title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1451 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Heavier- and lighter-load isolated lumbar extension resistance training produce similar strength increases, but different perceptual responses, in healthy males and females link: https://peerj.com/articles/6001 last-modified: 2018-11-22 description: ObjectivesMuscles dominant in type I muscle fibres, such as the lumbar extensors, are often trained using lighter loads and higher repetition ranges. However, literature suggests that similar strength adaptations can be attained by the use of both heavier- (HL) and lighter-load (LL) resistance training across a number of appendicular muscle groups. Furthermore, LL resistance exercise to momentary failure might result in greater discomfort.DesignThe aims of the present study were to compare strength adaptations, as well as perceptual responses of effort (RPE-E) and discomfort (RPE-D), to isolated lumbar extension (ILEX) exercise using HL (80% of maximum voluntary contraction; MVC) and LL (50% MVC) in healthy males and females.MethodsTwenty-six participants (n = 14 males, n = 12 females) were divided in to sex counter-balanced HL (23 ± 5 years; 172.3 ± 9.8 cm; 71.0 ± 13.1 kg) and LL (22 ± 2 years; 175.3 ± 6.3 cm; 72.8 ± 9.5 kg) resistance training groups. All participants performed a single set of dynamic ILEX exercise 1 day/week for 6 weeks using either 80% (HL) or 50% (LL) of their MVC to momentary failure.ResultsAnalyses revealed significant pre- to post-intervention increases in isometric strength for both HL and LL, with no significant between-group differences (p > 0.05). Changes in strength index (area under torque curves) were 2,891 Nm degrees 95% CIs [1,612–4,169] and 2,865 Nm degrees 95% CIs [1,587–4,144] for HL and LL respectively. Changes in MVC were 51.7 Nm 95% CIs [24.4–79.1] and 46.0 Nm 95% CIs [18.6–73.3] for HL and LL respectively. Mean repetitions per set, total training time and discomfort were all significantly higher for LL compared to HL (26 ± 8 vs. 8 ± 3 repetitions, 158.5 ± 47 vs. 50.5 ± 15 s, and 7.8 ± 1.8 vs. 4.8 ± 2.5, respectively; all p < 0.005).ConclusionsThe present study supports that that low-volume, low-frequency ILEX resistance exercise can produce similar strength increases in the lumbar extensors using either HL or LL. As such personal trainers, trainees and strength coaches can consider other factors which might impact acute performance (e.g. effort and discomfort during the exercise). This data might prove beneficial in helping asymptomatic persons reduce the risk of low-back pain, and further research, might consider the use of HL exercise for chronic low-back pain symptomatic persons. creator: James P. Fisher creator: Charlotte Stuart creator: James Steele creator: Paulo Gentil creator: Jürgen Giessing uri: https://doi.org/10.7717/peerj.6001 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Fisher et al. title: Classification of the glioma grading using radiomics analysis link: https://peerj.com/articles/5982 last-modified: 2018-11-22 description: BackgroundGrading of gliomas is critical information related to prognosis and survival. We aimed to apply a radiomics approach using various machine learning classifiers to determine the glioma grading.MethodsWe considered 285 (high grade n = 210, low grade n = 75) cases obtained from the Brain Tumor Segmentation 2017 Challenge. Manual annotations of enhancing tumors, non-enhancing tumors, necrosis, and edema were provided by the database. Each case was multi-modal with T1-weighted, T1-contrast enhanced, T2-weighted, and FLAIR images. A five-fold cross validation was adopted to separate the training and test data. A total of 468 radiomics features were calculated for three types of regions of interest. The minimum redundancy maximum relevance algorithm was used to select features useful for classifying glioma grades in the training cohort. The selected features were used to build three classifier models of logistics, support vector machines, and random forest classifiers. The classification performance of the models was measured in the training cohort using accuracy, sensitivity, specificity, and area under the curve (AUC) of the receiver operating characteristic curve. The trained classifier models were applied to the test cohort.ResultsFive significant features were selected for the machine learning classifiers and the three classifiers showed an average AUC of 0.9400 for training cohorts and 0.9030 (logistic regression 0.9010, support vector machine 0.8866, and random forest 0.9213) for test cohorts.DiscussionGlioma grading could be accurately determined using machine learning and feature selection techniques in conjunction with a radiomics approach. The results of our study might contribute to high-throughput computer aided diagnosis system for gliomas. creator: Hwan-ho Cho creator: Seung-hak Lee creator: Jonghoon Kim creator: Hyunjin Park uri: https://doi.org/10.7717/peerj.5982 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Cho et al. title: A new species of karst-dwelling freshwater crab of the genus Chinapotamon Dai & Naiyanetr, 1994 (Crustacea: Decapoda: Brachyura: Potamidae), from Guizhou, southwest China link: https://peerj.com/articles/5947 last-modified: 2018-11-22 description: Chinapotamon maolanense sp. n. from Maolan National Nature Reserve, Guizhou, southwest China, is described. C. maolanense sp. n. has diagnostic features of Chinapotamon, such as a slender and sinuous male first gonopod, prominently convex carapace, and one-third ratio of frons to carapace width. This new species can be distinguished from congeners by the combination of the following characters: relatively slender subterminal segment of the first gonopods, nearly oval-shaped carapace, anterolateral margin cristate of carapace and an oval-shaped gap between the fingers of the male major chela. In addition, we used a 16S rRNA gene fragment to explore the relationship between C. maolanense sp. n. and C. glabrum, C. depressum and other freshwater crabs distributed in Guizhou; the results support the new species being assigned to Chinapotamon and clearly different from other species used in the analysis. creator: Jie-xin Zou creator: Jun Bai creator: Xian-min Zhou uri: https://doi.org/10.7717/peerj.5947 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Zou et al. title: A needle in a haystack: Mesozoic origin of parasitism in Strepsiptera revealed by first definite Cretaceous primary larva (Insecta) link: https://peerj.com/articles/5943 last-modified: 2018-11-22 description: Twisted winged insects (Strepsiptera) are a highly specialized small order of parasitic insects. Whether parasitism developed at an early or late stage in the evolution of the group was unknown. Here we record and describe the first definite Mesozoic strepsipteran primary larva embedded in Burmese amber (∼99 million years ago). This extends the origin of parasitism back by at least ∼50 million years, and reveals that this specialized life style has evolved in the Mesozoic or even earlier in the group. The extremely small first instar displays all diagnostic characters of strepsipteran immatures of this stage and is nearly identical with those of Mengenillidae, one of the most “ancestral” extant strepsipteran taxa. This demonstrates a remarkable evolutionary stasis over  100 million years. The new finding strongly weakens the case of small larvae embedded in Cretaceous amber interpreted as strepsipteran immatures. They differ in many structural features from extant strepsipteran primary larvae and are very likely parasitic beetle larvae. creator: Hans Pohl creator: Jan Batelka creator: Jakub Prokop creator: Patrick Müller creator: Margarita I. Yavorskaya creator: Rolf G. Beutel uri: https://doi.org/10.7717/peerj.5943 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Pohl et al. title: Computer-aided autotransplantation of teeth with 3D printed surgical guides and arch bar: a preliminary experience link: https://peerj.com/articles/5939 last-modified: 2018-11-22 description: Background/AimAutotransplantation of teeth is a method to restore the missing teeth and computer-aided techniques have been applied in this field. The aim of this study was to describe a novel approach for computer-aided autotransplantation of teeth and to preliminarily assess its feasibility, accuracy, and stability.MethodsEight wisdom teeth with complete root formation of eight adult patients were autotransplanted. Individual replicas of donor teeth with local splints, surgical templates, and arch bars were virtually designed and fabricated using three-dimensional printing, these were then applied in the autotransplantation surgeries. Clinical and radiological outcomes were observed, the extra-alveolar time, success rate, and 1-year survival rate were analyzed, and accuracy and stability of this approach were evaluated.ResultsThe extra-alveolar time of donor teeth were less than 3 min. The average follow-up duration was 2.00 ± 1.06 years. All autotransplanted teeth showed normal masticatory function. Ankylosis was found in one patient, and the overall success rate was 87.5%, whereas the 1-year survival rate was 100%. Linear differences between the designed and the immediate autotransplanted positions at crowns and apexes of the donor teeth were 1.43 ± 0.57 and 1.77 ± 0.67 mm, respectively. Linear differences between immediate and the stable positions at crowns and apexes of the donor teeth were 0.66 ± 0.36 and 0.67 ± 0.48 mm, respectively.ConclusionThe present study illustrated the feasibility, clinical satisfied accuracy, and stability of a novel approach for computer-aided autotransplantation of teeth. This new approach facilitated the surgical procedure and might be a viable and predictable method for autotransplantation of teeth. creator: Wei He creator: Kaiyue Tian creator: Xiaoyan Xie creator: Enbo Wang creator: Nianhui Cui uri: https://doi.org/10.7717/peerj.5939 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 He et al. title: Identification of AaAtg8 as a marker of autophagy and a functional autophagy-related protein in Aedes albopictus link: https://peerj.com/articles/5988 last-modified: 2018-11-21 description: Aedes albopictus is a primary vector of hundreds of pathogens. Strong environmental adaptability and extensive global distribution of Aedes albopictus make it a severe threat to human health. Autophagy is a cellular process involved in maintenance of cellular homeostasis and recirculation of cytoplasm to generate macromolecule constituents and energy under different stress conditions. Many autophagy-related (Atg) proteins have been identified in yeast and were found in various organisms subsequently, indicating that the basic mechanism of autophagy is well conserved in eukaryotes. Among all Atg proteins, Atg8 plays important roles in autophagy and is widely used as a marker to monitor autophagic activity in yeast, Drosophila, nematodes, zebrafish and mammals. By now, Atg proteins in Aedes albopictus have not been reported yet and the autophagy pathway in Aedes albopictus remains unclear. This study identified a homolog of Atg8 from Aedes albopictus and named it AaAtg8. Sequence analysis revealed that AaAtg8 was highly conserved in the Atg8 family. This work proved that AaAtg8 was a functional Atg protein of Aedes albopictus and expressed during developmental and adult stages of Aedes albopictus. Moreover, the study also established the basic methods for autophagy study in C6/36 cells. First, it was proved that both rapamycin and starvation were applicable ways to induce autophagy in C6/36 cells, and that 3-methyladenine and chloroquine could be used to inhibit early and late stages of autophagy in C6/36 cells, respectively. Second, the results in this study showed that monodansylcadaverine staining could be used to detect autophagy in C6/36 cells. Additionally, the study revealed that the level of autophagy in C6/36 cells could be monitored by the turnover assay of AaAtg8 or fluorescent AaAtg8. Taken together, this study identified AaAtg8, the first reported Atg protein in Aedes albopictus. It also provided useful methods for studying autophagy in Aedes albopictus. To our knowledge, this is the first work about autophagy in Aedes albopictus. creator: Jialu Qiao creator: Dandan Zhang creator: Yu Wang creator: Xiaomei Li creator: Shengya Wang creator: Qingzhen Liu uri: https://doi.org/10.7717/peerj.5988 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Qiao et al. title: A systematic review of the validity of patient derived xenograft (PDX) models: the implications for translational research and personalised medicine link: https://peerj.com/articles/5981 last-modified: 2018-11-21 description: Patient-derived xenograft (PDX) models are increasingly being used in oncology drug development because they offer greater predictive value than traditional cell line models. Using novel tools to critique model validity and reliability we performed a systematic review to identify all original publications describing the derivation of PDX models of colon, prostate, breast and lung cancer. Validity was defined as the ability to recapitulate the disease of interest. The study protocol was registered with the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADES). Searches were performed in Embase, MEDLINE and Pubmed up to July 2017. A narrative data synthesis was performed. We identified 105 studies of model validations; 29 for breast, 29 for colon, 25 for lung, 23 for prostate and 4 for multiple tissues. 133 studies were excluded because they did not perform any validation experiments despite deriving a PDX. Only one study reported following the ARRIVE guidelines; developed to improve the standard of reporting for animal experimentation. Remarkably, half of all breast (52%) and prostate (50%) studies were judged to have high concern, in contrast to 16% of colon and 28% of lung studies. The validation criteria that most commonly failed (evidence to the contrary) were: tissue of origin not proven and histology of the xenograft not comparable to the parental tumour. Overall, most studies were categorized as unclear because one or more validation conditions were not reported, or researchers failed to provide data for a proportion of their models. For example, failure to demonstrate tissue of origin, response to standard of care agents and to exclude development of lymphoma. Validation tools have the potential to improve reproducibility, reduce waste in research and increase the success of translational studies. creator: Anne T. Collins creator: Shona H. Lang uri: https://doi.org/10.7717/peerj.5981 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Collins and Lang title: Characterization of vaginal microbiota in Thai women link: https://peerj.com/articles/5977 last-modified: 2018-11-21 description: BackgroundThe vaginal microbiota (VMB) plays a key role in women’s reproductive health. VMB composition varies with ethnicity, making it necessary to characterize the VMB of the target population before interventions to maintain and/or improve the vaginal health are undertaken. Information on the VMB of Thai women is currently unavailable. We therefore characterized the VMB in normal Thai women.MethodsVaginal samples derived from 25 Thai women were subjected to 16S rRNA gene next-generation sequencing (NGS) on the Ion Torrent PGM platform.ResultsTwo groups of VMB were detected, lactobacilli-dominated (LD) and non-lactobacilli dominated (NLD) groups. Lactobacillus iners was the most common species found in the LD group while Gardnerella vaginalis followed by Atopobium vaginae and Pseudumonas stutzeri were commonly found in the NLD group.ConclusionsThe VMB patterns present in normal Thai women is essential information to further determine the factors associated with VMB patterns in vaginal health and disease and to develop proper management of reproductive health of Thai women. creator: Auttawit Sirichoat creator: Pranom Buppasiri creator: Chulapan Engchanil creator: Wises Namwat creator: Kiatichai Faksri creator: Nipaporn Sankuntaw creator: Ekawat Pasomsub creator: Wasun Chantratita creator: Viraphong Lulitanond uri: https://doi.org/10.7717/peerj.5977 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Sirichoat et al. title: Catch fast and kill quickly: do tiger beetles use the same strategies when hunting different types of prey? link: https://peerj.com/articles/5971 last-modified: 2018-11-21 description: BackgroundTiger beetles (Coleoptera: Cicindelidae) are fast running predatory insects preying on different small insects and other terrestrial arthropods. Prey is located by sight and captured after short and fast pursuit interspersed with pause-and-look behaviour. At least some tiger beetle species can recognise the size and location of prey using memory, which probably allows them to achieve greater hunting success.Material and MethodsTwo eurytopic tiger beetle species known to occur in different types of habitat were used in the study: Cicindela hybrida hybrida, a very common central European beetle found even in artificial habitats such as sandy roads or gravel pits, and Calomera littoralis nemoralis, a species widely distributed in southern European countries and occurring on sandy sea beaches, in salt marshes, as well as on sandy banks of rivers and lakes. Both species are very similar in body size. Specimens used in the study were collected in the field and later tested in the laboratory. We checked whether tiger beetles use different hunting strategies when attacking prey of different sizes and abilities to escape as well as whether the sex of the studied species makes a difference in its hunting behaviour.ResultsThe hunting strategies of both tiger beetle species consist of the following main phases: identification, pursuit (often with stops), attack, and optional release of the prey, and then the secondary attack, abandonment of the prey, or consumption of the prey. Considerable differences were noticed in hunting behaviour depending on the type of prey, its movement ability and escape potential. Caterpillars were attacked without pursuit, in the head or directly behind the head where a concentration of nerves and main muscles responsible for walking are located. Effective attacks on beetles were executed at the connection between the thorax and the abdomen. Calomera littoralis strongly preferred slow moving prey, while Cicindela hybrida preferred in equal measure slow moving prey and medium-sized fast moving prey. The experiment on the preferred size of prey indicated small beetles and small caterpillars as favoured by Calomera littoralis, while Cicindela hybrida preferred medium-sized fast moving prey and large caterpillars.DiscussionThe hunting behaviour of Calomera littoralis and Cicindela hybrida is complicated and includes a number of phases allowing to locate, capture and kill the prey. Beetles are able to discriminate between different types of prey and apply different behavioural tactics to hunt it. As the particular strategies are used to increase hunting success, and as a result allow to accumulate energy for future activity of the predator, it can be expected that such a type of hunting behaviour is characteristic also of other tiger beetle species. creator: Tomasz Rewicz creator: Radomir Jaskuła uri: https://doi.org/10.7717/peerj.5971 license: http://creativecommons.org/licenses/by/4.0/ rights: ©2018 Rewicz and Jaskuła title: Regional fresh snowfall microbiology and chemistry are driven by geography in storm-tracked events, Colorado, USA link: https://peerj.com/articles/5961 last-modified: 2018-11-21 description: Snowfall is a global phenomenon highly integrated with hydrology and ecology. Forays into studying bioaerosols and their dependence on aeolian movement are largely constrained to either precipitation-independent analyses or in silico models. Though snowpack and glacial microbiological studies have been conducted, little is known about the biological component of meteoric snow. Through culture-independent phylogenetic and geochemical analyses, we show that the geographical location at which snow precipitates determines snowfall’s geochemical and microbiological composition. Storm-tracking, furthermore, can be used as a valuable environmental indicator to trace down what factors are influencing bioaerosols. We estimate annual aeolian snowfall deposits of up to ∼10 kg of bacterial/archaeal biomass per hectare along our study area of the eastern Front Range in Colorado. The dominant kinds of microbiota captured in an analysis of seven snow events at two different locations, one urban, one rural, across the winter of 2016/2017 included phyla Proteobacteria, Bacteroidetes, Firmicutes, and Acidobacteria, though a multitude of different kinds of organisms were found in both. Taxonomically, Bacteroidetes were more abundant in Golden (urban plain) snow while Proteobacteria were more common in Sunshine (rural mountain) samples. Chemically, Golden snowfall was positively correlated with some metals and anions. The work also hints at better informing the “everything is everywhere” hypotheses of the microbial world and that atmospheric transport of microbiota is not only common, but is capable of disseminating vast amounts of microbiota of different physiologies and genetics that then affect ecosystems globally. Snowfall, we conclude, is a significant repository of microbiological material with strong implications for both ecosystem genetic flux and general bio-aerosol theory. creator: Alexander S. Honeyman creator: Maria L. Day creator: John R. Spear uri: https://doi.org/10.7717/peerj.5961 license: http://creativecommons.org/licenses/by/4.0/ rights: © 2018 Honeyman et al.