Schlieren Techniques for Observations of Long Positive Sparks: Review and Application

Understanding the mechanism of positive leader discharge is important in lightning protection engineering and the external insulation design in high voltage power transmission systems. During the propagation of a positive leader, some processes without light-emitting, for example, the insulation recovery process after the breakdown, cannot be observed by optical photography techniques. With the combination of the digital high-speed imaging system, the conventional Schlieren techniques offer new vistas in the long air gap discharge observation. The important features of high spatial resolution, high sensitivity, and easy arrangement make Schlieren techniques powerful and effective tools for characterising the discharge processes without light-emitting. This work presents a brief review of current Schlieren techniques and discusses the design of the Schlieren optics system for long spark observations. Several interesting phenomena discovered at different phases of long sparks with high-speed Schlieren techniques are also presented

Effect of Microwave Treatment and Drying Time on the Antioxidant Activity of in Vitro Digested Dried Abalone

During oven drying of abalone muscle, microwave treatment was conducted at regular time intervals (0, 30, 60, 90 and 120 days). Abalone muscle digestion products (AMDP) were prepared by subjecting dried abalone to in vitro simulated digestion. Our aim was to investigate the effect of microwave treatment during the drying of abalone muscle on the in vitro and in vivo antioxidant activities of AMDP. The results showed that the half maximal inhibitory concentration (IC50) values of AMDP from fresh abalone muscle for scavenging capacity against hydroxyl (·OH) radicals, N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD) and 1,1-diphenyl-2-phenylhydrazine (DPPH) radical were 3.04, 15.18 and 21.12 mg/mL, respectively. The IC50 values for the scavenging of these three radical species decreased gradually with increasing the drying time of abalone muscle. After being fed AMDP from abalone muscle dried for 120 days, the body length of Caenorhabditis elegans increased from 768.90 to 1 034.62 μm, the head swing frequency increased from 206 to 281 times/min, and the life span was extended by 36.16% under normal conditions and by 59.41% and 38.48% under heat stress and oxidative stress conditions, respectively compared with the control group. Meanwhile, with prolonging the drying time of abalone muscle, the antioxidant enzyme activities, reduced glutathione (GSH) content and total antioxidant capacity of C. elegans fed AMDP increased, and the reactive oxygen species (ROS) content decreased. In summary, prolonging the drying time and using microwave treatment during the drying process could improve the antioxidant capacity of AMDP

The effect of water temperature on the pathogenicity of decapod iridescent virus 1 (DIV1) in Litopenaeus vannamei

Decapod iridescent virus 1 (DIV1) has caused huge losses to the shrimp breeding industry in recent years as a new shrimp virus. In this study, white leg shrimp, Litopenaeus vannamei, were cultured at different temperatures (26 ± 1 °C and 32 ± 1 °C) and the same salinity, then infected with DIV1 by intramuscular injection to determine the effects of water temperature on viral infection. The DIV1 copy counts in the gills, hepatopancreas, pleopods, intestines, and muscles of L. vannamei were measured in samples collected at 6, 12, and 24 h post-infection (hpi), and the survival rate of L. vannamei was assessed every 6 h after infection. At 96 hpi, the survival rates of L. vannamei in the high (32 ± 1 ℃) and standard (26 ± 1 ℃) water temperature groups were 2.22% and 4.44%, respectively. The peak time of mortality in the high-water temperature group was 6 h earlier than in the standard water temperature group. After 24 hours of DIV1 infection, the DIV1 copy counts in the standard water temperature treatment group were significantly higher than those in the high-water temperature treatment group. The tissues with the highest virus copy counts in the standard and high-temperature groups were the intestines (2.9×1011 copies/g) and muscles (7.0×108 copies/g). The effect of temperature on the pathogenicity of DIV1 differs from that of other previously studied viruses, such as white spot syndrome virus, Taura syndrome virus, and infectious hypodermal and hematopoietic necrosis virus, because the high-water temperature did not mitigate the damage caused by DIV1 infection

An analysis of the influencing factors of depression in older adults under the home care model

ObjectivesTo explore and analyze the influencing factors of depression in older adults living at home, so as to propose suggestions for improving the quality of older adults living at home.MethodsWe conducted a cross-sectional study on 498 older adults living at home based on questionnaire survey on the general information, daily living ability, health status, and care perception (including self-care, care for cohabitants, and care for non-cohabitants) of older adults living at home, as well as their willingness to help each other, and analyzed the influencing factors of depression among older adults living at home.ResultsThe results showed a willingness to help older adults, self-care, and total activities of daily living (ADL), health status was an influential factor for depression in older adults (p < 0.05).ConclusionIt aims to take targeted measures, such as encouraging older adults at home to actively participate in mutual assistance activities for older adults and care for themselves, so as to prevent and reduce the occurrence of depression in older adults

Effects of Land Cover Pattern Along Urban-Rural Gradient on Bird Diversity in Wetlands

Wetlands play an important role in the feeding, breeding, and lives of birds. However, available habitats for bird species are changing due to intensifying human activity, especially in the context of China’s mass urbanization. Urban sprawl has taken over the wetlands along the lakes in the past decades, which places tremendous pressure on wetland ecosystems and, therefore, on bird communities. However, the ways urban land cover pattern along the urban-rural gradient affects bird communities is still unclear. To investigate the influence of land cover pattern on the α and β diversity of birds in the urban-rural gradient we chose 31 sites distributed within the wetlands around the Dianchi Lake in Yunnan, China. We calculated the species richness to indicate α diversity and used the Morisita–Horn index to indicate β diversity. Meanwhile, we assessed the land cover pattern of each site by measuring the proportion of emergent plants, floating plants, submerged plants, ponds, forests, lawns, roads, agricultural lands and built lands in a quadrat of 1 square kilometer. Simple linear regressions, model selection, and an averaging approach based on corrected Akaike information criterion (AICc) were used to test the effects of land cover pattern on bird diversity. Using one-way ANOVA and Tukey’s HSD (honestly significant difference) test, we compared the difference between α and β diversity, respectively, along the urban-rural gradient. Based on our analyses, urban and suburban wetland birds were significantly homogeneous. The community structure in rural wetlands, however, was significantly different from that of the suburban and urban areas. According to our research, the land cover patterns that influenced bird species richness were the built lands acreage, submerged plants acreage, ponds acreage, and the edge density of emergent plants. Meanwhile, of these variables, the built lands acreage, ponds acreage and edge density of emergent plants were significantly different in urban, suburban, and rural wetlands. Therefore, to maintain high biodiversity in wetlands affected by urbanization, we must pay more attention to the land cover patterns

Effects of Dietary Supplementation with Glutamine on the Immunity and Intestinal Barrier Gene Expression in Broiler Chickens Infected with Salmonella Enteritidis

The effects of glutamine (Gln) on immunity and intestinal barrier gene expression levels in broilers challenged with Salmonella Enteritidis were evaluated. A total of 400 1-day-old broilers were randomly assigned to four groups, 10 repetition treatments per group with 10 broiler chickens for a 21-day feeding trial. The groups were the normal control group (CON, no infected group, fed with a basal diet); the S. Enteritidis-infected control group (SCC, infected with 2.0 × 104 CFU/mL of S. Enteritidis, fed a basal diet); and the Gln 1 and 2 groups, who were challenged with S. Enteritidis and fed a basal diet plus Gln at 0.5% and 1.0%, respectively. The results show that S. Enteritidis had adverse effects on the average daily feed intake, average daily gain, and the feed conversion ratio of infected broilers compared with those of CON broilers on d 7 (p < 0.05); decreased serum immunoglobulin A (IgA), immunoglobulin M (IgM), and immunoglobulin G (IgG) concentrations, and intestinal mucosa Bcl-2 mRNA expression levels (p < 0.05); increased the Lysozyme (LZM, only serum), NO, inducible NO synthase (iNOS) (except at 4 d), and total nitric oxide synthase (TNOS) (except at 4 d) activities in serum and the intestinal mucosa; and increased intestinal mucosa polymeric immunoglobulin receptor (pIgR) (except at 21 d), Avian beta-defensin 5 (AvBD5), AvBD14, Bax, and Bak mRNA expression levels during the experimental period (p < 0.05). Supplementation with Gln improved growth performance; increased serum IgA, IgG, and IgM concentrations and intestinal mucosa Bcl-2 mRNA expression levels (p < 0.05); decreased the LZM (only serum), NO, iNOS (except at 4 d), and TNOS (except at 4 d) activities in serum and the intestinal mucosa; and decreased intestinal mucosa pIgR (except at 21 d), AvBD5, AvBD14, Bax, and Bak mRNA expression levels during the experimental period (p < 0.05). These results suggest that Gln might lessen the inflammatory reaction of the small intestine and enlarge the small bowel mucosa immune and barrier function in broiler chickens challenged with S. Enteritidis

PM2.5 induced apoptosis in endothelial cell through the activation of the p53-bax-caspase pathway

Resenha de:VOMMARO, Gabriel; COMBES, Hélène. El clientelismo político:desde 1950 hasta nuestros días. Buenos Aires: Siglo XXI Editores,2016, 192 p. A obra resenhada apresenta um panorama didático e imprescindível dos estudos sobre o clientelismo, inclusive em sociedades contemporâneas. Representa uma contribuição fundamental para as ciências sociais, ao ampliar a perspectiva da denunciação, ressaltar que o clientelismo é noção dificilmente dissociada de uma intenção moral e, especialmente, indagar em que medida os diagnósticos intelectuais da patologia da política são mobilizados na condição de crítica, deslegitimação ou desqualificação das práticas dos oponentes na luta política

Association of Peridialysis Blood Pressure and Its Variability with Cardiovascular Events in Hemodialysis Patients

Background/Aims: Blood pressure variability (BPV) is a novel cardiovascular risk factor for the population undergoing hemodialysis (HD). Methods: We conducted a retrospective cohort study of 526 HD patients. Four short-term peridialysis BPV metrics were analyzed: systolic blood pressure (SBP) change, SBP coefficient of variation (CV), SBP intradialytic average real variability (ARV), and absolute SBP residual. Multi variate analysis with Cox regression models were used to account for the potential confounders. Results: Short-term BPV is found to be affected by age, pre-dialysis SBP, antihypertensive drugs, dialysis time, and vascular access. Calcium-channel blockers (CCBs) were found to be associated with lower BPV than those on non-CCB therapy or no antihypertensive drugs. Patients dialyzed in the morning had a greater absolute SBP change than those dialyzed in the afternoon or evening. Patients using fistulas had a lower BPV than catheters. Higher BPV metrics including SBP CV (unadjusted hazard ratio [HR]: 1.37, 95% confidence interval [CI] 1.14-1.66, p=0.001), SBP intradialytic ARV (unadjusted HR: 1.46, 95% CI: 1.20-1.77, p< 0.001), and SBP residual (unadjusted HR: 1.47, 95% CI: 1.21-1.79, p< 0.001) were associated with a greater risk of cardiovascular events. After complete multivariate adjustment for other potential confounders, the HR remained statistically significant for SBP intradialytic ARV (HR 1.31, 95% CI: 1.04-1.66, p=0.024). Conclusion: Peridialytic BPV may be a potential target for improved blood pressure (BP) management in HD patients. Each short-term BPV metric has different advantages and disadvantages and should be applied according to the clinical context and purpose