(trad auto)Based on a bibliographical study, this work aims to clarify the notion of stress (definition, etymology, concepts), to make a partial assessment of the studies carried out on fish in order to draw up a table of the short- and medium-term indicators used (except hematological indicators) and finally to present some applications. | A partir d'une étude bibliographique, ce travail a pour but d'éclaicir la notion de stress (définition, étymologie, concepts), de faire un bilan partiel des études menées sur les poissons afin de dresser un tableau des indicateurs à court et moyen terme utilisés (exception faite des indicateurs hématologiques) et enfin de présenter quelques applications.

We explored the relationships between classical estimators of autotrophic biomass and primary production, such as chlorophyll a concentration and 14C-fixation rates, and biochemical indices based on DNA and RNA determinations, which have been proposed as indicators of physiological state in natural plankton populations. The measurements were made during two cruises across the Catalan Front, carried out in May 1989 and February 1990, corresponding respectively, to periods of stratification and moderate mixing. DNA and RNA concentrations (measured by a double-staining fluorimetric technique) were significantly correlated with chlorophyll a in February 1990, but not in May 1989, when a marked deep chlorophyll maximum was present. Significant positive correlations between RNA concentration and primary production and between RNA: DNA and primary production were found during both surveys, probably reflecting both higher RNA concentrations per cell and enhanced bacterial and microheterotrophic growth in high primary production situations. The results support the potential usefulness, in biological oceanography, of biochemical indicators based on DNA and RNA concentrations | This work was supported by the FPI fellowship to E. B. of the Ministerio de Educación y Ciencia de España, and funds from CICYT Grant No. MAR88-0252

Soil quality is the most important factor for sustaining the global biosphere. Soil quality may be defined in several different ways including productivity, sustainability, environmental quality, and effects on human nutrition. To quantify soil quality, specific soil indicators need to be measured spatially. These indicators are mainly soil properties whose values relate directly to soil quality but may also include policy, economic, or environmental considerations. Because assessing soil quality is complex, the individual soil quality indicators need to be integrated to form a soil quality index. This integration needs to be flexible enough to evaluate soil quality at spatial scales ranging from the farm to the regional level, be applicable to all types of agricultural land use, and be able to incorporate all types of soil quality information. We have developed a multiple-variable indicator kriging (MVIK) procedure that may provide a means to integrate soil quality parameters into an index to produce soil quality maps on a landscape basis. These maps would indicate the areas on a landscape that have a high probability of having good soil quality according to predetermined criteria. This procedure can provide probability maps based on any range of chosen criteria and thus is universally applicable. In addition, it allows the identification of the indicator parameter(s) responsible for zones of low soil quality, thus allowing specific management plans or land use policies to be developed.

The capabilities of understorey plant species to indicate site productivity, as expressed by site index (H100), were examined using data from 222 sample plots from mature stands of Pinus sylvestris L. in southern Finland. The number of herb species was relatively strongly correlated with site index (r=0.81). Also, the presence of 20-30 species indicated site index well. The link between understorey vegetation and site productivity was primarily based on the distribution patterns of these indicators. In contrast, species cover was poorly related to site productivity. In regressions of species cover on site index, only ten species achieved r2 of 40% or more. No good indicators existed where site index was less than 21 m. The inclusion of soil deposit types (soil texture) in the prediction model compensated for the poor prediction power of understorey plants on sites of low productivity and increased the accuracy of site productivity estimation by approximately 15%. The estimation did not improve when temperature sum was included in the model.

Gives details of methods, results, conclusions and areas for further research from a project undertaken to find a biochemical marker which could be incorporated into selection procedure for sheep and cattle with greater rates of muscle growth, hence increased feed efficiency. There are inherited differences in protein deposition in sheep which are associated with alterations in protein degradation in muscle and the body as a whole, intake and digestion of feed and partition of nutrients between body and wool. There are differences in biochemical-hormonal indicators which could be developed to identify animals with superior muscle growth characteristics. Two of these indicators of efficient lean growth have been identified during the project work: plasma IGF-1 concentration and differences in insulin receptor number in muscle. With further study it may be possible to use measurements based on this information as part of a selection index for efficient lean growth in animals.

This paper examines changes over time in the importance of the lending channel in the transmission of monetary shocks to the real economy. We first use a simple extension of the Bernanke-Blinder model to isolate the observable factors that affect the strength of the lending channel. We then show that based on changes in the structure of banks assets, reserve requirements, and the composition of external firm finance, the lending channel should have been stronger before 1929 than during the post-World War II period, especially the first half of this period. Finally, we demonstrate that conventional indicators of the importance of the lending channel, such as the spread between the loan rate and the bond rate and the correlation between loans and output, do not show the predicted decline in the importance of lending over time. From this we conclude that either the traditional indicators are not useful measures of the strength of the lending channel or that the lending channel has not been quantitatively important in any era.

"Ruminants and especially bovids are considered to be excellent ecological indicators. In the first part of this study skeletons of 59 recent ruminant species and 7 nonruminant ungulate species are described and analysed. Three morphological types of ruminants are defined by numerous anatomic features related to locomotion in determined habitats. In the second part 50 fossil ruminants and 2 nonruminant artiodactyles are classified by the established morphological groups. Some important european and circummediterranean ruminants are picked out as 'ecological indicators' and compared with recent ruminants. Based on this classification the ecology of Western and Eastern Eurasian localities from MN 6 up to MN 13 is reconstructed. In this space of time four climatic phases indicating the evolution of four ecological systems sensu Margalef (1986) are distinguished. It is demonstrated that quantity and quality of specialization increase with the maturity of the ecological systems. In this process specialists are increasingly exposed to extinction while more plesiomorphic forms tolerate perturbations better. Therefore convergencies are more frequent within specialists"--P.5.

Objective. Compare milk-based, iron-fortified formulas containing 7.4 and 12.7 mg/L iron and breast-feeding during the first year of life. Design. Partially randomized, double-blind trial: non-breast-fed infants randomly assigned to receive one of two coded formulas, identical except for iron content; infants discontinuing breast-feeding between 1 and 8 weeks of age randomly assigned to a formula late-start group. Setting. Five general community pediatric practices in Missouri, Indiana, Illinois, and Pennsylvania. Participants. Sample of 347 healthy, term infants, enrolled within 1 week after birth; 172 included in statistical analyses. Outcome measures. Length, weight, and indicators of formula intolerance recorded at clinic visits; formula consumption, bowel movements, stool consistency, and other tolerance indicators recorded by parents on daily and weekly report forms; hemoglobin, hematocrit, and serum ferritin, iron, zinc, and copper measured at 6 and 12 months. Results. No significant differences between formula-fed groups in growth, attrition, formula consumption, bowel movements, hematocrit, hemoglobin level, and serum iron, zinc, and copper levels (P > .05); first 6-month weight and length changes of the breast-fed group significantly less than in both formula-fed groups (P < .008); serum ferritin level of the formula-fed, high-iron group significantly higher than that of the low-iron and breast-fed groups (P < .008), although all groups' values were normal; no apparent differences between formula groups in formula tolerance and stool characteristics but data were not analyzed statistically. Conclusions. Milk-based formulas containing either 7.4 or 12.7 mg/L iron support normal growth and iron status of healthy, term, normally fed infants during the first year and both are well tolerated and accepted.

COHMAP (Cooperative Holocene Mapping Project) had its start in the 1970s with the intent to compare atmospheric general circulation models with quantitative palaeoclimatic reconstructions based on stratigraphic pollen analysis. As the sophistication of the models increased and as additional palaeoclimatic indicators (lake levels, marine microfossils) were incorporated in the reconstructions, the programme expanded to global coverage through the participation of numerous collaborators. The carefully nurtured dual approach of modelling and data analysis was strengthened by continued testing of one against the other, with emphasis on interdisciplinary understanding fostered by workshops. With the development of new computer models that have higher spatial resolution and improved boundary conditions, and with diversification and enlargement of the geographic and temporal coverage of field and analytical data, substantial refinements can be anticipated in the understanding of global climatic changes since the last glacial maximum.

In 1991, members of the rural caucus proposed numerous bills designed to attenuate the rural-urban differences in health care delivery and health status. Implicit in the legislative process is the assumption that "rural America" differs systematically from "urban America." However, research has consistently demonstrated that there is not a single rural America but rather, those areas outside of the major metropolitan areas represent a complex mosaic of varying social and environmental settings. Rural communities differ in meaningful ways along a number of socioenvironmental parameters, and accordingly, health status indicators also differ across rural communities. Thus, health outcome statistics averaged across rural communities will often mask important health disparities experienced by certain population groups. Policies based on these aggregate indicators may overlook the needs of the most disadvantaged. While a number of measures of rurality have emerged in the last decade, much of the information presented to policy-makers is either too aggregated (i.e., metropolitan-nonmetropolitan) to identify important differences across the range of communities, or it is gathered in agency-specific categories that are not comparable. The central question under examination in the current context is the possibility of distorting the picture of infant health status by aggregating the diverse rural locales of the United States. Empirical results indicate that when considering infant mortality, any rural disadvantage is contingent upon how 'rural' and 'urban' have been defined. Further, the results indicate that conclusions must be conditioned on other important sociodemographic parameters such as region of the country and race.