bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solar Radiation Assisted Mixed Convection Flow Along a Vertical Plate
Authors: Siddiqa S. , Hossain M. A. 
Published: June 2014

ABSTRACTSolar radiation assisted mixed convection boundary layer flow of Newtonian fluid along a non- reflecting, non-absorbing and ideally transparent semi-infinite vertical plate is studied here. Beer's law is used to express the solar radiation term. It is convenient to transform the non-linear dimensionless parabolic partial differential equations into (i) primitive variable formulation (PVF) and (ii) stream function formulation (SFF) before applying the numerical schemes. Coupled equations thus obtained from PVF are integrated numerically through implicit finite difference method together with the Gaussian elimination technique whereas block tridiagonal Keller-box technique is adopted to simulate the system of equations obtained from SFF. Numerical results from these two methods are also compared graphically in order to test the validation of the two schemes. However, due to less computation time and accuracy numeric results of shear stress, local Nusselt number coefficient, velocity and temperature profiles are obtained via SFF. It is found that velocity as well as temperature of the non-absorbing fluid enhances owing to the increase in solar radiation parameter.
The Three-Dimensional Infinite Space and Half-Space Green's Functions for Orthotropic Materials
Authors: Lee V.-G. 
Published: June 2014

ABSTRACTCommon materials, ranging from natural wood to modern composites, have been recognized as ortho-tropic materials. The elastic properties of such materials are governed by nine elastic constants. In this paper the complete set of Green's functions for an infinite medium and a half space is given, which were not reported completely before. Analytic expressions for the infinite Green's functions are derived through the explicit form of the sextic equation given explicitly. For an orthotopic half space, the Green's function is derived by a superposition method. The mathematical concept is based on the addition of a complementary term to the Green's function in an orthotropic infinite domain to fulfill the boundary condition on the free surface. Both solutions are illustrated in certain directions to demonstrate the nature of orthotropy.
Mixed Convection Heat Transfer in an Anisotropic Porous Medium with Oblique Principal Axes
Authors: Vajravelu K. , Prasad K. V. 
Published: June 2014

AbstractIn this paper, a numerical study is carried out to investigate the mixed convection flow and heat transfer in a parallel-plate channel with an anisotropic permeable porous medium. The principal axis of the porous medium is orientated in a direction which is oblique to the gravity vector. Both clear (Newtonian) fluid dissipation and Darcy viscous dissipation are considered in the heat transport equation. In this model, the temperature dependent fluid properties are considered and their influence on the flow and heat transfer characteristics is brought out. The governing non-linear equations (in non-dimensional form) are solved numerically by a second order finite difference scheme. The directional permeability ratioA1is defined to combine the effects of the permeability ratio parameterK*= (K1/K2) and the orientation angle Φ1. The effects of the anisotropic permeability ratio, the orientation angle of the principal axis, and the temperature dependent variable properties on the mixed convection flow and heat transfer are investigated. It is demonstrated that both the anisotropic permeability of the porous medium and the variable transport properties have strong effects on the flow and heat transfer characteristics.
Otolaryngologist-performed head and neck ultrasound: outcomes and challenges in learning the technique
Authors: Badran K , Jani P , Berman L 
Published: June 2014

AbstractObjective:To assess the feasibility and accuracy of otolaryngologist-performed ultrasound in evaluating head and neck pathology.Method:An ENT trainee, who had undergone basic training in neck ultrasonography, performed this on patients referred with suspected neck pathology. The trainee recorded the presence and nature of any abnormality. Findings were compared with those from a repeated scan performed by an experienced head and neck radiologist.Results:The study included 250 patients. The absence or presence of lesion as reported by the trainee correlated with the radiologist's findings in 207 cases (83 per cent). There were 144 true positives, 63 true negatives, 32 false negatives and 11 false positives, yielding a sensitivity of 82 per cent, specificity of 85 per cent and accuracy of 83 per cent. Of the 144 true positive lesions, 81 per cent were interpreted concordantly with the radiologist.Conclusion:Neck ultrasonography performed by an otolaryngologist is less accurate than that performed by an experienced radiologist, but is still a useful adjunct to clinical assessment, facilitating assessment in a ‘one-stop’ clinical setting.
Danger and loss events and the incidence of anxiety and depressive disorders: a prospective-longitudinal community study of adolescents and young adults
Authors: Asselmann E. , Wittchen H.-U. , Lieb R. , Höfler M. , Beesdo-Baum K. 
Published: June 2014

BackgroundThere are inconclusive findings regarding whether danger and loss events differentially predict the onset of anxiety and depression.MethodA community sample of adolescents and young adults (n = 2304, age 14–24 years at baseline) was prospectively followed up in up to four assessments over 10 years. Incident anxiety and depressive disorders were assessed at each wave using the DSM-IV/M-CIDI. Life events (including danger, loss and respectively mixed events) were assessed at baseline using the Munich Event List (MEL). Logistic regressions were used to reveal associations between event types at baseline and incident disorders at follow-up.ResultsLoss events merely predicted incident ‘pure’ depression [odds ratio (OR) 2.4 per standard deviation, 95% confidence interval (CI) 1.5–3.9, p < 0.001] whereas danger events predicted incident ‘pure’ anxiety (OR 2.3, 95% CI 1.1–4.6, p = 0.023) and ‘pure’ depression (OR 2.5, 95% CI 1.7–3.5, p < 0.001). Mixed events predicted incident ‘pure’ anxiety (OR 2.9, 95% CI 1.5–5.7, p = 0.002), ‘pure’ depression (OR 2.4, 95% CI 1.6–3.4, p < 0.001) and their co-morbidity (OR 3.6, 95% CI 1.8–7.0, p < 0.001).ConclusionsOur results provide further evidence for differential effects of danger, loss and respectively mixed events on incident anxiety, depression and their co-morbidity. Since most loss events referred to death/separation from significant others, particularly interpersonal loss appears to be highly specific in predicting depression.
The influence of group formation on learner participation, language complexity, and corrective behaviour in synchronous written chat as part of academic German studies
Authors: Fredriksson Christine 
Published: June 2014

AbstractSynchronous written chat and instant messaging are tools which have been used and explored in online language learning settings for at least two decades. Research literature has shown that such tools give second language (L2) learners opportunities for language learning,e.g., the interaction in real time with peers and native speakers, the written mode of language, and the time available for planning and monitoring utterances. However, since the majority of the empirical work on chat and instant messaging has been conducted under experimental conditions, relatively little research has investigated how interaction in chat influences language learning opportunities under the conditions of an online academic language course where students have unequal status because of their different language background and level of L2 proficiency. This article presents an explorative study of the interaction in chat in a web-based academic language course between students with different L1s and different levels of L2. The aim is to shed light on how student interaction in an institutional context benefits the language learning environment in a manner that promotes L2 learners’ attention to linguistic items in their input and output, and that allow opportunities for functional practising. Based on a mainly quantitative analysis, this article illustrates how L2 learners’ participation, the complexity of their utterances, and their opportunities for self-correction and corrective feedback are influenced by group formation.
The challenges for environment and development economics
Authors: Barbier Edward B. 
Published: June 2014

I consider that the field of environment and development economics (EDE) began with the publication of The Control of Resources by Partha Dasgupta (1982). Although he did not confine his focus to developing countries, Dasgupta (1982: 10) suggested that managing environmental resources was much broader than conventional resource stock depletion or pollution control:
To sum up: environmental discussions need to be conducted in the face of a clear recognition that, (a) these resource are often common property, (b) resolutions of environmental problems usually involve changes in the allocation of property rights, (c) resource use may well be irreversible (e.g. it may lead to their exhaustion when in fact this could have been avoided), (d) resource stocks often affect welfare directly, (e) the environmental impact of certain types of activity are cumulative and only become noticeable at some time in the future, and (f) the environmental impact of certain types of activity are uncertain. It is no wonder that environmental problems are formidable to analyse, let alone solve.
Environment and development economics 20 years on
Authors: Perrings Charles 
Published: June 2014

AbstractThis paper reviews the evolution of the field of environment and development over the last two decades. I argue that a central concern of the field has been the relation between natural resource use, income and growth, under the institutional and market conditions that prevail in developing countries. Particular attention is paid to the demographic and other drivers of change in the asset base, the linkages between poverty, property rights and the allocation of natural resources, the valuation of environmental assets and investment of resource rents, and the development of policies for managing environmental externalities and environmental public goods. I consider how the balance between topics and the treatment of individual topics has changed over time, and indicate how the field might be expected to move in the future.
OPTIMAL ESTIMATES FOR THE SEMIDISCRETE GALERKIN METHOD APPLIED TO PARABOLIC INTEGRO-DIFFERENTIAL EQUATIONS WITH NONSMOOTH DATA
Authors: GOSWAMI DEEPJYOTI , PANI AMIYA K. , YADAV SANGITA 
Published: June 2014

AbstractWe propose and analyse an alternate approach to a priori error estimates for the semidiscrete Galerkin approximation to a time-dependent parabolic integro-differential equation with nonsmooth initial data. The method is based on energy arguments combined with repeated use of time integration, but without using parabolic-type duality techniques. An optimal$L^2$-error estimate is derived for the semidiscrete approximation when the initial data is in$L^2$. A superconvergence result is obtained and then used to prove a maximum norm estimate for parabolic integro-differential equations defined on a two-dimensional bounded domain.
EXACT SOLUTIONS FOR INTERFACIAL OUTFLOWS WITH STRAINING
Authors: FORBES LAWRENCE K. , BRIDESON MICHAEL A. 
Published: June 2014

AbstractIn models of fluid outflows from point or line sources, an interface is present, and it is forced outwards as time progresses. Although various types of fluid instabilities are possible at the interface, it is nevertheless of interest to know the development of its overall shape with time. If the fluids on either side are of nearly equal densities, it is possible to derive a single nonlinear partial differential equation that describes the interfacial shape with time. Although nonlinear, this equation admits a simple transformation that renders it linear, so that closed-form solutions are possible. Two such solutions are illustrated; for a line source in a planar straining flow and a point source in an axisymmetric background flow. Possible applications in astrophysics are discussed.
HOPF BIFURCATION ANALYSIS FOR A RATIO-DEPENDENT PREDATOR–PREY SYSTEM INVOLVING TWO DELAYS
Authors: KARAOGLU E. , MERDAN H. 
Published: June 2014

AbstractThe aim of this paper is to give a detailed analysis of Hopf bifurcation of a ratio-dependent predator–prey system involving two discrete delays. A delay parameter is chosen as the bifurcation parameter for the analysis. Stability of the bifurcating periodic solutions is determined by using the centre manifold theorem and the normal form theory introduced by Hassard et al. Some of the bifurcation properties including the direction, stability and period are given. Finally, our theoretical results are supported by some numerical simulations.
Risk of Stroke in Patients with Rheumatism: A Nationwide Longitudinal Population-based Study
Authors: Liou Tsan-Hon , Huang Shih-Wei , Lin Jia-Wei , Chang Yu-Sheng , Wu Chin-Wen , Lin Hui-Wen 
Published: June 2014

AbstractThe aim of this study was to investigate rheumatoid arthritis (RA) and systemic lupus erythematous (SLE) as risk factors for stroke. The study was analyzed by Using the Taiwan Longitudinal Health Insurance Database 2005 (LHID2005), this cohort study investigated patients with a recorded diagnosis of RA (N = 6114) and SLE (N = 621) between January 1, 2004 and December 31, 2007, with age-matched controls (1:4) (for RA, N = 24456; SLE, N = 2484). We used Cox proportional-hazard regressions to evaluate the hazard ratios (HRs) after adjusting confounding factors. Our study found 383 of 6114 RA patients, experienced stroke during the 20267 person-year follow-up period. The adjusted HR of stroke for RA patients was 1.24 (95% CI, 1.11 to 1.39) and for SLE patients was 1.88 (95% CI, 1.08 to 3.27). When steroid was added as additional confounding factor, the adjusted HR of ischemic stroke for RA patients was 1.32 (95% CI, 1.15 to 1.50) and for SLE patients was 1.31 (95% CI, 0.51 to 3.34). In conclusion, the rheumatic diseases of RA and SLE are all risk factors for stroke. After controlled the effect of steroid prescription, RA is risk factor for ischemic stroke.
B and N isolate-doped graphitic carbon nanosheets from nitrogen-containing ion-exchanged resins for enhanced oxygen reduction
Authors: Wang Lei , Yu Peng , Zhao Lu , Tian Chungui , Zhao Dongdong , Zhou Wei , Yin Jie , Wang Ruihong , Fu Honggang 
Published: June 2014

AbstractB,N-codoped carbon nanostructures (BNCS) can serve as alternative low-cost metal-free electrocatalysts for oxygen reduction reactions (ORR). However, the compensation effect between the p- (B atoms) and n-type (N atoms) dopants would make the covalent boron-nitride (BN) easily formed during the synthesis of BNCS, leading to a unsatisfactory ORR activity. Therefore, it has been challenging to develop facile and rapid synthetic strategies for highly active BNCS without forming the direct covalent BN. Here, a facile method is developed to prepare B and N isolate-doped graphitic nanosheets (BNGS) by using iron species for saving N element and simultaneous doping the B element from nitrogen-containing ion-exchanged resins (NR). The resulting BNGS exhibits much more onset potential (Eonset) compared with the B-doped graphitic carbon nanosheets (BGS), N-doped graphitic carbon nanosheets (NGS), as well as B,N-codoped disorder carbon (BNC). Moreover, the BNGS shows well methanol tolerance propery and excellent stability (a minimal loss of activity after 5,000 potential cycles) compared to that of commercial Pt/C catalyst. The goog performance for BNGS towards ORR is attributed to the synergistic effect between B and N and the well electrons transport property of graphitic carbon in BNGS.
Quantitative scoring of differential drug sensitivity for individually optimized anticancer therapies
Authors: Yadav Bhagwan , Pemovska Tea , Szwajda Agnieszka , Kulesskiy Evgeny , Kontro Mika , Karjalainen Riikka , Majumder Muntasir Mamun , Malani Disha , Murumägi Astrid , Knowles Jonathan , Porkka Kimmo , Heckman Caroline , Kallioniemi Olli , Wennerberg Krister , Aittokallio Tero 
Published: June 2014

AbstractWe developed a systematic algorithmic solution for quantitative drug sensitivity scoring (DSS), based on continuous modeling and integration of multiple dose-response relationships in high-throughput compound testing studies. Mathematical model estimation and continuous interpolation makes the scoring approach robust against sources of technical variability and widely applicable to various experimental settings, both in cancer cell line models and primary patient-derived cells. Here, we demonstrate its improved performance over other response parameters especially in a leukemia patient case study, where differential DSS between patient and control cells enabled identification of both cancer-selective drugs and drug-sensitive patient sub-groups, as well as dynamic monitoring of the response patterns and oncogenic driver signals during cancer progression and relapse in individual patient cells ex vivo. An open-source and easily extendable implementation of the DSS calculation is made freely available to support its tailored application to translating drug sensitivity testing results into clinically actionable treatment options.
miR-21/DDAH1 pathway regulates pulmonary vascular responses to hypoxia
Authors: Iannone Lucio , Zhao Lan , Dubois Olivier , Duluc Lucie , Rhodes Christopher J. , Wharton John , Wilkins Martin R. , Leiper James , Wojciak-Stothard Beata 
Published: June 2014

The NOS (nitric oxide synthase) inhibitor ADMA (asymmetric dimethylarginine) contributes to the pathogenesis of pulmonary hypertension. Reduced levels of the enzymes metabolizing ADMA, dimethylarginine dimethylaminohydrolases (DDAH1 and DDAH2) and increased levels of miR-21 are linked to disease pathology, but the mechanisms are not understood. In the present study we assessed the potential role of miR-21 in the regulation of hypoxia-induced changes in ADMA metabolism in vitro and in vivo. Hypoxia inhibited DDAH1 and DDAH2 expression and increased ADMA levels in cultured human pulmonary endothelial cells. In contrast, in human pulmonary smooth muscle cells, only DDAH2 was reduced whereas ADMA levels remained unchanged. Endothelium-specific down-regulation of DDAH1 by miR-21 in hypoxia induced endothelial dysfunction and was prevented by overexpression of DDAH1 and miR-21 blockade. DDAH1, but not DDAH2, mRNA levels were reduced, whereas miR-21 levels were elevated in lung tissues from patients with pulmonary arterial hypertension and mice with pulmonary hypertension exposed to 2 weeks of hypoxia. Hypoxic mice treated with miR-21 inhibitors and DDAH1 transgenic mice showed elevated lung DDAH1, increased cGMP levels and attenuated pulmonary hypertension. Regulation of DDAH1 by miR-21 plays a role in the development of hypoxia-induced pulmonary hypertension and may be of broader significance in pulmonary hypertension.
Comparing disturbance-sensitivity between plants and birds: a fine-grained analysis in a suburban remnant wetland
Authors: Fanelli Giuliano , Battisti Corrado 
Published: June 2014

Hemeroby is a concept widely employed in assessment of the effect of human activities on vegetation. In this study, we apply the concept to a set of bird species occurring in a Mediterranean remnant wetland. The aim was to obtain an average hemeroby index for two seasonally related bird assemblages (i.e. breeding and wintering) based on the information related to two levels of plant hemeroby. In a grid of 47 cells 100×100 m-wide, we sampled the fine-grained distribution of plant communities (Braun-Blanquet method/cell) in parallel with birds (point count method; one point count/cell), assigning an independent score of hemeroby to plants and birds on a scale from I to V, from pristine habitats with a lack of natural and/or anthropogenic disturbance (score = I) to completely artificial habitats (score = V). Whereas bird species ranged from categories II to V, vegetation types spanned only the categories III and IV. Therefore, bird species showed a higher variability in hemeroby.
By comparing hemeroby scores, we can deduce the effect that the vegetation disturbance may have on bird species. The mean hemeroby for breeding birds, calculated on all the species occurring in a determined plant hemeroby category, is not significantly different between sites with higher (= IV) and lower (= III) plant hemeroby (i.e. higher and lower level of disturbance). The mean hemeroby of the wintering birds was significantly different in the two levels of plant hemeroby (i.e. higher vs. lower hemeroby). Our data suggest that only the wintering birds had a hemeroby distribution pattern related to that of the plants, while the distribution of breeding birds showed no association, i.e. they appear in similar distribution in both plant hemeroby classes. This pattern may reflect the characteristics of the habitat types in relation to bird seasonality: a large section of wintering bird species are strictly water-related, linked to habitats with low plant hemeroby, so appearing more sensitive to change in plant hemeroby when compared to breeding species. Although explorative, our data may be useful in wildlife management, implying that in wetland–grassland mosaics the more sensitive wintering bird species are suitable as indicators aimed to test the effect of natural and anthropogenic disturbances.
Ion-beam-induced thin film stress in lithium niobate
Authors: Schmidt E , Steinbach T , Wesch W 
Published: June 2014

Abstract
The dominating modification of crystalline solids by energetic ions is the formation of lattice defects, which accumulate with ongoing irradiation. Many materials exhibit a phase transition from crystalline to the amorphous state at higher ion fluence. However, this ion-beam-induced structural modification involves the formation of mechanical stress, which is generally disadvantageous for the successful application of ion irradiation in the micro-device technology. Hence, a fundamental understanding of the ion-beam-induced stress evolution is crucial for the effective use of ion beam technology. Lithium niobate (LiNbO3) is a promising candidate for the application of integrated photonic structures. However, for the fabrication of such structures in LiNbO3 ion irradiation is indispensable. In order to get a fundamental and comprehensive understanding of the ion-beam-induced defect and stress evolution in LiNbO3, irradiations with varying parameters (ion energy and irradiation temperature) over a wide range of ion fluence for different crystallographic orientations were performed. The ion-beam-induced defect and stress evolution were studied by means of in situ Rutherford backscattering spectrometry and laser reflection technique, respectively.
The investigations demonstrate that ion-beam-induced defect and stress evolution in LiNbO3 is highly anisotropic. Moreover, a complex stress evolution is observed, i.e. with increasing ion fluence different stress formation and stress relaxation processes occur. It will be demonstrated that effects such as radiation-induced viscosity or anisotropic deformation that were suggested by previous models cannot explain the stress evolution in LiNbO3.
This work presents a new approach that describes the anisotropic stress and defect evolution in LiNbO3 by a complex defect formation mechanism, i.e. the presence of different defect types and their transformation into each other. Each defect type strains the surrounding crystal matrix and leads to a macroscopic deformation. The total stress is the superposition of the individual stress caused by different defect types.