A Phenomenologic-mathematical Model of Growth Dynamics

Starting point of the modelling procedure are measured courses of the body length increase of man (inverse problem) reaching from the time of conception up to the end of adolescence. First assumption: The whole growth process can be subdivided into independent partial processes for succeeding time periods of the individual's development each of them producess a more or less marked growth spurt. 2. Superposition of these partial processes means addition of the portions of body length which are generated by the spurts yielding in this manner the measured course of body length increase. 3. There is no change in dynamics for producing the several growth spurts, and this dynamics will be described by the differential equation of the logistic law of growth. These steps will be interpreted in control-theoretical terms. In this sense growth is a follow-up control process which is governed by the genetically fixed “biological program of growth” in form of a step function of reference values.     

The Value of the Value of Information

An important application of decision analysis is determining the value that information has to a decision maker. The expected value of information (EVOI) is the expected increase in the value (or decrease in the loss) associated with obtaining more information about quantities relevant to the decision process. The EVOI can be thought of as a measure of the importance of the uncertainty about a quantity in terms of the expected improvement in the decision that might be obtained from having additional information about it. Examples of EVOI quantities useful in risk management situations include the expected value of including uncertainty (EVIU), the expected value of perfect information (EVPI), and the expected value of sample information (EVSI). Value of information (VOI) analysis is useful because it makes the losses associated with decision errors explicit, balances competing probabilities and costs, helps identify the decision alternative that minimizes the expected loss, prioritizes spending on research, quantifies the value of the research to the decision maker, and provides an upper bound on what should be spent on getting information.     

Phytosociological and conservational study of the arable weed communities in western Hungary

Abstract

The present study surveyed the weed vegetation on extensively managed arable fields and unsprayed field edges in western Hungary, based on 1698 phytosociological relevés collected between 1995 and 2005. The separation of the 15 vegetation units was conducted with the traditional comparative tabular method, and the diagnostic species were determined with statistical fidelity measures. The numerical analyses show that the most important factor in the separation of weed communities is the fluctuating proportions of winter and summer annuals and cosmopolitan elements throughout the year. Soil chemical properties are the second most important whereas soil texture and climatic factors also contribute to the development of weed communities. The surveyed vegetation units support 41 red list weed species. Across all associations, the average proportion of insect-pollinated plant species is 68%, and the average proportion providing weed seed food sources for farmland birds is 47%. These factors illustrate the importance of weed communities in agro-ecosystem function and the need for their conservation.     

Contribution to the environmental ecology of Cryptogramma crispa (L.) R. Br. ex Hooker in the Alps

We studied the habitat characteristics in a number of Cryptogramma crispa stations throughout the Alps. Our objectives were: (1) to define the environmental ecology of C. crispa in the southern part of its distributional area in Europe; (2) to test the reliability of ecological indicator values of soil reaction, nutrient and dispersion status, light and temperature for this species. The habitats of C. crispa mostly consisted in coarse-grained stable screes (on rock slide deposits, talus cones, talus sheets, stone fields and moraines), within a broad elevation range with maximum frequency in the subalpine and lower alpine vegetation belts. At higher altitudes, C. crispa was mostly found on South-exposed slopes with high potential irradiance, whereas at low altitude it was most abundant on North-exposed rather gentle slopes formed of big boulders. The screes colonized by C. crispa were formed of acid metamorphic rocks or igneous rocks and had a coarse texture. The soil accumulated in the spaces among boulders had sandy texture and acidic reaction, with medium to high carbon and total nitrogen contents. Calcium lacks entirely in the soil. Our field data gave support to the Ellenberg–Landolt ecological indicator values of light and temperature, but not to those of soil reaction and soil nutrient content, for which some changes are proposed.     

Setting Risk-Based Occupational Exposure Limits for No-Threshold Carcinogens

Several regulators have recently issued so-called risk-based occupational exposure limits for carcinogenic substances, and also reported estimates of the risk of fatality that exposure to the limit value would give rise to. This practice provides an opportunity to study how differences in the exposure limits set by different regulators are influenced by differences in the scientific judgment (what is the risk at different levels?) and in the policy judgment (how should large risks be accepted?). Based on a broad search, a list was compiled of exposure limits for carcinogens that the respective regulator associates with a numerical risk estimate. For benzene, such data was available from six regulators. The differences in estimates of the risk/exposure relationship and in risk tolerance were about equal in size for benzene, while the range for acceptability was somewhat wider. A similar pattern was observed, although less clearly, for substances with data from only two or three regulators. It is concluded that the science factor and the policy factor both contribute to differences in exposure limits for carcinogens. It was not possible to judge which of these two factors has the larger influence.     

Diagnosing sulfur deficiency in field-grown oilseed rape (Brassica napus L.) and wheat ( Triticum aestivum L.)

The effects of increasing sulfur applications on field-grown oilseed rape (Brassica napus L.) and wheat (Triticum aestivum L.) were investigated in 1998 and 1999, and the critical values and efficiency of several diagnostic indicators for S deficiency were determined. Critical values for leaf concentrations of total S, sulfate and glutathione changed over time and were not suitable for diagnosing S deficiency early in the growth season. The N:S ratio was more reliable but involved two analytical measurements. A practical and reliable indicator for S deficiency was the malate:sulfate peak area ratio as measured by ion chromatography, which required only a single analysis and was independent of the time of sampling or calibration of the samples. A malate:sulfate ratio ≤ 1 indicated S sufficiency at the time of sampling, whereas a ratio > 1 suggested S deficiency at the time of sampling. The malate:sulfate ratio was reliable at growth stage 3.6–3.7 (flower stalks extending to first flowers yellow) for oilseed rape and at growth stage 22–25 (main stem and 2–5 tillers) for wheat, which was sufficiently early in the growth season to apply remedial sulfur fertilizer, if necessary. This revised version was published online in June 2006 with corrections to the Cover Date.     

Values-led conservation

In international nature conservation policy, value‐arguments based on science and economic rationalism increasingly overshadow the aesthetic and ethical arguments that originally inspired the conservation movement. We argue that this trend risks removing conservation from the public realm, in part because it facilitates the adoption by nongovernment conservation bodies of corporate values and/or their integration with government bureaucracies. By contrast, the explicit recognition of aesthetic and ethical values would complement arguments based on science and economic utility. We subscribe to a reformist view of globalization that accepts the inevitability of a globalizing world but argues that the process needs humanizing by incorporating quality of life values in the policy process. We argue that re‐emphasis of aesthetic and ethical arguments in international conservation policy would contribute to this goal by reasserting links between conservation bodies and the public, thereby leading to more effective action on the ground.     

Nationalism and the ‘idiocy’ of the countryside: The case of Serbia

The mobilization of the countryside has direct consequences for political discourse about national values and in times of social crisis, the ‘conservatism’ of the countryside has the potential to assume an aggressive, offensive posture. When rural mobilization is accompanied by religious revival, group loyalty and so‐called ‘traditional’ values are sacralized. When rural mobilization, ethnic mobilization, and religious revival occur simultaneously, it signifies that the society is undergoing profound destabilization. Examining the case of Serbia, this article argues that while Serbia is, in cultural and social terms, predominantly rural in character, Titoist Communism imposed the values of the city on that culture, while the 1987 coup by Slobodan Milosevic represented, among other things, the triumph of the countryside over the city in Serbia.

This article begins by characterizing the countryside in cultural terms, provides documentation of the importance of rural traditions in Serbian society, documents the rural character of the Serbian national movement, connecting its ideology and behaviour with populist appeals, and examines the contribution made by the Serbian Orthodox Church to the mobilization of the Serbian countryside.