秒杀 陷阱or馅饼

今天,你秒杀了吗?时下,许多网购爱好者都在津津乐道于秒杀话题:马尔代夫度假秒杀价1999元;iPhone手机秒杀价399元……果真有这样的好事?秒杀,就是以压倒性优势一招致命;在极短时     

秒杀 陷阱or馅饼

今天,你＂秒杀＂了吗？ 时下,许多网购爱好者都在津津乐道于＂秒杀＂话题：马尔代夫度假＂秒杀＂价1999元;iPhone手机＂秒杀＂价399元……果真有这样的好事？     

收养or助养需慎重

庄重的全国哀悼日结束了,但抗震救灾工作还在继续,灾后重建也正紧锣密鼓地展开。生活家园的灾后重建固然重要,但重建灾民的心灵家园,却是一场爱心加耐心的长跑。在心灵家园的重建中,地震孤儿的抚养问题又是重点、难点,因为孩子的未来不等人。一场不期而遇的灾难,顷刻间摧毁了无数个充满欢笑的家庭,数千个孩子失去至爱双亲,幼小的世界从此被恐惧包围。我们该怎样安慰痛苦的孩子们,又该怎样抚平他们受伤的心灵?     

Calophyllum inophyllum: recalcitrant or intermediate seed?

We studied seed storage behaviour of a multipurpose tree Calophyllum inophyllum (Clusiaseae). Seeds were collected at Roslyn bay (23°7′60″ S, 150°43’60″ E) Central Queensland. Seed drying and desiccation tolerance tests were carried out according to International Seed Testing Association (ISTA) rules. We found C. inophyllum seeds to be recalcitrant and vulnerable to chilling injury, hence, unsuited for cold storage. C. inophyllum seeds maintained their viability for an appreciable period (> 8 months) if stored in warmer environments.     

Carbon dynamics in trees: feast or famine?

Research on the degree to which carbon (C) availability limits growth in trees, as well as recent trends in climate change and concurrent increases in drought-related tree mortality, have led to a renewed focus on the physiological mechanisms associated with tree growth responses to current and future climate. This has led to some dispute over the role of stored non-structural C compounds as indicators of a tree's current demands for photosynthate. Much of the uncertainty surrounding this issue could be resolved by developing a better understanding of the potential functions of non-structural C stored within trees. In addition to functioning as a buffer to reconcile temporal asynchrony between C demand and supply, the storage of non-structural C compounds may be under greater regulation than commonly recognized. We propose that in the face of environmental stochasticity, large, long-lived trees may require larger C investments in storage pools as safety margins than previously recognized, and that an important function of these pools may be to maintain hydraulic transport, particularly during episodes of severe stress. If so, survival and long-term growth in trees remain a function of C availability. Given that drought, freeze-thaw events and increasing tree height all impose additional constraints on vascular transport, the common trend of an increase in non-structural carbohydrate concentrations with tree size, drought or cold is consistent with our hypothesis. If the regulated maintenance of relatively large constitutive stored C pools in trees serves to maintain hydraulic integrity, then the minimum thresholds are expected to vary depending on the specific tissues, species, environment, growth form and habit. Much research is needed to elucidate the extent to which allocation of C to storage in trees is a passive vs. an active process, the specific functions of stored C pools, and the factors that drive active C allocation to storage.     

地铁“脱裤族”:低碳or作秀?

不穿裤子搭地铁活动是新年伊始的网络热门词,到底是宣扬低碳生活方式,还是抄袭西方老外的作秀噱头,索性PK一把。     

会展经济:“助推器”or“止痛片”?

随着会展经济的蓬勃发展,会展业的放大效应正在显现。与此同时,快速发展所带来的行业弊端也逐渐显露出来。业内人士表示,无论从展馆面积、展览数量来看,中国都已成为全球展览大国,但要想从会展大国走向会展强国,急需加快改革与创新,只有在规范中才能求得更大的发展。数据显示,从2006年至2012年,中国展览场地面积增长了48%,而美国和德国则分别增长5%和2%。     

地铁“脱裤族”：低碳or作秀？

1月17日，从广州二号线万胜围站开出的地铁车厢里，20多名只穿短裤，露出大腿的青年男女旁若无人地翻阅报纸或看书。此举引来很多乘客的关注。据称，这群年轻人是想借此宣传环保，提倡低碳生活。     

Whitefly endosymbionts: IPM opportunity or tilting at windmills?

Whiteflies are sap-sucking insects responsible for high economic losses. They colonize hundreds of plant species and cause direct feeding damage and indirect damage through transmission of devastating viruses. Modern agriculture has seen a history of invasive whitefly species and populations that expand to novel regions, bringing along fierce viruses. Control efforts are hindered by fast virus transmission, insecticide-resistant populations, and a wide host range which permits large natural reservoirs for whiteflies. Augmentative biocontrol by parasitoids while effective in suppressing high population densities in greenhouses falls short when it comes to preventing virus transmission and is ineffective in the open field. A potential source of much needed novel control strategies lays within a diverse community of whitefly endosymbionts. The idea to exploit endosymbionts for whitefly control is as old as identification of these bacteria, yet it still has not come to fruition. We review where our knowledge stands on the aspects of whitefly endosymbiont evolution, biology, metabolism, multitrophic interactions, and population dynamics. We show how these insights are bringing us closer to the goal of better integrated pest management strategies. Combining most up to date understanding of whitefly–endosymbiont interactions and recent technological advances, we discuss possibilities of disrupting and manipulating whitefly endosymbionts, as well as using them for pest control.

     

Even-aged or uneven-aged modelling approach? A case for Pinus brutia

Context

The past management of Pinus brutia forests in Lebanon has led to diverse stand structures that cannot be easily classified as even-aged (EA) or uneven-aged (UA). Most stands are between these stand types, and they may be called as ??semi-even-aged??. This is a very common characteristic throughout the Mediterranean conifer forests and makes the choice between the EA and UA approaches problematic, in both management and modelling. However, previous research has devoted little attention to the performance of growth and yield models when applied to transitional stand structures.

Aims

The aim of this study was to find the best modelling approach and to recommend equations for simulating the dynamics of the semi-even-aged P. brutia stands of Lebanon on an individual-tree basis.

Methods

Fifty sample plots were measured in Lebanon. Individual-tree growth models were fitted to the whole dataset using either UA or EA modelling approach. Models were also fitted using two sub-samples containing the most EA and the most UA plots. The performance and accuracy of the two modelling approaches were evaluated in all three datasets.

Results

The article provides the first complete growth model for uneven-aged P. brutia stands. The EA sub-models presented better statistical fitting. However, the UA sub-models enabled more accurate predictions of wood production and were almost as good as the EA sub-models when predicting stand dynamics of the EA plots. The EA approach provided poor predictions, and the errors were high when it was applied to UA stands.

Conclusions

In structurally complex stands, the UA modelling approach is to be preferred since it predicts the whole stand dynamics more accurately and enables simulations of a broader range of silvicultural treatments.     

Tree-induced soil compaction in forest ecosystems: myth or reality?

Trees subjected to wind loading are supposed to induce a soil deformation. However, knowledge is lacking about this phenomenon. In the present contribution, we hypothesized that soil compaction is higher in the surroundings of the lateral roots and in particular at their distal part where the amplitude of the root movements is expected to be largest. To test this hypothesis, we focused on a shallowly rooted tree, the European beech (Fagus sylvatica), in a large forest situated south of Brussels. Mean soil compaction significantly increased as one moves away from the tree, up to a distance of 5 m. Soil compaction was not evenly distributed around tree trunks, the highest values being in the north direction. Only part of these results supports the hypothesis about soil compaction due to wind-induced movements within near-surface lateral roots in beechwoods on silt loams. The need for additional research is highlighted.     

More or less moose: how is the hunting value affected?

In Sweden, management of moose is important due to considerable values as well as costs associated with this game species. An overarching question is how much moose Sweden should have. This short communication is delimited to the question of what the hunting value of moose is and what the hunting value would be given alternative levels of moose population density and allowed harvest. It is based on data from a mail contingent valuation survey that involved randomly selected hunters from a national register. The results showed that moose was the economically most important game species in Swedish hunting. The results also suggested that the hunting value would increase, but at a decreasing rate, if the moose population density and allowed harvest were increased – and vice versa. The findings should be of considerable interest in the context of adaptive moose management.     

Deliberation or symbolic violence? The governance of community forestry in Nepal

The search for effective strategies to protect forests and improve livelihoods of the people dependent on them has led to several participatory approaches to governance over the past few decades globally. However, an important factor that hinders effective governance in most situations is the prevalence of complex interplay of power and knowledge among diverse groups of actors with unequal access to deliberative interactions related to governance. This means that improving governance must meet the challenges of modifying deep rooted, complex patterns of power that affect deliberative processes. Drawing on the concepts of deliberation (following Habermas) and symbolic violence (following Bourdieu), this paper explores the possibility and challenges of deliberative governance, taking the case of community forestry in Nepal. The central question this study seeks to address is how and to what extent various actors engage (or do not engage) in deliberative processes while enacting governance practices. It shows how a national forest governance programme is enacted as a complex economy of practices by a wide array of participants and analyses how certain groups continue to dominate the decision-making practices despite the growing rhetoric of participatory governance. Symbolic violence for our purpose occurs when claims to superior knowledge are used to legitimate closure in deliberation on forest governance practices and accepted by those excluded from effective deliberation. In the field of forest governance, we identify patterns of symbolic violence that limit the possibility of deliberation: creating boundaries in social field, cultivating internalised beliefs among governance actors, and sustaining unequal access to symbolic capital. The paper following Bourdieu, stipulates crisis as a necessary condition for the development of demands for increased deliberation by subordinated participants, and then explore sociological conditions for the development of crises into the situation of symbolic violence.     

Managing city forests for or in spite of recreation? Perspectives of forest managers

This paper provides insights into foresters’ perceptions of forest recreation and its management. It is based on qualitative interviews with foresters in Berlin and the region of Stuttgart, Germany (N = 16). The results highlight the lack of strategic planning concerned with recreation management at both locations. Moreover, recreation management seems to depend mostly on the local forester in charge. Foresters’ perceptions of recreation, in turn, appear to be closely linked with how they perceive their work. Three narratives of the foresters’ self-perception are constructed that address three key items: perception of foresters’ skills and tasks, perception of the societal and political context of the foresters’ work and of their own scope of action in this context, and visions for future recreation management. The first narrative emphasises classical forestry and silvicultural aspects; the second understands foresters as multifunctional service providers for communal clients; and the last criticises the classical orientation of forestry and highlights new challenges for foresters in urban areas. These three views of recreation management in urban forests relate to classical forestry culture in different ways: either embodying this culture; differentiating from it; or adopting a new view which challenges this culture. Further research needs are discussed. The paper lastly argues for increased awareness of the importance of the social dimensions of forest management as one of the crucial future challenges for the forestry profession.     

Regulation of research: is it a drug trial or a supplement trial?

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.     

Thriving or Surviving? Forester Responses to Private Forestland Parcelization in New York State

Consulting forester business practices are challenged by significant decreases in the sizes of private forest properties and the changes in landowner values that accompany forestland parcelization. Though researchers have discussed the potential ways entrepreneurial foresters could adapt to these new ownership patterns and landscape dynamics, actual responses by foresters working in parcelizing landscapes are largely undocumented. We conducted twenty in-depth interviews with foresters working in New York State to determine (1) how foresters have experienced parcelization of properties they work with, (2) what challenges are associated with forestry projects on decreasing property sizes, and (3) what kinds of changes foresters are making to adapt to decreasing property sizes. We found that foresters across the state observe decreasing sizes of forest properties and see values of forest owners shifting beyond timber production, although most do not consider these changes to be the most urgent challenges to sustainable forestry and profitable forest consulting. Professional foresters are reacting to parcelization in diverse ways; while some are trying entrepreneurial approaches to reach new clients or offer different services, others are primarily interested in maintaining their traditional practices and roles. These findings indicate that strictly relying on independent entrepreneurial responses by private foresters may not be sufficient to close the gap between the historical role of consulting foresters and the trajectory of modern forest parcels. Additional measures like specialized training and policy changes may also be required to address the management challenges associated with forestland parcelization.