bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of Airflow in Nozzle-ring Spinning using Computational Fluid Dynamics: Study on Reduction in Yarn Hairiness and the Role of Air Drag Forces and Angle of Impact of Air Current
Authors: Rengasamy R.S. , Patanaik Asis , Anandjiwala R.D.
Published: April 2008

In this paper we report on computational fluid dynamics (CFD) simulation of airflow inside the nozzles used in Nozzle-Ring spinning. Using the CFD, air velocities at different locations of the nozzle were obtained and then drag forces acting on hair and yarn were computed. Z-twisted carded cotton yarns were produced at ring spinning machine with and without placing nozzle. Three nozzles were used, each having air inlets at different axial angle. Using the results of simulation, the role of air drag forces and angle of impact of air current on reduction in yarn hairiness could be explained. Nozzle-Ring yarns had a lower number of S3-hairs than the regular ring yarn. The drag forces played a dominant role in reducing the hairs. The angle of air inlets controlled the impact angle of air on the hair. At very high impact angle, curving of protruding hair was bound to occur during its folding, signifying the difficulty in wrapping the hair over the yarn and, hence, a lower reduction in hairiness.
Influence of Pre-wetting on the Characteristics of a Sized Yarn
Authors: Sejri Nejib , Harzallah Omar , Viallier Prerre , Ben Amar Sami , Ben Nasrallah Sassi
Published: April 2008

The preparation of a warp yarn is a key element of the success of weaving. Under the economic pressure to which the world textile industry is subjected, an increased attention is given to the equipment, to the products and the processes used in the preparation of warp yarns for weaving. The yarn, the sizing equipment and the size must be adapted to each other, so powerful yarns able to resist the weaving requests with lower cost can be obtained. The aim of this work was the study of the mechanical behavior of sized yarns after a pre-wetting operation with hot water and the drying of these yarns on the sizing machine. First, we showed that the heat transfer coefficient was the same, no matter whether the yarn was pre-wetted or not. Pre-wetting did not decrease the production. However, despite containing less size, the yarn hairiness was reduced as compared to sizing without pre-wetting. The initial modulus of sized yarn with pre-wetting was higher than that of classically sized yarn and the sized yarn with this new technology of sizing presented a more important immediate recovery. Moreover, we studied the influence of a preliminary wetting on the structure of the size bridges between fibers by using scanning electron microscopy. Examination of the cross-section of sized yarn showed that if the yarn was pre-wetted, the bridges between fibers could be observed to a higher extent at the periphery of the yarn, which explained the good mechanical behavior.
Snippet Counting for Cotton Length Distribution Measurement Using Image Analysis
Authors: Weilin Xu  , Bugao Xu  , Wenbin Li  , Weigang Cui
Published: April 2008

This paper presents a new method of measuring the number-length distribution of cotton fibers using a snippet-counting method and image analysis techniques. The test samples were aligned at the baseline and combed to form a tuft web, or beard, which was cut into a number of segments of a specific length by a fiber cutter. The snippets in different cut segments were collected and distributed on separate black glossy papers, and then they were digitized and scanned in order into a computer for image analysis. The scanning order indicated the distance of each segment from the cutting baseline, and the number of the snippets on a glossy paper was the frequency of fibers present in the current segment. A specially designed image analysis program was used to trace all snippets in a scanned image, so that the number of snippets could be calculated. After all of the images were analyzed, the fiber numbers in different segments could be summarized, and from these number-length data the distribution, maximum length, mean length, and other fiber statistics could be derived.
Comparison of Test Methods for Measuring Water Vapor Permeability of Fabrics
Authors: Jianhua Huang  , Xiaoming Qian
Published: April 2008

There are a variety of test methods in use to measure the ability of fabrics to transport water vapor. They vary with respect to construction mechanisms, test conditions, and measurement parameters. Five testing instruments plus a new test apparatus were employed to evaluate the water vapor transport properties of fabrics with low, medium, and high vapor permeability. The test results show that the desiccant inverted cup method generated the highest water vapor transmission rate, followed by the new method, the dynamic moisture permeation cell (DMPC), the inverted cup method, and the upright cup method. The statistical analyses indicated that the new method is in good agreement with other standard test methods. Most of the correlations between any two of the methods are strong, except the upright cup method. The new test method offers a short test time and calls for a small sample size.
Relationships Between Recreation and Levels of Self-Determination for Adolescents and Young Adults With Disabilities
Authors: McGuire Jayne , McDonnell John
Published: April 2008

Self-determination continues to be a focus for secondary students who have intellectual disabilities. This study examined the relationship between recreation and self-determination for adolescents and young adults with intellectual disabilities. Students from secondary and post—high school special education programs tracked their involvement in recreation for a 2-week period. Then students were given the Arc's Self-Determination Scale. The results establish a predictive relationship between recreation and self-determination indicating that increased amounts of time adolescents and young adults spend actively involved in recreation were found to be predictive of higher levels of self-determination. The findings support that recreation may be a useful strategy for enhancing self-determination skills and that self-determination can be increased through experiences, not just through teaching explicit skills.
Agreement on Intimate Partner Violence Among a Sample of Blue-Collar Couples
Authors: Cunradi Carol B. , Bersamin Melina , Ames Genevieve
Published: April 2008

This study assessed agreement level about the occurrence of past-year male-to-female partner violence (MFPV) and female-to-male partner violence (FMPV) among a sample of 897 blue-collar couples. Intimate partner violence (IPV) was measured with the Physical Assault subscale of the revised Conflict Tactics Scales (CTS2). Agreement level was assessed with Cohen's kappa statistic. Lower-bound estimates (based on couple agreement that an IPV event occurred) and upper-bound estimates (based on uncorroborated reports from either partner that an IPV event occurred) were calculated. Results indicated low agreement for most IPV behaviors (κ < .40). Estimated lower- and upper-bound rates for MFPV were 6.7% and 21.2%, for FMPV, 7.1% and 24.2%, and for any IPV, 10.1% and 30.2%. Findings suggest that single-point IPV prevalence estimates are biased; lower- and upper-bound estimates using collateral reports should be calculated when possible. In addition, findings underscore the importance of conducting IPV research among understudied populations, such as working-class couples, that may be at elevated IPV risk.
Piercing The Bubble
Authors: Rosenbloom Al , Alejandro Cortes Juan
Published: April 2008

This article describes the current relationship between management education in Colombia and the efforts of the management program at Universidad Pontificia Bolivariana (UPB) in Medellín to reduce local poverty. The article uses the metaphor of “the bubble” to illustrate how social class, family socialization, and the current UPB management curriculum insulate management students from thinking about and interacting with the poor in Medellín. Based on the authors' experiences, five interventions are described that (a) integrate the issue of poverty more meaningfully throughout the management curriculum and (b) pierce this bubble within which UPB management expect to live their entire professional lives.
Affective Urbanism and the Event of Hope
Authors: Anderson Ben , Holden Adam
Published: April 2008

The article discusses how hope and hopefulness become part of the life of cities, drawing on a case study of cultural regeneration: the event of Liverpool receiving EU Capital of Culture status in June 2003. Through attention to the “eventness” of the event of “receiving Capital of Culture status” and the linked practices of urban regeneration, the article argues that the “European Capital of Culture” becomes part of the assemblages that compose Liverpool in three ways: as an advent, as a crystallization, and as a blank. Each of these registers involves the assembling of specific distributions of hope. Through this focus on the relation between the event and how hope takes place, the article explores an affective urbanism—that is, an urbanism animated by a conceptual vocabulary specific to the logics of affect and emotion.
Prompts and recasts: Differential effects on second language morphosyntax
Authors: Ammar Ahlem
Published: April 2008

The merits of recasts have been widely debated and investigated in and out of the language classroom. This quasi-experimental study examines the impact of recasts in comparison to prompts and no corrective feedback on francophone learners' acquisition of English third person possessive determiners. Sixty-four students from three intact intensive English as a second language classes carried out 11 communicative activities during which they received corrective feedback according to the condition they were assigned to. An oral picture-description task and a computerized fill-in-the-blank task that kept record of participants' latency to retrieve the correct forms were administered prior to the treatment and immediately after it ended. Four weeks later the oral picture description task was readministered. Analyses of individual participants' oral data revealed that prompts were more effective than recasts and no corrective feedback in helping learners move up to more advanced stages of a developmental possessive determiner scale. This was especially apparent for low-proficiency learners. Data from the computerized task showed that prompts allowed learners to retrieve possessive determiner knowledge faster than recasts.
Learning to self-assess oral performance in English: A longitudinal case study
Authors: Chen Yuh-Mei
Published: April 2008

This paper reports on a study that investigated students' learning to self-assess oral performance in English by comparing student assessment with teacher assessment. Twenty-eight Chinese students at a university in southern Taiwan participated in the study. The assessment program involved training, observation, evaluation, discussion, feedback, and response, including two weeks of training and 10 weeks of two-cycle assessment. The assessment components were developed by the teacher and students collaboratively during the first week. The criteria included four elements within a five-level scoring standard. Comparison between self- and teacher assessment was analyzed in terms of scores and comments given over two assessment cycles. Results showed that self- and teacher ratings differed significantly in the first cycle of assessment, but were closely aligned in the second. Comments generated by students themselves in the second cycle were more similar to the teacher's, becoming more positive and constructive. A majority of the students favored participation in assessment and considered self-assessment conducive to learning. This study demonstrated that through feedback and practice, participating students make significant progress in learning to assess their own oral performance and that inviting students to be assessment partners helps Chinese students achieve desired learning outcomes.
Attitudinal obstacles to curriculum and assessment reform
Authors: Nkosana Leonard
Published: April 2008

This paper first presents and then discusses the attitudes towards and perceptions of education officers regarding introducing a school-based continuous assessment of speaking in the Botswana General Certificate of Secondary Education (BGCSE) ESL examinations as provided for in the BGCSE English syllabus in Botswana. Three categories of education officers that are responsible for developing and evaluating syllabuses, teaching supervision (quality assurance), and assessment of the BGCSE ESL curriculum in senior secondary schools in Botswana were interviewed, using an interview guide. The findings indicate that there are two opposing views held by the various categories of education officers regarding the importance of speaking in English in the Botswana linguistic situation. While on the one hand Curriculum Development and Evaluation (CD & E) officers and Senior Education Officers (SEOs) generally regard English speaking in the Botswana linguistic situation to be just as important as reading or writing, Examinations, Research and Testing Division (ERTD) officers did not think that speaking in English was that important.
Culturally Consistent Treatment for Late Talkers
Authors: Wing Christine , Kohnert Kathryn , Pham Giang , Cordero Kelly Nett , Ebert Kerry Danahy , Pui Fong Kan  , Blaiser Kristina
Published: April 2008

The authors discuss cultural influences on clinical interactions when treating late talkers, 2- to 3-year-old children with primary language delays. They use the literature to examine the cultural relevance of core components of early language treatment and propose alternative professional actions in the cases of cultural mismatches. Alternative actions include triadic or multiparty treatments, the inclusion of siblings or others, more structured tasks or group settings for language training, and shaping of culturally congruent directive language techniques. Also discussed is the need for an emphasis on social language use and professional clarity regarding links between early child language ability and later achievements in order to motivate treatment.
Predictors of Police Contact Among Midwestern Homeless and Runaway Youth
Authors: Thrane Lisa , Xiaojin Chen  , Johnson Kurt , Whitbeck Les B.
Published: April 2008

Research has substantiated that homeless and runaway youth are at high risk for offending and deviant behavior. Although gender, abuse, and deviant peers have been implicated in arrests among homeless youth, we know less about whether these precursors operate similarly for police harassment as well as for postrunaway arrest. In a study of 361 Midwestern homeless and runaway youth, several differences were noted between the predictors of arrest and police harassment. First, path-analytic techniques demonstrated that having deviant friends promoted harassment but not arrest. Second, substance use was the impetus for police harassment, whereas age at first runaway was consequential for arrest. Third, physically abused youth encountered more harassment, yet minor delinquent behavior increased the risk of arrest.
Genome classification by gene distribution: An overlapping subspace clustering approach
Authors: Li Jason , Halgamuge Saman K , Tang Sen-Lin
Published: April 2008

Background

Genomes of lower organisms have been observed with a large amount of horizontal gene transfers, which cause difficulties in their evolutionary study. Bacteriophage genomes are a typical example. One recent approach that addresses this problem is the unsupervised clustering of genomes based on gene order and genome position, which helps to reveal species relationships that may not be apparent from traditional phylogenetic methods.

Results

We propose the use of an overlapping subspace clustering algorithm for such genome classification problems. The advantage of subspace clustering over traditional clustering is that it can associate clusters with gene arrangement patterns, preserving genomic information in the clusters produced. Additionally, overlapping capability is desirable for the discovery of multiple conserved patterns within a single genome, such as those acquired from different species via horizontal gene transfers. The proposed method involves a novel strategy to vectorize genomes based on their gene distribution. A number of existing subspace clustering and biclustering algorithms were evaluated to identify the best framework upon which to develop our algorithm; we extended a generic subspace clustering algorithm called HARP to incorporate overlapping capability. The proposed algorithm was assessed and applied on bacteriophage genomes. The phage grouping results are consistent overall with the Phage Proteomic Tree and showed common genomic characteristics among the TP901-like, Sfi21-like and sk1-like phage groups. Among 441 phage genomes, we identified four significantly conserved distribution patterns structured by the terminase, portal, integrase, holin and lysin genes. We also observed a subgroup of Sfi21-like phages comprising a distinctive divergent genome organization and identified nine new phage members to the Sfi21-like genus: Staphylococcus 71, phiPVL108, Listeria A118, 2389, Lactobacillus phi AT3, A2, Clostridium phi3626, Geobacillus GBSV1, and Listeria monocytogenes PSA.

Conclusion

The method described in this paper can assist evolutionary study through objectively classifying genomes based on their resemblance in gene order, gene content and gene positions. The method is suitable for application to genomes with high genetic exchange and various conserved gene arrangement, as demonstrated through our application on phages.
Identification and molecular characterisation of a fibrinogen binding protein from Streptococcus iniae.
Authors: Baiano Justice CF , Tumbol Reiny A , Umapathy Aarti , Barnes Andrew C
Published: April 2008

Background

Binding of serum components by surface M-related proteins, encoded by theemmgenes, in streptococci constitutes a major virulence factor in this important group of organisms. The present study demonstrates fibrinogen binding byS. iniae, a Lancefield non-typeable pathogen causing devastating fish losses in the aquaculture industry and an opportunistic pathogen of humans, and identifies the proteins involved and their encoding genes.

Results

Fibrinogen binding byS. iniaesignificantly reduced respiratory burst activity of barramundi peritoneal macrophages in primary cultures compared to BSA-treated or untreated controls, indicating a potentially important role for fibrinogen binding cell-surface proteins in avoiding phagocytic attack in fish. We describe a novelemm-like gene,simA, encoding a 57 kDa fibrinogen binding M-like protein inS. iniae. These SiM proteins and their corresponding tetrameric structures from some sequevar types (~230 kDa) bound fibrinogen in Western blots.simAwas most closely related (32% identity) to thedemAgene ofS. dysgalactiae. Genome walking and sequencing determined the genetic organization of thesimAregion had similarities to themgrCregulon in GCS and toS. uberis. Moreover, a putative multigene regulator,mgxwas orientated in the opposite direction to thesimAgene in common withS. uberis, but contrary to findings in GAS and GCS. In GAS, diversity amongemm-genes and consequent diversity of their M-related proteins results in substantial antigenic variation. However, an extensive survey ofS. iniaeisolates from diverse geographic regions and hosts revealed only three variants of the gene, with one sequevar accounting for all but two of the 50 isolates analysed.

Conclusion

These proteins play a role in avoiding oxidative attack by phagocytic cells during infection of fish byS. iniae, but genetic diversity amongst these key surface proteins has not yet arisen. This lack of diversity coupled with a functional role in macrophage resistance suggests that these proteins may constitute important targets for future vaccines againstS. iniaein fish.
Intramuscular recurrence in a Hepatocellular carcinoma patient with indolent disease course
Authors: Yau Thomas , Wong Hilda , Chan Pierre , To MC , Poon Ronnie T
Published: April 2008

Background

Hepatocellular carcinoma (HCC) is a common malignancy worldwide and treatment options are depended on the stage of the tumour. In general, the prognosis of HCC patients with extra-hepatic metastasis is poor. The most common sites of extra-hepatic metastasis are the lung, abdominal lymph nodes and bone.

Case presentation

Here, we reported a 54-year-old man with an indolent clinical course of HCC. He had multiple extra-hepatic recurrences after initial hepatectomy for HCC and was benefited from repeated resections with prolonged survival. Eventually, he developed intramuscular recurrence in the thigh, which was initially mistaken as deep vein thrombosis.

Conclusion

Selected patients with indolent disease course of HCC may benefit from repeated resections of extra-hepatic metastases with prolonged survival.
Expression patterns and prognostic value of Bag-1 and Bcl-2 in breast cancer
Authors: Nadler Yasmine , Camp Robert L , Giltnane Jennifer M , Moeder Christopher , Rimm David L , Kluger Harriet M , Kluger Yuval
Published: April 2008

Introduction

Bcl-2 antanogene-1 (Bag-1) binds the anti-apoptotic mediator Bcl-2, and enhances its activity. Bcl-2 and Bag-1 are associated with chemotherapy resistance in cancer cells. Drugs that target Bcl-2 are currently in clinical development. The purpose of the present study was to examine expression patterns of Bag-1 in a large cohort of breast tumors and to assess the association with Bcl-2, estrogen receptor, progesterone receptor and Her2/neu, and other clinical/pathological variables.

Methods

Tissue microarrays containing primary specimens from 638 patients with 10-year follow-up were employed, and the expression of Bag-1, Bcl-2, estrogen receptor, progesterone receptor and Her2/neu was assessed using our automated quantitative analysis method. We used cytokeratin to define pixels as breast cancer (tumor mask) within the array spot, and we measured biomarker expression within the mask using Cy5 conjugated antibodies.

Results

High Bcl-2 expression was associated with improved survival in the entire cohort and in the node-positive subset (P = 0.008 and P = 0.002, respectively). High Bag-1 expression was associated with improved survival in the node-positive subset (P = 0.006). On multivariable analysis, neither Bcl-2 nor Bag-1 retained their independence as prognostic markers. Strong associations were found between Bag-1, Bcl-2, estrogen receptor and progesterone receptor.

Conclusion

Bag-1 and Bcl-2 expression in breast tumors is associated with improved outcome and steroid receptor positivity. Evaluation of Bcl-2 and Bag-1 expression in breast cancer may identify a subset of patients with a favorable prognosis, who might not benefit from chemotherapy or who might benefit from Bcl-2 targeting agents in addition to antihormonal therapy.
Differential regulation of naïve and memory CD4+ T cells by alternatively activated dendritic cells
Authors: Anderson Amy E , Sayers Bethan L , Haniffa Muzlifah A , Swan David J , Diboll Julie , Wang Xiao-Nong , Isaacs John D , Hilkens Catharien M U
Published: April 2008

Promising immunotherapeutic tools for T cell-mediated pathologies are alternatively activated dendritic cells (aaDC), which exert their effect through the regulation and tolerization of T cells. As naïve and memory T cells have different susceptibilities to tolerogenic signals, it is important to understand the modulatory effects of aaDC on these T cell subsets. We have examined regulation of naïve and memory CD4+ T cells by human aaDC generated with dexamethasone, the active form of vitamin D3, 1α,25-dihydroxyvitamin D3, and LPS. Although aaDC induced low, primary, allogeneic responses by naïve and memory T cells, aaDC regulated the differentiation of these T cell subsets in a distinct manner. Naïve T cells primed by aaDC retained a strong, proliferative capacity upon restimulation but were skewed toward a low IFN-γ/high IL-10 cytokine profile. In contrast, memory T cells primed by aaDC became hyporesponsive in terms of proliferation and cytokine production. Induction of anergy in memory T cells by aaDC was not a result of the presence of CD25hi regulatory T cells and could be partially reversed by IL-2. Both T cell subsets acquired regulatory activity and inhibited primary CD4 and CD8 responses. Addition of exogenous IL-12p70 during T cell priming by aaDC prevented anergy induction in memory T cells and cytokine polarization in naïve T cells, indicating that the lack of IL-12p70 is a key feature of aaDC. Our finding that aaDC differentially regulate naïve and memory T cells is important for understanding and maximizing the therapeutic potential of aaDC.
Synthetic oligonucleotides as modulators of inflammation
Authors: Klinman Dennis , Shirota Hidekazu , Tross Debra , Sato Takashi , Klaschik Sven
Published: April 2008

Synthetic oligodeoxynucleotides (ODN) containing unmethylated CpG motifs mimic the immunostimulatory activity of bacterial DNA. CpG ODN directly stimulate human B cells and plasmacytoid dendritic cells, promote the production of Th1 and proinflammatory cytokines, and trigger the maturation/activation of professional APC. CpG ODN are finding use in the treatment of cancer, allergy, and infection. In contrast, ODN containing multiple TTAGGG motifs mimic the immunosuppressive activity of self-DNA, down-regulating the production of proinflammatory and Th1 cytokines. Preclinical studies suggest that “suppressive” ODN may slow or prevent diseases characterized by pathologic immune stimulation, including autoimmunity and septic shock. Extensive studies in animal models suggest that the therapeutic value of CpG and TTAGGG ODN may be optimized by early administration.
Influence of Age at Menarche on Forearm Bone Microstructure in Healthy Young Women
Authors: Chevalley Thierry , Bonjour Jean-Philippe , Ferrari Serge , Rizzoli Rene
Published: April 2008

Background: Shorter estrogen exposure from puberty onset to peak bone mass attainment may explain how late menarche is a risk factor for osteoporosis. The influence of menarcheal age (MENA) on peak bone mass, cortical, and trabecular microstructure was studied in 124 healthy women aged 20.4 ± 0.6 (sd) yr.

Methods: At distal radius, areal bone mineral density (aBMD) was measured by dual-energy x-ray absorptiometry, and volumetric bone mineral density (BMD) and microstructure were measured by high-resolution peripheral computerized tomography, including: total, cortical, and trabecular volumetric BMD and fraction; trabecular number, thickness, and spacing; cortical thickness (CTh); and cross-sectional area (CSA).

Results: Median MENA was 12.9 yr. Mean aBMD T score of the whole cohort was slightly positive. aBMD was inversely correlated to MENA for total radius (R = −0.21; P = 0.018), diaphysis (R = −0.18; P = 0.043), and metaphysis (R = −0.19; P = 0.031). Subjects with MENA more than the median [LATER: 14.0 ± 0.7 (±sd) yr] had lower aBMD than those with MENA less than the median (EARLIER: 12.1 ± 0.7 yr) in total radius (P = 0.026), diaphysis (P = 0.042), and metaphysis (P = 0.046). LATER vs. EARLIER displayed lower total volumetric BMD (315 ± 54 vs. 341 ± 56 mg HA/cm3; P = 0.010), cortical volumetric BMD (874 ± 49 vs. 901 ± 44 mg HA/cm3; P = 0.003), and CTh (774 ± 170 vs. 849 ± 191 μm; P = 0.023). CTh was inversely related to CSA (R = −0.46; P < 0.001). In LATER reduced CTh was associated with 5% increased CSA.

Conclusions: In healthy young adult women, a 1.9-yr difference in mean MENA was associated with lower radial aBMD T score, lower CTh without reduced CSA, a finding compatible with less endocortical accrual. It may explain how late menarche is a risk factor for forearm osteoporosis.
Effect of Weight Loss by Gastric Bypass Surgery Versus Hypocaloric Diet on Glucose and Incretin Levels in Patients with Type 2 Diabetes
Authors: Laferrère Blandine , Teixeira Julio , McGinty James , Tran Hao , Egger Joseph R. , Colarusso Antonia , Kovack Betty , Bawa Baani , Koshy Ninan , Lee Hongchan , Yapp Kimberly , Olivan Blanca
Published: April 2008

Context: Gastric bypass surgery (GBP) results in rapid weight loss, improvement of type 2 diabetes (T2DM), and increase in incretins levels. Diet-induced weight loss also improves T2DM and may increase incretin levels.

Objective: Our objective was to determine whether the magnitude of the change of the incretin levels and effect is greater after GBP compared with a low caloric diet, after equivalent weight loss.

Design and Methods: Obese women with T2DM studied before and 1 month after GBP (n = 9), or after a diet-induced equivalent weight loss (n = 10), were included in the study. Patients from both groups were matched for age, body weight, body mass index, diabetes duration and control, and amount of weight loss.

Setting: This outpatient study was conducted at the General Clinical Research Center.

Main Outcome Measures: Glucose, insulin, proinsulin, glucagon, gastric inhibitory peptide (GIP), and glucagon-like peptide (GLP)-1 levels were measured after 50-g oral glucose. The incretin effect was measured as the difference in insulin levels in response to oral and to an isoglycemic iv glucose load.

Results: At baseline, none of the outcome variables (fasting and stimulated values) were different between the GBP and diet groups. Total GLP-1 levels after oral glucose markedly increased six times (peak:17 ± 6 to 112 ± 54 pmol/liter; P < 0.001), and the incretin effect increased five times (9.4 ± 27.5 to 44.8 ± 12.7%; P < 0.001) after GBP, but not after diet. Postprandial glucose levels (P = 0.001) decreased more after GBP.

Conclusions: These data suggest that early after GBP, the greater GLP-1 and GIP release and improvement of incretin effect are related not to weight loss but rather to the surgical procedure. This could be responsible for better diabetes outcome after GBP.
Analysis of Fyn function in hemostasis and αIIbβ3-integrin signaling
Authors: Reddy Kumar B. , Smith Dawn M. , Plow Edward F.
Published: April 2008

Recent studies have shown that Src-family kinases (SFKs) play an important role in mediating integrin signalling, and the β3 subunit of αIIbβ3 integrin has been shown to interact with multiple SFK members. Here, we analyzed the interactions and functional consequences of Fyn and Src binding to αIIbβ3. Fyn associated with the β3 subunit in resting and thrombin-aggregated platelets, whereas interaction between Src and αIIbβ3 was seen predominantly in resting but not in thrombin-aggregated platelets. We have also observed that Fyn but not Src localized to focal adhesions in CHO cells adherent to fibrinogen through αIIbβ3. On the basis of these differences, we wanted to determine the sequence requirements for the interaction of Fyn and Src within the β3-cytoplasmic domain. Whereas Src association required the C-terminal region of β3, Fyn continued to interact with mutants that could no longer associate with Src and that contained as few as 13 membrane-proximal amino acids of the β3-cytoplasmic tail. Using deletion mutants of β3-cytoplasmic tails expressed as GST-fusion proteins, we narrowed down the Fyn-binding site even further to the amino acid residues 721-725 (IHDRK) of the β3-cytoplasmic domain. On the basis of these observations, we explored whether Fyn–/– mice exhibited any abnormalities in hemostasis and platelet function. We found that Fyn–/– mice significantly differed in their second bleeding times compared with wild-type mice, and platelets from Fyn–/– mice exhibited delayed spreading on fibrinogen-coated surfaces. Using mutant forms of Fyn, it appears that its kinase activity is required for its localization to focal adhesions and to mediate αIIbβ3-dependent cell spreading. Our results suggest that Fyn and Src have distinct requirements for interaction with αIIbβ3; and, consequently, the two SFK can mediate different functional responses.
The ins and outs of syntenin, a multifunctional intracellular adaptor protein
Authors: Beekman Jeffrey M. , Coffer Paul J.
Published: April 2008

One of the most challenging issues currently facing cell biologists is how signal specificity and compartmentalization is achieved, allowing extracellular stimulation to result in a unique and pre-defined intracellular outcome. For this to occur, intracellular components must be correctly positioned in both space and time. Adaptor molecules, which contain protein-interaction domains, are often involved in the assembly of multimeric complexes that organize intracellular signal-transduction pathways. One such protein is syntenin, a PDZ-domain-containing molecule that has a surprising variety and diversity of interaction partners. Here we assimilate and discuss current data that support a role for syntenin in regulating transmembrane-receptor trafficking, tumour-cell metastasis and neuronal-synapse function.
Riboswitch effectors as protein enzyme cofactors
Authors: Cochrane Jesse C. , Strobel Scott A.
Published: April 2008

The recently identified glmS ribozyme revealed that RNA enzymes, like protein enzymes, are capable of using small molecules as catalytic cofactors to promote chemical reactions. Flavin mononucleotide (FMN), S-adenosyl methionine (SAM), adenosyl cobalamin (AdoCbl), and thiamine pyrophosphate (TPP) are known ligands for RNA riboswitches in the control of gene expression, but are also catalytically powerful and ubiquitous cofactors in protein enzymes. If RNA, instead of just binding these molecules, could harness the chemical potential of the cofactor, it would significantly expand the enzymatic repertoire of ribozymes. Here we review the chemistry of AdoCbl, SAM, FMN, and TPP in protein enzymology and speculate on how these cofactors might have been used by ribozymes in the prebiotic RNA World or may still find application in modern biology.
Specificity of ADAR-mediated RNA editing in newly identified targets
Authors: Riedmann Eva M. , Schopoff Sandy , Hartner Jochen C. , Jantsch Michael F.
Published: April 2008

Adenosine deaminases that act on RNA (ADARs) convert adenosines to inosine in both coding and noncoding double-stranded RNA. Deficiency in either ADAR1 or ADAR2 in mice is incompatible with normal life and development. While the ADAR2 knockout phenotype can be attributed to the lack of editing of the GluR-B receptor, the embryonic lethal phenotype caused by ADAR1 deficiency still awaits clarification. Recently, massive editing was observed in noncoding regions of mRNAs in mice and humans. Moreover, editing was observed in protein-coding regions of four mRNAs encoding FlnA, CyFip2, Blcap, and IGFBP7. Here, we investigate which of the two active mammalian ADAR enzymes is responsible for editing of these RNAs and whether any of them could possibly contribute to the phenotype observed in ADAR knockout mice. Editing of Blcap, FlnA, and some sites within B1 and B2 SINEs clearly depends on ADAR1, while other sites depend on ADAR2. Based on our data, substrate specificities can be further defined for ADAR1 and ADAR2. Future studies on the biological implications associated with a changed editing status of the studied ADAR targets will tell whether one of them turns out to be directly or indirectly responsible for the severe phenotype caused by ADAR1 deficiency.
Can They Take It With Them? The Portability of Star Knowledge Workers' Performance
Authors: Groysberg Boris , Lee Linda-Eling , Nanda Ashish
Published: April 2008

This paper examines the portability of star security analysts' performance. Star analysts who switched employers experienced an immediate decline in performance that persisted for at least five years. This decline was most pronounced among star analysts who moved to firms with lesser capabilities and those who moved solo, without other team members. Star analysts who moved between two firms with equivalent capabilities also exhibited a drop in performance, but only for two years. Those who switched to firms with better capabilities and those who moved with other team members exhibited no significant decline in short-term or long-term performance. These findings suggest that firm-specific skills and firms' capabilities both play important roles in star analysts' performance. In addition, we find that firms that hire star analysts from competitors with better capabilities suffered more extreme negative stock-market reactions than those that hire from comparable or lesser firms. These findings suggest that hiring stars may be perceived as value destroying and may not improve a firm's competitive advantage.
Myosin II Activation and Actin Reorganization Regulate the Mode of Quantal Exocytosis in Mouse Adrenal Chromaffin Cells
Authors: Doreian Bryan W. , Fulop Tiberiu G. , Smith Corey B.
Published: April 2008

Chromaffin cells of the adrenal medulla are innervated by the sympathetic nervous system. Stimulation causes chromaffin cells to fire action potentials, leading to the exocytosis of various classes of transmitters into the circulation. Low-frequency electrical stimulation (action potentials delivered at 0.5 Hz) causes adrenal chromaffin cells to selectively release catecholamines through a kiss-and-run fusion event. Elevated electrical stimulation (action potentials at 15 Hz) evokes fusion pore dilation, full granule collapse, and additional release of the neuropeptide-containing proteinaceous granule core. Here we apply single-cell electrophysiological, electrochemical, and fluorescence measurements to investigate the cellular mechanism for this shift in exocytic behavior. We show that at low-frequency stimulation, a filamentous-actin cell cortex plays a key role in stabilizing the kiss-and-run fusion event. Increased stimulation disrupts the actin cortex, driving full granule collapse. We show that pharmacological perturbation of the actin cortex supersedes stimulus frequency in controlling exocytic mode. Finally, we show that nonmuscle myosin II activation contributes to the cytoskeleton-dependent control of the fusion event. Inhibition of myosin II or myosin light chain kinase under elevated stimulation frequencies inhibits fusion pore dilation and maintains the granule in a kiss-and-run mode of exocytosis. These results demonstrate an essential role for activity-evoked cytoskeletal rearrangement and the action of myosin II in the regulation of catecholamine and neuropeptide exocytosis and represent an essential element of the sympathetic stress response.
Transient Upregulation of Postsynaptic IP3-Gated Ca Release Underlies Short-Term Potentiation of Metabotropic Glutamate Receptor 1 Signaling in Cerebellar Purkinje Cells
Authors: Kim Sang Jeong , Jin Yunju , Kim Jun , Shin Jung Hoon , Worley Paul F. , Linden David J.
Published: April 2008

Synaptic plasticity lasting ∼100 s has been suggested to function as a temporary buffer for neural information. One example of this was reported by Batchelor and Garthwaite (1997), who found that a slow metabotropic glutamate receptor 1 (mGluR1)-evoked EPSP produced by burst stimulation of cerebellar parallel fiber–Purkinje cell synapses could be potentiated by a conditioning stimulus consisting of prior activation of climbing fiber synapses (or injection of depolarizing current) with a delay of up to 90 s. What is the molecular basis of the signal that spans this temporal gap? Here, we show that mGluR1-evoked slow EPSCs evoked by parallel fiber burst test stimuli show a similar form of short-term potentiation (mGluR1-STP) and that this phenomenon is also observed when parallel fiber bursts are replaced by pressure pulses of an exogenous mGluR1 agonist. Ca imaging experiments revealed that cytosolic Ca levels returned to baseline within several seconds after conditioning depolarization, indicating that this cannot underlie mGluR1-STP. To test the hypothesis that transient upregulation of inositol-1,4,5-trisphosphate (IP3)-gated Ca release underlies this phenomenon, we used local photolytic uncaging of IP3to deplete IP3-gated Ca stores. IP3uncaging in the interval between conditioning depolarization and the test pulse produced a complete blockade of mGluR1-STP, as did blockade of IP3receptors with heparin. When Ca transients evoked by IP3uncaging were used as a test stimulus, conditioning depolarization produced a large STP of Ca response amplitudes. These data suggest that transient upregulation of postsynaptic IP3-gated Ca signaling constitutes a novel form of short-term synaptic plasticity.
Bimodal Viral Vectors andIn VivoImaging Reveal the Fate of Human Neural Stem Cells in Experimental Glioma Model
Authors: Shah Khalid , Hingtgen Shawn , Kasmieh Randa , Figueiredo Jose Luiz , Garcia-Garcia Elisa , Martinez-Serrano Alberto , Breakefield Xandra , Weissleder Ralph
Published: April 2008

Transplantation of genetically engineered cells into the CNS offers immense potential for the treatment of several neurological disorders. Monitoring expression levels of transgenes and following changes in cell function and distribution over time is critical in assessing therapeutic efficacy of such cellsin vivo. We have engineered lentiviral vectors bearing fusions between different combinations of fluorescent and bioluminescent marker proteins and used bioluminescence imaging and intravital-scanning microscopy in real time to study the fate of human neural stem cells (hNSCs) at a cellular resolution in glioma-bearing brainsin vivo. UsingRenillaluciferase (Rluc)-DsRed2 or GFP-Rluc-expressing malignant human glioma model, transduced hNSCs were shown to migrate extensively toward gliomas, with hNSCs populating gliomas at 10 d after transplantation. Furthermore, transduced hNSCs survived longer in mice with gliomas than in normal brain, but did not modulate glioma progressionin vivo. These studies demonstrate the utility of bimodal viral vectors and real-time imaging in evaluating fate of NSCs in diseased models and thus provide a platform for accelerating cell-based therapies for CNS disorders.
Blind Saccades: An Asynchrony between Seeing and Looking
Authors: de'Sperati Claudio , Baud-Bovy Gabriel
Published: April 2008

Saccades may not always wait for the completion of the perceptual analysis. By taking advantage of a motion-induced illusion of position and of the spontaneous scatter of saccade latency, we showed that in normal observers, regular saccades (latency, ∼200 ms) were accurately directed to the target, whereas at higher latencies, saccades were increasingly biased by visual motion until they reflected the perceptual illusion. We reconstructed the time course of saccadic direction coding and identified an early phase in which saccades are mostly predictive (latencies less than ∼100 ms), followed by a phase in which saccades are guided by the target position signal (latencies ∼100–250 ms), and a later phase associated with the buildup of mislocalization (∼250–450 ms). This transient dissociation between action and perception indicates that seeing and looking are based on asynchronous processes, possibly because of independent thresholds for saccades and perceptual localization. The metrics of a saccade would then reflect the evolution of cortical visual signals from a predictive state to a perceptual state, passing through an intermediate visuomotor state. If saccades occur during the visuomotor state, they escape the tricks of perception.
Semaphorin 3F Confines Ventral Tangential Migration of Lateral Olfactory Tract Neurons onto the Telencephalon Surface
Authors: Ito Keisuke , Kawasaki Takahiko , Takashima Seiji , Matsuda Ikuo , Aiba Atsu , Hirata Tatsumi
Published: April 2008

Ventral tangential migration of neurons is the most prominent mode of neuronal translocation during earliest neurogenesis in the mouse telencephalon. A typical example of the neurons that adopt this migration mode is guidepost neurons in the lateral olfactory tract designated as lot cells. These neurons are generated from the neocortical neuroepithelium and migrate tangentially down to the ventral edge of the neocortex abutting the ganglionic eminence, on which the future lateral olfactory tract develops. We show here that this migration stream is repelled by a secreted axon guidance molecule, semaphorin 3F through interaction with its specific receptor, neuropilin-2. Accordingly, in mutant mice forsemaphorin 3Forneuropilin-2, lot cells ectopically penetrated into the deep brain domain, which normally expresses semaphorin 3F. These results reveal that semaphorin 3F is an important regulator of the ventral tangential migration stream, confining the migrating neurons on the telencephalon surface by repelling from the deeper domain.
Tonic Activation of CXC Chemokine Receptor 4 in Immature Granule Cells Supports Neurogenesis in the Adult Dentate Gyrus
Authors: Kolodziej Angela , Schulz Stefan , Guyon Alice , Wu Dai-Fei , Pfeiffer Manuela , Odemis Veysel , Höllt Volker , Stumm Ralf
Published: April 2008

Stromal-cell-derived factor-1 (SDF-1) and its receptor CXC chemokine receptor 4 (CXCR4) play a well-established role during embryonic development of dentate gyrus granule cells. However, little is known about the regulation and function of CXCR4 in the postnatal dentate gyrus. Here, we identify a striking mismatch between intense CXCR4 mRNA and limited CXCR4 protein expression in adult rat subgranular layer (SGL) neurons. We demonstrate that CXCR4 protein expression in SGL neurons is progressively lost during postnatal day 15 (P15) to P21. This loss of CXCR4 protein expression was paralleled by a reduction in the number of SDF-1-responsive SGL neurons and a massive upregulation of SDF-1 mRNA in granule cells. Intraventricular infusion of the CXCR4-antagonist AMD3100 dramatically increased CXCR4 protein expression in SGL neurons, suggesting that CXCR4 is tonically activated and downregulated by endogenous SDF-1. Infusion of AMD3100 also facilitated detection of CXCR4 protein in bromodeoxyuridine-, nestin-, and doublecortin-labeled cells and showed that the vast majority of adult-born granule cells transiently expressed CXCR4. Chronic AMD3100 administration impaired formation of new granule cells as well as neurogenesis-dependent long-term recognition of novel objects. Therefore, our findings suggest that tonic activation of CXCR4 in newly formed granule cells by endogenous SDF-1 is essential for neurogenesis-dependent long-term memory in the adult hippocampus.
Bradykinin Enhances AMPA and NMDA Receptor Activity in Spinal Cord Dorsal Horn Neurons by Activating Multiple Kinases to Produce Pain Hypersensitivity
Authors: Kohno Tatsuro , Wang Haibin , Amaya Fumimasa , Brenner Gary J. , Cheng Jen-Kun , Ji Ru-Rong , Woolf Clifford J.
Published: April 2008

Bradykinin potentiates synaptic glutamate release and action in the spinal cord via presynaptic and postsynaptic B2receptors, contributing thereby to activity-dependent central sensitization and pain hypersensitivity (Wang et al., 2005). We have now examined the signaling pathways that are responsible for the postsynaptic modulatory actions of bradykinin on glutamatergic action and transmission in superficial dorsal horn neurons. B2receptors are coexpressed in dorsal horn neurons with protein kinase A (PKA) and the δ isoform of protein kinase C (PKC), and we find that the augmentation by bradykinin of AMPA and NMDA receptor-mediated currents in lamina II neurons requires coactivation of both PKC and PKA. The activation of PKA is downstream of COX1 (cyclooxygenase-1). Extracellular signal-regulated kinase (ERK) activation is involved after the PKC and PKA coactivation, and intrathecal administration of bradykinin induces a thermal hyperalgesiain vivo, which is reduced by inhibition of ERK, PKA, and PKC. We conclude that bradykinin, by activating multiple kinases in dorsal horn neurons, potentiates glutamatergic synaptic transmission to produce pain hypersensitivity.