bluuebunny/crossref_metadata_2025 huggingface dataset:
Presentation and outcomes in hypertrophic pyloric stenosis: An 11‐year review
Authors: Vinycomb Toby I , Laslett Kirby , Gwini Stella M , Teague Warwick , Nataraja Ramesh M
Published: January 2019

Aim

To evaluate the trend in presentation and postoperative outcomes of infants with hypertrophic pyloric stenosis (HPS) over the last decade.

Methods

This was a multicentre retrospective study in two tertiary paediatric centres between 2005 and 2015 inclusive. Participants included 626 infants who underwent a pyloromyotomy for HPS. We collected data on presentation features (age, weight, clinical signs, blood gas results, ultrasound findings) and postoperative outcomes (length of stay (LOS), complications, time to first postoperative feed).

Results

No trend was identified during the study period with regards to age, weight, biochemical findings (pH, chloride, base excess) or pre‐operative ultrasound measurements. There was a downtrend in the number of palpated tumours over time, with a mean of 36% of tumours clinically palpated. Pyloric wall thickness had a moderate association with LOS in patients admitted for >8 days (correlation = 0.4752) but had a weak negative association with shorter lengths of stay (≤8 day, correlation = −0.094). Overall, median time to first feed was 7.80 h and improved yearly during the study period (hazard ratio = 1.07).

Conclusions

Patients presenting with HPS are not being identified at an earlier age or with fewer biochemical derangements, in contrast to our initial perceptions. Subsequently, biochemical derangements can still play an important role in the diagnosis of HPS, and attention needs to be given to fluid management and electrolyte correction in all patients with HPS.
A randomized controlled trial of bedtime music for insomnia disorder
Authors: Jespersen Kira Vibe , Otto Marit , Kringelbach Morten , Van Someren Eus , Vuust Peter
Published: January 2019

Music is often used as a self‐help tool to alleviate insomnia. To evaluate the effect of bedtime music listening as a strategy for improving insomnia, we conducted an assessor‐blinded randomized controlled trial. Fifty‐seven persons with insomnia disorder were included and randomized to music intervention (n = 19), audiobook control (n = 19) or a waitlist control group (n = 19). The primary outcome measure was the Insomnia Severity Index. In addition, we used polysomnography and actigraphy to evaluate objective measures of sleep, and assessed sleep quality and quality of life. The results showed no clear effect of music on insomnia symptoms as the group × time interaction only approached significance (effect size = 0.71, p = .06), though there was a significant improvement in insomnia severity within the music group. With regard to the secondary outcomes, we found a significant effect of the music intervention on perceived sleep improvement and quality of life, but no changes in the objective measures of sleep. In conclusion, music listening at bedtime appears to have a positive impact on sleep perception and quality of life, but no clear effect on insomnia severity. Music is safe and easy to administer, but further research is needed to assess the effect of music on different insomnia subtypes, and as an adjunctive or preventive intervention.
Perspectives from the Edge: Chaplains in Greater Boston, 1945–2015
Authors: Cadge Wendy , Wang Katherine , Rowe Mary
Published: January 2019

We follow Bender et al.’s (Religion on the Edge: De‐Centering and Recentering the Sociology of Religion) call to study religion “on the edge” by looking at the work of chaplains, religious professionals who work outside of congregations. Rather than studying chaplains within a single type of institution—the military, healthcare, or other sectors—we shift the unit of analysis to geography, asking where chaplains in Greater Boston worked between 1945 and the present. Based on coverage in theBoston Globe, we find that chaplains, mostly men, worked across Greater Boston between 1945 and 2015. The majority were Catholic with frequent minorities of Protestants and Jews, and—after 1995—a few Buddhists, Muslims, and Humanists. Most worked in higher education, healthcare, and prisons. While much of the chaplains’ work seems improvisational and varied, we identify services related to ceremonies, bearing witness, and working around death as common occurrences across the venues where chaplains worked. To the extent that these patterns are evident in other cities, they suggest that chaplains have regularly been a quiet part of the religious landscape, that they are a consistent part of the institutional field, and that their work has more commonalities across sectors than previous studies suggest.
Spatial variability of microzooplankton in the central Arabian Sea during spring intermonsoon
Authors: Sai Elangovan S. , Gauns Manguesh , Begum Mulla Amara , Ahmed Ayaz
Published: January 2019

Spatial variability of microzooplankton (MZP; organisms in size 20–200 μm) along with total heterotrophic bacteria (THB) and picophytoplankton in the upper 120‐m water column of the central Arabian Sea (AS) was studied during the spring intermonsoon period (March 2015). Six stations divided into three regions (northern, southern, and central) were sampled along 68°E transect, between 9°N and 21°N. A total of 25 species of MZP were recorded corresponding to loricate ciliates (11 species), aloricate ciliates (two species), and heterotrophic dinoflagellates (12 species). Along the transect, MZP total abundance that varied between 5 and 9 × 103 org./m3 was largely contributed by ciliates, especially loricate ciliates (30%–62%) followed by heterotrophic dinoflagellates (23%–26%). MZP counts were lower in the central region (SD ± 0.4, 7–8 × 103 org./m3) than in the northern and the southern regions (SD ± 0.7, 8–9 × 103 org./m3) of the Arabian Sea. Heterotrophic bacterial counts were higher in the northern (28–202 × 103 cells/ml) and southern (16–92 × 103 cells/ml) and lowest in the central (13–89 × 103 cells/ml) region. In contrast, picophytoplankton showed higher counts in central (3–54 × 103 cells/ml) and southern (4–113 × 103 cells/ml) regions and lowest in the north (1–45 × 103 cells/ml). Strong positive coupling of MZP–THB (0.05 > p > 0.01) than that of MZP–picophytoplankton density and MZP–chlorophyll a concentration suggests the spatial scale variability and functioning of microbial loop in the central Arabian Sea during the spring intermonsoon period.
Workers' sons rescue genetic diversity at the sex locus in an invasive honey bee population
Authors: Gloag Rosalyn S. , Christie Joshua R. , Ding Guiling , Stephens Ruby E. , Buchmann Gabriele , Oldroyd Benjamin P.
Published: January 2019

The hallmark of eusociality is the division of labour between reproductive (queen) and nonreproductive (worker) females. Yet in many eusocial insects, workers retain the ability to produce haploid male offspring from unfertilized eggs. The reproductive potential of workers has well‐documented consequences for the structure and function of insect colonies, but its implications at the population level are less often considered. We show that worker reproduction in honey bees can have an important role in maintaining genetic diversity at the sex locus in invasive populations. The honey bee sex locus is homozygous‐lethal, and, all else being equal, a higher allele number in the population lead to higher mean brood survival. In an invasive population of the honey beeApis ceranain Australia, workers contribute significantly to male production: 38% of male‐producing colonies are queenless, and these contribute one‐third of all males at mating congregations. Using a model, we show that such male production by queenless workers will increase the number of sex alleles retained in nascent invasive populations following founder events, relative to a scenario in which only queens reproduce. We conclude that by rescuing sex locus diversity that would otherwise be lost, workers' sons help honey bee populations to minimize the negative effects of inbreeding after founder events and so contribute to their success as invaders.
Trainees’ perspectives of assessment messages: a narrative systematic review
Authors: Scarff Catherine E , Bearman Margaret , Chiavaroli Neville , Trumble Steve
Published: January 2019

Objectives

This study was designed as a narrative systematic literature review of medical specialist trainees’ perspectives of the assessment messages they receive in the context of clinical performance assessments. The aim of the study was to determine if trainees value the information they receive through the formats designed to promote their development and, if not, the reasons for this.

Methods

The authors searched the ERIC, EMBASE, Ovid MEDLINE and PsycINFO databases for articles published up to 16 June 2018 that present original data on trainees’ perspectives of the assessment messages they receive in the context of work‐based assessments (WBAs) and in‐training assessments (ITAs) used within their training programmes. All authors screened 938 abstracts and 139 full‐text articles were assessed after this. Descriptions of quantitative data and thematic analysis of qualitative data were used to present the opinions of trainees.

Results

Thirty‐three articles met the inclusion criteria. Twenty‐six articles (79%) described trainees’ perspectives in the context of WBA and the remaining articles referred to ITA formats. Wide‐ranging opinions were reported. The analysis categorised these into three themes: trainees value developmental assessment messages; trainees become disengaged when assessment messages are not developmental, and trainees’ views depend on the environment, the assessor and themselves. Some trainees reported that the assessment messages were valuable and provided input on their performance to guide their development, but many disagreed. In particular, the trainee's own level of engagement with the assessments influenced his or her perspectives on the messages received.

Conclusions

Trainees do not universally perceive that clinical performance assessments provide them with the valuable developmental input on their performance they were designed to do. Factors related to the environment, the assessor and themselves influence their perspectives.
Where philosophy meets culture: exploring how coaches conceptualise their roles
Authors: Watling Christopher J , LaDonna Kori A
Published: January 2019

Context

Although conceptually attractive, coaching in medicine remains ill‐defined, with little examination of the transferability of coaching principles from other fields. Here we explore how coaching is enacted both within and outside of medicine; we aim to understand both the elements required for coaching to be useful and the factors that may influence its translation to the medical education context.

Methods

In this constructivist grounded theory study, we interviewed 24 individuals across three groups: physicians who consider themselves coaches in clinical learning settings (n = 8), physicians with experience as sports, arts or business coaches (n = 10), and sports coaches without medical backgrounds (n = 6). Data collection and analysis were conducted iteratively using constant comparison to identify themes and explore their relationships.

Results

We identified a shared philosophy of coaching, comprising three core elements that our participants endorsed regardless of the coaching context: (i) mutual engagement, with a shared orientation towards growth and development; (ii) ongoing reflection involving both learners and coaches, and (iii) an embrace of failure as a catalyst for learning. Enacting these features appeared to be influenced by culture, which affected how coaching was defined and developed, how the coaching role was positioned within the learning context, and how comfortably vulnerability could be expressed. Participants struggled to clearly define the coaching role in medicine, instead acknowledging that the lines between educational roles were often blurred. Further, the embrace of failure appeared challenging in medicine, where showing vulnerability was perceived as difficult for both learners and teachers.

Conclusions

Medical education's embrace of coaching should be informed by an understanding of both coach and learner behaviours that need to be encouraged and trained, and the cultural and organisational supports that are required to foster success.
A systematic review and meta‐analysis of the effectiveness of meal replacements for weight loss
Authors: Astbury Nerys M. , Piernas Carmen , Hartmann‐Boyce Jamie , Lapworth Sophia , Aveyard Paul , Jebb Susan A.
Published: January 2019

Meal replacements (MR) are generally not recommended in clinical guidelines for the management of obesity. The aim of this review is to provide an up‐to‐date systematic evaluation of the effect of weight loss interventions incorporating MR compared with alternative interventions on weight change at 1 year in adults with overweight or obesity. Six electronic databases were searched from inception to the end of August 2018 for randomized controlled trials comparing the effect of MR with interventions that did not include MR on weight at 1 year. We excluded studies using diets providing <3347 kJ/(800 kcal)/day and those which used total diet replacement (TDR) from this review. Risk of bias was assessed using the Cochrane risk of bias tool. Twenty‐three studies with 7884 adult participants were included. Six out of 23 studies were judged at low risk of bias across all domains, and 5/23 studies were judged at high risk of bias in at least one domain. Studies with similar intervention and comparators were grouped into five comparisons for analysis. Mean weight change at 1 year favoured the MR group relative to the control group in each comparison. In those comparisons where we conducted meta‐analysis, in people assigned to a diet incorporating MR, mean difference was −1.44 kg (−2.48 to −0.39 kg; I2 = 38%) compared with alternative kinds of diets. In those assigned to a MR diet along with support, mean difference was −2.22 kg (−3.99 to −0.45, I2 = 81%) compared with other diets with support and −3.87 kg (−7.34 to −0.40; I2 = 60%) compared with other kinds of diet without support. In those assigned a MR diet with an enhanced level of support, mean difference was −6.13 kg (−7.35 to −4.91, I2 = 19%) compared with alternative diets and regular support. Programmes incorporating meal replacements led to greater weight loss at 1 year than comparator weight loss programmes and should be considered as a valid option for management of overweight and obesity in community and health care settings.
Streptococcus mutans serotypes and collagen‐binding proteins Cnm/Cbm in children with caries analysed by PCR
Authors: Momeni Stephanie S. , Ghazal Tariq , Grenett Hernan , Whiddon Jennifer , Moser Stephen A. , Childers Noel K.
Published: January 2019

Streptococcus mutans, a primary bacterium associated with dental caries, has four known clinical serotypes (c, e, fand k). Certain serotypes, the presence of multiple serotypes and strains with collagen‐binding proteins (CBP, Cnm and Cbm) have been linked with systemic disease. Evaluation of S mutans serotype distribution and caries association is needed in the United States. The purpose of this study was to evaluate the prevalence of S mutans serotypes from two cohorts of African‐American children in rural Alabama using three sample types (saliva, plaque and individual S mutans isolates) by PCR detection for association with caries. Detection of CBP was also performed by PCR. In total, 129 children were evaluated and overall prevalence of serotypes were: serotype c(98%), e(26%), f(7%) and k(52%). Serotype c was statistically associated with higher caries scores in older children (P < 0.001) and serotype k was statistically more likely in females (P = 0.004). Fourteen per cent of children had CBP. Thirteen S mutans isolates from five children tested positive for both CBP. This study is the first to report on the prevalence of S mutans serotypes in a US population using the PCR‐based approach. The frequency of serotype k in this study is the highest reported in any population, illustrating the need for further study to determine the prevalence of this clinically relevant serotype in the US. This is the first study to report S mutans isolates with both Cnm and Cbm in the same strain, and further analysis is needed to determine the clinical significance of these strains.
Pediatric living donor liver transplant in a recipient with biliary atresia and portal vein duplication—How did we manage it?
Authors: Gondolesi Gabriel E. , Bitetti Lisandro , Rumbo Carolina , Sueiras Ines , Lobos Fernando David , Lieber Gonzalo , Oxilia Héctor , Villavicencio Roberto , Costaguta Alejandro , Barros Schelotto Pablo
Published: January 2019

Portal vein malformations might occur during the embryonic period, as a consequence of abnormal remodeling of vitelline veins during embryonic life. Patients suffering from biliary atresia are particularly prone to have vascular malformations; although being the most frequent indication for liver transplantation in the pediatric age, portal vein duplication has not been so far associated with biliary atresia, and to the best of our knowledge, there is no‐written evidence describing how to manage it when it is first diagnosed while performing a pediatric liver transplant. Therefore, we present a recent case from our group, describing the intraoperative diagnosis of a double portal system in a patient with biliary atresia and failed Kasai. We aim to describe its surgical management, understanding that it is a real challenge to find them unexpectedly during the surgical procedure in the setting of cirrhosis and portal hypertension, particularly in small patients; therefore, by reporting this case, we aim to make readers aware about the chance of finding it, and how to managed it, to include this approach as part of the surgical armamentarium.
Isolation and characterization of CAC antenna proteins and photosystem I supercomplex from the cryptophytic alga Rhodomonas salina
Authors: Kuthanová Trsková Eliška , Bína David , Santabarbara Stefano , Sobotka Roman , Kaňa Radek , Belgio Erica
Published: January 2019

In the present paper, we report an improved method combining sucrose density gradient with ion‐exchange chromatography for the isolation of pure chlorophyll a/c antenna proteins from the model cryptophytic alga Rhodomonas salina. Antennas were used for in vitro quenching experiments in the absence of xanthophylls, showing that protein aggregation is a plausible mechanism behind non‐photochemical quenching in R. salina. From sucrose gradient, it was also possible to purify a functional photosystem I supercomplex, which was in turn characterized by steady‐state and time‐resolved fluorescence spectroscopy. R. salina photosystem I showed a remarkably fast photochemical trapping rate, similar to what recently reported for other red clade algae such as Chromera velia and Phaeodactylum tricornutum. The method reported therefore may also be suitable for other still partially unexplored algae, such as cryptophytes.
A single injection of corifollitropin alfa supplemented with human chorionic gonadotropin increases follicular recruitment and transferable embryos in the rabbit
Authors: Viudes‐de‐Castro María Pilar , Marco‐Jiménez Francisco , Más Pellicer Alba , García‐Domínguez Ximo , Talaván Amparo M. , Vicente Jose Salvador
Published: January 2019

Contents

Superovulation protocols are designed to achieve maximum embryo yields. Nevertheless, ovarian response control and the quality of obtained embryos are still a challenge. On the other hand, to save the superovulated embryos until their subsequent use, it is usual to cryopreserve them, so it is also crucial to assess their cryotolerance. The aim of this study was to compare the efficacy of a single injection of corifollitropin alfa (FSH‐CTP) alone or supplemented with human chorionic gonadotropin (hCG) and to determine the impact of this stimulation on in vitro and in vivo development of fresh or devitrified embryos. Our outcomes showed that ovulation rate and recovered embryos were significantly increased when hCG was used. In vitro development of fresh and devitrified embryos and survival at birth were not significantly affected by superstimulation treatment. Results of this study suggest that a single injection of long‐acting FSH‐CTP supplemented with hCG can be effectively used in rabbits to elicit an increase in ovulation rate and number of recovered embryos. Furthermore, we demonstrated that hCG supplementation had no negative effects in embryo cryosurvival and development, showing similar survival rate at birth than FSH‐CTP alone group.
Rapid development of a restored oyster reef facilitates habitat provision for estuarine fauna
Authors: De Santiago Kevin , Palmer Terence A. , Dumesnil Mark , Pollack Jennifer B.
Published: January 2019

Oyster reef restoration has become a principal strategy for ameliorating the loss of natural Crassostrea virginica populations and increasing habitat provision. In 2014, a large‐scale, high‐relief, 23‐ha subtidal C. virginica reef was restored at the historically productive Half Moon Reef in Matagorda Bay, TX, using concrete and limestone substrates. Encrusting and motile fauna were sampled seasonally until 17 months postrestoration at the restored reef and at adjacent unrestored sites. Restored oysters developed rapidly and were most abundant 3 months postrestoration, with subsequent declines possibly due to interacting effects of larval settlement success on new substrate versus post‐settlement mortality due to competitors and predators. Oyster densities were 2× higher than in a restored oyster population in Chesapeake Bay that was reported to be the largest reestablished metapopulation of native oysters in the world. Resident fauna on the restored reef were 62% more diverse, had 433% greater biomass, and comprised a distinct faunal community compared to unrestored sites. The presence of three‐dimensional habitat was the most important factor determining resident faunal community composition, indicating that substrate limitation is a major hindrance for oyster reef community success in Texas and other parts of the Gulf of Mexico. There were only minor differences in density, biomass, and diversity of associated fauna located adjacent (13 m) versus distant (150 m) to the restored reef. The two substrate types compared had little influence on oyster recruitment or faunal habitat provision. Results support the use of reef restoration as a productive means to rebuild habitat and facilitate faunal enhancement.
Non‐native trout limit native brook trout access to space and thermal refugia in a restored large‐river system
Authors: Trego Cory T. , Merriam Eric R. , Petty J. Todd
Published: January 2019

We used direct observation via snorkeling surveys to quantify microhabitat use by native brook (Salvelinus fontinalis) and non‐native brown (Salmo trutta) and rainbow (Onchorynchus mykiss) trout occupying natural and restored pool habitats within a large, high‐elevation Appalachian river, United States. Permutational multivariate analysis of variance (PERMANOVA) and subsequent two‐way analysis of variance (ANOVA) indicated a significant difference in microhabitat use by brook and non‐native trout within restored pools. We also detected a significant difference in microhabitat use by brook trout occupying pools in allopatry versus those occupying pools in sympatry with non‐native trout—a pattern that appears to be modulated by size. Smaller brook trout often occupied pools in the absence of non‐native species, where they used shallower and faster focal habitats. Larger brook trout occupied pools with, and utilized similar focal habitats (i.e. deeper, slower velocity) as, non‐native trout. Non‐native trout consistently occupied more thermally suitable microhabitats closer to cover as compared to brook trout, including the use of thermal refugia (i.e. ambient–focal temperature >2°C). These results suggest that non‐native trout influence brook trout use of restored habitats by: (1) displacing smaller brook trout from restored pools, and (2) displacing small and large brook trout from optimal microhabitats (cooler, deeper, and lower velocity). Consequently, benefits of habitat restoration in large rivers may only be fully realized by brook trout in the absence of non‐native species. Future research within this and other large river systems should characterize brook trout response to stream restoration following removal of non‐native species.
An examination of the psychometric properties of scores on the Family Strain Index (FSI) in a general community sample
Authors: Lambek Rikke , Lange Anne‐Mette , Petersen Natasja , Gorrissen Anne Mette
Published: January 2019

Given the potentially harmful effects of parenting stress on parents, children, and their relationship, it is critical to have a reliable and valid measure of parenting stress in clinical and community samples. The Family Strain Index (FSI) is a brief questionnaire designed to measure stress and demand on parents of children with ADHD. The present study is the first to evaluate the psychometric properties of scores on the FSI in a general community sample. Parents (89% mothers) of 550 preschool children (aged 2–5 years; 50% boys) sampled through 17 kindergartens located in Danish cities and villages completed the FSI, the ADHD Rating Scale (RS)‐IV Preschool Version, and a background questionnaire. FSI scores were characterized by restricted range and floor effects. The scale's construct validity was not supported and the measurement repeatability after 1 month was low. The scale did have convergent validity as levels of parenting stress were associated with perceived ADHD behavior in off‐spring, but overall, results did not encourage the use of the FSI as a measure of parenting stress in the general population. Measures that include more normative events may be more appropriate when attempting to capture parenting stress in general community samples.
The impact of integrated STEM professional development on teacher quality
Authors: Du Wenbin , Liu Denghui , Johnson Carla C. , Sondergeld Toni A. , Bolshakova Virginia L. J. , Moore Tamara J.
Published: January 2019

This study of a state‐funded, 3‐year implementation of an integrated STEM professional development (PD) program for teachers from two middle schools in the midwestern U.S. examined if participants in the PD were enabled to transform their practice and perceptions of STEM. An integrated STEM approach includes a focus on the STEM disciplines, along with leveraging social studies/history and English/language arts as important context and tools for solving society’s biggest challenges. Findings in this study indicated that teachers implemented more effective STEM teaching strategies and had more positive perceptions regarding STEM overall. Further, participants became more aware of their personal needs for resources and support to teach through integrated STEM. Implications for research and practice are discussed.
The Effect of Price Reduction on Consumer’s Buying Behavior in the U.S. Differentiated Yogurt Market
Authors: Mohammed Rezgar , Murova Olga
Published: January 2019

Although price reduction is an interesting topic in marketing literature and has studied in numerous papers, less attention is paid to its effect on consumer behavior. This paper analyzes the effect of the price promotion on consumer’s behavior in terms of the percentage of buying and the brand loyalty in the U.S. differentiated yogurt market. This paper tries to answer the following questions. Is the choice of high preferred brands sensitive to the price promotion of less preferred brands? Are there loyal consumers in the yogurt market? How sensitive is the consumer loyalty of high preferred brands to the price promotion of less preferred brands? Results show that a unit increase in the frequency of price reduction of less popular brands will decrease the consumer’s choice of high popular brands significantly. Switching across brands is very common and there are less loyal consumers in the yogurt market where main brands have collectively only 12% loyal consumers. Loyalty of high popular brands is also sensitive to the price promotion of less popular brands as a unit increase in the frequency of price reduction for less preferred brands will decreases the share of households who are loyal to high popular brands of General Mills and Danone.
Hypoxic tachycardia is not a result of increased respiratory activity in healthy subjects
Authors: Paleczny Bartłomiej , Seredyński Rafał , Tubek Stanisław , Adamiec Dorota , Ponikowski Piotr , Ponikowska Beata
Published: January 2019

New Findings

What is the central question of this research?

Does increased ventilation contribute to the increase in heart rate during transient exposure to hypoxia in humans?

What is the main finding and its importance?

Voluntary suppression of the ventilatory response to transient hypoxia does not affect the magnitude of the heart rate response to the stimulus. This indicates that hypoxic tachycardia is not secondary to hyperpnoea in humans. Better understanding of the physiology underlying the cardiovascular response to hypoxia might help in identification of new markers of elevated chemoreceptor activity, which has been proposed as a target in treatment of sympathetically mediated diseases.

Animal data suggest that hypoxic tachycardia is secondary to hyperpnoea, and for years this observation has been extrapolated to humans, despite a lack of experimental evidence. We addressed this issue in 17 volunteers aged 29 ± 7 (SD) years. A transient hypoxia test, comprising several nitrogen‐breathing episodes, was performed twice in each subject. In the first test, the subject breathed spontaneously (spontaneous breathing). In the second test, the subject was repeatedly asked to adjust his or her depth and rate of breathing according to visual (real‐time inspiratory flow) and auditory (metronome sound) cues, respectively (controlled breathing), to maintain respiration at the resting level during nitrogen‐breathing episodes. Hypoxic responsiveness, including minute ventilation [Hyp‐VI; in liters per minute per percentage of blood oxygen saturation ()], tidal volume [Hyp‐VT; in litres per ], heart rate [Hyp‐HR; in beats per minute per ], systolic [Hyp‐SBP; in millimetres of mercury per ] and mean blood pressure [Hyp‐MAP; in millimetres of mercury per ] and systemic vascular resistance [Hyp‐SVR; in dynes seconds (centimetres)−5 per ] was calculated as the slope of the regression line relating the variable to , including pre‐ and post‐hypoxic values. The Hyp‐VI and Hyp‐VT were reduced by 69 ± 25 and 75 ± 10%, respectively, in controlled versus spontaneous breathing (Hyp‐VI, −0.30 ± 0.15 versus −0.11 ± 0.09; Hyp‐VT, −0.030 ± 0.024 versus −0.007 ± 0.004; both P < 0.001). However, the cardiovascular responses did not differ between spontaneous and controlled breathing (Hyp‐HR, −0.62 ± 0.24 versus −0.71 ± 0.33; Hyp‐MAP, −0.43 ± 0.19 versus −0.47 ± 0.21; Hyp‐SVR, 9.15 ± 5.22 versus 9.53 ± 5.57; all P ≥ 0.22), indicating that hypoxic tachycardia is not secondary to hyperpnoea. Hyp‐HR was correlated with Hyp‐SVR (r = −074 and −0.80 for spontaneous and controlled breathing, respectively; both P < 0.05) and resting barosensitivity assessed with the sequence technique (r = −0.60 for spontaneous breathing; P < 0.05). This might suggest that the baroreflex mechanism is involved.
Plastic Collapse Stresses for Pipes With Inner and Outer Circumferential Cracks
Authors: Mares Vratislav , Hasegawa Kunio , Li Yinsheng , Lacroix Valery
Published: January 2019

Bending stresses at incipient plastic collapse for pipes with circumferential surface cracks are predicted by net-section stress approach. Appendix C-5320 of ASME B&PV Code Section XI provides an equation of bending stress at the plastic collapse, where the equation is applicable for both inner and outer surface cracks. That is, the collapse stresses for pipes with inner and outer surface cracks are the same, because of the pipe mean radius at the cracked section being entirely the same. Authors considered the separated pipe mean radii at the cracked ligament and at the uncracked ligament. Based on the balances of axial force and bending moment, equations of plastic collapse stresses for both inner and outer cracked pipes were developed. It is found that, when the crack angle and depth are the same, the collapse stress for inner cracked pipe is slightly higher than that calculated by the Appendix C equation, and the collapse stress for outer cracked pipe is slightly lower than that by the Appendix C equation, as can be expected. The collapse stresses derived from the three equations are almost the same in most instances. However, for less common case where the crack angle and depth are very large for thick wall pipes, the differences among the three collapse stresses become large. Code users pay attention to the margins of plastic collapse stresses for outer cracked pipes, when using Appendix C equation.
Analysis of Shutdown System Effectiveness in the Canadian Super Critical Water Reactor Using Coupled Thermal Hydraulics and Three-Dimensional Neutron Kinetics
Authors: Hummel David William , Novog David Raymond
Published: January 2019

The Canadian supercritical water-cooled reactor concept features a re-entrant fuel channel wherein coolant first travels down a center flow tube and then up around the fuel elements. Previous work demonstrated that in cases of sudden coolant flow reduction or reversal (such as that which would result from a large pipe break near the core inlet), the coolant density reduction around the fuel has a positive reactivity effect that results in a power excursion. Such a transient is inherently self-terminating since the inevitable density reduction in the center flow tube has a very large negative reactivity effect. Nevertheless, a brief power pulse would ensue. In this work, the possibility of mitigating the power pulse with a fast-acting shutdown system was explored. The shutdown system model, consisting of bottom-inserted neutron absorbing blades and realistic estimates of insertion rates and trip conditions, was added to a full-core coupled spatial neutron kinetics and thermal-hydraulics model. It was demonstrated that such a system can effectively mitigate both the peak magnitude of the power excursion and its duration.
Quantification of Morphological Modulation, F-Actin Remodeling, and PECAM-1 (CD-31) Redistribution in Endothelial Cells in Response to Fluid-Induced Shear Stress Under Various Flow Conditions
Authors: Avari Hamed , Rogers Kem A. , Savory Eric
Published: January 2019

Cardiovascular diseases (CVDs) are the number one cause of death globally. Arterial endothelial cell (EC) dysfunction plays a key role in many of these CVDs, such as atherosclerosis. Blood flow-induced wall shear stress (WSS), among many other pathophysiological factors, is known to significantly contribute to EC dysfunction. The present study reports an in vitro investigation of the effect of quantified WSS on ECs, analyzing the EC morphometric parameters and cytoskeletal remodeling. The effects of four different flow cases (low steady laminar (LSL), medium steady laminar (MSL), nonzero-mean sinusoidal laminar (NZMSL), and laminar carotid (LCRD) waveforms) on the EC area, perimeter, shape index (SI), angle of orientation, F-actin bundle remodeling, and platelet endothelial cell adhesion molecule-1 (PECAM-1) localization were studied. For the first time, a flow facility was fully quantified for the uniformity of flow over ECs and for WSS determination (as opposed to relying on analytical equations). The SI and angle of orientation were found to be the most flow-sensitive morphometric parameters. A two-dimensional fast Fourier transform (2D FFT) based image processing technique was applied to analyze the F-actin directionality, and an alignment index (AI) was defined accordingly. Also, a significant peripheral loss of PECAM-1 in ECs subjected to atheroprone cases (LSL and NZMSL) with a high cell surface/cytoplasm stain of this protein is reported, which may shed light on of the mechanosensory role of PECAM-1 in mechanotransduction.
Effects of Squish Flow on Tangential Flow and Turbulence in a Diesel Engine
Authors: Sun Yanzhe , Sun Kai , Wang Tianyou , Li Yufeng , Lu Zhen
Published: January 2019

Emission and fuel consumption in swirl-supported diesel engines strongly depend on the in-cylinder turbulent flows. But the physical effects of squish flow on the tangential flow and turbulence production are still far from well understood. To identify the effects of squish flow, Particle image velocimetry (PIV) experiments are performed in a motored optical diesel engine equipped with different bowls. By comparing and associating the large-scale flow and turbulent kinetic energy (k), the main effects of the squish flow are clarified. The effect of squish flow on the turbulence production in the r−θ plane lies in the axial-asymmetry of the annular distribution of radial flow and the deviation between the ensemble-averaged swirl field and rigid body swirl field. Larger squish flow could promote the swirl center to move to the cylinder axis and reduce the deformation of swirl center, which could decrease the axial-asymmetry of annular distribution of radial flow, further, that results in a lower turbulence production of the shear stress. Moreover, larger squish flow increases the radial fluctuation velocity which makes a similar contribution to k with the tangential component. The understanding of the squish flow and its correlations with tangential flow and turbulence obtained in this study is beneficial to design and optimize the in-cylinder turbulent flow.
Supplementation of Probiotics and Its Effects on Physically Active Individuals and Athletes: Systematic Review
Authors: Möller Gabriella Berwig , da Cunha Goulart Maria Júlia Vieira , Nicoletto Bruna Bellincanta , Alves Fernanda Donner , Schneider Cláudia Dornelles
Published: January 2019

The aim of this study was to conduct a systematic review of the effects of probiotic supplementation on physically active individuals. The participants, interventions, comparisons, outcome and study design inclusion criteria were (a) studies involving healthy adults or older subjects of both sexes who did physical exercise (including athletes and physically active individuals), (b) interventions with probiotics, (c) inclusion of a control group, (d) outcomes not previously defined, and (e) clinical trials and randomized clinical trials, with no language or date restrictions. The search was conducted in the following scientific databases: MEDLINE, Embase, SciELO, Scopus, and Lilacs. Search terms were “Probiotics” OR “Prebiotics” OR “Microbiota” AND “Exercise” OR “Athletes.” The articles were first screened by title and abstract by two independent reviewers and disagreements resolved by a third reviewer. Data were extracted independently by the same two reviewers; results were extracted in duplicate and then compared to avoid errors. A total of 544 articles were retrieved and 24 were included. A total of 1,680 patients were included, most of them being male (n = 1,134, 67.5%), with a mean age of 30.9 ± 6.1 years. Following probiotic supplementation, positive effects have been reported for several outcomes including respiratory tract infection, immunologic markers, and gastrointestinal symptoms in both athletes and nonathletes. However, published studies have distinct protocols and measured outcomes, and some of them have small sample size and failed to prove beneficial effect on probiotic supplementation, leading to inconclusive results for standardized supplementation protocols.
The Potential to Change Pacing and Performance During 4000-m Cycling Time Trials Using Hyperoxia and Inspired Gas-Content Deception
Authors: Davies Michael J. , Clark Bradley , Garvican-Lewis Laura A. , Welvaert Marijke , Gore Christopher J. , Thompson Kevin G.
Published: January 2019

Purpose: To determine if a series of trials with fraction of inspired oxygen (FiO2) content deception could improve 4000-m cycling time-trial (TT) performance. Methods: A total of 15 trained male cyclists (mean [SD] body mass 74.2 [8.0] kg, peak oxygen uptake 62 [6] mL·kg−1·min−1) completed six 4000-m cycling TTs in a semirandomized order. After a familiarization TT, cyclists were informed in 2 initial trials they were inspiring normoxic air (NORM, FiO2 0.21); however, in 1 trial (deception condition), they inspired hyperoxic air (NORM-DEC, FiO2 0.36). During 2 subsequent TTs, cyclists were informed they were inspiring hyperoxic air (HYPER, FiO2 0.36), but in 1 trial, normoxic air was inspired (HYPER-DEC). In the final TT (NORM-INFORM), the deception was revealed and cyclists were asked to reproduce their best TT performance while inspiring normoxic air. Results: Greater power output and faster performances occurred when cyclists inspired hyperoxic air in both truthful (HYPER) and deceptive (NORM-DEC) trials than NORM (P < .001). However, performance only improved in NORM-INFORM (377 W; 95% confidence interval [CI] 325–429) vs NORM (352 W; 95% CI 299–404; P < .001) when participants (n = 4) completed the trials in the following order: NORM-DEC, NORM, HYPER-DEC, HYPER. Conclusions: Cycling performance improved with acute exposure to hyperoxia. Mechanisms for the improvement were likely physiological; however, improvement in a deception trial suggests an additional placebo effect. Finally, a particular sequence of oxygen deception trials may have built psychophysiological belief in cyclists such that performance improved in a subsequent normoxic trial.
Is the Functional Threshold Power Interchangeable With the Maximal Lactate Steady State in Trained Cyclists?
Authors: Klitzke Borszcz Fernando , Ferreira Tramontin Artur , Pereira Costa Vitor
Published: January 2019

Purpose: Functional threshold power (FTP), determined as 95% of the average power during a 20-min time trial, is suggested as a practical test for the determination of the maximal lactate steady state (MLSS) in cycling. Therefore, the objective of the present study was to determine the validity of FTP in predicting MLSS. Methods: A total of 15 cyclists, 7 classified as trained and 8 as well trained (mean [SD] maximal oxygen uptake 62.3 [6.4] mL·kg−1·min−1, maximal aerobic power 329 [30] W), performed an incremental test to exhaustion, an FTP test, and several constant-load tests to determine the MLSS. The bias ± 95% limits of agreement (LoA), typical error of the estimate (TEE), and Pearson coefficient of correlation (r) were calculated to assess validity. Results: For the power-output measures, FTP presented a bias ± 95% LoA of 1.4% ± 9.2%, a moderate TEE (4.7%), and nearly perfect correlation (r = .91) with MLSS in all cyclists together. When divided by training level, the bias ± 95% LoA and TEE were higher in the trained group (1.4% ± 11.8% and 6.4%, respectively) than in the well-trained group (1.3% ± 7.4% and 3.0%, respectively). For the heart-rate measurement, FTP presented a bias ± 95% LoA of −1.4% ± 8.2%, TEE of 4.0%, and very large correlation (r = .80) with MLSS. Conclusion: Therefore, trained and well-trained cyclists can use FTP as a noninvasive and practical alternative to estimate MLSS.
Effects of Resisted Sprints With Changes of Direction Through Several Relative Loads on Physical Performance in Soccer Players
Authors: Rodríguez-Osorio David , Gonzalo-Skok Oliver , Pareja-Blanco Fernando
Published: January 2019

Purpose: To compare the effects of resisted change-of-direction (COD) movements, using several relative loads, on soccer players’ physical performance. Methods: Fifty-four male soccer players were randomly assigned to 1 of the following 3 groups, which differed only in the magnitude of the external load used during the COD training: COD training without external load (COD-0; n = 16), COD training with a 12.5% body-mass external load (COD-12.5; n = 19), and COD training with a 50% body-mass external load (COD-50; n = 19). Participants performed the specific COD training twice per week for 6 wk. Before and after the training period, a battery of tests was completed: countermovement jump, 30-m running sprint (time in 10 m [T10], 20 m [T20], and 30 m [T30]), L-run test, and V-cut test. Results: Within-group comparisons showed substantial improvements in countermovement jump and T10 (likely) in COD-0, whereas countermovement jump, T10, and T20 were substantially enhanced (possibly to likely) in COD-50. COD-12.5 induced substantial improvements in all analyzed variables (likely to most likely). Between-groups comparisons showed better effects on all analyzed variables for COD-12.5 than for COD-0 (possibly to very likely), whereas COD-50 only showed possibly better effects than COD-0 on T10. In addition, COD-12.5 induced a better effect on L-run and V-cut tests than COD-50 (possibly to likely). Conclusions: These results indicate that COD training, especially moderate load (12.5% body mass) resisted COD training, may have a positive effect on COD skills, running sprint performance, and jumping ability in young soccer players.
Behavior Change Techniques Used in Theory of Planned Behavior Physical Activity Interventions Among Older Adults: A Systematic Review
Authors: Senkowski Valerie , Gannon Clara , Branscum Paul
Published: January 2019

Physical activity interventions among older adults vary widely in the techniques used to elicit behavior change. The purpose of this systematic review was to determine what behavior change techniques (BCTs) are used in interventions to increase physical activity among older adults using the theory of planned behavior and to make suggestions for BCTs that appear to be more effective. A database search identified peer-reviewed articles documenting interventions based on the theory of planned behavior. Seven articles (three randomized controlled trial, three quasi-experimental, and one n-of-1) from four countries (the United States, the United Kingdom, Australia, and the Netherlands) were included for review. Researchers independently coded BCTs using a hierarchical taxonomy of 93 BCTs. The most frequently coded BCTs included Goal Setting (n = 5 studies), Action Planning (n = 5 studies), and Credible Source (n = 5 studies). Of the 93 BCTs in the taxonomy, only 26 were used, indicating potential opportunities to implement and evaluate less commonly used techniques in future studies.
The Role of Genetic Profile in Functional Performance Adaptations to Exercise Training or Physical Activity: A Systematic Review of the Literature
Authors: Wilson Guy C. , Mavros Yorgi , Tajouri Lotti , Singh Maria Fiatarone
Published: January 2019

Background: Variations in genotype may contribute to heterogeneity in functional adaptations to exercise. Methods: A systematic search of eight databases was conducted, and 9,696 citations were screened. Results: Eight citations from seven studies measuring 10 single-nucleotide polymorphisms and nine different functional performance test outcomes were included in the review. There was one observational study of physical activity and six experimental studies of aerobic or resistance training. The ACE (D) allele, ACTN3 (RR) genotype, UCP2 (GG) genotype, IL-6-174 (GG) genotype, TNF-α-308 (GG) genotype, and IL-10-1082 (GG) genotype all predicted significantly superior adaptations in at least one functional outcome in older men and women after prescribed exercise or in those with higher levels of physical activity. Conclusion: There is a small amount of evidence that older adults may have better functional outcomes after exercise/physical activity if they have specific alleles related to musculoskeletal function or inflammation. However, more robust trials are needed.