Perforation of the skin by fragment impact is a key determinant of the severity of an injury and incapacitation during modern asymmetric warfare. Computational models validated against experimental data are thus desired for simulating the responses of a skin simulant against fragment impact. Toward this end, experiments and concurrent computational modeling were used to investigate the dynamic responses of the skin simulant against fragment impact. Fragment simulating projectiles (FSPs) of masses 1.10 g and 2.79 g were considered herein, and the responses of the skin simulant were investigated in terms of the threshold velocity, energy density, peak displacement, and failure mechanisms. The results illustrate numerous salient aspects. The skin simulant failure involved cavity shearing followed by elastic hole enlargement, and these results were sensitive to the strain rate. The best agreement between the simulated and experimental results was achieved when the input stress-strain curves to the simulation were based on the full spectrum of strain rates. When a single stress-strain curve corresponding to a specific strain rate was used as the input, the threshold velocity and peak displacement of the skin simulant were either underpredicted or overpredicted depending on the strain rate considered. The threshold velocity was also sensitive to the input failure strain; here, the best agreement was obtained when the failure strain was based on the theoretical limiting strain. When the FSP materials were changed to plastics, the threshold velocities increased by up to 33%; however, the energy densities and generated stresses exceeded the contusion and laceration thresholds of the skin.

Grandparents play different roles in families of children and adolescents on the autism spectrum. They are frequently engaged in caregiving tasks with the person on the autism spectrum, providing emotional and instrumental support to the family. However, despite their frequent involvement and the importance of their role in the family, there are few studies that address the experiences of these grandparents, particularly in the Spanish and southern Europe context. This study explores the impact and needs of having a grandchild on the autism spectrum and the resources that grandparents have and use to face the difficulties that arise. A semi-structured interview was carried out with 17 grandparents of children and adolescents on the autism spectrum. We conducted a coding reliability thematic analysis of the impact and used a quantitative content analysis of grandparents\' needs and resources. Results indicated three main aspects related to the impact: personal growth, wanting to help and not being able to, and suffering at three levels: for themselves, their sons and daughters, and grandchildren. Grandparents perceived needs in four contexts: their own needs, the needs of the nuclear family, the needs of the person on the autism spectrum, and the needs of society. The most frequent needs were informational and management of behavioral difficulties. In the resources, the most frequently used strategies were religious beliefs and informal support seeking. It is essential to address the quality of parents-grandparents\' relationships, and include grandparents in intervention programmes, as a way of addressing grandparents\' needs.

Cyberbullying is bullying with the use of digital technologies, which can take place on social media, messaging platforms, gaming platforms, and mobile phones. It is repeated behavior aimed at scaring, angering, or shaming those who are targeted. India happens to be one of the rapidly improving countries in the cyber world and thus faces a lot of problems regarding cyber crimes, especially cyberbullying. This narrative review aims to provide a thorough assessment of the impact of cyberbullying among Indian adolescents. The database engines such as PubMed, Google Scholar, and PsycINFO were searched relevant to the Indian context, focused on cyberbullying and victimization among adolescents, and published within the last 10 years (2014-2024) were included. Around 19 articles were reviewed and analyzed. Cyberbullying in India is on the rise due to increased technology access, social media, and insufficient awareness and prevention measures, with significant gender differences in aggression patterns. The severe psychological and physiological effects on victims, including depression and stress-related health issues, highlight the need for accurate data and culturally tailored interventions. Studies show varying prevalence rates, emphasizing the urgent need for focused efforts to combat cyberbullying among Indian youth. The review encompasses various aspects, including prevalence, standard methods, forms, causes, consequences, and effects on mental health factors contributing to cyberbullying in India. Additionally, the review explores cyberbullying during COVID-19 and interventions for cyberbullying and highlights the evidence from cohort studies, mixed-method studies, and systematic reviews. A growing number of adolescents are experiencing cyberbullying, which has a severe impact on their lives and leads to unexpected deviances. Cyberbullying remains a growing threat, requiring stronger, coordinated action by the government to genuinely make a difference and safeguard adolescents in India.

Ghana was the first sub-Saharan country to implement a National Health Insurance Scheme (NHIS). In furtherance of the nation\'s Universal Health Coverage (UHC) goals, in 2008, Ghana actualized plans for a Free Maternal Healthcare Policy (FMHCP) under the NHIS. The FMHCP was aimed at removing financial barriers to accessing maternal and neonatal health services. This scoping review was conducted to map out the literature on the effects of the FMHCP under the NHIS on the utilization of maternal and infant health care in Ghana. Six databases including CINAHL, PubMed, Sage Journals, Academic Search Premier, Science Direct, and Medline were searched in conducting this review with key terms. A total of 175 studies were retrieved after the search and finally, 23 articles were included in the study after various stages of elimination. The review followed the reporting guidelines stated in the Preferred Reporting Items for Systematic and Meta-analyses Extensions for Scoping Reviews (PRISMA-ScR). The results showed an overall increase in the utilization of antenatal care, facility-based delivery, and postnatal care services. However, certain systemic issues persist regarding access to maternal and infant healthcare. Socio-demographic inequalities such as maternal level of education, place of residence, and economic status likewise barriers such as the existence of out-of-pocket payments, long distance to health facilities, and poor distribution of resources in rural areas hindered the utilization of maternal and infant healthcare. The country faces significant work to eliminate existing barriers and inequalities to ensure that it achieves its UHC goals.

Freshwater ecosystems can serve as model systems that reveal insights into biological invasions. In this article, we summarize nine lessons about aquatic invasive species from the North Temperate Lakes Long-Term Ecological Research program and affiliated projects. The lessons about aquatic invasive species are as follows: Invasive species are more widespread than has been documented; they are usually at low abundance; they can irrupt from low-density populations in response to environmental triggers; they can occasionally have enormous and far-reaching impacts; they can affect microbial communities; reservoirs act as invasive species hotspots; ecosystem vulnerability to invasion can be estimated; invasive species removal can produce long-term benefits; and the impacts of invasive species control may be greater than the impacts of the invasive species. This synthesis highlights how long-term research on a freshwater landscape can advance our understanding of invasions.

Mystical-like states of consciousness may arise through means such as psychedelic substances, but may also occur unexpectedly during near-death experiences (NDEs). So far, research studies comparing experiences induced by serotonergic psychedelics and NDEs, along with their enduring effects, have employed between-subject designs, limiting direct comparisons. We present results from an online survey exploring the phenomenology, attribution of reality, psychological insights, and enduring effects of NDEs and psychedelic experiences (PEs) in individuals who have experienced both at some point during their lifetime. We used frequentist and Bayesian analyses to determine significant differences and overlaps (evidence for null hypotheses) between the two. Thirty-one adults reported having experienced both an NDE (i.e. NDE-C scale total score ≥27/80) and a PE (intake of lysergic acid diethylamide, psilocybin/mushrooms, ayahuasca, N,N-dimethyltryptamine, or mescaline). Results revealed areas of overlap between both experiences for phenomenology, attribution of reality, psychological insights, and enduring effects. A finer-grained analysis of the phenomenology revealed a significant overlap in mystical-like effects, while low-level phenomena (sensory effects) were significantly different, with NDEs displaying higher scores of disembodiment and PEs higher scores of visual imagery. This suggests psychedelics as a useful model for studying mystical-like effects induced by NDEs, while highlighting distinctions in sensory experiences.

The middle and lower reaches of the Jinsha River, which is the upper reach of the Yangtze River in China, play crucial roles in the water security of people living in the middle and lower reaches of the Yangtze River. The construction of 11 dams in this region has significantly altered the aquatic environment. Although researchers have investigated the effects of cascade hydropower station development in the middle and lower reaches of the Jinsha River based on factors such as flow, sediment, and fish, the overall impact of this station on the aquatic environment remains unclear. Therefore, the purpose of this study is to comprehensively investigate the effects of cascade hydropower station development on the aquatic environment based on three factors: river, aquatic organism, and ecosystem factors. In terms of river factors, the development of cascade hydropower stations increases runoff in the dry season and decreases it in the flood season, leading to sediment deposition and water temperature stratification in cascade reservoirs, and changes in water quality. In terms of aquatic organism factors, cascade hydropower development not only changes the species composition but also reduces biodiversity. Effects of ecosystem factors including the ecological flow, value, and landscape as well as sustainability are summarized, with results indicating positive and negative impacts on river ecosystems. Finally, recommendations for future research on the effects of cascade hydropower development on the aquatic environment of rivers are provided.

暂无摘要。

The detection of impact and depth defects in Glass Fiber Reinforced Polymer (GFRP) composites has been extensively studied to develop effective, reliable, and cost-efficient assessment methods through various Non-Destructive Testing (NDT) techniques. Challenges in detecting these defects arise from varying responses based on the geometrical shape, thickness, and defect types. Long Pulse Thermography (LPT), utilizing an uncooled microbolometer and a low-resolution infrared (IR) camera, presents a promising solution for detecting both depth and impact defects in GFRP materials with a single setup and minimal tools at an economical cost. Despite its potential, the application of LPT has been limited due to susceptibility to noise from environmental radiation and reflections, leading to blurry images. This study focuses on optimizing LPT parameters to achieve accurate defect detection. Specifically, we investigated 11 flat-bottom hole (FBH) depth defects and impact defects ranging from 8 J to 15 J in GFRP materials. The key parameters examined include the environmental temperature, background reflection, background color reflection, and surface emissivity. Additionally, we employed image processing techniques to classify composite defects and automatically highlight defective areas. The Tanimoto Criterion (TC) was used to evaluate the accuracy of LPT both for raw images and post-processed images. The results demonstrate that through parameter optimization, the depth defects in GFRP materials were successfully detected. The TC success rate reached 0.91 for detecting FBH depth defects in raw images, which improved significantly after post-processing using Canny edge detection and Hough circle detection algorithms. This study underscores the potential of optimized LPT as a cost-effective and reliable method for detecting defects in GFRP composites.

The large-scale use of composite materials reinforced with carbon-aramid hybrid fabric in various outdoor applications, which ensures increased mechanical resistance including in impact loadings, led to the need to investigate the effects of aggressive environmental factors (moisture absorption, temperature, thermal cycles, ultra-violet rays) on the variation of their mechanical properties. Since the literature is still lacking in research on this topic, this article aims to compare the low-velocity impact behaviour of two carbon-aramid hybrid composite materials (with and without rubber core) and to investigate the effects of water absorption on impact properties. The main objectives of this research were as follows: (i) the investigation of the mechanical behavior in tests for two impact energies of 25 J and 50 J; (ii) comparison of the results obtained in terms of the force, displacement, velocity, and energy related to the time; (iii) analysis of the water absorption data; (iii) low-velocity impact testing of wet specimens after saturation; (iv) comparison between the impact behaviour of the wet specimens with that of the dried ones. One of the main findings was that for the wet specimens without rubber core, absorbed impact energy was 16% less than the one recorded for dried specimens at an impact energy of 50 J. The failure modes of the dried specimens without rubber core are breakage for both carbon and aramid fibres, matrix cracks, and delamination at matrix-fibre interfaces. The degradation for the wet specimens with rubber core is much more pronounced because the decrease in the absorbed impact energy was 53.26% after 10,513 h of immersion in water and all the layers were broken.