bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer determination of peptide conformations in water: different roads to structure.
Authors: Simmerling C L , Elber R
Published: May 2006

Fragments of proteins (short peptides) that "fold" suggest a mechanism of how complete conformational search in protein folding is avoided. We used a computational method to determine structures of two foldable peptides in explicit water: RVEW and CSVTC. The optimization starts from random structures and no experimental constraints are used. In agreement with NMR data, the simulations find a hydrophobic pair (Val/Trp) in REVW. The structure of CSVTC is induced by a surface water that bridges two amide hydrogens, a drive to structure hypothesized by Ben-Naim [Ben-Naim, A. (1990) J. Chem. Phys. 93, 8196-8210] that is largely ignored in studies of folding. Tendency to structure in short peptide chains suggests a mechanism for the formation of short-range nucleation sites in protein folding.
Synthesis of "Nod"-like chitin oligosaccharides by the Xenopus developmental protein DG42.
Authors: Semino C E , Robbins P W
Published: May 2006

The Xenopus DG42 gene is expressed only between the late midblastula and neurulation stages of embryonic development. Recent database searches show that DG42 has striking sequence similarity to the Rhizobium NodC protein. NodC catalyzes the synthesis of chitin oligosaccharides which subsequently are transformed into bacterium-plant root signaling molecules. We find that the DG42 protein made in an in vitro coupled transcription-translation system catalyzes the synthesis of an array of chitin oligosaccharides. The result suggests the intriguing possibility that a bacterium-plant type of "Nod" signaling system may operate during early stages of vertebrate embryonic development and raises issues about the use of chitin synthase inhibitors as fungal-specific drugs.
A constant radius of curvature model for the organization of DNA in toroidal condensates.
Authors: Hud N V , Downing K H , Balhorn R
Published: May 2006

Toroidal DNA condensates have received considerable attention for their possible relationship to the packaging of DNA in viruses and in general as a model of ordered DNA condensation. A spool-like model has primarily been supported for DNA organization within toroids. However, our observations suggest that the actual organization may be considerably different. We present an alternate model in which DNA for a given toroid is organized within a series of equally sized contiguous loops that precess about the toroid axis. A related model for the toroid formation process is also presented. This kinetic model predicts a distribution of toroid sizes for DNA condensed from solution that is in good agreement with experimental data.
Distinct neural correlates of visual long-term memory for spatial location and object identity: a positron emission tomography study in humans.
Authors: Moscovitch C , Kapur S , Köhler S , Houle S
Published: May 2006

The purpose of the present study was to investigate by using positron emission tomography (PET) whether the cortical pathways that are involved in visual perception of spatial location and object identity are also differentially implicated in retrieval of these types of information from episodic long-term memory. Subjects studied a set of displays consisting of three unique representational line drawings arranged in different spatial configurations. Later, while undergoing PET scanning, subjects' memory for spatial location and identity of the objects in the displays was tested and compared to a perceptual baseline task involving the same displays. In comparison to the baseline task, each of the memory tasks activated both the dorsal and the ventral pathways in the right hemisphere but not to an equal extent. There was also activation of the right prefrontal cortex. When PET scans of the memory tasks were compared to each other, areas of activation were very circumscribed and restricted to the right hemisphere: For retrieval of object identity, the area was in the inferior temporal cortex in the region of the fusiform gyrus (area 37), whereas for retrieval of spatial location, it was in the inferior parietal lobule in the region of the supramarginal gyrus (area 40). Thus, our study shows that distinct neural pathways are activated during retrieval of information about spatial location and object identity from long-term memory.
A chloroplast homologue of the signal recognition particle subunit SRP54 is involved in the posttranslational integration of a protein into thylakoid membranes.
Authors: Li X , Henry R , Yuan J , Cline K , Hoffman N E
Published: May 2006

The mechanisms involved in the integration of proteins into the thylakoid membrane are largely unknown. However, many of the steps of this process for the light-harvesting chlorophyll a/b protein (LHCP) have been described and reconstituted in vitro. LHCP is synthesized as a precursor in the cytosol and posttranslationally imported into chloroplasts. Upon translocation across the envelope membranes, the N-terminal transit peptide is cleaved, and the apoprotein is assembled into a soluble "transit complex" and then integrated into the thylakoid membrane via three transmembrane helices. Here we show that 54CP, a chloroplast homologue of the 54-kDa subunit of the mammalian signal recognition particle (SRP54), is essential for transit complex formation, is present in the complex, and is required for LHCP integration into the thylakoid membrane. Our data indicate that 54CP functions posttranslationally as a molecular chaperone and potentially pilots LHCP to the thylakoids. These results demonstrate that one of several pathways for protein routing to the thylakoids is homologous to the SRP pathway and point to a common evolutionary origin for the protein transport systems of the endoplasmic reticulum and the thylakoid membrane.
The hepatitis B virus X protein targets the basic region-leucine zipper domain of CREB.
Authors: Williams J S , Andrisani O M
Published: May 2006

The X gene product encoded by the hepatitis B virus, termed pX, is a promiscuous transactivator of a variety of viral and cellular genes under the control of diverse cis-acting elements. Although pX does not appear to directly bind DNA, pX-responsive elements include the NF-kappa B, AP-1, and CRE (cAMP response element) sites. Direct protein-protein interactions occur between viral pX and the CRE-binding transcription factors CREB and ATF. Here we examine the mechanism of the protein-protein interactions occurring between CREB and pX by using recombinant proteins and in vitro DNA-binding assays. We demonstrate that pX interacts with the basic region-leucine zipper domain of CREB but not with the DNA-binding domain of the yeast transactivator protein Gal4. The interaction between CREB and pX increases the affinity of CREB for the CRE site by an order of magnitude, although pX does not alter the rate of CREB dimerization. Methylation interference footprinting reveals differences between the CREB DNA and CREB-pX DNA complexes. These experiments demonstrate that pX titers the way CREB interacts with the CRE DNA and suggest that the basic, DNA-binding region of CREB is the target of pX. Transfection assays in PC12 cells with the CREB-dependent somatostatin promoter demonstrate a nearly 15-fold transcriptional induction after forskolin stimulation in the presence of pX. These results support the significance of the CREB-pX protein-protein interactions in vivo.
Organismal duplication, inclusive fitness theory, and altruism: understanding the evolution of endosperm and the angiosperm reproductive syndrome.
Authors: Friedman W E
Published: May 2006

For almost a century, events relating to the evolutionary origin of endosperm, a unique embryo-nourishing tissue that is essential to the reproductive process in flowering plants, have remained a mystery. Integration of recent advances in phylogenetic reconstruction, comparative reproductive biology, and genetic theory can be used to elucidate the evolutionary events and forces associated with the establishment of endosperm. Endosperm is shown to be derived from one of two embryos formed during a rudimentary process of "double fertilization" that evolved in the ancestors of angiosperms. Acquisition of embryo-nourishing behavior (with accompanying loss of individual fitness) by this supernumerary fertilization product was dependent upon compensatory gains in the inclusive fitness of related embryos. The result of the loss of individual fitness by one of the two original products of double fertilization was the establishment of endosperm, a highly modified embryo/organism that reproduces cryptically through behavior that enhances the fitness of its associated embryo within a seed. Finally, although triploid endosperm remains a synapomorphy of angiosperms, inclusive fitness analysis demonstrates that the embryo-nourishing properties of endosperm initially evolved in a diploid condition.
Species specificity in the cell-free conversion of prion protein to protease-resistant forms: a model for the scrapie species barrier.
Authors: Kocisko D A , Priola S A , Raymond G J , Chesebro B , Lansbury P T , Caughey B
Published: May 2006

Scrapie is a transmissible neurodegenerative disease that appears to result from an accumulation in the brain of an abnormal protease-resistant isoform of prion protein (PrP) called PrPsc. Conversion of the normal, protease-sensitive form of PrP (PrPc) to protease-resistant forms like PrPsc has been demonstrated in a cell-free reaction composed largely of hamster PrPc and PrPsc. We now report studies of the species specificity of this cell-free reaction using mouse, hamster, and chimeric PrP molecules. Combinations of hamster PrPc with hamster PrPsc and mouse PrPc with mouse PrPsc resulted in the conversion of PrPc to protease-resistant forms. Protease-resistant PrP species were also generated in the nonhomologous reaction of hamster PrPc with mouse PrPsc, but little conversion was observed in the reciprocal reaction. Glycosylation of the PrPc precursors was not required for species specificity in the conversion reaction. The relative conversion efficiencies correlated with the relative transmissibilities of these strains of scrapie between mice and hamsters. Conversion experiments performed with chimeric mouse/hamster PrPc precursors indicated that differences between PrPc and PrPsc at residues 139, 155, and 170 affected the conversion efficiency and the size of the resultant protease-resistant PrP species. We conclude that there is species specificity in the cell-free interactions that lead to the conversion of PrPc to protease-resistant forms. This specificity may be the molecular basis for the barriers to interspecies transmission of scrapie and other transmissible spongiform encephalopathies in vivo.
Spatial organization of retinal information about the direction of image motion.
Authors: Amthor F R , Oyster C W
Published: May 2006

The visual stimuli that elicit neural activity differ for different retinal ganglion cells and these cells have been categorized by the visual information that they transmit. If specific visual information is conveyed exclusively or primarily by a particular set of ganglion cells, one might expect the cells to be organized spatially so that their sampling of information from the visual field is complete but not redundant. In other words, the laterally spreading dendrites of the ganglion cells should completely cover the retinal plane without gaps or significant overlap. The first evidence for this sort of arrangement, which has been called a tiling or tessellation, was for the two types of "alpha" ganglion cells in cat retina. Other reports of tiling by ganglion cells have been made subsequently. We have found evidence of a particularly rigorous tiling for the four types of ganglion cells in rabbit retina that convey information about the direction of retinal image motion (the ON-OFF direction-selective cells). Although individual cells in the four groups are morphologically indistinguishable, they are organized as four overlaid tilings, each tiling consisting of like-type cells that respond preferentially to a particular direction of retinal image motion. These observations lend support to the hypothesis that tiling is a general feature of the organization of information outflow from the retina and clearly implicate mechanisms for recognition of like-type cells and establishment of mutually acceptable territories during retinal development.
Rod photoreceptor-specific gene expression in human retinoblastoma cells.
Authors: Di Polo A , Farber D B
Published: May 2006

Retinoblastoma cells in culture have previously been shown to express cone-specific genes but not their rod counterparts. We have detected the messages for the rod alpha, beta, and gamma subunits of cGMP phosphodiesterase (PDE), the rod alpha subunit of transducin, rod opsin, and the cone alpha' subunit of PDE in RNA of human Y-79 retinoblastoma cells by reverse transcription-PCR. Quantitative analysis of the mRNAs for the rod alpha and cone alpha' PDE subunits revealed that they were expressed at comparable levels; however, the transcript encoding the rod beta PDE subunit was 10 times more abundant in these cells. Northern hybridization analysis of Y-79 cell RNA confirmed the presence of the transcripts for rod and cone PDE catalytic subunits. To test whether the transcriptional machinery required for the expression of rod-specific genes was endogenous in Y-79 retinoblastoma cells, cultures were transfected with a construct containing the promoter region of the rod beta PDE subunit gene attached to the firefly luciferase reporter vector. Significant levels of reporter enzyme activity were observed in the cell lysates. Our results demonstrate that the Y-79 retinoblastoma cell line is a good model system for the study of transcriptional regulation of rod-specific genes.
Peptide mimicry of the meningococcal group C capsular polysaccharide.
Authors: Westerink M A , Giardina P C , Apicella M A , Kieber-Emmons T
Published: May 2006

Sequence analysis of the variable regions of the heavy and light chains of the anti-idiotypic antibody 6F9, which mimics the meningococcal group C capsular polysaccharide (MCP), was performed. The immunogenic site on 6F9 responsible for inducing an anti-MCP antibody response was determined by means of sequence and computer model analysis of these data. Complementarity-determining region 3 (CDR3) was found to be unique in that the sequence tract YRY was exposed on the surface. A synthetic peptide spanning the CDR3 domain was synthesized and complexed to proteosomes (meningococcal group B outer membrane protein). Immunizations of BALB/c mice with the peptide-proteosome complex resulted in a significant anti-MCP antibody response. Immunized mice were protected against infection with a lethal dose of Neisseria meningitidis serogroup C.
Estimating Binding Affinities of the Nicotinic Receptor for Low-efficacy Ligands Using Mixtures of Agonists and Two-dimensional Concentration–Response Relationships
Authors: Purohit Yamini , Grosman Claudio
Published: May 2006

The phenomenon of ligand-induced ion channel gating hinges upon the ability of a receptor channel to bind ligand molecules with conformation-specific affinities. However, our understanding of this fundamental phenomenon is notably limited, not only because the changes in binding site structure and ligand conformation that occur upon gating are largely unknown but, also, because the strength of these ligand–receptor interactions are experimentally elusive. Both high- and low-efficacy ligands pose a number of analytical and experimental challenges that can render the estimation of their conformation-specific binding affinities impossible. In this paper, we present a novel assay that overcomes some of the hurdles presented by weak agonists of the muscle nicotinic receptor and allows the estimation of their closed-state affinities. The method, which we have termed the “activation-competition” assay, consists of a single-channel concentration–response assay performed in the presence of a binary mixture of ligands of widely different efficacies. By plotting the channel response (i.e., the open probability) as a function of the concentration of each agonist in the mixture, interpreting the observed response in the framework of a plausible kinetic scheme, and fitting the open probability surface with the corresponding function, the affinities of the closed receptor for the two agonists can be simultaneously extracted as free parameters. Here, we applied this methodology to estimate the closed-state affinity of the muscle nicotinic receptor for choline (a very weak agonist) using acetylcholine (ACh) as the partner in the mixture. We estimated the dissociation equilibrium constant of choline (KD) from the wild type's closed state to be 4.1 ± 0.5 mM (and that of ACh to be 106 ± 6 μM). We also discuss the use of accurate estimates of affinities for low-efficacy agonists as a tool to discriminate between binding and gating effects of mutations, and in the context of the rational design of therapeutic drugs.
Flectobacillus lacus sp. nov., isolated from a highly eutrophic pond in Korea
Authors: Hwang Chung Y. , Cho Byung C.
Published: May 2006

A Gram-negative, almost straight, rod-shaped, non-motile bacterium, designated CL-GP79T, was isolated from a highly eutrophic pond located within the campus of Seoul National University, Korea. Phylogenetic analyses based on 16S rRNA gene sequencing showed that strain CL-GP79T belongs to the family Flexibacteraceae, with Flectobacillus major as its closest relative (similarity of 95.7 %). The cellular fatty acids consist mainly of C16 : 1
ω5c (mean±sd, 26.9±10.8 %), iso-C15 : 0 2-OH and/or C16 : 1
ω7c (19.2±2.3 %) and iso-C15 : 0 (12.1±1.3 %). The DNA G+C content was found to be 38.3 mol%. Phenotypic, chemotaxonomic and phylogenetic analyses indicated that strain CL-GP79T could be assigned to the genus Flectobacillus, but could be distinguished from F. major. The strain CL-GP79T therefore represents a novel species, for which the name Flectobacillus lacus sp. nov. is proposed, with CL-GP79T (=KCCM 42271T=JCM 13398T) as the type strain.
The channel-tunnel HI1462 of Haemophilus influenzae reveals differences to Escherichia coli TolC
Authors: Polleichtner Georg , Andersen Christian
Published: May 2006

Efflux pumps play a major role in multidrug resistance of pathogenic bacteria. The TolC homologue HI1462 was identified as the single channel-tunnel in Haemophilus influenzae required to form a functional multidrug efflux pump. The outer-membrane protein was expressed in Escherichia coli, purified and reconstituted in black lipid membranes. It exhibited a comparatively small single-channel conductance of 43 pS in 1 M KCl and is the first known TolC homologue which is anion-selective. The HI1462 structure was modelled and an arginine residue lining the tunnel entrance was identified. The channel-tunnel of a mutant with the arginine substituted by an alanine residue was cation-selective and had a sevenfold higher single-channel conductance compared to wild-type. These results confirm that the arginine is responsible for anion selectivity and forms a salt bridge with a glutamate residue of the adjacent monomer, establishing a circular network, which keeps the tunnel entrance in a tightly closed conformation. In in vivo experiments, both the wild-type HI1462 and the mutant were able to substitute for E. coli TolC in the haemolysin secretion system, but not in the AcrAB/TolC multidrug efflux pump. The structure–function relationship of HI1462 is discussed in the context of the well-studied TolC channel-tunnel of E. coli.
NEW DEVICE TO PERFORM COAGULATION AND IRRIGATION SIMULTANEOUSLY DURING ENDOSCOPIC SUBMUCOSAL DISSECTION USING AN INSULATION‐TIPPED ELECTROSURGICAL KNIFE
Authors: Kume Keiichiro , Yamasaki Masahiro , Yoshikawa Ichiro , Otsuki Makoto
Published: May 2006

Background:  Although bleeding is an unavoidable complication of endoscopic submucosal dissection (ESD), endoscopic hemostasis using an insulation‐tipped electrosurgical knife (IT) knife is impossible because an insulator is mounted at the tip of the knife. We have developed a new type of hood which could perform both coagulation and irrigation simultaneously.

Methods:  Our new device was fabricated by drilling a side hole in the cap portion of a conventional transparent hood followed by attaching a machined papillotomy knife to the exterior surface of the hole.

Results:  Our new hood was useful for hemorrhage during ESD using IT knife.

Conclusions:  With this method, endoscopic hemostasis using IT knife is easy, as hemostatic procedure can be performed under irrigation and coagulation using conventional endoscopy.
VALUE OF COMPUTED TOMOGRAPHY FOR EVALUATING THE INJECTION SITE IN ENDOSONOGRAPHY‐GUIDED CELIAC PLEXUS NEUROLYSIS
Authors: Sakamoto Hiroki , Kitano Masayuki , Nishio Takeshi , Takeyama Yoshifumi , Yasuda Chikao , Kudo Masatoshi
Published: May 2006

Endosonography‐guided celiac plexus neurolysis (EUS‐CPN) safely and effectively relieves pain associated with intra‐abdominal malignancies when the neurolytic is accurately injected. We applied contrast medium to evaluate the ethanol injection sites in patients who received EUS‐CPN due to abdominal pain caused by malignancies. We injected, under the guidance of endoscopic ultrasonography (EUS), ethanol containing 10% contrast medium into the celiac plexus of patients with intra‐abdominal pain due to malignancies. Immediately after the endoscopic therapy, patients underwent computed tomography (CT) to confirm the injection site. Images of distribution of injected solutions were classified into three groups. Injected solution dispersed in unilateral and bilateral anterocrural space was defined as ‘unilateral injection’ or ‘bilateral injection’, respectively. Injected solution located out of the anterocrural space was defined as ‘inappropriate injection’. Pre‐ and postprocedure pain was assessed using a standard analog scale. Before and 2, 4, 8, 12, and 16 weeks after the procedure, pain scores were evaluated. From April 2003 to May 2005, 13 patients were enrolled in this study. Improvement of pain score in the ‘bilateral injection’ and ‘unilateral injection’ groups was significantly superior to the change in the ‘inappropriate injection’ group. Although EUS‐CPN was effective in eight of 13 patients (61.5%), additional EUS‐CPN to the ‘inappropriate injection group’ increased the response rate to 84.6%. Injection of ethanol to the anterocrural space by EUS‐CPN produced adequate pain relief. Immediate examination by CT for confirmation of injection sites after EUS‐CPN would increase the likelihood of induction of pain relief.
The differentiation of Stegastes partitus populations using lapillar and sagittal otolith chemistry
Authors: Chittaro P. M. , Gagnon J. , Fryer B. J.
Published: May 2006

The comparison of elemental concentrations of sagittal and lapillar otoliths from the same individuals of Stegastes partitus indicated significant differences for several elements. Sagittal otoliths were superior at differentiating individuals, yet the differentiation of individuals was further improved when the elemental concentrations of both otolith types were used in the same analysis.
Cloning and characterization of the homologous genes of firefly luciferase in the mealworm beetle, Tenebrio molitor
Authors: Oba Y. , Sato M. , Inouye S.
Published: May 2006

Three homologous genes of firefly luciferase were cloned from the non‐luminous beetle Tenebrio molitor. Three gene products for homologues, TmLL‐1, TmLL‐2 and TmLL‐3, showed fatty acyl‐coenzyme A (acyl‐CoA) synthetic activity, but not luciferase activity with firefly luciferin. The transcripts were detected through the developmental stages in T. molitor. These results suggested that firefly luciferase was evolved from a fatty acyl‐coenzyme A synthetase by gene duplications in the insect.
The rapid divergence of the ecdysone receptor is a synapomorphy for Mecopterida that clarifies the Strepsiptera problem
Authors: Bonneton F. , Brunet F. G. , Kathirithamby J. , Laudet V.
Published: May 2006

In arthropods, the regulation by ecdysteroids is mediated by the heterodimer between the ecdysone receptor (ECR; NR1H1) and ultraspiracle (USP/RXR; NR2B4) nuclear receptors. Both ECR and USP/RXR ligand‐binding domains experienced a strong acceleration of evolutionary rate in Diptera and Lepidoptera, which belong to the superorder Mecopterida. We performed a phylogenetic analysis of 28 ECR and 30 USP/RXR protein sequences from 36 arthropod species, including representatives from Trichoptera, Mecoptera and Siphonaptera. Our data show that the acceleration of ECR and USP/RXR was a unique event in the ancestor of Mecopterida. Our analysis shows further that Strepsiptera ECR and USP/RXR sequences are unambiguously placed outside of the Mecopterida clade. Protein alignments reveal that eight of 11 synapomorphies support an affinity between Strepsiptera and Coleoptera sequences. The affiliation of Strepsiptera to Diptera should therefore be rejected.
Vulnerable patients with a fractured neck of femur: nutritional status and support in hospital
Authors: Nematy M. , Hickson M. , Brynes A.E. , Ruxton C.H.S. , Frost G.S.
Published: May 2006

Background and aim  Malnutrition has serious consequences for recovery and increases the risk of complications in hospital patients. Fractured neck of femur (NOF) patients may be particularly at risk because of their old age and frail state of health. We conducted an observational study to evaluate the nutritional state and the nutritional support, which was provided to this group during their stay in hospital.

Methods  Twenty‐five consecutive people admitted to an orthopaedic ward with a fractured NOF at Charing Cross Hospital, London were recruited. Anthropometric measures, biochemical indices, 3 days dietary intake and dietetic referral rates were collected.

Results  Patients had a significantly lower body mass index (BMI) compared with the mean BMI for sex and age in an elderly UK population (21.97 ± 1.06 versus 26.73 ± 0.03 kg m−2; P < 0.005). They took just 58.6% of their energy requirements in hospital (4219 ± 319 versus 7199 ± 202 kJ mean−1 daily intake over 3 days in week 2). Using the hospitals own nutritional risk assessment tool 56% of patients were found to be at risk of malnutrition on admission, which increased to 68% after 2–3 weeks. Of these 64% were referred to a dietitian and were given nutritional supplements. Nutritional assessment revealed that their nutritional status worsened during stay.

Conclusions  This group of patients with fractured NOF is likely to be malnourished on admission and to show a rapid deterioration in its nutrition status during admission. Energy needs were not met in up to 50% of patients. These results reinforce the need to screen, supplement and monitor fractured NOF patients.
Culture Medium and Protein Supplementation in the Generation and Maturation of Dendritic Cells
Authors: Royer P.‐J. , Tanguy‐Royer S. , Ebstein F. , Sapede C. , Simon T. , Barbieux I. , Oger R. , Gregoire M.
Published: May 2006

Dendritic cells (DC) are powerful antigen‐presenting cells that have drawn many attentions due to the recent development of anti‐cancer vaccines. Clinical grade production of monocyte‐derived DC (Mo‐DC) is extensively studied, and many efforts are made to develop and improve clinical standard operating procedures. Most of the parameters involved, such as the cytokines and maturation agents, have been widely assessed. However, very few are investigated about how culture medium and additional protein components affect DC yield, viability and maturation. Thus, our study aimed to compare the impact of standard culture medium on Mo‐DC differentiation and maturation. Commercially available media for hematopoietic cell culture as well as different protein supplementations, that is foetal calf serum (FCS), autologous plasma (AP), human serum (HS) and human serum albumin (HSA) were tested. Culture yields, cell viability and DC maturation were investigated. Differentiation yields were similar between the conditions used. However, we evidenced significant differences in terms of cytotoxicity and DC maturation (phenotypic and functional). This underscores the importance of defining culture medium composition in clinical standard operating procedures to insure quality control, and also when preparing DC for experimental uses.
Early detection and chemoprevention of lung cancer
Authors: SHAIPANICH Tawimas , MCWILLIAMS Annette , LAM Stephen
Published: May 2006

Abstract:  Lung cancer is the most common cause of cancer death worldwide with more than 1.3 million people dying of the disease annually. While antitobacco initiatives in young people are important in preventing lung cancer in the long term, additional measures such as early detection and chemoprevention are needed for individuals already at risk due to past exposure to tobacco smoke. This review highlights the potential use of sputum, exhaled breath and blood biomarkers as well as thoracic CT and autofluorescence bronchoscopy for early detection. The current status of chemoprevention is summarized. The case for using a two‐step screening strategy is also discussed.
FAMILY STUDY SHOWING A CLOSE ASSOCIATION OF HLA DPB1*0202/0901 WITH ULCERATIVE COLITIS
Authors: Furukawa Hiroo , Morichi Hisako , Moriyasu Takayuki , Nishimura Tomomi , Ohmori Yasushi , Hiratsuka Takuya , Saiga Tatsuyoshi
Published: May 2006

Genetic disposition and environmental factors are closely related to the occurrence of ulcerative colitis (UC). The HLA haplotypes of major histocompatibility complex (MHC) Class II are considered to be the most important genetic factors in UC. The current report focuses on the genetic human leukocyte antigen (HLA) of a family in which UC crises have occurred in five of six members with identical MHC Class II haplotypes. Haplotypes A24/26 (A24/‐), BW4/6 (BW4/‐) and DQ1/3 (DQ1/‐) were found in all six members of the family. In DNA typing, characteristic loci common to this family were seen in DRB11502 and DQB10601. From the genetic investigation of this family, we concluded that HLA haplotypes are the most important genetic factors in the occurrence of UC.
Islamic Perspectives on Management and Organization – Abbas J. Ali
Authors: Vinten Gerald
Published: May 2006

Book reviewed:

Islamic Perspectives on Management and Organization, Abbas J. Ali, Edward Elgar 2005 (1‐84376‐766‐X), x + 260 pp., hb £59.95
Seeds of the Word: Orthodox Thinking on Other Religions – John Garvey
Authors: Lohr Christy
Published: May 2006

Book reviewed:

Seeds of the Word: Orthodox Thinking on Other Religions, John Garvey, St. Vladimir’s Seminary Press 2005 (0‐88141‐300‐3), 130 pp., pb $9.95
Laparoscopic‐Assisted Cystotomy for Urolith Removal in Geldings
Authors: RÖCKEN MICHAEL , STEHLE CHRISTIANE , MOSEL GESINE , RASS JULIA , LITZKE LUTZ F.
Published: May 2006

Objective—To describe a technique for laparoscopic‐assisted removal of cystic calculi in geldings and report outcome.

Study Design—Clinical report.

Animals—Four geldings with cystic calculi.

Methods—Laparoscopic‐assisted cystotomy and urolith retrieval was performed in 4 anesthetized geldings positioned in dorsal recumbency. With a laparoscope portal located at the umbilicus, the abdomen was insufflated and then the surgical table was tilted (30° head‐down position) before an instrumental portal was created parallel and 2–3 cm medial to the left external inguinal ring. Laparoscopic grasping forceps were inserted to grasp the cranial aspect of the bladder and elevate it to the ventral abdominal wall. With the instrumental portal as mid‐point, the parainguinal skin incision was longitudinally extended cranial and caudal (∼8–10 cm) to accommodate the size of the urolith. The apex of the bladder was exteriorized and sharply incised, the urolith extracted, and after cystotomy closure, the bladder was repositioned. The mini‐laparotomy and trocar incisions were closed in layers.

Results—There were no intra‐ or post‐operative complications. All horses had minor incisional swelling for 3–4 days. No signs of abdominal or incisional pain were observed. Hematuria and slight stranguria occurred until the 3rd or 4th day. Surgical time (skin incision to skin closure) was 35–40 minutes. On long‐term follow‐up (up to 12 months) no recurrence of clinical signs associated with cystic calculi occurred.

Conclusion—Uroliths (6–8 cm diameter) can be removed by laparoscopic‐assisted cystotomy in geldings.

Clinical Relevance—Laparoscopic‐assisted cystotomy combines the advantages of the parainguinal laparocystotomy with laparoscopic technique for removal of cystic calculi while avoiding their disadvantages.
The Use of Landscape Chemical Cycles for Indexing the Health Risks of Toxic Elements and Radionuclides
Authors: McKone Thomas E. , Kastenberg William E. , Okrent David
Published: May 2006

Analysis of energy‐system impacts requires quantifications of short‐ and long‐term local, regional, and global modifications. This paper describes and illustrates an approach for assessing long‐term health risks due to dispersion of naturally occurring radionuclide series and chemical toxins by normal and altered landscape‐chemical cycles. Health hazards are expressed as dose factors which convert environmental concentrations into a corresponding dose field (organ doses in rad for radionuclides; daily intake for toxic elements). The dose field is translated into a population health risk. The external environment is modelled by considering the manner in which elements are distributed and mobilized within the earth system. The landscape prism is presented as a tool for visualizing and mapping toxic material cycles near the crustal surface. An approach is provided for dividing the landscape into a set of compartments consistent with patterns of element circulation observed in the global environment. We investigate the response of regional landscapes to increases of 238U, 226Ra, arsenic and lead in soil and groundwater. It is found that each decay series or element imposes a hazard by its behavior in the total environment that cannot be quantified by a simple measure of toxicity.
How China is Reorganizing the World Economy*
Authors: EICHENGREEN Barry , TONG Hui
Published: May 2006

We analyze the impact of China's integration into the global economy on other countries, Asian countries in particular. We first examine how the growth of China's exports is affecting the exports of other countries in Asia and the rest of the world. Our innovation is to distinguish exports of capital goods, consumer goods, and intermediates and to disaggregate textiles and consumer electronics, the most visible sectors where China's presence is felt. We next look to the impact of China on direct foreign investment flows. Here our innovation is to distinguish vertical and horizontal foreign direct investment (FDI) and to consider how they are affected by supply‐chain relationships. We then look more closely at factors influencing the articulation of these supply chains, the fragmentation of production, and the emerging international division of labor, focusing on two industries, electronics and autos, that exhibit very different responses. The results suggest that countries specializing in the production and export of components and raw materials feel positive effects from China's growth, while countries specializing in the production of consumer goods feel negative effects. Similarly, countries that compete with China for horizontal FDI find it more difficult to attract foreign investment as a result of that country's emergence, while countries that are potentially attractive destinations for vertical FDI find it easier to attract foreign investment as a result of trade links, especially in components and intermediates, that allow them to take advantage of supply chains involving their large and dynamically growing neighbor.
Environmental Consequences of Rising Energy Use in China*
Authors: McKIBBIN Warwick J.
Published: May 2006

China is already the world's third largest energy producer and second largest energy consumer accounting for 10 percent of global energy use. This share is expected to rise to 15 percent by 2025. Energy use in China has important environmental consequences which are explored in this paper. A range of policy options are also discussed. It is argued that each major environmental issue requires a policy response that is a mix of direct government intervention as well as market based incentives. In coming decades, the choices made by China of how to tackle the environmental consequences of expanding energy use will have important implications for China, Asia and the world.
Surface Deformation and Convection in Electrostatically-Positioned Droplets of Immiscible Liquids Under Microgravity
Authors: Huo Y. , Li B. Q.
Published: May 2006

A numerical study is presented of the free surface deformation and Marangoni convection in immiscible droplets positioned by an electrostatic field and heated by laser beams under microgravity. The boundary element and the weighted residuals methods are applied to iteratively solve for the electric field distribution and for the unknown free surface shapes, while the Galerkin finite element method for the thermal and fluid flow field in both the transient and steady states. Results show that the inner interface demarking the two immiscible fluids in an electrically conducting droplet maintains its sphericity in microgravity. The free surface of the droplet, however, deforms into an oval shape in an electric field, owing to the pulling action of the normal component of the Maxwell stress. The thermal and fluid flow distributions are rather complex in an immiscible droplet, with conduction being the main mechanism for the thermal transport. The non-uniform temperature along the free surface induces the flow in the outer layer, whereas the competition between the interfacial surface tension gradient and the inertia force in the outer layer is responsible for the flows in the inner core and near the immiscible interface. As the droplet cools into an undercooled state, surface radiation causes a reversal of the surface temperature gradients along the free surface, which in turn reverses the surface tension driven flow in the outer layer. The flow near the interfacial region, on the other hand, is driven by a complimentary mechanism between the interfacial and the inertia forces during the time when the thermal gradient on the free surface has been reversed while that on the interface has not yet. After the completion of the interfacial thermal gradient reversal, however, the interfacial flows are largely driven by the inertia forces of the outer layer fluid.
Numerical Simulation of Flow Field and Heat Transfer of Streamlined Cylinders in Cross Flow
Authors: Li Zhihua , Davidson Jane H. , Mantell Susan C.
Published: May 2006

The drag and convective heat transfer coefficients along the outer surface of lenticular and elliptical tubes with minor-to-major axis ratios of 0.3, 0.5, and 0.8 were determined numerically for cross-flow Reynolds numbers from 500 to 104. The two-dimensional, unsteady Navier-Stokes equations and energy equation were solved using the finite volume method. Laminar flow was assumed from the front stagnation point up to the point of separation. Turbulent flow in the wake was resolved using the shear stress transport k-ω model. Local heat transfer, pressure and friction coefficients as well as the total drag coefficient and average Nusselt number are presented. The results for streamlined tubes are compared to published data for circular and elliptical cylinders. Drag of the elliptical and lenticular cylinders is similar and lower than a circular cylinder. Drag can be reduced by making the streamlined cylinders more slender. Drag is relatively insensitive to Reynolds number over the range studied. An elliptical cylinder with an axis ratio equal to 0.5 reduces pressure drop by 30–40% compared to that of a circular cylinder. The Nusselt numbers of lenticular and elliptical cylinders are comparable. The average Nusselt number of an elliptical or lenticular cylinder with axis ratio of 0.5 and 0.3 is 15–35% lower than that of a circular cylinder.
Film-Cooling Efficiency in a Laval Nozzle Under Conditions of High Freestream Turbulence
Authors: Lebedev Valery P. , Lemanov Vadim V. , Terekhov Victor I.
Published: May 2006

In the present work we experimentally examined the effect of enhanced freestream turbulence on the film-cooling efficiency in an axisymmetric supersonic nozzle. A considerable reduction in the film-cooling efficiency was observed with increasing level of flow turbulence, both in the subsonic and supersonic parts of the Laval nozzle. For instance, an increase in the freestream turbulence number from 0.2% to 15% resulted in more than twofold deterioration of film-cooling efficiency. A similar decrease of film-cooling efficiency was also observed under off-design flow conditions. At the same time, the increase in the freestream turbulence number had almost no effect on the recovery factor and on the distribution of static pressure over the length of the nozzle. The Kutateladze-Leont'ev asymptotic theory of gas cooling films was used to generalize the experimental data for nozzle flows with allowance for flow nonisothermality, compressibility, longitudinal pressure gradient, and high freestream turbulence number.
Soret and Dufour Effects in a Non-Darcy Porous Medium
Authors: Partha M. K. , Murthy P. V. S. N. , Raja Sekhar G. P.
Published: May 2006

The effect of double dispersion on free convection heat and mass transfer from a vertical surface embedded in a non-Darcy electrically conducting fluid saturated porous medium with Soret and Dufour effects is studied using similarity solution technique. The heat and mass transfer coefficients are effected greatly due to these secondary effects and also due to the complex interaction among the dispersion parameters Raγ,Raξ, and Lewis number Le and buoyancy ratio N. In both aiding and opposing buoyancies, Df and Sr have significant influence on the Nusselt and Sherwood numbers in the presence and absence of thermal and solutal dispersion in the medium. It is also observed that the magnetic field parameter lowered heat and mass transfer coefficients. The results are presented through comparison tables and plots.
Thermodynamics of Void Fraction in Saturated Flow Boiling
Authors: Collado Francisco J. , Monné Carlos , Pascau Antonio , Fuster Daniel , Medrano Andrés
Published: May 2006

Recently, Collado (Proc, IMECE 2001, Symposium on Fluid Physics and Heat Transfer for Macro- and Micro-Scale Gas-Liquid and Phase Change Flows) suggested calculating void fraction, an essential element in thermal-hydraulics, working with the “thermodynamic” quality instead of the usual “flow” quality. The “thermodynamic” quality is a state variable, which has a direct relation with the actual vapor volumetric fraction, or void fraction, through phase densities. This approach provides a procedure for predicting void fraction, if values of “thermodynamic” quality are available. However, the standard heat balance is usually stated as a function of the “flow” quality. Therefore, we should search for a new heat balance between the mixture enthalpy, based on “thermodynamic” quality, and the absorbed heat. This paper presents the results of such analysis based on the accurate measurements of the outlet void fraction measured during the Cambridge project by Knights (1960, “A Study of Two-Phase Pressure Drop and Density Determination in a High-Pressure Steam-Water Circuit,” Ph.D. thesis, Cambridge University Engineering Lab, Cambridge, UK) in the 1960s for saturated flow boiling. In the 286 tests analyzed, the pressure and mass fluxes range from 1.72 MPa to 14.48 MPa and from 561.4 to 1833.33 kgm−2s−1, respectively. As the main result, we find that the slip ratio would close this new thermodynamic heat balance. This has allowed the accurate calculation of void fraction from this balance, provided we can predict the slip ratio. Finally, the strong connection of this new thermodynamic heat balance with the standard one through the slip ratio is highlighted.
Pattern of Interhemispheric Synchronization in HVc During Singing Correlates With Key Transitions in the Song Pattern
Authors: Schmidt Marc F.
Published: May 2006

Many complex voluntary behaviors require that motor commands be tightly coordinated between cerebral hemispheres. The neural mechanisms underlying such coordination, however, remain poorly understood. Song production in birds is a highly stereotyped learned motor behavior that requires finely tuned coordination between hemispheres. In the present study, neural activity was recorded simultaneously from the song control nucleus HVc in each hemisphere of singing adult male zebra finches ( Taeniopygia guttata). In all cases, the pattern of recorded multiunit activity in each hemisphere was highly correlated during short segments of the song motor pattern. These correlated segments often consisted of multiple short bursts of activity. Because of the absence of interhemispheric connections between song control nuclei, these observations suggest that HVc activity is “synchronized” by common inputs to both hemispheres. Using sliding-window cross-covariance analyses, periods of high interhemispheric synchronization were found to be time-locked to the acoustic onset of syllables and notes. In some cases, precisely synchronized bursts in both hemispheres were also observed during periods associated with the intersyllable silent interval. In all cases, activity was correlated between hemispheres independently of the recording site, suggesting that all regions of HVc may be globally synchronized during these short segments of the song. Given the anatomical organization of the song system, inputs originating from either thalamus or midbrain are proposed to act as timing signals that initiate and synchronize intrinsic motor networks within each HVc thus allowing for the precise coordination of motor commands across hemispheres.
Limb Position Drift: Implications for Control of Posture and Movement
Authors: Brown Liana E. , Rosenbaum David A. , Sainburg Robert L.
Published: May 2006

In the absence of visual feedback, subject reports of hand location tend to drift over time. Such drift has been attributed to a gradual reduction in the usefulness of proprioception to signal limb position. If this account is correct, drift should degrade the accuracy of movement distance and direction over a series of movements made without visual feedback. To test this hypothesis, we asked participants to perform six series of 75 repetitive movements from a visible start location to a visible target, in time with a regular, audible tone. Fingertip position feedback was given by a cursor during the first five trials in the series. Feedback was then removed, and participants were to continue on pace for the next 70 trials. Movements were made in two directions (30° and 120°) from each of three start locations (initial shoulder angles of 30°, 40°, 50°, and initial elbow angles of 90°). Over the 70 trials, the start location of each movement drifted, on average, 8 cm away from the initial start location. This drift varied systematically with movement direction, indicating that drift is related to movement production. However, despite these dramatic changes in hand position and joint configuration, movement distance and direction remained relatively constant. Inverse dynamics analysis revealed that movement preservation was accompanied by substantial modification of joint muscle torque. These results suggest that proprioception continues to be a reliable source of limb position information after prolonged time without vision, but that this information is used differently for maintaining limb position and for specifying movement trajectory.