Effect of incubation period on epidemic spreading in complex networks

We study the effect of incubation period on epidemic spreading in the Barabasi-Albert scale-free network and the Watts-Strogatz small world network by using a Suspectable-Incubated-Infected-Suspectable model. Our analytical investigations show that the epidemic threshold is independent of incubation period in both networks, which is verified by our large-scale simulation results. We also investigate the effect of incubation period on the epidemic dynamics in a supercritical regime. It is found that with the increase of incubation period Ω, a damped oscillation evolution of ρT （the ratio of persons in incubated state） appears and the time needed to reach a saturation value increases. Moreover, the steady value of ρT increases and approaches to an asymptotic constant with the value of Ω increasing. As a result, the infected ratio ρI decreases with the increase of Ω according to a power law.

Influence of Harvest Periods on Cassava (Manihot esculenta Crantz) Agronomic Traits and Physiological Response to Post-Harvest Physiological Deterioration

Cassava (Manihot esculenta Crantz) is the third largest source of calories in tropical countries and the sixth most important food crop in the World. However, the short shelf life of its storage roots after harvest due to a rapid post-harvest physiological deterioration (PPD) makes the roots to be considered as a risky product to market. The objectives of this work were to investigate the influence of two harvest periods on cassava agronomic parameters and their physiological response to PPD. Three cassava cultivars 96/1414, I070593 and LMR were selected for the experiment and harvested at 10 and 12 months after planting (MAP). The response to PPD was assessed during storage at 0, 3, 8 and 15 days after harvest (DAH). Total proteins content, soluble sugars and starch, total polyphenols compounds, polyphenoloxidase and peroxidase activities were recorded during storage. Results showed large variation among the parameters at the two harvest periods across the cultivars. High number of tubers was recorded in all the cultivars at 12 MAP and a significant increase in storage roots length was observed in 96/1414 and LMR from 10 MAP to 12 MAP (25 ± 5.1 to 41.3 ± 5.9 and 22.6 ± 3.3 to 27.9 ± 4.8) respectively. A reduction of about 49% of tubers weight was observed in I070593 from 10 to 12 MAP while an increase of about 36% and 11% were recorded in LMR and 96/1414 respectively. Tubers from I070593 showed less susceptibility to PPD when harvested at 10 MAP compared to those from LMR and 96/1414 where less susceptibility to PPD were recorded at 12 MAP. An increase in soluble sugars content, total proteins content and peroxidase activity subsequently to a decrease in starch content were recorded during storage from 8 to 15 days after harvest especially at 10 MAP in I070593 and at 12 MAP in LMR and 96/1414. High content of total phenolic compounds and less activity of polyphenol oxidase were correlated to PPD susceptibility. This work opens a new insight issue of the consideration of the appropriate harvest time of the cultivars as a tool to better control the onset of postharvest physiological deterioration.

Asymptotic Periodicity in the Fecally-Orally Epidemic Model in a Heterogeneous Environment

To understand the influence of seasonal periodicity and environmental heterogeneity on the transmission dynamics of an infectious disease, we consider asymptotic periodicity in the fecally-orally epidemic model in a heterogeneous environment. By using the next generation operator and the related eigenvalue problems, the basic reproduction number is introduced and shows that it plays an important role in the existence and non-existence of a positive T-periodic solution. The sufficient conditions for the existence and non-existence of a positive T-periodic solution are provided by applying upper and lower solutions method. Our results showed that the fecally-orally epidemic model in a heterogeneous environment admits at least one positive T-periodic solution if the basic reproduction number is greater than one, while no T-periodic solution exists if the basic reproduction number is less than or equal to one. By means of monotone iterative schemes, we construct the true positive solutions. The asymptotic behavior of periodic solutions is presented. To illustrate our theoretical results, some numerical simulations are given. The paper ends with some conclusions and future considerations.

Investigation and Research on the Psychological Status of Children and Adolescents During the Epidemic Period of COVID-19

Objective:The paper was to analyze the investigation and study of the psychological status of children and adolescents during the epidemic period of COVID-19.Methods:From March 5th to 11th,2020,1766 students from 8 to 18 years old in Yan'an area were taken as the research objects,and the psychological characteristics of this group of people during the epidemic period of COVID-19 were analyzed by the online questionnaires.Results:In the questionnaire,all children and adolescents were in good psychological conditions,and they had not shown serious negative psychological emotions,and they attached great importance to COVID-19.Conclusion:The psychological changes of children and adolescents during the epidemic period of COVID-19 are diverse.Most children and adolescents have a good mental state,and a few have negative psychological emotions.It can strengthen the psychological management of children and adolescents during the epidemic,and promote the healthy growth of children and adolescents clinically.

Promotion and Renewal of the Outdoor Environment of the Collective Housing That Promotes Health <br/>—Based on the Post-Epidemic Perspective

The COVID-19 is a major global health event that has changed people’s lives and behaviors. As a fragile and sensitive area with high population density and poor living conditions in the city, collective housing is also an important construction area for future urban renewal. In the process of the spread of the new crown epidemic, the collective housing has exposed a series of weaknesses such as difficult community management, inconvenience of life, and insufficient outdoor space. Therefore, the update and transformation of the outdoor environment of the collective housing combined with the concept of public health is a problem that must be considered at present. This article combines the practice of renewal and transformation of the X community in Chaoyang District, Beijing, combined with survey methods such as questionnaires, interviews, and observations, combined with the needs of residents and the practical experience of the grassroots management unit, and carried out an overall renewal design of the external space environment of the collective housing. The epidemic is combined with the division of functional layout, refined design of outdoor activity space to ensure safe distance, and increased shared smart facilities to improve the quality of the outdoor environment of collective residences and strengthen community resilience;to achieve communication and sharing, epidemic prevention and control on the basis of ensuring safe social distance outdoor sports and other functions. In this way, the ability of collective housing to prevent, identify, and dispose of urban risks will be improved, and will provide residents with a better and livable community life.

STABILITY OF AN SEIS EPIDEMIC MODEL WITH CONSTANT RECRUITMENT AND A VARYING TOTAL POPULATION SIZE

This paper considers an SEIS epidemic model with infectious force in the latent period and a general population-size dependent contact rate. A threshold parameter R is identified. If R≤1, the disease-free equilibrium O is globally stable. If R〉1, there is a unique endemic equilibrium and O is unstable. For two important special cases of bilinear and standard incidence ,sufficient conditions for the global stability of this endemic equilibrium are given. The same qualitative results are obtained provided the threshold is more than unity for the corresponding SEIS model with no infectious force in the latent period. Some existing results are extended and improved.

Stochastic SIR Household Epidemic Model with Misclassification

In this work, we developed a theoretical framework leading to misclassification of the final size epidemic data for the stochastic SIR (Susceptible-Infective-Removed), household epidemic model, with false negative and false positive misclassification probabilities. Maximum likelihood based algorithm is then employed for its inference. We then analyzed and compared the estimates of the two dimensional model with those of the three and four dimensional models associated with misclassified final size data over arrange of theoretical parameters, local and global infection rates and corresponding proportion infected in the permissible region, away from its boundaries and misclassification probabilities. The adequacies of the three models to the final size data are examined. The four and three-dimensional models are found to outperform the two dimensional model on misclassified final size data.

The Effect of State-Dependent Control for an SIRS Epidemic Model with Varying Total Population

Based on the mechanism of prevention and control of infectious disease, we propose, in this paper, an SIRS epidemic model with varying total population size and state-dependent control, where the fraction of susceptible individuals in population is as the detection threshold value. By the Poincaré map, theory of differential inequalities and differential equation geometry, the existence and orbital stability of the disease-free periodic solution are discussed. Theoretical results show that by state-dependent pulse vaccination we can make the proportion of infected individuals tend to zero, and control the transmission of disease in population.

Feeding Behavior, Body Weight and Growth Rate during Post-Deprivation Period in Rats

Deprivation is an environmental experience that organisms are continually exposed to. However, few studies analyze deprivation effects on the consumption pattern during the post-deprivation period systematically. The aim of this study was to evaluate the deprivation effect on feeding pattern, growth rate and body weight during post-deprivation. Sixteen albino rats (3 months old at the beginning of the experiment) were exposed to 72-hour total food deprivation every 15 days. Food and water were freely available during non-deprivation periods. Rats completed three cycles comprised by a free access period followed by food deprivation. Once deprivation was removed, food and water consumption increased and then decreased, while body weight was recovered. Growth rate increased after every deprivation period and reached similar levels to those presented by the control group. Depriving rats from one commodity (i.e., food) cause them to restrain their consumption of the other freely available commodity (i.e., water). Results confirm that food deprivation modifies growth rate, water and food consumption. Additionally, during post-deprivation period, differences between males and females were not registered.

2023年度中国工业遗产研究学术报告

2023年,我国工业遗产研究总量呈现“稳中略降”的态势,在理论创新和实证分析方面均有所增益,研究体系较上一年表现为继承性与稳定性,延续了基础性研究、保护更新再利用研究、城市更新视角下的工业遗产研究三大主要研究板块。在基础性研究中,主要集中于理论研究、遗产本体研究与价值认定研究三个范畴;在保护更新再利用研究中,主要集中于工业遗产旅游、建筑活化与景观设计、场所精神识别与文化空间再造三个方面;而城市更新视角下的工业遗产研究,则着力于遗产再利用路径、城市公共空间改造及整体性更新、城市双修视角下的保护再利用三个部分。

小麦条锈病跨区域全周期绿色防控技术体系的构建与应用

小麦条锈病是我国小麦生产上一种跨区域流行的重大病害。1949年以来,我国小麦条锈病研究,治理能力明显提升,发病面积、流行程度、流行频率明显降低,但由于条锈菌Puccinia striiformis f.sp.tritici新毒性小种不断产生和气候异常变化等因素的影响,近年来其流行规律和成灾机制出现了新的变化,发生危害加重,严重威胁小麦生产和国家粮食安全。基于“十二五”以来我国在小麦条锈病菌毒性新小种产生、有性生殖、侵染循环和大区流行规律等方面的最新研究成果,作者在学习和实践以往病害治理经验的基础上,坚持长短结合、标本兼治、分区治理、综合防治的指导思想,制定了“以绿色防控为基础,以全周期管理为重点,以跨区域联防联控为保障”的防控策略,提出了精准监测预报、毒性小种变异监测、早期菌源控制、抗病品种合理布局和应急防控等关键技术,集成构建了全国小麦条锈病跨区域全周期绿色防控技术体系,制定了越夏易变区、冬季繁殖区(越冬区)和春季流行区分区防控技术体系。经在小麦条锈病主要流行区大面积试验示范,取得了防控效果85%以上,化学农药用量减少10%以上,小麦单产提高5%以上的成效。2022年-2023年在全国小麦主产区大范围组织推广应用,有效控制了小麦条锈病严重流行势头,全国病害发生面积出现了新低,有效减轻了灾害损失,保障了国家粮食安全。

基于安全社交距离的社区公共空间优化设计——以成都市玉林社区为例

以成都市玉林社区为研究对象,对居民在社区公共空间中的社交距离实现情况、活动行为数据进行统计,针对社交距离影响要素感知作问卷调查与半结构访谈。研究发现,居民日常在社区公共空间中安全社交距离的实现与社会政策、自然气候、日常作息、周边空间功能等密切相关。在物质空间层面,社区公共空间的空间承载量、物质空间布局、物质要素的灵活性对社交距离的实现存在影响;在社会意识层面,社会对居民的意识培养、社区总体管理规定、社区对于公共空间的管理对社交距离的实现存在影响。基于分析结果,提出了针对玉林社区社交距离安全性提升优化建议,并为未来健康社区公共空间规划设计提供了一般思路:空间利用集约化、空间规划弹性化、空间功能多样化、空间管理智慧化。

灾后社会景气变动趋势:基于后疫情期的考察

灾后社会景气作为表征性因素,是实质性恢复重建工作中长期潜在的隐蔽公理,对于更好促进灾后恢复重建具有重要的社会意义。通过对原有文献中社会景气概念的修复性界定,指出它不仅仅是主观满意度和信心的问题,更涉及客观景象的整体状况。基于后疫情期主客观社会景气的案例,通过实证比较分析进行具体考察,从而揭示疫灾过后经济社会恢复发展和社会景气回升繁荣的艰难之因。在此基础上,提出加强灾后社会景气研究和监测分析,着眼于宏观、中观、微观层面促进灾后恢复重建和社会景气回升。

后疫情时代课程思政在基础护理学实践课程中的实施和效果研究

目的:探究后疫情时代课程思政在基础护理学实践课程中的实施效果。方法:2020年9月至12月选择沈阳医学院186名护理专业大学生,随机分为对照组(n=92)和试验组(n=94)。对照组实施传统常规实践教学,试验组在对照组的基础上结合课程思政教学,调查两组护生的职业认同感、学生评价和考核成绩情况。结果:试验组护生职业认同感总分和各维度均高于对照组(P<0.05);试验组的学生评价和考核成绩均高于对照组(P<0.05)。结论:后疫情时代,在基础护理学实践课程中实施课程思政,有利于提高护生的职业认同感和操作技能水平。

基于风险评估模型的传染病预警体系的建立

目的建立一套基于风险评估模型的传染病预警体系,推动传染病管理水平的提升。方法通过搜集、整理最新的研究成果,参考相关的传染病预警评价指标体系的理论框架,构建基于风险评估模型的传染病预警体系。结果本次研究共纳入了12名专家,筛选出了三个一级指标,涉及流行前期指标、典型症状期指标、非典型症状期指标等,同时涉及7个二级指标。体系的必要性平均得分为8.27±0.24分,可获得性平均得分为7.74±0.34分。结论基于风险评估模型的传染病预警体系的建立有利于当地及时掌握传染病流行趋势,并进行调查指标分布趋势分析,然后提出相应的预警方案,可为有效预防传染病提供相关的依据。

后疫情时代以微课联合护生标准化病人为支撑的混合式教学模式在精神科护理教学中的应用效果观察

目的:通过探讨后疫情时代以微课联合护生标准化病人(SSP)为支撑的混合式教学模式在精神科护理教学中的应用效果,观察该教学模式对护生学习效果、学习态度及自主学习能力的影响。方法:选取某医学院校2019级470名护理本科生作为观察组,2018级490名护理本科生为对照组。对照组护生进行传统教学加小讲课,观察组护生开展以微课联合SSP为支撑的混合式教学。比较两组护生教学后的理论评分、实践技能评分、教学前后的护理专业学生学习态度量表及护理学专业学生自主学习能力量表评分。结果:教学后,观察组护生理论评分、实践技能评分结果均显著优于对照组,差异有统计学意义(Z=7.377、8.165,P<0.05)。教学前,两组护生学习态度量表、自主学习能力量表评分比较,差异无统计学意义(t=1.176、0.237、0.535、0.433、0.566、0.835、0.235,P>0.05)。教学后,观察组护生考核结果均高于对照组,差异有统计学意义(t=20.389、21.520、21.377、22.611、26.091、17.369、23.975,P<0.05)。结论:后疫情时代以微课联合SSP为支撑的混合式教学模式在精神科护理教学中具有良好的应用效果,可显著提升护生的学习效果、学习态度及自主学习的能力。

审视与定位:后冬奥时期我国滑雪产业高质量发展中的政府角色

政府角色的合理定位对滑雪产业高质量发展具有重要的推动与保障作用。通过文献资料、实地调研和访谈等研究方法对后冬奥时期滑雪产业高质量发展的内在表征及政府失灵的外在表现进行深入分析,审视滑雪产业发展中政府角色定位的实践特征,进而明确政府的应然角色。研究发现:后冬奥时期滑雪产业市场主体、市场环境和现代化治理之间有效协同才能实现滑雪产业的高质量发展,然而政府治理滑雪产业高质量发展过程中却存在角色缺位、错位、越位的风险。结合滑雪产业具有资源依赖性特征明显,产业容错率低;兼具商品属性和公益属性,具有正负外部性;属于重资产投资项目,受投融资政策影响;滑雪市场主体多元化,市场机制尚不健全等实践特征。后冬奥时期,政府应该扮演规划者、监督者、保障者和协调者等应然角色,不断优化政府行为,进而实现滑雪产业的高质量发展。

基于用户体验的母婴类厨具产品创新设计

根据后疫情时代发展需求及厨具产品迭代的分析,研究母婴厨具在使用过程中用户的体验,改进现有厨具的设计流程。基于用户体验研究,将社会需求融入母婴类厨具产品设计,从模块划分的背景分析、市场调研、设计实践、产品优化、产品落地5方面入手,分析产品的设计要素、使用场景、功能体验、包装运输等,以此选取适当的造型因子及功能结构。提出后疫情时代母婴厨具产品设计原则,归纳系统的母婴类厨具创新要点。通过这一系列探索研究,发现母婴类厨具发展的可能性,为其创新设计提供了新思路。

后疫情时代可持续与韧性理念下的社区农园设计研究

将韧性和可持续的概念运用于社区农园,从社区基础设施设计上实现韧性建设,以此提升社区空间应变力。进行实地调研,对社区农园产品和用户需求进行分析,为社区农园的设计实践提供依据。设计出提升社区农园韧性,满足居民需求的种植产品。在后疫情环境下,构建韧性与可持续社区农园是对该类突发性灾变给社区空间带来的影响进行及时缓解和调整的方法之一,以此保障社区系统的平衡状态。

后疫情时代大学生在线学习情绪状态和特征分析

关注大学生在线学习情绪发展态势、做好情绪疏导,是后疫情时代高校在线教育创新性发展的重要方向。在线学习情绪分析有助于理解学生的学习状态,为实施有效的在线学习情绪干预提供重要依据。将专业类别、课程类型、学习方式、学习资源纳入大学生在线学习情绪的影响因素,通过问卷调查获取大学生在线学习情绪状态数据,分别分析不同专业类别大学生在线学习情绪状态及主要特征差异。结果发现,大学生在线学习以积极情绪为主,不同专业类别的大学生在学习不同课程类型、使用不同学习方式,以及利用不同学习资源的在线课程时,其在线学习情绪状态均会存在显著性差异。基于此提出以下建议:依据情感需求,设计促进积极情绪的教学模式;灵活运用平台互动工具,提高在线学习参与度和临场感;注重学生情绪认知及管理,发挥教师情感支持作用。