title: PeerJ
description:  Articles published in PeerJ
link: https://peerj.com/articles/index.rss3?journal=peerj&page=1524
creator: info@peerj.com PeerJ
errorsTo: info@peerj.com PeerJ
language: en

title: Community involvement works where enforcement fails: conservation success through community-based management of Amazon river turtle nests
link: https://peerj.com/articles/4856
last-modified: 2018-06-01
description: Law enforcement is widely regarded as a cornerstone to effective natural resource management. Practical guidelines for the optimal use of enforcement measures are lacking particularly in areas protected under sustainable and/or mixed use management regimes and where legal institution are weak. Focusing on the yellow-spotted river turtles (Podocnemis unifilis) along 33 km of river that runs between two sustainable–use reserves in the Brazilian Amazon as an illustrative example, we show that two years of patrols to enforce lawful protection regulations had no effect on nest harvesting. In contrast, during one year when community-based management approaches were enacted harvest levels dropped nearly threefold to a rate (26%) that is likely sufficient for river turtle population recovery. Our findings support previous studies that show how community participation, if appropriately implemented, can facilitate effective natural resource management where law enforcement is limited or ineffective.
creator: Darren Norris
creator: Fernanda Michalski
creator: James P. Gibbs
uri: https://doi.org/10.7717/peerj.4856
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Norris et al.

title: Phytoregionalisation of the Andean páramo
link: https://peerj.com/articles/4786
last-modified: 2018-06-01
description: BackgroundThe páramo is a high-elevation biogeographical province in the northern Andes, known for its great biodiversity and ecosystem services. Because there have been very few biogeographic studies encompassing the entire province to date, this study aimed at conducting a phytogeographical regionalisation of the páramo. Specifically, (1) clustering analyses were conducted to identify the main phytogeographical units in the three altitudinal belts: sub-páramo, mid-páramo and super-páramo, and examine their diagnostic flora, (2) an ordination complemented the geo-climatic characterization of the obtained units and (3) a hierarchical classification transformation was obtained to evaluate the relationships between units.MethodsThe study area included the entire Andean páramo range in northern Peru, Ecuador, Colombia and Venezuela. The analyses were based on 1,647 phytosociological plots from the VegPáramo database. The K-means non-hierarchical clustering technique was used to obtain clusters identifiable as phytogeographical units, and the Ochiai fidelity index was calculated to identify their diagnostic species. A principal component analysis was conducted to obtain the geo-climatic characterization of each unit. Finally, the relationships between clusters were traced using a hierarchical plot-based classification.ResultsFifteen clusters were obtained, 13 natural and two artificial, of which two represented the sub-páramo, nine the mid-páramo and four the super-páramo. Even though data representativeness was a potential limitation to segregate certain sub-páramo and super-páramo units, the overall bioregionalisation was robust and represented important latitudinal, altitudinal and climatic gradients.DiscussionThis study is the first to bioregionalise the páramo province based on a substantial widely distributed biological dataset, and therefore provides important novel scientific insight on its biogeography. The obtained phytogeographical units can be used to support further research on the páramo at smaller scale and on the humid Neotropical high-elevation ecosystems at broader-scale. Finally, several units were highlighted in our results as particularly worthy of further scientific and conservation focus.
creator: Gwendolyn Peyre
creator: Henrik Balslev
creator: Xavier Font
uri: https://doi.org/10.7717/peerj.4786
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2018 Peyre et al.

title: Comparing the biomechanical characteristics between squat and standing serves in female table tennis athletes
link: https://peerj.com/articles/4760
last-modified: 2018-06-01
description: BackgroundThe table tennis serve involves complex spatial movements combined with biomechanial characteristics. Although the differences in lower-limb biomechanial characteristics to a great extent influence the translational and spinning velocity of the ball when using the different styles of table tennis serve, few researchers have studied their mechanics. Therefore, the aim of this study was to investigate the differences in lower-limb activity between the squat and standing serves during a table tennis short serve.MethodsTen advanced female table tennis participants performed a squat serve and standing serve in random order. A Vicon motion analysis system and a Novel Pedar insole plantar pressure measurement system were used to record kinematics and kinetics data, respectively.ResultsKey findings from the study were that the squat serve not only showed significantly larger hip and knee flexion, as well as ankle dorsiflexion, it also showed significantly larger hip adduction and external knee rotation, with larger changing angular rate of the lower limb joints in the sagittal and the transverse planes when the two serving styles were compared. In addition, the force-time integral (FTI) was higher in the rear foot area for the standing serve.DiscussionThe results demonstrated that the squat serve needs higher lower limb drive during a table tennis short serve compared with a standing serve. These biomechanical considerations may be beneficial for table tennis athletes and coaches as a method of optimizing performance characteristics during both competition and training.
creator: Changxiao Yu
creator: Shirui Shao
creator: Julien S. Baker
creator: Yaodong Gu
uri: https://doi.org/10.7717/peerj.4760
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Yu et al.

title: Sexually dimorphic venom proteins in long-jawed orb-weaving spiders (Tetragnatha) comprise novel gene families
link: https://peerj.com/articles/4691
last-modified: 2018-06-01
description: Venom has been associated with the ecological success of many groups of organisms, most notably reptiles, gastropods, and arachnids. In some cases, diversification has been directly linked to tailoring of venoms for dietary specialization. Spiders in particular are known for their diverse venoms and wide range of predatory behaviors, although there is much to learn about scales of variation in venom composition and function. The current study focuses on venom characteristics in different sexes within a species of spider. We chose the genus Tetragnatha (Tetragnathidae) because of its unusual courtship behavior involving interlocking of the venom delivering chelicerae (i.e., the jaws), and several species in the genus are already known to have sexually dimorphic venoms. Here, we use transcriptome and proteome analyses to identify venom components that are dimorphic in Tetragnatha versicolor. We present cDNA sequences including unique, male-specific high molecular weight proteins that have remote, if any, detectable similarity to known venom components in spiders or other venomous lineages and have no detectable homologs in existing databases. While the function of these proteins is not known, their presence in association with the cheliceral locking mechanism during mating together with the presence of prolonged male-male mating attempts in a related, cheliceral-locking species (Doryonychus raptor) lacking the dimorphism suggests potential for a role in sexual communication.
creator: Pamela A. Zobel-Thropp
creator: Emily A. Bulger
creator: Matthew H.J. Cordes
creator: Greta J. Binford
creator: Rosemary G. Gillespie
creator: Michael S. Brewer
uri: https://doi.org/10.7717/peerj.4691
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Zobel-Thropp et al.

title: Cytotoxic effects of zinc oxide nanoparticles on cyanobacterium Spirulina (Arthrospira) platensis
link: https://peerj.com/articles/4682
last-modified: 2018-06-01
description: BackgroundThe extensive usage of zinc oxide nanoparticles (ZnO NPs) in industrial and consumer products raises the risk of releasing their residues into the aquatic environment. The presence of ZnO NPs in the aquatic environment could potentially cause cytotoxic effects on aquatic organisms. Thus, investigating the cytotoxic effects of ZnO NPs on microalgae, which form the base for the food web of aquatic biota, is essential to gain information regarding the ecotoxicological effects of metallic oxide nanoparticles in the aquatic ecosystem. Therefore, the present study has investigated in detail the assorted cytotoxic effects of ZnO NPs on S. platensis using various concentrations of ZnO NPs (10–200 mg/L) from 6 to 96 h to explore the dose- and time-dependent cytotoxic effects.MethodsThe cytotoxic effects were all assessed through quantification of loss in cell viability, reduction in biomass and decrease in photosynthetic pigments such as chlorophyll-a, carotenoids and phycocyanin. The surface interactions of nanoparticles and the subsequent morphological alterations on algal cells were examined by optical and scanning electron microscopy (SEM). The intracellular alterations of algal cells were studied using transmission electron microscopy. Furthermore, Fourier transformed infrared (FTIR) spectrum was obtained to investigate the involvement of algal surface biomolecules in surface binding of ZnO NPs on algal cells.ResultsThe treatment of ZnO NPs on S. platensis exhibited a typical concentration- and time-dependent cytotoxicity. Results showed a significant (p < 0.05) cytotoxicity from 24 h onwards for all tested concentrations of ZnO NPs. The maximum cytotoxicity on algal cells was achieved at 96 h of exposure to ZnO NPs. In comparison with control, the algal cells that interacted with 200 mg/L of ZnO NPs for 96 h showed 87.3 ± 1% loss in cell viability, 76.1 ± 1.7% reduction in algal biomass, 92.5 ± 2.2%, 76.2 ± 2.2% and 74.1 ± 3.4% decrease in chlorophyll-a, carotenoids and phycocyanin contents respectively. Our study confirmed the cytotoxicity of ZnO NPs through the algal growth inhibition with 72 h EC10 and EC50 values of 1.29 and 31.56 mg/L, respectively. The microscopic examinations of the algal cells that interacted with ZnO NPs showed severe cell membrane and intracellular damage. The SEM EDX spectrum of ZnO NPs treated algal biomass evidenced the surface accumulation of zinc in the biomass. Finally, the FTIR spectrum confirmed the involvement of amino, hydroxyl and carboxylic groups of algal cell wall in the surface interaction of ZnO NPs on the algal cells.DiscussionThe results showed that the treatment of ZnO NPs on S. platensis triggered substantial cytotoxicity and caused cell death. Hence, S. platensis could be potentially used as a bioindicator for testing toxicity of ZnO NPs in aquatic environment.
creator: Sinouvassane Djearamane
creator: Yang Mooi Lim
creator: Ling Shing Wong
creator: Poh Foong Lee
uri: https://doi.org/10.7717/peerj.4682
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Djearamane et al.

title: Assessing canalisation of intraspecific variation on a macroevolutionary scale: the case of crinoid arms through the Phanerozoic
link: https://peerj.com/articles/4899
last-modified: 2018-05-31
description: Clades that represent a new ‘Bauplan’ have been hypothesised to exhibit more variability than more derived clades. Accordingly, there is an expectation of greater variation around the time of the origin of a clade than later in its evolutionary history. This ‘canalisation’ has been tested in terms of morphological disparity (interspecific variation), whereas intraspecific variation in macroevolution is rarely studied. We analysed extensive data of brachial counts in crinoid populations from the Ordovician to the Recent to test for canalisation in morphological intraspecific variation. Our results show no support for the canalisation hypothesis through the Phanerozoic. This lack of pattern is maintained even when considering crinoid subclades separately. Our study is an example of the lack of universality in such macroevolutionary patterns both in terms of organisms and in terms of modules within them. It is also an example on the challenges and limitations of palaeontological studies of macroevolutionary processes.
creator: Catalina Pimiento
creator: Kit Lam Tang
creator: Samuel Zamora
creator: Christian Klug
creator: Marcelo R. Sánchez-Villagra
uri: https://doi.org/10.7717/peerj.4899
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Pimiento et al.

title: Factors influencing the willingness to participate in medical research: a nationwide survey in Taiwan
link: https://peerj.com/articles/4874
last-modified: 2018-05-31
description: BackgroundParticipation rate is one of the main challenges medical researchers face. We examined how demographic background and trust in medical research affect the willingness of people to participate in medical research in Taiwan.MethodsData from the 2011 Taiwan Genomic Survey (a nationwide representative face-to-face survey) were analyzed. The survey included a vignette of a researcher conducting a clinical trial of an investigative medicinal product, and questions for interviewees regarding their willingness to participate in research after they were informed of the scenario description. A total of 3,159 people, aged 18 to 70 years, were sampled, and 1,538 of them completed the survey. With missing data excluded, a total of 1,389 respondents were included in the final analysis.ResultsAbout 12 percent of the respondents answered that they would be willing to participate in medical research. Respondents who had college degrees or above and were married or lived with significant others were less likely to participate in medical research. By contrast, male respondents, and respondents whose household family members had biomedicine-related degrees or had one themselves were more likely to participate in medical research. After adjustment for demographic factors, respondents were more likely to participate in medical research if: (1) they expressed trust in doctors conducting medical research; (2) they agreed that doctors would never ask them to join medical research studies that might harm them; (3) they thought that participating in a medical research study would be safe; and (4) they agreed that researchers had no selfish reasons for doing the medical research.DiscussionSome of our findings, such as the effects of education level and marital status on participation in medical research, are different from most findings of previous studies conducted in other countries. This study is useful for developing strategies to improve participant recruitment. Relevant discussions on research ethics and policies, such as the importance of public trust in medical researchers, could also be based on this study.
creator: Hung-En Liu
creator: Ming-Chieh Li
uri: https://doi.org/10.7717/peerj.4874
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Liu and Li

title: Some like it hot: factors impacting thermal preferences of two Ponto-Caspian amphipods Dikerogammarus villosus (Sovinsky, 1894) and Dikerogammarus haemobaphes (Eichwald, 1841)
link: https://peerj.com/articles/4871
last-modified: 2018-05-31
description: Temperature is a crucial factor determining biology and ecology of poikilothermic animals. It often constitutes an important barrier for invasive species originating from different climate zones but, on the other hand, may facilitate the invasion process of animals with wide thermal preferences and high resistance to extreme temperatures. In our experimental study, we investigated the thermal behaviour of two Ponto-Caspian amphipod crustaceans—Dikerogammarus villosus and Dikerogammarus haemobaphes. Both species are known to live under a wide range of thermal conditions which may promote their invasion. Moreover, both these amphipods are hosts for microsporidian parasites which co-evolved with them within the Ponto-Caspian region and spread in European waters. As the presence of a parasite may influence the thermal preferences of its host, we expected to observe behavioural changes in infected individuals of the studied amphipods leading to (1) behavioural fever (selecting a warmer habitat) or (2) anapyrexia (selecting a colder habitat). The experiment (N = 20) was carried out for 30 min in a 100 cm. 20 cm from boths sides were not avaliable for amphipods long thermal gradient (0–40 °C), using 30 randomly selected adult amphipod individuals of one species. At the end of each trial, we checked the position of amphipods along the gradient and determined their sex and infection status (uninfected or infected by one of microsporidium species). D. villosus was infected with Cucumispora dikerogammari whereas D. haemobaphes was a host for C. dikerogammari, Dictyocoela muelleri or D. berillonum. Thermal preferences of amphipods depended on their species and sex. Females of D. villosus preferred warmer microhabitats (often much above 30 °C) than conspecific males and females of D. haemobaphes, whereas no significant differences were found among males of both species and both sexes of D. haemobaphes. Moreover, infected males of D. villosus stayed in warmer water more often than uninfected males of this species, selecting temperatures higher than 30 °C, which may be explained either as a behavioural fever constituting a defence mechanism of a host against the infection, or as a parasite manipulation of the host behaviour increasing the parasite fitness. On the other hand, none of the parasite species affected the thermal preferences of D. haemobaphes, including also C. dikerogammari, changing the behaviour of D. villosus. Our research presents the complexity of the thermal behaviour of studied amphipods and the evidence that microsporidia may trigger a change in temperature preferendum of their host species and those observations may be the result of different host-parasite coevolution time which may vary for the two host species (Poulin, 2010).
creator: Michał Rachalewski
creator: Jarosław Kobak
creator: Eliza Szczerkowska-Majchrzak
creator: Karolina Bącela-Spychalska
uri: https://doi.org/10.7717/peerj.4871
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Rachalewski et al.

title: Current knowledge on bioacoustics of the subfamily Lophyohylinae (Hylidae, Anura) and description of Ocellated treefrog Itapotihyla langsdorffii vocalizations
link: https://peerj.com/articles/4813
last-modified: 2018-05-31
description: BackgroundAnuran vocalizations, such as advertisement and release calls, are informative for taxonomy because species recognition can be based on those signals. Thus, a proper acoustic description of the calls may support taxonomic decisions and may contribute to knowledge about amphibian phylogeny.MethodsHere we present a perspective on advertisement call descriptions of the frog subfamily Lophyohylinae, through a literature review and a spatial analysis presenting bioacoustic coldspots (sites with high diversity of species lacking advertisement call descriptions) for this taxonomic group. Additionally, we describe the advertisement and release calls of the still poorly known treefrog, Itapotihyla langsdorffii. We analyzed recordings of six males using the software Raven Pro 1.4 and calculated the coefficient of variation for classifying static and dynamic acoustic properties.Results and DiscussionWe found that more than half of the species within the subfamily do not have their vocalizations described yet. Most of these species are distributed in the western and northern Amazon, where recording sampling effort should be strengthened in order to fill these gaps. The advertisement call of I. langsdorffii is composed of 3–18 short unpulsed notes (mean of 13 ms long), presents harmonic structure, and has a peak dominant frequency of about 1.4 kHz. This call usually presents amplitude modulation, with decreasing intensity along the sequence of notes. The release call is a simple unpulsed note with an average duration of 9 ms, and peak dominant frequency around 1.8 kHz. Temporal properties presented higher variations than spectral properties at both intra- and inter-individual levels. However, only peak dominant frequency was static at intra-individual level. High variability in temporal properties and lower variations related to spectral ones is usual for anurans; The first set of variables is determined by social environment or temperature, while the second is usually related to species-recognition process. Here we review and expand the acoustic knowledge of the subfamily Lophyohylinae, highlighting areas and species for future research.
creator: Lucas Rodriguez Forti
creator: Roseli Maria Foratto
creator: Rafael Márquez
creator: Vânia Rosa Pereira
creator: Luís Felipe Toledo
uri: https://doi.org/10.7717/peerj.4813
license: http://creativecommons.org/licenses/by/4.0/
rights: ©2018 Forti et al.

title: The smallest biggest theropod dinosaur: a tiny pedal ungual of a juvenile Spinosaurus from the Cretaceous of Morocco
link: https://peerj.com/articles/4785
last-modified: 2018-05-30
description: We describe a nearly complete pedal ungual phalanx, discovered in the Kem Kem Beds (Cenomanian) of Tafilalt region, south-eastern Morocco. The bone is symmetric, pointed, low, elongate, and almost flat ventrally in lateral aspect. This peculiar morphology allows to refer the specimen to the smallest known individual of the genus Spinosaurus. The bone belongs to an early juvenile individual and it is proportionally identical to the ungual of the third digit of a large partial skeleton recently found, suggesting an isometric growth for this part of the pes and the retention of peculiar locomotor adaptations—such as traversing soft substrates or paddling—during the entire lifespan.
creator: Simone Maganuco
creator: Cristiano Dal Sasso
uri: https://doi.org/10.7717/peerj.4785
license: http://creativecommons.org/licenses/by/4.0/
rights: © 2018 Maganuco and Dal Sasso