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Humans rely on healthy forests to supply energy, building materials, and food and to provide services such as storing carbon, hosting biodiversity, and regulating climate. Defining forest health integrates utilitarian and ecosystem measures of forest condition and function, implemented across a range of spatial scales. Although native forests are adapted to some level of disturbance, all forests now face novel stresses in the form of climate change, air pollution, and invasive pests. Detecting how intensification of these stresses will affect the trajectory of forests is a major scientific challenge that requires developing systems to assess the health of global forests. It is particularly critical to identify thresholds for rapid forest decline, because it can take many decades for forests to restore the services that they provide.

The valence and salience of individual odorants are modulated by an animal’s innate preferences, learned associations, and internal state, as well as by the context of odorant presentation. The mechanisms underlying context-dependent flexibility in odor valence are not fully understood. Here, we show that the behavioral response of Caenorhabditis elegans to bacterially produced medium-chain alcohols switches from attraction to avoidance when presented in the background of a subset of additional attractive chemicals. This context-dependent reversal of odorant preference is driven by cell-autonomous inversion of the response to these alcohols in the single AWC olfactory neuron pair. We find that while medium-chain alcohols inhibit the AWC olfactory neurons to drive attraction, these alcohols instead activate AWC to promote avoidance when presented in the background of a second AWC-sensed odorant. We show that these opposing responses are driven via engagement of distinct odorant-directed signal transduction pathways within AWC. Our results indicate that context-dependent recruitment of alternative intracellular signaling pathways within a single sensory neuron type conveys opposite hedonic valences, thereby providing a robust mechanism for odorant encoding and discrimination at the periphery.

Different process strategies for anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) are reviewed weighing high-solids versus low-solids, mesophilic versus thermophilic and single-stage versus multi-stage processes. The influence of different waste characteristics such as composition of biodegradable fractions, C:N ratio and particle size is described. Generally, source sorting of OFMSW and a high content of food waste leads to higher biogas yields than the use of mechanically sorted OFMSW. Thermophilic processes are more efficient than mesophilic processes in terms of higher biogas yields at different organic loading rates (OLR). Highest biogas yields are achieved by means of wet thermophilic processes at OLRs lower than 6 kg-VS·m−3 d−1. High-solids processes appear to be relatively more efficient when OLRs higher than 6 kg-VS·m−3 d−1 are applied. Multi-stage systems show in some investigations a higher reduction of recalcitrant organic matter compared to single-stage systems, but they are seldom applied in full-scale. An extended cost-benefit calculation shows that the highest overall benefit of the process is achieved at an OLR that is lower and a hydraulic retention time (HRT) that is longer than those values of OLR and HRT, at which the highest biogas production is achieved.

Adaptation requires science that analyzes decisions, identifies vulnerabilities, improves foresight, and develops options. Informing the extensive preparations needed to manage climate risks, avoid damages, and realize emerging opportunities is a grand challenge for climate change science. U.S. President Obama underscored the need for this research when he made climate preparedness a pillar of his climate policy. Adaptation improves preparedness and is one of two broad and increasingly important strategies (along with mitigation) for climate risk management. Adaptation is required in virtually all sectors of the economy and regions of the globe, for both built and natural systems ( 1 ).

Carbohydrates provide the building blocks for plant structures as well as versatile resources for metabolic processes. The nonstructural carbohydrates (NSC), mainly sugars and starch, fulfil distinct functional roles, including transport, energy metabolism and osmoregulation, and provide substrates for the synthesis of defence compounds or exchange with symbionts involved in nutrient acquisition or defence. At the whole-plant level, NSC storage buffers the asynchrony of supply and demand on diel, seasonal or decadal temporal scales and across plant organs. Despite its central role in plant function and in stand-level carbon cycling, our understanding of storage dynamics, its controls and response to environmental stresses is very limited, even after a century of research. This reflects the fact that often storage is defined by what we can measure, that is, NSC concentrations, and the interpretation of these as a proxy for a single function, storage, rather than the outcome of a range of NSC source and sink functions. New isotopic tools allow direct quantification of timescales involved in NSC dynamics, and show that NSC-C fixed years to decades previously is used to support tree functions. Here we review recent advances, with emphasis on the context of the interactions between NSC, drought and tree mortality.

Measured profiles, which are crucial to treatment planning system commissioning, are generally affected by averaging effect linked to the size of sensitive volume of detectors used. Such averaging leads to deviation from the true profiles in water even when small field detectors are employed. In order to have access to profile data which are free from the influence of the measuring device, a guidance is required, on when and how much correction is required for a detector in use. Profile correction factors were determined as the ratio between true profiles in water and associated measured profiles, both as a function of off-axis distance. The identical free air profile is used to simulate measurement and to generate ‘measured’ profiles at different depths in water. The MC generated profiles in water without the detector were taken as true profiles. Based on such MC generated profile results, detector specific correction factors were determined. Additionally, such factors were approximated by an analytical function using a fit procedure for the function parameters. Optimized parameters were systematically compiled depending on measuring conditions such as beam size, depths in water for detectors-pinpoint, pinpoint 3D, microSilicon and microDiamond. The method to generate a common dataset of true profiles in water was successful. Also, measured and simulated profiles well agree for all measuring conditions. In addition, correction factors, as well as approximated correction functions were derived. Application of analytical correction functions to measured profiles for given conditions, well reproduced true profiles with the detector being absent. The MC method to derive correction factors for profile measurements is feasible for all detectors used in this study. Such correction factors can be well approximated by a simple analytical function. It is recommended that ionization chamber measured profiles generally need correction while solid state detectors measured profiles fairly approach the true profiles in water.

In the fungal phylum Ascomycota, the ability to cause disease in plants and animals has been gained and lost repeatedly during phylogenesis 1 . In monocotyledonous barley, loss-of-function mlo alleles result in effective immunity against the Ascomycete Blumeria graminis f. sp. hordei , the causal agent of powdery mildew disease 2 , 3 . However, mlo -based disease resistance has been considered a barley-specific phenomenon to date. Here, we demonstrate a conserved requirement for MLO proteins in powdery mildew pathogenesis in the dicotyledonous plant species Arabidopsis thaliana . Epistasis analysis showed that mlo resistance in A. thaliana does not involve the signaling molecules ethylene, jasmonic acid or salicylic acid, but requires a syntaxin, glycosyl hydrolase and ABC transporter 4 , 5 , 6 . These findings imply that a common host cell entry mechanism of powdery mildew fungi evolved once and at least 200 million years ago, suggesting that within the Erysiphales (powdery mildews) the ability to cause disease has been a stable trait throughout phylogenesis.

Homologues of barley Mlo encode the only family of seven-transmembrane (TM) proteins in plants. Their topology, subcellular localization, and sequence diversification are reminiscent of those of G-protein coupled receptors (GPCRs) from animals and fungi. We present a computational analysis of MLO family members based on 31 full-size and 3 partial sequences, which originate from several monocot species, the dicot Arabidopsis thaliana, and the moss Ceratodon purpureus. This enabled us to date the origin of the Mlo gene family back at least to the early stages of land plant evolution. The genomic organization of the corresponding genes supports a monophyletic origin of the Mlo gene family. Phylogenetic analysis revealed five clades, of which three contain both monocot and dicot members, while two indicate class-specific diversification. Analysis of the ratio of nonsynonymous-to-synonymous changes in coding sequences provided evidence for functional constraint on the evolution of the DNA sequences and purifying selection, which appears to be reduced in the first extracellular loop of 12 closely related orthologues. The 31 full-size sequences were examined for potential domain-specific intramolecular coevolution. This revealed evidence for concerted evolution of all three cytoplasmic domains with each other and the C-terminal cytoplasmic tail, suggesting interplay of all intracellular domains for MLO function.

The Arabidopsis (Arabidopsis thaliana) genome contains 15 genes encoding protein homologs of the barley mildew resistance locus o (MLO) protein biochemically shown to have a seven-transmembrane domain topology and localize to the plasma membrane. Towards elucidating the functions of MLOs, the largest family of seven-transmembrane domain proteins specific to plants, we comprehensively determined AtMLO gene expression patterns by a combination of experimental and in silico studies. Experimentation comprised analyses of transgenic Arabidopsis lines bearing promoter::Beta-glucuronidase (GUS) transcriptional fusions as well as semi-quantitative determination of transcripts by reverse transcription coupled to polymerase chain reaction (RT-PCR). These results were combined with information extracted from public gene profiling databases, and compared to the expression patterns of genes encoding the heterotrimeric G-protein subunits. We found that each AtMLO gene has a unique expression pattern and is regulated differently by a variety of biotic and/or abiotic stimuli, suggesting that AtMLO proteins function in diverse developmental and response processes. The expression of several phylogenetically closely-related AtMLO genes showed similar or overlapping tissue specificity and analogous responsiveness to external stimuli, suggesting functional redundancy, co-function, or antagonistic function(s).

With the first direct detection of merging black holes in 2015, the era of gravitational wave (GW) astrophysics began. A complete picture of compact object mergers, however, requires the detection of an electromagnetic (EM) counterpart. We report ultraviolet (UV) and x-ray observations by Swift and the Nuclear Spectroscopic Telescope Array of the EM counter part of the binary neutron star merger GW170817. The bright, rapidly fading UV emission indicates a high mass (≈0.03 solar masses) wind-driven outflow with moderate electron fraction (Yₑ ≈ 0.27). Combined with the x-ray limits, we favor an observer viewing angle of ≈30° away from the orbital rotation axis, which avoids both obscuration fromthe heaviest elements in the orbital plane and a direct view of any ultrarelativistic, highly collimated ejecta (a γ-ray burst afterglow).