bluuebunny/crossref_metadata_2025 huggingface dataset:
Insulin‐like Growth Factor Binding Protein 5: Contribution to Growth and Differentiation of Neuroblastoma Cells
Authors: CESI VINCENZO , VITALI ROBERTA , TANNO BARBARA , GIUFFRIDA MARIA LAURA , SESTI FABIOLA , MANCINI CAMILLO , RASCHELLÀ GIUSEPPE
Published: January 2005

Abstract: Neuroblastoma (NB) is a childhood tumor that depends on insulin‐like growth factors (IGFs) for its growth and metastatic spread. Some metastatic NBs acquire independence from the paracrine support of IGF by activating autocrine production of IGF‐2. Insulin‐like growth factor binding protein‐5 (IGFBP‐5), a member of the IGF binding protein family, is able to optimize binding between IGF itself and its receptor. NB cell lines retain the ability to differentiate in vitro toward neuronal, schwann‐like or melanocytic phenotypes upon treatment with retinoic acid (RA). Retinoids are currently used in NB therapy to achieve a mature postmitotic phenotype. Here, we present evidence that the expression of IGFBP‐5 is a common feature of neuroblastoma cell lines and that IGFBP‐5 acts in concert with IGF‐2 in inducing cell proliferation. RA‐induced differentiation causes a sharp increase of IGFBP‐5. Functional assays carried out in differentiating conditions demonstrate that IGFBP‐5 transcription is sensitive to RA treatment. We show that the effect of RA on the IGFBP‐5 promoter is exerted, at least in part, through a proximal 5′‐CACCC‐3′ tandem repeat (−147 bp to −137 bp from the transcription start site) that has previously been described as a cis‐acting element involved in the progesterone‐mediated response in osteoblasts. Given the relevance of IGF‐2 in determining the proliferative and metastatic behavior of NB, the role of IGFBP‐5 as a modulator of the IGF signal transduction pathway should be studied further for potential therapeutic applications.
Signaling Mechanisms That Mediate Invasion in Prostate Cancer Cells
Authors: BONACCORSI L , MARCHIANI S , MURATORI M , CARLONI V , FORTI G , BALDI E
Published: January 2005

Abstract: Recent evidence indicates that androgen‐sensitive prostate cancer cells have a less malignant phenotype characterized by reduced migration and invasion. We investigated whether the presence of the androgen receptor could affect EGFR‐mediated signaling by evaluating autotransphosphorylation of the receptor as well as activation of the downstream signaling pathway PI3K/AKT. Immunoprecipitation studies demonstrated a reduction of EGF‐induced tyrosine phosphorylation of EGFR in PC3‐AR cells. In addition, EGF‐stimulated PI3K activity, a key signaling pathway for invasion of these cells, was decreased in PC3‐AR cells and further reduced by treatment with R1881, indicating decreased functionality of EGFR. Our results suggest that the expression of androgen receptors by transfection in PC3 cells confers a less malignant phenotype by interfering with EGFR autophosphorylation and signaling leading to invasion in response to EGF. We used the selective tyrosine kinase inhibitor of the EGFR gefitinib (also known as Iressa or ZD1839) to further investigate the role of EGFR in the invasion and growth of PC cells. We demonstrate that in the androgen‐insensitive cell lines PC3 and DU145 this compound was able to decrease in vitro invasion of Matrigel by inhibiting EGFR autotransphosphorylation and subsequent PI3K activation. Gefitinib may be useful in the treatment of androgen‐independent prostate cancer to limit not only the proliferation but also the invasion of these tumors.
Molecular Biology and the Staging of Prostate Cancer
Authors: MARANDOLA P , BONGHI A , JALLOUS H , BOMBARDELLI E , MORAZZONI P , GERARDINI M , TISCIONE D , ALBERGATI F
Published: January 2005

Abstract: Cancer of the prostate is still controlled or cured by surgery, radiotherapy, and hormone therapy. The present criteria of complication and prediction are criticized more and more for not being sufficiently reliable, due to the high heterogeneity of prostatic cells. The continuing discoveries of intra‐ and extracellular mechanisms of the molecular informational network, which allow the continuity or discontinuity of the cell's life, are also related to prostate cancer. The role of androgen receptors is now under close scrutiny, in the light of the knowledge of regulatory genes and their molecular expression. In the near future, a complete study of prostate cancer's DNA is certainly envisaged. Looking forward to the extraordinary applications of molecular biology in this field, this article is aimed at establishing a clear link between the conventional ways of interpreting the clinical expression of prostate cancer and the oncoming applications of genomics and proteomics.
Molecularly Targeted Therapy in Acute Myeloid Leukemia
Authors: BERNASCONI PAOLO , BONI MARINA , CAVIGLIANO PAOLA MARIA , CALATRONI SILVIA , GIARDINI ILARIA , ROCCA BARBARA , ZAPPATORE RITA , CARESANA MARILENA , QUARNA JESSICA
Published: January 2005

Abstract: Meaningful progress has been made toward clarifying the molecular steps in the pathogenesis of acute myeloid leukemia (AML). Chromosome studies have established that translocations/inversions are the most common cytogenetic defects in AML. Cloning of chromosome breakpoints has shown that genes involved in the chromosome abnormalities are transcription factors, functional loss of which alters chromatin configuration and results in the disruption of myeloid differentiation. However, transgenic animal models have demonstrated that AML‐specific translocations/inversions alone are insufficient to cause overt leukemia, which occurs only when point mutations affecting receptor tyrosine kinases (RTKs) develop. Therefore, development of AML is now considered a two‐step process in which RTK mutations provide a proliferative and a survival advantage to a clonal cell population already marked by impaired differentiation. In addition, more accurate definition of such genetic lesions has led to a more precise insight as to how such lesions interact with cellular signaling pathways that are aberrantly regulated in AML. All these new data have profound clinical and therapeutic implications and will surely translate into the development of molecules that target specific mutations or signal transduction pathways.
Induction of Apoptosis and Inhibition of Cell Growth in Human Hepatocellular Carcinoma Cells by COX‐2 Inhibitors
Authors: FODERÀ DANIELA , D'ALESSANDRO NATALE , CUSIMANO ANTONELLA , POMA PAOLA , NOTARBARTOLO MONICA , LAMPIASI NADIA , MONTALTO GIUSEPPE , CERVELLO MELCHIORRE
Published: January 2005

Abstract: The aim of the present study was to examine the effects of nonselective (indomethacin) and selective cyclooxygenase‐2 (COX‐2) inhibitors (NS‐398, nimesulide, and CAY10404) on cell growth, cell cycle distribution, and apoptosis in three human hepatocellular carcinoma cell lines (HepG2, HuH‐6, and HA22T/VGH) with different characteristics of differentiation and biological behavior. The four COX inhibitors showed a dose‐dependent growth‐inhibitory effect in all the cell lines. No substantial arrests in the progression of the cells through the cell cycle were observed after treatment of HuH‐6 or HA22T/VGH for 48 h with the various inhibitors. On the other hand, there were significant increases in apoptosis, with the highest effect of cell kill being seen after treatment with indomethacin, especially in HuH‐6. Our findings support the suggestion that selective or, perhaps more efficiently, nonselective COX‐2 inhibitors may have potential therapeutic effects in hepatocellular carcinoma. Further studies must be carried out to better determine the possible mechanisms of these effects.
IGF‐II Binding to Insulin Receptor Isoform A Induces a Partially Different Gene Expression Profile from Insulin Binding
Authors: PANDINI GIUSEPPE , CONTE ENRICO , MEDICO ENZO , SCIACCA LAURA , VIGNERI RICCARDO , BELFIORE ANTONINO
Published: January 2005

Abstract: Insulin receptor isoform A (IR‐A) is a fetal insulin receptor isoform that is overexpressed in cancer. We investigated whether insulin‐like growth factor (IGF)‐II may elicit a different gene expression response from insulin in cells expressing only IR‐A and lacking IGF‐I receptor (R−/IR‐A cells). Cells were stimulated with either insulin or IGF‐II (at 0.5, 3, and 8 h), and global gene expression was studied by microarray technology. Results were validated by quantitative real‐time PCR. We found that 214 transcripts were similarly regulated by insulin and IGF‐II, whereas 45 transcripts were differentially regulated. of these 45 genes, 18 were responsive to only one of the two ligands (12 to insulin and 6 to IGF‐II). Twenty‐seven transcripts were regulated by both ligands but with a significant difference at at least one time point. IGF‐II was a more potent regulator than insulin for these genes. In conclusion, insulin and IGF‐II, acting via the same receptor (IR‐A), may differentially affect gene expression in cells. These findings provide a molecular basis in clarifying the biological role of IR‐A in embryonic/fetal life and in cancer.
Connectionism, Parallel Constraint Satisfaction Processes, and Gestalt Principles: (Re)Introducing Cognitive Dynamics to Social Psychology
Authors: Read Stephen J. , Vanman Eric J. , Miller Lynn C.
Published: January 2005

We argue that recent work in connectionist modeling, in particular the parallel constraint satisfaction processes that are central to many of these models, has great importance for understanding issues of both historical and current concern for social psychologists. We first provide a brief description of connectionist modeling, with particular emphasis on parallel constraint satisfaction processes. Second, we examine the tremendous similarities between parallel constraint satisfaction processes and the Gestalt principles that were the foundation for much of modern social psychology. We propose that parallel constraint satisfaction processes provide a computational implementation of the principles of Gestalt psychology that were central to the work of such seminal social psychologists as Asch, Festinger, Heider, and Lewin. Third, we then describe how parallel constraint satisfaction processes have been applied to three areas that were key to the beginnings of modern social psychology and remain central today: impression formation and causal reasoning, cognitive consistency (balance and cognitive dissonance), and goal-directed behavior. We conclude by discussing implications of parallel constraint satisfaction principles for a number of broader issues in social psychology, such as the dynamics of social thought and the integration of social information within the narrow time frame of social interaction.
Accurate Social Perception at Zero Acquaintance: The Affordances of a Gibsonian Approach
Authors: Zebrowitz Leslie A. , Collins Mary Ann
Published: January 2005

We review research on accurate social perception at zero acquaintance and apply a Gibsonian ecological approach to redress several shortcomings. We argue that recent use of Brunswik's lens model to determine what physical qualities accurately communicate psychological traits has limited utility because it fails to consider the structured information provided by configural physical qualities that is central to Gibson's (1979) theory. We elaborate a developmental model of relationships between physical and psychological qualities that highlights research needed to identify configural physical qualities that may inform accurate perceptions. This model and tenets of the ecological theory yield several hypotheses regarding such qualities. Finally, we advocate the value of studying perceived affordances (opportunities for acting, interacting, or being acted upon) because this will focus attention on the neglected issue of contextual influences on social perception accuracy, and because affordances may be perceived more accurately than global personality traits.
Reciprocal Strategies for Large Groups
Authors: Parks Craig D. , Komorita Samuel S.
Published: January 2005

Reciprocal strategies have been shown to be effective in inducing long-term cooperation in social dilemmas involving small, but not large, groups. In this article, we argue that group-based reciprocal strategies (GBRS)—under which one reciprocates cooperative factions, not individuals, within the group—can induce cooperation in large groups. Results of two computer simulations of 100-member groups show that a GBRS accumulates a significantly larger payoff than do other commonly advocated mixedmotive strategies. A third simulation showed that the size of the cooperative faction is influenced by the nature of the payoff matrix; when there is considerable temptation to defect, one should cooperate only after a large number of others have done so, but if there is little temptation to defect, one should reciprocate the cooperative actions of a smaller faction. We also found that the use of a “win-cooperate, lose-defect” heuristic led to substantial total outcomes. Our results suggest several psychological factors are important in facilitating cooperation, yet need empirical study.
Self-Reflection and Recognition: The Role of Metacognitive Knowledge in the Attribution of Recollective Experience
Authors: Strack Fritz , Förster Jens
Published: January 2005

We argue that to understand how a recognition task is solved, it is helpful to study the inferences that are drawn on the basis of psychological self-knowledge. This claim is supported by findings from 3 experiments in which participants' metacognitive knowledge was either measured or manipulated. Specifically, it was found that when the quality of a recollective experience was not associated with one particular cause, knowledge about whether one would have noted or remembered a stimulus is used. In conclusion, we argue that a perspective that is derived from attribution theory in social psychology may be fruitfully applied to phenomena of recognition.
On Bridging the Gap Between Social-Personality Psychology and Neuropsychology
Authors: Klein Stanley B. , Kihlstrom John F.
Published: January 2005

Although cognitive psychology has learned much from the study of patients with neuropsychological impairments, social and personality psychologists have been slow to do the same. In this article we argue that the domain of clinical neuropsychology holds considerable untapped potential for formulating and testing models within social and personality psychology and describe some of the ways in which questions of interest to social and personality psychologists can be addressed with neuropsychological data. Examples are drawn from a variety of neuropsychological syndromes, including amnesia, autism, anosognosia, commissurotomy, frontal lobe damage, and prosopagnosia. We conclude that consideration of the personal and social lives of patients with neuropsychological impairments ultimately will lead to a richer understanding of the person, one that bridges the gap between social and cognitive levels of analysis.
Perceptions of the Collective Other
Authors: Abelson Robert P. , Dasgupta Nilanjana , Park Jaihyun , Banaji Mahzarin R.
Published: January 2005

It is contended that perceptions of groups are affected by particular variables that do not apply to individuals (e.g., intragroup similarity and proximity). Importantly, the perception of outgroup threat has incomplete analogs at the individual level. Results from 3 studies support predictable distinctions between representations of individuals and of groups. Study I showed that priming of the word they produces more extreme negative judgments of the protagonist(s) in a story about 4 individuals acting jointly than in the same story with a single person acting alone. The opposite result holds for priming with the word he. Study 2, with Korean participants, demonstrates that actions by individuals or groups elicit differing preferences for redress. Individual responses (e.g., getting mad) to an individual racial insult (e.g., a snub by a waitress) are preferred to collective responses (e.g., circulating a petition), whereas the reverse preferences holdfor a group insult (e.g., taunts from a gang of White youths). In Study 3, cues to the entitivity of a group are introduced. This concept, introduced by Donald Campbell (1958), distinguishes different degrees of “groupness. ” Visual depictions of collections of unfamiliar humanoid creatures (greebles) were used to convey that they were either similar or dissimilar and either proximate or scattered. Results confirm the expectation that similarity and proximity-two entitive conditions-elicit more negative judgments of the group. Attention to other cues for entitivity may enrich social psychological views of stereotyping and prejudice by focusing on perceptions of groups as coordinated actors with the potential to bring about negative consequences. Such experiments point to the needfor greater research focus on the vastly understudied but fundamental problem of the social cognition of group behavior.
How People Explain Behavior: A New Theoretical Framework
Authors: Malle Bertram F.
Published: January 2005

This article presents a theoretical framework of how people explain behavior. The framework, based on the folk concept of intentionality, distinguishes two major modes of explanation—reason explanation and cause explanation—as well as two minor modes and identifies conditions under which they occur. Three studies provide empirical support for these distinctions. As part of the framework, a detailed model of people's reason explanations is developed, which emphasizes the unique conceptual and linguistic features of reasons. This model points to limitations of traditional attribution concepts, which are examined theoretically and empirically. Finally, the theoretical framework incorporates attribution concepts, which apply to some but not all modes of explanation. Several paths for future research are outlined—on novel topics such as the roles of rationality and subjectivity in explanations and on classic topics such as the actor-observer asymmetry and the self-serving bias.
Social Discrimination and Tolerance in Intergroup Relations: Reactions to Intergroup Difference
Authors: Mummendey Amélie , Wenzel Michael
Published: January 2005

In this article, we present a theoretical approach to social discrimination on the one hand and intergroup relations characterized by tolerance and plurality on the other hand. Central to the analysis is the question of how members deal with intergroup difference. If the outgroup's difference is judged to be nonnormative and inferior, devaluation, discrimination, and hostility are likely responses toward the outgroup. Judging the outgroup's difference to be normative or positive leads to acceptance and appreciation of this group. Following self-categorization theory, the criteria—being norms and values for judging intergroup differences—are derived from the superordinate category that is perceived to include both groups. More specifically, they are derived from the prototype, or representation, of this inclusive category. Social discrimination results from the generalization of ingroup attributes to the inclusive category, which then become criteria for judging the outgroup. Tolerance, on the other hand, is conceptualized as either a lack of inclusion of both groups in a higher order category or as the representation of the inclusive category in such a way as to also include the other group and designate it as normative.
Functional equivalence of Brn3 POU-domain transcription factors in mouse retinal neurogenesis
Authors: Pan Ling , Yang Zhiyong , Feng Liang , Gan Lin
Published: January 2005

POU-domain transcription factors play essential roles in cell proliferation and differentiation. Previous studies have shown that targeted deletion of each of the three POU-domain Brn3 factors in mice leads to the developmental failure and apoptosis of a unique set of sensory neurons in retina, dorsal root ganglia, trigeminal ganglia and inner ear. The specific defects associated with the removal of each Brn3 gene closely reflect their characteristic spatiotemporal expression patterns. Nevertheless, it remains elusive whether Brn3 factors are functionally equivalent and act through a common molecular mechanism to regulate the development and survival of these sensory neurons. By knocking-in Brn3a (Brn3aki)into the Brn3b locus, we showed here that Brn3akiwas expressed in a spatiotemporal manner identical to that of endogenous Brn3b. In addition, Brn3aki functionally restored the normal development and survival of retinal ganglion cells (RGCs) in the absence of Brn3b and fully reinstated the early developmental expression profiles of Brn3b downstream target genes in retina. These results indicate that Brn3 factors are functionally equal and that their unique roles in neurogenesis are determined by the distinctive Brn3 spatiotemporal expression patterns.
Preparation of YBCO and BSCCO Superconducting Thin Films by a New Chemical Precursor Method
Authors: Gunji Takahiro , Unno Mitsuo , Arimitsu Koji , Abe Yoshimoto , Long Nick , Bubendorfer Andrea
Published: January 2005

Homogeneous YBa2Cu3O7−δ (YBCO) and Bi2SrCa2Cu2O8+y (BSCCO) precursors were prepared by the reaction of triethanolamine with ethyl acetoacetato complexes of Y, Ba, and Cu and those of Bi, Sr, Ca, and Cu, respectively. These precursors showed melt-spinnability and converted to ceramics on heating with the elimination and combustion of organic groups. Superconductive thin films were prepared by depositing a solution on a substrate by spin-coating, followed by calcination. Epitaxial growth of the YBCO phase, with c axis normal to the substrate, was observed. The critical temperature was 88.7 K and the critical current density at 77 K and 0 T was 5 × 105 A/cm2. On the other hand, the epitaxial growth of the c axis aligned BSCCO phase was observed: the critical temperature was 77 K and the critical current density at 5 K was 6 × 104 A/cm2.
Molecular Design of Synthetic Receptors with Dynamic, Imprinting, and Allosteric Functions
Authors: Shinkai Seiji , Takeuchi Masayuki
Published: January 2005

Sugar recognition in an aqueous system has been achieved using a boronic acid–diol interaction. Combination with an intramolecular amino group has enabled us to read out the binding process as a change in the fluorescence intensity. This novel sugar-sensing method has been combined with a concept of “molecular machinery”, providing a new guest-binding mode with allosteric functions. When this method is combined with a concept of “molecular imprinting”, it becomes possible to design sugar-selective receptors created by a combinatorial method. The sugar recognition event is useful as a trigger to control molecular assemblies such as micelles, membranes, vesicles, and gels.
Propene Polymerization with Bis(phenoxy–imine) Group 4 Transition Metal Complexes
Authors: Makio Haruyuki , Fujita Terunori
Published: January 2005

Olefin polymerizations with group 4 transition metal complexes having two phenoxy–imine ligands (FI Catalysts) are reviewed with an emphasis on the characteristics and mechanisms of propene polymerization. The structures and properties of FI Catalysts can be easily modified by changing phenoxy–imine ligand structures. Such catalysts can be synthesized straightforwardly from readily available chemicals. An enormous library of FI Catalysts can be built up by combining a group 4 metal center and a variety of cocatalysts. The diversified library makes FI Catalysts so versatile that polyolefins with desired properties (molecular weight, molecular weight distribution, chain-end structure, tacticity, and so on) can be obtained sometimes predictably, by selecting the appropriate combination of ligand, metal, and cocatalyst. In propene polymerization, it remains a challenge to control the stereo- and regiochemistry of monomer enchainment in order to obtain commercially valuable products. FI Catalysts can produce syndiotactic and isotactic polypropene by Ti–FI catalysts/MAO and Zr– and Hf–FI catalysts/iBu3Al/Ph3CB(C6F5)4, respectively. Because of the well-defined and tunable nature of the catalysts, the coordination environment around the metal center can be controlled by the ligand structures to achieve extremely high stereoregularities, comparable to those of heterogeneous Ziegler–Natta catalysts and metallocene catalysts. These syndio- and isospecific FI Catalysts have contrasting reaction mechanisms, i.e., the syndiospecific polymerization is mediated via 2,1-insertion under chain-end control, while isospecificity arises from 1,2-insertion and a site control mechanism. The observed syndiospecificity can originate from the inherent fluxionality of FI Catalysts between configurational isomers.
Preparation of Spherical Particles with Quartz Single Crystal
Authors: Okabayashi Minahiro , Miyazaki Kenji , Kono Toshio , Tanaka Miyoko , Toda Yumio
Published: January 2005

Spherical particles with α-quartz single crystal were obtained from amorphous silica by heating in the atmospheric pressure. The silica particles containing a small amount of titanium oxide and calcium oxide were prepared from metal alkoxides and then were heated at 1000 °C in the atmospheric pressure. The resulting particle was determined to be a single crystal by means of a transmission electron microscopy and electron diffractometry.
Enhanced Efficiency and Regioselectivity of Intramolecular (2π + 2π) Photocycloaddition of 1-Cyanonaphthalene Derivative Using Microreactors
Authors: Maeda Hajime , Mukae Hirofumi , Mizuno Kazuhiko
Published: January 2005

The intramolecular photocycloaddition of a 1-cyanonaphthalene derivative in microreactors made of poly(dimethylsiloxane) (PDMS) was examined. By using the microreactors and flow system, both the efficiency and regioselectivity increased compared with those under batch conditions.
Bis(ethylenedioxy)-1,4,5,8-tetraselenanaphthalene: The First Example of Tetraselenanaphthalene
Authors: Watanabe Ryoji , Miyake Yoshihiro , Kuwatani Yoshiyuki , Iyoda Masahiko
Published: January 2005

The titled tetraselenanaphthalene derivative (BEDO-TSeN) has been synthesized using the reaction of 1,4-dioxene-2,3-diselenolate with tetraiodo- or tetrabromoethylene. The structure of this tetraselenanaphthalene derivative was confirmed by X-ray analysis. The π-donor property of this molecule was determined by CV analysis.
Lithium Acetate-catalyzed Trifluoromethylation of Carbonyl Compounds with (Trifluoromethyl)trimethylsilane
Authors: Mukaiyama Teruaki , Kawano Yoshikazu , Fujisawa Hidehiko
Published: January 2005

Trifluoromethylation of various aldehydes and ketones with (trifluoromethyl)trimethylsilane in the presence of a catalytic amount of a Lewis base such as lithium acetate proceeded smoothly to afford the corresponding trifluoromethylated adducts in good to high yields.
Liquid fraction in stratiform mixed‐phase clouds from in situ observations
Authors: Boudala Faisal S. , Isaac George A. , Cober Stewart G. , Fu Qiang
Published: January 2005

Liquid fractions in mixed‐phase clouds have been analysed using aircraft measurements taken in mid‐ and high latitude stratiform clouds. The liquid fraction generally increases with temperature but has a minimum at about −15°C, where the maximum ice crystal growth based on vapour deposition would be expected. The mean liquid fraction also depends on total water content. This suggests that segregation of cloud phase based on a simple linear relationship of phase fraction (ice or liquid) with temperature, as is used in some climate models, may be unrealistic. Parametrizations of mean liquid fraction in terms of temperature and total water content, and in terms of temperature alone, have been developed based on data averaged at 10 s resolution (1 km). These parametrizations agree reasonably well with the observations. Copyright © 2004 Royal Meteorological Society
Influence‐matrix diagnostic of a data assimilation system
Authors: Cardinali Carla , Pezzulli Sergio , Andersson Erik
Published: January 2005

The influence matrix is used in ordinary least‐squares applications for monitoring statistical multiple‐regression analyses. Concepts related to the influence matrix provide diagnostics on the influence of individual data on the analysis—the analysis change that would occur by leaving one observation out, and the effective information content (degrees of freedom for signal) in any sub‐set of the analysed data. In this paper, the corresponding concepts have been derived in the context of linear statistical data assimilation in numerical weather prediction. An approximate method to compute the diagonal elements of the influence matrix (the self‐sensitivities) has been developed for a large‐dimension variational data assimilation system (the four‐dimensional variational system of the European Centre for Medium‐Range Weather Forecasts). Results show that, in the boreal spring 2003 operational system, 15% of the global influence is due to the assimilated observations in any one analysis, and the complementary 85% is the influence of the prior (background) information, a short‐range forecast containing information from earlier assimilated observations. About 25% of the observational information is currently provided by surface‐based observing systems, and 75% by satellite systems.

Low‐influence data points usually occur in data‐rich areas, while high‐influence data points are in data‐sparse areas or in dynamically active regions. Background‐error correlations also play an important role: high correlation diminishes the observation influence and amplifies the importance of the surrounding real and pseudo observations (prior information in observation space). Incorrect specifications of background and observation‐error covariance matrices can be identified, interpreted and better understood by the use of influence‐matrix diagnostics for the variety of observation types and observed variables used in the data assimilation system. Copyright © 2004 Royal Meteorological Society
Complexation and Sorption of Europium(III) Ions onto Clay Minerals in the Presence of Fulvic Acids
Authors: Pshinko G. , Spasenova L. , Kornilovich B.
Published: January 2005

The effect of fulvic acids (FA) on the sorption of europium(III) ions from aqueous solution onto Gluhovsky kaolinite and Cherkasky montmorillonite was studied. Sorption of Eu(III) ions onto the mineral surface increased as the pH value of the aqueous solution increased from 1 to 8, but decreased when fulvic acids were present in solution. Over the concentration range studied, Eu(III) ion sorption occurred as free europium ions which were not bound as fulvate complexes. At pH ≥ 6 and at high Eu(III) ion concentrations (> 200 μmol/dm3), the increase in europium ion adsorption in the presence of fulvic acids was twice that observed in their absence. This demonstrated the formation, under these conditions, of a two-nucleus complex with a chain of the type sorbent-Eu-FA-Eu. In natural waters at pH > 6, Eu(III) exists mainly in the form of soluble complexes where binding occurs via the oxygen atoms of the phenol groups in FA.
Textural Properties and Adsorption of Dyes onto Carbons Derived from Cotton Stalks
Authors: Attia Amina A. , El-Hendawy Abdel-Nasser A. , Khedr Soheir A. , El-Nabarawy Th.
Published: January 2005

Non-activated carbon ‘C’, zinc chloride-activated carbon ‘Z’ and steam-activated carbon ‘S’ were prepared from cotton stalks available as an agricultural waste. These carbon adsorbents were investigated to determine their texture and their potential for dye adsorption. Cotton stalks after chopping, washing and drying were also investigated as an additional adsorbent, designated ‘P’.

The textural properties (surface area and porosity) of the sorbents were determined from the low-temperature adsorption of nitrogen at −196°C by carefully analyzing their nitrogen adsorption isotherms. The adsorption of Methylene Blue (MB) and Congo Red (CR) at 30, 40 and 50°C was investigated via kinetic and equilibrium adsorption measurements. Activated carbons ‘Z’ and ‘S’ exhibited high surface areas and high total pore volumes and possessed high dye uptakes. Non-activated carbon ‘C’ possessed a lower but satisfactory dye uptake while the raw material ‘P’ exhibited the lowest dye uptake.

The adsorption of MB and CR was controlled by pore diffusion and followed first-order kinetics. The adsorption of the two dyes decreased with increasing adsorption temperature. The adsorption of both MB and CR was associated with a decrease in ΔG but with an increase in ΔS.
Strengthening of RC Members Using Near-Surface Mounted FRP Composites: Design Overview
Authors: Parretti Renato , Nanni Antonio
Published: January 2005

Strengthening of reinforced and prestressed concrete (RC and PC) members using externally bonded FRP laminates is today a well-accepted technology that is becoming popular among designers and contractors. Near-surface mounted (NSM) FRP reinforcement represents an alternative way to improve flexural and shear performance of concrete structures. In some instance, it is the only suitable technology that can be efficiently applied, for example, when upgrading beam-column joints or for flexural strengthening of compression members. In this paper, bond related issues, flexural and shear design recommendations, and design examples are presented. The paper is an attempt to provide designers with a comprehensive protocol for the rational implementation of NSM technology.
Load-Deflection Response of Concrete Beams Reinforced with FRP Bars
Authors: Ou Jinping , Wang Bo , He Zheng , Zhang Xinyue , Qian Minzhong
Published: January 2005

This paper presents load-deflection relationships of 28 Fiber Reinforced Polymer (FRP) reinforced simply supported beams under third-point loading. The predictions of some approaches are compared with the experimental results by testing 28 concrete beams reinforced with Glass Fiber Reinforced Polymer (GFRP), Carbon Fiber Reinforced Polymer (CFRP) and Hybrid Fiber Reinforced Polymer (HFRP) bars. To improve the bond between FRP bars and concrete, the surface of the bar were either coated with sand or helically wound with fiber strands. Load-deflection response of FRP reinforced beams shows that the bond performance of sand coated FRP bars is superior to those treated by winding fiber strands around the FRP bars. The suggested model for predicting mid-span deflection, accurately estimated the deflection under third-point loading. Test results reveal that there is excellent agreement between the theoretical and experimental results.
Earthquake Input Energy to Soil-Structure Interaction Systems: A Frequency-Domain Approach
Authors: Takewaki Izuru , Fujimoto Hiroshi
Published: January 2005

A new evaluation method of earthquake input energy to soil-structure interaction systems is developed. The method is an approach in the frequency domain. Because the inertial interaction (foundation impedance) and the kinematic interaction (effective input motion) are well described by frequency-dependent functions, the present approach based on the frequency domain analysis is appropriate and effective. Especially it is demonstrated that even soil-structure interaction systems including embedded foundations can be treated in a simple way and effects of degree of the foundation embedment on the earthquake input energy to the super-structure can be clarified systematically. The proposed approach has a generality that, if the foundation impedance and the effective input motion are evaluated for any ground system, the earthquake input energies to the structure and to the structure-foundation-soil system can be obtained in a unified manner. It is also shown briefly that the formulation of the earthquake input energy in the frequency domain is effective for solving a critical excitation problem for the maximum earthquake input energy and deriving a bound on the earthquake input energy for a class of ground motions.
Axonal Propagation of Simple and Complex Spikes in Cerebellar Purkinje Neurons
Authors: Khaliq Zayd M. , Raman Indira M.
Published: January 2005

In cerebellar Purkinje neurons, the reliability of propagation of high-frequency simple spikes and spikelets of complex spikes is likely to regulate inhibition of Purkinje target neurons. To test the extent to which a one-to-one correspondence exists between somatic and axonal spikes, we made dual somatic and axonal recordings from Purkinje neurons in mouse cerebellar slices. Somatic action potentials were recorded with a whole-cell pipette, and the corresponding axonal signals were recorded extracellularly with a loose-patch pipette. Propagation of spontaneous and evoked simple spikes was highly reliable. At somatic firing rates of ∼200 spikes/sec, <10% of spikes failed to propagate, with failures becoming more frequent only at maximal somatic firing rates (∼260 spikes/sec). Complex spikes were elicited by climbing fiber stimulation, and their somatic waveforms were modulated by tonic current injection, as well as by paired stimulation to depress the underlying EPSCs. Across conditions, the mean number of propagating action potentials remained just above two spikes per climbing fiber stimulation, but the instantaneous frequency of the propagating spikes changed, from ∼375 Hz during somatic hyperpolarizations that silenced spontaneous firing to ∼150 Hz during spontaneous activity. The probability of propagation of individual spikelets could be described quantitatively as a saturating function of spikelet amplitude, rate of rise, or preceding interspike interval. The results suggest that ion channels of Purkinje axons are adapted to produce extremely short refractory periods and that brief bursts of forward-propagating action potentials generated by complex spikes may contribute transiently to inhibition of postsynaptic neurons.
Family genetic studies, suicide, and suicidal behavior
Authors: Brent David A. , Mann J. John
Published: January 2005

The extant adoption, twin, and family studies of suicide and suicidal behavior are reviewed. Suicidal behavior is highly familial, and on the basis of twin and adoption studies, heritable as well. Both completed and attempted suicide form part of the clinical phenotype that is familially transmitted, as rates of suicide attempt are elevated in the family members of suicide completers, and completion rates are elevated in the family members of attempters. A family history of suicidal behavior is associated with suicidal behavior in the proband, even after adjusting for presence of psychiatric disorders in the proband and family, indicating transmission of attempt that is distinct from family transmission of psychiatric disorder. Impulsive aggression in probands and family members is associated with family loading for suicidal behavior, and may contribute to familial transmission of suicidal behavior. Shared environment effects such as abuse, imitation, or transmission of psychopathology are other possible explanations. © 2005 Wiley‐Liss, Inc.
Synthesis and characterization of hydroxyethyl methacrylate/acrylamide responsive hydrogels
Authors: Nizam El‐Din Horia M. , El‐Naggar Abdel Wahab M.
Published: January 2005

Hydrogels based on an aqueous solution of hydroxyethyl methacrylate (HEMA) and acrylamide (AM) in the presence of trithioglycolic acid (TTGA) were prepared under the effect of gamma irradiation. These hydrogels were characterized by IR spectroscopy and thermogravimetric analysis and investigated for temperature‐ and pH‐responsive materials. It was found that TTGA is essential for the formation of HEMA/AM hydrogels at different compositions, in which the gel fraction depends on composition. A binary mixture of HEMA and AM at equal ratios was the critical composition that forms hydrogels, even in the presence of TTGA. The IR spectroscopic analysis showed that the formation of hydrogels depends on hydrogen bonding and crosslinking. The TGA investigations with respect to mass loss and the temperatures of the maximum value of the rate of reaction showed that HEMA/AM hydrogels possess higher thermal stability than that of pure HEMA and this stability increases with increasing ratio of the AM component. Also, it was observed that the temperature of the maximum value of the rate of thermal decomposition reaction depends on hydrogel composition. However, calculations of the activation energy showed that the hydrogel composed of 90% HEMA and 10% AM exhibits the highest thermal stability during the increasing or decreasing rate of reaction. Kinetic studies of swelling in water showed that HEMA/AM hydrogels displayed a temperature‐responsive character within the temperature range 25–30°C, and showed a stepwise swelling behavior in the pH range 2–10, depending on composition. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1105–1115, 2005
Preparation, characterization, and water‐sorption study of polyvinyl alcohol based hydrogels with grafted hydrophilic and hydrophobic segments
Authors: Shukla Sandeep , Bajpai A. K. , Kulkarni R. A.
Published: January 2005

The interpenetrating polymer network hydrogels based on poly(vinyl alcohol) were obtained by graft copolymerization of acrylamide and styrene onto polyvinyl alcohol in the presence of N,N′‐methylene bisacrylamide as a crosslinking agent. The hydrogels were characterized by optical microscopy, scanning electron microscopy, infrared spectral analysis, differential scanning calorimeter, and thermogravimetric analysis. The hydrogels showed enormous swelling in aqueous medium and displayed swelling characteristics, which were highly dependent on the chemical composition of the hydrogels and pH of the swelling medium. The kinetics of water uptake and the mechanisms of water transport were studied as a function of composition of the hydrogel and pH of the swelling medium. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1129–1142, 2005
Fabrication of a gradient refractive index preform using laminar shear mixing
Authors: Choi Jin Sung , Im Sang Hyuk , Song Min Young , Park O Ok , Cho Hansol , Hwang Jin Taek
Published: January 2005

A gradient refractive index rod was successfully prepared by a new fabrication method using laminar shear mixing, and a graded index polymer optical fiber that satisfied IEEE1394b was obtained from the method. To fabricate the gradient refractive index rod, a liquid monomer mixture with a relatively low refractive index was placed in a prepared cylindrical glass reactor and a transparent polymer rod with a higher refractive index was introduced at the center of the reactor. The reactor and the polymer rod were then rotated concurrently with a small rotating speed difference to generate a Couette flow in the liquid phase. The centrifugal force generated by rotation and the polymer diffusion into the liquid monomer mixture developed a graded concentration profile in a radial direction. The Couette flow could reduce the concentration fluctuation in a tangential direction. In addition, the graded index profile could be controlled by the copolymer composition of the rod and its diameter. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1100–1104, 2005
Adsorption of biopolymers at hydrophilic cellulose–water interface
Authors: Halder Ebrahim , Chattoraj D. K. , Das K. P.
Published: January 2005

The extent of adsorption (Γ) of bovine serum albumin (BSA), β‐lactoglobulin, lysozyme, gelatin, and DNA from aqueous solution onto the hydrophilic surface of cellulose has been measured as function of biopolymer concentration at different temperatures, pHs, and ionic strengths, and in the presence of a high concentration of inorganic salts and denaturants. In all cases, the value of Γ increases with the increase of biopolymer concentration (X2) in bulk and it attains a maximum value at a critical mole fraction concentration X. The value of Γ depends upon the nature of protein, temperature, pH, and ionic strength, as well as the nature of neutral salts present in excess. Γ for proteins at a fixed physicochemical condition stands in the following order:

The isotherms for adsorption of DNA nucleotides on cellulose surface at pH 4.0 have been compared at different temperatures and ionic strengths, and in the presence of high concentration of inorganic salts LiCl, NaCl, KCl, and Na2SO4. Values of Γ for different systems have been evaluated and critically compared. At pH 6.0 and 8.0, Γ values of DNA nucleotides on cellulose are all negative due to the excess positive hydration of cellulose. At pH 4.0, adsorption of nucleotides of acid, alkali, and heat‐denatured DNA widely differ from each other and in the presence of excess concentration of urea becomes negative. The probable mechanisms of biopolymer–cellulose adsorption in terms of polymer hydration, steric interaction, London–van der Waals, hydrophobic, and other types of interactions have been discussed qualitatively. The standard free energy change for the adsorption of protein and DNA nucleotides on the cellulose surface at the state of adsorption saturation has been calculated in kJ per kg of cellulose using an integrated form of the Gibbs adsorption equation. The relation between ΔG° and maximum affinities between biopolymers and the polysaccharide interface have been discussed for various systems. © 2005 Wiley Periodicals, Inc. Biopolymers 77: 286–295, 2005
Effect of ionic strength on the organization and dynamics of tryptophan residues in erythroid spectrin: A fluorescence approach
Authors: Kelkar Devaki A. , Chattopadhyay Amitabha , Chakrabarti Abhijit , Bhattacharyya Malyasri
Published: January 2005

The ionic strength of the medium plays an important role in the structure and conformation of erythroid spectrin. The spectrin dimer is a flexible rod at physiological ionic strength. However, lower ionic strength results in elongation and rigidification (stiffening) of spectrin as shown earlier by electron microscopy and hydrodynamic studies. The ionic strength induced structural transition does not involve any specific secondary structural changes. In this article, we have used a combination of fluorescence spectroscopic approaches that include red edge excitation shift (REES), fluorescence quenching, time‐resolved fluorescence measurements, and chemical modification of the spectrin tryptophans to assess the environment and dynamics of tryptophan residues of spectrin under different ionic strength conditions. Our results show that while REES, fluorescence anisotropy, lifetime, and chemical modification of spectrin tryptophans remain unaltered in low and high ionic strength conditions, quenching of tryptophan fluorescence by the aqueous quencher acrylamide (but not the hydrophobic quencher trichloroethanol) and resonance energy transfer to a dansyl‐labeled fatty acid show differences in tryptophan environment. These results, which report tertiary structural changes in spectrin upon change in ionic strength, are relevant in understanding the molecular details underlying the conformational flexibility of spectrin. © 2005 Wiley Periodicals, Inc. Biopolymers 77: 325–334, 2005
Unstructured moving grids for implicit calculation of unsteady compressible viscous flows
Authors: Jahangirian A. , Hadidoolabi M.
Published: January 2005

An efficient dual‐time implicit approach combined with unstructured moving grids is presented to solve unsteady turbulent flows. Unstructured grids suitable for both inviscid and turbulent viscous flow regions are generated using a successive refinement method and the grid is moved adaptively based on the boundary movements. Special care is taken to maintain the quality of the grid near the surface. The unsteady two‐dimensional compressible Navier–Stokes equations are discretized by an implicit approach in a real time basis. The resulting set of implicit non‐linear equations is then solved iteratively in pseudo‐time using a Runge–Kutta scheme. The k–ε turbulence model equations are solved together with the main flow equations in a fully coupled manner. Results are presented for an unsteady transonic test case (AGARD CT5) about a NACA0012 oscillating airfoil and comparisons with experimental data showed good agreements. Copyright © 2005 John Wiley & Sons, Ltd.