Evaluation of environmental contamination by toxic trace elements in Kazakhstan based on reviews of available scientific data

Environmental Science and Pollution Research - The environmental situation concerning pollution by (eco)toxic and persistent trace elements in Kazakhstan has been investigated by analytical reviews...     

Gaps,biases, and future directions in research on the impacts of anthropogenic land-use change on aquatic ecosystems: a topic-based bibliometric analysis

Environmental Science and Pollution Research - Anthropogenic land use change (ALUC) satisfies human needs but also impacts aquatic ecosystems. Aquatic ecosystems are intrinsically linked with...     

Towards a method to forecast the effectiveness of national road safety programmes

During the last three decades a more rational approach to political decision making has produced an increasing demand for scientific evaluation. A common understanding of evidence-based policy is that any new measures should have been proven to be effective. At best, these kinds of methodologically sound evaluation studies show the effect of a measure in a given situation. The results are then an essential basis for the design of a broader safety policy. However, at present there is generally little understanding of the effect of the measure in another situation, or of how it would interact with other measures in a programme. Yet, it is precisely such questions that need to be answered if the requirements of policy makers are to be met. Politicians need to be able to estimate whether the expected benefits of a programme justify the investment. Therefore, evidence-based road safety policy should not rely solely on evaluation studies of single measures and ex-post assessments of safety programmes. The method outlined here is for the ex-ante estimation of the potential of a road safety programme, which takes into account existing scientific research, an estimate of the degree of implementation that can be expected at a certain point in time, and the interaction between individual measures.     

Hybrid regimes of knowledge? Challenges for constructing scientific evidence in the context of the GMO-debate

Background, aim, and scope

Over the last two decades, there has been a remarkable shift of attention to the scientific and political fundamentals of the precautionary principle. The application of this principle has become a main strategy of coping with the different forms and problems related to non-knowledge. Thus, societies are increasingly confronted with the challenging and hitherto unresolved problem of political and technological decision-making under conditions of diverging framings of non-knowledge. At present, there seems to be no generally accepted scientific or institutional approach. This is why the fundamental question of how different scientific actors define and construct evidence is not answered yet. Hence, this paper is based on the consideration that the conflicts in risk policy concerning genetically modified organisms (GMO) depend on the unresolved conflicts about the diverging scientific strategies and structures of evidence-making between the epistemic cultures involved. Thus, this study investigates two questions: (1) do the epistemic strategies of evidence-making differ systematically with the scientific actors involved in the GMO-debate? (2) What consequences emerge considering institutionalized procedures of decision-making?

Main features

This article is based on a secondary analysis of findings and perspectives reported in the literature and on the methods of qualitative social empirical research, i.e., interviews with experts. A total number of 34 interviews were conducted to explore the different strategies of handling non-knowledge and constructing evidence. Actors from science, administration, business and NGOs were interviewed. In this way, typical epistemic cultures can be described. An epistemic culture is the constellation of methodological strategies, theoretical assumptions and practical-experimental settings which define in every speciality the ways how we know what we know.

Results

There are two main results. Firstly, it was worked out that the epistemic cultures involved in the GMO-debate use rather distinct strategies to define non-knowledge and to classify evidence. There are three types of constructing evidence, which correspond to different types of epistemic cultures. Secondly, the findings imply that the intensity of the conflicts in risk policy fields like the GMO-debate is due to a lack of knowledge politics. Usually, knowledge politics is restricted to the design of institutional procedures to compile knowledge provided by experts. The institutional setting of risk analysis and risk management is based on the premise of strict separation between knowledge and power. However, inadmissible mixing-up of knowledge and power is observable.

Discussion

It seems that non-knowledge leads to an epistemic no man’s land, and, hence, hybrid regimes of knowledge emerge. These regimes are hybrid with respect to the unclear and not explicitly reflected strategies of evidence-making. By lacking of knowledge politics, this situation opens up ‘windows of opportunity’ for actors with special interests in risk policy fields like the GMO-debate. Therefore, there is a difference between the visible institutionalized structures of risk policies and the rather invisible hybrid regimes of knowledge. Structure and scope of expertise have to be reflected and new instruments of knowledge politics have to be designed.

Conclusions

Different epistemic cultures can be qualified by describing their particular strategies of evidence-making. To solve the conflicts between these strategies, a meta-expertise is needed. Besides the institutionalized settings of knowledge politics, the underlying hybrid regimes of knowledge have to be identified.

Recommendations and perspectives

The concept of epistemic cultures and their strategies of evidence-making should be investigated more explicitly with respect to other risk policy fields The analysis of hybrid regimes of knowledge should be deepened by looking at the complex interactions between institutional, discursive and practical rules affecting risk assessment.

     

Humic substances

GOALS, SCOPE AND BACKGROUND: Changing environmental conditions and handling stress are well known to cause chronic or acute stress situations in fish with subsequent infections. These requires a therapy by means of antibiotics and chemicals. In contrast to the huge number of pathogens, only a few substances are permitted for application as therapeutics in German aquaculture. Hence, there emerges an urgent need for highly effective and residueless alternatives. MAIN FEATURES: The prophylactic stimulation and training of the defense system of fish by alternative approaches becomes increasingly necessary. One approach is the application of dissolved humic substances (HS) of natural or artificial origin. For example, there exist several reports on the positive effect of HS to fishes. These effects shall be considered in detail. Furthermore, the impact of HS on the constitution of parasites and pathogens will be displayed. The reports on this issue are diverse, if not inconsistent. We try to shed some light on these discrepancies. The last aspect covered by this review is the outdated paradigm that calcium ions act as antidotes. In the presence of HS, even the opposite effect may occur. APPROACH: To overcome old paradigms on HS and their potential interactions with fish and fish parasites, we reviewed recent international literature, as well as 'grey' literature. We also include results from own former and ongoing studies. RESULTS AND DISCUSSION: HS are able to increase the physiological condition of the individuals and to reduce adverse physiological and histological consequences caused by stress; the mechanism behind remains obscure. HS detoxify heavy metals and organic pollutants. Damages caused by several fish pathogens, such as bacteria and parasites, can be repaired more quickly in the presence of HS. Some parasites--mainly fungi--appear to be directly affected by HS. Comparing the fungicidal effects of HS from various sources, evidence is increasing that the aliphatic moiety may be the effective structures. However, further research is necessary to relate more physiological and anti-pathogenic effects to the chemical characteristics of HS. CONCLUSIONS: HS are not real alternatives to strong traditional therapeutics. However, they show different advantages in repairing secondary, stress induced damages in fish. The ecophysiological relevance of HS in either aquatic systems or aquaculture is getting conspicuously. PERSPECTIVES: The lack of therapeutic and antiparasitic substances in aquaculture requires new strategies and ways of thinking. The search for alternatives to the 'traditional' chemical therapeutics calls for the intensive research. Inevitably, this search will lead to an intensive contemplation on HS as 'health promoting substances' and/or even therapeutics. Basic research is needed to detect the functional groups of the HS responsible for the effects observed. Health promoting effects of first investigations made in vitro to affect pathogens via application of HS and several field studies with HS raises hopes for a broader utilisation of HS to reduce stress consequences in fish and fish pathogens residuelessly.     

Determination of selected pharmaceuticals and caffeine in sewage and seawater from Tromsø/Norway with emphasis on ibuprofen and its metabolites

Selected pharmaceuticals, among them analgesics, ss-blockers and anti-depressants as well as caffeine, the anti-bacterial triclosan and the insect repellent N,N-diethyl-3-toluamide (DEET) were determined in different sewage samples (sewage treatment plants, hospital effluents) from Troms?/Norway and in seawater from Troms?-Sound, into which the sewage is discharged. While caffeine, triclosan, ibuprofen and its major metabolites hydroxy- and carboxy-ibuprofen were present in all sewage samples, additional pharmaceuticals were observed in sewage containing hospital effluents. Concentrations were in the range of 20-293 microg/l (caffeine), 0.2-2.4 microg/l (triclosan) and 0.1-20 microg/l (sum ibuprofen + metabolites). In seawater, only caffeine (7-87 ng/l), DEET (0.4-13 ng/l) and ibuprofen + metabolites (sum concentration < LOQ-7.7 ng/l) were detected. Ibuprofen and its metabolites hydroxy- and carboxy-ibuprofen were quantified individually by use of the respective reference compounds. Relative amounts of the three compounds were determined in different types of water showing characteristic patterns, with hydroxy-ibuprofen being the major component in sewage whereas carboxy-ibuprofen was dominant in seawater samples. The patterns which were compared to those observed in similar samples from Germany indicated different transformation behaviour under limnic and marine conditions.     

Long-term simulation of effects of energy crop cultivation on nitrogen leaching and surface water quality in Saxony/Germany

The production of energy crops in Germany is a growing agronomic sector and is expected to occupy a substantial share of farmland in the near future. At the same time, there are concerns that energy crops might cause increased nitrogen pollution of soil water, surface water and groundwater. Therefore, the Federal State of Saxony, Germany, funded a study on potential effects of an intensified cultivation of energy crops. In frame of this study, we used the Web GIS-based model STOFFBILANZ to simulate N leaching from the rooting zone and N loads of surface water for a reference scenario and an energy crop scenario. For the reference scenario, we used data representing the crop cultivation for the year 2005 at municipality level. We found that the total loads for N leaching from the rooting zone of cropland are highest for the loess region (8,067 t year^?1), followed by mountainous region (6,797 t year^?1) and lowland (5,443 t year^?1). However, highest N fluxes in the leachate from rooting zones have been simulated for lowland (40.6 kg ha^?1 year^?1) and mountainous region (37.1 kg ha^?1 year^?1), while nitrate concentrations of leachate were highest for the lowland (101.8 mg l^?1). In terms of diffuse N input into surface water, the mountainous region is the most important source area (total N load 6,380 t year^?1, flux 34.6 kg ha^?1 year^?1). Retention by in-stream processes accounts for 15 % (3,784 t year^?1) of the total N load leaving the study area (25,136 t year^?1). In the 2020 energy crop scenario, shares of rape and silage maize (id., ensiled corn) were limited for each municipality to a maximum of 25 and 33 %, respectively. The conversion of grasslands to crop farming was not allowed. Under these conditions, we found slight to substantial reductions of nitrogen loads for leachate from the rooting zone and for surface waters. The simulated reduction depends strongly on local conditions. Only small reductions (ca. 4–8 %) were found for the lowlands and mountainous regions of Saxony, while reductions for the loess region were substantial (ca. 22 %). A major outcome of our study is that the cultivation of energy crops might reduce N loss if certain preconditions are assumed, for example, without conversion of grasslands to crop farming. However, effects might vary widely depending on local conditions.     

Visualizing different uranium oxidation states during the surface alteration of uraninite and uranium tetrachloride

Low-temperature alteration reactions on uranium phases may lead to the mobilization of uranium and thereby poses a potential threat to humans living close to uranium-contaminated sites. In this study, the surface alteration of uraninite (UO₂) and uranium tetrachloride (UCl₄) in air atmosphere was studied by confocal laser scanning microscopy (CLSM) and laser-induced fluorescence spectroscopy using an excitation wavelength of 408 nm. It was found that within minutes the oxidation state on the surface of the uraninite and the uranium tetrachloride changed. During the surface alteration process U(IV) atoms on the uraninite and uranium tetrachloride surface became stepwise oxidized by a one-electron step at first to U(V) and then further to U(VI). These observed changes in the oxidation states of the uraninite surface were microscopically visualized and spectroscopically identified on the basis of their fluorescence emission signal. A fluorescence signal in the wavelength range of 415–475 nm was indicative for metastable uranium(V), and a fluorescence signal in the range of 480–560 nm was identified as uranium(VI). In addition, the oxidation process of tetravalent uranium in aqueous solution at pH 0.3 was visualized by CLSM and U(V) was fluorescence spectroscopically identified. The combination of microscopy and fluorescence spectroscopy provided a very convincing visualization of the brief presence of U(V) as a metastable reaction intermediate and of the simultaneous coexistence of the three states U(IV), U(V), and U(VI). These results have a significant importance for fundamental uranium redox chemistry and should contribute to a better understanding of the geochemical behavior of uranium in nature. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

How to uncoil your partner—“mating songs” in giant pill-millipedes (Diplopoda: Sphaerotheriida)

The stridulation of the giant pill-millipede genus Sphaerotherium from South Africa, one of only three groups of millipedes that produce sounds, was studied. One hundred one stridulation series of a total of nine different species (Sphaerotherium dorsaloide, Sphaerotherium hanstroemi, Sphaerotherium mahaium, Sphaerotherium similare, Sphaerotherium punctulatum, Sphaerotherium convexitarsum, Sphaerotherium dorsale, Sphaerotherium rotundatum, and Sphaerotherium perbrincki) were analyzed. Stridulation sounds are produced only with a special field of ribs on the posterior surface of the posterior telopod, which is actively moved over a field of sclerotized nubs on the inner margin of the anal shield. The Sphaerotherium male usually stridulates only when in contact with a female to initiate mating. This seems to prevent the female from volvating into a ball or stimulate the female to uncoil when already rolled in. The sound analyzes revealed a broad frequency spectrum in all stridulation sounds produced, without obvious differences in frequency distribution among species. However, the temporal pattern of the stridulation varies greatly between species and seems to be species-specific, arguing for a species recognition function of the stridulation during courtship behavior. A single species (S. punctulatum) was found to stridulate during mating while three species also show postcopulatory stridulation. Apparently, pill-millipedes are not capable of acoustic perception, as no hearing organs are known, indicating that the communication is mainly based on perception of temporal vibration patterns, and not of the acoustic signal itself. The need to overcome the rolling-in reflex of the female is developed as a hypothesis why stridulation exists only in millipedes able to coil into a ball, and apparently evolved four times independently in the superorder Oniscomorpha.     

Climate trends and impacts on crop production in the Koshi River basin of Nepal

Understanding crop responses to climate is essential to cope with anticipated changes in temperature and precipitation. We investigated the climate–crop yield relationship and the impact of historical climate on yields of rice, maize and wheat in the Koshi basin of Nepal. The results show significant impact of growing season temperature and precipitation on crop production in the region. Rice, maize and wheat cultivated at altitudes below 1,100, 1,350 and 1,700 m amsl (above mean sea level), respectively, suffer from stress due to higher temperatures particularly during flowering and yield formation stages. Responses of crop yields to a unitary increment in growing season mean temperature vary from ?6 to 16 %, ?4 to 11 % and ?12 to 3 % for rice, maize and wheat, respectively, depending on the location and elevation in the basin. In most parts of the basin, we observe warming trends in growing season mean temperatures of rice, maize and wheat over the last few decades with clear evidence of negative impacts on yields. However, at some high-elevation areas, positive impacts of warming are also observed on rice and maize yields. If the observed trends in temperature continue in future, the impact is likely to be mostly negative on crop production in the basin. However, crop production may gain from the warming at relatively higher altitudes provided other conditions, e.g., water availability, soil fertility, are favorable.