionen wie Atom‐, Elektronen‐ und Hydridtransfer sowie Radikal‐ und Austauschreaktionen beteiligt sein. Es kommt im menschlichen Körper in zahlreichen Oxidationsstufen vor, von denen jede mit charakteristischen chemischen (z. B. Redox‐ und Metallbindungs‐) und biologischen Eigenschaften verknüpft ist. Durch die Position des Selens im Periodensystem der Elemente zwischen Metallen und Nichtmetallen werden Selenoproteine zu idealen Katalysatoren einer Vielzahl biologischer Redoxumwandlungen, sodass die chalkogenhaltigen Aminosäuren Cystein, Methionin, Selenocystein und Selenomethionin und ihre einzigartige Biochemie Gegenstand eines vielversprechenden Forschungsgebietes sind.
Recent Advances in the Activation of Boron and Silicon Reagents for Stereocontrolled Allylation Reactions
Authors: Kennedy Jason W. J. , Hall Dennis G. 
Published: October 2003

AbstractDespite the popularity of boron and silicon allylation reagents in stereocontrolled synthesis, they suffer from a number of inherent limitations that have slowed down their development as synthetic tools for nucleophilic additions to carbonyl compounds and imine derivatives. These limitations are the low reactivity and diastereoselectivity of allyl trialkylsilane reagents, and the lack of catalytic systems for the activation and substoichiometric control of enantioselectivity in the additions of allyl boron reagents. To develop more efficient and general methods for the control of absolute stereochemistry in the resulting homoallylic alcohols, new approaches aimed at solving the problem of activation of allylic boron and silicon reagents are needed. This Minireview describes a number of recent approaches that have been devised to address this problem.
Chronic upper extremity pain and co‐occurring symptoms in a general population
Authors: Gummesson Christina , Atroshi Isam , Ekdahl Charlotte , Johnsson Ragnar , Ornstein Ewald 
Published: October 2003

AbstractObjectiveTo estimate the prevalence of self reported chronic upper extremity pain associated with physical impairment in a general population, and its co‐occurrence with chronic upper extremity numbness or tingling and chronic pain at other locations.MethodsA general health questionnaire was mailed to 3,000 persons (age 25–74 years) who were randomly selected from a general population register.ResultsThe response rate was 83%. The prevalence of chronic upper extremity pain associated with physical impairment was 20.8% (95% confidence interval [95% CI] 19.2–22.5), and that of co‐occurring numbness or tingling was 6.7% (95% CI 5.7–7.7). Among the responders with chronic upper extremity pain associated with physical impairment, 84% reported more than 1 painful area.ConclusionChronic upper extremity pain associated with physical impairment and co‐occurring chronic upper extremity numbness or tingling were common in the general population. The presence of more than 1 location for pain in the upper extremity as well as in other parts of the body was frequent.
Mass Transfer in a Flat Gas/Liquid Interface using non‐Newtonian Media
Authors: Gómez‐Díaz D. , Navaza J.M. 
Published: October 2003

AbstractGas/liquid mass transfer has been investigated using a stirred vessel gas/liquid contactor using non‐Newtonian media and carbon dioxide as absorbent and gas phase, respectively. The volumetric mass transfer coefficients at different operational variables have been determined. Non‐Newtonian media (liquid phase) were prepared as aqueous solutions of sodium carboxymethyl cellulose salt. The influence of the rheological properties, polymer concentration, stirring rate, and gas flow rate on mass transfer was studied for these liquid phases. Kinematic viscosity and density experimental data were used to calculate the average molecular weight corresponding to the polymer employed. The Ostwald model has been used to fit the rheological behavior of aqueous solutions of the polymer employed as absorbent phase. Reasonably good agreement was found between the predictions of the proposed models and the experimental data of mass transfer coefficients.