PeerJ
type: channel
link: https://peerj.com/articles/
description: Articles published in PeerJ
publisher: PeerJ Inc.
publication name: PeerJ
issn: 2167-8359
items: A new Python library to analyse skeleton images confirms malaria parasite remodelling of the red blood cell membrane skeleton
items: Metagenomic analysis of orange colored protrusions from the muscle of Queen Conch Lobatus gigas (Linnaeus, 1758)
items: Life histories predict genetic diversity and population structure within three species of octopus targeted by small-scale fisheries in Northwest Mexico
items: Codominant grasses differ in gene expression under experimental climate extremes in native tallgrass prairie
items: Benthic grazing in a eutrophic river: cascading effects of zoobenthivorous fish mask direct effects of herbivorous fish
items: Catchment land use predicts benthic vegetation in small estuaries
items: Ontogeny of long-range vocalizations in a Neotropical fossorial rodent: the Anillaco Tuco-Tuco (Ctenomys sp.)
items: Different intensities of basketball drills affect jump shot accuracy of expert and junior players
items: The axial skeleton of Poposaurus langstoni (Pseudosuchia: Poposauroidea) and its implications for accessory intervertebral articulation evolution in pseudosuchian archosaurs
items: Factors associated with elevated blood pressure or hypertension in Afro-Caribbean youth: a cross-sectional study

A new Python library to analyse skeleton images confirms malaria parasite remodelling of the red blood cell membrane skeleton
type: item
type: AcademicArticle
description: We present Skan (Skeleton analysis), a Python library for the analysis of the skeleton structures of objects. It was inspired by the “analyse skeletons” plugin for the Fiji image analysis software, but its extensive Application Programming Interface (API) allows users to examine and manipulate any intermediate data structures produced during the analysis. Further, its use of common Python data structures such as SciPy sparse matrices and pandas data frames opens the results to analysis within the extensive ecosystem of scientific libraries available in Python. We demonstrate the validity of Skan’s measurements by comparing its output to the established Analyze Skeletons Fiji plugin, and, with a new scanning electron microscopy (SEM)-based method, we confirm that the malaria parasite Plasmodium falciparum remodels the host red blood cell cytoskeleton, increasing the average distance between spectrin-actin junctions.
format: application/pdf
format: text/html
creator: Juan Nunez-Iglesias
creator: Adam J. Blanch
creator: Oliver Looker
creator: Matthew W. Dixon
creator: Leann Tilley
subject: Biochemistry
subject: Bioinformatics
subject: Parasitology
subject: Computational Science
description: doi:10.7717/peerj.4312
publisher: PeerJ Inc.
rights: © 2018 Nunez-Iglesias et al.
abstract: We present Skan (Skeleton analysis), a Python library for the analysis of the skeleton structures of objects. It was inspired by the “analyse skeletons” plugin for the Fiji image analysis software, but its extensive Application Programming Interface (API) allows users to examine and manipulate any intermediate data structures produced during the analysis. Further, its use of common Python data structures such as SciPy sparse matrices and pandas data frames opens the results to analysis within the extensive ecosystem of scientific libraries available in Python. We demonstrate the validity of Skan’s measurements by comparing its output to the established Analyze Skeletons Fiji plugin, and, with a new scanning electron microscopy (SEM)-based method, we confirm that the malaria parasite Plasmodium falciparum remodels the host red blood cell cytoskeleton, increasing the average distance between spectrin-actin junctions.
bibliographic citation: Nunez-Iglesias et al. (2018) A new Python library to analyse skeleton images confirms malaria parasite remodelling of the red blood cell membrane skeleton. PeerJ 6:e4312 https://doi.org/10.7717/peerj.4312
date submitted: 2017-12-04
date accepted: 2018-01-11
issued: 2018-02-15
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Nunez-Iglesias
  given name: Juan
author list: Agent
  family name: Blanch
  given name: Adam J.
author list: Agent
  family name: Looker
  given name: Oliver
author list: Agent
  family name: Dixon
  given name: Matthew W.
author list: Agent
  family name: Tilley
  given name: Leann
doi: 10.7717/peerj.4312
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-15
copyright: ©2018 Nunez-Iglesias et al.
attribution name: Nunez-Iglesias et al.

Metagenomic analysis of orange colored protrusions from the muscle of Queen Conch Lobatus gigas (Linnaeus, 1758)
type: item
type: AcademicArticle
description: The endangered marine gastropod, Lobatus gigas, is an important fishery resource in the Caribbean region. Microbiological and parasitological research of this species have been poorly addressed despite its role in ecological fitness, conservation status and prevention of potential pathogenic infections. This study identified taxonomic groups associated with orange colored protrusions in the muscle of queen conchs using histological analysis, 454 pyrosequencing, and a combination of PCR amplification and automated Sanger sequencing. The molecular approaches indicate that the etiological agent of the muscle protrusions is a parasite belonging to the subclass Digenea. Additionally, the scope of the molecular technique allowed the detection of bacterial and fungi clades in the assignment analysis. This is the first evidence of a digenean infection in the muscle of this valuable Caribbean resource.
format: application/pdf
format: text/html
creator: Jaison H. Cuartas
creator: Juan F. Alzate
creator: Claudia X. Moreno-Herrera
creator: Edna J. Marquez
subject: Biodiversity
subject: Genomics
subject: Marine Biology
subject: Parasitology
description: doi:10.7717/peerj.4307
publisher: PeerJ Inc.
rights: © 2018 Cuartas et al.
abstract: The endangered marine gastropod, Lobatus gigas, is an important fishery resource in the Caribbean region. Microbiological and parasitological research of this species have been poorly addressed despite its role in ecological fitness, conservation status and prevention of potential pathogenic infections. This study identified taxonomic groups associated with orange colored protrusions in the muscle of queen conchs using histological analysis, 454 pyrosequencing, and a combination of PCR amplification and automated Sanger sequencing. The molecular approaches indicate that the etiological agent of the muscle protrusions is a parasite belonging to the subclass Digenea. Additionally, the scope of the molecular technique allowed the detection of bacterial and fungi clades in the assignment analysis. This is the first evidence of a digenean infection in the muscle of this valuable Caribbean resource.
bibliographic citation: Cuartas et al. (2018) Metagenomic analysis of orange colored protrusions from the muscle of Queen Conch Lobatus gigas (Linnaeus, 1758). PeerJ 6:e4307 https://doi.org/10.7717/peerj.4307
date submitted: 2017-01-20
date accepted: 2018-01-10
issued: 2018-02-15
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Cuartas
  given name: Jaison H.
author list: Agent
  family name: Alzate
  given name: Juan F.
author list: Agent
  family name: Moreno-Herrera
  given name: Claudia X.
author list: Agent
  family name: Marquez
  given name: Edna J.
doi: 10.7717/peerj.4307
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-15
copyright: ©2018 Cuartas et al.
attribution name: Cuartas et al.

Life histories predict genetic diversity and population structure within three species of octopus targeted by small-scale fisheries in Northwest Mexico
type: item
type: AcademicArticle
description: The fishery for octopus in Northwest Mexico has increased to over 2,000 tons annually, but to date the specific composition of the catch has been ignored. With at least three main species targeted by artisanal fisheries in the region with distinct life histories, the lack of basic biological information about the distribution, metapopulation size and structure of each species could impede effective fisheries management to avoid overexploitation. We tested if different life histories of three species of octopus could help predict observed patterns of genetic diversity, population dynamics, structure and connectivity and how this information could be relevant to the sustainable management of the fishery. We sequenced two mitochondrial genes and genotyped seven nuclear microsatellite loci to identify the distribution of each species in 20 locations from the Gulf of California and the west coast of the Baja California peninsula. We tested five hypotheses derived from population genetic theory based on differences in the fecundity and dispersal potential for each species. We discovered that Octopus bimaculoides with low fecundity and direct development (without a planktonic phase) had lower average effective population size and genetic diversity, but higher levels of kinship, population structure, and richness of private alleles, than the other two species. These features indicated limited dispersal and high local recruitment. In contrast, O. bimaculatus and O. hubbsorum with higher fecundity and planktonic phase as paralarvae had higher effective population size and genetic diversity, and overall lower kinship and population structure than O. bimaculoides. These observations supported higher levels of gene flow over a larger geographical scale. O. bimaculatus with the longest planktonic paralarval duration and therefore larger dispersal potential had differences in the calculated parameters possibly associated with increased connectivity. We propose O. bimaculoides is m…
format: application/pdf
format: text/html
creator: José F. Domínguez-Contreras
creator: Adrian Munguia-Vega
creator: Bertha P. Ceballos-Vázquez
creator: Marcial Arellano-Martínez
creator: Francisco J. García-Rodríguez
creator: Melanie Culver
creator: Hector Reyes-Bonilla
subject: Aquaculture, Fisheries and Fish Science
subject: Conservation Biology
subject: Genetics
subject: Marine Biology
subject: Natural Resource Management
description: doi:10.7717/peerj.4295
publisher: PeerJ Inc.
rights: © 2018
abstract: The fishery for octopus in Northwest Mexico has increased to over 2,000 tons annually, but to date the specific composition of the catch has been ignored. With at least three main species targeted by artisanal fisheries in the region with distinct life histories, the lack of basic biological information about the distribution, metapopulation size and structure of each species could impede effective fisheries management to avoid overexploitation. We tested if different life histories of three species of octopus could help predict observed patterns of genetic diversity, population dynamics, structure and connectivity and how this information could be relevant to the sustainable management of the fishery. We sequenced two mitochondrial genes and genotyped seven nuclear microsatellite loci to identify the distribution of each species in 20 locations from the Gulf of California and the west coast of the Baja California peninsula. We tested five hypotheses derived from population genetic theory based on differences in the fecundity and dispersal potential for each species. We discovered that Octopus bimaculoides with low fecundity and direct development (without a planktonic phase) had lower average effective population size and genetic diversity, but higher levels of kinship, population structure, and richness of private alleles, than the other two species. These features indicated limited dispersal and high local recruitment. In contrast, O. bimaculatus and O. hubbsorum with higher fecundity and planktonic phase as paralarvae had higher effective population size and genetic diversity, and overall lower kinship and population structure than O. bimaculoides. These observations supported higher levels of gene flow over a larger geographical scale. O. bimaculatus with the longest planktonic paralarval duration and therefore larger dispersal potential had differences in the calculated parameters possibly associated with increased connectivity. We propose O. bimaculoides is m…
bibliographic citation: Domínguez-Contreras et al. (2018) Life histories predict genetic diversity and population structure within three species of octopus targeted by small-scale fisheries in Northwest Mexico. PeerJ 6:e4295 https://doi.org/10.7717/peerj.4295
date submitted: 2017-06-10
date accepted: 2018-01-05
issued: 2018-02-15
is part of: PeerJ
license: http://creativecommons.org/publicdomain/zero/1.0/
author list: Agent
  family name: Domínguez-Contreras
  given name: José F.
author list: Agent
  family name: Munguia-Vega
  given name: Adrian
author list: Agent
  family name: Ceballos-Vázquez
  given name: Bertha P.
author list: Agent
  family name: Arellano-Martínez
  given name: Marcial
author list: Agent
  family name: García-Rodríguez
  given name: Francisco J.
author list: Agent
  family name: Culver
  given name: Melanie
author list: Agent
  family name: Reyes-Bonilla
  given name: Hector
doi: 10.7717/peerj.4295
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-15

Codominant grasses differ in gene expression under experimental climate extremes in native tallgrass prairie
type: item
type: AcademicArticle
description: Extremes in climate, such as heat waves and drought, are expected to become more frequent and intense with forecasted climate change. Plant species will almost certainly differ in their responses to these stressors. We experimentally imposed a heat wave and drought in the tallgrass prairie ecosystem near Manhattan, Kansas, USA to assess transcriptional responses of two ecologically important C4 grass species, Andropogon gerardii and Sorghastrum nutans. Based on previous research, we expected that S. nutans would regulate more genes, particularly those related to stress response, under high heat and drought. Across all treatments, S. nutans showed greater expression of negative regulatory and catabolism genes while A. gerardii upregulated cellular and protein metabolism. As predicted, S. nutans showed greater sensitivity to water stress, particularly with downregulation of non-coding RNAs and upregulation of water stress and catabolism genes. A. gerardii was less sensitive to drought, although A. gerardii tended to respond with upregulation in response to drought versus S. nutans which downregulated more genes under drier conditions. Surprisingly, A. gerardii only showed minimal gene expression response to increased temperature, while S. nutans showed no response. Gene functional annotation suggested that these two species may respond to stress via different mechanisms. Specifically, A. gerardii tends to maintain molecular function while S. nutans prioritizes avoidance. Sorghastrum nutans may strategize abscisic acid response and catabolism to respond rapidly to stress. These results have important implications for success of these two important grass species under a more variable and extreme climate forecast for the future.
format: application/pdf
format: text/html
creator: Ava M. Hoffman
creator: Meghan L. Avolio
creator: Alan K. Knapp
creator: Melinda D. Smith
subject: Ecosystem Science
subject: Plant Science
subject: Climate Change Biology
description: doi:10.7717/peerj.4394
publisher: PeerJ Inc.
rights: © 2018 Hoffman et al.
abstract: Extremes in climate, such as heat waves and drought, are expected to become more frequent and intense with forecasted climate change. Plant species will almost certainly differ in their responses to these stressors. We experimentally imposed a heat wave and drought in the tallgrass prairie ecosystem near Manhattan, Kansas, USA to assess transcriptional responses of two ecologically important C4 grass species, Andropogon gerardii and Sorghastrum nutans. Based on previous research, we expected that S. nutans would regulate more genes, particularly those related to stress response, under high heat and drought. Across all treatments, S. nutans showed greater expression of negative regulatory and catabolism genes while A. gerardii upregulated cellular and protein metabolism. As predicted, S. nutans showed greater sensitivity to water stress, particularly with downregulation of non-coding RNAs and upregulation of water stress and catabolism genes. A. gerardii was less sensitive to drought, although A. gerardii tended to respond with upregulation in response to drought versus S. nutans which downregulated more genes under drier conditions. Surprisingly, A. gerardii only showed minimal gene expression response to increased temperature, while S. nutans showed no response. Gene functional annotation suggested that these two species may respond to stress via different mechanisms. Specifically, A. gerardii tends to maintain molecular function while S. nutans prioritizes avoidance. Sorghastrum nutans may strategize abscisic acid response and catabolism to respond rapidly to stress. These results have important implications for success of these two important grass species under a more variable and extreme climate forecast for the future.
bibliographic citation: Hoffman et al. (2018) Codominant grasses differ in gene expression under experimental climate extremes in native tallgrass prairie. PeerJ 6:e4394 https://doi.org/10.7717/peerj.4394
date submitted: 2017-12-06
date accepted: 2018-01-30
issued: 2018-02-14
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Hoffman
  given name: Ava M.
author list: Agent
  family name: Avolio
  given name: Meghan L.
author list: Agent
  family name: Knapp
  given name: Alan K.
author list: Agent
  family name: Smith
  given name: Melinda D.
doi: 10.7717/peerj.4394
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-14
copyright: ©2018 Hoffman et al.
attribution name: Hoffman et al.

Benthic grazing in a eutrophic river: cascading effects of zoobenthivorous fish mask direct effects of herbivorous fish
type: item
type: AcademicArticle
description: Benthic grazing strongly controls periphyton biomass. The question therefore arises whether benthic grazing could be used as a tool to reduce excessive growth of periphyton in nutrient-enriched rivers. Although benthic invertebrate grazers reduce the growth of periphyton, this is highly context dependent. Here we assessed whether the only obligate herbivorous fish in European rivers, the common nase (Chondrostoma nasus L.), is able to reduce periphyton biomass in a eutrophic river. We conducted three consecutive in situ experiments at low, intermediate and high densities of nase in the river using standard tiles on the river bottom naturally covered with periphyton that were accessible to fish and tiles that excluded fish foraging with electric exclosures. The biomass of benthic invertebrate grazers was very low relative to nase. We hypothesised that nase would reduce periphyton biomass on accessible tiles and therefore expected higher periphyton biomass on the exclosure tiles, at least at intermediate and high densities of nase in the river. Contrary to our expectation, the impact of fish grazing was low even at high fish density, as judged by the significantly lower chlorophyll a concentration on exclosure tiles even though the ash-free dry mass on accessible and exclosure tiles did not differ. The lower chlorophyll a concentrations on exclosure tiles might be explained by a higher biomass of invertebrate grazers on the exclosure tiles, which would indicate that the effect of invertebrate grazers was stronger than that of herbivorous fish grazers. The high biomass of invertebrate grazers on exclosure tiles likely arose from the exclusion of zoobenthivorous fish, which occur in the river at high densities. The results of our small-scale experiments suggested that cascading top-down effects of zoobenthivorous fish have a higher impact on periphyton biomass than direct effects of herbivorous nase.
format: application/pdf
format: text/html
creator: Madlen Gerke
creator: Daniel Cob Chaves
creator: Marc Richter
creator: Daniela Mewes
creator: Jörg Schneider
creator: Dirk Hübner
creator: Carola Winkelmann
subject: Aquaculture, Fisheries and Fish Science
subject: Ecology
subject: Freshwater Biology
description: doi:10.7717/peerj.4381
publisher: PeerJ Inc.
rights: © 2018 Gerke et al.
abstract: Benthic grazing strongly controls periphyton biomass. The question therefore arises whether benthic grazing could be used as a tool to reduce excessive growth of periphyton in nutrient-enriched rivers. Although benthic invertebrate grazers reduce the growth of periphyton, this is highly context dependent. Here we assessed whether the only obligate herbivorous fish in European rivers, the common nase (Chondrostoma nasus L.), is able to reduce periphyton biomass in a eutrophic river. We conducted three consecutive in situ experiments at low, intermediate and high densities of nase in the river using standard tiles on the river bottom naturally covered with periphyton that were accessible to fish and tiles that excluded fish foraging with electric exclosures. The biomass of benthic invertebrate grazers was very low relative to nase. We hypothesised that nase would reduce periphyton biomass on accessible tiles and therefore expected higher periphyton biomass on the exclosure tiles, at least at intermediate and high densities of nase in the river. Contrary to our expectation, the impact of fish grazing was low even at high fish density, as judged by the significantly lower chlorophyll a concentration on exclosure tiles even though the ash-free dry mass on accessible and exclosure tiles did not differ. The lower chlorophyll a concentrations on exclosure tiles might be explained by a higher biomass of invertebrate grazers on the exclosure tiles, which would indicate that the effect of invertebrate grazers was stronger than that of herbivorous fish grazers. The high biomass of invertebrate grazers on exclosure tiles likely arose from the exclusion of zoobenthivorous fish, which occur in the river at high densities. The results of our small-scale experiments suggested that cascading top-down effects of zoobenthivorous fish have a higher impact on periphyton biomass than direct effects of herbivorous nase.
bibliographic citation: Gerke et al. (2018) Benthic grazing in a eutrophic river: cascading effects of zoobenthivorous fish mask direct effects of herbivorous fish. PeerJ 6:e4381 https://doi.org/10.7717/peerj.4381
date submitted: 2017-10-16
date accepted: 2018-01-29
issued: 2018-02-14
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Gerke
  given name: Madlen
author list: Agent
  family name: Cob Chaves
  given name: Daniel
author list: Agent
  family name: Richter
  given name: Marc
author list: Agent
  family name: Mewes
  given name: Daniela
author list: Agent
  family name: Schneider
  given name: Jörg
author list: Agent
  family name: Hübner
  given name: Dirk
author list: Agent
  family name: Winkelmann
  given name: Carola
doi: 10.7717/peerj.4381
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-14
copyright: ©2018 Gerke et al.
attribution name: Gerke et al.

Catchment land use predicts benthic vegetation in small estuaries
type: item
type: AcademicArticle
description: Many estuaries are becoming increasingly eutrophic from human activities within their catchments. Nutrient loads often are used to assess risk of eutrophication to estuaries, but such data are expensive and time consuming to obtain. We compared the percent of fertilized land within a catchment, dissolved inorganic nitrogen loads, catchment to estuary area ratio and flushing time as predictors of the proportion of macroalgae to total vegetation within 14 estuaries in south-eastern Australia. The percent of fertilized land within the catchment was the best predictor of the proportion of macroalgae within the estuaries studied. There was a transition to a dominance of macroalgae once the proportion of fertilized land in the catchment exceeded 24%, highlighting the sensitivity of estuaries to catchment land use.
format: application/pdf
format: text/html
creator: Perran L.M. Cook
creator: Fiona Y. Warry
creator: Paul Reich
creator: Ralph Mac Nally
creator: Ryan J. Woodland
subject: Ecosystem Science
subject: Coupled Natural and Human Systems
subject: Aquatic and Marine Chemistry
subject: Biogeochemistry
subject: Environmental Impacts
description: doi:10.7717/peerj.4378
publisher: PeerJ Inc.
rights: © 2018 Cook et al.
abstract: Many estuaries are becoming increasingly eutrophic from human activities within their catchments. Nutrient loads often are used to assess risk of eutrophication to estuaries, but such data are expensive and time consuming to obtain. We compared the percent of fertilized land within a catchment, dissolved inorganic nitrogen loads, catchment to estuary area ratio and flushing time as predictors of the proportion of macroalgae to total vegetation within 14 estuaries in south-eastern Australia. The percent of fertilized land within the catchment was the best predictor of the proportion of macroalgae within the estuaries studied. There was a transition to a dominance of macroalgae once the proportion of fertilized land in the catchment exceeded 24%, highlighting the sensitivity of estuaries to catchment land use.
bibliographic citation: Cook et al. (2018) Catchment land use predicts benthic vegetation in small estuaries. PeerJ 6:e4378 https://doi.org/10.7717/peerj.4378
date submitted: 2017-11-09
date accepted: 2018-01-27
issued: 2018-02-14
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Cook
  given name: Perran L.M.
author list: Agent
  family name: Warry
  given name: Fiona Y.
author list: Agent
  family name: Reich
  given name: Paul
author list: Agent
  family name: Mac Nally
  given name: Ralph
author list: Agent
  family name: Woodland
  given name: Ryan J.
doi: 10.7717/peerj.4378
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-14
copyright: ©2018 Cook et al.
attribution name: Cook et al.

Ontogeny of long-range vocalizations in a Neotropical fossorial rodent: the Anillaco Tuco-Tuco (Ctenomys sp.)
type: item
type: AcademicArticle
description: Tuco-tucos (Ctenomys spp.) are subterranean rodents that produce territorial, high intensity long-range vocalizations (LRVs) of broadband and low frequency that are essential for long-distance communication between individuals in different tunnel systems. Despite their importance, the development of LRVs remains poorly understood. In adult Anillaco Tuco-Tucos (Ctenomys sp.) the LRV is composed by two types of syllables (series and individual notes) that are repeated a variable number of times. We studied the development of the LRVs in eight juveniles of the Anillaco Tuco-Tuco ranging from 14–28 to 104–118 days after birth. We (1) tested whether the syllables followed any of three alternative developmental modes (retention of juvenile vocalizations, modification of juvenile precursors or de novo appearance in adults), (2) evaluated the development of structural and acoustic features of syllables, and (3) tested the prediction that juveniles should produce a greater proportion of atypical series in precursors of the LRV than adults, due to lack maturation and/or precise coupling of neuromuscular and anatomical structures. The LRV of the Anillaco Tuco-Tuco exhibited a mixed developmental mode: while series developed from juvenile precursors whose acoustic features gradually approached those of adults, individual notes appeared later in the ontogeny and de novo with acoustic features indistinguishable from those of adults. The number of series per vocalization increased through development and varied from one to 25 in juvenile males and from one to six in juvenile females. The structure of the most common series type (triad) did not exhibit ontogenetic changes and was present as such at the onset of the emission of vocalizations. On the contrary, acoustic features of juvenile triad notes changed with age in both sexes (duration 90% increased through development, while bandwidth 90% and peak frequency decreased). Furthermore, juveniles emitted a higher proportion of atyp…
format: application/pdf
format: text/html
creator: Juan Pablo Amaya
creator: Juan Ignacio Areta
subject: Animal Behavior
subject: Zoology
description: doi:10.7717/peerj.4334
publisher: PeerJ Inc.
rights: © 2018 Amaya and Areta
abstract: Tuco-tucos (Ctenomys spp.) are subterranean rodents that produce territorial, high intensity long-range vocalizations (LRVs) of broadband and low frequency that are essential for long-distance communication between individuals in different tunnel systems. Despite their importance, the development of LRVs remains poorly understood. In adult Anillaco Tuco-Tucos (Ctenomys sp.) the LRV is composed by two types of syllables (series and individual notes) that are repeated a variable number of times. We studied the development of the LRVs in eight juveniles of the Anillaco Tuco-Tuco ranging from 14–28 to 104–118 days after birth. We (1) tested whether the syllables followed any of three alternative developmental modes (retention of juvenile vocalizations, modification of juvenile precursors or de novo appearance in adults), (2) evaluated the development of structural and acoustic features of syllables, and (3) tested the prediction that juveniles should produce a greater proportion of atypical series in precursors of the LRV than adults, due to lack maturation and/or precise coupling of neuromuscular and anatomical structures. The LRV of the Anillaco Tuco-Tuco exhibited a mixed developmental mode: while series developed from juvenile precursors whose acoustic features gradually approached those of adults, individual notes appeared later in the ontogeny and de novo with acoustic features indistinguishable from those of adults. The number of series per vocalization increased through development and varied from one to 25 in juvenile males and from one to six in juvenile females. The structure of the most common series type (triad) did not exhibit ontogenetic changes and was present as such at the onset of the emission of vocalizations. On the contrary, acoustic features of juvenile triad notes changed with age in both sexes (duration 90% increased through development, while bandwidth 90% and peak frequency decreased). Furthermore, juveniles emitted a higher proportion of atyp…
bibliographic citation: Amaya et al. (2018) Ontogeny of long-range vocalizations in a Neotropical fossorial rodent: the Anillaco Tuco-Tuco (Ctenomys sp.). PeerJ 6:e4334 https://doi.org/10.7717/peerj.4334
date submitted: 2017-06-27
date accepted: 2018-01-17
issued: 2018-02-14
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Amaya
  given name: Juan Pablo
author list: Agent
  family name: Areta
  given name: Juan Ignacio
doi: 10.7717/peerj.4334
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-14
copyright: ©2018 Amaya and Areta
attribution name: Amaya and Areta

Different intensities of basketball drills affect jump shot accuracy of expert and junior players
type: item
type: AcademicArticle
description: Background In basketball a maximum accuracy at every game intensity is required while shooting. The aim of the present study was to investigate the acute effect of three different drill intensity simulation protocols on jump shot accuracy in expert and junior basketball players. Materials & Methods Eleven expert players (age 26 ± 6 yrs, weight 86 ± 11 kg, height 192 ± 8 cm) and ten junior players (age 18 ± 1 yrs, weight 75 ± 12 kg, height 184 ± 9 cm) completed three series of twenty jump shots at three different levels of exertion. Counter Movement Jump (CMJ) height was also measured after each series of jump shots. Exertion’s intensity was induced manipulating the basketball drills. Heart rate was measured for the whole duration of the tests while the rating of perceived exertion (RPE) was collected at the end of each series of shots. Results Heart rate and rating of perceived exertion (RPE) were statistically different in the three conditions for both expert and junior players. CMJ height remained almost unchanged in both groups. Jump shot accuracy decreased with increasing drills intensity both in experts and junior players. Expert players showed higher accuracy than junior players for all the three levels of exertion (83% vs 64%, p < 0.001; 75% vs 57%, p < 0.05; 76% vs 60%, p < 0.01). Moreover, for the most demanding level of exertion, experts showed a higher accuracy in the last ten shots compared to the first ten shots (82% vs 70%, p < 0.05). Discussion Experts coped better with the different exertion’s intensities, thus maintaining a higher level of performance. The introduction of technical short bouts of high-intensity sport-specific exercises into skill sessions should be proposed to improve jump shot accuracy during matches.
format: application/pdf
format: text/html
creator: Giuseppe Marcolin
creator: Nicola Camazzola
creator: Fausto Antonio Panizzolo
creator: Davide Grigoletto
creator: Antonio Paoli
subject: Anatomy and Physiology
subject: Kinesiology
description: doi:10.7717/peerj.4250
publisher: PeerJ Inc.
rights: © 2018 Marcolin et al.
abstract: Background In basketball a maximum accuracy at every game intensity is required while shooting. The aim of the present study was to investigate the acute effect of three different drill intensity simulation protocols on jump shot accuracy in expert and junior basketball players. Materials & Methods Eleven expert players (age 26 ± 6 yrs, weight 86 ± 11 kg, height 192 ± 8 cm) and ten junior players (age 18 ± 1 yrs, weight 75 ± 12 kg, height 184 ± 9 cm) completed three series of twenty jump shots at three different levels of exertion. Counter Movement Jump (CMJ) height was also measured after each series of jump shots. Exertion’s intensity was induced manipulating the basketball drills. Heart rate was measured for the whole duration of the tests while the rating of perceived exertion (RPE) was collected at the end of each series of shots. Results Heart rate and rating of perceived exertion (RPE) were statistically different in the three conditions for both expert and junior players. CMJ height remained almost unchanged in both groups. Jump shot accuracy decreased with increasing drills intensity both in experts and junior players. Expert players showed higher accuracy than junior players for all the three levels of exertion (83% vs 64%, p < 0.001; 75% vs 57%, p < 0.05; 76% vs 60%, p < 0.01). Moreover, for the most demanding level of exertion, experts showed a higher accuracy in the last ten shots compared to the first ten shots (82% vs 70%, p < 0.05). Discussion Experts coped better with the different exertion’s intensities, thus maintaining a higher level of performance. The introduction of technical short bouts of high-intensity sport-specific exercises into skill sessions should be proposed to improve jump shot accuracy during matches.
bibliographic citation: Marcolin et al. (2018) Different intensities of basketball drills affect jump shot accuracy of expert and junior players. PeerJ 6:e4250 https://doi.org/10.7717/peerj.4250
date submitted: 2017-09-13
date accepted: 2017-12-19
issued: 2018-02-14
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Marcolin
  given name: Giuseppe
author list: Agent
  family name: Camazzola
  given name: Nicola
author list: Agent
  family name: Panizzolo
  given name: Fausto Antonio
author list: Agent
  family name: Grigoletto
  given name: Davide
author list: Agent
  family name: Paoli
  given name: Antonio
doi: 10.7717/peerj.4250
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-14
copyright: ©2018 Marcolin et al.
attribution name: Marcolin et al.

The axial skeleton of Poposaurus langstoni (Pseudosuchia: Poposauroidea) and its implications for accessory intervertebral articulation evolution in pseudosuchian archosaurs
type: item
type: AcademicArticle
description: Dinosaurs and their close relatives grew to sizes larger than any other terrestrial animal in the history of life on Earth, and many enormous dinosaurs (e.g., Diplodocus, Spinosaurus, Tyrannosaurus) have accessory intervertebral articulations that have been suggested to support these large body sizes. Some pseudosuchian archosaurs have been reported to have these articulations as well, but few have been characterized in these taxa because of a lower abundance of complete, three-dimensional pseudosuchian vertebral material in relation to dinosaurs. We describe the axial column of the large (∼4–5 m) poposauroid pseudosuchian Poposaurus langstoni from the Upper Triassic of Texas (TMM Locality 31025 of the Otis Chalk localities; Dockum Group, Howard County, TX, USA). P. langstoni was originally named from pelvic girdle elements and vertebrae; here we describe newly discovered and prepared presacral vertebrae and a presacral rib from the original excavation of the holotype in the 1940s. The well-preserved vertebrae have well-defined vertebral laminae and clear hyposphene–hypantrum intervertebral articulations, character states mentioned in pseudosuchians but rarely described. The new material demonstrates variation present in the hyposphene–hypantrum articulation through the vertebral column. We compared these morphologies to other pseudosuchians with and without the hyposphene–hypantrum articulation. Based on these careful comparisons, we provide an explicit definition for the hyposphene–hypantrum articulation applicable across Archosauria. Within Pseudosuchia, we find the hyposphene–hypantrum appeared independently in the clade at least twice, but we also see the loss of these structures in clades that had them ancestrally. Furthermore, we found the presence of large body sizes (femoral lengths >∼300 mm) and the presence of the hyposphene–hypantrum is correlated in most non-crocodylomorph pseudosuchian archosaurs with a few exceptions. This result suggests that the pre…
format: application/pdf
format: text/html
creator: Candice M. Stefanic
creator: Sterling J. Nesbitt
subject: Evolutionary Studies
subject: Paleontology
description: doi:10.7717/peerj.4235
publisher: PeerJ Inc.
rights: © 2018 Stefanic et al.
abstract: Dinosaurs and their close relatives grew to sizes larger than any other terrestrial animal in the history of life on Earth, and many enormous dinosaurs (e.g., Diplodocus, Spinosaurus, Tyrannosaurus) have accessory intervertebral articulations that have been suggested to support these large body sizes. Some pseudosuchian archosaurs have been reported to have these articulations as well, but few have been characterized in these taxa because of a lower abundance of complete, three-dimensional pseudosuchian vertebral material in relation to dinosaurs. We describe the axial column of the large (∼4–5 m) poposauroid pseudosuchian Poposaurus langstoni from the Upper Triassic of Texas (TMM Locality 31025 of the Otis Chalk localities; Dockum Group, Howard County, TX, USA). P. langstoni was originally named from pelvic girdle elements and vertebrae; here we describe newly discovered and prepared presacral vertebrae and a presacral rib from the original excavation of the holotype in the 1940s. The well-preserved vertebrae have well-defined vertebral laminae and clear hyposphene–hypantrum intervertebral articulations, character states mentioned in pseudosuchians but rarely described. The new material demonstrates variation present in the hyposphene–hypantrum articulation through the vertebral column. We compared these morphologies to other pseudosuchians with and without the hyposphene–hypantrum articulation. Based on these careful comparisons, we provide an explicit definition for the hyposphene–hypantrum articulation applicable across Archosauria. Within Pseudosuchia, we find the hyposphene–hypantrum appeared independently in the clade at least twice, but we also see the loss of these structures in clades that had them ancestrally. Furthermore, we found the presence of large body sizes (femoral lengths >∼300 mm) and the presence of the hyposphene–hypantrum is correlated in most non-crocodylomorph pseudosuchian archosaurs with a few exceptions. This result suggests that the pre…
bibliographic citation: Stefanic et al. (2018) The axial skeleton of Poposaurus langstoni (Pseudosuchia: Poposauroidea) and its implications for accessory intervertebral articulation evolution in pseudosuchian archosaurs. PeerJ 6:e4235 https://doi.org/10.7717/peerj.4235
date submitted: 2017-06-21
date accepted: 2017-12-15
issued: 2018-02-14
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Stefanic
  given name: Candice M.
author list: Agent
  family name: Nesbitt
  given name: Sterling J.
doi: 10.7717/peerj.4235
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-14
copyright: © 2018 Stefanic and Nesbitt
attribution name: Stefanic et al.

Factors associated with elevated blood pressure or hypertension in Afro-Caribbean youth: a cross-sectional study
type: item
type: AcademicArticle
description: Background Although several studies have identified risk factors for high blood pressure (BP), data from Afro-Caribbean populations are limited. Additionally, less is known about how putative risk factors operate in young adults and how social factors influence the risk of high BP. In this study, we estimated the relative risk for elevated BP or hypertension (EBP/HTN), defined as BP ≥ 120/80 mmHg, among young adults with putative cardiovascular disease (CVD) risk factors in Jamaica and evaluated whether relative risks differed by sex. Methods Data from 898 young adults, 18–20 years old, were analysed. BP was measured with a mercury sphygmomanometer after participants had been seated for 5 min. Anthropometric measurements were obtained, and glucose, lipids and insulin measured from a fasting venous blood sample. Data on socioeconomic status (SES) were obtained via questionnaire. CVD risk factor status was defined using standard cut-points or the upper quintile of the distribution where the numbers meeting standard cut-points were small. Relative risks were estimated using odds ratios (OR) from logistic regression models. Results Prevalence of EBP/HTN was 30% among males and 13% among females (p < 0.001 for sex difference). There was evidence for sex interaction in the relationship between EBP/HTN and some of risk factors (obesity and household possessions), therefore we report sex-specific analyses. In multivariable logistic regression models, factors independently associated with EBP/HTN among men were obesity (OR 8.48, 95% CI [2.64–27.2], p < 0.001), and high glucose (OR 2.01, CI [1.20–3.37], p = 0.008), while high HOMA-IR did not achieve statistical significance (OR 2.08, CI [0.94–4.58], p = 0.069). In similar models for women, high triglycerides (OR 1.98, CI [1.03–3.81], p = 0.040) and high HOMA-IR (OR 2.07, CI [1.03–4.12], p = 0.039) were positively associated with EBP/HTN. Lower SES was also associated with higher odds for EBP/HTN (OR 4.63, CI [1.31–16.4], p = …
format: application/pdf
format: text/html
creator: Trevor S. Ferguson
creator: Novie O.M. Younger-Coleman
creator: Marshall K. Tulloch-Reid
creator: Nadia R. Bennett
creator: Amanda E. Rousseau
creator: Jennifer M. Knight-Madden
creator: Maureen E. Samms-Vaughan
creator: Deanna E. Ashley
creator: Rainford J. Wilks
subject: Cardiology
subject: Epidemiology
subject: Global Health
subject: Internal Medicine
subject: Public Health
description: doi:10.7717/peerj.4385
publisher: PeerJ Inc.
rights: © 2018 Ferguson et al.
abstract: Background Although several studies have identified risk factors for high blood pressure (BP), data from Afro-Caribbean populations are limited. Additionally, less is known about how putative risk factors operate in young adults and how social factors influence the risk of high BP. In this study, we estimated the relative risk for elevated BP or hypertension (EBP/HTN), defined as BP ≥ 120/80 mmHg, among young adults with putative cardiovascular disease (CVD) risk factors in Jamaica and evaluated whether relative risks differed by sex. Methods Data from 898 young adults, 18–20 years old, were analysed. BP was measured with a mercury sphygmomanometer after participants had been seated for 5 min. Anthropometric measurements were obtained, and glucose, lipids and insulin measured from a fasting venous blood sample. Data on socioeconomic status (SES) were obtained via questionnaire. CVD risk factor status was defined using standard cut-points or the upper quintile of the distribution where the numbers meeting standard cut-points were small. Relative risks were estimated using odds ratios (OR) from logistic regression models. Results Prevalence of EBP/HTN was 30% among males and 13% among females (p < 0.001 for sex difference). There was evidence for sex interaction in the relationship between EBP/HTN and some of risk factors (obesity and household possessions), therefore we report sex-specific analyses. In multivariable logistic regression models, factors independently associated with EBP/HTN among men were obesity (OR 8.48, 95% CI [2.64–27.2], p < 0.001), and high glucose (OR 2.01, CI [1.20–3.37], p = 0.008), while high HOMA-IR did not achieve statistical significance (OR 2.08, CI [0.94–4.58], p = 0.069). In similar models for women, high triglycerides (OR 1.98, CI [1.03–3.81], p = 0.040) and high HOMA-IR (OR 2.07, CI [1.03–4.12], p = 0.039) were positively associated with EBP/HTN. Lower SES was also associated with higher odds for EBP/HTN (OR 4.63, CI [1.31–16.4], p = …
bibliographic citation: Ferguson et al. (2018) Factors associated with elevated blood pressure or hypertension in Afro-Caribbean youth: a cross-sectional study. PeerJ 6:e4385 https://doi.org/10.7717/peerj.4385
date submitted: 2017-10-03
date accepted: 2018-01-29
issued: 2018-02-13
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Ferguson
  given name: Trevor S.
author list: Agent
  family name: Younger-Coleman
  given name: Novie O.M.
author list: Agent
  family name: Tulloch-Reid
  given name: Marshall K.
author list: Agent
  family name: Bennett
  given name: Nadia R.
author list: Agent
  family name: Rousseau
  given name: Amanda E.
author list: Agent
  family name: Knight-Madden
  given name: Jennifer M.
author list: Agent
  family name: Samms-Vaughan
  given name: Maureen E.
author list: Agent
  family name: Ashley
  given name: Deanna E.
author list: Agent
  family name: Wilks
  given name: Rainford J.
doi: 10.7717/peerj.4385
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-02-13
copyright: ©2018 Ferguson et al.
attribution name: Ferguson et al.

PeerJ
type: Periodical
uri: PeerJ
issn: 2167-8359