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1.
Chen ST 《Fitoterapia》2011,82(1):14-16
Investigators and sponsors of dietary supplement research need to know the relevant regulatory requirements and how to comply with them. This brief review describes how research on dietary supplements is regulated by FDA. In general, whether an FDA sanctioned Investigational New Drug (IND) application is required for a human research project on dietary supplement depends on the intended use and clinical setting of the clinical study, and not on the supplement's physical or chemical properties. Even if the study product is already available on the market as a dietary supplement, an IND will be required for products that will be used as a drug to treat, mitigate or prevent a disease or its related conditions in the proposed clinical study. On the other hand, for studies on structure and function endpoints, and not on drug use, no IND will be required. The paper also discusses the principles FDA uses to determine whether an IND is needed for clinical studies of surrogate endpoints that do not lead to approvable drug claims. Useful FDA contact information is also provided.  相似文献   

2.
Journal of Pest Science - A correction to this paper has been published: https://doi.org/10.1007/s10340-021-01386-z  相似文献   

3.
In 1998, Mexican gray wolves (Canis lupus baileyi) were introduced into the Blue Range Wolf Recovery Area (BRWRA) that spans adjacent portions of Arizona and New Mexico. In 2009 we selected three mixed-conifer sites on the Apache National Forest, within the BRWRA of east-central Arizona, to characterize long-term age structure of aspen (Populus tremuloides) and to check for the possible occurrence of a tri-trophic cascade involving Mexican wolves, Rocky Mountain elk (Cervus elaphus nelsoni), and aspen. These mixed-conifer sites included (a) a refugium site, (b) an old-growth site, and (c) a site thinned in 1991–1992. The refugium site was inaccessible to elk and cattle whereas the old-growth and thinned sites were accessible to elk, but not cattle. Age structure results indicated that aspen recruitment (i.e., the growth of sprouts/seedlings into tall saplings, poles, and eventually trees) at the refugium site had been ongoing over a period of many decades. In contrast, aspen recruitment at the old-growth and thinned sites decreased significantly (p < 0.05) during the two most recent decades when elk populations, as indexed by annual harvest levels, were relatively “high”. From 2000 to 2008, only 2.9 Mexican wolves per 1000 elk were present on the Apache National Forest compared to 9.3 western gray wolves (Canis lupus occidentalis) per 1000 elk in Yellowstone National Park where tri-trophic cascades involving wolves, elk, and aspen have been reported. The low number of Mexican wolves relative to their primary prey (elk) suggests that an ecologically effective density of wolves has not become established in east-central Arizona. Furthermore, the lack of recent aspen recruitment in stands accessible to elk indicates an absence, to date, of a tri-trophic cascade.  相似文献   

4.
Long range (or strategic) planning is an important tool for forest management to deal with the complex and unpredictable future. However, it is the ability to make meaningful predictions about the rapidly changing future that is questioned. What appears to be particularly neglected is the question of the length of time horizons and the limits (if any) to these horizons, despite being considered one of the most critical factors in strategic planning. As the future creation of values lies within individual responsibility, this research empirically explored the limits (if any) of individual foresters’ time horizons. To draw comparisons between countries with different traditions in forest management planning, data were collected through telephone surveys of forest managers in the state/national forest services of the Netherlands and Germany. In order to minimize other cultural differences, the research in Germany concentrated on the federal state of Nordrhein-Westfalen, which has considerable similarities with the Netherlands, e.g. in topography, forest types and forest functions. The results show that, in practice, 15 years appears to be the most distant horizon that foresters can identify with. This is in sharp contrast to the time horizons spanning decades and even generations that are always said to exist in forestry. The “doctrine of the long run”—the faith in the capacity of foresters to overcome the barriers of the uncertain future and look ahead and plan for long-range goals—which in many countries still underlies traditional forest management, can therefore be rejected.
Heiner SchanzEmail:
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5.
Journal of Pest Science - Biological control, or biocontrol, is the exploitation of living agents (incl. viruses) to combat pestilential organisms (incl. pathogens, pests, and weeds) for diverse...  相似文献   

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Despite its good environmental track record, the Finnish forest industry nonetheless causes harmful environmental impacts. This paper studies corporate environmental reports within the Finnish forest industry to determine the environmental performance of the industry at large. Fifteen years of environmental reports from the three biggest Finnish forest industry companies are analysed. The majority of these reports focus on inputs needed for production (especially energy) and unwanted outputs (especially air and water emissions) in the industry. The environmental impacts in areas of the industry taking place outside of mills, however, are less often reported and appear to be less important to the companies. This paper makes five contributions to the literature: First, the forest industry's reporting, as a less researched field, is studied in detail. Second, the forest industry's environmental reporting is diverse, comprised of multiple indicators and units of measurement. Third, the energy indicator reporting is both established and diversified. The diversity makes the reports as a weak source of comparison of environmental performance. Fourth, the case companies seldom report the environmental performance of their supply chains. Fifth, while the prior literature has analysed multiple environmental impacts of the forest industry, the case companies report on very few of them. The paper concludes by stating that future environmental reporting should especially address supply chains and multiple environmental impacts caused by the industry.  相似文献   

9.
Journal of Pest Science - A correction to this paper has been published: https://doi.org/10.1007/s10340-021-01393-0  相似文献   

10.
The famous “Faustmann” equation, which allows for identifying the most profitable tree species on a given unstocked piece of land, assumes constant timber prices. In reality, timber prices may fluctuate dramatically. Several authors have proven for monocultures that waiting for an acceptable timber price (reservation price) before harvesting (flexible harvest policy) increases the net present value of forest management. The first part of this paper investigates how efficient a flexible harvest strategy may be applied in mixed forests and whether the optimal species mixture is changed under such harvest policy. Mixtures of the conifer Norway spruce [Picea abies (L.) Karst] and the broadleaf European beech (Fagus sylvatica L.) were investigated. In order to evaluate mixed forests, the risks and the correlation of risks between tree species as well as the attitude towards risk of the decision-maker (risk-aversion is assumed) were considered according to the classical theory of optimal portfolio selection. In the second part we took up a recent critique on modern financial theory by Mandelbrot. Whether or not the assumption of normally distributed financial flows, which are supposed to occur under risk, would be appropriate to evaluate the risk of forest management was investigated. Market and hazard risks as well as their correlation were integrated in the evaluation of mixed forests by means of Monte-Carlo simulations (MCS). The risk of the timber price fluctuation was combined with the natural hazard risk, caused mainly by insects, snow and wind. Applying the μ-σ-rule, the mean net present value (NPV) from 1,000 simulations and their standard deviation were used for the optimisation. Given a low-return, risk-free interest rate to assess potential species mixtures of the Norway spruce and European beech, optimal proportions of European beech increased according to the theory of optimum portfolio selection with growing risk aversion from 0 (ignorance of risk) to 60% (great risk-aversion). In relation to a fixed harvest policy, the net present value of both, Norway spruce and European beech, could be increased significantly. Since the hazard risks of European beech were substantially lower compared with the Norway spruce (relation of susceptibility 1:4) beech benefited more from the flexible harvest policy. A comparison of simulated frequency distributions of the NPV with the expected density functions under the assumption of a normal distribution revealed significant differences. Only in the case of European beech was the general shape of the simulated frequency distribution similar to a normal distribution (bell-shaped curve). However, the density of NPV close to the mean was much greater than expected under the assumption of a normal distribution. Consequently, the frequency of a negative NPV for a European beech forest was greatly overestimated when applying the normal distribution. Though the shape of the simulated frequency distribution was rather different from a normal distribution for Norway spruce the simulated part of negative NPV was quite well approximated by the normal distribution. Therefore the simulated and expected frequencies of negative NPV were similar in case of Norway spruce; only a slight underestimation was seen in the assumption of a normal distribution. It can be concluded that actually simulated frequencies of negative NPV seem to be better measures for risk than computed probabilities of negative NPV, which assume normal distribution. As the risk for European beech was greatly overestimated by the conventional assumption of a normal distribution, the optimal proportions of European beech were surely rather underestimated according to the theory of portfolio. MCS on optimum mixtures derived by the classical portfolio theory seems necessary to test the robustness of such mixtures.
Thomas KnokeEmail: Phone: +49-8161-714700Fax: +49-8161-714616
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11.
The study espoused the access analytical framework to investigate how introduction of Participatory Forest Management (PFM) in Kenya has changed the various actors’ ability to benefit from the forest resources of Eastern Mau Forest Reserve. Data collected through key informant interviews, and a household survey showed that implementation of PFM has triggered new income opportunities for forest adjacent communities in seedling production and beekeeping. However, PFM bestowed no real decision-making powers to the established Community Forest Associations (CFAs) over important forest resources such as timber and firewood. Members of the local communities and other actors have continued to access these resources through various structural and relational means, in the same way as before the introduction of PFM. Further, it is documented that PFM has introduced additional burdens on the local communities, especially the poorest households, as a result of increased enforcement of rules. Based on these findings, it is suggested that the PFM policy in Kenya, in its current form, is unlikely to realize its dual objectives of forest conservation and livelihood enhancement. To attain them would require a further devolution of rights to the CFAs.  相似文献   

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Green-tree retention cutting (GTR) is a modification of traditional clear-cutting, aimed at better consideration of biodiversity. We reviewed 214 North American and European studies to answer whether, and under which circumstances, GTR meets its objectives: ‘lifeboats’ species over the regeneration phase, provides microhabitats for old-forest species in re-established forest stands and for disturbance-phase species on the recent cuts, and enhances species’ dispersal by increasing landscape connectivity. To answer these questions is complicated, partly because the target taxa differ regionally and due to research biases: 81% of the studies have been carried out in North America, 82% have been short term, and the objective of improving landscape connectivity has not been studied. A meta-analysis of GTR effects on species richness and abundance of different taxa indicated no negative responses, but birds and ectomycorrhizal fungi benefited most. Compared with clear-cutting, GTR lowered the harvest-related loss of populations or individuals in 72% of studies, and it nearly always improved the habitat for disturbance-phase insects and birds on the cuts and for forest species in the regenerated stand. Lifeboating was most successful for ectomycorrhizal fungi, epiphytic lichens and small ground-dwelling animals, and least successful for bryophytes and vascular plants. Retention tree species always contributed to the success of GTR, followed by tree density (65% of cases) and the spatial arrangement of the trees (50%); the influence of forest type is likely, but insufficiently studied. Ectomycorrhizal fungi, epiphytes, birds, and wood-dependent beetles may be suitable indicator taxa for measuring the success of GTR. For future research, we encourage clearly objective oriented studies of relevant taxa, spatially explicit landscape perspectives, and long-term (including retrospective) studies.  相似文献   

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The purpose of this study is to investigate the impact of non-economic motivations such as altruism and environmental concerns on social preferences and hence willingness to pay (WTP) for changes in forest management strategies in the Białowieża Forest in Poland. We used data from a discrete choice experiment (CE) with attributes describing changes in the quality of the forest and recreation. The choice experiment technique makes it possible to disentangle the effect of the trait of altruism and environmental concern with regard to different attributes and their levels. Environmental attitudes were measured using the New Ecological Paradigm (NEP) scale, whereas the trait of altruism was determined using the Self-Reported Altruism (SRA) scale. The parameterization employed in the survey was a WTP space model. Results show that both altruism and environmental concerns have significant effects on the amount people are willing to pay for changes in forest management.  相似文献   

16.

Key message

For an optimal deployment of poplar resistance to the gall-inducing aphid Phloeomyzus passerinii , a laboratory susceptibility assay has been developed. The nature of aphid–tree interactions during compatible and incompatible situations has been studied in detail. This should help at identifying specific resistance markers and at testing effects of site conditions on tree–pest interactions.

Context

P. passerinii is a major pest of poplar plantations in Europe, and the plantation of resistant poplar genotypes is regarded as the best long-term management strategy for this pest. This requires a sound knowledge of the interactions among the pest, its host and their environment.

Aims

Here, we review the recent advances aiming at developing an optimal deployment of host resistance versus P. passerinii.

Results

Investigations on aphid-host interactions demonstrated that P. passerinii induces pseudogalls within the bark of susceptible hosts. This results in a reduction of starch bark content during aphid outbreaks, which could be involved in tree death. The constitutive level of starch in the bark could be related to the tolerance level of trees. A susceptibility test has been designed for poplar genotypes, discriminating three categories of susceptibility depending on tree’s ability to totally or partially inhibit pseudogall induction. The test still has several limitations however. It neither takes into account the large level of individual genetic diversity of the aphid in France, nor the environmental modulation of tree resistance and tolerance, while water deficit and fertilization could potentially affect these parameters.

Conclusion

The hypotheses drawn regarding the processes leading to tree death or resistance should help at identifying resistance markers, and at testing effects of site conditions on tree–pest interactions.
  相似文献   

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ABSTRACT

The Mayan Biosphere Reserve in the region of Petén, Guatemala and the state of Quintana Roo, Mexico have well-established experiences of community-based forestry and community forestry enterprises within the area known as the Mayan forest. Context has been a key factor shaping the trajectories of these two cases. Several scholars have highlighted the usefulness of understanding the role of context in the emergence and functioning of common property regimes. However, scholarship has been dominated by the mainstream school of common property, which sees these regimes as arising out of voluntary, rational action with the main intent of conserving a common-pool natural resource. This paper seeks to answer the call for more research on context for common property regimes. The article discusses how policies, history, and culture have shaped the trajectory of community forestry in both countries. Policies present choices, opportunities, and constraints, while history and culture can facilitate or hinder taking advantage of such opportunities. Communities have agency not only to react, but also to adapt. These two cases present overriding themes that strengthen the alternative literature on common property regimes and also offer lessons to policy makers, practitioners, nongovernmental organizations, and communities practicing forestry.  相似文献   

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The Australian Master TreeGrower (MTG) program was launched in 1996 as an agroforestry extension initiative of The University of Melbourne. The program included a short course for landholders that provided knowledge and practical skills but also had a strong focus on developing the information and peer networks that would provide them, and their community, with on-going support as they implement their agroforestry activities. Since 2010 the MTG has been delivered by The Australian Agroforestry Foundation, a not-for-profit organisation, and integrated with the Peer Group Mentoring (PGM) concept developed by a regional farmer group in Australia. The PGM trains, then pays, past Master TreeGrowers to support other landholders as they design and develop their own agroforestry projects. More than 100 MTG courses have been run across Australia involving over 2000 landholders and more than fifty partner organisations. Independent evaluation shows that participants enthusiastically support the program, increase the area of tree cover on their land, adopt more intensive or purposeful management practices, are more inclined to want to grow trees for a mix of both public and private good outcomes, and, actively encourage others in their community to do the same. This paper reviews the development and delivery of the MTG and PGM in Australia and explores whether the models are transferable to developing countries. To date four MTG courses have been conducted in Africa (Uganda (2) and Niger (2)), seven in Indonesia and one in Timor-Leste. Whilst the structure of the international MTG courses was different to that commonly adopted in Australia the content was similar in that they included: information to support the development and implementation of agroforestry designs that reflect their particular interests and aspirations; a review of market opportunities for agroforestry products and services, training in tree and forest measurement, education in tree growth and silviculture; and, encouragement, guidance and support to encourage landholders to share their experience with others in their community. The response suggests that the MTG, originally developed for Australian farmers, may represent a very different model of agroforestry extension to what is commonly offered to farmers in developing countries, and that it may be worth developing in regions where farmers believe they have relatively secure land tenure and are able to make long-term land management decisions regarding tree establishment and management.  相似文献   

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