Restoring South African subtropical succulent thicket using Portulacaria afra: root growth of cuttings differs depending on the harvest site during a drought
The restoration of succulent thicket (the semi-arid components of the Albany Subtropical Thicket biome endemic to South Africa) has largely focused on the reintroduction of Portulacaria afra L. Jacq—a leaf- and stem-succulent shrub—through the planting of unrooted cuttings directly into field sites. However, there has been inconsistent establishment and survival rates, with low rates potentially due to a range of factors (e.g., post-planting drought, frost or herbivory), including the poor condition of source material used. Here we test the effect of parent-plant and harvesting site on the root development of P. afra cuttings in a common garden experiment. Ten sites were selected along a ∼110 km transect, with cuttings harvested from five parent-plants per site. Leaf moisture content was determined for each parent-plant at the time of harvesting as a proxy for plant condition. Root development—percentage of rooted cuttings and mean root dry weight—was recorded for a subset of cuttings from each parent-plant after 35, 42, 48, 56, and 103 days after planting in a common garden setting. We found evidence for cutting root development (rooting percentage and root dry mass) to be strongly associated with harvesting site across all sampling days (p < 0.005 for all tests). These differences are likely a consequence of underlying physiological factors; this was supported by the significant but weak correlation (r2 = 0.10–0.26) between the leaf moisture content of the parent-plant (at the time of harvesting) and dry root mass of the cuttings (at each of the sampling days). Our findings demonstrate that varying plant condition across sites can significantly influence root development during dry phases (i.e., intra- and inter-annual droughts) and that this may be a critical component that needs to be understood as part of any restoration programme. Further work is required to identify the environmental conditions that promote or impede root development in P. afra cuttings.
Potts et al. (2024) Restoring South African subtropical succulent thicket using Portulacaria afra: root growth of cuttings differs depending on the harvest site during a drought. PeerJ 12:e17471 https://doi.org/10.7717/peerj.17471
Combined uranium-series and electron spin resonance dating from the Pliocene fossil sites of Aves and Milo’s palaeocaves, Bolt’s Farm, Cradle of Humankind, South Africa
Bolt’s Farm is the name given to a series of non-hominin bearing fossil sites that have often been suggested to be some of the oldest Pliocene sites in the Cradle of Humankind, South Africa. This article reports the results of the first combined Uranium-Series and Electron Spin Resonance (US-ESR) dating of bovid teeth at Milo’s Cave and Aves Cave at Bolt’s Farm. Both tooth enamel fragments and tooth enamel powder ages were presented for comparison. US-ESR, EU and LU models are calculated. Overall, the powder ages are consistent with previous uranium-lead and palaeomagnetic age estimates for the Aves Cave deposit, which suggest an age between ~3.15 and 2.61 Ma and provide the first ages for Milo’s Cave dates to between ~3.1 and 2.7 Ma. The final ages were not overly dependent on the models used (US-ESR, LU or EU), which all overlap within error. These ages are all consistent with the biochronological age estimate (<3.4–>2.6 Ma) based on the occurrence of Stage I Metridiochoerus andrewsi. Preliminary palaeomagnetic analysis from Milo’s Cave indicates a reversal takes place at the site with predominantly intermediate directions, suggesting the deposit may date to the period between ~3.03 and 3.11 Ma within error of the ESR ages. This further suggests that there are no definitive examples of palaeocave deposits at Bolt’s Farm older than 3.2 Ma. This research indicates that US-ESR dating has the potential to date fossil sites in the Cradle of Humankind to over 3 Ma. However, bulk sample analysis for US-ESR dating is recommended for sites over 3 Ma.
Yu et al. (2024) Combined uranium-series and electron spin resonance dating from the Pliocene fossil sites of Aves and Milo’s palaeocaves, Bolt’s Farm, Cradle of Humankind, South Africa. PeerJ 12:e17478 https://doi.org/10.7717/peerj.17478
Internet addiction among adolescents during the COVID-19 pandemic: Associations with sociodemographic and psychological distress
Background The COVID-19 pandemic has had tremendous implications for billions of adolescents worldwide due to school closures, forcing students to embrace internet usage for daily tasks. Uncontrolled use of the internet among adolescents makes them vulnerable to internet addiction (IA). This study aims to determine the prevalence of IA among adolescents and assess its association with sociodemographic factors, smartphone use, and psychological distress during the pandemic. Method A cross-sectional self-administered online survey was conducted among students aged 13–17 from May 15th, 2021, until May 30th, 2021, using the Malay version of the Internet Addiction Test (MVIAT), the Depression, Anxiety, and Stress Scale (DASS-21), and the Coronavirus Impacts Questionnaires, as well as a sociodemographic information form. The data was analyzed with IBM SPSS Statistics version 23. Results A total of 420 adolescents participated in the survey. The majority of them (70.7%) were female, with a mean age of 15.47 years (±1.49 years old). About 45.5% of the respondents were classified as internet addicted users. The Chi-square test analysis showed that age (p = 0.002), smartphone usage (p = 0.010), rate of midnight use (p < 0.001), frequency (p < 0.001), duration (p < 0.001) of device usage, and presence of depression, anxiety, and stress (p < 0.001) were all significantly associated with IA. Multiple logistic regression showed age (aOR = 1.16, 95% CI [1.00–1.35], p = 0.048), smartphone usage (aOR =3.52, 95% CI [1.43–8.67], p = 0.006), mild or moderate depression (aOR = 2.43, 95% CI [1.36–4.34], p = 0.003), severe or extremely severe stress (aOR = 6.41, 95% CI [2.18–18.82], p = 0.001) were significantly related to IA. Conclusions Late adolescence, the use of smartphones, and the presence of psychological distress like depression, and stress were potentially associated with IA. Wise use of smartphones and early identification of any psychological distress among adolescents are warranted, especially during the pandemic.
Md Bukhori et al. (2024) Internet addiction among adolescents during the COVID-19 pandemic: Associations with sociodemographic and psychological distress. PeerJ 12:e17489 https://doi.org/10.7717/peerj.17489
Impact of white blood cell count on the development of contrast-induced acute kidney injury in patients receiving percutaneous coronary intervention
This study aimed to investigate the efficacy of a pre-procedural white blood cell (WBC) count in the prediction of contrast-induced acute kidney injury (CI-AKI) risk in coronary artery disease patients receiving a percutaneous coronary intervention (PCI). This observational study comprises a sample of 1,013 coronary artery disease patients (including ACS and stable angina) receiving PCI, gathered from September 2015 to July 2017. CI-AKI incidence in the study population was 4.8% (49/1013). Patients in the CI-AKI group had significantly higher WBC counts than those in the non-CI-AKI group (10.41 ± 5.37 vs. 8.09 ± 3.10, p = 0.004). Logistic analysis showed that WBC count (odds ratio [OR]: 1.12, 95% CI [1.03–1.21], P = 0.006) was a significant and independent predictor of CI-AKI risk in patients receiving PCI, Receiver-operating characteristic (ROC) curve analysis found that pre-procedural WBC count ≥11.03*109/L was the optimal cut-off value in the prediction of CI-AKI risk with a sensitivity of 41.0% and a specificity of 86.5%. Patients with CI-AKI had a significantly worse 1-year survival rate than patients without CI-AKI (91.8% vs. 97.6%, P = 0.012). In summary, increased pre-procedural WBC count is associated with an increased risk of developing CI-AKI in patients receiving PCI.
Fu et al. (2024) Impact of white blood cell count on the development of contrast-induced acute kidney injury in patients receiving percutaneous coronary intervention. PeerJ 12:e17493 https://doi.org/10.7717/peerj.17493
Wing mechanics and acoustic communication of a new genus of sylvan katydid (Orthoptera: Tettigoniidae: Pseudophyllinae) from the Central Cordillera cloud forest of Colombia
Stridulation is used by male katydids to produce sound via the rubbing together of their specialised forewings, either by sustained or interrupted sweeps of the file producing different tones and call structures. There are many species of Orthoptera that remain undescribed and their acoustic signals are unknown. This study aims to measure and quantify the mechanics of wing vibration, sound production and acoustic properties of the hearing system in a new genus of Pseudophyllinae with taxonomic descriptions of two new species. The calling behaviour and wing mechanics of males were measured using micro-scanning laser Doppler vibrometry, microscopy, and ultrasound sensitive equipment. The resonant properties of the acoustic pinnae of the ears were obtained via μ-CT scanning and 3D printed experimentation, and numerical modelling was used to validate the results. Analysis of sound recordings and wing vibrations revealed that the stridulatory areas of the right tegmen exhibit relatively narrow frequency responses and produce narrowband calls between 12 and 20 kHz. As in most Pseudophyllinae, only the right mirror is activated for sound production. The acoustic pinnae of all species were found to provide a broadband increased acoustic gain from ~40–120 kHz by up to 25 dB, peaking at almost 90 kHz which coincides with the echolocation frequency of sympatric bats. The new genus, named Satizabalus n. gen., is here derived as a new polytypic genus from the existing genus Gnathoclita, based on morphological and acoustic evidence from one described (S. sodalis n. comb.) and two new species (S. jorgevargasi n. sp. and S. hauca n. sp.). Unlike most Tettigoniidae, Satizabalus exhibits a particular form of sexual dimorphism whereby the heads and mandibles of the males are greatly enlarged compared to the females. We suggest that Satizabalus is related to the genus Trichotettix, also found in cloud forests in Colombia, and not to Gnathoclita.
Holmes et al. (2024) Wing mechanics and acoustic communication of a new genus of sylvan katydid (Orthoptera: Tettigoniidae: Pseudophyllinae) from the Central Cordillera cloud forest of Colombia. PeerJ 12:e17501 https://doi.org/10.7717/peerj.17501
Utilization of ripe coconut water in the development of probiotic gelatin
Background Desserts with vegetable ingredients are a constantly expanding global market due to the search for alternatives to cow’s milk. Fermentation of these matrices by lactic acid bacteria can add greater functionality to the product, improving its nutritional, sensory, and food safety characteristics, as well as creating bioactive components with beneficial effects on health. Concern for health and well-being has aroused interest in byproducts of the industry that have functional properties for the body, such as mature coconut water, a normally discarded residue that is rich in nutrients. This study aimed to develop a probiotic gelatin based on pulp and water from mature coconuts and evaluate the physicochemical characteristics, viability of the Lacticaseibacillus rhamnosus LR32 strain in the medium, as well as the texture properties of the product. Methods After collection and cleaning, the physicochemical characterization, mineral analysis, analysis of the total phenolic content and antioxidant activity of mature coconut water were carried out, as well as the centesimal composition of its pulp. Afterwards, the gelling was developed with the addition of modified corn starch, gelatin, sucrose, and probiotic culture, being subjected to acidity analysis, texture profile and cell count, on the first day and every 7 days during 21 days of storage, under refrigeration at 5 °C. An analysis of the centesimal composition was also carried out. Results The main minerals in coconut water were potassium (1,932.57 mg L−1), sodium (19.57 mg L−1), magnesium (85.13 mg L−1) calcium (279.93 mg L−1) and phosphorus (11.17 mg L−1), while the pulp had potassium (35.96 g kg−1), sodium (0.97 g kg−1), magnesium (2.18 g kg−1), 37 calcium (1.64 g kg−1), and phosphorus (3.32 g kg−1). The phenolic content of the water and pulp was 5.72 and 9.77 mg gallic acid equivalent (GAE) 100 g−1, respectively, and the antioxidant capacity was 1.67 and 0.98 39 g of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) mg−1, respectively. The coconut pulp had 2.81 g 100 g−1of protein, 1.11 g 100 g−1 of 40 ash, 53% moisture, and 5.81 g 100 g−1 of carbohydrates. The gelatin produced during the storage period presented firmness parameters ranging from 145.82 to 206.81 grams-force (gf), adhesiveness from 692.85 to 1,028.63 gf sec, cohesiveness from 0.604 to 0.473, elasticity from 0.901 to 0.881, gumminess from 86.27 to 97.87 gf, and chewiness from 77.72 to 91.98 gf. Regarding the viability of the probiotic microorganism, the dessert had 7.49 log CFU g−1 that remained viable during the 21-day storage, reaching 8.51 CFU g−1. Acidity ranged from 0.15 to 0.64 g of lactic acid 100 g−1. The centesimal composition of the product showed 4.88 g 100 g−1 of protein, 0.54 g 100 g−1 of ash, 85.21% moisture, and 5.37g 100 g−1 of carbohydrates. The development of the gelatin made it possible to obtain a differentiated product, contributing to diversification in the food sector, providing a viable alternative for maintaining consumer health and reducing costs compared to desserts already available on the market.
Patricio Rocha et al. (2024) Utilization of ripe coconut water in the development of probiotic gelatin. PeerJ 12:e17502 https://doi.org/10.7717/peerj.17502
Response of the subalpine bunchgrasses to wildfires and its effects in the relative abundance of the volcano rabbit in the Ajusco-Chichinautzin Mountain Range
The volcano rabbit (Romerolagus diazi) is a lagomorph endemic to the central mountains of the Trans-Mexican Volcanic Belt and is classified as threatened at extinction risk. It is a habitat specialist in bunchgrass communities. The annual wildfires that occur throughout its distribution range are a vulnerability factor for the species. However, the effects of wildfires on volcano rabbit populations are not fully understood. We evaluated the occupancy and change in the volcano rabbit relative abundance index in the burned bunchgrass communities of the Ajusco-Chichinautzin Mountain Range during an annual cycle of wildfire events. Additionally, we assessed the factors that favor and limit occupation and reoccupation by the volcano rabbit using the relative abundance index in burned plots as an indicator of these processes. The explanatory factors for the response of the volcano rabbit were its presence in the nearby unburned bunchgrasses, the height of three species of bunchgrass communities, the proportion of different types of vegetation cover within a 500 m radius around the burned plots, heterogeneity of the vegetation cover, and the extent of the wildfire. Statistical analyses indicated possible reoccupation in less than a year in burned bunchgrass communities adjacent to unburned bunchgrass communities with volcano rabbits. The relative abundance index of volcano rabbits was not favored when the maximum height of the Muhlenbergia macroura bunchgrass community was less than 0.77 m. When the vegetation around the burned plots was dominated by forest (cover >30% of the buffer) and the fire was extensive, the number of latrines decreased per month but increased when the bunchgrass and shrub cover was greater around the burned plots. While the statistical results are not conclusive, our findings indicate a direction for future projects, considering extensive monitoring to obtain a greater number of samples that contribute to consolidating the models presented.
Uriostegui-Velarde et al. (2024) Response of the subalpine bunchgrasses to wildfires and its effects in the relative abundance of the volcano rabbit in the Ajusco-Chichinautzin Mountain Range. PeerJ 12:e17510 https://doi.org/10.7717/peerj.17510
Molecular characterization of Pectobacterium atrosepticum infecting potato and its management through chemicals
Potato farming is a vital component of food security and the economic stability especially in the under developing countries but it faces many challenges in production, blackleg disease caused by Pectobacterium atrosepticum (Pa) is one of the main reason for damaging crop yield of the potato. Effective management strategies are essential to control these losses and to get sustainable potato crop yield. This study was focused on characterizing the Pa and the investigating new chemical options for its management. The research was involved a systematic survey across the three district of Punjab, Pakistan (Khanewal, Okara, and Multan) to collect samples exhibiting the black leg symptoms. These samples were analyzed in the laboratory where gram-negative bacteria were isolated and identified through biochemical and pathogenicity tests for Pa. DNA sequencing further confirmed these isolates of Pa strains. Six different chemicals were tested to control blackleg problem in both vitro and vivo at different concentrations. In vitro experiment, Cordate demonstrated the highest efficacy with a maximum inhibition zones of 17.139 mm, followed by Air One (13.778 mm), Profiler (10.167 mm), Blue Copper (7.7778 mm), Spot Fix (7.6689 mm), and Strider (7.0667 mm). In vivo, Cordate maintained its effectiveness with the lowest disease incidence of 14.76%, followed by Blue Copper (17.49%), Air One (16.98%), Spot Fix (20.67%), Profiler (21.45%), Strider (24.99%), and the control group (43.00%). The results highlight Cordate’s potential as a most effective chemical against Pa, offering promising role for managing blackleg disease in potato and to improve overall productivity.
Hameed et al. (2024) Molecular characterization of Pectobacterium atrosepticum infecting potato and its management through chemicals. PeerJ 12:e17518 https://doi.org/10.7717/peerj.17518
Effect of glucocorticoid blockade on inflammatory responses to acute sleep fragmentation in male mice
The association between sleep and the immune-endocrine system is well recognized, but the nature of that relationship is not well understood. Sleep fragmentation induces a pro-inflammatory response in peripheral tissues and brain, but it also activates the hypothalamic-pituitary-adrenal (HPA) axis, releasing glucocorticoids (GCs) (cortisol in humans and corticosterone in mice). It is unclear whether this rapid release of glucocorticoids acts to potentiate or dampen the inflammatory response in the short term. The purpose of this study was to determine whether blocking or suppressing glucocorticoid activity will affect the inflammatory response from acute sleep fragmentation (ASF). Male C57BL/6J mice were injected i.p. with either 0.9% NaCl (vehicle 1), metyrapone (a glucocorticoid synthesis inhibitor, dissolved in vehicle 1), 2% ethanol in polyethylene glycol (vehicle 2), or mifepristone (a glucocorticoid receptor antagonist, dissolved in vehicle 2) 10 min before the start of ASF or no sleep fragmentation (NSF). After 24 h, samples were collected from brain (prefrontal cortex, hypothalamus, hippocampus) and periphery (liver, spleen, heart, and epididymal white adipose tissue (EWAT)). Proinflammatory gene expression (TNF-α and IL-1β) was measured, followed by gene expression analysis. Metyrapone treatment affected pro-inflammatory cytokine gene expression during ASF in some peripheral tissues, but not in the brain. More specifically, metyrapone treatment suppressed IL-1β expression in EWAT during ASF, which implies a pro-inflammatory effect of GCs. However, in cardiac tissue, metyrapone treatment increased TNF-α expression in ASF mice, suggesting an anti-inflammatory effect of GCs. Mifepristone treatment yielded more significant results than metyrapone, reducing TNF-α expression in liver (only NSF mice) and cardiac tissue during ASF, indicating a pro-inflammatory role. Conversely, in the spleen of ASF-mice, mifepristone increased pro-inflammatory cytokines (TNF-α and IL-1β), demonstrating an anti-inflammatory role. Furthermore, irrespective of sleep fragmentation, mifepristone increased pro-inflammatory cytokine gene expression in heart (IL-1β), pre-frontal cortex (IL-1β), and hypothalamus (IL-1β). The results provide mixed evidence for pro- and anti-inflammatory functions of corticosterone to regulate inflammatory responses to acute sleep loss.
Hasan et al. (2024) Effect of glucocorticoid blockade on inflammatory responses to acute sleep fragmentation in male mice. PeerJ 12:e17539 https://doi.org/10.7717/peerj.17539
The best of two worlds: reprojecting 2D image annotations onto 3D models
Imagery has become one of the main data sources for investigating seascape spatial patterns. This is particularly true in deep-sea environments, which are only accessible with underwater vehicles. On the one hand, using collaborative web-based tools and machine learning algorithms, biological and geological features can now be massively annotated on 2D images with the support of experts. On the other hand, geomorphometrics such as slope or rugosity derived from 3D models built with structure from motion (sfm) methodology can then be used to answer spatial distribution questions. However, precise georeferencing of 2D annotations on 3D models has proven challenging for deep-sea images, due to a large mismatch between navigation obtained from underwater vehicles and the reprojected navigation computed in the process of building 3D models. In addition, although 3D models can be directly annotated, the process becomes challenging due to the low resolution of textures and the large size of the models. In this article, we propose a streamlined, open-access processing pipeline to reproject 2D image annotations onto 3D models using ray tracing. Using four underwater image datasets, we assessed the accuracy of annotation reprojection on 3D models and achieved successful georeferencing to centimetric accuracy. The combination of photogrammetric 3D models and accurate 2D annotations would allow the construction of a 3D representation of the landscape and could provide new insights into understanding species microdistribution and biotic interactions.
Spatial and Geographic Information Science
Marcillat et al. (2024) The best of two worlds: reprojecting 2D image annotations onto 3D models. PeerJ 12:e17557 https://doi.org/10.7717/peerj.17557