KE-Rod Initial Velocity of Hollow Cylindrical Charge

KE-rod warhead is a kind of forward interception warhead. To control the KE-rods to disperse uniformly, the hollow cylindrical charge is applied. Initial velocity is crucial to KE-rods distribution and the coordination between the fuze and the warhead. Therefore, based on the classical Gurney formula of cylindrical charge and tabulate interlayer charge, a mathematical model for calculating the KE-rod initial velocity of hollow cylindrical charge has been deduced based on certain assumptions, of which the basis theory is energy and momentum conservation. To validate this deduced equation, high-speed photography and metal-pass target experimental methods were applied simultaneously to test the initial velocity of designed KE-rod warhead. Testing results clearly indicate that the calculated results of the derived mathematical model coincides with the experimental  results, and with the increase in hollow radius, the calculated results become much closer to the experimental results. But the calculated results of classical Gurney formula are far above the experimental results, and the relative error increases with increase in the hollow diameter. The derived mathematical model with satisfactory accuracy is applicable to calculate the KE-rod initial velocity of hollow cylindrical charge in engineering applications.Defence Science Journal, 2011, 61(1), pp.25-29, DOI:http://dx.doi.org/10.14429/dsj.61.7

Western life courses challenged in life stories collected in contemporary China

IntroductionThe life course describes the progression of life as a social role, from birth to death. Traditional Western life-history studies of the life course usually describe a continuous lifeline with occasional interruptions in between. The extraordinary temporal events of the Anti-Japanese War (AJW), Civil War (CW), Great Famine (GF), Cultural Revolution (CR), and the Reform and Opening-up of China in just few decades mean that the life history of contemporary Chinese older adults may be quite different from those of their western peers.MethodsThe study used qualitative research methods to conduct in-depth interviews with 16 older adults and collect their life stories through a standardized list of questions. Grounded theory was employed to condense, compare, conceptualize, and synthesize patterns within the collected data, approaching the investigation with a “naturalistic” perspective.ResultsBased on a generalized analysis of the Interview transcripts, we can find that Chinese old adults’ life stories were shaped by recurring exceptional and rapidly changing environmental conditions. The themes and sub-themes of Chinese old adults’ life stories were focus on (1) violence, loss of family member, escape and unstable life in their early life which are related to AJW and CW; (2) poverty and starvation in daily life when they were adolescents and young adults which are related to GF; (3) discontinuity, timed opportunities, categorizations in order to split the social relationships and networks in CR. The data also suggest that education is an important part of the life story and that its value changes over time.DiscussionThe discontinuity and instability of the life stories of the Chinese old adults are unexpected according to the dominant Western-influenced life course theories, which enriches life course theory and provides a new perspective for studying the individual life course in a society of constant and rapid change

What happened to parents’ views of school success for autistic children during the COVID-19 pandemic?

BackgroundThe educational views of parents with autistic children directly impacts their children’s academic success. However, little research has been done on how the COVID-19 pandemic impacted parents’ academic and social views.AimThis study analyzes parents’ views of school success for their autistic children in the context of the COVID-19 pandemic and examines the relationships among pandemic stress, parental involvement, and parents’ views of school success for autistic children in mainland China.MethodsIn this study, 713 parents of autistic children completed measures assessing their pandemic stress, parental involvement, and views of school success; linear regression and structural equation modeling were used to analyze the data.ResultsParents’ views of school success were influenced by factors such as parents’ level of education, household income, parents’ gender, and children’s age. The effects of pandemic stress on views of school success for parents of autistic children are complex: physical and mental reaction has a negative direct effect on views of school success, a positive indirect effect mediated by parental involvement, and a net positive effect; risk perception and concern has a negative indirect effect; and both the direct and indirect effects of pragmatic hopefulness are positive. Education policymakers and practitioners need to seriously and carefully assess these results’ implications for modern, inclusive education

Cost-effectiveness of policy options for sustainable wetland conservation : a case study of Qixinghe Wetland, China

The study aims to assist policy makers in deciding how best to balance economic development with wetland conservation. Agriculture accounts for more than 75% of the total water use in the Qixinghe Wetlands area. As the flow of water entering the wetlands is diverted, its ecosystem is damaged. This problem affects many wetland areas in China. Research evidence supports recommendations to local government to reconstruct the irrigation system in the area surrounding the Qixinghe Wetlands. These wetlands are the most important breeding ground and migration route for waterfowls in Northeastern Asia

Expression profiles of five FT-like genes and functional analysis of PhFT-1 in a Phalaenopsis hybrid

Background: Phalaenopsis is an important ornamental flowering plant that belongs to the Orchidaceae family and is cultivated worldwide. Phalaenopsis has a long juvenile phase; therefore, it is important to understand the genetic elements regulating the transition from vegetative phase to reproductive phase. In this study, FLOWERING LOCUS T (FT) homologs in Phalaenopsis were cloned, and their effects on flowering were analyzed. Results: A total of five FT-like genes were identified in Phalaenopsis. Phylogenetic and expression analyses of these five FT-like genes indicated that some of these genes might participate in the regulation of flowering. A novel FT-like gene, PhFT-1, distantly related to previously reported FT genes in Arabidopsis and other dicot crops, was also found to be a positive regulator of flowering as heterologous expression of PhFT-1 in Arabidopsis causes an early flowering phenotype. Conclusions: Five FT homologous genes from Phalaenopsis orchid were identified, and PhFT-1 positively regulates flowering

Effects of Extracellular Vesicles from Osteogenic Differentiated Human BMSCs on Osteogenic and Adipogenic Differentiation Capacity of Naïve Human BMSCs

Osteoporosis, or steroid-induced osteonecrosis of the hip, is accompanied by increased bone marrow adipogenesis. Such a disorder of adipogenic/osteogenic differentiation, affecting bone-marrow-derived mesenchymal stem cells (BMSCs), contributes to bone loss during aging. Here, we investigated the effects of extracellular vesicles (EVs) isolated from human (h)BMSCs during different stages of osteogenic differentiation on the osteogenic and adipogenic differentiation capacity of naïve (undifferentiated) hBMSCs. We observed that all EV groups increased viability and proliferation capacity and suppressed the apoptosis of naïve hBMSCs. In particular, EVs derived from hBMSCs at late-stage osteogenic differentiation promoted the osteogenic potential of naïve hBMSCs more effectively than EVs derived from naïve hBMSCs (naïve EVs), as indicated by the increased gene expression of COL1A1 and OPN. In contrast, the adipogenic differentiation capacity of naïve hBMSCs was inhibited by treatment with EVs from osteogenic differentiated hBMSCs. Proteomic analysis revealed that osteogenic EVs and naïve EVs contained distinct protein profiles, with pro-osteogenic and anti-adipogenic proteins encapsulated in osteogenic EVs. We speculate that osteogenic EVs could serve as an intercellular communication system between bone- and bone-marrow adipose tissue, for transporting osteogenic factors and thus favoring pro-osteogenic processes. Our data may support the theory of an endocrine circuit with the skeleton functioning as a ductless gland

Curcumin-primed human BMSC-derived extracellular vesicles reverse IL-1β-induced catabolic responses of OA chondrocytes by upregulating miR-126-3p

Background Curcumin has anti-inflammatory effects and qualifies as a potential candidate for the treatment of osteoarthritis (OA). However, curcumin has limited bioavailability. Extracellular vesicles (EVs) are released by multiple cell types and act as molecule carrier during intercellular communication. We assume that EVs can maintain bioavailability and stability of curcumin after encapsulation. Here, we evaluated modulatory effects of curcumin-primed human (h)BMSC-derived EVs (Cur-EVs) on IL-1β stimulated human osteoarthritic chondrocytes (OA-CH). Methods CellTiter-Blue Viability- (CTB), Caspase 3/7-, and live/dead assays were used to determine range of cytotoxic curcumin concentrations for hBMSC and OA-CH. Cur-EVs and control EVs were harvested from cell culture supernatants of hBMSC by ultracentrifugation. Western blotting (WB), transmission electron microscopy, and nanoparticle tracking analysis were performed to characterize the EVs. The intracellular incorporation of EVs derived from PHK26 labeled and curcumin-primed or control hBMSC was tested by adding the labeled EVs to OA-CH cultures. OA-CH were pre-stimulated with IL-1β, followed by Cur-EV and control EV treatment for 24 h and subsequent analysis of viability, apoptosis, and migration (scratch assay). Relative expression of selected anabolic and catabolic genes was assessed with qRT-PCR. Furthermore, WB was performed to evaluate phosphorylation of Erk1/2, PI3K/Akt, and p38MAPK in OA-CH. The effect of hsa-miR-126-3p expression on IL-1β-induced OA-CH was determined using CTB-, Caspase 3/7-, live/dead assays, and WB. Results Cur-EVs promoted viability and reduced apoptosis of IL-1β-stimulated OA-CH and attenuated IL-1β-induced inhibition of migration. Furthermore, Cur-EVs increased gene expression of BCL2, ACAN, SOX9, and COL2A1 and decreased gene expression of IL1B, IL6, MMP13, and COL10A1 in IL-1β-stimulated OA-CH. In addition, phosphorylation of Erk1/2, PI3K/Akt, and p38 MAPK, induced by IL-1β, is prevented by Cur-EVs. Cur-EVs increased IL-1β-reduced expression of hsa-miR-126-3p and hsa-miR-126-3p mimic reversed the effects of IL-1β. Conclusion Cur-EVs alleviated IL-1β-induced catabolic effects on OA-CH by promoting viability and migration, reducing apoptosis and phosphorylation of Erk1/2, PI3K/Akt, and p38 MAPK thereby modulating pro-inflammatory signaling pathways. Treatment of OA-CH with Cur-EVs is followed by upregulation of expression of hsa-miR-126-3p which is involved in modulation of anabolic response of OA-CH. EVs may be considered as promising drug delivery vehicles of curcumin helping to alleviate OA

Impact of Vehicular Countdown Signals on Driving Psychologies and Behaviors: Taking China as an Example

Countdown signal control is a relatively new control mode that can inform a driver in advance about the remaining time to pass through intersections or the time needed to wait for other drivers and pedestrians. At present, few countries apply vehicular countdown signals. However, in China, some cities have applied vehicular countdown signals for years, though it is unclear how and how much such signals influence driving psychologies and behaviors compared with non-countdown signal controls. The present work aims to clarify the impact of vehicular countdown signals on driving psychologies and behaviors on the cognitive level. A questionnaire survey with 32 questions about driving psychologies and behaviors was designed, and an online survey was conducted. A total of 1051 valid questionnaires were received. The survey data were analyzed, and the main results indicate that most of the surveyed drivers prefer countdown signal controls and think that such controls can improve not only traffic safety but also traffic operational efficiency. The surveyed drivers also think that countdown signal controls have an impact on driving psychologies and behaviors and the survey results have demonstrated that the driving behaviors of female drivers surveyed are not conservative under the clear conditions of green countdown signal control. Further studies and methods concerning the effects of countdown signals on driving psychologies and behaviors are discussed. Document type: Articl

Effects of white matter hyperintensity on cognitive function in PD patients: a meta-analysis

BackgroundParkinson’s disease (PD) is often accompanied by cognitive dysfunction, which imposes a heavy burden on patients, their families, and society. Early identification and intervention are particularly important, but reliable biomarkers for identifying PD-related cognitive impairment at an early stage are currently lacking. Although numerous clinical studies have investigated the association between brain white matter hyperintensity (WMH) and cognitive decline, the findings regarding the relationships between WMH and cognitive dysfunction in PD patients have been inconsistent. Therefore, this study aims to conduct a meta-analysis of the effect of WMH on PD cognitive function.MethodsThis study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines. We systematically searched relevant literature from databases such as PubMed, Web of Science, EMBASE, CNKI, and CBM. The retrieval time was limited to database records created up until December 31, 2022. Additionally, we manually retrieved references for full-text reading. Statistical data analysis was performed using RevMan 5.3 and Stata 15.0 software.ResultsThis study encompassed 23 individual studies and involved 2,429 patients with PD. The group of PD with mild cognitive impairment (PD-MCI) exhibited a significantly higher overall level of WMH than the group of PD with normal cognitive function (PD-NC) (SMD = 0.37, 95% CI: 0.21–0.52, p < 0.01). This finding was consistent across subgroup analyses based on different ethnicities (Asian or Caucasian), WMH assessment methods (visual rating scale or volumetry), and age matching. In addition to the overall differences in WMH load between the PD-MCI and PD-NC groups, the study found that specific brain regions, including periventricular white matter hyperintensity (PVH) and deep white matter hyperintensity (DWMH), had significantly higher WMH load in the PD-MCI group compared to the PD-NC group. The study also conducted a meta-analysis of WMH load data for PD with dementia (PDD) and PD without dementia (PDND), revealing that the overall WMH load in the PDD group was significantly higher than that in the PDND group (SMD = 0.98, 95% CI: 0.56–1.41, p < 0.01). This finding was consistent across subgroup analyses based on different ethnicities and age matching. Moreover, regarding specific brain regions (PVH or DWMH), the study found that the PDD group had significantly higher WMH load than the PDND group (p < 0.01).ConclusionWMH was associated with PD cognitive dysfunction. The early appearance of WMH may indicate PD with MCI