title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=591 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Assessing factors influencing students’ perceptions towards animal species conservation link: https://peerj.com/articles/14553 last-modified: 2023-01-09 description: BackgroundThe way humans perceive and interact with non-human animals is particular to each person, from antipathetic interactions evidenced by fear, aversion or repulsion, to empathy evidenced by feelings of affection, enchantment and interest in the animal. In this sense, herein we investigated the perception of university students about species belonging to different classes of wild vertebrates and the influence of social and educational factors on that.MethodsData were obtained through online forms answered by 700 university students from nine Brazilian states, 328 females and 372 males, aged between 18 and 65 years. The form had eight sentences to be answered in relation to 17 species of wild vertebrates. The agreement level for each of these sentences was to be indicated using a five-point Likert scale. The sentences were designed to assess aesthetic, risk, utilitarian, and preservation perceptions attributed to each species by students.ResultsWe found that species perceived as useful by the students are generally also perceived as beautiful and as those that should be preserved. On the other hand, we found similarity between the species perceived as ugly and those that should not be preserved; and between the species perceived as harmful and those considered dangerous. Female and lower-income students more often agree that animals are harmful. We found that perceptions of danger in relation to animals were predominantly associated with younger respondents. However, this did not lead to less support for conservation among these students, as students of all age groups agree that species should be preserved. Our results show that students’ knowledge area was an important predictor associated with empathetic and antipathetic perceptions. Environmental area students showed greater empathy in all analyzed categories (beauty, usefulness, harmlessness, and preservation) than non-environmental areas students. On the other hand, students from the area of the exact sciences showed greater dislike in all analyzed categories than students from other areas. We found a strong relationship between the areas “Environmental” and “Humanities, Languages and Arts” for the attitudinal factors associated with utility and preservation, suggesting a similar empathetic worldview for students in these areas.ConclusionsWe found that the perception directed towards wild vertebrates varies according to the gender, age, income and study area of the students, in addition to the taxon considered. Finally, our results indicate that negative perceptions should be taken into account in environmental education efforts, educational policies and in planning fauna conservation plans which should incorporate the most diverse audiences, and not only encompass charismatic species but extend to animals that arouse great aversion from the part of people. creator: Heliene Mota Pereira creator: Franciany Braga-Pereira creator: Luane Maria Melo Azeredo creator: Luiz Carlos Serramo Lopez creator: Rômulo Romeu Nóbrega Alves uri: https://doi.org/10.7717/peerj.14553 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2023 Mota Pereira et al. title: Differences in histomorphology and expression of key lipid regulated genes of four adipose tissues from Tibetan pigs link: https://peerj.com/articles/14556 last-modified: 2023-01-09 description: Tibetan pigs, an indigenous pig breed in China, have high overall fat deposition and flavorful and tasty meat. They are thus good models for studying adipogenesis. Few studies have been conducted focusing on expression of lipid regulated genes in different adipose tissues of Tibetan pigs. Therefore, we compared the difference of histomorphology and expression level of lipid regulated genes through qPCR and western blot in subcutaneous fat, perirenal fat, omental adipose tissue, and inguinal fat of Tibetan pigs. Our results showed that the area of subcutaneous adipocytes in Tibetan pigs was smaller, while the other three adipose tissues (perirenal fat, greater omentum fat, inguinal fat) had cell areas of similar size. The gene expression of FABP4, FASN, FABP3, and ME1 in subcutaneous fat was significantly higher than that in perirenal fat. Furthermore, the protein expression of FABP4 was significantly lower in subcutaneous fat than in perirenal fat (p < 0.05), and the expression of FASN was higher in greater omentum fat than in subcutaneous fat (p = 0.084). The difference in adipocyte cell size and expression of lipid-regulated genes in adipose tissues from the various parts of the pig body is likely due to the different cellular lipid metabolic processes. Specially, FABP4 and FASN may be involved in the regulation of fat deposition in different adipose tissues of Tibetan pigs. creator: Chenghong Lin creator: Zexia Dong creator: Jia Song creator: Sutian Wang creator: Ying Yang creator: Hua Li creator: Zheng Feng creator: Yangli Pei uri: https://doi.org/10.7717/peerj.14556 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2023 Lin et al. title: The effects of soil drought stress on growth characteristics, root system, and tissue anatomy of Pinus sylvestris var. mongolica link: https://peerj.com/articles/14578 last-modified: 2023-01-09 description: The main purpose of this study was to study the changes in growth, root system, and tissue anatomical structure of Pinus sylvestris var. mongolica under soil drought conditions. In this study, the growth indexes and photosynthesis of P. sylvestris var. mongolica seedlings under soil drought stress were studied by pot cultivation. Continuous pot water control experiment of the indoor culture of P. sylvestris var. mongolica was carried out, ensuring that the soil water content of each treatment reached 80%, 40%, and 20% of the field moisture capacity as control, moderate drought and severe drought, respectively. The submicroscopic structures of the needles and roots were observed using a scanning electron microscope and a transmission electron microscope. The response of soil roots to drought stress was studied by root scanning. Moderate drought stress increased needle stomatal density, while under severe drought stress, stomatal density decreased. At the same time, the total number of root tips, total root length, root surface area, and root volume of seedlings decreased with the deepening of the drought. Furthermore, moderate drought and severe drought stress significantly reduced the chlorophyll a and chlorophyll b content in P. sylvestris var. mongolica seedlings compared to the control group. The needle cells were deformed and damaged, and chloroplasts and mitochondria were damaged, gradually disintegrated, and the number of osmiophiles increased. There was also an increase in nuclear vacuolation. creator: Fanjun Meng creator: Tianze Zhang creator: Dachuan Yin uri: https://doi.org/10.7717/peerj.14578 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2023 Meng et al. title: Eight single nucleotide polymorphisms and their association with food habit domestication traits and growth traits in largemouth bass fry (Micropterus salmoides) based on PCR-RFLP method link: https://peerj.com/articles/14588 last-modified: 2023-01-09 description: BackgroundThe largemouth bass (Micropterus salmoides), an economically important freshwater fish species widely farmed in China, is traditionally cultured using a diet of forage fish. However, given the global decline in forage fish fisheries and increasing rates of waterbody pollution and disease outbreaks during traditional culturing, there is a growing trend of replacing forage fish with formulated feed in the largemouth bass breeding industry. The specific molecular mechanisms associated with such dietary transition in this fish are, nevertheless, poorly understood.MethodsTo identify single nucleotide polymorphisms (SNPs) related to food habit domestication traits and growth traits in largemouth bass fry, we initially genotyped fry using eight candidate SNPs based on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, with genetic parameters being determined using Popgen32 and Cervus 3.0. Subsequently, we assessed the associations between food habit domestication traits of largemouth bass fry and these SNPs using the Chi-square test or Fisher’s exact test. Furthermore, we used a general linear model to assess the relationships between the growth traits of largemouth bass fry and these SNPs. The Pearson correlation coefficient between growth traits and the SNPs was also determined using bivariate correlation analysis in IBM SPSS Statistics 22. Finally, the phenotypic variation explained (PVE) by the SNPs was calculated by regression analysis in Microsoft Excel.ResultsThe genotyping results obtained based on PCR-RFLP analysis were consistent with those of direct sequencing. Five SNPs (SNP01, SNP02, SNP04, SNP05, and SNP06) were found to be significantly correlated with the food habit domestication traits of fry (P < 0.05); SNP01 (P = 0.0011) and SNP04 (P = 0.0055) particularly, had showed highly significant associations. With respect to growth traits, we detected significant correlations with the two SNPs (SNP01 and SNP07) (P < 0.05), with SNP01 being significantly correlated with body length, and height (P < 0.05), and SNP07 being significantly correlated with body height only (P < 0.05).ConclusionsOur findings indicated that the PCR-RFLP can be used as a low-cost genotyping method to identify SNPs related to food habit domestication and growth traits in largemouth bass, and that these trait-related SNPs might provide a molecular basis for the future breeding of new varieties of largemouth bass. creator: Jiao Cui creator: Zhou Jiang creator: Zerui Wang creator: Jiaqi Shao creator: Chuanju Dong creator: Lei Wang creator: Xuejun Li creator: Jinxing Du creator: Shengjie Li creator: Zhigang Qiao creator: Meng Zhang uri: https://doi.org/10.7717/peerj.14588 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2023 Cui et al. title: Novel ethyl p-methoxy cinnamate rich Kaempferia galanga (L.) essential oil and its pharmacological applications: special emphasis on anticholinesterase, anti-tyrosinase, α-amylase inhibitory, and genotoxic efficiencies link: https://peerj.com/articles/14606 last-modified: 2023-01-09 description: BackgroundKaempferia galanga (L.) is one of the prospective therapeutic plants with an aromatic rhizome, and belongs to the Zingiberaceae family. This herb is commonly used by local practitioners in traditional Asian medicine.MethodsIn the present investigation, the novel Kaempferia galanga rhizome essential oil rich in ethyl p-methoxy cinnamate (EMCKG) was evaluated using GC/MS for chemical composition analysis. EMCKG was analyzed for its possible antimicrobial, neurodegenerative inhibitory, acetylcholinesterase, anti-inflammatory, and antioxidant activities as well as for the genotoxic effects using the standard methodologies. ANOVA and post hoc was performed to test the statistical significance of the study.ResultsGC/MS analysis identified ethyl p-methoxy cinnamate as the major component of EMCKG essential oil with an area percentage of 66.39%. The EMCKG exhibited moderate (DPPH assay IC50 = 15.64 ± 0.263 µg/mL; ABTS assay IC50 = 16.93 ± 0.228 µg/mL) antioxidant activity than standard ascorbic acid (DPPH assay IC50 = 21.24 ± 0.413 µg/mL; ABTS assay IC50 = 21.156 ± 0.345 µg/mL). Similarly, EMCKG showed comparable activity in albumin denaturation (IC50 = 2.93 ± 0.59 µg/mL) and protease inhibitor assay (IC50 = 17.143 ± 0.506 µg/mL) to that of standard sodium diclofenac (IC50 = 23.87 ± 0.729 µg/mL and IC50 = 19.18 ± 0.271 µg/mL, respectively). The EMCKG exhibited a dose-dependent antimicrobial activity pattern with the highest inhibitory activity at 500 µg/mL against Staphylococcus aureus and considerable anticholinesterase activities (IC50 = 21.94 ± 0.109 µg/mL) compared to the standard galanthamine (IC50 = 27.18 ± 0.511 µg/mL). EMCKG also showed strong anti-diabetic activity (IC50 = 18.503 ± 0.480 µg/mL) and anti-tyrosinase activity (IC50 = 14.756 ± 0.325 µg/mL) as compared to the standards used (acarbose IC50 = 20.39 ± 0.231 µg/mL and kojic acid IC50 = 17.73 ± 0.192 µg/mL) in the study. Genotoxicity analysis of EMCKG revealed that at 1 µg/mL concentration has no toxic effects in mitosis of Allium cepa roots (Mitotic Index MI = 13.56% and chromosomal aberration CA = 07.60%). The ANOVA confirmed that except for the anticholinesterase activity, there is insignificant difference for essential oil and standards used for all the other bioactivities thus confirming their interchangeable applicability.ConclusionsCurrent research provides the basis for the fact that besides being a rich source of ethyl p-methoxycinnamate, EMCKG has the potential for future formulation and development of an inexpensive skin-care agent and for the preparation of anti-diabetic drugs. creator: Twahira Begum creator: Roktim Gogoi creator: Neelav Sarma creator: Sudin Kumar Pandey creator: Mohan Lal uri: https://doi.org/10.7717/peerj.14606 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2023 Begum et al. title: Exosomes derived from M1 macrophages inhibit the proliferation of the A549 and H1299 lung cancer cell lines via the miRNA-let-7b-5p-GNG5 axis link: https://peerj.com/articles/14608 last-modified: 2023-01-09 description: BackgroundAlmost all cells are capable of secreting exosomes (Exos) for intercellular communication and regulation. Therefore, Exos can be used as a natural therapeutic platform to regulate genes or deliver drugs to treat diseases. M1 macrophages inhibit tumor growth by releasing pro-inflammatory factors. This study explored the applicability of M1 macrophage exosomes (M1-Exos) as gene carriers and the effects on GNG5 protein, and further examined whether macrophage repolarization could inhibit tumor activity.MethodsM0 macrophages were polarized toward M1 using vitexin. Exos were obtained from M1 macrophages by ultra-centrifugation. The transwell non-contact co-culture system was used to co-culture M1 macrophages with HLF-α human lung epithelial cells or A549 or H1299 lung cancer cells. MTT, scratch, and transwell assays were used to detect the cell viability, migration, and invasion ability of cells in the four groups. Flow cytometry was used to detect the apoptosis rate of each group, and western blot (WB) analysis was performed to detect the change in the expression of proliferation- and apoptosis-related proteins. We screened the differentially expressed microRNAs using quantitative polymerase chain reaction technology. Luciferase reporter analysis was performed to explore the interaction between miRNA and protein. We used Xenografted A549 tumors in nude mice to study the effect of M1-Exos on tumor cell growth in vivo.ResultsThe results showed that, under the M1 macrophage co-culture system, lung cancer cell viability, invasion, and migration ability decreased, and the number of apoptotic cells increased, will all indicators being statistically significant (P < 0.05). The expression levels of PCNA, KI67, and Bcl-2 decreased significantly, but that of Bax increased (P < 0.05). Exosomes can have the same effect on tumor cells as M1 macrophages. Exosomes can transport miR-let-7b-5p to tumor cells, and miR-let-7b-5p can inhibit tumor cell proliferation and promote tumor cell apoptosis by regulating the GNG5 protein level.ConclusionsM1-Exos inhibit the proliferation, invasion, and metastasis of lung cancer cells through miRNA-let-7b-5p and GNG5 signaling pathways and inhibit the anti-apoptotic ability of lung cancer cells. creator: Jingcui Peng creator: Sa Li creator: Bin Li creator: WenXia Hu creator: Cuimin Ding uri: https://doi.org/10.7717/peerj.14608 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2023 Peng et al. title: The relationship of low-density lipoprotein cholesterol and all-cause or cardiovascular mortality in patients with type 2 diabetes: a retrospective study link: https://peerj.com/articles/14609 last-modified: 2023-01-09 description: BackgroundThe optimal levels of low-density lipoprotein cholesterol (LDL-C) in patients with type 2 diabetes (T2D) are not currently clear. In this study, we determined the relationship between various mean LDL-C and all-cause or cardiovascular mortality risks in patients with T2D, stratifying by albumin level, age, sex, and antilipid medication use. We also evaluated the association of LDL-C standard deviation (LDL-C-SD) and all-cause and cardiovascular mortality by type of antilipid medication use.MethodsA total of 46,675 T2D patients with a prescription for antidiabetic agents >6 months from outpatient visits (2003–2018) were linked to Taiwan’s National Death Registry to identify all-cause and cardiovascular mortality. The Poisson assumption was used to estimate mortality rates, and the Cox proportional hazard regression model was used to assess the relative hazards of respective mortality in relation to mean LDL-C in patient cohorts by albumin level, age, sex, and antilipid use adjusting for medications, comorbidities, and laboratory results. We also determined the overall, and anti-lipid-specific mortality rates and relative hazards of all-cause and cardiovascular mortality associated with LDL-C-SD using the Poisson assumption and Cox proportional hazard regression model, respectively.ResultsAll-cause and cardiovascular mortality rates were the lowest in T2D patients with a mean LDL-C > 90-103.59 mg/dL in the normal albumin group (≥ 3.5 g/dL). Compared to T2D patients with a mean LDL-C > 90–103.59 mg/dL, those with a mean LDL-C ≤ 77 mg/dL had an elevated risk of all-cause mortality in both the normal and lower albumin groups. T2D patients with a mean LDL-C ≤ 90 and > 103.59–119 mg/dL had relatively higher risk of cardiovascular mortality in the normal albumin group, but in the lower albumin group (<3.5 g/dL), any level of mean LDL-C ≤ 119 mg/dL was not significantly associated with cardiovascular mortality. Increased risks of all-cause and cardiovascular mortality were observed in patients with a mean LDL-C ≤ 77 mg/dL in both sexes and in all age groups except in those aged <50 years, a lower mean LDL-C was not associated with cardiovascular mortality. Similarly, patients with an LDL-C-SD <10th and > 90th percentiles were associated with significant risks of all-cause and cardiovascular mortality. In statin users, but not fibrate users, lower and higher levels of mean LDL-C and LDL-C-SD were both associated with elevated risks of all-cause and cardiovascular mortality.ConclusionsThe optimal level of LDL-C was found to be >90–103.59 mg/dL in T2D patients. Lower and higher levels of mean LDL-C and LDL-C-SD were associated with all-cause and cardiovascular mortality, revealing U-shaped associations. Further studies are necessary to validate the relationship between optimal LDL-C levels and all-cause and cardiovascular mortality in patients with diabetes. creator: Chin-Huan Chang creator: Shu-Tin Yeh creator: Seng-Wei Ooi creator: Chung-Yi Li creator: Hua-Fen Chen uri: https://doi.org/10.7717/peerj.14609 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Chang et al. title: Be positive: customized reference databases and new, local barcodes balance false taxonomic assignments in metabarcoding studies link: https://peerj.com/articles/14616 last-modified: 2023-01-09 description: BackgroundIn metabarcoding analyses, the taxonomic assignment is crucial to place sequencing data in biological and ecological contexts. This fundamental step depends on a reference database, which should have a good taxonomic coverage to avoid unassigned sequences. However, this goal is rarely achieved in many geographic regions and for several taxonomic groups. On the other hand, more is not necessarily better, as sequences in reference databases belonging to taxonomic groups out of the studied region/environment context might lead to false assignments.MethodsWe investigated the effect of using several subsets of a cytochrome c oxidase subunit I (COI) reference database on taxonomic assignment. Published metabarcoding sequences from the Mediterranean Sea were assigned to taxa using COInr, which is a comprehensive, non-redundant and recent database of COI sequences obtained both from BOLD and NCBI, and two of its subsets: (i) all sequences except insects (COInr-WO-Insecta), which represent the overwhelming majority of COInr database, but are irrelevant for marine samples, and (ii) all sequences from taxonomic families present in the Mediterranean Sea (COInr-Med). Four different algorithms for taxonomic assignment were employed in parallel to evaluate differences in their output and data consistency.ResultsThe reduction of the database to more specific custom subsets increased the number of unassigned sequences. Nevertheless, since most of them were incorrectly assigned by the less specific databases, this is a positive outcome. Moreover, the taxonomic resolution (the lowest taxonomic level to which a sequence is attributed) of several sequences tended to increase when using customized databases. These findings clearly indicated the need for customized databases adapted to each study. However, the very high proportion of unassigned sequences points to the need to enrich the local database with new barcodes specifically obtained from the studied region and/or taxonomic group. Including novel local barcodes to the COI database proved to be very profitable: by adding only 116 new barcodes sequenced in our laboratory, thus increasing the reference database by only 0.04%, we were able to improve the resolution for ca. 0.6–1% of the Amplicon Sequence Variants (ASVs). creator: Francesco Mugnai creator: Federica Costantini creator: Anne Chenuil creator: Michèle Leduc creator: José Miguel Gutiérrez Ortega creator: Emese Meglécz uri: https://doi.org/10.7717/peerj.14616 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2022 Mugnai et al. title: Different types of plantar vibration affect gait characteristics differently while walking on different inclines link: https://peerj.com/articles/14619 last-modified: 2023-01-09 description: BackgroundPlantar vibration has been widely used to strengthen the sensation of the somatosensory system, further enhancing balance during walking on a level surface in patients with stroke. However, previous studies with plantar vibration only involved the level surface, which neglected the importance of inclined/declined walking in daily life. Thus, combining the plantar vibration and inclined/declined walking might answer a critical research question: whether different types of plantar vibration had different effects on gait characteristics during walking on different inclines.MethodsEighteen healthy young adults were recruited. Fifteen walking conditions were assigned randomly to these healthy adults (no, sub-, and supra-threshold plantar vibration × five different inclines: +15%, +8%, 0%, −8%, −15% grade). A motion capture system with eight cameras captured 12 retro-reflective markers and measured the stride time, stride length, step width, and respective variabilities.ResultsA significant interaction between vibration and inclination was observed in the stride time (p < 0.0001) and step width (p = 0.015). Post hoc comparisons found that supra-threshold vibration significantly decreased the stride time (−8%: p < 0.001; −15%: p < 0.001) while the sub-threshold vibration significantly increased the step width (−8%: p = 0.036) in comparison with no plantar vibration.ConclusionsWhen walking downhill, any perceivable (supra-threshold) vibration on the plantar area decreased the stride time. Also, the increase in step width was observed by non-perceivable (sub-threshold) plantar vibration while walking uphill. These observations were crucial as follows: (1) applying sub-threshold plantar vibrations during uphill walking could increase the base of support, and (2) for those who may need challenges in locomotor training, applying supra-threshold vibration during downhill walking could reach this specific training goal. creator: Haoyu Xie creator: Haolan Liang creator: Jung H. Chien uri: https://doi.org/10.7717/peerj.14619 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2023 Xie et al. title: Dominance of Bacillus species in the wheat (Triticum aestivum L.) rhizosphere and their plant growth promoting potential under salt stress conditions link: https://peerj.com/articles/14621 last-modified: 2023-01-09 description: Wheat (Triticum aestivum L.) is a major source of calorific intake in its various forms and is considered one of the most important staple foods. Improved wheat productivity can contribute substantially to addressing food security in the coming decades. Soil salinity is the most serious limiting factor in crop production and fertilizer use efficiency. In this study, 11 bacteria were isolated from wheat rhizosphere and examined for salt tolerance ability. WGT1, WGT2, WGT3, WGT6, WGT8, and WGT11 were able to tolerate NaCl salinity up to 4%. Bacterial isolates were characterized in vitro for plant growth-promoting properties including indole-3-acetic acid (IAA) production, phosphate solubilization, nitrogen fixation, zinc solubilization, biofilm formation, and cellulase-pectinase production. Six isolates, WGT1, WGT3, WGT4, WGT6, WGT8, and WGT9 showed IAA production ability ranging from 0.7–6 µg m/L. WGT8 displayed the highest IAA production. Five isolates, WGT1, WGT2, WGT5, WGT10, and WGT11, demonstrated phosphate solubilization ranging from 1.4–12.3 µg m/L. WGT2 showed the highest phosphate solubilization. Nitrogen fixation was shown by only two isolates, WGT1 and WGT8. Zinc solubilization was shown by WGT1 and WGT11 on minimal media. All isolates showed biofilm formation ability, where WGT4 exhibited maximum potential. Cellulase production ability was noticed in WGT1, WGT2, WGT4, and WGT5, while pectinase production was observed in WGT2 and WGT3. Phylogenetic identification of potential bacteria isolates confirmed their close relationship with various species of the genus Bacillus. WGT1, WGT2, and WGT3 showed the highest similarity with B. cereus, WGT6 with B. tianshenii, WGT8 with B. subtilis, and WGT11 with B. thuringiensis. Biofertilizer characteristics of salt-tolerant potential rhizospheric bacteria were evaluated by inoculating wheat plants under controlled conditions and field experiments. B. cereus WGT1 and B. thuringiensis WGT11 displayed the maximum potential to increase plant growth parameters and enhance grain yield by 37% and 31%, respectively. Potential bacteria of this study can tolerate salt stress, have the ability to produce plant growth promoting substances under salt stress and contribute significantly to enhance wheat grain yield. These bacterial isolates have the potential to be used as biofertilizers for improved wheat production under salinity conditions and contribute to the sustainable agriculture. creator: Syeda Tahseen Zahra creator: Mohsin Tariq creator: Muhammad Abdullah creator: Farrukh Azeem creator: Muhammad Arslan Ashraf uri: https://doi.org/10.7717/peerj.14621 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2023 Zahra et al.