Gradient Genogeographic Analysis of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. Populations in Europe

Gradients of Nei's genetic distances between 15 samples of Pinus sylvestris L. trees were analyzed along three submeridional transects, from Scandinavia to the Mediterranean and Transcaucasia. As a result, distinct chorogenetic differentiation was revealed between the populations of this species growing in climatically specific regions of northern and southern Europe. Considerable Nei's distances (DN = 0.045–0.056) and their gradients, combined with differences in stable phenotypic characters (the composition of monoterpenes and morphological parameters of cones) determined at the Pyrenean and Caucasian mountain borders, suggest that the P. sylvestris species structure includes two South Eurasian subspecies, the Pyrenean P. sylvestris L., ssp. iberica Svoboda and the Transcaucasian P. sylvestris L., ssp. hamata (Stev.) Fomin.     

Ecological Mechanisms of the Formation of Biological Rhythms in Hibernators of the Family Sciuridae in Northeastern Siberia

A mechanism of the formation of biological rhythms in hibernators at cold temperatures is proposed. Certain ecophysiological characteristics have been studied in three hibernating species: the ground squirrels Citellus undulatus Pallas, 1778 and C. parryi Richardson, 1825 and the chipmunk Tamias sibiricus Laxmann, 1769. The changes in body temperature and the temperature of litter in wintering nests during hibernation seasons have been studied. The dependences of metabolic rate on ambient temperature and the size and species of animals have been studied.     

Recent Levels of Radionuclide Contamination in the Eastern Ural Radioactive Trace and Biological Effects in Local Populations of <Emphasis Type="Italic">Plantago major</Emphasis> L.

The results of the study have shown that the stocks of ⁹⁰Sr and ¹³⁷Cs in the frontal part of the EURT are 6700–15000 and 200–400 kBq/m², respectively. The coefficients of their accumulation in different herbaceous plant species in this impact zone are lower than in other areas. The accumulative capability of plants has probably decreased in the course of selection as an adaptation to the effect of radiation. The viability and growth parameters of Plantago major L. seeds from the EURT zone are similar to those of seeds from the background sample. Cenopopulations chronically exposed to radiation are characterized by a higher mutation rate in the progeny and an unstable response to additional acute irradiation in most characters studied. A high level of inbreeding is observed in all P. major cenopopulations of plantain. The cenopopulation of the impact zone is characterized by a lower variation of allozyme loci, which may be a result of stringent selection for individuals better adapted to the complex of conditions existing in its habitat.     

The crash severity impacts of fixed roadside objects

INTRODUCTION: This study analyzes the in-service performance of roadside hardware on the entire urban State Route system in Washington State by developing multivariate statistical models of injury severity in fixed-object crashes using discrete outcome theory. The objective is to provide deeper insight into significant factors that affect crash severities involving fixed roadside objects, through improved statistical efficiency along with disaggregate and multivariate analysis. METHOD: The developed models are multivariate nested logit models of injury severity and they are estimated with statistical efficiency using the method of full information maximum likelihood. RESULTS: The results show that leading ends of guardrails and bridge rails, along with large wooden poles (e.g. trees and utility poles) increase the probability of fatal injury. The face of guardrails is associated with a reduction in the probability of evident injury, and concrete barriers are shown to be associated with a higher probability of lower severities. Other variables included driver characteristics, which showed expected results, validating the model. For example, driving over the speed limit and driving under the influence of alcohol increase the probability of fatal accidents. Drivers that do not use seatbelts are associated with an increase in the probability of more severe injuries, even when an airbag is activated. IMPACT ON INDUSTRY: The presented models show the contribution of guardrail leading ends toward fatal injuries. It is therefore important to use well-designed leading ends and to upgrade badly performing leading ends on guardrails and bridges. The models also indicate the importance of protecting vehicles from crashes with rigid poles and tree stumps, as these are linked with greater severities and fatalities.     

Identifying best practices states in motorcycle rider education and licensing

PROBLEM: After decreasing to a historic low in 1997, motorcycle crash-related fatalities are increasing. Although causes remain unclear, motorcycle rider education and licensing play key roles in reducing motorcycle crashes and injuries. Yet, little is known about what constitutes effective rider training and licensing. This study develops a model of best practices in motorcycle rider education and licensing and combines primary and secondary data to identify states that most closely adhere to this model. Evidence on the validity of the model is also examined. METHOD: States were rated along three areas of best practices: (a) program administration; (b) rider education; and (c) licensing based on 2001 data collected for a National Highway Traffic Safety Administration (NHTSA)-sponsored study. RESULTS: Results indicate wide variation in states' adherence to best practices; several states meet most, others very few. When the areas of best practices are considered separately, a state tends to behave similarly on all three. Initial evidence supports the validity of the model, with high best practices states having the lowest rates of motorcycle fatalities. IMPACT ON TRAFFIC SAFETY: As motorcycle-related crashes increase and state and federal support for rider education programs diminishes, it is critical that states identify deficiencies in their program and learn from successful states about efficient, cost-effective strategies for increasing best practices in motorcycle rider education and licensing.     

Comparisons of pastoralists perceptions about rangeland resource utilisation in the Middle Awash Valley of Ethiopia

Pastoralism is the most dominant land use form in the arid rangelands of Sub-Saharan Africa, but this rangeland-based lifestyle is under threat. As a consequence a study was conducted in the Middle Awash Valley of Ethiopia with the main objectives of assessing and comparing the broad perceptions of two pastoral groups (the Oromo ethnic group living in Kereyu-Fantale and the Afar ethnic group living in Awash-Fantale) on the usage of the existing rangeland resources, and their views on constraints and possible solutions. Data were collected from 90 Oromo and 55 Afar households. Despite the difference in ethnicity both of these groups share common problems. They derive their main income from the sale of animals and animal products, but with the difference that milk products rank first in the case of the Afar and last in the case of the Oromo. Both pastoral groups depend heavily on native grasses for animal feed and to a lesser extent on woody plants as a source of browse. The majority of respondents were of the opinion that the condition of the rangelands is poor, mainly due to overgrazing, droughts and increases in the human population. Availability of water is also regarded as a problem, mainly by the Oromo. Migration is the first measure taken to solve shortages of livestock feed, but many of the pastoralists replied that migration is an undesirable practise which is mostly done out of necessity. Because of the limited resources most respondents of both groups still prefer communal land tenure where resources are shared. It is concluded that the problems facing the pastoralists in the Middle Awash Valley have been created over many years and the solutions will also require time. With the current approach of the communal grazing systems, sustainable utilisation of the rangeland ecosystem is not possible. Solutions to the poor condition of the existing rangelands will require a definite commitment and full participation not only of the pastoralists, but also of government and non-governmental organisations that are directly or indirectly involved in rangeland resources utilisation, management, conservation and other related activities.     

Environmental threats to buried archaeological remains

The last century's environmental pollution has created health problems, acidification of ground and lakes, and serious damage to our cultural heritage. Outdoor monuments suffer from this pollution, but so do buried archaeological remains. However, research on the deterioration of archaeological artifacts underground has so far been limited, and it is important to draw attention to this neglected field. This article presents results obtained at the Swedish National Heritage Board on the degradation of archaeological objects of bronze and iron and of bones from prehistoric graves, materials of which seem to be most affected by pollutants. The investigation methods, which were employed, are described. Other relevant studies are briefly reviewed. It is obvious that the deterioration rate of archaeological artifacts, especially of inorganic materials, has accelerated in recent years, and that this increased deterioration to a large part can be attributed to anthropogenic pollution. Regions that might be endangered are exemplified.     

Comparative study of responses in four Datura species to a zinc stress

The effects of zinc toxicity on the growth and the photosynthetic activities of four Datura species (Datura metel, Datura innoxia, Datura sanguinea, Datura tatula) were studied using various ZnSO4 concentrations (0, 1, 2.5 and 5 mM) added in the Coic Lessaint solution. Growth, photosynthesis, chlorophyll fluorescence and chlorophyll concentration were measured after 20 days of zinc stress. These parameters were severely reduced by this heavy metal. The zinc excess involves the stomate closing, the increase of CO2 concentration in the leaves, the inhibition of certain enzyme of the Calvin cycle, a degradation of photosystem and the chlorophyll decomposition. These phenomena allow the decrease of the net photosynthesis to be partially explained. These key parameters to assess photosynthetic performance allow the plants to be classified according to their resistance to zinc. Compared with the three other species, D. innoxia showed a very strong capacity to protect itself against toxic zinc concentrations; a large amount of ZnSO4 (5 mM) was required to inhibit 43% of the photosynthesis.     

UV-absorbing compounds in subarctic herbarium bryophytes

The UV-B-absorbing compounds of herbarium specimens of 10 subarctic bryophyte species collected during the years 1926-1996 and available at the Botanical Museum, University of Oulu, were studied. We studied whether herbarium specimens reflect changes in the past radiation climate through their methanol-extractable compounds. The order of gametophytes based on the average amount of total compounds (sum of A280-320 nm) per mass from the lowest to the highest was Polytrichum commune, Pleurozium schreberi, Hylocomium splendens, Sphagnum angustifolium, Dicranum scoparium, Funaria hygrometrica, Sphagnum fuscum, Sphagnum warnstorfii, Sphagnum capillifolium and Polytrichastrum alpinum, and the amount of UV-B-absorbing compounds per specific surface area correlated with the summertime daily global radiation and latitude. P. alpinum, F. hygrometrica and three Sphagnum species seem to be good indicators for further studies. The amount of UV-B-absorbing compounds revealed no significant trends from the 1920s till the 1990s, with the exception of S. capillifolium, which showed a significant decreasing trend.