Foliar and soil nutrient relationships in red oak and white pine forests

Red oak (Quercus rubra L.) and white pine (Pinus strobus L.) forests on sandy soils of the northeastern U.S. may have been depleted of nutrient cations by acid precipitation and intensive land use. Foliar Ca in oak was 5257 mg Ca kg\sp{-1} matter, or over 3 times the amount of Ca in white pine foliage. Red oak also has more Mg, K, and N than white pine. Foliar Al concentration for white pine, 132 mg Al kg\sp{-1} dry matter, is twice that of red oak foliage. Foliar Ca and N are correlated with basal area increment. Foliar Ca:Al ratios and Mg levels in pine foliage suggest a risk to tree health. In the organic horizons of both oak and pine forests, bases occupied 80% of the exchange sites. However, in the mineral horizons, Al occupied 96% of the exchange sites. These data indicate that both forest types are susceptible to nutrient imbalances and deficiencies that result from atmospheric deposition and harvest. A microwave oven was used to digest standard reference materials for foliage and organic and mineral soils. We achieved recovery rates for total Al, Ca, Fe, K, Mg, Mn, and P from mineral soils of 87% to 114% with CV\u27s of less than 10%. Recovery rates greater than 90% were achieved for Ca, K, Mg, Mn, and P for Pine foliage. Total nitrogen recovery was 99.3% (CV 9.2%) for B horizon soils. Hyperspectral analysis techniques have proven useful for determining cellulose, lignin, and nitrogen in foliar material. These same techniques may be able to predict other foliar element concentrations thereby reducing the need for acid digestion of foliar material. Near infrared reflectance spectroscopy (NIRS) was evaluated for its effectiveness at predicting Al, Ca, Fe, K, Mg, Mn and P concentrations in white pine (Pinus strobus L.) and red oak (Quercus rubra L.) foliage. A near infrared spectrophotometer was used to scan dried, ground foliage samples. Predictions were satisfactory for Al, Ca, K, and Mg, producing CVs ranging from 14 (Mg) to 28% (Al) and explained variance ranging from 78% for Mg to 97% for Ca

DIRECT ESTIMATION OF ABOVEGROUND FOREST PRODUCTIVITY THROUGH HYPERSPECTRAL REMOTE SENSING OF CANOPY NITROGEN

The concentration of nitrogen in foliage has been related to rates of net photosynthesis across a wide range of plant species and functional groups and thus represents a simple and biologically meaningful link between terrestrial cycles of carbon and nitrogen. Although foliar N is used by ecosystem models to predict rates of leaf‐level photosynthesis, it has rarely been examined as a direct scalar to stand‐level carbon gain. Establishment of such relationships would greatly simplify the nature of forest C and N linkages, enhancing our ability to derive estimates of forest productivity at landscape to regional scales. Here, we report on a highly predictive relationship between whole‐canopy nitrogen concentration and aboveground forest productivity in diverse forested stands of varying age and species composition across the 360 000‐ha White Mountain National Forest, New Hampshire, USA. We also demonstrate that hyperspectral remote sensing can be used to estimate foliar N concentration, and hence forest production across a large number of contiguous images. Together these data suggest that canopy‐level N concentration is an important correlate of productivity in these forested systems, and that imaging spectrometry of canopy N can provide direct estimates of forest productivity across large landscapes

Ionic liquid-based strategy for predicting protein aggregation propensity and thermodynamic stability

Novel drug candidates are continuously being developed to combat the most life-threatening diseases; however, many promising protein therapeutics are dropped from the pipeline. During biological and industrial processes, protein therapeutics are exposed to various stresses such as fluctuations in temperature, solvent pH, and ionic strength. These can lead to enhanced protein aggregation propensity, one of the greatest challenges in drug development. Recently, ionic liquids (ILs), in particular, biocompatible choline chloride ([Cho]Cl)-based ILs, have been used to hinder stress-induced protein conformational changes. Herein, we develop an IL-based strategy to predict protein aggregation propensity and thermodynamic stability. We examine three key variables influencing protein misfolding: pH, ionic strength, and temperature. Using dynamic light scattering, zeta potential, and variable temperature circular dichroism measurements, we systematically evaluate the structural, thermal, and thermodynamic stability of fresh immunoglobin G4 (IgG4) antibody in water and 10, 30, and 50 wt % [Cho]Cl. Additionally, we conduct molecular dynamics simulations to examine IgG4 aggregation propensity in each system and the relative favorability of different [Cho]Cl-IgG4 packing interactions. We re-evaluate each system following 365 days of storage at 4 °C and demonstrate how to predict the thermodynamic properties and protein aggregation propensity over extended storage, even under stress conditions. We find that increasing [Cho]Cl concentration reduced IgG4 aggregation propensity both fresh and following 365 days of storage and demonstrate the potential of using our predictive IL-based strategy and formulations to radically increase protein stability and storage

Citizen science can enhance strategies to detect and manage invasive forest pests and pathogens

Incorporating a citizen science approach into biological invasion management strategies can enhance biosecurity. Many citizen science projects exist to strengthen the management of forest pest and pathogen invasions within both pre- and post-border scenarios. Besides the value of citizen science initiatives for early detection and monitoring, they also contribute widely to raising awareness, informing decisions about eradication and containment efforts to minimize pest and pathogen spread, and even finding resistant plant material for restoration of landscapes degraded by disease. Overall, many projects actively engage citizens in the different stages of forest pest and pathogen invasions, but it is unclear how they work together across all stages of the entire biological invasion process to enhance biosecurity. Here we provide examples of citizen science projects for each stage of the biological invasion process, discuss options for developing a citizen science program to enhance biosecurity, and suggest approaches for integrating citizen science into biosecurity measures to help safeguard forest resources in the future

Direct estimation of aboveground forest productivity through hyperspectral remote sensing of canopy nitrogen

Abstract. The concentration of nitrogen in foliage has been related to rates of net photosynthesis across a wide range of plant species and functional groups and thus represents a simple and biologically meaningful link between terrestrial cycles of carbon and nitrogen. Although foliar N is used by ecosystem models to predict rates of leaf-level photosynthesis, it has rarely been examined as a direct scalar to stand-level carbon gain. Establishment of such relationships would greatly simplify the nature of forest C and N linkages, enhancing our ability to derive estimates of forest productivity at landscape to regional scales. Here, we report on a highly predictive relationship between whole-canopy nitrogen concentration and aboveground forest productivity in diverse forested stands of varying age and species composition across the 360 000-ha White Mountain National Forest, New Hampshire, USA. We also demonstrate that hyperspectral remote sensing can be used to estimate foliar N concentration, and hence forest production across a large number of contiguous images. Together these data suggest that canopy-level N concentration is an important correlate of productivity in these forested systems, and that imaging spectrometry of canopy N can provide direct estimates of forest productivity across large landscapes

On the alleged simplicity of impure proof

Roughly, a proof of a theorem, is “pure” if it draws only on what is “close” or “intrinsic” to that theorem. Mathematicians employ a variety of terms to identify pure proofs, saying that a pure proof is one that avoids what is “extrinsic,” “extraneous,” “distant,” “remote,” “alien,” or “foreign” to the problem or theorem under investigation. In the background of these attributions is the view that there is a distance measure (or a variety of such measures) between mathematical statements and proofs. Mathematicians have paid little attention to specifying such distance measures precisely because in practice certain methods of proof have seemed self- evidently impure by design: think for instance of analytic geometry and analytic number theory. By contrast, mathematicians have paid considerable attention to whether such impurities are a good thing or to be avoided, and some have claimed that they are valuable because generally impure proofs are simpler than pure proofs. This article is an investigation of this claim, formulated more precisely by proof- theoretic means. After assembling evidence from proof theory that may be thought to support this claim, we will argue that on the contrary this evidence does not support the claim

Life satisfaction and economic conditions in East and West Germany pre- and post-unification

Economic disruption in East Germany at the time of unification resulted in a noticeable drop in life satisfaction. By the late 1990s East Germany's life satisfaction had recovered to about its 1990 level, and its shortfall relative to West Germany was slightly less than that before unification. In West Germany life satisfaction was fairly constant before unification, but subsequently trended moderately downward, with Turkish life satisfaction declining noticeably relative to Germans. Changes in life satisfaction in East and West Germany both for Germans and foreigners are most closely associated with relative income variables, not absolute income

Cost-eff ectiveness of diff erent strategies to monitor adults on antiretroviral treatment: a combined analysis of three mathematical models

Background WHO’s 2013 revisions to its Consolidated Guidelines on antiretroviral drugs recommend routine viral load monitoring, rather than clinical or immunological monitoring, as the preferred monitoring approach on the basis of clinical evidence. However, HIV programmes in resource-limited settings require guidance on the most costeff ective use of resources in view of other competing priorities such as expansion of antiretroviral therapy coverage. We assessed the cost-eff ectiveness of alternative patient monitoring strategies. Methods We evaluated a range of monitoring strategies, including clinical, CD4 cell count, and viral load monitoring, alone and together, at diff erent frequencies and with diff erent criteria for switching to second-line therapies. We used three independently constructed and validated models simultaneously. We estimated costs on the basis of resource use projected in the models and associated unit costs; we quantifi ed impact as disability-adjusted life years (DALYs) averted. We compared alternatives using incremental cost-eff ectiveness analysis. Findings All models show that clinical monitoring delivers signifi cant benefi t compared with a hypothetical baseline scenario with no monitoring or switching. Regular CD4 cell count monitoring confers a benefi t over clinical monitoring alone, at an incremental cost that makes it aff ordable in more settings than viral load monitoring, which is currently more expensive. Viral load monitoring without CD4 cell count every 6–12 months provides the greatest reductions in morbidity and mortality, but incurs a high cost per DALY averted, resulting in lost opportunities to generate health gains if implemented instead of increasing antiretroviral therapy coverage or expanding antiretroviral therapy eligibility. Interpretation The priority for HIV programmes should be to expand antiretroviral therapy coverage, fi rstly at CD4 cell count lower than 350 cells per μL, and then at a CD4 cell count lower than 500 cells per μL, using lower-cost clinical or CD4 monitoring. At current costs, viral load monitoring should be considered only after high antiretroviral therapy coverage has been achieved. Point-of-care technologies and other factors reducing costs might make viral load monitoring more aff ordable in future

Understanding the Impact of Male Circumcision Interventions on the Spread of HIV in Southern Africa

BACKGROUND: Three randomised controlled trials have clearly shown that circumcision of adult men reduces the chance that they acquire HIV infection. However, the potential impact of circumcision programmes--either alone or in combination with other established approaches--is not known and no further field trials are planned. We have used a mathematical model, parameterised using existing trial findings, to understand and predict the impact of circumcision programmes at the population level. FINDINGS: Our results indicate that circumcision will lead to reductions in incidence for women and uncircumcised men, as well as those circumcised, but that even the most effective intervention is unlikely to completely stem the spread of the virus. Without additional interventions, HIV incidence could eventually be reduced by 25-35%, depending on the level of coverage achieved and whether onward transmission from circumcised men is also reduced. However, circumcision interventions can act synergistically with other types of prevention programmes, and if efforts to change behaviour are increased in parallel with the scale-up of circumcision services, then dramatic reductions in HIV incidence could be achieved. In the long-term, this could lead to reduced AIDS deaths and less need for anti-retroviral therapy. Any increases in risk behaviours following circumcision, i.e. 'risk compensation', could offset some of the potential benefit of the intervention, especially for women, but only very large increases would lead to more infections overall. CONCLUSIONS: Circumcision will not be the silver bullet to prevent HIV transmission, but interventions could help to substantially protect men and women from infection, especially in combination with other approaches