Evolutionary history determines how plant productivity responds to phylogenetic diversity and species richness

The relationship between biodiversity and ecosystem function has received a great deal of attention in ecological research and recent results, from re-analyses, suggest that ecosystem function improves with increases in phylogenetic diversity. However, many of these results have been generalized across a range of different species and clades, and plants with different evolutionary histories could display different relationships between biodiversity and ecosystem function. To experimentally test this hypothesis, we manipulated species richness and phylogenetic diversity using 26 species from two subgenera of the genus Eucalyptus (subgenus Eucalyptus and subgenus Symphyomyrtus). We found that plant biomass (a measurement of ecosystem function) sometimes, but not always, responded to increases in species richness and phylogenetic diversity. Specifically, Symphyomyrtus plants showed a positive response while no comparable effect was observed for Eucalyptus plants, showing that responses to biodiversity can vary across different phylogenetic groups. Our results show that the impacts of evolutionary history may complicate the relationship between the diversity of plant communities and plant biomass

Trait Variation Along Elevation Gradients in a Dominant Wood Shrub is Population-Specific and Driven by Plasticity

Elevation gradients are frequently used as space-for-time substitutions to infer species’ trait responses to climate change. However, studies rarely investigate whether trait responses to elevation are widespread or population specific within a species, and the relative genetic and plastic contributions to such trait responses may not be well understood. Here, we examine plant trait variation in the dominant woody shrub, Rhododendron maximum, along elevation gradients in three populations in the South Central Appalachian Mountains, USA, in both field and common garden environments. We ask the following: (1) do plant traits vary along elevation? (2) do trait responses to elevation differ across populations, and if so, why? and (3) does genetic differentiation or phenotypic plasticity drive trait variation within and among populations? We found that internode length, shoot length, leaf dry mass, and leaf area varied along elevation, but that these responses were generally unique to one population, suggesting that trait responses to environmental gradients are population-specific. A common garden experiment identified nogenetic basis to variation along elevation or among populations in any trait, suggesting that plasticity drives local and regional trait variation and may play a key role in the persistence of plant species such as R. maximum with contemporary climate change. Overall, our findings highlight the importance of examining multiple locations in future elevation studies and indicate that, for a given plant species, the magnitude of trait responses to global climate change may vary by location

Shifts in Species Interactions Due to the Evolution of Functional Differences between Endemics and Non-Endemics: An Endemic Syndrome Hypothesis

Species ranges have been shifting since the Pleistocene, whereby fragmentation, isolation, and the subsequent reduction in gene flow have resulted in local adaptation of novel genotypes and the repeated evolution of endemic species. While there is a wide body of literature focused on understanding endemic species, very few studies empirically test whether or not the evolution of endemics results in unique function or ecological differences relative to their widespread congeners; in particular while controlling for environmental variation. Using a common garden composed of 15 Eucalyptus species within the subgenus Symphyomyrtus (9 endemic to Tasmania, 6 non-endemic), here we hypothesize and show that endemic species are functionally and ecologically different from non-endemics. Compared to non-endemics, endemic Eucalyptus species have a unique suite of functional plant traits that have extended effects on herbivores. We found that while endemics occupy many diverse habitats, they share similar functional traits potentially resulting in an endemic syndrome of traits. This study provides one of the first empirical datasets analyzing the functional differences between endemics and non-endemics in a common garden setting, and establishes a foundation for additional studies of endemic/non-endemic dynamics that will be essential for understanding global biodiversity in the midst of rapid species extinctions and range shifts as a consequence of global change

Dietary predictors of visceral adiposity in overweight young adults

The purpose of the present study was to determine the dietary predictors of visceral adipose tissue (VAT) area in overweight young adults. A total of 109 young adults (fifty males and fifty-nine females) ate ad libitum in a university cafeteria for 14 d. All food and beverages consumed in the cafeteria were measured using observer-recorded weighed plate waste. Food consumption outside the cafeteria (i.e. snacks) was assessed by multiple-pass 24 h recall procedures. VAT was determined using computed tomography. Stepwise regression demonstrated that the best predictor of visceral adiposity in women was total dietary fat (P# 0–05). In men, the model for predicting visceral adiposity included Ca and total dietary fat. We concluded that total dietary fat is the best predictor of VAT area in both men and women. While this relationship was independent in women, in men there was a synergistic relationship between dietary fat consumption and Ca consumption in predicting VAT

Evolutionary History and Novel Biotic Interactions Determine Plant Responses to Elevated CO2 and Nitrogen Fertilization

A major frontier in global change research is predicting how multiple agents of global change will alter plant productivity, a critical component of the carbon cycle. Recent research has shown that plant responses to climate change are phylogenetically conserved such that species within some lineages are more productive than those within other lineages in changing environments. However, it remains unclear how phylogenetic patterns in plant responses to changing abiotic conditions may be altered by another agent of global change, the introduction of non-native species. Using a system of 28 native Tasmanian Eucalyptus species belonging to two subgenera, Symphyomyrtus and Eucalyptus, we hypothesized that productivity responses to abiotic agents of global change (elevated CO2 and increased soil N) are unique to lineages, but that novel interactions with a nonnative species mediate these responses. We tested this hypothesis by examining productivity of 1) native species monocultures and 2) mixtures of native species with an introduced hardwood plantation species, Eucalyptus nitens, to experimentally manipulated soil N and atmospheric CO2. Consistent with past research, we found that N limits productivity overall, especially in elevated CO2 conditions. However, monocultures of species within the Symphyomyrtus subgenus showed the strongest response to N (gained 127% more total biomass) in elevated CO2 conditions, whereas those within the Eucalyptus subgenus did not respond to N. Root:shoot ratio (an indicator of resource use) was on average greater in species pairs containing Symphyomyrtus species, suggesting that functional traits important for resource uptake are phylogenetically conserved and explaining the phylogenetic pattern in plant response to changing environmental conditions. Yet, native species mixtures with E. nitens exhibited responses to CO2 and N that differed from those of monocultures, supporting our hypothesis and highlighting that both plant evolutionary history and introduced species will shape community productivity in a changing world

LS Peg: A Low-Inclination SW Sextantis-Type Cataclysmic Binary with High-Velocity Balmer Emission Line Wings

We present time-resolved spectroscopy and photometry of the bright cataclysmic variable LS Peg (= S193). The Balmer lines exhibit broad, asymmetric wings Doppler-shifted by about 2000 km/s at the edges, while the HeI lines show phase-dependent absorption features strikingly similar to SW Sextantis stars, as well as emission through most of the phase. The CIII/NIII emission blend does not show any phase dependence. From velocities of Halpha emission lines, we determine an orbital period of 0.174774 +/- 0.000003 d (= 4.1946 h), which agrees with Szkody's (1995) value of approximately 4.2 hours. No stable photometric signal was found at the orbital period. A non-coherent quasi-periodic photometric signal was seen at a period of 20.7 +/- 0.3 min. The high-velocity Balmer wings most probably arise from a stream re-impact point close to the white dwarf. We present simulated spectra based on a kinematic model similar to the modified disk-overflow scenario of Hellier & Robinson (1994). The models reproduce the broad line wings, though some other details are unexplained. Using an estimate of dynamical phase based on the model, we show that the phasing of the emission- and absorption-line variations is consistent with that in (eclipsing) SW Sex stars. We therefore identify LS Peg as a low-inclination SW Sex star. Our model suggests i = 30 deg, and the observed absence of any photometric signal at the orbital frequency establishes i < 60 deg. This constraint puts a severe strain on interpretations of the SW Sex phenomenon which rely on disk structures lying slightly out of the orbital plane.Comment: 29 pages, 13 figures, to be published in PASP Feb. 199

Physical activity across the curriculum: year one process evaluation results

<p>Abstract</p> <p>Background</p> <p>Physical Activity Across the Curriculum (PAAC) is a 3-year elementary school-based intervention to determine if increased amounts of moderate intensity physical activity performed in the classroom will diminish gains in body mass index (BMI). It is a cluster-randomized, controlled trial, involving 4905 children (2505 intervention, 2400 control).</p> <p>Methods</p> <p>We collected both qualitative and quantitative process evaluation data from 24 schools (14 intervention and 10 control), which included tracking teacher training issues, challenges and barriers to effective implementation of PAAC lessons, initial and continual use of program specified activities, and potential competing factors, which might contaminate or lessen program effects.</p> <p>Results</p> <p>Overall teacher attendance at training sessions showed exceptional reach. Teachers incorporated active lessons on most days, resulting in significantly greater student physical activity levels compared to controls (p < 0.0001). Enjoyment ratings for classroom-based lessons were also higher for intervention students. Competing factors, which might influence program results, were not carried out at intervention or control schools or were judged to be minimal.</p> <p>Conclusion</p> <p>In the first year of the PAAC intervention, process evaluation results were instrumental in identifying successes and challenges faced by teachers when trying to modify existing academic lessons to incorporate physical activity.</p

Efficient Passive ICS Device Discovery and Identification by MAC Address Correlation

Owing to a growing number of attacks, the assessment of Industrial Control Systems (ICSs) has gained in importance. An integral part of an assessment is the creation of a detailed inventory of all connected devices, enabling vulnerability evaluations. For this purpose, scans of networks are crucial. Active scanning, which generates irregular traffic, is a method to get an overview of connected and active devices. Since such additional traffic may lead to an unexpected behavior of devices, active scanning methods should be avoided in critical infrastructure networks. In such cases, passive network monitoring offers an alternative, which is often used in conjunction with complex deep-packet inspection techniques. There are very few publications on lightweight passive scanning methodologies for industrial networks. In this paper, we propose a lightweight passive network monitoring technique using an efficient Media Access Control (MAC) address-based identification of industrial devices. Based on an incomplete set of known MAC address to device associations, the presented method can guess correct device and vendor information. Proving the feasibility of the method, an implementation is also introduced and evaluated regarding its efficiency. The feasibility of predicting a specific device/vendor combination is demonstrated by having similar devices in the database. In our ICS testbed, we reached a host discovery rate of 100% at an identification rate of more than 66%, outperforming the results of existing tools.Comment: http://dx.doi.org/10.14236/ewic/ICS2018.