Proactive or Reactive? Optimal Management of an Invasive Forest Pest in a Spatial Framework

This paper offers a preliminary investigation into the conditions under which it might be optimal to engage in proactive management of a non-timber forest resource in the presence of an invasive species whose spread is unaffected by management action. Proactive management is defined as treating an uninfected area in order to encourage healthy ecosystem function, given that the arrival of the invasive is inevitable. Inspired by the problem of white pine blister rust in the Rocky Mountain west, the model was solved under varying assumptions concerning the scale of management action, benefit and costs, the discount rate, and uncertainty of spread. Results showed that proactive strategies tended to be optimal when, ceteris paribus, a) more resources are available for treatment; b) the costs of treatment are rapidly increasing in forest health, or conversely, the benefits of healthy and unhealthy stands are relatively similar; and c) the discount rate is low. The introduction of uncertainty did not significantly affect the likelihood of a proactive management strategy being optimal, but did show that the conditional probabilities of infection play important role in the decision of which uninfected stand should be treated if a choice is available to the manager.Crop Production/Industries, Resource /Energy Economics and Policy,

Simvastatin add-on to escitalopram in patients with comorbid obesity and major depression (SIMCODE): study protocol of a multicentre, randomised, double-blind, placebo-controlled trial

Introduction: Major depressive disorder (MDD) and obesity are both common disorders associated with significant burden of disease worldwide. Importantly, MDD and obesity often co-occur, with each disorder increasing the risk for developing the other by about 50%-60%. Statins are among the most prescribed medications with well-established safety and efficacy. Statins are recommended in primary prevention of cardiovascular disease, which has been linked to both MDD and obesity. Moreover, statins are promising candidates to treat MDD because a meta-analysis of pilot randomised controlled trials has found antidepressive effects of statins as adjunct therapy to antidepressants. However, no study so far has tested the antidepressive potential of statins in patients with MDD and comorbid obesity. Importantly, this is a difficult-to-treat population that often exhibits a chronic course of MDD and is more likely to be treatment resistant. Thus, in this confirmatory randomised controlled trial, we will determine whether add-on simvastatin to standard antidepressant medication with escitalopram is more efficacious than add-on placebo over 12 weeks in 160 patients with MDD and comorbid obesity. Methods and analysis: This is a protocol for a randomised, placebo-controlled, double-blind multicentre trial with parallel-group design (phase II). One hundred and sixty patients with MDD and comorbid obesity will be randomised 1:1 to simvastatin or placebo as add-on to standard antidepressant medication with escitalopram. The primary outcome is change in the Montgomery-angstrom sberg Depression Rating Scale (MADRS) score from baseline to week 12. Secondary outcomes include MADRS response (defined as 50% MADRS score reduction from baseline), MADRS remission (defined as MADRS score <10), mean change in patients' self-reported Beck Depression Inventory (BDI-II) and mean change in high-density lipoprotein, low-density lipoprotein and total cholesterol from baseline to week 12. Ethics and dissemination: This protocol has been approved by the ethics committee of the federal state of Berlin (Ethik-Kommission des Landes Berlin, reference: 19/0226-EK 11) and by the relevant federal authority (Bundesinstitut fur Arzneimittel und Medizinprodukte (BfArM), reference: 4043387). Study findings will be published in peer-reviewed journals and will be presented at (inter)national conferences

Neutrophil depletion reduces edema formation and tissue loss following traumatic brain injury in mice

Background: Brain edema as a result of secondary injury following traumatic brain injury (TBI) is a major clinical concern. Neutrophils are known to cause increased vascular permeability leading to edema formation in peripheral tissue, but their role in the pathology following TBI remains unclear. Methods: In this study we used controlled cortical impact (CCI) as a model for TBI and investigated the role of neutrophils in the response to injury. The outcome of mice that were depleted of neutrophils using an anti-Gr-1 antibody was compared to that in mice with intact neutrophil count. The effect of neutrophil depletion on blood-brain barrier function was assessed by Evan's blue dye extravasation, and analysis of brain water content was used as a measurement of brain edema formation (24 and 48 hours after CCI). Lesion volume was measured 7 and 14 days after CCI. Immunohistochemistry was used to assess cell death, using a marker for cleaved caspase-3 at 24 hours after injury, and microglial/macrophage activation 7 days after CCI. Data were analyzed using Mann-Whitney test for non-parametric data. Results: Neutrophil depletion did not significantly affect Evan's blue extravasation at any time-point after CCI. However, neutrophil-depleted mice exhibited a decreased water content both at 24 and 48 hours after CCI indicating reduced edema formation. Furthermore, brain tissue loss was attenuated in neutropenic mice at 7 and 14 days after injury. Additionally, these mice had a significantly reduced number of activated microglia/macrophages 7 days after CCI, and of cleaved caspase-3 positive cells 24 h after injury. Conclusion: Our results suggest that neutrophils are involved in the edema formation, but not the extravasation of large proteins, as well as contributing to cell death and tissue loss following TBI in mice

Is Resistance to Mountain Pine Beetle Associated with Genetic Resistance to White Pine Blister Rust in Limber Pine?

Limber pine (Pinus flexilis James) co-evolved with the mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB) and is now also challenged by the non-native pathogen Cronartium ribicola (J.C. Fisch.) that causes the lethal disease white pine blister rust (WPBR). Previous research suggests that trees infected with WPBR can be preferred hosts for MPB. Using resin duct traits associated with MPB resistance, we tested for a relationship between resistance to MPB and WPBR in limber pine, in the absence of either biological agent. These analyses will help evaluate if MPB historically may have contributed to natural selection for WPBR resistance in advance of WPBR invasion, and could help explain the unusually high frequency of the dominant Cr4 allele for complete resistance to WPBR in limber pine populations of the Southern Rocky Mountains. Resin duct production, density and relative duct area did not differ between healthy trees previously inferred to carry the dominant Cr4 allele and trees that lack it at 22 sites, though some duct traits varied with elevation. MPB resistance does not appear to have played an evolutionary role in contributing to the high frequency of Cr4 in na&iuml;ve populations, however, MPB may affect the future evolution of resistance to WPBR in the pines where the two pests coincide and WPBR will affect forest recovery after MPB epidemics. MPB-WPBR interactions in a changing climate will affect the future trajectory of limber pine

Fire and High-Elevation, Five-Needle Pine (Pinus aristata & P. flexilis) Ecosystems in the Southern Rocky Mountains: What Do We Know?

Rocky Mountain bristlecone pine (Pinus aristata Engelm) and limber pine (P. flexilis James) are high-elevation, five- needle pines of the southern Rocky Mountains. The pre-settlement role of fire in bristlecone and limber pine forests remains the sub- ject of considerable uncertainty; both species likely experienced a wide range of fire regimes across gradients of site productivity and connectivity of fuels and flammable landscapes. In dense stands and more continuous forests, stand history reconstructions provide evidence for infrequent, high-severity fires. Limber pine can be dispersed long distances by Clark’s nutcrackers (Nucifraga colum- biana), and in the high-elevation subalpine forests of the northern Colorado Front Range, it is an early colonist of extensive, high- severity burns. However, this relationship with fire may not be general to the southern Rockies. The degree to which high-severity fire was typical of bristlecone pine, and the spatial extent of such fires, is uncertain. Following fire, bristlecone pine regeneration tends to be constrained to burn edges or beneath surviving trees. In both five-needle pines, regeneration dynamics take decades to centuries. Where open stands border grassy openings both species frequently exhibit fire scars indicative of fairly frequent but low- intensity fire; because of the great ages attained by both species, they offer potentially very long fire history reconstructions in such settings. Whether or not fire suppression has led to declines in either species—through successional shifts to shade-tolerant com- petitors or by shifts to a stand replacing fire-regime—remains an open question that deserves further inquiry. In any case, re-estab- lishing pre-settlement fire regimes, whatever they were, may not be as important as determining appropriate disturbance regimes given current conditions and management objectives. Both species are highly susceptible to rapid declines caused by white pine blister rust (Cronartium ribicola) and mountain pine beetles (Dendroctonus ponderosae). In the face of these threats, and uncertain consequences of climate change, fire management (both prevention and applica- tion) can be a tool to promote resilient landscapes. Appropriate fire management may be used to conserve valuable stands, pro- mote regeneration and diversify age class structures, and/or alter the balance between these species and their competitors. Many of these themes and questions indicate the need for further basic and applied research

Carbon Costs of Constitutive and Expressed Resistance to a Non-Native Pathogen in Limber Pine - Fig 2

<p><b>Mean (A) total heights, (B) annual growth increments and (C) relative growth rates of Uninoculated and Inoculation Survivor bulk lots of limber pine following inoculation with <i>C</i>. <i>ribicola</i> in September, 2009.</b> Relative growth rate was calculated as the ln of plant height at the end of one year minus the ln of the plant’s height at the end of the previous year. Statistically significant differences are denoted as follows: *: P < 0.05, **: P < 0.01; ***: P < 0.001.</p

Leaf life span and the mobility of "non-mobile" mineral nutrients : the case of boron in conifers

mineral nutrients – the case of boron in conifers. Silva Fennica 36(3): 671–680. Nutrient conservation is considered important for the adaptation of plants to infertile environments. The importance of leaf life spans in controlling mean residence time of nutrients in plants has usually been analyzed in relation to nutrients that can be retranslocated within the plant. Longer leaf life spans increase the mean residence time of all mineral nutrients, but for non-mobile nutrients long leaf life spans concurrently cause concentrations in tissues to increase with leaf age, and consequently may reduce non-mobile nutrient use effi ciency. Here we analyze how the role of leaf life span is related to the mobility of nutrients within the plant. We use optimality concepts to derive testable hypotheses, and preliminar-ily test them for boron (B), a nutrient for which mobility varies among plant species. We review published and unpublished data and use a simple model to assess the quantitative importance of B retranslocation for the B budget of mature conifer forests and as a mechanism for avoiding toxicity