7,567 research outputs found
Effects of presenting forest simulation results on the forest values and attitudes of forestry professionals and other forest users in Central Labrador
This research tested whether demonstration of the long term effect of different forest management scenarios in a large forested area changes people's forest values and attitudes. Forestry professionals and other forest users in Central Labrador were shown simulation results of three alternative forest management scenarios illustrating possible long term effects on various indicators. Forest values and attitudes towards forestry were measured before and after the presentation. Our conception of values and attitudes is based on the cognitive hierarchy model of human behaviour which states that values are more enduring and more difficult to change than attitudes. It was thus hypothesized that attitudes would change but not values and that change in forestry professionals would be less than in other forest users since foresters are trained to think about long-term effects and large-scale processes of forest management scenarios. We also hypothesized that a greater number of people would have an opinion on forest management after the presentation. All three hypotheses were partially supported by the results. The results indicated that some attitude change occurred, but that values also changed somewhat. Most of the significant changes occurred when persons with no clear opinion on several forest-related questions formed an opinion. Long-term, landscape simulation results provide valuable information and enhance understanding of both forestry professionals and other forest users. However, being provided the same information, the two groups learned different things. While forest users gained more confidence in the current forest management plan and were motivated to further participate, professionals learned more specific things. This reflects differences between technical and local knowledge
Evaluation of fine root length and diameter measurements obtained using RHIZO image analysis
Image analysis systems facilitate rapid measurement of root length and diameter, but their accuracy is not easily determined. The objective of this study was to develop a set of simple experiments for evaluating the accuracy of fine root measurements obtained using image analysis. Using the system RHIZO (trademark of Regent Instruments, Quebec), we tested the accuracy of (i) length measurements made over a range of root lengths per unit area, (ii) average diameter measurements and length per diameter distributions in string, wire, and fine root samples of varying diameter, and (iii) diameter measurements on short segments of diagonally oriented objects. Our results suggest that preliminary testing of image analysis systems is absolutely necessary for producing reliable root measurements. Total length was accurately determined for typically encountered length per unit areas of <1.5cm cm-2. For samples with higher values, however, the method underestimated total length by >5%. It is therefore recommended that users of image analysis systems determine this maximum length per unit area for accurate determinations of total root length. In samples that contained different string diameters, the total sample length and average string diameter could accurately be measured. However, the length per diameter class was underestimated by >20% when the string diameter was less than one pixel smaller than the upper limit of the diameter class. Adjustment of diameter intervals and increasing the scanner resolution are required to reduce this underestimation. Both the length and the angle of the short segments analyzed were found to influence diameter measurements. Similar sets of experiments are proposed for a rigorous evaluation of the performance of other image analysis systems on root measurements
Peut-on concilier politique nataliste et féminisme?
Après avoir présenté le contexte dans lequel s’inscrit le débat actuel au Québec, l’auteur résume les expériences menées en France et en Europe de l’Est en terme d’efficacité des politiques natalistes. Compte tenu de ces résultats et de la place qu’occupent les femmes sur le marché du travail, l’auteur évalue l’impact possible de certaines mesures natalistes appliquées au Québec. Ensuite, on présente les principes qui sous-tendent l’analyse de la maternité réalisée dans une perspective féministe. Enfin, sont précisés les éléments de politique considérés essentiels à une réelle conciliation entre le travail rémunéré et la maternité pour les femmes
(Mis)Understanding the Atmospheric Neutrino Anomaly
The apparent attenuation of muon neutrinos relative to electron neutrinos is
a bit too low to be compatible with the most popular values of .
Fits to favor values of eV. The fit
minimized by the Super Kamioka group in estimating neutrino oscillation
parameters neglects systematic errors. The fit is dominated by systematic
effects. The data being combined in recent fits may not be compatible since
there appear to be significant variations in the properties of the data with
time. A simple two component neutrino oscillation with in the
range of 10 to 10 eV seems unable to account for the
observations.Comment: 7 pages, 3 figures, talk given at the Sixth International Workshop on
Tau Lepton Physics, Victoria, BC Canada, September 19, 200
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