bluuebunny/crossref_metadata_2025 huggingface dataset:
Serotonergic modulation of murine fundic tone
Authors: Xue Lin , Camilleri Michael , Locke G. Richard , Schuurkes Jan A. J. , Meulemans Ann , Coulie Bernard J. , Szurszewski Joseph H. , Farrugia Gianrico
Published: July 2006

Fundic tone is maintained through a balance of excitatory and inhibitory input to fundic smooth muscle. The aim of this study was to determine the role of serotonin (5-HT) and 5-HT receptors in modulating murine fundic tone. Muscle strips were prepared from the murine fundus. Intracellular recordings were made from circular smooth muscle cells, and the effects of 5-HT on tone and excitatory and inhibitory junction potentials evoked by electrical field stimulation (EFS) were determined. 5-HT induced a concentration-dependent contraction and smooth muscle depolarization that was tetrodotoxin resistant. The 5-HT1B/D receptor antagonists GR-127935 and BRL-155172 significantly inhibited 5-HT-induced contractions. The 5-HT1B/D agonist sumatriptan contracted murine fundic muscle. The 5-HT1A receptor agonist buspirone relaxed fundic smooth muscle, and the relaxation was inhibited by WAY-100135 but not by Nω-nitro-l-arginine or tetrodotoxin. 5-HT enhanced both the excitatory and inhibitory responses to EFS. The 5-HT3 receptor antagonist MDL-72222 partly inhibited both the excitatory and inhibitory response elicited by EFS, whereas the 5-HT4 receptor antagonist GR-113808 partly inhibited the EFS-evoked inhibitory response. The 5-HT reuptake inhibitor fluoxetine contracted smooth muscle strips, a contraction that was partially inhibited by GR-127935 and abolished by tetrodotoxin. In conclusion, the data suggest that 5-HT modulates murine fundic contractile activity through several different receptor subtypes. Sustained release of 5-HT maintains fundic tone through postjunctional 5-HT1B/D receptors. 5-HT3 receptors modulate excitatory neural input to murine fundic smooth muscle, and both 5-HT3 and 5-HT4 receptors modulate inhibitory neural input to murine fundic smooth muscle.
Different Serotonin Receptor Agonists Have Distinct Effects on Sound-Evoked Responses in Inferior Colliculus
Authors: Hurley Laura M.
Published: July 2006

The neuromodulator serotonin has a complex set of effects on the auditory responses of neurons within the inferior colliculus (IC), a midbrain auditory nucleus that integrates a wide range of inputs from auditory and nonauditory sources. To determine whether activation of different types of serotonin receptors is a source of the variability in serotonergic effects, four selective agonists of serotonin receptors in the serotonin (5-HT) 1 and 5-HT2 families were iontophoretically applied to IC neurons, which were monitored for changes in their responses to auditory stimuli. Different agonists had different effects on neural responses. The 5-HT1A agonist had mixed facilitatory and depressive effects, whereas 5-HT1B and 5-HT2C agonists were both largely facilitatory. Different agonists changed threshold and frequency tuning in ways that reflected their effects on spike count. When pairs of agonists were applied sequentially to the same neurons, selective agonists sometimes affected neurons in ways that were similar to serotonin, but not to other selective agonists tested. Different agonists also differentially affected groups of neurons classified by the shapes of their frequency-tuning curves, with serotonin and the 5-HT1 receptors affecting proportionally more non-V-type neurons relative to the other agonists tested. In all, evidence suggests that the diversity of serotonin receptor subtypes in the IC is likely to account for at least some of the variability of the effects of serotonin and that receptor subtypes fulfill specialized roles in auditory processing.
Dyspnea as a Noxious Sensation: Inspiratory Threshold Loading May Trigger Diffuse Noxious Inhibitory Controls in Humans
Authors: Morélot-Panzini Capucine , Demoule Alexandre , Straus Christian , Zelter Marc , Derenne Jean-Philippe , Willer Jean-Claude , Similowski Thomas
Published: July 2006

Dyspnea, a leading respiratory symptom, shares many clinical, physiological, and psychological features with pain. Both activate similar brain areas. The neural mechanisms of dyspnea are less well described than those of pain. The present research tested the hypothesis of common pathways between the two sensations. Six healthy men (age 30–40 yr) were studied. The spinal nociceptive flexion reflex (RIII) was first established in response to electrical sural stimulation. Dyspnea was then induced through inspiratory threshold loading, forcing the subjects to develop 70% of their maximal inspiratory pressure to inhale. This led to progressive inhibition of the RIII reflex that reached 50 ± 12% during the fifth minute of loading ( P < 0.001), was correlated to the intensity of the self-evaluated respiratory discomfort, and had recovered 5 min after removal of the load. The myotatic H-reflex was not inhibited by inspiratory loading, arguing against postsynaptic alpha motoneuron inhibition. Dyspnea, like pain, thus induced counterirritation, possibly indicating a C-fiber stimulation and activation of diffuse noxious inhibitory descending controls known to project onto spinal dorsal horn wide dynamic range neurons. This confirms the noxious nature of certain types of breathlessness, thus opening new physiological and perhaps therapeutic perspectives.
Light-Induced Depolarization of Neurons Using a Modified Shaker K+ Channel and a Molecular Photoswitch
Authors: Chambers James J. , Banghart Matthew R. , Trauner Dirk , Kramer Richard H.
Published: July 2006

To trigger action potentials in neurons, most investigators use electrical or chemical stimulation. Here we describe an optical stimulation method based on semi-synthetic light-activated ion channels. These SPARK (synthetic photoisomerizable azobenzene-regulated K+) channels consist of a synthetic azobenzene-containing photoswitch and a genetically modified Shaker K+ channel protein. SPARK channels with a wild-type selectivity filter elicit hyperpolarization and suppress action potential firing when activated by 390 nm light. A mutation in the pore converts the K+-selective Shaker channel into a nonselective cation channel. Activation of this modified channel with the same wavelength of light elicits depolarization of the membrane potential. Expression of these depolarizing SPARK channels in neurons allows light to rapidly and reversibly trigger action potential firing. Hence, hyper- and depolarizing SPARK channels provide a means for eliciting opposite effects on neurons in response to the same light stimulus.
The Transmembrane Sodium Gradient Influences Ambient GABA Concentration by Altering the Equilibrium of GABA Transporters
Authors: Wu Yuanming , Wang Wengang , Richerson George B.
Published: July 2006

Tonic inhibition is widely believed to be caused solely by “spillover” of GABA that escapes the synaptic cleft and activates extrasynaptic GABAA receptors. However, an exclusively vesicular source is not consistent with the observation that tonic inhibition can still occur after blocking vesicular release. Here, we made patch-clamp recordings from neurons in rat hippocampal cultures and measured the tonic current that was blocked by bicuculline or gabazine. During perforated patch recordings, the tonic GABA current was decreased by the GAT1 antagonist SKF-89976a. Zero calcium solution did not change the amount of tonic current, despite a large reduction in vesicular GABA release. Perturbations that would be expected to alter the transmembrane sodium gradient influenced the tonic current. For example, in zero calcium Ringer, TTX (which can decrease cytosolic [Na+]) reduced tonic current, whereas veratridine (which can increase cytosolic [Na+]) increased tonic current. Likewise, removal of extracellular sodium led to a large increase in tonic current. The increases in tonic current induced by veratridine and sodium removal were completely blocked by SKF89976a. When these experiments were repeated in hippocampal slices, similar results were obtained except that a GAT1- and GAT3-independent nonvesicular source(s) of GABA was found to contribute to the tonic current. We conclude that multiple sources can contribute to ambient GABA, including spillover and GAT1 reversal. The source of GABA release may be conceptually less important in determining the amount of tonic inhibition than the factors that control the equilibrium of GABA transporters.
Substance, Desire and Control: Water in the New Forest
Authors: Garner Andrew
Published: July 2006

Water, like much else in the landscape of the New Forest, England, is highly contested. Recent major environmental works have changed the flow of water by adjusting river beds, slowing flows and holding up water in parts of the Forest. These changes are elaborated as reversing past interventions, restoring rivers and increasing environmental values. Under the rubric of conservation, some of the greatest physical changes in 150 years are taking place in the Forest. This paper traces how, since the early nineteenth century, ideas about water have shaped management interventions and dramatically changed the flow of water over the Forest landscape. The works have also given new impetus to arguments about the meaning and value of water, rights of access and the control of water resources in both economic terms and in terms of social status and identity. How value is assigned by small-holders and visitors to waterscapes is compared to that of the agencies managing the environment. A key cause for conflict is shown to lie in the different ways of measuring and constructing value, and in two forms of environmental expression.
Fluid Bodies in the Sea: An Ethnography of Underwater Spear Gun Fishing in Palau, Micronesia
Authors: Ota Yoshitaka
Published: July 2006

Underwater spear gun fishing is the most popular fishing method used in indigenous inshore fishing in Palau, West Micronesia. Two major characteristics of this method are: first, the opportunity offered to fishermen to enter and experience another sphere of the seascape, the underwater world; and, second, the extreme physical challenge involved in the fishermen's constant bodily movement in and under the water. Fishermen skin-dive deep into coral reefs in order to shoot fish with hand-made spear-guns, swimming through the water swiftly to approach their targets. In this form of fishing, they experience the fluid nature of the underwater domain at the level of their skin, and move their bodies in accord with the visibility, auditory experience and the physicality of the particular environment. This paper argues that the fishermen's focus on bodily movement contributes to their constructions of masculinity, and culturally embodies the fluidity of underwater seascapes.
A Systematic Review of Research on Culturally Relevant Issues for Hispanics With Diabetes
Authors: Caban Arlene , Walker Elizabeth A.
Published: July 2006

Purpose

The purpose of this review is to provide a description of current research on culturally relevant issues among Hispanics subgroups with diabetes throughout the United States.

Methods

A search of 2655 abstracts was conducted using Medline, PubMed, and Psychlit. Sixty articles were identified, and 33 were reviewed.

Results

Most studies focused on Mexican Americans, and little is known about the unique and shared health beliefs of different Hispanics subgroups within the United States. Personal models of illness varied across groups and were influenced by levels of acculturation. Definitions and treatments for susto varied considerably: Puerto Ricans did not identify it as a cause of diabetes. Patients'thoughts about God and diabetes differed, and little is known about how these thoughts affect diabetes self-management. There is also limited research on Hispanics' use of curanderos (folk healers) for diabetes-related care, and only some participants reported using alternative treatments in conjunction with standard medical care. There is limited evidence that fatalistic thinking is unique to Hispanic culture, and its relationship to diabetes self-management remains unclear.

Conclusions

More research is needed to determine how cultural factors influence Hispanics' approaches to diabetes self-management. Clinicians and educators would benefit from exploring cultural belief systems with patients, as they may enhance the patient-provider relationship and serve as tools in identifying appropriate treatment strategies.
Screening for Type 2 Diabetes in Children With Acanthosis Nigricans
Authors: Hardin Dana S.
Published: July 2006

Acanthosis nigricans is a physical finding of the skin that appears to be a marker for insulin resistance. Because of the association of insulin resistance and type 2 diabetes, acanthosis nigricans may also be a marker for type 2 diabetes. Some states have recommended statewide screening for acanthosis nigricans. However, this has led to a large referral of children to pediatric endocrinologists. Presented is a schema for primary care physicians and school nurses to use as a guideline for referral of children with acanthosis nigricans.
Interventions to Improve Diabetes Self-management
Authors: Leeman Jennifer
Published: July 2006

Purpose

The purpose of this study was to review publications of research on diabetes self-management interventions and assess whether the interventions are relevant for practice.

Methods

A content analysis was performed on research reports published between 1993 and 2004 of interventions designed to improve patients' diabetes self-management. Information was abstracted relevant to the intervention's generalizability to other settings and its compatibility and feasibility in practice.

Results

Publications included only limited information relevant to an intervention's generalizability across populations and settings. Many of the interventions tested were not designed to be compatible with the realities of current practice or to be delivered in the settings in which most diabetes care is provided. Many of the interventions were very complex, requiring multiple delivery modes and contacts, proactive scheduling, and coordination across disciplines.

Conclusions

In view of the prevalence of diabetes, it is critical that effective self-management interventions be adopted and implemented. Interventions need to be designed so that their findings have greater relevance and utility for practice and can be generalized across practice settings.
Effect of Functional Bracing on Knee Injury in Skiers with Anterior Cruciate Ligament Reconstruction
Authors: Sterett William I. , Briggs Karen K. , Farley Timothy , Steadman J. Richard
Published: July 2006

Background

The role of knee bracing in anterior cruciate ligament reconstructions is controversial.

Hypothesis

Functional bracing will have an effect on subsequent knee injury in skiers with anterior cruciate ligament reconstruction.

Study Design

Cohort study; Level of evidence, 3.

Methods

From 1991 to 1997, 11606 skiers at a major destination ski resort underwent preseason knee screening. The anterior cruciate ligamentreconstructed group consisted of 820 skiers who had had an anterior cruciate ligament reconstruction 2 years or more earlier. Of these, 257 skiers selected the use of functional knee brace during skiing. The dependent variable was subsequent knee injury, identified via workers compensation records. Covariates included age, gender, ski occupation, Lachman grade, pivot-shift grade, KT-1000 arthrometer manual maximum displacement, and use of a functional brace. Univariate and multivariate risk factors for subsequent knee injury were determined.

Results

In this study, 257 skier-employees with anterior cruciate ligament reconstruction wore braces and 563 skier-employees with anterior cruciate ligament reconstruction did not. Braced skiers had significantly higher preseason rates of grade II or higher Lachman and pivot-shift tests (braced, 29% and 22%, respectively; nonbraced, 11% and 10%, respectively;P >. 05). Sixty-one subsequent knee injuries were identified, 51 (8.9 injuries/100 knees/ski season) in the nonbraced group and 10 (4.0 injuries/100 knees/ski season) in the braced group (P=. 009). Nonbraced skiers were 2.74 times more likely to suffer subsequent injury than were braced skiers (odds ratio, 2.74 [confidence interval, 1.2-4.9]). Logistic regression modeling identified nonbracing as a significant independent multivariate risk factor for subsequent knee injury in the high-demand skiers with anterior cruciate ligament reconstruction.

Conclusion

Because of the increased risk of subsequent knee injury in nonbraced skiers, the authors recommend functional bracing for skiers with anterior cruciate ligament reconstruction. Whether the protective effect of functional bracing can be extrapolated to other high-demand patients is yet to be determined.
Otcomes of Anterior Cruciate Ligament Injuries to Running Backs and Wide Receivers in the National Football League
Authors: Carey James L. , Huffman G. Russell , Parekh Selene G. , Sennett Brian J.
Published: July 2006

Background

Anterior cruciate ligament injuries are common in professional football players, and their career impact is unclear.

Purpose

To quantify the affect of anterior cruciate ligament injuries on professional football player performance.

Study Design

Cohort study (prognosis); Level of evidence, 2.

Methods

Anterior cruciate ligament injury data from the National Football League were collected during a 5-year period (1998-2002) for running backs and wide receivers. Recorded variables included player age, experience, position, time to return to competition, and yearly total yards and touchdowns. Power ratings (total yards divided by 10 plus touchdowns multiplied by 6) were calculated for the injury season as well as for the 3 seasons before and after injury. A control group consisted of all running backs and wide receivers without an identified anterior cruciate ligament injury who competed in the 2000 season.

Results

Data were analyzed for 31 running backs and wide receivers with 33 anterior cruciate ligament injuries. More than one fifth of players never returned to a National Football League game. Returning players first competed in a game 55.8 ± 5.4 weeks (mean ± standard error) after injury. For the 24 anterior cruciate ligament–injured players with a minimum total power rating (sum of all 7 seasons) of 200 points, power rating per game played decreased from 9.9 ± 1.1 preinjury to 6.5 ± 0.9 postinjury. This decline in power rating per game played was statistically significant (P =. 002) when compared with the change for the 146 control players.

Conclusion

Nearly four fifths of National Football League running backs and wide receivers who sustain an anterior cruciate ligament injury return to play in a game. On return to competition, player performance of injured players is reduced by one third.
Unreliable narrators? ‘Inconsistency’ (and some inconstancy) in interviews
Authors: Watson Cate
Published: July 2006

A potentially problematic aspect of the qualitative interview is the propensity towards tensions that emerge - ambiguities, inconsistencies, contradictions etc. - especially when transcripts are analysed. In this article, I draw on material from an interview in which the presence of contradictory data had surprising results, initially producing shock, but subsequently causing me to reflect on the ‘meaning’ inherent in these lapses of coherence. In so doing, I present a framework for analysis, based on Ernesto Laclau and Chantal Mouffe’s discourse theory, and suggest that narratives serve to construct the relational process of ‘identification with’ that links individuals to discourses. This framework enables a kind of situated reliability to emerge from the very aspects of the interview that may be held to be problematic in terms of our being ‘unreliable narrators’.
Credibility, authenticity and voice: dilemmas in online interviewing
Authors: James Nalita , Busher Hugh
Published: July 2006

This article explores the methodological issues encountered when using email as a web-based interview in on-line qualitative research. By drawing on two separate research studies that used this method to explore participants’ understandings of their professional experiences and developing professional identities, the researchers consider the methodological implications in using this approach. These include issues affecting the credibility and trustworthiness of the research design of the studies, and issues around the authenticity of participants’ voices and how that was affected by power and control in the interview process. Despite these dilemmas, the article recognizes the contribution that web-based approaches can make to research by allowing researchers to hold asynchronous conversations with participants, especially when they are distant from the researcher, and to generating reflective, descriptive data. It leads us to conclude that it is worth refining our methodological framework to strengthen the trustworthiness and credibility of future research studies that use email.
Radial Compressive Properties of the Biodegradable Braided Regeneration Tubes for Peripheral Nerve Repair
Authors: Liu G. H. , Hu H. , Zhang P. H. , Wang W. Z.
Published: July 2006

Different regeneration tubes braided from biodegradable material poly (glycolide-co-L-lactide) (PGLA) for peripheral nerve repair and their radial compressive properties are presented. The influences of the braided structure and braiding angle are discussed. The results have shown that the nerve tube braided with the triaxial structure and the braiding angle at 60 has a higher ability to resist the radial compressions.
Evaluation of Antibacterial Properties of a Textile Product with Antimicrobial Finish in a Hospital Environment
Authors: Renaud François N. R. , Doré Jeanne , Freney H. Jean , Coronel Bernard , Dusseau Jean-Yves
Published: July 2006

The objective of this study is to evaluate the antibacterial activity of a textile product with an antimicrobial finish in real-life hospital conditions. Sixty antibacterial samples and nonactive controls are tested on garments worn by nurses during their working day. The number of colony forming units (CFU) is significantly lower on antibacterial textiles than on the nonactive ones. Moreover, the higher the contamination, the more this contamination was reduced, up to 50% reduction.
Thermal Insulation Properties of Cellulosic-based Nonwoven Composites
Authors: Yachmenev Val , Negulescu Ioan , Yan Chen
Published: July 2006

The use of cellulosic fibers, such as cotton, kenaf, ramie, jute, flax, and bagasse, in the manufacturing of nonwoven composites for a variety of automotive parts, such as headliners, wall panels, and trunk liners, can significantly enhance their ‘end of life’ biodegradability and also improve their thermal insulation properties. Currently, automotive nonwovens are made from synthetic, petro-based polymer materials that are not biodegradable, thus creating significant environmental problems. Three different sets of ‘sandwich-type’ nonwoven materials are manufactured by layering the cellulosic webs, with recycled thermoplastic synthetic fibers and/or using readily biodegradable binders such as polyvinyl alcohol (PVA) and Eastar Biocopolymer (EBC). A ‘steady state’ heat flow meter is used for the evaluation of the thermal insulation properties of these biodegradable, low-cost nonwoven composites. The results show that the thermal insulation properties of cellulosic-based nonwoven composite materials vary significantly, depending on the type of the vegetable fibers, the ratios of the cellulosic to synthetic fibers, the nature and quantity of the binder, the design, and the resulting bulk density of the composites.
Relative Permeabilities of Cement-based Materials: Influence of the Tortuosity Function
Authors: Wardeh George , Perrin Bernard
Published: July 2006

The macroscopic physical modeling of humidity-, energy-, and air-coupled transport in unsaturated porous materials requires their water retention characteristics and transport coefficients to be known. Among the most sensitive properties are the air and liquid permeabilities.

As their direct determination is often difficult and time consuming, relations have long been proposed starting from experimental properties that are easier to obtain, such as water pressure head as a function of the degree of saturation or isothermal sorption curves.

In the first part, existing model relationships are compared with experimentation. The data obtained show that a parameter in these relationships has to be modified. The proposed modifications are interesting for practical applications, but the authors have also tried, in the second part of the study, to generalize the approach by starting from the porosity of the cement-based materials studied here.

Expressions for the relative permeabilities are given as functions of tortuosity and capillary pressure, which can be deduced from the pore size distribution.

An expression is proposed for the tortuosity. The relative influence of the porosity and the tortuosity of the cement-based materials on gas and liquid permeabilities, according to the relative degree of saturation, are discussed.
Comparative Analysis of Response-factor and Finite-volume based Methods for predicting Heat and Moisture Transfer through Porous Building Materials
Authors: Abadie Marc , Mendes Nathan
Published: July 2006

Many of the now well-known building energy simulation programs use the response factor method developed in the early 1970s by Stephenson and Mitalas. These are TRNSYS, EnergyPlus, Blast, and DOE-2, to name but a few. Others, such as PowerDomus, ESP-r, and BSim, perform finite-volume or finite-difference calculations to solve the heat and mass transfer through the building envelope. These two different approaches are known to have strengths and weaknesses. The main objective of the present exercise is to compare the prediction of both methods. A two-step procedure is employed here. The first deals with the pure thermal problem, i.e., without moisture calculation. Three different cases of increasing complexity are studied and compared to analytical solutions. The second step focuses on the moisture problem alone by comparing the responses obtained with a two-layer buffer storage model and a finite-volume discretization for moisture transfer. Results show that time step values are determinant even for pure thermal cases where the classical value of 1 h can lead to notable errors. For problems with moisture sorption in the wall, it has been shown that grid refinement is a very decisive parameter, while the time step has to be set, to unusually small values, to achieve a good response.
The Financialization of the American Credit Card Industry
Authors: Montgomerie Johnna
Published: July 2006

This paper asks, what can account for the rapid expansion and growing profitability of the US credit card industry since the mid-1980s? And, what does this mean to the study of global finance within IPE? It is argued that the advent of asset-backed securities, a financial innovation known as securitization, was the key to the enormous expansion of credit card profits and the continued proliferation and growth of the credit card market in the US. This is because securitization moved credit card receivables off-balance sheet, allowing loan pools to be re-capitalized, lowering the cost of borrowing and increasing revenues from payments on securities issued. This financial innovation attracted non-banks, mostly large MNCs, into the credit card market, facilitating greater integration between finance and the ‘real’ economy. The deepening integration facilitated mounting competition and lower costs of borrowing and was the catalyst for the rapid expansion of the credit card market and its unsurpassed profitability.
Ownership and Security: Individualised Pensions and Pension Policy in the United Kingdom and the United States
Authors: Waine Barbara
Published: July 2006

The paper discusses plans, supported by President George W. Bush, to introduce individualised pension provision as a form of privatisation of social security in the United States in the context of the experience of analogous policies in the United Kingdom. It argues that UK experience, which has been largely ignored by proponents of individualised pensions in the US, has pointed to a number of serious problems with such forms. ‘Personal’ pensions, developed under the 1986 Social Security Act in the UK, led to large numbers opting out of the then State Earnings Related Pensions Scheme. However, such individualised schemes came under attack on the grounds that they were a problematic means of providing adequate retirement incomes. Such criticisms were based on problems related to high transaction costs, misleading information provided in the marketing of such ‘financial products’ and falling annuity rates. Subsequent attempts to offer a more regulated form of individualised provision, under Labour governments, through the ‘Stakeholder Pension’ have proved problematic, with levels of take up below expected targets, arguably reflecting a lack of public confidence in personal pensions. It is suggested that individualised forms of pension provision such as those implemented in the UK and advocated in the US involve a central contradiction. Supporters of such schemes stress the desirability of individual ownership/assumption of risk in pension schemes. Such a rationale is necessarily universal and thus encompasses individuals on low incomes. Such individuals are, however, particularly vulnerable to the problems of individualised provision illustrated in the British experience.
Application of magnetic field control technology in plasma arc surfacing
Authors: Liu Z. J. , Chen H. , Liu C. , Cheng J. B. , Su Y. H. , Liu D.
Published: July 2006

In order to control the shape and distribution of hard phases in a surfacing deposit, a longitudinal DC magnetic field was applied during plasma arc surfacing of low carbonsted with two iron based alloys (Fe 5 and Fe 3). Hardness and wear testing as well as microstructural X-ray diffraction analyses and microstructure of two surfacing deposits were investigated. The results show that the surfacing deposit subjected to a magnetic field exhibits higher hardness and better wear resistance than that produced without the application of magnetic field. When the magnetic field current is 3 A, properties of the surfacing deposit are optimal. Under this processing condition, both α and γ solid solutions are sufficiently refined and such hard phases as Cr7C3 and CrB can be obtained.
Effect of aeration on superficial residual stress level of carburised and quenched gears treated by water cavitation peening
Authors: Ju D. Y. , Qin M. , Koubayashi T. , Oba R.
Published: July 2006

Cavitation impacts, which are generally considered as the dominant factor affecting cavitation erosion of hydraulic machinery, can also be applied to introduce compressive residual stress in the surface layer of mechanical components in a similar way to traditional shot peening. By using a high speed submerged water jet instrument, in which high pressure water is passed through a jet nozzle to the specimen, a uniform cloud of large bubbles can be generated. Bubble collapse on the surface of the specimen will produce an impact effect very similar to shot peening. Therefore, the design of the jet nozzle is very important to obtain the optimum pressure of bubble collapse. In the present study, a new nozzle design with air addition was used, the effect of the air addition flux on the impulse pressure of bubble collapse was investigated, and a comparative study of the residual stress in a carburising quenched gear treated by water cavitation peening with and without air addition was carried out. The results show that after the new nozzle with air addition is adopted, the saturation time of peening is reduced from 30 to 10 min and a superficial compressive residual stress increase of about 30–40% is obtained. The increase in pressure of bubble collapse caused by air addition is responsible for such improvement.
Influence of sol compositions on formation of crack free barium ferrite thick film synthesised by sol–gel processing
Authors: Ghasemi A. , Salehi M. , Saatchi A. , Hossienpour A.
Published: July 2006

In the present research work, the development of thick barium ferrite films on alumina substrate synthesised by sol–gel processing has been investigated. XRD, SEM and EDX evaluated the structure and composition of the coatings. In order to investigate the crack formation mechanism, thermogravimetric analysis (TGA) was used to identify the heating rate of coated samples from room temperature to final sintering temperature. The sols were produced with different molar ratios of iron and barium nitrates in deionised water and ethylene glycol. The coating was subsequently introduced to the substrates. XRD results showed that the single phase M type barium ferrite coatings were produced at Fe/Ba molar ratios of 10·5 and 11·3. The results of SEM and EDX indicate that a uniform and crack free coating of barium ferrite with 15 μm thickness can be produced at above molar ratios with good deal of consistency.
A fast SCOP fold classification system using content-based E-Predict algorithm
Authors: Chi Pin-Hao , Shyu Chi-Ren , Xu Dong
Published: July 2006

Background

Domain experts manually construct the Structural Classification of Protein (SCOP) database to categorize and compare protein structures. Even though using the SCOP database is believed to be more reliable than classification results from other methods, it is labor intensive. To mimic human classification processes, we develop an automatic SCOP fold classification system to assign possible known SCOP folds and recognize novel folds for newly-discovered proteins.

Results

With a sufficient amount of ground truth data, our system is able to assign the known folds for newly-discovered proteins in the latest SCOP v 1.69 release with 92.17% accuracy. Our system also recognizes the novel folds with 89.27% accuracy using 10 fold cross validation. The average response time for proteins with 500 and 1409 amino acids to complete the classification process is 4.1 and 17.4 seconds, respectively. By comparison with several structural alignment algorithms, our approach outperforms previous methods on both the classification accuracy and efficiency.

Conclusion

In this paper, we build an advanced, non-parametric classifier to accelerate the manual classification processes of SCOP. With satisfactory ground truth data from the SCOP database, our approach identifies relevant domain knowledge and yields reasonably accurate classifications. Our system is publicly accessible at http://ProteinDBS.rnet.missouri.edu/E-Predict.php.
A multi-class predictor based on a probabilistic model: application to gene expression profiling-based diagnosis of thyroid tumors
Authors: Yukinawa Naoto , Oba Shigeyuki , Kato Kikuya , Taniguchi Kazuya , Iwao-Koizumi Kyoko , Tamaki Yasuhiro , Noguchi Shinzaburo , Ishii Shin
Published: July 2006

Background

Although microscopic diagnosis has been playing the decisive role in cancer diagnostics, there have been cases in which it does not satisfy the clinical need. Differential diagnosis of malignant and benign thyroid tissues is one such case, and supplementary diagnosis such as that by gene expression profile is expected.

Results

With four thyroid tissue types, i.e., papillary carcinoma, follicular carcinoma, follicular adenoma, and normal thyroid, we performed gene expression profiling with adaptor-tagged competitive PCR, a high-throughput RT-PCR technique. For differential diagnosis, we applied a novel multi-class predictor, introducing probabilistic outputs. Multi-class predictors were constructed using various combinations of binary classifiers. The learning set included 119 samples, and the predictors were evaluated by strict leave-one-out cross validation. Trials included classical combinations, i.e., one-to-one, one-to-the-rest, but the predictor using more combination exhibited the better prediction accuracy. This characteristic was consistent with other gene expression data sets. The performance of the selected predictor was then tested with an independent set consisting of 49 samples. The resulting test prediction accuracy was 85.7%.

Conclusion

Molecular diagnosis of thyroid tissues is feasible by gene expression profiling, and the current level is promising towards the automatic diagnostic tool to complement the present medical procedures. A multi-class predictor with an exhaustive combination of binary classifiers could achieve a higher prediction accuracy than those with classical combinations and other predictors such as multi-class SVM. The probabilistic outputs of the predictor offer more detailed information for each sample, which enables visualization of each sample in low-dimensional classification spaces. These new concepts should help to improve the multi-class classification including that of cancer tissues.
Influence of plant diversity and elevated atmospheric carbon dioxide levels on belowground bacterial diversity
Authors: Grüter Dominique , Schmid Bernhard , Brandl Helmut
Published: July 2006

Background

Changes in aboveground plant species diversity as well as variations of environmental conditions such as exposure of ecosystems to elevated concentrations of atmospheric carbon dioxide may lead to changes in metabolic activity, composition and diversity of belowground microbial communities, both bacterial and fungal.

Results

We examined soil samples taken from a biodiversity × CO2 grassland experiment where replicate plots harboring 5, 12, or 31 different plant species had been exposed to ambient or elevated (600 ppm) levels of carbon dioxide for 5 years. Analysis of soil bacterial communities in these plots by temporal temperature gradient gel electrophoresis (TTGE) showed that dominant soil bacterial populations varied only very little between different experimental treatments. These populations seem to be ubiquitous. Likewise, screening of samples on a high-resolution level by terminal restriction fragment length polymorphism (T-RFLP) showed that increased levels of carbon dioxide had no significant influence on both soil bacterial community composition (appearance and frequency of operational taxonomic units, OTUs) and on bacterial richness (total number of different OTUs). In contrast, differences in plant diversity levels had a significant effect on bacterial composition but no influence on bacterial richness. Regarding species level, several bacterial species were found only in specific plots and were related to elevated carbon dioxide or varying plant diversity levels. For example, analysis of T-RFLP showed that the occurrence of Salmonella typhimurium was significantly increased in plots exposed to elevated CO2 (P < 0.05).

Conclusion

Plant diversity levels are affecting bacterial composition (bacterial types and their frequency of occurrence). Elevated carbon dioxide does not lead to quantitative alteration (bacterial richness), whereas plant diversity is responsible for qualitative changes (bacterial diversity).
AtMND1 is required for homologous pairing during meiosis in Arabidopsis
Authors: Panoli Aneesh P , Ravi Maruthachalam , Sebastian Jose , Nishal Bindu , Reddy Thamalampudi V , Marimuthu Mohan PA , Subbiah Veeraputhiran , Vijaybhaskar Virupapuram , Siddiqi Imran
Published: July 2006

Background

Pairing of homologous chromosomes at meiosis is an important requirement for recombination and balanced chromosome segregation among the products of meiotic division. Recombination is initiated by double strand breaks (DSBs) made by Spo11 followed by interaction of DSB sites with a homologous chromosome. This interaction requires the strand exchange proteins Rad51 and Dmc1 that bind to single stranded regions created by resection of ends at the site of DSBs and promote interactions with uncut DNA on the homologous partner. Recombination is also considered to be dependent on factors that stabilize interactions between homologous chromosomes. In budding yeast Hop2 and Mnd1 act as a complex to promote homologous pairing and recombination in conjunction with Rad51 and Dmc1.

Results

We have analyzed the function of the Arabidopsis orthologue of the budding yeast MND1 gene (AtMND1). Loss of AtMND1 did not affect normal vegetative development but caused fragmentation and missegregation of chromosomes in male and female meiosis, formation of inviable gametes, and sterility. Analysis of the Atmnd1 Atspo11-1 double mutant indicated that chromosome fragmentation in Atmnd1 was suppressed by loss of Atspo11-1. Fluorescence in situ hybridization (FISH) analysis showed that homologous pairing failed to occur and homologues remained apart throughout meiosis. AtMND1 showed strong expression in meiocytes as revealed by RNA in situs.

Conclusion

We conclude that AtMND1 is required for homologous pairing and is likely to play a role in the repair of DNA double strand breaks during meiosis in Arabidopsis, thus showing conservation of function with that of MND1 during meiosis in yeast.
Identification of candidate categories of the International Classification of Functioning Disability and Health (ICF) for a Generic ICF Core Setbased on regression modelling
Authors: Cieza Alarcos , Geyh Szilvia , Chatterji Somnath , Kostanjsek Nenad , Üstün Bedirhan T , Stucki Gerold
Published: July 2006

Background

The International Classification of Functioning, Disability and Health (ICF) is the framework developed by WHO to describe functioning and disability at both the individual and population levels.

While condition-specific ICF Core Sets are useful, a Generic ICF Core Set is needed to describe and compare problems in functioning across health conditions.

Methods

The aims of the multi-centre, cross-sectional study presented here were: a) to propose a method to select ICF categories when a large amount of ICF-based data have to be handled, and b) to identify candidate ICF categories for a Generic ICF Core Set by examining their explanatory power in relation to item one of the SF-36.

The data were collected from 1039 patients using the ICF checklist, the SF-36 and a Comorbidity Questionnaire.

ICF categories to be entered in an initial regression model were selected following systematic steps in accordance with the ICF structure. Based on an initial regression model, additional models were designed by systematically substituting the ICF categories included in it with ICF categories with which they were highly correlated.

Results

Fourteen different regression models were performed. The variance the performed models account for ranged from 22.27% to 24.0%. The ICF category that explained the highest amount of variance in all the models was sensation of pain. In total, thirteen candidate ICF categories for a Generic ICF Core Set were proposed.

Conclusion

The selection strategy based on the ICF structure and the examination of the best possible alternative models does not provide a final answer about which ICF categories must be considered, but leads to a selection of suitable candidates which needs further consideration and comparison with the results of other selection strategies in developing a Generic ICF Core Set.
An investigation of polymorphisms in the 17q11.2-12 CC chemokine gene cluster for association with multiple sclerosis in Australians
Authors: Bugeja Matthew J , Booth David , Bennetts Bruce , Heard Robert , Rubio Justin , Stewart Graeme
Published: July 2006

Background

Multiple sclerosis (MS) is a disorder of the central nervous system (CNS) characterised by inflammation and neuronal degeneration. It is believed to result from the complex interaction of a number of genes, each with modest effect. Chemokines are vital to the migration of cells to sites of inflammation, including the CNS, and many are implicated in MS pathogenesis. Most of the CC chemokine genes are encoded in a cluster on chromosome 17q11.2-12, which has been identified in a number of genome wide screens as being potentially associated with MS.

Methods

We conducted a two-stage analysis to investigate the chemokine gene cluster for association with MS. After sequencing the chemokine genes in several DNA pools to identify common polymorphisms, 12 candidate single-nucleotide polymorphisms (SNPs) were genotyped in a cohort of Australian MS trio families.

Results

Marginally significant (uncorrected) transmission distortion was identified for four of the SNPs after stratification for several factors. We also identified marginally significant (uncorrected) transmission distortion for haplotypes encompassing theCCL2andCCL11genes, using two independent cohorts, which was consistent with recent reports from another group.

Conclusion

Our results implicate several chemokines as possibly being associated with MS susceptibility, and given that chemokines and their receptors are suitable targets for therapeutic agents, further investigation is warranted in this region.
Resident-generated versus instructor-generated cases in ethics and professionalism training
Authors: Kon Alexander A
Published: July 2006

Background

The emphasis on ethics and professionalism in medical education continues to increase. Indeed, in the United States the ACGME will require residency programs to include professionalism training in all curricula by 2007. Most courses focus on cases generated by the course instructors rather than on cases generated by the trainees. To date, however, there has been no assessment of the utility of these two case discussion formats. In order to determine the utility of instructor-generated cases (IGCs) versus resident-generated cases (RGCs) in ethics and professionalism training, the author developed an innovative course that included both case formats. The IGCs were landmark cases and cases from the experience of the course instructors, while the RGCs were selected by the residents themselves. Residents were then surveyed to assess the strengths and weaknesses of each format.

Results

Of twenty-two second and third year residents, fourteen completed surveys (response rate 64%). Residents were nearly evenly split in preferring RGCs (38%), IGCs (31%), or not preferring one to the other (31%). 29% stated that they learn more from the RGCs, 21% stated that they learn more from the IGCs, and 50% stated that they did not find a difference in their learning based on format. In general, residents surveyed prefer a mix of formats. Residents tended to find the RGCs more relevant and interesting, and felt the IGCs were necessary to ensure adequate breadth of cases and concepts.

Conclusion

Based on our relatively small sample at a single institution, we believe that educators should consider incorporating both instructor-generated and resident-generated cases in their ethics and professionalism curricula, and should evaluate the utility of such a model at their own institution. Further work is needed to illuminate other potential improvements in ethics and professionalism education.