title: PeerJ
description:  Articles published in PeerJ
link: https://peerj.com/articles/index.rss3?journal=peerj&page=1921
creator: info@peerj.com PeerJ
errorsTo: info@peerj.com PeerJ
language: en

title: A comparison of two gluteus maximus EMG maximum voluntary isometric contraction positions
link: https://peerj.com/articles/1261
last-modified: 2015-09-22
description: Background. The purpose of this study was to compare the peak electromyography (EMG) of the most commonly-used position in the literature, the prone bent-leg (90°) hip extension against manual resistance applied to the distal thigh (PRONE), to a novel position, the standing glute squeeze (SQUEEZE).Methods. Surface EMG electrodes were placed on the upper and lower gluteus maximus of thirteen recreationally active females (age = 28.9 years; height = 164 cm; body mass = 58.2 kg), before three maximum voluntary isometric contraction (MVIC) trials for each position were obtained in a randomized, counterbalanced fashion.Results. No statistically significant (p < 0.05) differences were observed between PRONE (upper: 91.94%; lower: 94.52%) and SQUEEZE (upper: 92.04%; lower: 85.12%) for both the upper and lower gluteus maximus. Neither the PRONE nor SQUEEZE was more effective between all subjects.Conclusions. In agreement with other studies, no single testing position is ideal for every participant. Therefore, it is recommended that investigators employ multiple MVIC positions, when possible, to ensure accuracy. Future research should investigate a variety of gluteus maximus MVIC positions in heterogeneous samples.
creator: Bret Contreras
creator: Andrew D. Vigotsky
creator: Brad J. Schoenfeld
creator: Chris Beardsley
creator: John Cronin
uri: https://doi.org/10.7717/peerj.1261
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2015 Contreras et al.

title: Metatranscriptomic analysis of a high-sulfide aquatic spring reveals insights into sulfur cycling and unexpected aerobic metabolism
link: https://peerj.com/articles/1259
last-modified: 2015-09-22
description: Zodletone spring is a sulfide-rich spring in southwestern Oklahoma characterized by shallow, microoxic, light-exposed spring water overlaying anoxic sediments. Previously, culture-independent 16S rRNA gene based diversity surveys have revealed that Zodletone spring source sediments harbor a highly diverse microbial community, with multiple lineages putatively involved in various sulfur-cycling processes. Here, we conducted a metatranscriptomic survey of microbial populations in Zodletone spring source sediments to characterize the relative prevalence and importance of putative phototrophic, chemolithotrophic, and heterotrophic microorganisms in the sulfur cycle, the identity of lineages actively involved in various sulfur cycling processes, and the interaction between sulfur cycling and other geochemical processes at the spring source. Sediment samples at the spring’s source were taken at three different times within a 24-h period for geochemical analyses and RNA sequencing. In depth mining of datasets for sulfur cycling transcripts revealed major sulfur cycling pathways and taxa involved, including an unexpected potential role of Actinobacteria in sulfide oxidation and thiosulfate transformation. Surprisingly, transcripts coding for the cyanobacterial Photosystem II D1 protein, methane monooxygenase, and terminal cytochrome oxidases were encountered, indicating that genes for oxygen production and aerobic modes of metabolism are actively being transcribed, despite below-detectable levels (<1 µM) of oxygen in source sediment. Results highlight transcripts involved in sulfur, methane, and oxygen cycles, propose that oxygenic photosynthesis could support aerobic methane and sulfide oxidation in anoxic sediments exposed to sunlight, and provide a viewpoint of microbial metabolic lifestyles under conditions similar to those seen during late Archaean and Proterozoic eons.
creator: Anne M. Spain
creator: Mostafa S. Elshahed
creator: Fares Z. Najar
creator: Lee R. Krumholz
uri: https://doi.org/10.7717/peerj.1259
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2015 Spain et al.

title: Temporal and spatial strategies in an active place avoidance task on Carousel: a study of effects of stability of arena rotation speed in rats
link: https://peerj.com/articles/1257
last-modified: 2015-09-22
description: The active place avoidance task is a dry-arena task used to assess spatial navigation and memory in rodents. In this task, a subject is put on a rotating circular arena and avoids an invisible sector that is stable in relation to the room. Rotation of the arena means that the subject’s avoidance must be active, otherwise the subject will be moved in the to-be-avoided sector by the rotation of the arena and a slight electric shock will be administered. The present experiment explored the effect of variable arena rotation speed on the ability to avoid the to-be-avoided sector. Subjects in a group with variable arena rotation speed learned to avoid the sector with the same speed and attained the same avoidance ability as rats in a group with a stable arena rotation speed. Only a slight difference in preferred position within the room was found between the two groups. No difference was found between the two groups in the dark phase, where subjects could not use orientation cues in the room. Only one rat was able to learn the avoidance of the to-be-avoided sector in this phase. The results of the experiment suggest that idiothetic orientation and interval timing are not crucial for learning avoidance of the to-be-avoided sector. However, idiothetic orientation might be sufficient for avoiding the sector in the dark.
creator: Štěpán Bahník
creator: Aleš Stuchlík
uri: https://doi.org/10.7717/peerj.1257
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2015 Bahník and Stuchlík

title: Demographics and density estimates of two three-toed box turtle (Terrapene carolina triunguis) populations within forest and restored prairie sites in central Missouri
link: https://peerj.com/articles/1256
last-modified: 2015-09-22
description: Box turtles (Terrapene carolina) are widely distributed but vulnerable to population decline across their range. Using distance sampling, morphometric data, and an index of carapace damage, we surveyed three-toed box turtles (Terrapene carolina triunguis) at 2 sites in central Missouri, and compared differences in detection probabilities when transects were walked by one or two observers. Our estimated turtle densities within forested cover was less at the Thomas S. Baskett Wildlife Research and Education Center, a site dominated by eastern hardwood forest (d = 1.85 turtles/ha, 95% CI [1.13, 3.03]) than at the Prairie Fork Conservation Area, a site containing a mix of open field and hardwood forest (d = 4.14 turtles/ha, 95% CI [1.99, 8.62]). Turtles at Baskett were significantly older and larger than turtles at Prairie Fork. Damage to the carapace did not differ significantly between the 2 populations despite the more prevalent habitat management including mowing and prescribed fire at Prairie Fork. We achieved improved estimates of density using two rather than one observer at Prairie Fork, but negligible differences in density estimates between the two methods at Baskett. Error associated with probability of detection decreased at both sites with the addition of a second observer. We provide demographic data on three-toed box turtles that suggest the use of a range of habitat conditions by three-toed box turtles. This case study suggests that habitat management practices and their impacts on habitat composition may be a cause of the differences observed in our focal populations of turtles.
creator: Kelly M. O’Connor
creator: Chadwick D. Rittenhouse
creator: Joshua J. Millspaugh
creator: Tracy A.G. Rittenhouse
uri: https://doi.org/10.7717/peerj.1256
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2015 O’Connor et al.

title: Novel epitopes identified from efflux pumps of Mycobacterium tuberculosis could induce cytotoxic T lymphocyte response
link: https://peerj.com/articles/1229
last-modified: 2015-09-22
description: Overcoming drug-resistance is one of the major challenges to control tuberculosis (TB). The up-regulation of efflux pumps is one common mechanism that leads to drug-resistance. Therefore, immunotherapy targeting these efflux pump antigens could be promising strategy to be combined with current chemotherapy. Considering that CD8+ cytotoxic T lymphocytes (CTLs) induced by antigenic peptides (epitopes) could elicit HLA-restricted anti-TB immune response, efflux pumps from classical ABC family (Mycobacterium tuberculosis, Mtb) were chosen as target antigens to identify CTL epitopes. HLA-A2 restricted candidate peptides from Rv2937, Rv2686c and Rv2687c of Mycobacterium tuberculosis were predicted, synthesized and tested. Five peptides could induce IFN-γ release and cytotoxic activity in PBMCs from HLA-A2+ PPD+ donors. Results from HLA-A2/Kb transgenic mice immunization assay suggested that four peptides Rv2937-p168, Rv2937-p266, Rv2686c-p151, and Rv2686c-p181 could induce significant CTL response in vivo. These results suggested that these novel epitopes could be used as immunotherapy candidates to TB drug-resistance.
creator: Ming-xia Zhai
creator: Fei Chen
creator: Yuan-yuan Zhao
creator: Ya-hong Wu
creator: Guo-dong Li
creator: Yan-feng Gao
creator: Yuan-ming Qi
uri: https://doi.org/10.7717/peerj.1229
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2015 Zhai et al.

title: Improved estimates of age, growth and reproduction for the regionally endemic Galapagos sailfin grouper Mycteroperca olfax (Jenyns, 1840)
link: https://peerj.com/articles/1270
last-modified: 2015-09-17
description: The Galapagos Sailfin grouper, Mycteroperca olfax, locally known as bacalao and listed as vulnerable by the IUCN, is culturally, economically, and ecologically important to the Galapagos archipelago and its people. It is regionally endemic to the Eastern Tropical Pacific, and, while an important fishery resource that has shown substantial declines in recent years, to date no effective management regulations are in place to ensure the sustainability of the Galapagos fishery for this species. Previous estimates of longevity and size at maturity for bacalao are inconsistent with estimates for congeners, which brings into question the accuracy of prior estimates. We set out to assess the age, growth, and reproductive biology of bacalao in order to provide more accurate life history information to inform more effective fisheries management for this species. The oldest fish in our sample was 21 years old, which is 2–3 times greater than previously reported estimates of longevity. Parameter estimates for the von Bertalanffy growth function (k = 0.11, L∞ = 110 cm TL, and to = − 1.7 years) show bacalao to grow much slower and attain substantially larger asymptotic maximum length than previous studies. Mean size at maturity (as female) was estimated at 65.3 cm TL, corresponding to a mean age of 6.5 years. We found that sex ratios were extremely female biased (0.009 M:1F), with a large majority of the individuals in our experimental catch being immature (79%). Our results show that bacalao grow slower, live longer, and mature at a much larger size and greater age than previously thought, with very few mature males in the population. These findings have important implications for the fishery of this valuable species and provide the impetus for a long-overdue species management plan to ensure its long-term sustainability.
creator: Paolo Usseglio
creator: Alan M. Friedlander
creator: Edward E. DeMartini
creator: Anna Schuhbauer
creator: Eva Schemmel
creator: Pelayo Salinas de Léon
uri: https://doi.org/10.7717/peerj.1270
license: http://creativecommons.org/publicdomain/zero/1.0/
rights: 

title: Moth flies and sand flies (Diptera: Psychodidae) in Cretaceous Burmese amber
link: https://peerj.com/articles/1254
last-modified: 2015-09-17
description: One new subfamily, four new genera and 10 new species of Psychodidae are described from Burmese amber which significantly increases our knowledge about this group in the Cretaceous. Protopsychodinae n. subfam. probably represents the oldest known ancestor of modern Psychodinae and includes three species within two genera: Datzia setosa gen. et sp. n., Datzia bispina gen. et sp. n., and Mandalayia beumersorum gen. et sp. n. Sycoracinae and Phlebotominae are represented by two genera each in the studied material, Palaeoparasycorax globosus gen. et sp. n., Palaeoparasycorax suppus gen. et sp. n., Parasycorax simplex sp. n., and Phlebotomites aphoe sp. n. and Phlebotomus vetus sp. n., respectively. Bruchomyiinae is represented by Nemopalpus quadrispiculatus sp. n. Furthermore, one genus of an incertae sedis subfamily, Bamara groehni gen. et sp. n., is described. The systematic positions of the new taxa are discussed.
creator: Frauke Stebner
creator: Mónica M. Solórzano Kraemer
creator: Sergio Ibáñez-Bernal
creator: Rüdiger Wagner
uri: https://doi.org/10.7717/peerj.1254
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2015 Stebner et al.

title: Detection of Alzheimer’s disease by displacement field and machine learning
link: https://peerj.com/articles/1251
last-modified: 2015-09-17
description: Aim. Alzheimer’s disease (AD) is a chronic neurodegenerative disease. Recently, computer scientists have developed various methods for early detection based on computer vision and machine learning techniques.Method. In this study, we proposed a novel AD detection method by displacement field (DF) estimation between a normal brain and an AD brain. The DF was treated as the AD-related features, reduced by principal component analysis (PCA), and finally fed into three classifiers: support vector machine (SVM), generalized eigenvalue proximal SVM (GEPSVM), and twin SVM (TSVM). The 10-fold cross validation repeated 50 times.Results. The results showed the “DF + PCA + TSVM” achieved the accuracy of 92.75 ± 1.77, sensitivity of 90.56 ± 1.15, specificity of 93.37 ± 2.05, and precision of 79.61 ± 2.21. This result is better than or comparable with not only the other proposed two methods, but also ten state-of-the-art methods. Besides, our method discovers the AD is related to following brain regions disclosed in recent publications: Angular Gyrus, Anterior Cingulate, Cingulate Gyrus, Culmen, Cuneus, Fusiform Gyrus, Inferior Frontal Gyrus, Inferior Occipital Gyrus, Inferior Parietal Lobule, Inferior Semi-Lunar Lobule, Inferior Temporal Gyrus, Insula, Lateral Ventricle, Lingual Gyrus, Medial Frontal Gyrus, Middle Frontal Gyrus, Middle Occipital Gyrus, Middle Temporal Gyrus, Paracentral Lobule, Parahippocampal Gyrus, Postcentral Gyrus, Posterior Cingulate, Precentral Gyrus, Precuneus, Sub-Gyral, Superior Parietal Lobule, Superior Temporal Gyrus, Supramarginal Gyrus, and Uncus.Conclusion. The displacement filed is effective in detection of AD and related brain-regions.
creator: Yudong Zhang
creator: Shuihua Wang
uri: https://doi.org/10.7717/peerj.1251
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2015 Zhang and Wang

title: Diet, exercise and mental-wellbeing of healthcare professionals (doctors, dentists and nurses) in Pakistan
link: https://peerj.com/articles/1250
last-modified: 2015-09-17
description: Background. “Health is wealth” is a time tested adage. Health becomes more relevant when it comes to professionals whose job is to provide people with services that maintain an optimum state of mental, physical and social well-being. Healthcare professionals (HCP) differ from general population in regards to the nature of their work, stress, burnout etc. which begs the need to have a robust state of health for the ones who provide it to others. We initiated this study to see if healthcare professionals “practice what they preach others.”Methods. We employed a cross-sectional study design with convenience-sampling technique. Questionnaires were administered directly to the three groups of healthcare professionals (Doctors, Dentists and Nurses) across the province Punjab after their consent. 1,319 healthcare professionals took part in the study (response rate of 87.35). Warwick Edinburg Mental Wellbeing Scale (WEMWBS) was used to assess mental wellbeing. USDA Dietary Guidelines-2010 were employed to quantify diet. American Heart Association (AHA) guidelines were employed for the analysis of exercise.Results. A total of 1,190 healthcare professionals formed the final sample with doctors and nurses forming the major proportion. Out of 1,190 participants only one healthcare professional was found to eat according to USDA Dietary Guidelines; others ate more of protein group and less of fruits, dairy and vegetable groups. 76% did not perform any exercise. 71.5% worked >48 h/week. More than 50% of healthcare professionals were sleeping <7 h/day. WEMWBS score of the entire sample was 47.97 ± 9.53 S.D.Conclusion. Our findings suggest that healthcare professionals do not practice what they preach. Their mental wellbeing, diet and exercise habits are not up to the mark and should be improved to foster the whole healthcare system for individual and community benefits.
creator: Waqas Ahmad
creator: Frances Taggart
creator: Muhammad Shoaib Shafique
creator: Yumna Muzafar
creator: Shehnam Abidi
creator: Noor Ghani
creator: Zahra Malik
creator: Tehmina Zahid
creator: Ahmed Waqas
creator: Naila Ghaffar
uri: https://doi.org/10.7717/peerj.1250
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2015 Ahmad et al.

title: Chinese Interpreting Studies: a data-driven analysis of a dynamic field of enquiry
link: https://peerj.com/articles/1249
last-modified: 2015-09-17
description: Over the five decades since its beginnings, Chinese Interpreting Studies (CIS) has evolved into a dynamic field of academic enquiry with more than 3,500 scholars and 4,200 publications. Using quantitative and qualitative analysis, this scientometric study delves deep into CIS citation data to examine some of the noteworthy trends and patterns of behavior in the field: how can the field’s progress be quantified by means of citation analysis? Do its authors tend repeatedly to cite ‘classic’ papers or are they more drawn to their colleagues’ latest research? What different effects does the choice of empirical vs. theoretical research have on the use of citations in the various research brackets? The findings show that the field is steadily moving forward with new papers continuously being cited, although a number of influential papers stand out, having received a stream of citations in all the years examined. CIS scholars also have a tendency to cite much older English than Chinese publications across all document types, and empirical research has the greatest influence on the citation behavior of doctoral scholars, while theoretical studies have the largest impact on that of article authors. The goal of this study is to demonstrate the merits of blending quantitative and qualitative analyses to uncover hidden trends.
creator: Ziyun Xu
creator: Leonid Pekelis
uri: https://doi.org/10.7717/peerj.1249
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2015 Xu and Pekelis