bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance‐driven muscle‐based facial animation
Authors: Choe Byoungwon , Lee Hanook , Ko Hyeong‐Seok
Published: January 2005

We describe a system to synthesize facial expressions by editing captured performances. For this purpose, we use the actuation of expression muscles to control facial expressions. We note that there have been numerous algorithms already developed for editing gross body motion. While the joint angle has direct effect on the configuration of the gross body, the muscle actuation has to go through a complicated mechanism to produce facial expressions. Therefore,we devote a significant part of this paper to establishing the relationship between muscle actuation and facial surface deformation. We model the skin surface using the finite element method to simulate the deformation caused by expression muscles. Then, we implement the inverse relationship, muscle actuation parameter estimation, to find the muscle actuation values from the trajectories of the markers on the performer's face. Once the forward and inverse relationships are established, retargeting or editing a performance becomes an easy job. We apply the original performance data to different facial models with equivalent muscle structures, to produce similar expressions. We also produce novel expressions by deforming the original data curves of muscle actuation to satisfy the key‐frame constraints imposed by animators.Copyright © 2001 John Wiley & Sons, Ltd.
Animating radiosity environments through the Multi‐Frame Lighting Method
Authors: Besuievsky Gonzalo , Pueyo Xavier
Published: January 2005

Realistic rendering animation is known to be an expensive processing task when physically based global illumination methods are used in order to improve illumination details. This paper presents the Multi‐Frame Lighting Method, an efficient algorithm to compute animations in radiosity environments. The method, based on global Monte Carlo techniques, performs the lighting simulation of groups of consecutive frames in a single process. All frames computed have the same accuracy as if they were computed independently while a significant high speed‐up is achieved. Results show that the method it is an interesting alternative for computing non‐interactive radiosity animations for moderately complex scenarios. Copyright © 2001 John Wiley &Sons, Ltd.
Multilayer garments using isosurfaces and physics
Authors: Rudomín Isaac , Pérez‐Urbiola Roberto , Elena Melón Maria , Luis Castillo Jose
Published: January 2005

This article extends our previously published technique that allows several layers of clothing to be placed and animated over an articulated character by using implicit ellipsoidal muscles to generate a scalar field and placing each layer of clothing on a separate isosurface, thereby avoiding the use of any collision detection calculations between the different layers. The method is first extended to a class of characters that include a surface skin generated by a commercial animation package. A second extension combines isosurface placement with physically based methods. These extensions afford increased realism while retaining the performance obtained by using isosurfaces. Copyright © 2001 John Wiley & Sons, Ltd.
Numerical simulations of photon transport inside a beam guide
Authors: Sánchez Héctor Jorge , Valentinuzzi María Cecilia
Published: January 2005

This paper presents a mathematical model based on actual experimental parameters to study the behavior of beam guides for TXRF under different conditions. The model is based on numerical simulation of photon transport inside beam guides. A brief description of these devices is given and the mathematical model for simulation is explained. Different kinds of beam guides in several configurations are analyzed and the intensity of the transmitted photons is studied as a function of several experimental parameters. By means of this model, the working principles of beam guides and their range of application could be studied, showing that they are suitable tools for XRF experiments. The calculations show a uniform distribution of photons on the sample area, a wide range of incident angles for operation, a good level of excitation in total reflection conditions and other relevant results. Finally, a comparison of the calculated values with preliminary experimental results is presented. Copyright © 2005 John Wiley & Sons, Ltd.
How do deer affect tree seedlings on a dwarf bamboo‐dominated forest floor?
Authors: Itô Hiroki , Hino Teruaki
Published: January 2005

A field experiment was conducted in Mt. Ôdaigahara, west‐central Japan, to reveal the effects of two herbivores, Sika deer (Cervus nippon) and mice (Apodemus spp.), on the seedlings of five cohorts of three tree species, Abies homolepis, Fraxinus lanuginosa f. serrata and Fagus crenata. The forest floor of the study site was covered with dwarf bamboo, Sasa nipponica, which would also affect the seedlings. Eight combinations of three treatments were set: exclusion of deer, exclusion of mice and removal of dwarf bamboo. Deer were expected to affect the seedlings not only negatively by foraging but also positively by browsing dwarf bamboo that overshadows seedlings. The survival of these cohorts was analyzed by survival analysis and the differences in their survival between the treatments were investigated. The results of the experiment showed that: (1) exclusion of deer increased the aboveground biomass of dwarf bamboo and made it more difficult for seedlings to survive under the regenerated dwarf bamboo stand, and (2) deer negatively affected the seedlings, but they had positive, indirect effects in some cohorts by decreasing the aboveground biomass of dwarf bamboo. However, such effects were not detected in some cohorts which were affected excessively by deer or dwarf bamboo. No clear results on the effect of mice on seedlings were obtained. We conclude that a positive, indirect effect of deer on seedling survivorship would be observable when the magnitude of a positive, indirect effect caused by decreasing dwarf bamboo is larger than that of a negative, direct effect of deer.
Isolation and the stress of being bullied
Authors: Newman Matthew L. , Holden George W. , Delville Yvon
Published: January 2005

Approximately one‐third of children report being victims of bullying, and this victimization has been linked to a number of negative psychological outcomes. In the present study, we examined the effects of perceived isolation on the link between victimization before and during high school and stress symptoms during college. Consistent with our predictions, victimization appears to do the most damage to those who felt isolated during high school. These results suggest that schools should reframe their approach to the bullying problem, and devote more resources to helping students feel less isolated.
Effects of a small‐scale, very short‐term service‐learning experience on college students
Authors: Reed Virginia A. , Christian Jernstedt G. , Hawley Jill K. , Reber Emily S. , DuBois Courtney A.
Published: January 2005

This study examined the effects of a small‐scale, very short‐term (8–10 h) service‐learning experience on college undergraduates. Repeated measures analysis of variance indicated that students participating in this experience reported maintenance of their sense of social responsibility, an increased sense of the meaningfulness of college, and an increased likelihood of choosing a service‐related occupation, when compared to non‐participating matched counterparts. These findings provide support for the notion that minimally resource‐intensive service‐learning programs can provide students with some of the benefits of service‐learning that have been identified in longer, more intensive experiences.
Individual differences in adolescent health symptoms: the effects of gender and coping
Authors: Wilson Gregory S. , Pritchard Mary E. , Revalee Brian
Published: January 2005

Previous studies have suggested that adult men and women experience different types and severities of physical and psychological health symptoms. This study examined whether in the case of adolescents these reported gender differences in physical and psychological health symptoms could actually be the result of differences in coping styles. Five hundred and forty‐six adolescents were questioned on their coping styles and symptoms. We found gender differences in physical and psychological health symptoms (e.g. anger, depression, tension, negative moods), as well as in coping styles. We also found that the relation between health symptoms and coping varied significantly by gender. The results of this study suggest that doctors, school counselors and family therapists may want to take gender differences in coping styles into account when seeing adolescent patients for physical or psychological health symptoms, and find ways to help the adolescents cope more effectively with their stressors.
Adolescents’ experience with sex on the web: results from online focus groups
Authors: Cameron Kenzie A. , Salazar Laura F. , Bernhardt Jay M. , Burgess‐Whitman Nan , Wingood Gina M. , DiClemente Ralph J.
Published: January 2005

To discover adolescent Internet users’ experiences with, exposure to, and perceptions of sexually oriented websites (SOW) and sexually explicit websites (SEW), four web‐based focus groups () were conducted. Participants (ages 14–17) reported high levels of exposure to SEW and SOW, which was intentional for some and unsolicited for others. Female adolescents found SEW to be socially distasteful; some adolescent males avoided SEW while others were willing consumers. Participants believed exposure to SEW had no influence on them, and reported that their parents were unaware of what they view online. Future research should explore the effects of exposure to SEW and to SOW and mediating factors.
Identity development and alcohol consumption: current and retrospective self‐reports by college students
Authors: Bishop David I. , Weisgram Erica S. , Holleque Kristine M. , Lund Kecia E. , Wheeler‐Anderson Jenna R.
Published: January 2005

First‐year college students were asked to complete alcohol consumption and identity status questionnaires—currently and retrospectively. Trend analyses of the retrospective data and current data revealed somewhat similar inverse linear trends for identity status on absolute annual alcohol consumption. In both cases, identity sophistication was associated with lower levels of consumption. Of the students who reported an increase in consumption from the junior year of high school to the first year of college, those displaying progressive identity development reported a relatively lower increase in consumption than those displaying stable identity status. This difference approached the conventional level of significance. The implications of these findings are explored.
Age at puberty and father absence in a national probability sample
Authors: Bogaert Anthony F.
Published: January 2005

The relations between intactness of the parental unit (e.g., father absent at age 14) and pubertal timing in both men and women were examined in a US national probability sample. In both men and women, an absent father at age 14 predicted an earlier age of puberty (e.g., early menarche or voice change). There was little evidence that an absent mother or the presence of a stepfather, independent of a father's absence, was related to early puberty in either men or women. The results extend previous research and suggest that certain psychosocial factors (i.e., father absence) may affect growth and development in both adolescent girls and boys.
Comparing acceptance‐ and control‐based coping instructions on the cold‐pressor pain experiences of healthy men and women
Authors: Keogh Edmund , Bond Frank W. , Hanmer Ruth , Tilston Jackie
Published: January 2005

The current study reflects recent developments in psychotherapy by examining the effect of acceptance‐based coping instructions, when compared to the opposite, more control/distraction‐based instructions, on cold‐pressor pain. Since previous research indicates gender differences in how people cope with pain, we also sought to determine whether differences would be found between healthy men and women. As predicted, results indicated that women reported lower pain threshold and tolerance level than did men. Furthermore, the acceptance‐based instruction resulted in lower sensory pain reports when compared to the opposite instructions. Finally, for affective pain, acceptance instructions only benefited women. These results suggest that acceptance‐based coping may be particular useful in moderating the way in which individuals, especially women, cope with pain.
Pain‐related fear at the start of a new low back pain episode
Authors: Sieben Judith M. , Portegijs Piet J.M. , Vlaeyen Johan W.S. , Knottnerus J. André
Published: January 2005

Previous research supports the fear‐avoidance model in explaining chronic low back pain (LBP) disability. The aims of the present study were to determine: (1) whether fear‐avoidance model variables are associated already during acute stages of LBP and (2) whether (increases in) pain‐related fear are associated with other patient characteristics routinely assessed by the General Practitioner (GP).

General practice patients consulting because of a new episode of LBP completed questionnaires on pain‐related fear, avoidance, pain and disability. A sample of 247 acute LBP patients (median duration of current episode was 5 days) was collected. Significant associations were found between pain intensity, pain‐related fear, avoidance behaviour and disability, but correlations were generally modest. A strong association was found between pain and disability. Pain‐related fear was slightly higher in patients reporting low job satisfaction and in those taking bedrest.

These results suggest that the fear‐avoidance model as it was developed and tested in chronic LBP, might not entirely apply to acute LBP patients. Future research should focus on the transition from acute to chronic LBP and the shifts that take place between fear‐avoidance model associations.
Self‐organizing‐map‐based molecular signature representing the development of hepatocellular carcinoma
Authors: Iizuka Norio , Oka Masaaki , Yamada-Okabe Hisafumi , Mori Naohide , Tamesa Takao , Okada Toshimasa , Takemoto Norikazu , Sakamoto Kazuhiko , Hamada Kenji , Ishitsuka Hideo , Miyamoto Takanobu , Uchimura Shunji , Hamamoto Yoshihiko
Published: January 2005

Using high‐density oligonucleotide array, we comprehensively analyzed expression levels of 12 600 genes in 50 hepatocellular carcinoma (HCC) samples with positive hepatitis C virus (HCV) serology (well (G1), moderately (G2), and poorly (G3) differentiated tumors) and 11 non‐tumorous livers (L1 and L0) with and without HCV infection. We searched for discriminatory genes of transition (L0 vs. L1, L1 vs. G1, G1 vs. G2, G2 vs. G3) with a supervised learning method, and then arranged the samples by self‐organizing map (SOM) with the discriminatory gene sets. The SOM arranged the five clusters on a unique sigmoidal curve in the order L0, L1, G1, G2, and G3. The sample arrangement reproduced development‐related features of HCC such as p53 abnormality. Strikingly, G2 tumors without venous invasion were located closer to the G1 cluster, and most G2 tumors with venous invasion were located closer to the G3 cluster (P
= 0.001 by Fisher's exact test). Our present profiling data will serve as a framework to understand the relation between the development and dedifferentiation of HCC.
1.15 Å Crystal structure of the X. tropicalis Spred1 EVH1 domain suggests a fourth distinct peptide‐binding mechanism within the EVH1 family
Authors: Harmer Nicholas J. , Sivak Jeremy M. , Amaya Enrique , Blundell Tom L.
Published: January 2005

The recently described Spred protein family has been implicated in the modulation of receptor tyrosine kinase signalling. We report the crystal structure of the Enabled/vasodilator‐stimulated phosphoprotein homology‐1 (EVH1) domain from Xenopus tropicalis Spred1, solved to 1.15 Å resolution. This structure confirms that the Spred EVH1 adopts the pleckstrin‐homology fold, with a similar secondary structure to Enabled. A translation of one of the peptide‐binding groove β‐strands narrows this groove, whilst one end of the groove shows structural flexibility. We propose that Spred1 will bind peptides that are less proline‐rich than other EVH1 domains, with conformational changes indicating an induced fit.
Quaternary structure of LOV‐domain containing polypeptide of Arabidopsis FKF1 protein
Authors: Nakasako Masayoshi , Matsuoka Daisuke , Zikihara Kazunori , Tokutomi Satoru
Published: January 2005

Flavin‐binding, Kelch repeat, F‐box (FKF1) protein is a photoreceptor to regulate flowering of Arabidopsis. The protein has a light, oxygen and voltage (LOV)‐sensing domain binding a flavin mononucleotide. The photo‐activation of the domain is an indispensable step to initiate the cellular signaling for flowering. In the present study, a LOV‐containing polypeptide of FKF1 was prepared by an overexpression system, and the quaternary structure of it was studied by size exclusion chromatography and small‐angle X‐ray scattering. The apparent molecular weight from chromatography suggested a globular trimeric or an anisotropic‐shaped dimeric association of the polypeptide in solution. The scattering experiment demonstrated a dimeric association of the polypeptides with an elongated molecular shape displaying the radius of gyration of 27 Å and the maximum dimension of 94 Å. The molecular shape simulated from scattering profiles suggests an antiparallel association of the LOV domains in the dimer. Though the absorption spectrum of blue‐light irradiated polypeptide was stable in the photoactivated state for a long period, the scattering profiles showed very small changes between the dark and light conditions. Based on the homologies in the amino‐acid sequences and the scattering profiles, these results are discussed in connection with the structures and function of LOV domains of phototropin.
The T‐domain of cytosolic tRNAVal, an essential determinant for mitochondrial import
Authors: Laforest Marie-Josée , Delage Ludovic , Maréchal-Drouard Laurence
Published: January 2005

Import of tRNAs into plant mitochondria appears to be highly specific. We recently showed that the anticodon and the D‐domain sequences are essential determinants for tRNAVal import into tobacco cell mitochondria. To determine the minimal set of elements required to direct import of a cytosol‐specific tRNA species, tobacco cells were transformed with an Arabidopsis thaliana intron‐containing tRNAMet‐e gene carrying the D‐domain and the anticodon of a valine tRNA. Although well expressed and processed into tobacco cells, this mutated tRNA was shown to remain in the cytosol. Furthermore, a mutant tRNAVal carrying the T‐domain of the tRNAMet‐e, although still efficiently recognized by the valyl‐tRNA synthetase, is not imported into mitochondria. Altogether these results suggest that mutations affecting the core of a tRNA molecule also alter its import ability into plant mitochondria.
Genetically modified rice seeds accumulating GLP‐1 analogue stimulate insulin secretion from a mouse pancreatic beta‐cell line
Authors: Sugita Koichi , Endo-Kasahara Saori , Tada Yoshifumi , Lijun Yang , Yasuda Hiroshi , Hayashi Yuji , Jomori Takahito , Ebinuma Hiroyasu , Takaiwa Fumio
Published: January 2005

Glucagon‐like peptide‐1 (7‐36) amide (GLP‐1) is the most potent physiological insulinotropic hormone in humans. We produced large amounts of a GLP‐1 analogue, [Ser8, Gln26, Asp34]‐GLP‐1, which is resistant to trypsin‐digestion, as part of a chimeric rice seed storage protein, a 26 kDa globulin, in genetically modified rice seeds. Junction sites between GLP‐1 analogue and globulin were replaced by tryptic cleavage sites. The highest level of GLP‐1 analogue accumulation was ≈20–50 μg per seed. We found that GLP‐1 analogue derived from trypsin‐digested genetically modified rice seeds stimulated insulin secretion from a mouse pancreatic beta‐cell line, MIN6.
Selective involvement of members of the eukaryotic initiation factor 4E family in the infection of Arabidopsis thaliana by potyviruses
Authors: Sato Masanao , Nakahara Kenji , Yoshii Motoyasu , Ishikawa Masayuki , Uyeda Ichiro
Published: January 2005

Arabidopsis thaliana plants with mutations in the genes encoding eukaryotic initiation factor (eIF4E) or isoform of eIF4E (eIF(iso)4E) were tested for susceptibility to Clover yellow vein virus (ClYVV), a member of the genus Potyvirus. ClYVV accumulated in both inoculated and upper uninoculated leaves of mutant plants lacking eIF(iso)4E, but not in mutant plants lacking eIF4E. In contrast, Turnip mosaic virus (TuMV), another member of the genus Potyvirus, multiplied in mutant plants lacking eIF4E but not in mutant plants lacking eIF(iso)4E. These results suggest the selective involvement of members of the eIF4E family in infection by potyviruses.
A generic system for the Escherichia coli cell‐surface display of lipolytic enzymes
Authors: Becker Stefan , Theile Sebastian , Heppeler Nele , Michalczyk Anja , Wentzel Alexander , Wilhelm Susanne , Jaeger Karl-Erich , Kolmar Harald
Published: January 2005

EstA is an outer membrane‐anchored esterase from Pseudomonas aeruginosa. An inactive EstA variant was used as an anchoring motif for the Escherichia coli cell‐surface display of lipolytic enzymes. Flow cytometry analysis and measurement of lipase activity revealed that Bacillus subtilis lipase LipA, Fusarium solani pisi cutinase and one of the largest lipases presently known, namely Serratia marcescens lipase were all efficiently exported by the EstA autotransporter and also retained their lipolytic activities upon cell surface exposition. EstA provides a useful tool for surface display of lipases including variant libraries generated by directed evolution thereby enabling the identification of novel enzymes with interesting biological and biotechnological ramifications.
Inhibitory effects of anticancer peptide from Mercenaria on the BGC‐823 cells and several enzymes
Authors: Leng Bo , Liu Xiao-Dan , Chen Qing-Xi
Published: January 2005

An anti‐cancer peptide was purified from the Mercenaria (Meretrix meretrix Linnaeus) by the method of chromatography on Sephadex G‐25 and FPLC, and its molecular weight was determined to be 3147 Da by the way of MALDI‐TOF mass spectrum. The effects of this peptide on human gastric gland carcinoma cells (BGC‐823) and their cytoskeletal morphology were investigated. The results showed that the peptide could inhibit the proliferation of BGC‐823 cells and obviously destroy the skeletal structures of the cells. When the concentration of the peptide reached 4.0 μg/ml, the inhibition percentage of the cell growth was about 60%. The effects of this anticancer peptide on the activities of superoxide dismutase (SOD), alkaline phosphatase (ALP) and tyrosinase were studied. The results showed that the peptide activated ALP and SOD, but inhibit the tyrosinase activity. When the concentration of the peptide reached to 0.5 μg/ml, the relative activities of SOD, ALP and tyrosinase were determined to be 188.5%, 122.0% and 27.5%, respectively.
DLC‐1, a Rho GTPase‐activating protein with tumor suppressor function, is essential for embryonic development
Authors: Durkin Marian E. , Avner Miriam R. , Huh Chang-Goo , Yuan Bao-Zhu , Thorgeirsson Snorri S. , Popescu Nicholas C.
Published: January 2005

DLC‐1 (deleted in liver cancer 1) is a Rho GTPase‐activating protein that is able to inhibit cell growth and suppress tumorigenesis. We have used homologous recombination to inactivate the mouse DLC‐1 gene (Arhgap7). Mice heterozygous for the targeted allele were phenotypically normal, but homozygous mutant embryos did not survive beyond 10.5 days post coitum. Histological analysis revealed that DLC‐1−/− embryos had defects in the neural tube, brain, heart, and placenta. Cultured fibroblasts from DLC‐1‐deficient embryos displayed alterations in the organization of actin filaments and focal adhesions.
Denervation‐induced spatiotemporal upregulation of ephrin‐A2 in the mouse hippocampus after transections of the perforant path
Authors: Wang Yan , Ni Zi-Mei , Zhou Chang-Fu
Published: January 2005

Transections of the entorhinal afferent fibers to hippocampus, perforant path (PP), result in the denervation in specific hippocampal subregions, which is followed by a series of plastic events including axon sprouting and reactive synaptogenesis. Many growth‐associated molecules are thought to participate in these events. In the present study, we proved the upregulation of ephrin‐A2 in the denervated areas of the ipsilateral hippocampus following PP transections. Interestingly, when the elevation of ephrin‐A2 reached the maximum axon sprouting in the denervated areas almost finished, implying the possible inhibitory effect of ephrin‐A2 on sprouting. In addition, ephrin‐A2 expression was observed in synapses during reactive synaptogenesis, suggesting that this molecule might also be implicated in the formation and maturation of synapses in the denervated areas.
Cd2+‐ or Hg2+‐binding proteins can replace the Cu+‐chaperone Atx1 in delivering Cu+ to the secretory pathway in yeast
Authors: Morin Isabelle , Cuillel Martine , Lowe Jennifer , Crouzy Serge , Guillain Florent , Mintz Elisabeth
Published: January 2005

Copper delivery to Ccc2 – the Golgi Cu+‐ATPase – was investigated in vivo, replacing the Cu+‐chaperone Atx1 by various structural homologues in an atx1‐Δ yeast strain. Various proteins, displaying the same ferredoxin‐like fold and (M/L)(T/S)CXXC metal‐binding motif as Atx1 and known as Cu+‐, Cd2+‐ or Hg2+‐binding proteins were able to replace Atx1. Therefore, regardless of their original function, these proteins could all bind copper and transfer it to Ccc2, suggesting that Ccc2 is opportunistic and can interact with many different proteins to gain Cu+. The possible role of electrostatic potential surfaces in the docking of Ccc2 with these Atx1‐homologues is discussed.
Regulation of the amyloid precursor protein ectodomain shedding by the 5‐HT4 receptor and Epac
Authors: Robert Sylvain , Maillet Marjorie , Morel Eric , Launay Jean-Marie , Fischmeister Rodolphe , Mercken Luc , Lezoualc'h Frank
Published: January 2005

The serotonin 5‐hydroxytryptamine (5‐HT4) receptor is of potential interest for the treatment of Alzheimer's disease because it increases memory and learning. In this study, we investigated the effect of zinc metalloprotease inhibitors on the amyloid precursor protein (APP) processing induced by the serotonin 5‐HT4 receptor in vitro. We show that secretion of the non‐amyloidogenic form of APP, sAPPα induced by the 5‐HT4(e) receptor isoform was not due to a general boost of the constitutive secretory pathway but rather to its specific effect on α‐secretase activity. Although the h5‐HT4(e) receptor increased IP3 production, inhibition of PKC did not modify its effect on sAPPα secretion. In addition, we found that α secretase activity is regulated by the cAMP‐regulated guanine nucleotide exchange factor, Epac and the small GTPase Rac.
The yeast CLC chloride channel is proteolytically processed by the furin‐like protease Kex2p in the first extracellular loop
Authors: Wächter Andrea , Schwappach Blanche
Published: January 2005

CLC chloride channels are a family of channel proteins mediating chloride transport across the plasma membrane and intracellular membranes. The single yeast CLC protein Gef1p is localized to the Golgi and endosomal system. Investigating epitope‐tagged variants of Gef1p, we found that the channel is proteolytically processed in the secretory pathway. Proteolytic cleavage occurs in the first extracellular loop of the protein at residues KR136/137 and is carried out by the Kex2p protease. Fragments mimicking the N‐ and C‐terminal products of the cleavage reaction are non‐functional when expressed alone. However, functional channels can assemble when the two fragments are co‐expressed.
Crystal structure of the kainate receptor GluR5 ligand‐binding core in complex with (S)‐glutamate
Authors: Naur Peter , Vestergaard Bente , Skov Lars K. , Egebjerg Jan , Gajhede Michael , Kastrup Jette Sandholm
Published: January 2005

The X‐ray structure of the ligand‐binding core of the kainate receptor GluR5 (GluR5‐S1S2) in complex with (S)‐glutamate was determined to 1.95 Å resolution. The overall GluR5‐S1S2 structure comprises two domains and is similar to the related AMPA receptor GluR2‐S1S2J. (S)‐glutamate binds as in GluR2‐S1S2J. Distinct features are observed for Ser741, which stabilizes a highly coordinated network of water molecules and forms an interdomain bridge. The GluR5 complex exhibits a high degree of domain closure (26°) relative to apo GluR2‐S1S2J. In addition, GluR5‐S1S2 forms a novel dimer interface with a different arrangement of the two protomers compared to GluR2‐S1S2J.
No evidence for a forced‐unfolding mechanism during ATP/GroES binding to substrate‐bound GroEL: no observable protection of metastable Rubisco intermediate or GroEL‐bound Rubisco from tritium exchange
Authors: Park Eun Sun , Fenton Wayne A. , Horwich Arthur L.
Published: January 2005

In tritium–hydrogen exchange experiments, the large GroEL substrate Rubisco was unfolded and exchanged in urea/acid/tritiated water, then diluted into either protic buffer or protic buffer containing GroEL. The respective Rubisco metastable folding intermediate or Rubisco‐GroEL binary complex was then separated from residual tritium after varying times of exchange by centrifugation through P‐10 or G‐25 resin. No significant tritium was recovered in either case, in contrast to an earlier report. Thus, although the earlier‐proposed forced unfolding mechanism for the action of GroEL on a bound polypeptide, occurring during ATP/GroES binding, remains an attractive hypothesis, the data here do not provide any indication that it is involved in the folding of Rubisco.
Auxin‐induced reactive oxygen species production requires the activation of phosphatidylinositol 3‐kinase
Authors: Joo Jung Hee , Yoo Ho Jung , Hwang Inhwan , Lee June Seung , Nam Kyoung Hee , Bae Yun Soo
Published: January 2005

We recently reported that production of reactive oxygen species (ROS) is essential for auxin‐induced gravitropic signaling. Here, we investigated the role of phosphatidylinositol 3‐kinase and its product, PtdIns(3)P, in auxin‐mediated ROS production and the root gravitropic response. Pretreatment with LY294002, an inhibitor of PtdIns 3‐kinase activity, blocked auxin‐mediated ROS generation, and reduced the sensitivity of root tissue to gravistimulation. The amount of PtdIns(3)P increased in response to auxin, and this effect was abolished by pretreatment with LY294002. In addition, sequestration of PtdIns(3)P by transient expression of the endosome binding domain in protoplasts abrogated IAA‐induced ROS accumulation. These results indicate that activation of PtdIns 3‐kinase and its product PtdIns(3)P are required for auxin‐induced production of ROS and root gravitropism.
Auditory processing deficits in rats with neonatal hypoxic‐ischemic injury
Authors: McClure Melissa M. , Peiffer Ann M. , Rosen Glenn D. , Fitch R. Holly
Published: January 2005

Hypoxia‐ischemia (HI) refers to reduced blood oxygenation and/or a diminished amount of blood perfusing the brain, and is associated with premature birth/very low birth weight (VLBW). HI represents a common cause of injury to the perinatal brain. Indeed, a significant number of premature/VLBW infants go on to demonstrate cognitive/behavioral deficits, with particularly high incidence of disruptions in language development. Auditory processing deficits, in turn, have been suggested to play a causal role in the development of language impairments. Specifically, the inability to identify fast elements in speech is purported to exert cascading detrimental effects on phonological discrimination, processing, and identification. Based on this convergent evidence, the current studies address auditory processing evaluation in a rodent model of HI injury induced on postnatal days 1, 7, or 10 (which in turn is well accepted as modeling HI‐related injury to the perinatal human). Induced injuries were followed by a battery of auditory testing, and a spatial maze assessment, performed both during juvenile and adult periods. Results indicate that rats suffering from these early HI insults performed significantly worse than shams on tasks requiring rapid auditory processing, and on a test of spatial learning (Morris water maze (MWM)), although these effects were not seen on simpler versions of auditory tasks or on a water escape assessment (thus ruling out hearing/motor impairments). Correlations were found between performance on rapid auditory and spatial behavioral tasks and neuroanatomical measures for HI animals such as: the volume of the hippocampus, cerebral cortex, ventricles, and/or the area of the corpus callosum. Cumulative findings suggest that perinatal HI injury in the rat may lead to neurodevelopmental damage associated, in turn, with auditory processing and/or learning and memory impairments. As such, the current model may have critical implications for the study of neurophysiological underpinnings of cognitive deficits in premature/VLBW infants.
Prognostic significance of DNA quantification by flow cytometry in ovarian tumors
Authors: Kim Y.T. , Zhao M. , Kim S.H. , Lee C.S. , Kim J.H. , Kim J.W.
Published: January 2005

Objective

The objective of our study is to evaluate prognostic significance of DNA quantification by flow cytometry in ovarian tumor.

Methods

A prospective analysis was performed on 56 ovarian tumor patients treated in the Yonsei Medical Center from Feb. 2000 to Jan. 2003.

Results

Regarding the association between tumor grade and the DNA quantitative analysis, as tumor grade increased, the quantity of aneuploid cells and S‐phase fraction (SPF) increased. In addition, SPF was increased significantly in the advanced staged patients (P=0.04) and SPF was significantly increased in aneuploid tumors (P=0.03). The overall survival rate was poor for patients with aneuploid tumors and for patients with tumors showing over SPF (10%).

Conclusion

Our data demonstrated that the prognosis was poor for patients with aneuploid cancers or increased SPF. Therefore, DNA quantification by flow cytometry may provide important information for predicting the prognosis of the disease.
Mode of delivery and pelvic floor muscle strength and sexual function after childbirth
Authors: Baytur Y.B. , Deveci A. , Uyar Y. , Ozcakir H.T. , Kizilkaya S. , Caglar H.
Published: January 2005

Objective

To investigate the respective roles of the mode of delivery and strength of pelvic floor muscles in the sexual function of women.

Method

Thirty‐two women who were delivered vaginally and 21 women who underwent cesarean delivery at the Celal Bayar University School of Medicine Obstetrics Department were enrolled in the study, and 15 nulliparas were recruited as controls. Sexual function was assessed in all women by a validated questionnaire (the Female Sexual Function Index). Desire, arousal, lubrication, orgasm, satisfaction, and pain were measured separately, and pelvic floor muscle strength was assessed by a perineometer. Sexual function was compared among the 3 groups. The correlation between pelvic floor muscle strength and sexual function was also investigated.

Results

Pelvic floor muscle strength was significantly lower in the group vaginally delivered compared with the group delivered by cesarean section and the nulliparous group (P<0.05). There was no difference between the groups regarding sexual function (P>0.05), and there was also no correlation between sexual function and pelvic muscle strength.

Conclusion

Pelvic floor muscle strength and mode of delivery did not affect sexual function in our study participants. The muscular component of female sexual function should be further investigated.
Four cats with fungal rhinitis
Authors: Whitney Beth L , Broussard John , Stefanacci Joseph D
Published: January 2005

Fungal rhinitis is uncommon in the cat and cases of nasal aspergillosis–penicilliosis have been rarely reported. Signs of fungal rhinitis include epistaxis, sneezing, mucopurulent nasal discharge and exophthalmous. Brachycephalic feline breeds seem to be at increased risk for development of nasal aspergillosis–penicilliosis. Computed tomography (CT) imaging and rhinoscopy are useful in assessing the extent of the disease and in obtaining diagnostic samples. Fungal culture may lead to false negative or positive results and must be used in conjunction with other diagnostic tests. Serological testing was not useful in two cats tested. The cats in this study were treated with oral itraconazole therapy. When itraconazole therapy was discontinued prematurely, clinical signs recurred. Hepatotoxicosis is a possible sequel to itraconazole therapy.
Effects of moisture and temperature on the osteoinductivity of demineralized bone matrix
Authors: Han Bo , Yang Zhi , Nimni Marcel
Published: January 2005

Demineralized bone matrix (DBM) is a well established osteoinductive bone graft material. It has been mixed with a variety of carriers to adjust to different forms of handling for a variety of applications. The impact of the various carriers on osteoinductivity remains largely unknown. Using an in vitro cell culture assay and in vivo intramuscular implantations into nude rats, the effects of moisture from water‐based carriers and the storage temperature on osteoinductivity were studied. In the dry state, DBM can preserve its osteoinductive activity when temperatures reached 65 °C, but in the presence of moisture, the activity decreases with incubation time. Nearly 90% of the DBM activity is lost when maintained for 5 weeks at 65 °C. This study further indicates that the structure and stability of the collagen network in DBM not only provide a scaffold for osteogenitor cell proliferation and differentiation, but also controls the release rate of osteoinductive growth factors. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Global change, nitrification, and denitrification: A review
Authors: Barnard Romain , Leadley Paul W. , Hungate Bruce A.
Published: January 2005

We reviewed responses of nitrification, denitrification, and soil N2O efflux to elevated CO2, N availability, and temperature, based on published experimental results. We used meta‐analysis to estimate the magnitude of response of soil N2O emissions, nitrifying enzyme activity (NEA), denitrifying enzyme activity (DEA), and net and gross nitrification across experiments. We found no significant overall effect of elevated CO2 on N2O fluxes. DEA and NEA significantly decreased at elevated CO2; however, gross nitrification was not modified by elevated CO2, and net nitrification increased. The negative overall response of DEA to elevated CO2 was associated with decreased soil [NO3−], suggesting that reduced availability of electron acceptors may dominate the responses of denitrification to elevated CO2. N addition significantly increased field and laboratory N2O emissions, together with gross and net nitrification, but the effect of N addition on field N2O efflux was not correlated to the amount of N added. The effects of elevated temperature on DEA, NEA, and net nitrification were not significant: The small number of studies available stress the need for more warming experiments in the field. While N addition had large effects on measurements of nitrification and denitrification, the effects of elevated CO2 were less pronounced and more variable, suggesting that increased N deposition is likely to affect belowground N cycling with a magnitude of change that is much larger than that caused by elevated CO2.
Astrocytic Function Assessed from 1-14C-Acetate Metabolism after Temporary Focal Cerebral Ischemia in Rats
Authors: Thoren Anna E , Helps Stephen C , Nilsson Michael , Sims Neil R
Published: January 2005

Astrocytes play many roles essential for normal brain activity. The ability of these cells to recover after temporary focal cerebral ischemia is likely to be one important determinant of the extent of brain dysfunction and tissue damage. We have assessed astrocytic function based on the incorporation of radiolabel from 1-14C-acetate into glutamine at 1 hour of recirculation after middle cerebral artery occlusion for 2 or 3 hours in rats. There were marked differences in the response between subregions within the tissue subjected to ischemia, but the overall pattern of changes was similar after each ischemic period. The striatum, which forms part of the severely ischemic focal tissue during arterial occlusion, showed a large (44% to 68%) decrease in glutamine labeling compared with equivalent tissue from the contralateral hemisphere. In contrast, 14C-glutamine content was not significantly altered in perifocal tissue in the cerebral cortex, which was subjected to more moderate ischemia. Cortical focal tissue also was not significantly affected, but the response was much more variable between rats. In these brain subregions, the extent of recovery of the 14C-acetate metabolism after ischemia was not a good predictor of the likelihood of subsequent infarct development. Interestingly, a similar pattern of responses persisted when recirculation was extended to 4 hours. These results indicate that many astrocytes, particularly in the cortex, remain viable and capable of at least some complex oxidative metabolism during the first few hours of recirculation.
Wave packet dynamics of H2(v1=8–14)+H2(v2=–2): The role of the potential energy surface on different reactive and dissociative processes
Authors: Bartolomei Massimiliano , Hernández Marta I. , Campos-Martínez José
Published: January 2005

A time-dependent wave packet method has been used to study different competing products of H2+H2 collisions: four center reaction, collision induced dissociation, reactive dissociation, and three-body complex formation. A three-degree-of-freedom reduced dimensionality model has been used for five different geometries of the colliding complex (parallel H, crossed X, collinear L, and two T-shaped geometries TI and TII), with reactants in selected vibrational states with one diatom vibrationally “hot” and the other one vibrationally “cold.” Product probabilities have been calculated using two potential energy surfaces [J. Chem. Phys. 101, 4004 (1994); J. Chem. Phys. 116, 666 (2002)] in order to compare their performance in the dynamics. The regions of the potential energy surfaces responsible of the threshold behavior of the probabilities have been identified. Overall, we have found that the most recent potential energy surface is less anisotropic, provides a smaller propensity for insertion-type processes, and gives lower energy thresholds.
Achieving large magnetoresistance in Sr2FeMoO6 thin films
Authors: Song J. H. , Park J.-H. , Jeong Y. H.
Published: January 2005

In order to find a way to achieve large magnetoresistance in thin films of Sr2FeMoO6, structural, magnetic, and transport properties were systematically investigated for the films grown on SrTiO3 substrates under different conditions. Crystallinity, morphology, resistivity, and magnetization of the films depended sensitively on the growth temperature and post-anneal treatment. The film grown at 935°C and post-annealed at the same temperature for an hour displayed both large resistance and magnetoresistance; the low-field magnetoresistance, in particular, was as large as that of a polycrystalline bulk. Structural analysis revealed that the film possessed large grains, and the large magnetoresistance is accounted for in terms of spin-polarized tunneling between these grains.
Effect of particle geometry on phase transitions in two-dimensional liquid crystals
Authors: Martínez-Ratón Yuri , Velasco Enrique , Mederos Luis
Published: January 2005

Using a version of density-functional theory which combines Onsager approximation and fundamental-measure theory for spatially nonuniform phases, we have studied the phase diagram of freely rotating hard rectangles and hard discorectangles. We find profound differences in the phase behavior of these models, which can be attributed to their different packing properties. Interestingly, bimodal orientational distribution functions are found in the nematic phase of hard rectangles, which cause a certain degree of biaxial order, albeit metastable with respect to spatially ordered phases. This feature is absent in discorectangles, which always show unimodal behavior. This result may be relevant in the light of recent experimental results which have confirmed the existence of biaxial phases. We expect that some perturbation of the particle shapes (either a certain degree of polydispersity or even bimodal dispersity in the aspect ratios) may actually destabilize spatially ordered phases thereby stabilizing the biaxial phase.
High-temperature modeling and characterization of 6H silicon carbide metal-oxide-semiconductor field-effect transistors
Authors: Powell Stephen K. , Goldsman Neil , Lelis Aivars , McGarrity James M. , McLean Flynn B.
Published: January 2005

We expand upon previous work [S. K. Powell, N. Goldsman, J. M. McGarrity, J. Bernstein, C. J. Scozzie, and A. Lelis, J. Appl. Phys. 92, 4053 (2002)] by applying the device model to 6H silicon carbide metal-oxide-semiconductor field-effect transistors operating at high temperatures. We compare the model predictions with the device measurements from room temperature to 200 °C and find agreement.
Structure and electronic properties of zirconium and hafnium nitrides and oxynitrides
Authors: Bazhanov D. I. , Knizhnik A. A. , Safonov A. A. , Bagatur’yants A. A. , Stoker M. W. , Korkin A. A.
Published: January 2005

The atomic structure, stability and electronic properties of zirconium and hafnium nitrides and oxynitrides (MN, M3N4, and M2N2O; M=Zr, Hf) have been studied using first-principles density functional theory calculations. It is found that the orthorhombic Pnam structure of M3N4, which was observed experimentally for zirconium nitride, is more stable for this stoichiometry than the cubic spinel and rock-salt-type structures. The calculated band structures and electronic densities of states demonstrate that both the MN and M3N4 phases of zirconium and hafnium nitrides in the rock-salt-type structure are characterized by metallic properties, while the orthorhombic structure of the M3N4 phase exhibits an insulating behavior in agreement with experimental observations. The formation of nitrogen vacancies in the insulating M3N4 phase converts it into the metallic MN phase. Calculations of Zr2N2O and Hf2N2O in the cubic Bixbyite-type and hexagonal P3–ml crystal structures predict that these materials are insulators and that the Bixbyite-type structure found experimentally is lower in energy than the P3–ml phase.
Friction-induced nonequilibrium phase transformation of low-temperature ice
Authors: Liang H. , Martin J. M. , Le Mogne Th.
Published: January 2005

We used an ultrahigh vacuum chamber to form an ice layer, then conducted friction experiments at temperatures below 123K, a range much lower than previous experiments conducted in atmosphere environments. We found melting and vaporization induced by friction at temperatures below 145K. At such a low temperature, the liquid and vapor phases are not in equilibrium. Simple analysis indicated that such metastable phases are possible with sufficient mechanical energy through friction stimulation.
Monte Carlo investigation of current voltage and avalanche noise in GaN double-drift impact diodes
Authors: Reklaitis Antanas , Reggiani Lino
Published: January 2005

By Monte Carlo simulations, we investigate the current voltage characteristics and the current noise in GaN homojunction double-drift impact avalanche diodes. We have found that a suppression of avalanche noise from the standard excess noise factor starts when the dielectric relaxation time becomes comparable or less than the carrier transit time. The suppression reaches values down to three orders of magnitude when the current approaches the electrical breakdown regime. The negative feedback between fluctuations of the space charge and of the number of electron-hole pairs generated under avalanche conditions is found to be responsible for this giant suppression of noise.