Prediction of knot size in uneven-sized Norway spruce stands in Sweden

The size of knots is negatively correlated with bending strength in sawn timber and it is therefore used as a quality grading criterion in national roundwood grading standards. Some standards even use the size of the largest knot as the sole estimate for individual log knottiness. The size of knots is determined by crown horizontal extension, which in turn is dependent on the impact of competing trees. Thus, with knot size models that are competition-dependent, roundwood quality due to knottiness can be simulated for different management alternatives. However, these types of models, calibrated on uneven-sized Norway spruce in Fennoscandia, are currently not available. Therefore, the objective of this study is to develop a competition-dependent model framework for prediction of the largest knot size per stem height section, for application within uneven-sized Norway spruce stands. Data from terrestrial laser scanning of an uneven-sized stand in southern Sweden are used to calibrate a modular prediction framework, consisting of interlinked allometric statistical models. Alternative framework sub-models are presented and the preferred model combination can be selected according to context and available input data. The flexible modular format enables further development of separate sub-components for adaptation to growing conditions not covered by the current calibration range

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society

Constraints on the cosmic expansion history from GWTC–3

We use 47 gravitational wave sources from the Third LIGO–Virgo–Kamioka Gravitational Wave Detector Gravitational Wave Transient Catalog (GWTC–3) to estimate the Hubble parameter H(z), including its current value, the Hubble constant H0. Each gravitational wave (GW) signal provides the luminosity distance to the source, and we estimate the corresponding redshift using two methods: the redshifted masses and a galaxy catalog. Using the binary black hole (BBH) redshifted masses, we simultaneously infer the source mass distribution and H(z). The source mass distribution displays a peak around 34 M⊙, followed by a drop-off. Assuming this mass scale does not evolve with the redshift results in a H(z) measurement, yielding ${H}_{0}={68}_{-8}^{+12}\,\mathrm{km}\ \,\ {{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ (68% credible interval) when combined with the H0 measurement from GW170817 and its electromagnetic counterpart. This represents an improvement of 17% with respect to the H0 estimate from GWTC–1. The second method associates each GW event with its probable host galaxy in the catalog GLADE+, statistically marginalizing over the redshifts of each event's potential hosts. Assuming a fixed BBH population, we estimate a value of ${H}_{0}={68}_{-6}^{+8}\,\mathrm{km}\ \,\ {{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ with the galaxy catalog method, an improvement of 42% with respect to our GWTC–1 result and 20% with respect to recent H0 studies using GWTC–2 events. However, we show that this result is strongly impacted by assumptions about the BBH source mass distribution; the only event which is not strongly impacted by such assumptions (and is thus informative about H0) is the well-localized event GW190814

Promoting seedling physiological performance and early establishment in degraded Mediterranean-type ecosystems

Mediterranean climate ecosystems (MCEs) are amongst the most heavily degraded ecosystems worldwide. Restoration efforts are challenged by high vulnerability to extreme drought, which is projected to become more frequent with future climate change. The aim of our study was to determine whether restoration efforts could be enhanced through the individual and combined effects of the site preparation technique of soil ripping and the addition of fertilisers. We tested the effects of ripping and fertiliser (±surfactant) on survival, shoot height, crown health, root biomass and leaf physiology of Eucalyptus gomphocephala seedlings in degraded MCEs in Western Australia. Restoration treatments had a much stronger impact under closed canopy (forest) compared to open canopy (woodland) conditions. In the forest, soil ripping doubled seedling survival and together with fertiliser application enhanced shoot height 2.35-fold relative to control seedlings. Ripping resulted in more favourable leaf water potentials and enhanced stomatal conductance suggesting increased water availability compared to unripped soil. In the woodland, fertilisation improved seedling survival and stimulated shoot height (+45 %) and root biomass (>2-fold). Our results demonstrate that restoration techniques targeting the co-limitation by water and nutrients can greatly increase chances of successful restoration in these types of ecosystems

Global biogeography and invasion risk of the plant pathogen genus Phytophthora

A global database of the pathogen genus Phytophthora, comprising ca. 12,500 disease reports over 142 years, was collated to benchmark and examine the genus-wide distribution and invasiveness. Rarefaction was used to estimate global Phytophthora species richness. We applied a framework, leveraging geographically and economically biased pathogen data against environmental and socioeconomic metrics to model their distribution. Hierarchical clustering of host and country range allowed characterisation of invasion potential. Phytophthora descriptions rose to 86 by the year 2000, surging to over 180 species to date driven primarily by novel molecular techniques, resulting in a species richness estimate of 326 (95% CI: 274–378). Countries with diverse ecosystems and entrenched agricultural and forestry industries supported by intensive research programmes reported the highest diversity. Constructing principal components from enviro-socioeconomic factors highlighted national data deficits, showing that two-thirds of trading nations have reported lower-than-predicted species numbers. Phytophthora species clustered into two main invasiveness groups as either cosmopolitan generalists or specialists, historically tied to agriculture. Further spread and detection of Phytophthora pathogens are inevitable with increasing global trade, especially in developing and emerging economies. Adoption of best practice diagnostics and enhanced resource and data sharing are crucial for coordinated global pathogen surveillance and biosecurity. This research aimed to test the following hypotheses: • The global distribution of Phytophthora species is associated with environmental, social and economic traits of different country’s. • Models for Phytophthora diversity, incorporating environmental, social and economic characteristics, can be used to predict a countries trade risk. • Phytophthora species biogeography and host range can be used to predict invasiveness and a country’s conduciveness to infection

Discovery and characterization of alamandine, a novel component of the renin-angiotensin system

Rationale: The renin-angiotensin system (RAS) is a key regulator of the cardiovascular system, electrolyte and water balance. Here we report identification and characterization of alamandine, a new heptapeptide generated by catalytic action of ACE2 angiotensin A, or directly from angiotensin-(1-7). Objective: To characterize a novel component of the RAS, alamandine. Methods and Results: Using Mass Spectrometry we observed that alamandine circulates in human blood and can be formed from angiotensin-(1-7) in the heart. Alamandine produces several physiological actions that resemble those produced by angiotensin-(1-7), including vasodilation, anti-fibrosis, anti-hypertensive and central effects. Interestingly, our data reveals that its actions are independent of the known vasodilator receptors of the RAS, Mas and AT2. Rather, we demonstrate that alamandine acts through the Mas-related G-Protein coupled receptor, MrgD. Binding of alamandine to MrgD is blocked by D-Pro7-Ang-(1-7), the MrgD ligand beta-alanine and PD-123319, but not by the Mas antagonist A-779. In addition, oral administration of an inclusion compound of alamandine/beta-hydroxypropyl cyclodextrin produced a long-lasting anti-hypertensive effect in spontaneously hypertensive rats and anti-fibrotic effects in isoproterenol-treated rats. Alamandine had no noticeable proliferative or anti-proliferative effect in human tumoral cell lines. Conclusions: The identification of these two novel components of the RAS, alamandine and its receptor, provides new insights for the understanding of the physiological and pathophysiological role of the RAS, and may help to develop new therapeutic strategies for treating human cardiovascular diseases and other related disorders