PeerJ
type: channel
link: https://peerj.com/articles/
description: Articles published in PeerJ
publisher: PeerJ Inc.
publication name: PeerJ
issn: 2167-8359
items: Braincase and endocranial anatomy of two thalattosuchian crocodylomorphs and their relevance in understanding their adaptations to the marine environment
items: Serum lipid level is not associated with symptomatic intracerebral hemorrhage after intravenous thrombolysis for acute ischemic stroke
items: Not all brawn, but some brain. Strength gains after training alters kinematic motor abundance in hopping
items: Formation of sclerotia in Sclerotinia ginseng and composition of the sclerotial exudate
items: Effects of blood parasite infection and innate immune genetic diversity on mating patterns in a passerine bird breeding in contrasted habitats
items: Changing trends in elephant camp management in northern Thailand and implications for welfare
items: Optimal and near-optimal exponent-pairs for the Bertalanffy-Pütter growth model
items: Effects of a six-week weighted-implement throwing program on baseball pitching velocity, kinematics, arm stress, and arm range of motion
items: Morpho-histological development of the somatic embryos of Typha domingensis
items: Heavier- and lighter-load isolated lumbar extension resistance training produce similar strength increases, but different perceptual responses, in healthy males and females

Braincase and endocranial anatomy of two thalattosuchian crocodylomorphs and their relevance in understanding their adaptations to the marine environment
type: item
type: AcademicArticle
description: Thalattosuchians are a group of Mesozoic crocodylomorphs known from aquatic deposits of the Early Jurassic–Early Cretaceous that comprises two main lineages of almost exclusively marine forms, Teleosauridae and Metriorhynchoidea. Teleosaurids were found in shallow marine, brackish and freshwater deposits, and have been characterized as semiaquatic near-shore forms, whereas metriorhynchids are a lineage of fully pelagic forms, supported by a large set of morphological characters of the skull and postcranial anatomy. Recent contributions on Thalattosuchia have been focused on the study of the endocranial anatomy. This newly available information provides novel evidence to suggest adaptations on the neuroanatomy, senses organs, vasculature, and behavioral evolution of these crocodylomorphs. However, is still not clear if the major morphological differences between teleosaurids and metriorhynchids were also mirrored by changes in the braincase and endocranial anatomy. Based on X-ray CT scanning and digital endocast reconstructions we describe the braincase and endocranial anatomy of two well-preserved specimens of Thalattosuchia, the semiaquatic teleosaurid Steneosaurus bollensis and the pelagic metriorhynchid Cricosaurus araucanensis. We propose that some morphological traits, such as: an enlarged foramen for the internal carotid artery, a carotid foramen ventral to the occipital condyle, a single CN XII foramen, absence of brain flexures, well-developed cephalic vascular system, lack of subtympanic foramina and the reduction of the paratympanic sinus system, are distinctive features of Thalattosuchia. It has been previously suggested that the enlarged foramen for the internal carotid artery, the absence of brain flexures, and the hypertrophied cephalic vascular system were synapomorphies of Metriorhynchidae; however, new information revealed that all of these features were already established at the base of Thalattosuchia and might have been exapted later on their evo…
format: application/pdf
format: text/html
creator: Yanina Herrera
creator: Juan Martín Leardi
creator: Marta S. Fernández
subject: Evolutionary Studies
subject: Paleontology
subject: Taxonomy
subject: Zoology
description: doi:10.7717/peerj.5686
publisher: PeerJ Inc.
rights: © 2018 Herrera et al.
abstract: Thalattosuchians are a group of Mesozoic crocodylomorphs known from aquatic deposits of the Early Jurassic–Early Cretaceous that comprises two main lineages of almost exclusively marine forms, Teleosauridae and Metriorhynchoidea. Teleosaurids were found in shallow marine, brackish and freshwater deposits, and have been characterized as semiaquatic near-shore forms, whereas metriorhynchids are a lineage of fully pelagic forms, supported by a large set of morphological characters of the skull and postcranial anatomy. Recent contributions on Thalattosuchia have been focused on the study of the endocranial anatomy. This newly available information provides novel evidence to suggest adaptations on the neuroanatomy, senses organs, vasculature, and behavioral evolution of these crocodylomorphs. However, is still not clear if the major morphological differences between teleosaurids and metriorhynchids were also mirrored by changes in the braincase and endocranial anatomy. Based on X-ray CT scanning and digital endocast reconstructions we describe the braincase and endocranial anatomy of two well-preserved specimens of Thalattosuchia, the semiaquatic teleosaurid Steneosaurus bollensis and the pelagic metriorhynchid Cricosaurus araucanensis. We propose that some morphological traits, such as: an enlarged foramen for the internal carotid artery, a carotid foramen ventral to the occipital condyle, a single CN XII foramen, absence of brain flexures, well-developed cephalic vascular system, lack of subtympanic foramina and the reduction of the paratympanic sinus system, are distinctive features of Thalattosuchia. It has been previously suggested that the enlarged foramen for the internal carotid artery, the absence of brain flexures, and the hypertrophied cephalic vascular system were synapomorphies of Metriorhynchidae; however, new information revealed that all of these features were already established at the base of Thalattosuchia and might have been exapted later on their evo…
bibliographic citation: Herrera et al. (2018) Braincase and endocranial anatomy of two thalattosuchian crocodylomorphs and their relevance in understanding their adaptations to the marine environment. PeerJ 6:e5686 https://doi.org/10.7717/peerj.5686
date submitted: 2018-06-01
date accepted: 2018-08-30
issued: 2018-11-26
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Herrera
  given name: Yanina
author list: Agent
  family name: Leardi
  given name: Juan Martín
author list: Agent
  family name: Fernández
  given name: Marta S.
doi: 10.7717/peerj.5686
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-26
copyright: © 2018 Herrera et al.
attribution name: Herrera et al.

Serum lipid level is not associated with symptomatic intracerebral hemorrhage after intravenous thrombolysis for acute ischemic stroke
type: item
type: AcademicArticle
description: Background This study assessed whether serum lipid levels are associated with the risk of symptomatic intracerebral hemorrhage (sICH) and functional outcomes in patients with acute ischemic stroke after receiving intravenous thrombolysis. Methods We retrospectively analyzed consecutive ischemic stroke patients who were treated with intravenous tissue plasminogen activator between January 2007 and January 2017. Lipid levels on admission, including total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride levels, as well as potential predictors of sICH were tested using univariate and multivariate analyses. Results Of the 229 enrolled patients (100 women, aged 68 ± 13 years), 14 developed sICH and 103 (45%) had favorable functional outcomes at 3 months. The patients with sICH more often had diabetes mellitus (71% vs. 26%, P = 0.01) and had more severe stroke (mean National Institutes of Health Stroke Scale [NIHSS] score of 16 vs. 13, P = 0.045). Regarding lipid subtype, total cholesterol, LDL-C, HDL-C, and triglyceride levels were not associated with sICH or functional outcomes. According to the results of multivariate analysis, the frequency of sICH was independently associated with diabetes mellitus (odds ratio [OR] = 6.04; 95% CI [1.31–27.95]; P = 0.02) and the NIHSS score (OR = 1.12; 95% CI [1.02–1.22]; P = 0.01). A higher NIHSS score was independently associated with unfavorable functional outcomes (OR = 0.86; 95% CI [0.81–0.91]; P < 0.001). Conclusions Serum lipid levels on admission, including total cholesterol, LDL-C, HDL-C, and triglyceride levels, were not associated with sICH or 3-month functional outcomes after intravenous thrombolysis for acute ischemic stroke.
format: application/pdf
format: text/html
creator: Ting-Chun Lin
creator: Yen-Kuang Lin
creator: Chin-I Chen
creator: Lung Chan
creator: Nai-Fang Chi
creator: Rey-Yue Yuan
creator: Jau-Jiuan Sheu
creator: Chun-Ren Wei
creator: Jui-Ping Tsai
creator: Tu-Hsueh Yeh
subject: Neuroscience
subject: Neurology
description: doi:10.7717/peerj.6021
publisher: PeerJ Inc.
rights: © 2018 Lin et al.
abstract: Background This study assessed whether serum lipid levels are associated with the risk of symptomatic intracerebral hemorrhage (sICH) and functional outcomes in patients with acute ischemic stroke after receiving intravenous thrombolysis. Methods We retrospectively analyzed consecutive ischemic stroke patients who were treated with intravenous tissue plasminogen activator between January 2007 and January 2017. Lipid levels on admission, including total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride levels, as well as potential predictors of sICH were tested using univariate and multivariate analyses. Results Of the 229 enrolled patients (100 women, aged 68 ± 13 years), 14 developed sICH and 103 (45%) had favorable functional outcomes at 3 months. The patients with sICH more often had diabetes mellitus (71% vs. 26%, P = 0.01) and had more severe stroke (mean National Institutes of Health Stroke Scale [NIHSS] score of 16 vs. 13, P = 0.045). Regarding lipid subtype, total cholesterol, LDL-C, HDL-C, and triglyceride levels were not associated with sICH or functional outcomes. According to the results of multivariate analysis, the frequency of sICH was independently associated with diabetes mellitus (odds ratio [OR] = 6.04; 95% CI [1.31–27.95]; P = 0.02) and the NIHSS score (OR = 1.12; 95% CI [1.02–1.22]; P = 0.01). A higher NIHSS score was independently associated with unfavorable functional outcomes (OR = 0.86; 95% CI [0.81–0.91]; P < 0.001). Conclusions Serum lipid levels on admission, including total cholesterol, LDL-C, HDL-C, and triglyceride levels, were not associated with sICH or 3-month functional outcomes after intravenous thrombolysis for acute ischemic stroke.
bibliographic citation: Lin et al. (2018) Serum lipid level is not associated with symptomatic intracerebral hemorrhage after intravenous thrombolysis for acute ischemic stroke. PeerJ 6:e6021 https://doi.org/10.7717/peerj.6021
date submitted: 2018-08-30
date accepted: 2018-10-29
issued: 2018-11-23
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Lin
  given name: Ting-Chun
author list: Agent
  family name: Lin
  given name: Yen-Kuang
author list: Agent
  family name: Chen
  given name: Chin-I
author list: Agent
  family name: Chan
  given name: Lung
author list: Agent
  family name: Chi
  given name: Nai-Fang
author list: Agent
  family name: Yuan
  given name: Rey-Yue
author list: Agent
  family name: Sheu
  given name: Jau-Jiuan
author list: Agent
  family name: Wei
  given name: Chun-Ren
author list: Agent
  family name: Tsai
  given name: Jui-Ping
author list: Agent
  family name: Yeh
  given name: Tu-Hsueh
doi: 10.7717/peerj.6021
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-23
copyright: ©2018 Lin et al.
attribution name: Lin et al.

Not all brawn, but some brain. Strength gains after training alters kinematic motor abundance in hopping
type: item
type: AcademicArticle
description: Background The effects of resistance training on a muscle’s neural, architectural, and mechanical properties are well established. However, whether resistance training can positively change the coordination of multiple motor elements in the control of a well-defined lower limb motor performance objective remains unclear. Such knowledge is critical given that resistance training is an essential and ubiquitous component in gait rehabilitation. This study aimed to investigate if strength gains of the ankle and knee extensors after resistance training increases kinematic motor abundance in hopping. Methods The data presented in this study represents the pooled group results of a sub-study from a larger project investigating the effects of resistance training on load carriage running energetics. Thirty healthy adults performed self-paced unilateral hopping, and strength testing before and after six weeks of lower limb resistance training. Motion capture was used to derive the elemental variables of planar segment angles of the foot, shank, thigh, and pelvis, and the performance variable of leg length. Uncontrolled manifold analysis (UCM) was used to provide an index of motor abundance (IMA) in the synergistic coordination of segment angles in the stabilization of leg length. Bayesian Functional Data Analysis was used for statistical inference, with a non-zero crossing of the 95% Credible Interval (CrI) used as a test of significance. Results Depending on the phase of hop stance, there were significant main effects of ankle and knee strength on IMA, and a significant ankle by knee interaction effect. For example at 10% hop stance, a 1 Nm/kg increase in ankle extensor strength increased IMA by 0.37 (95% CrI [0.14–0.59]), a 1 Nm/kg increase in knee extensor strength decreased IMA by 0.29 (95% CrI [0.08–0.51]), but increased the effect of ankle strength on IMA by 0.71 (95% CrI [0.10–1.33]). At 55% hop stance, a 1 Nm/kg increase in knee extensor strength increase IMA by 0.24 …
format: application/pdf
format: text/html
creator: Bernard X.W. Liew
creator: Andrew Morrison
creator: Hiroaki Hobara
creator: Susan Morris
creator: Kevin Netto
subject: Biophysics
subject: Neuroscience
subject: Kinesiology
description: doi:10.7717/peerj.6010
publisher: PeerJ Inc.
rights: © 2018 Liew et al.
abstract: Background The effects of resistance training on a muscle’s neural, architectural, and mechanical properties are well established. However, whether resistance training can positively change the coordination of multiple motor elements in the control of a well-defined lower limb motor performance objective remains unclear. Such knowledge is critical given that resistance training is an essential and ubiquitous component in gait rehabilitation. This study aimed to investigate if strength gains of the ankle and knee extensors after resistance training increases kinematic motor abundance in hopping. Methods The data presented in this study represents the pooled group results of a sub-study from a larger project investigating the effects of resistance training on load carriage running energetics. Thirty healthy adults performed self-paced unilateral hopping, and strength testing before and after six weeks of lower limb resistance training. Motion capture was used to derive the elemental variables of planar segment angles of the foot, shank, thigh, and pelvis, and the performance variable of leg length. Uncontrolled manifold analysis (UCM) was used to provide an index of motor abundance (IMA) in the synergistic coordination of segment angles in the stabilization of leg length. Bayesian Functional Data Analysis was used for statistical inference, with a non-zero crossing of the 95% Credible Interval (CrI) used as a test of significance. Results Depending on the phase of hop stance, there were significant main effects of ankle and knee strength on IMA, and a significant ankle by knee interaction effect. For example at 10% hop stance, a 1 Nm/kg increase in ankle extensor strength increased IMA by 0.37 (95% CrI [0.14–0.59]), a 1 Nm/kg increase in knee extensor strength decreased IMA by 0.29 (95% CrI [0.08–0.51]), but increased the effect of ankle strength on IMA by 0.71 (95% CrI [0.10–1.33]). At 55% hop stance, a 1 Nm/kg increase in knee extensor strength increase IMA by 0.24 …
bibliographic citation: Liew et al. (2018) Not all brawn, but some brain. Strength gains after training alters kinematic motor abundance in hopping. PeerJ 6:e6010 https://doi.org/10.7717/peerj.6010
date submitted: 2018-06-22
date accepted: 2018-10-26
issued: 2018-11-23
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Liew
  given name: Bernard X.W.
author list: Agent
  family name: Morrison
  given name: Andrew
author list: Agent
  family name: Hobara
  given name: Hiroaki
author list: Agent
  family name: Morris
  given name: Susan
author list: Agent
  family name: Netto
  given name: Kevin
doi: 10.7717/peerj.6010
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-23
copyright: ©2018 Liew et al.
attribution name: Liew et al.

Formation of sclerotia in Sclerotinia ginseng and composition of the sclerotial exudate
type: item
type: AcademicArticle
description: Background Sclerotinia ginseng is a major devastating soil-borne pathogen of ginseng that can cause irreparable damage and large economic losses. This pathogen produces sclerotia, which are among the most persistent resting structures produced by filamentous fungi. The production of an exudate is a common feature of sclerotial development. Methods S. ginseng was cultured on 10 different media and the following parameters were measured: mycelial growth rate (mm/day), initial formation time of exudate droplets, total quantity of exudate, number of sclerotia per dish, and sclerotial fresh/dry weight. The composition of the sclerotial exudate was analyzed using four methods (high performance liquid chromatography, gas chromatography-mass spectrometry, flame atomic absorption spectrometry, and Nessler’s reagent spectrophotometry). Results We found that PDA was the optimal medium for exudate production, while SDA medium resulted in the highest mycelial growth rate. The earliest emergence of exudate droplets from sclerotia was on OA-YE and V8 media. The largest amount of sclerotia and the smallest sclerotia were produced on V8 medium. The maximum and minimum dry/fresh weight were obtained on MEA medium and V8 medium, respectively. The exudate contained organic acids (oxalic acid, gallic acid, ferulic acid, vanillic acid, caffeic acid, and tannic acid), carbohydrates (inositol, glucose, and trehalose), various ions (potassium, sodium, and magnesium), and ammonia. Discussion The functions of the identified compounds are discussed within the context of pathogenicity, sclerotial development, and antimicrobial activity. Our findings provide information about the production of sclerotia and the composition of sclerotial exudate that may be useful to develop strategies to control this disease.
format: application/pdf
format: text/html
creator: Dan Wang
creator: Junfan Fu
creator: Rujun Zhou
creator: Zibo Li
creator: Yujiao Xie
creator: Xinran Liu
creator: Yueling Han
subject: Microbiology
subject: Mycology
description: doi:10.7717/peerj.6009
publisher: PeerJ Inc.
rights: © 2018 Wang et al.
abstract: Background Sclerotinia ginseng is a major devastating soil-borne pathogen of ginseng that can cause irreparable damage and large economic losses. This pathogen produces sclerotia, which are among the most persistent resting structures produced by filamentous fungi. The production of an exudate is a common feature of sclerotial development. Methods S. ginseng was cultured on 10 different media and the following parameters were measured: mycelial growth rate (mm/day), initial formation time of exudate droplets, total quantity of exudate, number of sclerotia per dish, and sclerotial fresh/dry weight. The composition of the sclerotial exudate was analyzed using four methods (high performance liquid chromatography, gas chromatography-mass spectrometry, flame atomic absorption spectrometry, and Nessler’s reagent spectrophotometry). Results We found that PDA was the optimal medium for exudate production, while SDA medium resulted in the highest mycelial growth rate. The earliest emergence of exudate droplets from sclerotia was on OA-YE and V8 media. The largest amount of sclerotia and the smallest sclerotia were produced on V8 medium. The maximum and minimum dry/fresh weight were obtained on MEA medium and V8 medium, respectively. The exudate contained organic acids (oxalic acid, gallic acid, ferulic acid, vanillic acid, caffeic acid, and tannic acid), carbohydrates (inositol, glucose, and trehalose), various ions (potassium, sodium, and magnesium), and ammonia. Discussion The functions of the identified compounds are discussed within the context of pathogenicity, sclerotial development, and antimicrobial activity. Our findings provide information about the production of sclerotia and the composition of sclerotial exudate that may be useful to develop strategies to control this disease.
bibliographic citation: Wang et al. (2018) Formation of sclerotia in Sclerotinia ginseng and composition of the sclerotial exudate. PeerJ 6:e6009 https://doi.org/10.7717/peerj.6009
date submitted: 2018-08-20
date accepted: 2018-10-26
issued: 2018-11-23
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Wang
  given name: Dan
author list: Agent
  family name: Fu
  given name: Junfan
author list: Agent
  family name: Zhou
  given name: Rujun
author list: Agent
  family name: Li
  given name: Zibo
author list: Agent
  family name: Xie
  given name: Yujiao
author list: Agent
  family name: Liu
  given name: Xinran
author list: Agent
  family name: Han
  given name: Yueling
doi: 10.7717/peerj.6009
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-23
copyright: ©2018 Wang et al.
attribution name: Wang et al.

Effects of blood parasite infection and innate immune genetic diversity on mating patterns in a passerine bird breeding in contrasted habitats
type: item
type: AcademicArticle
description: Genetic diversity at immune genes and levels of parasitism are known to affect patterns of (dis)assortative mating in several species. Heterozygote advantage and/or good genes should shape mate choice originating from pathogen/parasite-driven selection at immune genes. However, the stability of these associations, and whether they vary with environmental conditions, are still rarely documented. In this study, we describe mating patterns in a wild population of tree swallows (Tachycineta bicolor) over 4 years and assess the effects of haemosporidian parasite infection and immune genetic diversity at β-defensin genes on those patterns within two habitats of contrasting environmental quality, in southern Québec, Canada. We first show that mating patterns were only very weakly related to individual status of infection by haemosporidian parasites. However, we found a difference between habitats in mating patterns related to infection status, which was likely due to a non-random distribution of individuals, as non-infected mating pairs were more frequent in lower quality habitats. Mating patterns also differed depending on β-defensin heterozygosity at AvBD2, but only for genetic partners outside of the social couple, with heterozygous individuals pairing together. Our study underlines the importance of considering habitat heterogeneity in studies of sexual selection.
format: application/pdf
format: text/html
creator: Dany Garant
creator: Audrey Bourret
creator: Clarence Schmitt
creator: Audrey Turcotte
creator: Fanie Pelletier
creator: Marc Bélisle
subject: Animal Behavior
subject: Evolutionary Studies
description: doi:10.7717/peerj.6004
publisher: PeerJ Inc.
rights: © 2018 Garant et al.
abstract: Genetic diversity at immune genes and levels of parasitism are known to affect patterns of (dis)assortative mating in several species. Heterozygote advantage and/or good genes should shape mate choice originating from pathogen/parasite-driven selection at immune genes. However, the stability of these associations, and whether they vary with environmental conditions, are still rarely documented. In this study, we describe mating patterns in a wild population of tree swallows (Tachycineta bicolor) over 4 years and assess the effects of haemosporidian parasite infection and immune genetic diversity at β-defensin genes on those patterns within two habitats of contrasting environmental quality, in southern Québec, Canada. We first show that mating patterns were only very weakly related to individual status of infection by haemosporidian parasites. However, we found a difference between habitats in mating patterns related to infection status, which was likely due to a non-random distribution of individuals, as non-infected mating pairs were more frequent in lower quality habitats. Mating patterns also differed depending on β-defensin heterozygosity at AvBD2, but only for genetic partners outside of the social couple, with heterozygous individuals pairing together. Our study underlines the importance of considering habitat heterogeneity in studies of sexual selection.
bibliographic citation: Garant et al. (2018) Effects of blood parasite infection and innate immune genetic diversity on mating patterns in a passerine bird breeding in contrasted habitats. PeerJ 6:e6004 https://doi.org/10.7717/peerj.6004
date submitted: 2018-07-17
date accepted: 2018-10-26
issued: 2018-11-23
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Garant
  given name: Dany
author list: Agent
  family name: Bourret
  given name: Audrey
author list: Agent
  family name: Schmitt
  given name: Clarence
author list: Agent
  family name: Turcotte
  given name: Audrey
author list: Agent
  family name: Pelletier
  given name: Fanie
author list: Agent
  family name: Bélisle
  given name: Marc
doi: 10.7717/peerj.6004
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-23
copyright: ©2018 Garant et al.
attribution name: Garant et al.

Changing trends in elephant camp management in northern Thailand and implications for welfare
type: item
type: AcademicArticle
description: Background Elephant camps are among the most attractive destinations in Thailand for tourists from many countries. A wide range of management strategies are used by these camps, which can have varied impacts on health and welfare of elephants. Methods This study surveyed 33 camps with 627 elephants in northern Thailand to quantify the types of management practices and work activities experienced by captive elephants. The survey consisted of an interview with camp owners, and direct observations of camp operations. Results Data revealed considerable variation in elephant demographics, work activities, elephant care (i.e., housing, restraint, nutrition, health care, and breeding), and mahout management among the camps. In general, older camps (those in existence for >16 years) were involved in more intensive activities, like riding with saddles and shows. By contrast, newer camps provided more one-on-one activities for tourists and elephants, and emphasized more intimate, relaxing experiences (e.g., feeding, bathing, walking) than entertainment. A demographic shift also was observed, with elephants 20 years of age and younger having a sex ratio closer to 1:1 compared to elephants in older age categories (1:4.1–1:9.8). Discussion Shifts in elephant management to less intensive activities were observed, which could have positive implications for elephant welfare. The shifting sex ratio suggests successful captive breeding is resulting in the birth of more males, which could present new welfare challenges in the future, because bulls can be more difficult to manage and socialize, and are more likely to be kept isolated during musth. Ultimately, the goal is to understand how camp activities affect welfare, and to develop science-based guidelines and standards to aid in the management of both male and female elephants used in tourism.
format: application/pdf
format: text/html
creator: Pakkanut Bansiddhi
creator: Janine L. Brown
creator: Chatchote Thitaram
creator: Veerasak Punyapornwithaya
creator: Chaleamchat Somgird
creator: Katie L. Edwards
creator: Korakot Nganvongpanit
subject: Agricultural Science
subject: Veterinary Medicine
subject: Coupled Natural and Human Systems
subject: Environmental Impacts
description: doi:10.7717/peerj.5996
publisher: PeerJ Inc.
rights: © 2018 Bansiddhi et al.
abstract: Background Elephant camps are among the most attractive destinations in Thailand for tourists from many countries. A wide range of management strategies are used by these camps, which can have varied impacts on health and welfare of elephants. Methods This study surveyed 33 camps with 627 elephants in northern Thailand to quantify the types of management practices and work activities experienced by captive elephants. The survey consisted of an interview with camp owners, and direct observations of camp operations. Results Data revealed considerable variation in elephant demographics, work activities, elephant care (i.e., housing, restraint, nutrition, health care, and breeding), and mahout management among the camps. In general, older camps (those in existence for >16 years) were involved in more intensive activities, like riding with saddles and shows. By contrast, newer camps provided more one-on-one activities for tourists and elephants, and emphasized more intimate, relaxing experiences (e.g., feeding, bathing, walking) than entertainment. A demographic shift also was observed, with elephants 20 years of age and younger having a sex ratio closer to 1:1 compared to elephants in older age categories (1:4.1–1:9.8). Discussion Shifts in elephant management to less intensive activities were observed, which could have positive implications for elephant welfare. The shifting sex ratio suggests successful captive breeding is resulting in the birth of more males, which could present new welfare challenges in the future, because bulls can be more difficult to manage and socialize, and are more likely to be kept isolated during musth. Ultimately, the goal is to understand how camp activities affect welfare, and to develop science-based guidelines and standards to aid in the management of both male and female elephants used in tourism.
bibliographic citation: Bansiddhi et al. (2018) Changing trends in elephant camp management in northern Thailand and implications for welfare. PeerJ 6:e5996 https://doi.org/10.7717/peerj.5996
date submitted: 2018-07-23
date accepted: 2018-10-25
issued: 2018-11-23
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Bansiddhi
  given name: Pakkanut
author list: Agent
  family name: Brown
  given name: Janine L.
author list: Agent
  family name: Thitaram
  given name: Chatchote
author list: Agent
  family name: Punyapornwithaya
  given name: Veerasak
author list: Agent
  family name: Somgird
  given name: Chaleamchat
author list: Agent
  family name: Edwards
  given name: Katie L.
author list: Agent
  family name: Nganvongpanit
  given name: Korakot
doi: 10.7717/peerj.5996
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-23
copyright: © 2018 Bansiddhi et al.
attribution name: Bansiddhi et al.

Optimal and near-optimal exponent-pairs for the Bertalanffy-Pütter growth model
type: item
type: AcademicArticle
description: The Bertalanffy–Pütter growth model describes mass m at age t by means of the differential equation dm/dt = p * ma − q * mb. The special case using the von Bertalanffy exponent-pair a = 2/3 and b = 1 is most common (it corresponds to the von Bertalanffy growth function VBGF for length in fishery literature). Fitting VBGF to size-at-age data requires the optimization of three model parameters (the constants p, q, and an initial value for the differential equation). For the general Bertalanffy–Pütter model, two more model parameters are optimized (the pair a < b of non-negative exponents). While this reduces bias in growth estimates, it increases model complexity and more advanced optimization methods are needed, such as the Nelder–Mead amoeba method, interior point methods, or simulated annealing. Is the improved performance worth these efforts? For the case, where the exponent b = 1 remains fixed, it is known that for most fish data any exponent a < 1 could be used to model growth without affecting the fit to the data significantly (when the other parameters were optimized). We hypothesized that the optimization of both exponents would result in a significantly better fit of the optimal growth function to the data and we tested this conjecture for a data set (20,166 fish) about the mass-growth of Walleye (Sander vitreus), a fish from Lake Erie, USA. To this end, we assessed the fit on a grid of 14,281 exponent-pairs (a, b) and identified the best fitting model curve on the boundary a = b of the grid (a = b = 0.686); it corresponds to the generalized Gompertz equation dm/dt = p * ma − q * ln(m) * ma. Using the Akaike information criterion for model selection, the answer to the conjecture was no: The von Bertalanffy exponent-pair model (but not the logistic model) remained parsimonious. However, the bias reduction attained by the optimal exponent-pair may be worth the tradeoff with complexity in some situations where predictive power is solely preferred. Therefore, we…
format: application/pdf
format: text/html
creator: Katharina Renner-Martin
creator: Norbert Brunner
creator: Manfred Kühleitner
creator: Werner-Georg Nowak
creator: Klaus Scheicher
subject: Aquaculture, Fisheries and Fish Science
subject: Computational Biology
subject: Mathematical Biology
subject: Computational Science
subject: Natural Resource Management
description: doi:10.7717/peerj.5973
publisher: PeerJ Inc.
rights: © 2018 Renner-Martin et al.
abstract: The Bertalanffy–Pütter growth model describes mass m at age t by means of the differential equation dm/dt = p * ma − q * mb. The special case using the von Bertalanffy exponent-pair a = 2/3 and b = 1 is most common (it corresponds to the von Bertalanffy growth function VBGF for length in fishery literature). Fitting VBGF to size-at-age data requires the optimization of three model parameters (the constants p, q, and an initial value for the differential equation). For the general Bertalanffy–Pütter model, two more model parameters are optimized (the pair a < b of non-negative exponents). While this reduces bias in growth estimates, it increases model complexity and more advanced optimization methods are needed, such as the Nelder–Mead amoeba method, interior point methods, or simulated annealing. Is the improved performance worth these efforts? For the case, where the exponent b = 1 remains fixed, it is known that for most fish data any exponent a < 1 could be used to model growth without affecting the fit to the data significantly (when the other parameters were optimized). We hypothesized that the optimization of both exponents would result in a significantly better fit of the optimal growth function to the data and we tested this conjecture for a data set (20,166 fish) about the mass-growth of Walleye (Sander vitreus), a fish from Lake Erie, USA. To this end, we assessed the fit on a grid of 14,281 exponent-pairs (a, b) and identified the best fitting model curve on the boundary a = b of the grid (a = b = 0.686); it corresponds to the generalized Gompertz equation dm/dt = p * ma − q * ln(m) * ma. Using the Akaike information criterion for model selection, the answer to the conjecture was no: The von Bertalanffy exponent-pair model (but not the logistic model) remained parsimonious. However, the bias reduction attained by the optimal exponent-pair may be worth the tradeoff with complexity in some situations where predictive power is solely preferred. Therefore, we…
bibliographic citation: Renner-Martin et al. (2018) Optimal and near-optimal exponent-pairs for the Bertalanffy-Pütter growth model. PeerJ 6:e5973 https://doi.org/10.7717/peerj.5973
date submitted: 2018-08-24
date accepted: 2018-10-19
issued: 2018-11-23
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Renner-Martin
  given name: Katharina
author list: Agent
  family name: Brunner
  given name: Norbert
author list: Agent
  family name: Kühleitner
  given name: Manfred
author list: Agent
  family name: Nowak
  given name: Werner-Georg
author list: Agent
  family name: Scheicher
  given name: Klaus
doi: 10.7717/peerj.5973
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-23
copyright: © 2018 Renner-Martin et al.
attribution name: Renner-Martin et al.

Effects of a six-week weighted-implement throwing program on baseball pitching velocity, kinematics, arm stress, and arm range of motion
type: item
type: AcademicArticle
description: Background Weighted-baseball training programs are used at the high school, collegiate, and professional levels of baseball. The purpose of this study was to evaluate the effects of a six-week training period consisting of weighted implements, manual therapy, weightlifting, and other modalities on shoulder external rotation, elbow valgus stress, pitching velocity, and kinematics. Hypothesis A six-week training program that includes weighted implements will increase pitching velocity along with concomitant increases in arm angular velocities, joint kinetics, and shoulder external rotation. Methods Seventeen collegiate and professional baseball pitchers (age range 18–23, average: 19.9 ± 1.3) training at Driveline Baseball were evaluated via a combination of an eight-camera motion-capture system, range-of-motion measurements and radar- and pitch-tracking equipment, both before and after a six-week training period. Each participant received individualized training programs, with significant overlap in training methods for all athletes. Twenty-eight biomechanical parameters were computed for each bullpen trial, four arm range-of-motion measurements were taken, and pitching velocities were recorded before and after the training period. Pre- and post-training period data were compared via post-hoc paired t tests. Results There was no change in pitching velocity across the seventeen subjects. Four biomechanical parameters for the holistic group were significantly changed after the training period: internal rotational velocity was higher (from 4,527 ± 470 to 4,759 ± 542 degrees/second), shoulder abduction was lower at ball release (96 ± 7.6 to 93 ± 5.4°), the shoulder was less externally rotated at ball release (95 ± 15 to 86 ± 18°) and shoulder adduction torque was higher (from 103 ± 39 to 138 ± 53 N-m). Among the arm range of motion measurements, four were significantly different after the training period: the shoulder internal rotation range of motion and total range of m…
format: application/pdf
format: text/html
creator: Joseph A. Marsh
creator: Matthew I. Wagshol
creator: Kyle J. Boddy
creator: Michael E. O’Connell
creator: Sam J. Briend
creator: Kyle E. Lindley
creator: Alex Caravan
subject: Anatomy and Physiology
subject: Kinesiology
description: doi:10.7717/peerj.6003
publisher: PeerJ Inc.
rights: © 2018 Marsh et al.
abstract: Background Weighted-baseball training programs are used at the high school, collegiate, and professional levels of baseball. The purpose of this study was to evaluate the effects of a six-week training period consisting of weighted implements, manual therapy, weightlifting, and other modalities on shoulder external rotation, elbow valgus stress, pitching velocity, and kinematics. Hypothesis A six-week training program that includes weighted implements will increase pitching velocity along with concomitant increases in arm angular velocities, joint kinetics, and shoulder external rotation. Methods Seventeen collegiate and professional baseball pitchers (age range 18–23, average: 19.9 ± 1.3) training at Driveline Baseball were evaluated via a combination of an eight-camera motion-capture system, range-of-motion measurements and radar- and pitch-tracking equipment, both before and after a six-week training period. Each participant received individualized training programs, with significant overlap in training methods for all athletes. Twenty-eight biomechanical parameters were computed for each bullpen trial, four arm range-of-motion measurements were taken, and pitching velocities were recorded before and after the training period. Pre- and post-training period data were compared via post-hoc paired t tests. Results There was no change in pitching velocity across the seventeen subjects. Four biomechanical parameters for the holistic group were significantly changed after the training period: internal rotational velocity was higher (from 4,527 ± 470 to 4,759 ± 542 degrees/second), shoulder abduction was lower at ball release (96 ± 7.6 to 93 ± 5.4°), the shoulder was less externally rotated at ball release (95 ± 15 to 86 ± 18°) and shoulder adduction torque was higher (from 103 ± 39 to 138 ± 53 N-m). Among the arm range of motion measurements, four were significantly different after the training period: the shoulder internal rotation range of motion and total range of m…
bibliographic citation: Marsh et al. (2018) Effects of a six-week weighted-implement throwing program on baseball pitching velocity, kinematics, arm stress, and arm range of motion. PeerJ 6:e6003 https://doi.org/10.7717/peerj.6003
date submitted: 2018-05-30
date accepted: 2018-10-25
issued: 2018-11-23
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Marsh
  given name: Joseph A.
author list: Agent
  family name: Wagshol
  given name: Matthew I.
author list: Agent
  family name: Boddy
  given name: Kyle J.
author list: Agent
  family name: O’Connell
  given name: Michael E.
author list: Agent
  family name: Briend
  given name: Sam J.
author list: Agent
  family name: Lindley
  given name: Kyle E.
author list: Agent
  family name: Caravan
  given name: Alex
doi: 10.7717/peerj.6003
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-23
copyright: ©2018 Marsh et al.
attribution name: Marsh et al.

Morpho-histological development of the somatic embryos of Typha domingensis
type: item
type: AcademicArticle
description: Background Sustainable methods of propagation of Typha domingensis through somatic embryogenesis can help mitigate its current condition of ecological marginalization and overexploitation. This study examined whether differentiation up to coleoptilar embryos could be obtained in an embryogenic line proliferated with light and high auxin concentration. Methods Murashige and Skoog medium at half ionic strength and containing 3% sucrose and 0.1% ascorbic acid was used for the three embryogenic phases. Induction started with aseptic 9-day-old germinated seeds cultured in 0.5 mg L−1 2,4-dichlorophenoxyacetic (2,4-D). Proliferation of the embryogenic callus was evaluated at 2,4-D concentrations ranging from 0 to 2 mg L−1 in cultures maintained in the dark. The dominant embryogenic products obtained in each treatment were used as embryogenic lines in the third phase. Thus, maturation of the somatic embryos (SEs) was analyzed using four embryogenic lines and under light vs. dark conditions. Embryogenic differentiation was also monitored histologically. Results Proliferation of the nine morphogenetic products was greater in the presence of 2,4-D, regardless of the concentration, than in the absence of auxin. Among the products, a yellow callus was invariably associated with the presence of an oblong SE and suspended cells in the 2,4-D treatments, and a brown callus with scutellar somatic embryos (scSEs) in the treatment without 2,4-D. During the maturation phase, especially the embryogenic line but also the light condition resulted in significant differences, with the highest averages of the nine morphogenetic products obtained under light conditions and the maximum concentration of auxin (YC3 embryogenic line). Only this line achieved scSE growth, under both light and dark conditions. Structurally complete coleoptilar somatic embryos (colSEs) could be anatomically confirmed only during the maturation phase. Discussion In the embryogenic line cultured with the highest auxin …
format: application/pdf
format: text/html
creator: Guadalupe Hernández-Piedra
creator: Violeta Ruiz-Carrera
creator: Alberto J. Sánchez
creator: Arlette Hernández-Franyutti
creator: Alfonso Azpeitia-Morales
subject: Biotechnology
subject: Developmental Biology
subject: Histology
subject: Freshwater Biology
description: doi:10.7717/peerj.5952
publisher: PeerJ Inc.
rights: © 2018 Hernández-Piedra et al.
abstract: Background Sustainable methods of propagation of Typha domingensis through somatic embryogenesis can help mitigate its current condition of ecological marginalization and overexploitation. This study examined whether differentiation up to coleoptilar embryos could be obtained in an embryogenic line proliferated with light and high auxin concentration. Methods Murashige and Skoog medium at half ionic strength and containing 3% sucrose and 0.1% ascorbic acid was used for the three embryogenic phases. Induction started with aseptic 9-day-old germinated seeds cultured in 0.5 mg L−1 2,4-dichlorophenoxyacetic (2,4-D). Proliferation of the embryogenic callus was evaluated at 2,4-D concentrations ranging from 0 to 2 mg L−1 in cultures maintained in the dark. The dominant embryogenic products obtained in each treatment were used as embryogenic lines in the third phase. Thus, maturation of the somatic embryos (SEs) was analyzed using four embryogenic lines and under light vs. dark conditions. Embryogenic differentiation was also monitored histologically. Results Proliferation of the nine morphogenetic products was greater in the presence of 2,4-D, regardless of the concentration, than in the absence of auxin. Among the products, a yellow callus was invariably associated with the presence of an oblong SE and suspended cells in the 2,4-D treatments, and a brown callus with scutellar somatic embryos (scSEs) in the treatment without 2,4-D. During the maturation phase, especially the embryogenic line but also the light condition resulted in significant differences, with the highest averages of the nine morphogenetic products obtained under light conditions and the maximum concentration of auxin (YC3 embryogenic line). Only this line achieved scSE growth, under both light and dark conditions. Structurally complete coleoptilar somatic embryos (colSEs) could be anatomically confirmed only during the maturation phase. Discussion In the embryogenic line cultured with the highest auxin …
bibliographic citation: Hernández-Piedra et al. (2018) Morpho-histological development of the somatic embryos of Typha domingensis. PeerJ 6:e5952 https://doi.org/10.7717/peerj.5952
date submitted: 2018-04-25
date accepted: 2018-10-18
issued: 2018-11-23
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Hernández-Piedra
  given name: Guadalupe
author list: Agent
  family name: Ruiz-Carrera
  given name: Violeta
author list: Agent
  family name: Sánchez
  given name: Alberto J.
author list: Agent
  family name: Hernández-Franyutti
  given name: Arlette
author list: Agent
  family name: Azpeitia-Morales
  given name: Alfonso
doi: 10.7717/peerj.5952
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-23
copyright: © 2018 Hernández-Piedra et al.
attribution name: Hernández-Piedra et al.

Heavier- and lighter-load isolated lumbar extension resistance training produce similar strength increases, but different perceptual responses, in healthy males and females
type: item
type: AcademicArticle
description: Objectives Muscles 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. Design The 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. Methods Twenty-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. Results Analyses 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). Conclusions The 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 …
format: application/pdf
format: text/html
creator: James P. Fisher
creator: Charlotte Stuart
creator: James Steele
creator: Paulo Gentil
creator: Jürgen Giessing
subject: Anatomy and Physiology
subject: Evidence Based Medicine
subject: Health Policy
subject: Kinesiology
subject: Public Health
description: doi:10.7717/peerj.6001
publisher: PeerJ Inc.
rights: © 2018 Fisher et al.
abstract: Objectives Muscles 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. Design The 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. Methods Twenty-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. Results Analyses 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). Conclusions The 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 …
bibliographic citation: Fisher et al. (2018) Heavier- and lighter-load isolated lumbar extension resistance training produce similar strength increases, but different perceptual responses, in healthy males and females. PeerJ 6:e6001 https://doi.org/10.7717/peerj.6001
date submitted: 2018-07-27
date accepted: 2018-10-23
issued: 2018-11-22
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Fisher
  given name: James P.
author list: Agent
  family name: Stuart
  given name: Charlotte
author list: Agent
  family name: Steele
  given name: James
author list: Agent
  family name: Gentil
  given name: Paulo
author list: Agent
  family name: Giessing
  given name: Jürgen
doi: 10.7717/peerj.6001
volume: 6
issn: 2167-8359
publication name: PeerJ
publication date: 2018-11-22
copyright: ©2018 Fisher et al.
attribution name: Fisher et al.

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