bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface modification of CP-Ti and Ti–6Al–4V alloy by fluidised bed carburisation
Authors: Wu T.-I
Published: September 2008

A fluidised bed carburising process was developed to see the effects on surface modification of CP-Ti and Ti–6Al–4V alloy. The performance of a patented molten salt carburising process was also cited in comparison. A mixture of diamond, graphite and rutile were identified to form on the outermost surface for both processes. The major product at the near surface layer for both processes was carbon deficient titanium carbide TiC1−x. The lattice constants ao of TiC1−x and the associate stoichiometric ratios (1− x) were obtained by Nelson–Riley approach and interpolation respectively. Depth profiles used to quantitatively analysing the effects of processing parameters on the distribution of interstitial elements were achieved by the application of glow discharge optical spectrometry. The enhancement of surface hardness was more pronounced by employing fluidised bed carburising process.
Biomimetic hydroxyapatite coatings deposited onto heat and alkali treated Ti6Al4V surface
Authors: Fatehi K. , Moztarzadeh F. , Solati-Hashjin M. , Tahriri M. , Rezvannia M. , Saboori A.
Published: September 2008

In the present work, time of calcium phosphate formation on Ti6Al4V alloy with or without alkali and heat treatments was investigated. Specimens were soaked in 0, 5 and 10M solutions of NaOH at temperatures of 60 and 80°C for 1 and 3 days and then their surfaces were characterised by using scanning electron microscopy and thin film X-ray diffraction. It was found that optimum condition is 3 days soaking in 5M NaOH in 80°C. Specimens treated under these optimum conditions were subsequently heat treated at 500, 600 and 700°C for 1 h to consolidate the sodium titanate hydrogel layer. With heat treatment at 600°C for 1 h and then soaking in simulated body fluid, apatite formed within 3 days. However, there were no signs of apatite formation in control samples (without alkali and heat treatment) up to 7 days soaking in SBF.
Common variants in NLRP2 and NLRP3 genes are strong prognostic factors for the outcome of HLA-identical sibling allogeneic stem cell transplantation
Authors: Granell Miquel , Urbano-Ispizua Álvaro , Pons Aina , Aróstegui Juan Ignacio , Gel Bernat , Navarro Alfons , Jansa Sonia , Artells Rosa , Gaya Anna , Talarn Carme , Fernández-Avilés Francesc , Martínez Carmen , Rovira Montserrat , Carreras Enric , Rozman Ciril , Juan Manel , Yagüe Jordi , Montserrat Emili , Monzó Mariano
Published: September 2008

The inflammasomes are macromolecular cytosolic complexes involved in the production of interleukin-1β (IL-1β) and IL-18 in response to several pathogen-derived stimuli. Such interleukins have been implicated in the origin of severe allogeneic stem cell transplant (allo-SCT) complications. We analyzed the relationship between the interindividual variability in inflammasome protein-encoding genes in donors and patients and clinical outcome after allo-SCT. Fourteen common genetic variants in 5 genes of the inflammasome, namely, NLRP1, NLRP2, NLRP3, CARD8, and CASP5, were genotyped in 133 human leukocyte antigen-identical sibling pairs undergoing allo-SCT. In the multivariate analysis, donor variants in NLRP2 and NLRP3 were the most important prognostic factors for the clinical outcome after allo-SCT. Thus, donor TT genotype at rs10925027 in NLRP3 was associated with disease relapse (odds ratio (OR) = 6.3, P = 1 × 10−7), and donor GG genotype at rs1043684 in NLRP2 was associated with nonrelapse mortality (OR = 4.4, P = 6 × 10−4) and overall survival (OR = 3.1, P = .001). In addition, patient AA genotype at rs5862 in NLRP1 was associated with nonrelapse mortality (OR = 2.8, P = .005) and overall survival (OR = 2.0, P = .009). These results suggest that inflammasome genetic variants are important prognostic factors for the outcome of allo-SCT. If validated in larger studies, including unrelated allo-SCT, NLRPs genotype would become an important factor in donor selection.
Bone marrow microenvironment controls the in vivo differentiation of murine dendritic cells into osteoclasts
Authors: Wakkach Abdelilah , Mansour Anna , Dacquin Romain , Coste Emmanuel , Jurdic Pierre , Carle Georges F. , Blin-Wakkach Claudine
Published: September 2008

Finding that activated T cells control osteoclast (OCL) differentiation has revealed the importance of the interactions between immune and bone cells. Dendritic cells (DCs) are responsible for T-cell activation and share common precursors with OCLs. Here we show that DCs participate in bone resorption more directly than simply through T-cell activation. We show that, among the splenic DC subsets, the conventional DCs have the higher osteoclastogenic potential in vitro. We demonstrate that conventional DCs differentiate into functional OCLs in vivo when injected into osteopetrotic oc/oc mice defective in OCL resorptive function. Moreover, this differentiation involves the presence of activated CD4+ T cells controlling a high RANK-L expression by bone marrow stromal cells. Our results open new insights in the differentiation of OCLs and DCs and offer new basis for analyzing the relations between bone and immune systems.
Thrombin generation and activated protein C resistance in patients with essential thrombocythemia and polycythemia vera
Authors: Marchetti Marina , Castoldi Elisabetta , Spronk Henri M. H. , van Oerle René , Balducci Donatella , Barbui Tiziano , Rosing Jan , ten Cate Hugo , Falanga Anna
Published: September 2008

We used the thrombin generation assay to evaluate the hypercoagulable state according to JAK2V617F mutational status in essential thrombocythemia (ET) and polycythemia vera (PV) patients. Thrombin generation was determined in the presence and absence of activated protein C (APC), and APC resistance was expressed as normalized APC sensitivity ratio (nAPCsr). Tissue factor pathway inhibitor (TFPI), total and free protein S (PS), prothrombin (FII), factor V (FV), and neutrophil elastase were measured in plasma; CD11b was measured on neutrophils. Compared with normal controls, patients had a lower endogenous thrombin potential in the absence of APC but had a higher endogenous thrombin potential in the presence of APC, showing the occurrence of APC resistance. The nAPCsr increased in JAK2V617F carriers compared with noncarriers and was highest in JAK2V617F homozygous patients. FII, FV, free PS, and TFPI levels were reduced in patients, mainly in JAK2V617F carriers. Multiple regression analysis indicated the low free PS level as major determinant of the increased nAPCsr. Elastase was increased in patients and inversely correlated with free PS. In conclusion, these data indicate the occurrence of acquired APC resistance in ET and PV patients, probably because of a reduction in free PS levels. The APC-resistant phenotype is influenced by the JAK2V617F mutational load.
Docking of molecules identified in bioactive medicinal plants extracts into the p50 NF-kappaB transcription factor: correlation with inhibition of NF-kappaB/DNA interactions and inhibitory effects on IL-8 gene expression
Authors: Piccagli Laura , Fabbri Enrica , Borgatti Monica , Bezzerri Valentino , Mancini Irene , Nicolis Elena , Dechecchi Maria C , Lampronti Ilaria , Cabrini Giulio , Gambari Roberto
Published: September 2008

Background

The transcription factor NF-kappaB is a very interesting target molecule for the design on anti-tumor, anti-inflammatory and pro-apoptotic drugs. However, the application of the widely-used molecular docking computational method for the virtual screening of chemical libraries on NF-kappaB is not yet reported in literature. Docking studies on a dataset of 27 molecules from extracts of two different medicinal plants to NF-kappaB-p50 were performed with the purpose of developing a docking protocol fit for the target under study.

Results

We enhanced the simple docking procedure by means of a sort of combined target- and ligand-based drug design approach. Advantages of this combination strategy, based on a similarity parameter for the identification of weak binding chemical entities, are illustrated in this work with the discovery of a new lead compound for NF-kappaB. Further biochemical analyses based on EMSA were performed and biological effects were tested on the compound exhibiting the best docking score. All experimental analysis were in fairly good agreement with molecular modeling findings.

Conclusion

The results obtained sustain the concept that the docking performance is predictive of a biochemical activity. In this respect, this paper represents the first example of successfully individuation through molecular docking simulations of a promising lead compound for the inhibition of NF-kappaB-p50 biological activity and modulation of the expression of the NF-kB regulated IL8 gene.
Clinicopathologic features and outcomes following surgery for pancreatic adenosquamous carcinoma
Authors: Hsu Jun-Te , Chen Han-Ming , Wu Ren-Chin , Yeh Chun-Nan , Yeh Ta-Sen , Hwang Tsann-Long , Jan Yi-Yin , Chen Miin-Fu
Published: September 2008

Background

Pancreatic adenosquamous carcinoma (ASC) is a rare pancreatic malignancy subtype. We investigated the clinicopathological features and outcome of pancreatic ASC patients after surgery.

Methods

The medical records of 12 patients with pancreatic ASC undergoing surgical treatment (1993 to 2006) were retrospectively reviewed. Survival data of patients with stage IIB pancreatic adenocarcinoma and ASC undergoing surgical resection were compared.

Results

Symptoms included abdominal pain (91.7%), body weight loss (83.3%), anorexia (41.7%) and jaundice (25.0%). Tumors were located at pancreatic head in 5 (41.7%) patients, tail in 5 (41.7%), and body in 4 (33.3%). Median tumor size was 6.3 cm. Surgical resection was performed on 7 patients, bypass surgery on 3, and exploratory laparotomy with biopsy on 2. No surgical mortality was identified. Seven (58.3%) and 11 (91.7%) patients died within 6 and 12 months of operation, respectively. Median survival of 12 patients was 4.41 months. Seven patients receiving surgical resection had median survival of 6.51 months. Patients with stage IIB pancreatic ASC had shorter median survival compared to those with adenocarcinoma.

Conclusion

Aggressive surgical management does not appear effective in treating pancreatic ASC patients. Strategies involving non-surgical treatment such as chemotherapy, radiotherapy or target agents should be tested.
Simultaneous circulation of genotypes I and III of dengue virus 3 in Colombia
Authors: Usme-Ciro Jose A , Mendez Jairo A , Tenorio Antonio , Rey Gloria J , Domingo Cristina , Gallego-Gomez Juan C
Published: September 2008

Background

Dengue is a major health problem in tropical and subtropical regions. In Colombia, dengue viruses (DENV) cause about 50,000 cases annually, 10% of which involve Dengue Haemorrhagic Fever/Dengue Shock Syndrome. The picture is similar in other surrounding countries in the Americas, with recent outbreaks of severe disease, mostly associated with DENV serotype 3, strains of the Indian genotype, introduced into the Americas in 1994.

Results

The analysis of the 3'end (224 bp) of the envelope gene from 32 DENV-3 strains recently recovered in Colombia confirms the circulation of the Indian genotype, and surprisingly the co-circulation of an Asian-Pacific genotype only recently described in the Americas.

Conclusion

These results have important implications for epidemiology and surveillance of DENV infection in Central and South America. Molecular surveillance of the DENV genotypes infecting humans could be a very valuable tool for controlling/mitigating the impact of the DENV infection.
Multicystic urothelial carcinoma of the bladder with gland-like lumina and with signet-ring cells. A case report
Authors: Alvarado-Cabrero Isabel , Pérez-Montiel Delia , Hes Ondrej
Published: September 2008

We present the case of 80-year-old male with superficial papillary urothelial carcinoma of the urinary bladder with striking multicystic architecture with a combination of features of urothelial carcinoma with gland-like lumina, with signet-ring cell differentiation and microcystic pattern. However, the tumor shared the morphologic features of several variants of urothelial carcinoma, the most important differential diagnosis covered so-called florid Brunneriosis, cystitis cystica, and primary adenocarcinomas of the urinary bladder.
Bacterial infection alters the kinetics and function of iNKT cell responses
Authors: Choi Hak-Jong , Xu Honglin , Geng Yanbiao , Colmone Angela , Cho Hoonsik , Wang Chyung-Ru
Published: September 2008

CD1d-restricted Vα14 invariant NKT cells (iNKT) are innate-like, immunoregulatory lymphocytes that play critical roles in autoimmunity, tumor surveillance, and infectious disease. Although iNKT cells are activated during microbial infection, the impacts of infection on the function of iNKT cells have not been fully characterized. Using a Listeria monocytogenes (LM) infection model, we found that iNKT cells failed to expand after infection, resulting in prolonged loss in the spleen, in contrast to the typical expansion and contraction of conventional T cells. iNKT cells from LM-infected mice responded more rapidly to secondary LM infection; however, they became functionally hyporesponsive to antigenic challenge for at least 1 month. This infection-induced hyporesponsiveness was also induced by Mycobacteria infection and was more profound in LM-infected, thymectomized mice, suggesting that infection-primed iNKT cells might have altered functionality. Interestingly, activation with α-galactosylceramide-loaded dendritic cells was able to overcome infection-induced hyporesponsiveness of iNKT cells, suggesting a role for extrinsic factors in this functional deficit. Taken together, these findings suggest that infection affects iNKT cell responses quantitatively and qualitatively. As humans are under constant microbial insult, predictions of iNKT cell function based on naïve animal models may not accurately reflect iNKT cell behavior in a clinical setting.
Regulation of WAVE1 expression in macrophages at multiple levels
Authors: Dinh Hang , Scholz Glen M , Hamilton John A
Published: September 2008

M-CSF (or CSF-1) controls macrophage lineage development and function. A CSF-1-dependent culture system was established, which monitored the differentiation of CSF-1-responsive macrophage populations over time and upon adherence. Wiskott-Aldrich syndrome protein verprolin homologous (WAVE) proteins are involved in actin reorganization, a process critical to many cell functions. WAVE2 but not WAVE1 has been considered significant for macrophage function. Using the CSF-1-dependent differentiation system, we were able to demonstrate the contrasting regulation of the expression of WAVE1 and WAVE2; the levels of the latter rose over time and as the macrophage population became adherent, although those of the former increased over time but were down-regulated upon adherence. Evidence was obtained that WAVE1 was also cleaved to a novel, 60-kDa fragment by macrophage adherence and by another pathway involving calpain-mediated proteolysis. Mutagenesis studies indicated that cleavage of WAVE1 by calpain results in the removal of the verprolin-homology, cofilin-like, and acidic domain and thus, the loss of WAVE1 activity. We suggest that WAVE1 is also important for macrophage biology and that it could have separate functions to those of WAVE2.
Comparison of Referring and Final Pathology for Patients With Non-Hodgkin's Lymphoma in the National Comprehensive Cancer Network
Authors: LaCasce Ann S. , Kho Michelle E. , Friedberg Jonathan W. , Niland Joyce C. , Abel Gregory A. , Rodriguez Maria Alma , Czuczman Myron S. , Millenson Michael M. , Zelenetz Andrew D. , Weeks Jane C.
Published: September 2008

Purpose

Before the implementation of the WHO lymphoma classification system, disagreement about pathologic diagnosis was common. We sought to estimate the impact of expert review in the modern era by comparing final pathologic diagnoses at five comprehensive cancer centers with diagnoses assigned at referring centers.

Patients and Methods

Patients in the National Comprehensive Cancer Network (NCCN) non-Hodgkin's lymphoma (NHL) database with a documented pathologic diagnosis before presentation and a final pathologic diagnosis of any of five common B-cell NHLs were eligible. After central review of discordant cases, we estimated the rate of pathologic concordance, then investigated the etiology of discordance as well its potential impact on prognosis and treatment.

Results

The overall pathologic discordance rate was 6% (43 of 731 patients; 95% CI, 4% to 8%). For the majority of cases in which the referring diagnosis was apparently final, no additional studies were conducted at the NCCN center, and the change in diagnosis reflected a different interpretation of existing data. Concordance was highest for diffuse large B-cell lymphoma (95%) and follicular lymphoma (FL; grades 1, 2, and not otherwise specified, 95%) and lowest for grade 3 FL (88%). Of the 43 pathologically discordant cases, 81% (35 patients) might have experienced a change in treatment as a result of the pathologic reclassification.

Conclusion

In the era of the WHO lymphoma classification system, the majority of common B-cell NHLs diagnosed in the community were unchanged by second opinion review by an expert hematopathologist. However, for one patient in 20, there was a discordance in diagnosis that could have altered therapy.
Different Outcomes of Unliganded and Liganded Estrogen Receptor-α on Neurite Outgrowth in PC12 Cells
Authors: Mérot Yohann , Ferrière François , Gailhouste Luc , Huet Guillaume , Percevault Frédéric , Saligaut Christian , Flouriot Gilles
Published: September 2008

A precise description of the mechanisms by which estrogen receptor-α (ERα) exerts its influences on cellular growth and differentiation is still pending. Here, we report that the differentiation of PC12 cells is profoundly affected by ERα. Importantly, depending upon its binding to 17β-estradiol (17βE2), ERα is found to exert different effects on pathways involved in nerve growth factor (NGF) signaling. Indeed, upon its stable expression in PC12 cells, unliganded ERα is able to partially inhibit the neurite outgrowth induced by NGF. This process involves a repression of MAPK and phosphatidylinositol 3-kinase/Akt signaling pathways, which leads to a negative regulation of markers of neuronal differentiation such as VGF and NFLc. This repressive action of unliganded ERα is mediated by its D domain and does not involve its transactivation and DNA-binding domains, thereby suggesting that direct transcriptional activity of ERα is not required. In contrast with this repressive action occurring in the absence of 17βE2, the expression of ERα in PC12 cells allows 17βE2 to potentiate the NGF-induced neurite outgrowth. Importantly, 17βE2 has no impact on NGF-induced activity of MAPK and Akt signaling pathways. The mechanisms engaged by liganded ERα are thus unlikely to rely on an antagonism of the inhibition mediated by the unliganded ERα. Furthermore, 17βE2 enhances NGF-induced response of VGF and NFLc neuronal markers in PC12 clones expressing ERα. This stimulatory effect of 17βE2 requires the transactivation functions of ERα and its D domain, suggesting that an estrogen-responsive element-independent transcriptional mechanism is potentially relevant for the neuritogenic properties of 17βE2 in ERα-expressing PC12 cells.

In the absence of its ligand, ERα partially inhibits the nerve growth factor-induced neurite outgrowth of PC12 cells, whereas, once liganded, it enhances differentiation.
Moderate Daily Exercise Activates Metabolic Flexibility to Prevent Prenatally Induced Obesity
Authors: Miles Jennifer L. , Huber Korinna , Thompson Nichola M. , Davison Michael , Breier Bernhard H.
Published: September 2008

Obesity and its associated comorbidities are of major worldwide concern. It is now recognized that there are a number of metabolically distinct pathways of obesity development. The present paper investigates the effect of moderate daily exercise on the underlying mechanisms of one such pathway to obesity, through interrogation of metabolic flexibility. Pregnant Wistar rats were either fed chow ad libitum or undernourished throughout pregnancy, generating control or intrauterine growth restricted (IUGR) offspring, respectively. At 250 d of age, dual-emission x-ray absorptiometry scans and plasma analyses showed that moderate daily exercise, in the form of a measured amount of wheel running (56 m/d), prevented the development of obesity consistently observed in nonexercised IUGR offspring. Increased plasma C-peptide and hepatic atypical protein kinase Cζ levels explained increased glucose uptake and increased hepatic glycogen storage in IUGR offspring. Importantly, whereas circulating levels of retinol binding protein 4 were elevated in obese, nonexercised IUGR offspring, indicative of glucose sparing without exercise, retinol binding protein 4 levels were normalized in the exercised IUGR group. These data suggest that IUGR offspring have increased flexibility of energy storage and use and that moderate daily exercise prevents obesity development through activation of distinct pathways of energy use. Thus, despite a predisposition to develop obesity under sedentary conditions, obesity development was prevented in IUGR offspring when exercise was available. These results emphasize the importance of tailored lifestyle changes that activate distinct pathways of metabolic flexibility for obesity prevention.

Obesity induced by prenatal undernutrition is effectively prevented by moderate daily exercise through the activation of distinct pathways of hepatic metabolic flexibility.
Transient Congenital Hypothyroidism Caused by Biallelic Mutations of the Dual Oxidase 2 Gene in Japanese Patients Detected by a Neonatal Screening Program
Authors: Maruo Yoshihiro , Takahashi Hiroko , Soeda Ikumi , Nishikura Noriko , Matsui Katsuyuki , Ota Yoriko , Mimura Yu , Mori Asami , Sato Hiroshi , Takeuchi Yoshihiro
Published: September 2008

Context: Mutations in dual oxidase (DUOX2) have been proposed as a cause of congenital hypothyroidism. Previous reports suggest that biallelic mutations of DUOX2 cause permanent congenital hypothyroidism and that monoallelic mutations cause transient congenital hypothyroidism.

Objective: To clarify the inheritance of hypothyroidism, we looked at the DUOX2 gene in patients with transient congenital hypothyroidism.

Design: DUOX2, thyroid peroxidase, Na+/I− symporter and dual oxidase maturation factor 2 genes were analyzed in eight patients with transient congenital hypothyroidism, using the PCR-amplified direct sequencing method.

Patients: The eight patients were found by a neonatal screening program. Six of these patients belonged to two independent families; the other two were unrelated. Their serum TSH values varied from 24.8–233.0 mU/liter. Six of the eight patients had a low serum freeT4 level (0.19–0.84 ng/dl). Seven of the eight patients were treated with thyroid hormone replacement therapy, which ceased to be necessary by 9 yr of age.

Results: Eight novel mutations were detected in the DUOX2 gene. Four patients in one family were compound heterozygous for p.L479SfsX2 and p.K628RfsX10. Two patients in a second family were compound heterozygous for p.K530X and p.[E876K;L1067S]. The two remaining unrelated patients were also compound heterozygous, for p.H678R/p.L1067S and p.A649E/p.R885Q, respectively.

Conclusion: All eight patients had biallelic mutations in the DUOX2 gene. We find that loss of DUOX2 activity results in transient congenital hypothyroidism and that transient congenital hypothyroidism caused by DUOX2 mutations is inherited as an autosomal recessive trait.
Effects of the Selective Progesterone Receptor Modulator Asoprisnil on Uterine Artery Blood Flow, Ovarian Activity, and Clinical Symptoms in Patients with Uterine Leiomyomata Scheduled for Hysterectomy
Authors: Wilkens Julia , Chwalisz Kristof , Han Cong , Walker Jane , Cameron Iain T. , Ingamells Susan , Lawrence Alexandra C. , Lumsden Mary Ann , Hapangama Dharani , Williams Alistair R. W. , Critchley Hilary O. D.
Published: September 2008

Introduction: Asoprisnil, a novel orally active selective progesterone receptor modulator, is being studied for the management of symptomatic uterine leiomyomata. The exact mechanism of action is not yet discerned. The primary objectives of this double-blind, randomized, placebo-controlled study included evaluation of the effect of asoprisnil on uterine artery blood flow. Furthermore, we assessed effects of asoprisnil on leiomyoma symptoms.

Patients and Methods: Thirty-three premenopausal patients scheduled for hysterectomy due to symptomatic uterine leiomyomata were recruited in four centers and treated with 10 or 25 mg asoprisnil or placebo for 12 wk before surgery. At baseline and before hysterectomy, all patients underwent sonographic assessment to measure impedance to uterine artery blood flow, determined by resistance index and pulsatility index, as well as volumes of largest leiomyoma and uterus. In addition, patients recorded intensity and frequency of menstrual bleeding on a menstrual pictogram. Each asoprisnil treatment was compared with placebo.

Results: The increased pulsatility index in both asoprisnil groups and the statistically significantly increased resistance index within the 25-mg asoprisnil group suggest a moderately decreased uterine artery blood flow. Analysis of menstrual pictogram scores showed a statistically significant larger decrease in frequency and intensity of bleeding for both asoprisnil groups compared with placebo. Bleeding was suppressed by asoprisnil 25mg in 91% of patients. Asoprisnil treatment was well tolerated when administered daily for a 12-wk period, and no serious adverse events occurred.

Conclusion: Asoprisnil moderately reduced uterine artery blood flow. This effect may contribute in part to the clinical effects of asoprisnil.
The In-House Conference
Authors: Daniell Beth , Davis Laura , Stewart Linda , Taber Ellen
Published: September 2008

The first-year writing program at Kennesaw State University has found its in-house conference (IHC) to be an important venue for faculty development. Based on the assumption that teachers actually know what they are doing, the IHC invites teachers of all ranks to propose a presentation on a selected topic and then to present those papers at conference sessions that other teachers attend. The IHC invites part-time faculty into the community, generates intellectual conversation about teaching across the lines of rank and hierarchy, allows the conversation to continue long after the conference since participants can see each other daily, and invites reflection on and modification of teaching. The success of the IHC serves as a reminder that some faculty development should be discipline-specific and local. In addition, the IHC asks teachers of writing to actually write themselves and allows them the opportunity for scholarship. The professional development that the IHC offers is not, however, limited to a writing program but can be used to stimulate intellectual engagement across the English department and, beyond that, to other departments across the university.
The Dynamics of Teacher Development
Authors: Kinzy Dana , Minter Deborah
Published: September 2008

This essay explores the underlying dynamics that inform postsecondary English teacher development efforts. In particular, it argues for a more expansive understanding of “context” in order to emphasize the inevitability of conflict and the productive potential of surfacing the meaningful contextual differences of our teaching lives. Such differences include varying philosophies of teaching and learning, competing motivations and expectations for participation in teacher development, and differing institutional teaching contexts where very different values might inhere. The essay offers strategies for engaging such differences with a view toward discerning collective (as well as individual) commitments. Such an orientation toward teacher development is crucial in the current climate, where plans for reform increasingly locate the work of remaking higher education outside of postsecondary classrooms. The kind of postsecondary teacher development work this essay calls for, then, seeks to support teachers' growth as agents of educational change.
Writing Centers and Cross-Curricular Literacy Programs as Models for Faculty Development
Authors: Bergmann Linda S.
Published: September 2008

The books under review here envision models of professional development not as episodes of developing skills or training faculty to conform to changing laws, rules, and pet projects of administrators, but rather as collaborative processes of education and reflection that encourage faculty to rethink their practices. They draw on research in composition theory and pedagogy, suggesting that more effective learning takes place when teachers trust learners to consider their own need for knowledge, invite learners to devise variations and applications of received knowledge, and resist keeping things simple to be sure they are correct. Applying different focuses, these books consider how to put teacher-learners at the center of the process of their own professional development. Jeffrey Jablonski argues that the expertise developed in composition studies needs to be recognized and respected in initiatives to implement Cross-Curricular Literacy programs. The writers of The Everyday Writing Center consider how, in the midst of increased professionalization, to maintain the serendipitous—even carnivalesque, at times—learning and teaching that the intimate and nonhierarchical space of a writing center can foster. And the collective wisdom in The Writing Center Director's Resource Book surveys the current state of writing center theory and practice, providing a reflective guide for developing the expertise of writing center administrators, who are (or could be) leaders in campus faculty development efforts.
Recruitment of mismatch repair proteins to the site of DNA damage in human cells
Authors: Hong Zehui , Jiang Jie , Hashiguchi Kazunari , Hoshi Mikiko , Lan Li , Yasui Akira
Published: September 2008

Mismatch repair (MMR) proteins contribute to genome stability by excising DNA mismatches introduced by DNA polymerase. Although MMR proteins are also known to influence cellular responses to DNA damage, how MMR proteins respond to DNA damage within the cell remains unknown. Here, we show that MMR proteins are recruited immediately to the sites of various types of DNA damage in human cells. MMR proteins are recruited to single-strand breaks in a poly(ADP-ribose)-dependent manner as well as to double-strand breaks. Using mutant cells, RNA interference and expression of fluorescence-tagged proteins, we show that accumulation of MutSβ at the DNA damage site is solely dependent on the PCNA-binding domain of MSH3, and that of MutSα depends on a region near the PCNA-binding domain of MSH6. MSH2 is recruited to the DNA damage site through interactions with either MSH3 or MSH6, and is required for recruitment of MLH1 to the damage site. We found, furthermore, that MutSβ is also recruited to UV-irradiated sites in nucleotide-excision-repair- and PCNA-dependent manners. Thus, MMR and its proteins function not only in replication but also in DNA repair.
The GPI-anchored superoxide dismutase SodC is essential for regulating basal Ras activity and for chemotaxis of Dictyostelium discoideum
Authors: Veeranki Sudhakar , Kim Bohye , Kim Leung
Published: September 2008

A genetic screen for Dictyostelium mutant displaying high level of constitutive phosphatidylinositol (3,4,5)-trisphosphate led to the finding that the glycosylphosphatidylinositol (GPI)-anchored superoxide dismutase SodC regulates small GTPase Ras. Cells that lack SodC exhibited constitutively high levels of active Ras, more membrane localization of GFP-PHcrac, and defects in chemoattractant sensing, cell polarization and motility. These defects of SodC-lacking cells were partially restored by expression of wild-type SodC but not by the catalytically inactive mutant SodC (H245R, H247Q). Furthermore, an inhibition of PI3K activity in SodC-deficient cells by LY294002 only partially restored chemoattractant sensing and cell polarization, consistent with the fact that SodC-deficient cells have aberrantly high level of active Ras, which functions upstream of PI3K. A higher level of active GFP-RasG was observed in SodC-deficient cells, which significantly decreased upon incubation of SodC-deficient cells with the superoxide scavenger XTT. Having constitutively high levels of active Ras proteins and more membrane localization of GFP-PHcrac, SodC-deficient cells exhibited severe defects in chemoattractant sensing, cell polarization and motility.
A crucial role in cell spreading for the interaction of Abl PxxP motifs with Crk and Nck adaptors
Authors: Antoku Susumu , Saksela Kalle , Rivera Gonzalo M. , Mayer Bruce J.
Published: September 2008

The dynamic reorganization of actin structures helps to mediate the interaction of cells with their environment. The Abl non-receptor tyrosine kinase can modulate actin rearrangement during cell attachment. Here we report that the Abl PxxP motifs, which bind Src homology 3 (SH3) domains, are indispensable for the coordinated regulation of filopodium and focal adhesion formation and cell-spreading dynamics during attachment. Candidate Abl PxxP-motif-binding partners were identified by screening a comprehensive SH3-domain phage-display library. A combination of protein overexpression, silencing, pharmacological manipulation and mutational analysis demonstrated that the PxxP motifs of Abl exert their effects on actin organization by two distinct mechanisms, involving the inhibition of Crk signaling and the engagement of Nck. These results uncover a previously unappreciated role for Abl PxxP motifs in the regulation of cell spreading.
Rab11 is required for synchronous secretion of chondroitin proteoglycans after fertilization inCaenorhabditis elegans
Authors: Sato Miyuki , Grant Barth D. , Harada Akihiro , Sato Ken
Published: September 2008

We previously identified a novel type of caveolin-enriched secretory vesicle in Caenorhabditis elegans oocytes. These vesicles undergo synchronous fusion with the plasma membrane immediately after fertilization, suggesting that they could be cortical granules that have been described in diverse animal species. Here, we report that these vesicles are indeed cortical granules, delivering essential chondroitin proteoglycans and mucin-like glycoproteins to the early embryonic extracellular matrices (ECMs). Furthermore, we have found that the small GTPase RAB-11 and the target-SNARE SYN-4 are required for cortical granule excoytosis after fertilization. In oocytes, SYN-4 localizes mainly to the plasma membrane, whereas GFP::RAB-11 accumulates transiently on the cortical granules during ovulation, immediately prior to fertilization. Importantly, cytokinesis defects in early embryos are commonly observed after depletion of either rab-11 or syn-4, producing a phenotype very similar to that observed after blockade of chondroitin synthesis. Taken together, our results indicate that at least part of the essential role for RAB-11 and SYN-4 in early embryogenesis is in the targeting of cortical granules to the plasma membrane during the precisely regulated secretion of ECM components.
Natural odor ligands for olfactory receptor neurons of the female mosquito Aedes aegypti: use of gas chromatography-linked single sensillum recordings
Authors: Ghaninia Majid , Larsson Mattias , Hansson Bill S. , Ignell Rickard
Published: September 2008

Female Aedes aegypti are vectors of dengue and yellow fever. Odor volatiles are the predominant cues that drive the host-seeking behavior of Ae. aegypti. Odorant molecules are detected and discriminated by olfactory receptor neurons (ORNs) housed in sensory hairs, sensilla, located on the antennae and maxillary palps. In a previous study, we used odor volatiles that are behaviorally and/or electrophysiologically active for Ae. aegypti and other mosquito species to show that antennal ORNs of female Ae. aegypti are divided into functionally different classes. In the present study, we have, for the first time, conducted gas chromatography-coupled single sensillum recordings (GC–SSR) from antennal trichoid and intermediate sensilla of female Ae. aegypti in order to screen for additional putative host attractants and repellents. We used headspace collections from biologically relevant sources, such as different human body parts (including feet, trunk regions and armpit), as well as a plant species used as a mosquito repellent, Nepeta faassenii. We found that a number of ORN types strongly responded to one or more of the biological extracts. GC–SSR recordings revealed several active components, which were subsequently identified through GC-linked mass spectrometry (GC–MS). Electrophysiologically active volatiles from human skin included heptanal, octanal, nonanal and decanal.
Research on diffusion behaviour of the computer integrated manufacturing philosophy
Authors: Xue C G , Cao H W , Gao W
Published: September 2008

The acceptance of the computer integrated manufacturing (CIM) approach is studied. In particular the uptake of improved versions of the original CIM concept is considered. The question arises of when faced with several versions of the CIM philosophy as well as different influencing factors, how can an enterprise make decisions on whether or not to implement the CIM approach. The adoption behavior is studied in terms of a diffusion process. First, under some assumptions, a non-linear differential model is constructed based on the Bass model, in which three kinds of enterprises are considered, and in which government influence is regarded as an important factor. Second, the stability of the model is analysed through a planar phasic chart, and qualitative results are given. Third, the non-linear model is simulated using the C programming language, and the results are found to be consistent with the qualitative results. Finally, the application of the diffusion model is discussed. The diffusion model assists enterprises to analyse the implementation and trends of the CIM philosophy, make reasonable decisions, and improve their competitive edge.
Key characteristics management in product lifecycle management: A survey of methodologies and practices
Authors: Zheng L Y , McMahon C A , Li L , Ding L , Jamshidi J
Published: September 2008

Key characteristics (KCs) play a significant role in product lifecycle management (PLM) and in collaborative and global product development. Over the last decade, KCs methodologies and tools have been studied and practiced in several domains of the product lifecycle, and many world-class companies have introduced KCs considerations into their product development practices. However, there has been no systematic survey of KCs techniques, methodologies, and practices in this respect. This paper aims to give a comprehensive survey of KCs methodologies, and practices from the perspective of enterprise integration and PLM. The paper firstly presents a holistic framework of KCs methodologies and practices through the product lifecycle, and summarizes the fundamentals of KCs including their definition and classification, KC flowdown, and the identification and selection of KCs. A review of the KCs methods and practices in the product lifecycle is then presented, particularly in engineering design, manufacturing planning, production and testing as well as information and knowledge management respectively. Finally, the problems and challenges for future research on KCs techniques are discussed.
Natural convection in porous media-filled triangular enclosure with a conducting thin fin on the hot vertical wall
Authors: Varol Y , Oztop H F , Pop I
Published: September 2008

The flow and heat transfer in a triangular enclosure filled with a fluid-saturated porous medium with a conducting thin fin on the hot vertical wall has been numerically analysed. The Darcy law model was used to write the governing equations and they were solved using a finite-difference method. Computations were carried out to analyse the effects of the Rayleigh number, length and location of fin, and thermal conductivity ratio. Results were presented for the local and mean Nusselt numbers, streamlines, and isotherms. It was found that attaching the conductive thin fin affects the heat transfer, flow fields, and temperature distributions. It was also found that heat transfer was reduced when the thin fin was attached onto the wall.
A theoretical—experimental method for the identification of the modified Cockroft—Latham ductile fracture criterion
Authors: Alexandrov S , Vilotic D
Published: September 2008

The primary objective of the present study is to show that in many practical cases of free surface fracture, the modified Cockroft—Latham ductile fracture criterion is reduced to a relation between two in-surface principal strains. This finding can be combined with an appropriate set of experimental data to determine the input parameter of the criterion and/or verify it. An illustrative example is provided.
Dynamic analysis of rotor's radial rub-impact in full degrees of freedom accounting for turborotor's non-linear clearance-excitation force
Authors: Yuan Zhenwei , Wang Sanbao , Yue Ximing , Li Zhinong , Chu Fulei
Published: September 2008

Dynamic behaviours of rotor's radial rub-impact in the presence of turborotor's non-linear clearance-excitation force are analysed by numerical simulations in all the six degrees of freedom of a rotor, which represent all the three kinds of vibrations: lateral, axial, and torsional vibrations. Results are displayed by bifurcation diagrams, waveforms, frequency spectrums, orbits, Poincare maps, and frequency waterfalls. Much more complicated dynamic behaviours are represented in these results. Compared with the case of pure rub-impact that does not involve any other non-linear elements, the stable motion regime is largely reduced, correspondingly the rotating speed threshold of rub-impact is also reduced slightly, and the complicated motion patterns appear in the early stage of rub-impact. Thick superharmonics and subharmonics emerge in axial and torsional vibrations, respectively, which are the typical characteristics of a chaotic motion. This indicates that the main motion pattern of the system is chaos. In the full range of investigated speed, the lateral vibrations nearly take on a sole synchronous component, and the axial vibration shows very rich superharmonic components, which mainly scatter in three thick superharmonic bands that approach to three fixed frequency components with their amplitudes growing as the rotating speed increases. The torsional vibration demonstrates rich subharmonics near half-time-frequency components, and the amplitudes of which increase with rotating speed. These conclusions are of great significance to the rotordynamic design and fault diagnostics of turborotor systems.
Reliability-based optimum design for mechanical problems using genetic algorithms
Authors: Tsai Y-T , Chang H-C
Published: September 2008

A reliability oriented design approach for mechanical or structural components is implemented primarily based on strength—stress interference (SSI) theory. This paper demonstrates a principle for combining SSI theory and an optimization technique for developing a reliability-based optimum design for mechanical problems. The independently paired information (strength and stress distributions) are basic while progressing reliability design. For a complex system, the independently paired information sometimes is not easily clarified due to the structural complexity or the coupled relationship of the loads. To treat these problems, the paper proposes to express the independently paired information from the viewpoint of supply-requirement of a design in performance. The supply (provided by a design) is analogized to the strength as well as the requirement (requested by the customer) to the stress. Based on the viewpoint of supply-requirement, the paper presents four types of performance-related reliability measurement to fulfil reliability design for mechanical problems. The reliability measurements are derived according to the related design variables that formulate the performance indexes. Next, the designed problem expressed with probabilistic formulation is transformed into an unconstrained minimization problem subjected to the constraints of the performance needs and its reliability target. Genetic algorithms (GAs) are used to find the optimal solution for the reliability design problem. The related theories and an example of design are reported in this paper to depict the proposed method.
Study on dynamic characteristics of angular ball bearing with non-linear vibration of rotor system
Authors: Wang L-Q , Cui L , Gu L , Zheng D-Z
Published: September 2008

A rotor system supported by an angular ball bearing displays very complicated non-linear behaviour due to non-linear Hertzian contact force. The non-linear force and moment caused by the ball bearing are calculated on the basis of the relationship between deflection, and five-degree-of-freedom dynamic equations of the rotor ball bearing system are established. The Newmark-β method and the Newton—Raphson method are used to solve the non-linear equations. The dynamic characteristics of angular ball bearings are computed, considering the non-linear vibration of the rotor system. Taking angular ball bearing QJS208ACQ4C1/HNP4 as an example, the effects of the vibration of the rotor system on bearing dynamic characteristics are analysed. The results show that the spin-to-roll ratio of balls, the slide ratio of the cage, and stiffness of the bearing all vary obviously with the non-periodic vibration range of the rotor; initial contact angle and axial load of the ball bearing change the non-linear dynamic nature of the rotor system and dynamic characteristics of the bearing. The rotor ball bearing system can work stably by choosing the structural and operation parameters reasonably.
Energy-free adjustment of gravity equilibrators by adjusting the spring stiffness
Authors: van Dorsser W D , Barents R , Wisse B M , Schenk M , Herder J L
Published: September 2008

Static balancing is a useful concept to reduce the operating effort of mechanisms. Spring mechanisms are used to achieve a constant total potential energy, thus eliminating any preferred position. Quasi-statically, the mechanism, once statically balanced, can be moved virtually without the operating energy. In some cases, it is desirable to adjust the characteristic of the balancer, for instance, due to a change in the payload in a gravity balanced mechanism. The adjustment of current static balancers requires significant operating energy. This paper will present a novel variant to adjust the spring- and linkage-based static balancers without the need for external energy. The variant makes use of the possibility to adjust the spring stiffness in an energy-conserving way by adjusting the number of active coils. The conditions under which it functions properly will be given, and a proof of the concept model will be shown.
Analytical solution for primary resonances of a rotating shaft with stretching non-linearity
Authors: Hosseini S A A , Khadem S E
Published: September 2008

In this paper, primary resonances of a simply supported rotating shaft with stretching non-linearity are studied. Rotary inertia and gyroscopic effects are included, but shear deformation is neglected. The equations of motion are derived with the aid of Hamilton's principle and then transformed to the complex form. To analyse the primary resonances, the method of multiple scales is directly applied to the partial differential equation of motion. The frequency—response curves are plotted for the first two modes. It is shown that these resonance curves are of the hardening type. The effects of eccentricity and the damping coefficient are investigated on the steady-state response of the rotating shaft.