37 research outputs found
Prescribed-Time Nash Equilibrium Seeking for Pursuit-Evasion Game
Dear Editor, this letter is concerned with prescribed-time Nash equilibrium (PTNE) seeking problem in a pursuit-evasion game (PEG) involving agents with second-order dynamics. In order to achieve the prior given and user-defined convergence time for the PEG, a PTNE seeking algorithm has been developed to facilitate collaboration among multiple pursuers for capturing the evader without the need for any global information. Then, it is theoretically proved that the prescribed-time convergence of the designed algorithm for achieving Nash equilibrium of PEG. Eventually, the effectiveness of the PTNE method was validated by numerical simulation results
Ku Regulates the Non-Homologous End Joining Pathway Choice of DNA Double-Strand Break Repair in Human Somatic Cells
The repair of DNA double-strand breaks (DSBs) is critical for the maintenance of genomic integrity and viability for all organisms. Mammals have evolved at least two genetically discrete ways to mediate DNA DSB repair: homologous recombination (HR) and non-homologous end joining (NHEJ). In mammalian cells, most DSBs are preferentially repaired by NHEJ. Recent work has demonstrated that NHEJ consists of at least two sub-pathways—the main Ku heterodimer-dependent or “classic” NHEJ (C-NHEJ) pathway and an “alternative” NHEJ (A-NHEJ) pathway, which usually generates microhomology-mediated signatures at repair junctions. In our study, recombinant adeno-associated virus knockout vectors were utilized to construct a series of isogenic human somatic cell lines deficient in the core C-NHEJ factors (Ku, DNA-PKcs, XLF, and LIGIV), and the resulting cell lines were characterized for their ability to carry out DNA DSB repair. The absence of DNA-PKcs, XLF, or LIGIV resulted in cell lines that were profoundly impaired in DNA DSB repair activity. Unexpectedly, Ku86-null cells showed wild-type levels of DNA DSB repair activity that was dominated by microhomology joining events indicative of A-NHEJ. Importantly, A-NHEJ DNA DSB repair activity could also be efficiently de-repressed in LIGIV-null and DNA-PKcs-null cells by subsequently reducing the level of Ku70. These studies demonstrate that in human cells C-NHEJ is the major DNA DSB repair pathway and they show that Ku is the critical C-NHEJ factor that regulates DNA NHEJ DSB pathway choice
A Biomechanical Waist Comfort Model for Manual Material Lifting
Low back pain (LBP) is a common disorder that affects the working population worldwide. LBP causes more disability than any other conditions all around the world. Most existing studies focus on the occupational physical factors in association with LBP, while few focus on individual factors, especially the lack of quantitative calculation of waist comfort in biomechanics. Based on the physical statistics of Chinese men, this research used human posture analysis (HPA) to establish the waist strength formula and analyzed the waist strength during a manual material handling. It also explored the influence of weight and height of lifting objects on the L5-S1 spinal load. On this basis, a waist comfort model was proposed in combination with the recommended weight limit (RWL) recommended by NIOSH, and the parameter selection and waist comfort value were verified by Jack simulation software. The results show that pulling force of the Erector Spinae of the waist is closely related to the weight and lifting height of the object. Parameter verification and Jack software simulation results show that the force of L5-S1 is less than 3400 N, which proves that the waist force under this posture is acceptable. The developed waist comfort model can be applied to evaluate work risk, to adjust working intensity and powered exoskeleton design, aiming to decrease the prevalence of LBP
Infinitely many solutions for Kirchhoff-type problems depending on a parameter
In this article, we study a Kirchhoff type problem with a positive parameter
,
\displaylines{
-K\Big( \int_{\Omega }|\nabla u|^{2}dx\Big) \Delta u=\lambda
f(x,u) , \quad \text{in } \Omega , \cr
u=0, \quad \text{on } \partial \Omega ,
}
where is a continuous
function and is a
-Caratheodory function. Under suitable assumptions
on K(t) and f(x,u), we obtain the existence of infinitely many
solutions depending on the real parameter .
Unlike most other papers, we do not require any symmetric condition
on the nonlinear term . Our proof is based on variational methods
Development and Validation of the Haze Risk Perception Scale and Influencing Factor Scale—A Study Based on College Students in Beijing
Although Beijing’s air quality has improved, there is still a long way to go for haze governance. In order to understand haze risk perception and related influencing factors among college students in Beijing, we developed and verified two scales, with college students as the survey object, and analyzed the theoretical framework and realistic level of haze risk perception and influencing factors through empirical research. We showed that the reliability and validity of the two scales are excellent, and they can be used as a powerful tool to measure college students’ perception of haze. The haze risk perception scale (HRPS) is divided into four dimensions. The degrees of perception ranked from high to low are: direct consequences perception, indirect consequences perception, risk responsibility perception and risk source perception. The haze risk perception influencing factor scale (HRPIFS) is divided into three dimensions. The degrees of influence ranked from high to low are: personal emotion, media communication and government policy; the three influencing factors all have a significant positive correlation to overall haze risk perception, but personal emotions and media communication are only significantly related to the three dimensions of direct consequence perception, indirect consequence perception and risk source perception. Government policy is only significantly related to the three dimensions of direct consequence perception, indirect consequence perception and risk liability perception. This paper proves the important role of media in haze risk perception and puts forward some policy suggestions to guide the public to form a rational risk perception. These findings can help improve theoretical and practical research related to haze risk
Effect of Supplemental Cyanocobalamin on the Growth Performance and Hematological Indicators of the White Pekin Ducks from Hatch to Day 21
The experiment was conducted to evaluate the requirement of cyanocobalamin of male Pekin ducks from hatch to 21 days of age. A total of three-hundred-eighty-four, one-day-old meat-type male Pekin ducks were randomly allocated to six treatments, i.e., dietary cyanocobalamin (vitamin B12) concentrations of 0.00, 0.02, 0.04, 0.06, 0.08 and 1.00 mg/kg, respectively in their feed. Each treatment had eight replicated pens with eight ducks for each pen. Feed and water were provided ad libitum. The experiment was conducted for 21 days. Different growth parameters including average daily weight gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), and hematological indicators were evaluated because, on the basis of hematological indicators, the health and nutritional status of an animal can be accessed. It is observed that supplemental cyanocobalamin has no significant effect on ADG, ADFI, and FCR but it improves hematological parameters such as white blood cells, red blood cells, and its indices and platelet counts compared to the control group (p < 0.05). On the basis of growth performance and hematological indicators it is concluded that 0.02 mg cyanocobalamin/kg of feed is the dietary requirement of male Pekin ducks from hatch to day 21 of age
Study on Desiccation Tolerance and Biochemical Changes of <i>Sassafras tzumu</i> (Hemsl.) Hemsl. Seeds
The deciduous tree species Sassafras tzumu (Hemsl.) Hemsl., unique to China, holds significant economic and ecological value. However, its seeds exhibit poor storage tolerance and rapid decline in seed vigor. This study primarily investigates the desiccation tolerance of S. tzumu seeds. The results show that S. tzumu seeds have recalcitrant seed characteristics, with a semi-inactivation water content (at which point half of the seeds lose viability) of 20.7%. As desiccation progresses, seed viability decreases significantly; at a reduced water content of 11.93%, only 18.3% of the seeds remain viable, while most lose their viability completely. Relative electrolytic leakage (REC) and H2O2 content gradually increase during this process, while MDA content initially decreases before increasing again, exhibiting distinct trends compared to antioxidant enzyme activities such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). SOD and POD activities exhibit an initial increase followed by a rapid decrease, whereas CAT activity shows a decline followed by a rapid increase. Dehydration to 15% water content in seeds is a key turning point in the process of seed desiccation in S. tzumu, and CAT is an enzyme key to maintaining seed viability. Both the accumulation of toxins and the decline in the activity of the antioxidant system contribute to the susceptibility of S. tzumu seeds to drought stress, a characteristic common to all recalcitrant seeds. To maintain high seed viability above 70% during storage, it is crucial to ensure water content above 23.58%
Dynamic Evolution of Public’s Positive Emotions and Risk Perception for the COVID-19 Pandemic: A Case Study of Hubei Province of China
The spread of COVID-19 pandemic and the participation of Internet information are continually changing the public’s positive emotions and risk perception. However, relatively little is known about the underlying mechanism of how the COVID-19 dynamic situation affects the public’s risk perception and emotions. This study uses the social risk amplification framework (SRAF) as the theoretical basis to collect and analyze Hubei Province data from January 20 to April 8, 2020, including the number of newly diagnosed people per day, the proportion of positive emotional posts in Weibo, and the Baidu search index (BSI). The autoregressive integrated moving average (ARIMAbased time-series prediction model is used to analyze the dynamic evolution laws and fluctuation trends of Weibo positive emotions and risk perception during the development of the pandemic. The conclusion of the study is that positive emotions are negatively correlated with risk perception, the severity of the pandemic situation is negatively correlated with positive emotions, and the severity of the pandemic situation is positively correlated with risk perception. The public has a keen response to the dynamics of the pandemic situation and the government’s decision-making behavior, which is manifested by the significant changes in positive emotions and risk perception in the corresponding period. The research results can provide a reference for government departments to guide the public to establish an objective risk perception and maintain positive and stable emotions in similar catastrophes
Effects of the Dietary Replacement of Soybean Oil with Rubber Seed Oil on the Growth Performance, Carcass Trait, and Status of Lipid Metabolism in Pekin Ducks
The objective of this study is to determine the effects of the dietary replacement of soybean oil (SO) with rubber seed oil (RSO) on the growth performance, carcass trait, and lipid metabolism in Pekin ducks. A total of 160 1-day-old Pekin ducks were randomly allocated to four experimental treatments and fed diets with different ratios of SO to RSO as follows: 3:0 (control), 2:1, 1:2, and 0:3. Dietary RSO supplementation had no effect on their growth performance; however, it significantly decreased the yield of abdominal fat (p p p p p FABP1, ME1, SREBP1c, FASN, DGAT2, and HMGCR (p ABCA1 gene (p < 0.05) in the liver of the ducks. In conclusion, dietary RSO supplementation reduced fat deposition and enhanced n-3 PUFA levels without affecting the growth performance of Pekin ducks
Feeding Laying Ducks <i>Eucommia ulmoides oliv.</i> Leaves Increases the n-3 Fatty Acids Content and Decreases the n-6: n-3 PUFA Ratio in Egg Yolk without Affecting Laying Performance or Egg Quality
The objective was to determine the effects of supplementing duck diets with Eucommia ulmoides oliv. leaf powder (EUL). Laying ducks (n = 480) were randomly allocated into 4 experimental treatments and fed diets containing 0, 1, 2, or 4% EUL. Dietary inclusion of EUL had no effect (p > 0.05) on laying performance or egg quality, but linearly increased (p p p p p p >0.05)