bluuebunny/crossref_metadata_2025 huggingface dataset:
Contextual blending of ingroup/outgroup face stimuli and word valence: LPP modulation and convergence of measures
Authors: Hurtado Esteban , Haye Andrés , González Ramiro , Manes Facundo , Ibáñez Agustiń
Published: June 2009

Background

Several event related potential (ERP) studies have investigated the time course of different aspects of evaluative processing in social bias research. Various reports suggest that the late positive potential (LPP) is modulated by basic evaluative processes, and some reports suggest that in-/outgroup relative position affects ERP responses. In order to study possible LPP blending between facial race processing and semantic valence (positive or negative words), we recorded ERPs while indigenous and non-indigenous participants who were matched by age and gender performed an implicit association test (IAT). The task involved categorizing faces (ingroup and outgroup) and words (positive and negative). Since our paradigm implies an evaluative task with positive and negative valence association, a frontal distribution of LPPs similar to that found in previous reports was expected. At the same time, we predicted that LPP valence lateralization would be modulated not only by positive/negative associations but also by particular combinations of valence, face stimuli and participant relative position.

Results

Results showed that, during an IAT, indigenous participants with greater behavioral ingroup bias displayed a frontal LPP that was modulated in terms of complex contextual associations involving ethnic group and valence. The LPP was lateralized to the right for negative valence stimuli and to the left for positive valence stimuli. This valence lateralization was influenced by the combination of valence and membership type relevant to compatibility with prejudice toward a minority. Behavioral data from the IAT and an explicit attitudes questionnaire were used to clarify this finding and showed that ingroup bias plays an important role. Both ingroup favoritism and indigenous/non-indigenous differences were consistently present in the data.

Conclusion

Our results suggest that frontal LPP is elicited by contextual blending of evaluative judgments of in-/outgroup information and positive vs. negative valence association and confirm recent research relating in-/outgroup ERP modulation and frontal LPP. LPP modulation may cohere with implicit measures of attitudes. The convergence of measures that were observed supports the idea that racial and valence evaluations are strongly influenced by context. This result adds to a growing set of evidence concerning contextual sensitivity of different measures of prejudice.
Phylogenetic analysis and molecular evolution of the dormancy associated MADS-box genes from peach
Authors: Jiménez Sergio , Lawton-Rauh Amy L , Reighard Gregory L , Abbott Albert G , Bielenberg Douglas G
Published: June 2009

Background

Dormancy associated MADS-box (DAM) genes are candidates for the regulation of growth cessation and terminal bud formation in peach. These genes are not expressed in the peach mutant evergrowing, which fails to cease growth and enter dormancy under dormancy-inducing conditions. We analyzed the phylogenetic relationships among and the rates and patterns of molecular evolution within DAM genes in the phylogenetic context of the MADS-box gene family.

Results

The peach DAM genes grouped with the SVP/StMADS11 lineage of type II MIKCC MADS-box genes. Phylogenetic analyses suggest that the peach SVP/StMADS11-like gene family, which contains significantly more members than annual model plants, expanded through serial tandem gene duplication. We found evidence of strong purifying selection acting to constrain functional divergence among the peach DAM genes and only a single codon, located in the C-terminal region, under significant positive selection.

Conclusion

Because all DAM genes are expressed in peach and are subjected to strong purifying selection we suggest that the duplicated genes have been maintained by subfunctionalization and/or neofunctionalization. In addition, this pattern of selection suggests that the DAM genes are important for peach growth and development.
Leiomyosarcoma of the inferior vena cava: Radical surgery and vascular reconstruction
Authors: Alexander Andrea , Rehders Alexander , Raffel Andreas , Poremba Christopher , Knoefel Wolfram T , Eisenberger Claus F
Published: June 2009

Background

Vascular leiomyosarcoma are rare tumors typically originating from the inferior vena cava (IVC). Due to nonspecific clinical signs most tumors are diagnosed at advanced stages. Complete surgical resection remains the only potential curative therapeutic option. Surgical strategy is particularly influenced by the level of the IVC affected. Due to the topographic relation to the renal veins level-II involvement of the IVC raises special surgical challenges with respect to the maintenance of venous outflow.

Case presentation

We herein report two cases of leiomyosarcoma of the IVC with successful en bloc resection and individualized caval reconstruction. One patient presented with a large intramural and intraluminal mass and received a complete circumferential resection. Reconstruction was performed by graft replacement of the caval segment affected. The other patient displayed a predominantly extraluminal tumor growth and underwent semicircumferential resection of the IVC including the confluence of the left renal vein. In this case vascular reconstruction was performed by cavoplasty and reinsertion of the left renal vein into the proximal portion of the IVC. Resection margins of both patients were tumor free and no clinical signs of venous insufficiency of the lower extremity occurred.

Conclusion

This paper presents two cases of successfully managed leiomyosarcomas of the vena cava and exemplifies two different options for vascular reconstruction in level II sarcomas and includes a thorough review of the literature.
Development and Validation of a HPV-32 Specific PCR Assay
Authors: Herrel Nicholas R , Johnson Nadia L , Cameron Jennifer E , Leigh Janet , Hagensee Michael E
Published: June 2009

Background

Human Papillomavirus-32 (HPV-32) has traditionally been associated with focal-epithelial-hyperplasia (FEH). It is also present in 58% of oral warts of HIV-positive individuals whose prevalence is increasing. Current methods for the detection of HPV-32 are labor-intensive and insensitive so the goal of this work was to develop a highly sensitive and easy to use specific polymerase chain reaction (PCR) assay.

Materials and methods

An HPV-32 L1 specific PCR assay was developed and optimized. The sensitivity and specificity was compared to previous assays utilized for detection (PGMY and MY09/11 PCR with dot blot hybridization) using cloned HPV-32 L1, the closely related HPV-42 L1 as well as clinical samples (oral swabs and fluids from 89 HIV-positive subjects).

Results

The HPV-32 specific PCR assay showed improved sensitivity to 5 copies of HPV-32 as compared to the PGMY PCR, MY09/11 PCR and dot blot which had a limit of detection of approximately 3,000 copies. Using the HPV-32 dot blot hybridization assay as the gold standard, the HPV-32 specific PCR assay has a sensitivity of 95.8% and 88.9% by sample and subject, respectively, and specificity was 87.8% and 58.8% by sample and subject, respectively. The low sensitivity is due to the HPV-32 specific PCR assays ability to detect more HPV-32 positive samples and may be the new gold standard.

Conclusion

Due to the ease, sensitivity, and specificity the HPV-32 specific PCR assay is superior to previous assays and is ideal for detection of HPV-32 in large cohorts. This assay provides an excellent tool to study the natural history of HPV-32 infection and the development of oral warts.
Excitatory Neurotransmitters in Brain Regions in Interictal Migraine Patients
Authors: Prescot Andrew , Becerra Lino , Pendse Gautam , Tully Shannon , Jensen Eric , Hargreaves Richard , Renshaw Perry , Burstein Rami , Borsook David
Published: July 2009

Objective

To examine biochemical differences in the anterior cingulate cortex (ACC) and insula during the interictal phase of migraine patients. We hypothesized that there may be differences in levels of excitatory amino acid neurotransmitters and/or their derivatives in migraine group based on their increased sensitivity to pain.

Methods

2D J-resolved proton magnetic resonance spectroscopy (1H-MRS) data were acquired at 4.0 Tesla (T) from the ACC and insula in 10 migraine patients (7 women, 3 men, age 43 ± 11 years) and 8 age gender matched controls (7 women, 3 men, age 41 ± 9 years).

Results

Standard statistical analyses including analysis of variance (ANOVA) showed no significant metabolite differences between the two subject cohorts in the ACC nor the insula. However, linear discriminant analysis (LDA) introduced a clear separation between subject cohorts based on N-acetyl aspartylglutamate (NAAG) and glutamine (Gln) in the ACC and insula.

Conclusion

These results are consistent with glutamatergic abnormalities in the ACC and insula in migraine patients during their interictal period compared to healthy controls. An alteration in excitatory amino acid neurotransmitters and their derivatives may be a contributing factor for migraineurs for a decrease in sensitivity for migraine or a consequence of the chronic migraine state. Such findings, if extrapolated to other regions of the brain would offer new opportunities to modulate central system as interictal or preemptive medications in these patients.
Synaptically Evoked Glutamate Transporter Currents in Spinal Dorsal Horn Astrocytes
Authors: Zhang Haijun , Xin Wenjun , Dougherty Patrick M
Published: July 2009

Background

Removing and sequestering synaptically released glutamate from the extracellular space is carried out by specific plasma membrane transporters that are primarily located in astrocytes. Glial glutamate transporter function can be monitored by recording the currents that are produced by co-transportation of Na+ ions with the uptake of glutamate. The goal of this study was to characterize glutamate transporter function in astrocytes of the spinal cord dorsal horn in real time by recording synaptically evoked glutamate transporter currents.

Results

Whole-cell patch clamp recordings were obtained from astrocytes in the spinal substantia gelatinosa (SG) area in spinal slices of young adult rats. Glutamate transporter currents were evoked in these cells by electrical stimulation at the spinal dorsal root entry zone in the presence of bicuculline, strychnine, DNQX and D-AP5. Transporter currents were abolished when synaptic transmission was blocked by TTX or Cd2+. Pharmacological studies identified two subtypes of glutamate transporters in spinal astrocytes, GLAST and GLT-1. Glutamate transporter currents were graded with stimulus intensity, reaching peak responses at 4 to 5 times activation threshold, but were reduced following low-frequency (0.1 – 1 Hz) repetitive stimulation.

Conclusion

These results suggest that glutamate transporters of spinal astrocytes could be activated by synaptic activation, and recording glutamate transporter currents may provide a means of examining the real time physiological responses of glial cells in spinal sensory processing, sensitization, hyperalgesia and chronic pain.
CHOP5'UTR-c.279T>C and +nt30C>T variants are not associated with overweight condition or with tumors/cancer in Italians – a case-control study
Authors: Meenakshisundaram Ramachandran , Piumelli Nunzia , Pierpaoli Laura , Gragnoli Claudia
Published: June 2009

Background

Type 2 diabetes (T2D) is associated with obesity and has been shown recently to be associated with tumors/cancer. HNF1-beta and JAZF1 genes are associated with T2D and prostate cancer. We have previously shown that CHOP 5'UTR-c.279T>C and +nt30C>T haplotype variants contribute to T2D. CHOP deficiency causes obesity in mice, thus CHOP gene variants may contribute to human obesity. Furthermore, CHOP mediates apoptosis and is implicated in cancer pathogenesis. Hence, we aimed at identifying any potential association of CHOP 5'UTR-c.279T>C and +nt30C>T genotypes and corresponding haplotypes with overweight condition/pre-obesity and tumors/cancer in an Italian dataset.

Methods

We recruited from Italy 45 overweight subjects (body mass index (BMI) ≥ 25) and 44 control subjects (BMI < 25) as well as 54 cases with at least one cancer or at least one tumor and 43 control subjects without tumors/cancer from the general population. We excluded allelic departure from Hardy-Weinberg equilibrium in cases and control subjects, separately.

Results

We assessed the power to detect risk odds ratios by association tests in our datasets. We tested the hypothesis of association of CHOP 5'UTR-c.279T>C and +nt30C>T genotypes and haplotypes with tumors/cancer and, separately, with overweight condition. Both associations were not significant.

Conclusion

From our study, we may conclude that CHOP 5'UTR-c.279T>C and +nt30C>T genotypes and corresponding haplotypes are not associated with tumors/cancer and pre-obesity. However, more studies are warranted to establish the role of CHOP variants in tumor/cancer predisposition and in overweight condition.
Serotonin transporter genotype, morning cortisol and subsequent
depression in adolescents
Authors: Goodyer Ian M. , Bacon Alison , Ban Maria , Croudace Tim , Herbert Joe
Published: July 2009

Background

The short (s) allele of the serotonin transporter gene promoter
(5-HTTLPR) may be associated with exposure to social adversities and the
subsequent onset of depressive illness in adulthood.

Aims

To test in adolescents at high risk for depression whether the short ‘s’
allele is associated with levels of morning cortisol and the subsequent
onset of a depressive episode.

Method

High-risk adolescents (n = 403) were genotyped for
5-HTTLPR. Salivary samples were obtained on four consecutive school days
within 1 h of waking from 393 (97.5%) individuals and 367 (91%) underwent
a mental state reassessment at 12 months.

Results

Multilevel analysis revealed higher levels of salivary cortisol in short
allele carriers (s/s>s/l>l/l). A subsequent episode of depression
was increased in those with higher cortisol and the ‘s’ allele, and
independently by depressive symptoms at entry, in both genders.

Conclusions

The short allele of 5-HTTLPR may moderate the association between morning
cortisol and the subsequent onset of a depressive episode.
Moderation of antidepressant response by the serotonin transporter gene
Authors: Huezo-Diaz Patricia , Uher Rudolf , Smith Rebecca , Rietschel Marcella , Henigsberg Neven , Marušiˇ Andrej , Mors Ole , Maier Wolfgang , Hauser Joanna , Souery Daniel , Placentino Anna , Zobel Astrid , Larsen Erik Roj , Czerski Piotr M. , Gupta Bhanu , Hoda Farzana , Perroud Nader , Farmer Anne , Craig Ian , Aitchison Katherine J. , McGuffin Peter
Published: July 2009

Background

There have been conflicting reports on whether the length polymorphism in the promoter of the serotonin transporter gene (5-HTTLPR) moderates the antidepressant effects of selective serotonin reuptake inhibitors (SSRIs). We hypothesised that the pharmacogenetic effect of 5-HTTLPR is modulated by gender, age and other variants in the serotonin transporter gene.

Aims

To test the hypothesis that the 5-HTTLPR differently influences response to escitalopram (an SSRI) compared with nortriptyline (a noradrenaline reuptake inhibitor).

Method

The 5-HTTLPR and 13 additional markers across the serotonin transporter gene were genotyped in 795 adults with moderate-to-severe depression treated with escitalopram or nortriptyline in the Genome Based Therapeutic Drugs for Depression (GENDEP) project.

Results

The 5-HTTLPR moderated the response to escitalopram, with long-allele carriers improving more than short-allele homozygotes. A significant three-way interaction between 5-HTTLPR, drug and gender indicated that the effect was concentrated in males treated with escitalopram. The single-nucleotide polymorphism rs2020933 also influenced outcome.

Conclusions

The effect of 5-HTTLPR on antidepressant response is SSRI specific conditional on gender and modulated by another polymorphism at the 5' end of the serotonin transporter gene.
Developing an animal model for infantile spasms: pathogenesis, problems and progress
Authors: Marsh Eric D. , Golden Jeffrey A.
Published: July 2009

Infantile spasms (IS), the most common of the early epileptic encephalopathies, afflicts thousands of children each year and results in significant disability. Also known as West syndrome, IS is characterized by intractable stereotyped seizures, poor developmental outcome and a characteristic electroencephalogram (EEG) pattern. IS often progresses into another epileptic encephalopathy known as Lennox-Gastaut syndrome, and continues with the patient being burdened by lifelong epilepsy and varying degrees of mental retardation. Little is known about the biological basis of IS. As the etiologies of IS are diverse, the multiple causes must converge into a final common pathway that results in this specific epilepsy phenotype. Finding a model or models to test this final pathway is necessary both to understand why the greatest susceptibility to seizure development occurs during infancy and early childhood, and what underlies the decreased cognitive potential associated with IS. Furthermore, appropriate models would permit better testing of potential therapies directed specifically at IS. This review will describe the clinical features and etiologies of IS; the ideal features that IS models should contain; and the IS models that exist currently. Finally, we will discuss the limitations of these models and the potential avenues for future research on IS.
Mitochondrial dysfunction and Parkinson’s disease genes: insights from Drosophila
Authors: Park Jeehye , Kim Yongsung , Chung Jongkyeong
Published: July 2009

Parkinson’s disease (PD), one of the most common neurodegenerative disorders worldwide, currently lacks a cure. Although most PD cases occur sporadically, studies from rare genetic mutations give significant insights into addressing the pathological mechanism of not only familial PD, but also sporadic PD. Recent PD research focuses on generating genetic mutant animal models that recapitulate the features of human PD patients. Significant advances in PD research have resulted from studying Drosophila mutants of several identified PD-associated genes because they show strikingly visible phenotypes. In particular, previous studies with the Drosophila mutants parkin and PINK1, which are two common causative genes among PD familial forms, have suggested strongly that mitochondrial dysfunction is the prominent cause for the PD pathogenesis and that these two PD genes are in a common pathway, with Parkin downstream of PINK1. Recent genetic studies have revealed that the PINK1-Parkin pathway is involved in regulating the mitochondrial remodeling process. In addition, PINK1 was recently found to regulate the localization of Parkin through direct phosphorylation. Here, we briefly review these new and exciting findings in Drosophila PD models and discuss how using these models can further advance PD studies.
Researchers focus on inflammation at the Istituto Clinico Humanitas
Authors: Kain Kristin H.
Published: July 2009

With international recognition as a premier medical institute, the Istituto Clinico Humanitas pulls disease questions from their patients in the clinic into their preclinical work in the lab investigates.
Transmembrane segments of the dynamin Msp1p uncouple its functions in the control of mitochondrial morphology and genome maintenance
Authors: Diot Alan , Guillou Emmanuelle , Daloyau Marlène , Arnauné-Pelloquin Laetitia , Emorine Laurent J. , Belenguer Pascale
Published: July 2009

Mitochondrial morphology depends on the equilibrium between antagonistic fission and fusion forces acting on mitochondrial membranes. Inactivation of fusion induces the loss of mtDNA. When both fusion and fission are simultaneously inactivated, the loss of mtDNA is alleviated, along with mitochondrial fragmentation. Mechanisms involved in mtDNA maintenance thus seem to depend on a coordinated regulation of fusion and fission forces. We have studied the role of the dynamin Msp1p, a fusion effector in mitochondrial morphology, in relation to the maintenance of mtDNA. Two hydrophobic regions of Msp1p, predicted to be transmembrane segments, were shown to anchor the long form of the protein into mitochondrial membranes, whereas the short form, lacking these two domains, behaved as a peripheral membrane protein. Both domains were essential for the fusogenic activity of Msp1p, but deletion of the second domain alone induced loss of mtDNA and thus lethality. Our results demonstrate that the role of Msp1p in the control of mitochondrial morphology is distinct from that required for genome maintenance, and that only the latter function is essential for cell viability. This parallels recent observations that have distinguished the role of OPA1, the human orthologue of Msp1p, in mitochondrial dynamics from that in cristae organization and apoptosis. Furthermore, our observations may contribute to our understanding of the pathological mechanisms resulting from mutations in OPA1 that give rise to the ADOA syndromes.
Mouse ACF7 andDrosophilaShort stop modulate filopodia formation and microtubule organisation during neuronal growth
Authors: Sanchez-Soriano Natalia , Travis Mark , Dajas-Bailador Federico , Gonçalves-Pimentel Catarina , Whitmarsh Alan J. , Prokop Andreas
Published: July 2009

Spectraplakins are large actin-microtubule linker molecules implicated in various processes, including gastrulation, wound healing, skin blistering and neuronal degeneration. Expression data for the mammalian spectraplakin ACF7 and genetic analyses of the Drosophila spectraplakin Short stop (Shot) suggest an important role during neurogenesis. Using three parallel neuronal culture systems we demonstrate that, like Shot, ACF7 is essential for axon extension and describe, for the first time, their subcellular functions during axonal growth. Firstly, both ACF7 and Shot regulate the organisation of neuronal microtubules, a role dependent on both the F-actin- and microtubule-binding domains. This role in microtubule organisation is probably the key mechanism underlying the roles of Shot and ACF7 in growth cone advance. Secondly, we found a novel role for ACF7 and Shot in regulating the actin cytoskeleton through their ability to control the formation of filopodia. This function in F-actin regulation requires EF-hand motifs and interaction with the translational regulator Krasavietz/eIF5C, indicating that the underlying mechanisms are completely different from those used to control microtubules. Our data provide the basis for the first mechanistic explanation for the role of Shot and ACF7 in the developing nervous system and demonstrate their ability to coordinate the organisation of both actin and microtubule networks during axonal growth.
Wear analysis and prediction of the life of a riveting die used in the automotive industry
Authors: Tan C S , Ghassemieh E , Goh W T
Published: June 2009

Knowledge on the life span of the riveting dies used in the automotive industry is sparse. It is often the case that only when faulty products are produced are workers aware that their tool needs to be changed. This is of course costly both in terms of time and money. Responding to this challenge, this paper proposes a methodology which integrates wear and stress analysis to quantify the life of a riveting die. Experiments are carried out to measure the applied load required to split a rivet. The obtained results (i.e. force curves) are used to validate the wear mechanisms of the die observed using scanning electron microscopy. Sliding, impact, and adhesive wears are observed on the riveting die after a certain number of riveting cycles. The stress distribution on the die during riveting is simulated using a finite element (FE) approach. In order to confirm the accuracy of the FE model, the experimental force results are compared with the ones produced from FE simulation. The maximum and minimum von Mises' stresses generated from the FE model are input into a Goodman diagram and an S—N curve to compute the life of the riveting die. It is found that the riveting die is predicted to run for 4 980 000 cycles before failure.
Experimental investigation into selective laser melting of austenitic and martensitic stainless steel powder mixtures
Authors: Jerrard P G E , Hao L , Evans K E
Published: June 2009

Selective laser melting (SLM) is a novel additive layer manufacturing method that has been used to directly consolidate a wide range of metallic powders to form net-shape metallic parts for various engineering applications. It is capable of processing steel powders in a range of grades and also allowing the creation of custom alloys by consolidating the mixed powders of two or more grades. This study investigates the effects of varying the ratio of austenitic and martensitic powder mixtures on the laser consolidation of steel parts. Specimens were fabricated by SLM processing from 316L austenitic and 17-4PH martensitic stainless steel powder mixtures with varying composition ratios. Mechanical and magnetic properties of the specimens were assessed by micro-hardness testing and comparison of ‘magnetic adherence’ forces. The composition ratios of the mixed powders have been found to influence the laser consolidation mechanisms and the resulting microstructures in the specimens. The microstructures play an important role in altering the micro-hardness and the magnetic properties of the specimens and determining a definite relationship between these two properties. The results of this study prove that a new stainless steel grade can be produced via the SLM process to have tailored mechanical and magnetic properties.
Rail corrugation: Characteristics, causes, and treatments
Authors: Grassie S L
Published: June 2009

Rail corrugation is a phenomenon of great diversity but appears now to be substantially understood. This review proposes some differences in classification of the phenomenon to take account of work undertaken since a widely cited review was published by Grassie and Kalousek in 1993, it attempts to fill holes in an overall understanding of the problem, and answers questions that remained open in 1993 and several that have arisen since. All types of corrugation that have been documented to date are essentially constant-frequency phenomena. By treating the vehicle—track system in its entirety, treatments are proposed that impinge upon track and vehicle design as well as upon the wheel—rail interface where corrugation appears. There is no neat solution to rail corrugation, but it can be treated comprehensively and in many cases also prevented by using products that are already commercially available. Since the frequency of common wavelength-fixing mechanisms varies roughly in the range 50—1200 Hz, trains travelling at different speeds can produce corrugation of substantially similar wavelength by different mechanisms in different locations. Although historical data can no longer be checked, this is the most likely explanation of the belief that rail corrugation was a substantially constant-wavelength phenomenon.
Robust stability of stochastic genetic network with Markovian jumping parameters
Authors: Wang G , Cao J , Liang J
Published: June 2009

In this paper, the robust exponential stability problem is investigated for a class of Markovian jumping genetic networks which involve both uncertain parameters and stochastic disturbances. Under the assumption that the jumping parameters are generated from a continuous-time discrete-state homogeneous Markov process, the stability problem is first studied for a deterministic genetic model. By constructing suitable Lyapunov functionals and conducting some stochastic analysis, the stability criteria are derived in the form of linear matrix inequalities (LMIs), which can be easily checked in practice. Then, based on the derived results, sufficient LMI conditions are obtained explicitly for an indeterministic genetic system where the parameter uncertainties are norm-bounded. An illustrative example is presented to demonstrate the effectiveness and usefulness of the proposed stability criteria.
Passive output feedback control for non-linear systems with time delays
Authors: Luan X , Liu F , Shi P
Published: June 2009

This paper focuses on the passive output feedback control problem for a class of non-linear systems with time delays. By using multilayer neural networks as an off-line-aided design tool, a dynamic output feedback controller with certain dissipation is developed using the passive control theory in terms of linear matrix inequalities (LMIs), which guarantees the closed-loop system asymptotically stable and strictly passive. It is shown that the solvability of the passive controller design problem is implied by the feasibility of LMIs. A numerical example is given to demonstrate the validity of the proposed approach.
Emerging roles of microRNAs as molecular switches in the integrated circuit of the cancer cell
Authors: Sotiropoulou Georgia , Pampalakis Georgios , Lianidou Evi , Mourelatos Zissimos
Published: June 2009

Transformation of normal cells into malignant tumors requires the acquisition of six hallmark traits, e.g., self-sufficiency in growth signals, insensitivity to antigrowth signals and self-renewal, evasion of apoptosis, limitless replication potential, angiogenesis, invasion, and metastasis, which are common to all cancers (Hanahan and Weinberg 2000). These new cellular traits evolve from defects in major regulatory microcircuits that are fundamental for normal homeostasis. The discovery of microRNAs (miRNAs) as a new class of small non-protein-coding RNAs that control gene expression post-transcriptionally by binding to various mRNA targets suggests that these tiny RNA molecules likely act as molecular switches in the extensive regulatory web that involves thousands of transcripts. Most importantly, accumulating evidence suggests that numerous microRNAs are aberrantly expressed in human cancers. In this review, we discuss the emergent roles of microRNAs as switches that function to turn on/off known cellular microcircuits. We outline recent compelling evidence that deregulated microRNA-mediated control of cellular microcircuits cooperates with other well-established regulatory mechanisms to confer the hallmark traits of the cancer cell. Furthermore, these exciting insights into aberrant microRNA control in cancer-associated circuits may be exploited for cancer therapies that will target deregulated miRNA switches.
Application-Specific R&D Capabilities and the Advantage of Incumbents: Evidence from the Anticancer Drug Market
Authors: Sosa M. Lourdes
Published: June 2009

This paper examines the proposition that during competence-destroying technological changes, incumbents are incompetent in researching in house a radically new technology. They only retain market leadership if their undestroyed, proprietary complementary assets compensate for their research incompetence. In contrast to prior research, I propose that there is not one but two sets of capabilities necessary to execute research and development (R&D), sets that differ in their market specificity: a technology-specific set (i.e., technological platforms that are non-market specific) and an application-specific set (i.e., knowledge of the application that is therefore market specific). Although all markets require both sets of capabilities to execute R&D, prior research has analyzed cases where the application was not as complex, and therefore application-specific capabilities did not represent strategic factors. Because at the start of a technological discontinuity application-specific capabilities are undestroyed and have accrued only to incumbents, when complex enough, these capabilities can represent a source of competitive advantage for these firms, even in the face of competition from diversifying entrants reusing previously acquired technological platforms. I find evidence consistent with my proposition based on data on outcomes from drug discovery (as estimated through clinical endpoints in phase I trials) for firms competing in the anticancer drug market, one of the most complex markets within pharmaceuticals, as the market transitions into the biotechnology revolution. The proposition in this paper implies that although technological platforms can help firms move across markets, application-specific R&D capabilities can help firms retain leadership within a market across technological discontinuities.
Are We Wise About the Wisdom of Crowds? The Use of Group Judgments in Belief Revision
Authors: Mannes Albert E.
Published: June 2009

Recent research has advanced our understanding of how people use the advice of others to update their beliefs. Because groups and teams play a significant role in organizations and collectively are wiser than their individual members, it is important to understand their influence on belief revision as well. I report the results of four studies examining intuitions about group wisdom and the informational influence of groups. In their overt assessments, experimental participants rated larger groups as more accurate than smaller groups and discriminated more between them when group size was salient. When provided advice, participants relied more on groups than individuals to update their beliefs, but were only modestly sensitive to group size. Most were suboptimal in the use of that advice, overweighting their initial beliefs and underweighting the more valid judgment of the group. Thus although acknowledged in principle, the wisdom of crowds is only shallowly manifest in observed behavior.
Asymptotic Normality for EMS Option Price Estimator with Continuous or Discontinuous Payoff Functions
Authors: Yuan Zhushun , Chen Gemai
Published: June 2009

Empirical martingale simulation (EMS) was proposed by Duan and Simonato (Duan, J.-C., J.-G. Simonato. 1998. Empirical martingale simulation for asset prices. Management Sci. 44(9) 1218–1233) as an adjustment to the standard Monte Carlo simulation to reduce simulation errors. The EMS price estimator of derivative contracts was shown to be asymptotically normally distributed in Duan et al. (Duan, J.-C., G. Gauthier, J.-G. Simonato. 2001. Asymptotic distribution of the EMS option price estimator. Management Sci. 47(8) 1122–1132) when the payoffs are piecewise linear and continuous. In this paper, we extend the asymptotic normality result to more general continuous payoffs, and for discontinuous payoffs we make a conjecture.
Optimal Policies for Inventory Systems with Separate Delivery-Request and Order-Quantity Decisions
Authors: Li Qing , Wu Xiaoli , Cheung Ki Ling
Published: June 2009

Motivated by logistics practices, we consider a retailer that replenishes its inventory by making a delivery request without specifying a quantity, then deciding the quantity when the delivery vehicle arrives after one period. A fixed cost is incurred whenever a delivery request is made, regardless of the quantity ordered later. The new feature of this research relative to previous work is the separation of the delivery request and the quantity decision, or the postponement of ordering until one-period demand information is observed. Due to such separation, both the state space and the action space must be augmented in the model. We show that the optimal policy for delivery requests is of a threshold type: A delivery request is made if and only if the inventory on hand is below a threshold. The optimal decision on ordering is more complex, and there might be multiple order-up-to levels. Our numerical studies show, nonetheless, that the cost of an ordering policy that considers (at most) two order-up-to levels is close to the minimal when the planning horizon is not too short. We also identify conditions under which a base-stock policy is optimal for ordering. To understand the effects of ordering postponement, we compare our model with the traditional model in which the two decisions must be made at the same time. We show that postponement leads not only to a lower cost, but also a higher threshold for making delivery requests.
OR FORUM–Rocket Science Retailing: The 2006 Philip McCord Morse Lecture
Authors: Fisher Marshall
Published: June 2009

Retailing is a huge industry. In the United States, retail business represents about 40% of the economy and is the largest employer. Retail supply chain management is still more art than science, but this is changing rapidly as retailers begin to apply analytic models to the huge volume of data they are collecting on consumer purchases and preferences. This industry-wide movement resembles the transformation of Wall Street that occurred in the 1970s when physicists and other “rocket scientists” applied their analytic skills to investment decisions.

The Consortium for Operational Excellence in Retailing (COER) (codirected by Ananth Raman, Harvard Business School, and myself) is a group of academics working with about 50 leading retailers to assess their progress towards rocket science retailing and to accelerate that progress through selected research projects.

After some brief comments on the current state of industry practice in retail supply chain management, this paper will describe examples of COER research in four areas: assortment planning, pricing, inventory optimization, and store execution.
Evaluation of Hardness and Colour Change of Soft Liners after Accelerated Ageing
Authors: Mancuso Daniela Nardi , Goiato Marcelo Coelho , Zuccolotti Bruna Carolina Rossatti , Moreno Amália , Santos Daniela Micheline dos
Published: June 2009

Introduction

Soft liners have been developed to offer comfort to denture wearers. However, this comfort is compromised when there is a change in the properties of the material, causing colour change, solubility, absorption and hardening. These characteristics can compromise the longevity of soft liners.

Aim

The aim of this in vitro study was to investigate the effect of ageing on both the hardness and colour change of two soft liners following accelerated ageing.

Methods

Two denture liners, one resin based (Trusoft, Bosworth, Illinois, USA) and one silicone based (Ufi Gel P, Voco GMBH, Cuxhaven, Germany), were tested in this study for both hardness (using the Shore A scale) and colour change (using the CIE L*a*b* colour scale), initially and after 1008 hours (6 weeks) of accelerated ageing. Statistical analysis was performed using the unpaired t-test with the Welch correction.

Results

These indicated that both materials increased in hardness and underwent colour change after accelerated ageing. The initial hardness of Trusoft was far lower than that of Ufi Gel P (18.2 Shore A units vs 34.8 Shore A units). However, for Trusoft the changes for both hardness (from 18.2 to 52.1 Shore A units) and colour change (16.85 on the CIE L*a*b* colour scale) were greater than those for Ufi Gel P, for which hardness changed from 34.8 to 36.5 Shore A units and the colour change was 5.19 on the CIE L*a*b* colour scale.

Conclusions

Ufi Gel P underwent less hardness and colour change after accelerated ageing than Trusoft. On the other hand, the use of Trusoft may be preferable in cases where initial softness is a major consideration, such as when relining an immediate denture after implant surgery.
An Investigation of the Attitudes and Fears of Vocational Dental Practitioners in England and Wales in 2007
Authors: Willett Jane A , Palmer Nikolaus OA
Published: June 2009

Aim

The aim of this study was to investigate whether recent changes in the National Health Service (NHS) dental contract may have caused increased anxiety and concern among vocational dental practitioners (VDPs).

Method

A total of 606 questionnaires, which had previously been piloted, were distributed to VDPs across England and Wales at the end of the vocational training (VT) year in 2007. The questionnaires contained a range of questions about VDPs’ attitudes and fears, the influence that they perceived the new dental contract for the General Dental Services of the NHS had on their VT training experience, and their expectations for the future.

Results

A 71% response rate was achieved. The results reflected changes in opinion about the dental profession among VDPs between when they applied for university and six years later on their completion of VT. During this period, they reported that their feelings of job security had declined from 93.1% (n=390) to 34.1% (n=145) and financial security from 94.8% (n=405) to 51.5% (n=219). Anxiety about the potential lack of funding in the NHS was felt by 77.6% (n=330). The effect of increasing numbers of dental graduates on employment prospects produced anxiety in 72.5% (n=305) of VDPs. On completion of VT, 19.4% (n=83) of VDPs did not have employment for the following year.

Conclusion

At present, the future is more uncertain for new dental graduates than in the past. The dental profession needs to become more aware of the pressures that graduates are facing and further research is needed to investigate them and the effects that they are having on the future of dentistry.
Homeless who Accessed a Healthy Living Centre in Swansea, South Wales: An Assessment of the Impact of Oral Ill-Health
Authors: Richards Wayne , Keauffling Janet
Published: June 2009

Aim

To quantify the way that oral diseases affect the lives of homeless and vulnerable people in Swansea, using the short-form Oral Health Impact Profile (OHIP-14).

Method

A convenience sample of people using the services of a healthy living centre for the homeless was surveyed using a questionnaire and the short-form OHIP-14.

Results

One hundred subjects were recruited to the study. The mean score for the OHIP-14 was 21.8 (SD 17.0). The most commonly reported impacts experienced were problems with toothache, discomfort, ability to relax, and feeling ashamed regarding the appearance of teeth. Of the different categories of homeless people, rough sleepers experienced higher levels of impact ( P=0.004). Those having more than 20 teeth were more likely to experience lower levels of impact ( P=0.001).

Conclusion

The survey highlighted an increased prevalence of oral health impacts in this special needs group. In addition to physical factors, psychosocial factors must be considered, particularly with regard to appearance and psychological disability and discomfort, in the development of services.
Audit of Dental Practice Record-Keeping: A PCT-Coordinated Clinical Audit by Worcestershire Dentists
Authors: Cole Andrew , McMichael Alan
Published: June 2009

A collaborative audit of clinical record-keeping standards was performed among Worcestershire dentists.

Aims

Its aims were to improve the quality of National Health Service (NHS) patient care and to assist dentists to perform well during Dental Reference Service practice visits.

Methods

Worcestershire dentists with NHS contracts were invited to take part in this audit. Each dentist audited a random selection of 30 of their dental clinical records against a common framework comprising eight domains. Record-keeping, and the presence or absence of key diagnostic and treatment planning details were recorded. Grading was applied in four categories, in which grades 1 and 2 were good (1) and adequate (2), captured on data-collection sheets and centrally analysed for frequency of each grade.

Results

Out of a total of 184 Worcestershire general dental practitioners, 161 (87.5%) submitted usable responses. The audit revealed wide variation between dentists in clinical record-keeping. The recording of soft tissues (36% below grade 2), periodontal status (30%), radiographic review (27%), and note-taking (25%) all fell below the standard that had been set (brackets show proportion not meeting the standard).

Conclusions

The results provided baseline information about the standard of record-keeping in NHS dental practices in Worcestershire. The collaborative nature of the audit enabled dissemination of individual results to participants, to facilitate comparison (anonymously) against their peers. The audit provided impetus for the Primary Care Trust (PCT) to arrange postgraduate education on record-keeping and to raise awareness among local dentists about record-keeping. The subsequent report to dentists explored the record-keeping standards expected during practice inspections undertaken by the Dental Reference Service. Worcestershire PCT's method of collaborative dental audit could potentially replace the previous national programme of dental audit, formerly coordinated locally.
Multiple Supernumerary Premolars in Two Siblings: A Case Report
Authors: Cho Shiu-Yin
Published: June 2009

The presence of three or more supernumerary teeth in one patient is uncommon. Genetic as well as environmental causes have been suggested as possible aetiological factors in the pathogenesis of supernumerary teeth. This report describes the dental findings and management of multiple supernumerary premolars in two siblings. The number and locations of the supernumeraries in both cases were almost identical. The findings from these cases give further support to the important role of genetic factors in the aetiology of supernumerary teeth. Primary care dentists who treat children should be aware of the possibility of familial occurrence of supernumerary teeth.
A Pilot Study of the Prevalence of Orofacial and Head Injuries in Schoolboy Cricketers at Eight Private Schools in England and Australia
Authors: Jagger Robert G , Vaithianathan Vinny , Jagger Daryll C
Published: June 2009

Aims

The aims of this pilot study were to determine the prevalence of head, face and dental injuries sustained by schoolboys while playing cricket and to compare the prevalence of those injuries in England and Australia.

Methods

A questionnaire that determined distribution and prevalence of orofacial injuries sustained when playing cricket was distributed to all players (n=411) who played cricket in four private schools in England and four private schools in Australia. There was a 100% response rate.

Results

Fifty subjects (24.1%) from English schools and 52 subjects (25.5%) from Australian schools reported injury/injuries to the head, face and teeth. Australian cricketers reported more injuries per player. The distribution of injuries between the two countries was similar. Sixteen players had sustained loosened or broken teeth. Two players reported avulsed teeth.

Conclusion

It was concluded that there was a high prevalence of head and orofacial injuries among the schoolboy cricketers but relatively few dental injuries. The distribution of types of head, face and dental injury in England and Australia were similar.
Mentoring. A Quality Assurance Tool for Dentists Part 4: Some Tools for Mentoring and Coaching. The Mentoring Encounter
Authors: Holt Vernon P , Ladwa Russ
Published: June 2009

This paper reviews a range of tools that a mentor may use to facilitate the mentoring process. In particular, six ‘Master Tools’ are highlighted and discussed. Some tools represent mentor qualities and attitudes whereas others represent particular strategies, especially asking questions, which may be employed to move the conversation in a helpful direction for a mentee. The use of ‘scripts’ is described as part of a mentor's preparation for dealing with difficult or unexpected situations or questions. Because it is important for mentors to be able to give feedback effectively, a section of the paper is devoted to this aspect in which some specific tools are described. A brief description of transactional analysis is given and a template for use of the GROW model is illustrated.