PeerJ
type: channel
link: https://peerj.com/articles/
description: Articles published in PeerJ
publisher: PeerJ Inc.
publication name: PeerJ
issn: 2167-8359
items: Is there a hybridization barrier between Gentiana lutea color morphs?
items: Effects of in situ climate warming on monarch caterpillar (Danaus plexippus) development
items: The nonlinear variation of drought and its relation to atmospheric circulation in Shandong Province, East China
items: Evaluation of nutritional and economic feed values of spent coffee grounds and Artemisia princeps residues as a ruminant feed using in vitro ruminal fermentation
items: Mammalian bone palaeohistology: a survey and new data with emphasis on island forms
items: Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants
items: Frailty severity is significantly associated with electrocardiographic QRS duration in chronic dialysis patients
items: Migration in the social stage of Dictyostelium discoideum amoebae impacts competition
items: Astrocyte activation in the anterior cingulate cortex and altered glutamatergic gene expression during paclitaxel-induced neuropathic pain in mice
items: Cheetahs (Acinonyx jubatus) running the gauntlet: an evaluation of translocations into free-range environments in Namibia

Is there a hybridization barrier between Gentiana lutea color morphs?
type: item
type: AcademicArticle
description: In Gentiana lutea two varieties are described: G. lutea var. aurantiaca with orange corolla colors and G. lutea var. lutea with yellow corolla colors. Both color varieties co-occur in NW Spain, and pollinators select flower color in this species. It is not known whether a hybridization barrier exists between these G. lutea color varieties. We aim to test the compatibility between flower color varieties in G. lutea and its dependence on pollen vectors. Within a sympatric population containing both flower color morphs, we analyzed differences in reproductive success (number, weight, viability and germinability of seeds) depending on fertilization treatments (autogamy and xenogamy within variety and among varieties). We found a 93% reduction in number of seeds and a 37% reduction in seed weight respectively of autogamy treatments compared to xenogamy crossings. Additionally, reproductive success is higher within color varieties than among varieties, due to a 45% seed viability reduction on hybrids from different varieties. Our results show that G. lutea reproductive success is strongly dependent on pollinators and that a partial hybridization barrier exists between G. lutea varieties.
format: application/pdf
format: text/html
creator: María Losada
creator: Tania Veiga
creator: Javier Guitián
creator: José Guitián
creator: Pablo Guitián
creator: Mar Sobral
subject: Biogeography
subject: Conservation Biology
subject: Ecology
subject: Evolutionary Studies
subject: Plant Science
description: doi:10.7717/peerj.1308
publisher: PeerJ Inc.
rights: © 2015 Losada et al.
abstract: In Gentiana lutea two varieties are described: G. lutea var. aurantiaca with orange corolla colors and G. lutea var. lutea with yellow corolla colors. Both color varieties co-occur in NW Spain, and pollinators select flower color in this species. It is not known whether a hybridization barrier exists between these G. lutea color varieties. We aim to test the compatibility between flower color varieties in G. lutea and its dependence on pollen vectors. Within a sympatric population containing both flower color morphs, we analyzed differences in reproductive success (number, weight, viability and germinability of seeds) depending on fertilization treatments (autogamy and xenogamy within variety and among varieties). We found a 93% reduction in number of seeds and a 37% reduction in seed weight respectively of autogamy treatments compared to xenogamy crossings. Additionally, reproductive success is higher within color varieties than among varieties, due to a 45% seed viability reduction on hybrids from different varieties. Our results show that G. lutea reproductive success is strongly dependent on pollinators and that a partial hybridization barrier exists between G. lutea varieties.
bibliographic citation: Losada et al. (2015) Is there a hybridization barrier between Gentiana lutea color morphs?. PeerJ 3:e1308 https://doi.org/10.7717/peerj.1308
date submitted: 2015-07-21
date accepted: 2015-09-19
issued: 2015-10-27
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Losada
  given name: María
author list: Agent
  family name: Veiga
  given name: Tania
author list: Agent
  family name: Guitián
  given name: Javier
author list: Agent
  family name: Guitián
  given name: José
author list: Agent
  family name: Guitián
  given name: Pablo
author list: Agent
  family name: Sobral
  given name: Mar
doi: 10.7717/peerj.1308
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-27
copyright: © 2015 Losada et al.
attribution name: Losada et al.

Effects of in situ climate warming on monarch caterpillar (Danaus plexippus) development
type: item
type: AcademicArticle
description: Climate warming will fundamentally alter basic life history strategies of many ectothermic insects. In the lab, rising temperatures increase growth rates of lepidopteran larvae but also reduce final pupal mass and increase mortality. Using in situ field warming experiments on their natural host plants, we assessed the impact of climate warming on development of monarch (Danaus plexippus) larvae. Monarchs were reared on Asclepias tuberosa grown under ‘Ambient’ and ‘Warmed’ conditions. We quantified time to pupation, final pupal mass, and survivorship. Warming significantly decreased time to pupation, such that an increase of 1 °C corresponded to a 0.5 day decrease in pupation time. In contrast, survivorship and pupal mass were not affected by warming. Our results indicate that climate warming will speed the developmental rate of monarchs, influencing their ecological and evolutionary dynamics. However, the effects of climate warming on larval development in other monarch populations and at different times of year should be investigated.
format: application/pdf
format: text/html
creator: Nathan P. Lemoine
creator: Jillian N. Capdevielle
creator: John D. Parker
subject: Climate Change Biology
subject: Ecology
subject: Entomology
description: doi:10.7717/peerj.1293
publisher: PeerJ Inc.
rights: © 2015
abstract: Climate warming will fundamentally alter basic life history strategies of many ectothermic insects. In the lab, rising temperatures increase growth rates of lepidopteran larvae but also reduce final pupal mass and increase mortality. Using in situ field warming experiments on their natural host plants, we assessed the impact of climate warming on development of monarch (Danaus plexippus) larvae. Monarchs were reared on Asclepias tuberosa grown under ‘Ambient’ and ‘Warmed’ conditions. We quantified time to pupation, final pupal mass, and survivorship. Warming significantly decreased time to pupation, such that an increase of 1 °C corresponded to a 0.5 day decrease in pupation time. In contrast, survivorship and pupal mass were not affected by warming. Our results indicate that climate warming will speed the developmental rate of monarchs, influencing their ecological and evolutionary dynamics. However, the effects of climate warming on larval development in other monarch populations and at different times of year should be investigated.
bibliographic citation: Lemoine et al. (2015) Effects of in situ climate warming on monarch caterpillar (Danaus plexippus) development. PeerJ 3:e1293 https://doi.org/10.7717/peerj.1293
date submitted: 2015-07-15
date accepted: 2015-09-15
issued: 2015-10-27
is part of: PeerJ
license: http://creativecommons.org/publicdomain/zero/1.0/
author list: Agent
  family name: Lemoine
  given name: Nathan P.
author list: Agent
  family name: Capdevielle
  given name: Jillian N.
author list: Agent
  family name: Parker
  given name: John D.
doi: 10.7717/peerj.1293
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-27

The nonlinear variation of drought and its relation to atmospheric circulation in Shandong Province, East China
type: item
type: AcademicArticle
description: Considerable attention has recently been devoted to the linear trend of drought at the decadal to inter-decadal time scale; however, the nonlinear variation of drought at multi-decadal scales and its relation to atmospheric circulation need to be further studied. The linear and nonlinear variations of the Palmer drought severity index (PDSI) in Shandong from 1900 to 2012 and its relations to the Pacific decadal oscillation (PDO), El Niño-Southern Oscillation (ENSO), Siberian high (SH) and Southern Oscillation (SO) phase changes from multi-scale are detected using linear regression, the Mann–Kendall test, ensemble empirical mode decomposition (EEMD) and the Pearson correlation analysis method. The results indicate that the PDSI shows no statistically significant linear change trend from 1900 to 2012; however, before (after) the late 1950s, PDSI shows a significant upward (downward) trend (P < 0.01) with a linear rate of 0.28/decade (−0.48/decade). From 1900 to 2012, the PDSI also exhibits a nonlinear variation trend at the inter-annual scale (quasi-3 and quasi-7-year), inter-decadal scale (quasi-14-year) and multi-decadal scale (quasi-46 and quasi-65-year). The variance contribution rate of components from the inter-annual scale is the largest, reaching 38.7%, and that from the inter-decadal scale and multi-decadal scale are 18.9% and 19.0%, respectively, indicating that the inter-annual change exerts a huge influence on the overall PDSI change. The results also imply that the effect of the four atmospheric circulations (PDO, ENSO, SH, SO) on PDSI at the multi-decadal variability scale are more important than that at the other scales. Consequently, we state that PDSI variation at the inter-annual scale has more instability, while that at the inter-decadal and multi-decadal scale is more strongly influenced by natural factors.
format: application/pdf
format: text/html
creator: Baofu Li
creator: Zhongsheng Chen
creator: Xingzhong Yuan
subject: Ecology
subject: Environmental Sciences
subject: Spatial and Geographic Information Science
description: doi:10.7717/peerj.1289
publisher: PeerJ Inc.
rights: © 2015 Li et al.
abstract: Considerable attention has recently been devoted to the linear trend of drought at the decadal to inter-decadal time scale; however, the nonlinear variation of drought at multi-decadal scales and its relation to atmospheric circulation need to be further studied. The linear and nonlinear variations of the Palmer drought severity index (PDSI) in Shandong from 1900 to 2012 and its relations to the Pacific decadal oscillation (PDO), El Niño-Southern Oscillation (ENSO), Siberian high (SH) and Southern Oscillation (SO) phase changes from multi-scale are detected using linear regression, the Mann–Kendall test, ensemble empirical mode decomposition (EEMD) and the Pearson correlation analysis method. The results indicate that the PDSI shows no statistically significant linear change trend from 1900 to 2012; however, before (after) the late 1950s, PDSI shows a significant upward (downward) trend (P < 0.01) with a linear rate of 0.28/decade (−0.48/decade). From 1900 to 2012, the PDSI also exhibits a nonlinear variation trend at the inter-annual scale (quasi-3 and quasi-7-year), inter-decadal scale (quasi-14-year) and multi-decadal scale (quasi-46 and quasi-65-year). The variance contribution rate of components from the inter-annual scale is the largest, reaching 38.7%, and that from the inter-decadal scale and multi-decadal scale are 18.9% and 19.0%, respectively, indicating that the inter-annual change exerts a huge influence on the overall PDSI change. The results also imply that the effect of the four atmospheric circulations (PDO, ENSO, SH, SO) on PDSI at the multi-decadal variability scale are more important than that at the other scales. Consequently, we state that PDSI variation at the inter-annual scale has more instability, while that at the inter-decadal and multi-decadal scale is more strongly influenced by natural factors.
bibliographic citation: Li et al. (2015) The nonlinear variation of drought and its relation to atmospheric circulation in Shandong Province, East China. PeerJ 3:e1289 https://doi.org/10.7717/peerj.1289
date submitted: 2015-07-22
date accepted: 2015-09-13
issued: 2015-10-27
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Li
  given name: Baofu
author list: Agent
  family name: Chen
  given name: Zhongsheng
author list: Agent
  family name: Yuan
  given name: Xingzhong
doi: 10.7717/peerj.1289
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-27
copyright: © 2015 Li et al.
attribution name: Li et al.

Evaluation of nutritional and economic feed values of spent coffee grounds and Artemisia princeps residues as a ruminant feed using in vitro ruminal fermentation
type: item
type: AcademicArticle
description: Much research on animal feed has focused on finding alternative feed ingredients that can replace conventional ones (e.g., grains and beans) to reduce feed costs. The objective of this study was to evaluate the economic, as well as nutritional value of spent coffee grounds (SCG) and Japanese mugwort (Artemisia princeps) residues (APR) as alternative feed ingredients for ruminants. We also investigated whether pre-fermentation using Lactobacillus spp. was a feasible way to increase the feed value of these by-products. Chemical analyses and an in vitro study were conducted for SCG, APR, and their pre-fermented forms. All the experimental diets for in vitro ruminal fermentation were formulated to contain a similar composition of crude protein, neutral detergent fiber and total digestible nutrients at 1x maintenance feed intake based on the dairy National Research Council (NRC). The control diet was composed of ryegrass, corn, soybean meal, whereas the treatments consisted of SCG, SCG fermented with Lactobacillus spp. (FSCG), APR, and its fermented form (FAPR). The treatment diets replaced 100 g/kg dry matter (DM) of the feed ingredients in the control. Costs were lower for the all treatments, except FAPR, than that of the control. After 24-h incubation, the NDF digestibility of the diets containing SCG and its fermented form were significantly lower than those of the other diets (P < 0.01); pre-fermentation tended to increase NDF digestibility (P = 0.07), especially for APR. Supplementation of SCG significantly decreased total gas production (ml/g DM) after 24-h fermentation in comparison with the control (P < 0.05); however, there were no significant differences between the control and the SCG or the APR diets in total gas production, as expressed per Korean Won (KRW). Diets supplemented with SCG or FSCG tended to have a higher total volatile fatty acid (VFA) concentration, expressed as per KRW, compared with the control (P = 0.06). Conversely, the fermentation proces…
format: application/pdf
format: text/html
creator: Jakyeom Seo
creator: Jae Keun Jung
creator: Seongwon Seo
subject: Agricultural Science
subject: Food Science and Technology
description: doi:10.7717/peerj.1343
publisher: PeerJ Inc.
rights: © 2015 Seo et al.
abstract: Much research on animal feed has focused on finding alternative feed ingredients that can replace conventional ones (e.g., grains and beans) to reduce feed costs. The objective of this study was to evaluate the economic, as well as nutritional value of spent coffee grounds (SCG) and Japanese mugwort (Artemisia princeps) residues (APR) as alternative feed ingredients for ruminants. We also investigated whether pre-fermentation using Lactobacillus spp. was a feasible way to increase the feed value of these by-products. Chemical analyses and an in vitro study were conducted for SCG, APR, and their pre-fermented forms. All the experimental diets for in vitro ruminal fermentation were formulated to contain a similar composition of crude protein, neutral detergent fiber and total digestible nutrients at 1x maintenance feed intake based on the dairy National Research Council (NRC). The control diet was composed of ryegrass, corn, soybean meal, whereas the treatments consisted of SCG, SCG fermented with Lactobacillus spp. (FSCG), APR, and its fermented form (FAPR). The treatment diets replaced 100 g/kg dry matter (DM) of the feed ingredients in the control. Costs were lower for the all treatments, except FAPR, than that of the control. After 24-h incubation, the NDF digestibility of the diets containing SCG and its fermented form were significantly lower than those of the other diets (P < 0.01); pre-fermentation tended to increase NDF digestibility (P = 0.07), especially for APR. Supplementation of SCG significantly decreased total gas production (ml/g DM) after 24-h fermentation in comparison with the control (P < 0.05); however, there were no significant differences between the control and the SCG or the APR diets in total gas production, as expressed per Korean Won (KRW). Diets supplemented with SCG or FSCG tended to have a higher total volatile fatty acid (VFA) concentration, expressed as per KRW, compared with the control (P = 0.06). Conversely, the fermentation proces…
bibliographic citation: Seo et al. (2015) Evaluation of nutritional and economic feed values of spent coffee grounds and Artemisia princeps residues as a ruminant feed using in vitro ruminal fermentation. PeerJ 3:e1343 https://doi.org/10.7717/peerj.1343
date submitted: 2015-08-14
date accepted: 2015-10-01
issued: 2015-10-22
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Seo
  given name: Jakyeom
author list: Agent
  family name: Jung
  given name: Jae Keun
author list: Agent
  family name: Seo
  given name: Seongwon
doi: 10.7717/peerj.1343
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-22
copyright: © 2015 Seo et al.
attribution name: Seo et al.

Mammalian bone palaeohistology: a survey and new data with emphasis on island forms
type: item
type: AcademicArticle
description: The interest in mammalian palaeohistology has increased dramatically in the last two decades. Starting in 1849 via descriptive approaches, it has been demonstrated that bone tissue and vascularisation types correlate with several biological variables such as ontogenetic stage, growth rate, and ecology. Mammalian bone displays a large variety of bone tissues and vascularisation patterns reaching from lamellar or parallel-fibred to fibrolamellar or woven-fibred bone, depending on taxon and individual age. Here we systematically review the knowledge and methods on cynodont and mammalian bone microstructure as well as palaeohistology and discuss potential future research fields and techniques. We present new data on the bone microstructure of two extant marsupial species and of several extinct continental and island placental mammals. Extant marsupials display mainly parallel-fibred primary bone with radial and oblique but mainly longitudinal vascular canals. Three juvenile specimens of the dwarf island hippopotamid Hippopotamus minor from the Late Pleistocene of Cyprus show reticular to plexiform fibrolamellar bone. The island murid Mikrotia magna from the Late Miocene of Gargano, Italy displays parallel-fibred primary bone with reticular vascularisation and strong remodelling in the middle part of the cortex. Leithia sp., the dormouse from the Pleistocene of Sicily, is characterised by a primary bone cortex consisting of lamellar bone and a high amount of compact coarse cancellous bone. The bone cortex of the fossil continental lagomorph Prolagus oeningensis and three fossil species of insular Prolagus displays mainly parallel-fibred primary bone and reticular, radial as well as longitudinal vascularisation. Typical for large mammals, secondary bone in the giant rhinocerotoid Paraceratherium sp. from the Late Oligocene of Turkey is represented by dense Haversian bone. The skeletochronological features of Sinomegaceros yabei, a large-sized deer from the Pleistocene of …
format: application/pdf
format: text/html
creator: Christian Kolb
creator: Torsten M. Scheyer
creator: Kristof Veitschegger
creator: Analia M. Forasiepi
creator: Eli Amson
creator: Alexandra A.E. Van der Geer
creator: Lars W. Van den Hoek Ostende
creator: Shoji Hayashi
creator: Marcelo R. Sánchez-Villagra
subject: Evolutionary Studies
subject: Paleontology
subject: Histology
description: doi:10.7717/peerj.1358
publisher: PeerJ Inc.
rights: © 2015 Kolb et al.
abstract: The interest in mammalian palaeohistology has increased dramatically in the last two decades. Starting in 1849 via descriptive approaches, it has been demonstrated that bone tissue and vascularisation types correlate with several biological variables such as ontogenetic stage, growth rate, and ecology. Mammalian bone displays a large variety of bone tissues and vascularisation patterns reaching from lamellar or parallel-fibred to fibrolamellar or woven-fibred bone, depending on taxon and individual age. Here we systematically review the knowledge and methods on cynodont and mammalian bone microstructure as well as palaeohistology and discuss potential future research fields and techniques. We present new data on the bone microstructure of two extant marsupial species and of several extinct continental and island placental mammals. Extant marsupials display mainly parallel-fibred primary bone with radial and oblique but mainly longitudinal vascular canals. Three juvenile specimens of the dwarf island hippopotamid Hippopotamus minor from the Late Pleistocene of Cyprus show reticular to plexiform fibrolamellar bone. The island murid Mikrotia magna from the Late Miocene of Gargano, Italy displays parallel-fibred primary bone with reticular vascularisation and strong remodelling in the middle part of the cortex. Leithia sp., the dormouse from the Pleistocene of Sicily, is characterised by a primary bone cortex consisting of lamellar bone and a high amount of compact coarse cancellous bone. The bone cortex of the fossil continental lagomorph Prolagus oeningensis and three fossil species of insular Prolagus displays mainly parallel-fibred primary bone and reticular, radial as well as longitudinal vascularisation. Typical for large mammals, secondary bone in the giant rhinocerotoid Paraceratherium sp. from the Late Oligocene of Turkey is represented by dense Haversian bone. The skeletochronological features of Sinomegaceros yabei, a large-sized deer from the Pleistocene of …
bibliographic citation: Kolb et al. (2015) Mammalian bone palaeohistology: a survey and new data with emphasis on island forms. PeerJ 3:e1358 https://doi.org/10.7717/peerj.1358
date submitted: 2015-06-02
date accepted: 2015-10-07
issued: 2015-10-22
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Kolb
  given name: Christian
author list: Agent
  family name: Scheyer
  given name: Torsten M.
author list: Agent
  family name: Veitschegger
  given name: Kristof
author list: Agent
  family name: Forasiepi
  given name: Analia M.
author list: Agent
  family name: Amson
  given name: Eli
author list: Agent
  family name: Van der Geer
  given name: Alexandra A.E.
author list: Agent
  family name: Van den Hoek Ostende
  given name: Lars W.
author list: Agent
  family name: Hayashi
  given name: Shoji
author list: Agent
  family name: Sánchez-Villagra
  given name: Marcelo R.
doi: 10.7717/peerj.1358
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-22
copyright: © 2015 Kolb et al.
attribution name: Kolb et al.

Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants
type: item
type: AcademicArticle
description: Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i) ant abundance and species richness would be higher in high-complexity urban habitats, (ii) ant assemblages would differ between low- and high-complexity habitats and (iii) ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size.
format: application/pdf
format: text/html
creator: Alessandro Ossola
creator: Michael A. Nash
creator: Fiona J. Christie
creator: Amy K. Hahs
creator: Stephen J. Livesley
subject: Biodiversity
subject: Conservation Biology
subject: Ecology
subject: Entomology
subject: Zoology
description: doi:10.7717/peerj.1356
publisher: PeerJ Inc.
rights: © 2015 Ossola et al.
abstract: Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i) ant abundance and species richness would be higher in high-complexity urban habitats, (ii) ant assemblages would differ between low- and high-complexity habitats and (iii) ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size.
bibliographic citation: Ossola et al. (2015) Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants. PeerJ 3:e1356 https://doi.org/10.7717/peerj.1356
date submitted: 2015-07-28
date accepted: 2015-10-07
issued: 2015-10-22
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Ossola
  given name: Alessandro
author list: Agent
  family name: Nash
  given name: Michael A.
author list: Agent
  family name: Christie
  given name: Fiona J.
author list: Agent
  family name: Hahs
  given name: Amy K.
author list: Agent
  family name: Livesley
  given name: Stephen J.
doi: 10.7717/peerj.1356
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-22
copyright: © 2015 Ossola et al.
attribution name: Ossola et al.

Frailty severity is significantly associated with electrocardiographic QRS duration in chronic dialysis patients
type: item
type: AcademicArticle
description: End-stage renal disease (ESRD) patients are at increased risk of sudden cardiac death, the risk of which is presumably related to arrhythmia. Electrocardiographic (ECG) parameters have been found to correlate with arrhythmia and predict cardiovascular outcomes in ESRD patients. Frailty is also a common feature in this population. We investigate whether the severity of dialysis frailty is associated with ECG findings, including PR interval, QRS duration, and QTc interval. Presence and severity of frailty was ascertained using six different self-report questionnaires with proven construct validity. Correlation analysis between frailty severity and ECG was made, and those with significant association entered into multiple regression analysis for confirmation. Among a cohort of chronic hemodialysis patients, we found that frailty severity, assessed by the Edmonton frailty scale, is significantly associated with QRS duration (r = − 0.3, p < 0.05). Dialysis patients with QRS longer than 120 ms had significantly lower severity of frailty than those with QRS less than 120 ms (p = 0.01 for the Edmonton frailty scale and 0.05 for simple FRAIL scale). Regression analysis showed that frailty severity, assessed by the Edmonton frailty scale and simple FRAIL scale, was significantly associated with QRS duration independent of serum electrolyte levels. In conclusion, a significant relationship exists between the severity of frailty and QRS duration in ESRD patients. This might be an under-recognized link between frailty and its adverse cardiovascular impact in these patients.
format: application/pdf
format: text/html
creator: Chia-Ter Chao
creator: Jenq-Wen Huang
subject: Cardiology
subject: Geriatrics
subject: Nephrology
description: doi:10.7717/peerj.1354
publisher: PeerJ Inc.
rights: © 2015 Chao and Huang
abstract: End-stage renal disease (ESRD) patients are at increased risk of sudden cardiac death, the risk of which is presumably related to arrhythmia. Electrocardiographic (ECG) parameters have been found to correlate with arrhythmia and predict cardiovascular outcomes in ESRD patients. Frailty is also a common feature in this population. We investigate whether the severity of dialysis frailty is associated with ECG findings, including PR interval, QRS duration, and QTc interval. Presence and severity of frailty was ascertained using six different self-report questionnaires with proven construct validity. Correlation analysis between frailty severity and ECG was made, and those with significant association entered into multiple regression analysis for confirmation. Among a cohort of chronic hemodialysis patients, we found that frailty severity, assessed by the Edmonton frailty scale, is significantly associated with QRS duration (r = − 0.3, p < 0.05). Dialysis patients with QRS longer than 120 ms had significantly lower severity of frailty than those with QRS less than 120 ms (p = 0.01 for the Edmonton frailty scale and 0.05 for simple FRAIL scale). Regression analysis showed that frailty severity, assessed by the Edmonton frailty scale and simple FRAIL scale, was significantly associated with QRS duration independent of serum electrolyte levels. In conclusion, a significant relationship exists between the severity of frailty and QRS duration in ESRD patients. This might be an under-recognized link between frailty and its adverse cardiovascular impact in these patients.
bibliographic citation: Chao et al. (2015) Frailty severity is significantly associated with electrocardiographic QRS duration in chronic dialysis patients. PeerJ 3:e1354 https://doi.org/10.7717/peerj.1354
date submitted: 2015-08-06
date accepted: 2015-10-06
issued: 2015-10-22
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Chao
  given name: Chia-Ter
author list: Agent
  family name: Huang
  given name: Jenq-Wen
doi: 10.7717/peerj.1354
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-22
copyright: © 2015 Chao and Huang
attribution name: Chao and Huang

Migration in the social stage of Dictyostelium discoideum amoebae impacts competition
type: item
type: AcademicArticle
description: Interaction conditions can change the balance of cooperation and conflict in multicellular groups. After aggregating together, cells of the social amoeba Dictyostelium discoideum may migrate as a group (known as a slug) to a new location. We consider this migration stage as an arena for social competition and conflict because the cells in the slug may not be from a genetically homogeneous population. In this study, we examined the interplay of two seemingly diametric actions, the solitary action of kin recognition and the collective action of slug migration in D. discoideum, to more fully understand the effects of social competition on fitness over the entire lifecycle. We compare slugs composed of either genetically homogenous or heterogeneous cells that have migrated or remained stationary in the social stage of the social amoeba Dictyostelium discoideum. After migration of chimeric slugs, we found that facultative cheating is reduced, where facultative cheating is defined as greater contribution to spore relative to stalk than found for that clone in the clonal state. In addition our results support previous findings that competitive interactions in chimeras diminish slug migration distance. Furthermore, fruiting bodies have shorter stalks after migration, even accounting for cell numbers at that time. Taken together, these results show that migration can alleviate the conflict of interests in heterogeneous slugs. It aligns their interest in finding a more advantageous place for dispersal, where shorter stalks suffice, which leads to a decrease in cheating behavior.
format: application/pdf
format: text/html
creator: Chandra N. Jack
creator: Neil Buttery
creator: Boahemaa Adu-Oppong
creator: Michael Powers
creator: Christopher R.L. Thompson
creator: David C. Queller
creator: Joan E. Strassmann
subject: Cell Biology
subject: Evolutionary Studies
description: doi:10.7717/peerj.1352
publisher: PeerJ Inc.
rights: © 2015 Jack et al.
abstract: Interaction conditions can change the balance of cooperation and conflict in multicellular groups. After aggregating together, cells of the social amoeba Dictyostelium discoideum may migrate as a group (known as a slug) to a new location. We consider this migration stage as an arena for social competition and conflict because the cells in the slug may not be from a genetically homogeneous population. In this study, we examined the interplay of two seemingly diametric actions, the solitary action of kin recognition and the collective action of slug migration in D. discoideum, to more fully understand the effects of social competition on fitness over the entire lifecycle. We compare slugs composed of either genetically homogenous or heterogeneous cells that have migrated or remained stationary in the social stage of the social amoeba Dictyostelium discoideum. After migration of chimeric slugs, we found that facultative cheating is reduced, where facultative cheating is defined as greater contribution to spore relative to stalk than found for that clone in the clonal state. In addition our results support previous findings that competitive interactions in chimeras diminish slug migration distance. Furthermore, fruiting bodies have shorter stalks after migration, even accounting for cell numbers at that time. Taken together, these results show that migration can alleviate the conflict of interests in heterogeneous slugs. It aligns their interest in finding a more advantageous place for dispersal, where shorter stalks suffice, which leads to a decrease in cheating behavior.
bibliographic citation: Jack et al. (2015) Migration in the social stage of Dictyostelium discoideum amoebae impacts competition. PeerJ 3:e1352 https://doi.org/10.7717/peerj.1352
date submitted: 2015-04-25
date accepted: 2015-10-05
issued: 2015-10-22
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Jack
  given name: Chandra N.
author list: Agent
  family name: Buttery
  given name: Neil
author list: Agent
  family name: Adu-Oppong
  given name: Boahemaa
author list: Agent
  family name: Powers
  given name: Michael
author list: Agent
  family name: Thompson
  given name: Christopher R.L.
author list: Agent
  family name: Queller
  given name: David C.
author list: Agent
  family name: Strassmann
  given name: Joan E.
doi: 10.7717/peerj.1352
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-22
copyright: © 2015 Jack et al.
attribution name: Jack et al.

Astrocyte activation in the anterior cingulate cortex and altered glutamatergic gene expression during paclitaxel-induced neuropathic pain in mice
type: item
type: AcademicArticle
description: Spinal astrocyte activation contributes to the pathogenesis of paclitaxel-induced neuropathic pain (PINP) in animal models. We examined glial fibrillary acidic protein (GFAP; an astrocyte marker) immunoreactivity and gene expression of GFAP, glutamate transporters and receptor subunits by real time PCR in the anterior cingulate cortex (ACC) at 7 days post first administration of paclitaxel, a time point when mice had developed thermal hyperalgesia. The ACC, an area in the brain involved in pain perception and modulation, was chosen because changes in this area might contribute to the pathophysiology of PINP. GFAP transcripts levels were elevated by more than fivefold and GFAP immunoreactivity increased in the ACC of paclitaxel-treated mice. The 6 glutamate transporters (GLAST, GLT-1 EAAC1, EAAT4, VGLUT-1 and VGLUT-2) quantified were not significantly altered by paclitaxel treatment. Of the 12 ionotropic glutamate receptor subunits transcripts analysed 6 (GLuA1, GLuA3, GLuK2, GLuK3, GLuK5 and GLuN1) were significantly up-regulated, whereas GLuA2, GLuK1, GLuK4, GLuN2A and GLuN2B were not significantly altered and GLuA4 was lowly expressed. Amongst the 8 metabotropic receptor subunits analysed only mGLuR8 was significantly elevated. In conclusion, during PINP there is astrocyte activation, with no change in glutamate transporter expression and differential up-regulation of glutamate receptor subunits in the ACC. Thus, targeting astrocyte activation and the glutamatergic system might be another therapeutic avenue for management of PINP.
format: application/pdf
format: text/html
creator: Willias Masocha
subject: Anesthesiology and Pain Management
subject: Molecular Biology
subject: Neuroscience
subject: Pharmacology
description: doi:10.7717/peerj.1350
publisher: PeerJ Inc.
rights: © 2015 Masocha
abstract: Spinal astrocyte activation contributes to the pathogenesis of paclitaxel-induced neuropathic pain (PINP) in animal models. We examined glial fibrillary acidic protein (GFAP; an astrocyte marker) immunoreactivity and gene expression of GFAP, glutamate transporters and receptor subunits by real time PCR in the anterior cingulate cortex (ACC) at 7 days post first administration of paclitaxel, a time point when mice had developed thermal hyperalgesia. The ACC, an area in the brain involved in pain perception and modulation, was chosen because changes in this area might contribute to the pathophysiology of PINP. GFAP transcripts levels were elevated by more than fivefold and GFAP immunoreactivity increased in the ACC of paclitaxel-treated mice. The 6 glutamate transporters (GLAST, GLT-1 EAAC1, EAAT4, VGLUT-1 and VGLUT-2) quantified were not significantly altered by paclitaxel treatment. Of the 12 ionotropic glutamate receptor subunits transcripts analysed 6 (GLuA1, GLuA3, GLuK2, GLuK3, GLuK5 and GLuN1) were significantly up-regulated, whereas GLuA2, GLuK1, GLuK4, GLuN2A and GLuN2B were not significantly altered and GLuA4 was lowly expressed. Amongst the 8 metabotropic receptor subunits analysed only mGLuR8 was significantly elevated. In conclusion, during PINP there is astrocyte activation, with no change in glutamate transporter expression and differential up-regulation of glutamate receptor subunits in the ACC. Thus, targeting astrocyte activation and the glutamatergic system might be another therapeutic avenue for management of PINP.
bibliographic citation: Masocha (2015) Astrocyte activation in the anterior cingulate cortex and altered glutamatergic gene expression during paclitaxel-induced neuropathic pain in mice. PeerJ 3:e1350 https://doi.org/10.7717/peerj.1350
date submitted: 2015-07-17
date accepted: 2015-10-05
issued: 2015-10-22
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Masocha
  given name: Willias
doi: 10.7717/peerj.1350
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-22
copyright: © 2015 Masocha
attribution name: Masocha

Cheetahs (Acinonyx jubatus) running the gauntlet: an evaluation of translocations into free-range environments in Namibia
type: item
type: AcademicArticle
description: Following dramatic range and population declines, the cheetah is Africa’s most endangered large felid. In Namibia, private land managers still trap cheetahs but increasingly consider moving animals instead of killing them. Across Africa, managers have translocated perceived conflict carnivores for decades, but rarely evaluated their actions. We analyse the outcomes of 15 cheetah translocations (for 23 adults and 10 dependent offspring) into free-range environments in Namibia. We released cheetahs at an average distance of 419.6 km ± 216.1 km SD (range: 71–816 km) after captive periods ranging from 1–1,184 days (350.6 days ± 439.0 days SD). An individual’s ability to survive the first year predominantly determined the overall translocation success of 40%. Post-release conflict and homing had less impact on success. Cheetah survival was lowest in the first three months after release. Human persecution (50% of deaths) and spotted hyaenas (29% of deaths) had the highest effect on survival. The degree of habituation to humans acquired during captivity significantly influenced chances of survival. Cheetahs surviving the initial post-release period (∼90 days) often settled into ranges and females reproduced successfully. However, all individuals exhibited extensive movements, frequently roaming >4,000 km2 in the first six months after release (with a maximum of 19,743 km2 in 112 days), resulting in low release site fidelity. Soft release and larger recipient area size did not improve site fidelity. Based on these outcomes, we evaluated which unfenced conservation areas in Namibia could potentially receive cheetahs. We found that there are currently few public and/or private reserves large enough to contain the movement profiles we observed in this study. This suggests that most translocations will result in cheetahs re-entering farmlands where they face a high risk of persecution. In conclusion, translocations into unconfined areas can successfully conserve individual chee…
format: application/pdf
format: text/html
creator: Florian J. Weise
creator: Joseph R. Lemeris
creator: Stuart J. Munro
creator: Andrew Bowden
creator: Cicelia Venter
creator: Marlice van Vuuren
creator: Rudie J. van Vuuren
subject: Biosphere Interactions
subject: Conservation Biology
subject: Ecology
subject: Natural Resource Management
description: doi:10.7717/peerj.1346
publisher: PeerJ Inc.
rights: © 2015 Weise et al.
abstract: Following dramatic range and population declines, the cheetah is Africa’s most endangered large felid. In Namibia, private land managers still trap cheetahs but increasingly consider moving animals instead of killing them. Across Africa, managers have translocated perceived conflict carnivores for decades, but rarely evaluated their actions. We analyse the outcomes of 15 cheetah translocations (for 23 adults and 10 dependent offspring) into free-range environments in Namibia. We released cheetahs at an average distance of 419.6 km ± 216.1 km SD (range: 71–816 km) after captive periods ranging from 1–1,184 days (350.6 days ± 439.0 days SD). An individual’s ability to survive the first year predominantly determined the overall translocation success of 40%. Post-release conflict and homing had less impact on success. Cheetah survival was lowest in the first three months after release. Human persecution (50% of deaths) and spotted hyaenas (29% of deaths) had the highest effect on survival. The degree of habituation to humans acquired during captivity significantly influenced chances of survival. Cheetahs surviving the initial post-release period (∼90 days) often settled into ranges and females reproduced successfully. However, all individuals exhibited extensive movements, frequently roaming >4,000 km2 in the first six months after release (with a maximum of 19,743 km2 in 112 days), resulting in low release site fidelity. Soft release and larger recipient area size did not improve site fidelity. Based on these outcomes, we evaluated which unfenced conservation areas in Namibia could potentially receive cheetahs. We found that there are currently few public and/or private reserves large enough to contain the movement profiles we observed in this study. This suggests that most translocations will result in cheetahs re-entering farmlands where they face a high risk of persecution. In conclusion, translocations into unconfined areas can successfully conserve individual chee…
bibliographic citation: Weise et al. (2015) Cheetahs (Acinonyx jubatus) running the gauntlet: an evaluation of translocations into free-range environments in Namibia. PeerJ 3:e1346 https://doi.org/10.7717/peerj.1346
date submitted: 2015-08-31
date accepted: 2015-10-03
issued: 2015-10-22
is part of: PeerJ
license: http://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Weise
  given name: Florian J.
author list: Agent
  family name: Lemeris
  given name: Joseph R.
author list: Agent
  family name: Munro
  given name: Stuart J.
author list: Agent
  family name: Bowden
  given name: Andrew
author list: Agent
  family name: Venter
  given name: Cicelia
author list: Agent
  family name: van Vuuren
  given name: Marlice
author list: Agent
  family name: van Vuuren
  given name: Rudie J.
doi: 10.7717/peerj.1346
volume: 3
issn: 2167-8359
publication name: PeerJ
publication date: 2015-10-22
copyright: © 2015 Weise et al.
attribution name: Weise et al.

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