Assessment of the Physical Capabilities of Heart Failure Patients before and after Cardiovascular Rehabilitation: A Study of 125 Patients from West Africa, Dakar, Senegal

Background: Cardiac rehabilitation represents a critical therapeutic strategy for patients suffering from chronic heart failure. The physical capacity of patients with heart failure, assessed using the exercise test and the 6-minute walk test, is the measure of the patient’s overall functional ability to perform physical activities and tolerate exercise loads. The objective of this study was to assess the impact of cardiac rehabilitation on patients’ physical capabilities and to conduct a thorough comparison of data obtained via exercise testing and the 6-minute walk test before and after the rehabilitation programme. Methods: This was a descriptive and analytical cross-sectional study, conducted from 1 February 2021 to 31 June 2022. Included were heart failure patients who had participated in an outpatient cardiovascular rehabilitation programme. The collected data included anamnestic, clinical, paraclinical data, and the 6-minute walk test. Informed consent was obtained. Data analysis, word processing, and charting were performed using Microsoft Word 2016, Excel 2013, and Sphinx version 5.1.0.2. Data analysis was performed using SPSS (Statistical Package for Social Sciences) version 24.0. Any difference less than 0.05 was considered statistically significant. Results: In a Senegalese study, heart failure patients undergoing rehabilitation in a cardiac unit represented 45.59% of all cases, with a prevalence rate of 3.21%. The average participant was 57.97 years old, with those aged 61 to 70 forming the largest group (35.5%). The study noted a male predominance (sex ratio of 2.1) and identified dyslipidaemia (80.6%) and sedentarism (71%), as prevalent cardiovascular risk factors. All participants initially suffered from NYHA stage 2 or 3 dyspnoea, yet 80.65% showed no symptoms following rehabilitation. Significant improvements were recorded in resting heart rate (from 79 to 67 bpm), and the 6-minute walk test distance (from 328 m to 470 m). Enhanced exercise tolerance and walking test outcomes were particularly notable in patients with LVEF ≥ 50%, women, non-obese individuals, those initially walking less than 300 m, achieving more than 3 METs, and non-smokers. Conclusion: The findings underscore the effectiveness of cardiovascular rehabilitation in improving symptoms, physical capability, and overall quality of life for heart failure patients in Senegal.

Socioenvironmental Drivers of Farmers’ Perceptions of Climate Change Risk in Agroforestry Parklands of West Atacora in Benin (West Africa)

Throughout the world, climate change is threatening the human population. In West Africa, smallholder farmers in indigenous agricultural societies typically hold considerable knowledge. Therefore, this study was conducted in West Atacora of Benin Republic to assess the drivers of farmers’ perceptions of climate change risk. We used a random sampling technique to select 360 households’ heads who were interviewed regarding different climate change risks perception. Binomial logistic regression was used to assess the drivers of farmers’ perceptions of climate change risks. The results showed that the farmers in drier areas had a higher perception of the global risk of climate change than those in humid areas. The same trend was observed for the seven different individual’s climate change risk investigated. The study identified also membership of farm organizations as main sociodemographic characteristic that explains farmers’ perception of climate change risk perception. These findings are helpful tools to sensitize the local people on climate change risk and cope with the risk in agricultural lands.

Use of Topical Complementary and Alternative Medicines (CAM) in Diabetic Septic Foot Disease in Makkah Region, Western of Saudi Arabia, an Exploratory Study

Diabetes is a chronic condition that is significantly impacted daily by environment. At least one in five Saudis, suffer from diabetes. “Diabetes is a pandemic of unprecedented magnitude spiraling out of control” (Boulton). Saudi Arabia ranks the second highest in the Middle East, and is the seventh in the world for the prevalence of diabetes (WHO). Diabetes mellitus (DM) has been found to be related to high mortality, morbidity accompanied by poor general health and lower quality of life. Current Saudi diabetes patients’ behaviors, practices, and beliefs regarding foot health problems such as ulcers, are not well investigated. Diabetic patients frequently utilize natural remedies and Herbs for self-medication as a part of complementary and alternative Medicine. Aim of study: To explore the widespread use of the alternative remedies in the local communities of the Western Saudi Arabia, the drives behind using and to focus on the potential adverse effects following their usage. Method: A descriptive, cross-sectional study of 386 diabetic patients with feet problems in Makkah Region, West of Saudi Arabia during the period April - June 2023. Results: Out of the 531 participants, only 386 participants reported diabetic foot disorder (DFD). Most of the participant were above 65 years of age group (24.61 %). Male (52.08%) more than female (47.92%) in the research group. All of the participants had diabetic foot disorders at least once. The prevalence of complementary and alternative medicines (CAM) use among them was 67.88%, as solitary or in combination with hospital medicines. Honey headed the list followed by myrrh and black seeds. Acquaintances advice (59.54%) was the most reason for using the alternative medicine. 60.30% of Diabetic foot patient complained of adverse effects during CAM remedies use. Conclusion: Consumption of CAM remedies among diabetic patients for Diabetic Foot Disorder (DFD) is common. Honey headed the list followed by myrrh and black seeds. Additional wide-scale research is required to establish their actual efficacy, safety and potential adverse out-comes and to generalize the outcomes.

Isolated Hyperacute T-Waves in West Nile Encephalitis Indicating Atypical Variant of Stress-Induced Cardiomyopathy

Several cardiac outcomes have been reported with West Nile-encephalitis;however, the underlying pathophysiology remains complex. We present a 42-year-old female, with multiple sclerosis, whose neurological symptoms and respiratory decline were finally explained by the diagnosis of West Nile-encephalitis. During her admission, the isolated peaked T-waves indicated the underlying stress-induced cardiomyopathy. The absence of all other causes of hyperacute T-waves, their subsequent resolution with the resolution of infection and improvement in wall motion abnormalities, further supported the association. This case highlights the importance of considering hyperacute T-waves in an approach towards the diagnosis of WNV-encephalitis related atypical variant of stress-induced cardiomyopathy.

Influence of Continental Atmospheric Forcing on the Decadal Variability of the West African Monsoon

The West African Monsoon (WAM) is characterized by strong decadal and multi-decadal variability and the impacts can be catastrophic for the local populations. One of the factors put forward to explain this variability involves the role of atmospheric dynamics, linked in particular to the Saharan Heat Low (SHL). This article addresses this question by comparing the sets of preindustrial control and historical simulation data from climate models carried out in the framework of the CMIP5 project and observations data over the 20th century. Through multivariate statistical analyses, it was established that decadal modes of ocean variability and decadal variability of Saharan atmospheric dynamics significantly influence decadal variability of monsoon precipitation. These results also suggest the existence of external anthropogenic forcing, which is superimposed on the decadal natural variability inducing an intensification of the signal in the historical simulations compared to preindustrial control simulations. We have also shown that decadal rainfall variability in the Sahel, once the influence of oceanic modes has been eliminated, appears to be driven mainly by the activity of the Arabian Heat Low (AHL) in the central Sahel, and by the structure of the meridional temperature gradient over the inter-tropical Atlantic in the western Sahel.

西秦岭成矿带古生界控矿特征及有关成矿作用

西秦岭成矿带下古生界的赋矿地层分布于南带,主要为志留系,次为寒武系;而上古生界的赋矿地层在南带和北带均有分布,主要为泥盆系,次为石炭系—二叠系。其中,寒武系主要赋存后生浅成中-低温热液作用有关金矿(伴生铜、铀、钼、锑、硒等)。志留系赋存同生沉积作用有关钼钒(伴生镍、铀)、磷、石煤、锰和灰岩矿,后生浅成中-低温热液作用有关金、银、锑、汞和铀矿(伴生铜、钼、镍、钒),局部有表生风化淋滤作用有关褐铁矿、铀矿。南带泥盆系赋存同生沉积作用有关煤、白云岩、石膏、铁和磷矿,后生浅成中-低温热液作用有关铁、金、汞和硫铁矿,局部有表生风化淋滤作用有关褐铁矿;北带泥盆系赋存喷流沉积-改造作用有关铅锌矿及铜矿,后生浅成中-低温热液作用有关铁、铜、金、锑和汞矿,局部有表生风化作用有关白铅矿-菱锌矿。南带石炭系—二叠系赋存沉积作用有关灰岩、白云岩,后生浅成中-低温热液作用有关金和汞矿。北带石炭系—二叠系赋存火山沉积-改造作用有关铅锌矿,后生浅成中-低温热液作用有关金和锑矿等。此外,在西秦岭向东昆仑过渡地带,石炭系—二叠系赋存有火山沉积-改造作用有关铜和锡矿。总之,地层控矿基本分两类:①含矿(同生及准同生关系),矿体是地层的组成部分,成矿时代同于含矿地层时代(志留纪、泥盆纪、石炭纪、二叠纪)。②容矿(后生及表生风化关系),矿体不是地层的组成部分,成矿时代明显晚于容矿地层的时代,区内后生浅成中-低温热液作用主要发生在中生代,风化作用主要发生在新生代。沉积-改造型矿床可视为两种控矿类型的叠加。容矿地层是否矿源层,需具体情况具体分析。

西准噶尔构造带包古图地层小区上泥盆统红山梁组的建立及地质意义

西准噶尔构造带包古图地层小区白碱滩北红山梁剖面上新发现一套晚泥盆世红色“硅质岩、粉砂质硅质岩、凝灰质硅质岩”海相沉积组合,与上覆包古图组深灰色—灰黑色含碳粉砂岩呈整合接触。经区域对比确认,该套地层显著有别于研究区乃至整个西准噶尔构造带地层分区已发现的全部上泥盆统各组岩石地层,符合“野外可识别、界面可区别、区域可对比、图面可表达”的原则,据此新建红山梁组。本次于红山梁组枕状玄武岩、玄武岩、安山岩中分别获得365.9±5.0Ma、370.6±7.4Ma和374.6±3.6Ma的LA-ICP-MS锆石U-Pb年龄,佐证其时代为晚泥盆世。红山梁组与包古图组连续沉积之确认,消除了包古图组老于希贝库拉斯组这一存疑,建立了完整的下石统地层序列,新增了包古图地层小区泥盆纪的沉积记录,为区域沉积与构造演化研究提供了新资料。

Commercialization of Cow Milk Production in West Hararghe Zone, Oromia National Regional State, Ethiopia

Livestock plays a vital role in the livelihood of many people in Ethiopia. However, a number of challenges hindered the development of the dairy sector along with its commercialization. Advancing commercialization of the rural generations was a foundation of the advancement and poverty reduction policies of Ethiopia. Cross-sectional data from 385 randomly selected households in Eastern Ethiopia were used in this study to assess the commercialization of cow milk producers. Descriptive statistics and the two limit Tobit econometric models were used to analyze the data. The average commercialization index was 0.434, indicating that each household sold 43.4 percent of the milk produced during the survey period. Ownership of improved breed cow, cooperative participation, access to market information, and quantity of milk produce influenced milk commercialization positively, but household size and distance to the nearest market influenced it negatively. The study suggests strengthening policies to improve rural family planning, strengthening farmer cooperatives to reinforce knowledge sharing among farmers for enhancing farmer resource endowment, and promoting improved breed varieties. The commercialization of milk producers will also expand as a result of policies that try to lower the transaction costs of accessing markets, improve the capacity of rural institutions, and encourage value addition and market links among various market players.

NDVI-Derived Vegetation Trends and Driving Factors in West African Sudanian Savanna

The Sudanian savanna is a key vegetation biome in West Africa providing food and vital ecosystem services. Recently, it has been reported alarming vegetation loss in this biome, calling for more investigation, relevant to tackle land degradation and ensure food security. However, vegetation dynamics in this area remains a matter of debate, and one of the main challenges is to document consistently the underlying driving factors. This study aimed at assessing vegetation trends and driving factors from 2000 to 2022. NDVI trend, detected using the Mann-Kendall’s monotonic trend test, was used as proxy to express vegetation dynamics. In addition to the non-parametric Spearman correlation analysis, variables importance scores, derived from Random Forest (RF) classifications, were used to determine key driving factors among climatic, topographic, edaphic, accessibility and demographic factors. During 2000-2022, no significant trends largely characterised the vegetation cover of the study area. However, patterns of strong (weak) browning and strong (weak) greening affected 7.1% (10.6%) and 12.8% (19.1%) of the study area respectively. According to the driving factors analysis, the observed vegetation trends were mainly driven by rainfall dynamics (trend and mean annual), population growth and anthropogenic activities. The results of this study can support the development of efficient strategies for safeguarding vegetation cover in the Sudanian savanna of Burkina Faso.

中西非裂谷系富油凹陷石油地质特征与勘探方向

基于地震、钻井、烃源岩测试分析等资料,对中西非裂谷系主要盆地富油凹陷石油地质特征进行研究,并探讨未来油气勘探方向。研究表明:中非裂谷系发育下白垩统湖相优质烃源岩,西非裂谷系发育上白垩统陆源海相优质烃源岩,两类烃源岩为中西非裂谷系油气富集提供了物质基础。中西非裂谷系发育包括基岩在内的多套储集层,并存在下白垩统、上白垩统和古近系3套区域盖层。晚中生代以来,受中非剪切带右旋走滑作用等地球动力学因素的影响,中西非裂谷系不同方向的盆地在裂谷作用期次、区域盖层发育层段、圈闭类型及成藏模式等方面存在差异。其中,北东—南西向盆地主要保存了早白垩世一期裂谷层序,区域盖层位于下白垩统裂陷期地层内,形成反转背斜、花状构造及基岩潜山等圈闭类型,发育“源储一体、源内成藏”及“源上储下、源下成藏”两种成藏模式;北西—南东向盆地具有多期裂谷叠置特征,发育上白垩统和古近系区域盖层,形成披覆背斜、断背斜、反向断块等圈闭类型,以“源下储上、源上成藏”为主要成藏模式。多期叠置裂谷盆地的源内成藏组合、强反转盆地的源内岩性油藏及页岩油是中西非裂谷系盆地未来勘探的重要领域。

Hydro-Geochemistry and Application of Water Quality Index (WQI) for Ground Water Quality Assessment, Wadi Al-Samen—Hebron—West Bank

Located south of the West Bank, Wadi Al-Samen is considered one of the most important sources of groundwater recharge for the eastern aquifer in Hebron. It is polluted by sewage originating from domestic and industrial consumption in the Hebron area. Water quality assessment is an important criterion for achieving sustainable development. To evaluate water quality, twenty samples were collected from groundwater sources for two seasons and were analyzed for Physical properties (Total dissolved solids (TDS), Electrical conductivity (EC), potential hydrogen (pH), Temperature (T)), Four major cations (Mg2+, Ca2+, Na+ and K+), and the Major anions (HCO-3, Cl-, and SO2-4);geochemical methods such as Piper scheme were used for the sample result analysis. To characterize wastewater components, six samples were collected from the Wadi discharge for two seasons and were analyzed (potential hydrogen (pH), Electrical Conductivity (EC), Total Dissolved Solid (TDS), Total Suspended Solids (TDS), Total Suspended Solids (TSS), Biological Oxygen Demand (BOD5), and Chemical Oxygen Demand (COD). The results of nitrate levels showed that 20% of the ground water samples exceeded the standard limit of the World Health Organization (WHO). The quality of drinking water was assessed using the Water Quality Index (WQI), which suggests that 10% of samples are classified from poor to very poor. The abundance of cations from highest to lowest was found to be: Ca;Mg;Na, and for the anions it is HCO3;Cl;SO4. The dominant hydrochemical facies of 35% of collected aquifer samples reveal that Ca-Mg-Na-Cl-HCO3 are in the domain. Evaluation of irrigation suitability was performed using parameters of Sodium adsorption ratio (SAR), electric conductivity (EC), and Salinity. The results in both rounds for EC showed that all water sources are suitable for irrigation according to Todd’s classification. SAR was not suitable in three water resources samples. Wilcox analysis for the two seasons revealed that 85% of samples are not appropriate for irrigation uses.

共同富裕目标下东西部协作机制重构研究

东西部协作是推动区域协调发展、协同发展、共同发展,从而实现共同富裕的大战略、大举措。党的十八大以来,东西部协作和对口支援的规模不断扩大、路径不断拓宽,西部地区全面建设小康社会成果显著。进入新发展阶段,要实现党的二十大报告提出的全体人民共同富裕的中国式现代化要求,东西部协作机制需要释放“倍增效应”。为此,需要响应以巩固拓展脱贫攻坚成果同乡村振兴有效衔接为起点,以缩小东西部区域城乡差距和群体收入差距为导向,以协同推进全国统一大市场建设为路径,遵循共同富裕目标下东西部协作机制的重构逻辑,以东西部协作机制重构赋能乡村振兴与区域协调发展。新发展阶段,以东西部协作机制重构赋能共同富裕,要推动“产业+园区”协作治理模式提档升级,强化“消费+就业”协作治理模式创新,探索“资源+服务”协作治理模式。

Flood Forecasting and Warning System: A Survey of Models and Their Applications in West Africa

Flood events occurrences and frequencies in the world are of immense worry for the stability of the economy and life safety. Africa continent is the third continent the most negatively affected by the flood events after Asia and Europe. Eastern Africa is the most hit in Africa. However, Africa continent is at the early stage in term of flood forecasting models development and implementation. Very few hydrological models for flood forecasting are available and implemented in Africa for the flood mitigation. And for the majority of the cases, they need to be improved because of the time evolution. Flash flood in Bamako (Mali) has been putting both human life and the economy in jeopardy. Studying this phenomenon, as to propose applicable solutions for its alleviation in Bamako is a great concern. Therefore, it is of upmost importance to know the existing scientific works related to this situation in Mali and elsewhere. The main aim was to point out the various solutions implemented by various local and international institutions, in order to fight against the flood events. Two types of methods are used for the flood events adaptation: the structural and non-structural methods. The structural methods are essentially based on the implementation of the structures like the dams, dykes, levees, etc. The problem of these methods is that they may reduce the volume of water that will inundate the area but are not efficient for the prediction of the coming floods and cannot alert the population with any lead time in advance. The non-structural methods are the one allowing to perform the prediction with acceptable lead time. They used the hydrological rainfall-runoff models and are the widely methods used for the flood adaptation. This review is more accentuated on the various types non-structural methods and their application in African countries in general and West African countries in particular with their strengths and weaknesses. Hydrologiska Byråns Vattenbalansavdelning (HBV), Hydrologic Engineer Center Hydrologic Model System (HEC-HMS) and Soil and Water Assessment Tool (SWAT) are the hydrological models that are the most widely used in West Africa for the purpose of flood forecasting. The easily way of calibration and the weak number of input data make these models appropriate for the West Africa region where the data are scarce and often with bad quality. These models when implemented and applied, can predict the coming floods, allow the population to adapt and mitigate the flood events and reduce considerably the impacts of floods especially in terms of loss of life.

从古今中西之争到新的文化生命体

在文化传承发展座谈会上的讲话中,习近平总书记作出了“我们比以往任何一个时代都更有条件破解‘古今中西之争’”的论断。近代以来,面对西方冲击,以儒家文化为核心的旧文化生命体濒临解体,如何处理中与西、古与今的关系,再造新的文化生命体,构筑文化自信赖以依托的文化主体性,找回并坚定文化意义上的自我,重构国家认同的文化基础,就成为一个摆在中国人民和中华民族面前的重大课题。马克思主义传入中国后,以真理之光激活了中华文明基因,推动了中华文明的生命更新和现代转型,发展出了中华文明的现代形态、中国式现代化的文化形态,“造就了一个有机统一的新的文化生命体”,“巩固了文化主体性”。这就为破解“古今中西之争”创造了根本条件。

Rainfall Variability and Trends in West Africa

Rainfall variability associated with climate change has enormous impacts on ecosystems, agriculture and people in West Africa but few studies have been devoted to it. Monthly rainfall data from 1901 to 2013, provided by the Global Precipitation Climatology Center dataset, were analyzed using segmentation and empirical modal decomposition (EMD) methods to increase our knowledge on past and recent spatio-temporal rainfall trends and their impacts on the West African region. The results obtained showed that the peak of rainfall during the short rainy season is observed in September in Côte d’Ivoire, Ghana and Liberia. The temporal variability of this rainfall is marked by several breakpoints whose durations range from 2 to 70 years. The periods of change in the rainfall regime, characterized by the appearance of breakpoints, vary from one country to another and are of unequal duration. The main breakpoint appears after 1960. Periods of relative or normal increase or decrease in precipitation are observed before and after 1960. The long-term variability of this rainfall is characterized by a decrease in the amount of rainfall over all West African countries. The results of this study can be used as a tool to help raise awareness among populations for sustainable management of water resources in response to climate change and its adverse effects.

Plant Diversity and Carbon Stock Assessment in an Informal Settlement of the City of Yaounde, Cameroon: The Case of Elig-Effa West

Due to rapid demographic growth, economic and technological changes, urban environments are highly exposed to the impacts of climate change and environmental catastrophes. Despite the pressure to which urban forests are exposed, they still play important roles through the service they provide: air quality, shade, and reduction of dioxide of carbon. The present study was carried out in the city of Yaoundé, Cameroon, especially in one of its suburb areas, Elig-Effa West, a neighborhood with spontaneous settlements. The study aimed at assessing the plant species diversity, and carbon sequestration potentials of diverse trees recorded using indirect methods. Six sampling plots of 100 × 100 m were established in the study area. Our results recorded a total of 16 species grouped into 12 families. Apocynaceae, Mimosaceae and Moraceae were the most represented families. The most represented species throughout the sampling plots were Mangifera indica, Persea americana, Annona muricata and Psidium gaujava, which are all fruiting trees. Carbon stock for the study area was estimated at 16.08 ± 5.60 tC with an average of 0.23 ± 0.08 tC/ha. The results also showed the species to be considered in a potential restoration program should be first fruiting trees, followed by non-fruiting trees useful to population, especially those that have their trunk peeled, a sign that they are used by the population. Nevertheless, informal settlements contribute to carbon sequestration, that well targeted urban reforestation will substantially improve.

Determining the Effects of Selected Organic Fertilizer on Growth and Yields of Tomato (Lycopersicon esculentum: Var. Rio Grande Tomatoes) in Mundri West County, Western Equatoria State, South Sudan

Worldwide, the demand for agro-organic foods that are healthy, nutritious, and environmentally friendly is increasing dramatically across all nations among consumers. Tomatoes being one of the dietary requirements in almost every meal is not exceptional and its availability in the market all year round is very important to farmers as well as consumers because it is highly demanded as a vegetable par excellence;which is either eaten raw in salads, cooked or processed into liquid ingredients. This study investigates the impact of chicken, goat, and cow manure treatments on tomato plant growth response to height, leaf length, and width, as well as fruit yield. The experimental field trials were conducted over two planting seasons in Mundri West County. It followed a Complete Randomized Design (CRD) approach, consisting of four blocks. Each block contained three treatments replicated four times and a control group. The data of measured parameters from all 16 plots were subjected to one-way Analysis of Variance (ANOVA) using the Gen Stat 14th Edition software. The findings indicate significant differences (P < 0.05) among all the different organic manure applications on tomato plant growth parameters compared to the control group. Chicken manure resulted in the tallest tomato plants (30.1 and 37.9 cm), longest leaves (9.9 and 10.4 cm), and widest leaves (2.1 and 2.5 cm) in both seasons respectively. The study showed plots treated with chicken manure had a highly significant impact (P < 0.05) on the prevalence of aphids (1.0) and white flies (1.4) with the lowest value compared to those with cow and goat manure applied. Additionally, chicken manure led to the highest yields (39.30 and 49.49 tons/ha) in both seasons. Based on these findings, it can be concluded that using chicken manure effectively improves the performance of Rio Grande Tomatoes, and thus, farmers are encouraged to utilize chicken manure to maximize their tomato yields.

当代中西方规范权力与资本关系的德法之道

自从习近平总书记提出政商关系“亲、清”两原则以来,我国学术界围绕新时代政商关系抑或权力与资本关系的探讨日渐深入。由于中西方对待市场经济本质与作用的认知态度各不相同,致使其权力资本化的方式方法形同质异,资本权力化的生成路径迥然有别。特别是在全球经济数字化条件下,中西方权力与资本之间的运演机制面临更加复杂的伦理挑战:就数字权力资本化而言,它呈现出多种多样的表现形态;就数字资本权力化而言,也同样生成了类型各异的表现形式。为求解这些难题,必须对当代中西方权力与资本良性互动的底线道德、伦理规则和法治原则进行深度理论辨析,正确处理好三大问题:以何种态度对待弱势群体是权力与资本良性互动的道德前提,持续构建权力与资本良性互动的伦理规则体系,不断增强权力与资本良性互动的法治保障。唯其如此,才能有效应对和求解新时代我国政商关系(权力与资本关系)在理论和实践层面遇到的各种难题。

海温异常对长江流域夏季典型旱涝的影响研究

为研究长江流域夏季旱涝特征及其与海温异常之间的关联性,基于中国326个气象站降水量、NCEP/NCAR再分析资料等,采用合成分析、EOF分解等方法,分析了长江流域夏季典型旱涝年的降水分布、同期大气环流及前期海温特征,并以2018年为例,初步揭示了2018年前期海温异常对大气环流的可能影响。结果表明:①长江流域夏季典型旱年,仅嘉陵江和岷沱江会表现出局部偏涝,全国为典型的Ⅰ类雨型,多雨区位于黄河流域及以北地区。前期冬季赤道太平洋表现出类拉尼娜的东冷西暖分布,同时黑潮区海温偏低,西风漂流区海温偏暖。受多海域协同作用,同期欧亚环流场上自西北向东南呈现出“+-+”三极型分布,东亚地区为自北向南“-+-”的EAP负位相。长江流域典型涝年,全国多为典型的Ⅱ类和Ⅲ类雨型,环流及海温呈现出相反特征。②2018年为典型的长江中下游偏旱年,仅在岷沱江降水偏多近3成,为历史第4多,与长江流域夏季降水的主模态正位相类似,解释方差达24%。③2018年前冬出现弱拉尼娜、春末夏初西风漂流区异常偏暖、NAT异常正位相,三者共同作用,使得东亚副热带西风急流偏北,东亚沿岸出现EAP负位相,大陆热低压明显偏强,东亚夏季风为1961年以来最强,同时副高脊线最北,造成夏季降水主雨带北推至华北、西北地区,岷沱江、嘉陵江异常多,而长江中下游异常少,为典型的Ⅰ类雨型。研究成果可为长江流域旱涝预测、水资源调度提供参考。

“科幻西方”的一种解构——阿瑟·克拉克作品中“沉默巨物”意象的美学思考

作为一种以西方意识形态为背景的类型文艺,科幻小说中长期充斥着以“西方中心论”为特质的话语。而英国作家阿瑟·克拉克则在其科幻创作中,有意无意地呈现了对“科幻西方”的一种解构。这尤其鲜明地体现于他围绕“沉默巨物”意象展开的三种美学演绎:通过重新塑造飞船悬停于城市上空的场景,克拉克将欧洲文学中的神学哲思传统与科幻题材相融合;他对外星文明遗迹的描绘,在宏大尺度上消解了西方文明的例外论;他对“太空电梯”的格外推崇,则进一步反映了他在技术时代的浪漫主义理想。以阿瑟·克拉克为例,我们可以看到真正有价值的科幻创作,需要在解构“科幻西方”的基础上实现超越。