PeerJ
type: channel
link: https://peerj.com/articles/
description: Articles published in PeerJ
publisher: PeerJ Inc.
publication name: PeerJ
issn: 2167-8359
items: Uptake of a plasticizer (di-n-butyl phthalate) impacts the biochemical and physiological responses of barley
items: https://peerj.com/articles/12896
items: Quantification of human enteric viruses as alternative indicators of fecal pollution to evaluate wastewater treatment processes
items: Defense mechanism responses to COVID-19
items: A synergistic, global approach to revising the trypanorhynch tapeworm family Rhinoptericolidae (Trypanobatoida)
items: Carbon isotope discrimination and the factors affecting it in a summer maize field under different tillage systems
items: Genetic variability studies for tuber yield and yield attributes in Ethiopian released potato (Solanum tuberosum L.) varieties
items: Vertical and temporal variations of soil bacterial and archaeal communities in wheat-soybean rotation agroecosystem
items: Determinants of quality of life and well-being in cognitively unimpaired older adults: a systematic review
items: The effect of farmland on the surface water of the Aral Sea Region using Multi-source Satellite Data

Uptake of a plasticizer (di-n-butyl phthalate) impacts the biochemical and physiological responses of barley
type: item
type: AcademicArticle
description: Background DBP is one of the most commonly used plasticizers for imparting desirable properties to polymers. The introduction of phthalates is reported to have occurred in the late 1920s, and there has been a significant rise in their release into the environment in past decades due to a lack of covalent bonding with the parent matrix. Because of their numerous applications in day-to-day life, phthalates have become ubiquitous and also classified as endocrine disruptors. Hence, several studies have been conducted to investigate the phthalate-mediated toxicities in animals; however, plants have not been explored to the same amount. Methods Therefore, in the present study, the accumulation and translocation along with morpho-physiological perturbations in barley plants after 15, 30, 60, and 120 days of exposure to di-n-butyl phthalate (DBP) are investigated using standard protocols. Results The maximal accumulation and translocation of DBP in the roots and shoots of barley plants was observed after 60 days of exposure. The exposure of DBP from 15 to 120 days was recorded to decline all the morphological indices (i.e., dry weight, net primary productivity, seed number per spike, and seed weight) of barley plants. The pigments content declined under DBP treatment for all exposure durations except 120 days exposure. Carbohydrate content increased after 15–30 days of exposure afterward it was observed to be decreased under 60 and 120 days of exposure. The protein content was declined in DBP stressed plants for 15–120 days. Proline content was increased in all exposure durations and maximal percent increase was recorded in 120 days of exposure. MDA content showed an increase at earlier exposure durations then followed by a decline in long-term exposure. Hydrogen peroxide content increased at all exposure durations. There were significant alterations observed in the activities of all antioxidative enzymes in comparison to the control. Furthermore, DBP stressed plants after …
format: application/pdf
format: text/html
creator: Arpna Kumari
creator: Rajinder Kaur
subject: Agricultural Science
subject: Plant Science
subject: Soil Science
subject: Ecotoxicology
description: doi:10.7717/peerj.12859
publisher: PeerJ Inc.
rights: © 2022 Kumari and Kaur
abstract: Background DBP is one of the most commonly used plasticizers for imparting desirable properties to polymers. The introduction of phthalates is reported to have occurred in the late 1920s, and there has been a significant rise in their release into the environment in past decades due to a lack of covalent bonding with the parent matrix. Because of their numerous applications in day-to-day life, phthalates have become ubiquitous and also classified as endocrine disruptors. Hence, several studies have been conducted to investigate the phthalate-mediated toxicities in animals; however, plants have not been explored to the same amount. Methods Therefore, in the present study, the accumulation and translocation along with morpho-physiological perturbations in barley plants after 15, 30, 60, and 120 days of exposure to di-n-butyl phthalate (DBP) are investigated using standard protocols. Results The maximal accumulation and translocation of DBP in the roots and shoots of barley plants was observed after 60 days of exposure. The exposure of DBP from 15 to 120 days was recorded to decline all the morphological indices (i.e., dry weight, net primary productivity, seed number per spike, and seed weight) of barley plants. The pigments content declined under DBP treatment for all exposure durations except 120 days exposure. Carbohydrate content increased after 15–30 days of exposure afterward it was observed to be decreased under 60 and 120 days of exposure. The protein content was declined in DBP stressed plants for 15–120 days. Proline content was increased in all exposure durations and maximal percent increase was recorded in 120 days of exposure. MDA content showed an increase at earlier exposure durations then followed by a decline in long-term exposure. Hydrogen peroxide content increased at all exposure durations. There were significant alterations observed in the activities of all antioxidative enzymes in comparison to the control. Furthermore, DBP stressed plants after …
bibliographic citation: Kumari et al. (2022) Uptake of a plasticizer (di-n-butyl phthalate) impacts the biochemical and physiological responses of barley. PeerJ 10:e12859 https://doi.org/10.7717/peerj.12859
date submitted: 2021-07-07
date accepted: 2022-01-09
issued: 2022-02-14
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Kumari
  given name: Arpna
author list: Agent
  family name: Kaur
  given name: Rajinder
doi: 10.7717/peerj.12859
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-14
copyright: ©2022 Kumari and Kaur
attribution name: Kumari and Kaur

https://peerj.com/articles/12896
type: item
type: AcademicArticle
title: Assessment of the effects of storage temperature on fatty acid analysis using dried blood spot cards from managed southern white rhinoceroses (Ceratotherium simum simum): implications for field collection and nutritional care
description: Background Southern white rhinoceroses (Ceratotherium simum simum) are an endangered species in decline due to poaching and negative habitat changes. Conservation of the species has become increasingly important and a focus on better human management has become prevalent. One area of management that impacts southern white rhinoceroses is nutritional health monitoring, which is often conducted through blood analysis. Blood analysis conducted during field research can be difficult due to temperature, distance, and limited technological resources, so new methods of fast, and relatively stable blood collection are being pursued. One method that has been used in humans for many years is beginning to make its way into wildlife studies: the use of dried blood spot (DBS) cards. These cards are used as a tool to store single drops of whole blood on specialized filter paper and, once dried, can be used for nutritional biomarker analysis. An area of interest for southern white rhinoceroses and nutrition is monitoring fatty acid percentages for cardiovascular, immune, and reproductive health. The time and temperature limitations for storing blood fractions or liquid whole blood when analyzing fatty acids have been investigated, but few studies have performed storage studies on DBS cards colder than −20 °C or in non-human species. Methods In order to better understand the limitations of DBS cards and the impact of temperature on fatty acid DBS samples in long-term storage, triplicate samples from seven adult southern white rhinoceroses at the North Carolina Zoo were collected and subjected to three storage treatments (immediate, room temperature (23 °C), or frozen (−80 °C) for 1 year). Results Stearidonic (18:4w3) (Δ 0.3%), arachdic (20:0) (Δ 0.1%), eicosatetraenoic (20:4w3) (Δ 0.2%), and erucic acid (22:1w9) (Δ 0.1%) were in higher concentration in frozen than initial. Fatty acids in higher concentrations in the initial samples than frozen were myristic (14:0) (Δ 0.2%), mead (2…
format: application/pdf
format: text/html
creator: Jordan Wood
creator: Larry J. Minter
creator: Doug Bibus
creator: Troy N. Tollefson
creator: Kimberly Ange-van Heugten
subject: Biochemistry
subject: Biotechnology
subject: Veterinary Medicine
description: doi:10.7717/peerj.12896
publisher: PeerJ Inc.
rights: © 2022 Wood et al.
abstract: Background Southern white rhinoceroses (Ceratotherium simum simum) are an endangered species in decline due to poaching and negative habitat changes. Conservation of the species has become increasingly important and a focus on better human management has become prevalent. One area of management that impacts southern white rhinoceroses is nutritional health monitoring, which is often conducted through blood analysis. Blood analysis conducted during field research can be difficult due to temperature, distance, and limited technological resources, so new methods of fast, and relatively stable blood collection are being pursued. One method that has been used in humans for many years is beginning to make its way into wildlife studies: the use of dried blood spot (DBS) cards. These cards are used as a tool to store single drops of whole blood on specialized filter paper and, once dried, can be used for nutritional biomarker analysis. An area of interest for southern white rhinoceroses and nutrition is monitoring fatty acid percentages for cardiovascular, immune, and reproductive health. The time and temperature limitations for storing blood fractions or liquid whole blood when analyzing fatty acids have been investigated, but few studies have performed storage studies on DBS cards colder than −20 °C or in non-human species. Methods In order to better understand the limitations of DBS cards and the impact of temperature on fatty acid DBS samples in long-term storage, triplicate samples from seven adult southern white rhinoceroses at the North Carolina Zoo were collected and subjected to three storage treatments (immediate, room temperature (23 °C), or frozen (−80 °C) for 1 year). Results Stearidonic (18:4w3) (Δ 0.3%), arachdic (20:0) (Δ 0.1%), eicosatetraenoic (20:4w3) (Δ 0.2%), and erucic acid (22:1w9) (Δ 0.1%) were in higher concentration in frozen than initial. Fatty acids in higher concentrations in the initial samples than frozen were myristic (14:0) (Δ 0.2%), mead (2…
bibliographic citation: Wood et al. (2022) Assessment of the effects of storage temperature on fatty acid analysis using dried blood spot cards from managed southern white rhinoceroses (Ceratotherium simum simum): implications for field collection and nutritional care. PeerJ 10:e12896 https://doi.org/10.7717/peerj.12896
date submitted: 2021-10-28
date accepted: 2022-01-16
issued: 2022-02-14
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Wood
  given name: Jordan
author list: Agent
  family name: Minter
  given name: Larry J.
author list: Agent
  family name: Bibus
  given name: Doug
author list: Agent
  family name: Tollefson
  given name: Troy N.
author list: Agent
  family name: Ange-van Heugten
  given name: Kimberly
doi: 10.7717/peerj.12896
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-14
copyright: © 2022 Wood et al.
attribution name: Wood et al.

Quantification of human enteric viruses as alternative indicators of fecal pollution to evaluate wastewater treatment processes
type: item
type: AcademicArticle
description: We investigated the potential use and quantification of human enteric viruses in municipal wastewater samples of Winnipeg (Manitoba, Canada) as alternative indicators of contamination and evaluated the processing stages of the wastewater treatment plant. During the fall 2019 and winter 2020 seasons, samples of raw sewage, activated sludge, effluents, and biosolids (sludge cake) were collected from the North End Sewage Treatment Plant (NESTP), which is the largest wastewater treatment plant in the City of Winnipeg. DNA (Adenovirus and crAssphage) and RNA enteric viruses (Pepper mild mottle virus, Norovirus genogroups GI and GII, Rotavirus Astrovirus, and Sapovirus) as well as the uidA gene found in Escherichia coli were targeted in the samples collected from the NESTP. Total nucleic acids from each wastewater treatment sample were extracted using a commercial spin-column kit. Enteric viruses were quantified in the extracted samples via quantitative PCR using TaqMan assays. Overall, the average gene copies assessed in the raw sewage were not significantly different (p-values ranged between 0.1023 and 0.9921) than the average gene copies assessed in the effluents for DNA and RNA viruses and uidA in terms of both volume and biomass. A significant reduction (p-value ≤ 0.0438) of Adenovirus and Noroviruses genogroups GI and GII was observed in activated sludge samples compared with those for raw sewage per volume. Higher GCNs of enteric viruses were observed in dewatered sludge samples compared to liquid samples in terms of volume (g of sample) and biomass (ng of nucleic acids). Enteric viruses found in gene copy numbers were at least one order of magnitude higher than the E. coli marker uidA, indicating that enteric viruses may survive the wastewater treatment process and viral-like particles are being released into the aquatic environment. Viruses such as Noroviruses genogroups GI and GII, and Rotavirus were detected during colder months. Our results suggest that Adenov…
format: application/pdf
format: text/html
creator: Audrey Garcia
creator: Tri Le
creator: Paul Jankowski
creator: Kadir Yanaç
creator: Qiuyan Yuan
creator: Miguel I. Uyaguari-Diaz
subject: Microbiology
subject: Molecular Biology
subject: Virology
subject: Environmental Impacts
description: doi:10.7717/peerj.12957
publisher: PeerJ Inc.
rights: © 2022 Garcia et al.
abstract: We investigated the potential use and quantification of human enteric viruses in municipal wastewater samples of Winnipeg (Manitoba, Canada) as alternative indicators of contamination and evaluated the processing stages of the wastewater treatment plant. During the fall 2019 and winter 2020 seasons, samples of raw sewage, activated sludge, effluents, and biosolids (sludge cake) were collected from the North End Sewage Treatment Plant (NESTP), which is the largest wastewater treatment plant in the City of Winnipeg. DNA (Adenovirus and crAssphage) and RNA enteric viruses (Pepper mild mottle virus, Norovirus genogroups GI and GII, Rotavirus Astrovirus, and Sapovirus) as well as the uidA gene found in Escherichia coli were targeted in the samples collected from the NESTP. Total nucleic acids from each wastewater treatment sample were extracted using a commercial spin-column kit. Enteric viruses were quantified in the extracted samples via quantitative PCR using TaqMan assays. Overall, the average gene copies assessed in the raw sewage were not significantly different (p-values ranged between 0.1023 and 0.9921) than the average gene copies assessed in the effluents for DNA and RNA viruses and uidA in terms of both volume and biomass. A significant reduction (p-value ≤ 0.0438) of Adenovirus and Noroviruses genogroups GI and GII was observed in activated sludge samples compared with those for raw sewage per volume. Higher GCNs of enteric viruses were observed in dewatered sludge samples compared to liquid samples in terms of volume (g of sample) and biomass (ng of nucleic acids). Enteric viruses found in gene copy numbers were at least one order of magnitude higher than the E. coli marker uidA, indicating that enteric viruses may survive the wastewater treatment process and viral-like particles are being released into the aquatic environment. Viruses such as Noroviruses genogroups GI and GII, and Rotavirus were detected during colder months. Our results suggest that Adenov…
bibliographic citation: Garcia et al. (2022) Quantification of human enteric viruses as alternative indicators of fecal pollution to evaluate wastewater treatment processes. PeerJ 10:e12957 https://doi.org/10.7717/peerj.12957
date submitted: 2021-08-06
date accepted: 2022-01-27
issued: 2022-02-14
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Garcia
  given name: Audrey
author list: Agent
  family name: Le
  given name: Tri
author list: Agent
  family name: Jankowski
  given name: Paul
author list: Agent
  family name: Yanaç
  given name: Kadir
author list: Agent
  family name: Yuan
  given name: Qiuyan
author list: Agent
  family name: Uyaguari-Diaz
  given name: Miguel I.
doi: 10.7717/peerj.12957
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-14
copyright: ©2022 Garcia et al.
attribution name: Garcia et al.

Defense mechanism responses to COVID-19
type: item
type: AcademicArticle
description: The COVID-19 pandemic has had a wide range of negative physical and mental impacts. This review begins with a theoretical explanation of the psychological defense mechanisms used to deal with the pandemic. It then discusses different categories of defense mechanisms and their roles in managing the impacts of psychological distress. The aim of this review is to highlight the various psychological defense mechanisms individuals use to deal with the pandemic and to discuss how adjustment mechanisms can protect individuals from internal and external threats by shielding the integrity of the ego (the mind) and helping individuals maintain their self-schema.
format: application/pdf
format: text/html
creator: Nouf Altwaijri
creator: Turki Abualait
creator: Mohammed Aljumaan
creator: Raidah Albaradie
creator: Zahid Arain
creator: Shahid Bashir
subject: Psychiatry and Psychology
subject: Mental Health
subject: COVID-19
description: doi:10.7717/peerj.12811
publisher: PeerJ Inc.
rights: © 2022 Altwaijri et al.
abstract: The COVID-19 pandemic has had a wide range of negative physical and mental impacts. This review begins with a theoretical explanation of the psychological defense mechanisms used to deal with the pandemic. It then discusses different categories of defense mechanisms and their roles in managing the impacts of psychological distress. The aim of this review is to highlight the various psychological defense mechanisms individuals use to deal with the pandemic and to discuss how adjustment mechanisms can protect individuals from internal and external threats by shielding the integrity of the ego (the mind) and helping individuals maintain their self-schema.
bibliographic citation: Altwaijri et al. (2022) Defense mechanism responses to COVID-19. PeerJ 10:e12811 https://doi.org/10.7717/peerj.12811
date submitted: 2021-10-11
date accepted: 2021-12-28
issued: 2022-02-11
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Altwaijri
  given name: Nouf
author list: Agent
  family name: Abualait
  given name: Turki
author list: Agent
  family name: Aljumaan
  given name: Mohammed
author list: Agent
  family name: Albaradie
  given name: Raidah
author list: Agent
  family name: Arain
  given name: Zahid
author list: Agent
  family name: Bashir
  given name: Shahid
doi: 10.7717/peerj.12811
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-11
copyright: ©2022 Altwaijri et al.
attribution name: Altwaijri et al.

A synergistic, global approach to revising the trypanorhynch tapeworm family Rhinoptericolidae (Trypanobatoida)
type: item
type: AcademicArticle
description: Since 2010, the trypanorhynch tapeworm family Rhinoptericolidae Carvajal & Campbell, 1975 has housed just two distinctive, monotypic genera (Rhinoptericola Carvajal & Campbell, 1975 and Nataliella Palm, 2010). However, global collections of tapeworms from sharks and rays over the last more than three decades brought to light the need for major revision of the family by suggesting a much greater species-level diversity for the nominal genus Rhinoptericola. Through synonymy and the description of new species, the number of species in the genus is increased from one to eight. A phylogenetic analysis of the D1–D3 gene region of 28S rRNA (28S), including seven of the now nine species of rhinoptericolids, and a broad sampling of the other Trypanobatoida is the first to recover a monophyletic Rhinoptericolidae. In addition to systematic revision, this study allowed for the first evaluation of the degree of intraspecific vs interspecific variation in 28S for adult trypanorhynchs across the various hosts and geographic localities from which they have been reported, suggesting a relatively consistent boundary for Rhinoptericola. It is further suggested that detailed scanning electron microscopy (SEM) images of both the basal and metabasal armatures greatly aid in the interpretation of hook arrangement and shape. A schematic to streamline determination of the tentacular surface presented in scanning electron micrographs and line drawings of trypanorhynchs is presented for species with both two and four bothria. In combination, these methodological refinements can now be used as a model to resolve issues of classification and non-monophyly within both major lineages of the Trypanorhyncha. As a result of the taxonomic work, Rhinoptericola megacantha Carvajal & Campbell, 1975 (previously only known from the American cownose ray from the Chesapeake Bay and the Ticon cownose ray from the Gulf of Mexico, Venezuela, and Brazil) is now known from an additional species of cownose ray a…
format: application/pdf
format: text/html
creator: Kaylee S. Herzog
creator: Kirsten Jensen
subject: Biodiversity
subject: Marine Biology
subject: Parasitology
subject: Taxonomy
subject: Zoology
description: doi:10.7717/peerj.12865
publisher: PeerJ Inc.
rights: © 2022 Herzog and Jensen
abstract: Since 2010, the trypanorhynch tapeworm family Rhinoptericolidae Carvajal & Campbell, 1975 has housed just two distinctive, monotypic genera (Rhinoptericola Carvajal & Campbell, 1975 and Nataliella Palm, 2010). However, global collections of tapeworms from sharks and rays over the last more than three decades brought to light the need for major revision of the family by suggesting a much greater species-level diversity for the nominal genus Rhinoptericola. Through synonymy and the description of new species, the number of species in the genus is increased from one to eight. A phylogenetic analysis of the D1–D3 gene region of 28S rRNA (28S), including seven of the now nine species of rhinoptericolids, and a broad sampling of the other Trypanobatoida is the first to recover a monophyletic Rhinoptericolidae. In addition to systematic revision, this study allowed for the first evaluation of the degree of intraspecific vs interspecific variation in 28S for adult trypanorhynchs across the various hosts and geographic localities from which they have been reported, suggesting a relatively consistent boundary for Rhinoptericola. It is further suggested that detailed scanning electron microscopy (SEM) images of both the basal and metabasal armatures greatly aid in the interpretation of hook arrangement and shape. A schematic to streamline determination of the tentacular surface presented in scanning electron micrographs and line drawings of trypanorhynchs is presented for species with both two and four bothria. In combination, these methodological refinements can now be used as a model to resolve issues of classification and non-monophyly within both major lineages of the Trypanorhyncha. As a result of the taxonomic work, Rhinoptericola megacantha Carvajal & Campbell, 1975 (previously only known from the American cownose ray from the Chesapeake Bay and the Ticon cownose ray from the Gulf of Mexico, Venezuela, and Brazil) is now known from an additional species of cownose ray a…
bibliographic citation: Herzog et al. (2022) A synergistic, global approach to revising the trypanorhynch tapeworm family Rhinoptericolidae (Trypanobatoida). PeerJ 10:e12865 https://doi.org/10.7717/peerj.12865
date submitted: 2021-09-20
date accepted: 2022-01-10
issued: 2022-02-11
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Herzog
  given name: Kaylee S.
author list: Agent
  family name: Jensen
  given name: Kirsten
doi: 10.7717/peerj.12865
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-11
copyright: © 2022 Herzog and Jensen
attribution name: Herzog and Jensen

Carbon isotope discrimination and the factors affecting it in a summer maize field under different tillage systems
type: item
type: AcademicArticle
description: Based on two years of field experiments, under different soil tillage methods and straw management practices, which included conventional tillage (CT), subsoiling (SS), rotary tillage (RT), and no-tillage (NT), combined with either straw return (S) or straw removal (0), we characterized the dynamic changes in Δ13C among three height layers [upper (U, 240 cm above the ground), middle (M, 120 cm above the ground), and lower (L, 30 cm above the ground)] of the summer maize canopy. The Δ13C, the factors affecting it, and the relationships between Δ13C and soil water content (SWC), the leaf area index (LAI), canopy microclimate, and the CO2 concentration were elucidated. The results indicated that the Δ13C of summer maize at the pre-filling stage was greater than that at the post-filling stage. Δ13C also varied at different heights, with the order of the Δ13C values being L > U > M. Among the different tillage methods, the Δ13C values were ordered SSS > CTS > RTS > NTS. SSS and NTS significantly increased the LAI; air temperature and relative humidity tended to gradually decrease with the increase in height of summer maize. Correlation analyses of the various influencing factors and Δ13C showed that SWC, LAI, air temperature, and CO2 concentration were all positively correlated with Δ13C, in which LAI and air temperature were significantly or extremely significantly positively correlated with Δ13C. In addition, we show that Δ13C can be used as a prediction index for summer maize yield, providing a theoretical basis for future yield research that may save precious time in summer maize breeding efforts.
format: application/pdf
format: text/html
creator: Jichao Cui
creator: Huifang Han
subject: Agricultural Science
subject: Ecology
subject: Plant Science
subject: Soil Science
description: doi:10.7717/peerj.12891
publisher: PeerJ Inc.
rights: © 2022 Cui and Han
abstract: Based on two years of field experiments, under different soil tillage methods and straw management practices, which included conventional tillage (CT), subsoiling (SS), rotary tillage (RT), and no-tillage (NT), combined with either straw return (S) or straw removal (0), we characterized the dynamic changes in Δ13C among three height layers [upper (U, 240 cm above the ground), middle (M, 120 cm above the ground), and lower (L, 30 cm above the ground)] of the summer maize canopy. The Δ13C, the factors affecting it, and the relationships between Δ13C and soil water content (SWC), the leaf area index (LAI), canopy microclimate, and the CO2 concentration were elucidated. The results indicated that the Δ13C of summer maize at the pre-filling stage was greater than that at the post-filling stage. Δ13C also varied at different heights, with the order of the Δ13C values being L > U > M. Among the different tillage methods, the Δ13C values were ordered SSS > CTS > RTS > NTS. SSS and NTS significantly increased the LAI; air temperature and relative humidity tended to gradually decrease with the increase in height of summer maize. Correlation analyses of the various influencing factors and Δ13C showed that SWC, LAI, air temperature, and CO2 concentration were all positively correlated with Δ13C, in which LAI and air temperature were significantly or extremely significantly positively correlated with Δ13C. In addition, we show that Δ13C can be used as a prediction index for summer maize yield, providing a theoretical basis for future yield research that may save precious time in summer maize breeding efforts.
bibliographic citation: Cui et al. (2022) Carbon isotope discrimination and the factors affecting it in a summer maize field under different tillage systems. PeerJ 10:e12891 https://doi.org/10.7717/peerj.12891
date submitted: 2021-07-01
date accepted: 2022-01-14
issued: 2022-02-11
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Cui
  given name: Jichao
author list: Agent
  family name: Han
  given name: Huifang
doi: 10.7717/peerj.12891
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-11
copyright: © 2022 Cui and Han
attribution name: Cui and Han

Genetic variability studies for tuber yield and yield attributes in Ethiopian released potato (Solanum tuberosum L.) varieties
type: item
type: AcademicArticle
description: Information on the extent of genetic variability and association among quantitative traits are vital for any crop improvement program and the development of suitable selection strategies. Limited research has been carried out thus far on potato genetic variability and trait association. This study on genetic variability and association among quantitative traits was conducted to assess the extent of genetic variability among yield and agronomic traits to identify superior varieties for the breeding program. To this effect, 20 improved varieties and a local cultivar were planted at two locations in central Ethiopia during the main cropping season of 2017/18 in a randomized complete block design using three replications. Analysis of variance of tuber yield and yield traits at each location and over locations, revealed the existence of highly significant (P < 0.01) differences among varieties in all agronomic and yield traits. Phenotypic coefficient of variation values ranged from 0.75% (specific gravity) to 32.22% (total starch yield) while the genotypic coefficient of variation values ranged between 0.70% (specific gravity) to 30.22% (total starch yield). Maximum difference between phenotypic and genotypic coefficient of variation values were noted for stem number, average tuber number, average tuber weight, number of leaves per plant and tuber yield. Hence, these traits are substantially influenced by the physiological status of the seed tuber at planting and by the environment, post emergence. Range of variability for most of the traits was high, indicating ample scope for selection and improvement in these traits. The estimated values for broad sense heritability and genetic advance, as percent of mean, ranged from 33.52% to 98.66% and 1.35% to 58.26%, respectively. All the traits had high heritability values, except average tuber number per hill, days to physiological maturity, average tuber weight and number of leaves per plant with moderate heritability values.
format: application/pdf
format: text/html
creator: Gebrehanna Lemma Tessema
creator: Ali Wassu Mohammed
creator: Desta Tesfaye Abebe
subject: Agricultural Science
subject: Genetics
subject: Plant Science
description: doi:10.7717/peerj.12860
publisher: PeerJ Inc.
rights: © 2022 Gebrehanna et al.
abstract: Information on the extent of genetic variability and association among quantitative traits are vital for any crop improvement program and the development of suitable selection strategies. Limited research has been carried out thus far on potato genetic variability and trait association. This study on genetic variability and association among quantitative traits was conducted to assess the extent of genetic variability among yield and agronomic traits to identify superior varieties for the breeding program. To this effect, 20 improved varieties and a local cultivar were planted at two locations in central Ethiopia during the main cropping season of 2017/18 in a randomized complete block design using three replications. Analysis of variance of tuber yield and yield traits at each location and over locations, revealed the existence of highly significant (P < 0.01) differences among varieties in all agronomic and yield traits. Phenotypic coefficient of variation values ranged from 0.75% (specific gravity) to 32.22% (total starch yield) while the genotypic coefficient of variation values ranged between 0.70% (specific gravity) to 30.22% (total starch yield). Maximum difference between phenotypic and genotypic coefficient of variation values were noted for stem number, average tuber number, average tuber weight, number of leaves per plant and tuber yield. Hence, these traits are substantially influenced by the physiological status of the seed tuber at planting and by the environment, post emergence. Range of variability for most of the traits was high, indicating ample scope for selection and improvement in these traits. The estimated values for broad sense heritability and genetic advance, as percent of mean, ranged from 33.52% to 98.66% and 1.35% to 58.26%, respectively. All the traits had high heritability values, except average tuber number per hill, days to physiological maturity, average tuber weight and number of leaves per plant with moderate heritability values.
bibliographic citation: Tessema et al. (2022) Genetic variability studies for tuber yield and yield attributes in Ethiopian released potato (Solanum tuberosum L.) varieties. PeerJ 10:e12860 https://doi.org/10.7717/peerj.12860
date submitted: 2020-06-11
date accepted: 2022-01-09
issued: 2022-02-10
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Tessema
  given name: Gebrehanna Lemma
author list: Agent
  family name: Mohammed
  given name: Ali Wassu
author list: Agent
  family name: Abebe
  given name: Desta Tesfaye
doi: 10.7717/peerj.12860
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-10
copyright: © 2022 Gebrehanna et al.
attribution name: Gebrehanna et al.

Vertical and temporal variations of soil bacterial and archaeal communities in wheat-soybean rotation agroecosystem
type: item
type: AcademicArticle
description: Soil microbes are an essential component of terrestrial ecosystems and drive many biogeochemical processes throughout the soil profile. Prior field studies mainly focused on the vertical patterns of soil microbial communities, meaning their temporal dynamics have been largely neglected. In the present study, we investigated the vertical and temporal patterns of soil bacterial and archaeal communities in a wheat-soybean rotation agroecosystem at a depth of millions of sequences per sample. Our results revealed different vertical bacterial and archaeal richness patterns: bacterial richness was lowest in the deep soil layer and peaked in the surface or middle soil layer. In contrast, archaeal richness did not differ among soil layers. PERMANOVA analysis indicated that both bacterial and archaeal community compositions were significantly impacted by soil depth but unaffected by sampling time. Notably, the proportion of rare bacteria gradually decreased along with the soil profile. The rare bacterial community composition was the most important indicator for soil nutrient fertility index, as determined by random forest analysis. The soil prokaryotic co-occurrence networks of the surface and middle soil layers are more connected and harbored fewer negative links than that of the deep soil layer. Overall, our results highlighted soil depth as a more important determinant than temporal variation in shaping the soil prokaryotic community and interspecific interactions and revealed a potential role of rare taxa in soil biogeochemical function.
format: application/pdf
format: text/html
creator: Mika Yokota
creator: Yupeng Guan
creator: Yi Fan
creator: Ximei Zhang
creator: Wei Yang
subject: Agricultural Science
subject: Microbiology
subject: Molecular Biology
subject: Soil Science
description: doi:10.7717/peerj.12868
publisher: PeerJ Inc.
rights: © 2022 Yokota et al.
abstract: Soil microbes are an essential component of terrestrial ecosystems and drive many biogeochemical processes throughout the soil profile. Prior field studies mainly focused on the vertical patterns of soil microbial communities, meaning their temporal dynamics have been largely neglected. In the present study, we investigated the vertical and temporal patterns of soil bacterial and archaeal communities in a wheat-soybean rotation agroecosystem at a depth of millions of sequences per sample. Our results revealed different vertical bacterial and archaeal richness patterns: bacterial richness was lowest in the deep soil layer and peaked in the surface or middle soil layer. In contrast, archaeal richness did not differ among soil layers. PERMANOVA analysis indicated that both bacterial and archaeal community compositions were significantly impacted by soil depth but unaffected by sampling time. Notably, the proportion of rare bacteria gradually decreased along with the soil profile. The rare bacterial community composition was the most important indicator for soil nutrient fertility index, as determined by random forest analysis. The soil prokaryotic co-occurrence networks of the surface and middle soil layers are more connected and harbored fewer negative links than that of the deep soil layer. Overall, our results highlighted soil depth as a more important determinant than temporal variation in shaping the soil prokaryotic community and interspecific interactions and revealed a potential role of rare taxa in soil biogeochemical function.
bibliographic citation: Yokota et al. (2022) Vertical and temporal variations of soil bacterial and archaeal communities in wheat-soybean rotation agroecosystem. PeerJ 10:e12868 https://doi.org/10.7717/peerj.12868
date submitted: 2021-08-30
date accepted: 2022-01-10
issued: 2022-02-10
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Yokota
  given name: Mika
author list: Agent
  family name: Guan
  given name: Yupeng
author list: Agent
  family name: Fan
  given name: Yi
author list: Agent
  family name: Zhang
  given name: Ximei
author list: Agent
  family name: Yang
  given name: Wei
doi: 10.7717/peerj.12868
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-10
copyright: ©2022 Yokota et al.
attribution name: Yokota et al.

Determinants of quality of life and well-being in cognitively unimpaired older adults: a systematic review
type: item
type: AcademicArticle
description: Objective It is important to know the psychological variables that are related to quality of life and well-being in healthy elderly people. The main objective of the present review is to analyse which factors, through psychological variables, are determinant on the adaptive processes that acquire relevance in the last stage of life. Data sources An electronic search was conducted in WOS, Science Direct, PsycARTICLES, Psychology Database and Psycinfo. Study selection The search terms used were derived from the combination of the following search string: ((“Emotional Factors” OR “Emotional Effects”) AND (“Emotional Intelligence” OR “Emotional Regulation”) AND (“Quality of Life” OR “Personal Satisfaction”) AND (“Healthy Old People” OR “Healthy Old Adults”) AND (“Healthy Aging” OR “Successful Aging”)). Data extraction 11th April 2021. Data synthesis In total, 13 articles were selected. Conclusions The articles showed the importance of social support, proactive coping strategies (emotional regulation) and emotional intelligence as key factors in the elderly population for their positive influence on variables such as quality of life and well-being. Prospero ID: CRD42021224789
format: application/pdf
format: text/html
creator: María Dolores Frías-Luque
creator: Abel Toledano-González
subject: Geriatrics
subject: Psychiatry and Psychology
subject: Rehabilitation
description: doi:10.7717/peerj.12900
publisher: PeerJ Inc.
rights: © 2022 Frías-Luque and Toledano-González
abstract: Objective It is important to know the psychological variables that are related to quality of life and well-being in healthy elderly people. The main objective of the present review is to analyse which factors, through psychological variables, are determinant on the adaptive processes that acquire relevance in the last stage of life. Data sources An electronic search was conducted in WOS, Science Direct, PsycARTICLES, Psychology Database and Psycinfo. Study selection The search terms used were derived from the combination of the following search string: ((“Emotional Factors” OR “Emotional Effects”) AND (“Emotional Intelligence” OR “Emotional Regulation”) AND (“Quality of Life” OR “Personal Satisfaction”) AND (“Healthy Old People” OR “Healthy Old Adults”) AND (“Healthy Aging” OR “Successful Aging”)). Data extraction 11th April 2021. Data synthesis In total, 13 articles were selected. Conclusions The articles showed the importance of social support, proactive coping strategies (emotional regulation) and emotional intelligence as key factors in the elderly population for their positive influence on variables such as quality of life and well-being. Prospero ID: CRD42021224789
bibliographic citation: Frías-Luque et al. (2022) Determinants of quality of life and well-being in cognitively unimpaired older adults: a systematic review. PeerJ 10:e12900 https://doi.org/10.7717/peerj.12900
date submitted: 2021-07-15
date accepted: 2022-01-17
issued: 2022-02-10
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Frías-Luque
  given name: María Dolores
author list: Agent
  family name: Toledano-González
  given name: Abel
doi: 10.7717/peerj.12900
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-10
copyright: © 2022 Frías-Luque and Toledano-González
attribution name: Frías-Luque and Toledano-González

The effect of farmland on the surface water of the Aral Sea Region using Multi-source Satellite Data
type: item
type: AcademicArticle
description: Background The improper land utilization has brought tremendous pressure on the surface water of the Aral Sea Region in the past decades. It was seriously hindered for construction of the Green Silk Road Economic Belt by the fragile environment. Therefore, it is of great necessity for environmental protection and social development to monitor the change of surface water in the Aral Sea Region. Methods In this study, LandTrendr algorithm was used on Landsat time-series data to characterize the change in farmland on the Google Earth Engine platform. Based on multi-source data, the water area changes of the Aral Sea were extracted based on the Google Earth Engine, and the mean method was utilized to extract the changes in water level and water storage. Finally, a water-farmland coupling degree model was utilized to evaluate the impact of farmland changes on the surface water in the Aral Sea Region. Results As a result, the change of farmland is as follows: the farmland area of the Aral Sea Region has abandoned 3,129 km2 from 1987 to 2019, with overall accuracy of 85.3%. The farmland change had increased the drainage downstream of the Amu Darya River and the Syr Darya River. It has led area of the Aral Sea to decrease each year continuously. The area of the Aral Sea shrank by 1,606.36 km2 per year from 1987 to 2019. Furthermore, Aral Sea’s water level decreased by 0.13 m per year from 2003 to 2009. The amount of water storage in the Aral Sea Region also showed a downward trend from 2002 to 2016. There was a high-quality coupling coordination 0.903 relationship between surface water and farmland. It will increase the burden of water for people’s normal daily life by the water loss resources caused by abandoned farmland. This study emphasized threat of unreasonable farmland management to surface water of the Aral Sea Region. The findings contributed for decision makers to formulating effective reasonable policies to protect surface water and use land of the Aral Sea Regio…
format: application/pdf
format: text/html
creator: Jiancong Shi
creator: Qiaozhen Guo
creator: Shuang Zhao
creator: Yiting Su
creator: Yanqing Shi
subject: Agricultural Science
subject: Plant Science
subject: Coupled Natural and Human Systems
subject: Natural Resource Management
subject: Spatial and Geographic Information Science
description: doi:10.7717/peerj.12920
publisher: PeerJ Inc.
rights: © 2022 Shi et al.
abstract: Background The improper land utilization has brought tremendous pressure on the surface water of the Aral Sea Region in the past decades. It was seriously hindered for construction of the Green Silk Road Economic Belt by the fragile environment. Therefore, it is of great necessity for environmental protection and social development to monitor the change of surface water in the Aral Sea Region. Methods In this study, LandTrendr algorithm was used on Landsat time-series data to characterize the change in farmland on the Google Earth Engine platform. Based on multi-source data, the water area changes of the Aral Sea were extracted based on the Google Earth Engine, and the mean method was utilized to extract the changes in water level and water storage. Finally, a water-farmland coupling degree model was utilized to evaluate the impact of farmland changes on the surface water in the Aral Sea Region. Results As a result, the change of farmland is as follows: the farmland area of the Aral Sea Region has abandoned 3,129 km2 from 1987 to 2019, with overall accuracy of 85.3%. The farmland change had increased the drainage downstream of the Amu Darya River and the Syr Darya River. It has led area of the Aral Sea to decrease each year continuously. The area of the Aral Sea shrank by 1,606.36 km2 per year from 1987 to 2019. Furthermore, Aral Sea’s water level decreased by 0.13 m per year from 2003 to 2009. The amount of water storage in the Aral Sea Region also showed a downward trend from 2002 to 2016. There was a high-quality coupling coordination 0.903 relationship between surface water and farmland. It will increase the burden of water for people’s normal daily life by the water loss resources caused by abandoned farmland. This study emphasized threat of unreasonable farmland management to surface water of the Aral Sea Region. The findings contributed for decision makers to formulating effective reasonable policies to protect surface water and use land of the Aral Sea Regio…
bibliographic citation: Shi et al. (2022) The effect of farmland on the surface water of the Aral Sea Region using Multi-source Satellite Data. PeerJ 10:e12920 https://doi.org/10.7717/peerj.12920
date submitted: 2021-07-30
date accepted: 2022-01-20
issued: 2022-02-10
is part of: PeerJ
license: https://creativecommons.org/licenses/by/4.0/
author list: Agent
  family name: Shi
  given name: Jiancong
author list: Agent
  family name: Guo
  given name: Qiaozhen
author list: Agent
  family name: Zhao
  given name: Shuang
author list: Agent
  family name: Su
  given name: Yiting
author list: Agent
  family name: Shi
  given name: Yanqing
doi: 10.7717/peerj.12920
volume: 10
issn: 2167-8359
publication name: PeerJ
publication date: 2022-02-10
copyright: © 2022 Shi et al.
attribution name: Shi et al.

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