bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sexually dimorphic basal water absorption at the isolated pelvic patch of Japanese tree frog, Hyla japonica
Authors: Kohno Satomi , Fujime Makoto , Kamishima Yoshihisa , Iguchi Taisen 
Published: April 2004

AbstractFrogs ingest little water orally, but absorb the majority of the water needed for normal physiological performance through a specific region of the ventral skin, the pelvic patch. We observed non‐stimulated (basal water absorption, BWA) water flux through the isolated pelvic patch in vitro in Japanese tree frog (Hyla japonica). We found that water flux through non‐stimulated skin from the pelvic patch was greater in males than females. This water flux was confirmed as BWA by observing no effect following the in vitro administration of propranolol and [adamantaneacetyl1, O‐Et‐D‐Tyr2, Val1, aminobutyryl6, Arg8, 9] vasopressin, which are a β‐adrenergic receptor antagonist and a vasopressin V2 receptor antagonist, respectively. We further examined this phenomenon following gonadectomy, treatment with sex hormones (E2, 17β‐estradiol; TP, testosterone propionate), estrogenic chemicals (BPA, bisphenol A; MTX, methoxychlor) or prolactin (PRL, a hormone regulated by sex hormones that has osmoregulatory activity). Ovariectomy increased BWA in females. Injection (in vivo treatment) of E2 or PRL reduced BWA in males, whereas TP injection increased BWA in females. However, the in vitro addition of E2, TP, or PRL to the Ringer's solution on the serosal side of the ventral skin patch did not alter BWA. Subsequently, we injected (in vivo treatment) BPA or MTX, environmental chemical contaminants with known hormonal actions in mammals. Injection of BPA or MTX reduced BWA in males as observed following treatment with E2. These results provide the first evidence of sexual dimorphism in BWA through the isolated pelvic patch. The gonad appears essential for observed sexual dimorphism in BWA, and we hypothesize that sex hormones regulate the release of PRL, that in turn influences BWA indirectly. E2 is known to exert a specific stimulatory effect on PRL secretion. In addition, we have observed that some endocrine disrupting contaminants also eliminate the sexual dimorphism in BWA observed in the Japanese tree frog. J. Exp. Zool. 301A:428–438, 2004. © 2004 Wiley‐Liss, Inc.
Soft tissue enhancement on time‐resolved peripheral magnetic resonance angiography
Authors: Zhang Hong Lei , Kent K. Craig , Bush Harry L. , Winchester Priscilla A. , Watts Richard , Wang Yi , Prince Martin R. 
Published: April 2004

AbstractPurposeTo evaluate the incidence and locations of soft tissue enhancement on time‐resolved two‐dimensional projection magnetic resonance angiography (MRA) of the calf and foot.Materials and MethodsTime‐resolved two‐dimensional projection MRA of the knee, calf, and foot, performed at 1.5 Tesla using the head coil, was retrospectively reviewed in 326 patients. Soft tissue enhancement of the foot was identified and graded by blinded review. Subsequently, patient medical records were reviewed to determine the presence or absence of diabetes, cellulitis, gangrene, and ulceration of the foot and presence of neuropathic joints.ResultsEnhancing spots were identified in 228 patients. For those feet without clinical abnormalities, diabetic patients had an average of 1.2 enhancing spots per foot, while nondiabetics had only 0.6 (P < 0.001). Higher‐grade lesions were more prevalent in diabetics and in heavier patients. Of 64 patients with follow‐up, 8 (13%) developed cellulitis (N = 4) or ulceration (N = 4) at the location of an enhancing spot, including 5 diabetic and 3 nondiabetic patients.ConclusionPedal soft tissue enhancement frequently occurs on time‐resolved gadolinium (Gd):MRA of the feet. The etiology is uncertain, but the high frequency in diabetic patients and observation of progression to cellulitis/ulceration suggest this soft tissue enhancement may identify sites of subclinical pedal soft tissue injury. J. Magn. Reson. Imaging 2004;19:590–597. © 2004 Wiley‐Liss, Inc.
Emotional intelligence in leaders: an antidote for cynicism towards change?
Authors: Ferres Natalie , Connell Julia 
Published: April 2004

Abstract

Business leaders everywhere have encountered the reality of resistance and cynicism when introducing change initiatives.
This paper identifies some of the associations between the challenges of organizational change in the 21st century and the emotional competencies required of contemporary change leaders.
The aim of this paper is to explore the impact of leader emotional intelligence (EI) on levels of employee cynicism towards change.
Results from a survey of 448 employees supported the hypothesis that employees would report less change cynicism if managed by leaders whom subordinates rated as emotionally intelligent.
This study will be of interest to managers and people concerned with leadership, change management, emotional intelligence and securing a competitive advantage.

Copyright © 2004 John Wiley & Sons, Ltd.
Primary retroperitoneal teratomas: A review of the literature
Authors: Gatcombe Heather G. , Assikis Vasily , Kooby David , Johnstone Peter A.S. 
Published: April 2004

AbstractTeratomas are uncommon neoplasms comprised of mixed dermal elements derived from the three germ cell layers. Historically, teratomas were attributed to demons, sexual misconduct, and abnormal fertilization. They attract attention because of their bizarre histology and gross appearance. While the majority of teratomas present congenitally in the sacrococcygeal region, within the ovaries of adolescent females and within the testes of young men, they have been identified throughout the body. Extragonadal teratomas tend to occur in midline structures as the anterior mediastinum, retroperitoneum, sacrococcygeal region, and pineal gland. Retroperitoneal teratomas represent only 1–11% of primary retroperitoneal tumors. Incidence is bimodal with peaks in the first 6 months of life and in early adulthood. Due to their location, they are usually identified only after they have grown to huge proportions. There is a 25% chance of malignancy. Surgical resection remains the mainstay of therapy and is required for definitive diagnosis. This article reviews the literature on the histopathology, classification, genetic abnormalities, and theories of origin of teratomas as well as the presentation, diagnosis, and management of retroperitoneal teratomas. J. Surg. Oncol. 2004;86:107–113. © 2004 Wiley‐Liss, Inc.
1. History of CA and evolution of the markets
Authors: Rustemeyer Paul 
Published: April 2004

AbstractAn overlook is given of the 100 years of technical, industrial and chemical development of cellulose acetate. CA has been used as raw material in the fields of laquer, plastics, textile, Filter Tow, film, membrane and others. In the field of applications for plastics and textiles CA was quite successful for many years, but was then slowly substituted by other polymers. Total cellulose acetate demand is growing, especially for Filter Tow in cigarettes filters and film for polarisers in LCD‐displays.
4. Characteristics of cellulose acetates 4.1 Characterization and physical properties of cellulose acetates
Authors: Zugenmaier Peter 
Published: April 2004

AbstractAn overview is provided of the basic features of cellulose acetate of various degree of substitution in the solid and liquid crystalline state as well as in solution. These features represent a necessity for an understanding of the properties of these cellulose derivatives and further for mixed esters, which are not presented in this paper. Specifically, the crystal structure of cellulose triacetate will be addressed as well as structures in dilute and semi‐dilute solutions. Thermal, viscoelastic and further properties in the solid state are discussed as well as flow behavior of solutions and their application in molecular weight determination, including false viscosity of commercial 2.5 cellulose acetates.
Role of basic helix‐loop‐helix (bHLH) and CREB transcription factors in the regulation of sertoli cell androgen‐binding protein expression
Authors: Saxlund Melissa A. , Sadler‐Riggleman Ingrid , Skinner Michael K. 
Published: April 2004

AbstractDifferentiation of Sertoli cells is marked by the presence of novel gene products such as transferrin and androgen‐binding protein (ABP). Transcriptional regulation of Sertoli cell differentiation is, in part, controlled through the binding of specific transcription factors to response elements within these genes promoters. Transferrin gene expression has been shown to be regulated by the binding and interactions of basic helix‐loop‐helix (bHLH) and cAMP response element binding protein (CREB) to an E‐box and cyclic AMP response element (CRE), respectively. Interaction between the bHLH and CREB is facilitated through subsequent binding of CREB‐binding protein (CBP)/p300. The hypothesis tested in the current study is that ABP expression is regulated by a similar mechanism. The ABP promoter activation was analyzed through the use of transfection assays, site‐directed mutagenesis, and electromobility shift assays (EMSA). Transient transfections of rat Sertoli cells used a reporter construct containing the proximal 619 bp of the ABP promoter. Observations suggest that cAMP and follicle stimulating hormone (FSH) upregulate the expression of ABP. Mutational studies of the three E‐boxes and the CRE of the 619‐bp ABP promoter indicate that all of these elements are critical for stimulation of promoter activity. EMSA revealed a weak interaction between an E‐box‐2 and the CRE that are overlapping in the promoter. An artificial promoter that contains only an E‐box and CRE was created to further test this hypothesis. The artificial promoter was stimulated by both FSH and cAMP. Experiments with mutants of the artificial promoter demonstrate that both response elements contribute to the optimal activation of the promoter construct. The overexpression of the bHLH inhibitor Id (i.e., inhibitor of differentiation) that binds bHLH proteins and eliminates DNA binding was found to suppress hormone activation of the ABP promoter. Combined observations of the ABP promoter and artificial promoter provide insight into a common mechanism for gene regulation in differentiated Sertoli cells involving a role for both the bHLH and CREB family of transcription factors. Mol. Reprod. Dev. 68: 269–278, 2004. © 2004 Wiley‐Liss, Inc.
Both blastomeres of the mouse 2‐cell embryo contribute to the embryonic portion of the blastocyst
Authors: Chróścicka Anna , Komorowski S. , Maleszewski Marek 
Published: April 2004

AbstractTo track the lineage of both blastomeres of 2‐cell embryos during mouse preimplantation development, each cell was injected with dextran solutions conjugated with different fluorochromes. The fate of the progeny of the first two blastomeres was followed with confocal microscopy during cleavage and during the formation of the blastocyst. We observed that in most of cleaving embryos the cells derived from the two first blastomeres intermingled in both the trophectoderm and the inner cell mass (ICM) and did not form two discrete groups. We conclude that embryonic parts of blastocysts contain descendants of both blastomeres of 2‐cell embryo. Mol. Reprod. Dev. 68: 308–312, 2004. © 2004 Wiley‐Liss, Inc.
The precise computation for wave propagation in stratified materials
Authors: Zhong W.‐X. , Lin J. H. , Gao Q. 
Published: April 2004

AbstractThe problem of random wave travelling along stratified materials is important for earthquake engineering. The soil is considered multi‐layered and located above the base‐rock, whose material property is assumed to be much stiffer than the soil, and the power spectrum density of the random excitation is given at the base rock. The soils can be arbitrarily anisotropic for each layer. The governing differential equations are derived in frequency and wavenumber domain and only a set of ordinary differential equations must then be solved. The eigensolution expansion method is used to solve for the responses of the layers. The precise integration algorithm in combination with the extended W–W algorithm is applied to obtain all the eigensolutions of the ODE (ordinary differential equation). Thereafter, the recently developed pseudo‐excitation method for structural random vibration is transplanted to the solution of the layered soil responses.Numerical results are given and compared with some classical results. This shows the relevance of the presented method. Copyright © 2004 John Wiley & Sons, Ltd.
Adaptive finite element analysis and modelling of solids and structures. Findings, problems and trends
Authors: Stein Erwin , Rüter Marcus , Ohnimus Stephan 
Published: April 2004

AbstractThe main purpose of this paper is two‐fold: first, to present a critical review of available error‐controlled adaptive finite element methods—with absolute global and goal‐oriented error estimates—for approximate solutions of a given mathematical model and the model error of the considered mathematical model and its dimensions, enhanced with our own recent results in fracture mechanics. The second related important matter is which physical/mathematical models—including various boundary layers and other disturbances—and which accuracy of the finite element solutions in which norm are prescribed and necessary for the safety and reliability of a certain engineering problem, e.g. in structural engineering, of course depending on materials, systems and the type as well as the magnitude of prescribed loadings (i.e. actions in a factorized concept) acting on a specific structure. It is hard to understand why the current regulations for structural engineering design in Europe—especially the European Standards (Eurocodes) and the relevant German DIN‐Codes (DIN: Deutsches Institut für Normung e. V.)—do not lay out any rules or bounds for the prescribed accuracy of the material and structural resistance, i.e. the validity of mechanical modelling and the accuracy of associated numerical methods, usually today the finite element method. It can be observed that behind the existing codes there still lies the old thinking of, e.g., classical elastic beam theory of so‐called second order for stability problems and the corresponding elastic potential for plates and shells in buckling. Modern flexible finite element modelling by deriving theories in variational form for thin‐walled beams, plates and shells from rather general 3D theories, for both linear and non‐linear problems, capturing inelastic deformations and layer effects by material and dimensional expansions are not addressed in the Eurocodes for structural engineering. The necessary consequence is that joint work of computational mechanics specialists and structural engineers, working in national and international code‐committees, is absolutely necessary, in order to avoid a lot of costly troubles and dangers of today by improving and updating the codes. Copyright © 2004 John Wiley & Sons, Ltd.
Variational time integrators
Authors: Lew A. , Marsden J. E. , Ortiz M. , West M. 
Published: April 2004

AbstractThe purpose of this paper is to review and further develop the subject of variational integration algorithms as it applies to mechanical systems of engineering interest. In particular, the conservation properties of both synchronous and asynchronous variational integrators (AVIs) are discussed in detail. We present selected numerical examples which demonstrate the excellent accuracy, conservation and convergence characteristics of AVIs. In these tests, AVIs are found to result in substantial speed‐ups, at equal accuracy, relative to explicit Newmark. A mathematical proof of convergence of the AVIs is also presented in this paper. Finally, we develop the subject of horizontal variations and configurational forces in discrete dynamics. This theory leads to exact path‐independent characterizations of the configurational forces acting on discrete systems. Notable examples are the configurational forces acting on material nodes in a finite element discretisation; and the J‐integral at the tip of a crack in a finite element mesh. Copyright © 2004 John Wiley & Sons, Ltd.
Ethylene‐co‐vinyl acetate copolymer crosslinking through ester–alkoxysilane exchange reaction catalyzed by dibutyltin oxide: mechanistic aspects investigated through model compounds by multinuclear NMR spectroscopy
Authors: Bounor‐Legaré Véronique , Monnet Christiane , Llauro Marie‐France , Michel Alain 
Published: April 2004

AbstractIt was shown that the crosslinking of ethylene‐co‐vinyl acetate (EVA) copolymer by a tetraalkoxysilane in molten state, in the temperature range 100–250 °C, was obtained only in the presence of dibutyltin oxide. At this temperature EVA pendant ester groups readily react with dibutyltin oxide to give a dimeric 1‐alkoxy‐3‐acetoxytetrabutyldistannoxane distributed along the polymer chains. The exact role of this tin compound in the ester–alkoxysilane reaction was elucidated through reactions of the tetraalkoxysilane with parent tin compounds: tributylethoxytin, dimeric diacyloxydistannoxane and finally a dimeric 1‐alkoxy‐3‐acyloxydistannoxane, obtained by reaction of the dibutyltin oxide with a model ester instead of the EVA‐ester pendant group. Ligand exchanges on tin atoms characterized by multinuclear NMR spectroscopy (1H, 13C and 119Sn) showed that substitutions were selective and concern only the exo‐cyclic tin ligand (OR or OCOR′) without alteration of the dimeric distannoxane structure. Furthermore, these ligand exchanges occurred at room temperature. This approach with model compounds gave evidence that the crosslinking occurred via an alkoxy‐Sn/alkoxy‐Si exchange on the exo‐cyclic sites of the distannoxane structure formed in situ. This distannoxane was shown to be an efficient catalyst of this transesterification. The temperature of formation of this catalytic species governed the temperature of the beginning of the crosslinking reaction. Copyright © 2004 Society of Chemical Industry
New thermoplastic vulcanizate, composed of polypropylene and ethylene–vinyl acetate copolymer crosslinked by tetrapropoxysilane: evolution of the blend morphology with respect to the crosslinking reaction conversion
Authors: Verbois Agnès , Cassagnau Philippe , Michel Alain , Guillet Jacques , Raveyre Claude 
Published: April 2004

AbstractA thermoplastic vulcanizate (TPV) is tailored by a dynamic vulcanization process. TPVs can be processed as thermoplastics and have properties similar to conventional vulcanized rubbers. The main objective of our recent works was to tailor, by using the reactive extrusion process, a new TPV composed of polypropylene homopolymer (PP) as thermoplastic phase and ethylene–vinyl acetate copolymer (EVA) as elastomer phase, which is crosslinked by tetrapropoxysilane (TPOS) as crosslinking agent in the presence of dibutyl tin oxide (DBTO) as catalyst. Crosslinking is carried out through a transesterification reaction between the ester groups of EVA and the alkoxysilane groups of TPOS. This exchange reaction is catalyzed by DBTO at temperatures above 100 °C. The main advantage of this chemistry that it is non‐radical, and so prevent the degradation of PP, in comparison with crosslinking reactions using peroxides as initiators.Different reactive blends were prepared in the internal mixer of a Haake Plasticorder. In order to know how the crosslinking reaction has advanced, the EVA gel content and the volume swelling rate of the blend were measured. The aim of this study was to get a better understanding of the dispersion mechanism of EVA in the major phase during its dynamic vulcanization in the presence of PP in the minor phase. This paper deals with the correlation that exists between the evolution of the two‐phase blend morphology and the extent of the crosslinking reaction on the elastomer phase during the elaboration of a TPV. In particular, we showed that the correlation was almost the same for the elaboration of the TPV in the internal mixer of the Haake Plasticorder (discontinuous process) and in a twin‐screw extruder (continuous process). Copyright © 2004 Society of Chemical Industry
Addition–fragmentation chain transfer: Molecular weight distributions and retardation in the system methyl methacrylate/methyl α‐(bromomethyl)acrylate
Authors: Zetterlund Per B. , Miyake Kazuki , Goto Kunihiro , Yamada Bunichiro 
Published: April 2004

AbstractA detailed investigation of addition–fragmentation chain transfer (AFCT) in the free‐radical polymerization of methyl methacrylate (MMA) in the presence of methyl α‐(bromomethyl)acrylate (MBMA) was carried out to elucidate mechanistic details with efficient macromonomer synthesis as an underlying goal. Advanced modeling techniques were used in connection with the experimental work. Curve fitting of simulated and experimental molecular weight distributions with respect to the rate coefficient for addition of propagating radicals to MBMA (kadd) over 60–120 °C resulted in Eadd = 21.7 kJ mol−1 and Aadd = 2.18 × 106 M−1 s−1 and a very weak temperature dependence of the chain‐transfer constant (Eadd ≈ Ep). The rate coefficient for fragmentation of adduct radicals at 60 °C was estimated as kf ≈ 39 s−1 on the basis of experimental data of the MMA conversion and the concentration of 2‐carbomethoxy‐2‐propenyl end groups. The approach developed is generic and can be applied to any AFCT system in which copolymerization does not occur and in which the resulting unsaturated end groups do not undergo further reactions. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2640–2650, 2004
Management of conversion reaction in five adolescent girls
Authors: Brooksbank Donald J. 
Published: April 2004

AbstractHysteria is a topic which has produced a plethora of articles on adults but, in comparison, there is a scarcity when it involves children and young adolescents. There is considerable confusion in definition, classification, incidence and management. More agreement seems to be found when conversion reactions are specifically considered.This article attempts to present the dilemma that confronts the clinician when faced with an individual patient with a conversion reaction. This may especially apply to the present day practitioner who is likely not to have had much personal experience in managing this condition. Some of the relevant literature is summarized and the five patients are presented in tabular form and individually, together with their outcome at follow‐up. The findings are discussed and some conclusions are drawn.
Rapprochement in late adolescent separation‐individuation: a structural equations approach
Authors: Quintana Stephen M. , Lapsley Daniel K. 
Published: April 2004

AbstractAdolescents' movements toward individuation are believed to be supported by secure attachments to parents. Previous research has found that individuation could be operationalized with indices of connectedness and separateness, but the relationship between these variables has not been fully explored. The present study demonstrated that attachment and differentiation variables were positively related using different and multiple operationalization procedures. Furthermore, a more comprehensive model of adolescent ego development was proposed which included parental control, individuation, and ego identity constructs. Results suggest parental control restricts successful individuation, but that adjustment on individuation indices predicts advanced identity development.