bluuebunny/crossref_metadata_2025 huggingface dataset:
Exposure and injury risk in Swedish elite football: a comparison between seasons 1982 and 2001
Authors: Hägglund Martin , Waldén Markus , Ekstrand Jan
Published: November 2003

The long‐term development of injury risk in Swedish male elite football was studied. Two prospective cohort studies from seasons 1982 and 2001 were compared with respect to exposure to football, injury incidence and injury severity.

The mean number of training sessions during the season had increased by 68% between 1982 and 2001 (142 vs. 238, P<0.001), whereas teams played more matches in 1982 (49 vs. 41, P=0.02). The total exposure to football had increased by 27%. Three out of four players incurred an injury in both seasons. In 2001, players suffered more training injuries due to an increased training exposure. Accounting for risk exposure, there was no difference in injury incidence or severity between the two seasons. The incidence was 8.3 injuries/ 1000 h of total exposure (4.6 in training and 20.6 in matches) in 1982, compared to 7.8 1000 h−1 (5.2 in training and 25.9 in matches) in 2001. Major injuries accounted for 9% of all injuries, corresponding to an incidence of 0.8 /1000 h of football, in both seasons.

A trend from semi‐professionalism to full professionalism in Swedish elite football was seen during the last two decades. The injury risk did not change over the same period.
Comparison of two intervention programmes in young female players in European handball – with and without ankle disc
Authors: Wedderkopp N. , Kaltoft M. , Holm R. , Froberg K.
Published: November 2003

Introduction: The prevention of injuriesin all sports calls for a structured plan. The plan consists, as earlier described, of four steps. We have previously presented studies incorporating all four steps. The studies have shown that it is possible to prevent most injuries in young female players in European handball by applying a training programme combining the use of an ankle disc with functional strength training. In the previous studies we were not able to discriminate whether the preventive effect was due to the functional strength training or the training with the ankle disc. The aim of this study was to compare a programme with ankle disc and functional strength training with a programme with functional strength training only.

Methods: Twenty handball teams were asked to participate, and 16 of 20 handball teams agreed to participate. The teams were cluster randomised to either the programme with or without an ankle disc.

Results: The group using the programme without the ankle disc had a significantly higher number of traumatic injuries (16 vs. 6). The incidences of traumatic injuries in the ankle disc group were 2.4 (95% CI 0.7; 6.2) injuries per 1000 h of match and 0.2 (95% CI 0.02; 0.7) injuries per 1000 h of practice. In the group without ankle disc the incidences were 6.9 (95% CI 3.3; 12.7) injuries per 1000 h of match and 0.6 (95% CI 0.2; 1.3) injuries per 1000 h of practice. A significantly higher multivariate odds ratio (4.8) was found in the group not using the ankle disc. In addition the group using the ankle disc had significantly fewer moderate and major injuries.

Conclusion: By adding ankle disc training to a training programme with functional strength training, it is possible to reduce the number of injuries significantly, especially the number of moderate and major injuries.
Analysis of Core Buckling Defects in Sheet Metal Coil Processing
Authors: Lin P. M. , Wickert J. A.
Published: November 2003

The elastic stability of a wound coil comprising a central core and many layers of sheet metal is modeled and analyzed. A common failure mode resulting from unfavorable internal stresses—called v-buckling—is characterized by a section of the core buckling inward, possibly with several nearby sheet metal layers. In the present study, the core is modeled as a thin cylinder that is subjected to (i) the uniform external pressure generated by the coil’s wound-in stresses and (ii) a nonuniform elastic foundation around its circumference that represents core-coil contact or loss thereof. The model and an iterative numerical technique are used to predict the critical winding pressure along the core-coil interface and the core’s ensuing buckled shape. The role of geometric imperfection in the core, and the sensitivity of the buckling pressure to such initial defects, are also examined. Critical imperfection wavenumbers that facilitate the onset of significant deformations are identified with a view toward applying the results to improve quality and core inspection procedures. The predicted buckling pressure and the maximum radial stress developed in the coil, as based on a nonlinear stress model, are together used to determine factors of safety against core buckling over a range of manufacturing process parameters. Three case studies evaluate sensitivity with respect to process tension, core radius, and core thickness. The results are intended to guide the development of solutions to control the stability and quality of coils in sheet metal manufacturing.
Transcription of the Toxin Genes Present within the Staphylococcal Phage φSa3ms Is Intimately Linked with the Phage's Life Cycle
Authors: Sumby Paul , Waldor Matthew K.
Published: November 2003

φSa3ms, a lysogenic bacteriophage encoding the staphylococcal enterotoxins SEA, SEG, and SEK and the fibrinolytic enzyme staphylokinase (Sak), was identified in the unannotated genome sequence of the hypervirulent community-acquired
Staphylococcus aureus
strain 476. We found that mitomycin C induction of φSa3ms led to increased transcription of all four virulence factors. The increase in
sea
and
sak
transcription was a result of read-through transcription from upstream latent phage promoters and an increase in phage copy number. The majority of the
seg2
and
sek2
transcripts were shown to initiate from the upstream phage
cI
promoter and hence were regulated by factors influencing
cI
transcription. The lysogeny module of φSa3ms was shown to have some λ-like features with divergent
cI
and
cro
genes. Band shift assays were used to identify binding sites for both CI and Cro within the region between these genes, suggesting a mechanism of control for the φSa3ms lytic-lysogenic switch. Our findings suggest that the production of phage-encoded virulence factors in
S. aureus
may be regulated by processes that govern lysogeny.
pH-Dependent Modulation of Cyclic AMP Levels and GadW-Dependent Repression of RpoS Affect Synthesis of the GadX Regulator andEscherichia coliAcid Resistance
Authors: Ma Zhuo , Richard Hope , Foster John W.
Published: November 2003

Extreme acid resistance is a remarkable property of virulent and avirulentEscherichia coli. The ability to resist environments in which the pH is 2.5 and below is predicted to contribute significantly to the survival ofE. coliduring passage through the gastric acid barrier. One acid resistance system imports glutamate from acidic environments and uses it as a proton sink during an intracellular decarboxylation reaction. Transcription of the genes encoding the glutamate decarboxylases and the substrate-product antiporter required for this system is induced under a variety of conditions, including the stationary phase and a low pH. Acid induction during log-phase growth in minimal medium appears to occur through multiple pathways. We recently demonstrated that GadE, the essential activator of the genes, was itself acid induced. In this report we present evidence that there is a regulatory loop involving cross-repression of two AraC-like regulators, GadX and GadW, that can either assist or interfere with GadE activation of thegaddecarboxylase and antiporter genes, depending on the culture conditions. Balancing cross-repression appears to be dependent on cAMP and the cAMP regulator protein (CRP). The control loop involves the GadX protein repressing the expression ofgadWand the GadW protein repressing or inhibiting RpoS, which is the alternative sigma factor that drives transcription ofgadX. CRP and cAMP appear to influence GadX-GadW cross-repression from outside the loop by inhibiting production of RpoS. We found that GadW represses the decarboxylase genes in minimal medium and that growth under acidic conditions lowers the intracellular cAMP levels. These results indicate that CRP and cAMP can mediate pH control overgadXexpression and, indirectly, expression of the decarboxylase genes. Mutational or physiological lowering of cAMP levels increases the level of RpoS and thereby increases the production of GadX. Higher GadX levels, in turn, repressgadWand contribute to induction of thegaddecarboxylase genes. The presence of multiple pH control pathways governing expression of this acid resistance system is thought to reflect different environmental routes to a low pH.
Slipped-Strand Mispairing Can Function as a Phase Variation Mechanism in
Escherichia coli
Authors: Torres-Cruz Joshua , van der Woude Marjan W.
Published: November 2003

Slipped-strand mispairing (SSM) has not been identified as a mechanism of phase variation in
Escherichia coli
. Using a reporter gene, we show that sequences that cause phase variation by SSM in
Haemophilus influenzae
also lead to phase variation when introduced onto the chromosome of
E. coli,
and the frequencies of switching are in the biologically relevant range. Thus, the absence of SSM-mediated phase variation in
E. coli
does not appear to be due to a mechanistic constraint.
Markers of Coagulation and Angiogenesis in Cancer-Associated Venous Thromboembolism
Authors: Goldenberg Neil , Kahn Susan R. , Solymoss Susan
Published: November 2003

Purpose: We sought to determine whether venous thromboembolism in cancer patients is associated with aberrant plasma levels of hemostatic and angiogenic factors.

Patients and Methods: Peripheral blood was collected before anticoagulant therapy from cancer patients with acute deep venous thrombosis (DVT; DVT + cancer group, n = 32), those without DVT (cancer control group, n = 36), and patients with acute DVT but no cancer (DVT control group, n = 58). Plasma assays of activation and inhibition of coagulation and fibrinolysis, as well as angiogenesis activation, were then performed.

Results: Median levels of thrombin-antithrombin complex, prothrombin fragments 1 + 2, and von Willebrand factor antigen were significantly greater in the DVT + cancer group than in the cancer control and DVT control groups (17.8 ng/mL v 4.6 ng/mL and 9.8 ng/mL, P = .0001 and P = .003, respectively; 3.65 nmol/L v 1.60 nmol/L and 2.71 nmol/L, P < .0001 and P = .011, respectively; and 4.04 U/mL v 2.26 U/mL and 2.06 U/mL, P < .0001, respectively). Median levels of tissue-type plasminogen activator were also significantly higher, while protein C activity was lower in the DVT + cancer group than in the DVT control group (14.6 ng/mL v 9.50 ng/mL, respectively, P = .0005; 0.89 U/mL v 1.11 U/mL, respectively, P = .0008).

Conclusion: These data not only support prior observations of coagulation activation in patients with malignancy, but also provide new evidence for enhanced coagulation activation in the setting of acute venous thromboembolism in cancer. Future prospective studies are warranted to determine whether these and other potential markers of hypercoagulability may help to identify cancer patients at highest risk for venous thromboembolism.
Risk Model Predictive of Severe Anemia Requiring RBC Transfusion After Chemotherapy in Pediatric Solid Tumor Patients
Authors: Marec-Berard Perrine , Blay Jean Yves , Schell Matthias , Buclon Murielle , Demaret Corrine , Ray-Coquard Isabelle
Published: November 2003

Purpose: Severe anemias requiring RBC transfusions is a frequent complication of chemotherapy. A model elaborated by Ray-Coquard et al in adults pointed to three independent risk factors for RBC transfusion: performance status (PS) more than 1, hemoglobin less than 12 g/dL, and prechemotherapy absolute lymphocyte count (ALC) ≤ 700/μL. This model is tested on a pediatric population.

Patients and Methods: One hundred nineteen children with solid tumors consecutively admitted for conventional chemotherapy throughout 1 year were included. The study end point was the RBC-transfusion risk in the month following chemotherapy. Only one course was considered for each patient. Age, sex, number of courses, platinum-containing regimens, PS, and hemoglobin and lymphocyte count at day 1 were tested in univariate and multivariate analyses.

Results: Thirty-one (26%) of 119 children required RBC transfusion within 31 days of chemotherapy. Three factors correlated to transfusion risk in the univariate analysis: PS more than 1 (P < .001), hemoglobin less than 12 g/dL (P = .007), and pretreatment ALC ≤ 700/μL (P < .001). In the multivariate analysis, hemoglobin less than 12 g/dL, PS more than 1, and ALC ≤ 700/μL were identified as independent factors predicting RBC transfusion. The calculated probability of receiving RBC transfusion within 31 days of chemotherapy was high with three risk factors (96%), intermediate with two risk factors (53% to 77%), low with one risk factor (10% to 26%), and very low when no risk factor was present (2%). The difference of transfusion needs was significant (P < .001).

Conclusion: The risk model elaborated for adults may also segregate children at high risk of postchemotherapy RBC transfusion, thus facilitating assessment of risk of transfusion and/or prophylactic erythropoietin support.
Electrochemical Deposition of Gold Metal Particles into 3‐Dimensional Polypyrrole Film Deposited on a Highly Oriented Pyrolytic Graphite
Authors: Hwang Bing Joe , Santhanam Raman , Lin Yi Liang
Published: November 2003

Electrochemical techniques and lateral friction microscopy (LFM) are exploited to characterize the deposition of gold metal particles onto the 3‐dimensional (3‐D) polypyrrole (PPy) film deposited on 2‐dimensional (2‐D) highly oriented pyrolytic graphite (HOPG) substrate surface in an aqueous solution involving 0.01 M pyrrole and 0.1 M LiClO4⋅ 3H2O. Cyclic voltammetry is utilized to find the gold deposition potential onto the PPy film from 0.001 M KAu(CN)2/KOH solution. The gold deposition potential is found to be in the range of −1.2 V to −1.4 V. Chronoamperometry is used to find out the nucleation and growth mechanism of gold metal particles onto PPy film. When the PPy film is thin, the mechanism follows the 3‐D instantaneous and moved towards 3‐D progressive as the film thickness increases. Considering the high resistance of thick PPy film and insulating and compact nature of the film at more cathodic potentials, it is suggested that the gold nuclei are formed first on the HOPG substrate surface, move to the PPy film surface and then distributed inside the PPy matrix. Since the friction of gold and the PPy film is different, the LFM is found to be an effective tool to see the distribution of gold particles in the domain boundaries of the PPy film.
The Current‐Potential Characteristics for Simple Surface Electrode Reactions
Authors: López Fonseca J. Miguel , Sastre de Vicente Manuel E.
Published: November 2003

A treatment based on equations for the Convention II activity coefficients of the components of two‐dimensional solutions in combination with the transition state theory has been developed. As a result, two types of current‐potential characteristics have been derived for quasi‐reversible simple surface electrode reactions. The molecular features of the surface solutions to which each current‐potential relation applies have been established. The current‐potential characteristics obtained in this work coincide with those derived by Laviron using a less straigth and general treatment.
Characterization of the Analytical Response of ISFET Sensors for Quantitative and Thermodynamic Assessment in Glacial Acetic Acid
Authors: Romero Giaan A. Álvarez , Rojas Hernández Alberto , Ramírez Silva Ma. Teresa , Romo Mario A. Romero , Hernández Pablo Rogelio
Published: November 2003

This work presents the results of the studies on the operating characteristics of ISFET sensors, which had a silicon nitride membrane, using glacial acetic acid as solvent. The stability periods found were between five and seven minutes with response time in the range of 50 to 70 seconds. Pyridine was determined quantitatively and the results were compared with those obtained with a commercial glass electrode; the analysis of variance (ANOVA) demonstrated that there were no significant differences for the results from either type of sensor. The Biederman and Sillén calibration method was applied to the potentiometric system: the linear response range found was 4.3<pH<10.4. The ISFET presented different sensitivities for the acid and basic regions, such that with usage the sensitivity increased toward the acetate ion while that for the solvated proton decreased, and so did the reproducibility as well. The initial analytical properties of the sensor are restored upon regeneration of the silicon nitride membrane. The equilibrium constants for the protonated pyridine and diethylamine perchlorates were determined: the values found do not differ statistically in respect to those reported in the literature. Also, it was found that upon regeneration of the selective membrane, the ISFET can be used in aqueous and glacial acetic media.
The Interference of Oxygen on Diaphorase from Clostridium kluveri in the Mediated Electrocatalytic Oxidation of Reduced Dihydronicotinamide Adenine Dinucleotide
Authors: Antiochia Riccarda , Lavagnini Irma , Magno Franco
Published: November 2003

The effect of oxygen on the mediated electrocatalytic oxidation of nicotinamide adenine dinucleotide (NADH) by diaphorase from Clostridium kluveri (DI) was studied using cyclic voltammetry, UV‐vis spectrophotometry and NMR spectrometry. The enzyme was found to be able to use molecular oxygen as an electron acceptor. NADH could therefore be oxidized by two competitive electron acceptors: a redox mediator, for istance p‐methylamino‐phenolsulfate (MAP) or ferrocene monocarboxylic acid (FMCA) properly added to the solution, and molecular oxygen. Some considerations on the consequence of the use of diaphorase from Clostridium kluveri in amperometric biosensors were also reported.
Electrochemically Initiated Catalytic Oxidation of 5‐Thio‐2‐Nitrobenzoic Acid (TNBA) in the Presence of Thiols at a Boron Doped Diamond Electrode: Implications for Total Thiol Detection
Authors: Nekrassova Olga , Lawrence Nathan S. , Compton Richard G.
Published: November 2003

The electrochemical response of 5,5‐dithiobis(2‐nitrobenzoic acid) (DTNB) to increasing additions of thiol species has been examined at a boron doped diamond electrode. A reaction has been shown to occur with a range of biologically relevant thiols and proceeds via a CECC' process. A total thiol detection methodology has been developed showing that the sensitivities of the standard addition plots are independent of the individual thiol species added to the solution. The analytical utility of the reaction process has been assessed using chronoamperometry with the corresponding data producing detection limits of 5.7 μM, 4.4 μM and 5.8 μM for the detection of cysteine, homocysteine and glutathione respectively.
Hydrolytic cleavage of purine ribonucleosides in Aspergillus phoenicis
Authors: Abdel‐Fatah Osama M. , Elsayed Maysa A. , Elshafei Ali M.
Published: November 2003

Cell‐free extracts of nitrate‐grown Aspergillus phoenicis could catalyze the hydrolytic cleavage of the N‐glycosidic bond of inosine, guanosine and adenosine to the corresponding base and ribose by the nucleoside hydrolase. No evidence was obtained concerning the hydrolytic degradation of N‐glycosidic bond of pyrimidine ribonucleosides namely cytidine and uridine by the same extracts. Optimum pH and temperature for adenosine, guanosine and inosine hydrolysis were the same at pH 3.5 and 55 °C, respectively. Citrate buffer showed the highest hydrolase activity when compared to the analogous activity obtained with the other buffers used. The rate of hydrolysis of the three nucleosides was in the order inosine > guanosine > adenosine. Incubation of extracts at 55 °C for 15 minutes caused about 85%, 75% and 62% loss of activity with adenosine, guanosine and inosine respectively. Dialyzing the extract caused a decrease in enzyme activity. Addition of inorganic arsenate to the reaction mixture (containing adenosine, guanosine or inosine) did not affect the amount of ribose liberated. Addition of EDTA at a concentration of 5 × 10−3 M caused an inhibition of about 50%, however a complete inhibition for enzyme activity was obtained at 10−2 M EDTA. MgSO4, CoSO4 and ZnSO4 at a final concentration of 5 × 10−3 M showed activation of ribonucleoside hydrolase.
Biotransformation of N‐(2‐alkylamino‐4‐phenylimidazol‐1‐yl)‐acetamides and kinetic studies by using cells and laccase from Trametes versicolor
Authors: Mikolasch Annett , Schauer Frieder
Published: November 2003

The product pattern of biotransformation of different N‐(2‐alkylamino‐4‐phenylimidazol‐1‐yl)‐acetamides were compared. N‐(2‐alkylamino‐4‐phenylimidazol‐1‐yl)‐acetamides were transformed by Trametes versicolor into two types of aromatic products identified by chemical structure analysis: 1. Novel heteroaromatic compounds, such as: 2‐(alkylamino)‐4‐phenylimidazoles, N‐(2‐alkylamino‐5‐formyl‐4‐phenylimidazol‐1‐yl)‐acetamides, N‐(2‐alkylimino‐3‐hydroxy‐4‐phenyl‐2,3‐dihydroimidazol‐1‐yl)‐acetamides and N‐(2‐alkylimino‐5‐oxo‐4‐phenyl‐2,5‐dihydroimidazol‐1‐yl)‐acetamides, 2. Novel compounds arising from coupling of two molecules of the substrate. These aromatic compounds were produced from the beginning of incubation by cultures of T. versicolor.

In addition to these two types of biotransformation products, monoaromatics such as oxophenyl acetic acid, benzoic acid, and benzyl alcohol were formed as degradation products resulting from an extended incubation of the substrates and from the degradation of the first two types of transformation products.

Crude preparations of laccase from T. versicolor catalysed only the formation of novel heteroaromatic compounds, though they do so with higher yields and in shorter time than cultures of T. versicolor.
Using application service providers: yes or no?
Authors: Focacci Luisa , Dologite Dorothy G. , Mockler Robert J. , Gartenfeld Marc E.
Published: November 2003

A firm should do whatever is necessary to survive and prosper and therefore its strategy should depend on the particular situation and the critical importance of the key core activity involved.

One specific question might be whether or not to go outside its boundaries and use an application service provider (ASP) in strategically significant core activity areas where knowledge and information networks are critical to its success.

This paper develops some contingency guidelines for making this specific decision that can be adapted to similar decisions in other core activity business process areas.

Copyright © 2003 John Wiley & Sons, Ltd.
Towards global analysis of mosquito chorion proteins through sequential extraction, two‐dimensional electrophoresis and mass spectrometry
Authors: Yao Ruiliang , Li Jianyong
Published: November 2003

This study describes the separation and identification of chorion proteins through two‐dimensional electrophoresis (2‐DE) and matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry (MALDI‐TOF MS) techniques. Due to their high hydrophobicity, chorion proteins are difficult to be solubilized and absorbed into the immobilized pH gradient strip for isoelectric focusing. By optimizing the applied conditions for chorion protein extraction and sample application, we were able to solubilize the majority of the chorion proteins and resolve them by 2‐DE. Under optimized conditions, there are more than 700 protein spots resolved by 2‐D analysis. Trypsin digestions of individual protein spots, MALDI‐TOF MS analysis of their digested peptides, and subsequent BLAST search of peptide masses resulted in the tentative identification of 38 protein spots. Our data show that sequential extraction of the isolated chorion, 2‐DE of the solubilized chorion proteins, in‐gel digestion of the resolved protein and MALDI‐TOF MS analysis of the protein digests is an effective overall strategy towards determination of chorion proteins in mosquitoes. The merits of the method described for the determination of mosquito chorion proteins and its feasibility for the separation and identification of membrane proteins and chorion or eggshell proteins from other insect species are discussed.
Parvovirus B19 and the pathogenesis of anaemia
Authors: Chisaka Hiroshi , Morita Eiji , Yaegashi Nobuo , Sugamura Kazuo
Published: November 2003

Human parvovirus B19 (B19) infection causes human bone marrow failure, by affecting erythroid‐lineage cells which are well‐known target cells for B19. The anaemia induced by B19 infection is of minor clinical significance in healthy children and adults, however, it becomes critical in those afflicted with haemolytic diseases. This condition is called transient aplastic crisis, and the pathogenesis is explained by the short life‐span of red blood cells. Similarly, fetuses are thought to be severely affected by B19‐intrauterine infection in the first and second trimester, as the half‐life of red blood cells is apparently shorter than RBC at the bone marrow haematopoietic stage. On the other hand, B19 is also the causative agent of persistent anaemia in immunocompromised patients, transplant recipients and infants. The deficiencies of appropriate immune responses to B19 impair viral elimination in vivo, which results in enlargement of B19‐infected erythroid‐lineage cells. The B19‐associated damage of erythroid lineage cells is due to cytotoxicity mediated by viral proteins. B19‐infected erythroid‐lineage cells show apoptotic features, which are thought to be induced by the non‐structural protein, NS1, of B19. In addition, B19 infection induces cell cycle arrests at the G1 and G2 phases. The G1 arrest is induced by NS1 expression prior to apoptosis induction in B19‐infected cells, while the G2 arrest is induced not only by infectious B19 but also by UV‐inactivated B19, which lacks the ability to express NS1. In this review, we address the clinical manifestations and molecular mechanisms for B19‐induced anaemia in humans and a mouse model, and of B19‐induced cell cycle arrests in erythroid cells. Copyright © 2003 John Wiley & Sons, Ltd.
Towards cellular receptors for prions
Authors: Lee Kil Sun , Linden Rafael , Prado Marco Antônio M. , Brentani Ricardo R. , Martins Vilma R.
Published: November 2003

Transmissible spongiform encephalopathies (TSE) are attributed to the conversion of the cellular prion protein (PrPc) into an abnormal isoform (PrPsc). This can be caused by the invasion of living organisms by infectious particles, or be inherited due to mutations on the PrPc gene. One of the most intriguing problems of prion biology is the inability to generate the infectious agent in vitro. This argues strongly that other cellular proteins besides those added in test tubes or found in cellular preparations are necessary for infection. Despite recent progress in the understanding of prion pathology, the subcellular compartments in which the interaction and conversion of PrPc into PrPsc take place are still controversial. PrPc interacts with various macromolecules at the cell membrane, in endocytic compartments and in the secretory pathway, all of which may play specific roles in the internalisation of PrPsc and conversion of PrPc. A specific interacting protein required for the propagation of prions was originally proposed as a prion receptor, and later referred to as a ligand, a cofactor, protein X, or a partner. However, current studies indicate that PrPc associates with multi‐molecular complexes, which mediate a variety of functions in distinct cellular compartments. It is proposed that a deeper understanding of the mechanics of such interactions, coupled to a better knowledge of the corresponding signalling pathways and ensuing cellular responses, will have a major impact on the prevention and treatment of TSE. Copyright © 2003 John Wiley & Sons, Ltd.
Oscillation theorems for discrete nonlinear delay wave equations
Authors: Kubiaczyk I. , Saker S.H.
Published: November 2003

In this paper we shall discuss the oscillatory behavior of the solutions of nonlinear discrete delay wave equation. We will reduce the oscillation of the boundary value problem to the oscillation of the ordinary difference equation with damped term. By using the Riccati transformation techniques we will establish some new oscillation criteria for all solutions in the domain under consideration.
A half space moment approximation to the radiative heat transfer equations
Authors: Dubroca B. , Frank M. , Klar A. , Thömmes G.
Published: November 2003

A half space moment method to approximate the radiative heat transfer equations is investigated in one dimension. This approach leads to a hyperbolic system of equations coupled to the heat equation. Numerical results are presented together with a comparison with previous approximations.
Spreading melts with basal solidification
Authors: Bunk M.A. , King J.R.
Published: November 2003

Spreading of melts under the influence of solidification has a wide range of applications in engineering and nature. The isothermal spreading process of a viscous melt under the influence of gravity has been well studied in the literature. Features of many practical spreading flows, however, cannot be described with an isothermal model, non‐isothermal effects often being non‐negligible. Due to the range of properties of the melt and possible thermal boundary conditions, many different problems suggest themselves; this paper concerns the spreading of melts on a horizontal substrate under the influence of basal solidification. Using lubrication theory for spreading flows in the viscous/gravitational regime the influence of solidification on the spreading flow is considered for melts with a large release of latent heat. We consider two‐dimensional melts with cross‐sectional area be proportional to tα. The results show different spreading regimes, depending on the parameter α. We get complete solidification for α = 0, retreating contact lines for 0 < α < 1/2, stagnating contact lines for α = 1/2, and advancing contact lines for α > 1/2. The asymptotic behaviour for short and large times is discussed, clarifying the various regimes.
Ultrasonographic findings of intestinal intussusception in seven cats
Authors: Patsikas MN , Papazoglou LG , Papaioannou N.G. , Savvas I. , Kazakos G.M. , Dessiris A.K.
Published: November 2003

The medical records of seven cats with intestinal intussusception that were diagnosed by abdominal ultrasonography and exploratory laparotomy were reviewed. In transverse ultrasonographic sections the intussusception appeared as a target-like mass consisting of one, two or more hyperechoic and hypoechoic concentric rings surrounding a C-shaped, circular or non-specific shaped hyperechoic centre. Part of the intestine representing the inner intussusceptum, located close to the hyperechoic centre and surrounded by concentric rings, was also detected. In longitudinal sections the intussusception appeared as multiple hyperechoic and hypoechoic parallel lines in four cases and as an ovoid mass in three cases. In one case the ovoid mass had a ‘kidney’ configuration. Additional ultrasonographic findings associated with intestinal intussusception included an intestinal neoplasm in one cat. The results of the present study demonstrate that the ultrasonographic findings of intestinal intussusception in cats bear some similarities to those described in dogs and humans, are relatively consistent, and facilitate a specific diagnosis.
Small, highly reflective ice crystals in low‐latitude cirrus
Authors: Garrett T. J. , Gerber H. , Baumgardner D. G. , Twohy C. H. , Weinstock E. M.
Published: November 2003

At low latitudes, cirrus are ubiquitous and can be in excess of 100°C colder than the surface, limiting the amount of sunlight absorbed by the earth's atmosphere and surface, and reducing its loss of heat. Here we present aircraft measurements within cirrus over southern Florida indicating that ice crystals have smaller sizes and are more reflective than is assumed in most current climate models. If the measurements are generally representative of low‐latitude cirrus, they point to a first‐order correction to representations of how these clouds affect the earth's climate.
Plasmapause response to geomagnetic storms: CRRES results
Authors: Moldwin M. B. , Mayerberger S. , Rassoul H. K. , Barnicki T. , Anderson R. R.
Published: November 2003

The response of the plasmapause following a geomagnetic storm is examined statistically using plasmapause observations made by the Combined Release and Radiation Effects Satellite (CRRES) plasma wave receiver instrument. The plasmapause was identified as the inner most steep density gradient. Due to CRRES' 10‐hour orbital period, the plasmapause is generally sampled at two distinct local time sectors each orbit. The results from a study of 22 storms (with minimum Dst < −30 nT) show that the plasmapause generally moves earthward one L in the night and dawnside following a storm sudden commencement but is highly variable and statistically moves out in the dusk sector. This new result emphasizes that the plasmapause can have significant local time asymmetries that are amplified due to storm dynamics.
Raft disorganization leads to reduced plasmin activity in Alzheimer's disease brains
Authors: Ledesma Maria Dolores , Abad‐Rodriguez José , Galvan Cristian , Biondi Elisa , Navarro Pilar , Delacourte Andre , Dingwall Colin , Dotti Carlos G
Published: November 2003

The serine protease plasmin can efficiently degrade amyloid peptide in vitro, and is found at low levels in the hippocampus of patients with Alzheimer's disease (AD). The cause of such paucity remains unknown. We show here that the levels of total brain plasminogen and plasminogen‐binding molecules are normal in these brain samples, yet plasminogen membrane binding is greatly reduced. Biochemical analysis reveals that the membranes of these brains have a mild, still significant, cholesterol reduction compared to age‐matched controls, and anomalous raft microdomains. This was reflected by the loss of raft‐enriched proteins, including plasminogen‐binding and ‐activating molecules. Using hippocampal neurons in culture, we demonstrate that removal of a similar amount of membrane cholesterol is sufficient to induce raft disorganization, leading to reduced plasminogen membrane binding and low plasmin activity. These results suggest that brain raft alterations may contribute to AD by rendering the plasminogen system inefficient.
Flight of male Cadra cautella along plumes of air and pheromone superimposed on backgrounds of pheromone
Authors: Schofield Steven W. , Justus Kristine A. , Mafra‐Neto Agenor , Cardé Ring T.
Published: November 2003

Male Cadra cautella were presented with five heterogeneous pheromone clouds (created from source doses of 0, 0.01, 1, 100, and 10 000 ng) with and without superimposed plumes of either clean air or sex pheromone in a wind tunnel. Moths provided with the lowest doses of background clouds without a superimposed plume did not fly upwind. Moths provided with higher doses of background clouds, with or without superimposed air plumes, increased their track, course, and drift angles (i.e., their zigzags headed more towards crosswind) with increased dose, but slowed their velocity. No differences in flight track parameters were observed for moths provided with a superimposed pheromone plume, regardless of the background cloud dose. Moreover, moths were able to locate the source of superimposed air plumes in the highest background dose, and of superimposed pheromone plumes in any background dose. The significance of these results is discussed in the context of mating disruption.
The E‐economy and the Rise of Technocapitalism: Networks, Firms, and Transportation
Authors: Suarez‐Villa Luis
Published: November 2003

ABSTRACT The e‐economy is part of a larger phenomenon, technocapitalism, that is transforming business organizations and the ways in which they transact, produce, and ship their goods. Technocapitalism is an evolution of market capitalism that is rooted in technological innovation and supported by such intangibles as creativity and knowledge. This paper considers first the main characteristics of networks that support the e‐economy and its source phenomenon, the emergence of technocapitalism. Networks are thought to be the main vehicle through which the e‐economy spreads, and they have major effects on the organization of business firms. The culture of technocapitalism, with its emphasis on continuous innovation and rapid adjustment, is largely behind the rising importance of networks. A second section then considers the deconstruction of business firms and its relation to networks, the e‐economy, and the rise of technocapitalism. A historical perspective is provided to show the contrast with previous eras. The deconstruction of business organizations involves a major transformation of the norms and ways in which firms are run and structured. Finally, the likely implications for transportation and shipping of the rise of the e‐economy, its networks, and the deconstruction of firms are discussed. The logistics, pricing, and infrastructure of shipping are likely to be substantially affected by the spread of the e‐economy, its networks, and the deconstruction of firms.
Emerging Global Logistics Networks: Implications for Transport Systems and Policies
Authors: Tavasszy L.A. , Ruijgrok .C.J. , Thissen M.J.P.M.
Published: November 2003

ABSTRACT Logistics chains are constantly changing to facilitate increasingly global movements. In qualitative terms, long term trends in logistics services indicate a growing degree of product customization and an increased responsiveness in order delivery. These trends impact on the development of technology and the growth of welfare in different world regions in different ways. This paper drafts a research agenda which will help to improve understanding of the interrelationships between trade, logistics, transport, and regional development at a global scale. Rather than being an exhaustive or detailed inventory of trends, the paper provides a focus on “supply chain by thinking.” The key starting point is the need for more and more efficient transportation and sophisticated logistics processes. Three subjects are treated: First, the strategic implications of borderless supply chain management on the choice of alternative logistics structures in supply chains are considered; second, the possible impacts of the expected changes in supply chain processes upon regional economic activities are examined; third, the impacts of changes in global logistic processes on the transportation system and, in turn, on the environment are explored. This discussion leads to the identification of some new research challenges in the field of transportation and logistics.
ICT and Sustainable Mobility: From Impacts to Policy
Authors: Wiegmans Bart W. , Beekman Nanou , Boschker Astrid , Dam Wim Van , Nijhof Norbert
Published: November 2003

ABSTRACT The question “Will using Information and Communication Technology (ICT) systems enable a more sustainable mobility?” is answered through analyzing current ICT policy in the EU and the United States of America (USA), through developing a conceptual model to structure the expected direct and indirect effects of ICT systems on mobility, and through building models for three selected ICT systems to estimate their quantitative effects on mobility. Based on the models, ICT systems seem to have limited mobility reduction potential (in terms of CO2 emissions and kilometer savings). On the short term, because of efficiency gains, ICT systems have a positive impact. In the long term, better quality of mobility will attract new demand and this will again result in an increase of travel. For policymakers this implies that ICT systems in the short run can make mobility more efficient. In the long run, to prevent the more efficient mobility from attracting new traffic, the implementation of any ICT system should be accompanied by a stronger pricing policy.
Early loading of endosseous implants in the augmented maxilla: a 1‐year prospective study
Authors: Raghoebar Gerry M. , Schoen Pieter , Meijer Henny J. A. , Stellingsma Kees , Vissink Arjan
Published: November 2003

Abstract: In 10 patients, 68 endosseous implants were inserted in the augmented edentulous maxilla using a one‐stage implant placement technique. Three months before implant insertion, the width and height of the alveolar crest were augmented with autologous bone grafts from the iliac crest. In all cases, the resulting bone volume was sufficient for implant insertion. According to an early loading protocol, the implant‐supported overdenture was fabricated 2 months after insertion of the implants. Evaluation was performed according to a standardised protocol immediately and 1 year after fabrication of the prosthetic construction. The protocol included assessment of both clinical (bleeding score, pocket depth, implant mobility) and radiographic (marginal bone level on standardised radiographs) parameters. Three implants in two patients in the upper jaw were lost (survival rate: 95.6%). The peri‐implant tissues had a healthy appearance and bone loss was minimal. Overall, the patients were very satisfied with the prosthetic construction. From this preliminary study, it is concluded that in selected cases, early loading of implants may develop into a predictable treatment modality after augmentation of the maxilla.
Simultaneous or staged installation with guided bone augmentation of transmucosal titanium implants
Authors: Christensen Dorte Kaarup , Karoussis Ioannis K. , Joss Andreas , Hämmerle Christoph H.F. , Lang Niklaus P.
Published: November 2003

Abstract: A prospective cohort study of 45 nonsmoking consecutively admitted patients was studied for the treatment outcomes following jaw bone augmentation in conjunction with installment of oral implants. Twenty‐eight patients were treated for both bone augmentation and implant treatment simultaneously, while 17 patients were treated with a staged approach with the bone augmentation being performed 6–8 months prior to implant installation. Three months following this, prosthetic reconstructions were incorporated. One year thereafter, baseline data and 3 years after reconstruction, follow‐up data were obtained. Moderately low mean scores for the bleeding on probing percentage were found at baseline (24%) and after 3 years of function (17%), while the corresponding values at the implant sites were 40.6% and 52.4%, respectively. However, the modified gingival index (mGI)=2 was found in only 4.8%, and 6.9% at the baseline and 3‐year examinations. Peri‐implant Probing depth (PPD) and level of attachment mean values did not vary between baseline and follow‐up examinations. Only a small proportion of 1.8% yielded PPD=6.0 mm after 3 years of function. Radiographic bone level measurements showed that 18.2% of the implants lost 0.5 mm during the observation period. Seventy percent of the sites were considered completely stable. It was concluded that predictable treatment outcomes resulted for oral implant installation combined with or staged after jawbone augmentation. Only 6.5% of the sites had lost 1.5% crestal bone with the staged approach while 14% of the sites had lost 1.5 mm, when the implants were placed simultaneously. This suggests that the staged approach may have a lower risk for greater amounts of crestal bone loss as the simultaneous approach. In general, crestal bone loss encountered in the present study corresponded very well with that reported following placement of the same implant system into nonaugmented bone.
A Measure of Fundamental Volatility in the Commercial Property Market
Authors: Bond Shaun A. , Hwang Soosung
Published: November 2003

The low level of volatility observed in appraisal‐based commercial property indices relative to other asset classes has been frequently noted and extensively commented on in the real estate finance literature. However, the volatility of such commercial property indices is only one source of information on the second moment of commercial property returns. The volatility of securitized property returns forms another potential source of information, though there is some uncertainty about how closely the volatility of securitized returns may match the volatility of the underlying asset. Each measure of volatility has a potential source of noise associated with it. This paper proposes a fundamental measure of volatility for the commercial property market by using a stochastic volatility model to filter out the signal in the different sources of volatility information. This allows for different measures of volatility to be decomposed into transitory noise and unobserved fundamental volatility. The suitability of such an approach and the properties of the underlying fundamental volatility series are analyzed using data from the U.K. property market.
Microbial population dynamics related to temporal variations in nitrification in three arable fields
Authors: Wheatley R. E. , Caul S. , Crabb D. , Daniell T. J. , Griffiths B. S. , Ritz K.
Published: November 2003

It seems possible that soil potential nitrification rates (PNRs) are determined by the size and structure of both the eubacterial and nitrifier populations. We have examined this possibility by comparing the structure of the eubacterial community with the subcomponents and dynamics of the ammonium‐oxidizer population, within and between three arable fields. PNRs were significantly different between the three fields and also showed significantly different temporal patterns within each field. The use of eubacterial primers in polymerase chain reaction–denaturing gel gradient electrophoresis (PCR–DGGE) analyses indicated that the bacterial community structure in each field was significantly different from that in the others, and that the bacterial components of these communities changed with time through the season. In contrast, PCR–DGGE analyses specific to ammonium oxidizers suggested that the populations in all three fields were similar in types and did not vary with time. Competitive PCR suggested that there were large and biologically significant differences in the size of the nitrifier population between the three fields, but that within each individual field populations did not change over time. Sequencing identified the ammonium oxidizers in the Nitrosospira spp. cluster. There was also no relation between the size of the nitrifier populations and PNR. Functional expression, as PNR, apparently responded to changes in eubacterial community structure.