bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of weather influence on mechanical and viscoelastic properties of polyetherimide/carbon fiber composites
Authors: Batista Natassia L , Iha Koshun , Botelho Edson C
Published: May 2013

In order to investigate how environmental degradation affects the mechanical and thermal performance of polyetherimide/carbon fiber laminates, in this work different weathering were conducted. Additionally, dynamic mechanical analysis, interlaminar shear strength tests and non-destructive inspections were performed on this composite before and after being submitted to hygrothermal, UV radiation and thermal shock weathering. According to our results, hygrothermally aged samples had their glass transition temperature and elastic and storage moduli reduced by plasticization effect. Photooxidation, due to UV radiation exposure, occurred only on the surface of the laminates. Thermal shock induced a reversible stress on the composite’s interface region. The results revealed that the mechanical behavior can vary during weather exposure but since this variation is only subtle, this thermoplastic laminate can be considered for high-performance applications, such as aerospace.
An investigation on blunt notch behavior of fiber metal laminates containing notch with different shapes
Authors: Sadeghpour Ebrahim , Sadighi Mojtaba , Dariushi Soheil
Published: May 2013

In this study, the blunt notch strength of a fiber metal laminate with circular, elliptic and square notch shape has been studied up to failure point. Investigation of the stress concentration does not give a good idea about the strength in anisotropic plates and a failure criterion should be employed to evaluate failure. Therefore, an analytical method has been developed to evaluate stress components and predict the failure around the holes with different shapes. In order to obtain empirical results, specimens were manufactured by alternatively stacking aluminum and E-glass-epoxy layers according to the Glare standard. Analytical results show that the yielding of aluminum layers is the damage occurring to the plate initially. As a result, after the onset of the plastic flow in metallic layers the plate is not homogenous anymore, and conventional analysis cannot not be applied. An analytical model has been suggested to inspect the behavior of the plate at its ultimate load and is verified by ANSYS simulation. Comparison of different models indicates that numerical and theoretical models agree well with experimental test results. Also, the effect of aluminum thickness on strength has been examined analytically.
Stovepiping
Authors: Gailmard Sean , Patty John W
Published: May 2013

In hierarchical organizations lower-level agents can often censor the information that a higher-level principal has available to make a decision. We present a model of this interaction in which the principal can also access an independent source of unfiltered but lower-quality information besides that provided by the agent. This provision of outside information can be thought of as ‘stovepiping,’ the transmission of unfiltered information from analysts directly to decision-makers. Stovepiping can, in equilibrium, result in the agent passing along more information to the principal, precisely because the outsider’s information is of lower quality than the agent’s. But it can also lead the agent to ‘destroy’ information so that there is no basis for any policy change. Accordingly, stovepiping has countervailing effects on the principal’s utility. We discuss the comparative statics of equilibrium levels of information transmission with respect to the preferences of the principal, the outsider, and the probability that the outsider has access to the information held by the agent.
Discursive representations of a dissident: The case of Liu Xiaobo in China’s English press
Authors: Alvaro Joseph J
Published: May 2013

This article is a critical analysis of media discourses in which a dissident social actor is represented in China’s state-run English-language press. Specifically, it looks at media coverage of Liu Xiaobo, author of Charter 2008, a document calling for democracy and human rights in China. He was imprisoned for 11 years by the Chinese government for disseminating Charter 2008, but subsequently (to the government’s chagrin) was awarded the 2010 Nobel Peace Prize for his work in advocating human rights. This investigation examines articles from China’s English press on Liu Xiaobo. A transitivity analysis is conducted followed by an investigation of identifying and attributive relational processes in the texts. The findings show the use of passive agent deletion, definition/re-definition, and the attribution of derogating qualities to dissidents with the purpose of introducing biased ideological representations (positive- Self/negative- Other) into the discourse.
Interleukin-10 promoter polymorphisms and expression in Thai children with juvenile systemic lupus erythematosus
Authors: Rianthavorn P , Chokedeemeeboon C , Deekajorndech T , Suphapeetiporn K
Published: May 2013

Interleukin (IL)-10 expression is regulated by its promoter and correlated with the activity of adult-onset lupus (systemic lupus erythematosus (SLE)). As the pathogenesis of adult-onset SLE may differ from SLE with the age at onset <18 years old (juvenile SLE or JSLE), we evaluated polymorphisms at positions −1082A/G, −819T/C and −592A/C of the IL-10 promoter and serum IL-10 levels in 71 patients with JSLE. Disease activity was determined by the SLE disease activity index (SLEDAI). Active SLE was defined by SLEDAI ≥6 and inactive SLE was defined by SLEDAI equal to zero. The mean age was 14.5 ± 2.8 years. Nephritis occurred in 57 patients. In JSLE patients, −592 CC and −819 CC were identified with a higher frequency than in controls with the odds ratio (OR) of 2.75 (95% confidence interval (CI) 1.11–6.81, p = 0.04). GCC increased the susceptibility to nephritis in patients with JSLE (OR 2.16, 95% CI 1.07–4.35, p = 0.03). Serum IL-10 levels were significantly higher in 20 JSLE patients with active disease than in 27 patients with inactive disease and in 15 healthy children ( p < 0.001). In conclusion, IL-10 expression was upregulated in active JSLE. The −819 CC and −592 CC genotypes increased the susceptibility to JSLE and GCC increased the susceptibility to nephritis.
ESD and the Rio Conventions
Authors: Sarabhai Kartikeya V. , Ravindranath Shailaja , Schwarz Rixa , Vyas Purvi
Published: May 2013

Chapter 36 of Agenda 21, a key document of the 1992 Earth Summit, emphasised reorienting education towards sustainable development. While two of the Rio conventions, the Convention on Biological Diversity (CBD) and the United Nations Framework Convention on Climate Change (UNFCCC), developed communication, education and public awareness (CEPA) strategies, the United Nations Convention to Combat Desertification (UNCCD) established their awareness raising, communication and education (ARCE) unit in the secretariat. The concept of education for sustainable development (ESD) largely evolved independently through the leadership of United Nations Educational, Scientific and Cultural Organization (UNESCO) and United Nations Environment Programme (UNEP) and has had, as yet, little impact on the programmes of the conventions. However, recent developments seem to lay the foundation for ESD to be integrated into the conventions. UNCCD has started infusing ESD thinking into its educational programmes. The recently concluded CBD Conference of Parties (COP 11) is important because it not only set education high on the agenda but also connected ESD with the CBD approach towards achieving its targets. Similarly, UNFCCC at COP 18 held at Doha saw 33 multilateral agencies announce the formation of the UN Alliance on Climate Change, Training and Public Awareness. The challenge for the ESD community is to carry this process forward and put in place institutional mechanisms to integrate ESD with the goals of the conventions as we move towards 2014 and beyond.
Biodiversity and Education for Sustainable Development in Teacher Education Programmes of Four Jamaican Educational Institutions
Authors: Collins-Figueroa Marceline
Published: May 2013

This article presents an account of biodiversity education in a national teacher education project in Jamaica. Four case studies are examined here. Document analyses and interviews of educators and student teachers are used to explore how biodiversity was addressed in teacher education curricula, the processes and outcomes of learning in education for sustainable development (ESD) and how learning contributed to sustainable development. It concludes that the project facilitated ESD through whole college, cross-curricular, collaborative, thematic, active learning to varying degrees. Interdisciplinary approaches were achieved in extra-curricular clubs, but rarely in the discipline-bound college curricula. Few colleges included valuing or explored the controversial nature of biodiversity. Ecological, social, cultural and economic outcomes are identified; however, systemic interconnections of these dimensions are limited.
Parisara: Developing a Collaborative, Free, Public Domain Knowledge Resource on Indian Environment
Authors: Gadgil Madhav
Published: May 2013

To address the important challenge of taking good care of India’s environment, substantial, good quality information is crucial. Unfortunately, pertinent information is in very short supply. Much of the nationally collected information lacks quality and is incomplete. Modern science has demonstrated that good information flows from an open, transparent process that welcomes participation of all interested parties. Such a broad based, open, participatory process should be established to develop a sound, comprehensive base of information on India’s environment.

All over the world, citizens are a great repository of detailed information on many facets of their local environment. India’s citizens, especially students and teachers, therefore have to play an important role in this process of building up a good information resource on India’s environment. Rapidly advancing information and communication technology (ICT) tools hold much promise in facilitating such a participatory process of knowledge generation.

In India, such a programme may involve interested citizens of a locality working with a consortium of both urban and rural high schools, junior and undergraduate colleges. It would take advantage of the fact that it is now mandatory for students in Classes 11–12, as well as for the second year undergraduates in all branches, to undertake a major project on environment. It could also build upon the provisions of the Biological Diversity Act, 2002 that mandates all panchayats and nagar palikas throughout the country to undertake documentation of local biodiversity resources and associated knowledge in the form of ‘People’s Biodiversity Registers’.

 In the long run, this process would establish a transparent, publicly accessible information resource on India’s environment with accreditation to concerned students, teachers and other interested citizens for all items of information.
Educating the Imagination: Teaching for Sustainability through a Bioregional Literacy Curriculum
Authors: Howard Patrick
Published: May 2013

In Canada, a national framework proposes to integrate learning outcomes into existing K-12 curricula to teach the values, skills and behaviours of sustainability. This article describes a research project designed to identify existing curricula that may contribute to education for sustainable development (ESD). The province of Newfoundland and Labrador, Canada, has a tradition of developing bioregional curriculum resources that reflect the unique landscape, history and culture of the province. This article presents research investigating the Newfoundland curriculum to determine to what extent it correlates with, and teaches to, the values of ESD as represented by the Decade for Education for Sustainable Development (2005–14) initiative. High school students involved in a four-week unit of study were carefully observed, and the texts they generated were analysed for themes of pedagogical value in an attempt to determine the potential of the Newfoundland bioregional curriculum to foster values associated with ESD. It was found that literacy curricula containing imaginative, creative texts can be used to deepen student awareness of the cultural and living landscapes in which they dwell. Further research is needed to support the use of existing curricular resources and the development of new bioregional curricula specific to unique cultures, communities and bioregions across Canada and other countries.
Brief Family Therapy for Refugee Children
Authors: Björn Gunilla Jarkman , Bodén Christina , Sydsjö Gunilla , Gustafsson Per A.
Published: May 2013

The aim of this study was to compare refugee children’s psychological well-being before and after brief family therapy. Families from Bosnia-Herzegovina with one child aged 5–12 years received three family therapy sessions. Psychological assessments using the Erica play-diagnostic method and parental interviews were made before and after the intervention. The main finding was that more children built normal sandboxes (showing no pathological findings)after the intervention than before, indicating that the rather short intervention had a positive effect on the children’s psychological well-being. To conclude, it might be valuable to offer refugee families a few family therapy sessions even if the children do not have psychiatric symptoms with the aim of helping them adapt to a new system of society.
Association of personality, neighbourhood, and civic participation with the level of perceived social support: The HUNT study, a cross-sectional survey
Authors: Grav Siv , Romild Ulla , Hellzèn Ove , Stordal Eystein
Published: May 2013

Aim: The aim of the current study was to examine the association of personality, neighbourhood, and civic participation with the level of perceived social support if needed. Methods: The sample consists of a total of 35,797 men (16,035) and women (19,762) drawn from the Nord-Trøndelag Health Study 3 (HUNT3), aged 20–89, with a fully completed short version of the Eysenck Personality Questionnaire (EPQ) including a complete response to questions regarding perceived social support. A multinomial logistic regression model was used to investigate the association between the three-category outcomes (high, medium, and low) of perceived social support. Results: The Chi-square test detected a significant ( p < 0.001) association between personality, sense of community, civic participation, self-rated health, living arrangement, age groups, gender, and perceived social support, except between perceived social support and loss of social network, in which no significance was found. The crude and adjusted multinomial logistic regression models show a relation between medium and low scores on perceived social support, personality, and sources of social support. Interactions were observed between gender and self-rated health. Conclusions: There is an association between the level of perceived social support and personality, sense of community in the neighbourhood, and civic participation. Even if the interaction between men and self-reported health decreases the odds for low and medium social support, health professionals should be aware of men with poor health and their lack of social support.
Enriching the care of patients with dementia in acute settings? The Dementia Champions Programme in Scotland
Authors: Banks Pauline , Waugh Anna , Henderson Jenny , Sharp Barbara , Brown Margaret , Oliver Joanne , Marland Glenn
Published: May 2013

Admission to hospital has been found to have a negative impact on people with dementia. The Scottish Dementia Champions programme was developed to prepare health and social service Dementia Champions working in acute settings as Change Agents. The programme was initially delivered to a cohort of 100 health professionals via blended learning, and comprised five study days, a half day spent in a local community setting, and e-learning. In order to complete the programme and graduate, participants were required to complete and submit reports relating to three work-based activities.

The evaluation of the project adopted a two-pronged approach: Impact on programme participants was assessed by scores derived from the Approaches to Dementia Questionnaire (ADQ) ( Lintern, 1996 ) completed at Study Days 1 and 5, and analysis of qualitative data derived from the three written assignments. Participants were asked to evaluate course materials and input for each of the five study days, as well as satisfaction with delivery.

Analysis of data derived from the ADQ and 100 reflective reports of the community experience indicate that participants’ perceptions of people with dementia shifted significantly during the Programme. Participants identified a range of issues which should be addressed with a view to improving the experiences of people with dementia in acute settings, and put in place actions to bring about change. The format of the programme provided a cost effective means to prepare NHS and Social Service Dementia Champions as Change Agents for practice within a relatively short period of time, and would be transferrable to other staff groups as well as different organisational structures in other countries.
Cigarette Smoking Among Asian American and Pacific Islander College Students
Authors: Romero Devan R. , Pulvers Kim
Published: May 2013

Asian Americans (AA) and Pacific Islanders (PI) are an understudied population for health and tobacco use, which is alarming for a fast growing U.S. population. Research in smoking among AA and PI college students is limited, despite 50% of AA and 20% of PI having obtained a college degree. A cross-sectional tobacco survey was administered in a large racially diverse Southern California university (N = 490) that examined smoking behavior, psychosocial, and perceptual factors related to smoking among AA and PI compared with Caucasians. Overall, 19% of participants were smokers. The prevalence of current smoking by race was 26% PI, 19% AA, and 17% Caucasian. AA and PI are light, infrequent smokers who smoke mainly for social reasons and in social locations. Most AA and PI made quit attempts and reported intention to quit smoking. Low to moderate risk perceptions for addiction, disease and difficulty in quitting were observed. Social norms center on family influences, therefore it is recommended that cessation approaches target cigarette smoking norms within this social environment to increase perceptual risks of smoking. Smoking cessation should be placed in college health outreach programs based on culturally tailored approaches for AA and PI that target their unique smoking characteristics.
Ultrasound of the Groin: A Pictorial Review
Authors: Chiu Keith , Antoniades Georgios , Parker Pamela , Razack Abdul , Taylor Damien
Published: May 2013

The groin is a complex and clinically important area involving numerous fascia, muscles and neurovascular structures. Physical findings can be confusing and accurate diagnosis of groin pathology often relies on imaging. Ultrasound is considered by many as the modality of choice for evaluating groin pain or mass. This review aims to illustrate the sonographic anatomy of this region, the techniques in imaging hernia orifices, characteristic features of various types of hernias and groin masses.
Semi-Markov models for performance evaluation of failure-prone IP multimedia subsystem core networks
Authors: Guida Maurizio , Longo Maurizio , Postiglione Fabio , Trivedi Kishor S , Yin Xiaoyan
Published: May 2013

Next generation telecommunication core networks are typically based on the Third Generation Partnership Project Internet protocol (IP) multimedia subsystem (IMS). Their planning and deployment must take into account the occurrence of random failures causing performance degradations, in order to assess and maintain a high level of quality of service. In particular, IMS signalling servers can be modelled as repairable multi-state elements where states correspond to different performance levels. This article provides an evaluation of IMS signalling network performance in long runs in terms of two metrics adopted in the practice, such as the number of call set-up sessions that the network can manage at the same time and the call set-up delay. A semi-Markov model has been adopted for the IMS servers, which allows as well for non-exponential probability distributions of sojourn times, as often observed in real networks. Furthermore, a redundancy optimization problem is solved in an IMS-based realistic scenario, to the aim of minimizing the deployment cost of a telecommunication network with a given availability requirement.
Diagnostic effectiveness of 75 g oral glucose tolerance test for gestational diabetes in India based on the International Association of the Diabetes and Pregnancy Study Groups guidelines
Authors: Surapaneni Tarakeswari , Nikhat Irfana , Nirmalan Praveen K
Published: May 2013

Background

To determine the diagnostic effectiveness of the fasting and one-hour plasma glucose levels for gestational diabetes (GDM) based on International Association of the Diabetes and Pregnancy Study Groups (IADPSG) criteria.

Methods

A Cross-sectional study that included 2348 pregnant women booked for antenatal care in 2011 at a tertiary care perinatal institute. Pregnant women underwent a 75 g oral glucose tolerance test (OGTT) between 24 and 28 weeks of gestation. Outcome measures include the incidence of GDM based on the IADPSG criteria and the diagnostic effectiveness of the recommended fasting and one-hour plasma glucose cut-off if used in isolation.

Results

The incidence of GDM was 21.81% ( n = 520, 95% CI: 20.15, 23.57) with the IADPSG criteria. A fasting plasma glucose cut-off 92 mg/dL, in isolation, correctly classified 87.16% of GDM, with a specificity of 96.08%, clinically significant positive likelihood ratio (14.08) and a post-test probability of 79.71%. The one-hour 75 g test, in isolation, correctly classified 85.74% of GDM, had specificity of 99.68% and clinically significant positive likelihood ratio (111.12) and post-test probability of 96.87%. The application of the World Health Organization criteria would misclassify 11.91% (95% CI: 10.66, 13.26) of GDM as normal.

Conclusions

Additional testing of plasma glucose levels can be avoided for 18.25% ( n = 435, 95% CI: 16.73, 19.84) if the IADPSG diagnostic criteria for GDM are applied with exit on a positive fasting or one-hour test result.
Right aortic arch and Kommerell's diverticulum associated with acute aortic dissection and pericardial tamponade
Authors: Ebner Lukas , Huber Andreas , Christe Andreas
Published: May 2013

The right-sided aorta associated with an aberrant left subclavian artery is a rare anomaly of the aortic branches in the upper mediastinum. We present a 62-year-old patient suffering from an acute dissection of the ascending aorta associated with hemopericardium. In this case, there was also aneurysmal dilatation of the origin of the left subclavian artery, known as diverticulum of Kommerell.
Slow-growing primary marginal zone B-cell lymphoma arising in the chest wall in a patient without a history of tuberculosis
Authors: Ueda Ken , Nakanishi Katsuyuki , Satoh Yukihisa , Sakai Mio , Naka Norifumi , Araki Nobuhito , Tomita Yasuhiko , Tomiyama Noriyuki
Published: May 2013

A 57-year-old man with a 15-year history of a right chest wall mass lesion without follow-up for 5 years was admitted to our hospital without any symptoms or evidence of malignancy. On MRI, an additional small subcutaneous mass lesion was found. Histology of both lesions revealed marginal zone B-cell lymphomas. Primary chest wall marginal zone B-cell lymphomas are rare; this report discusses the case and the literature on chest wall lymphomas.
Genetic analysis of the roles of agaA, agaI, and agaS genes in the N-acetyl-D-galactosamine and D-galactosamine catabolic pathways in Escherichia colistrains O157:H7 and C
Authors: Hu Zonglin , Patel Isha R , Mukherjee Amit
Published: May 2013

Background

The catabolic pathways of N-acetyl-D-galactosamine (Aga) and D-galactosamine (Gam) in E. coli were proposed from bioinformatic analysis of the aga/gam regulon in E. coli K-12 and later from studies using E. coli C. Of the thirteen genes in this cluster, the roles of agaA, agaI, and agaS predicted to code for Aga-6-P-deacetylase, Gam-6-P deaminase/isomerase, and ketose-aldolase isomerase, respectively, have not been experimentally tested. Here we study their roles in Aga and Gam utilization in E. coli O157:H7 and in E. coli C.

Results

Knockout mutants in agaA, agaI, and agaS were constructed to test their roles in Aga and Gam utilization. Knockout mutants in the N-acetylglucosamine (GlcNAc) pathway genes nagA and nagB coding for GlcNAc-6-P deacetylase and glucosamine-6-P deaminase/isomerase, respectively, and double knockout mutants ΔagaA ΔnagA and ∆agaI ∆nagB were also constructed to investigate if there is any interplay of these enzymes between the Aga/Gam and the GlcNAc pathways. It is shown that Aga utilization was unaffected in ΔagaA mutants but ΔagaA ΔnagA mutants were blocked in Aga and GlcNAc utilization. E. coli C ΔnagA could not grow on GlcNAc but could grow when the aga/gam regulon was constitutively expressed. Complementation of ΔagaA ΔnagA mutants with either agaA or nagA resulted in growth on both Aga and GlcNAc. It was also found that ΔagaI, ΔnagB, and ∆agaI ΔnagB mutants were unaffected in utilization of Aga and Gam. Importantly, ΔagaS mutants were blocked in Aga and Gam utilization. Expression analysis of relevant genes in these strains with different genetic backgrounds by real time RT-PCR supported these observations.

Conclusions

Aga utilization was not affected in ΔagaA mutants because nagA was expressed and substituted for agaA. Complementation of ΔagaA ΔnagA mutants with either agaA or nagA also showed that both agaA and nagA can substitute for each other. The ∆agaI, ∆nagB, and ∆agaI ∆nagB mutants were not affected in Aga and Gam utilization indicating that neither agaI nor nagB is involved in the deamination and isomerization of Gam-6-P. We propose that agaS codes for Gam-6-P deaminase/isomerase in the Aga/Gam pathway.
Phenotypic and genotypic properties of Microbacterium yannicii, a recently described multidrug resistant bacterium isolated from a lung transplanted patient with cystic fibrosis in France
Authors: Sharma Poonam , Diene Seydina M , Thibeaut Sandrine , Bittar Fadi , Roux Véronique , Gomez Carine , Reynaud-Gaubert Martine , Rolain Jean-Marc
Published: May 2013

Background

Cystic fibrosis (CF) lung microbiota consists of diverse species which are pathogens or opportunists or have unknown pathogenicity. Here we report the full characterization of a recently described multidrug resistant bacterium, Microbacterium yannicii, isolated from a CF patient who previously underwent lung transplantation.

Results

Our strain PS01 (CSUR-P191) is an aerobic, rod shaped, non-motile, yellow pigmented, gram positive, oxidase negative and catalase positive bacterial isolate. Full length 16S rRNA gene sequence showed 98.8% similarity with Microbacterium yannicii G72T type strain, which was previously isolated from Arabidopsis thaliana. The genome size is 3.95Mb, with an average G+C content of 69.5%. In silico DNA-DNA hybridization analysis between our Microbacterium yannicii PS01isolate in comparison with Microbacterium testaceum StLB037 and Microbacterium laevaniformans OR221 genomes revealed very weak relationship with only 28% and 25% genome coverage, respectively. Our strain, as compared to the type strain, was resistant to erythromycin because of the presence of a new erm 43 gene encoding a 23S rRNA N-6-methyltransferase in its genome which was not detected in the reference strain. Interestingly, our patient received azithromycin 250 mg daily for bronchiolitis obliterans syndrome for more than one year before the isolation of this bacterium.

Conclusions

Although significance of isolating this bacterium remains uncertain in terms of clinical evolution, this bacterium could be considered as an opportunistic human pathogen as previously reported for other species in this genus, especially in immunocompromised patients.
Endoscopist specialty is associated with colonoscopy quality
Authors: Jiang Mengzhu , Sewitch Maida J , Barkun Alan N , Joseph Lawrence , Hilsden Robert J
Published: May 2013

Background

Some studies have shown that endoscopist specialty is associated with colorectal cancers missed by colonoscopy. We sought to examine the relationship between endoscopist specialty and polypectomy rate, a colonoscopy quality indicator. Polypectomy rate is defined as the proportion of colonoscopies that result in the removal of one or more polyps.

Methods

A cross-sectional study was conducted of endoscopists and their patients from 7 Montreal and 2 Calgary endoscopy clinics. Eligible patients were aged 50–75 and covered by provincial health insurance. A patient questionnaire assessed family history of colorectal cancer, history of large bowel conditions and symptoms, and previous colonoscopy. The outcome, polypectomy status, was obtained from provincial health administrative databases. For each city, Bayesian hierarchical logistic regression was used to estimate the odds ratio for polypectomy comparing surgeons to gastroenterologists. Model covariates included patient age, sex, family history of colorectal cancer, colonoscopy indication, and previous colonoscopy.

Results

In total, 2,113 and 538 colonoscopies were included from Montreal and Calgary, respectively. Colonoscopies were performed by 38 gastroenterologists and 6 surgeons in Montreal, and by 31 gastroenterologists and 5 surgeons in Calgary. The adjusted odds ratios comparing surgeons to gastroenterologists were 0.48 (95% CI: 0.32–0.71) in Montreal and 0.73 (95% CI: 0.43–1.21) in Calgary.

Conclusions

An association between endoscopist specialty and polypectomy was observed in both cities after adjusting for patient-level covariates. Results from Montreal suggest that surgeons are half as likely as gastroenterologists to remove polyps, while those from Calgary were associated with a wide, non-significant Bayesian credible interval. However, residual confounding from patient-level variables is possible, and further investigation is required.
Construction of Escherichia coli strains with chromosomally integrated expression cassettes for the synthesis of 2′-fucosyllactose
Authors: Baumgärtner Florian , Seitz Lyudmila , Sprenger Georg A , Albermann Christoph
Published: May 2013

Background

The trisaccharide 2′-fucosyllactose (2′-FL) is one of the most abundant oligosaccharides found in human milk. Due to its prebiotic and anti-infective properties, 2′-FL is discussed as nutritional additive for infant formula. Besides chemical synthesis and extraction from human milk, 2′-FL can be produced enzymatically in vitro and in vivo. The most promising approach for a large-scale formation of 2′-FL is the whole cell biosynthesis in Escherichia coli by intracellular synthesis of GDP-L-fucose and subsequent fucosylation of lactose with an appropriate α1,2-fucosyltransferase. Even though whole cell approaches have been demonstrated for the synthesis of 2′-FL, further improvements of the engineered E. coli host are required to increase product yields. Furthermore, an antibiotic-free method of whole cell synthesis of 2′-FL is desirable to simplify product purification and to avoid traces of antibiotics in a product with nutritional purpose.

Results

Here we report the construction of the first selection marker-free E. coli strain that produces 2′-FL from lactose and glycerol. To construct this strain, recombinant genes of the de novo synthesis pathway for GDP-L-fucose as well as the gene for the H. pylori fucosyltransferase futC were integrated into the chromosome of E. coli JM109 by using the λ-Red recombineering technique. Strains carrying additional copies of the futC gene and/or the gene fkp (from Bacteroides fragilis) for an additional salvage pathway for GDP-L-fucose production were used and shown to further improve production of 2′-FL in shake flask experiments. An increase of the intracellular GDP-L-fucose concentration by expression of fkp gene as well as an additional copy of the futC gene lead to an enhanced formation of 2′-FL. Using an improved production strain, feasibility of large scale 2′-FL production was demonstrated in an antibiotic-free fed-batch fermentation (13 l) with a final 2′-FL concentration of 20.28 ± 0.83 g l-1 and a space-time-yield of 0.57 g l-1 h-1.

Conclusions

By chromosomal integration of recombinant genes, altering the copy number of these genes and analysis of 2′-FL and intracellular GDP-L-fucose levels, we were able to construct and improve the first selection marker-free E. coli strain which is capable to produce 2′-FL without the use of expression plasmids. Analysis of intracellular GDP-L-fucose levels identified the de novo synthesis pathway of GDP-L-fucose as one bottleneck in 2′-FL production. In antibiotic-free fed-batch fermentation with an improved strain, scale-up of 2′-FL could be demonstrated.
Particulate matter components and subclinical atherosclerosis: common approaches to estimating exposure in a Multi-Ethnic Study of Atherosclerosis cross-sectional study
Authors: Sun Min , Kaufman Joel D , Kim Sun-Young , Larson Timothy V , Gould Timothy R , Polak Joseph F , Budoff Matthew J , Diez Roux Ana V , Vedal Sverre
Published: May 2013

Background

Concentrations of outdoor fine particulate matter (PM2.5) have been associated with cardiovascular disease. PM2.5 chemical composition may be responsible for effects of exposure to PM2.5.

Methods

Using data from the Multi-Ethnic Study of Atherosclerosis (MESA) collected in 2000–2002 on 6,256 US adults without clinical cardiovascular disease in six U.S. metropolitan areas, we investigated cross-sectional associations of estimated long-term exposure to total PM2.5 mass and PM2.5 components (elemental carbon [EC], organic carbon [OC], silicon and sulfur) with measures of subclinical atherosclerosis (coronary artery calcium [CAC] and right common carotid intima-media thickness [CIMT]). Community monitors deployed for this study from 2007 to 2008 were used to estimate exposures at baseline addresses using three commonly-used approaches: (1) nearest monitor (the primary approach), (2) inverse-distance monitor weighting and (3) city-wide average.

Results

Using the exposure estimate based on nearest monitor, in single-pollutant models, increased OC (effect estimate [95% CI] per IQR: 35.1 μm [26.8, 43.3]), EC (9.6 μm [3.6,15.7]), sulfur (22.7 μm [15.0,30.4]) and total PM2.5 (14.7 μm [9.0,20.5]) but not silicon (5.2 μm [−9.8,20.1]), were associated with increased CIMT; in two-pollutant models, only the association with OC was robust to control for the other pollutants. Findings were generally consistent across the three exposure estimation approaches. None of the PM measures were positively associated with either the presence or extent of CAC. In sensitivity analyses, effect estimates for OC and silicon were particularly sensitive to control for metropolitan area.

Conclusion

Employing commonly-used exposure estimation approaches, all of the PM2.5 components considered, except silicon, were associated with increased CIMT, with the evidence being strongest for OC; no component was associated with increased CAC. PM2.5 chemical components, or other features of the sources that produced them, may be important in determining the effect of PM exposure on atherosclerosis. These cross-sectional findings await confirmation in future work employing longitudinal outcome measures and using more sophisticated approaches to estimating exposure.
Plasmon-mediated resonance energy transfer by metallic nanorods
Authors: Yu Yi-Cong , Liu Jia-Ming , Jin Chong-Jun , Wang Xue-Hua
Published: May 2013

We investigate the enhancement of the resonance energy transfer rate between donor and acceptor associated by the surface plasmons of the Ag nanorods on a SiO2 substrate. Our results for a single nanorod with different cross sections reveal that the cylinder nanorod has the strongest ability to enhance the resonance energy transfer rate. Moreover, for donor and acceptor with nonparallel polarization directions, we propose simple V-shaped nanorod structures which lead to the remarkable resonance energy transfer enhancement that is ten times larger than that by the single nanorod structure. We demonstrate that these structures have good robustness and controllability. Our work provides a way to improve the resonance energy transfer efficiency in integrated photonic devices.

PACS

78.67.Qa, 73.20.Mf, 42.50.Ex
Baclofen into the lateral parabrachial nucleus induces hypertonic sodium chloride intake during cell dehydration
Authors: Kimura Everton H , De Oliveira Lisandra B , Menani José V , Callera João C
Published: May 2013

Background

Activation of GABAB receptors with baclofen into the lateral parabrachial nucleus (LPBN) induces ingestion of water and 0.3 M NaCl in fluid replete rats. However, up to now, no study has investigated the effects of baclofen injected alone or combined with GABAB receptor antagonist into the LPBN on water and 0.3 M NaCl intake in rats with increased plasma osmolarity (rats treated with an intragastric load of 2 M NaCl). Male Wistar rats with stainless steel cannulas implanted bilaterally into the LPBN were used.

Results

In fluid replete rats, baclofen (0.5 nmol/0.2 μl), bilaterally injected into the LPBN, induced ingestion of 0.3 M NaCl (14.3 ± 4.1 vs. saline: 0.2 ± 0.2 ml/210 min) and water (7.1 ± 2.9 vs. saline: 0.6 ± 0.5 ml/210 min). In cell-dehydrated rats, bilateral injections of baclofen (0.5 and 1.0 nmol/0.2 μl) into the LPBN induced an increase of 0.3 M NaCl intake (15.6 ± 5.7 and 21.5 ± 3.5 ml/210 min, respectively, vs. saline: 1.7 ± 0.8 ml/210 min) and an early inhibition of water intake (3.5 ± 1.4 and 6.7 ± 2.1 ml/150 min, respectively, vs. saline: 9.2 ± 1.4 ml/150 min). The pretreatment of the LPBN with 2-hydroxysaclofen (GABAB antagonist, 5 nmol/0.2 μl) potentiated the effect of baclofen on 0.3 M NaCl intake in the first 90 min of test and did not modify the inhibition of water intake induced by baclofen in cell-dehydrated rats. Baclofen injected into the LPBN did not affect blood pressure and heart rate.

Conclusions

Thus, injection of baclofen into the LPBN in cell-dehydrated rats induced ingestion of 0.3 M NaCl and inhibition of water intake, suggesting that even in a hyperosmotic situation, the blockade of LPBN inhibitory mechanisms with baclofen is enough to drive rats to drink hypertonic NaCl, an effect independent of changes in blood pressure.
Optimization of transplastomic production of hemicellulases in tobacco: effects of expression cassette configuration and tobacco cultivar used as production platform on recombinant protein yields
Authors: Kolotilin Igor , Kaldis Angelo , Pereira Eridan Orlando , Laberge Serge , Menassa Rima
Published: May 2013

Background

Chloroplast transformation in tobacco has been used extensively to produce recombinant proteins and enzymes. Chloroplast expression cassettes can be designed with different configurations of the cis-acting elements that govern foreign gene expression. With the aim to optimize production of recombinant hemicellulases in transplastomic tobacco, we developed a set of cassettes that incorporate elements known to facilitate protein expression in chloroplasts and examined expression and accumulation of a bacterial xylanase XynA. Biomass production is another important factor in achieving sustainable and high-volume production of cellulolytic enzymes. Therefore, we compared productivity of two tobacco cultivars – a low-alkaloid and a high-biomass - as transplastomic expression platforms.

Results

Four different cassettes expressing XynA produced various mutant phenotypes of the transplastomic plants, affected their growth rate and resulted in different accumulation levels of the XynA enzyme. The most productive cassette was identified and used further to express XynA and two additional fungal xylanases, Xyn10A and Xyn11B, in a high-biomass tobacco cultivar. The high biomass cultivar allowed for a 60% increase in XynA production per plant. Accumulation of the fungal enzymes reached more than 10-fold higher levels than the bacterial enzyme, constituting up to 6% of the total soluble protein in the leaf tissue. Use of a well-characterized translational enhancer with the selected expression cassette revealed inconsistent effects on accumulation of the recombinant xylanases. Additionally, differences in the enzymatic activity of crude plant extracts measured in leaves of different age suggest presence of a specific xylanase inhibitor in the green leaf tissue.

Conclusion

Our results demonstrate the pivotal importance of the expression cassette design and appropriate tobacco cultivar for high-level transplastomic production of recombinant proteins.
From meta-omics to causality: experimental models for human microbiome research
Authors: Fritz Joëlle V , Desai Mahesh S , Shah Pranjul , Schneider Jochen G , Wilmes Paul
Published: May 2013

Large-scale ‘meta-omic’ projects are greatly advancing our knowledge of the human microbiome and its specific role in governing health and disease states. A myriad of ongoing studies aim at identifying links between microbial community disequilibria (dysbiosis) and human diseases. However, due to the inherent complexity and heterogeneity of the human microbiome, cross-sectional, case–control and longitudinal studies may not have enough statistical power to allow causation to be deduced from patterns of association between variables in high-resolution omic datasets. Therefore, to move beyond reliance on the empirical method, experiments are critical. For these, robust experimental models are required that allow the systematic manipulation of variables to test the multitude of hypotheses, which arise from high-throughput molecular studies. Particularly promising in this respect are microfluidics-based in vitro co-culture systems, which allow high-throughput first-pass experiments aimed at proving cause-and-effect relationships prior to testing of hypotheses in animal models. This review focuses on widely used in vivo, in vitro, ex vivo and in silico approaches to study host-microbial community interactions. Such systems, either used in isolation or in a combinatory experimental approach, will allow systematic investigations of the impact of microbes on the health and disease of the human host. All the currently available models present pros and cons, which are described and discussed. Moreover, suggestions are made on how to develop future experimental models that not only allow the study of host-microbiota interactions but are also amenable to high-throughput experimentation.
Attitudinal and perceptual factors in body image distortion: an exploratory study in patients with anorexia nervosa
Authors: Waldman Amanda , Loomes Rachel , Mountford Victoria A , Tchanturia Kate
Published: May 2013

Background

Body image disturbance is a core feature of anorexia nervosa (AN). Attitudinal and cognitive biases as well as fundamental perceptual differences have been hypothesized to play a role in this disturbance.

Method

This study investigated body image dissatisfaction and distortion, haptic perception and perfectionism in 30 patients with AN and 31 age-matched healthy controls. Participants completed perceptual tasks and self-report measures.

Results

As predicted, participants with AN scored significantly higher on body dissatisfaction, perfectionism measures and had greater body distortion (as assessed by a body size estimation task). Cognitive–affective factors and perfectionism were highly correlated with body image distortion in AN. No significant differences were found between groups on the generic perception task.

Conclusions

Findings did not confirm the hypothesis of fundamental perceptual inefficiencies in body image disturbance in individuals with AN. Despite renewed interest in fundamental perceptual factors implicated in body image disturbance, these findings suggest that it continues to be important to focus treatment on cognitive affective biases versus fundamental perceptual inefficiencies.
The role of location in evaluating racial wage disparity
Authors: Black Dan A , Kolesnikova Natalia , Sanders Seth G , Taylor Lowell J
Published: May 2013

A standard object of empirical analysis in labor economics is a modified Mincer wage function in which an individual’s log wage is a function of education, experience, and race. We analyze this approach in a context where individuals live and work in different locations (thus facing different housing prices and wages). Our model justifies the traditional approach, but with the important caveat that the regression should include location-specific fixed effects. Empirical analysis of men in U.S. labor markets demonstrates that failure to condition on location causes us to significantly overstate the decline in black-white wage disparity over the past 60 years.

JEL codes

J31, J71, R23
Spatial sampling, migration aliasing, and migrated amplitudes
Authors: Gray Samuel H.
Published: May 2013

Seismic migration is a multichannel process, in which some of the properties depend on various grid spacings. First, there is the acquisition grid, which actually consists of two grids: a grid of source locations and, for each source location, a grid of receiver locations. In addition, there is a third grid, the migration grid, whose spacings also affect properties of the migration. Sampling theory imposes restrictions on migration, limiting the frequency content that can be migrated reliably given the grid spacings. The presence of three grids complicates the application of sampling theory except in unusual situations (e.g., the isolated migration of a single shot record). I analyzed the effects of the grids on different types of migration (Kirchhoff, wavefield extrapolation migration, and slant-stack migration), specifically in the context of migration operator antialiasing. I evaluated general antialiasing criteria for the different types of migration; my examples placed particular emphasis on one style of data acquisition, orthogonal source and receiver lines, which is commonly used on land and which presents particular challenges for the analysis. It is known that migration artifacts caused by inadequate antialiasing can interfere with velocity and amplitude analyses. I found, in addition, that even migrations with adequate antialiasing protection can have the side effect of inaccurate amplitudes resulting from a given acquisition, and I tested how this effect can be compensated.
Non-suicidal self-injury v. attempted suicide:
new diagnosis or false dichotomy?
Authors: Kapur Navneet , Cooper Jayne , O'Connor Rory C. , Hawton Keith
Published: May 2013

Non-suicidal self-injury (NSSI) is a term that is becoming popular
especially in North America and it has been proposed as a new diagnosis in
DSM-5. In this paper we consider what self-harm research can tell us about
the concept of NSSI and examine the potential pitfalls of introducing NSSI
into clinical practice.
Crustal Deformation Associated with the 2011 Tohoku-Oki Earthquake: An Overview
Authors: Hashimoto Manabu
Published: May 2013

The 2011 Tohoku-oki earthquake generated large displacements in and around the Japanese islands that were detected by the nationwide GPS network, sea-floor geodetic surveys, and space-borne radars. The east-west extension exerted on the Japanese islands by this event induced inland events of Mw6 or larger earthquakes. Coseismic subsidence of up to 1 m was observed along the coast where subsidence was found during the interseismic period. This observation contradicts expectations based on the concept of the recurrence of inter-plate earthquakes. Therefore, postseismic motions or other large events are expected to resolve this paradox.