This paper examines the nutrition impacts of using non-solid cooking fuel on under-five children in developing countries.We draw on data from more than 1.12 million children in 62 developing countries from the Demogra...This paper examines the nutrition impacts of using non-solid cooking fuel on under-five children in developing countries.We draw on data from more than 1.12 million children in 62 developing countries from the Demographic and Health Surveys(DHS).Results from both fixed effects(FE)and instrumental variable(IV)estimates show that using non-solid cooking fuel significantly improves the nutrition outcomes of under-five children.Compared with their peers from households mainly using solid fuel,children from households mainly using non-solid fuel exhibit a lower probability of experiencing stunting(by 5.9 percentage points)and being underweight(by 1.2 percentage points).Our further investigation provides evidence for several underlying mechanisms,such as improved indoor air quality,induced reduction in children’s respiratory symptoms,benefits on maternal health,and reduction in maternal time spent on fuel collection or cooking.Heterogenous analyses suggest that the nutrition benefits of using non-solid cooking fuel are more prominent among boys,children above three years old,and those from households of lower socioeconomic status,rural areas,and Southeast Asia.展开更多
Since 1976, eradicating hunger has become one of the priority objectives of the United Nations, which is included in the Charter of Human Rights;the right to get adequate food. The qualification of food security in ti...Since 1976, eradicating hunger has become one of the priority objectives of the United Nations, which is included in the Charter of Human Rights;the right to get adequate food. The qualification of food security in time and space must analyze not only the three components it covers but also the relationships that these three components maintain. Climate change contributes to food insecurity, but it is not the only factor. To address food insecurity in various forms, greater food security must be combined with improved sustainable agricultural practices with minimal strain on the environment. This review of literature insists on the principles of food security, which in particular allows a better understanding of food insecurity in developing countries and favors a greater contribution of agriculture and food systems in general to nutritional progress.展开更多
Cultural ancient roads,known in Chinese as gudao,serve as heritage trails that carry historical exchanges across various regions in China.Due to their extensive preservation,wide geographical distribution,diverse them...Cultural ancient roads,known in Chinese as gudao,serve as heritage trails that carry historical exchanges across various regions in China.Due to their extensive preservation,wide geographical distribution,diverse thematic variations,and considerable tourist appeal,these paths have emerged as representative heritage trails,increasingly transforming into a novel tourism product experience that is highly favored by tourists and recognized by government authorities.However,research on ancient roads for tourism in China currently lacks a systematic theoretical framework,as well as relevant policies,regulations,and standards to guide their practical development.Therefore,there is a pressing need to draw upon international best practices and conduct foundational research to develop an experience element system that aligns with the perceptions,behaviors,and consumption characteristics of Chinese tourists,thereby advancing theoretical exploration in this field.This study focuses on the representative Ancient Shu Road as a case study and employs a mixed-method approach that integrates qualitative and quantitative research.It aims to construct a tourist-centric scale for the experience elements of ancient road tourism while analyzing the interactive relationship between these experience elements and tourist needs.This study addresses a significant gap in the development of indicator systems for domestic studies of ancient road tourism experiences.Ultimately,the study establishes a comprehensive scale that encompasses three core categories—trail resources and environment,facilities and services,and modes of tourism activities—along with eight primary dimensions:core resources,surrounding cultural environment,surrounding natural environment,tourism reception facilities and services,infrastructure and support services,information facilities and information services,and outdoor and recreational activities.This scale consists of thirty-two specific items,providing a robust reference for future research endeavors.Additionally,the study proposes specific development strategies related to key mechanisms,spatial configuration,and facility construction to enhance the overall development of ancient road tourism.展开更多
While a plethora of studies has been conducted to explore demotivation and its impact on mental health in second language(L2)education,scanty research focuses on demotivation in L2 speaking learning.Particularly,littl...While a plethora of studies has been conducted to explore demotivation and its impact on mental health in second language(L2)education,scanty research focuses on demotivation in L2 speaking learning.Particularly,little research explores the measures to quantify L2 speaking demotivation.The present two-phase study attempts to develop and validate an English Speaking Demotivation Scale(ESDS).To this end,an independent sample of 207 Chinese tertiary learners of English as a Foreign Language(EFL)participated in the development phase,and another group of 188 Chinese EFL learners was recruited for the validation of the scale.Exploratory Factor Analysis(EFA)and Confirmatory Factor Analysis(CFA)were employed to determine the factor structure of the scale.The EFA results revealed a six-factor solution with Teacher-related Factors in Learning Spoken English(TFLSE),Interest and Valence in Learning Spoken English(IVLSE),Self-efficacy in Learning Spoken English(SELSE),Negative Peer Influence in Learning Spoken English(NPILSE),Undesirable Environment for Learning Spoken English(UELSE),and Negative Influence of Assessment and Learning Materials in speaking class(NIALM).In the validation phase,Confirmatory Factor Analysis(CFA)was performed to validate the internal structure of the scale.The CFA results showed that the model fits the data well.Overall,the ESDS is a robust and trustworthy psychometric tool that could be utilized to examine L2 speaking demotivation.Implications for diminishing EFL learners’demotivation,lessening their aversive emotions and promoting their mental health are also discussed.展开更多
Kidney transplantation(KT)is the optimal form of renal replacement therapy for patients with end-stage renal diseases.However,this health service is not available to all patients,especially in developing countries.The...Kidney transplantation(KT)is the optimal form of renal replacement therapy for patients with end-stage renal diseases.However,this health service is not available to all patients,especially in developing countries.The deceased donor KT programs are mostly absent,and the living donor KT centers are scarce.Single-center studies presenting experiences from developing countries usually report a variety of challenges.This review addresses these challenges and the opposing strategies by reviewing the single-center experiences of developing countries.The financial challenges hamper the infrastructural and material availability,coverage of transplant costs,and qualification of medical personnel.The sociocultural challenges influence organ donation,equity of beneficence,and regular follow-up work.Low interests and motives for transplantation may result from high medicolegal responsibilities in KT practice,intense potential psychosocial burdens,complex qualification protocols,and low productivity or compensation for KT practice.Low medical literacy about KT advantages is prevalent among clinicians,patients,and the public.The inefficient organizational and regulatory oversight is translated into inefficient healthcare systems,absent national KT programs and registries,uncoordinated job descriptions and qualification protocols,uncoordinated on-site investigations with regulatory constraints,and the prevalence of commercial KT practices.These challenges resulted in noticeable differences between KT services in developed and developing countries.The coping strategies can be summarized in two main mechanisms:The first mechanism is maximizing the available resources by increasing the rates of living kidney donation,promoting the expertise of medical personnel,reducing material consumption,and supporting the establishment and maintenance of KT programs.The latter warrants the expansion of the public sector and the elimination of non-ethical KT practices.The second mechanism is recruiting external resources,including financial,experience,and training agreements.展开更多
In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting t...In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting the cargo of proteins,lipids,and other molecules to appropriate compartments via transport vesicles or intermediates.These processes are strictly regulated by various small GTPases such as the RAS-like in rat brain(RAB)protein family,which is the largest subfamily of the RAS superfamily.Dysfunction of membrane trafficking affects tissue homeostasis and leads to a wide range of diseases,including neurological disorders and neurodegenerative diseases.Therefore,it is important to understand the physiological and pathological roles of RAB proteins in brain function.RAB35,a member of the RAB family,is an evolutionarily conserved protein in metazoans.A wide range of studies using cultured mammalian cells and model organisms have revealed that RAB35 mediates various processes such as cytokinesis,endocytic recycling,actin bundling,and cell migration.RAB35 is also involved in neurite outgrowth and turnover of synaptic vesicles.We generated brain-specific Rab35 knockout mice to study the physiological roles of RAB35 in brain development and function.These mice exhibited defects in anxiety-related behaviors and spatial memory.Strikingly,RAB35 is required for the precise positioning of pyramidal neurons during hippocampal development,and thereby for normal hippocampal lamination.In contrast,layer formation in the cerebral cortex occurred superficially,even in the absence of RAB35,suggesting a predominant role for RAB35 in hippocampal development rather than in cerebral cortex development.Recent studies have suggested an association between RAB35 and neurodegenerative diseases,including Parkinson's disease and Alzheimer's disease.In this review,we provide an overview of the current understanding of subcellular functions of RAB35.We also provide insights into the physiological role of RAB35 in mammalian brain development and function,and discuss the involvement of RAB35 dysfunction in neurodegenerative diseases.展开更多
Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-li...Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.展开更多
The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and contin...The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development studies.Thus,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo retina.In this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in vivo.Initially,we used SOX2 and PAX6 immunostaining to identify retinal progenitor cells.We then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,respectively.Ki-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between groups.Additionally,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,respectively.The timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant retinas.Our study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina development.The findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.展开更多
The ultrastructure of the epidermis and flesh of apple ( Malus domestica Borkh cv. Red Fuji) fruit was systematically observed during the fruit development via transmission electron microscopy. The results showed t...The ultrastructure of the epidermis and flesh of apple ( Malus domestica Borkh cv. Red Fuji) fruit was systematically observed during the fruit development via transmission electron microscopy. The results showed that, in spite of the ultrastructural changes in many aspects of the developing fruit epidermal cells, it remained almost unchanged throughout the whole developmental process that the cytoplasm was filled with numerous endoplasmic reticula (ER). Most of these endoplasmic reticula were tube_like and rough_ER with enlarged cisterna from which many vesicles were produced. Some of the vesicles were shown to merge into vacuole. Some dynamic Golgi bodies were also found. All the ultrastructural characteristics showed that the epidermal cells have the features of excretory cells. The ultrastructure of the fruit flesh cells at the young fruit stage were shown to be metabolically active, characterized by the presence of numerous clustered plasmodesmata, cisterna enlarged_ and rough_ER filling the cytoplasm, plenty of vesicles and Golgi bodies, indicating their dynamic cellular transport function. Some giant_circular rough_ERs were found. All the ultrastructural features at this early developmental stage should be closely associated with the enlargement of the young fruit. At the rapid growing phase of the fruit the main changes were characterized by: the starch grain_filled amyloplasts, furcating of the single orifice of plasmodesmata, and the cytoplasm enrichment of both the Golgi body_formed vesicles and other vesicles. These features correspond well with those of a photoassimilate sink_cell. An ultrastructural degeneration phenomenon was observed at the fruit ripening stage, but the mitochondria and plasmalemma still remained intact, which might be related to the continuous development of fruit quality during the fruit ripening.展开更多
Objective To investigate the cell proliferation and differentiation in the developing brain of mouse. Methods C57/BL6 mice were divided into 3 groups at random. Bromodeoxyuridine (BrdU) was injected into the brains ...Objective To investigate the cell proliferation and differentiation in the developing brain of mouse. Methods C57/BL6 mice were divided into 3 groups at random. Bromodeoxyuridine (BrdU) was injected into the brains in different development periods once a day for 7 d. The brains were retrieved 4 weeks after the last BrdU injection. Immunohistochemical and immunofluorescent studies were carried out for detecting cell proliferation (BrdU) and cell differentiation (NeuN, APC, lbal, and S 100β), respectively. Results The number of BrdU labeled cells decreased significantly with the development of the brain. Cell proliferation was prominent in the cortex and striatum. A small portion of BrdU and NeuN double labeled cells could be detected in the cortex at the early stage of development, and in the striatum and CA of the hippocampus in all groups. The majority of BrdU labeled cells were neuroglia, and the number of neuroglia cells decreased dramatically with brain maturation. Neurogenesis is the major cytogenesis in the dentate gyrus. Conclusion These results demonstrated that cell proliferation, differentiation and survival were age and brain region related.展开更多
Benin, a tropical country in west Africa, is one of the Ieast deveIoped countries confirmed by the United Nations. Benin is highIy dependent on agricuIture and reIativeIy rich in agricuIture resources. It's espec...Benin, a tropical country in west Africa, is one of the Ieast deveIoped countries confirmed by the United Nations. Benin is highIy dependent on agricuIture and reIativeIy rich in agricuIture resources. It's especial y suitabIe for agricuIture be-cause of the sufficient sunIight, raln and suitabIe temperature. AgricuIture export in Benin pIays an important part for both government and farmers. But the Iack of new varieties, appropriate technoIogy and modern service makes it difficuIt to deveI-op the agricuIture production rapidIy. Based on the introduction of agricuIture re-sources incIuding cIimate and Iand, this articIe malnIy showed the maln agricuIture productions and potential probIems in Benin, and then Iooked into the distance and deveIoping strategy on how to soIve the probIems. In order to deveIop the agricuI-ture sustalnabIy in Benin, it’s also suggested that the worId shouId strengthen the ald and share the fruits of new products, appropriate technoIogy and good man-agement methods.展开更多
How to comprehensively,scientifically,objectively and impartially evaluate the multiple learning achievements of the PBL model should be highlighted when PBL is introduced and applied.A questionnaire of a total of 23 ...How to comprehensively,scientifically,objectively and impartially evaluate the multiple learning achievements of the PBL model should be highlighted when PBL is introduced and applied.A questionnaire of a total of 23 items involving such dimensions of language proficiency,subject contents and 21 st Century skills was designed.Its reliability and validity were tested and well-met with the statistical requirements.展开更多
The status, advantages and disadvantages of rice production in East Timor were investigated and analyzed, the results of comparison test and demonstrative cultivation through introducing 15 Chinese hybrid rice combina...The status, advantages and disadvantages of rice production in East Timor were investigated and analyzed, the results of comparison test and demonstrative cultivation through introducing 15 Chinese hybrid rice combinations into East Timor were summarized, the feasibility of developing hybrid rice in East Timor to realize food self-sufficiency were discussed and demonstrated, and the main corresponding technical strategies were proposed in this paper.展开更多
Hepatitis B virus(HBV)infection is a serious global public health problem.The infection may be transmitted through sexual intercourse,parenteral contact or from an infected mother to the baby at birth and,if contracte...Hepatitis B virus(HBV)infection is a serious global public health problem.The infection may be transmitted through sexual intercourse,parenteral contact or from an infected mother to the baby at birth and,if contracted early in life,may lead to chronic liver disease,including cirrhosis and hepatocellular carcinoma.On the basis of the HBV carrier rate,the world can be divided in 3 regions of high,medium and low endemicity.The major concern is about high endemicity countries,where the most common route of infection remains vertical transmission from mother to child.Screening of all pregnant women and passive immunization with human hepatitis B immunoglobulin are not affordable for many developing countries.The infection rate can be reduced by modifying behavior,improving individual education,testing all blood donations,assuring asepsis in clinical practice and screening all pregnant women.However,availability of a safe and efficacious vaccine and adoption of appropriate immunization strategies are the most effective means to prevent HBV infection and its consequences.The unsolved problem for poorest countries,where the number of people currently infected is high,is the cost of the vaccine.A future challenge is to overcome the social and economic hurdles of maintaining and improving a prevention policy worldwide to reduce the global burden of the disease.展开更多
Hepatitis A is the most common form of acute viral hepatitis in the world.Major geographical differences in endemicity of hepatitis A are closely related to hygienic and sanitary conditions and other indicators of the...Hepatitis A is the most common form of acute viral hepatitis in the world.Major geographical differences in endemicity of hepatitis A are closely related to hygienic and sanitary conditions and other indicators of the level of socioeconomic development.The anti-hepatitis A virus(HAV)seroprevalence rate is presently decreasing in many parts of the world,but in less developed regions and in several developing countries,HAV infection is still very common in the first years of life and seroprev-alence rates approach 100%.In areas of intermediate endemicity,the delay in the exposure to the virus has generated a huge number of susceptible adolescents and adults and significantly increased the average age at infection.As the severity of disease increases with age,this has led to outbreaks of hepatitis A.Several factors contribute to the decline of the infection rate,including rising socioeconomic levels,increased access to clean water and the availability of a hepatitis A vaccine that was developed in the 1990s.For populations with a high proportion of susceptible adults,implementing vaccination programs may be considered.In this report,we review available epidemiological data and implementation of vaccination strategies,particularly focusing on developing countries.展开更多
Colorectal cancer(CRC)is one of the leading causes of cancer and cancer-related mortality worldwide.The disease has been traditionally a major health problem in industrial countries,however the CRC rates are increasin...Colorectal cancer(CRC)is one of the leading causes of cancer and cancer-related mortality worldwide.The disease has been traditionally a major health problem in industrial countries,however the CRC rates are increasing in the developing countries that are undergoing economic growth.Several environmental risk factors,mainly changes in diet and life style,have been suggested to underlie the rise of CRC in these populations.Diet and lifestyle impinge on nuclear receptors,on the intestinal microbiota and on crucial molecular pathways that are implicated in intestinal carcinogenesis.In this respect,the epidemiological transition in several regions of the world offers a unique opportunity to better understand CRC carcinogenesis by studying the disease phenotypes and their environmental and molecular associations in different populations.The data from these studies may have important implications for the global prevention and treatment of CRC.展开更多
AIM: To compare the short-term, including oncologic, outcomes of open vs laparoscopic colectomy for cancer in a developing country. METHODS: The records of patients who underwent elective open and laparoscopic colecto...AIM: To compare the short-term, including oncologic, outcomes of open vs laparoscopic colectomy for cancer in a developing country. METHODS: The records of patients who underwent elective open and laparoscopic colectomies for cancer at the University Hospital of the West Indies between January 2005 and December 2010 were retrospectively reviewed. Demographic(age, gender, Charlson comorbidity index score), peri-operative, post-operative and oncologic data were collected for each patient. Specific oncologic variables included lymph node yield, pathologic stage, grade, proximal, distal and circumferential margin involvement. Fisher's exact, Mann-Whitney, and binary logistic regression tests were used for analysis. Significance level was set atP < 0.05. RESULTS: There were 87 cases for open colectomy(OC) and 17 cases for laparoscopic colectomy(LC). Demographics did not significantly differ between OC and LC groups. Intra-operative blood loss and postoperative analgesic requirements did not significantly differ between groups. There was a trend towards longer operating times in OC group and shorter hospital stay in the LC group. Lymph node yield(14 vs 14, P = 0.619), proximal(10 cm vs 7 cm, P = 0.353) and distal(8 cm vs 8 cm, P = 0.57) resection margin distance and circumferential margin involvement(9 vs 0, P = 0.348) did not significantly differ between groups. Thirty-day morbidity was equivalent between groups(22 vs 6, P = 0.774). There were 6 deaths within 30 d of initial procedure, all in the OC group(6.9%). CONCLUSION: Laparoscopic colectomy in a developing country is oncologically safe and represents a option for colonic malignancies in these regions. Such data encourage the continued laparoscopic development.展开更多
In this study, we developed a comprehensive index system for forestry sustainability of Heilongjiang Province, which includes forest resources sustainability,sustainable economic development, sustainable social develo...In this study, we developed a comprehensive index system for forestry sustainability of Heilongjiang Province, which includes forest resources sustainability,sustainable economic development, sustainable social development and sustainable advancement in science and technology. Based on this system and the regional forest development, we further evaluated the sustainability of Heilongjiang Province for year 2008-2013. The results show that even though the regional forestry has been preliminarily on the track of sustainable development, it is fragile. Four indicators, e.g. soil and water retention rate,forest stand growth(per unit area), the proportion of national investment and the annual carbon sequestration have important impact on the sustainability, with a weight of 39.0 % in all the indicators. We also analyzed the factors hindering the sustainable development. It turns out that soil and water retention rate, forest stand growth(per unit area),the proportion of science and technology funds, per capita GDP and the proportion of the tertiary industry production are the main factors hindering regional sustainable development, which accounts for 50.94 % of the total obstacle degrees in the system. At last, we discussed how to promote the regional sustainable development from the perspectives of forest resources sustainability, economic development sustainability, society development sustainability and the sustainable advancement of science and technology.展开更多
The development of pericarp, seed coat, starchy endosperm and aleurone of the rice caryopsis was investigated, histochemically and structurally, from the time of flowering to maturity. The results showed that during i...The development of pericarp, seed coat, starchy endosperm and aleurone of the rice caryopsis was investigated, histochemically and structurally, from the time of flowering to maturity. The results showed that during its growth, the maximum length of the caryopsis was attained first, followed by width and then thickness. Histochemical examination of the caryopsis showed that starch was mainly accumulated in the endosperm, but the endosperm showed no metabolic activity, while embryo and pericarp contained a few starch grains, and embryo and aleurone were strongly active. Aleuronic cells contained many aleurone grains and spherosomes, and aleurone in the dorsal region developed earlier and contained more layers of cells. Amyloplasts in endosperm contained many starch granules and were spherical at early stages but polyhedric at late stages. The protein bodies appeared later than amyloplasts, and the number of protein bodies in subaleurone was greater than those in the starchy endosperm. The white-belly portion of endosperm might be relative to the status of amyloplast development.展开更多
基金This work was supported by the National Natural Science Foundation of China(71861147003 and 71925009).
文摘This paper examines the nutrition impacts of using non-solid cooking fuel on under-five children in developing countries.We draw on data from more than 1.12 million children in 62 developing countries from the Demographic and Health Surveys(DHS).Results from both fixed effects(FE)and instrumental variable(IV)estimates show that using non-solid cooking fuel significantly improves the nutrition outcomes of under-five children.Compared with their peers from households mainly using solid fuel,children from households mainly using non-solid fuel exhibit a lower probability of experiencing stunting(by 5.9 percentage points)and being underweight(by 1.2 percentage points).Our further investigation provides evidence for several underlying mechanisms,such as improved indoor air quality,induced reduction in children’s respiratory symptoms,benefits on maternal health,and reduction in maternal time spent on fuel collection or cooking.Heterogenous analyses suggest that the nutrition benefits of using non-solid cooking fuel are more prominent among boys,children above three years old,and those from households of lower socioeconomic status,rural areas,and Southeast Asia.
文摘Since 1976, eradicating hunger has become one of the priority objectives of the United Nations, which is included in the Charter of Human Rights;the right to get adequate food. The qualification of food security in time and space must analyze not only the three components it covers but also the relationships that these three components maintain. Climate change contributes to food insecurity, but it is not the only factor. To address food insecurity in various forms, greater food security must be combined with improved sustainable agricultural practices with minimal strain on the environment. This review of literature insists on the principles of food security, which in particular allows a better understanding of food insecurity in developing countries and favors a greater contribution of agriculture and food systems in general to nutritional progress.
文摘Cultural ancient roads,known in Chinese as gudao,serve as heritage trails that carry historical exchanges across various regions in China.Due to their extensive preservation,wide geographical distribution,diverse thematic variations,and considerable tourist appeal,these paths have emerged as representative heritage trails,increasingly transforming into a novel tourism product experience that is highly favored by tourists and recognized by government authorities.However,research on ancient roads for tourism in China currently lacks a systematic theoretical framework,as well as relevant policies,regulations,and standards to guide their practical development.Therefore,there is a pressing need to draw upon international best practices and conduct foundational research to develop an experience element system that aligns with the perceptions,behaviors,and consumption characteristics of Chinese tourists,thereby advancing theoretical exploration in this field.This study focuses on the representative Ancient Shu Road as a case study and employs a mixed-method approach that integrates qualitative and quantitative research.It aims to construct a tourist-centric scale for the experience elements of ancient road tourism while analyzing the interactive relationship between these experience elements and tourist needs.This study addresses a significant gap in the development of indicator systems for domestic studies of ancient road tourism experiences.Ultimately,the study establishes a comprehensive scale that encompasses three core categories—trail resources and environment,facilities and services,and modes of tourism activities—along with eight primary dimensions:core resources,surrounding cultural environment,surrounding natural environment,tourism reception facilities and services,infrastructure and support services,information facilities and information services,and outdoor and recreational activities.This scale consists of thirty-two specific items,providing a robust reference for future research endeavors.Additionally,the study proposes specific development strategies related to key mechanisms,spatial configuration,and facility construction to enhance the overall development of ancient road tourism.
基金the Humanities and Social Sciences Project,China’s Ministry of Education(Grant Number:22YJA740016)the Key Project of Hubei Provincial Department of Education Philosophy and Social Science Research Fund(No.21ZD051)the Teaching and Research Fund of Hubei University of Technology(No.Xiao2022018).
文摘While a plethora of studies has been conducted to explore demotivation and its impact on mental health in second language(L2)education,scanty research focuses on demotivation in L2 speaking learning.Particularly,little research explores the measures to quantify L2 speaking demotivation.The present two-phase study attempts to develop and validate an English Speaking Demotivation Scale(ESDS).To this end,an independent sample of 207 Chinese tertiary learners of English as a Foreign Language(EFL)participated in the development phase,and another group of 188 Chinese EFL learners was recruited for the validation of the scale.Exploratory Factor Analysis(EFA)and Confirmatory Factor Analysis(CFA)were employed to determine the factor structure of the scale.The EFA results revealed a six-factor solution with Teacher-related Factors in Learning Spoken English(TFLSE),Interest and Valence in Learning Spoken English(IVLSE),Self-efficacy in Learning Spoken English(SELSE),Negative Peer Influence in Learning Spoken English(NPILSE),Undesirable Environment for Learning Spoken English(UELSE),and Negative Influence of Assessment and Learning Materials in speaking class(NIALM).In the validation phase,Confirmatory Factor Analysis(CFA)was performed to validate the internal structure of the scale.The CFA results showed that the model fits the data well.Overall,the ESDS is a robust and trustworthy psychometric tool that could be utilized to examine L2 speaking demotivation.Implications for diminishing EFL learners’demotivation,lessening their aversive emotions and promoting their mental health are also discussed.
文摘Kidney transplantation(KT)is the optimal form of renal replacement therapy for patients with end-stage renal diseases.However,this health service is not available to all patients,especially in developing countries.The deceased donor KT programs are mostly absent,and the living donor KT centers are scarce.Single-center studies presenting experiences from developing countries usually report a variety of challenges.This review addresses these challenges and the opposing strategies by reviewing the single-center experiences of developing countries.The financial challenges hamper the infrastructural and material availability,coverage of transplant costs,and qualification of medical personnel.The sociocultural challenges influence organ donation,equity of beneficence,and regular follow-up work.Low interests and motives for transplantation may result from high medicolegal responsibilities in KT practice,intense potential psychosocial burdens,complex qualification protocols,and low productivity or compensation for KT practice.Low medical literacy about KT advantages is prevalent among clinicians,patients,and the public.The inefficient organizational and regulatory oversight is translated into inefficient healthcare systems,absent national KT programs and registries,uncoordinated job descriptions and qualification protocols,uncoordinated on-site investigations with regulatory constraints,and the prevalence of commercial KT practices.These challenges resulted in noticeable differences between KT services in developed and developing countries.The coping strategies can be summarized in two main mechanisms:The first mechanism is maximizing the available resources by increasing the rates of living kidney donation,promoting the expertise of medical personnel,reducing material consumption,and supporting the establishment and maintenance of KT programs.The latter warrants the expansion of the public sector and the elimination of non-ethical KT practices.The second mechanism is recruiting external resources,including financial,experience,and training agreements.
基金supported by the Japan Society for the Promotion of Science KAKENHI(grant Nos.23K05678 to IM,19H05711 and 20H00466 to KS)the Joint Research Program of Institute for Molecular and Cellular Regulation,Gunma University(to KS)。
文摘In eukaryotic cells,organelles in the secretory,lysosomal,and endocytic pathways actively exchange biological materials with each other through intracellular membrane trafficking,which is the process of transporting the cargo of proteins,lipids,and other molecules to appropriate compartments via transport vesicles or intermediates.These processes are strictly regulated by various small GTPases such as the RAS-like in rat brain(RAB)protein family,which is the largest subfamily of the RAS superfamily.Dysfunction of membrane trafficking affects tissue homeostasis and leads to a wide range of diseases,including neurological disorders and neurodegenerative diseases.Therefore,it is important to understand the physiological and pathological roles of RAB proteins in brain function.RAB35,a member of the RAB family,is an evolutionarily conserved protein in metazoans.A wide range of studies using cultured mammalian cells and model organisms have revealed that RAB35 mediates various processes such as cytokinesis,endocytic recycling,actin bundling,and cell migration.RAB35 is also involved in neurite outgrowth and turnover of synaptic vesicles.We generated brain-specific Rab35 knockout mice to study the physiological roles of RAB35 in brain development and function.These mice exhibited defects in anxiety-related behaviors and spatial memory.Strikingly,RAB35 is required for the precise positioning of pyramidal neurons during hippocampal development,and thereby for normal hippocampal lamination.In contrast,layer formation in the cerebral cortex occurred superficially,even in the absence of RAB35,suggesting a predominant role for RAB35 in hippocampal development rather than in cerebral cortex development.Recent studies have suggested an association between RAB35 and neurodegenerative diseases,including Parkinson's disease and Alzheimer's disease.In this review,we provide an overview of the current understanding of subcellular functions of RAB35.We also provide insights into the physiological role of RAB35 in mammalian brain development and function,and discuss the involvement of RAB35 dysfunction in neurodegenerative diseases.
基金supported by the National Key R&D Program of China,No.2019YFA0110300(to ZG)the National Natural Science Foundation of China,Nos.81773302(to YF),32070862(to ZG).
文摘Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.
基金supported by the National Natural Science Foundation of China,Nos.81901156(to ZZ),82271200(to ZZ),82171308(to XC)the Fundamental Research Funds for the Central Universities,No.xzy012022035(to ZZ)+1 种基金the Natural Science Foundation of Shaanxi Province,Nos.2021JM-261(to QK),2023-YBSF-303(to ZZ)Traditional Chinese Medicine Project of Shaanxi Province,No.2019-ZZ-JC047(to QK)。
文摘The organotypic retinal explant culture has been established for more than a decade and offers a range of unique advantages compared with in vivo experiments and cell cultures.However,the lack of systematic and continuous comparison between in vivo retinal development and the organotypic retinal explant culture makes this model controversial in postnatal retinal development studies.Thus,we aimed to verify the feasibility of using this model for postnatal retinal development studies by comparing it with the in vivo retina.In this study,we showed that postnatal retinal explants undergo normal development,and exhibit a consistent structure and timeline with retinas in vivo.Initially,we used SOX2 and PAX6 immunostaining to identify retinal progenitor cells.We then examined cell proliferation and migration by immunostaining with Ki-67 and doublecortin,respectively.Ki-67-and doublecortin-positive cells decreased in both in vivo and explants during postnatal retinogenesis,and exhibited a high degree of similarity in abundance and distribution between groups.Additionally,we used Ceh-10 homeodomain-containing homolog,glutamate-ammonia ligase(glutamine synthetase),neuronal nuclei,and ionized calcium-binding adapter molecule 1 immunostaining to examine the emergence of bipolar cells,Müller glia,mature neurons,and microglia,respectively.The timing and spatial patterns of the emergence of these cell types were remarkably consistent between in vivo and explant retinas.Our study showed that the organotypic retinal explant culture model had a high degree of consistency with the progression of in vivo early postnatal retina development.The findings confirm the accuracy and credibility of this model and support its use for long-term,systematic,and continuous observation.
文摘The ultrastructure of the epidermis and flesh of apple ( Malus domestica Borkh cv. Red Fuji) fruit was systematically observed during the fruit development via transmission electron microscopy. The results showed that, in spite of the ultrastructural changes in many aspects of the developing fruit epidermal cells, it remained almost unchanged throughout the whole developmental process that the cytoplasm was filled with numerous endoplasmic reticula (ER). Most of these endoplasmic reticula were tube_like and rough_ER with enlarged cisterna from which many vesicles were produced. Some of the vesicles were shown to merge into vacuole. Some dynamic Golgi bodies were also found. All the ultrastructural characteristics showed that the epidermal cells have the features of excretory cells. The ultrastructure of the fruit flesh cells at the young fruit stage were shown to be metabolically active, characterized by the presence of numerous clustered plasmodesmata, cisterna enlarged_ and rough_ER filling the cytoplasm, plenty of vesicles and Golgi bodies, indicating their dynamic cellular transport function. Some giant_circular rough_ERs were found. All the ultrastructural features at this early developmental stage should be closely associated with the enlargement of the young fruit. At the rapid growing phase of the fruit the main changes were characterized by: the starch grain_filled amyloplasts, furcating of the single orifice of plasmodesmata, and the cytoplasm enrichment of both the Golgi body_formed vesicles and other vesicles. These features correspond well with those of a photoassimilate sink_cell. An ultrastructural degeneration phenomenon was observed at the fruit ripening stage, but the mitochondria and plasmalemma still remained intact, which might be related to the continuous development of fruit quality during the fruit ripening.
基金This work was supported by the grant of National Natural Science Foundation of China (No. 30470598).
文摘Objective To investigate the cell proliferation and differentiation in the developing brain of mouse. Methods C57/BL6 mice were divided into 3 groups at random. Bromodeoxyuridine (BrdU) was injected into the brains in different development periods once a day for 7 d. The brains were retrieved 4 weeks after the last BrdU injection. Immunohistochemical and immunofluorescent studies were carried out for detecting cell proliferation (BrdU) and cell differentiation (NeuN, APC, lbal, and S 100β), respectively. Results The number of BrdU labeled cells decreased significantly with the development of the brain. Cell proliferation was prominent in the cortex and striatum. A small portion of BrdU and NeuN double labeled cells could be detected in the cortex at the early stage of development, and in the striatum and CA of the hippocampus in all groups. The majority of BrdU labeled cells were neuroglia, and the number of neuroglia cells decreased dramatically with brain maturation. Neurogenesis is the major cytogenesis in the dentate gyrus. Conclusion These results demonstrated that cell proliferation, differentiation and survival were age and brain region related.
基金Supported by the Aid Project on Science and Technology to the Developing Countries from the Ministry of Science and Technology of the PRC:Research Cooperation for key Ttechnologies to Improve Food Production in AfricaGuangxi Scientific Research and Technology Development Project(10100020-1,1346009-4)Fundamental Research Funds for the GXAAS(2014YZ38)~~
文摘Benin, a tropical country in west Africa, is one of the Ieast deveIoped countries confirmed by the United Nations. Benin is highIy dependent on agricuIture and reIativeIy rich in agricuIture resources. It&#39;s especial y suitabIe for agricuIture be-cause of the sufficient sunIight, raln and suitabIe temperature. AgricuIture export in Benin pIays an important part for both government and farmers. But the Iack of new varieties, appropriate technoIogy and modern service makes it difficuIt to deveI-op the agricuIture production rapidIy. Based on the introduction of agricuIture re-sources incIuding cIimate and Iand, this articIe malnIy showed the maln agricuIture productions and potential probIems in Benin, and then Iooked into the distance and deveIoping strategy on how to soIve the probIems. In order to deveIop the agricuI-ture sustalnabIy in Benin, it’s also suggested that the worId shouId strengthen the ald and share the fruits of new products, appropriate technoIogy and good man-agement methods.
文摘How to comprehensively,scientifically,objectively and impartially evaluate the multiple learning achievements of the PBL model should be highlighted when PBL is introduced and applied.A questionnaire of a total of 23 items involving such dimensions of language proficiency,subject contents and 21 st Century skills was designed.Its reliability and validity were tested and well-met with the statistical requirements.
基金Supported by Foreign Aid Funds of Ministry of CommerceAid East Timor Agricultural Technology of Hybrid Rice Cooperation Project~~
文摘The status, advantages and disadvantages of rice production in East Timor were investigated and analyzed, the results of comparison test and demonstrative cultivation through introducing 15 Chinese hybrid rice combinations into East Timor were summarized, the feasibility of developing hybrid rice in East Timor to realize food self-sufficiency were discussed and demonstrated, and the main corresponding technical strategies were proposed in this paper.
文摘Hepatitis B virus(HBV)infection is a serious global public health problem.The infection may be transmitted through sexual intercourse,parenteral contact or from an infected mother to the baby at birth and,if contracted early in life,may lead to chronic liver disease,including cirrhosis and hepatocellular carcinoma.On the basis of the HBV carrier rate,the world can be divided in 3 regions of high,medium and low endemicity.The major concern is about high endemicity countries,where the most common route of infection remains vertical transmission from mother to child.Screening of all pregnant women and passive immunization with human hepatitis B immunoglobulin are not affordable for many developing countries.The infection rate can be reduced by modifying behavior,improving individual education,testing all blood donations,assuring asepsis in clinical practice and screening all pregnant women.However,availability of a safe and efficacious vaccine and adoption of appropriate immunization strategies are the most effective means to prevent HBV infection and its consequences.The unsolved problem for poorest countries,where the number of people currently infected is high,is the cost of the vaccine.A future challenge is to overcome the social and economic hurdles of maintaining and improving a prevention policy worldwide to reduce the global burden of the disease.
文摘Hepatitis A is the most common form of acute viral hepatitis in the world.Major geographical differences in endemicity of hepatitis A are closely related to hygienic and sanitary conditions and other indicators of the level of socioeconomic development.The anti-hepatitis A virus(HAV)seroprevalence rate is presently decreasing in many parts of the world,but in less developed regions and in several developing countries,HAV infection is still very common in the first years of life and seroprev-alence rates approach 100%.In areas of intermediate endemicity,the delay in the exposure to the virus has generated a huge number of susceptible adolescents and adults and significantly increased the average age at infection.As the severity of disease increases with age,this has led to outbreaks of hepatitis A.Several factors contribute to the decline of the infection rate,including rising socioeconomic levels,increased access to clean water and the availability of a hepatitis A vaccine that was developed in the 1990s.For populations with a high proportion of susceptible adults,implementing vaccination programs may be considered.In this report,we review available epidemiological data and implementation of vaccination strategies,particularly focusing on developing countries.
基金Supported by Institutional NRSA,clinical oncology research training program,No.T32 CA079447(Bishehsari F)the Associazione Italiana per la Ricerca sul Cancro(AIRC),Milan to Mariani-Costantini R+3 种基金the Office for Internationalization,G.d’Annunzio University,Chietithe Carichieti Foundation,ChietiMinistero dell’Istruzione,dell’Universitàe della Ricerca(MIUR),Rome,Italythe Fondazione Umberto Veronesi,Milan,Italy and the MRC(5PT57)to Vacca M
文摘Colorectal cancer(CRC)is one of the leading causes of cancer and cancer-related mortality worldwide.The disease has been traditionally a major health problem in industrial countries,however the CRC rates are increasing in the developing countries that are undergoing economic growth.Several environmental risk factors,mainly changes in diet and life style,have been suggested to underlie the rise of CRC in these populations.Diet and lifestyle impinge on nuclear receptors,on the intestinal microbiota and on crucial molecular pathways that are implicated in intestinal carcinogenesis.In this respect,the epidemiological transition in several regions of the world offers a unique opportunity to better understand CRC carcinogenesis by studying the disease phenotypes and their environmental and molecular associations in different populations.The data from these studies may have important implications for the global prevention and treatment of CRC.
文摘AIM: To compare the short-term, including oncologic, outcomes of open vs laparoscopic colectomy for cancer in a developing country. METHODS: The records of patients who underwent elective open and laparoscopic colectomies for cancer at the University Hospital of the West Indies between January 2005 and December 2010 were retrospectively reviewed. Demographic(age, gender, Charlson comorbidity index score), peri-operative, post-operative and oncologic data were collected for each patient. Specific oncologic variables included lymph node yield, pathologic stage, grade, proximal, distal and circumferential margin involvement. Fisher's exact, Mann-Whitney, and binary logistic regression tests were used for analysis. Significance level was set atP < 0.05. RESULTS: There were 87 cases for open colectomy(OC) and 17 cases for laparoscopic colectomy(LC). Demographics did not significantly differ between OC and LC groups. Intra-operative blood loss and postoperative analgesic requirements did not significantly differ between groups. There was a trend towards longer operating times in OC group and shorter hospital stay in the LC group. Lymph node yield(14 vs 14, P = 0.619), proximal(10 cm vs 7 cm, P = 0.353) and distal(8 cm vs 8 cm, P = 0.57) resection margin distance and circumferential margin involvement(9 vs 0, P = 0.348) did not significantly differ between groups. Thirty-day morbidity was equivalent between groups(22 vs 6, P = 0.774). There were 6 deaths within 30 d of initial procedure, all in the OC group(6.9%). CONCLUSION: Laparoscopic colectomy in a developing country is oncologically safe and represents a option for colonic malignancies in these regions. Such data encourage the continued laparoscopic development.
文摘In this study, we developed a comprehensive index system for forestry sustainability of Heilongjiang Province, which includes forest resources sustainability,sustainable economic development, sustainable social development and sustainable advancement in science and technology. Based on this system and the regional forest development, we further evaluated the sustainability of Heilongjiang Province for year 2008-2013. The results show that even though the regional forestry has been preliminarily on the track of sustainable development, it is fragile. Four indicators, e.g. soil and water retention rate,forest stand growth(per unit area), the proportion of national investment and the annual carbon sequestration have important impact on the sustainability, with a weight of 39.0 % in all the indicators. We also analyzed the factors hindering the sustainable development. It turns out that soil and water retention rate, forest stand growth(per unit area),the proportion of science and technology funds, per capita GDP and the proportion of the tertiary industry production are the main factors hindering regional sustainable development, which accounts for 50.94 % of the total obstacle degrees in the system. At last, we discussed how to promote the regional sustainable development from the perspectives of forest resources sustainability, economic development sustainability, society development sustainability and the sustainable advancement of science and technology.
文摘The development of pericarp, seed coat, starchy endosperm and aleurone of the rice caryopsis was investigated, histochemically and structurally, from the time of flowering to maturity. The results showed that during its growth, the maximum length of the caryopsis was attained first, followed by width and then thickness. Histochemical examination of the caryopsis showed that starch was mainly accumulated in the endosperm, but the endosperm showed no metabolic activity, while embryo and pericarp contained a few starch grains, and embryo and aleurone were strongly active. Aleuronic cells contained many aleurone grains and spherosomes, and aleurone in the dorsal region developed earlier and contained more layers of cells. Amyloplasts in endosperm contained many starch granules and were spherical at early stages but polyhedric at late stages. The protein bodies appeared later than amyloplasts, and the number of protein bodies in subaleurone was greater than those in the starchy endosperm. The white-belly portion of endosperm might be relative to the status of amyloplast development.