A schematic view of resources,technology and environment in agricultural development

Agricultural production systems can be viewed as consisting of three interrelated components: resources, technology, and environment (R-T-E). The quantities, qualities and terms of availability of resources condition the kinds of technology available to farmers and their choices among them. The technologies employed, in turn, may damage the environment, generating demands for policies to reduce the damages, and they also affect the future terms of availability of resources. The components of R-T-E systems are thus interdependent, and the relations among them change with time.In thinking about the future of world R-T-E systems in agriculture it is useful to group countries in four categories, given presently available technologies: (1) low productivity potential/high land potential; (2) high productivity potential/high land potential; (3) high productivity potential/low land potential; and (4) low productivity potential/low land potential. Given prospective increases in real prices, or scarcity of energy, fertilizer, and water for irrigation, farmers in Category 1 countries (e.g., the United States) are likely to respond by adopting more land-using technologies than in the past, and soil erosion is likely to be the most important resulting environmental problem. In Category 2 countries (e.g., Brazil) also, land-using technologies will appear attractive, but the use of agricultural chemicals will also increase sharply. Environmental problems of erosion, habitat loss and pesticide damage are likely to increase. Category 3 countries (e.g., India) will adopt more land-saving technologies despite rising prices of non-land inputs, and environmental problems associated with large irrigation systems are likely to become more important. The options for Category 4 countries (e.g., Western Europe) are more limited. The most likely response will be towards larger farms rather than major changes in technology. Environmental impacts of agriculture are not now of major importance in these countries and this is not likely to change.Governments have three broad options for dealing with energing problems of agricultural R-T-E systems. The traditional approaches rely on regulations or on a variety of financial inducements to move farmers towards more socially desirable patterns of resource use. A third, less traditional, approach is to invest in development of new technologies which simultaneously are economically attractive to farmers and less damaging to the environment.     

Biosensors: new approaches in drug discovery

The development of biosensors for analytical purposes has attracted a great deal of attention in recent years. A biosensor is defined as an analytical device consisting of a biological component (e.g., enzyme, antibody, entire cell, DNA) and a physical transducer (e.g., electrode, optical device). Biosensors are mostly designed for routine analysis, such as clinical diagnosis, quality control of food, in-process control of fermentations, and in environmental analysis. Many of these sensors are also suitable for screening purposes in order to find new drugs. Such systems should yield information either about compounds with known bioactivity or about the bioactivity of samples with known or unknown chemical composition. Biosensors intended for the latter purpose are essentially based on whole cells carrying receptors and ion channels at their surfaces. Miniaturization of structures, primarily based on silicon, allows integration of many sensors into arrays, which may be suitable for the screening of natural and chemical products as well as combinatorial libraries. Until now, no commercially available sensors of this kind exist but they are expected in the near future. Different biosensors, based on enzymes, antibodies, cells, artificial membranes and entire animal tissues, which can be used in drug discovery and may lead to efficient screening systems in the future, are described in this review.     

Possibilities and limitations in cancer prevention

The possibilities and limitations in cancer prevention are shown by means of some examples and historical facts. A necessary prerequisite for effective prevention is to know the exact cause of cancer. This is known for some tumor types (e.g., bronchial cancer), while for others it is hardly known (e.g., breast cancer). There are many factors which influence the whole process of carcinogenesis. Exposure to environmental pollutants in a wide sense represents only one of many possible etiologies. This has to be taken into consideration.     

Climate change, aerobiology, and public health in the Northeast United States

The epidemiological implications with respect to climate change and public health (e.g., shifts in disease vectors) are beginning to be acknowledged. Less recognized however, are the potential links between climate, plant biology and public health. In addition to being affected by climate (e.g., temperature determines plant range), carbon dioxide (CO₂) represents the raw material needed for photosynthesis and its rapid increase in the atmosphere is expected to stimulate plant growth. While there are a number of means by which plant biology intersects with human health (e.g., plant nutrition), one of the most widely recognized is aerobiology; specifically, the ability of plants to both produce pollen and to serve as a substrate for molds/fungi (e.g., sporulation). The current review represents an initial attempt to coalesce what is known regarding the likely impacts of climate/CO₂ on plant pollen/fungal spores and associated allergic disease that are, or could be, specific to the Northeast United States. Although the current results indicate a number of potentially unfavorable effects, we wish to stress that the current data are based on a small number of experiments. Additional data are crucial to both reduce epidemiological uncertainty and to derive a robust set of mitigation / adaptation strategies.     

Eisen und Eisenversorgung des Warmblüter-Organismus

An adult man contains roughly 4-5 g of iron. Nearly 70% of this amount is present in hemoglobin and myoglobin. About 11% is accounted for by iron enzymes, e.g., heme enzymes that play a decisive role in cellular metabolism. Almost 19% of the body iron are deposed in iron stores. The distribution of iron in the body to the tissues and organs is handled by transferrin, a protein that binds iron so tightly that scarcely any free, i.e., ionized and hence toxic iron can exist. Since iron can only be excreted to an insignificant extent either in the urine or bile, the metabolism of iron is balanced almost exclusively by the absorption of this metal from food. This is especially true in the case of iron deficiency, e.g., in the young and growing organism, in pregnant females, or after iron loss.     

Risks in urban rooftop agriculture: Assessing stakeholders’ perceptions to ensure efficient policymaking

Rooftop agriculture (RA) is an innovative form of urban agriculture that takes advantage of unused urban spaces while promoting local food production. However, the implementation of RA projects is limited due to stakeholders’ perceived risks. Such risks should be addressed and minimized in policymaking processes to ensure the sustainable deployment of RA initiatives. This paper evaluates the risks that stakeholders perceive in RA and compares these perceptions with the currently available knowledge, including scientific literature, practices and market trends. Qualitative interviews with 56 stakeholders from Berlin and Barcelona were analyzed for this purpose. The results show that perceived risks can be grouped into five main categories: i) risks associated with urban integration (e.g., conflicts with images of “agriculture”), ii) risks associated with the production system (e.g., gentrification potential), iii) risks associated with food products (e.g., soil-less growing techniques are “unnatural”), iv) environmental risks (e.g., limited organic certification) and v) economic risks (e.g., competition with other rooftop uses). These risks are primarily related to a lack of (scientific) knowledge, insufficient communication and non-integrative policymaking. We offer recommendations for efficient project design and policymaking processes. In particular, demonstration and dissemination activities as well as participatory policymaking can narrow the communication gap between RA developers and citizens.     

Airborne bioaerosols and their impact on human health

Bioaerosols consist of aerosols originated biologically such as metabolites, toxins, or fragments of microorganisms that are present ubiquitously in the environment. International interests in bioaerosols have increased rapidly to broaden the pool of knowledge on their identification,quantification, distribution, and health impacts(e.g., infectious and respiratory diseases,allergies, and cancer). However, risk assessment of bioaerosols based on conventional culture methods has been hampered further by several factors such as:(1) the complexity of microorganisms or derivatives to be investigated;(2) the purpose, techniques, and locations of sampling; and(3) the lack of valid quantitative criteria(e.g., exposure standards and dose/effect relationships). Although exposure to some microbes is considered to be beneficial for health,more research is needed to properly assess their potential health hazards including inter-individual susceptibility, interactions with non-biological agents, and many proven/unproven health effects(e.g., atopy and atopic diseases).     

Photoacoustic in-vivo spectra of recent stromatolites

In-vivo photoacoustic spectra (PAS) of pure cultures of cyanobacteria and photosynthetic bacteria (Chromatiaceae) which usually occur in stromatolitic microbial mats were measured. The PA spectra of the pure cultures were compared to PA spectra measured directly on different layers of microbial mats from Mellum (North Sea). The advantages of PAS of opaque, solid samples (e.g., sediment, rock), and of particle suspensions (e.g., light-scattering cell cultures with interference by sulfur globules) over conventional spectroscopy using classical in-vivo or extraction photometry are discussed.     

Shadows and lights of GSCM (Green Supply Chain Management): determinants and effects of these practices based on a multi-national study

Green Supply Chain Management (GSCM) is an increasingly widely-diffused practice among companies that are seeking to improve their environmental performance. The motivation for the introduction of GSCM may be ethical (e.g., reflecting the values of managers) and/or commercial (e.g., gaining a possible competitive advantage by signalling environmental concern). Drawing upon a database of over 4000 manufacturing facilities in seven OECD countries this paper assesses the determinants and motivations for the implementation of GSCM. We find that GSCM is strongly complementary with other advanced management practices, and that it contributes to improved environmental performance. The effects on commercial performance are more ambiguous.     

Der vorindustrielle Mensch in den Ökosystemen der Erde

Preindustrial man influenced and changed the earth's ecosystems decisively. The disappearance of large animals from all continents (Eurasia, e.g., mammoth; America, e.g., the giant sloths and the giant armadillo) after the Pleistocene was most probably due to a large extent to the early hunters and collectors. Corn-growing and breeding of domestic animals led to the disappearance of their wild forms (e.g., the wild form of today's old world camel is unknown) and the cultivation of huge monocultures. The increasing need for wood resulted in the disappearance of forests almost all over Europe. Specific needs, such as pig-raising or bee-keeping, supported the formation of particular landscapes, e.g., sparsely wooded forests and extensive heathlands. All these factors resulted in extreme soil erosion and the disappearance of nutritionally important minerals from the soil, which was thus severely depleted.     

Measuring the Incremental Costs of Global Environment Protection: The Case of Grid-Connected Wind Turbines in Morocco

An application is presented of the methodology used bythe Global Environment Facility (GEF) to measureincremental costs. Incremental cost estimates are usedby the GEF to determine its financial contribution toprojects that protect the global environment, such asinvestments in renewable energy. The importance ofadopting a system-wide view in certain types ofprojects (such as investments in grid-connected power)is illustrated using the case of wind power inMorocco. A narrow plant-by-plant comparison wouldneglect the adjustments in the system expansion planthat may be warranted when one type of plant (e.g., acoal fired thermal plant) is replaced by another (e.g.,a wind farm).     

再生液添加NaHCO3对硝酸盐选择性去除工艺的影响

在NaCl再生液中添加pH缓冲剂NaHCO₃,重点调查了添加NaHCO₃对失效再生液电解效果和地下水硝酸盐选择性离子交换-再生-失效再生液电解工艺长期运行稳定性的影响。结果表明:在6 g/L NaCl再生液中添加10 g/L NaHCO₃后,电解8 h硝酸盐的去除率达到96%,溶液pH值变化较小,硝酸盐去除效果优于不调节pH或加稀盐酸调节pH,Fe阴极无显著腐蚀现象;再生液NaCl浓度从6 g/L提高到36 g/L,电解反应的硝酸盐去除率降低;地下水选择性离子交换-再生-失效再生液电解工艺长期运行过程中（13个工作循环）,在6 g/L NaCl再生液中添加NaHCO₃对产水水质、树脂选择性、再生液洗脱能力和硝酸盐积累规律均无负面影响,产水水质稳定、优良。     

秸秆焚烧影响南京空气质量的成因探讨

综合利用卫星遥感的火点和云覆盖信息,结合气团后向轨迹分析,探讨了由秸秆焚烧造成的空气污染物的区域尺度输送和本地源对城市空气质量的影响.结果表明,在一定气象条件下,污染物可以发生区域尺度的输送,上风火点与下风城市的污染有明显的相关,将空气污染分为局地型(如,2006年5月31日、2009年11月8日)、区域型(如,2008年10月28日),以及局地区域相结合型(如,2006年6月14日、2007年6月5日、2008年6月2日)3种.应用本文的方法,在有云时,可以通过部分火点和气团后向轨迹分析推测污染物源地.空气污染气象条件分析表明,秸秆焚烧若伴随高空(500hPa)有槽(或位于槽前),低空存在弱切变,气流由周边向中心辐合;同时,若在均压场控制下,等压线稀疏,风速较小或静风,污染物则易积聚而不易输送;逆温层的形成将污染物禁锢在混合层以下,不利于垂直扩散;再加上较大的相对湿度,有利于霾的形成,造成严重空气污染.     

电动修复技术去除土壤重金属污染研究进展

电动修复技术可能是唯一可行的低渗透性污染土壤原位修复方法,受到广泛关注。本文尝试总结论述了电动修复技术去除土壤重金属污染的相关研究进展,介绍了电动修复技术的基本原理及局限性,探讨比较各种强化电动修复技术的方法,包括电极接近法、交换电极法、离子交换膜、电场强化法(垂直电场、交流电场、脉冲电场)、试剂强化法(pH调节、螯合剂、表面活性剂),重点阐述目前新的螯合剂和表面活性剂的开发研究状况,以及电动修复目前主要的联用技术类型(电动-淋洗、电动-植物、电动-微生物、电动-可渗透反应墙)。此外,简要论述了电动修复对变价金属(Hg、Cr、As)的修复效果。最后在回顾总结该技术研究的基础上,对电动修复技术在去除土壤重金属污染的发展方向进行展望。     

Effect of activated sludge treatment on the formation of Nnitrosamines under different chloramination conditions

Municipal wastewater discharge is considered as one of the main sources of N-nitrosamine precursors which can impact the qualities of downstream source waters and reclaimed wastewaters for potable reuse. NNitrosamine precursors can be removed to various degrees during biological wastewater treatment (e.g., the activated sludge (AS) process). So far, little is known about the impact of the AS process on N-nitrosamine formation under practical disinfection condition (e.g., uniform formation condition (UFC)). In this study, N-nitrosamine UFC from selected model compounds, sewage components (i.e., blackwaters and greywaters) and sewage samples were comprehensively investigated during batch AS treatment tests. NNitrosodimethylamine (NDMA) formation from the tested precursor compounds (i.e., trimethylamine (TMA) and sumatriptan (SMTR)) under UFC chloramination decreased mostly after 6 or 24 hr treatment with different types of AS (i.e., domestic rural AS, domestic urban AS, and textile AS), and the reductions in NDMA UFC were comparable to their NDMA formation potential (FP) reductions. In urine and feces blackwaters, NDMA UFC increased after 6 or 24 hr treatment with the domestic (i.e., rural and urban) AS, while NDMA FP decreased substantially. The increases in NDMA UFC after AS treatment was presumably attributed to the removal of bulk organic matters (e.g., dissolved organic carbon (DOC)) which favored NDMA formation under UFC. On the other hand, in laundry greywaters having relatively abundant DOC, N-nitrosamine UFC was less affected by DOC removal before or after AS treatment, but decreased to similar degrees with N-nitrosamine FP. In sewage samples collected from wastewater treatment plants, N-nitrosamines UFC tended to increase or remain constant during AS treatment, despite the decreases in their FPs. These results suggest that biological wastewater treatment (e.g., the AS process) may not effectively reduce N-nitrosamine formation (e.g., measured under UFC) partially because the concurrent removal of bulk organic matters (e.g., DOC) favored N-nitrosamine formation in s econdary effluents.     

Engineered nanoparticles: safer substitutes for toxic materials, or a new hazard?

Nanotechnology has the potential for the development of new materials and processes that can substitute for toxic materials now used in industry. Excitement over this possibility is tempered, however, by the potential adverse environmental health and safety aspects of the new nanomaterials. Although a few examples from the literature are encouraging, e.g., wire and cable insulation, great care must be taken to perform complete alternatives assessment evaluations of any new nanotechnology-enabled product before its adoption.     

Governance across the land-sea interface: A systematic review

Governance across the land-sea interface is an emerging challenge. The propensity for, and intensity of social-ecological interactions across this interface (e.g., eutrophication, sedimentation) are being exacerbated by cross-system threats (e.g., climate change). We draw on a systematic review of 151 peer-reviewed papers on governance and land-sea connections to (1) outline the current state of the literature, (2) examine the predominance of different approaches to address land-sea interactions, (3) characterize how governance is conceptualized within these approaches, (4) investigate governance challenges, and (5) provide insights into effective governance. The review finds that the number of relevant papers published per year has generally been increasing, and most of these papers are found in interdisciplinary journals. Ecosystem-based management is the most predominant approach found in the literature as a means to address land-sea interactions. Papers referring to ecosystem-based management are more likely than those referring to alternative management approaches (e.g., integrated management) to highlight science-policy integration and the need to account for interactions between ecosystem components as elements of effective governance. The main governance challenges include determining boundaries, addressing cross-scale effects, and accessing knowledge. However, few empirical studies of governance across the land-sea interface have been completed. A richer conceptual framework of governance is required to improve our ability to navigate the rapid social and environmental change occurring across the land-sea interface.     

地球化学动力学反应器原理和速率方程测定

主要介绍了地球化学动力学实验研究中的三种反应器类型，即间歇反应器、活塞流反应器和混合流反应器，概述了它们的工作原理和速率方程测定方法，最后对比了三类反应器的性能，指出混合流反应器最适合于测定矿物－水反应速率。     

How does the brown mussel Perna perna respond to environmental pollution? A review on pollution biomarkers

The brown mussel Perna perna (Linnaeus, 1758) is a valuable resource for aquaculture in tropical and subtropical coastal regions. It presents desirable characteristics for biomonitoring, including being sessile, widely distributed and abundant, and is a filter-feeder able to accumulate several classes of pollutants (e.g., metals, hydrocarbons, among others). Mussels’ biological responses to pollution exposure can be measured as biomarkers, which include alterations ranging from molecular to physiological levels, to estimate the degree of environmental contamination and its effects on biota. This full review compiles two decades (2000–2020) of literature concerning biological effects on P. perna mussel caused by environmental pollutants (i.e., metals, hydrocarbons, and emerging pollutants), considering environmental and farm-based biomonitoring. Biochemical markers related to mussels’ oxidative status were efficient for the biomonitoring of metals (i.e., antioxidant enzymes associated with oxidative damage in biomolecules). Genotoxicity and cytotoxicity indicators (i.e., comet, micronucleus, and neutral red assays) provided a depiction of hydrocarbon contamination. The neutral red assay gave a time-concentration cytotoxic response to a wide range of pollutants, including emerging pollutants (e.g., pharmaceuticals and biocides) and hydrocarbons. Perna perna hemocyte parameters provided a useful approach for biocide biomonitoring. This paper summarizes useful biomarkers from molecular to physiological levels in this mussel species used to identify and quantify the degree of coastal pollution. An integrated biomarker analysis may provide a way to overcome possible biomarker variations and assess multi-polluted sites. Nevertheless, it is necessary to investigate biomarker variations according to natural factors (e.g., season and gonad maturation stage) to standardize them for trustworthy biomonitoring.     

全球饮用水标准中消毒副产物管控指标对比与启示

饮用水水质安全是关乎千家万户的重大民生问题,其中消毒工艺是保障饮用水微生物安全不可或缺的重要措施,然而由消毒剂与前体物反应生成的DBPs（消毒副产物）被发现具有潜在的健康风险,如致癌及引起发育副作用等.随着对饮用水中DBPs的重视程度不断提高,世界上多个国家、地区或组织将DBPs指标纳入标准.为对我国饮用水水质标准中DBPs指标的制定和修订提出可参考的建议,比较了国内外饮用水和再生水饮用回用水质标准中的DBPs指标,包括DBPs种类、对应的浓度限值和监测要求等.结果表明:①我国饮用水水质标准中涵盖的DBPs种类较多,其中地方标准相较于国标而言对DBPs指标的要求更为严格,但较少考虑综合性指标（如总有机卤素）和高毒性含氮DBPs（如卤乙腈）;②国外多部饮用水水质标准或准则中包含一些无浓度限值规定但已知具有较高健康风险的DBPs,此举可指导有关部门进一步开展浓度调研和毒性试验,为未来水质标准的制定提供参考依据.研究显示,我国饮用水标准中DBPs指标需要考虑综合性指标的选取与管控以及高风险指标的甄别和筛查,另外还需因地制宜加强地方性标准的建设工作.