bluuebunny/crossref_metadata_2025 huggingface dataset:
Profile beams with adaptive bending–twist coupling by adjustable shear centre location
Authors: Raither Wolfram , Bergamini Andrea , Ermanni Paolo
Published: August 2012

Semi-active structural elements based on variable stiffness represent a promising approach to the solution of the conflict of requirements between load-carrying capability and shape adaptivity in morphing lightweight structures. In the present work, a structural concept with adaptive bending–twist coupling aiming at a broad adjustment range of coupling stiffness while maintaining high flexural rigidity is investigated by analysis, simulation and experiment.
Health Care Experiences of Hispanics in New and Traditional U.S. Destinations
Authors: Gresenz Carole Roan , Derose Kathryn Pitkin , Ruder Teague , Escarce José J.
Published: August 2012

Over the past 15 years, striking new settlement patterns have emerged that have brought about unprecedented geographic dispersion in the population of approximately 45 million Hispanics in the United States. In this study, the authors compare the health care experiences of working age U.S.-born Mexican Americans and Mexican immigrants living in new and traditional Hispanic destinations. They use a geocoded version of the Medical Expenditure Panel Survey Household Component linked to contextual data from secondary sources. They characterize destinations as new or traditional using information on the percentage of the population that was Hispanic in 1990 and the growth in percent Hispanic between 1990 and 2000. The authors find that, compared with living in destinations with a well-established Hispanic presence, U.S.-born Mexican Americans living in new destinations have less favorable health care outcomes, including a greater probability of having an unmet need for or delay in receiving medical care and reduced satisfaction with care.
Improving the Effectiveness of Health Care Innovation Implementation
Authors: Birken Sarah A. , Lee Shoou-Yih Daniel , Weiner Bryan J. , Chin Marshall H. , Schaefer Cynthia T.
Published: August 2012

The rate of successful health care innovation implementation is dismal. Middle managers have a potentially important yet poorly understood role in health care innovation implementation. This study used self-administered surveys and interviews of middle managers in health centers that implemented an innovation to reduce health disparities to address the questions: Does middle managers’ commitment to health care innovation implementation influence implementation effectiveness? If so, in what ways does their commitment influence implementation effectiveness? Although quantitative survey data analysis results suggest a weak relationship, qualitative interview data analysis results indicate that middle managers’ commitment influences implementation effectiveness when middle managers are proactive. Scholars should account for middle managers’ influence in implementation research, and health care executives may promote implementation effectiveness by hiring proactive middle managers and creating climates in which proactivity is rewarded, supported, and expected.
Validity of Reported Medicare Part D Enrollment in the Medical Expenditure Panel Survey
Authors: Hill Steven C. , Zuvekas Samuel H. , Zodet Marc W.
Published: August 2012

The authors validate reported Part D coverage in the Medical Expenditure Panel Survey (MEPS) and assess the impact of misreporting on descriptive and behavioral analyses. MEPS participants with Medicare coverage during 2006 to 2007 were matched to Medicare administrative data. A summary measure of Part D coverage based on several questions has substantial validity (κ = .70) and an agreement rate of 85.1%. Some beneficiaries confused Part D and private drug coverage, leading to both under- and overreported Part D coverage. Accuracy varies little by sociodemographic group. Standard regression models of the determinants of Part D enrollment were estimated with both MEPS-based and administrative data–based measures of Part D enrollment. In this analysis, the signs of the marginal effects were the same, the magnitudes were similar, and mostly the same variables had statistically significant effects in both regressions. Thus, behavioral analyses are largely unaffected by misreporting.
Evaluation of the Duration of Action and Comparative Effectiveness of Lisdexamfetamine Dimesylate and Behavioral Treatment in Youth With ADHD in a Quasi-Naturalistic Setting
Authors: Manos Michael J. , Caserta Donald A. , Short Elizabeth J. , Raleigh Kristina L. , Giuliano Kimberly C. , Pucci Nicole C. , Frazier Thomas W.
Published: August 2012

Objective: This study compared the relative effects of three treatment conditions: long-acting stimulant medication (MED), behavior modification, and medication/behavioral treatments combined (COM) in children with ADHD. Method: A total of 25 children, aged 6 to 12 years, received the three treatment conditions during a 7-week Summer Treatment Program in an alternating treatments design. Counselors completed behavioral ratings from 0.5 to 12.5 hr post dose, and parents completed nighttime ratings. Results: Ratings for SKAMP (Swanson, Kotkin, Agler, M-Flynn, and Pelham) and for following instructions indicated COM and MED improved symptoms over BEH treatment beginning 3 hr post dose ( p = .008), with ratings maintained 12.5 hr post dose ( p = .001 and .006). Results for frustration tolerance indicated significant improvement in all three conditions until 9 hr post dose. Conclusion: MED and COM separated from BEH at 3 hr post dose, and sustained benefit was observed across the day for two of three measures. BEH appears to have an additive effect, extending the duration of frustration tolerance.
The Relationships Among ADHD, Self-Esteem, and Test Anxiety in Young Adults
Authors: Dan Orrie , Raz Sivan
Published: August 2012

Objective: The comorbidity of adult ADHD with test anxiety (TA) has not been previously reported. This comorbidity can potentially affect clinical and academic interventions among individuals with ADHD. The present study investigated the relationships among ADHD, self-esteem, and three subscales of TA among young adults: Cognitive Obstruction, Social Derogation, and Tenseness. Method: A total of 25 female participants diagnosed with ADHD and 30 female controls without ADHD of comparable age and education completed an Online Continuous Performance Test, an ADHD questionnaire, a self-esteem inventory, and a TA questionnaire. Results: Participants with ADHD exhibited significantly higher levels of TA on all three subscales and lower levels of self-esteem compared with controls. Self-esteem served as a partial mediator between ADHD and cognitive obstruction TA and as a full mediator between ADHD and social derogation TA, but had no mediation effect in the relationships between ADHD and tenseness TA. Conclusion: The findings of this study suggest that TA, well known to affect success on tests, is correlated with ADHD. Therefore, interventions for ADHD should include components aimed at reducing TA.
Intratask Variability As a Correlate for DRD4 and SLC6A3 Variants
Authors: Henríquez-Henríquez Marcela , Villarroel Luis , Henríquez Hugo , Zamorano Francisco , Rothhammer Francisco , Aboitiz Francisco
Published: August 2012

Behavioral variability may be an ADHD key feature. Currently used ex-Gaussian/Fast Fourier Transform analyses characterize general distribution and oscillatory/rhythmic components of performance but are unable to demonstrate slow cumulative changes over entire tasks. Objective: To explore how performance of ADHD children and unaffected sibs gradually evolves in relation to genetic variants linked to ADHD. Method: A total of 40 kids (20 ADHD-discordant sib pairs) between 8 and 13 years resolved a visual Go/NoGo with 10% NoGo probability. Variable number tandem repeats (VNTRs) at DRD4 and SLC6A3 were identified following standard protocols. Performance changes were assessed by linear/logistic mixed-effect models. Results: Models exploring SLC6A3 effects demonstrated less accentuated increments of response time (RT) ( p = .046) and cumulative increments in the correct responses to “NoGo” ( p = .00027) in 10R/10R participants. Models for DRD4 showed faster decline of correct responses to “Go” ( p = .0078) in 2R/7R carriers. Conclusion: Dynamical analysis of attention/inhibition measures may unravel new correlates to DRD4 and SLC6A3 variants.
Job-Related Burnout Among Civilian and Sworn Police Personnel
Authors: McCarty William P. , Skogan Wesley G.
Published: August 2012

Employee burnout can affect workers’ health, motivation, and job performance, and speed staff turnover. In law enforcement, burnout has been attributed to a variety of job-related, organizational, and personal factors, ranging from the danger inherent to the job to the liabilities of late shift work, tension with supervisors, and gender relations in the organization. Overlooked in almost all of these studies has been the place of civilians in police work, and how their burnout experiences differ from—or resemble—those of their sworn counterparts. This study is based on surveys of both sworn and civilian employees of 12 police agencies from across the United States. In the survey they described their extent of emotional exhaustion, and reported on features of their lives and work that have been hypothesized to magnify or minimize this stress reaction. The study found that the burnout process is a universal one, driven by virtually the same factors among both civilians and sworn officers. Difficulties balancing work and life responsibilities, the support they receive from coworkers and supervisors, the fairness of personnel policies, and several personal factors contributed to burnout levels. The implications of these findings for both research and practice are also explored.
The prosody of focus in the Spanish of Quechua-Spanish bilinguals: A case study on noun phrases
Authors: van Rijswijk Remy , Muntendam Antje
Published: August 2012

This study examines the prosody of focus in the Spanish of 16 Quechua-Spanish bilinguals near Cusco, Peru. Data come from a dialogue game that involved noun phrases consisting of a noun and an adjective. The questions in the game elicited broad focus, contrastive focus on the noun (non-final position) and contrastive focus on the adjective (final position). The phonetic analysis in Praat included peak alignment, peak height, local range and duration of the stressed syllable and word. The study revealed that Cusco Spanish differs from other Spanish varieties. In other Spanish varieties, contrastive focus is marked by early peak alignment, whereas broad focus involves a late peak on the non-final word. Furthermore, in other Spanish varieties contrastive focus is indicated by a higher F0 maximum, a wider local range, post-focal pitch reduction and a longer duration of the stressed syllable/word. For Cusco Spanish no phonological contrast between early and late peak alignment was found. However, peak alignment on the adjective in contrastive focus was significantly earlier than in the two other contexts. For women, similar results were found for the noun in contrastive focus. An additional prominence-lending feature marking contrastive focus concerned duration of the final word. Furthermore, the results revealed a higher F0 maximum for broad focus than for contrastive focus. The findings suggest a prosodic change, which is possibly due to contact with Quechua. The study contributes to research on information structure, prosody and contact-induced language change.
Early bilingualism influences early and subsequently later acquired languages in cortical regions representing control functions
Authors: Wattendorf Elise , Festman Julia , Westermann Birgit , Keil Ursula , Zappatore Daniela , Franceschini Rita , Luedi Georges , Radue Ernst-Wilhelm , Münte Thomas F. , Rager Günter , Nitsch Cordula
Published: August 2012

Early acquisition of a second language influences the development of language abilities and cognitive functions. In the present study, we used functional Magnetic Resonance Imaging (fMRI) to investigate the impact of early bilingualism on the organization of the cortical language network during sentence production. Two groups of adult multilinguals, proficient in three languages, were tested on a narrative task; early multilinguals acquired the second language before the age of three years, late multilinguals after the age of nine. All participants learned a third language after nine years of age. Comparison of the two groups revealed substantial differences in language-related brain activity for early as well as late acquired languages. Most importantly, early multilinguals preferentially activated a fronto-striatal network in the left hemisphere, whereas the left posterior superior temporal gyrus (pSTG) was activated to a lesser degree than in late multilinguals. The same brain regions were highlighted in previous studies when a non-target language had to be controlled. Hence the engagement of language control in adult early multilinguals appears to be influenced by the specific learning and acquisition conditions during early childhood. Remarkably, our results reveal that the functional control of early and subsequently later acquired languages is similarly affected, suggesting that language experience has a pervasive influence into adulthood. As such, our findings extend the current understanding of control functions in multilinguals.
Misfire detection and re-ignition control by ion current signal feedback during cold start in two-stage direct-injection engines
Authors: Fan Qianwang , Bian Jiang , Lu Haifeng , Tong Sinyu , Li Liguang
Published: August 2012

A misfire detection and re-ignition control device based on an ion current signal is designed, and a method for calculating the threshold level of an ion current integral signal is proposed to judge a misfire event. Based on the combustion cycle control strategy, start-up combustion cycle misfire detection and re-ignition control are investigated in a TSDI-Two Stage Direct Injection gasoline engine using ion current signal feedback. The results show that it is feasible for the ion current integral signal to be used for misfire detection and re-ignition control. In the experiment, when the ion current integral signal is larger than the misfire threshold level ( Umisfire>0.5 V), the ion current exists in the combustion chamber, the in-cylinder fuel–air mixture combusts, and the re-ignition event cannot occur. When the ion current integral signal is smaller than the misfire threshold level ( Umisfire<0.5 V), the ion current is close to zero, the misfire event occurs, and re-ignition takes place. As far as hydrocarbon emissions are concerned, the level of unburnt hydrocarbons under successful ignition is lowest, the level of unburnt hydrocarbons under successful re-ignition is higher, and the level of unburnt hydrocarbons under unsuccessful ignition and re-ignition is the highest. Hence, the start-up combustion cycle misfire detection and re-ignition control based ion current signal feedback strategy is favorable for reducing unburnt hydrocarbon emissions.
Identification, Emotional Reactions, and Perceived Threat to Persons With Alzheimer’s Disease
Authors: Kalaitzaki Argyroula E. , Kateri Evangellia , Pattakou-Parasyri Vassiliki
Published: August 2012

Background/rationale:

The identification of Alzheimer’s Disease (AD), the emotional reactions, and the perceived threat to AD were compared across 3 Greek samples: 147 primary care health professionals (PCHPs), 74 health and social service graduate students, and 99 laypersons. Within the group of PCHPs, physicians, nurses, and social workers were compared. The factors associated with emotional reactions were examined. Finally, the Emotional Reactions Scale’s (ERS) latent structure was validated.

Methods:

The participants were asked to identify the disease of a vignette, respond to the ERS and in 3 indices of perceived threat.

Results:

The PCHPs identified AD equally accurate to laypersons. Students and laypersons reported the most intense emotions. Social workers perceived higher consequences than physicians and nurses. Age, personal experience, education, and perceived concern predicted emotional reactions.

Conclusions:

Findings underscore the importance of implementing education and training actions to increase AD identification, reduce negative emotions, and further advance care for patients.
The Development of Motivation to Lead and Leader Role Identity
Authors: Waldman David A. , Galvin Benjamin M. , Walumbwa Fred O.
Published: August 2012

Leadership development has been continually recognized by organizations as a competence and a mind-set that is worthy of substantial time and resources. Although various approaches have stressed the development of skills or behaviors, it is becoming increasingly apparent that the development of attitudes and belief systems is also relevant. In an effort to increase knowledge in this area, the authors conducted a quasi-experimental study to understand whether motivation to lead (social-normative) and leader role identity would increase in business students exposed to behavior-modeling methods emphasizing the importance of transformational leadership. The results show that, in comparison with students in an introduction to management course, the quasi-experimental–condition students significantly increased the value that they placed on the leader role, as well as their identity as leaders. The findings are discussed in terms of both theoretical and practical implications.
Comparison of the resonance behaviour of ottertail and voyageur style canoe paddles during the J-stroke
Authors: Runciman R John , Lyle Kara
Published: August 2012

The canoe paddle has immense cultural and historical significance. Recognized throughout the world, the paddle has remained largely unchanged since its inception thousands of years ago.

A major characteristic of performance in a recreational canoe paddle, and one that distinguishes a good paddle from a bad one, involves its tendency to resonate during use. With paddle resonance comes increased fluid resistance and a less efficient stroke. This study compared resonance tendencies of two major types of recreational canoe paddles, the ottertail and voyageur styles, in stiff and flexible formats. Data was acquired during open water canoe use and canoe velocities up to 2.0 m/s

During testing two 3-axis accelerometers were mounted on the shaft of the subject paddle. These accelerometers were then connected to onboard data collection instrumentation to record paddle resonance behaviour. Concurrent GPS-based canoe velocities were also recorded. The conventional J-stroke was used for all testing, and the canoe was repeatedly paddled between known points spaced approximately 100 m apart.

Fluid driven resonance was observed at two specific phases of the J-stroke, the beginning of the control phase and the beginning of the recovery phase. The magnitude and characteristics of paddle resonance varied with the specific phase of the stroke, canoe paddle stiffness, style and velocity. The combination of these factors that resulted in the lowest paddle resonance of the combinations studied was a flexible ottertail style paddle, being paddled in the range of 1–1.8 m/s.
Efficacy, safety and tolerability of tocilizumab in patients with systemic juvenile idiopathic arthritis
Authors: Yokota Shumpei , Tanaka Toshio , Kishimoto Tadamitsu
Published: August 2012

Systemic juvenile idiopathic arthritis (SJIA), a subtype of juvenile idiopathic arthritis, is characterized by systemic features, such as spiking fever, salmon-colored macular rash, serositis, lymphadenopathy, hepatosplenomegaly, and joint inflammation. It is also often complicated with growth retardation, osteoporosis, and sometimes macrophage activation syndrome (MAS) develops, a potentially fatal disease. Pathogenesis of SJIA and MAS is not yet fully understood, but activation of the innate immune system, which causes phagocytosis by dendritic cells, monocytes, and macrophages to produce proinflammatory cytokines such as interleukin-6 (IL-6), IL-1β and IL-18, is thought to be a primary abnormality associated with SJIA. Dysregulated production of IL-6 plays a major role in the development of systemic clinical features. The blockade of IL-6 might thus represent a novel strategy for the treatment of SJIA. Several phase II and III clinical trials of a humanized anti-IL-6 receptor antibody, tocilizumab, proved its outstanding efficacy and tolerable safety profile for SJIA refractory to conventional treatment regimens. This resulted in the approval of tocilizumab for the treatment of SJIA in Japan, India, the EU and the USA.
Management and evaluation of extra-articular manifestations in spondyloarthritis
Authors: van der Horst-Bruinsma Irene E. , Nurmohamed Michael T.
Published: August 2012

Spondyloarthritis (SpA) is a chronic inflammatory disease with either predominantly axial symptoms of the spine and sacroiliac joints (axial SpA, including ankylosing spondylitis) or predominantly arthritis (peripheral SpA). Next to these spinal and articular symptoms, many patients with SpA also have extra-articular manifestations (EAMs). EAMs associated with SpA include anterior uveitis (25–30%), psoriasis (10–25%) or inflammatory bowel disease (IBD) (5–10%) and cardiovascular manifestations. Peripheral arthritis occurs in approximately 30% of patients, especially in large joints, and shows an asymmetrical, oligoarticular pattern. Other common joint complaints are due to enthesitis, which manifest as extra-articular bony tenderness in areas such as the Achilles tendon. Acute anterior uveitis presents with acute pain, loss of vision and redness in one eye that usually subsides spontaneously after several weeks. Rapid treatment by an ophthalmologist is required to prevent synechiae formation which could ultimately result in glaucoma and blindness. Although less common, organ involvement in SpA can also be located in the heart, lungs or kidneys. The risk of cardiovascular events is increased in SpA. Cardiac manifestations can involve the aortic valve (1–10%) or the atrioventricular node and the risk of atherosclerotic events is increased in this group. Treatment of SpA includes physical exercise and nonsteroidal anti-inflammatory drugs (NSAIDs), and in case of peripheral arthritis, sulphasalazine can be added. When there is insufficient response to NSAIDs, tumor necrosis factor blockers, especially infliximab, etanercept, adalimumab and golimumab, are very effective in treating axial manifestations, arthritis, enthesitis and psoriasis. Anterior uveitis in SpA can be treated adequately by the ophthalmologist and in the case of refractory uveitis, treatment with adalimumab and infliximab seems to be more effective compared with etanercept. When IBD occurs with SpA, the use of NSAIDs should be minimized, except for celecoxib, and infliximab or adalimumab are preferred to etanercept. The incidence of atherosclerotic events or SpA-specific cardiac manifestations may be decreased by cardiovascular risk management or effective antirheumatic treatment. Overall it is important to realize that extra-articular manifestations frequently occur in patients with SpA and should be taken into account in the choice of treatment.
New technique of filling friction stir welding
Authors: Huang Y X , Han B , Tian Y , Liu H J , Lv S X , Feng J C , Leng J S , Li Y
Published: August 2012

A new technique of filling friction stir welding (FFSW) relying on a semiconsumable joining tool has been developed to repair the keyhole left at the end of friction stir welding (FSW) seam. The conventional non-consumable tool of FSW was transformed, and a semiconsumable joining tool consisting of alloy steel shoulder and aluminium alloy joining bit was designed to create a solid state joint. Using the combined plastic deformation and flow of the consumable joining bit and the wall of the keyhole, the FFSW process is able to repair the keyhole with both metallurgical and mechanical bonding characteristics, and the FSW seam can be achieved without keyhole or other defects. The relative tensile strength and elongation of the FFSW joint are 84·3 and 98·9% of the base weld without defects respectively.
Design of optimal joining for friction stir spot welding of polypropylene sheets
Authors: Mert Ş , Arıcı A
Published: August 2012

The aim of this paper is to investigate the joint strength of adhesive bonding, friction stir spot welding (FSSW) and hybrid joining as FSSW–adhesive bonding on lap joints of polypropylene plates separately. In addition, the different overlap configurations were studied. The FSSW and weld bonding had higher joint strengths than adhesive bonding, but the FSSW joint was the highest. It reached 93% of the base material strength for the configuration of welded type 2 design.
Autogenous laser welding investigations on modified 9Cr–1Mo (P91) steel
Authors: Shanmugarajan B , Padmanabham G , Kumar H , Albert S K , Bhaduri A K
Published: August 2012

Modified 9Cr–1Mo steel plates of 6 mm thickness have been laser welded using CO2 laser. The effects of beam intensity and overall heat input (168-1500J/mm) on the bead characteristics, microstructure and mechanical properties of the welds have been investigated by varying the laser welding parameters such as laser beam mode, power and welding speed. The microhardness survey carried out on the welds after post-weld heat treatment did not reveal any soft zones in the intercritical heat affected zone for welds made with a heat input of up to 420 J mm−1. The tensile strengths of the welds were comparable to that of the base material. Charpy impact tests on subsize specimens revealed that the welds have good toughness. δ-Ferrite was observed in the fusion zone of the welds made at heat input of 700 J mm−1 and above, the content of which increased with the increased heat input.
Minimising electrode wear in resistance spot welding of aluminium alloys
Authors: Patil R R , Anurag Tilak C J K , Srivastava V , De A
Published: August 2012

Rapid electrode wear due to localised random alloying between copper and aluminium at high temperature is by far the greatest challenge for the resistance spot welding of aluminium alloys. An effective recourse would be to enhance the overall electrical conductivity along the electrode/sheet interface to reduce the resistive heating of copper electrode and to prohibit direct contact between electrode and sheet during welding. We propose here the application of carbon black paste in fluidic form as a barrier along the electrode/sheet interface both for the enhancement of electrical conductivity and for the prohibition of direct electrode to sheet contact. Carbon black is chemically inert to both copper and aluminium and in fluidic form allows the enhancement of thermal and electrical conductance due to better conformability within a pressurised contact. The present experimental study has shown a significant enhancement in electrode life in the presence of the carbon black based barrier coating along the interface.
Development of Ag based brazing filler metal with low melting point
Authors: Watanabe T , Yanagisawa A , Sasaki T
Published: August 2012

This study was carried out to develop cadmium free silver based brazing filler metals that meet the following requirements. First, they have to have a melting point lower than that of BAg-1 brazing filler metal. Second, they have to have not only good wetting characteristics and the ability to produce a sound joint with excellent mechanical properties but also plastic formability. Using the calculated phase diagrams on Ag–Cu–Zn–Sn quaternary system alloys, the authors selected several alloys with a possibility of meeting the above requirements. The melting point and other properties, such as hardness and brazeability of the selected alloys, were evaluated. As a result, the authors successfully developed silver based brazing filler metals that have a low melting point below ∼600°C and meet the above requirements by adding a small amount of indium as an alloying element into the Ag–Cu–Zn–Sn quaternary system alloy. The newly developed brazing filler metals are slightly inferior in wetting characteristics to BAg-1; however, the brazing filler metal containing ∼3 mass-% indium element showed wetting characteristics comparable to those of BAg-1. Furthermore, the new brazing filler metals could produce joints with a high tensile strength equivalent to ∼83% of that of a joint brazed using BAg-1.
Martensite nucleation site and grain refinement in duplex titanium alloy weldment by active flux with nanoparticle addition
Authors: Hsu P-W , Chen R-S , Kao F-H , Wang S-H , Yang J-R , Tsai S-Y , Duh J-G
Published: August 2012

The effects of activating flux containing nanoparticles on the welding microstructure and hardness distribution of titanium alloy were investigated. The fluxes, consisting of NaF with 1 wt-% of either nano-TiO2 or nanodiamond, effectively yielded refined grain size and deep weld penetration. The hardness of the weldment was close to that of the base metal for 99 wt-% NaF plus 1 wt-% diamond, leading to a desirable uniform mechanical property in the weld design. In the meantime, the transmission electron microscopy images illustrate that the nanoparticles promote β phase coarsening and martensitic α′ phase formation at the β veins.
Fatigue crack growth of bainitic rail steel welds
Authors: Allie A , Aglan H , Fateh M
Published: August 2012

The objective of the present study is to develop and evaluate novel weld repairs of bainitic rail steel defects, such as detail fracture, induced by in service loading. Slots were machined in the bainitic rail steel to simulate the removal of service defects. Multipass gas metal arc welding was used to fill and repair the slots. Three-point bend tests of the parent and welded steels revealed that the flexural weld efficiency was 75%. Fatigue crack propagation (FCP) tests were performed on specimens from the welded joints and compared with the parent materials to determine the mechanical integrity of the slot repairs. The fatigue lifetime and FCP kinetics were similar for the parent and slot welded bainitic steels, indicating similar resistance to FCP. The fatigue fracture surface morphology of the parent and welded bainitic rail steels both revealed mostly a ductile fracture mechanism in all the three FCP stages.
Resistance microwelding of 316L stainless steel wire to block
Authors: Friis K S , Khan M I , Bay N , Zhou Y
Published: August 2012

The excellent corrosion resistance of low carbon vacuum melted 316 stainless steel coupled with its non-magnetic properties makes it ideal for biomedical applications. The typical joint geometry for microcomponents, such as medical implants, includes joining of fine wire to a larger block. However, this type of joint has received little attention in the current literature. The present study was conducted to examine the microstructure and mechanical properties of low carbon vacuum melted 316 stainless steel wire welded to a larger block. Results revealed solid state bonding occurring at low currents, while fusion bonding occurred at higher currents. This was due to the highly asymmetrical heat generation resulting in almost complete melting of the wire before the initiation of interfacial melting. This is a distinctly different bonding mechanism compared to previous studies on crossed wire joints.
Shear strength of Cu/In–48Sn/Cu diffusion soldered interconnections
Authors: Wojewoda-Budka J , Zieba P
Published: August 2012

This paper presents the results of shear tests performed on Cu/In–48Sn/Cu diffusion soldered interconnections at the room and elevated temperatures of 373 and 423 K. Before the tests, the microstructure characterisation and chemical microanalysis of the joint area were performed. Termination of the diffusion soldering process led to the significant increase in the ultimate shear strength values. These values differed because of the type of the intermetallic phase that fulfilled the joined area: 11·2 MPa for [Cu6(Sn,In)5] and 28·5 MPa for [Cu41(Sn,In)11] phase. The shear tests performed at higher temperatures revealed a very good strength of the joints (9·8 MPa), especially for those with only the [Cu41(Sn,In)11] phase where fracture occurred inside the copper substrate. In the case of joints where unconsumed solder, [Cu6(Sn,In)5] and/or [Cu41(Sn,In)11], phases were present, the fracture surfaces observations allowed concluding that the crack propagated mostly through the intermetallic/solder interface or inside the intermetallic phase.
Dysfunctional Vγ9Vδ2 T cells are negative prognosticators and markers of dysregulated mevalonate pathway activity in chronic lymphocytic leukemia cells
Authors: Coscia Marta , Vitale Candida , Peola Silvia , Foglietta Myriam , Rigoni Micol , Griggio Valentina , Castella Barbara , Angelini Daniela , Chiaretti Sabina , Riganti Chiara , Guarini Anna , Drandi Daniela , Ladetto Marco , Bosia Amalia , Foà Robin , Battistini Luca , Boccadoro Mario , Fournié Jean-Jacques , Massaia Massimo
Published: August 2012

The role of Vγ9Vδ2 T cells in chronic lymphocytic leukemia (CLL) is unexplored, although these cells have a natural inclination to react against B-cell malignancies. Proliferation induced by zoledronic acid was used as a surrogate of γδ TCR-dependent stimulation to functionally interrogate Vγ9Vδ2 T cells in 106 untreated CLL patients. This assay permitted the identification of responder and low-responder (LR) patients. The LR status was associated with greater baseline counts of Vγ9Vδ2 T cells and to the expansion of the effector memory and terminally differentiated effector memory subsets. The tumor immunoglobulin heavy chain variable region was more frequently unmutated in CLL cells of LR patients, and the mevalonate pathway, which generates Vγ9Vδ2 TCR ligands, was more active in unmutated CLL cells. In addition, greater numbers of circulating regulatory T cells were detected in LR patients. In multivariate analysis, the LR condition was an independent predictor of shorter time-to-first treatment. Accordingly, the time-to-first treatment was significantly shorter in patients with greater baseline numbers of total Vγ9Vδ2 T cells and effector memory and terminally differentiated effector memory subpopulations. These results unveil a clinically relevant in vivo relationship between the mevalonate pathway activity of CLL cells and dys-functional Vγ9Vδ2 T cells.
Elevated serum soluble CD40 ligand in cancer patients may play an immunosuppressive role
Authors: Huang Jianping , Jochems Caroline , Talaie Tara , Anderson Austin , Jales Alessandra , Tsang Kwong Y. , Madan Ravi A. , Gulley James L. , Schlom Jeffrey
Published: August 2012

Tumor cells can induce certain cytokines and soluble receptors that have a suppressive effect on the immune system. In this study, we showed that an extracellular portion of a membrane-bound ligand of CD40 (soluble CD40 ligand; sCD40L) was significantly elevated in the serum of cancer patients compared with healthy donors. In addition, PBMCs from cancer patients had a relatively larger population of myeloid-derived suppressor cells (MDSCs), defined as CD33+HLA-DR− cells, and these cells expressed higher levels of CD40. T-cell proliferation and IFN-γ production decreased when stimulated T cells were cocultured with an increased amount of autologous MDSCs. The addition of recombinant monomeric sCD40L enriched MDSCs and had an additive inhibitory effect on T-cell proliferation. PBMCs cultured in vitro with sCD40L also showed an expansion of regulatory T cells (CD4+CD25highFoxp3+), as well as induction of cytokines, such as IL-10 and IL-6. Moreover, sCD40L-induced enrichment of programmed death-1–expressing T cells was greater in cancer patients than in healthy donors. Preexisting sCD40L also inhibited IL-12 production from monocytes on activation. These data suggest that the higher levels of sCD40L seen in cancer patients may have an immunosuppressive effect. These studies were registered at www.clinicaltrials.gov as NCT00060528, NCT00019695, NCT00179309, NCT00514072, NCT00081848, and NCT00436956.
Roles of microRNAs in atherosclerosis and restenosis
Authors: Chen Li-Jing , Lim Seh Hong , Yeh Yi-Ting , Lien Sheng-Chieh , Chiu Jeng-Jiann
Published: August 2012

Atherosclerosis is commonly appreciated to represent a chronic inflammatory response of the vascular wall, and its complications cause high mortality in patients. Angioplasty with stent replacement is commonly performed in patients with atherosclerotic disease. However, the restenosis usually has a high incidence rate in angioplasty patients. Although the pathophysiological mechanisms underlying atherosclerosis and restenosis have been well established, new signaling molecules that control the progress of these pathologies have continuously been discovered. MicroRNAs (miRs) have recently emerged as a novel class of gene regulators that work via transcriptional degradation and translational inhibition or activation. Over 30% of genes in the cell can be directly regulated by miRs. Thus, miRs are recognized as crucial regulators in normal development, physiology and pathogenesis. AIterations of miR expression profiles have been revealed in diverse vascular diseases. A variety of functions of vascular cells, such as cell differentiation, contraction, migration, proliferation and inflammation that are involved in angiogenesis, neointimal formation and lipid metabolism underlying various vascular diseases, have been found to be regulated by miRs. This review summarizes current research progress and knowledge on the roles of miRs in regulating vascular cell function in atherosclerosis and restenosis. These discoveries are expected to present opportunities for clinical diagnostic and therapeutic approaches in vascular diseases resulting from atherosclerosis and restenosis.
Daidzein induces neuritogenesis in DRG neuronal cultures
Authors: Yang Shih-Hung , Liao Chih-Chen , Chen Ying , Syu Jhih-Pu , Jeng Chung-Jiuan , Wang Seu-Mei
Published: August 2012

Absract

Background

Daidzein, a phytoestrogen found in isoflavone, is known to exert neurotrophic and neuroprotective effects on the nervous system. Using primary rat dorsal root ganglion (DRG) neuronal cultures, we have examined the potential neurite outgrowth effect of daidzein.

Methods

Dissociated dorsal root ganglia (DRG) cultures were used to study the signaling mechanism of daidzein-induced neuritogenesis by immunocytochemistry and Western blotting.

Results

In response to daidzein treatment, DRG neurons showed a significant increase in total neurite length and in tip number per neuron. The neuritogenic effect of daidzein was significantly hampered by specific blockers for Src, protein kinase C delta (PKCδ) and mitogen-activated protein kinase/extracellular signal-regulated kinase kinases (MEK/ERK), but not by those for estrogen receptor (ER). Moreover, daidzein induced phosphorylation of Src, PKCδ and ERK. The activation of PKCδ by daidzein was attenuated in the presence of a Src kinase inhibitor, and that of ERK by daidzein was diminished in the presence of either a Src or PKCδ inhibitor.

Conclusion

Daidzein may stimulate neurite outgrowth of DRG neurons depending on Src kinase, PKCδ and ERK signaling pathway.
Comparative study of classification algorithms for immunosignaturing data
Authors: Kukreja Muskan , Johnston Stephen Albert , Stafford Phillip
Published: August 2012

Background

High-throughput technologies such as DNA, RNA, protein, antibody and peptide microarrays are often used to examine differences across drug treatments, diseases, transgenic animals, and others. Typically one trains a classification system by gathering large amounts of probe-level data, selecting informative features, and classifies test samples using a small number of features. As new microarrays are invented, classification systems that worked well for other array types may not be ideal. Expression microarrays, arguably one of the most prevalent array types, have been used for years to help develop classification algorithms. Many biological assumptions are built into classifiers that were designed for these types of data. One of the more problematic is the assumption of independence, both at the probe level and again at the biological level. Probes for RNA transcripts are designed to bind single transcripts. At the biological level, many genes have dependencies across transcriptional pathways where co-regulation of transcriptional units may make many genes appear as being completely dependent. Thus, algorithms that perform well for gene expression data may not be suitable when other technologies with different binding characteristics exist. The immunosignaturing microarray is based on complex mixtures of antibodies binding to arrays of random sequence peptides. It relies on many-to-many binding of antibodies to the random sequence peptides. Each peptide can bind multiple antibodies and each antibody can bind multiple peptides. This technology has been shown to be highly reproducible and appears promising for diagnosing a variety of disease states. However, it is not clear what is the optimal classification algorithm for analyzing this new type of data.

Results

We characterized several classification algorithms to analyze immunosignaturing data. We selected several datasets that range from easy to difficult to classify, from simple monoclonal binding to complex binding patterns in asthma patients. We then classified the biological samples using 17 different classification algorithms. Using a wide variety of assessment criteria, we found ‘Naïve Bayes’ far more useful than other widely used methods due to its simplicity, robustness, speed and accuracy.

Conclusions

‘Naïve Bayes’ algorithm appears to accommodate the complex patterns hidden within multilayered immunosignaturing microarray data due to its fundamental mathematical properties.
Regulatory elements of Caenorhabditis elegans ribosomal protein genes
Authors: Sleumer Monica C , Wei Guifeng , Wang Yunfei , Chang Hao , Xu Tao , Chen Runsheng , Zhang Michael Q
Published: August 2012

Background

Ribosomal protein genes (RPGs) are essential, tightly regulated, and highly expressed during embryonic development and cell growth. Even though their protein sequences are strongly conserved, their mechanism of regulation is not conserved across yeast, Drosophila, and vertebrates. A recent investigation of genomic sequences conserved across both nematode species and associated with different gene groups indicated the existence of several elements in the upstream regions of C. elegans RPGs, providing a new insight regarding the regulation of these genes in C. elegans.

Results

In this study, we performed an in-depth examination of C. elegans RPG regulation and found nine highly conserved motifs in the upstream regions of C. elegans RPGs using the motif discovery algorithm DME. Four motifs were partially similar to transcription factor binding sites from C. elegans, Drosophila, yeast, and human. One pair of these motifs was found to co-occur in the upstream regions of 250 transcripts including 22 RPGs. The distance between the two motifs displayed a complex frequency pattern that was related to their relative orientation.

We tested the impact of three of these motifs on the expression of rpl-2 using a series of reporter gene constructs and showed that all three motifs are necessary to maintain the high natural expression level of this gene. One of the motifs was similar to the binding site of an orthologue of POP-1, and we showed that RNAi knockdown of pop-1 impacts the expression of rpl-2. We further determined the transcription start site of rpl-2 by 5’ RACE and found that the motifs lie 40–90 bases upstream of the start site. We also found evidence that a noncoding RNA, contained within the outron of rpl-2, is co-transcribed with rpl-2 and cleaved during trans-splicing.

Conclusions

Our results indicate that C. elegans RPGs are regulated by a complex novel series of regulatory elements that is evolutionarily distinct from those of all other species examined up until now.
CYP98A22, a phenolic ester 3’-hydroxylase specialized in the synthesis of chlorogenic acid, as a new tool for enhancing the furanocoumarin concentration in Ruta graveolens
Authors: Karamat Fazeelat , Olry Alexandre , Doerper Sébastien , Vialart Guilhem , Ullmann Pascaline , Werck-Reichhart Danièle , Bourgaud Frédéric , Hehn Alain
Published: August 2012

Background

Furanocoumarins are molecules with proven therapeutic properties and are produced in only a small number of medicinal plant species such as Ruta graveolens. In vivo, these molecules play a protective role against phytophageous insect attack. Furanocoumarins are members of the phenylpropanoids family, and their biosynthetic pathway is initiated from p-coumaroyl coA. The enzymes belonging to the CYP98A cytochrome P450 family have been widely described as being aromatic meta-hydroxylases of various substrates, such as p-coumaroyl ester derivatives, and are involved in the synthesis of coumarins such as scopoletin. In furanocoumarin-producing plants, these enzymes catalyze the step directly downstream of the junction with the furanocoumarin biosynthetic pathway and might indirectly impact their synthesis.

Results

In this work, we describe the cloning and functional characterization of the first CYP98A encoding gene isolated from R. graveolens. Using Nicotiana benthamiana as a heterologous expression system, we have demonstrated that this enzyme adds a 3-OH to p-coumaroyl ester derivatives but is more efficient to convert p-coumaroyl quinate into chlorogenic acid than to metabolize p-coumaroyl shikimate. Plants exposed to UV-B stress showed an enhanced expression level of the corresponding gene. The R. graveolens cyp98a22 open reading frame and the orthologous Arabidopsis thaliana cyp98a3 open reading frame were overexpressed in stable transgenic Ruta plants. Both plant series were analyzed for their production of scopoletin and furanocoumarin. A detailed analysis indicates that both genes enhance the production of furanocoumarins but that CYP98A22, unlike CYP98A3, doesn’t affect the synthesis of scopoletin.

Conclusions

The overexpression of CYP98A22 positively impacts the concentration of furanocoumarins in R. graveolens. This gene is therefore a valuable tool to engineer plants with improved therapeutical values that might also be more resistant to phytophageous insects.