bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparisons of recursive partitioning analysis and conventional methods for selection of uncuffed endotracheal tubes for pediatric patients
Authors: Cho Ah Reum , Kim Eun Soo , Lee Do Won , Hong Jung Min , Kwon Jae Young , Kim Hae Kyu , Kim Tae Kyun
Published: February 2015

Background

Numerous studies have investigated the best method of selecting the appropriate size of endotracheal tube (ETT) for children. However, none of the methods or formulae for selection of ETT size have shown better prediction over another, and they have required complex formulae calculation or even use of cumbersome equipment. Recursive partitioning analysis creates a decision tree that is more likely to enable clearer and easier visualization of decision charts compared to other data mining methods.

Objectives

The aim of the current study was to develop a clinically practical and intuitive chart for prediction of ETT size.

Methods

Pediatric patients aged 2–9 years undergoing general anesthesia were intubated with uncuffed ETT. The tube size was considered optimal when a tracheal leak was detected at an inflation pressure between 10 and 25 cmH2O. The observed ETT size was compared with the predicted ETT size calculated using Cole's formula, multivariate regression analysis, ultrasonographic measurements, and recursive partitioning tree structure analysis. Preference among the prediction methods was also investigated by asking physicians about their preference of methods.

Results

Correct prediction rates were 33.3%, 50%, 61.9%, and 59.5%, and close prediction rates were 61.9%, 83.3%, 88.1%, and 93.7% for Cole's formulae, multivariate regression analysis, ultrasonographic measurements, and recursive partitioning tree model, respectively. Fourteen of 16 physicians prefer to use the easy‐to‐interpret tree model.

Conclusions

Analysis of the tree model by recursive partitioning structure analysis accomplished a high correct and close prediction rate for selection of an appropriate ETT size. The intuitive and easy‐to‐interpret tree model would be a quick and helpful tool for selection of an ETT tube for pediatric patients.
Functional analyses of cellulose synthase genes in flax (Linum usitatissimum) by virus‐induced gene silencing
Authors: Chantreau Maxime , Chabbert Brigitte , Billiard Sylvain , Hawkins Simon , Neutelings Godfrey
Published: February 2015

Flax (Linum usitatissimum) bast fibres are located in the stem cortex where they play an important role in mechanical support. They contain high amounts of cellulose and so are used for linen textiles and in the composite industry. In this study, we screened the annotated flax genome and identified 14 distinct cellulose synthase (CESA) genes using orthologous sequences previously identified. Transcriptomics of ‘primary cell wall’ and ‘secondary cell wall’ flax CESA genes showed that some were preferentially expressed in different organs and stem tissues providing clues as to their biological role(s) in planta. The development for the first time in flax of a virus‐induced gene silencing (VIGS) approach was used to functionally evaluate the biological role of different CESA genes in stem tissues. Quantification of transcript accumulation showed that in many cases, silencing not only affected targeted CESA clades, but also had an impact on other CESA genes. Whatever the targeted clade, inactivation by VIGS affected plant growth. In contrast, only clade 1‐ and clade 6‐targeted plants showed modifications in outer‐stem tissue organization and secondary cell wall formation. In these plants, bast fibre number and structure were severely impacted, suggesting that the targeted genes may play an important role in the establishment of the fibre cell wall. Our results provide new fundamental information about cellulose biosynthesis in flax that should facilitate future plant improvement/engineering.
Electron Spin Exchange in Linked Phenothiazine–Viologen Charge Transfer Complexes Incorporated in “Through‐Ring” (Rotaxane) α‐Cyclodextrins
Authors: Yonemura Hiroaki , Forbes Malcolm D. E.
Published: February 2015

A series of covalently bound phenothiazine (PHZ) donor and methylviologen (V) acceptor compounds with polymethylene chain spacers (C8, C10, C12) were incorporated in a “through‐ring” (rotaxane) fashion to α‐cyclodextrin (α‐CD) hosts such that the alkyl chains were fully extended, with the donor and acceptor on opposite sides of the α‐CD cylinder. Photoexcitation of the PHZ unit induces electron transfer from the PHZ first excited triplet state to the V moiety, forming a biradicaloid charge‐separated state. Time‐resolved electron paramagnetic resonance (TREPR) spectroscopy at the X‐band and Q‐band microwave frequencies was used to investigate the spin exchange interaction, J, in these biradicaloids. Simulation of the spectra using a “static” model for spin‐correlated radical pairs allows extraction of the J values, which are negative in sign and have absolute values range from 2 to 1000 Gauss. Comparison of the PHZnV (n = 8, 10, 12) spectra to those obtained using phenyl ether spacers indicates that π‐bonds may assist the electronic coupling. The results are discussed in terms of through‐bond vs through‐space electronic coupling mechanisms.
Immunology in wild nonmodel rodents: an ecological context for studies of health and disease
Authors: Jackson J. A.
Published: February 2015

Transcriptomic methods are set to revolutionize the study of the immune system in naturally occurring nonmodel organisms. With this in mind, the present article focuses on ways in which the use of ‘nonmodel’ rodents (not the familiar laboratory species) can advance studies into the classical, but ever relevant, epidemiologic triad of immune defence, infectious disease and environment. For example, naturally occurring rodents are an interesting system in which to study the environmental stimuli that drive the development and homeostasis of the immune system and, by extension, to identify where these stimuli are altered in anthropogenic environments leading to the formation of immunopathological phenotypes. Measurement of immune expression may help define individual heterogeneity in infectious disease susceptibility and transmission and facilitate our understanding of infection dynamics and risk in the natural environment; furthermore, it may provide a means of surveillance that can filter individuals carrying previously unknown acute infections of potential ecological or zoonotic importance. Finally, the study of immunology in wild animals may reveal interactions within the immune system and between immunity and other organismal traits that are not observable under restricted laboratory conditions. Potentiating much of this is the possibility of combining gene expression profiles with analytical tools derived from ecology and systems biology to reverse engineer interaction networks between immune responses, other organismal traits and the environment (including symbiont exposures), revealing regulatory architecture. Such holistic studies promise to link ecology, epidemiology and immunology in natural systems in a unified approach that can illuminate important problems relevant to human health and animal welfare and production.
The Wrong Solution at the Right Time: The Failure of the Kyoto Protocol on Climate Change
Authors: Rosen Amanda M.
Published: February 2015

This article argues that the Kyoto Protocol on climate change is a fundamentally flawed agreement that set back solutions on climate change by two decades. Using a systematic framework focused on compliance, efficiency, and effectiveness, I analyze the Kyoto Protocol and argue it is a clear case of institutional failure, with the design itself bearing substantial blame for this outcome. The study points to how particular features of the Protocol—its short time frame for action, binding targets, emission reduction measures, and provision for future commitment periods—have resulted in short‐sighted behavior by member states and path‐dependent structures that failed to make a substantial impact on the climate problem.

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Pre‐ and Post‐Welfare Reform Media Portrayals of Poverty in the United States: The Continuing Importance of Race and Ethnicity
Authors: van Doorn Bas W.
Published: February 2015

This article analyzes racial and ethnic patterns in media coverage of poverty in the United States, with a particular focus on depictions of African Americans and Hispanics. A content analysis of photos accompanying poverty‐related stories published in Time, Newsweek, and U.S. News & World Report from 1992 to 2010 shows that while Hispanics are underrepresented in media portrayals of the poor, African Americans are overrepresented, especially alongside stories on welfare, in times of economic growth and low unemployment, and in coverage unsympathetic to the poor more generally. I conclude that media coverage of poverty is unrepresentative in a manner consistent with stereotypes concerning African Americans and Hispanics, likely contributing to the endurance of such stereotypes and explaining the fact that welfare is as unpopular after welfare reform as it was prior to reform.

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Gainous, Jason,
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State Regulation of Religion and the Quality of Governance
Authors: Tusalem Rollin F.
Published: February 2015

The effect of state regulation of religion on governance has been explored theoretically by scholars, but it has not been tested empirically across nation states. The theory posits that secular states are more likely to benefit from better governance because of the absence of clerical involvement in politics, paving the way for the expansion of civil society and the passage of progressive political, economic, and social reforms. Using a unique dataset of more than 100 nation states, I find that countries with higher levels of state intervention on religion are more likely to suffer from inferior governance as reflected by higher levels of corruption and political instability and lower levels of rule of law entrenchment, bureaucratic effectiveness, and regulatory quality. Furthermore, states wherein there is no distinct separation between church and state are more likely to have lower levels of political openness and accountability.

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The Formation of Left‐Right Identification: Pathways and Correlates of Parental Influence
Authors: Rico Guillem , Jennings M. Kent
Published: February 2015

Given the significance of the left‐right dimension as one of the most frequently employed capping term of ideological thought in most western democracies, the question arises as to how people come to identify themselves along this continuum. Drawing on a set of parent‐child pairs located in Catalonia, we seek to determine whether the processes found elsewhere with respect to the intergenerational transmission of partisanship and issue stances also apply to left‐right ideology, in a novel context characterized by the presence of a distinctive, partially cross‐cutting dimension based on center‐periphery loyalties. Results provide strong support for the principles of the direct transmission model as derived from social learning theory, while also showing the significant role of parents' place identities in conditioning the passing on of left‐right orientations.
Undiagnosed Metabolic Dysfunction and Sudden Infant Death Syndrome – A Case‐Control Study
Authors: Rosenthal Ning An , Currier Robert J. , Baer Rebecca J. , Feuchtbaum Lisa , Jelliffe‐Pawlowski Laura L.
Published: February 2015

Background

Decades of research has yielded few clues about causes of sudden infant death syndrome (SIDS). While some studies have shown a link to inborn errors of metabolism (IEMs), few have examined the link in a large population‐based sample. This population‐based case–control study assessed the association between undiagnosed IEMs and SIDS.

Methods

Children born in California during 2005–08 who died from SIDS were obtained from death records and linked to the newborn screening, birth certificate, and hospital discharge databases. Individuals with known chromosomal and neural tube defects, genetic disorders, and non‐singleton births were excluded. Five controls were matched to each case on tandem mass spectrometry testing date and lab code. Rates of undiagnosed IEMs were compared between cases and controls using conditional logistic regression adjusting for known confounding factors.

Results

After adjusting for known confounding factors, SIDS cases had similar risk of having IEMs as controls (adjusted hazard ratio [HR] 1.3, 95% confidence interval [CI] 0.3, 5.5). Infants who were male, Black, and born preterm had higher risk of SIDS with the highest risk observed for those born preterm [adjusted HR = 1.7, 95% CI 1.3, 2.2]. Younger maternal age at delivery, mother being born in the US, parity after current birth >3, and delayed prenatal care were also significantly associated with higher risk of SIDS.

Conclusions

While many maternal and infant factors are associated with an increased risk of SIDS, there is no evidence that undiagnosed IEMs are associated with increased risk.
Amygdala response to anticipation of dyspnea is modulated by 5‐HTTLPR genotype
Authors: Stoeckel M. Cornelia , Esser Roland W. , Gamer Matthias , Kalisch Raffael , Büchel Christian , von Leupoldt Andreas
Published: February 2015

Dyspnea anticipation and perception varies largely between individuals. To investigate whether genetic factors related to negative affect such as the 5‐HTTLPR polymorphism impact this variability, we investigated healthy, 5‐HTTLPR stratified volunteers using resistive load induced dyspnea together with fMRI. Alternating blocks of severe and mild dyspnea (“perception”) were differentially cued (“anticipation”) and followed by intensity and unpleasantness ratings. In addition, volunteers indicated their anticipatory fear during the anticipation periods. There were no genotype‐based group differences concerning dyspnea intensity and unpleasantness or brain activation during perception of severe vs. mild dyspnea. However, in risk allele carriers, higher anticipatory fear was paralleled by stronger amygdala activation during anticipation of severe vs. mild dyspnea. These results suggest a role of the 5‐HTTLPR genotype in fearful dyspnea anticipation.
Role of Embryonic and Maternal Genotype on Prenatal Survival and Foetal Growth in Rabbit
Authors: Naturil‐Alfonso C , Marco‐Jiménez F , Jiménez‐Trigos E , Saenz‐de‐Juano MD , Viudes‐de‐Castro MP , Lavara R , Vicente JS
Published: February 2015

Contents

The aim of this work was to evaluate the influence of maternal and embryonic genotype on prenatal survival and foetal growth during pregnancy. Embryos were recovered at 48 h of gestation from two different donor lines (R = 46 and A = 40) and transferred to nulliparous recipient does (26 R and 24 A). Each recipient doe received six embryos into one oviduct from line R, and six embryos form line A into the other. Laparoscopy was performed at Day 14 to determine implantation rate. Recipient females were slaughter at Days 14, 24 and 30 (12, 24, and 14, respectively) to determine the number of live foetuses and the weight of live foetuses, foetal placenta and maternal placenta. A transcriptome analysis was performed to search for differences between foetal placentas at Days 14 and 24 of development. Prenatal survival at Days 14, and 24 was affected by embryonic genotype and determined by maternal genotype at Day 30. Foetal weight at Day 14 was influenced by both genotypes, being the weight higher for group A/A (0.29 ± 0.01 g vs 0.19 ± 0.01 g, for group R/R). However, both genotypes were determinant for foetal placenta weight at Day 24, while those genotypes affected maternal placenta weight at Day 30. Nevertheless, no differences in foetal placenta at transcriptome level and progesterone and IGF‐I plasma levels in recipient does were found. In conclusion, results indicate that the influence of embryo and maternal genotype on the prenatal survival and growth seems to be changing over gestation.
Vocalizations During Electroejaculation in Anaesthetized Adult and Young Pampas Deer (Ozotoceros bezoarticus) Males
Authors: Fumagalli F , Damián JP , Ungerfeld R
Published: February 2015

Contents

The aim of this study was to characterize the vocalizations produced during electroejaculation under general anaesthesia in pampas deer males and to determine whether the characteristics of those vocalizations differ in adult and young pampas deer males. Electroejaculation was applied to 13 adults (AM) and 13 young (YM) males under general anaesthesia. Vocalizations were digitally recorded, and the number and duration of vocalizations, the latency in relation to each voltage, the total time vocalizing, and the structure of the fundamental frequency (F0) [initial frequency (Fstart), maximal frequency (Fmax), minimal frequency (Fmin) and final frequency (Fend)] were analysed. No male vocalized with 0 V; the number of animals that vocalized increased at 2 and 3 V and increased again at 4, 5 and 6 V (p < 0.05). The latency time from the beginning of each series (each voltage) decreased until 4 V (p < 0.01). The number of vocalizations/voltage increased from 4 V (p < 0.05). The length of each vocalization and the total time during which animals vocalized were greater in YM than AM (p = 0.02 and p = 0.01, respectively). Similarly, the fundamental frequencies were higher in YM than AM (p ≤ 0.05). Overall, we concluded that the vocalizations emitted during electroejaculation in pampas deer under general anaesthesia are related to the voltage applied during the process. Young males vocalize more time, probably due to a greater sensibility to the electric stimulation. The differences in the characteristics of the vocalizations between adult and young males may be related to the anatomic differences in the neck of adult or young males.
Resolving the value of the dingo in ecological restoration
Authors: Newsome Thomas M. , Ballard Guy‐Anthony , Crowther Mathew S. , Dellinger Justin A. , Fleming Peter J. S. , Glen Alistair S. , Greenville Aaron C. , Johnson Chris N. , Letnic Mike , Moseby Katherine E. , Nimmo Dale G. , Nelson Michael Paul , Read John L. , Ripple William J. , Ritchie Euan G. , Shores Carolyn R. , Wallach Arian D. , Wirsing Aaron J. , Dickman Christopher R.
Published: February 2015

There is global interest in restoring populations of apex predators, both to conserve them and to harness their ecological services. In Australia, reintroduction of dingoes (Canis dingo) has been proposed to help restore degraded rangelands. This proposal is based on theories and the results of studies suggesting that dingoes can suppress populations of prey (especially medium‐ and large‐sized herbivores) and invasive predators such as red foxes (Vulpes vulpes) and feral cats (Felis catus) that prey on threatened native species. However, the idea of dingo reintroduction has met opposition, especially from scientists who query the dingo's positive effects for some species or in some environments. Here, we ask ‘what is a feasible experimental design for assessing the role of dingoes in ecological restoration?’ We outline and propose a dingo reintroduction experiment—one that draws upon the existing dingo‐proof fence—and identify an area suitable for this (Sturt National Park, western New South Wales). Although challenging, this initiative would test whether dingoes can help restore Australia's rangeland biodiversity, and potentially provide proof‐of‐concept for apex predator reintroductions globally.
Lasso Regression: Estimation and Shrinkage via the Limit of Gibbs Sampling
Authors: Rajaratnam Bala , Roberts Steven , Sparks Doug , Dalal Onkar
Published: February 2015

The application of the lasso is espoused in high dimensional settings where only a small number of the regression coefficients are believed to be non-zero (i.e. the solution is sparse). Moreover, statistical properties of high dimensional lasso estimators are often proved under the assumption that the correlation between the predictors is bounded. In this vein, co-ordinatewise methods, which are the most common means of computing the lasso solution, naturally work well in the presence of low-to-moderate multicollinearity. The computational speed of co-ordinatewise algorithms, although excellent for sparse and low-to-moderate multicollinearity settings, degrades as sparsity decreases and multicollinearity increases. Though lack of sparsity and high multicollinearity can be quite common in contemporary applications, model selection is still a necessity in such settings. Motivated by the limitations of co-ordinatewise algorithms in such ‘non-sparse’ and ‘high multicollinearity’ settings, we propose the novel ‘deterministic Bayesian lasso’ algorithm for computing the lasso solution. This algorithm is developed by considering a limiting version of the Bayesian lasso. In contrast with co-ordinatewise algorithms, the performance of the deterministic Bayesian lasso improves as sparsity decreases and multicollinearity increases. Importantly, in non-sparse and high multicollinearity settings the algorithm proposed can offer substantial increases in computational speed over co-ordinatewise algorithms. A rigorous theoretical analysis demonstrates that the deterministic Bayesian lasso algorithm converges to the lasso solution and it leads to a representation of the lasso estimator which shows how it achieves both l1- and l2-types of shrinkage simultaneously. Connections between the deterministic Bayesian lasso and other algorithms are also provided. The benefits of the deterministic Bayesian lasso algorithm are then illustrated on simulated and real data.
Semiparametric Estimation in the Secondary Analysis of Case–Control Studies
Authors: Ma Yanyuan , Carroll Raymond J.
Published: February 2015

We study the regression relationship between covariates in case–control data: an area known as the secondary analysis of case–control studies. The context is such that only the form of the regression mean is specified, so that we allow an arbitrary regression error distribution, which can depend on the covariates and thus can be heteroscedastic. Under mild regularity conditions we establish the theoretical identifiability of such models. Previous work in this context has either specified a fully parametric distribution for the regression errors, specified a homoscedastic distribution for the regression errors, has specified the rate of disease in the population (we refer to this as the true population) or has made a rare disease approximation. We construct a class of semiparametric estimation procedures that rely on none of these. The estimators differ from the usual semiparametric estimators in that they draw conclusions about the true population, while technically operating in a hypothetical superpopulation. We also construct estimators with a unique feature, in that they are robust against the misspecification of the regression error distribution in terms of variance structure, whereas all other non-parametric effects are estimated despite the biased samples. We establish the asymptotic properties of the estimators and illustrate their finite sample performance through simulation studies, as well as through an empirical example on the relationship between red meat consumption and hetero-cyclic amines. Our analysis verified the positive relationship between red meat consumption and two forms of hetro-cyclic amines, indicating that increased red meat consumption leads to increased levels of MeIQx and PhIP, both being risk factors for colorectal cancer. Computer software as well as data to illustrate the methodology are available from http://www.stat.tamu.edu/~carroll/matlab__programs/software.php .
The Lasso for High Dimensional Regression with a Possible Change Point
Authors: Lee Sokbae , Seo Myung Hwan , Shin Youngki
Published: February 2015

We consider a high dimensional regression model with a possible change point due to a covariate threshold and develop the lasso estimator of regression coefficients as well as the threshold parameter. Our lasso estimator not only selects covariates but also selects a model between linear and threshold regression models. Under a sparsity assumption, we derive non-asymptotic oracle inequalities for both the prediction risk and the l1-estimation loss for regression coefficients. Since the lasso estimator selects variables simultaneously, we show that oracle inequalities can be established without pretesting the existence of the threshold effect. Furthermore, we establish conditions under which the estimation error of the unknown threshold parameter can be bounded by a factor that is nearly n−1 even when the number of regressors can be much larger than the sample size n. We illustrate the usefulness of our proposed estimation method via Monte Carlo simulations and an application to real data.
Methodology for Non-Parametric Deconvolution When the Error Distribution is Unknown
Authors: Delaigle Aurore , Hall Peter
Published: February 2015

In the non-parametric deconvolution problem, to estimate consistently a density or distribution from a sample of data contaminated by additive random noise, it is often assumed that the noise distribution is completely known or that an additional sample of replicated or validation data is available. Methods also have been suggested for estimating the scale of the error distribution, but they require somewhat restrictive smoothness assumptions on the signal distribution, which can be difficult to verify in practice. We take a completely new approach to the problem, not requiring extra data of any type. We argue that data rarely come from a simple regular distribution, and that this can be exploited to estimate the signal distributions by using a simple procedure. Our method can be extended to other problems involving errors in variables, such as non-parametric regression estimation. Its performance in practice is remarkably good, often equalling (even unexpectedly) the performance of techniques that use additional data to estimate the unknown error distribution.
Non-Parametric Estimation of Finite Mixtures from Repeated Measurements
Authors: Bonhomme Stéphane , Jochmans Koen , Robin Jean-Marc
Published: February 2015

This paper provides methods to estimate finite mixtures from data with repeated measurements non-parametrically. We present a constructive identification argument and use it to develop simple two-step estimators of the component distributions and all their functionals. We discuss a computationally efficient method for estimation and derive asymptotic theory. Simulation experiments suggest that our theory provides confidence intervals with good coverage in small samples.
Recurrent spring‐fed rivers in a Middle to Late Pleistocene semi‐arid grassland: Implications for environments of early humans in the Lake Victoria Basin, Kenya
Authors: Beverly Emily J. , Driese Steven G. , Peppe Daniel J. , Johnson Cara R. , Michel Lauren A. , Faith J. Tyler , Tryon Christian A. , Sharp Warren D.
Published: February 2015

The effect of changing palaeoclimate and palaeoenvironment on human evolution during the Pleistocene is debated, but hampered by few East African records directly associated with archaeological sites prior to the Last Glacial Maximum. Middle to Late Pleistocene deposits on the shoreline of eastern Lake Victoria preserve abundant vertebrate fossils and Middle Stone Age arte‐facts associated with riverine tufas at the base of the deposits, which are ideal for palaeoenvironmental reconstructions. New data from tufas identified on Rusinga Island and on the mainland near Karungu, Kenya are provided from outcrop, thin sections, mineralogical, stable isotopic and U‐series dating analyses. Tufa is identified in four sites: Nyamita (94·0 ± 3·3 and 111·4 ± 4·2 ka); Kisaaka, Aringo (455 ± 45 ka); and Obware. The age ranges of these tufa deposits demonstrate that spring‐fed rivers were a recurrent, variably preserved feature on the Pleistocene landscape for ca 360 kyr. Poor sorting of clastic facies from all sites indicates flashy, ephemeral discharge, but these facies are commonly associated with barrage tufas, paludal environments with δ13C values of ca 10‰ indicative of C3 plants and fossil Hippopotamus, all of which indicate a perennial water source. Other tufa deposits from Nyamita, Obware and Aringo have a mixed C3/C4 signature consistent with a semi‐arid C4 grassland surrounding these spring‐fed rivers. The δ18O values of tufa from Nyamita are on average ca 1‰ more negative than calcite precipitated from modern rainfall in the region, suggesting greater contribution of depleted monsoonal input, similar to the Last Glacial Maximum. Microdebitage and surface‐collected artefacts indicate that early modern humans were utilizing these spring‐fed rivers. The presence of spring−fed rivers would have afforded animals a reliable water source, sustaining a diverse plant and animal community in an otherwise arid environment.
High prevalence of common respiratory viruses and no evidence of Middle East Respiratory Syndrome Coronavirus in Hajj pilgrims returning to Ghana, 2013
Authors: Annan Augustina , Owusu Michael , Marfo Kwadwo Sarfo , Larbi Richard , Sarpong Francisca Naana , Adu‐Sarkodie Yaw , Amankwa Joseph , Fiafemetsi Samuel , Drosten Christian , Owusu‐Dabo Ellis , Eckerle Isabella
Published: February 2015

Objective

The Middle East respiratory syndrome coronavirus (MERS‐CoV) emerged in 2012 on the Arabian Peninsula and has caused severe respiratory disease with more than 800 laboratory‐confirmed cases. The return of infected pilgrims to their home countries with a putative spread of MERS‐CoV necessitates further surveillance.

Methods

A cross sectional study of 839 adult African Hajj pilgrims returning to Accra in Ghana, West Africa, was conducted in 2013 to assess the prevalence of respiratory symptoms as well as of MERS‐CoV, human rhinovirus (HRV), respiratory syncytial virus (RSV) and influenza A virus (FLU A) infection.

Results

Six hundred and fifty‐one (77.6%) pilgrims had respiratory symptoms. Tests were positive for at least one of the viruses other than MERS‐CoV in 179 (21.3%) of all pilgrims, with 22.4% detection in symptomatic vs. 17.6% detection in asymptomatic pilgrims. No MERS‐CoV was detected, although common respiratory viruses were prevalent, with positive findings for HRV in 141 individuals (16.8%), RSV in 43 individuals (5.1%) and FLU A in 11 individuals (1.3%). Results were positive for more than one virus in 16 (1.9%) individuals, including 14 (1.7%) RSV/HRV co‐infections and 2 (0.2%) FLU A/HRV co‐infections. A total 146 (22.4%) of the symptomatic returnees tested positive for at least one respiratory virus compared with 33 (17.6%) of the asymptomatic pilgrims who had at least one detectable virus in their sample.

Conclusions

The prevalence of viral respiratory infections among Hajj pilgrims in both symptomatic and asymptomatic subjects was high. Although it is reassuring that MERS‐CoV was not detected in the tested population, there is a need for active surveillance of Hajj pilgrims.
Tumourigenic canine osteosarcoma cell lines associated with frizzled‐6 up‐regulation and enhanced side population cell frequency
Authors: de Sá Rodrigues L. C. , Holmes K. E. , Thompson V. , Newton M. A. , Stein T. J.
Published: February 2015

An increased serum alkaline phosphatase concentration is known to be associated with a negative prognosis in canine and human osteosarcoma. To expand upon previous studies regarding the biological relevance of increased serum alkaline phosphatase as a negative prognostic factor, xenogeneic heterotopic transplants were performed using six canine primary osteosarcoma cell lines generated from patients with differing serum alkaline phosphatase concentrations (three normal and three increased). Three of the six cell lines were capable of generating tumours and tumour formation was independent of the serum alkaline phosphatase status of the cell line. Microarray analysis identified 379 genes as being differentially expressed between the tumourigenic and non‐tumourigenic cell lines. Frizzled‐6 was upregulated to the greatest extent (7.78‐fold) in tumourigenic cell lines compared with non‐tumourigenic cell lines. Frizzled‐6, a co‐receptor for Wnt ligands has been associated with enhanced tumour‐initiating cells and poor prognosis for other tumours. The increased expression of frizzled‐6 was confirmed by quantitative reverse transcription polymerase chain reaction (QPCR) and Western blot analysis. Additionally, the tumourigenic cell lines also had an increase in the percentage of side population cells compared with non‐tumourigenic cell lines (5.89% versus 1.58%, respectively). There were no differences in tumourigenicity, frizzled‐6 or percentage of side population cells noted between osteosarcoma cell lines generated from patients of differing serum alkaline phosphatase concentration. However, to our knowledge this is the first study to identified frizzled‐6 as a possible marker of osteosarcoma cell populations with enhanced tumourigenicity and side population cells. Future work will focus on defining the role of frizzled‐6 in osteosarcoma tumourigenesis and tumour‐initiating cells.
Handheld tympanometer measurements in conscious dogs for the evaluation of the middle ear and auditory tube
Authors: Strain George M. , Fernandes Asia J.
Published: February 2015

Background

Otitis externa is frequently accompanied by otitis media, yet it can be difficult to evaluate the tympanum, middle ear and auditory tube without the use of advanced radiographic imaging.

Hypothesis/Objectives

The objective was to develop techniques for tympanometry testing in conscious dogs and to present normative data for clinical use of this equipment to enable assessment of the tympanum, middle ear and auditory tube.

Animals

Sixteen hounds (14 female) from a school teaching colony.

Methods

Dogs were gently restrained in a standing position. After cleaning of the ear canal, a tympanometer probe tip extension was placed in the vertical canal and automated testing performed using a handheld device. Both ears were tested in all dogs.

Results

Acceptable recordings were obtained from both ears of 13 dogs, from one ear in each of two dogs and from neither ear of one dog, resulting in data from 28 of 32 (88%) ears. Otoscopic examination confirmed the absence of inflammation or any other obvious explanation for the noncompliant dogs. No significant differences were seen between ears for any measure. Normative data are reported for peak compliance, peak compliance pressure, gradient and ear canal volume.

Conclusions and clinical importance

Tympanograms can be recorded in conscious dogs to assist in the evaluation of the middle ear structures.
Riverine habitat specificity constrains dispersion in a Neotropical fish (Characidae) along Southern Brazilian drainages
Authors: Hirschmann Alice , Malabarba Luiz R. , Thomaz Andréa Tonolli , Fagundes Nelson J Rosa
Published: February 2015

Freshwater fishes often display a marked phylogeographic structure strongly associated with historical and ecological changes in the aquatic environment. Different ecological conditions in the same river drainage may act as permeable barriers to dispersion and gene flow. Previous studies recognized two discrete spatial components for the ichthyofauna in the freshwater coastal drainages of southern Brazil: the lowland fish fauna in the lagoons and the fish fauna of the rivers flowing in the valleys. In order to test if the coastal lagoons may limit the dispersion of a riverine species, we describe the phylogeographic structure among populations of Cyanocharax itaimbe, a species endemic to this region. We analysed 55 specimens characterized for two mitochondrial and one nuclear genes. Sequences were analysed using gene trees and species tree approaches, together with standard population genetics methods. Molecular analyses indicated three evolutionary groups which diverged from each other between an estimated 1,600,000 and 450,000 years before the present. However, two currently isolated river systems share the same evolutionary clade, whereas a single drainage contains two different lineages. Our results indicate strong genetic structure among populations along with generally conserved morphology. The strong genetic structure among populations living in the same drainage system may be explained by ecological differences between lagoons and rivers (or palaeochannels) that act as barriers to dispersion.
Heat Transfer and Film Cooling Effectiveness in a Linear Airfoil Cascade
Authors: Abuaf N. , Bunker R. , Lee C. P.
Published: February 2015

A warm (315 C) wind tunnel test facility equipped with a linear cascade of film cooled vane airfoils was used in the simultaneous determination of the local gas side heat transfer coefficients and the adiabatic film cooling effectiveness. The test rig can be operated in either a steady-state or a transient mode. The steady-state operation provides adiabatic film cooling effectiveness values while the transient mode generates data for the determination of the local heat transfer coefficients from the temperature-time variations and of the film effectiveness from the steady wall temperatures within the same aero-thermal environment. The linear cascade consists of five airfoils. The 14% cascade inlet free stream turbulence intensity is generated by a perforated plate, positioned upstream of the airfoil leading edge. For the first transient tests, five cylinders having roughly the same blockage as the initial 20% axial chord of the airfoils were used. The cylinder stagnation point heat transfer coefficients compare well with values calculated from correlations. Static pressure distributions measured over an instrumented airfoil agree with inviscid predictions. Heat transfer coefficients and adiabatic film cooling effectiveness results were obtained with a smooth airfoil having three separate film injection locations, two along the suction side, and the third one covering the leading edge showerhead region. Near the film injection locations, the heat transfer coefficients increase with the blowing film. At the termination of the film cooled airfoil tests, the film holes were plugged and heat transfer tests were conducted with non-film cooled airfoils. These results agree with boundary layer code predictions.
Transient Liquid Crystal Technique for Convective Heat Transfer on Rough Surfaces
Authors: Barlow Douglas N. , Kim Yong W.
Published: February 2015

The local heat transfer coefficients are obtained on a rough planar surface simulating in-service turbine stator vane sections. A transient experimental technique is presented that permits the determination of local heat transfer coefficients for a rough planar surface using thermochromic liquid crystals. The technique involves the use of a composite test surface in the form of a thin foil of stainless steel with roughness elements laminated over a transparent substrate. Tests are conducted on a splitter plate to provide momentum boundary layer thicknesses to roughness heights appropriate for actual turbine stator vanes. Data are reported for two roughness geometries and two free stream velocities. The range of Reynolds numbers along with the ratio of average roughness value to momentum thickness matches conditions encountered on the pressure side of the first stage stator vanes in current high performance turbofan engines. A numerical simulation is conducted to validate the test method. Results for the investigated rough surfaces are compared with an available empirical relationship.
Total-Coverage Discrete Hole Wall Cooling
Authors: Cho Hyung Hee , Goldstein Richard J.
Published: February 2015

The present study investigates heat/mass transfer for flow through perforated plates for application to combustor wall and turbine blade film cooling. The experiments are conducted for hole length-to-diameter ratios of 0.68 to 1.5, for hole pitch-to-diameter ratios of 1.5 and 3.0, for gap distance between two parallel perforated plates of 0 to 3 hole diameters, and for Reynolds numbers of 60 to 13,700. Local heat/mass transfer coefficients near and inside the cooling holes are obtained using a naphthalene sublimation technique. Detailed knowledge of the local transfer coefficients is essential to analyze thermal stress in turbine components. The results indicate that the heat/mass transfer coefficients inside the hole surface vary significantly due to flow separation and reattachment. The transfer coefficient near the reattachment point is about four and half times that for a fully developed circular tube flow. The heat/mass transfer coefficient on the leeward surface has the same order as that on the windward surface because of a strong recirculation flow between neighboring jets from the array of holes. For flow through two in-line layers, the transfer coefficient affected by the gap spacing is approximately 100% higher on the windward surface of the second wall and is about 20% lower on the inside hole surface than that with a single layer. The transfer coefficient on the leeward surface is not affected by upstream flow conditions due to probably strong recirculation in the wake flow.
Turbulent Flow Heat Transfer and Friction in a Rectangular Channel With Varying Number of Ribbed Walls
Authors: Chandra Pankaj R. , Niland Michael E. , Han Je-Chin
Published: February 2015

An experimental study of wall heat transfer and friction characteristics of a fully-developed turbulent air flow in a rectangular channel with transverse ribs on one, two, and four walls is reported. Tests were performed for Reynolds numbers ranging from 10,000 to 80,000. The pitch-to-rib height ratio, P/e, was kept at 8 and rib height-to-channel hydraulic diameter ratio, e/Dh, was kept at 0.0625. The channel length-to-hydraulic diameter ratio, L/Dh, was 15.

The heat transfer coefficient and friction factor values were enhanced with the increase in the number of ribbed walls. The friction roughness function, R(e+), was almost constant over the entire range of tests performed and was within comparable limits of the previously published data. The heat transfer roughness function, G(e+), decreased with additional ribbed walls and compared well with previous work in this area. Friction data obtained experimentally for the case with four ribbed walls compared well with the values predicted by the assumed theoretical relationship used in the present study and past publications. Results of this investigation could be used in various applications of internal channel turbulent flows involving different number of roughened walls.
Pressure Gradient Effects on Film Cooling
Authors: Schmidt Donald L. , Bogard David G.
Published: February 2015

Film cooling effectiveness was studied experimentally using a flat plate test facility with a single row of inclined round holes which injected high density, cryogenically cooled air. A pressure distribution representative of the suction side of a gas turbine blade was imposed on the test plate using a top wall contour. Values of the acceleration parameter ranged from K = 1.5 × 10−6 at the injection location to K = −0.5 × 10−6 at 50 D downstream. Effectiveness results were compared with previously reported zero pressure gradient results obtained in the same facility. Experiments were performed at a density ratio of DR = 1.6 with a range of blowing ratios from M = 0.4 to 1.5 and momentum flux ratios from I = 0.10 to 1.4. Lateral distributions of adiabatic effectiveness results were determined at streamwise distances from 3 D to 15 D downstream of the injection holes. When the cooling jets did not completely detach, the application of the pressure gradient improved the lateral spread of the jets immediately downstream of the film cooling holes and increased the decay rate of the laterally averaged effectiveness. However, overall changes in effectiveness were small. When the cooling jets were completely detached (at I = 1.4, M = 1.5), the pressure gradient distribution had essentially no effect on the jet effectiveness.
Simulation of Film-Cooling Aerodynamics With a 2D Navier-Stokes Solver Using Unstructured Meshes
Authors: Irmisch Stefan
Published: February 2015

This paper describes the application of an unstructured mesh, solution-adaptive, 2D Navier-Stokes solver to the numerical simulation of the flow through film-cooled turbine cascades. The Navier-Stokes equations are solved using a cell-vertex explicit finite-volume method. Integration in time, to a steady-state solution, is performed by a five-stage Runge-Kutta algorithm. Turbulence effects are accounted for by a k-ε model.

The use of unstructured meshes, based on Delaunay triangulation, allows to mesh the entire flow domain, including internal coolant passages, without any geometrical limitations. In combination with a solution-dependent mesh-adaption technique, the strong interactions between coolant and outer flow, leading to complex flow features, can be simulated in a realistic and efficient way.

Solutions are presented for several test cases with and without film-cooling and are compared with experimental data, illustrating the capabilities of the presented flow solver.