生态用水及其核算方法

生态用水研究是近年来国内外关注的热点。在综合分析国内外生态用水研究进展情况的基础上,针对河流、植被、湿地以及城市4种生态用水类型,对其核算方法进行了分析,比较了不同方法的优缺点及适用范围。提出目前生态用水研究还存在如下问题：(1)生态用水核算中采用的不同方法都有其各自的局限性,但又都是针对具体的研究区域、特定的生态系统的较实用方法。因此在生态用水的核算方法上关键是方法的选择和结合具体案例对核算方法在深度、精度上的进一步探讨;(2)生态用水的机理研究不够深入。以往研究直接以植被生长用水量、鱼类等需保护动物用水量等作为替代生态用水量,难以反映生态系统需水的真实状况;(3)在研究尺度上往往都显得过于宽泛,对研究区域的基本情况、生态条件及水资源现状很难有详细明确的认识,因此数据的真实性及结果的可应用性也必然降低。文章最后认为,今后生态用水研究应点面结合,加强机理研究,增强研究结果的实践意义。     

重庆市土地利用冲突多尺度时空演化与多情景演化模拟

土地利用冲突是区域土地开发利用过程中存在的客观问题,对区域经济社会发展和生态安全具有重要影响。识别、测度区域土地利用冲突,明晰其时空演化格局,有助于优化区域土地利用结构,促进土地资源的可持续利用。以重庆市为例,基于景观格局构建了土地利用冲突测度模型,从县域、镇域以及格网3个尺度全面和系统地分析了1995-2020年重庆市土地利用冲突的时空演化特征,并耦合多目标规划(Multi-Objective Programming,MOP)-斑块生成土地利用变化模拟模型(Ptach-generating Land Use Simulation,PLUS)模拟了重庆市2030年不同发展情景下土地利用冲突格局。结果表明:(1)1995-2020年重庆市县域、镇域与格网不同尺度下的土地利用冲突格局具有较大相似性,不同尺度的土地利用重度冲突区主要分布在重庆中心城区及周边地区,区县建成区。土地利用一般冲突区主要分布于渝东南和渝东北地区。研究期内土地利用冲突有所加剧,其中土地利用重度冲突区占比增加了3.09%。(2) 1995-2005年重庆市土地利用冲突区主体位于乡村地域,但冲突程度较低,随着工业化、城市化进程及人口的集聚,2005年后土地利用冲突热点区域的城市地域集聚效应显著,城市及周边地区土地利用冲突区面积和土地利用冲突度均显著提升。(3) 区域土地利用冲突空间格局不仅受到了人为经济社会活动的驱动影响,在空间格局上受自然生态环境基底影响显著,其中地形地貌的限制加剧了土地利用重度冲突区。(4)不同发展情景模拟中经济优先发展情景下土地利用冲突最为严重,生态优先发展情景下土地利用冲突最小,可持续发展情景兼顾了经济和生态发展的用地需求,土地利用冲突强度处于中间范围,但区域发展总福利最大,是未来区域发展路径最优选择。     

Use of complementary and alternative therapies by overweight and obese adults

Objective: Obesity is associated with higher health‐care costs due, in part, to higher use of traditional health care. Few data are available on the relationship between obesity and the use of complementary and alternative medicine (CAM). Methods and Procedures: We analyzed data on CAM use from the 2002 National Health Interview Survey (NHIS) Alternative Medicine Supplement (n = 31,044). We compared the use of CAM overall, within the past 12 months, between normal weight (BMI from 18 to <25), overweight (from 25 to <30), mildly obese (from 30 to <35), moderately obese (from 35 to <40), and extremely obese (>40) adults. For the primary analysis, our multivariable model was adjusted for sociodemographic factors, insurance status, medical conditions, and health behaviors. We performed additional analyses to explore the association of BMI and the use of seven CAM modalities. Results: We found that adults with obesity have lower prevalence of use of yoga therapy, and similar prevalence of use of several CAM modalities, including relaxation techniques, natural herbs, massage, chiropractic medicine, tai chi, and acupuncture, compared to normal‐weight individuals. After adjustment for sociodemographic factors, insurance status, medical conditions, and health behaviors, adults with obesity were generally less likely to use most individual CAM modalities, although the magnitude of these differences were quite modest in many cases. Discussion: Even though adults with obesity have a greater illness burden and higher utilization of traditional medical care, adults with higher BMIs were no more likely to use each of the individual CAM therapies studied. Additional research is needed to improve our understanding of CAM use by adults with obesity.     

Size-dependent resource limitation and foraging-predation risk trade-offs: growth and habitat use in young arctic char

Variation in growth and habitat use is closely connected to individual responses to habitat specific resource levels and predation risk. In three mountain lakes which differed in the density of young-of-the-year (YOY) arctic char ( Salvelinus alpinus ), we studied the growth, diets and habitat use of YOY char in relation to resource levels. With two model approaches, we further examined the extent to which YOY and 1-yr old char were resource limited and, if so, whether resource limitation was associated with habitat use and small char densities. Benthic prey dominated the diet of YOY char and YOY char habitat use was restricted to the near-shore habitat in all lakes. In all lakes were chironomid densities higher in the near-shore habitat than in the offshore benthic habitat whereas zooplankton densities were higher in the pelagic than in the near-shore habitat. Growth of YOY char in all lakes was close to predicted maximum growth despite large variation in YOY densities between lakes. Model results suggested that density dependent resource limitation in YOY char is unlikely to occur despite restricted near-shore habitat use. In contrast, strong density dependent resource limitation was predicted in 1-yr old char with a restricted habitat use to the near-shore habitat. Correspondingly, field data suggested that the habitat use of 1-yr old char was density dependent as the use of the offshore habitat increased earlier in time and to a larger extent at high densities. As small individuals are vulnerable to predation but constrained by their low food processing capacity relative to their encounter capacity, we suggest that resource limitation in small individuals should be less pronounced and habitat use should mainly depend on predation risk. A trade-off in habitat use between foraging gain and predation risk is therefore expected to be more likely for individuals, large enough to be resource limited but still small enough to be vulnerable to predation.     

Shoal and prey patch choice by co-occurring fishes and prawns: inter-taxa use of socially transmitted cues

Animals can use socially transmitted information to learn about the distribution and quality of resources without incurring the costs associated with having to search for and sample them first hand. Recently, it has been shown that the use of chemical social information specific to patterns of diet and habitat use is an important mechanism underpinning recognition and social organization in shoaling fishes. In this study we revealed that the use of resource-specific chemical information is not limited to conspecifics, or even members of the same taxon. In a series of laboratory experiments, we showed that threespine sticklebacks (Gasterosteus aculeatus) could recognize similar patterns of habitat use in common prawns (Leander serratus), preferentially orientating towards groups of prawns exposed to the same habitats as themselves, and even selecting foraging patches located close to them. Prawns were seen to use habitat-specific cues generated by conspecifics, but not by sticklebacks, suggesting that the benefits of forming these heterospecific social association patterns may be unequal for prawns and fishes. Our findings suggest that some species might use co-occurring, unrelated species as information centres in order to orient and locate resources within their surroundings.     

Time preference and nutrition label use: Evidence from China

The assumption that label use behavior is, to some extent, intertemporal decision behavior because the benefit of label use cannot be realized instantly, is insufficiently considered. This paper is the first to examine directly if food nutrition label use is associated with behavioral inclinations in time preference. Using a theoretical analysis, this paper illustrates that individuals with lower present bias and higher long-run patience tend to use nutrition labels more frequently. In an empirical investigation, an analysis of a nationwide survey of 1220 Chinese adults confirmed that time preference relates to label use behavior, not only via impatience but also via hyperbolic discounting. Results of this study can help to better understand label-use behavior. They also provide important policy implications for the design of proper strategies for improving food nutrition label use, as well as help consumers in China and other developing countries choose healthier diets.     

Use of maternal-child health services and contraception in Guatemala and Panama

This paper presents data from 2 recent maternal-child health (MCH) and family planning surveys in Guatemala and Panama and examines the extent to which the use of contraception is influenced by the use of MCH services as compared with the influence of an increase in parity. Fieldwork was initiated in July 1984 but not completed until April 1985. A total of 8240 women aged 15-49 years, of all marital statuses, completed interviews, representing 91% of households with eligible respondents. The findings suggest that utilization of MCH services and parity independently are associated with a woman's decision to use contraception. The study also found 2 groups that appear to be particularly in need of both MCH and family planning services: high parity women and Indians. Nonuse of MCH and family planning services may be due in part to their strong cultural beliefs. In both Guatemala and Panama, improved health care services for these 2 groups should be a priority. Contraceptive use in Panama was over twice as high as in Guatemala. However, method choice and residence-ethnicity patterns of use were similar in each country. In both countries and in all residence-ethnicity groups, female sterilization was the most prevalent method in use, followed by oral contraceptives, except for Panama rural Indians. In Panama, contraceptive use increases up to ages 30-34 and then declines, with a sharp decline for women 40-44. In Guatemala, contraceptive use is generally low for ages 15-24, then increases to a fairly constant level for ages 25-39.     

东江流域景观格局演变分析及变化预测

以东江流域土地利用解译结果为基础,采用转移矩阵、移动窗口法和景观格局指数对1990—2016年对东江流域的景观格局时空变化进行分析,并结合地形因子、交通通达度因子和限制转化因子采用FLUS(Future Land Use Simulation)模型对流域未来景观格局进行预测。结果表明:(1)自1990年以来,研究区的7种土地利用类型皆发生了变化,其中建设用地由于林地和耕地的大量转入增加最明显。(2)1990—2016年,流域景观破碎化呈现以河道为中心向东西两侧减小的趋势,景观多样性呈现流域上游小,下游大的趋势,且高值区在经济较发达的城镇地区。园地的景观破碎程度最高、林地的优势度减弱,城镇建设用地的集聚度增加。(3)2016—2042年,流域各用地类型变化率不大,景观破碎化和多样性程度虽有增加但增长速度相对放缓。     

Explanatory Variables for per Capita Stocks and Flows of Copper and Zinc

A number of potential explanatory variables for the stocks and flows of copper and zinc in contemporary technological societies are co-analyzed with the tools of exploratory data analysis. A one-year analysis (circa 1994) is performed for 50 countries that comprise essentially all anthropogenic stocks and flows of the two metals. The results show that (1) The key explanatory variable for metal use is gross domestic product (GDP) per capita (purchasing power parity, PPP). By itself, GDP explains between one-third and one-half of the variance of per capita copper and zinc use. Other variables that were significantly correlated with copper and zinc use included stock of passenger cars and television sets (per 1, 000 people); two infrastructure variables, wired telephone connections, urban population, and value added inmanufacturing. The results do not provide evidence supporting the Kuznets curve hypothesis for these metals. (2) Metal use per capita can be estimated using multiple regression equations. For copper, the natural logarithm of use is related to the explanatory variables GDP (PPP), value added in manufacturing, and urban population. This model explains 80% of the variance among the different countries (r²= 0.79). The natural logarithm of zinc use is related to GDP (PPP) and value added in manufacturing with an r² of 0.75; (3) For both metals, rates of metal fabrication, use, net addition to stock, and discard in low-and high-income countries differ significantly from each other. Our statistical analyses thus provide a basis for estimating the potential development of metal use, net addition to stock, and discard, using data on explanatory variables that are available at the international level.     

Contrasting palm species and use diversity in the Yucatan Peninsula and the Ecuadorian Amazon

We analyze the relationship between palm species diversity and diversity of palm use in two areas (Amazonian Ecuador; Yucatan Peninsula) of equivalent size but with contrasting characteristics in palm species diversity and morphology, and in the phylogenetic composition of palm flora. The areas also differ in their cultural and socioeconomic contexts. Palm use diversity is significantly higher in the Ecuadorian Amazon than in the Yucatan Peninsula and the lower species diversity of palms in the Yucatan Peninsula is not matched by a more intensive use of the fewer species found there. The taxonomic composition of the palm flora is a poor predictor of extent of use and morphological characteristics of palm species affect usefulness only in the Ecuadorian Amazon. The Yucatecans’ more limited reliance on forest products might explain the observed patterns. Ornamental palm use is an indicator of a general change in plant use patterns associated with tourism and macro-economic development in the Yucatan Peninsula. We find a positive relationship between ecosystem plant diversity and plant use diversity, but socioeconomic factors such as market integration strongly influence the use of local biodiversity. Palms represent a diverse and important natural resource that deserves further investigation to secure its sustainable management and conservation in the two studied sites, regardless of their degree of market integration.     

Land use and cover with intensity of agriculture for Canada from satellite and census data

Aim To develop the first national databases on land use and agricultural land use intensity in Canada for a wide variety of environmental monitoring applications. Location Canada. Methods In this paper, we describe a new system for the construction of both land use and land use intensity (within agricultural regions) called LUCIA (land use and cover with intensity of agriculture). Our methodology combines the highly detailed Canadian Census of Agriculture and recent growing season composites derived from the SPOT4/VEGETATION sensor. Census data are of much coarser resolution than the remotely sensed data but, by removing non‐agricultural pixels from each census sampling area, we were able to refine the census data sufficiently to allow their use as ground truth data in some areas. The ‘refined’ census data were then used in the final step of an unsupervised classification of the remotely sensed data. Results and main conclusions The results of the land use classification are generally consistent with the input census data, indicating that the LUCIA output reflects actual land use trends as determined by national census information. Land use intensity, defined as the principal component of census variables that relate to agricultural inputs and outputs (e.g. chemical inputs, fertilizer inputs and manure outputs), is highest in the periphery of the great plains region of central Canada but is also very high in southern Ontario and Québec.     

Indicators of Dematerialization and the Materials Intensity of Use

We review the major empirical analyses of the related concepts of dematerialization and intensity of use. Dematerialization refen to the absolute or relative reduction in the quantity of materials used and/or the quantity of waste generated in the production of a unit of economic output A common indicator is the intensity of material use, which is the quantity of material used per unit of economic output. Our discussion focuses on seven topics: the environmental Kuznets curve for materials, material use and long wave theory material decomposition analysis, statistical, inpuboutput and dynamic models of material use, and analyses of national material use. We examine the measurement of aggregate material use and waste emissions, hypothesis testing, the importance of imports, and forces that countervail dematerialization such as rising affluence and the "rebound effect." We conclude that: our knowledge of the extent of and mechanisms behind the patterns of material use are limited largely to individual materials or very specific industries, and most of those examples are metals; the economy is getting "lighter" but the aggregate economic significance of that trend, if any, is unknown; there is no compelling macroeconomic evidence that the US. economy is "decoupled" from material inputs; and we know even less about the net environmental effects of many changes in materials use. We caution against gross generalizations about material use, particularly the "gut" feeling that technical change, substitution, and a shift t o the "information age" inexorably lead to decreased materials intensity and reduced environmental impact. We end with some suggestions for research that may help answer these important questions.     

The effect of local land use and loss of forests on bats and nocturnal insects

Land‐use intensification at local and landscape level poses a serious threat to biodiversity and affects species interactions and ecosystem function. It is thus important to understand how interrelated taxa respond to land‐use intensification and to consider the importance of different spatial scales. We investigated whether and how local land‐use intensity and landscape features affect the predator–prey interaction of bats and insects. Bats and nocturnal insects were assessed on 50 grassland sites in the Schorfheide‐Chorin. We analyzed the effect of local land use and distance to forested areas as a proxy for site accessibility on bats and insects and their biological interaction measured in bat's feeding activity. Insect abundance increased with higher land‐use intensity, while size and diversity of insects decreased. In contrast, bat activity, diversity, and species composition were determined by the distance to forested areas and only slightly by land‐use intensity. Feeding attempts of bats increased with higher insect abundance and diversity but decreased with insect size and distance to forested areas. Finally, our results revealed that near forested areas, the number of feeding attempts was much lower on grassland sites with high, compared to those with low land‐use intensity. In contrast, far from forests, the feeding attempts did not differ significantly between intensively and extensively managed grassland sites. We conclude that the two interrelated taxa, bats and insects, respond to land‐use intensification on very different scales. While insects respond to local land use, bats are rather influenced by surrounding landscape matrix. Hereby, proximity to forests reveals to be a prerequisite for higher bat species diversity and a higher rate of feeding attempts within the area. However, proximity to forest is not sufficient to compensate local high land‐use intensity. Thus, local land‐use intensification in combination with a loss of forest remnants weakens the interaction of bats and insects.     

A short review and critique of methodology used in fish growth and nutrition studies

A number of the techniques commonly employed in fish growth and nutrition studies are evaluated and limitations imposed by their use are indicated. Total and digestible energy values of dietary formulations should be measured directly and the use of caloric conversion coefficients and assumed digestibility values may lead to serious error. There is considerable misunderstanding relating to the term metabolizable energy and metabolizable energy has been estimated in a number of ways, all of which are unreliable. In view of this, it is suggested that there is a good case to be made for ceasing to use the term.     

Hearing Loss and Cognition: The Role of Hearing Aids,Social Isolation and Depression

Hearing loss is associated with poor cognitive performance and incident dementia and may contribute to cognitive decline. Treating hearing loss with hearing aids may ameliorate cognitive decline. The purpose of this study was to test whether use of hearing aids was associated with better cognitive performance, and if this relationship was mediated via social isolation and/or depression. Structural equation modelling of associations between hearing loss, cognitive performance, social isolation, depression and hearing aid use was carried out with a subsample of the UK Biobank data set (n = 164,770) of UK adults aged 40 to 69 years who completed a hearing test. Age, sex, general health and socioeconomic status were controlled for as potential confounders. Hearing aid use was associated with better cognition, independently of social isolation and depression. This finding was consistent with the hypothesis that hearing aids may improve cognitive performance, although if hearing aids do have a positive effect on cognition it is not likely to be via reduction of the adverse effects of hearing loss on social isolation or depression. We suggest that any positive effects of hearing aid use on cognition may be via improvement in audibility or associated increases in self-efficacy. Alternatively, positive associations between hearing aid use and cognition may be accounted for by more cognitively able people seeking and using hearing aids. Further research is required to determine the direction of association, if there is any direct causal relationship between hearing aid use and better cognition, and whether hearing aid use results in reduction in rates of cognitive decline measured longitudinally.     

Energy use and recovery strategies within wastewater treatment and sludge handling at pulp and paper mills

This paper presents an inclusive approach with focus on energy use and recovery in wastewater management, including wastewater treatment (WWT) and sludge handling. Process data from three Swedish mills and a mathematical model were used to evaluate seven sludge handling strategies. The results indicate that excess energy use in WWT processes counters the potential energy recovery in the sludge handling systems. Energy use in WWT processes is recommended to aim for sufficient effluent treatment, not for sludge reduction. Increased secondary sludge production is favourable from an energy point of view provided it is used as a substrate for heat, biogas or electricity production.     

Genetic vulnerability and susceptibility to substance dependence

The development of substance dependence requires the initiation of substance use and the conversion from experimental use to established use before development of dependence. Numerous large twin studies have indicated a significant genetic contribution to this process. Genetic studies to date have been most successful at identifying genetic factors that influence the transition from regular use to dependence. The availability of large cohort samples for nicotine and alcohol dependence has resulted in significant progress being made in understanding at least some of the genetic contributions to these addictions. Fewer studies have replicated specific genetic contributions to illicit drug use, though it is clear that there is a strong genetic component involved here as well. Substance dependence can be thought of as a pharmacogenetic illness, and most likely hundreds and more probably thousands of genetic variants will be required to fully explain the genetic input to this disease.     

Addiction and the brain: the neurobiology of compulsion and its persistence

People take addictive drugs to elevate mood, but with repeated use these drugs produce serious unwanted effects, which can include tolerance to some drug effects, sensitization to others, and an adapted state - dependence - which sets the stage for withdrawal symptoms when drug use stops. The most serious consequence of repetitive drug taking, however, is addiction: a persistent state in which compulsive drug use escapes control, even when serious negative consequences ensue. Addiction is characterized by a long-lasting risk of relapse, which is often initiated by exposure to drug-related cues. Substantial progress has been made in understanding the molecular and cellular mechanisms of tolerance, dependence and withdrawal, but as yet we understand little of the neural substrates of compulsive drug use and its remarkable persistence. Here we review evidence for the possibility that compulsion and its persistence are based on a pathological usurpation of molecular mechanisms that are normally involved in memory.     

Substance use and mating success

Psychoactive substance use has been typical of most traditional and modern societies and is maintained in the population despite the potential for abuse and related harms, raising the possibility that it (or its underlying causes) confers fitness benefits that offset its costs. Although it seems plausible that psychoactive substances have facilitated survival among ancestral and modern humans, it is not clear that this enhancement has translated into Darwinian fitness through mating and ultimately reproductive success. In the current study, we discuss potential mechanisms by which substance use might make unique contributions to mating success, attend to the possibility that the effects between substance use and mating success are instead confounded, and use structural equations and nationally representative data to determine whether these effects are more likely causal or spurious. Our findings indicate that once we know participants' scores on “third” variables at each round in early young adulthood, their substance use gives us little additional information about their current prospects for acquiring sexual partners and no additional information about of their future prospects. Thus, if adaptations for substance use evolved, their adaptive value does not seem to be found in mating success.