bluuebunny/crossref_metadata_2025 huggingface dataset:
Community‐Based Groundwater Monitoring Network Using a Citizen‐Science Approach
Authors: Little Kathleen E. , Hayashi Masaki , Liang Steve
Published: March 2015

Water level monitoring provides essential information about the condition of aquifers and their responses to water extraction, land‐use change, and climatic variability. It is important to have a spatially distributed, long‐term monitoring well network for sustainable groundwater resource management. Community‐based monitoring involving citizen scientists provides an approach to complement existing government‐run monitoring programs. This article demonstrates the feasibility of establishing a large‐scale water level monitoring network of private water supply wells using an example from Rocky View County (3900 km2) in Alberta, Canada. In this network, community volunteers measure the water level in their wells, and enter these data through a web‐based data portal, which allows the public to view and download these data. The close collaboration among the university researchers, county staff members, and community volunteers enabled the successful implementation and operation of the network for a 5‐year pilot period, which generated valuable data sets. The monitoring program was accompanied by education and outreach programs, in which the educational materials on groundwater were developed in collaboration with science teachers from local schools. The methodology used in this study can be easily adopted by other municipalities and watershed stewardship groups interested in groundwater monitoring. As governments are starting to rely increasingly on local municipalities and conservation authorities for watershed management and planning, community‐based groundwater monitoring provides an effective and affordable tool for sustainable water resources management.
Prognostic factors in patients with penile carcinoma and inguinal lymph node metastasis
Authors: da Costa Walter Henriques , Rosa de Oliveira Renato Almeida , Santana Thiago Borges , Benigno Bruno Santos , da Cunha Isabela Werneck , de Cássio Zequi Stênio , Guimaraes Gustavo Cardoso , Lopes Ademar
Published: March 2015

Objectives

To identify prognostic factors in patients with penile carcinoma and confirmed lymph node metastasis.

Methods

Patients were selected from a historical series of patients with penile carcinoma. An experienced pathologist reviewed all cases. Information regarding the total number of lymph nodes excised, the number of positive lymph nodes and the presence of extranodal extension were used. Lymph node ratio was categorized as <0.15 and >0.15.

Results

The 5‐year recurrence‐free survival and disease‐specific survival rates were 55.3% and 64.1%, respectively. Lymphovascular invasion, lymph node ratio and pN status influenced survival rates in univariate analysis. Lymphovascular invasion and lymph node ratio remained as independent predictors of disease‐specific survival and recurrence‐free survival in the multivariate analysis. A risk stratification of death and tumor recurrence was observed when patients were grouped into three categories: absence of risk factors; the presence of one risk factor; and the presence of two or more risk factors.

Conclusions

The presence of one or more of the following parameters is correlated with a significantly higher risk of death and tumor recurrence in patients with penile carcinoma and inguinal lymph node metastasis: extranodal extension, lymph node ratio >0.15 and lymphovascular invasion.
Being reflexive in qualitative grounded theory: discussion and application of a model of reflexivity
Authors: Engward Hilary , Davis Geraldine
Published: March 2015

Aim

A discussion of the meaning of reflexivity in research with the presentation of examples of how a model of reflexivity was used in a grounded theory research project.

Background

Reflexivity requires the researcher to make transparent the decisions they make in the research process and is therefore important in developing quality in nursing research. The importance of being reflexive is highlighted in the literature in relation to nursing research, however, practical guidance as to how to go about doing research reflexively is not always clearly articulated.

Design

This is a discussion paper.

Data sources

The concept of reflexivity in research is explored using the Alvesson and Skoldberg model of reflexivity and practical examples of how a researcher developed reflexivity in a grounded theory project are presented.

Implications for nursing

Nurse researchers are encouraged to explore and apply the concept of reflexivity in their research practices to develop transparency in the research process and to increase robustness in their research. The Alvesson and Skoldberg model is of value in applying reflexivity in qualitative nursing research, particularly in grounded theory research.

Conclusion

Being reflexive requires the researcher to be completely open about decisions that are made in the research process. The Alvesson and Skolberg model of reflexivity is a useful model that can enhance reflexivity in the research process. It can be a useful practical tool to develop reflexivity in grounded theory research.
Pandemic influenza: an evolutionary concept analysis
Authors: Devereaux Alana
Published: March 2015

Aim

The aim of this paper was to provide a concept analysis of ‘pandemic influenza’.

Background

Pandemic influenza can have a devastating impact as individuals have little to no immunity towards the newly encountered virus. It is a persistent societal threat due to the advancement of multiple technological processes. Nurses work in multiple roles in pandemics. As such, a thorough understanding of the concept and its implications from a nursing perspective is required.

Design

Rodgers’ Evolutionary Method was used to conduct the concept analysis of the term ‘pandemic influenza’.

Data sources

Forty‐nine papers were examined from the disciplines of public health, medicine, law, bioethics and healthcare policy. Papers were found from the PubMed,CINAHLand Google Scholar databases all dates up to December 2013. Limits were set to include peer‐reviewed, English language articles.

Methods

Identified papers were critically analyzed to explore the concept's antecedents, attributes and consequences. Surrogate and related terms, and an exemplar, were identified.

Results

Attributes of pandemic include original viral structure, increased human susceptibility, younger vulnerable populations and unpredictable time frames. Antecedents include processes that enable the increased geographical transmission of a newly created influenza. Consequences include higher morbidity and mortality rates and the need for an efficient pandemic response.

Conclusions

This analysis identified the attributes of pandemic influenza through a synthesis of the current pandemic literature. However, no articles were identified as specifically nursing in nature. Therefore, more research is required to examine the impact of a pandemic declaration on the nursing profession.
Systematic Reviews of the Health or Health care of People with Intellectual Disabilities: A Systematic Review to Identify Gaps in the Evidence Base
Authors: Robertson Janet , Hatton Chris , Baines Susannah , Emerson Eric
Published: March 2015

Background

Systematic reviews are important in evaluating evidence concerning the health of people with intellectual disabilities. This study conducts a systematic review to identify strengths and gaps in this evidence.

Method

Electronic literature searches and email requests identified systematic reviews published in English from 2008 to 2013 on the health or health care of people with intellectual disabilities. Reviews were categorized using ICD‐10 chapter headings and information extracted regarding methods, number of studies reviewed and findings.

Results

Ninety‐four reviews were identified: 52 related to ICD‐10 Chapter V: Mental or behavioural disorders, 28 to Chapter XXI: Factors influencing health status and contact with services, and 14 related to other chapters or encompassed multiple chapters. Nine reviews were ‘empty’. No reviews were found for many ICD‐10 chapter headings.

Conclusions

Systematic reviews are heavily weighted towards mental health, with little coverage of several areas important to the health and mortality of people with intellectual disabilities.
Novel mechanism of cardiac protection by valsartan: synergetic roles of TGF‐β1 and HIF‐1α in Ang II‐mediated fibrosis after myocardial infarction
Authors: Sui Xizhong , Wei Hongchao , Wang Dacheng
Published: March 2015

Transforming growth factor (TGF)‐β1 is a known factor in angiotensin II (Ang II)‐mediated cardiac fibrosis after myocardial infarction (MI). Hypoxia inducible factor‐1 (Hif‐1α) was recently demonstrated to involve in the tissue fibrosis and influenced by Ang II. However, whether Hif‐1α contributed to the Ang II‐mediated cardiac fibrosis after MI, and whether interaction or synergetic roles between Hif‐1α and TGF‐β pathways existed in the process was unclear. In vitro, cardiac cells were incubated under hypoxia or Ang II to mimic ischaemia. In vivo, valsartan was intravenously injected into Sprague–Dawley rats with MI daily for 1 week; saline and hydralazine (another anti‐hypertensive agent like valsartan) was used as control. The fibrosis‐related proteins were detected by Western blotting. Cardiac structure and function were assessed with multimodality methods. We demonstrated in vitro that hypoxia would induce the up‐regulation of Ang II, TGF‐β/Smad and Hif‐1α, which further induced collagen accumulation. By blocking with valsartan, a blocker of Ang II type I (AT1) receptor, we confirmed that the up‐regulation of TGF‐β/Smad and Hif‐1α was through the Ang II‐mediated pathway. By administering TGF‐β or dimethyloxalylglycine, we determined that both TGF‐β/Smad and Hif‐1α contributed to Ang II‐mediated collagen accumulation and a synergetic effect between them was observed. Consistent with in vitro results, valsartan significantly attenuated the expression of TGF‐β/Smad, Hif‐1α and fibrosis‐related protein in rats after MI. Heart function, infarcted size, wall thickness as well as myocardial vascularization of ischaemic hearts were also significantly improved by valsartan compared with saline and hydralazine. Our study may provide novel insights into the mechanisms of Ang II‐induced cardiac fibrosis as well as into the cardiac protection of valsartan.
Prognostic role of the CDNK1B V109G polymorphism in multiple endocrine neoplasia type 1
Authors: Circelli Luisa , Ramundo Valeria , Marotta Vincenzo , Sciammarella Concetta , Marciello Francesca , Del Prete Michela , Sabatino Lina , Pasquali Daniela , Izzo Francesco , Scala Stefania , Colao Annamaria , Faggiano Antongiulio , Colantuoni Vittorio ,   the Multidisciplinary Group for NeuroEndocrine Tumours of Naples
Published: March 2015

CDKN1B encodes the cyclin‐dependent kinase inhibitor p27/Kip1. CDKN1B mutations and polymorphisms are involved in tumorigenesis; specifically, the V109G single nucleotide polymorphism has been linked to different tumours with controversial results. Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant syndrome, characterized by the development of different types of neuroendocrine tumours and increased incidence of other malignancies. A clear genotype–phenotype correlation in MEN1 has not been established yet. In this study, we assessed whether the CDKN1B V109G polymorphism was associated with the development of aggressive tumours in 55 consecutive patients affected by MEN1. The polymorphism was investigated by PCR amplification of germline DNA followed by direct sequencing. Baseline and follow‐up data of tumour types and their severity were collected and associated with the genetic data. MEN1‐related aggressive and other malignant tumours of any origin were detected in 16.1% of wild‐type and 33.3% of polymorphism allele‐bearing patients (P = NS). The time interval between birth and the first aggressive tumour was significantly shorter in patients with the CDKN1B V109G polymorphism (median 46 years) than in those without (median not reached; P = 0.03). Similarly, shorter was the time interval between MEN1 diagnosis and age of the first aggressive tumour (P = 0.02). Overall survival could not be estimated as 96% patients were still alive at the time of the study. In conclusion, CDKN1B V109G polymorphism seems to play a role in the development of aggressive tumours in MEN1.
CXCR4 attenuates cardiomyocytes mitochondrial dysfunction to resist ischaemia‐reperfusion injury
Authors: Cai Wen‐Feng , Kang Kai , Huang Wei , Liang Jia‐Liang , Feng Yu‐Liang , Liu Guan‐Sheng , Chang De‐Hua , Wen Zhi‐Li , Paul Christian , Xu Meifeng , Millard Ronald W. , Wang Yigang
Published: March 2015

The chemokine (C‐X‐C motif) receptor 4 (CXCR4) is expressed on native cardiomyocytes and can modulate isolated cardiomyocyte contractility. This study examines the role of CXCR4 in cardiomyocyte response to ischaemia‐reperfusion (I/R) injury. Isolated adult rat ventricular cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) to simulate I/R injury. In response to H/R injury, the decrease in CXCR4 expression was associated with dysfunctional energy metabolism indicated by an increased adenosine diphosphate/adenosine triphosphate (ADP/ATP) ratio. CXCR4‐overexpressing cardiomyocytes were used to determine whether such overexpression (OE) can prevent bio‐energetic disruption‐associated cell death. CXCR4 OE was performed with adenoviral infection with CXCR4 encoding‐gene or non‐translated nucleotide sequence (Control). The increased CXCR4 expression was observed in cardiomyocytes post CXCR4‐adenovirus transduction and this OE significantly reduced the cardiomyocyte contractility under basal conditions. Although the same extent of H/R‐provoked cytosolic calcium overload was measured, the hydrogen peroxide‐induced decay of mitochondrial membrane potential was suppressed in CXCR4 OE group compared with control group, and the mitochondrial swelling was significantly attenuated in CXCR4 group, implicating that CXCR4 OE prevents permeability transition pore opening exposure to overload calcium. Interestingly, this CXCR4‐induced mitochondrial protective effect is associated with the enhanced signal transducer and activator of transcription 3 (expression in mitochondria. Consequently, in the presence of H/R, mitochondrial dysfunction was mitigated and cardiomyocyte death was decreased to 65% in the CXCR4 OE group as compared with the control group. I/R injury leads to the reduction in CXCR4 in cardiomyocytes associated with the dysfunctional energy metabolism, and CXCR4 OE can alleviate mitochondrial dysfunction to improve cardiomyocyte survival.
Cardiosome mediated regulation of MMP9 in diabetic heart: role of mir29b and mir455 in exercise
Authors: Chaturvedi Pankaj , Kalani Anuradha , Medina Ilza , Familtseva Anastasia , Tyagi Suresh C
Published: March 2015

‘Cardiosomes’ (exosomes from cardiomyocytes) have recently emerged as nanovesicles (30–100 nm) released in the cardiosphere by myocytes and cardiac progenitor cells, though their role in diabetes remains elusive. Diabetic cardiovascular complications are unequivocally benefitted from exercise; however, the molecular mechanisms need exploration. This novel study is based on our observation that exercise brings down the levels of activated (Matrix Metalloprotease 9) in db/db mice in a model of type 2 diabetes. We hypothesize that exosomes that are released during exercise contain microRNAs (mir455, mir29b, mir323‐5p and mir466) that bind to the 3′ region of MMP9 and downregulate its expression, hence mitigating the deleterious downstream effects of MMP9, which causes extracellular matrix remodeling. First, we confirmed the presence of exosomes in the heart tissue and serum by electron microscopy and flow cytometry, respectively, in the four treatment groups: (i) db/control, (ii) db/control+exercise, (iii) db/db and (iv) db/db+exercise. Use of exosomal markers CD81, Flottilin 1, and acetylcholinesterase activity in the isolated exosomes confirmed enhanced exosomal release in the exercise group. The microRNAs isolated from the exosomes contained mir455, mir29b, mir323‐5p and mir466 as quantified by qRTPCR, however, mir29b and mir455 showed highest upregulation. We performed 2D zymography which revealed significantly lowered activity of MMP9 in the db/db exercise group as compared to non‐exercise group. The immunohistochemical analysis further confirmed the downregulated expression of MMP9 after exercise. Since MMP9 is involved in matrix degradation and leads to fibrosis and myocyte uncoupling, the present study provides a strong evidence how exercise can mitigate these conditions in diabetic patients.
Shared Use and Safe Routes to School: Managing the Fear of Liability
Authors: Winig Benjamin D. , Spengler John O. , Etow Alexis M.
Published: April 2015

This paper examines two policy initiatives that research shows can increase opportunities for physical activity and, in turn, improve health outcomes. These initiatives — shared use and Safe Routes to School (SRTS) — can and should be embraced by schools to improve student and community health. Fear of liability, however, has made many schools reluctant to support these efforts despite their proven benefits. This paper addresses school administrators’ real and perceived liability concerns and identifies four strategies for managing the fear of liability and mitigating any potential liability exposure.
Behaviour of geochronometers and timing of metamorphic reactions during deformation at lower crustal conditions: phase equilibrium modelling and U–Pb dating of zircon, monazite, rutile and titanite from the Kalak Nappe Complex, northern Norway
Authors: Gasser D. , Jeřábek P. , Faber C. , Stünitz H. , Menegon L. , Corfu F. , Erambert M. , Whitehouse M. J.
Published: March 2015

This study investigates the behaviour of the geochronometers zircon, monazite, rutile and titanite in polyphase lower crustal rocks of the Kalak Nappe Complex, northern Norway. A pressure–temperature–time–deformation path is constructed by combining microstructural observations with P–T conditions derived from phase equilibrium modelling and U–Pb dating. The following tectonometamorphic evolution is deduced: A subvertical S1 fabric formed at ~730–775 °C and ~6.3–9.8 kbar, above the wet solidus in the sillimanite and kyanite stability fields. The event is dated at 702 ± 5 Ma by high‐U zircon in a leucosome. Monazite grains that grew in the S1 fabric show surprisingly little variation in chemical composition compared to a large spread in (concordant) U–Pb dates from c. 800 to 600 Ma. This age spread could either represent protracted growth of monazite during high‐grade metamorphism, or represent partially reset ages due to high‐T diffusion. Both cases imply that elevated temperatures of >600 °C persisted for over c. 200 Ma, indicating relatively static conditions at lower crustal levels for most of the Neoproterozoic. The S1 fabric was overprinted by a subhorizontal S2 fabric, which formed at ~600–660 °C and ~10–12 kbar. Rutile that originally grew during the S1‐forming event lost its Zr‐in‐rutile and U–Pb signatures during the S2‐forming event. It records Zr‐in‐rutile temperatures of 550–660 °C and Caledonian ages of 440–420 Ma. Titanite grew at the expense of rutile at slightly lower temperatures of ~550 °C during ongoing S2 deformation; U–Pb ages of c. 440–430 Ma date its crystallization, giving a minimum estimate for the age of Caledonian metamorphism and the duration of Caledonian shearing. This study shows that (i) monazite can have a large spread in U–Pb dates despite a homogeneous composition; (ii) rutile may lose its Zr‐in‐rutile and U–Pb signature during an amphibolite facies overprint; and (iii) titanite may record crystallization ages during retrograde shearing. Therefore, in order to correctly interpret U–Pb ages from different geochronometers in a polyphase deformation and reaction history, they are ideally combined with microstructural observations and phase equilibrium modelling to derive a complete P–T–t–d path.
Class II functional orthopaedic treatment: a systematic review of systematic reviews
Authors: D'Antò V. , Bucci R. , Franchi L. , Rongo R. , Michelotti A. , Martina R.
Published: March 2015

This Systematic Review (SR) aims to assess the quality of SRs and Meta‐Analyses (MAs) on functional orthopaedic treatment of Class II malocclusion and to summarise and rate the reported effects. Electronic and manual searches were conducted until June 2014. SRs and MAs focusing on the effects of functional orthopaedic treatment of Class II malocclusion in growing patients were included. The methodological quality of the included papers was assessed using the AMSTAR (Assessment of Multiple Systematic Reviews). The design of the primary studies included in each SR was assessed with Level of Research Design scoring. The evidence of the main outcomes was summarised and rated according to a scale of statements. 14 SRs fulfilled the inclusion criteria. The appliances evaluated were as follows: Activator (2 studies), Twin Block (4 studies), headgear (3 studies), Herbst (2 studies), Jasper Jumper (1 study), Bionator (1 study) and Fränkel‐2 (1 study). Four studies reviewed several functional appliances, as a group. The mean AMSTAR score was 6 (ranged 2–10). Six SRs included only controlled clinical trials (CCTs), three SRs included only randomised controlled trials (RCTs), four SRs included both CCTs and RCTs and one SR included also expert opinions. There was some evidence of reduction of the overjet, with different appliances except from headgear; there was some evidence of small maxillary growth restrain with Twin Block and headgear; there was some evidence of elongation of mandibular length, but the clinical relevance of this results is still questionable; there was insufficient evidence to determine an effect on soft tissues.
Systolic cardiac function assessment by feature tracking echocardiography in dogs with myxomatous mitral valve disease
Authors: Mantovani M. M. , Muzzi R. A. L. , Pereira G. G. , Yamato R. J. , Silva A. C. , Reis G. F. , Muzzi L. A. L. , Guimarães E. C.
Published: March 2015

OBJECTIVES

To evaluate endomyocardial and epimyocardial left ventricular circumferential and longitudinal peak systolic strain and strain rate in dogs with myxomatous mitral valve disease using two‐dimensional feature tracking imaging echocardiography.

MATERIALS AND METHODS

Epimyocardial and endomyocardial global and regional myocardial peak systolic strain and strain rate using two‐dimensional feature tracking imaging were evaluated in healthy dogs and those in stages B1, B2 and C of myxomatous mitral valve disease. Strain and strain rate in circumferential and longitudinal aspect were evaluated in 48 small‐ and medium‐sized dogs.

RESULTS

Global endomyocardial circumferential strain and global epimyocardial circumferential strain systolic peak were lower in stage C than in stage B2 (P = 0 · 04 and P = 0 · 02) and similar to healthy dogs. Endomyocardial circumferential strain rate in septal and inferior segments were lower in stage C compared to B2 (P = 0 · 0007 and P = 0 · 0056), but not different from healthy dogs. There were no statistical differences in the epimyocardial circumferential strain rate, longitudinal strain and strain rate between healthy and affected dogs.

CLINICAL SIGNIFICANCE

Two‐dimensional feature tracking imaging determination of myocardial deformation in epimyocardial and endomyocardial layers allows detection of increased compensatory circumferential left ventricular myocardial systolic performance due to volume overload and absence of this response as disease advances to congestive heart failure.
Studies into Computational Intelligence and Evolutionary Approaches for Model‐Free Identification of Hysteretic Systems
Authors: Bolourchi Ali , Masri Sami F. , Aldraihem Osama J.
Published: March 2015

This article introduces a robust hybrid computational method for the data‐driven model‐free identification of nonlinear systems that exhibit hysteretic behavior. The proposed approach combines Genetic Programming, which incorporates discontinuous basis functions, for discovering the structure of the governing differential equations, Genetic Algorithms for optimizing the parameters of the differential equations, and Computer Algebra for simplifying mathematical expressions symbolically, and consequently, controlling bloat through condensing dependent terms. A similar technique has been previously proposed by the authors for the identification of nonhysteretic Single Degree of Freedom (SDOF) systems. That technique is extended in this article and is utilized to provide parsimonious differential equations that represent the Bouc–Wen model and the bilinear hysteretic oscillator—both exhibit abrupt change in their memory‐dependent response. The representative models are subjected to validation excitations that are substantially different from the probing signals to confirm the generalizability of the models for different dynamical phenomena. The results verify the effectiveness of the approach and the accuracy of the subsequent differential operators that characterize the behavior of the studied hysteretic systems even under new dynamical conditions. Beside the presented application of this approach, the introduced methodology is more general and can be employed across different disciplines, specifically in data analytics for mathematical modeling of various complex systems.
Distinct contribution of Toxoplasma gondii rhomboid proteases 4 and 5 to micronemal protein protease 1 activity during invasion
Authors: Rugarabamu George , Marq Jean‐Baptiste , Guérin Amandine , Lebrun Maryse , Soldati‐Favre Dominique
Published: April 2015

Host cell entry by the Apicomplexa is associated with the sequential secretion of invasion factors from specialized apical organelles. Secretion of micronemal proteins (MICs) complexes by Toxoplasma gondii facilitates parasite gliding motility, host cell attachment and entry, as well as egress from infected cells. The shedding of MICs during these steps is mediated by micronemal protein proteases MPP1, MPP2 and MPP3. The constitutive activity of MPP1 leads to the cleavage of transmembrane MICs and is linked to the surface rhomboid protease 4 (ROM4) and possibly to rhomboid protease 5 (ROM5). To determine their importance and respective contribution to MPP1 activity, in this study ROM4 and ROM5 genes were abrogated using Cre‐recombinase and CRISPR‐Cas9 nuclease, respectively, and shown to be dispensable for parasite survival. Parasites lacking ROM4 predominantly engage in twirling motility and exhibit enhanced attachment and impaired invasion, whereas intracellular growth and egress is not affected. The substrates MIC2 and MIC6 are not cleaved in rom4‐ko parasites, in contrast, intramembrane cleavage of AMA1 is reduced but not completely abolished. Shedding of MICs and invasion are not altered in the absence of ROM5; however, this protease responsible for the residual cleavage of AMA1 is able to cleave other AMA family members and exhibits a detectable contribution to invasion in the absence of ROM4.
Social communities and spatiotemporal dynamics of association patterns in estuarine bottlenose dolphins
Authors: Titcomb Elizabeth Murdoch , O'Corry‐Crowe Greg , Hartel Elizabeth F. , Mazzoil Marilyn S.
Published: April 2015

Network analysis has recently been used to delve into the dynamics of cetacean sociality. Few studies, however, have addressed how habitat shape influences sociality, specifically how linear water bodies constrain the space where individuals might interact. We utilized network and spatiotemporal analyses to investigate association patterns and community structure in a bottlenose dolphin population in a linear estuarine system, the Indian River Lagoon (IRL), Florida. Using sighting histories from a multiyear photo‐identification study we examined association patterns for 185 individuals collected over a 6.5 yr period (2002–2008). The population was highly differentiated (S = 0.723) and organized into six distinct social communities (Q = 0.544), spread in an overlapping pattern along the linear system. Social organization differed between communities, with some displaying highly interconnected networks and others comprising loosely affiliated individuals with more ephemeral associations. Temporal patterns indicated short‐term associations were a significant feature of the fission‐fusion dynamics of this population. Spatial analyses revealed that social structure was shaped by an individual's ranging patterns and by social processes including preference and avoidance behavior. Finally, we found that habitat “narrowness” may be a major driving force behind the sociality observed.
Species diversity and identity effects on the water consumption of tree sapling assemblages under ample and limited water supply
Authors: Lübbe Torben , Schuldt Bernhard , Coners Heinz , Leuschner Christoph
Published: April 2015

Studies examining the influence of biodiversity on ecosystem functioning have rarely considered water turnover, the quantitatively most important biogeochemical flux in ecosystems and a process with high sensitivity to climate warming. With a tree sapling experiment consisting of three diversity levels (1, 3, 5 species), 11 different species combinations and two soil moisture levels (moist and dry), we examined the influence of tree species diversity and species identity on stand transpiration (T) under ample and restricted water supply. We further asked whether growth in mixture leads to adaptive responses in the hydraulic system and water loss regulation in plants with heterospecific neighbors compared to plants in monoculture. In moist soil, T was on average ∼11% higher in the mixtures than in the monocultures (significant net diversity effect), which can mostly be attributed to a selection effect. Overyielding in T was highest in mixtures when Tilia cordata and/or Fraxinus excelsior were present. Both species developed larger leaf areas (LA) and sapwood areas (SA) in monocultures than the other species and furthermore increased LA and SA from the monocultures to the mixtures. Thus, inherent species differences in LA and hydraulics, but also neighbor effects on these traits determined T to a large extend. In dry soil, the diversity effect on T was not larger but slightly smaller, which is not in agreement with other published studies. We conclude that differences between pure and mixed sapling assemblages in stand water consumption and drought response are mainly caused by species identity effects, while species diversity seems to be less influential.
Childhood asthma and spirometric indices are associated with polymorphic markers of two vitamin D 25‐hydroxylase genes
Authors: Leung Ting Fan , Wang Susan Shuxin , Tang Man Fung , Kong Alice Pik‐shan , Sy Hing Yee , Hon Kam Lun , Chan Juliana Chung‐ngor , Wong Gary Wing‐kin
Published: April 2015

Background

Polymorphic markers of vitamin D pathway genes have been associated with asthma traits in different White populations. This study investigated the relationship between asthma phenotypes and single nucleotide polymorphisms (SNPs) of vitamin D receptor (VDR), vitamin D binding protein (GC), two 25‐hydroxylases (CYP2R1 and CYP27A1), and 1α‐hydroxylase (CYP27B1) in Hong Kong Chinese children.

Methods

23 SNPs of the five vitamin D pathway genes were successfully genotyped in 914 asthmatic children and 1231 non‐allergic controls. Genotypic and haplotypic associations with asthma phenotypes (diagnosis, spirometric indices, total IgE, and eosinophil percentage) were analyzed by multivariate regression. Generalized multifactor dimensionality reduction was used to detect epistatic interactions between SNPs for asthma phenotypes.

Results

Several SNPs of CYP27A1, CYP27B1, GC, and CYP2R1 were associated with asthma or spirometric indices, although only the association between FEV1 and CYP2R1 rs7935792 passed Bonferroni correction (p = 2.73 × 10−4). Patients with CC genotype of rs7935792 had higher FEV1 than those with the other two genotypes. Asthma was also associated with TT haplotype of CYP27A1 and AGGATA haplotype of CYP2R1 (p = 0.021 and 0.024, respectively). Besides, strong association was found between FEV1 and GATAG of CYP2R1 (β = 13.37, p = 4.83 × 10−4). GMDR failed to identify any 2‐locus to 4‐locus interaction that modulated asthma or spirometric indices.

Conclusions

Several SNPs and haplotypes of CYP2R1 are associated with asthma diagnosis and FEV1 in children. Asthma is also modestly associated with a CYP27A1 haplotype. These two 25‐hydroxylase genes may be genetic determinants for asthma phenotypes in children.
Analysing Behavioural Risk Factor Surveillance Data by Using Spatially and Temporally Varying Coefficient Models
Authors: Assaf Shireen , Campostrini Stefano , Xu Fang , Gotway Crawford Carol
Published: April 2015

The study of temporal and spatial trends in large databases, such as behavioural risk factor surveillance data, can be a great challenge, especially when the intent is to study the time-related effects of multiple independent variables; this is an issue which is not usually addressed in trend analysis in epidemiological studies. This study demonstrates the use of varying coefficient models using non-parametric techniques, which can show how coefficients vary in time or space; it is a useful statistical tool that is applied for the first time to health surveillance data. Using the US ‘Behavioral risk factor surveillance system’, a varying coefficient model is constructed using obesity as an outcome measure. Odds ratio plots and probability maps illustrate the temporal or spatial changes in coefficients of the independent variables; these results can be used to identify changes in at-risk subgroups of the population for the odds of obesity.
Optimal laparoscopic ergonomics in gynaecology
Authors: Quinn Declan , Moohan James
Published: March 2015

Key content

Laparoscopic surgery in gynaecology is mainstream and widely practised.

While this brings many benefits to the patient, injury to the surgeon is often under‐reported.

Careful theatre layout and correct instruments minimise the risk to the surgeon.

There is a lack of gynaecology‐specific guidelines/training in optimal theatre layout and surgeon positioning.

This article examines the current available evidence and suggests changes that clinicians can make in order to optimise their working environment.

Learning objectives

To appreciate the many ways the operating theatre can be changed to facilitate optimal ergonomics.

To be aware of the different equipment available to facilitate comfort when operating.

To recognise the short‐term and long‐term repercussions of poor ergonomics.

Ethical issues

Should this form part of every surgeon's training?

Despite obvious benefits for patients, should employers pay closer attention to the health of their staff?
A Particle-Continuum Hybrid Framework for Transport Phenomena and Chemical Reactions in Multicomponent Systems at the Micro and Nanoscale
Authors: Alexiadis Alessio , Lockerby Duncan A. , Borg Matthew K. , Reese Jason M.
Published: March 2015

The particle-continuum hybrid Laplacian method is extended as a framework for modeling all transport phenomena in fluids at the micro and nanoscale including multicomponent mass transfer and chemical reactions. The method is explained, and the micro-to-macro and macro-to-micro coupling steps are discussed. Two techniques for noise reduction (namely, the bonsai box (BB) and the seamless strategy) are discussed. Comparisons with benchmark full-molecular dynamics (MD) cases for micro and nano thermal and reacting flows show excellent agreement and good computational efficiency.
Atomistic-Continuum Hybrid Simulation of Heat Transfer Between Argon Flow and Copper Plates
Authors: Mao Yijin , Zhang Yuwen , Chen C. L.
Published: March 2015

A simulation work aiming to study heat transfer coefficient between argon fluid flow and copper plate is carried out based on atomistic-continuum hybrid method. Navier–Stokes equations for continuum domain are solved through the pressure implicit with splitting of operators (PISO) algorithm, and the atom evolution in molecular domain is solved through the Verlet algorithm. The solver is validated by solving Couette flow and heat conduction problems. With both momentum and energy coupling method applied, simulations on convection of argon flows between two parallel plates are performed. The top plate is kept as a constant velocity and has higher temperature, while the lower one, which is modeled with FCC copper lattices, is also fixed but has lower temperature. It is found that the heat transfer between argon fluid flow and copper plate in this situation is much higher than that at macroscopic when the flow is fully developed.
Numerical Model of Thermoelectric Topping Cycle of Coal-Fired Power Plant
Authors: Silaen Armin K. , Wu Bin , Zhou Chenn , Yazawa Kazuaki , Shakouri Ali
Published: March 2015

Traditional fossil fuel power generation process typically has low efficiency. Large amount of the energy loss in Rankine cycle steam turbines (ST) is due to the temperature difference between the combustion flame temperature ∼2250 K (adiabatic) and the high pressure steam temperature up to 900 K. However, some of this energy can be harvested using solid-state thermoelectric (TE) power generators which are placed into the gap between the flame temperature and the steam temperature that produce additional electrical power. This study investigates the potential placement of TE on water tube wall inside a boiler at a coal-fired power plant. Three-dimensional (3D) numerical model of a simplified TE module is developed, and hot gas temperature and steam temperature from the boiler are used as boundary conditions at the hot side and cold side of the TE. The numerical results are compared with analytical calculations. The 3D effects of the thermal spreading in the TE module are investigated. Parameters such as TE leg cross section area and TE fill factor are examined in order to maximize the electrical power production of the TE without sacrificing the boiler efficiency (i.e., reducing the steam temperature). The study also looks into the various locations inside the boiler that have good potential for TE installation.
Ultrasonic Effect on Heat Transfer Performance of Oscillating Heat Pipes
Authors: Zhao Nannan , Fu Benwei , Ma Hongbin , Su Fengmin
Published: March 2015

The ultrasonic effect on the heat transfer performance in oscillating heat pipes (OHPs) was investigated experimentally. Ultrasonic sound was applied to the evaporating section of the OHP by using electrically controlled piezoelectric ceramics. The heat pipes were tested with or without the ultrasonic effect. The effects of heat input, filling ratio, orientation, operating temperature, and working fluids (water and acetone) were investigated. The experimental results showed that ultrasonic sound can affect the oscillating motions and enhance the heat transfer performance of an OHP. However, the heat transfer enhancement mainly occurs at low heat input. In addition, it was found that heat transfer enhancement of the ultrasonic effect depends on the working fluid and operating temperature. At an operating temperature of 20 °C, the enhancement percentage of the water OHP is higher than acetone OHP. However, when the operating temperature was increased to 40 °C, the enhancement percentage of the water OHP was lower than the acetone OHP.
Theoretical Analysis and Testing of Nanofluids-Based Solar Photovoltaic/Thermal Hybrid Collector
Authors: Saroha Siddharth , Mittal Tarun , Modi Poojan J. , Bhalla Vishal , Khullar Vikrant , Tyagi Himanshu , Taylor Robert A. , Otanicar Todd P.
Published: March 2015

Solar energy can be harvested via thermal, photovoltaic, and photovoltaic/thermal (PV/T) hybrid technologies. PV/T systems are advantageous because they utilize more of the solar spectrum and achieve a higher combined efficiency. One approach to PV/T design is to keep the operating temperature of the PV low while achieving a high temperature for the thermal absorber. Various designs of PV/T hybrids (both flat plate and concentrated) have already been proposed which utilize air or water to remove the heat from PV cells in order to enhance the overall efficiency of PV/T hybrid collector. We propose that a nanofluid can be used instead, doubling as both the heat transfer medium and an optical filter, which allows for thermal isolation of the PV and thermal receiver. Thus, unwanted IR and UV light is filtered before it hits the PV cells, which allows for higher overall efficiencies. In this study, a new design of a PV/T hybrid collector was proposed and two nanofluid filters (based on gold and silver nanoparticles) were tested with a silicon (Si) PV cell. The corresponding stagnation temperatures of PV/T hybrid collector were measured and compared with a theoretical model. The experimental measurements validate the theoretical model, giving similar results over the range of parameters tested. The silver nanofluid design achieved the highest thermal, PV and overall efficiency and both nanofluid configurations out-performed an analogous surface absorber PV/T design under similar conditions. Overall, this study shows that nanofluids represent a feasible and viable multifunctional (optical filter and heat transfer) media in PV/T solar systems.
A Numerical Study of Droplet Splitting and Merging in a Parallel-Plate Electrowetting-on-Dielectric Device
Authors: Guan Yin , Tong Albert Y.
Published: March 2015

Microwater droplet splitting and merging in a parallel-plate electrowetting-on-dielectric (EWOD) device have been studied numerically. The transient governing equations for the microfluidic flow are solved by a finite volume scheme with a two-step projection method on a fixed computational domain. The interface between liquid and gas is tracked by a coupled level set (LS) and volume-of-fluid (CLSVOF) method. A continuum surface force (CSF) model is employed to model the surface tension at the interface. Contact angle hysteresis which is an essential component in EWOD modeling is implemented together with a simplified model for the viscous stresses exerted by the two plates at the solid–liquid interface. The results of the numerical model have been validated with published experimental data and the physics of droplet motion within the EWOD device has been examined. A parametric study has been performed in which the effects of channel height and several other parameters on the fluid motion have been studied.
Quantifying the Growth Rate and Morphology of Ice Crystals Growth in Cryoprotectants Via High-Speed Camera and Cryomicroscope
Authors: Xue Xu , Jin Hai-Lan , He Zhi-Zhu , Liu Jing
Published: March 2015

Recently, several significant progresses have been made on the studies of extracellular and intracellular ice formation based on high-speed camera and cryomicroscope. This experimental methodology could accurately capture the rapid formation process of ice crystals at microscale. However, quantitative interpretation on such phase change behavior still reserved a tough issue. Here, in this paper, we quantitatively studied the ice crystals growth in three kinds of cryoprotectants like dimethyl sulfoxide (DMSO), sucrose, and trehalose via high-speed camera, cryomicroscope as well as the proposed data processing method. Several critical impact factors such as the concentration of cryoprotectants and the cooling rate have been investigated. Particularly, an efficient image processing technology has been developed to quantify the growth rate and morphology of the ice crystals. The results indicate that the species and concentration of cryoprotectants and the cooling rate could significantly affect the growth rate and morphology of ice crystals. DMSO is better than trehalose and sucrose as cryoprotectant because of the molecular structure. This work established a new methodology to quantify the ice crystals growth and would enhance current understanding of the factors for ice crystals formation. It is also expected to help optimize the cryopreservation process in the near future.
Thermal Radiative Properties of a Two-Dimensional Silicon Carbide Grating Mediated With a Photonic Crystal
Authors: Wang Weijie , Zhao Yi , Tan Wenchang , Fu Ceji
Published: March 2015

We present in this paper numerical simulation results of the thermal radiative properties of a two-dimensional (2D) rectangular SiC grating atop a photonic crystal (PC). The results show that surface phonon polaritons (SPhPs) can be excited by both TE and TM waves when they are scattered by the 2D grating. Excitation of SPhPs, PC modes, and magnetic polaritons (MPs), and interactions between them give rise to great enhancement of the emissivity. Distinct effects of the grating geometry on the resonance of SPhPs, PC modes, and MPs were revealed, which suggest a way to effectively manipulate the emissivity by tuning the structure's geometry. Furthermore, the results indicate that quasi-diffuse emissivity of the structure can be obtained for both TE and TM waves.
Thermal Effect on Microchannel Electro-osmotic Flow With Consideration of Thermodiffusion
Authors: Zhou Yi , Xie Yongqi , Yang Chun , Cheong Lam Yee
Published: March 2015

Electro-osmotic flow (EOF) is widely used in microfluidic systems. Here, we report an analysis of the thermal effect on EOF under an imposed temperature difference. Our model not only considers the temperature-dependent thermophysical and electrical properties but also includes ion thermodiffusion. The inclusion of ion thermodiffusion affects ionic distribution, local electrical potential, as well as free charge density, and thus has effect on EOF. In particular, we formulate an analytical model for the thermal effect on a steady, fully developed EOF in slit microchannel. Using the regular perturbation method, we solve the model analytically to allow for decoupling several physical mechanisms contributing to the thermal effect on EOF. The parametric studies show that the presence of imposed temperature difference/gradient causes a deviation of the ionic concentration, electrical potential, and electro-osmotic velocity profiles from their isothermal counterparts, thereby giving rise to faster EOF. It is the thermodiffusion induced free charge density that plays a key role in the thermodiffusion induced electro-osmotic velocity.
Performance Evaluation of Heat Transfer Enhancement for Offset Strip Fins Used in Plate-Fin Heat Exchangers
Authors: Yang Yujie , Li Yanzhong , Si Biao , Zheng Jieyu
Published: March 2015

In general, offset strip fin (OSF) used in plate-fin heat exchangers is able to provide a greater heat transfer coefficient than the plain fin with the same cross section, but it will also cause the increase of flow friction and pressure drop owing to the fin offset. A new parameter denoted by Ψ*, called relative entropy generation distribution factor, is proposed in this paper to comprehensively reflect the thermodynamic performance of different passage structures in plate-fin heat exchanger. This parameter physically represents relative changes of entropy generation and irreversibility, which are induced by both heat transfer and friction loss due to the utilization of OSF fins. The high magnitude of Ψ* represents a beneficial contribution of OSF with higher degree of the heat transfer enhancement. The proposed method is more reasonable and comprehensive than either the conventional augmentation entropy generation number, Ns,a, or the entropy generation distribution factor, ψ, to evaluate the heat transfer enhancement for OSF cores subject to various operating conditions. With the proposed method, the relative effects of the geometrical parameters of OSF fins, such as the fin thickness-to-height ratio α, fin density γ, and fin thickness-to-length ratio δ, on the heat transfer enhancement are discussed in detail. The results show that relatively small δ results in a better performance, while the parameter α or γ, which contribute to a higher degree of heat transfer enhancement of OSF fin, should be determined after the selection of the other two geometric parameters.