title: PeerJ description: Articles published in PeerJ link: https://peerj.com/articles/index.rss3?journal=peerj&page=1020 creator: info@peerj.com PeerJ errorsTo: info@peerj.com PeerJ language: en title: Fire weather effects on flammability of indigenous and invasive alien plants in coastal fynbos and thicket shrublands (Cape Floristic Region) link: https://peerj.com/articles/10161 last-modified: 2020-11-11 description: BackgroundGlobally, and in the Cape Floristic Region of South Africa, extreme fires have become more common in recent years. Such fires pose societal and ecological threats and have inter alia been attributed to climate change and modification of fuels due to alien plant invasions. Understanding the flammability of different types of indigenous and invasive alien vegetation is essential to develop fire risk prevention and mitigation strategies. We assessed the flammability of 30 species of indigenous and invasive alien plants commonly occurring in coastal fynbos and thicket shrublands in relation to varying fire weather conditions.MethodsFresh plant shoots were sampled and burnt experimentally across diverse fire weather conditions to measure flammability in relation to fire weather conditions, live fuel moisture, fuel load and vegetation grouping (fynbos, thicket and invasive alien plants). Flammability measures considered were: burn intensity, completeness of burn, time-to-ignition, and the likelihood of spontaneous ignition. We also investigated whether the drying of plant shoots (simulating drought conditions) differentially affected the flammability of vegetation groups.ResultsFire weather conditions enhanced all measures of flammability, whereas live fuel moisture reduced burn intensity and completeness of burn. Live fuel moisture was not significantly correlated with fire weather, suggesting that the mechanism through which fire weather enhances flammability is not live fuel moisture. It furthermore implies that the importance of live fuel moisture for flammability of evergreen shrublands rests on inter-specific and inter-vegetation type differences in fuel moisture, rather than short-term intra-specific fluctuation in live fuel moisture in response to weather conditions. Fuel load significantly increased burn intensity, while reducing ignitability. Although fire weather, live fuel moisture, and fuel load had significant effects on flammability measures, vegetation and species differences accounted for most of the variation. Flammability was generally highest in invasive alien plants, intermediate in fynbos, and lowest in thicket. Fynbos ignited rapidly and burnt completely, whereas thicket was slow to ignite and burnt incompletely. Invasive alien plants were slow to ignite, but burnt with the highest intensity, potentially due to volatile organic composition. The drying of samples resulted in increases in all measures of flammability that were comparable among vegetation groups. Flammability, and by implication fire risk, should thus not increase disproportionately in one vegetation group compared to another under drought conditions—unless the production of dead fuels is disproportionate among vegetation groups. Thus, we suggest that the dead:live fuel ratio is a potentially useful indicator of flammability of evergreen shrublands and that proxies for this ratio need to be investigated for incorporation into fire danger indices. creator: Samukelisiwe T. Msweli creator: Alastair J. Potts creator: Herve Fritz creator: Tineke Kraaij uri: https://doi.org/10.7717/peerj.10161 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2020 Msweli et al. title: Chemical analysis of callus extracts from toxic and non-toxic varieties of Jatropha curcas L. link: https://peerj.com/articles/10172 last-modified: 2020-11-11 description: Jatropha curcas L. belongs to Euphorbiaceae family, and it synthesizes flavonoid and diterpene compounds that have showed antioxidant, anti-inflammatory, anticancer, antiviral, antimicrobial, antifungal and insecticide activity. Seeds of this plant accumulate phorbol esters, which are tigliane type diterpenes, reported as toxic and, depending on its concentration, toxic and non-toxic varieties has been identified. The aim of this work was to characterize the chemical profile of the extracts from seeds, leaves and callus of both varieties (toxic and non-toxic) of Jatropha curcas, to verify the presence of important compounds in dedifferentiated cells and consider the possibility of using these cultures for the massive production of metabolites. Callus induction was obtained using NAA (1.5 mg L−1) and BAP (1.5 mg L−1) after 21 d for both varieties. Thin layer chromatography analysis showed differences in compounds accumulation in callus from non-toxic variety throughout the time of culture, diterpenes showed an increase along the time, in contrast with flavonoids which decreased. Based on the results obtained through microQTOF-QII spectrometer it is suggested a higher accumulation of phorbol esters, derived from 12-deoxy-16-hydroxy-phorbol (m/z 365 [M+H]+), in callus of 38 d than those of 14 d culture, from both varieties. Unlike flavonoids accumulation, the MS chromatograms analysis allowed to suggest lower accumulation of flavonoids as the culture time progresses, in callus from both varieties. The presence of six glycosylated flavonoids is also suggested in leaf and callus extracts derived from both varieties (toxic and non-toxic), including: apigenin 6-C-α-L-arabinopyranosyl-8-C-β-D-xylopyranoside (m/z 535 [M+H]+), apigenin 4′-O-rhamnoside (m/z 417 [M+H]+), vitexin (m/z 433 [M+H]+), vitexin 4′-O-glucoside-2″-O-rhamnoside (m/z 741 [M+H]+), vicenin-2 (m/z 595 [M+H]+), and vicenin-2,6″-O-glucoside (m/z 757 [M+H]+). creator: Gerardo Leyva-Padrón creator: Pablo Emilio Vanegas-Espinoza creator: Silvia Evangelista-Lozano creator: Alma Angélica Del Villar-Martínez creator: Crescencio Bazaldúa uri: https://doi.org/10.7717/peerj.10172 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Leyva-Padrón et al. title: Variation in female reproductive tract morphology across the reproductive cycle in the zebra finch link: https://peerj.com/articles/10195 last-modified: 2020-11-11 description: BackgroundIn seasonally breeding birds, the reproductive tract undergoes a dramatic circannual cycle of recrudescence and regression, with oviduct size increasing 5–220 fold from the non-breeding to the breeding state. Opportunistically breeding birds can produce multiple clutches sequentially across an extended period in response primarily to environmental rather than seasonal cues. In the zebra finch, it has been shown that there is a significant reduction in gonadal morphology in non-breeding females. However, the scale of recrudescence and regression of reproductive tissue within a single breeding cycle is unknown and yet important to understand the cost of breeding, and the physiological readiness to breed in such flexible breeders.MethodsWe examined the reproductive tissue of breeding female zebra finches at six stages in the nesting cycle from pre-breeding to fledging offspring. We quantified the wet mass of the oviduct, the volume of the largest pre-ovulatory follicle, and the total number of pre-ovulatory follicles present on the ovary.ResultsMeasures of the female reproductive tract were highest during nesting and laying stages and declined significantly in the later stages of the breeding cycle. Importantly, we found that the mass of reproductive tissue changes as much across a single reproductive event as that previously characterized between birds categorized as breeding and non-breeding. However, the regression of the ovary is less dramatic than that seen in seasonal breeders. This could reflect low-level maintenance of reproductive tissues in opportunistic breeders, but needs to be confirmed in wild non-breeding birds. creator: Laura L. Hurley creator: Ondi L. Crino creator: Melissah Rowe creator: Simon C. Griffith uri: https://doi.org/10.7717/peerj.10195 license: https://creativecommons.org/licenses/by/4.0/ rights: © 2020 Hurley et al. title: Cathepsin D in prawn reproductive system: its localization and function in actin degradation link: https://peerj.com/articles/10218 last-modified: 2020-11-11 description: Cathepsin D (CAT-D) is a well-known aspartic protease that serves a function as house-keeping lysosomal enzyme in all somatic cells. Its existence in reproductive tissues is highly variable, even in the somatic derived epithelial cells of reproductive tract. In Macrobrachium rosenbergii, existence of MrCAT-D and its translational product was detected in both somatic cells (Sertoli-like supporting cells) and developing spermatogenic cells as well as along accessory spermatic ducts. Specifically, MrCAT-D was localized onto the sperm surface rather than within the acrosomal matrix, as evident by similar staining pattern of anti-CAT-D on live and aldehyde fixed sperm. MrCAT-D in testicular extracts and sperm isolates showed active enzyme activities towards its specific fluorogenic substrate (MCA-Gly-Lys-Pro-Ile-Leu-Phe-Phe-Arg-Leu-Lys (Dnp)-D-Arg-NH2). MrCAT-D also exerted its function towards hydrolyzing filamentous actin, the meshwork of which is shown to be localized at the junction between germ cells and supporting cells and spermatogonia in M. rosenbergii testicular epithelium. Together, we have localized MrCAT-D transcript and its translational product in both supporting and germ cells of testis and claimed its enzymatic function towards actin degradation, which may be related to sperm release from the epithelial cell interaction. creator: Chompoonut Sukonset creator: Piyaporn Surinlert creator: Orawan Thongsum creator: Atthaboon Watthammawut creator: Monsicha Somrit creator: Jirasuda Nakeim creator: Wattana Weerachatyanukul creator: Somluk Asuvapongpatana uri: https://doi.org/10.7717/peerj.10218 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Sukonset et al. title: Emerging roles of APLN and APELA in the physiology and pathology of the female reproductive system link: https://peerj.com/articles/10245 last-modified: 2020-11-11 description: APLN, APELA and their common receptor APLNR (composing the apelinergic axis) have been described in various species with extensive body distribution and multiple physiological functions. Recent studies have witnessed emerging intracellular cascades triggered by APLN and APELA which play crucial roles in female reproductive organs, including hypothalamus-pituitary-gonadal axis, ovary, oviduct, uterus and placenta. However, a comprehensive summary of APLN and APELA roles in physiology and pathology of female reproductive system has not been reported to date. In this review, we aim to concentrate on the general characteristics of APLN and APELA, as well as their specific physiological roles in female reproductive system. Meanwhile, the pathological contexts of apelinergic axis dysregulation in the obstetrics and gynecology are also summarized here, suggesting its potential prospect as a diagnostic biomarker and/or therapeutic intervention in the polycystic ovary syndrome, ovarian cancer, preeclampsia and gestational diabetes mellitus. creator: Xueying Wang creator: Xiaofei Liu creator: Zifan Song creator: Xin Shen creator: Siying Lu creator: Yan Ling creator: Haibin Kuang uri: https://doi.org/10.7717/peerj.10245 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Wang et al. title: Improving decolorization of dyes by laccase from Bacillus licheniformis by random and site-directed mutagenesis link: https://peerj.com/articles/10267 last-modified: 2020-11-11 description: BackgroundDye wastewater increases cancer risk in humans. For the treatment of dyestuffs, biodegradation has the advantages of economy, high efficiency, and environmental protection compared with traditional physical and chemical methods. Laccase is the best candidate for dye degradation because of its multiple substrates and pollution-free products.MethodsHere, we modified the laccase gene of Bacillus licheniformis by error-prone PCR and site-directed mutagenesis and expressed in E. coli. The protein was purified by His-tagged protein purification kit. We tested the enzymatic properties of wild type and mutant laccase by single factor test, and further evaluated the decolorization ability of laccase to acid violet, alphazurine A, and methyl orange by spectrophotometry.ResultsMutant laccase Lacep69and D500G were superior to wild type laccase in enzyme activity, stability, and decolorization ability. Moreover, the laccase D500G obtained by site-directed mutagenesis had higher enzyme activity in both, and the specific activity of the purified enzyme was as high as 426.13 U/mg. Also, D500G has a higher optimum temperature of 70 °C and temperature stability, while it has a more neutral pH 4.5 and pH stability. D500G had the maximum enzyme activity at a copper ion concentration of 12 mM. The results of decolorization experiments showed that D500G had a strong overall decolorization ability, with a lower decolorization rate of 18% for methyl orange and a higher decolorization rate of 78% for acid violet.ConclusionCompared with the wild type laccase, the enzyme activity of D500G was significantly increased. At the same time, it has obvious advantages in the decolorization effect of different dyes. Also, the advantages of temperature and pH stability increase its tolerance to the environment of dye wastewater. creator: Tongliang Bu creator: Rui Yang creator: YanJun Zhang creator: Yuntao Cai creator: Zizhong Tang creator: Chenglei Li creator: Qi Wu creator: Hui Chen uri: https://doi.org/10.7717/peerj.10267 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Bu et al. title: Forelimb joints contribute to locomotor performance in reindeer (Rangifer tarandus) by maintaining stability and storing energy link: https://peerj.com/articles/10278 last-modified: 2020-11-11 description: Reindeer (Rangifer tarandus) have lengthy seasonal migrations on land and their feet possess excellent locomotor characteristics that can adapt to complex terrains. In this study, the kinematics and vertical ground reaction force (GRF) of reindeer forelimb joints (interphalangeal joint b, metacarpophalangeal joint c, and wrist joint d) under walk, trot 1, and trot 2 were measured using a motion tracking system and Footscan pressure plates. Significant differences among different locomotor activities were observed in the joint angles, but not in changes of the joint angles (αb, αc, αd) during the stance phase. Peak vertical GRF increased as locomotor speed increased. Net joint moment, power, and work at the forelimb joints were calculated via inverse dynamics. The peak joint moment and net joint power related to the vertical GRF increased as locomotor speed increased. The feet absorbed and generated more energy at the joints. During different locomotor activities, the contribution of work of the forelimbs changed with both gait and speed. In the stance phase, the metacarpophalangeal joint absorbed more energy than the other two joints while trotting and thus performed better in elastic energy storage. The joint angles changed very little (∼5°) from 0 to 75% of the stance phase, which reflected the stability of reindeer wrist joints. Compared to typical ungulates, reindeer toe joints are more stable and the stability and energy storage of forelimb joints contribute to locomotor performance in reindeer. creator: Guoyu Li creator: Rui Zhang creator: Dianlei Han creator: Hao Pang creator: Guolong Yu creator: Qingqiu Cao creator: Chen Wang creator: Lingxi Kong creator: Wang Chengjin creator: Wenchao Dong creator: Tao Li creator: Jianqiao Li uri: https://doi.org/10.7717/peerj.10278 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Li et al. title: Gene signature for prognosis in comparison of pancreatic cancer patients with diabetes and non-diabetes link: https://peerj.com/articles/10297 last-modified: 2020-11-11 description: BackgroundPancreatic cancer (PC) has much weaker prognosis, which can be divided into diabetes and non-diabetes. PC patients with diabetes mellitus will have more opportunities for physical examination due to diabetes, while pancreatic cancer patients without diabetes tend to have higher risk. Identification of prognostic markers for diabetic and non-diabetic pancreatic cancer can improve the prognosis of patients with both types of pancreatic cancer.MethodsBoth types of PC patients perform differently at the clinical and molecular levels. The Cancer Genome Atlas (TCGA) is employed in this study. The gene expression of the PC with diabetes and non-diabetes is used for predicting their prognosis by LASSO (Least Absolute Shrinkage and Selection Operator) Cox regression. Furthermore, the results are validated by exchanging gene biomarker with each other and verified by the independent Gene Expression Omnibus (GEO) and the International Cancer Genome Consortium (ICGC). The prognostic index (PI) is generated by a combination of genetic biomarkers that are used to rank the patient’s risk ratio. Survival analysis is applied to test significant difference between high-risk group and low-risk group.ResultsAn integrated gene prognostic biomarker consisted by 14 low-risk genes and six high-risk genes in PC with non-diabetes. Meanwhile, and another integrated gene prognostic biomarker consisted by five low-risk genes and three high-risk genes in PC with diabetes. Therefore, the prognostic value of gene biomarker in PC with non-diabetes and diabetes are all greater than clinical traits (HR = 1.102, P-value < 0.0001; HR = 1.212, P-value < 0.0001). Gene signature in PC with non-diabetes was validated in two independent datasets.ConclusionsThe conclusion of this study indicated that the prognostic value of genetic biomarkers in PCs with non-diabetes and diabetes. The gene signature was validated in two independent databases. Therefore, this study is expected to provide a novel gene biomarker for predicting prognosis of PC with non-diabetes and diabetes and improving clinical decision. creator: Mingjun Yang creator: Boni Song creator: Juxiang Liu creator: Zhitong Bing creator: Yonggang Wang creator: Linmiao Yu uri: https://doi.org/10.7717/peerj.10297 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Yang et al. title: Development and validation of Egyptian developmental screening chart for children from birth up to 30 months link: https://peerj.com/articles/10301 last-modified: 2020-11-11 description: BackgroundDetecting developmental delay in children is an ongoing world commitment, especially for those below three years. To accurately assess the development of children; a culturally appropriate screening tool must be used. Egypt lacks such tool and multiple studies have shown that western tools are not suitable in other cultures.ObjectivesTo develop and validate an easy, rapid, culturally appropriate and applicable screening chart for early detection of developmental delay among Egyptian children from birth up to 30 months and develop a Z-score chart for motor and mental development follow up based on our Egyptian screening chart.MethodsA cross sectional randomized study was carried out on 1503 Egyptian children of both genders aged from birth up to 30 months assumed to have normal development according to the inclusion and exclusion criteria. They were selected from vaccination centers and well-baby clinics. Developmental milestones from Baroda development screening test (BDST) were applied on them after items were translated and adapted to Egyptian culture. Egyptian children developmental milestones scores were analyzed and carefully prepared in tables and charts. A 97% pass level of developmental achievements represents the threshold below which children are considered delayed. A Z-score chart for motor and mental development follow up was designed by calculating each age group achievement. The developed Egyptian developmental screening chart (EDSC) was validated against Ages and Stages Questionnaires (ASQ-3) as a reference standard in another different sample of 337 children in different age groups.ResultsThe developed EDSC is represented in a chart format with two curves 50% and 97% pass level. Children considered delayed when the score below 97% pass level. Results revealed a statistically significant difference between EDSC and BDST at 50% and 97% pass levels. A Z-score chart for motor and mental development follow up was designed by calculating each age group achievement. EDSC sensitivity and specificity were calculated 84.38 (95% CI [67.21%–94.72%]) and 98.36 (95% CI [96.22%–99.47%]) respectively with an overall test accuracy 97.03 (95% CI [94.61%–98.57%]) (p ≤ .001). Agreement between EDSC and ASQ-3 was high (kappa score was 0.827) with negative and positive agreement 98.36 and 84.38, respectively.ConclusionsExtensive revision of the BDST was needed in order to create and validate a more culturally appropriate Egyptian screening chart. This is the first study to create and validate an Egyptian-specific screening tool, to be rapid and easy to use in Egypt for early detection of developmental delay and enabling early intervention practices. A Z-score curve is reliable for follow up motor and mental development by calculating each age group achievement. creator: Ali M. El Shafie creator: Zein A.L. Omar creator: Mai M. Bashir creator: Sorour F. Mahmoud creator: Elsayedamr M. Basma creator: Ahmed E. Hussein creator: Alaa Mosad Mostafa creator: Wael A. Bahbah uri: https://doi.org/10.7717/peerj.10301 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 El Shafie et al. title: Maternal sitagliptin treatment attenuates offspring glucose metabolism and intestinal proinflammatory cytokines IL-6 and TNF-α expression in male rats link: https://peerj.com/articles/10310 last-modified: 2020-11-11 description: Increasing evidence shows that maternal overnutrition may increase the risk of diabetes in offspring. We hypothesized that maternal sitagliptin intervention may improve glucose intolerance through gut targeting. Female Sprague-Dawley (SD) rats were fed a normal diet (ND) or a high-fat diet (HFD) for 4 weeks before mating. ND pregnant rats were divided into two subgroups: ND group (ND alone) and the ND-sitagliptin group (ND combined with 10 mg/kg/day sitagliptin treatment). HFD pregnant rats were randomized to one of two groups: HFD group (HFD alone) and the HFD-sitagliptin group (HFD combined with 10 mg/kg/day sitagliptin treatment) during pregnancy and lactation. Glucose metabolism was assessed in offspring at weaning. Intestinal gene expression levels were investigated. Maternal sitagliptin intervention moderated glucose intolerance and insulin resistance in male pups. Moreover, maternal sitagliptin treatment inhibited offspring disordered intestinal expression of proinflammatory markers, including interleukin-6 (Il6), ll1b, and tumor necrosis factor (Tnf), at weaning and reduced intestinal IL-6, TNF-α expression by immunohistochemical staining and serum IL-6, TNF-α levels. However, maternal sitagliptin intervention did not affect offspring serum anti-inflammatory cytokine IL-10 level. Our results are the first to show that maternal sitagliptin intervention moderated glucose metabolism in male offspring. It may be involved with moderating intestinal IL-6 and TNF-α expression in male rat offspring. creator: Qian Zhang creator: Xinhua Xiao creator: Jia Zheng creator: Ming Li creator: Miao Yu creator: Fan Ping creator: Tong Wang creator: Xiaojing Wang uri: https://doi.org/10.7717/peerj.10310 license: https://creativecommons.org/licenses/by/4.0/ rights: ©2020 Zhang et al.