title: PeerJ
description:  Articles published in PeerJ
link: https://peerj.com/articles/index.rss3?journal=peerj&page=501
creator: info@peerj.com PeerJ
errorsTo: info@peerj.com PeerJ
language: en

title: The cytotoxicity effect of 7-hydroxy-3,4-dihydrocadalene from Heterotheca inuloides and semisynthetic cadalenes derivates towards breast cancer cells: involvement of oxidative stress-mediated apoptosis
link: https://peerj.com/articles/15586
last-modified: 2023-06-20
description: BackgroundHeterotheca inuloides, traditionally employed in Mexico, has demonstrated anticancer activities. Although it has been proven that the cytotoxic effect is attributed to cadinane-type sesquiterpenes such as 7-hydroxy-3,4-dihydrocadalene, the mechanism of action by which these agents act in tumor lines and their regulation remain unknown. This study was undertaken to investigate for first time the cytotoxic activity and mechanism of action of 7-hydroxy-3,4-dihydrocadalene and two semi-synthetic cadinanes derivatives towards breast cancer cells.MethodsCell viability and proliferation were assayed by thiazolyl blue tetrazolium bromide (MTT) assay and Trypan blue dye exclusion assay. Cell migration measure was tested by wound-healing assay. Moreover, the reactive oxygen species (ROS) and lipid peroxidation generation were measured by 2′,7′-dichlorofluorescein diacetate (DCFH-DA) assay and thiobarbituric acid reactive substance (TBARS) assay, respectively. Furthermore, expression of caspase-3, Bcl-2 and GAPDH were analyzed by western blot.ResultsThe results showed that 7-hydroxy-3,4-dihydrocadalene inhibited MCF7 cell viability in a concentration and time dependent manner. The cytotoxic potency of semisynthetic derivatives 7-(phenylcarbamate)-3,4-dihydrocadalene and 7-(phenylcarbamate)-cadalene was remarkably lower. Moreover, in silico studies showed that 7-hydroxy-3,4-dihydrocadalene, and not so the semi-synthetic derivatives, has optimal physical-chemical properties to lead a promising cytotoxic agent. Further examination on the action mechanism of 7-hydroxy-3,4-dihydrocadalene suggested that this natural product exerted cytotoxicity via oxidative stress as evidenced in a significantly increase of intracellular ROS levels and in an induction of lipid peroxidation. Furthermore, the compound increased caspase-3 and caspase-9 activities and slightly inhibited Bcl-2 levels. Interestingly, it also reduced mitochondrial ATP synthesis and induced mitochondrial uncoupling.ConclusionTaken together, 7-hydroxy-3,4-dihydrocadalene is a promising cytotoxic compound against breast cancer via oxidative stress-induction.
creator: Alan Mendoza-Fuentes
creator: Elena González-Burgos
creator: Omar Emiliano Aparicio Trejo
creator: Guillermo Delgado-Lamas
creator: José Luis Rodríguez-Chávez
creator: José Pedraza-Chaverri
creator: M. Pilar Gómez-Serranillos
creator: Daniela Araiza-Olivera
uri: https://doi.org/10.7717/peerj.15586
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2023 Mendoza-Fuentes et al.

title: C/EBPα involvement in microglial polarization via HDAC1/STAT3 pathway aggravated sevoflurane-induced cognitive impairment in aged rats
link: https://peerj.com/articles/15466
last-modified: 2023-06-19
description: BackgroundPostoperative cognitive dysfunction (POCD) is a clinically frequent postoperative complication in the elderly, which is mainly manifested by the occurrence of cognitive dysfunction after anesthetized surgery in patients. To explore the involvement of C/EBPα in microglial polarization in sevoflurane anesthesia induced cognitive impairment in aged rats.MethodsSprague-Dawley (SD) rats were anesthetized by inhalation of 3% sevoflurane for 6 h to establish the POCD model. The histopathological structure of hippocampus was observed by hematoxylin and eosin (HE) staining. Associative learning and memory function and spatial learning and memory function were assessed by conditioned fear test and water maze test. The concentrations of inflammatory factors in the hippocampus were measured by ELISA. The levels of microglial activation marker (Iba1) and microglial M1 (CD86) and M2 (CD206) polarization markers were determined by immunofluorescence staining and RT-qPCR, respectively. The transcriptional regulation of HDAC1 by C/EBPα was confirmed by dual luciferase reporter assay and ChIP assay.ResultsSevoflurane-induced pathomorphological damage in the hippocampal tissue of aged rats, accompanied by elevated expression of C/EBPα. Silencing of C/EBPα alleviated hippocampal histopathological injury, inhibited M1 microglial activation and the expression of M1 marker CD86, enhanced the expression of M2 marker CD206. C/EBPα transcriptionally activated HDAC1. Knockdown of C/EBPα downregulated the expression of HDAC1 and STAT3 phosphorylated proteins, which inhibited the pro-inflammatory factors (IL-6 and TNF-α) and accelerated anti-inflammatory factors (IL-10 and TGF-β) secretion. In addition, silencing of C/EBPα caused rats to have a delayed freezing time in contextual conditioned fear, a shorter escape latency, and an increased number of platform crossings.ConclusionInhibition of C/EBPα promotes the M2 polarization of microglia and reduces the production of pro-inflammatory cytokines to alleviate the cognitive dysfunction of sevoflurane-induced elderly rats by HDAC1/STAT3 pathway.
creator: Zhao Xu
creator: Xi Yao
creator: Yikang Zhao
creator: Bo Yao
uri: https://doi.org/10.7717/peerj.15466
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2023 Xu et al.

title: Phylogenetic diversity and the structure of host-epiphyte interactions across the Neotropics
link: https://peerj.com/articles/15500
last-modified: 2023-06-19
description: Understanding the mechanisms driving community assembly has been a major focus of ecological research for nearly a century, yet little is known about these mechanisms in commensal communities, particularly with respect to their historical/evolutionary components. Here, we use a large-scale dataset of 4,440 vascular plant species to explore the relationship between the evolutionary distinctiveness (ED) (as measured by the ’species evolutionary history’ (SEH)) of host species and the phylogenetic diversity (PD) of their associated epiphyte species. Although there was considerable variation across hosts and their associated epiphyte species, they were largely unrelated to host SEH. Our results mostly support the idea that the determinants of epiphyte colonization success might involve host characteristics that are unrelated to host SEH (e.g., architectural differences between hosts). While determinants of PD of epiphyte assemblages are poorly known, they do not appear to be related to the evolutionary history of host species. Instead, they might be better explained by neutral processes of colonization and extinction. However, the high level of phylogenetic signal in epiphyte PD (independent of SEH) suggests it might still be influenced by yet unrecognized evolutionary determinants. This study highlights how little is still known about the phylogenetic determinants of epiphyte communities.
creator: Marcio R. Pie
creator: Fernanda S. Caron
creator: Thom Dallimore
creator: Helena Einzmann
creator: Peter Hietz
creator: Michael Kessler
creator: Flavio Nunes Ramos
creator: João Pedro Costa Elias
creator: Holger Kreft
creator: Thorsten Krömer
creator: Maria Judith Carmona Higuita
creator: Daniel Zuleta
creator: Giesta Machado
creator: André Luís de Gasper
creator: Gerhard Zotz
creator: Glenda Mendieta Leiva
creator: Derio Antonio Jimenez-Lopez
creator: Alex Fernando Mendes
creator: Pedro Brancalion
creator: Sara Mortara
creator: Christopher Thomas Blum
creator: Mariana Victória Irume
creator: Nayely Martínez-Meléndez Nayely
creator: Ana Maria Benavides
creator: Carlos Renato Boelter
creator: Sven Batke
uri: https://doi.org/10.7717/peerj.15500
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2023 Pie et al.

title: Identifying successful combinations by fertility index in old garden roses and hybrid tea roses crosses
link: https://peerj.com/articles/15526
last-modified: 2023-06-19
description: The success of rose breeding programs is low due to poor seed sets and germination rates. Determining fertile parents and cross combinations that show high compatibility could increase the effectiveness of breeding programs. In this study, three rose varieties belonging to Rosa × hybrida (Jumilia, First Red and Magnum), and two old garden rose species (Black Rose and Cabbage Rose) with known ploidy levels were reciprocally crossbred under controlled conditions to determine the successful crosses by checking fertility. The pollen germination rate (PG), crossability rate (CR), seed number per fruit (SNpF), seed production efficiency (SPE), seed germination rate (SGR), fruit weight (FW), seed weight (SW) and stigma number (SiN), etc. were recorded. Comprehensive fertility index value was calculated. Principal component analysis (PCA), correlation matrix, and hierarchical heat map were used to evaluate the data. The findings showed that old garden roses had more viable pollen than hybrid tea roses. The crossing success improved as pollen fertility increased. Also, female parent fertility improved crossing success just as much as pollen fertility. Although the pollen fertility and stigma numbers were low, some combinations had higher CR and SPE. The maximum SPE (from 8.67% to 19.46%) was determined in combinations where Black Rose was the female parent despite the lower stigma number and low pollen fertility. The highest CR was recorded in Black Rose × First Red (94.36%). All combinations in which Black Rose was used as the female parent had a more stable CR. The SNpF of combinations where hybrid rose varieties were female parents and old garden roses were pollen parents was higher than other combinations where hybrid rose varieties were both female and pollen parents. The SPE in intraspecific crosses was lower than that obtained from interspecific crosses. Moreover, the SGR decreased in combinations that produced heavier seeds. The results suggested that SPE is a more accurate parameter than SNpF in demonstrating combination success in breeding programs. Black Rose × First Red, Black Rose × Jumilia, Black Rose × Magnum and Black Rose × Cabbage Rose combinations can be used successfully as the PCA and heat map showed. Black Rose showed better performance as both seed and pollen parents according to the comprehensive fertility index. From the correlation matrix, it is understood that the number of stigmas cannot be an important criterion in parent selection. Old garden roses can be used as parents to increase the success of breeding programs. However, it is necessary to reveal how successful they are in transferring desired characteristics such as scent, petal number, and color.
creator: Tuğba Kılıç
uri: https://doi.org/10.7717/peerj.15526
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2023 Kılıç

title: Effects of disturbances and environmental changes on an aridland riparian generalist
link: https://peerj.com/articles/15563
last-modified: 2023-06-19
description: Anthropogenic climate change and ecosystem disturbances can detrimentally affect habitats and species. Areas with concentrated biodiversity, such as aridland riparian zones, often yield the greatest number of vulnerable species. A better understanding of ecological and environmental relationships can guide more effective conservation strategies. We used both visual transects and external (tape) radio telemetry to study the behavioral and spatial ecology of black-necked gartersnakes (Thamnophis cyrtopsis; n = 81)—a dietary generalist yet aquatic habitat specialist—in a heterogenous aridland riparian zone of lower Sabino Canyon, Tucson, Arizona, between 2018 and 2021. Our objectives were to (1) understand how extrinsic conditions influence population ecology dynamics, including immediately prior to and after major disturbances and environmental extremes; (2) analyze behavioral activity and microhabitat usage in relation to environmental factors; and (3) assess the efficacy of a less-invasive telemetry strategy. Between late spring 2020 and early summer 2021, ecosystem disturbances included near-record heat and drought, wildfire, and low overwinter precipitation. Many aquatic habitats either completely dried or were spatially disjunct; gartersnake prey species were noticeably sparse. Extreme drought rapidly shifted to excessive flooding during the 2021 monsoon that brought above-average streamflow magnitude and duration. Between 2019 and 2021, we observed a dramatic decline in T. cyrtopsis; odds of detection reduced by 92.8% (CI [56.0–99.1%]). Strong spatiotemporal links relative to the extent and timing of available surface water appear important. Prior to the onset of monsoonal stream recharge in early summer, shallow and drying aquatic habitats are used as parturition sites and foraging grounds; all age classes took advantage to corral fishes trapped in isolated and shrinking pools. Ambient conditions had varying effects on gartersnake behaviors. Variation in microhabitat assemblages occurred with distance from water, activity level, and developmental age class. Interestingly, associations remained consistent across seasons and years, which suggests a reliance on heterogenous habitat structure. Sampling techniques complemented each other, however, bioclimatic parameters rendered limitations and should be considered in methodological decisions. Overall, disadvantageous responses to major disturbances and climatic extremes by a presumably adaptable generalist like T. cyrtopsis are concerning. Insights from long-term monitoring of responses by common yet environmentally sensitive species such as T. cyrtopsis may serve to more broadly highlight demographic challenges that other taxa with similar semi-aquatic life histories may face in changing systems. Such information could inform more effective conservation management strategies in warming and drying ecosystems.
creator: Brian R. Blais
creator: Samantha L. Johnson
creator: John L. Koprowski
uri: https://doi.org/10.7717/peerj.15563
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2023 Blais et al.

title: The impact of sanctuary visits on children’s knowledge and attitudes toward primate welfare and conservation
link: https://peerj.com/articles/15074
last-modified: 2023-06-16
description: Primate sanctuaries provide a solution for the increasing number of primates being taken from their home countries to support the demands of the illegal pet trade. To help end the primate trade and raise awareness about the risks this trade poses to delicate ecosystems, sanctuaries are increasingly developing conservation education programs. Education and raising awareness must be one of the primary roles of primate sanctuaries. However, there are few evaluations of the impacts of conservation education programs for school children published in scientific literature. To address this gap, we conducted an evaluation of educator-led visits of school children at Fundació Mona, a primate sanctuary located in Catalunya, Spain. Questionnaires for an experimental and control group were conducted with 3,205 school children, ages 8 to 18 from 83 different schools, to evaluate changes in their attitudes and knowledge of primate welfare and conservation. We found that Fundació Mona’s program of environmental activities had a positive impact on children, both female and male students, in terms of attitudes and knowledge of primate welfare and conservation. Although female students gave better responses regarding welfare and conservation, all children showed gains in pro-conservation responses. This study demonstrates that environmental education activities focused on children can help shape a change in knowledge and attitudes toward primate welfare and conservation. Educator-led visits of school children to primate sanctuaries such as Fundació Mona can also serve to amplify biodiversity conservation messages among children and their families. We encourage primate sanctuaries to promote empirical studies of attitudes and knowledge of primate welfare and conservation and to conduct systematical evaluations to strengthen their educational activities.
creator: Olga Feliu
creator: Arturo González-Zamora
creator: David Riba
creator: Teresa Sauquet
creator: Sònia Sánchez-López
creator: Carmen Maté
uri: https://doi.org/10.7717/peerj.15074
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2023 Feliu et al.

title: Diverse migration patterns and seasonal habitat use of Stone’s sheep (Ovis dalli stonei)
link: https://peerj.com/articles/15215
last-modified: 2023-06-16
description: We describe temporal and spatial patterns of seasonal space-use and migration by 16 GPS-collared Stone’s sheep (Ovis dalli stonei) from nine bands in the Cassiar Mountains of northern British Columbia, Canada. Our objectives were to identify the timing of spring and fall migrations, characterize summer and winter ranges, map and describe migration routes and use of stopover sites, and document altitudinal change across seasons. Our last objective was to assess individual migration strategies based on patterns of geographic migration, altitudinal migration, or residency. Median start and end dates of the spring migration were 12 and 17 Jun (range: 20 May to 05 Aug), and of the fall migration were 30 Aug and 22 Sep (range: 21 Aug to 07 Jan). The median area of winter and summer ranges for geographic migrants were 630.8 ha and 2,829.0 ha, respectively, with a broad range from about 233.6 to 10,196.2 ha. Individuals showed high fidelity to winter ranges over the limited duration of the study. The winter and summer ranges of most individuals (n = 15) were at moderate to high elevations with a median summer elevation of 1,709 m (1,563–1,827 m) and 1,673 m (1,478–1,751 m) that varied <150 m between ranges. Almost all collared females (n = 14) exhibited changes in elevation use that coincide with abbreviated altitudinal migration. Specifically, these females descended to lower spring elevations from their winter range (Δ > 150 m), and then gradually moved up to higher-elevation summer ranges (Δ > 150 m). In the fall, they descended to lower elevations (Δ > 100 m) before returning to their higher winter ranges. The median distance travelled along geographic migration routes was 16.3 km (range: 7.6–47.4 km). During the spring migration, most geographic migrants (n = 8) used at least one stopover site (median = 1.5, range: 0–4), while almost all migrants (n = 11) used stopover sites more frequently in the fall (median = 2.5, range: 0–6). Of the 13 migratory individuals that had at least one other collared individual in their band, most migrated at about the same time, occupied the same summer and winter ranges, used similar migration routes and stopover sites, and exhibited the same migration strategy. We found collared females exhibited four different migration strategies which mostly varied across bands. Migration strategies included long-distance geographic migrants (n = 5), short-distance geographic migrants (n = 5), vacillating migrants (n = 2), and abbreviated altitudinal migrants (n = 4). Different migratory strategies occurred within one band where one collared individual migrated and two did not. We conclude that female Stone’s sheep in the Cassiar Mountains displayed a diverse assemblage of seasonal habitat use and migratory behaviors. By delineating seasonal ranges, migration routes and stopover sites, we identify potential areas of priority that can help inform land-use planning and preserve the native migrations of Stone’s sheep in the region.
creator: Grace E. Enns
creator: Bill Jex
creator: Mark S. Boyce
uri: https://doi.org/10.7717/peerj.15215
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2023 Enns et al.

title: Physiologic effects of surgical masking in children versus adults
link: https://peerj.com/articles/15474
last-modified: 2023-06-16
description: BackgroundSurgical masks remain a focal part of the CDC guidelines to decrease COVID-19 transmission. Evidence refuting significant effects of masking on ventilation is mostly limited to small studies, with a paucity of studies on children, and none comparing children to adults.MethodsA total of 119 subjects were enrolled (71 adults, 49 children) in a prospective interventional study with each subject serving as their own mask-free control. End tidal CO2 (ETCO2), inspired CO2 (ICO2), and respiratory rate were measured by nasal cannula attached to an anesthesia machine D-fend module. Pulse oximetry and heart rate were also followed. After the mask-free period, an ASTM Level 3 disposable surgical mask was donned and 15 min of mask-worn data were collected.ResultsA steady state was confirmed for ETCO2 and ICO2 over the masked period, and mean ICO2 levels rose significantly (p < 0.001) after masking in all age groups. The increase in ICO2 for the 2- to 7-year-old group of 4.11 mmHg (3.23–4.99), was significantly higher (p < 0.001) than the final ΔICO2 levels for both the 7- to 14-year-old group, 2.45 mmHg (1.79–3.12), and adults, 1.47 mmHg (1.18–1.76). For the pediatric group there was a negative, significant correlation between age and ΔICO2, r = −0.49, p < 0.001. Masking resulted in a statistically significant (p < 0.01) rise in ETCO2 levels of 1.30 mmHg in adults and 1.36 mmHg in children. The final respective ETCO2 levels, 34.35 (33.55–35.15) and 35.07 (34.13–36.01), remained within normal limits. Pulse oximetry, heart rate, and respiratory rate were not significantly affected.DiscussionThe physiology of mechanical dead space is discussed, including the inverse relationship of subject age vs ICO2. The methodology and results are compared to previously published studies which detracted from the physiologic safety of surgical masking.ConclusionsThe wearing of a surgical mask results in a statistically significant rise in ICO2 and a smaller rise in ETCO2. Because ETCO2 and other variables remain well within normal limits, these changes are clinically insignificant.
creator: J Patrick Brooks
creator: Jill Layman
creator: Jessica Willis
uri: https://doi.org/10.7717/peerj.15474
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2023 Brooks et al.

title: Weighted multiple testing procedures in genome-wide association studies
link: https://peerj.com/articles/15369
last-modified: 2023-06-15
description: Multiple testing procedures controlling the false discovery rate (FDR) are increasingly used in the context of genome wide association studies (GWAS), and weighted multiple testing procedures that incorporate covariate information are efficient to improve the power to detect associations. In this work, we evaluate some recent weighted multiple testing procedures in the specific context of GWAS through a simulation study. We also present a new efficient procedure called wBHa that prioritizes the detection of genetic variants with low minor allele frequencies while maximizing the overall detection power. The results indicate good performance of our procedure compared to other weighted multiple testing procedures. In particular, in all simulated settings, wBHa tends to outperform other procedures in detecting rare variants while maintaining good overall power. The use of the different procedures is illustrated with a real dataset.
creator: Ludivine Obry
creator: Cyril Dalmasso
uri: https://doi.org/10.7717/peerj.15369
license: https://creativecommons.org/licenses/by/4.0/
rights: ©2023 Obry et al.

title: Development of the first high-density linkage map in the maize weevil, Sitophilus zeamais
link: https://peerj.com/articles/15414
last-modified: 2023-06-15
description: The maize weevil, Sitophilus zeamais, is a worldwide pest that disproportionately affects subsistence farmers in developing countries. Damage from this pest threatens food security in these communities as widely available and effective control methods are lacking. With advances over the last decade in the development of genetic pest management techniques, addressing pest issues at the ecosystem level as opposed to the farm level may be a possibility. However, pest species selected for genetic management techniques require a well-characterized genome and few genomic tools have been developed for S. zeamais. Here, we have measured the genome size and developed the first genetic linkage map for this species. The genome size was determined using flow cytometry as 682 Mb and 674 Mb for females and males, respectively. The linkage map contains 11 linkage groups, which correspond to the 10 autosomes and 1 X-chromosome found in the species and it contains 1,121 SNPs. This linkage map will be useful for assembling a complete genome for S. zeamais.
creator: Jennifer Fountain Baltzegar
creator: Fred Gould
uri: https://doi.org/10.7717/peerj.15414
license: https://creativecommons.org/licenses/by/4.0/
rights: © 2023 Baltzegar and Gould