bluuebunny/crossref_metadata_2025 huggingface dataset:
Crafting Mass Dairy Production: Immigration and Community in Rural America
Authors: Garni Alisa
Published: July 2017

In many parts of rural America, agrofood producers compete for a larger share of global markets by mechanizing, deskilling, and flexibly relocating to reduce labor costs. They recruit new immigrant workers but sow transience rather than sustainable rural growth. The industrialization of U.S. dairy farming appears to be aligned with these processes, and yet the large‐scale dairy farmers who have replaced small craft producers face a paradox: The more they rationalize production on their farms, the more vulnerable their herds become to stress and illness, compromising production. Focusing on three competing dairies in Kansas, I examine how farmers variously organize work among immigrant employees to promote herd health while expanding their operations. Evidence from 22 months of ethnographic research and repeated interviews with farm owners, managers, employees, and extension agents suggests that enhancing production requires promoting employee citizenship at work—especially among immigrant employees possessing the fewest citizenship rights outside of work. In contrast to the high labor turnover endemic to other forms of industrialized food production, the distinctive human‐animal relations central to dairying encourage farm owners and employees to cooperate, with promising results for farms and rural communities.
Impact of drugs on intradialytic hypotension: Antihypertensives and vasoconstrictors
Authors: Chang Tara I.
Published: July 2017

Intradialytic hypotension (IDH) is a common complication of hemodialysis and is associated with numerous adverse outcomes including cardiovascular events, inadequate dialysis, loss of vascular access, and death. It is estimated that approximately 20%‐30% of all dialysis sessions are affected by IDH. In seeking ways to reduce the occurrence of IDH, dialysis providers often turn to pharmacological approaches: withholding antihypertensive medications prior to hemodialysis or administering vasoconstrictor medications. This review will focus on what is known about the relation between antihypertensive medications and IDH, and summarize studies that have examined the efficacy of vasoconstrictor medications on IDH, including midodrine, arginine vasopressin, and droxidopa. However, there is currently scant evidence that any pharmacological approach is particularly effective in reducing IDH. Additional studies of potential treatments for IDH are needed, and should examine not only hemodynamic effects such as changes in nadir blood pressure during dialysis, but also on patient‐centered and clinical outcomes such as symptoms of IDH, quality of life, and cardiovascular events.
Magnetic resonance imaging appearance of the brain and cervical spinal cord in an edema disease affected pig
Authors: Dieste‐Pérez Lucía , Dobak Tetyda P. , Vilaplana Grosso Federico R. , Bergmann Wilhelmina , Tobias Tijs J.
Published: July 2017

A 7‐week‐old male pig was presented with signs of a central nervous system disorder. An MRI of the head and cervical spine was performed immediately after euthanasia. The MRI revealed multifocal bilaterally symmetric T2‐weighted hyperintense lesions in the brain and spinal cord, likely due to a toxic metabolic process. Histopathological examination supported the MRI findings and confirmed the diagnosis of edema disease due to Shiga‐like toxin produced by Escherichia coli. This is the first case published of the MRI findings in an edema disease affected pig.
Matched guise effects can be robust to speech style
Authors: Tamminga Meredith
Published: July 2017

When investigating how listeners evaluate the social meaning of variability in speech, researchers using the Matched Guise Technique (MGT) must decide whether to use read speech or conversational speech stimuli. An MGT experiment comparing social evaluation of /ɪŋ/ ∼ /ɪn/ variation in read and conversational speech styles found no evidence that the social evaluation of this variation differed across frame utterance styles. This suggests that use of read speech stimuli can be an appropriate methodological choice in MGT research.
Does Physical Activity Mediate the Association Between Perceived Neighborhood Aesthetics and Overweight/Obesity Among South African Adults Living in Selected Urban and Rural Communities?
Authors: Malambo Pasmore , Kengne Andre P. , Lambert Estelle V. , De Villiers Anniza , Puoane Thandi
Published: July 2017

Background: To investigate the mediation effects of physical activity (PA) on the relationship between the perceived neighborhood aesthetic environment and overweight/obesity in free-living South Africans. Methods: A cross-sectional study of 671 adults aged ≥ 35 years was analyzed. PA was assessed using the validated International Physical Activity Questionnaire. Perceived neighborhood aesthetics was assessed using the Neighborhood Environment Walkability Scale Questionnaire. Results: Of 671 participants, 76.0% were women, 34.1% aged 45–54 years, and 69.2% were overweight or obese. In adjusted logistic regression models, overweight/obesity was significantly associated with neighborhood aesthetics [odds ratio (OR) = 0.68; 95% confidence interval (CI), 0.50–0.93] and PA (OR = 0.65; 95% CI, 0.65–0.90). In expanded multivariable models, overweight/obesity was associated with age 45–55 years (OR = 1.59; 95% CI, 1.05–2.40), female gender (OR = 6.24; 95% CI, 3.95–9.86), tertiary education (OR = 4.05; 95% CI, 1.19–13.86), and urban residence (OR = 2.46; 95% CI, 1.66–3.65). Conclusion: Aesthetics was positively associated with PA; both aesthetics and PA were negatively associated with overweight and obesity. There was no evidence to support a significant mediating effect of PA on the relationship between aesthetics and overweight/obesity. Future studies should consider objective assessment of aesthetics and PA. In addition, future studies should consider using longitudinal design to evaluate food-related environments, which are related to overweight or obesity.
Effect of Child Gender and Psychosocial Factors on Physical Activity From Fifth to Sixth Grade
Authors: Forthofer Melinda , Dowda Marsha , O’Neill Jennifer R. , Addy Cheryl L. , McDonald Samantha , Reid Lauren , Pate Russell R.
Published: July 2017

Background: Gender differences in physical activity (PA) trajectories during adolescence are well documented, yet little research has examined whether the determinants of these trajectories vary by child’s gender. This study is one of few prospective examinations of gender differences in the influences of psychosocial and socioenvironmental factors on changes in objectively measured PA. Methods: Students and parents from elementary and middle schools located in 2 school districts in South Carolina were enrolled in a prospective cohort study of changes in children’s PA from elementary to middle school. Measures included children’s and/or parents’ ratings of various psychosocial and socioenvironmental factors as well as objectively measured PA, children’s anthropometric characteristics, and neighborhood factors at fifth and sixth grades. Results: Parents’ reports of children’s sport and class participation, parent-reported support for PA, and neighborhood resources for PA were protective against declines in PA for both boys and girls. The effects of 2 factors—children’s self-efficacy and parents’ leisure-time PA—on changes in PA over time were moderated by the child’s gender. Conclusions: A better understanding of these dynamics may inform the development of interventions.
How Is the Practice of Yoga Related to Weight Status? Population-Based Findings From Project EAT-IV
Authors: Neumark-Sztainer Dianne , MacLehose Richard F. , Watts Allison W. , Eisenberg Marla E. , Laska Melissa N. , Larson Nicole
Published: July 2017

Background: Yoga may provide a strategy for healthy weight management in young adults. This study examined prevalence and characteristics of young adults’ yoga practice and associations with changes in body mass index. Methods: Surveys were completed by 1830 young adults (31.1 ± 1.6 y) participating in Project EAT-IV. Cross-sectional and 5-year longitudinal analyses were conducted stratified by initial weight status. Results: Two-thirds (66.5%) of nonoverweight women and 48.9% of overweight women reported ever doing yoga, while 27.2% of nonoverweight women and 16.4% of overweight women practiced regularly (≥30 min/wk). Fewer men practiced yoga. Among young adults practicing regularly (n = 294), differences were identified in intensity, type, and location of yoga practice across weight status. Young adults who were overweight and practiced yoga regularly showed a nonsignificant 5-year decrease in their body mass index (−0.60 kg/m2; P = .49), whereas those not practicing regularly had significant increases in their body mass index (+1.37 kg/m2; P < .01). Frequency of yoga was inversely associated with weight gain among both overweight and nonoverweight young adults practicing yoga regularly. Conclusions: Young adults of different body sizes practice yoga. Yoga was associated with less weight gain over time, particularly in overweight young adults. Practicing yoga on a regular basis may help with weight gain prevention.
Effect of Exercise Training on Cardiac Biomarkers in At-Risk Populations: A Systematic Review
Authors: Glenney Susan Sullivan , Brockemer Derrick Paul , Ng Andy C. , Smolewski Michael A. , Smolgovskiy Vladimir M. , Lepley Adam S.
Published: July 2017

Background: Studies have demonstrated beneficial effects of exercise on cardiovascular disease biomarkers for healthy individuals; however, a comprehensive review regarding the effect of exercise on cardiovascular disease biomarkers in at-risk populations is lacking. Methods: A literature search was performed to identify studies meeting the following criteria: randomized controlled study, participants with pathology/activity limitations, biomarker outcome (total cholesterol, high-density lipoprotein, low-density lipoprotein, C-reactive protein, insulin, triglycerides, or glucose), and exercise intervention. Means and standard deviations from each biomarker were used to calculate standardized Cohen’s d effect sizes with 95% confidence intervals. Results: In total, 37 articles were included. The majority (44/57; 77%) of data points demonstrated moderate to strong effects for the reduction in total cholesterol, triglycerides, and low-density lipoprotein, and elevation in high-density lipoprotein following exercise. The majority of data points demonstrated strong effects for reductions in blood glucose (24/30; 80%) and insulin (23/24; 96%) levels following exercise intervention. Conclusion: Evidence is heterogeneous regarding the influence of exercise on cardiovascular disease biomarkers in at-risk patients, which does not allow a definitive conclusion. Favorable effects include reductions in triglycerides, total cholesterol, low-density lipoprotein, glucose, and insulin, and elevation in high-density lipoprotein following exercise intervention. The strongest evidence indicates that exercise is favorable for the reduction in glucose and cholesterol levels among obese patients, and reduction of insulin regardless of population.
Indoor and Outdoor Context-Specific Contributions to Early Adolescent Moderate to Vigorous Physical Activity as Measured by Combined Diary, Accelerometer, and GPS
Authors: Pearce Matthew , Saunders David H. , Allison Peter , Turner Anthony P.
Published: July 2017

Background: The distribution of adolescent moderate to vigorous physical activity (MVPA) across multiple contexts is unclear. This study examined indoor and outdoor leisure time in terms of being structured or unstructured and explored relationships with total daily MVPA. Methods: Between September 2012 and January 2014, 70 participants (aged 11–13 y) from 4 schools in Edinburgh wore an accelerometer and global positioning system receiver over 7 days, reporting structured physical activity using a diary. Time spent and MVPA were summarized according to indoor/outdoor location and whether activity was structured/unstructured. Independent associations between context-specific time spent and total daily MVPA were examined using a multivariate linear regression model. Results: Very little time or MVPA was recorded in structured contexts. Unstructured outdoor leisure time was associated with an increase in total daily MVPA almost twice that of unstructured indoor leisure time [b value (95% confidence interval), 8.45 (1.71 to 14.48) vs 4.38 (0.20 to 8.22) minute increase per hour spent]. The association was stronger for time spent in structured outdoor leisure time [35.81 (20.60 to 52.27)]. Conclusions: Research and interventions should focus on strategies to facilitate time outdoors during unstructured leisure time and maximize MVPA once youth are outdoors. Increasing the proportion of youth engaging in structured activity may be beneficial given that, although time spent was limited, association with MVPA was strongest.
A Multicomponent Schoolyard Intervention Targeting Children’s Recess Physical Activity and Sedentary Behavior: Effects After 1 Year
Authors: Van Kann Dave H.H. , de Vries Sanne I. , Schipperijn Jasper , de Vries Nanne K. , Jansen Maria W.J. , Kremers Stef P.J.
Published: July 2017

Background: The aim of the study was to test the 12-month effects of a multicomponent physical activity (PA) intervention at schoolyards on morning recess PA levels of sixth- and seventh-grade children in primary schools, using accelerometry and additional global positioning system data. Methods: A quasi-experimental study design was used with 20 paired intervention and control schools. Global positioning system confirmatory analyses were applied to validate attendance at schoolyards during recess. Accelerometer data from 376 children from 7 pairs of schools were included in the final analyses. Pooled intervention effectiveness was tested by multilevel linear regression analyses, whereas effectiveness of intervention components was tested by multivariate linear regression analyses. Results: Children exposed to the multicomponent intervention increased their time spent in light PA (+5.9%) during recess. No pooled effects on moderate to vigorous PA were found. In-depth analyses of intervention components showed that physical schoolyard interventions particularly predicted a decrease in time spent in sedentary behavior during recess at follow-up. Intervention intensity and the school’s commitment to the project strengthened this effect. Conclusions: The multicomponent schoolyard PA intervention was effective in making children spend a larger proportion of recess time in light PA, which was most likely the result of a shift from sedentary behavior to light PA.
Effects of Water-Based Exercise Training on the Cognitive Function and Quality of Life of Healthy Adult Women
Authors: Ayán Carlos , Carvalho Paulo , Varela Silvia , Cancela José María
Published: July 2017

Background: Research regarding the impact of aquatic exercise on cognition is scarce. This study aimed at identifying the effects of water-based exercise training on the cognitive function and quality of life of healthy adult women. Methods: Fifty-one healthy women [mean age: 46.5 (12.3) y] were assigned to group A or B and followed a water-based exercise program for 6 months. During the first 3 months, the sessions performed by group A were focused on stimulating cognitive function. For the next 3 months, the sessions were mainly aimed at improving physical fitness. Participants in group B followed the same program in reverse order. The trail making and symbol digit modality tests were used to assess the impact of the program on cognition. The effects of the intervention on the participants’ physical and mental health were measured by means of the medical outcomes study 36-item short-form health survey. Results: Once the intervention ended, significant improvements were observed in the participants’ cognitive function and mental health domain, regardless of the group in which they were initially included. Conclusion: Water-based exercise is a training modality capable of enhancing cognitive function and quality of life through improvements in mental health in healthy adult women.
Affect and Cognitive Performance in High School Wrestlers Undergoing Rapid Weight Loss
Authors: Landers Daniel M. , Arent Shawn M. , Lutz Rafer S.
Published: July 2017

Recent research has demonstrated transient affective changes and impairment of short-term memory in college wrestlers as a result of rapid weight loss (RWL) of at least 5% body weight prior to competition. This study examined the effects of RWL on cognition and affect in high school wrestlers. Wrestlers were considered to be engaging in RWL if they were losing over 5% of body weight (n = 14). Those losing less than 1% of body weight (n = 14) were considered maintainers and served as the control group. Both groups were given a battery of tests assessing cognitive performance (Trail Making Tests A & B, Stroop color-word test, Wechsler digit span, and choice reaction/movement time) and affective state (PANAS) at normal weight (5 to 10 days prior to competition) and again 8 to 12 hours prior to weigh-in. Results indicated an average loss of 4.68 kg in the RWL group and 0.29 kg in the control group. A group-by-time MANOVA and univariate follow-up tests indicated a significant group-by-time interaction for positive affect, p < .014, with the RWL wrestlers having less positive affect than the control group just prior to weigh-in. However, none of the cognitive performance tests demonstrated significant differential changes for RWL vs. control groups, p > .10. Given the control for competition effects in the present study, results suggest there are affective disturbances, but not cognitive impairments, associated with RWL of at least 5% body weight in high school wrestlers.
Persistence and Effort in Moving Achievement Goal Research Forward: A Response to Treasure and Colleagues
Authors: Harwood Chris , Hardy Lew
Published: July 2017

In their response to our recent paper (Harwood, Hardy, & Swain, 2000), Treasure et al. (2001) claimed to have clarified our misconceptions and misrepresentations of achievement goal research. After first of all commenting on the apparently rather emotive nature of their response, we logically deal with each of their criticisms. Specifically, we present sound theoretical arguments to show that: (a) personal theories of achievement hold primacy over achievement goals; (b) we are not “particularly confused” (or even a little confused) in our understanding of conceptions of ability; (c) there are excellent reasons for examining the possibility of a tripartite approach to goal orientation and goal involvement; and (d) the issue of measurement in achievement goal research needs to be carefully reconsidered. Further, in response to the status quo offered by Treasure and colleagues, we call for more innovative research that will help progress the impact of achievement goal theory in competitive sport.
Extracellular polymeric substances are transient media for microbial extracellular electron transfer
Authors: Xiao Yong , Zhang Enhua , Zhang Jingdong , Dai Youfen , Yang Zhaohui , Christensen Hans E. M. , Ulstrup Jens , Zhao Feng
Published: July 2017

Extracellular polymeric substances play important roles in microbial extracellular electron transfer processes.
Exploring and Exploiting Proteome Organization during Viral Infection
Authors: Jean Beltran Pierre M. , Cook Katelyn C. , Cristea Ileana M.
Published: July 2017

Viral replication in eukaryotes is a process inherently organized in both space and time. Viral components target subcellular organelles to access host machineries required for replication and spread. Diverse viruses are known to alter organelle shape, composition, function, and dynamics as part of their replication cycles. Here, we highlight recent advances in microscopy and proteomic methods that have helped and will continue to help define mechanisms used by viruses to exploit host proteome organization.
Mutational Analysis of Lassa Virus Glycoprotein Highlights Regions Required for Alpha-Dystroglycan Utilization
Authors: Acciani Marissa , Alston Jacob T. , Zhao Guohui , Reynolds Hayley , Ali Afroze M. , Xu Brian , Brindley Melinda A.
Published: July 2017

Lassa virus (LASV) is an enveloped RNA virus endemic to West Africa and responsible for severe cases of hemorrhagic fever. Virus entry is mediated by the glycoprotein complex consisting of a stable-signal peptide, a receptor-binding subunit, GP1, and a viral-host membrane fusion subunit, GP2. Several cellular receptors can interact with the GP1 subunit and mediate viral entry, including alpha-dystroglycan (αDG) and lysosome-associated membrane protein 1 (LAMP1). In order to define the regions within GP1 that interact with the cellular receptors, we implemented insertional mutagenesis, carbohydrate shielding, and alanine scanning mutagenesis. Eighty GP constructs were engineered and evaluated for GP1-GP2 processing, surface expression, and the ability to mediate cell-to-cell fusion after low-pH exposure. To examine virus-to-cell entry, 49 constructs were incorporated onto vesicular stomatitis virus (VSV) pseudoparticles and transduction efficiencies were monitored in HAP1 and HAP1-ΔDAG1 cells that differentially produce the αDG cell surface receptor. Seven constructs retained efficient transduction in HAP1-ΔDAG1 cells yet poorly transduced HAP1 cells, suggesting that they are involved in αDG utilization. Residues H141, N146, F147, and Y150 cluster at the predicted central core of the trimeric interface and are important for GP-αDG interaction. Additionally, H92A-H93A, 150HA, 172HA, and 230HA displayed reduced transduction in both HAP1 and HAP1-ΔDAG1 cells, despite efficient cell-to-cell fusion activity. These mutations may interfere with interactions with the endosomal receptor LAMP1 or interfere at another stage in entry that is common to both cell lines. Insight gained from these data can aid in the development of more-effective entry inhibitors by blocking receptor interactions.

IMPORTANCE
Countries in which Lassa virus is endemic, such as Nigeria, Sierra Leone, Guinea, and Liberia, usually experience a seasonal outbreak of the virus from December to March. Currently, there is neither a preventative vaccine nor a therapeutic available to effectively treat severe Lassa fever. One way to thwart virus infection is to inhibit interaction with cellular receptors. It is known that the GP1 subunit of the Lassa glycoprotein complex plays a critical role in receptor recognition. Our results highlight a region within the Lassa virus GP1 protein that interacts with the cellular receptor alpha-dystroglycan. This information may be used for future development of new Lassa virus antivirals.
Coordinated Changes in Mutation and Growth Rates Induced by Genome Reduction
Authors: Nishimura Issei , Kurokawa Masaomi , Liu Liu , Ying Bei-Wen
Published: July 2017

Genome size is determined during evolution, but it can also be altered by genetic engineering in laboratories. The systematic characterization of reduced genomes provides valuable insights into the cellular properties that are quantitatively described by the global parameters related to the dynamics of growth and mutation. In the present study, we analyzed a small collection of W3110
Escherichia coli
derivatives containing either the wild-type genome or reduced genomes of various lengths to examine whether the mutation rate, a global parameter representing genomic plasticity, was affected by genome reduction. We found that the mutation rates of these cells increased with genome reduction. The correlation between genome length and mutation rate, which has been reported for the evolution of bacteria, was also identified, intriguingly, for genome reduction. Gene function enrichment analysis indicated that the deletion of many of the genes encoding membrane and transport proteins play a role in the mutation rate changes mediated by genome reduction. Furthermore, the increase in the mutation rate with genome reduction was highly associated with a decrease in the growth rate in a nutrition-dependent manner; thus, poorer media showed a larger change that was of higher significance. This negative correlation was strongly supported by experimental evidence that the serial transfer of the reduced genome improved the growth rate and reduced the mutation rate to a large extent. Taken together, the global parameters corresponding to the genome, growth, and mutation showed a coordinated relationship, which might be an essential working principle for balancing the cellular dynamics appropriate to the environment.

IMPORTANCE
Genome reduction is a powerful approach for investigating the fundamental rules for living systems. Whether genetically disturbed genomes have any specific properties that are different from or similar to those of natively evolved genomes has been under investigation. In the present study, we found that
Escherichia coli
cells with reduced genomes showed accelerated nucleotide substitution errors (mutation rates), although these cells retained the normal DNA mismatch repair systems. Intriguingly, this finding of correlation between reduced genome size and a higher mutation rate was consistent with the reported evolution of mutation rates. Furthermore, the increased mutation rate was quantitatively associated with a decreased growth rate, indicating that the global parameters related to the genome, growth, and mutation, which represent the amount of genetic information, the efficiency of propagation, and the fidelity of replication, respectively, are dynamically coordinated.
Bacterial Physiological Adaptations to Contrasting Edaphic Conditions Identified Using Landscape Scale Metagenomics
Authors: Malik Ashish A. , Thomson Bruce C. , Whiteley Andrew S. , Bailey Mark , Griffiths Robert I.
Published: July 2017

Environmental factors relating to soil pH are important regulators of bacterial taxonomic biodiversity, yet it remains unclear if such drivers affect community functional potential. To address this, we applied whole-genome metagenomics to eight geographically distributed soils at opposing ends of a landscape soil pH gradient (where “low-pH” is ~pH 4.3 and “high-pH” is ~pH 8.3) and evaluated functional differences with respect to functionally annotated genes. First, differences in taxonomic and functional diversity between the two pH categories were assessed with respect to alpha diversity (mean sample richness) and gamma diversity (total richness pooled for each pH category). Low-pH soils, also exhibiting higher organic matter and moisture, consistently had lower taxonomic alpha and gamma diversity, but this was not apparent in assessments of functional alpha and gamma diversity. However, coherent changes in the relative abundances of annotated genes between low- and high-pH soils were identified; with strong multivariate clustering of samples according to pH independent of geography. Assessment of indicator genes revealed that the acidic organic-rich soils possessed a greater abundance of cation efflux pumps, C and N direct fixation systems, and fermentation pathways, indicating adaptations to both acidity and anaerobiosis. Conversely, high-pH soils possessed more direct transporter-mediated mechanisms for organic C and N substrate acquisition. These findings highlight the distinctive physiological adaptations required for bacteria to survive in soils of various nutrient availability and edaphic conditions and more generally indicate that bacterial functional versatility with respect to functional gene annotations may not be constrained by taxonomy.

IMPORTANCE
Over a set of soil samples spanning Britain, the widely reported reductions in bacterial taxonomic richness at low pH were found not to be accompanied by significant reductions in the richness of functional genes. However, consistent changes in the abundance of related functional genes were observed, characteristic of differential ecological and nutrient acquisition strategies between high-pH mineral soils and low-pH organic anaerobic soils. Our assessment at opposing ends of a soil gradient encapsulates the limits of functional diversity in temperate climates and identifies key pathways that may serve as indicators for soil element cycling and C storage processes in other soil systems. To this end, we make available a data set identifying functional indicators of the different soils; as well as raw sequences, which given the geographic scale of our sampling should be of value in future studies assessing novel genetic diversity of a wide range of soil functional attributes.
Adaptation of
Bacillus subtilis
to Life at Extreme Potassium Limitation
Authors: Gundlach Jan , Herzberg Christina , Hertel Dietrich , Thürmer Andrea , Daniel Rolf , Link Hannes , Stülke Jörg
Published: July 2017

Potassium is the most abundant metal ion in every living cell. This ion is essential due to its requirement for the activity of the ribosome and many enzymes but also because of its role in buffering the negative charge of nucleic acids. As the external concentrations of potassium are usually low, efficient uptake and intracellular enrichment of the ion is necessary. The Gram-positive bacterium
Bacillus subtilis
possesses three transporters for potassium, KtrAB, KtrCD, and the recently discovered KimA. In the absence of the high-affinity transporters KtrAB and KimA, the bacteria were unable to grow at low potassium concentrations. However, we observed the appearance of suppressor mutants that were able to overcome the potassium limitation. All these suppressor mutations affected amino acid metabolism, particularly arginine biosynthesis. In the mutants, the intracellular levels of ornithine, citrulline, and arginine were strongly increased, suggesting that these amino acids can partially substitute for potassium. This was confirmed by the observation that the supplementation with positively charged amino acids allows growth of
B. subtilis
even at the extreme potassium limitation that the bacteria experience if no potassium is added to the medium. In addition, a second class of suppressor mutations allowed growth at extreme potassium limitation. These mutations result in increased expression of KtrAB, the potassium transporter with the highest affinity and therefore allow the acquisition and accumulation of the smallest amounts of potassium ions from the environment.

IMPORTANCE
Potassium is essential for every living cell as it is required for the activity for many enzymes and for maintaining the intracellular pH by buffering the negative charge of the nucleic acids. We have studied the adaptation of the soil bacterium
Bacillus subtilis
to life at low potassium concentrations. If the major high-affinity transporters are missing, the bacteria are unable to grow unless they acquire mutations that result in the accumulation of positively charged amino acids such as ornithine, citrulline, and arginine. Supplementation of the medium with these amino acids rescued growth even in the absence of externally added potassium. Moreover, these growth conditions, which the bacteria experience as an extreme potassium limitation, can be overcome by the acquisition of mutations that result in increased expression of the high-affinity potassium transporter KtrAB. Our results indicate that positively charged amino acids can partially take over the function of potassium.
In Vivo
Indicators of Cytoplasmic, Vacuolar, and Extracellular pH Using pHluorin2 in Candida albicans
Authors: Tournu Hélène , Luna-Tapia Arturo , Peters Brian M. , Palmer Glen E.
Published: July 2017

Candida albicans
is an opportunistic fungal pathogen that colonizes the reproductive and gastrointestinal tracts of its human host. It can also invade the bloodstream and deeper organs of immunosuppressed individuals, and thus it encounters enormous variations in external pH
in vivo
. Accordingly, survival within such diverse niches necessitates robust adaptive responses to regulate intracellular pH. However, the impact of antifungal drugs upon these adaptive responses, and on intracellular pH in general, is not well characterized. Furthermore, the tools and methods currently available to directly monitor intracellular pH in
C. albicans
, as well as other fungal pathogens, have significant limitations. To address these issues, we developed a new and improved set of pH sensors based on the pH-responsive fluorescent protein pHluorin. This includes a cytoplasmic sensor, a probe that localizes inside the fungal vacuole (an acidified compartment that plays a central role in intracellular pH homeostasis), and a cell surface probe that can detect changes in extracellular pH. These tools can be used to monitor pH within single
C. albicans
cells or in cell populations in real time through convenient and high-throughput assays.
Risk of recurrent spontaneous preterm birth: a systematic review and meta-analysis
Authors: Phillips Courtney , Velji Zain , Hanly Ciara , Metcalfe Amy
Published: July 2017

Objective

To determine the risk of recurrent spontaneous preterm birth (sPTB) following sPTB in singleton pregnancies.

Design

Systematic review and meta-analysis using random effects models.

Data sources

An electronic literature search was conducted in OVID Medline (1948–2017), Embase (1980–2017) and ClinicalTrials.gov (completed studies effective 2017), supplemented by hand-searching bibliographies of included studies, to find all studies with original data concerning recurrent sPTB.

Study eligibility criteria

Studies had to include women with at least one spontaneous preterm singleton live birth (<37 weeks) and at least one subsequent pregnancy resulting in a singleton live birth. The Newcastle-Ottawa Scale was used to assess study quality.

Results

Overall, 32 articles involving 55 197 women, met all inclusion criteria. Generally studies were well conducted and had a low risk of bias. The absolute risk of recurrent sPTB at <37 weeks’ gestation was 30% (95% CI 27% to 34%). The risk of recurrence due to preterm premature rupture of membranes (PPROM) at <37 weeks gestation was 7% (95% CI 6% to 9%), while the risk of recurrence due to preterm labour (PTL) at <37 weeks gestation was 23% (95% CI 13% to 33%).

Conclusions

The risk of recurrent sPTB is high and is influenced by the underlying clinical pathway leading to the birth. This information is important for clinicians when discussing the recurrence risk of sPTB with their patients.
The association of dietary quality with colorectal cancer among normal weight, overweight and obese men and women: a prospective longitudinal study in the USA
Authors: Torres Stone Rosalie A , Waring Molly E , Cutrona Sarah L , Kiefe Catarina I , Allison Jeroan , Doubeni Chyke A
Published: July 2017

Objective

Lower body mass index (BMI) and higher dietary quality reduce the risk of colorectal cancer (CRC). A full understanding of how these associations vary by sex and weight is lacking.

Methods

We used data from the National Institutes of Health - American Association of Retired Persons (NIH)-AARP) Diet and Health Study for 398 458 persons who were 50–71 years old in 1995–1996 and followed through 2006. Exposures were dietary quality as reflected by the Mediterranean Diet, the Healthy Eating Index-2010 and the Dietary Approaches to Stop Hypertension score, stratified by BMI category. The outcome was CRC diagnosis from cancer registry data. Cox regression models were adjusted for disease risk factors.

Results

Over a mean duration of 123 months of follow-up, there were 6515 new diagnoses of CRC (1953 among the normal weight, 2924 among the overweight and 1638 among the obese; 4483 among men and 2032 among women). For normal weight and overweight men, we found a strong dose–response pattern for the association of increasing quintile of dietary quality with decreasing risk of CRC; this pattern was observed for obese men as well, but less consistently across the three measures of dietary quality. The findings were of smaller magnitude and less consistent for women but still suggesting associations of similar direction.

Conclusion

We observed that increased dietary quality was associated with lower risk of incident CRC up to 10 years later for men regardless of baseline weight category.
Protocol for a mixed-methods realist evaluation of a health service user feedback system in Bangladesh
Authors: Ebenso Bassey , Huque Rumana , Azdi Zunayed , Elsey Helen , Nasreen Shammi , Mirzoev Tolib
Published: July 2017

Introduction

Responsiveness to service users’ views is a widely recognised objective of health systems. A key component of responsive health systems is effective interaction between users and service providers. Despite a growing literature on patient feedback from high-income settings, less is known about effectiveness of such systems in low-income and middle-income countries.

Methodology and analysis

This paper disseminates the protocol for an 18-month ‘RESPOND’ project that aims to evaluate the system of collecting and responding to user feedback in Bangladesh. This mixed-method study uses a realist evaluation approach to examine user feedback systems at two Upazila health complexes in Comilla District of Bangladesh, and comprises three steps: (1) initial theory development; (2) theory validation; and (3) theory refinement and development of lessons learnt. The project also uses (1) process evaluation to understandcausal mechanismsandcontexts of implementation; (2) statistical analysis of patient feedback to clarify the nature of issues reported; (3) social science methods to illuminate feedback processes and user and provider experiences; and (4) health policy and systems research to clarify issues related to integration of feedback systems with quality assurance and human resource management. During data analysis, qualitative and quantitative findings will be integrated throughout to help achieve study objectives. Analysis of qualitative and quantitative data will be done using a convergent mixed-methods model, involving continuous triangulation of multiple data sets to facilitate greater understanding of the context of user feedback systems including the links with relevant policies, practices and programmes.

Ethics and dissemination

Ethics approvals were obtained from the University of Leeds and the Bangladesh Medical Research Council. All data collected for this study will be anonymised, and identifying characteristics of respondents will not appear in a final manuscript or reports. The study findings will be presented at scientific conferences and published in peer-reviewed journals.
Randomised controlled study to assess skill retention at 6 vs 12 months after simulation training in shoulder dystocia
Authors: Lee Menelik M H , Chan Chao Ngan , Lau Betty Y T , Ma Teresa W L
Published: July 2017

Introduction

Current evidence suggests annual training in the management of shoulder dystocia is adequate. The aim of this trial is to test our hypothesis that skills start to decline at 6 months after training and further decline at 12 months.

Methods

In this randomised, single-blinded study, 13 obstetricians and 51 midwives were randomly assigned to attend a 1-hour mixed lecture and simulation session on shoulder dystocia management. Training was conducted on group 2 at month ‘0’ and on group 1 at month ‘6’. Their knowledge scores (primary outcome) were assessed before (pre-training), immediately after the training (at-training) and retested at month ‘12’ (post-training).

Results

Two-way repeated-measures analysis of variance showed a statistically significant interaction between the testing time frame (pre-training, at-training and post-training) on the score (p<0.001), but no significant interaction between the groups on the score (p=0.458).

Compared to pre-training, the score increased after the simulation training (at-training) in both group 1 (8.69 vs 14.34, p<0.001) and group 2 (9.53 vs 14.66, p< 0.001), but decreased at 6 months post- training in group 1 (14.34 vs 11.71, p<0.001) and at 12 months post-training in group 2 (14.66 vs 11.96, p< 0.001). However the score was better than before the training. There was no significant difference in the post –training score (11.71vs 11.96, p=0.684) between both groups.

Conclusions

Our study demonstrated that simulation training results in short-term and long-term improvement in shoulder dystocia management however knowledge degrades over time. Ongoing training is suggested at a minimum of 12 months’ interval for all members of the obstetrics team including midwives and doctors.
Assessing the measurement properties of a Frailty Index across the age spectrum in the Canadian Longitudinal Study on Aging
Authors: Kanters David M , Griffith Lauren E , Hogan David B , Richardson Julie , Patterson Christopher , Raina Parminder
Published: July 2017

Background

Frailty is a way to appreciate the variable vulnerability to declining health status of people as they age. No consensus for measuring frailty has been established. This study aimed to adapt a Frailty Index (FI) to the Canadian Longitudinal Study on Aging (CLSA) and evaluate its applicability in both younger and older adults.

Methods

An FI was created based on 90 potential health deficits collected from adults aged 45–85 years at recruitment (N=21 241, 49.0% male). The construct validity of this instrument and the factor structure of the health deficits were evaluated.

Results

The direction of associations between the FI and other variables were consistent witha priorihypotheses for construct validity. FI values were significantly associated with age (r=0.17; p<0.001), falls (r=0.12; p<0.001), injuries (r=0.12; p<0.001), formal home care (r =0.30; p<0.001), informal home care (r=0.32; p<0.001) and use of assistive devices (r=0.40; p<0.001). Values were negatively associated with male sex (r=−0.12; p<0.001), income (r=−0.34; p<0.001) and education (r=−0.17; p<0.001). Key factors among the health indicators were physical functioning, satisfaction with life and depressive symptoms. Results did not change when the sample was stratified by age and sex.

Conclusion

The FI is a feasible method to evaluate frailty and capture frailty-related heterogeneity in populations aged 45–85 years. In this study, the FI had good construct validity in middle-aged and older adults, showing expected correlations with sociodemographic factors consistently across age groups. This method can be easily reproduced in similar datasets, making the FI a generalisable instrument.
Timing and pattern of postexercise protein ingestion affects whole-body protein balance in healthy children: a randomized trial
Authors: Volterman Kimberly A. , Moore Daniel R. , Breithaupt Peter , Grathwohl Dominik , Offord Elizabeth A. , Karagounis Leonidas G. , Timmons Brian W.
Published: July 2017

The dose and timing of postexercise protein ingestion can influence whole-body protein balance (WBPB) in adults, although comparable data from children are scarce. This study investigated how protein intake (both amount and distribution) postexercise can affect WBPB in physically active children. Thirty-five children (26 males; 9–13 years old) underwent a 5-day adaptation diet, maintaining a protein intake of 0.95 g·kg−1·day−1. Participants consumed [15N]glycine (2 mg·kg−1) before performing 3 × 20 min of variable-intensity cycling, and whole-body protein kinetics were assessed over 6 and 24 h of recovery. Fifteen grams of protein was distributed across 2 isoenergetic carbohydrate-containing beverages (15 and 240 min postexercise) containing reciprocal amounts of protein (i.e., 0 + 15 g, 5 + 10 g, 10 + 5 g, and 15 + 0 g for Groups A–D, respectively). Over the 6 h that included the exercise bout and consumption of the first beverage at 15 min postexercise, WBPB (i.e., synthesis – breakdown) demonstrated a linear increase of 0.647 g·kg−1·day−1 per 1 g protein intake (P < 0.001). Over 24 h, robust regression revealed that WBPB was best modeled by a parabola (P < 0.05), suggesting that a maximum in WBPB was achieved between groups B and C. In conclusion, despite a dose response early in recovery, a periodized protein intake with multiple smaller doses after physical activity may be more beneficial than a single bolus dose in promoting daily WBPB in healthy active children.
Pattern of ovulation in an ancient, solitary mole-rat lineage:Heliophobius argenteocinereus eminifrom Tanzania
Authors: Katandukila Jestina V. , Ngalameno Mungo K. , Mgode Georgies F. , Bastos Armanda D.S. , Bennett Nigel C.
Published: July 2017

The genus Heliophobius Peters, 1846 is an ancient subterranean rodent lineage within the family Bathyergidae that displays seasonal breeding over a broad geographical range. In East Africa, reproduction in these solitary mole-rats has been shown to coincide with the long rains, but it is not clear whether the silvery mole-rat subspecies Heliophobius argenteocinereus emini Noack, 1894 from Tanzania is an induced or spontaneous ovulator. To address this, urinary progesterone was measured every second day over a period of 132 days in six wild-caught females subjected to three sequential experimental treatments. In the first, control (C) treatment, females were housed singly for a period of 44 days, following which nonphysical contact (NPC) with a vasectomised male and then physical contact (PC) with the same vasectomised male occurred in each of the subsequent 44-day treatments. Noninvasive monitoring of ovarian cyclicity confirmed that mean urinary progesterone concentration was higher during PC than during either NPC or C, despite the fact that the males were vasectomised and incapable of fertilising the females. Examination of penile morphology revealed that males possess epidermal projections on the glans penis, which probably bring about cervical stimulation during coitus. These findings together with the female progesterone profiles imply the species is an induced ovulator stimulated by penile intromission.
Improvement of the Image Sub-Segmentation for Identification and Differentiation of Atypical Regions
Authors: Ojeda-Magaña B. , Quintanilla-Domínguez J. , Ruelas R. , Barba L. Gómez , Andina D.
Published: July 2017

A new sub-segmentation method has been proposed in 2009 which, in digital images, help us to identify the typical pixels, as well as the less representative pixels or atypical of each segmented region. This method is based on the Possibilistic Fuzzy c-Means (PFCM) clustering algorithm, as it integrates absolute and relative memberships. Now, the segmentation problem is related to isolate each one of the objects present in an image. However, and considering only one segmented object or region represented by gray levels as its only feature, the totality of pixels is divided in two basic groups, the group of pixels representing the object, and the others that do not represent it. In the former group, there is a sub-group of pixels near the most representative element of the object, the prototype, and identified here as the typical pixels, and a sub-group corresponding to the less representative pixels of the object, which are the atypical pixels, and generally located at the borders of the pixels representing the object. Besides, the sub-group of atypical pixels presents greater tones (brighter or towards the white color) or smaller tones (darker or towards black color). So, the sub-segmentation method offers the capability to identify the sub-region of atypical pixels, although without performing a differentiation between the brighter and the darker ones. Hence, the proposal of this work contributes to the problem of image segmentation with the improvement on the detection of the atypical sub-regions, and clearly recognizing between both kind of atypical pixels, because in many cases only the brighter or the darker atypical pixels are the ones that represent the object of interest in an image, depending on the problem to be solved. In this study, two real cases are used to show the contribution of this proposal; the first case serves to demonstrate the pores detection in soil images represented by the darker atypical pixels, and the second one to demonstrate the detection of microcalcifications in mammograms, represented in this case by the brighter atypical pixels.