bluuebunny/crossref_metadata_2025 huggingface dataset:
The Physiology of Willpower: Linking Blood Glucose to Self-Control
Authors: Gailliot Matthew T. , Baumeister Roy F.
Published: October 2007

Past research indicates that self-control relies on some sort of limited energy source. This review suggests that blood glucose is one important part of the energy source of self-control. Acts of self-control deplete relatively large amounts of glucose. Self-control failures are more likely when glucose is low or cannot be mobilized effectively to the brain (i.e., when insulin is low or insensitive). Restoring glucose to a sufficient level typically improves self-control. Numerous self-control behaviors fit this pattern, including controlling attention, regulating emotions, quitting smoking, coping with stress, resisting impulsivity, and refraining from criminal and aggressive behavior. Alcohol reduces glucose throughout the brain and body and likewise impairs many forms of self-control. Furthermore, self-control failure is most likely during times of the day when glucose is used least effectively. Self-control thus appears highly susceptible to glucose. Self-control benefits numerous social and interpersonal processes. Glucose might therefore be related to a broad range of social behavior.
No Refuge from Terror: The Impact of Detention on the Mental Health of Trauma-affected Refugees Seeking Asylum in Australia
Authors: Silove Derrick , Austin Patricia , Steel Zachary
Published: October 2007

The final decades of the twentieth century were accompanied by an upsurge in the number of persons fleeing persecution and regional wars. To stem the flow of asylum seekers, several countries in the west introduced policies of deterrence, including detention. Although many countries detain asylum seekers, Australia has been unique in establishing a policy of mandatory, indefinite detention. The impact of prolonged detention on the mental health of asylum seekers drew commentary from mental health professionals soon after the policy was introduced, but administrators and politicians disputed the assertion that detention was a factor in causing or exacerbating mental disorder. This overview examines the impact of mandatory, indefinite detention on the mental health of asylum seekers by drawing on evidence gathered during Commissions of Inquiry, from observations of health and mental health professionals who have worked in detention centres, and from the small body of systematic research undertaken among immigration detainees. The data from all sources converge in demonstrating that prolonged detention has adverse mental health and psychosocial impacts on adults, families and children. Recent studies suggest that the mental health effects may be prolonged, extending well beyond the point of release into the community. The Australian experience offers general lessons to health professionals worldwide about the importance of remaining vigilant in protecting the rights of vulnerable groups, and more specifically, to ensure that the traumas that cause mental suffering in refugees are not compounded as a consequence of immigration policy decisions in recipient countries. Documentation and research can be vital in achieving policy change in these settings.
Ethical Research in Refugee Communities and the Use of Community Participatory Methods
Authors: Ellis B. Heidi , Kia-Keating Maryam , Yusuf Siraad Aden , Lincoln Alisa , Nur Abdirahman
Published: October 2007

This article describes the distinct challenges associated with conducting ethical research with refugees. A case example of an ongoing study of stigma and access to mental health treatment among Somali refugee adolescents resettled in the USA is presented. In developing the study, standard research paradigms were critically examined in order to take account of the unique aspects of Somali culture and experience. Community participatory methods were adopted to uphold both ethical and methodological rigor in the research. A participatory approach for developing ethical protocols within different refugee communities is recommended.
The Consumer Diaries, or, Autoethnography in the Inverted World
Authors: Chin Elizabeth
Published: October 2007

Using the form of an ethnographic diary, this article explores the complexity of contemporary consumer life as it is enmeshed with everyday experience. Built around three ethnographic diary entries that track the author's miscarriage, the article's aim is to insist on the humanity of consumption even as it poses profound problems. Scholars and scholarship are not exempt from suffering the very problems we seek to analyze. To further this point, this article also explores aspects of the consumer lives of Karl Marx and his wife Jenny, showing how even for them, negotiating the demands of commodity capitalism was complex, contradictory, and painful.
Material Culture and the Living Room
Authors: Money Annemarie
Published: October 2007

This article draws on findings of qualitative research that considers the importance and meanings people attach to domestic decoration and surroundings via an exploration of the material culture of living rooms. In attending to issues and debates concerning everyday consumption practices within the domestic sphere, the following discussion suggests an approach that firmly places an understanding on how `goods' and `things' are used, lived with and appropriated into everyday life. Drawing on in-depth interviews carried out in the homes of 50 respondents in Greater Manchester, UK, the article develops and complements existing ideas and research in cultural anthropology, consumer studies and, more recently, sociology of consumption, which focus on understanding aspects of the complex relationships that exist between subjects and objects, and how these operate within the boundaries of ordinary, mundane and routine consumption practices. It will be shown that one aspect of this relationship relates to the ways in which `things' act as the embodiment of meaningful social relations and significant connections between family members, friends and even wider social networks, and offers one way of understanding material culture consumption within the home. This is explored via three observed processes of display, acquisition and appropriation within the home: gift objects as familial obligation; objects as markers of memory; and the commemorative potential of objects.
Destination New Orleans
Authors: Gotham Kevin Fox
Published: October 2007

This article uses a case study of New Orleans to illustrate the nexus of commodification and rationalization in the development of urban tourism during the first half of the 20th century. Tourism is exemplary of the consumption of space and involves the circulation of people to particular locations to consume local culture, nature, history, or otherness. I examine the role of urban literary writers, visitor guidebooks, and the New Orleans Association of Commerce in constructing a `destination image'. As a collection of symbols and motifs representing a locale, a destination image is a visual cue that acts both as an attraction for potential tourists and as a cultural framework for authenticating the tourists' experience once they arrive in the city. I argue that creating and (re)producing a destination image and assorted urban symbols requires an institutional system or set of formal organizations. Institutions and organizations create the rules, routines, and structures that shape how tourism markets and destination images develop, how actors present and arrange symbols to persuade people to invest in and travel to cities, and how actors develop promotional strategies. Analysis of rationalization and commodification in the production of a destination image offers a unique perspective for understanding tourism as a major consumption practice constituted by a set of `distant' processes and `local' practices.
promoting high quality early childhood education and care services
Authors: Fenech Marianne , Sumsion Jennifer
Published: October 2007

Whilst regulation is utilized by governments in Australia and internationally as a means of promoting quality standards in early childhood education and care (ECEC) services, a growing body of literature is critical of the detrimental effect of this regulation. Drawing on our investigation into early childhood teachers' perceptions of the impact of regulation on quality practices we suggest that the way regulation is constructed limits its capacity to effect high quality standards. After problematizing the use of risk management and performative constructs of regulation, we call for regulatory reform that transcends these dominant constructions. We contend that a transformed system of regulatory accountability underpinned by notions of `a decent and non-humiliating society', socially just policies and professional trust presents as a useful way forward.
Microstructure, hardness and abrasive wear behaviour of flame sprayed Co based alloy coating
Authors: Harsha S. , Dwivedi D. K.
Published: October 2007

In the present paper, the influence of the post-spray heat treatment on microstructure, microhardness and abrasive wear behaviour of flame sprayed stellite (EWAC 1006 EE) coatings deposited on mild steel has been reported. Coatings were deposited by oxyacetylene flame spraying torch. The post-spray heat treatment of the coatings was carried out at 800°C for 2 h. Wear behaviour of coatings was evaluated using pin on plate wear system against SiC abrasive medium of 120 and 600 grade at 5, 10, 15 and 20 N normal load. It has been found that the influence of normal load on wear behaviour of these coating is governed by the microstructure, hardness and abrasive grit size. Heat treatment decreases average microhardness of the coating. Heat treatment improved the abrasive wear resistance against fine grit size abrasive medium, while it deteriorated wear resistance against coarse abrasive. Scanning electron microscopy (SEM) study indicates that the wear is largely governed by groove formation, microcutting and scoring mechanisms.
Adhesion tests for thermal spray coatings: Correlation of bond strength and interfacial toughness
Authors: Hadad M. , Marot G. , Démarécaux P. , Chicot D. , Lesage J. , Rohr L. , Siegmann S.
Published: October 2007

In this paper, experiments for determining the adhesion properties have been performed using two test methods; tensile adhesive test which is widely used in industry and interfacial indentation test still under development in research laboratories. Therefore, only few experimental data on the accuracy of the methods and on the potential in an industrial context are available. For that reason, dissimilar coating–substrate combinations covering different ranges of type of thermal spray coating–substrate systems were tested. Ceramic (Al2O3) and metallic (80Ni–20Cr) coatings were deposited by flame spraying system with two different thicknesses on titanium alloy and steel substrates exhibiting each two distinct roughness levels. The distinguished coating properties include the interfacial toughness and adhesive strength. The impacts of interfacial roughness and the thickness of the coating on the adhesion were conducted, and some adhesion tendency was also observed. Typical bond strength values measured were from 40 up to 100 MPa, and the interfacial toughness obtained from 1 to 4 MPa m0·5. The correlation of tensile adhesive strength and interfacial toughness has been discussed.
Characterising of internal stresses in duplex coating by FEM
Authors: Wu C.-W. , Zhang K. , Chen G.-N.
Published: October 2007

The internal stresses in a duplex coating involving a prequenched layer are believed to change if it is exposed to thermal loading. To characterise the internal stresses in such a duplex coating, a gradient model of finite element method is set up. The initial stress within the substrate developed in as quenching and the internal stresses due to the tempering of the prequenched layer (TPQL) in such a duplex coating are calculated. The synthetical internal stresses in coating can be estimated by superposing uniform initial stresses developed during plating. The results indicate that the residual tensile stresses due to fabrication in coating will be decreased greatly, or even synthetical compressive internal stresses may arise in the coating.
Expansion of CD4+CD25+ regulatory T cells by intravenous immunoglobulin: a critical factor in controlling experimental autoimmune encephalomyelitis
Authors: Ephrem Amal , Chamat Souleima , Miquel Catherine , Fisson Sylvain , Mouthon Luc , Caligiuri Giuseppina , Delignat Sandrine , Elluru Sriramulu , Bayry Jagadeesh , Lacroix-Desmazes Sebastien , Cohen José L. , Salomon Benoît L. , Kazatchkine Michel D. , Kaveri Srini V. , Misra Namita
Published: October 2007

The clinical use of intravenous immunoglobulin (IVIg) based on its immunomodulatory and anti-inflammatory potential remains an ongoing challenge. Fcγ receptor-mediated effects of IVIg, although well elucidated in certain pathologies, cannot entirely account for its proven benefit in several autoimmune disorders mediated by autoreactive T cells. In this study, we show that prophylactic infusion of IVIg prevents the development of experimental autoimmune encephalomyelitis (EAE), an accepted animal model for multiple sclerosis (MS). The protection was associated with peripheral increase in CD4+CD25+Foxp3+ regulatory T cell (Treg) numbers and function. The protection was Treg-mediated because IVIg failed to protect against EAE in mice that were depleted of the Treg population. Rather than inducing de novo generation from conventional T cells, IVIg had a direct effect on proliferation of natural Treg. In conclusion, our results highlight a novel mechanism of action of IVIg and provide a rationale to test the use of IVIg as an immunomodulatory tool to enhance Treg in early onset MS and other autoimmune and inflammatory conditions.
Furin-mediated release of soluble hemojuvelin: a new link between hypoxia and iron homeostasis
Authors: Silvestri Laura , Pagani Alessia , Camaschella Clara
Published: October 2007

The liver peptide hepcidin regulates iron absorption and recycling. Hemojuvelin (HJV) has a key role in hepcidin regulation, and its inactivation causes severe iron overload both in humans and in mice. Membrane HJV (m-HJV) acts as a coreceptor for bone morphogenetic proteins (BMPs), whereas soluble HJV (s-HJV) may down-regulate hepcidin in a competitive way interfering with BMP signaling. s-HJV is decreased by iron in vitro and increased by iron deficiency in vivo. However, the mechanisms regulating the 2 HJV isoforms remain unclear. Here we show that s-HJV originates from a furin cleavage at position 332–335. s-HJV is reduced in the cleavage mutant R335Q as well as in cells treated with a furin inhibitor, and increased in cells overexpressing exogenous furin, but not in cells overexpressing an inactive furin variant. Furin is up-regulated by iron deficiency and hypoxia in association with the stabilization of HIF-1α. Increased s-HJV in response to HIF-1α occurs during differentiation of murine muscle cells expressing endogenous Hjv. Our data are relevant to the mechanisms that relate iron metabolism to the hypoxic response. The release of s-HJV might be a tissue-specific mechanism, signaling the local iron requests of hypoxic skeletal muscles independently of the oxygen status of the liver.
Patterns of intron gain and conservation in eukaryotic genes
Authors: Carmel Liran , Rogozin Igor B , Wolf Yuri I , Koonin Eugene V
Published: October 2007

Background:

The presence of introns in protein-coding genes is a universal feature of eukaryotic genome organization, and the genes of multicellular eukaryotes, typically, contain multiple introns, a substantial fraction of which share position in distant taxa, such as plants and animals. Depending on the methods and data sets used, researchers have reached opposite conclusions on the causes of the high fraction of shared introns in orthologous genes from distant eukaryotes. Some studies conclude that shared intron positions reflect, almost entirely, a remarkable evolutionary conservation, whereas others attribute it to parallel gain of introns. To resolve these contradictions, it is crucial to analyze the evolution of introns by using a model that minimally relies on arbitrary assumptions.

Results:

We developed a probabilistic model of evolution that allows for variability of intron gain and loss rates over branches of the phylogenetic tree, individual genes, and individual sites. Applying this model to an extended set of conserved eukaryotic genes, we find that parallel gain, on average, accounts for only ~8% of the shared intron positions. However, the distribution of parallel gains over the phylogenetic tree of eukaryotes is highly non-uniform. There are, practically, no parallel gains in closely related lineages, whereas for distant lineages, such as animals and plants, parallel gains appear to contribute up to 20% of the shared intron positions. In accord with these findings, we estimated that ancestral introns have a high probability to be retained in extant genomes, and conversely, that a substantial fraction of extant introns have retained their positions since the early stages of eukaryotic evolution. In addition, the density of sites that are available for intron insertion is estimated to be, approximately, one in seven basepairs.

Conclusion:

We obtained robust estimates of the contribution of parallel gain to the observed sharing of intron positions between eukaryotic species separated by different evolutionary distances. The results indicate that, although the contribution of parallel gains varies across the phylogenetic tree, the high level of intron position sharing is due, primarily, to evolutionary conservation. Accordingly, numerous introns appear to persist in the same position over hundreds of millions of years of evolution. This is compatible with recent observations of a negative correlation between the rate of intron gain and coding sequence evolution rate of a gene, suggesting that at least some of the introns are functionally relevant.
Global comparative analysis of ESTs from the southern cattle tick, Rhipicephalus (Boophilus) microplus
Authors: Wang Minghua , Guerrero Felix D , Pertea Geo , Nene Vishvanath M
Published: October 2007

Background

The southern cattle tick, Rhipicephalus (Boophilus) microplus, is an economically important parasite of cattle and can transmit several pathogenic microorganisms to its cattle host during the feeding process. Understanding the biology and genomics of R. microplus is critical to developing novel methods for controlling these ticks.

Results

We present a global comparative genomic analysis of a gene index of R. microplus comprised of 13,643 unique transcripts assembled from 42,512 expressed sequence tags (ESTs), a significant fraction of the complement of R. microplus genes. The source material for these ESTs consisted of polyA RNA from various tissues, lifestages, and strains of R. microplus, including larvae exposed to heat, cold, host odor, and acaricide. Functional annotation using RPS-Blast analysis identified conserved protein domains in the conceptually translated gene index and assigned GO terms to those database transcripts which had informative BlastX hits. Blast Score Ratio and SimiTri analysis compared the conceptual transcriptome of the R. microplus database to other eukaryotic proteomes and EST databases, including those from 3 ticks. The most abundant protein domains in BmiGI were also analyzed by SimiTri methodology.

Conclusion

These results indicate that a large fraction of BmiGI entries have no homologs in other sequenced genomes. Analysis with the PartiGene annotation pipeline showed 64% of the members of BmiGI could not be assigned GO annotation, thus minimal information is available about a significant fraction of the tick genome. This highlights the important insights in tick biology which are likely to result from a tick genome sequencing project. Global comparative analysis identified some tick genes with unexpected phylogenetic relationships which detailed analysis attributed to gene losses in some members of the animal kingdom. Some tick genes were identified which had close orthologues to mammalian genes. Members of this group would likely be poor choices as targets for development of novel tick control technology.
Synthetic xylan-binding modules for mapping of pulp fibres and wood sections
Authors: Filonova Lada , Gunnarsson Lavinia Cicortas , Daniel Geoffrey , Ohlin Mats
Published: October 2007

Background

The complex carbohydrate composition of natural and refined plant material is not known in detail but a matter that is of both basic and applied importance. Qualitative assessment of complex samples like plant and wood tissues requires the availability of a range of specific probes. Monoclonal antibodies and naturally existing carbohydrate binding modules (CBMs) have been used in the past to assess the presence of certain carbohydrates in plant tissues. However, the number of natural CBMs is limited and development of carbohydrate-specific antibodies is not always straightforward. We envisage the use of sets of very similar proteins specific for defined targets, like those developed by molecular evolution of a single CBM scaffold, as a suitable strategy to assess carbohydrate composition. An advantage of using synthetic CBMs lies in the possibility to study fine details of carbohydrate composition within non-uniform substrates like plant cell walls as made possible through minor differences in CBM specificity of the variety of binders that can be developed by genetic engineering.

Results

A panel of synthetic xylan-binding CBMs, previously selected from a molecular library based on the scaffold of CBM4-2 from xylanase Xyn10A of Rhodothermus marinus, was used in this study. The wild type CBM4-2 and evolved modules both showed binding to wood sections. However, differences were observed in the staining patterns suggesting that these modules have different xylan-binding properties. Also the staining stability varied between the CBMs, the most stable staining being obtained with one (X-2) of the synthetic modules. Treatment of wood materials resulted in altered signal intensities, thereby also demonstrating the potential application of engineered CBMs as analytical tools for quality assessment of diverse plant material processes.

Conclusion

In this study we have demonstrated the usefulness of synthetic xylan-binding modules as specific probes in analysis of hemicelluloses (xylan) in wood and fibre materials.
The histone deacetylase inhibitor belinostat (PXD101) suppresses bladder cancer cell growth in vitro and in vivo
Authors: Buckley Michael T , Yoon Joanne , Yee Herman , Chiriboga Luis , Liebes Leonard , Ara Gulshan , Qian Xiaozhong , Bajorin Dean F , Sun Tung-Tien , Wu Xue-Ru , Osman Iman
Published: October 2007

Background

Treatment options for patients with recurrent superficial bladder cancer are limited, necessitating aggressive exploration of new treatment strategies that effectively prevent recurrence and progression to invasive disease. We assessed the effects of belinostat (previously PXD101), a novel histone deacetylase inhibitor, on a panel of human bladder cancer cell lines representing superficial and invasive disease, and on a transgenic mouse model of superficial bladder cancer.

Methods

Growth inhibition and cell cycle distribution effect of belinostat on 5637, T24, J82, and RT4 urothelial lines were assessed. Ha-ras transgenic mice with established superficial bladder cancer were randomized to receive either belinostat or vehicle alone, and assessed for bladder weight, hematuria, gene expression profiling, and immunohistochemistry (IHC).

Results

Belinostat had a significant linear dose-dependent growth inhibition on all cell lines (IC50 range of 1.0–10.0 μM). The 5637 cell line, which was derived from a superficial papillary tumor, was the most sensitive to treatment. Belinostat (100 mg/kg, intraperitoneal, 5 days each week for 3 weeks) treated mice had less bladder weight (p < 0.05), and no hematuria compared with 6/10 control mice that developed at least one episode. IHC of bladder tumors showed less cell proliferation and a higher expression of p21WAF1 in the belinostat-treated mice. Gene expression profile analysis revealed 56 genes significantly different in the treated group; these included the upregulation of p21WAF1, induction of core histone deacetylase (HDAC), and cell communication genes.

Conclusion

Our data demonstrate that belinostat inhibits bladder cancer and supports the clinical evaluation of belinostat for the treatment of patients with superficial bladder cancer.
Evidence that α-Calcitonin Gene-Related Peptide Is a Neurohormone that Controls Systemic Lipid Availability and Utilization
Authors: Danaher Rachel N. , Loomes Kerry M. , Leonard Bridget L. , Whiting Lynda , Hay Debbie L. , Xu Lance Yi , Kraegen Edward W. , Phillips Anthony R. J. , Cooper Garth J. S.
Published: October 2007

α-Calcitonin gene-related peptide (αCGRP) is released mainly from sensory and motor nerves in response to physiological stimuli. Despite well-documented pharmacological effects, its primary physiological role has thus far remained obscure. Increased lipid content, particularly in skeletal muscle and liver, is strongly implicated in the pathogenesis of insulin resistance, but the physiological regulation of organ lipid is imperfectly understood. Here we report our systematic investigations of the effects of αCGRP on in vitro and in vivo indices of lipid metabolism. In rodents, levels of αCGRP similar to those in the blood markedly stimulated fatty acid β-oxidation and evoked concomitant mobilization of muscle lipid via receptor-mediated activation of muscle lipolysis. αCGRP exerted potent in vivo effects on lipid metabolism in muscle, liver, and the blood via receptor-mediated pathways. Studies with receptor antagonists were consistent with tonic regulation of lipid metabolism by an endogenous CGRP agonist. These data reveal that αCGRP is a newly recognized regulator of lipid availability and utilization in key tissues and that it may elevate the availability of intramyocellular free fatty acids to meet muscle energy requirements generated by contraction by evoking their release from endogenous triglyceride.
Pulsatile Gonadotropin-Releasing Hormone Stimulation of Gonadotropin Subunit Transcription in Rat Pituitaries: Evidence for the Involvement of Jun N-Terminal Kinase But Not p38
Authors: Haisenleder D. J. , Burger L. L. , Walsh H. E. , Stevens J. , Aylor K. W. , Shupnik M. A. , Marshall J. C.
Published: October 2007

We investigated whether Jun N-terminal kinase (JNK) and p38 mediate gonadotropin subunit transcriptional responses to pulsatile GnRH in normal rat pituitaries. A single pulse of GnRH or vehicle was given to female rats in vivo, pituitaries collected, and phosphorylated JNK and p38 measured. GnRH stimulated an increase in JNK phosphorylation within 5 min, which peaked 15 min after GnRH (3-fold). GnRH also increased p38 phosphorylation 2.3-fold 15 min after stimulus. Rat pituitary cells were given 60-min pulses of GnRH or media plus the JNK inhibitor SP600125 (SP, 20 μm), p38 inhibitor SB203580 (20 μm), or vehicle. In vehicle-treated groups, GnRH pulses increased LHβ and FSHβ primary transcript (PT) levels 3-fold. SP suppressed both basal and GnRH-induced increases in FSHβ PT by half, but the magnitude of responses to GnRH was unchanged. In contrast, SP had no effect on basal LHβ PT but suppressed the stimulatory response to GnRH. SB203580 had no effect on the actions of GnRH on either LH or FSHβ PTs. Lβ-T2 cells were transfected with dominant/negative expression vectors for MAPK kinase (MKK)-4 and/or MKK-7 plus a rat LHβ promoter-luciferase construct. GnRH stimulated a 50-fold increase in LHβ promoter activity, and the combination of MKK-4 and -7 dominant/negatives suppressed the response by 80%. Thus, JNK (but not p38) regulates both LHβ and FSHβ transcription in a differential manner. For LHβ, JNK is essential in mediating responses to pulsatile GnRH. JNK also regulates FSHβ transcription (i.e. maintaining basal expression) but does not play a role in responses to GnRH.
Neural induction requires continued suppression of both Smad1 and Smad2 signals during gastrulation
Authors: Chang Chenbei , Harland Richard M.
Published: October 2007

Vertebrate neural induction requires inhibition of bone morphogenetic protein (BMP) signaling in the ectoderm. However, whether inhibition of BMP signaling is sufficient to induce neural tissues in vivo remains controversial. Here we have addressed why inhibition of BMP/Smad1 signaling does not induce neural markers efficiently in Xenopus ventral ectoderm, and show that suppression of both Smad1 and Smad2 signals is sufficient to induce neural markers. Manipulations that inhibit both Smad1 and Smad2 pathways, including a truncated type IIB activin receptor, Smad7 and Ski, induce early neural markers and inhibit epidermal genes in ventral ectoderm; and co-expression of BMP inhibitors with a truncated activin/nodal-specific type IB activin receptor leads to efficient neural induction. Conversely, stimulation of Smad2 signaling in the neural plate at gastrula stages results in inhibition of neural markers, disruption of the neural tube and reduction of head structures, with conversion of neural to neural crest and mesodermal fates. The ability of activated Smad2 to block neural induction declines by the end of gastrulation. Our results indicate that prospective neural cells are poised to respond to Smad2 and Smad1 signals to adopt mesodermal and non-neural ectodermal fates even at gastrula stages,after the conventionally assigned end of mesodermal competence, so that continued suppression of both mesoderm- and epidermis-inducing Smad signals leads to efficient neural induction.
TheC. elegansCBFβ homologue BRO-1 interacts with the Runx factor, RNT-1, to promote stem cell proliferation and self-renewal
Authors: Kagoshima Hiroshi , Nimmo Rachael , Saad Nicole , Tanaka Junko , Miwa Yoshihiro , Mitani Shohei , Kohara Yuji , Woollard Alison
Published: October 2007

In this report, we investigate the C. elegans CBFβ homologue,BRO-1. bro-1 mutants have a similar male-specific sensory ray loss phenotype to rnt-1 (the C. elegans homologue of the mammalian CBFβ-interacting Runx factors), caused by failed cell divisions in the seam lineages. Our studies indicate that BRO-1 and RNT-1 form a cell proliferation-promoting complex, and that BRO-1 increases both the affinity and specificity of RNT-1-DNA interactions. Overexpression of bro-1,like rnt-1, leads to an expansion of seam cell number and co-overexpression of bro-1 and rnt-1 results in massive seam cell hyperplasia. Finally, we find that BRO-1 appears to act independently of RNT-1 in certain situations. These studies provide new insights into the function and regulation of this important cancer-associated DNA-binding complex in stem cells and support the view that Runx/CBFβ factors have oncogenic potential.
Slit and Robo control the development of dendrites inDrosophilaCNS
Authors: Furrer Marie-Pierre , Vasenkova Irina , Kamiyama Daichi , Rosado Yaira , Chiba Akira
Published: October 2007

The molecular mechanisms that generate dendrites in the CNS are poorly understood. The diffusible signal molecule Slit and the neuronally expressed receptor Robo mediate growth cone collapse in vivo. However, in cultured neurons, these molecules promote dendritic development. Here we examine the aCC motoneuron, one of the first CNS neurons to generate dendrites in Drosophila. Slit displays a dynamic concentration topography that prefigures aCC dendrogenesis. Genetic deletion of Slit leads to complete loss of aCC dendrites. Robo is cell-autonomously required in aCC motoneurons to develop dendrites. Our results demonstrate that Slit and Robo control the development of dendrites in the embryonic CNS.
Spalt4mediates invagination and otic placode gene expression in cranial ectoderm
Authors: Barembaum Meyer , Bronner-Fraser Marianne
Published: October 2007

Vertebrate placodes are regions of thickened head ectoderm that contribute to paired sensory organs and cranial ganglia. We demonstrate that the transcription factor Spalt4 (also known as Sall4) is broadly expressed in chick preplacodal epiblast and later resolves to otic, lens and olfactory placodes. Ectopic expression of Spalt4 by electroporation is sufficient to induce invagination of non-placodal head ectoderm and prevent neurogenic placodes from contributing to cranial ganglia. Conversely, loss of Spalt4 function in the otic placode results in abnormal otic vesicle development. Intriguingly, Spalt4 appears to initiate a placode program appropriate for the axial level but is not involved in later development of specific placode fates. Fgfs can regulate Spalt4,since implantation of Fgf2 beads into the area opaca induces its expression. The results suggest that Spalt4 is involved in early stages of placode development, initiating cranial ectodermal invagination and region-specific gene regulatory networks.
Finite element modelling of multi-pass fusion welding with application to complex geometries
Authors: Jiang W , Yahiaoui K
Published: October 2007

The current paper presents recently completed work in the development of advanced multi-pass weld modelling procedures, with the ultimate objective of predicting weld residual stress distributions in thick-walled complex geometries. The modelling technique was first developed using simple three-dimensional geometries, for which experimental data was available for validation purposes. All the non-linearities associated with welding, including geometry, material, and boundary non-linearities, as well as heat source movement were taken into account. The element removal/reactivate technique was employed to simulate the deposition of filler material. Combined with a newly developed meshing technique, the model was then applied to predict residual stress distributions for a relatively thick stainless steel piping branch junction. Finally, a parametric study was conducted to assess the effects of various manufacture-related welding parameters on the final residual stress fields. The interpass temperature and cooling rate were found to be the two most sensitive parameters affecting resultant residual stresses. The residual stress profiles can be optimized relatively easily by adjusting these parameters. This research demonstrated that the developed modelling technique has potential in multi-pass welding process optimization and wide industrial applications including weld repairs.
Effect of nano-trenches on the ultrathin liquid polymer film spreading and free surface undulations on solid surfaces
Authors: Mayeed M. S. , Al-Mekhnaqi A. M. , Newaz G. M. , Kato T
Published: October 2007

An NVT Monte Carlo (MC) simulation for perfluoropolyether (PFPE) Z was performed using a Rouse-like algorithm applied to a simplified bead-spring off-lattice polymer model. A bead-bead Lennard-Jones (LJ) potential and a substrate-bead LJ potential were used. Simulations were performed with 2000 and 4000 g/mol molecular weights, assuming room temperature and pressure conditions. It was observed that the calculated average radius of gyration (Rg) for bulk condition is almost equal to the bulk experimental value. An ultrathin liquid film of about 2 nm film thickness was, first, equilibrated on a flat carbon surface. Then, this film was allowed to spread under the influence of dispersive interaction with the flat surface. A nano-scale trench was made parallel to the spreading edge and the film was allowed to spread across the trench. Several trench widths and depths were used in different simulation platforms. The spreading rate of the spreading over a flat surface was compared with those over the trenched surfaces. Moreover, the effects of these nano-scale trenches over the undulations of the free surfaces were observed and analysed with respect to different trench widths and depths as well as molecular weights.
Clicked Interlocked Molecules
Authors: Aprahamian Ivan , Miljanic Ognjen Š , Dichtel William R , Isoda Kyosuke , Yasuda Takuma , Kato Takashi , Stoddart J Fraser
Published: October 2007

The CuI-catalyzed Huisgen 1,3-dipolar cycloaddition, popularized as “click chemistry,” is one of the latest acquisitions to the synthetic arsenal for the making of mechanically interlocked molecular compounds. The high efficiency and functional group tolerance of “click chemistry” allows this reaction to be employed at the stoppering step in the “threading-followed-by-stoppering” sequence that produces rotaxanes, and in the macrocyclization step that affords catenanes. The use of this kind of “click chemistry” alleviates some of the drawbacks associated with previous approaches to the template-directed synthesis of mechanically interlocked molecular compounds—approaches such as “clipping;”—and opens up the way to more exotic mechanically interlocked molecules. Employing this new approach, [2]-, [3]-, and [4]rotaxanes and [2]catenanes have all been prepared in a convergent and efficient manner. Their template-directed synthesis relies, in the beginning, on the formation of [n]pseudorotaxanes, which can either (i) be stoppered, affording [n]rotaxanes, or (ii) induced to undergo an intramolecular cyclization, affording [2]catenanes. This new synthetic approach has also been employed in the template-directed synthesis of a self-complexing system as well as a two-station, degenerate [2]rotaxane (molecular shuttle) which was used to measure the energy barrier (15 kcal mol−1) to shuttling by a cyclobis(paraquat-p-phenylene) ring between two identical 1,5-dioxynaphthalene (DNP) stations across a 1,2,3-triazole unit. It has also been found that the CuI-salt, employed in the click reaction between an azide and an alkyne, can act as both a catalyst and a template in the formation of [2]rotaxanes. The “click” approach has also been used in the formation of a bistable [2]rotaxane containing a DNP station and a tetrathiafulvalene one. Electrochemical experiments performed on this compound indicate that the presence of the triazole unit does not influence the kinetics or thermodynamics of the redox-controlled switching process. Finally, the synthesis of a liquid-crystalline bistable [2]rotaxane, which shows smectic A phase behavior over a wide range of temperatures, is described.
Theoretical Study on the Kinetic and Mechanism of H+HO2 Reaction
Authors: Mousavipour Seyed Hosein , Saheb Vahid
Published: October 2007

The kinetics and mechanism of reaction of a hydroperoxyl radical (HO2) with a hydrogen atom on both singlet and triplet surfaces were studied by employing DFT, CCSD, and G3 methods along with the Aug-cc-pVTZ basis set. MC-SCF and CCD methods were used to explore potential energy surfaces. Major end products from different channels were H2O+O, H2+O2, and OH. Formation of chemically activated hydrogen peroxide HOOH was the most exothermic path in this system that dissociates to the ground state OH(2Π) radicals. Another energized transient species was water oxide H2OO, which has local minimum on the singlet potential-energy surface. The energized water oxide rapidly isomerized to hydrogen peroxide HOOH or dissociated to H2O + O(1D). Transition state theory and RRKM theory were used to calculate the rate constants for different channels.
Phase Separation of Aqueous Poly(vinyl methyl ether) Solutions Induced by the Photon Pressure of a Focused Near-Infrared Laser Beam
Authors: Tsuboi Yasuyuki , Nishino Masayuki , Matsuo Yasutaka , Ijiro Kuniharu , Kitamura Noboru
Published: October 2007

We demonstrate that phase separation of an aqueous poly(vinyl methyl ether) (PVME) solution can be triggered not only by a temperature change but also by photon pressure. A near-infrared continuous wave laser beam (λ=1064 nm) was focused through an objective lens into a heavy water (D2O) solution of PVME. A single PVME microparticle was produced and trapped at the focal point of the laser beam within several hundreds of seconds after switching on the laser. The origin of the microparticle formation (phase separation) is ascribed essentially to the photon force of the laser beam, and not to a rise in the local temperature, since heavy water is transparent at 1064 nm. The structures of the PVME microparticles produced by laser irradiation were studied in detail using confocal Raman microspectroscopy. Raman spectra of the microparticles and coiled/globular PVME were observed successfully over a wide wavenumber region. It was confirmed that the phase transition of the polymer chains from coiled to globular states proceeded during microparticle formation. The fundamental mechanism of photo-induced phase separation of PVME is discussed in terms of the interactions between the polymer and the photon force.
Influence of Temperature, Pressure, and pH on the Group-Inclusion Equilibrium in Water Soluble Calixarenes
Authors: Sueishi Yoshimi , Negi Mieko , Kotake Yashige
Published: October 2007

Previously, we demonstrated, for the first time, that guest probes having more than one bulky group could produce a pair of bidirectional inclusion complexes with water soluble calixarene (Chem. Lett.2006, 35, 772). The use of unique free radical probes and electron spin resonance has made this finding possible. In this report, we investigated thermodynamic and pH-dependent properties of the group-inclusion complex formation, i.e., the effects of temperature, pressure and the medium pH on group inclusion by p-sulfonatocalixarenes were determined. Temperature-dependence study indicated that enthalpy portions in ΔG play dominant roles in the group-in complexation. Pressure dependence experiments allowed us to calculate the reaction volumes, i.e., intrinsic volume changes related to inclusion into the calixarene cavity, which ranged from −5.1 to −16.3 cm3 mol−1. Data on pH dependence clarified the role of oxyanions in the entrant group of calixarenes. It should be emphasized that pressure-dependent study provided unique information on the structure of the group-inclusion complex.
Difference in the Potential Energy Surfaces from the Fragment MO Method and Conventional Ab Initio SCF-MO Method. A Case of a Surface for Ring Rotation of (−)-Epicatechin Gallate Using the STO-3G Basis Set
Authors: Tamura Katsuhiro , Watanabe Toshio , Ishimoto Takayoshi , Nagashima Umpei
Published: October 2007

Difference in the potential energy surfaces (ΔE) obtained from the fragment MO (FMO) method and conventional ab initio Hartree–Fock SCF-MO (HFMO) method was investigated using the best fragmentation pattern of (−)-epicatechin gallate. In the lower energy region (<23.06 kcal mol−1 from the minimum), the average ΔE at each grid point was 1.1 kcal mol−1. The FMO method is applicable to quantum MD calculation of large molecular system at around the standard temperature.
Tetrameric, Tri-Titanium(IV)-Substituted Polyoxometalates with an α-Dawson Substructure as Soluble Metal Oxide Analogues. Synthesis and Molecular Structure of Three Giant “Tetrapods” Encapsulating Different Anions (Br−, I−, and NO3−)
Authors: Sakai Yoshitaka , Yoshida Shoko , Hasegawa Takeshi , Murakami Hideyuki , Nomiya Kenji
Published: October 2007

Preparation and structural characterization of giant “tetrapod”-shaped polyoxometalates (POMs) with approximately Td symmetry, [{α-P2W15Ti3O59(OH)3}4{μ3-Ti(H2O)3}4X]21− (X=Br− (1a), I− (2a), and NO3− (3a)), consisting of four tri-titanium(IV)-substituted α-Dawson subunits, four octahedral Ti(H2O)3 bridging groups and one encapsulated anion X, are described. Sodium salts of three giant “tetrapod”-shaped POMs encapsulating different anions 1–3 were prepared as analytically pure crystals in 1:5 molar-ratio reactions in water of the tri-lacunary Dawson POM with the in situ-generated “TiX4” (X=Br−, I−, and NO3−), which were prepared by the reactions of Ti(SO4)2 with BaX2 in aqueous solution [Note: The polyoxoanion is represented by 1a, 2a, 3a, …, and the whole formula, which contains counter ions, polyoxoanion, hydrated waters, and so on, is represented by 1, 2, 3, …]. The compounds were characterized by using elemental analysis, thermogravimetric and differential thermal analyses (TG/DTA), solid-state and solution IR, solid-state and solution 31P NMR spectroscopy, and X-ray crystallography. Molecular structures of 1a–3a are analogous to the previously prepared POM with X=Cl− (4a). The fact that encapsulation of the different anions (Cl−, Br−, I−, and NO3−) was achieved in the central cavity of the giant “tetrapod”-shaped POM shows the cationic character of the central framework constituted by the protonated Ti–O–Ti bonds, i.e., the Ti–OH–Ti bonds. The solid-state and solution 31P NMR measurements showed that 1a–3a were stable in the solid-state and in DMSO, but in water, they partially decomposed. These properties of 1a–3a in water are in contrast to that of 4a.
Effects of Polyethylene Glycol on DNA Duplex Stability at Different NaCl Concentrations
Authors: Karimata Hisae , Nakano Shu-ichi , Sugimoto Naoki
Published: October 2007

Although the thermodynamic stability of ordered DNA is known to be affected by interactions with cations and water molecules, there is scarce quantitative information about the behavior of DNA under conditions of molecular crowding as found inside the cell. In this study, we measured the thermal stability of DNA base pairs under conditions of molecular crowding caused by polyethylene glycol (PEG) and at different concentrations of NaCl. Even though PEG 200 and 8000 (average molecular weights of 200 and 8000, respectively) decreased the stability of DNA base pairs at high NaCl concentrations, PEG 8000 substantially increased the stability at low NaCl concentrations. Quantitative analyses of the thermodynamic parameters made it possible to determine the numbers of water molecules (−Δnw) and sodium ions (−ΔnNa+) bound to the hairpin DNA. These measurements showed that PEG decreased the −ΔnNa+ value without changing the −Δnw value, suggesting that PEG buffers sodium ion binding but may not affect the hydration status of the nucleotide or sodium ion. These results should help clarify the effects of molecular crowding on DNA stability and function and provide quantitative information about the effects of molecular crowding in cells and on chips and nanoparticles.
Direct Decomposition of NO into N2 and O2 on SrFe0.7Mg0.3O3 Perovskite Oxide
Authors: Iwakuni Hideharu , Shinmyou Yusuke , Matsumoto Hiroshige , Ishihara Tatsumi
Published: October 2007

NO direct decomposition on doped SrFeO3 perovskite oxide was investigated. The ability of SrFeO3 for direct decomposition of NO is strongly affected by the dopant in Fe sites. Among the examined dopants and compositions, the highest yield of N2 was achieved on SrFe0.7Mg0.3O3. When SrFe0.7Mg0.3O3 was loaded with Pt, the N2 yield further improved, and the light-off temperature fell by 100 K. On this catalyst, the yields of N2 and O2 were 56 and 35%, respectively, at 1123 K. On the Pt-loaded SrFe0.7Mg0.3O3 catalyst, the NO decomposition rate increased with increase in the NO partial pressure with PNO1.31. The presence of oxygen slightly decreased the N2 yield with PO2−0.12. Therefore, the effect of oxygen poisoning on NO decomposition upon Pt-loaded SrFe0.7Mg0.3O3 is small. From the result of O2-TPD, Pt loading possibly weakens the adsorption strength of surface oxygen and enhances NO adsorption. In summary, this study shows that the substitution of Fe with lower valence cation in SrFeO3 and also loading a small amount of Pt are highly effective for increasing the NO decomposition activity.
Enantioselecitve Elimination of Pd–H from η3-Allylpalladium–Tol BINAP Complexes. Evidence of Syn Elimination Pathway
Authors: Ogawa Ryohei , Shigemori Yusuke , Uehara Koichi , Sano Jiro , Nakajima Takayuki , Shimizu Isao
Published: October 2007

The palladium-catalyzed elimination of the bicyclic cis-acetate 1b using Pd catalyst and (R)-p-Tol BINAP gave the (S)-diene 2 with 58% ee. Bicyclic η3-allylpalladium complex 3a with (R)-p-Tol BINAP, considered as an intermediate in the catalytic reaction from 1b, was prepared. Enantioselectivity in decomposition of 3a is dependent on the reaction conditions. The thermal decomposition of 3a without base gave the (S)-2 with 70% ee. However, the decomposition of 3a in the presence of excess base gave (R)-2 with 58% ee. Syn elimination from 3a was found to proceed preferentially from the decomposition results of the deuterium-labeled complexes.