bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of cambers on gliding and hovering performance of corrugated dragonfly airfoils
Authors: Shi Xing , Huang Xianwen , Zheng Yao , Zhao Susu
Published: May 2016

Purpose

– The purpose of this paper is to explore the effects of the camber on gliding and hovering performance of two-dimensional corrugated airfoils. While the flying mechanism of natural flyers remains a myth up to nowadays, the simulation serves as a minor step toward understanding the steady and unsteady aerodynamics of the dragonfly flight.

Design/methodology/approach

– The lattice Boltzmann method is used to simulate the flow past the cambered corrugated dragonfly airfoil at low Reynolds numbers. For gliding flight, the maximum camber, the distance of the location of maximum camber point from the leading edge and Reynolds number are regarded as control variables; for hovering flight, the maximum camber, the flapping amplitude and trajectory are considered as control variables. Then corresponding simulations are performed to evaluate the implications of these factors.

Findings

– Greater gliding ratio can be reached by increasing the maximum camber of the dragonfly wing section. When the location of the maximum camber moves backward along the wing chord, large scale flow separation can be delayed. These two effects result in better gliding performances. For hovering performances, it is found that for different flapping amplitudes along an inclined plane, the horizontal force exerted on the airfoils increases with the camber, and the drag growths first but then drops. It is also found that the elliptic flapping trajectory is most sensitive to the camber of the cambered corrugated dragonfly wing section.

Originality/value

– The effects of the camber on gliding and hovering performance of the cambered dragonfly wing section are explored in detail. The data obtained can be helpful when designing micro aerial vehicles.
The effects of shape on the performance of cathode catalyst agglomerates in polymer electrolyte fuel cells
Authors: Ismail Mohammed , Ingham Derek , Hughes Kevin J , Ma Lin , Pourkashanian Mohamed
Published: May 2016

Purpose

– The purpose of this paper is to numerically investigate the effects of the shape on the performance of the cathode catalyst agglomerate used in polymer electrolyte fuel cells (PEFCs). The shapes investigated are slabs, cylinders and spheres.

Design/methodology/approach

– Three 1D models are developed to represent the slab like, cylindrical and spherical agglomerates, respectively. The models are solved for the concentration of the dissolved oxygen using a finite element software, COMSOL Multiphysics®. “1D” and “1D axisymmetric” schemes are used to model the slab like and cylindrical agglomerates, respectively. There is no one-dimensional scheme available in COMSOL Multiphysics® for spherical coordinate systems. To resolve this, the governing equation in “1D” scheme is mathematically modified to match that of the spherical coordinate system.

Findings

– For a given length of the diffusion path, the variation in the performances of the investigated agglomerates is dependent on the operational overpotential. Under low magnitudes of the overpotentials, where the performance is mainly limited by reaction, the slab-like agglomerate outperforms the spherical and cylindrical agglomerates. In contrast, under high magnitudes of the overpotentials where the agglomerate performance is mainly limited by diffusion, the spherical and cylindrical agglomerates outperform the slab-like agglomerate.

Practical implications

– The current advances in the nano-fabrication technology gives more flexibility in designing the catalyst layers in PEFCs to the desired structures. If the design of the agglomerate catalyst is to be assessed, the current micro-scale modelling offers an efficient and rapid way forward.

Originality/value

– The current micro-scale modelling is an efficient alternative to developing a full (or half) fuel cell model to evaluate the effects of the agglomerate structure.
New benchmark solutions for transient natural convection in partially porous annuli
Authors: Massarotti Nicola , Ciccolella Michela , Cortellessa Gino , Mauro Alessandro
Published: May 2016

Purpose

– The purpose of this paper is to focus on the numerical analysis of transient free convection heat transfer in partially porous cylindrical domains. The authors analyze the dependence of velocity and temperature fields on the geometry, by analyzing transient flow behavior for different values of cavity aspect ratio and radii ratio; both inner and outer radius are assumed variable in order to not change the difference ro-ri. Moreover, several Darcy numbers have been considered.

Design/methodology/approach

– A dual time-stepping procedure based on the transient artificial compressibility version of the characteristic-based split algorithm has been adopted in order to solve the transient equations of the generalized model for heat and fluid flow through porous media. The present model has been validated against experimental data available in the scientific literature for two different problems, steady-state free convection in a porous annulus and transient natural convection in a porous cylinder, showing an excellent agreement.

Findings

– For vertically divided half porous cavities, with Rayleigh numbers equal to 3.4×106 for the 4:1 cavity and 3.4×105 for the 8:1 cavity, the numerical results show that transient oscillations tend to disappear in presence of cylindrical geometry, differently from what happens for rectangular one. The magnitude of this phenomenon increases with radii ratio; the porous layer also affects the stability of velocity and temperature fields, as oscillations tend to decrease in presence of a porous matrix with lower value of the Darcy number.

Research limitations/implications

– A proper analysis of partially porous annular cavities is fundamental for the correct estimation of Nusselt numbers, as the formulas provided for rectangular domains are not able to describe these problems.

Practical implications

– The proposed model represents a useful tool for the study of transient natural convection problems in porous and partially porous cylindrical and annular cavities, typical of many engineering applications. Moreover, a fully explicit scheme reduces the computational costs and ensures flexibility.

Originality/value

– This is the first time that a fully explicit finite element scheme is employed for the solution of transient natural convection in partially porous tall annular cavities.
Variational multi-scale finite element approximation of the compressible Navier-Stokes equations
Authors: Bayona Roa Camilo Andrés , Baiges Joan , Codina R
Published: May 2016

Purpose

– The purpose of this paper is to apply the variational multi-scale framework to the finite element approximation of the compressible Navier-Stokes equations written in conservation form. Even though this formulation is relatively well known, some particular features that have been applied with great success in other flow problems are incorporated.

Design/methodology/approach

– The orthogonal subgrid scales, the non-linear tracking of these subscales, and their time evolution are applied. Moreover, a systematic way to design the matrix of algorithmic parameters from the perspective of a Fourier analysis is given, and the adjoint of the non-linear operator including the volumetric part of the convective term is defined. Because the subgrid stabilization method works in the streamline direction, an anisotropic shock capturing method that keeps the diffusion unaltered in the direction of the streamlines, but modifies the crosswind diffusion is implemented. The artificial shock capturing diffusivity is calculated by using the orthogonal projection onto the finite element space of the gradient of the solution, instead of the common residual definition. Temporal derivatives are integrated in an explicit fashion.

Findings

– Subsonic and supersonic numerical experiments show that including the orthogonal, dynamic, and the non-linear subscales improve the accuracy of the compressible formulation. The non-linearity introduced by the anisotropic shock capturing method has less effect in the convergence behavior to the steady state.

Originality/value

– A complete investigation of the stabilized formulation of the compressible problem is addressed.
Freemium business model: construct development and measurement validation
Authors: Huang Hao-Chen
Published: May 2016

Purpose

– In recent years, the freemium model is popular with online users in internet markets. Regarding operation, the characteristics of the freemium business model are the focus of all websites and software managers. However, research lacks the literature on the development of the dimensions of the freemium business model and validation of measurement. Hence, the purpose of this paper is to probe into the development of the dimensions of the freemium business model and validate the measurement.

Design/methodology/approach

– First, by related literature and practical observations, this study reorganizes the characteristics of the freemium business model and develops dimensions and items of the freemium business model to design the items of scale. The development of scale is based on the procedures of standardized testing, including draft, expert consultation, and pretest and test analysis, in order to test the reliability and validity of the scale. This study treated online users as the questionnaire subjects and analyzed 1,016 valid questionnaires.

Findings

– Regarding empirical analysis, confirmatory factor analysis is conducted to test the internal quality of the model, including composite reliability, convergent validity, and discriminant validity. According to the empirical result, the freemium business model can be divided into basic free tier, two-sided markets, revenue sharing, service convenience, and network effect, which are the key factors of users’ selection of freemium products or services. This study developed 25 items of scale for the freemium business model.

Originality/value

– Finally, this study plans to develop a scale of the freemium business model, which can serve as an appropriate measurement tool to measure the freemium business model, as well as help websites and software developers to plan or execute the introduction of freemium products and services. Hence, it can develop and design products and services meeting the needs of online consumers. Website and software managers can adjust their products and services to satisfy online users’ needs.
Predicting good deeds in virtual communities of consumption
Authors: Hsu Sheila Hsuan-Yu , Yen Hsiuju Rebecca
Published: May 2016

Purpose

– Motivated by situational strength theory and multi-level theory, the purpose of this paper is to propose a cross-level model to examines whether virtual community citizenship behaviors (VCCBs) are affected by consumers’ individual differences on reciprocity, other consumers’ collective citizenship behaviors at community-level (members citizenship behaviors, MCBs), and their interaction effects.

Design/methodology/approach

– The research model is tested with a sample of 340 consumers collected from the 34 virtual communities of consumptions (VCCs). Because consumers are embedded in communities, the authors employ the hierarchical linear modeling for data analyses.

Findings

– The findings reveal positive effects of individual’s prosocial values and community-level MCBs, and a negative effect of exchange ideology, on VCCBs. There is a significant cross-level moderation effect of MCBs such that MCBs reduce the negative influence of exchange ideology on VCCBs.

Research limitations/implications

– This research suggests that participation in VCCs could be simultaneously driven by the dispositions to help and to get fair reciprocity, while such effects are constrained by others’ citizenship behaviors within the VCC. Future research should identify other contextual factors that could confine or amplify the personality-behavior links in the context of VCCs.

Practical implications

– Managers who intend to build a VCC of high co-creation should establish mechanisms that could facilitate norm of VCCBs. Also, it is crucial to take into account the participants’ dispositions on reciprocity in recruiting community members and developing member portfolio.

Originality/value

– This is one of the first studies to offer insights regarding the role of community-level citizenship behavior as a strong situation to mitigating the influences of individuals’ reciprocity-based dispositions.
Kenneth Fisher’s heuristics
Authors: Massironi Carlo , Chesini Giusy
Published: May 2016

Purpose

The authors are interested in building descriptive – real life – models of successful investors’ investment reasoning and decision-making. Models designed to be useful for trying to replicate and evolve their reasoning and decision-making. The purpose of this paper, a case study, is to take the substantial material – on innovating the investing tools – published in four books (2006/2012, 2010, 2011, 2015) by a US stock investor named Kenneth Fisher (CEO of Fisher Investments, Woodside, California) and sketch Fisher’s investment innovating reasoning model.

Design/methodology/approach

To sketch Fisher’s investment innovating reasoning model, the authors used the Radical constructivist theory of knowledge, a framework for analyzing human action and reasoning called Symbolic interactionism and a qualitative analytic technique called Conceptual analysis. The authors have done qualitative research applied to the study of investment decision-making of a single professional investor.

Findings

In the paper, the authors analyzed and described the heuristics used by Fisher to build subsequent generations of investing tools (called by Fisher “Capital Markets Technology”) to try to make better forecasts to beat the stock market. The authors were interested in studying the evolutive dimensions of the tools to make forecasts of a successful investor: the “how to build it” and “how to evolve it” dimension.

Originality/value

The paper offers an account of Kenneth Fisher’s framework to reason the innovation of investing tools. The authors believe that this paper could be of interest to professional money managers and to all those who are involved in the study and development of the tools of investing. This work is also an example of the use of the Radical constructivist theory of knowledge, the Symbolic interactionist framework and the Conceptual analysis to build descriptive models of investment reasoning of individual investors, models designed to enable the reproduction/approximation of the conceptual operations of the investor.
Light availability experienced in the field affects ability of following generations to respond to shading in an annual grassland plant
Authors: Heger Tina
Published: May 2016

For plants competing for light, grasslands represent complex environments. Grassland microhabitats vary in the amount of available light and in the spatial distribution of patches with full sunlight, light shade and deep shade. Plant populations have been shown to adapt to specific competitors and shading conditions, but it is an open question how tightly the responses of populations to different shading situations are linked to the light availability previously experienced in the field.

Using maternal families collected in grasslands ranging from open to closed canopies, I tested the effects of no shading, homogeneous and heterogeneous shade created in the glasshouse on trait expression in the annual Erodium cicutarium. Heterogeneous shading was simulated by a patchwork of single and double layers of light filters lowering the R:FR ratio of transmitted light and clear filters simulating gaps.

Heterogeneous shading induced a stronger shade avoidance response than homogeneous shading, with larger leaf length, greater vegetative height and larger specific leaf area. Time to first flowering was longer under heterogeneous shading, and plants produced less fruits.

Populations differed in their time to first flowering under the shading treatments, and these differences could be traced back to light availability measured in the field. Plants from populations with lower light availability showed a postponed date of first flowering even if they were not shaded. These differences were attributable to plasticity of the maternal families. Across shading treatments, plants from low‐light environments produced more above‐ground biomass.

Synthesis. This study indicates that there is a close linkage between the light availability experienced in the field and the ability of following generations to respond to shading. Low average light availability experienced in the past seems to induce a trade‐off of vegetative growth against early flowering, providing the following generations with the capacity to overtop neighbours. This capacity is utilized especially if plants experience a mixture of gaps and deep shade.
Land‐use history augments environment–plant community relationship strength in a Puerto Rican wet forest
Authors: Hogan James Aaron , Zimmerman Jess K. , Uriarte María , Turner Benjamin L. , Thompson Jill
Published: May 2016

Environmental heterogeneity influences the species composition of tropical forests, with implications for patterns of diversity and species coexistence in these hyperdiverse communities. Many studies have examined how variability in soil nutrients and topography influence plant community composition, with differing results. None have quantified the relative contribution of environmental heterogeneity versus endogenous processes to variability in forest community composition over time and with respect to successional recovery.

Using five consecutive trees censuses of a forest plot in Puerto Rico, conducted between 1990 and 2011, we evaluated the influence of edaphic and topographic variability on community composition. The plot has a well‐documented land‐use history and is subject to periodic hurricane disturbance. Using multiple canonical distance‐based redundancy analyses, we studied how spatial heterogeneity in soil nutrients and topography structure community composition over time, as the forest recovers from long‐term land‐use effects and two major hurricanes in 1989 and 1998.

For the entire plot, spatial variables (principle coordinates of neighbourhood matrices), representing the autocorrelation of tree species in the community, explained the majority (49–57%) of the variability in tree community composition. The explanatory power of spatial variables decreased over time, as forest structure recovered from hurricane damage and the stems in the understorey died. Soil nutrients and topography, collectively, explained a moderate portion (33–37%) of the species compositional variation and were slightly more robust in explaining compositional differences in areas of more intense past land use.

Areas of less‐intense past land use showed weaker community–environmental trends overall, illustrating a tendency for stronger resource competition (i.e. light, water and soil nutrients) between species in these areas. This illustrates how environmental–plant community interactions are strengthened by the lasting effects of human land‐use legacies, which persist for decades to centuries.

Synthesis. Our findings confirm past land use to be a fundamental driver of the structure and composition of secondary forests through its impacts on the tree community, the abiotic terrestrial environment and their interaction. Since the extent of second‐growth tropical forests continues to increase, our findings highlight the importance of understanding the processes that determine the rate and nature of their succession.
Hyperoxia‐mediated LC3B activation contributes to the impaired transdifferentiation of type II alveolar epithelial cells (AECIIs) to type I cells (AECIs)
Authors: Zhang Liang , Zhao Shuang , Yuan Lijie , Wu Hongmin , Jiang Hong , Luo Gang
Published: May 2016

Life‐saving mechanical ventilation can also cause lung injury through the overproduction of reactive oxygen species (ROS), leading to bronchopulmonary dysplasia (BPD)‐like symptoms in preterm infants. It is reported that the autophagic protein microtubule‐associated protein‐1 light chain (LC)‐3B can confer protection against hyperoxia‐induced DNA damage in lung alveolar epithelium. However, its role in the transdifferentiation of type II alveolar epithelial cells (AECIIs) to type I cells (AECIs) is unclear and requires further investigation. In this study, newborn Sprague‐Dawley rats were exposed to 90% oxygen for up to 14 days to mimic BPD in human infants, with neonatal pups exposed to room air (21% oxygen) as controls. Primary rat AECIIs were cultured under hyperoxic conditions for up to 24 hours to further investigate the underlying mechanisms. This study found that hyperoxia promoted a significant and time‐dependent increase of AECII marker surfactant protein (SP)‐C in the lung. The increase of AECI marker T1α was repressed by hyperoxia during lung development. These results indicated an impaired AECII transdifferentiation. Pulmonary ROS concentration and expression of autophagic protein LC‐3B were increased gradually in response to hyperoxia exposure. Furthermore, AECIIs produced more ROS when cultured under hyperoxic conditions in vitro. Both the LC3B expression and the conversion from LC3BI to LC3BII were enhanced in hyperoxic AECs. Interestingly, inhibition of LC3B either by ROS inhibitor N‐acetyl‐l‐cysteine (NAC) or adenovirus‐mediated LC3B shRNA could partly restore AECII transdifferentiation under hyperoxia condition. In summary, the current study reveals a novel role of activated LC3B induced by hyperoxia in AECII transdifferentiation.
Two Cheers for Richards and Smith: Beyond Anti‐Politics?
Authors: Marsh David , Vines Emma , Halupka Max
Published: May 2016

In a recent issue of The Political Quarterly, Richards and Smith critiqued Flinders’ work on anti‐politics, suggesting that there needs to be much more focus on supply‐side explanations and recognising that much of the problem lies with politicians, contra Flinders. Here, we argue instead that it is crucial to recognise how supply‐side and demand side explanations interact. For us, politicians need to be more responsive to citizens, but, at the same time, citizens need to recognise problems of contemporary governing. Overall, much is changing in the way in which citizens engage and it is crucial that these changes are understood.
Fair Value Accounting and Debt Contracting: Evidence from Adoption of SFAS 159
Authors: DEMERJIAN PETER R. , DONOVAN JOHN , LARSON CHAD R.
Published: May 2016

We examine how fair value accounting affects debt contract design, specifically the use and definition of financial covenants in private loan contracts. Using SFAS 159 adoption as our setting, we find that a small but significant proportion of loans (14.5%) modify covenant definitions to exclude the effects of SFAS 159 fair values. Only a limited number of these modifications exclude assets elected at fair value (less than 7%), while all exclude liabilities elected at fair value. Notably, we document that covenant definition modification is unassociated with ex ante fair value elections. We find that covenant definition modification positively varies with common incentive problems attributed to fair value accounting and negatively varies with benefits attributed to fair value accounting. Our results suggest that fair value accounting is not uniformly detrimental for debt contracting and fair value adjustments are included when they are most likely to improve performance measurement.
1 Archaeology of the Human Experience: An Introduction
Authors: Hegmon Michelle
Published: May 2016

The Archaeology of the Human Experience (AHE) is concerned with understanding what it was like to live in the past, an endeavor that speaks to established archaeological traditions and to much broader audiences. AHE has four components: (1) Investigating the conditions of life; (2) Understanding how those conditions came to be; (3) Considering how those conditions are part of, and affect, the larger social and cultural context; and (4) Exploring the experience of those conditions. Many established methods can be used to investigate the first three; the fourth raises delicate questions about whether and how we can know others. Future work will continue to develop systematic measures that might shed light on how and why conditions worsen or improve in some cases.
3 The Variability of the Human Experience: Marginal People and the Creation of Power
Authors: Cameron Catherine M.
Published: May 2016

Archaeologists often characterize small scale societies as egalitarian and uniform. We tend to see the experiences of the people who made up these societies as similar. I argue instead that most small scale societies contained people of a variety of statuses, including those whose social position was marginal. I examine one such category of social person, captives, who were common in small scale societies worldwide. I suggest that their lives could be significantly different from those of other group members and that their presence, labor, and skills could create status and power for their captor and other group members.
6 The Social Costs of Resilience: An Example from the Faroe Islands
Authors: Brewington Seth D.
Published: May 2016

When viewed at the level of social‐ecological system, the Faroe Islands are a model of long‐term resilience and sustainable resource management. But what have been the costs of this system‐level success in terms of human well‐being? In this chapter I focus on two key components of well‐being—food and environmental security—during the transformative 12th and 13th centuries. Though faced with a series of significant environmental and political challenges, medieval‐period Faroese society appears to have adequately maintained food and environmental security, due in large part to a number of legal restrictions on access to key natural resources. The social costs of doing so were not benign, however, as these policies, while effective as conservation measures, disproportionately excluded those with the least socio‐economic power.
10 The Bioarchaeology of Pain and Suffering: Human Adaptation and Survival during Troubled Times
Authors: Martin Debra L. , Harrod Ryan P.
Published: May 2016

Ancient human remains can be analyzed with an eye toward clarifying the limits of human adaptation to many of life's hardships. Data collected from the remnants of skeletonized bodies provides information on the costs of living under trying times and the pain, suffering, and disability experienced. Focusing on the survivors of stressful conditions such as colonization, endemic warfare, climate change, or slavery provides a way to examine the experience of survival as well as the human costs of adapting to the environmental or political‐economic processes creating the condition.
Ginkgolide K protects the heart against endoplasmic reticulum stress injury by activating the inositol‐requiring enzyme 1α/X box‐binding protein‐1 pathway
Authors: Wang Shoubao , Wang Zhenzhong , Fan Qiru , Guo Jing , Galli Gina , Du Guanhua , Wang Xin , Xiao Wei
Published: May 2016

Background and Purpose

Endoplasmic reticulum (ER) stress is increasingly recognized as an important causal factor of many diseases. Targeting ER stress has now emerged as a new therapeutic strategy for treating cardiovascular diseases. Here, we investigated the effects and underlying mechanism of ginkgolide K (1,10‐dihydroxy‐3,14‐didehydroginkgolide, GK) on cardiac ER stress.

Experimental Approach

Cell death, apoptosis and ER stress‐related signalling pathways were measured in cultured neonatal rat cardiomyocytes, treated with the ER stress inducers tunicamycin, hydrogen peroxide and thapsigargin. Acute myocardial infarction was established using left coronary artery occlusion in mice, and infarct size was measured by triphenyltetrazolium chloride staining. Echocardiography was used to assess heart function and transmission electron microscopy for evaluating ER expansion.

Key Results

Ginkgolide K (GK) significantly decreased ER stress‐induced cell death in both in vitro and in vivo models. In ischaemic injured mice, GK treatment reduced infarct size, rescued heart dysfunction and ameliorated ER dilation. Mechanistic studies revealed that the beneficial effects of GK occurred through enhancement of inositol‐requiring enzyme 1α (IRE1α)/X box‐binding protein‐1 (XBP1) activity, which in turn led to increased ER‐associated degradation‐mediated clearance of misfolded proteins and autophagy. In addition, GK was also able to partly repress the pro‐apoptotic action of regulated IRE1‐dependent decay and JNK pathway.

Conclusions and Implications

In conclusion, GK acts through selective activation of the IRE1α/XBP1 pathway to limit ER stress injury. GK is revealed as a promising therapeutic agent to ameliorate ER stress for treating cardiovascular diseases.
The Missing Memory of Canadian Sociology: Reflexive Government and “the Social Science”
Authors: Curtis Bruce
Published: May 2016

The modest literature on the history of Canadian Sociology takes the appearance of a named academic discipline as its object. Canadian Sociology is held to have had some precursors in the 1880s, but really to appear only in the 1920s. It is described as a foreign import and as an activity first of intellectual speculation and moral reform. Observational and analytic practice are absent before 1880. The activities of state agents and government departments in the social field are not discussed. This article offers a richer account through an examination of the larger field from which Sociology was extracted, “the social science,” which was practiced actively in colonial Canada from the early nineteenth century. The social science shaped and was itself shaped by colonial conditions. The article outlines three interrelated moments in social science to carry its claims: inventory‐making, the emergence of “population‐thinking,” and “reflexive government.” Attending to the social science underlines the complex and convoluted relations of sociology with state power.

Les rares oeuvrages académiques portant sur l'histoire de la sociologie canadienne prend pour objet l'apparition du terme  dans le contexte universitaire. Dans cet optique, ils signalent certains précurseurs de la sociologie canadienne dès les années 1880, mais en fait ils affirment que cette discipline n'apparaît que dans les années 1920. Cette discipline est présentée comme une importation académique et, d'abord et avant tout, comme de la spéculation intellectuelle et comme un projet de réforme morale. D'après cette vision, les pratiques d'observation et d'analyse sociales ne semblent pas exister avant 1880, et les acteurs politiques et administratifs sont absents du terrain. Notre article propose un examen plus riche du vaste champ duquel la sociologie académique fut arrachée:  activement pratiquée au Canada à l'époque coloniale dès le début du XIXe siècle. La science sociale forma et fut formée par les conditions sociales et politiques existant dans la colonie. Notre article expose trois moments pertinents et inter‐reliés de la science sociale: la fabrication d'inventaires sociaux; l'émergence du , et l'exercice du . La réintégration de l'histoire de la sociologie canadienne dans la science sociale accentue la relation complexe et incontournable entre sociologie et pouvoir étatique.
Trends in the epidemiology of head and neck cancer in London
Authors: Tataru D. , Mak V. , Simo R. , Davies E.A. , Gallagher J.E.
Published: May 2016

Background

Head and neck cancers [HNCs] are biologically heterogeneous tumours. The objectives of this study were to describe trends in incidence of HNCs amongst London residents by sex, age, anatomical site, deprivation and ethnicity.

Methods

Annual age‐standardised incidence rates [ASRs] were calculated on HNC registration data, overall and for specific cancer sites, by sex and morphology (1985–2010) and area‐based socio‐economic deprivation score (2006–2010). Age‐standardised incidence rate ratios [IRRs] for the main ethnic groups were calculated by cancer site, using White males and females as the reference groups (1998–2009).

Results

The ASR of HNC in males increased by 40% from 17.3 [95% CI: 15.8–18.6] to 24.2 [95% CI: 22.5–25.8] per 100 000 and in females by 87% from 7.0 [95% CI: 6.2–7.8] to 13.1 [95% CI: 11.9–14.2] per 100 000. Seventy‐three per cent of cases spanned four cancer sites: larynx, thyroid, oral and oropharynx. Larynx was most common (23%), and had the highest male: female ratio (6 : 1); ASRs decreased significantly over time, most notably in males [P < 0.001]. Oral cavity was the second most common (21%), with a male: female ratio of 2 : 1, and increasing ASRs in both sexes [P < 0.001]. The majority of cases were male (64%) and from deprived areas (59%). Deprivation was associated with a significantly higher incidence for larynx (males), oropharynx (males and females) and oral cavity (females) [P < 0.05]. The age‐specific rate for middle‐aged adults (45–64 years) was high for oropharyngeal cancer. The incidence of thyroid cancers increased significantly in both sexes [P < 0.001], and this was the only site more common in females. One in five cases with known ethnicity was from a non‐White group (20%). Compared with their White counterparts, Bangladeshi females had a higher incidence of oral, laryngeal and thyroid cancers; Chinese males and females had a higher incidence of nasopharyngeal cancer; and Pakistani and Indian females and Indian males also had higher incidence of oral cancer.

Conclusions

HNCs are increasing in London males and females with significant variation by cancer site over time; oral and oropharyngeal cancers show the most significant rise, with implications for public health action and service provision.
Learning and the transformative potential of citizen science
Authors: Bela Györgyi , Peltola Taru , Young Juliette C. , Balázs Bálint , Arpin Isabelle , Pataki György , Hauck Jennifer , Kelemen Eszter , Kopperoinen Leena , Van Herzele Ann , Keune Hans , Hecker Susanne , Suškevičs Monika , Roy Helen E. , Itkonen Pekka , Külvik Mart , László Miklós , Basnou Corina , Pino Joan , Bonn Aletta
Published: May 2016

The number of collaborative initiatives between scientists and volunteers (i.e., citizen science) is increasing across many research fields. The promise of societal transformation together with scientific breakthroughs contributes to the current popularity of citizen science (CS) in the policy domain. We examined the transformative capacity of citizen science in particular learning through environmental CS as conservation tool. We reviewed the CS and social‐learning literature and examined 14 conservation projects across Europe that involved collaborative CS. We also developed a template that can be used to explore learning arrangements (i.e., learning events and materials) in CS projects and to explain how the desired outcomes can be achieved through CS learning. We found that recent studies aiming to define CS for analytical purposes often fail to improve the conceptual clarity of CS; CS programs may have transformative potential, especially for the development of individual skills, but such transformation is not necessarily occurring at the organizational and institutional levels; empirical evidence on simple learning outcomes, but the assertion of transformative effects of CS learning is often based on assumptions rather than empirical observation; and it is unanimous that learning in CS is considered important, but in practice it often goes unreported or unevaluated. In conclusion, we point to the need for reliable and transparent measurement of transformative effects for democratization of knowledge production.
How Off‐farm Employment Affects Technical Efficiency of China's Farms: The Case of Jiangsu
Authors: Zhang Linxiu , Su Weiliang , Eriksson Tor , Liu Chengfang
Published: May 2016

Using three‐wave survey data for four villages of Jiangsu Province in China, the present paper examines whether and to what extent off‐farm employment affects the technical efficiency of agricultural production. The level of technical efficiency is measured using a stochastic frontier production function approach. Based on estimation results from instrumental variable panel quantile regressions we find that there is a positive significant effect of off‐farm employment on the level of farm technical efficiency. We also find that fragmentation of farmland is a barrier to the improvement of technical efficiency. In addition, we find a downward trend in the level of agricultural technical efficiency among our sample. Therefore, the Chinese Government should stimulate agricultural mechanization and the development of farming techniques to improve technical efficiency in the context of increasing off‐farm employment.
Effects of Parental Migration on Mental Health of Left‐behind Children: Evidence from Northwestern China
Authors: Shi Yaojiang , Bai Yu , Shen Yanni , Kenny Kaleigh , Rozelle Scott
Published: May 2016

China's rapid development and urbanization have induced large numbers of rural residents to migrate from their homes in the countryside to urban areas in search of higher wages. It is estimated that there are more than 60 million “left‐behind children” (LBC) remaining in the countryside after their parents migrate, typically living with surrogate caregivers. Extensive research has focused on the impact of parental out‐migration on children's mental health, but less attention has been paid to the effects of parental return‐migration. The present paper examines the changes in mental health before and after the parents of fourth and fifth grade students out‐migrate or return‐migrate. We draw on a panel dataset collected by the authors of more than 19000 students from 252 rural primary schools in northwestern China. Using DID and propensity score matching approaches, our results indicate that parental out‐migration has a significant negative impact on the mental health of LBC, as they tend to exhibit higher levels of anxiety and lower levels of self‐esteem. However, we find that parental return‐migration has no significant effect on the mental health of LBC.
Factors limiting romantic relationship formation for individuals with early psychosis
Authors: Pillay Rowena , Lecomte Tania , Abdel‐Baki Amal
Published: May 2016

Background

Although many young adults with early psychosis (EP) desire to engage in a romantic relationship, many report having difficulties in engaging in such a relationship. However, almost no research has been conducted on factors potentially explaining impairments in their ability to form romantic relationships.

Aim

To compare an EP single young adult sample with single students or students in stable romantic relationships on factors that can cause difficulties in romantic relationship initiation processes

Methods

Cross‐sectional study comparing these three groups (n = 83) on self‐esteem, attachment, social functioning and perceived difficulties in dating.

Results

No significant group differences were found on self‐esteem, although lack of confidence was the second most frequent reason evoked by EP participants when asked why they were single. EP participants had greater attachment preoccupation than students involved in a relationship. Single EP individuals rated their social interaction abilities higher compared with single students, but did not engage in social interactions more often. Both single EP participants and single students had more negative perceptions of their intimacy abilities and fewer intimacy behaviours compared with participants involved in a relationship.

Conclusions

Potential interventions to improve EP young adult's capacity to engage in romantic relationships could target perception of their interaction skills, preoccupation about being loved, negative perception of their intimacy abilities, frequency of intimacy related behaviours and lack of confidence.
Zircon M127 – A Homogeneous Reference Material for SIMS U–Pb Geochronology Combined with Hafnium, Oxygen and, Potentially, Lithium Isotope Analysis
Authors: Nasdala Lutz , Corfu Fernando , Valley John W. , Spicuzza Michael J. , Wu Fu‐Yuan , Li Qiu‐Li , Yang Yue‐Heng , Fisher Chris , Münker Carsten , Kennedy Allen K. , Reiners Peter W. , Kronz Andreas , Wiedenbeck Michael , Wirth Richard , Chanmuang Chutimun , Zeug Manuela , Váczi Tamás , Norberg Nicholas , Häger Tobias , Kröner Alfred , Hofmeister Wolfgang
Published: May 2016

In this article, we document a detailed analytical characterisation of zircon M127, a homogeneous 12.7 carat gemstone from Ratnapura, Sri Lanka. Zircon M127 has TIMS‐determined mean U–Pb radiogenic isotopic ratios of 0.084743 ± 0.000027 for 206Pb/238U and 0.67676 ± 0.00023 for 207Pb/235U (weighted means, 2s uncertainties). Its 206Pb/238U age of 524.36 ± 0.16 Ma (95% confidence uncertainty) is concordant within the uncertainties of decay constants. The δ18O value (determined by laser fluorination) is 8.26 ± 0.06‰ VSMOW (2s), and the mean 176Hf/177Hf ratio (determined by solution ICP‐MS) is 0.282396 ± 0.000004 (2s). The SIMS‐determined δ7Li value is −0.6 ± 0.9‰ (2s), with a mean mass fraction of 1.0 ± 0.1 μg g−1 Li (2s). Zircon M127 contains ~ 923 μg g−1 U. The moderate degree of radiation damage corresponds well with the time‐integrated self‐irradiation dose of 1.82 × 1018 alpha events per gram. This observation, and the (U–Th)/He age of 426 ± 7 Ma (2s), which is typical of unheated Sri Lankan zircon, enable us to exclude any thermal treatment. Zircon M127 is proposed as a reference material for the determination of zircon U–Pb ages by means of SIMS in combination with hafnium and stable isotope (oxygen and potentially also lithium) determination.
The impact of prescribed opioids on CD4 cell count recovery among HIV‐infected patients newly initiating antiretroviral therapy
Authors: Edelman EJ , Gordon KS , Tate JP , Becker WC , Bryant K , Crothers K , Gaither JR , Gibert CL , Gordon AJ , Marshall BDL , Rodriguez‐Barradas MC , Samet JH , Skanderson M , Justice AC , Fiellin DA
Published: May 2016

Objectives

Certain prescribed opioids have immunosuppressive properties, yet their impact on clinically relevant outcomes, including antiretroviral therapy (ART) response among HIV‐infected patients, remains understudied.

Methods

Using the Veterans Aging Cohort Study data, we conducted a longitudinal analysis of 4358 HIV‐infected patients initiating ART between 2002 and 2010 and then followed them for 24 months. The primary independent variable was prescribed opioid duration, categorized using pharmacy data as none prescribed, short‐term (< 90 days) and long‐term (≥ 90 days). Outcomes included CD4 cell count over time. Analyses adjusted for demographics, comorbid conditions, ART type and year of initiation, and overall disease severity [ascertained with the Veterans Aging Cohort Study (VACS) Index]. Sensitivity analyses examined whether effects varied according to baseline CD4 cell count, achievement of viral load suppression, and opioid properties (i.e. dose and known immunosuppressive properties).

Results

Compared to those with none, patients with short‐term opioids had a similar increase in CD4 cell count (mean rise per year: 74 vs. 68 cells/μL; P = 0.11), as did those with long‐term prescribed opioids (mean rise per year: 74 vs. 75 cells/μL; P = 0.98). In sensitivity analysis, compared with no opioids, the effects of short‐term prescribed opioids were statistically significant among those with a baseline CD4 cell count ≥ 500 cells/μL (mean rise per year: 52 cells/μL for no opioids vs. 20 cells/μL for short‐term opioids; P = 0.04); findings were otherwise unchanged.

Conclusions

Despite immunosuppressive properties intrinsic to opioids, prescribed opioids appeared to have no effect on CD4 cell counts over 24 months among HIV‐infected patients initiating ART.
Psychiatric and substance use disorders in HIV/hepatitis C virus (HCV)‐coinfected patients: does HCV clearance matter? [Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS) HEPAVIH CO13 cohort]
Authors: Michel L , Lions C , Winnock M , Lang J‐P , Loko M‐A , Rosenthal E , Marchou B , Valantin M‐A , Morlat P , Roux P , Sogni P , Spire B , Poizot‐Martin I , Lacombe K , Lascoux‐Combe C , Duvivier C , Neau D , Dabis F , Salmon‐Ceron D , Carrieri MP ,   the ANRS HEPAVIH CO13 study group
Published: May 2016

Objectives

The objective of this nested study was to assess the prevalence of psychiatric disorders in a sample of HIV/hepatitis C virus (HCV)‐coinfected patients according to their HCV status.

Methods

The nested cross‐sectional study, untitled HEPAVIH‐Psy survey, was performed in a subset of HIV/HCV‐coinfected patients enrolled in the French Agence Nationale de Recherche sur le SIDA et les Hépatites Virales (ANRS) CO13 HEPAVIH cohort. Psychiatric disorders were screened for using the Mini International Neuropsychiatric Interview (MINI 5.0.0).

Results

Among the 286 patients enrolled in the study, 68 (24%) had never received HCV treatment, 87 (30%) were treatment nonresponders, 44 (15%) were currently being treated and 87 (30%) had a sustained virological response (SVR). Of the 286 patients enrolled, 121 patients (42%) screened positive for a psychiatric disorder other than suicidality and alcohol/drug abuse/dependence, 40 (14%) screened positive for alcohol abuse/dependence, 50 (18%) screened positive for drug abuse/dependence, 50 (17.5%) were receiving an antidepressant treatment and 69 (24%) were receiving an anxiolytic. Patients with an SVR did not significantly differ from the other groups in terms of psychiatric disorders. Patients receiving HCV treatment screened positive less often for an anxiety disorder. The highest rate of drug dependence/abuse was among HCV treatment‐naïve patients.

Conclusions

Psychiatric disorders were frequent in HIV/HCV‐coinfected patients and their rates were comparable between groups, even for patients achieving an SVR. Our results emphasize the need for continuous assessment and care of coinfected patients, even after HCV clearance. Drug addiction remains an obstacle to access to HCV treatment. Despite the recent advent and continued development of directly acting antiviral agents (DAAs), it is still crucial to offer screening and comprehensive care for psychiatric and addictive disorders.
Does enhancing personal care assistants’ own oral health influence their attitudes and practices towards oral care for residents – a pilot study
Authors: Knevel RJM , Foley J , Gussy M , Karimi L
Published: May 2016

Objectives

To investigate whether, within a residential care facility, increasing personal care assistants’ (PCAs) awareness of their own oral health status and self‐care skills would alter existing attitudes and behavioural intentions related to the oral health care of residents.

Methods

PCAs (n = 15) in the dementia care unit of a residential care facility in Melbourne, Australia, were invited to participate in a small research project that appeared to test the effectiveness of a work‐place oral health educational programme in enhancing their own oral health whilst masking the actual outcome of interest, namely its effect on PCAs oral healthcare attitudes and practices towards the residents.

Results

Post‐intervention, the self‐reported confidence of the PCAs to identify their personal risk for oral health problems, identifying common oral health conditions and determining the factors contributing to their personal oral health was increased significantly (P < 0.05). Post‐intervention, the self‐reported confidence of the PCAs to feeling confident to identify factors that could contribute to poor oral health of residents, identify resident's higher risk for poor oral health and feeling confident in identifying common oral health conditions in residents was also increased significantly (P < 0.05).

Conclusion

The results of this pilot study show that the educational intervention to increase the personal care assistants’ (PCAs) awareness of their own oral health status and self‐care skills increased the confidence of the carers to identify oral health risks in the residents, as well as increasing their self‐reported confidence in providing oral care to residents.