Dendritic ecological networks (DENs) are a unique form of ecological networks that exhibit a dendritic network topology (e.g. stream and cave networks or plant architecture). DENs have a dual spatial representation; as points within the network and as points in geographical space. Consequently, some analytical methods used to quantify relationships...
Gene expression profiles of the biological control strain Pseudomonas protegens Pf-5 inhabiting pea seed surfaces were revealed using a whole-genome oligonucleotide microarray. We identified genes expressed by Pf-5 under the control of two global regulators (GacA and RpoS) known to influence biological control and secondary metabolism. Transcript levels of 897...
Zinc is an important nutrient but can be lacking in some soil environments, influencing the physiology of soil-dwelling bacteria. Hence, we studied the global effect of zinc limitation on the transcriptome of the rhizosphere biocontrol strain Pseudomonas protegens Pf-5 (formerly Pseudomonas fluorescens). We observed that the expression of the putative...
Epigenetic variation is likely to contribute to the phenotypic plasticity and adaptative
capacity of plant species, and may be especially important for long-lived
organisms with complex life cycles, including forest trees. Diverse environmental
stresses and hybridization/polyploidization events can create reversible heritable
epigenetic marks that can be transmitted to subsequent generations...
Assessing the ecological importance of clouds has substantial implications for our basic understanding of ecosystems
and for predicting how they will respond to a changing climate. This study was conducted in a coastal Bishop pine
forest ecosystem that experiences regular cycles of stratus cloud cover and inundation in summer. Our...
It is critical to study factors that are important for origin and maintenance of biological
diversity. A comparative approach involving a large number of populations is
particularly useful.We use this approach to study the relationship between ecological
factors and phenotypic diversity in Icelandic Arctic charr (Salvelinus alpinus).
Numerous populations of...
Predatorprey interactions are a primary structuring force vital to the resilience of marine communities and sustainability of the worlds oceans. Human influences on marine ecosystems mediate changes in species interactions. This generality is evinced by the cascading effects of overharvesting top predators on the structure and function of marine ecosystems....
Fungal mitospores may function as dispersal units and/ or spermatia, and thus play a role in
distribution and/or mating of species that produce them. Mitospore production in
ectomycorrhizal (EcM) Pezizales is rarely reported, but here we document mitospore production
by a high diversity of EcM Pezizales on three continents, in...
Organisms eating each other are only one of many types of well documented and important interactions among species. Other such types include habitat modification, predator interference and facilitation. However, ecological network research has been typically limited to either pure food webs or to networks of only a few (<3) interaction...
We examined variability in growth rate during the larval stage of northern anchovy (Engraulis mordax) in response to physical and biological environmental factors in 2005 and 2006. The onset of spring upwelling was anomalously delayed by 2–3 months until mid-July in 2005; in contrast, spring upwelling in 2006 began as...
Eddy covariance flux research has relied on open- or closed-path gas analyzers for producing estimates of net ecosystem exchange of carbon dioxide (CO₂) and water vapor (H₂O). The two instruments have had different challenges that have led to development of an enclosed design that is intended to maximize strengths and...
Co-occurring species often have different strategies for tolerating daily cycles of water stress. One underlying parameter that can link together the suite of traits that enables a given strategy is wood density. Here we compare hydraulic traits of two pioneer species from a tropical forest in Panama that differ in...
Generalized additive models (GAMs) were used to investigate the relationships between annual recruitment of natural coho salmon (Oncorhynchus kisutch) from Oregon coastal rivers and indices of the physical ocean environment. Nine indices were examined, ranging from large-scale ocean indicators, e.g., Pacific Decadal Oscillation (PDO), to indicators of the local ecosystem...
Fisheries management based on catch shares – divisions of annual fleet-wide quotas among individuals or groups – has been strongly supported for their economic benefits, but biological consequences have not been rigorously quantified. We used a global meta-analysis of 345 stocks to assess whether fisheries under catch shares were more...
The degradation of organic carbon in subseafloor sediments on continental margins contributes to the largest reservoir of methane on Earth. Sediments in the Andaman Sea are composed of ~ 1% marine-derived organic carbon and biogenic methane is present. Our objective was to determine microbial abundance and diversity in sediments that...
The Pseudomonas aeruginosa antimetabolite L-2-amino-4-methoxy-trans-3-butenoic acid (AMB) shares biological activities with 4-formylaminooxyvinylglycine, a related molecule produced by Pseudomonas fluorescens WH6. We found that culture filtrates of a P.aeruginosa strain overproducing AMB weakly interfered with seed germination of the grassy weed Poa annua and strongly inhibited growth of Erwinia amylovora, the...
Many Gram-negative bacteria use a type III secretion system (T3SS) to establish associations with their hosts. The T3SS is a conduit for direct injection of type-III effector proteins into host cells, where they manipulate the host for the benefit of the infecting bacterium. For plant-associated pathogens, the variations in number...
Overfished species of rockfish, Sebastes spp., from the Northeast Pacific experience high bycatch mortality because of ‘barotrauma’, a condition induced from the rapid change in pressure during capture. Field experiments show that it may be possible for rockfish to recover from barotrauma if quickly recompressed; however, no work has followed...
Objective: To examine the associations between the 2008 economic collapse in Iceland and smoking behaviour at the national and individual levels.
Design: A population-based, prospective cohort study based on a mail survey (Health and Wellbeing in Iceland) assessed in 2007 and 2009.
Setting: National mail survey.
Participants: Representative cohort (n=3755)...
Resolving the debate surrounding the nature and controls of seasonal variation in the structure and metabolism of Amazonian rainforests is critical to understanding their response to climate change. In situ studies have observed higher photosynthetic and evapotranspiration rates, increased litterfall and leaf flushing during the Sunlight-rich dry season. Satellite data...
The manuscript reports on simulations of the intrinsic dissipation of standing and traveling
flexural vibrations in carbon nanotubes. It is found that extended traveling and standing waves
exhibit anomalous dissipation, during which the excited modes experience massive damping
that is triggered by the accumulation of energy in special gateway modes....
The spectrum of the interior transmission problem is related to the unique determination of the acoustic properties of a body in thermoacoustic imaging. Under a non-trapping hypothesis, we show that sparsity of the interior transmission spectrum implies a range separation condition for the thermoacoustic operator. In odd dimensions greater than...
We investigate the response of multi-layer epitaxial graphene and chemical vapor deposition (CVD)-grown single-layer graphene to strong terahertz (THz) fields. Contrary to theoretical predictions of strong nonlinear response, the transmitted fields exhibit no harmonic generation, indicating that the nonlinear response is limited by fast electron thermalization due to carrier-carrier scattering....
Context: Retrospective exposure assessment in population-based case-control studies poses a major challenge
due to the wide range of occupations and industries involved. The FINJEM is a generic job-exposure
matrix developed in Finland which represents a potentially cost effective exposure assessment tool.
While FINJEM has been used in several studies outside...
Accurate quantification of terrestrial carbon storage and its change is of key importance to improved understanding of global carbon dynamics. Forest management influences carbon sequestration and release patterns, and gap models are well suited for evaluating carbon storage. An individual-based gap model of forest dynamics, FAREAST, is applied across Russia...
Ocean acidification results in co-varying inorganic carbon system variables. Of these, an explicit focus on pH and organismal acid-base regulation in has failed to distinguish the mechanism of failure in highly sensitive bivalve larvae. With unique chemical manipulations of seawater we show definitively that larval bivalve shell development and growth...
The study of time-dependent, many-body transport phenomena is increasingly within reach of ultra-cold atom experiments. We show that the introduction of spatially inhomogeneous interactions, e.g., generated by optically controlled collisions, induce negative differential conductance in the transport of atoms in one-dimensional optical lattices. Specifically, we simulate the dynamics of interacting...
A state selected at random from the Hilbert space of a many-body system is overwhelmingly likely to exhibit highly non-classical correlations. For these typical states, half of the environment must be measured by an observer to determine the state of a given subsystem. The objectivity of classical reality—the fact that...
A state selected at random from the Hilbert space of a many-body system is overwhelmingly likely to exhibit highly non-classical correlations. For these typical states, half of the environment must be measured by an observer to determine the state of a given subsystem. The objectivity of classical reality—the fact that...