bluuebunny/crossref_metadata_2025 huggingface dataset:
Appraisal of two methods for determining the toughness of different polymers
Authors: Dear J P
Published: April 2011

The use of polymers for engineering products has dramatically increased in recent decades. For some applications, polymers have a significant advantage over metals. This is, for example, because of the corrosion problems of steels and other metals. When evaluating a material's suitability for a product, the resistances of the material to crack initiation and crack propagation are important. Particular care is needed when comparing the toughness of polymers with those of metals being considered for the same product. A problem is that many evaluation methods originally devised for metals are less suitable for evaluating polymers. In this study, both impact and steady state fracture evaluation methods for polymers are researched.
Influence of strain rate on superelastic behaviour of TiNi shape memory alloy
Authors: Tobushi H , Takata K , Shimeno Y , Nowacki W K , Gadaj S P
Published: April 2011

The influence of the strain rate on the superelastic behaviour associated with the martensitic transformation is investigated by tensile tests for TiNi shape memory alloy. The results are summarized as follows. The increase in the temperature due to the stress-induced martensitic transformation measured by a non-contact method is an order of magnitude larger than that measured through a thermocouple. The increase in the transformation stress associated with an increase in the strain rate appears to be due to the temperature rise. The superelastic behaviour depending on the strain rate is well expressed by the proposed constitutive equation considering the temperature variation. The proposed equation is useful for the design of superelastic elements.
Dielectric studies of ageing in aluminium epoxy adhesively bonded structures: Design implications
Authors: Halliday S T , Banks W M , Pethrick R A
Published: April 2011

The ageing behaviour of aluminium epoxy-aluminium, adhesively bonded structures is investigated using high-frequency dielectric analysis, mechanical shear and cleavage experiments. The joints are aged at 70 °C and 100 per cent humidity and exhibit significant loss of strength over a prolonged period of exposure. The frequency domain dielectric data indicate the rate at which water is absorbed in the joint structure and whether or not significant corrosion of the oxide layer at the interface between the adhesive and the substrate has occurred. Time domain data indicate whether the joint cross-section has undergone significant change with exposure to the ageing environment. A good correlation appears between the extent of change in the joint structure as characterized by the dielectric data and the loss of mechanical strength. There is evidence of toughening due to plasticization of the adhesive from the fracture toughness data.
Measurements of thermal expansion coefficients of anodized aluminium substrates for hybrid circuits
Authors: Manning A S , Liu X
Published: April 2011

High-power substrates for hybrid circuits that combine aluminium with an anodic coating are highly efficient as the heat generated from chips mounted on the coated substrates can be dissipated rapidly. However, due to the difference between the thermal expansion coefficients of the two materials, a large thermal tensile stress can be built up during heating of the substrate, which causes cracking in the coating and subsequently the loss of electrical integrity. In this investigation a simple method of measuring the thermal expansion coefficient for an anodic substrate is described. Measurements were taken from an aluminium/coating composite and the thermal expansion coefficient of the coating was determined using the principles of elementary mechanics.
Developing mental health social work for asylum seekers: A proposed model for practice
Authors: Masocha Shepard , Simpson Murray K
Published: April 2011

• Summary: This article provides a critique of the epidemiological research that currently informs mental health social work with asylum seekers. Most of the literature that currently informs social work practice with asylum seekers with mental health difficulties comes from psychiatric studies which are largely underpinned by a medical model.

• Findings: It is argued that aetiological accounts, predominantly deriving from psychiatry and based largely on biological causation, are untenable. A more comprehensive model is presented, which considers both biological causation and a social perspective and locates the mental health difficulties experienced by asylum seekers in a much wider context. The model is further divided into pre-, post- and migratory stress factors.

• Application: The aim is to provide social work with a practical tool to make sense of the mental health difficulties faced by asylum seekers, help in the development of assessment tools, and help multidisciplinary agencies to define the roles and remit of staff as well as contribute towards the development of policy and practice.
Burnout among mental health care providers
Authors: Acker Gila M
Published: April 2011

• Summary: The new mental health care delivery system in the USA strives to provide efficient quality care at a lower cost. This cost-effective approach and focus on short-term treatment modalities and measurable outcomes has created new challenges especially for those who work with clients with severe mental illness. This study explores the relationships between workplace conditions, role stress, burnout, and intent to quit. The direct and indirect effects of role stress on emotional exhaustion and emotional exhaustion on intent to quit are illuminated in order to better understand the complex process of becoming stressed and disillusioned with one’s work.

• Findings: The results support the author’s expectations that role stress mediates the association between workplace variables and emotional exhaustion; and that emotional exhaustion mediates the association between role stress and intent to quit.

• Applications: These results indicate that agencies and social work schools need to prepare students and new workers for the realistic aspects of mental health work, and provide them with the necessary skills required in order to balance the financial and the clinical aspects of mental health work. Supervisory support, peer support groups, and in-service training should also be considered as important interventions that can reduce workers burnout and its negative consequences.
‘Jack of all trades, master of none?’ Social work identity and homelessness in Australian cities
Authors: Zufferey Carole
Published: April 2011

• Summary: Professional social work identity emerges from particular historical, sociopolitical and organizational contexts. This article examines social work practices and identities in the context of Australian social work responses to homelessness. It draws on historical and contemporary literature and a qualitative study that interviewed 39 social workers employed in the area of homelessness in Adelaide, Melbourne and Sydney, Australia.

• Findings: The findings of this research indicate that social workers employed in the field of homelessness constructed their professional identities by drawing on historical debates in social work literature including structural and/or individual approaches to social problems, as well as by reflecting on the personal and professional tensions that arise from their practice contexts. It also found that professional social work identity is overshadowed by managerial organizational contexts, influencing social work practice in the field of homelessness.

• Application: Debates have existed about social work identity since its inception. A critically informed approach to social work research, practice and literature provides significant insights into the challenges faced by social workers in this new and emerging area of practice and enables social workers to question social inequalities that disadvantage people experiencing homelessness. Further research is needed to identify differences and similarities between Australian and international social worker experiences in homelessness services.
Co-production in scholarly activity: Valuing the social capital of lay people and volunteers
Authors: Fenge Lee-Ann , Fannin Ann , Hicks Christina
Published: April 2011

• Summary: Within the domains of health and social care the expertise of patients, service users, volunteers and carers is becoming increasingly recognized and valued. Their involvement in various aspects of research and service development is becoming more common through ‘co-production’, emphasizing the social capital of these groups in contributing to new types of knowledge and service development. This article develops the notion of ‘co-production’ further by discussing the value of involving lay people, volunteers, service users and carers in scholarly writing and dissemination activities, and will explore ways of achieving this. Bourdieu’s General Theoretical Framework is used to explore how the field of ‘higher education’ can embrace the social and cultural capital of those outside of the academy in both research and scholarly writing activities, and how volunteers and lay researchers can be supported in such activities.

• Findings: In producing this article, two volunteers were asked to reflect on their experiences of becoming researchers, and their thoughts about disseminating the research findings through scholarly writing. The social capital of experts by experience can be valued within scholarly writing, and through this creative process different representations and understandings of the social world we live in begin to emerge.

• Application: The importance of synthesizing alternate epistemologies within academic debate and discourse is centrally important when involving lay people and volunteers in research. This serves to stretch the boundaries of professional knowledge further, and contributes ‘insider’ perspectives to our understanding of social life.
Researching young people’s outcomes in children’s services: Findings from a longitudinal study
Authors: Wigley Veronica , Preston-Shoot Michael , McMurray Isabella , Connolly Helen
Published: April 2011

• Summary: This article reports findings from a longitudinal study of outcomes for a sample of children who had become, or who were considered at risk of becoming looked after. Using a multi-case study design, two stages of the project are reported here. In Stage One, information was gathered from and relating to 21 young people. In Stage Two, semi-structured interviews were undertaken with 32 social workers, and 31 parents and carers regarding 52 children. Eleven of these young people also volunteered to be interviewed. Standardized measures were utilized including the Strengths and Difficulties Questionnaire, Adolescent Well-Being Scale, and Rosenberg Self-Esteem and Self-Efficacy scale.

• Findings: The study highlights the need for preventive multi-agency work with families with multiple risk factors and the importance of education and children’s social care working co-operatively together on behalf of children in need. The study demonstrates the ongoing challenges in providing low level emotional therapeutic work, building on young people’s prosocial relationships with peers, and finding effective ways of improving children’s self esteem and self efficacy. In this local authority children did not feel routinely involved in decision-making. Placement stability, meeting the short and longer-term needs of all placed children, and addressing the needs of foster carers and residential children’s home staff, also presented challenges.

• Application: The study highlights the importance of the organizational context when meeting young people’s needs, including strong leadership, quality assurance, ongoing assessment and focused interventions.
Ultimate compressive strength of plate elements with pit corrosion wastage
Authors: Paik J K , Lee J M , Ko M J
Published: April 2011

The aim of the present paper is to investigate the ultimate strength characteristics of plate elements with pit corrosion wastage under axial compressive loads. Collapse tests on a box column type of steel-plated structures with different degrees of pit corrosion damage are undertaken. A series of ANSYS non-linear finite element analyses for steel plate elements under axial compressive loads are carried out, varying the degree of pit corrosion intensity and plate geometric properties. In this paper, a new parameter, i.e. the smallest cross-sectional area, is proposed to represent the ultimate strength reduction characteristics due to localized corrosion. It is proved that the proposed parameter-based approach is more useful than the traditional approach based on equivalent thickness in terms of the accuracy of ultimate strength predictions of pitted plates. Closed-form design formulae for the ultimate compressive strength of pitted plates, which are needed for the ultimate limit state-based risk or reliability assessment of corroded structures, are derived by regression analysis of the experimental and numerical results obtained from the present study. The insights developed will be very useful for the damage-tolerant design of plated structures with pit corrosion damage.
Accumulation of water on the vehicle deck
Authors: Pawlowski M
Published: April 2011

A mathematical model is presented for the accumulation of water on the vehicle deck of a damaged ro-ro (roll on-roll off) vessel. The model leads to a simple theoretical relationship between the mean elevation of water accumulated on the deck above the sea level, freeboard at the damage opening (including negative freeboard) and the significant height of relative motion due to ship motions. The two characteristic values are indispensable for the theoretical justification of the static equivalency method, used for the assessment of damage stability of ro-ro vessels. Standard deviation of the elevation of water is also provided, derived from the theoretical analysis.
Non-linear damping coefficients from an asymmetric roll decay time series: An analytical method
Authors: Spyrou K J
Published: April 2011

A method to extract non-linear ship roll damping coefficients from an asymmetric roll decay record is developed by following an analytical route. Customarily, the existence of bias in the roll equation is dealt with either through a constant term in the external forcing or through an asymmetric restoring. With suitable variable transformations and time scaling, the conditions of equivalence between these two representations are established. The main body of the paper begins with the derivation of the law of (asymmetric and non-linear) roll motion decay, initiated from an angle near to the vanishing angle. This involves the following three steps: (a) finding the solution (‘orbit’) of the corresponding Hamiltonian system, (b) using the velocity along the Hamiltonian orbit for approximating the amount of energy dissipated in a half-cycle of the real system, through exact analytical calculation of a number of elliptic integrals and (c) extracting the decay law by balancing the dissipated energy against the lost potential one. The use of this law for deriving non-linear roll damping coefficients is subsequently described. The applicability of the proposed methodology is demonstrated with an example.
Studying atmospheric exposure risks during oil spills using a localized computational model
Authors: Zhou T , Wong K V
Published: April 2011

This paper has investigated the risk of atmospheric exposure during oil spills. Air levels of volatile components (VCs) arising from oil spills under some hypothetical scenarios have been studied using a computational model. The computational results indicate that overexposure to benzene may exist under general conditions. A table summarizing the exposure risks under various conditions is presented which may be useful in exposure risk analysis during oil spill response. The exposure to other volatile hydrocarbon components is negligible. Exposure to sulphur components occurs, but the duration is very short.
Flow past a ship radiating a bore in a channel
Authors: Gourlay T , Cook S
Published: April 2011

A theoretical and experimental investigation is made into the phenomenon of ship-radiated bores caused by a vessel travelling in a shallow, narrow channel at a supercritical speed. The very large drag of this flow phenomenon is studied, as well as the conditions under which it occurs. An improved one-dimensional theory is described for predicting the bore properties, and a new theory is put forward for predicting flow velocity and free surface height back to the stern of the ship. Results are compared with an experimental investigation of the same phenomenon, for a ship either fixed vertically in its rest position or free to squat.
Quantifying external costs of emissions due to ship operation
Authors: Isensee J , Bertram V
Published: April 2011

The authors attempt to express the environmental impact of ships in one metric to allow engineering comparison or optimization of ships in terms of the environmental impact. Emissions are shown to be the most important environmental impact factor for ships. The model includes only emissions in the quantitative metric, but other factors are discussed qualitatively. Emissions depend decisively on ship speed and fuel quality. Estimates based on this metric show that using residual fuels for ship diesels causes globally much higher costs in terms of environmental damage than they save in operating cost.
A fuzzy Kalman filter optimized using a multi-objective genetic algorithm for enhanced autonomous underwater vehicle navigation
Authors: Loebis D , Sutton R , Chudley J
Published: April 2011

In an autonomous underwater vehicle integrated navigation system, short-term temporal accuracy is provided by an inertial navigation subsystem (INS) and long-term accuracy by a global positioning system (GPS). The Kalman filter has been a popular method for integrating the data produced by the two systems to provide optimal estimates of autonomous underwater vehicle position and attitude. In this paper, a sequential use of a linear Kalman filter and extended Kalman filter is proposed. The former is used to fuse the data from a variety of INS sensors whose output is used as an input to the latter where integration with GPS data takes place. The use of a fuzzy-rule-based adaptation scheme to cope with the divergence problem caused by the insufficiently known a priori filter statistics is also explored. The choice of fuzzy membership functions for an adaptation scheme is first carried out using a heuristic approach. Multiobjective genetic algorithm techniques are then used to optimize the parameters of the membership functions with respect to a certain performance criteria in order to improve the overall accuracy of the integrated navigation system. Simulation results are presented that show that the proposed algorithms can provide a significant improvement in the overall navigation performance of an autonomous underwater vehicle navigation system.
Integrity of hybrid steel-to-composite joints for marine application
Authors: Boyd S W , Blake J I R , Shenoi R A , Kapadia A
Published: April 2011

There are many instances where the use of weight-saving polymer composite material for an entire structure is either too complex, too expensive or unfeasible. In these circumstances the use of a hybrid structure can incorporate the benefits of traditional (e.g. steel) construction coupled with the advantages of composite materials [e.g. glass-reinforced polymers, glass-reinforced plastic (GRP)] in weight-critical areas. A number of studies have been carried out on the static strength of hybrid steel-to-composite joints.

In the present study, an experimental investigation was undertaken into the fatigue life characterization of a hybrid steel-to-GRP joint. It was found that the fatigue data correlated well with the statistical-based Weibull cumulative distribution function. In addition, post fatigue (in-plane and out-of-plane) residual strength tests were undertaken to ascertain the joint structural performance after cyclic loading. Finite-element-based progressive damage analyses incorporating damage initiation and propagation characteristics, showed good correlation with experimental results.
Numerical methods for design of bonded joints for ship structures
Authors: Wang X , Mieth U , Cappelletti A M
Published: April 2011

In the EU project BONDSHIP adhesive bonding has been introduced into shipbuilding for joining similar or dissimilar lightweight materials. For the investigation of bonded structural behaviour the finite element method provides versatile numerical tools. While for the design of large structures a cost-efficient modelling method using a substitute system of one-dimensional spring elements is necessary, the non-linear finite element methods with hyperelastic material models using three-dimensional solid elements are required for detailed joint analysis. Numerical simulations of mechanical tests on a bonded aluminium structure have been performed with the finite element codes ABAQUS Standard and MSC. Marc. The global and local finite element analyses incorporating both modelling methods through the submodelling technique are presented. The structural behaviour under both bending and shear loads was investigated using inductive measurement. A comparison of two modelling methods with the test results is presented in this paper.
Evaluation of the Avon Foundation Community Education and Outreach Initiative Community Patient Navigation Program
Authors: Mason Tamara A. , Thompson Winifred Wilkins , Allen Dana , Rogers Dana , Gabram-Mendola Sheryl , Jacob Arriola Kimberly R.
Published: April 2011

Introduction. Black women in the United States experience disproportionate breast cancer mortality. Culturally appropriate community education on the importance of breast health coupled with the availability of free or low-cost mammography screening services may help improve the use of mammography screening services among Black women. The Avon Foundation Community Patient Navigation Program seeks to fill this need. The current study presents a process and outcome evaluation of this program. Method. Trained and uniformed community patient navigators (PNs) host breast health education events where they recruit community members to complete a mammography interest form. Participants are referred to a nurse practitioner who determines eligibility for a free or low-cost mammogram. The community PN delivers telephone follow-up to encourage participants to make and keep their mammogram appointments. Results. Over a 15-month period, 22 community PNs hosted 207 breast health events, which included 9,601 attendees. Three hundred and four participants completed a mammography interest form, and 21% of these individuals received mammograms at the collaborating health facility. Participants who reported breast symptoms were twice as likely to get a mammogram as those who did not report symptoms. Discussion. Community patient navigation may be a useful resource for encouraging mammography screening among underserved women.
Enhanced Left-Finger Deftness Following Dominant Upper- and Lower-Limb Amputation
Authors: Swanberg Kelley M. , Clark Abigail M. , Kline Julia E. , Yurkiewicz Ilana R. , Chan Brenda L. , Pasquina Paul F. , Heilman Kenneth M. , Tsao Jack W.
Published: April 2011

Background. After amputation, the sensorimotor cortex reorganizes, and these alterations might influence motor functions of the remaining extremities. Objective. The authors examined how amputation of the dominant or nondominant upper or lower extremity alters deftness in the intact limbs. Methods. The participants were 32 unilateral upper- or lower-extremity amputees and 6 controls. Upper-extremity deftness was tested by coin rotation (finger deftness) and pegboard (arm, hand, and finger deftness) tasks. Results. Following right-upper- or right-lower-extremity amputation, the left hand’s finger movements were defter than the left-hand fingers of controls. In contrast, with left-upper- or left-lower-extremity amputation, the right hand’s finger performance was the same as that of the controls. Conclusions. Although this improvement might be related to increased use (practice), the finding that right-lower-extremity amputation also improved the left hand’s finger deftness suggests an alternative mechanism. Perhaps in right-handed persons the left motor cortex inhibits the right side of the body more than the right motor cortex inhibits the left side, and the physiological changes induced by right-sided amputation reduced this inhibition.
Hamstring Injuries in Professional Football Players
Authors: Cohen Steven B. , Towers Jeffrey D. , Zoga Adam , Irrgang Jay J. , Makda Junaid , Deluca Peter F. , Bradley James P.
Published: April 2011

Background: Magnetic resonance imaging (MRI) allows for detailed evaluation of hamstring injuries; however, there is no classification that allows prediction of return to play.

Purpose: To correlate time for return to play in professional football players with MRI findings after acute hamstring strains and to create an MRI scoring scale predictive of return to sports.

Study Design: Descriptive epidemiologic study.

Methods: Thirty-eight professional football players (43 cases) sustained acute hamstring strains with MRI evaluation. Records were retrospectively reviewed, and MRIs were evaluated by 2 musculoskeletal radiologists, graded with a traditional radiologic grade, and scored with a new MRI score. Results were correlated with games missed.

Results: Players missed 2.6 ± 3.1 games. Based on MRI, the hamstring injury involved the biceps femoris long head in 34 cases and the proximal and distal hamstrings in 25 and 22 cases, respectively. When < 50% of the muscle was involved, the average number of games missed was 1.8; if > 75%, then 3.2. Ten players had retraction, missing 5.5 games. By MRI, grade I injuries yielded an average of 1.1 missed games; grade II, 1.7; and grade III, 6.4. Players who missed 0 or 1 game had an MRI score of 8.2; 2 or 3 games, 11.1; and 4 or more games, 13.9.

Conclusions: Rapid return to play (< 1 week) occurred with isolated long head of biceps femoris injures with < 50% of involvement and minimal perimuscular edema, correlating to grade I radiologic strain (MRI score < 10). Prolonged recovery (missing > 2 or 3 games) occurs with multiple muscle injury, injuries distal to musculotendinous junction, short head of biceps injury, > 75% involvement, retraction, circumferential edema, and grade III radiologic strain (MRI score > 15).

Clinical Relevance: MRI grade and this new MRI score are useful in determining severity of injury and games missed—and, ideally, predicting time missed from sports.
Impact Forces of Plyometric Exercises Performed on Land and in Water
Authors: Donoghue Orna A. , Shimojo Hirofumi , Takagi Hideki
Published: April 2011

Background: Aquatic plyometric programs are becoming increasingly popular because they provide a less stressful alternative to land-based programs. Buoyancy reduces the impact forces experienced in water.

Purpose: To quantify the landing kinetics during a range of typical lower limb plyometric exercises performed on land and in water.

Study Design: Crossover design.

Methods: Eighteen male participants performed ankle hops, tuck jumps, a countermovement jump, a single-leg vertical jump, and a drop jump from 30 cm in a biomechanics laboratory and in a swimming pool. Land and underwater force plates (Kistler) were used to obtain peak impact force, impulse, rate of force development, and time to reach peak force for the landing phase of each jump.

Results: Significant reductions were observed in peak impact forces (33%-54%), impulse (19%-54%), and rate of force development (33%-62%) in water compared with land for the majority of exercises in this study (P < 0.05).

Conclusions: The level of force reduction varies with landing technique, water depth, and participant height and body composition.

Clinical Relevance: This information can be used to reintroduce athletes to the demands of plyometric exercises after injury.
Body Mass Index and Percentage of Body Fat as Indicators for Obesity in an Adolescent Athletic Population
Authors: Etchison William C. , Bloodgood Elizabeth A. , Minton Cholly P. , Thompson Nancy J. , Collins Mary Ann , Hunter Stephen C. , Dai Hongying
Published: April 2011

Background: Body mass index (BMI) is widely accepted in determining obesity. Skinfold thickness measurements have been commonly used to determine percentage of body fat.

Hypothesis: The authors hypothesize that because BMI does not measure fat directly but relies on body weight alone, a large percentage of athletic adolescents will be misclassified as obese by BMI.

Design: Cross-sectional study.

Methods: To compare BMI and skinfold measurements as indicators for obesity in the adolescent athletic population, anthropometric data (height, weight, percentage body fat, age, and sex) were recorded from 33 896 student athletes (average age, 15 years; range, 11-19 years) during preparticipation physical examinations from 1985 to 2003. BMI was calculated from height and weight. Percentage of body fat was determined by measuring skinfold thickness.

Results: According to their BMI percentile, 13.31% of adolescent athletes were obese. Using the skinfold method, only 5.95% were obese. Of those classified as obese by the BMI, 62% were considered false positives by the skinfold method. In contrast, there was a 99% probability that the nonobese by BMI would not be obese by the skinfold method (negative predictive value = 0.99).

Conclusions: BMI is a measurement of relative body weight, not body composition. Because lean mass weighs far more than fat, many adolescent athletes are incorrectly classified as obese based on BMI. Skinfold testing provides a more accurate body assessment than BMI in adolescent athletes.

Clinical Relevance: Correct body composition data can help to provide better diet and activity guidelines and prevent the psychological problems associated with being labeled as obese.
Microbiota Found in Protective Athletic Mouthguards
Authors: Glass Richard T. , Conrad Robert S. , Köhler Gerwald A. , Warren Aric J. , Bullard James W.
Published: April 2011

Background: Protective athletic mouthguards (PAM) produce oral mucosal injuries and may be associated with other systemic conditions.

Hypothesis: With wear, PAM become contaminated by a range of microorganisms. The number of microorganisms in PAM can be reduced by daily use of an antimicrobial solution. Study Type: Case series.

Study Design and Methods: Sixty-two division I football player volunteers were divided into 4 groups, using PAM for varying lengths of time before surrendering them for microbial analysis. One group had their PAM soaked in an antimicrobial solution between uses. The PAM were analyzed qualitatively and quantitatively for bacteria, yeasts, and fungi, using previously accepted methods.

Results: The 62 football players surrendered a total of 81 PAM for microbial analysis. The PAM yielded 154 gram-positive cocci, 150 gram-positive bacilli, 21 gram-negative cocci, 31 gram-negative bacilli, 22 yeasts, and 107 molds. The most common species of gram-positive cocci were Staphylococcus spp. and Micrococcus spp. Only 3 PAM (4%) were positive for Staphylococcus aureus. The most common species of gram-positive bacilli were Brevibacterium spp. and Cellulomonas spp. The most common species of yeasts were Candida parapsilosis and Rhodotorula mucilaginosa, while the most common species of mold were Cochliobolus spp. and Penicillium chrysogenum. Soaking the PAM in an antimicrobial solution between uses substantially reduced the numbers of microorganisms.

Conclusions: Substantial microbial contamination of PAM occurs with use. The microbial load can be reduced by soaking in an antimicrobial solution between uses. Clinical Relevance: PAM are contaminated by microorganisms that have the potential to produce oral and systemic diseases. They should be sanitized daily and changed when they become sharp and/or jagged.
Combinatorial effects of microRNAs to suppress the Myc oncogenic pathway
Authors: Bueno María J. , Gómez de Cedrón Marta , Gómez-López Gonzalo , Pérez de Castro Ignacio , Di Lisio Lorena , Montes-Moreno Santiago , Martínez Nerea , Guerrero Manuel , Sánchez-Martínez Ruth , Santos Javier , Pisano David G. , Piris Miguel Angel , Fernández-Piqueras José , Malumbres Marcos
Published: April 2011

Many mammalian transcripts contain target sites for multiple miRNAs, although it is not clear to what extent miRNAs may coordinately regulate single genes. We have mapped the interactions between down-regulated miRNAs and overexpressed target protein-coding genes in murine and human lymphomas. Myc, one of the hallmark oncogenes in these lymphomas, stands out as the up-regulated gene with the highest number of genetic interactions with down-regulated miRNAs in mouse lymphomas. The regulation of Myc by several of these miRNAs is confirmed by cellular and reporter assays. The same approach identifies MYC and multiple Myc targets as a preferential target of down-regulated miRNAs in human Burkitt lymphoma, a pathology characterized by translocated MYC oncogenes. These results indicate that several miRNAs must be coordinately down-regulated to enhance critical oncogenes, such as Myc. Some of these Myc-targeting miRNAs are repressed by Myc, suggesting that these tumors are a consequence of the unbalanced activity of Myc versus miRNAs.
A novel TNFR1-triggered apoptosis pathway mediated by class IA PI3Ks in neutrophils
Authors: Geering Barbara , Gurzeler Ursina , Federzoni Elena , Kaufmann Thomas , Simon Hans-Uwe
Published: April 2011

The most common form of neutrophil death is apoptosis. In the present study, we report surprising differences in the molecular mechanisms used for caspase activation between FAS/CD95-stimulated and TNF receptor 1 (TNFR1)–stimulated neutrophils. Whereas FAS-induced apoptosis was followed by caspase-8 activation and required Bid to initiate the mitochondrial amplification loop, TNF-α–induced apoptosis involved class IA PI3Ks, which were activated by MAPK p38. TNF-α–induced PI3K activation resulted in the generation of reactive oxygen species, which activated caspase-3, a mechanism that did not operate in neutrophils without active NADPH oxidase. We conclude that in neutrophils, proapoptotic pathways after TNFR1 stimulation are initiated by p38 and PI3K, but not by caspase-8, a finding that should be considered in anti-inflammatory drug-development strategies.
Circulating human B lymphocytes are deficient in nucleotide excision repair and accumulate mutations upon proliferation
Authors: Hyka-Nouspikel Nevila , Lemonidis Kimon , Lu Wei-Ting , Nouspikel Thierry
Published: April 2011

Faithful repair of DNA lesions is a crucial task that dividing cells must actively perform to maintain genome integrity. Strikingly, nucleotide excision repair (NER), the most versatile DNA repair system, is specifically down-regulated in terminally differentiated cells. This prompted us to examine whether NER attenuation might be a common feature of all G0-arrested cells, and in particular of those that retain the capacity to reenter cell cycle and might thus convert unrepaired DNA lesions into mutations, a prerequisite for malignant transformation. Here we report that quiescent primary human B lymphocytes down-regulate NER at the global genome level while maintaining proficient repair of constitutively expressed genes. Quiescent B cells exposed to an environment that causes both DNA damage and proliferation accumulate point mutations in silent and inducible genes crucial for cell replication and differentiation, such as BCL6 and Cyclin D2. Similar to differentiated cells, NER attenuation in quiescent cells is associated with incomplete phosphorylation of the ubiquitin activating enzyme Ube1, which is required for proficient NER. Our data establish a mechanistic link between NER attenuation during quiescence and cell mutagenesis and also support the concept that oncogenic events targeting cell cycle- or activation-induced genes might initiate genomic instability and lymphomagenesis.
Platelet CD36 surface expression levels affect functional responses to oxidized LDL and are associated with inheritance of specific genetic polymorphisms
Authors: Ghosh Arunima , Murugesan Gurunathan , Chen Kan , Zhang Li , Wang Qing , Febbraio Maria , Anselmo Rita Marie , Marchant Kandice , Barnard John , Silverstein Roy L.
Published: April 2011

CD36 modulates platelet function via binding to oxidized LDL (oxLDL), cell-derived microparticles, and thrombospondin-1. We hypothesized that the level of platelet CD36 expression may be associated with inheritance of specific genetic polymorphisms and that this would determine platelet reactivity to oxLDL. Analysis of more than 500 subjects revealed that CD36 expression levels were consistent in individual donors over time but varied widely among donors (200-14 000 molecules per platelet). Platelet aggregometry and flow cytometry in a subset of subjects with various CD36 expression levels revealed a high level of correlation (r2 = 0.87) between platelet activation responses to oxLDL and level of CD36 expression. A genome-wide association study of 374 white subjects from the Cleveland Clinic ASCLOGEN study showed strong associations of single nucleotide polymorphisms in CD36 with platelet surface CD36 expression. Most of these findings were replicated in a smaller subset of 25 black subjects. An innovative gene-based genome-wide scan provided further evidence that single nucleotide polymorphisms in CD36 were strongly associated with CD36 expression. These studies show that CD36 expression on platelets varies widely, correlates with functional responses to oxLDL, and is associated with inheritance of specific CD36 genetic polymorphisms, and suggest that inheritance of specific CD36 polymorphisms could affect thrombotic risk.
In vivomonitoring of cystic fibrosis-like lung disease in mice by volumetric computed tomography
Authors: Wielpütz M.O. , Eichinger M. , Zhou Z. , Leotta K. , Hirtz S. , Bartling S.H. , Semmler W. , Kauczor H-U. , Puderbach M. , Mall M.A.
Published: April 2011

The onset and spontaneous development of cystic fibrosis (CF) lung disease remain poorly understood. In the present study, we used volumetric computed tomography (VCT) as a new method for longitudinalin vivomonitoring of early lesions and disease progression in CF-like lung disease in β-epithelial Na+channel (ENaC)-transgenic (TG) mice.

Using a VCT scanner prototype (80 kV, 50 mA·s, scan time 19 s and spatial resolution 200 μm), βENaC-TG mice and wild-type (WT) littermates were examined longitudinally at 10 time-points from neonatal to adult ages, and VCT images were assessed by qualitative and quantitative morphological parameters.

We demonstrate that VCT detected early-onset airway mucus obstruction, diffuse infiltrates, atelectasis and air trapping as characteristic abnormalities in βENaC-TG mice. Furthermore, we show that early tracheal mucus obstruction predicted mortality in βENaC-TG mice and that the density of lung parenchyma was significantly reduced at all time-points in βENaC-TG compared with WT mice (median±sem-558±8 HU in WTversus-686±16 HU in βENaC-TG at 6 weeks of age; p<0.005).

Our study demonstrates that VCT is a sensitive, noninvasive technique for early detection and longitudinal monitoring of morphological abnormalities of CF-like lung disease in mice, and may thus provide a useful tool for pre-clinicalin vivoevaluation of novel treatment strategies for CF.
SERPINE1-675 4G/5G polymorphism is associated with asthma severity and inhaled corticosteroid response
Authors: Dijkstra A. , Postma D.S. , Bruinenberg M. , van Diemen C.C. , Boezen H.M. , Koppelman G.H. , Timens W. , Vonk J.M.
Published: April 2011

Asthma is characterised by chronic airway inflammation and remodelling, which can be (partially) suppressed by inhaled corticosteroids (ICSs). Plasminogen activator inhibitor-1, encoded by theSERPINE1gene,is the key inhibitor of the plasminogen activator system, which affects tissue repair and remodelling.

We studied associations between a functionalSERPINE1-675 4G/5G promoter polymorphism and asthma development, severity and response to ICSs.

Longitudinal cohorts of 281 asthmatics and their nonasthmatic spouses, and the general population (n=1,390) were studied. No significant associations were found with asthma development and immunoglobulin (Ig)E levels, or with forced expiratory volume in 1 s (FEV1) in nonasthmatic controls. Asthmatic subjects carrying theSERPINE15G allele had higher IgE and lower lung function levels at follow-up, lower maximally attained lung function levels, and faster lung function decline compared with individuals with the 4G/4G genotype. ICS treatment showed an immediate improvement in FEV1in asthmatics carrying the 5G allele. However, these asthmatics still had the fastest rate of FEV1decline after initiating ICS treatment. Finally, the 5G allele was associated with a lower prevalence of complete asthma remission at follow-up.

These findings suggest thatSERPINE1is not an asthma susceptibility gene, but rather affects the severity, progression and long-term ICS response in asthma.
Inhaled dry powder mannitol in cystic fibrosis: an efficacy and safety study
Authors: Bilton D. , Robinson P. , Cooper P. , Gallagher C.G. , Kolbe J. , Fox H. , Jaques A. , Charlton B.
Published: April 2011

This international phase III study of inhaled dry powder mannitol was a randomised, double-blind, 26-week study, followed by a further 26-week, open-label (OL) extension. 324 cystic fibrosis (CF) patients were randomised, in a 3:2 ratio, to mannitol (400 mgb.i.d.) and control groups. The primary efficacy end-point was to determine the change in forced expiratory volume in 1 s (FEV1) over the double-blind phase. Secondary end-points included changes in forced vital capacity and pulmonary exacerbations.

A significant improvement in FEV1was seen over 26 weeks (p<0.001) and was apparent by 6 weeks, irrespective of concomitant recombinant human deoxyribonuclease (rhDNase) use. At 26 weeks, there was a significant improvement in FEV1of 92.9 mL for subjects receiving mannitol compared with controls (change from baseline 118.9 mL (6.5%)versus26.0 mL (2.4%); p<0.001). Improvements in FEV1were maintained up to 52 weeks in the OL part of the study. There was a 35.4% reduction in the incidence of having an exacerbation on mannitol (p=0.045).

The incidence of adverse events (AEs) was similar in both groups, although treatment-related AEs were higher in the mannitol compared with the control group. The most common mannitol-related AEs were cough, haemoptysis and pharyngolaryngeal pain.

Mannitol showed sustained, clinically meaningful benefit in airway function in CF, irrespective of concomitant rhDNase use. Mannitol appears to have an acceptable safety profile for patients with CF.
An open-label trial of rituximab therapy in pulmonary alveolar proteinosis
Authors: Kavuru M.S. , Malur A. , Marshall I. , Barna B.P. , Meziane M. , Huizar I. , Dalrymple H. , Karnekar R. , Thomassen M.J.
Published: April 2011

Rituximab, a monoclonal antibody directed against the B-lymphocyte antigen CD20, has shown promise in several autoimmune disorders. Pulmonary alveolar proteinosis (PAP) is an autoimmune disorder characterised by autoantibodies to granulocyte-macrophage colony-stimulating factor (GM-CSF).

An open-label, proof-of-concept phase II clinical trial was conducted in 10 PAP patients. The intervention consisted of two intravenous infusions of rituximab (1,000 mg) 15 days apart. Bronchoalveolar lavage (BAL) fluid and peripheral blood samples were collected.

The primary outcome was improvement in arterial blood oxygenation. Both arterial oxygen tension and alveolar–arterial oxygen tension difference in room air improved in seven out of the nine patients completing the study. Lung function and high-resolution computed tomography scans, which were secondary outcomes, also improved. Peripheral blood CD19+ B-lymphocytes decreased from mean±sem15±2% to <0.05% (n=10) 15 days post-therapy. This decrease persisted for 3 months in all patients; at 6 months, CD19+ B-cells were detected in four out of seven patients (5±2%). Total anti-GM-CSF immunoglobulin (Ig)G levels from baseline to 6 months were decreased in BAL fluids (n=8) but unchanged in sera (n=9).

In this PAP cohort: 1) rituximab was well-tolerated and effectively ameliorated lung disease; and 2) reduction in anti-GM-CSF IgG levels in the lung correlated with disease changes, suggesting that disease pathogenesis is related to autoantibody levels in the target organ.
Processing SPARQL queries with regular expressions in RDF databases
Authors: Lee Jinsoo , Pham Minh-Duc , Lee Jihwan , Han Wook-Shin , Cho Hune , Yu Hwanjo , Lee Jeong-Hoon
Published: April 2011

Background

As the Resource Description Framework (RDF) data model is widely used for modeling and sharing a lot of online bioinformatics resources such as Uniprot (dev.isb-sib.ch/projects/uniprot-rdf) or Bio2RDF (bio2rdf.org), SPARQL - a W3C recommendation query for RDF databases - has become an important query language for querying the bioinformatics knowledge bases. Moreover, due to the diversity of users’ requests for extracting information from the RDF data as well as the lack of users’ knowledge about the exact value of each fact in the RDF databases, it is desirable to use the SPARQL query with regular expression patterns for querying the RDF data. To the best of our knowledge, there is currently no work that efficiently supports regular expression processing in SPARQL over RDF databases. Most of the existing techniques for processing regular expressions are designed for querying a text corpus, or only for supporting the matching over the paths in an RDF graph.

Results

In this paper, we propose a novel framework for supporting regular expression processing in SPARQL query. Our contributions can be summarized as follows. 1) We propose an efficient framework for processing SPARQL queries with regular expression patterns in RDF databases. 2) We propose a cost model in order to adapt the proposed framework in the existing query optimizers. 3) We build a prototype for the proposed framework in C++ and conduct extensive experiments demonstrating the efficiency and effectiveness of our technique.

Conclusions

Experiments with a full-blown RDF engine show that our framework outperforms the existing ones by up to two orders of magnitude in processing SPARQL queries with regular expression patterns.