bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolutionary transformation from muscular to hydraulic movements in spider (Arachnida, Araneae) genitalia: A study based on histological serial sections
Authors: Huber Bernhard A. 
Published: July 2004

AbstractThe male genitalia of 107 spider species representing 73 families were serially sectioned and studied with an emphasis on muscles moving the genital bulb. As a rule, most non‐Entelegynae have two bulbal muscles, most Entelegyne have none, but many exceptions occur. Variation also occurs with regard to origin and attachment of bulbal muscles. There appears to be a trend towards a shift of the origin from proximal (Liphistius, Atypus) to more distal palpal segments (Haplogynae). In most Entelegynae the muscular movement is replaced by hydraulic movement caused by expanding membranes (hematodochae). Hematodochae probably permit increased bulbal rotation and movements of higher complexity. New evidence is presented arguing against Palpimanidae being representatives of Entelegynae. Bulbal glands other than those discharging into the sperm duct (previously known in Amaurobiidae and Dictynidae only) are described in several entelegyne families. J. Morphol. 261:364–376, 2004. © 2004 Wiley‐Liss, Inc.
Synthesis of Chlorotitanium(IV) Schiff‐Base Complexes and their Application to Styrene Polymerization
Authors: Kim Il , Ha Yun Sun , Zhang Dan Feng , Ha Chang‐Sik , Lee Uk 
Published: July 2004

AbstractSummary: A [TiCl2(salen)] complex and its derivatives with the formula [TiCl2(L)] [L = salen(tBu), salen(di‐Me), salen(di‐tBu), salen(Me)] were synthesized in high yield by reacting the Schiff‐base ligands with TiCl4. [TiCl2{salen(tBu)}] and [TiCl2{salen(di‐tBu)}] have been characterized by single‐crystal X‐ray diffraction. Styrene polymerizations carried out with [TiCl2(salen)] and its derivatives co‐catalyzed by MAO yielded syndiotactic polystyrenes. The catalytic activity and syndiospecificity were dependent on the bulkiness of the ortho substituents in the aryl ring of ligand.
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Cu Crystal Growth on a Chelating Fiber with Different Amine Chain Lengths
Authors: Ko Young Gun , Shin Dong Hun , Choi Ung Su 
Published: July 2004

AbstractSummary: Poly(acryloamidino ethyleneamine) (PAEA) and poly(acryloamidino diethylene diamine) (PADD) have been synthesized for the observation of CuII complex and Cu(OH)2 crystal‐growth on the surface of different numbers of amino groups immobilized on polyacrylonitrile (PAN) fibers. The shape of CuII crystal growth depends on the amine chain length of the chelating fiber; Cu(OH)2 crystals grow on the surface of the chelating fiber after CuII adsorption.
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POCA: pattern‐oriented channel assignment scheme for wireless cellular networks
Authors: Ahmed Rana Ejaz , Cardan Robin 
Published: July 2004

AbstractThis paper presents a new decentralized dynamic channel allocation scheme which uses a ‘clustering’ concept to allocate channels efficiently. Simulation results show that the proposed scheme performs better than fixed channel assignment and some other dynamic channel allocation schemes under low and moderate traffic load conditions. Copyright © 2004 John Wiley & Sons, Ltd.
Frame‐level performance measurement in an ATM test‐bed environment: methodologies and experiences
Authors: Ahmed Rana E. , Khan Hasan A. , Mouftah Hussein T. 
Published: July 2004

AbstractPerformance testing is related to user‐perceived performance of asynchronous transfer mode (ATM) technology. We describe the test methodologies used to measure various frame‐level quality of service metrics, such as throughput and latency. Some practical issues encountered in performance testing in an ATM test‐bed environment are addressed. Copyright © 2004 John Wiley & Sons, Ltd.
Early‐onset gastric carcinomas display molecular characteristics distinct from gastric carcinomas occurring at a later age
Authors: Carvalho Ralph , Milne Anya NA , van Rees Bastiaan P , Caspers Eric , Cirnes Luís , Figueiredo Céu , Offerhaus G Johan A , Weterman Marian AJ 
Published: July 2004

AbstractGastric cancer is thought to result from a combination of environmental factors and accumulation of specific genetic alterations, and consequently mainly affects older patients (>50 years of age). Fewer than 10% of patients present with the disease before 45 years of age and these young patients are thought to develop carcinomas with a different molecular genetic profile from that of sporadic carcinomas occurring at a later age. Forty early‐onset gastric carcinoma resection specimens were characterized for microsatellite instability (MSI) and loss of heterozygosity status using 22 polymorphic microsatellite markers. Twenty‐four biopsies were additionally evaluated for the presence of MSI. No MSI was observed in any of the cases analysed. Losses were infrequent, but were most common for the D1S234 (26.1%) and D1S1676 (17.4%) markers, flanking the RUNX3 gene; for the p53ALU (23.1%) and TP53 (15.4%) markers, near the TP53 gene; and for the D16S2624 (17.2%) marker, near the E‐cadherin (CDH1) gene. All cases with loss of CDH1, as well as 6/7 cases with loss of TP53, displayed aberrant staining of the corresponding proteins, pointing to a functional role for these proteins in early‐onset gastric carcinogenesis. No germline CDH1, TP53 or RUNX3 mutations were detected in any of the cases analysed. No correlation was observed between non‐functional E‐cadherin and the histological type of the tumours analysed. Finally, Epstein–Barr virus was not detected in any of the cases analysed. On the basis of these results, early‐onset gastric carcinomas appear to have characteristics distinct from gastric carcinomas occurring at a later age. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Structural and energetic characterization of nucleic acid‐binding to the fingers domain of Moloney murine leukemia virus reverse transcriptase
Authors: Crowther Robert L. , Remeta David P. , Minetti Conceição A.S.A. , Das Debanu , Montano Sherwin P. , Georgiadis Millie M. 
Published: July 2004

AbstractReverse transcriptase is an essential retroviral enzyme that replicates the single‐stranded RNA genome of the retrovirus producing a double‐stranded DNA copy, which is subsequently integrated into the host's genome. We have previously reported that processive DNA synthesis of Moloney murine leukemia virus reverse transcriptase (MMLV RT) is severely compromised by substitution of an Ala for the fingers domain residue Arg 116. In order to further investigate the role of Arg 116 in interactions of MMLV RT with nucleic acids, we have determined the crystal structure of the R116A N‐terminal fragment and characterized the binding of two self‐complementary DNA duplexes [d(CATGCATG)2 and d(CGCGCGCG)2] to both the wild‐type and R116A fragments by isothermal titration calorimetry. The resultant thermodynamic profiles extrapolated to 25°C reveal that binding of the wild‐type N‐terminal fragment to both DNA duplexes is enthalpy‐driven and characterized by an unfavorable entropy. Although the temperature dependence of the respective protein–DNA binding enthalpies is markedly different reflecting distinct heat capacity changes, the binding free energies are nearly identical and relatively invariant to temperature (ΔG ∼ −6.0 kcal · mol−1). In contrast to the wild‐type fragment, the R116A fragment exhibits no measurable affinity for either DNA duplex, yet its crystal structure reveals no significant changes when compared to the wild‐type structures. We suggest that hydrogen‐bonding interactions involving the fingers domain residue Arg 116 are critical for DNA binding as well as processive DNA synthesis by MMLV RT. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Kinetics of interaction of three carbamate pesticides with Indian soils: Aligarh district
Authors: Bansal OP 
Published: July 2004

AbstractThe kinetics of interaction with soil of three carbamate pesticides (I, II, III) used as nematicides and herbicides was studied at four different temperatures from solutions of six soil samples of Aligarh district. The values obtained for rate constants for adsorption and desorption were in good agreement with those obtained from the Lindstrom model, which proved useful in the simultaneous evaluation of adsorption (k1) and desorption (k2) rate constants. The rate constants for pesticides were in the order III > I > II on all the six soil samples. The data for rate constants, activation energies, heats of activation, entropy of activation and thermodynamic parameters indicated a partly physical and partly chemical adsorption of pesticide on the soil surfaces. Adsorption occurred via coordination and/or protonation of the exchangeable cations with the amidic carbonyl group, and hydrogen bonding and dipole association at the crystal edge and basal surfaces. The adsorptivity of the soils may be attributed to the organic matter content and percentage clay content. Copyright © 2004 Society of Chemical Industry
STM study of large organic molecules adsorption on Si(100)‐2 × 1
Authors: Rada Tomás , Chen Qiao , Richardson Neville 
Published: July 2004

AbstractThe adsorption of large organic molecules, including tetracene and perylene, on clean Si(100) is followed by scanning tunnelling microscopy (STM) in an ultra high vacuum environment. Different adsorption sites have been observed for these organic molecules. Two types of tetracene adsorption are indicated by filled state images but three types can be distinguished in empty state images. Molecules aligned both along and perpendicular to the silicon dimer rows can be observed. Measurements of the length of this molecule in all configurations indicate that the molecule stays intact during the adsorption process. High resolution of STM images reveal that the perylene molecules bond to the substrate in a vertical orientation and forming packs of perylene aligned perpendicular to the silicon dimmer rows. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Donor‐related photoionization cross‐section of GaAs–(Ga, Al)As quantum dots: hydrostatic pressure effects
Authors: Correa J. D. , Porras‐Montenegro N. , Duque C. A. 
Published: July 2004

AbstractUsing a variational method and the effective‐mass approximation, we calculated the binding energy for shallow‐donor impurities in spherical GaAs–(Ga, Al)As quantum dots. In this paper we present results for different dimensions of the structure and radial impurity positions. Calculations include the hydrostatic pressure effects. We discuss the hydrostatic pressure dependence on the binding energy and the photoionization cross‐section. The measurement of photoionization in such systems would be of great interest in understanding the optical properties of carriers in quantum dots. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Finite‐Elemente‐Berechnungen zum Trag‐ und Verformungsverhalten von Kopfbolzendübeln
Authors: Hegger Josef , Goralski Claus , Rauscher Sabine , Kerkeni Naceur 
Published: July 2004

AbstractDie Verbundfuge zwischen Betongurt und Stahlträger wird bei der numerischen Simulation von Verbundträgern durch Federn oder Interface‐Elemente mit bi‐ oder trilinearen Schubkraft‐Schlupfgesetzen abgebildet. Mit diesen in der Praxis bewährten Methoden läßt sich das globale Tragverhalten für beliebige Verdübelungsgrade berechnen. Zur Abbildung einer konzentrierten Lasteinleitung, z. B. bei Verankerungen, ist jedoch eine dreidimensionale Modellierung des Verbundmittels erforderlich. Der Aufsatz beschreibt ein dreidimensionales, nichtlineares Finite‐Elemente‐Modell, mit dem das lokale Trag‐ und Verformungsverhalten von Kopfbolzendübeln unter Abscherbeanspruchung bestimmt werden kann. Zur Kalibrierung des Modells dienten eigene Abscherversuche für Einzeldübel. In Parameterstudien wird der Einfluß der Betonfestigkeit, der Schaftlänge und der Schweißwulstgeometrie untersucht. Gleichzeitig werden die Grenzen in der Simulation von Abscherversuchen mit der Finiten‐Elemente‐Methode aufgezeigt.
Ermittlung von Eigenwerten und Eigenformen für Stäbe und Stabwerke
Authors: Kindmann Rolf , Laumann Jörg 
Published: July 2004

AbstractFür die Bemessung stabilitätsgefährdeter Stäbe und Stabwerke hat die Ermittlung von Eigenwerten und Eigenformen zentrale Bedeutung. Da aus der Literatur zahlreiche, z. T. stark unterschiedliche Berechnungsverfahren bekannt sind, wird die Frage geklärt, welche Verfahren aufgrund der spezifischen Problemstellung am besten geeignet sind. Mit einem modifizierten Vektoriterationsverfahren und einem speziell angepaßten Matrizenzerlegungsverfahren wird auf zwei Methoden detailliert eingegangen. Darüber hinaus wird die Ermittlung von Eigenwerten und Eigenformen mit Hilfe von EDV‐Programmen und die Beurteilung ihrer Ergebnisse erläutert.
A new modelling technique using a subsystem for structural schematic design of tall buildings
Authors: Kim Hansoo , Jung Jonghyun , Cho Sukhee 
Published: July 2004

AbstractIn the schematic design of a tall building structure, a structural designer builds structural analysis models for many schemes. However, conventional modelling techniques force the designer to view the scheme as an assembly of many members related in a complicated manner. Therefore, the modelling scheme is laborious, prone to error and time‐consuming. In this study, we present a new modelling technique that uses a subsystem—that is, the assembly of the members participated in a specific type of load transfer—as the primary modelling unit. We expect this modelling technique to allow simple modelling of a scheme. Copyright © 2004 John Wiley & Sons, Ltd.
Neuropathological consequences of prenatal cocaine exposure in the mouse
Authors: Ren Jia‐Qian , Malanga C.J. , Tabit Eddy , Kosofsky Barry E. 
Published: July 2004

AbstractWe have developed an animal model in Swiss Webster mice to identify mechanisms by which prenatal exposure to cocaine results in persistent alterations in brain structure and function. Clinical data suggests that children who demonstrate the largest impairments in prenatal brain growth, which are positively correlated with the highest level of prenatal cocaine exposure, are more likely to demonstrate selective impairment in postnatal brain growth, as well as postnatal impairments in motor function, attention and language skills. We conducted neuroanatomic studies to identify the postnatal evolution of structural changes in the primary somatosensory (SI) cortex of the developing mouse brain following prenatal exposure to cocaine. Our previous work, and that of others, provides evidence that many of the processes underlying corticogenesis are disrupted by gestational exposure of the developing mouse brain to cocaine, and that from the earliest phases of corticogenesis that there is an imprecision in the development of cortical lamination. We performed morphometric comparisons between the brains of animals prenatally exposed to varying amounts of cocaine with vehicle and malnutrition controls on postnatal (P) days P9 and P50. We found that on P50, but not P9, the relative number of cortical neurons in S1 is significantly less in cocaine exposed animals as compared with controls. The significant decrease in the number of cells in cocaine exposed animals on P50 is evident as a decreased density of cells restricted to the infragranular compartment (layers V and VI). Those changes are not seen in malnourished animals.Taken together our findings support the conclusion that cocaine‐induced alterations in SI cortical cytoarchitectonics are in part a consequence of altered postnatal survival of infragranular cortical neurons, which are lost during the interval between P9 and P50. Determining whether a similar process is evident in a subset of humans following in utero cocaine exposure is a high priority for future clinical brain imaging studies, because analogous structural changes could impact the brain function and behavioral repertoire of infants and children following significant prenatal exposures.
Maternal administration of thalidomide or valproic acid causes abnormal serotonergic neurons in the offspring: implication for pathogenesis of autism
Authors: Miyazaki Kaoru , Narita Naoko , Narita Masaaki 
Published: July 2004

AbstractEmbryonic exposure to thalidomide (THAL) or valproic acid (VPA) before neural tube closure has been demonstrated as a useful model for human autism in rats. Abnormalities of the serotonergic system which are often observed in human autism have been shown in these rats. Thus, we examined whether early serotonergic neuronal development is perturbed by THAL/VPA. When pregnant rats were exposed to THAL or VPA on embryonic day 9, a dramatic shift of the distribution of serotonergic neurons in the dorsal raphe nucleus was observed on postnatal day 50. This alteration is thought to reflect abnormality of serotonergic neuronal differentiation and migration. In vitro studies revealed that VPA retards the maturation of serotonergic neuron from ES cell‐derived neuronal progenitors, whereas exogenously added Sonic hedgehog, a morphogen that has been implicated in serotonergic cell fate, partially prevented this retardation. These results indicate that disruption of early serotonergic neuronal development might be involved in the etiology of autism.
Surgery of the Hand in Severe Systemic Sclerosis
Authors: GILBART M. K. , JOLLES B. M. , LEE P. , BOGOCH E. R. 
Published: July 2004

Ten patients with scleroderma and severe hand problems required surgery, and seven were available for follow-up (two died from scleroderma-related complications and one was lost to follow-up). The mean duration of follow-up was 4 (range 1.5–9) years. Thirty-three procedures were carried out, including five metacarpophalangeal joint exisional arthroplasties, 13 proximal interphalangeal joint fusions, ten distal interphalangeal joint fusions, and one thumb interphalangeal joint fusion. The metacarpophalangeal joint excision arthroplasties and proximal interphalangeal joint fusions were performed for the correction of severe fixed “finger-in-palm” deformities. Lesions of cutaneous calcinosis were removed in four patients. Fixation was satisfactory in all cases of interphalangeal joint fusion, with no cases of non-union. Wound healing was satisfactory in six of seven patients. A second surgical procedure was required in three patients for the removal of tension band wires following interphalangeal fusion. Calcinosis was effectively removed using a high-speed dental burr. The results of hand surgery for systemic sclerosis are reliable, but goals must be limited and patient expectations should be modest.
Expression of bone morphogenetic proteins, receptors, and tissue inhibitors in human fetal, adult, and osteoarthritic articular cartilage
Authors: Chen Andrew L. , Fang Carrie , Liu Chuanju , Leslie Michael P. , Chang Eric , Di Cesare Paul E. 
Published: July 2004

AbstractCoordinate expression of BMPs and their receptors and inhibitors is likely necessary for physiologic BMP regulation and activity. To characterize the expression of such factors in fetal, normal adult, and end‐stage osteoarthritic articular cartilage, samples from these sources were analyzed. PCR‐amplified sequences (BMPs 1–11), receptors (IA, IB, II), TGF‐β1, TGF‐β2, inhibitors noggin and follistatin, CDMP‐1, COMP, and GAPDH from cDNAs generated from extracted total RNA were resolved by gel electrophoresis. Protein levels of BMPs 3, 7, and 8 were also analyzed by SDS‐PAGE and Western blotting. RT‐PCR revealed that BMPs 1, 2, 4–6, and 11, BMPR‐IA and II, noggin, follistatin, CDMP‐1, COMP, and GAPDH mRNAs were expressed in similar fashion in both fetal and adult (normal or osteoarthritic) cartilage. BMPs 9 and 10 mRNAs were not expressed in either group. BMPs 7, 8, and BMPR‐IB mRNAs were consistently expressed in fetal but not in adult cartilage. BMP‐3 mRNA was expressed in fetal and normal adult, but not in osteoarthritic samples. TGF‐β1 was expressed in both adult normal and osteoarthritic, but not fetal, samples. Similarly, Western blotting demonstrated BMPs 7 and 8 to be present in fetal but not in adult samples. BMP‐3 protein was present in fetal and adult normal samples, to a lesser extent, but absent in osteoarthritic cartilage. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Environmental and social influences on emerging infectious diseases: past, present and future
Authors: McMichael A. J. 
Published: July 2004

During the processes of human population dispersal around the world over the past 50 000–100 000 years, along with associated cultural evolution and inter–population contact and conflict, there have been several major transitions in the relationships ofHomo sapienswith the natural world, animate and inanimate. Each of these transitions has resulted in the emergence of new or unfamiliar infectious diseases.The three great historical transitions since the initial advent of agriculture and livestock herding, fromca. 10 000 years ago, occurred when: (i) early agrarian–based settlements enabled sylvatic enzootic microbes to make contact withHomo sapiens; (ii) early Eurasian civilizations (such as the Greek and Roman empires, China and south Asia) came into military and commercial contact,ca. 3000–2000 years ago, swapping their dominant infections; and (iii) European expansionism, over the past five centuries, caused the transoceanic spread of often lethal infectious diseases. This latter transition is best known in relation to the conquest of the Americas by Spanishconquistadores, when the inadvertent spread of measles, smallpox and influenza devastated the Amerindian populations.Today, we are living through the fourth of these great transitional periods. The contemporary spread and increased lability of various infectious diseases, new and old, reflect the combined and increasingly widespread impacts of demographic, environmental, behavioural, technological and other rapid changes in human ecology. Modern clinical medicine has, via blood transfusion, organ transplantation, and the use of hypodermic syringes, created new opportunities for microbes. These have contributed to the rising iatrogenic problems of hepatitis C, HIV/AIDS and several other viral infections. Meanwhile, the injudicious use of antibiotics has been a rare instance of human action actually increasing ‘biodiversity’.Another aspect of this fourth transition is that modern hyper–hygienic living restricts microbial exposure in early life. This, in the 1950s, may have contributed to an epidemic of more serious, disabling, poliomyelitis, affecting older children than those affected in earlier, more endemic decades.As with previous human–microbe transitions, a new equilibrial state may lie ahead. However, it certainly will not entail a world free of infectious diseases. Any mature, sustainable, human ecology must come to terms with both the need for, and the needs of, the microbial species that help to make up the interdependent system of life on Earth. Humans and microbes are not ‘at war’; rather, both parties are engaged in amoral, self–interested, coevolutionary struggle. We need to understand better, and therefore anticipate, the dynamics of that process.