bluuebunny/crossref_metadata_2025 huggingface dataset:
Addressing basic resource needs to improve primary care quality: a community collaboration programme
Authors: Berkowitz Seth A , Hulberg A Catherine , Hong Clemens , Stowell Brian J , Tirozzi Karen J , Traore Carine Y , Atlas Steven J
Published: December 2015

Background

Unmet basic resource needs, such as difficulty affording healthcare, medications, food and housing, may contribute to worse healthcare quality indicators, but interventions are hampered by lack of specific knowledge regarding the distribution of unmet basic resource needs and their association with priority clinical conditions and health service use patterns.

Methods

Cross-sectional study of primary care patients in two urban academic practices from 1 October 2013 to 30 April 2014. Patients were screened for unmet needs and enrolled in a programme to link them with community resources. Key measures included patient report of unmet basic resource needs, clinical conditions prioritised by quality improvement programmes (hypertension, diabetes and depression), and health service use patterns such as frequent emergency department (ED) visits (>2 in the preceding year) and frequent clinic ‘no-shows’ (>1 in the preceding year).

Results

416 patients with unmet needs were included, and compared with 2750 patients who did not report needs. The most common types of needs reported were: difficulties affording healthcare (46.5%), food (40.1%) and utilities (36.3%). Patients who reported unmet needs were more likely to have depression (17.8% vs 9.5%, p<0.0001), diabetes (32.7% vs 20.4%, p<0.0001), hypertension (54.3% vs 46.3%, p=0.002), be frequent ED users (11.3% vs 5.4%, p<0.0001), and have frequent ‘no-shows’ to clinic (21.6% vs 11.9%, p<0.0001).

Conclusions

Difficulty affording healthcare and food are particularly common needs among patients with priority conditions. Strategies to identify and address unmet needs as part of routine care may be an important way to improve healthcare quality.
A comparison of formalin and GEWF in fixation of colorectal carcinoma specimens: rates of lymph node retrieval and effect on TNM staging
Authors: Horne Joanne , Carr Norman J , Bateman Adrian C , Kandala Ngianga , Adams Jody , Silva Sónia , Ryder Isobel
Published: December 2015

Aims

The Royal College of Pathologists recommend that a median of at least 12 lymph nodes should be harvested during pathological staging of colorectal cancer. It is not always easy to harvest the required number, especially in patients with rectal cancer receiving neoadjuvant therapy. Lymph node revealing solutions, for example, GEWF, may improve nodal yield. GEWF is safe, cheap and easy to use.

Methods

In a controlled trial, lymph node yields were compared after secondary specimen dissection following either 24 h of further fixation in formalin (n=101) or GEWF immersion (n=99). The number, size and tumour status of additional lymph nodes identified were compared between groups. Twenty-seven cases that received long-course neoadjuvant therapy were also assessed.

Results

Median lymph node yield at primary dissection met national standards overall (19) but also in the long-course neoadjuvant therapy group (13). Lymph nodes were smaller in neoadjuvant cases compared with non-neoadjuvant cases (mean size range 1.3–5.6 mm vs 1.5–8.9 mm). The use of further fixation and GEWF detected more nodes at secondary dissection. The mean number of additional nodes harvested was greater with formalin (8.3) than GEWF (7.3). There was no significant difference in the mean size of the additional lymph nodes detected between groups (point estimate 1.02; 95% CI −0.58 to 2.63; p=0.211). Upstaging triggering adjunct chemotherapy occurred in 1% (2/200) of cases.

Conclusions

The routine use of adjunct techniques to identify additional lymph nodes is unnecessary with underlying high-quality dissection practice. Emphasis should be placed upon education and training, spending appropriate time dissecting and ensuring specimens are sufficiently fixed beforehand.
Reduction in diarrhoeal rates through interventions that prevent unnecessary antibiotic exposure early in life in an observational birth cohort
Authors: Rogawski Elizabeth T , Meshnick Steven R , Becker-Dreps Sylvia , Adair Linda S , Sandler Robert S , Sarkar Rajiv , Kattula Deepthi , Ward Honorine D , Kang Gagandeep , Westreich Daniel J
Published: December 2015

Background

Antibiotic treatment early in life is often not needed and has been associated with increased rates of subsequent diarrhoea. We estimated the impact of realistic interventions, which would prevent unnecessary antibiotic exposures before 6 months of age, on reducing childhood diarrhoeal rates.

Methods

In data from a prospective observational cohort study conducted in Vellore, India, we used the parametric g-formula to model diarrhoeal incidence rate differences contrasting the observed incidence of diarrhoea to the incidence expected under hypothetical interventions. The interventions prevented unnecessary antibiotic treatments for non-bloody diarrhoea, vomiting and upper respiratory infections before 6 months of age. We also modelled targeted interventions, in which unnecessary antibiotic use was prevented only among children who had already stopped exclusive breast feeding.

Results

More than half of all antibiotic exposures before 6 months (58.9%) were likely unnecessary. The incidence rate difference associated with removing unnecessary antibiotic use before 6 months of age was −0.28 (95% CI −0.46 to −0.08) episodes per 30 child-months. This implies that preventing unnecessary antibiotic exposures in just 4 children would reduce the incidence of diarrhoea by 1 from 6 months to 3 years of age.

Conclusions

Interventions to reduce unnecessary antibiotic use among young children could result in an important reduction in diarrhoeal rates. This work provides an example application of statistical methods which can further the aim of presenting epidemiological findings that are relevant to public health practice.
Integration of family planning with maternal health services: an opportunity to increase postpartum modern contraceptive use in urban Uttar Pradesh, India
Authors: Achyut Pranita , Mishra Anurag , Montana Livia , Sengupta Ranajit , Calhoun Lisa M , Nanda Priya
Published: December 2015

Background

Maternal health (MH) services provide an invaluable opportunity to inform and educate women about family planning (FP). It is expected that this would enable women to choose an appropriate method and initiate contraception early in the postpartum period. In this study we examined interactions with health providers for MH services, and the effect of FP information provision during these interactions on the postpartum use of modern contraceptive methods.

Methods

This study used midline data collected from 990 women who had delivered a live birth between January 2010 and the date of the midline survey in 2012. These women were asked a series of questions about their last delivery, including interactions with health providers during pregnancy, delivery and the postpartum period, if they received FP information during these interactions, and their contraceptive use during the postpartum period.

Results

The study found that FP information provision as part of antenatal care in the third trimester, delivery and the postpartum period have a positive association with postpartum modern contraceptive use in urban Uttar Pradesh. However, health providers often miss these opportunities. Despite a high proportion of women coming into contact with health providers when utilising MH services, only a small proportion received FP information during these interactions.

Conclusions

Integration of FP with MH services can increase postpartum modern contraceptive use. With the launch of the National Urban Health Mission, there now exists appropriate policy and programmatic environments for integration of FP and MH services in urban settings in India. However, this will require a concentrated effort both to enhance the capacity of health providers and encourage supportive supervision.
Effect of catheter ablation on quality of life in patients with atrial fibrillation and its correlation with arrhythmia outcome
Authors: Raine Daniel , Langley Philip , Shepherd Ewen , Lord Stephen , Murray Stephen , Murray Alan , Bourke John P
Published: December 2015

Objective

To assess the effect of catheter ablation on atrial fibrillation (AF) symptoms and quality of life (QoL).

Methods

Patients with AF scheduled for ablation were recruited. Pulmonary vein isolation (PVI) was performed and complex fractionated atrial electrogram (CFAE)±linear ablation undertaken in patients in AF despite PVI. QoL and AF symptoms were assessed using SF-36 V2 and Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaires before and 3 months after ablation. Change in QoL scores after ablation was correlated with clinical parameters and the extent of ablation. Magnitude of QoL change was compared between AFEQT and SF-36 physical component summary (PCS) and mental component summary (MCS) scores and correlated with arrhythmia outcome.

Results

80 patients were studied. Summative and individual health scores for both AFEQT (51.5±22.0 vs 81.3±18.2; p<0.01) and SF-36 (PCS 43.3±10.5 vs 47.9±11.3; p<0.01 and MCS 45.0±11.5 vs 51.5±9.4; p<0.01) improved significantly in patients who maintained sinus rhythm after ablation, but not in those with recurrent AF. Improvement in AFEQT (25.4±19) was significantly greater than change in PCS (6.8±6.4; p<0.01) and MCS (8.5±7.9; p<0.01) scores and correlated more closely with arrhythmia outcome (AFEQT r=0.55; PCS r=0.26; MCS r=0.30).

Conclusions

Patients who maintained sinus rhythm after ablation had a significant improvement in AF symptoms and QoL; however, no improvement was observed in patients with recurrent AF. QoL change after ablation did not correlate with baseline clinical parameters or ablation strategy. AF specific QoL scales are more responsive to change and correlate better with ablation outcome.
Imaging assessment of traumatic brain injury
Authors: Currie Stuart , Saleem Nayyar , Straiton John A , Macmullen-Price Jeremy , Warren Daniel J , Craven Ian J
Published: December 2015

Traumatic brain injury (TBI) constitutes injury that occurs to the brain as a result of trauma. It should be appreciated as a heterogeneous, dynamic pathophysiological process that starts from the moment of impact and continues over time with sequelae potentially seen many years after the initial event. Primary traumatic brain lesions that may occur at the moment of impact include contusions, haematomas, parenchymal fractures and diffuse axonal injury. The presence of extra-axial intracranial lesions such as epidural and subdural haematomas and subarachnoid haemorrhage must be anticipated as they may contribute greatly to secondary brain insult by provoking brain herniation syndromes, cranial nerve deficits, oedema and ischaemia and infarction. Imaging is fundamental to the management of patients with TBI. CT remains the imaging modality of choice for initial assessment due to its ease of access, rapid acquisition and for its sensitivity for detection of acute haemorrhagic lesions for surgical intervention. MRI is typically reserved for the detection of lesions that may explain clinical symptoms that remain unresolved despite initial CT. This is especially apparent in the setting of diffuse axonal injury, which is poorly discerned on CT. Use of particular MRI sequences may increase the sensitivity of detecting such lesions: diffusion-weighted imaging defining acute infarction, susceptibility-weighted imaging affording exquisite data on microhaemorrhage. Additional advanced MRI techniques such as diffusion tensor imaging and functional MRI may provide important information regarding coexistent structural and functional brain damage. Gaining robust prognostic information for patients following TBI remains a challenge. Advanced MRI sequences are showing potential for biomarkers of disease, but this largely remains at the research level. Various global collaborative research groups have been established in an effort to combine imaging data with clinical and epidemiological information to provide much needed evidence for improvement in the characterisation and classification of TBI and in the identity of the most effective clinical care for this patient cohort. However, analysis of collaborative imaging data is challenging: the diverse spectrum of image acquisition and postprocessing limits reproducibility, and there is a requirement for a robust quality assurance initiative. Future clinical use of advanced neuroimaging should ensure standardised approaches to image acquisition and analysis, which can be used at the individual level, with the expectation that future neuroimaging advances, personalised to the patient, may improve prognostic accuracy and facilitate the development of new therapies.
Determining the provenance of Triassic sedimentary rocks in northeastern British Columbia and western Alberta using detrital zircon geochronology, with implications for regional tectonics
Authors: Golding M.L. , Mortensen J.K. , Ferri F. , Zonneveld J.-P. , Orchard M.J.
Published: December 2015

Triassic rocks of the Western Canada Sedimentary Basin (WCSB) have previously been interpreted as being deposited on the passive margin of North America. Recent detrital zircon provenance studies on equivalent Triassic rocks in the Yukon have suggested that these rocks were in part derived from the pericratonic Yukon–Tanana terrane and were deposited in a foreland basin related to the Late Permian Klondike orogeny. Detrital zircons within a number of samples collected from Triassic sediments of the WCSB throughout northeastern British Columbia and western Alberta suggest that the bulk of the sediment was derived from recycled sediments of the miogeocline along western North America, with a smaller but significant proportion coming from the Innuitian orogenic wedge in the Arctic and from local plutonic and volcanic rocks. There is also evidence of sediment being derived from the Yukon–Tanana terrane, supporting the model of terrane accretion occurring prior to the Triassic. The age distribution of detrital zircons from the WCSB in British Columbia is similar to those of the Selwyn and Earn sub-basins in the Yukon and is in agreement with previous observations that sediment deposited along the margin of North America during the Triassic was derived from similar source areas. Together these findings support the model of deposition within a foreland basin, similar to the one inferred in the Yukon. Only a small proportion of zircon derived from the Yukon–Tanana terrane is present within Triassic strata in northeastern British Columbia, which may be due to post-Triassic erosion of the rocks containing these zircons.
Brook trout passage performance through culverts
Authors: Goerig Elsa , Castro-Santos Theodore , Bergeron Normand Émile
Published: December 2015

Culverts can restrict access to habitat for stream-dwelling fishes. We used passive integrated transponder telemetry to quantify passage performance of >1000 wild brook trout (Salvelinus fontinalis) attempting to pass 13 culverts in Quebec under a range of hydraulic and environmental conditions. Several variables influenced passage success, including complex interactions between physiology and behavior, hydraulics, and structural characteristics. The probability of successful passage was greater through corrugated metal culverts than through smooth ones, particularly among smaller fish. Trout were also more likely to pass at warmer temperatures, but this effect diminished above 15 °C. Passage was impeded at higher flows, through culverts with steep slopes, and those with deep downstream pools. This study provides insight on factors influencing brook trout capacity to pass culverts as well as a model to estimate passage success under various conditions, with an improved resolution and accuracy over existing approaches. It also presents methods that could be used to investigate passage success of other species, with implications for connectivity of the riverscape.
Different Scales of Cortical Organization are Selectively Targeted in the Progression to Alzheimer’s Disease
Authors: Romero-Garcia Rafael , Atienza Mercedes , Cantero Jose L.
Published: December 2015

Previous studies have shown that the topological organization of the cerebral cortex is altered in Alzheimer’s disease (AD). However, it remains unknown whether different levels of the cortical hierarchy are homogeneously affected during disease progression, and which of these levels are mostly involved in the breakdown of metabolic (functional) connectivity. To fulfill these goals, we acquired structural magnetic resonance images (MRI) and positron emission tomography (PET) with the radiotracer 18F-fludeoxyglucose (FDG) in 29 healthy old (HO) adults, 29 amnestic mild cognitive impairment (aMCI) and 29 mild AD patients. Structural and metabolic connections were obtained from inter-regional correlations of cortical thickness and glucose consumption, respectively. Results showed that AD and HO groups differed at all levels of cortical organization (i.e. whole cortex, hemisphere, lobe and node), whereas differences among the three groups were only evident at the lobe and node levels. The correlation between structural and metabolic connectivity (F–S coupling) was also disturbed during AD progression, affecting to different connectivity scales: it decreased at the local level, revealing a progressive increase of metabolic connections in those local communities with fewer structural connections; whereas it increased at the global level, likely due to a parallel reduction of cortical thickness and glucose consumption between long-distance cortical regions. Collectively, these results reveal that different levels of cortical organization are selectively affected during the transition from normal aging to dementia, which could be helpful to track cortical dysfunctions in the progression to AD.
An Extended Membrane System with Active Membranes to Solve Automatic Fuzzy Clustering Problems
Authors: Peng Hong , Wang Jun , Shi Peng , Pérez-Jiménez Mario J. , Riscos-Núñez Agustín
Published: December 2015

This paper focuses on automatic fuzzy clustering problem and proposes a novel automatic fuzzy clustering method that employs an extended membrane system with active membranes that has been designed as its computing framework. The extended membrane system has a dynamic membrane structure; since membranes can evolve, it is particularly suitable for processing the automatic fuzzy clustering problem. A modification of a differential evolution (DE) mechanism was developed as evolution rules for objects according to membrane structure and object communication mechanisms. Under the control of both the object’s evolution-communication mechanism and the membrane evolution mechanism, the extended membrane system can effectively determine the most appropriate number of clusters as well as the corresponding optimal cluster centers. The proposed method was evaluated over 13 benchmark problems and was compared with four state-of-the-art automatic clustering methods, two recently developed clustering methods and six classification techniques. The comparison results demonstrate the superiority of the proposed method in terms of effectiveness and robustness.
Incidence stratifications on Hilbert schemes of smooth surfaces, and an application to Poisson structures
Authors: Ran Ziv
Published: December 2015

Given a smooth curve on a smooth surface, the Hilbert scheme of points on the surface is stratified according to the length of the intersection with the curve. The strata are highly singular. We show that this stratification admits a natural log-resolution, namely the stratified blowup. As a consequence, the induced Poisson structure on the Hilbert scheme of a Poisson surface has unobstructed deformations.
Exploring the influence of human mobility on information spreading in mobile networks
Authors: Li Zhigang , Shi Yan , Chen Shanzhi
Published: December 2015

In recent years, the dynamic spread of information has captured researchers’ attention. Therefore, identifying influential spreaders of information has become a fundamental element of information spreading research. Many studies have measured the influence of spreaders by considering the centrality indexes of network topology characteristics, such as degree, betweenness and closeness centrality. Additionally, some works have identified influential spreaders by analyzing human mobility characteristics such as contact frequency, contact time and inter-contact time. In this paper, we mainly explore the influence of the step size and radius of gyration on information spreading. Using a real and large-scale dataset of human mobility, we apply the susceptible-infected-recovered (SIR) model to investigate the spread of information. The simulation result shows that the influence of information spreading does not increase with the increase in the step size or radius of gyration of spreaders. Instead, both the step size and radius of gyration have a great influence on the spread of information when they are near the median value. Regardless of whether they have a large or small value, their influence on the spread of information is small. Therefore, the step size and radius of gyration of spreaders can be used to control or guide the spread of information.
Scaling analysis of heart beat fluctuations data and its relationship with cyclic alternating pattern data during sleep
Authors: De León-Lomelí R. , Murguía J. S. , Chouvarda I. , Méndez M. O. , González-Galván E. , Alba A.
Published: December 2015

During sleep there exists a nonlinear dynamic phenomenon, which is called cyclic alternating pattern. This phenomenon is generated in the brain and is composed of a series of events of short duration known as A-phases. It has been shown that A-phases can be found in other physiological systems such as the cardiovascular. However, there is no evidence that shows the temporal influence of the A-phases with the cardiovascular system. For this purpose, we consider the scaling method known as detrended fluctuation analysis (DFA). The analysis was carried out in well sleepers and insomnia people, and the numerical results show an increment in the scaling parameter for the insomnia subjects compared with the normal ones. In addition, the results of the heart dynamics suggests a persistent behavior toward the [Formula: see text]-noise.
Electroacupuncture for Acute Ischemic Stroke: A Meta-Analysis of Randomized Controlled Trials
Authors: Liu Ai-Ju , Li Ji-Huang , Li Hui-Qin , Fu Deng-Lei , Lu Lin , Bian Zhao-Xiang , Zheng Guo-Qing
Published: December 2015

Electroacupuncture (EA) is an extension technique of acupuncture based on traditional acupuncture combined with modern electrotherapy. Here, we conducted a systematic review specifically to assess the effectiveness and safety of EA for acute ischemic stroke. Eight databases were searched for randomized-controlled clinical trials (RCTs) of EA for acute ischemic stroke published from inception to June 2013. Ultimately, 67 studies claimed to be RCTs. Eighteen studies with 1411 individuals were selected for the analyses, which got [Formula: see text] “yes” in the domains of Cochrane risk of bias tool. The meta-analysis showed a significant effect of EA for improving Barthel Index ([Formula: see text]), Fugl–Meyer Assessment ([Formula: see text]), National Institutes of Health Stroke Scale ([Formula: see text]) and Revised Scandinavian Stroke Scale ([Formula: see text]) compared with western conventional treatments (WCTs). In an analysis of the total clinical efficacy rate, there was a significant difference between EA and WCTs ([Formula: see text]). Adverse effects were monitored in 6 studies, and were well tolerated in all stroke patients. According to the GRADE approach, the quality of evidence was mostly high or moderate. In conclusion, this systematic review revealed the evidence in support of the use of EA for acute ischemic stroke, although further larger sample-size and rigorously designed RCTs are required.
Tanshinone IIA Prevents Leu27IGF-II-Induced Cardiomyocyte Hypertrophy Mediated by Estrogen Receptor and Subsequent Akt Activation
Authors: Weng Yueh-Shan , Wang Hsueh-Fang , Pai Pei-Ying , Jong Gwo-Ping , Lai Chao-Hung , Chung Li-Chin , Hsieh Dennis Jine-Yuan , HsuanDay Cecilia , Kuo Wei-Wen , Huang Chih-Yang
Published: December 2015

IGF-IIR plays important roles as a key regulator in myocardial pathological hypertrophy and apoptosis, which subsequently lead to heart failure. Salvia miltiorrhiza Bunge (Danshen) is a traditional Chinese medicinal herb used to treat cardiovascular diseases. Tanshinone IIA is an active compound in Danshen and is structurally similar to 17[Formula: see text]-estradiol (E[Formula: see text]. However, whether tanshinone IIA improves cardiomyocyte survival in pathological hypertrophy through estrogen receptor (ER) regulation remains unclear. This study investigates the role of ER signaling in mediating the protective effects of tanshinone IIA on IGF-IIR-induced myocardial hypertrophy. Leu27IGF-II (IGF-II analog) was shown in this study to specifically activate IGF-IIR expression and ICI 182,780 (ICI), an ER antagonist used to investigate tanshinone IIA estrogenic activity. We demonstrated that tanshinone IIA significantly enhanced Akt phosphorylation through ER activation to inhibit Leu27IGF-II-induced calcineurin expression and subsequent NFATc3 nuclear translocation to suppress myocardial hypertrophy. Tanshinone IIA reduced the cell size and suppressed ANP and BNP, inhibiting antihypertrophic effects induced by Leu27IGF-II. The cardioprotective properties of tanshinone IIA that inhibit Leu27IGF-II-induced cell hypertrophy and promote cell survival were reversed by ICI. Furthermore, ICI significantly reduced phospho-Akt, Ly294002 (PI3K inhibitor), and PI3K siRNA significantly reduced the tanshinone IIA-induced protective effect. The above results suggest that tanshinone IIA inhibited cardiomyocyte hypertrophy, which was mediated through ER, by activating the PI3K/Akt pathway and inhibiting Leu27IGF-II-induced calcineurin and NFATC3. Tanshinone IIA exerted strong estrogenic activity and therefore represented a novel selective ER modulator that inhibits IGF-IIR signaling to block cardiac hypertrophy.
Melting properties of Pt and its transport coefficients in liquid states under high pressures
Authors: Wang Pan-Pan , Shao Ju-Xiang , Cao Qi-Long
Published: December 2015

Molecular dynamics (MD) simulations of the melting and transport properties in liquid states of platinum for the pressure range (50–200 GPa) are reported. The melting curve of platinum is consistent with previous ab initio MD simulation results and the first-principles melting curve. Calculated results for the pressure dependence of fusion entropy and fusion volume show that the fusion entropy and the fusion volume decrease with increasing pressure, and the ratio of the fusion volume to fusion entropy roughly reproduces the melting slope, which has a moderate decrease along the melting line. The Arrhenius law well describes the temperature dependence of self-diffusion coefficients and viscosity under high pressure, and the diffusion activation energy decreases with increasing pressure, while the viscosity activation energy increases with increasing pressure. In addition, the entropy-scaling law, proposed by Rosenfeld under ambient pressure, still holds well for liquid Pt under high pressure conditions.
An algorithm for finding a basis of the fixed point subgroup of an automorphism of a free group
Authors: Bogopolski Oleg , Maslakova Olga
Published: December 2015

We describe an algorithm which, given an automorphism [Formula: see text] of a free group [Formula: see text] of finite rank, computes a basis of the fixed point subgroup [Formula: see text].
Projective curves of degree=codimension+2 II
Authors: Lee Wanseok , Park Euisung
Published: December 2015

Let [Formula: see text] be a nondegenerate projective integral curve of degree [Formula: see text] which is not linearly normal. In this paper, we continues the study begun in [E. Park, Projective curves of degree=codimension+2, Math. Z. 256 (2007) 685–697] for the minimal free resolution of [Formula: see text]. It is well-known that [Formula: see text] is an isomorphic projection of a rational normal curve [Formula: see text] from a point [Formula: see text]. Our main result is about how the graded Betti numbers of [Formula: see text] are determined by the rank of [Formula: see text] with respect to [Formula: see text], which is a measure of the relative location of [Formula: see text] from [Formula: see text].
Buckling Strength of Corroded Pipelines with Interacting Corrosion Defects: Numerical Analysis
Authors: Kuppusamy Chandra Sekhar , Karuppanan Saravanan , Patil Santosh S.
Published: December 2015

Pipelines in the oil and gas industry are prone to extensive internal corrosion which leads to premature failures. Furthermore, corrosion defects within certain proximity interact to reduce the overall strength of a pipe and are termed as interacting corrosion defects. Pipelines may also experience complex loadings due to geotechnical movements such as landslides and internal pressure. Therefore, an understanding of the behavior of corroded pipelines under multiple loadings is important for the safe operation of pipelines. Extensive literature review indicates that major design codes only consider the effect of interacting corrosion defects on the burst pressure of pipes, with less attention paid to the structural behavior of steel pipes under multiple loadings. Therefore, this study focuses on the effect of interacting corrosion defects of equal depth on the local buckling strength of X46 steel pipes using the finite element analysis (FEA). Results showed that the corrosion defects interact to reduce the overall buckling strength of the pipe. Furthermore, circumferentially aligned corrosion defects are more critical than axially aligned corrosion defects, due to the greater loss of material along the circumference of the pipe. Besides, the effect of interactions of corrosion defects on the buckling strength decreases as the internal pressure increases. Lastly, as the depth of the defects increases, their interactions become more severe, which can significantly reduce the overall buckling strength of the steel pipe.
On properties of the lower central series of associative algebras
Authors: Abughazalah Nabilah , Etingof Pavel
Published: December 2015

We give an accessible introduction into the theory of lower central series of associative algebras, exhibiting the interplay between algebra, geometry and representation theory that is characteristic for this subject, and discuss some open questions. In particular, we provide shorter and clearer proofs of the main results of this theory. We also discuss some new theoretical and computational results and conjectures on the lower central series of the free algebra in two generators modulo a generic homogeneous relation.
TEMPERATURE DISTRIBUTION AND THERMAL DAMAGE OF PERIPHERAL TISSUE IN HUMAN LIMBS DURING HEAT STRESS: A MATHEMATICAL MODEL
Authors: AIJAZ MIR , KHANDAY M. A.
Published: December 2015

The physiological processes taking place in human body are disturbed by the abnormal changes in climate. The changes in environmental temperature are not effective only to compete with thermal stability of the system but also in the development of thermal injuries at the skin surfaces. Therefore, it is of great importance to estimate the temperature distribution and thermal damage in human peripherals at extreme temperatures. In this paper, the epidermis, dermis and subcutaneous tissue were modeled as uniform elements with distinct thermal properties. The bioheat equation with appropriate boundary conditions has been used to estimate the temperature profiles at the nodal points of the skin and subcutaneous tissue with variable ambient heat and metabolic activities. The model has been solved by variational finite element method and the results of the changes in temperature distribution of the body and the damage to the exposed living tissues has been interpreted graphically in relation with various atmospheric temperatures and rate of metabolic heat generation. By involving the metabolic heat generation term in bioheat equation and using the finite element approach the results obtained in this paper are more reasonable and appropriate than the results developed by Moritz and Henriques, Diller and Hayes, and Jiang et al.
DEA by sequential exclusion of alternatives in heterogeneous samples
Authors: Aleskerov Fuad , Petrushchenko Vsevolod
Published: December 2015

Data Envelopment Analysis (DEA) is a well-known nonparametric technique of efficiency evaluation which is actively used in many economic applications. However, DEA is not very well applicable when a sample consists of firms operating under drastically different conditions. We offer a new method of efficiency estimation in heterogeneous samples based on a sequential exclusion of alternatives and standard DEA approach. We show a connection between efficiency scores obtained via standard DEA model and the ones obtained via our algorithm. We also illustrate our model by evaluating 28 Russian universities and compare the results obtained by two techniques.
A Hybrid Method for Pythagorean Fuzzy Multiple-Criteria Decision Making
Authors: Zeng Shouzhen , Chen Jianping , Li Xingsen
Published: December 2015

As a generalization of intuitionistic fuzzy set, the Pythagorean fuzzy set is interesting and very useful in modeling uncertain information in real-world decision-making problems. In this paper, we develop a new method for Pythagorean fuzzy multiple-criteria decision-making (MCDM) problems with aggregation operators and distance measures. First, we present the Pythagorean fuzzy ordered weighted averaging weighted average distance (PFOWAWAD) operator. The main advantage of the PFOWAWAD operator is that it uses distance measures in a unified framework between the ordered weighted averaging (OWA) operator and weighted average (WA) that considers the degree of importance of each concept in the aggregation. Some of its main properties and special cases are studied. Then, based on the proposed operator, a hybrid TOPSIS method, called PFOWAWAD-TOPSIS is introduced for Pythagorean fuzzy MCDM problem. Finally, a numerical example is provided to illustrate the practicality and feasibility of the developed method.
Photodetached electron spectrum of H- near a surface having spherical dent
Authors: Haneef Muhammad , Bakhtawar  , Arif Suneela , Akbar Jehan , Shah Nasrullah
Published: December 2015

The detached electron flux and photodetachment cross section are derived using the theoretical imaging method and quantum approach for system comprising of hydrogen negative ion ([Formula: see text]) placed near a surface having spherical dent. The dent is modeled like a spherical concave surface. It is observed that the spherical dent generates additional oscillatory and smooth structure in the detached electron flux and photodetachment cross section, respectively. The radius of curvature, inter-ion surface distance and the dent factor strongly manipulate the results. When the inter-ion surface distance is equal to the focal length of the concave surface, the detached electron flux and photodetachment cross section are not well behaved. The photodetachment cross section is also not well behaved for the inter-ion surface distance equal to the radius of curvature. The focus and center of curvature of the concave surface act as a spherical singularity. This study gives new understanding on the photodetachment of negative ions in the vicinity of concave surfaces.
Effect of Crystal Size and Ag Concentration on the Thermoluminescent Response of Pure and Ag-Doped LiF Cubes
Authors: Vallejo Miguel A. , Sosa Modesto A. , Rivera Esteban , Azorín Juan C. , Bernal Jesús , Navarro Ricardo , Encarnación Emma K. , Díaz-Torres Luis A.
Published: December 2015

In this paper, the co-precipitation method was used to synthesize pure and Ag-doped LiF crystals and the effect of crystalline cube sizes and Ag concentration on the thermoluminescent (TL) response is reported. The synthesized materials were characterized by scanning electron microscopy and their morphology and size distributions were determined. Crystal sizes were found to be strongly dependent on the ethanol:water ratio, varying from 4.1[Formula: see text][Formula: see text]m to 150[Formula: see text]nm for pure LiF crystals. For Ag-doped samples, the best ethanol:water ratio was found to be 9:1, giving crystals from 0.50[Formula: see text][Formula: see text]m to 1.21[Formula: see text][Formula: see text]m. A single cubic crystalline phase was determined by XRD for all synthesized samples. The photoluminescence spectra as well as UV-Vis absorbance were also analyzed. The TL response to X-ray irradiation was studied for an exposition of 43[Formula: see text]R. Two effects were observed in the TL response. The first concerns with a significant dependence of the TL intensity on the size of the crystals, being larger for the smallest crystals for pure LiF, and second, for Ag-doped samples the TL intensity augmented almost linearly with the Ag concentration.
Heat and Mass Transfer to Air in a Cross Flow Heat Exchanger with Surface Deluge Cooling
Authors: Diani Andrea , Rossetto Luisa , Dall’Olio Roberto , De Zen Daniele , Masetto Filippo
Published: December 2015

Cross flow heat exchangers, when applied to cool data center rooms, use external air (process air) to cool the air stream coming from the data center room (primary air). However, an air–air heat exchanger is not enough to cope with extreme high heat loads in critical conditions (high external temperature). Therefore, water can be sprayed in the process air to increase the heat dissipation capability (wet mode). Water evaporates, and the heat flow rate is transferred to the process air as sensible and latent heat. This paper proposes an analytical approach to predict the behavior of a cross flow heat exchanger in wet mode. The theoretical results are then compared to experimental tests carried out on a real machine in wet mode conditions. Comparisons are given in terms of calculated versus experimental heat flow rate and evaporated water mass flow rate, showing a good match between theoretical and experimental values.
The effectiveness of concept mapping and retrieval practice as learning strategies in an undergraduate physiology course
Authors: Burdo Joseph , O'Dwyer Laura
Published: December 2015

Concept mapping and retrieval practice are both educational methods that have separately been reported to provide significant benefits for learning in diverse settings. Concept mapping involves diagramming a hierarchical representation of relationships between distinct pieces of information, whereas retrieval practice involves retrieving information that was previously coded into memory. The relative benefits of these two methods have never been tested against each other in a classroom setting. Our study was designed to investigate whether or not concept mapping or retrieval practice produced a significant learning benefit in an undergraduate physiology course as measured by exam performance and, if so, was the benefit of one method significantly greater than the other. We found that there was a trend toward increased exam scores for the retrieval practice group compared with both the control group and concept mapping group, and that trend achieved statistical significance for one of the four module exams in the course. We also found that women performed statistically better than men on the module exam that contained a substantial amount of material relating to female reproductive physiology.
A multidisciplinary guided practical on type I diabetes engaging students in inquiry-based learning
Authors: Mingueneau M. , Chaix A. , Scotti N. , Chaix J. , Reynders A. , Hammond C. , Thimonier J.
Published: December 2015

In the present article, we describe a 3-day experimental workshop on type I diabetes aimed at helping high school students to understand how fundamental research on glycemia regulation contributes to the development of scientific knowledge and therapeutic strategies. The workshop engaged students in open-ended investigations and guided experiments. Each class was divided into three or four groups, with each group working with a trained doctoral student or postdoctoral fellow. During an initial questioning phase, students observed slides depicting the glycemia of individuals in various situations. Students identified hyperglycemic individuals relative to the average glycemia of the displayed population. Students were asked to devise a treatment for these diabetics. They quickly realized that they couldn't experiment on patients and understood the need for laboratory models. Each group gave ideas of experiments to perform. We then explained, taking into account their propositions, the protocols students could execute to address one of the following questions: Which criteria must an animal model of diabetes fulfill? How do pancreatic cells maintain glycemia? Is there a way to produce an insulin protein similar to the one released by human pancreatic cells? We used two different evaluation metrics of the workshop: a questionnaire filled out by the students before and after the workshop and a poster produced by students at the end of the workshop. We found that this educational approach successfully improved student awareness and understanding of the scientific reasoning and research process.
Redox signaling in skeletal muscle: role of aging and exercise
Authors: Ji Li Li
Published: December 2015

Skeletal muscle contraction is associated with the production of ROS due to altered O2distribution and flux in the cell. Despite a highly efficient antioxidant defense, a small surplus of ROS, such as hydrogen peroxide and nitric oxide, may serve as signaling molecules to stimulate cellular adaptation to reach new homeostasis largely due to the activation of redox-sensitive signaling pathways. Recent research has highlighted the important role of NF-κB, MAPK, and peroxisome proliferator-activated receptor-γ coactivator-1α, along with other newly discovered signaling pathways, in some of the most vital biological functions, such as mitochondrial biogenesis, antioxidant defense, inflammation, protein turnover, apoptosis, and autophagy. There is evidence that the inability of the cell to maintain proper redox signaling underlies some basic mechanisms of biological aging, during which inflammatory and catabolic pathways eventually predominate. Physical exercise has been shown to activate various redox signaling pathways that control the adaptation and remodeling process. Although this stimulatory effect of exercise declines with aging, it is not completed abolished. Thus, aged people can still benefit from regular physical activity in the appropriate forms and at proper intensity to preserve muscle function.
A physiologist's view of homeostasis
Authors: Modell Harold , Cliff William , Michael Joel , McFarland Jenny , Wenderoth Mary Pat , Wright Ann
Published: December 2015

Homeostasis is a core concept necessary for understanding the many regulatory mechanisms in physiology. Claude Bernard originally proposed the concept of the constancy of the “milieu interieur,” but his discussion was rather abstract. Walter Cannon introduced the term “homeostasis” and expanded Bernard's notion of “constancy” of the internal environment in an explicit and concrete way. In the 1960s, homeostatic regulatory mechanisms in physiology began to be described as discrete processes following the application of engineering control system analysis to physiological systems. Unfortunately, many undergraduate texts continue to highlight abstract aspects of the concept rather than emphasizing a general model that can be specifically and comprehensively applied to all homeostatic mechanisms. As a result, students and instructors alike often fail to develop a clear, concise model with which to think about such systems. In this article, we present a standard model for homeostatic mechanisms to be used at the undergraduate level. We discuss common sources of confusion (“sticky points”) that arise from inconsistencies in vocabulary and illustrations found in popular undergraduate texts. Finally, we propose a simplified model and vocabulary set for helping undergraduate students build effective mental models of homeostatic regulation in physiological systems.
Reform in teaching preclinical pathophysiology
Authors: Li Yong-Yu , Li Kun , Yao Hong , Xu Xiao-Juan , Cai Qiao-Lin
Published: December 2015

Pathophysiology is a scientific discipline that studies the onset and progression of pathological conditions and diseases, and pathophysiology is one of the core courses in most preclinical medical curricula. In China, most medical schools house a Department of Pathophysiology, in contrast to medical schools in many developed countries. The staff in Chinese Departments of Pathophysiology generally consists of full-time instructors or lecturers who teach medical students. These lecturers are sometimes lacking in clinic knowledge and experiences. To overcome this, in recent years, we have been trying to bring new trends in teaching pathophysiology into our curriculum. Our purpose in writing this article was to share our experiences with our colleagues and peers worldwide in the hope that the insights we have gained in pathophysiology teaching will be of some value to educators who advocate teaching reform in medical schools.
Cardioprotective and nonprotective regimens of chronic hypoxia diversely affect the myocardial antioxidant systems
Authors: Kasparova Dita , Neckar Jan , Dabrowska Ludmila , Novotny Jiri , Mraz Jaroslav , Kolar Frantisek , Zurmanova Jitka
Published: December 2015

It has been documented that adaptation to hypoxia increases myocardial tolerance to ischemia-reperfusion (I/R) injury depending on the regimen of adaptation. Reactive oxygen species (ROS) formed during hypoxia play an important role in the induction of protective cardiac phenotype. On the other hand, the excess of ROS can contribute to tissue damage caused by I/R. Here we investigated the relationship between myocardial tolerance to I/R injury and transcription activity of major antioxidant genes, transcription factors, and oxidative stress in three different regimens of chronic hypoxia. Adult male Wistar rats were exposed to continuous normobaric hypoxia (FiO20.1) either continuously (CNH) or intermittently for 8 h/day (INH8) or 23 h/day (INH23) for 3 wk period. A control group was kept in room air. Myocardial infarct size was assessed in anesthetized open-chest animals subjected to 20 min coronary artery occlusion and 3 h reperfusion. Levels of mRNA transcripts and the ratio of reduced and oxidized glutathione (GSH/GSSG) were analyzed by real-time RT-PCR and by liquid chromatography, respectively. Whereas CNH as well as INH8 decreased infarct size, 1 h daily reoxygenation (INH23) abolished the cardioprotective effect and decreased GSH/GSSG ratio. The majority of mRNAs of antioxidant genes related to mitochondrial antioxidant defense (manganese superoxide dismutase, glutathione reductase, thioredoxin/thioredoxin reductase, and peroxiredoxin 2) were upregulated in both cardioprotective regimens (CNH, INH8). In contrast, INH23 increased only PRX5, which was not sufficient to induce the cardioprotective phenotype. Our results suggest that the increased mitochondrial antioxidant defense plays an important role in cardioprotection afforded by chronic hypoxia.