title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1488 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Tibia functionality and Division II female and male collegiate athletes from multiple sports link: https://peerj.com/articles/5550 last-modified: 2018-09-11 description: BackgroundBone strength is developed through a combination of the size and shape (architecture) of a bone as well as the bone’s material properties; and therefore, no one outcome variable can measure a positive or negative adaptation in bone. Skeletal robusticity (total area/ bone length) a measure of bones external size varies within the population and is independent of body size, but robusticity has been associated with bone strength. Athletes may have similar variability in robusticity values as the general population and thus have a wide range of bone strengths based on the robustness of their bones. Therefore, the purpose of this study was to determine if an athlete’s bone strength and cortical area relative to body size was dependent on robusticity. The second aim was to determine if anthropometry or muscle function measurements were associated with bone robusticity.MethodsBone variables contributing to bone strength were measured in collegiate athletes and a reference group using peripheral quantitative computed tomography (pQCT) at the 50% tibial site. Bone functionality was assessed by plotting bone strength and cortical area vs body size (body weight x tibial length) and robustness (total area/length) vs body size. Bone strength was measured using the polar strength-strain index (SSIp). Based on the residuals from the regression, an athlete’s individual functionality was determined, and two groups were formed “weaker for size” (WS) and “stronger for size” (SS). Grip strength, leg extensor strength and lower body power were also measured.ResultsDivision II athletes exhibited a natural variation in (SSIp) relative to robusticity consistent with previous studies. Bone strength (SSIp) was dependent on the robusticity of the tibia. The bone traits that comprise bone strength (SSIp) were significantly different between the SS and WS groups, yet there were minimal differences in the anthropometric data and muscle function measures between groups. A lower percentage of athletes from ball sports were “weaker for size” (WS group) and a higher percentage of swimmers were in the WS group.DiscussionA range of strength values based on robusticity occurs in athletes similar to general populations. Bones with lower robusticity (slender) were constructed with less bone tissue and had less strength. The athletes with slender bones were from all sports including track and field and ball sports but the majority were swimmers.ConclusionsAthletes, even after optimal training for their sport, may have weaker bones based on robusticity. Slender bones may therefore be at a higher risk for fracture under extreme loading events but also yield benefits to some athletes (swimmers) due to their lower bone mass. creator: Vanessa R. Yingling creator: Benjamin Ferrari-Church creator: Ariana Strickland uri: https://doi.org/10.7717/peerj.5550 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Yingling et al. title: A short, robust brain activation control task optimised for pharmacological fMRI studies link: https://peerj.com/articles/5540 last-modified: 2018-09-11 description: BackgroundFunctional magnetic resonance imaging (fMRI) is a popular method for examining pharmacological effects on the brain; however, the BOLD response is dependent on intact neurovascular coupling, and potentially modulated by a number of physiological factors. Pharmacological fMRI is therefore vulnerable to confounding effects of pharmacological probes on general physiology or neurovascular coupling. Controlling for such non-specific effects in pharmacological fMRI studies is therefore an important consideration, and there is an additional need for well-validated fMRI task paradigms that could be used to control for such effects, or for general testing purposes.MethodsWe have developed two variants of a standardized control task that are short (5 minutes duration) simple (for both the subject and experimenter), widely applicable, and yield a number of readouts in a spatially diverse set of brain networks. The tasks consist of four functionally discrete three-second trial types (plus additional null trials) and contain visual, auditory, motor and cognitive (eye-movements, and working memory tasks in the two task variants) stimuli. Performance of the tasks was assessed in a group of 15 subjects scanned on two separate occasions, with test-retest reliability explicitly assessed using intra-class correlation coefficients.ResultsBoth tasks produced robust patterns of brain activation in the expected brain regions, and region of interest-derived reliability coefficients for the tasks were generally high, with four out of eight task conditions rated as ‘excellent’ or ‘good’, and only one out of eight rated as ‘poor’. Median values in the voxel-wise reliability measures were also >0.7 for all task conditions, and therefore classed as ‘excellent’ or ‘good’. The spatial concordance between the most highly activated voxels and those with the highest reliability coefficients was greater for the sensory (auditory, visual) conditions than the other (motor, cognitive) conditions.DiscussionEither of the two task variants would be suitable for use as a control task in future pharmacological fMRI studies or for any other investigation where a short, reliable, basic task paradigm is required. Stimulus code is available online for re-use by the scientific community. creator: Jessica-Lily Harvey creator: Lysia Demetriou creator: John McGonigle creator: Matthew B. Wall uri: https://doi.org/10.7717/peerj.5540 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Harvey et al. title: DNA mismatch repair and CD133-marked cancer stem cells in colorectal carcinoma link: https://peerj.com/articles/5530 last-modified: 2018-09-11 description: BackgroundExcept for a few studies with contradictory observations, information is lacking on the possibility of association between DNA mismatch repair (MMR) status and the presence of cancer stem cells in colorectal carcinoma (CRC), two important aspects in colorectal carcinogenesis.MethodsEighty (40 right-sided and 40 left-sided) formalin-fixed, paraffin-embedded primary CRC were immunohistochemically studied for CD133, a putative CRC stem cell marker, and MMR proteins MLH1, MSH2, MSH6 and PMS2. CD133 expression was semi-quantitated for proportion of tumor immunopositivity on a scale of 0–5 and staining intensity on a scale of 0–3 with a final score (units) being the product of proportion and intensity of tumor staining. The tumor was considered immunopositive only when the tumor demonstrated moderate to strong intensity of CD133 staining (a decision made after analysis of CD133 expression in normal colon). Deficient MMR (dMMR) was interpreted as unequivocal loss of tumor nuclear staining for any MMR protein despite immunoreactivity in the internal positive controls.ResultsCD133 was expressed in 36 (90.0%) left-sided and 28 (70.0%) right-sided tumors (p < 0.05) and CD133 score was significantly higher in left- (mean ± SD = 9.6 ± 5.3 units) compared with right-sided tumors (mean ± SD = 6.8 ± 5.6 units) p < 0.05). dMMR was noted in 14 (35%) right-sided and no (0%) left-sided CRC. When stratified according to MMR status, dMMR cases showed a lower frequency of CD133 expression (42.9%) and CD133 score (mean ± SD = 2.5 ± 3.6 units) compared with pMMR tumors on the right (frequency = 84.6%; mean score ± SD = 9.2 ± 5.0 units) as well as pMMR tumors on the left (frequency = 90.0%; mean score ± SD = 9.6 ± 5.3 units) (p < 0.05). Interestingly, frequencies of CD133 immunoreactivity and CD133 scores did not differ between pMMR CRC on the right versus the left (p > 0.05).ConclusionProficient MMR correlated with high levels of CD133-marked putative cancer stem cells in both right- and left-sided tumors, whereas significantly lower levels of CD133-marked putative cancer stem cells were associated with deficient MMR status in colorectal carcinomas found on the right. creator: Phaik-Leng Cheah creator: Jing Li creator: Lai-Meng Looi creator: Kean-Hooi Teoh creator: Diana Bee-Lan Ong creator: Mark J. Arends uri: https://doi.org/10.7717/peerj.5530 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Cheah et al. title: Growth under cold conditions in a wide perennial ryegrass panel is under tight physiological control link: https://peerj.com/articles/5520 last-modified: 2018-09-11 description: BackgroundPerennial ryegrass is a cool-season grass species from the family Poaceae and is widely cultivated in temperate regions because it exhibits rapid growth and establishment, and possesses high forage quality. The extension of the growing season in Ireland in spring and autumn is a breeding target to make farming more profitable since a grass-fed diet based on grazing is the cheapest way of nutrition for ruminants.MethodsFifty-seven perennial ryegrass accessions were screened for their ability to grow under typical Irish spring conditions as taken from long term temperature records in controlled climate chambers. They were grown in low temperature (8 °C/2 °C day/night) and control conditions (15 °C/8 °C day/night) in three consecutive independent experiments. Fresh weight, height, chlorophyll content and electrolyte leakage were measured, and these parameters were used to rank plant performance under low temperature growth conditions.ResultsThe results showed that height, yield and electrolyte leakage are excellent measures for the impact of cold stress tolerance. Little variation in growth was seen under cold stress, but a wide variety of responses were observed under control conditions.DiscussionOur results suggest that cold stress is under tight physiological control. Interestingly, the various genotypes responded differentially to more amenable control conditions, indicating that a quick response to more amenable growth conditions is a better target for breeding programmes. creator: Lena Förster creator: Jim Grant creator: Thibauld Michel creator: Carl Ng creator: Susanne Barth uri: https://doi.org/10.7717/peerj.5520 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Förster et al. title: A comparison of perceptions of nuts between the general public, dietitians, general practitioners, and nurses link: https://peerj.com/articles/5500 last-modified: 2018-09-11 description: BackgroundNut consumption at the population level remains low despite the well-documented benefits of their consumption, including their cardioprotective effects. Studies have suggested that advice from health professionals may be a means to increase nut consumption levels. Understanding how nuts are perceived by the public and health professionals, along with understanding the public’s perceptions of motivators of and deterrents to consuming nuts, may inform the development of initiatives to improve on these low levels of consumption. The aim of this cross-sectional study was to compare perceptions of nuts among three groups of health professionals (dietitians, general practioners, and practice nurses) and the general public in New Zealand (NZ), along with motivators of and deterrents to consuming nuts amongst the general public and their experiences of receiving advice around nut consumption.MethodsThe NZ electoral roll was used to identify dietitians, general practitioners (GPs), and practice nurses, based on their free-text occupation descriptions, who were then invited to complete a questionnaire with 318, 292, and 149 respondents respectively. 1,600 members of the general public were randomly selected from the roll with 710 respondents. Analyses were performed using chi-squared tests to look at differences in categorical variables and linear regression for differences in other variables between the four survey groups.ResultsAlthough there were significant differences between the four groups regarding the perceptions of nuts, in general there was agreement that nuts are healthy, high in protein and fat, are filling, and some nuts are high in selenium. We noted frequent agreement that the general public participants would consume more if nuts: improved health (67%), were more affordable (60%), or improved the nutrient content (59%) and balance of fats (58%) within their diets. Over half the respondents reported they would eat more nuts if they were advised to do so by a dietitian or doctor, despite less than 4% reporting they had received such advice. The most frequently selected deterrents to increasing nut consumption were: cost (67%), potential weight gain (66%), and leading to eating too much fat (63%).DiscussionIt is concerning that so few among the general public report receiving advice to consume more nuts from health professionals, especially given their apparent responsiveness to such advice. Health professionals could exploit the motivators of nut consumption, while also addressing the deterrents, to promote nut intake. These factors should also be addressed in public health messages to encourage regular nut consumption among the public. Educational initiatives could also be used to improve the nutritional knowledge of GPs and practice nurses with regard to nuts, although even dietitians were unsure of their knowledge in some cases. creator: Rachel Clare Brown creator: Andrew Robert Gray creator: Lee Ching Yong creator: Alex Chisholm creator: Sook Ling Leong creator: Siew Ling Tey uri: https://doi.org/10.7717/peerj.5500 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Brown et al. title: A novel experimental design for the measurement of metacarpal bone loading and deformation and fingertip force link: https://peerj.com/articles/5480 last-modified: 2018-09-11 description: BackgroundMusculoskeletal and finite element modelling are often used to predict joint loading and bone strength within the human hand, but there is a lack of in vitro evidence of the force and strain experienced by hand bones.MethodsThis study presents a novel experimental setup that allows the positioning of a cadaveric digit in a variety of postures with the measurement of force and strain experienced by the third metacarpal. The setup allows for the measurement of fingertip force as well. We tested this experimental setup using three cadaveric human third digits in which the flexor tendons were loaded in two tendon pathways: (1) parallel to the metacarpal bone shaft, with bowstringing; (2) a semi-physiological condition in which the tendons were positioned closer to the bone shaft.ResultsThere is substantial variation in metacarpal net force, metacarpal strain and fingertip force between the two tendon pathways. The net force acting on the metacarpal bone is oriented palmarly in the parallel tendon condition, causing tension along the dorsum of the metacarpal shaft, while the force increases and is oriented dorsally in the semi-physiological condition, causing compression of the dorsal metacarpal shaft. Fingertip force is also greater in the semi-physiological condition, implying a more efficient grip function. Inter-individual variation is observed in the radioulnar orientation of the force experienced by the metacarpal bone, the fingertip force, and the strain patterns on the metacarpal shaft.ConclusionThis study demonstrates a new method for measuring force and strain experienced by the metacarpal, and fingertip force in cadaveric digits that can, in turn, inform computation models. Inter-individual variation in loads experienced by the third digit suggest that there are differences in joint contact and/or internal bone structure across individuals that are important to consider in clinical and evolutionary contexts. creator: Szu-Ching Lu creator: Evie E. Vereecke creator: Alexander Synek creator: Dieter H. Pahr creator: Tracy L. Kivell uri: https://doi.org/10.7717/peerj.5480 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Lu et al. title: Effects of resveratrol, exercises and their combination on Farnesoid X receptor, Liver X receptor and Sirtuin 1 gene expression and apoptosis in the liver of elderly rats with nonalcoholic fatty liver link: https://peerj.com/articles/5522 last-modified: 2018-09-10 description: BackgroundNon-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder. This study aims to consider effects of resveratrol, exercise and their combination on Farnesoid X receptor (Fxr), the liver X receptor (Lxr) and Sirtuin 1 (Sirt 1) genes expression in the liver of elderly rats with NAFLD.MethodsRats with NAFLD were randomly divided into seven groups including patient, saline, resveratrol (RSV), interval exercise, continuous exercise, interval exercise + RSV and continuous exercise + RSV. Levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in the liver tissue were measured using specific ELISA kits. A TUNEL assay kit was used for the assessment of hepatic cells apoptosis. Lipid profiles were considered by measuring the serum triglyceride, cholesterol, LDL, and HDL. Expression of Sirt1, Lxr and Fxr genes was considered using RT-PCR.ResultsResveratrol administration alone or combined with exercise training significantly improved the expression of Sirt1, Lxr and Fxr genes (p < 0.05) in the hepatic tissue of rats with NAFLD, while levels of AST, ALT, ALP enzymes, as well as apoptotic cells were significantly decreased (p < 0.05).DiscussionAlthough resveratrol alone improves the expression of Sirt1, Lxr and Fxr, as well as liver function, combined therapy with exercise training is more effective to improve NAFLD. creator: Amir Hajighasem creator: Parvin Farzanegi creator: Zohreh Mazaheri creator: Marjan Naghizadeh creator: Ghoncheh Salehi uri: https://doi.org/10.7717/peerj.5522 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Hajighasem et al. title: Association of burnout with doctor–patient relationship and common stressors among postgraduate trainees and house officers in Lahore—a cross-sectional study link: https://peerj.com/articles/5519 last-modified: 2018-09-10 description: IntroductionBurnout is defined as a prolonged state of physical and psychological exhaustion. Doctors, due to the demanding nature of their job, are susceptible to facing burnout, which has far reaching implications on their productivity and motivation. It affects the quality of care they provide to patients, thus eroding the doctor–patient relationship which embodies patient centeredness and autonomy. The study aims at addressing the stressors leading to burnout and its effect on the doctor–patient relationship.MethodsA descriptive, cross-sectional study design with convenience (non-probability) sampling technique was employed in six major hospitals of Lahore, Pakistan. A total of 600 doctors were approached for the study which included house officers or “HOs” (recent graduates doing their 1 year long internship) and post-graduate trainees or “PGRs” (residents for 4–5 years in their specialties). Burnout was measured using the Copenhagen Burnout Inventor (CBI) while attitudes towards the doctor–patient relationship was measured using the Patient Practitioner Orientation Scale (PPOS), which measures two components of the relationship: power sharing and patient caring. Pearson correlation and linear regression analysis were used to analyze the data via SPSS v.21.ResultsA total of 515 doctors consented to take part in the study (response rate 85.83%). The final sample consisted of 487 doctors. The burnout score was not associated with the total and caring domain scores of PPOS (P > 0.05). However, it was associated with the power sharing sub-scale of PPOS. Multiple linear regression analysis yielded a significant model, by virtue of which CBI scores were positively associated with factors such as female gender, feeling of burn out, scoring high on sharing domain of PPOS and a lack of personal control while CBI scores were negatively associated with private medical college education, having a significant other, accommodation away from home and a sense of never ending competition. Burnout levels varied significantly between house officers and post graduate trainees. Twenty-three percent of the participants (mostly house officers) had high/very high burnout levels on the CBI (Kristenson’s burnout scoring). Both groups showed significant differences with respect to working hours, smoking status and income.ConclusionAlthough burnout showed no significant association with total and caring domain scores of PPOS (scale used to assess doctor–patient relationship), it showed a significant association with the power sharing domain of PPOS suggesting some impact on the overall delivery of patient care. Thus, it necessitates the monitoring of stressors in order to provide an atmosphere where patient autonomy can be practiced. creator: Waqas Ahmad creator: Huma Ashraf creator: Afnan Talat creator: Aleena Ahmad Khan creator: Ammad Anwar Baig creator: Iqra Zia creator: Zohak Sarfraz creator: Hifsa Sajid creator: Marium Tahir creator: Usman Sadiq creator: Hira Imtiaz uri: https://doi.org/10.7717/peerj.5519 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Ahmad et al. title: Effects of environmental and anthropogenic landscape features on mule deer harvest in Nebraska link: https://peerj.com/articles/5510 last-modified: 2018-09-10 description: Understanding the habitat use of wildlife species is important for effective management. Nebraska has a variety of habitat types, with the majority being covered by rangeland and cropland. These habitat types likely influence the harvest of mule deer (MD; Odocoileus hemionus) in Nebraska, but their specific effects are unknown, and moreover, harvest may also be influenced by the accessibility of deer habitats for hunters. We modeled which environmental and anthropogenic landscape features influenced harvest densities. Spatial analysis in a Geographic Information System was used to determine the mean values of environmental and anthropogenic landscape features at the county level. We then used a generalized linear model to determine which of those factors influenced MD harvest from 2014–2016. We found that NDVI amplitude, hunter effort, road density, terrain roughness, and canopy cover influence MD harvest in Nebraska. According to our model, MD harvest densities are significantly greater areas with NDVI amplitude ∼38, increasing hunter effort, road densities near 1,750 m/km2, increasing terrain roughness, and decreasing canopy cover. Understanding increased harvest densities of MD can be beneficial for wildlife managers, allowing for more efficient allocation of efforts and expenses by managers for population management. creator: Bryan J. O’Connor creator: Nicolas J. Fryda creator: Dustin H. Ranglack uri: https://doi.org/10.7717/peerj.5510 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 O’Connor et al. title: Unconscious response inhibition differences between table tennis athletes and non-athletes link: https://peerj.com/articles/5548 last-modified: 2018-09-07 description: BackgroundResponse inhibition is associated with successful sporting performance. However, research on response inhibition in athletes from open-skill sports has mainly focused on a consciously triggered variety; little is known about open-skill athletes’ response inhibition elicited by unconscious stimuli.MethodsHere, we explored unconscious response inhibition differences between table tennis athletes (n = 20) and non-athletes (n = 19) using the masked go/no-go task and event-related potentials technique (ERPs).ResultsAt the behavioral level, table tennis athletes displayed shorter go-response times (RTs) than non-athletes in the conscious condition. Furthermore, table tennis athletes exhibited longer response time–slowing (RT-slowing) than non-athletes in the unconscious condition. At the neural level, table tennis athletes displayed shorter event-related potential N2 component latencies than non-athletes for all conditions. More importantly, athletes displayed larger no-go event-related potential P3 component amplitudes than non-athletes at both the conscious and unconscious levels.DiscussionThe present study results suggested that table tennis athletes have superior conscious and unconscious response inhibition compared to non-athletes. creator: Yihong You creator: Yiming Ma creator: Zhiguang Ji creator: Fanying Meng creator: Anmin Li creator: Chunhua Zhang uri: https://doi.org/10.7717/peerj.5548 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 You et al.