Network virtualization is an enabling technology of running multiple virtual networks on a shared substrate network. It aims to deal with the ossification of current network architecture. As a crucial component of net...Network virtualization is an enabling technology of running multiple virtual networks on a shared substrate network. It aims to deal with the ossification of current network architecture. As a crucial component of network virtualization, virtual network embedding(VNE) can efficiently and effectively allocates the substrate resource to proposed virtual network requests. According to the optimization strategy, VNE approaches can be classified into three categories: exact, heuristic and meta-heuristic solution. The VNE exact solution is the foundation of its corresponding heuristic and meta-heuristic solutions. This paper presents a survey of existing typical VNE exact solutions, and open problems for the future research of VNE exact solutions are proposed.展开更多
Background During the outbreak of COVID-19,the national policy of home quarantine may affect the mental health of parents.However,few studies have investigated the mental health of parents during the COVID-19 pandemic...Background During the outbreak of COVID-19,the national policy of home quarantine may affect the mental health of parents.However,few studies have investigated the mental health of parents during the COVID-19 pandemic.Aims To investigate the depression,anxiety and stress of the students'parents during the COVID-19 pandemic,and to explore the influence factors,especially the influence of social support and family-related factors.Methods The Generalised Anxiety Disorder-7,Patient Health Questionnaire-9,Perceived Stress Scale-10 and Social Support Rating Scale were applied to 1163 parents to measure the parents'depression,anxiety,stress and social support.Results(1)The detection rates of depression and anxiety in parents were 6.1%and 4.0%.The depression,anxiety and perceived stress of parents in central China were significantly higher than those in non-central China.The anxiety of college students'parents was lower than that of parents of the primary,middle and high school students.The depression,anxiety and perceived stress of parents with conflicts in the family were significantly higher than those with a harmonious family.Other factors that influence parents’depression,anxiety and perceived stress include marital satisfaction,social support,parents*history of mental illness and parenting style,etc.(2)The regression analysis results showed that perceived stress,social support,marital satisfaction,family conflicts,child's learning stage as well as parents'history of mental illness had significant effects on parents'anxiety and depression.Conclusion During the COVID-19 pandemic,the mental health of parents was affected by a variety of factors.Good marital relationships,good social support,family harmony and parents without a history of mental illness may be protective factors for parents*mental health,while perceived stress and child in middle or high school are risk factors for parents’mental health.展开更多
Expression of double-stranded RNAs in plastids offers great potential for the efficient control of chewing insects.However,many insect pests do not consume plant tissue but rather feed on the host plant by sucking sap...Expression of double-stranded RNAs in plastids offers great potential for the efficient control of chewing insects.However,many insect pests do not consume plant tissue but rather feed on the host plant by sucking sap from the vascular system.Whether or not plastid-mediated RNA interference(RNAi)can be employed to control sap-sucking insects is unknown.Here,we show that five species of sap-sucking hemipteran insects acquire plastid RNA upon feeding on plants.We generated both nuclear transgenic and transplastomic tobacco plants expressing double-stranded RNAs targeting the MpDhc64C gene,a newly identified efficient target gene of RNAi whose silencing causes lethality to the green peach aphid Myzus persicae.In a whole-plant bioassay,transplastomic plants exhibited significant resistance to aphids,as evidenced by reduced insect survival,impaired fecundity,and decreased weight of survivors.The protective effect was comparable with that conferred by the best-performing nuclear transgenic plants.We found that the proportion of aphids on mature leaves of transplastomic plants was significantly lower compared with that of nuclear transgenic plants.When aphids were allowed to infest.only the mature leaves,transplastomic plants grew significantly faster and were overall better protected from the pest compared with nuclear transgenic plants.When monitored by electrical-penetration-graph analyses and aphid avoidance response experiments,the insects displayed remarkable alterations in feeding behavior,which was different in nuclear transgenic and transplastomic plants,likely reflecting specific avoidance strategies to toxic RNA molecules.Taken together,our study demonstrates that plastid-mediated RNAi provides an efficient strategy for controlling at least some sap-sucking insect pests,even though there is most likely no or only very little chloroplast RNA in the sap.展开更多
基金supported by the National Basic Research Program of China(973 Program)under Grant 2013CB329104the National Natural Science Foundation of China under Grants 61372124 and 61427801the Key Projects of Natural Science Foundation of Jiangsu University under Grant 11KJA510001
文摘Network virtualization is an enabling technology of running multiple virtual networks on a shared substrate network. It aims to deal with the ossification of current network architecture. As a crucial component of network virtualization, virtual network embedding(VNE) can efficiently and effectively allocates the substrate resource to proposed virtual network requests. According to the optimization strategy, VNE approaches can be classified into three categories: exact, heuristic and meta-heuristic solution. The VNE exact solution is the foundation of its corresponding heuristic and meta-heuristic solutions. This paper presents a survey of existing typical VNE exact solutions, and open problems for the future research of VNE exact solutions are proposed.
基金This study was funded by Shanghai Clinical Research Center for Mental Health(SCRC-MH)(19MC1911100)National Natural Science Foundation of China(81771461)+1 种基金Shanghai Municipal Health Commission(2019ZB0201)Xuhui District Health and Family Planning Commission Important Disease Joint Research Project(XHLHGG201808).
文摘Background During the outbreak of COVID-19,the national policy of home quarantine may affect the mental health of parents.However,few studies have investigated the mental health of parents during the COVID-19 pandemic.Aims To investigate the depression,anxiety and stress of the students'parents during the COVID-19 pandemic,and to explore the influence factors,especially the influence of social support and family-related factors.Methods The Generalised Anxiety Disorder-7,Patient Health Questionnaire-9,Perceived Stress Scale-10 and Social Support Rating Scale were applied to 1163 parents to measure the parents'depression,anxiety,stress and social support.Results(1)The detection rates of depression and anxiety in parents were 6.1%and 4.0%.The depression,anxiety and perceived stress of parents in central China were significantly higher than those in non-central China.The anxiety of college students'parents was lower than that of parents of the primary,middle and high school students.The depression,anxiety and perceived stress of parents with conflicts in the family were significantly higher than those with a harmonious family.Other factors that influence parents’depression,anxiety and perceived stress include marital satisfaction,social support,parents*history of mental illness and parenting style,etc.(2)The regression analysis results showed that perceived stress,social support,marital satisfaction,family conflicts,child's learning stage as well as parents'history of mental illness had significant effects on parents'anxiety and depression.Conclusion During the COVID-19 pandemic,the mental health of parents was affected by a variety of factors.Good marital relationships,good social support,family harmony and parents without a history of mental illness may be protective factors for parents*mental health,while perceived stress and child in middle or high school are risk factors for parents’mental health.
基金supported from the National Natural Science Foundation of China(31872035 and 32102297)the Science and Technology Department of Hubei Province of China(2020CFA012)+1 种基金the Foundation of Hubei Hongshan Laboratory(2021 hszd011)the Innovation Base for Introducing Talents of Discipline of Hubei Province(2019BJH021)。
文摘Expression of double-stranded RNAs in plastids offers great potential for the efficient control of chewing insects.However,many insect pests do not consume plant tissue but rather feed on the host plant by sucking sap from the vascular system.Whether or not plastid-mediated RNA interference(RNAi)can be employed to control sap-sucking insects is unknown.Here,we show that five species of sap-sucking hemipteran insects acquire plastid RNA upon feeding on plants.We generated both nuclear transgenic and transplastomic tobacco plants expressing double-stranded RNAs targeting the MpDhc64C gene,a newly identified efficient target gene of RNAi whose silencing causes lethality to the green peach aphid Myzus persicae.In a whole-plant bioassay,transplastomic plants exhibited significant resistance to aphids,as evidenced by reduced insect survival,impaired fecundity,and decreased weight of survivors.The protective effect was comparable with that conferred by the best-performing nuclear transgenic plants.We found that the proportion of aphids on mature leaves of transplastomic plants was significantly lower compared with that of nuclear transgenic plants.When aphids were allowed to infest.only the mature leaves,transplastomic plants grew significantly faster and were overall better protected from the pest compared with nuclear transgenic plants.When monitored by electrical-penetration-graph analyses and aphid avoidance response experiments,the insects displayed remarkable alterations in feeding behavior,which was different in nuclear transgenic and transplastomic plants,likely reflecting specific avoidance strategies to toxic RNA molecules.Taken together,our study demonstrates that plastid-mediated RNAi provides an efficient strategy for controlling at least some sap-sucking insect pests,even though there is most likely no or only very little chloroplast RNA in the sap.
