bluuebunny/crossref_metadata_2025_split huggingface dataset:
A longitudinal study of the educational and career trajectories of female participants of an urban informal science education program
Authors: Fadigan Kathleen A. , Hammrich Penny L. 
Published: August 2004

AbstractThe purpose of this longitudinal case study is to describe the educational trajectories of a sample of 152 young women from urban, low‐income, single‐parent families who participated in the Women in Natural Sciences (WINS) program during high school. Utilizing data drawn from program records, surveys, and interviews, this study also attempts to determine how the program affected the participants' educational and career choices to provide insight into the role informal science education programs play in increasing the participation of women and minorities in science, math, engineering, and technology (SMET)‐related fields. Findings revealed 109 participants (93.16%) enrolled in a college program following high school completion. Careers in medical or health‐related fields followed by careers in SMET emerged as the highest ranking career paths with 24 students (23.76%) and 21 students (20.79%), respectively, employed in or pursuing careers in these areas. The majority of participants perceived having staff to talk to, the job skills learned, and having the museum as a safe place to go as having influenced their educational and career decisions. These findings reflect the need for continued support of informal science education programs for urban girls and at‐risk youth. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 835–860, 2004
Teaching evolutionary biology: Pressures, stress, and coping
Authors: Griffith Joyce A. , Brem Sarah K. 
Published: August 2004

AbstractUnderstanding what teachers need to be more comfortable and confident in their profession is crucial to the future of effective teachers and scientific literacy in public schools. This study focuses on the experiences of Arizona biology teachers in teaching evolution, using a clinical model of stress to identify sources of pressure, the resulting stresses, and coping strategies they employ to alleviate these stresses. We conducted focus groups, one‐on‐one interviews, and written surveys with 15 biology teachers from the Phoenix area. On the basis of their responses, teachers were clustered into three categories: “Conflicted,” who struggle with their own beliefs and the possible impact of their teaching, “Selective,” who carefully avoid difficult topics and situations, and “Scientists,” who see no place for controversial social issues in their science classroom. Teachers from each group felt that they could be more effective in teaching evolution if they possessed the most up‐to‐date information about evolution and genomics, a safe space in which to reflect on the possible social and personal implications with their peers, and access to richer lesson plans for teaching evolution that include not only science but personal stories regarding how the lessons arose, and what problems and opportunities they created. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 791–809, 2004
Uniqueness of motion by mean curvature perturbed by stochastic noise
Authors: Yip N.K , Souganidis P.E 
Published: August 2004

We present some uniqueness (non-fattening) results for the motion by mean curvature perturbed by stochastic noise. It is well known that for special initial data, the deterministic motion has multiple solutions, i.e., it develops interior. Our result for a particular evolution of curves in

ℝ^2

illustrates that stochastic perturbations can select a unique solution in a natural way. The noise we use is white in time and constant in space. The results are formulated both almost surely and in probability law.

Résumé

Nous présentons des résultats d’unicité pour le mouvement par courbure moyenne, perturbé par un bruit stochastique. Il est bien connu que pour certaines conditions initiales, le mouvement a plusieurs solutions, i.e. il acquiert un intérieur. Notre résultat pour l’évolution de courbes spécifiques dans

ℝ^2

illustre le fait que les perturbations stochastiques peuvent sélectionner une unique solution de manière naturelle. Le bruit utilisé ici est blanc dans le temps et constant dans l’espace. Nous donnons nos résultats en termes presque sũrs ainsi qu’en loi de probabilité.
Regularity results for parabolic systems related to a class of non-Newtonian fluids
Authors: Seregin G.A , Acerbi E , Mingione G 
Published: August 2004

We consider a class of parabolic systems of the type:

u_t-\mathrm{div}\, a (x,t,Du)=0

where the vector field

a (x,t,F)

exhibits non-standard growth conditions. These systems arise when studying certain classes of non-Newtonian fluids such as electrorheological fluids or fluids with viscosity depending on the temperature. For properly defined weak solutions to such systems, we prove various regularity properties: higher integrability, higher differentiability, partial regularity of the spatial gradient, estimates for the (parabolic) Hausdorff dimension of the singular set.

Résumé
Nous étudions une classe de systèmes paraboliques du type :

u_t-\mathrm{div}\, a (x,t,Du)=0

où le champ vectoriel

a (x,t,F)

possède des conditions de croissance non standard. Ces systèmes se présentent dans l’étude de certaines classes de fluides non Newtoniens comme les fluides electro-rhéologiques ou les fluides dont la viscosité dépend de la température. Nous prouvons différentes propriétés de régularité pour des solutions faibles convenables de tels systémes : intégrabilité et différentiabilité améliorées, régularité partielle du gradient spatial et estimations pour la dimension de Hausdorff (parabolique) de l’ensemble des points singuliers.
On planar selfdual Electroweak vortices
Authors: Chae Dongho , Tarantello Gabriella 
Published: August 2004

By perturbation techniques, we obtain a new class of selfdual Electroweak vortices in

ℝ^2

, whose asymptotic behavior we control in an “optimal” way to yield a sort of “quantization” property for the corresponding flux.

Our class of vortex-solutions complements that constructed by Spruck and Yang [Comm. Math. Phys. 144 (1992) 215–234].

Résumé

En utilisant des techniques de perturbation, nous obtenons une nouvelle classe de vortex Électrofaibles autoduaux dans

ℝ^2

, dont nous pouvons contrôler de façon « optimale » le comportement asymptotique en donnant une propriété de « quantisation » pour le flot correspondant.

Notre classe de solutions complète celles construites par Spruck et Yang [Comm. Math. Phys. 144 (1992) 215–234].
Blow-up solutions for the Schrödinger equation in dimension three with a concentrated nonlinearity
Authors: Figari Rodolfo , Teta Alessandro , Adami Riccardo , Dell'Antonio Gianfausto 
Published: August 2004

We present some results on the blow-up phenomenon for the Schrödinger equation in dimension three with a nonlinear term supported in a fixed point. We find sufficient conditions for the blow-up exploiting the moment of inertia of the solution and the uncertainty principle. In the critical case, we discuss the additional symmetries of the equation and construct a family of explicit blow-up solutions.

Résumé
On présente des résultats sur le phénomène de l’explosion pour l’équation de Schrödinger en trois dimensions avec un terme nonlinéaire concentré en un point fixé. On trouve des conditions suffisantes pour l’explosion en utilisant le moment d’inertie de la solution et le principe d’indétermination. Dans le cas critique, on met en évidence l’existence de quelques symétries supplémentaires et l’on construit une famille de solutions explosives explicites.
Droplet spreading under weak slippage: the waiting time phenomenon
Authors: Grün Günther 
Published: August 2004

We prove the occurrence of a waiting time phenomenon in space dimensions
N
<4 for the thin film equation subjected to Navier’s slip condition or even weaker slip conditions. We state a sufficient criterion on the smoothness of initial data which guarantees a local delay of the onset of spreading wherever the support of initial data locally satisfies an exterior cone condition. Our method combines a Hardy-type inequality valid on infinite cones with recently established weighted energy estimates and a novel iteration technique developed in [R. Dal Passo, L. Giacomelli, G. Grün, Ann. Scuola Norm. Sup. Pisa 30 (2001) 437–463]. On account of formal considerations, we conjecture our criterion to be optimal.

Résumé

Dans cet article nous nous intéressons au comportement qualitatif de la frontière libre des solutions de l’équation des films minces soumise aux conditions de glissement de type Navier ou aux conditions de glissement plus faibles. Nous montrons l’apparition d’un phénomène de temps d’attente dans les dimensions d’espace

N<4

. Nous formulons un critère suffisant pour la régularité des données initiales, qui garantit un délai local pour le début de la propagation, où que soit satisfaite localement une condition cônique extérieure par le support des données initiales. Notre méthode combine une inégalité de type Hardy valide sur un cône infini avec des estimations récentes pondérées d’énergie, et avec une nouvelle technique d’itération développée dans [R. Dal Passo, L. Giacomelli, G. Grün, Ann. Scuola Norm. Sup. Pisa 30 (2001) 437–463]. En raison de considérations formelles, nous formons la conjecture que notre critère est optimal.
Nonexistence of local solutions to semilinear partial differential inequalities
Authors: Pohozaev Stanislav I , Tesei Alberto 
Published: August 2004

We investigate nonexistence of local nonnegative solutions for some semilinear elliptic and parabolic inequalities with first order terms and singular coefficients. In contrast with previous investigations of the subject, no use of the maximum principle is made. Instead, a direct bootstrap argument is used, which relies on a suitable choice of the functions used to test the differential inequalities.

Résumé
Nous étudions la non existence de solutions locales non négatives pour quelques inégalités elliptiques et paraboliques avec termes du premier ordre et coefficients singuliers. Au lieu de méthodes faisant appel au principe du maximum, on utilise une méthode directe de “bootstrap” basée sur un choix convenable des fonctions test.
Existence by minimisation of solitary water waves on an ocean of infinite depth
Authors: Buffoni B 
Published: August 2004

The abstract minimisation method introduced in a recent work by E. Séré, J.F. Toland and the author [Minimisation methods for quasi-linear problems, with an application to periodic water waves, preprint] gives a new proof of the existence of capillary-gravity solitary water waves on the surface of a two-dimensional ocean of infinite depth. This problem was first studied by Iooss and Kirrmann [Arch. Rational Mech. Anal. 136 (1998) 1–19] in the setting of normal form theory for reversible infinite-dimensional “spatial” dynamical systems.

Résumé
La méthode de minimisation abstraite introduite dans un travail récent de E. Séré, J.F. Toland et l’auteur, donne une nouvelle preuve de l’existence d’ondes solitaires à la surface d’un océan infiniment profond, sous l’action de la gravité et de tension superficielle. Ce problème a été étudié par Iooss et Kirrmann [Arch. Rational Mech. Anal. 136 (1998) 1–19] à l’aide de la théorie des formes normales pour les systèmes dynamiques “spatiaux”, réversibles et de dimension infinie.
In vitro biocorrosion of CoCrMo implant alloy by macrophage cells
Authors: Lin Hsin‐Yi , Bumgardner Joel D. 
Published: August 2004

AbstractWe hypothesized that macrophage cells and their released reactive chemical species (RCS) affect CoCrMo alloy's corrosion properties and that alloy corrosion products change macrophage cell behavior. A custom cell culture corrosion cell was used to evaluate how culture medium, cells, and RCS altered alloy corrosion in 3‐day tests. Corrosion was evaluated by measuring total charge transfer at a constant potential using a potentiostat and metal ion release by atomic emission spectroscopy. Viability, proliferation, and NO (nitric oxide) and IL‐1β (interlukin‐1β) release were used to assess cellular response to alloy corrosion products. In the presence of activated cells, total charge transfers and Co ion release were the lowest (p< 0.05). This was attributed to an enhancement of the surface oxide by RCS. Cr and Mo release were not different between cells and activated cells. Low levels of metal ions did not affect cell viability, proliferation, or NO release, though IL‐1β released from the activated cells was higher on the alloy compared to the controls. These data support the hypothesis that macrophage cells and their RCS affect alloy corrosion. Changes in alloy corrosion by cells may be important to the development of host responses to the alloy and its corrosion products. © 2004 Orthopaedic Research Society. Published y Elsevier Ltd. All rights reserved.
Gliding resistance of the extensor pollicis brevis tendon and abductor pollicis longus tendon within the first dorsal compartment in fixed wrist positions
Authors: Kutsumi Keiji , Amadio Peter C. , Zhao Chunfeng , Zobitz Mark E. , An Kai‐Nan 
Published: August 2004

AbstractPurpose: While the etiology of de Quervain's disease is unknown, repetitive motion coupled with awkward wrist position and septation within the first dorsal compartment are considered causative factors. We hypothesize that these conditions might produce high gliding resistance, which could then induce micro‐damage of the tendons and retinaculum. The purpose of this study was to measure the gliding resistance of the extensor pollicis brevis and abductor pollicis longus tendons within the first dorsal compartment in a human cadaver model.Methods: Fifteen human cadaver wrists, which included eight septation and seven non‐septation wrists in the first dorsal compartment, were used. Gliding resistance of the extensor pollicis brevis and abductor pollicis longus tendons was measured in seven wrist positions: 60° extension, 30° extension, 0°, 30° flexion, 60° flexion in neutral deviation and 30° ulnar deviation, 15° radial deviation in neutral extension/flexion.Results: The overall gliding resistance was not different between septation and non‐septation wrists (0.21 versus 0.19 N for abductor pollicis longus and 0.21 versus 0.15 N for extensor pollicis brevis, respectively), but there was a significant effect on gliding resistance due to wrist position (p < 0.05) in both tendons. Interaction between wrist position and septation status was observed in the extensor pollicis brevis tendon (p < 0.05). With septation, the gliding resistance of the extensor pollicis brevis was significantly higher in 60° wrist flexion (0.51 N) compared to all other wrist positions tested (all less than 0.26 N) (p < 0.05). In the non‐septation group, gliding resistance was significantly higher in 60° flexion (0.20 N) and 60° extension (0.22 N) compared to the other five wrist positions (all less than 0.15 N) (p < 0.05). Although no significant difference was observed, the extensor pollicis brevis tendon with septation tended to have higher gliding resistance than that without septation in wrist flexion. In 60° of wrist flexion the abductor pollicis longus tendon had significantly higher gliding resistance (0.33 N) than the other wrist positions (all less than 0.26 N) (p < 0.05).Conclusions: A combination of septation and wrist position significantly affected extensor pollicis brevis tendon gliding resistance in this cadaver model. These factors may contribute to the development of de Quervain's disease. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Detection of changes in articular cartilage proteoglycan by T1ρ magnetic resonance imaging
Authors: Wheaton Andrew J. , Dodge George R. , Borthakur Arijitt , Kneeland J. Bruce , Schumacher H. Ralph , Reddy Ravinder 
Published: August 2004

AbstractThe purpose of this work is to demonstrate the feasibility of T1ρ‐weighted magnetic resonance imaging (MRI) to quantitatively measure changes in proteoglycan content in cartilage. The T1ρ MRI technique was implemented in an in vivo porcine animal model with rapidly induced cytokine‐mediated cartilage degeneration. Six pigs were given an intra‐articular injection of recombinant porcine interleukin‐1β (IL‐1β) into the knee joint before imaging to induce changes in cartilage via matrix metalloproteinase (MMP) induction. The induction of MMPs by IL‐1 was used since it has been extensively studied in many systems and is known to create conditions that mimic in part characteristics similar to those of osteoarthritis. The contralateral knee joint was given a saline injection to serve as an internal control. T1ρ‐weighted MRI was performed on a 4 T whole‐body clinical scanner employing a 2D fast spin‐echo‐based T1ρ imaging sequence. T1ρ relaxation parameter maps were computed from the T1ρ‐weighted image series. The average T1ρ relaxation rate, R1ρ (1/T1ρ) of the IL‐1β‐treated patellae was measured to be on average 25% lower than that of saline‐injected patellae indicating a loss of proteoglycan. There was an average reduction of 49% in fixed charge density, measured via sodium MRI, of the IL‐1β‐treated patellae relative to control corroborating the loss of proteoglycan. The effects of IL‐1β, primarily loss of PG, were confirmed by histological and immunochemical findings. The results from this study demonstrate that R1ρ is able to track proteoglycan content in vivo. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Purification of Drosophila DNA polymerase ζ by REV1 protein-affinity chromatography
Authors: TAKEUCHI Ryo , OSHIGE Masahiko , UCHIDA Makiyo , ISHIKAWA Gen , TAKATA Kei-ichi , SHIMANOUCHI Kaori , KANAI Yoshihiro , RUIKE Tatsushi , MORIOKA Hiroshi , SAKAGUCHI Kengo 
Published: August 2004

Studies on the biochemical properties of very-large-size eukaryotic DNA polymerases have been limited by the difficulty in obtaining sufficient purified forms of each enzyme. Our aim was to determine and elucidate the biochemical properties of one such polymerase, pol ζ (DNA polymerase ζ) from Drosophila melanogaster (Dmpol ζ). Using an REV1 (UV-revertible gene 1) protein-affinity column, we have isolated the enzyme directly from Drosophila embryos. Completely purified Dmpol ζ was found to have a molecular mass of approx. 240 kDa, and to be sensitive to aphidicolin and resistant to ddTTP (2′,3′-dideoxythymidine-5-triphosphate) and N-ethylmaleimide. The enzyme has a preference for poly(dA)/oligo(dT)10:1 as a template primer and has high processivity for DNA synthesis. Moreover, Dmpol ζ showed significantly higher fidelity compared with Rattus norvegicus DNA polymerase, an error-prone DNA polymerase, in an M13 forward mutation assay. The activities of bypassing pyrimidine dimers and (6-4) photoproducts and extending from mismatched primer-template termini in (6-4) photoproduct by Dmpol ζ were not detected. Drosophila REV7 interacted with Dmpol ζ in vitro, but did not influence the DNA synthesis activity of Dmpol ζ. The present study is the first report about characterization of purified pol ζ from multicellular organisms, and the second concerning the characterization of yeast pol ζ.
Characterization of a UDP-N-acetyl-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase with an unusual lectin domain from the platyhelminth parasite Echinococcus granulosus
Authors: FREIRE Teresa , FERNÁNDEZ Cecilia , CHALAR Cora , MAIZELS Rick M. , ALZARI Pedro , OSINAGA Eduardo , ROBELLO Carlos 
Published: August 2004

As part of a general project aimed at elucidating the initiation of mucin-type O-glycosylation in helminth parasites, we have characterized a novel ppGalNAc-T (UDP-N-acetyl-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase) from the cestode Echinococcus granulosus (Eg-ppGalNAc-T1). A full-length cDNA was isolated from a library of the tissue-dwelling larval stage of the parasite, and found to code for a 654-amino-acid protein containing all the structural features of ppGalNAc-Ts. Functional characterization of a recombinant protein lacking the transmembrane domain showed maximal activity at 28 °C, in the range 6.5–7.5 pH units and in the presence of Cu2+. In addition, it transferred GalNAc to a broad range of substrate peptides, derived from human mucins and O-glycosylated parasite proteins, including acceptors containing only serine or only threonine residues. Interestingly, the C-terminal region of Eg-ppGalNAc-T1 bears a highly unusual lectin domain, considerably longer than the one from other members of the family, and including only one of the three ricin B repeats generally present in ppGalNAc-Ts. Furthermore, a search for conserved domains within the protein C-terminus identified a fragment showing similarity to a recently defined domain, specialized in the binding of organic phosphates (CYTH). The role of the lectin domain in the determination of the substrate specificity of these enzymes suggests that Eg-ppGalNAc-T1 would be involved in the glycosylation of a special type of substrate. Analysis of the tissue distribution by in situ hybridization and immunohistochemistry revealed that this transferase is expressed in the hydatid cyst wall and the subtegumental region of larval worms. Therefore it could participate in the biosynthesis of O-glycosylated parasite proteins exposed at the interface between E. granulosus and its hosts.
Enhancement of correct protein folding in vivo by a non-lytic baculovirus
Authors: HO Yu , LO Huei-Ru , LEE Tzu-Ching , WU Carol P. Y. , CHAO Yu-Chan 
Published: August 2004

The BEVS (baculovirus expression vector system) is widely used for the production of proteins. However, engineered proteins frequently experience the problem of degradation, possibly due to the lytic nature of the conventional BEVS (herein referred to as L-BEVS). In the present study, a non-lytic BEVS (N-BEVS) was established by random mutagenesis of viral genomes. At 5 days post-infection, N-BEVS showed only 7% cell lysis, whereas L-BEVS showed 60% lysis of cells. The quality of protein expressed in both N- and L-BEVSs was examined further using a novel FRET (fluorescence resonance energy transfer)-based assay. To achieve this, we constructed a concatenated fusion protein comprising LUC (luciferase) sandwiched between EYFP (enhanced yellow fluorescent protein) and ECFP (enhanced cyan fluorescent protein). The distance separating the two fluorescent proteins in the fusion protein EYFP–LUC–ECFP (designated hereafter as the YLC construct) governs energy transfer between EYFP and ECFP. FRET efficiency thus reflects the compactness of LUC, indicating its folding status. We found more efficient FRET in N-BEVS compared with that obtained in L-BEVS, suggesting that more tightly folded LUC was produced in N-BEVS. YLC expression was also analysed by Western blotting, revealing significantly less protein degradation in N-BEVS than in L-BEVS, in which extensive degradation was observed. This FRET-based in vivo folding technology showed that YLC produced in N-BEVS is more compact, correlating with improved resistance to degradation. N-BEVS is thus a convenient alternative for L-BEVS for the production of proteins vulnerable to degradation using baculoviruses.