南非的“链式输送“模式:解决农村贫困人口可持续性供水问题的新办法

南非政府最近贯彻了一项免费向消费者,特别是贫困人口,供应基本用水的政策.通过被称之为"链式输送"的创新公私合作计划,一直在为农村提供用水基础设施.在重视合理使用政府开支、维护可持续性以及实现社会目标的同时,"链式输送"在确保提供用水和卫生设备工作快速进行中发挥了积极作用.     

Acoustic orientation via sequential comparison in an ultrasonic moth

Orientation of female lesser wax moths (Achroia grisella) to male calling song was tested on a locomotion-compensator device that withheld all inter-aural acoustic differences from the insect. Under these circumstances, females remained longer in the vicinity of the sound source if they experienced a variable sound level that increased when approaching the source rather than a level that remained constant at all times. Analyses of orientation paths revealed that greater retention near the source was achieved by enhanced turning when the perceived sound level remained unchanged or decreased but retaining the previous heading when the level increased. These findings suggest that acoustic orientation can be supplemented by mechanisms based on sequential, as opposed to instantaneous, comparison of auditory input. Such mechanisms may be valuable when binaural hearing is impaired or asymmetric or in environments where acoustic differences at the two ears are unreliable indications of direction to the sound source.     

Ecotoxicological Characterisation and Classification of Existing Chemicals

GOAL, SCOPE AND BACKGROUND: In 1998, the International Council of Chemical Associations (ICCA) launched a global initiative to investigate more than 1,000 HPV chemicals (High Production Volume, > or = 1,000 t/a) within the refocused OECD HPV Chemicals Programme. Up to the OECD SIDS Initial Assessment Meeting in April 2004 (SIAM 18) 147 ICCA dossiers (ca. 230 CAS-No) have been assessed based on a harmonised data set. The environmental profile and an ecotoxicological characterisation of these chemicals are presented here. Data for acute aquatic toxicity were correlated among each other, as well as data for fish (LC50, LD50) and rodents (LD50). The data for acute aquatic toxicity are compared with other existing chemicals. METHODS: Data of the ICCA HPV chemicals from the OECD SIAM 11-18 are presented for: log Kow (as an indicator for bioaccumulation potential), biodegradation, acute aquatic toxicity and availability of long-term toxicity data. Correlation analysis was performed with log transformed data and a linear regression model was fitted to the data, if a significant correlation was found. Acute toxicity for fish and acute oral toxicity for rodents were correlated on a molar basis. Acute aquatic toxicity of the chemicals is compared with data from BUA reports 1-234 and a random EINECS sample (Knacker et al. 1995). RESULTS AND DISCUSSION: According to the dossier information, 71 of the 147 ICCA chemicals are not 'readily biodegradable', 21 have a log Kow > or = 3, and 44 are 'toxic' (LC/EC50 < or = 10 mg/L) or 'very toxic' (LC/EC50 < or = 1 mg/L) to aquatic organisms. For 77, only the base set (acute fish, Daphnia and algae) is available, for the rest at least one long-term test (fish or Daphnia) is available and three tests for a mere 14 others. Based on the data presented, the SIAM gives recommendations for Environment and Human Health. 22 chemicals have been identified as a 'candidate for further work' for Environment and 16 for Human Health. The highest correlation coefficient was obtained correlating fish and Daphnia (r2 = 0.79). LC50 (fish) is significantly correlated with LD50 (rodent), but data are widely scattered. The correlation is not improved after transforming LC50 (fish) to LD50 (fish), using BCF QSAR. Based on acute aquatic toxicity, 25.1% of the chemicals from the BUA reports 1-234 are classified as 'very toxic' (LC/EC50 < or = 1 mg/L). This proportion is 2.5-fold higher than the ICCA HPV chemicals and 1.4-fold higher than the random EINECS sample. CONCLUSIONS: Correlation coefficients for aquatic toxicity data are rather uniform (0.57-0.79) compared with literature data, but also the best correlation was observed between fish and Daphnia. Because the scatter around the regression lines is still considerable, simple predictions of ecotoxicity between species are not possible. Correlation of LC50 (fish) and LD50 (rodent) indicates that toxicity is different. Surprisingly, the correlation of fish and rodent toxicity is not improved by transforming LC50 values to internal LD50s. The selection of ICCA chemicals by market significance (production volume) leads to a classification of toxicity, which is more comparable to a random sample of EINECS chemicals than to German BUA chemicals. The latter were chosen for concern (for Environment or Human Health). RECOMMENDATIONS AND OUTLOOK: Of 147 dossiers assessed between SIAM 11-18, ca. 75% were sponsored by the three following countries: Germany (42), USA (37) and Japan (33). The current output is about 50 dossiers per year (70-100 CAS-No), but a trend for an increase of output is noticeable. Industry, national authorities, and OECD work on a further development to speed up the output. The number of chemicals with 'low priority for further work' and the work recommended for the 'candidates' (mainly exposure assessment) indicate that the data presented were adequate for an initial hazard assessment according to OECD requirements. From the ICCA HPV list (n = 880, state of 1999) 44% of the chemicals have data available to cover all SIDS endpoints for Environment and only 33% for Human Health (Allanou et al. 1999). This indicates the importance of the Initiative to provide information on existing chemicals. The authors agree with the expectation "...that the scientific information provided by this global initiative will be considered as an internationally accepted and harmonised basis for further steps of chemicals management." (ICCA 2002 b).     

Emission of biocides from treated materials test procedures for water and air

Methods for the determination of biocide emissions from treated materials into water and air were developed and tested in order to support a comparative ecological assessment of biocidal products. Leaching tests, experiments with simulated rain, extraction cleaning of carpets and emission chamber tests were performed with a series of treated materials. The experiments focused on the effect of changes in the procedure as well as characteristics of the specimens and demonstrate the suitability of the proposed methods for biocides of different product types. It was demonstrated that emissions of biocides into water can be compared on the basis of leaching tests in which the emission kinetics of the active ingredients are recorded. However, the water volume per surface area and the timetable for water changes have to be defined in such tests. Functions of flux rates related to time can be well described for inorganic compounds, whereas modelling of the data is more complicated for organic substances. Emission chamber tests using 20-litre and 23-litre glass exsiccators, originally developed to study volatile organic compounds, were successfully adapted for the investigation of the emission of biocides from treated materials which are usually semi volatile organic compounds. However test parameters and the method of analysis have to be adapted to the substances to be determined. Generally, it was found that the emission curves for the semi volatile organic compounds investigated differ from those of volatile organic compounds.     

Synchronous spawnings of 105 scleractinian coral species on the Great Barrier Reef

Following observations of mass spawning of hermatypic corals on the Great Barrier Reef in 1981 and 1982, spawning dates were successfully predicted and documented at five reefs on the Central and Northern Great Barrier Reef in 1983. During the predicted times, 105 species from 36 genera and 11 families were observed to spawn. Of these, 15 species were shown to have an annual gametogenic cycle. All but two of the species observed during mass spawnings shed gametes which underwent external fertilization and development. Synchronous spawning was observed both within and between the five reefs studied, which were separated by as much as 5° of latitude (500 km) or almost a quarter of the length of the Great Barrier Reef. The mass spawning of corals took place on only a few nights of the year, between the full and lastquarter moon in late spring. Maturation of gametes coincided with rapidly rising spring sea temperatures. Lunar and diel cycles may provide cues for the synchronization of gamete release in these species. The hour and night on which the greatest number of species and individuals spawned coincided with low-amplitude tides. Multispecific synchronous spawning, or mass spawning, of scleractinian and some alcyonacean corals represents a phenomenon which is, so far, unique in both marine and terrestrial communities.     

Who owns the Earth? A challenge for the land system science community

ABSTRACT

Reflecting on the 2019 Open Science Meeting of the Global Land Program and on commentaries since, we argue that the time is ripe for the land system science community to fully embrace the thorny issue of land ownership and control. Beyond land governance and institutions, the issue of who actually owns and controls land, and how land holding and rents are distributed across society, is central to the future of sustainability initiatives, biodiversity protection, social justice, climate change mitigation, and long-term food security and sovereignty. By explicitly tracking and visualizing just Who Owns the Earth, the land system science community could provide much-needed data and insights to inform public debate and advance political action in these arenas.     

The bottlenose dolphin community of Doubtful Sound features a large proportion of long-lasting associations

More than 12 studies of different bottlenose dolphin populations, spanning from tropical to cold temperate waters, have shown that the species typically lives in societies in which relationships among individuals are predominantly fluid. In all cases dolphins lived in small groups characterised by fluid and dynamic interactions and some degree of dispersal from the natal group by both sexes. We describe a small, closed population of bottlenose dolphins living at the southern extreme of the species' range. Individuals live in large, mixed-sex groups in which no permanent emigration/immigration has been observed over the past 7 years. All members within the community are relatively closely associated (average half-weight index>0.4). Both male–male and female–female networks of preferred associates are present, as are long-lasting associations across sexes. The community structure is temporally stable, compared to other bottlenose dolphin populations, and constant companionship seems to be prevalent in the temporal association pattern. Such high degrees of stability are unprecedented in studies of bottlenose dolphins and may be related to the ecological constraints of Doubtful Sound. Fjords are low-productivity systems in which survival may easily require a greater level of co-operation, and hence group stability. These conditions are also present in other cetacean populations forming stable groups. We therefore hypothesise that ecological constraints are important factors shaping social interactions within cetacean societies.Communicated by D. Watts     

Early impacts of alcoholic beverage warning labels: national study findings relevant to drinking and driving behavior

After November, 1989 Federal law required a standard health warning label on all alcoholic beverage containers sold for consumption in the U.S. Results are reported from a cross-sectional national household telephone interview survey of adults, occurring approximately 6 months after implementation of the warning labels (N=2000). Implications for health warnings with respect to information processing theory, the Health Belief Model, and other theories relevant to precaution adoption are briefly reviewed and two derivative hypotheses are tested using log-linear analysis. Relationships between various personal characteristics and (a) seeing the label and (b) recalling the driving impairment message are examined for consistency with theoretical expectations. We also examine associations between message recall, drinking style, and two precautionary behaviors undertaken to avoid drinking and driving. Adjusting for apparent false positives, approximately a quarter of the sample have noticed the label 6 months after its introduction; 16% recalled the specific driving impairment message. As hypothesized, exposure to the warning was predicted primarily by consumption pattern but also was associated with a personal salience factor, that is, ever having drunk alcohol so as to be at risk when driving. About a quarter of the heavy drinkers (5 drinks or more per occasion sometime and drinking at least weekly) who ever drank and drove saw the specific warning. Of two self-regulation strategies — limiting driving after drinking and limiting drinking when about to drive — the latter was the more prevalent. Both strategies were reported more by those who were heavy drinkers, those recalling the driving impairment message, and those perceiving driving after drinking to be very dangerous, than by other individuals.     

Phytovolatilisation organischer Chemikalien

During the phytoremediation of contaminated soils and water, a multitude of pathways, partly not yet quantified, are activated. ‘Phytovolatilisation’ is considered to be a process, where primarily organic compounds are emitted from the above-ground sections of the plant into the atmosphere. Thus, all compounds are included which are taken up by the root, partly transformed within the roots and transported into the sprout. The phytovolatilisation is particularly suitable for the elimination of volatile compounds in shallow groundwater contaminations. In gas exchange experiments, the dynamics of these emissions were examined and, on the basis of a model, the compounds which are preferentially emitted by plants due to their physical characteristics was estimated.