Genetic change following fire in populations of a seed-banking perennial plant

Disturbances such as fire have the potential to remove genetic variation, but seed banks may counter this loss by restoring alleles through a reservoir effect. We used allozyme analysis to characterize genetic change in two populations of the perennial Hypericum cumulicola, an endemic of the fire-prone Florida scrub. We assessed genetic variation before and 1, 2, and 3 years after fire that killed nearly all aboveground plants. Populations increased in size following fire, with most seedlings likely recruited from a persistent seed bank. Four of five loci were variable. Most alleles were present in low frequencies, but our large sample sizes allowed detection of significant trends. Expected heterozygosity increased, and allele presence and allele frequencies showed marked shifts following fire. The post-fire seedling cohort contained new alleles to the study and one new allele to the species. Population differentiation between the two study sites did not change. Our study is the first to directly documents genetic changes following fire, a dominant ecological disturbance worldwide, and is also one of the few to consider shifts in a naturally recruiting post-disturbance seedling cohort. We demonstrate the potential of seed banks to restore genetic variation lost between disturbances. Our study demonstrates that rapid genetic change can occur with disturbance and that fire can have positive effects on the genetics of rare species

Crossover from ballistic to diffusive thermal transport in suspended graphene membranes

We report heat transport measurements on suspended single-layer graphene disks with radius of 150-1600 nm using a high-vacuum scanning thermal microscope. The results of this study revealed a radius-dependent thermal contact resistance between tip and graphene, with values between 1.15 and 1.52 × 10 KW. The observed scaling of thermal resistance with radius is interpreted in terms of ballistic phonon transport in suspended graphene discs with radius smaller than 775 nm. In larger suspended graphene discs (radius >775 nm), the thermal resistance increases with radius, which is attributed to in-plane heat transport being limited by phonon-phonon resistive scattering processes, which resulted in a transition from ballistic to diffusive thermal transport. In addition, by simultaneously mapping topography and steady-state heat flux signals between a self-heated scanning probe sensor and graphene with 17 nm thermal spatial resolution, we demonstrated that the surface quality of the suspended graphene and its connectivity with the Si/SiO substrate play a determining role in thermal transport. Our approach allows the investigation of heat transport in suspended graphene at sub-micrometre length scales and overcomes major limitations of conventional experimental methods usually caused by extrinsic thermal contact resistances, assumptions on the value of the graphene's optical absorbance and limited thermal spatial resolution

Stochastic Cooling at the ESR

Stochastic precooling at the ESR storage ring of GSI will be used mainly for experiments with stored radioactive fragment beams. They arrive from the fragment separator with momentum spreads and emittances for which electron cooling is too slow. The installation of components at the ESR is now complete and first commissioning experiments have been performed. Both longitudinal and transverse stochastic cooling have been demonstrated. The paper gives a short account of the system architecture, and of the response of quarter-wave plates and superelectrodes at intermediate energies. The preparation of fragment beams suitable for subsequent electron cooling is discussed for the case that a mixture of different ion species is present in the cooler ring. Results of commissioning and future prospects are presented

Exploring population responses to environmental change when there is never enough data: a factor analytic approach

© 2018 The Authors. Methods in Ecology and Evolution published by John Wiley & Sons Ltd on behalf of British Ecological Society Temporal variability in the environment drives variation in vital rates, with consequences for population dynamics and life-history evolution. Integral projection models (IPMs) are data-driven structured population models widely used to study population dynamics and life-history evolution in temporally variable environments. However, many datasets have insufficient temporal replication for the environmental drivers of vital rates to be identified with confidence, limiting their use for evaluating population level responses to environmental change. Parameter selection, where the kernel is constructed at each time step by randomly selecting the time-varying parameters from their joint probability distribution, is one approach to including stochasticity in IPMs. We consider a factor analytic (FA) approach for modelling the covariance matrix of time-varying parameters, whereby latent variable(s) describe the covariance among vital rate parameters. This decreases the number of parameters to estimate and, where the covariance is positive, the latent variable can be interpreted as a measure of environmental quality. We demonstrate this using simulation studies and two case studies. The simulation studies suggest the FA approach provides similarly accurate estimates of stochastic population growth rate to estimating an unstructured covariance matrix. We demonstrate how the latent parameter can be perturbed to show how selection on reproductive delays in the monocarp Carduus nutans changes under different environmental conditions. We develop a demographic model of the fire dependent herb Eryngium cuneifolium to show how a putative driver of the variation in environmental quality can be incorporated with the addition of a single parameter. Using perturbation analyses we determine optimal management strategies for this species. This approach estimates fewer parameters than previous approaches and allows novel eco-evolutionary insights. Predictions on population dynamics and life-history evolution under different environmental conditions can be made without necessarily identifying causal factors. Putative environmental drivers can be incorporated with relatively few parameters, allowing for predictions on how populations will respond to changes in the environment

Electrical and Thermal Transport at the Planckian Bound of Dissipation in the Hydrodynamic Electron Fluid of WP2

Materials with strongly-correlated electrons exhibit interesting phenomena such as metal-insulator transitions and high-temperature superconductivity. In stark contrast to ordinary metals, electron transport in these materials is thought to resemble the flow of viscous fluids. Despite their differences, it is predicted that transport in both, conventional and correlated materials, is fundamentally limited by the uncertainty principle applied to energy dissipation. Here we discover hydrodynamic electron flow in the Weyl-semimetal tungsten phosphide (WP2). Using thermal and magneto-electric transport experiments, we observe the transition from a conventional metallic state, at higher temperatures, to a hydrodynamic electron fluid below 20 K. The hydrodynamic regime is characterized by a viscosity-induced dependence of the electrical resistivity on the square of the channel width, and by the observation of a strong violation of the Wiedemann-Franz law. From magneto-hydrodynamic experiments and complementary Hall measurements, the relaxation times for momentum and thermal energy dissipating processes are extracted. Following the uncertainty principle, both are limited by the Planckian bound of dissipation, independent of the underlying transport regime

Outcomes in studies regarding older patients with prostate cancer: A systematic review

INTRODUCTION: Older patients are often deemed ineligible for clinical research, and many frequently-used endpoints and outcome measures are not as relevant for older patients for younger ones. This systematic review aimed to present an overview of outcomes used in clinical research regarding patients over the age of 65 years with prostate cancer. MATERIALS AND METHODS: PubMed and Embase were systematically searched to identify studies on prostate cancer (treatment) in patients aged ≥65 between 2016 and 2023. Data on title, study design, number of participants and age, stage of disease, treatment, and investigated outcomes were synthesized and descriptively analyzed. RESULTS: Sixty-eight studies were included. Of these most included patients over 65 years, while others used a higher age. Overall, 39 articles (57.3%) reported on survival-related outcomes, 22 (32.4%) reported on progression of disease and 38 (55.9%) used toxicity or adverse events as an outcome measure. Health-related quality of life and functional outcomes were investigated in 29.4%, and cognition in two studies. The most frequently investigated survival-related outcomes were overall and cancer-specific survival (51.3%); however, 38.5% only studied overall survival. DISCUSSION: The main focus of studies included in this review remains survival and disease progression. There is limited attention for health-related quality of life and functional status, although older patients often prioritize the latter. Future research should incorporate outcome measures tailored to the aged population to improve care for older patients with prostate cancer

Lightweight conical components for rotational parabolic domes: geometric definition, structural behaviour, optimisation and digital fabrication

Although initially intended for academic purposes, the research shown in this paper was drawn towards the development of hollow lightweight conical com-ponents to materialise rotational parabolic domes. The starting point is a projec-tive interpretation of an Archimedean property of rotational paraboloid planar sections. This is used to discretise the parabolic surface with a set of tangent ellipses obtained via planar circle-packing algorithms. The ellipses are then mate-rialised with components composed of three truncated conical surfaces, which may be composed of several laminar materials. The geometry and economy of the material, the good structural behaviour, the simple solution for fabrication and assembly, and the tests on a full-scale prototype prove this component to be an efficient self-supporting system for wide-span structures against the use of solid boundary rings, not only for rotational parabolic domes, but also for a possible translation to other types of surface

Responsibility and appropriate blame: The no difference view

How do the fact that an agent is morally responsible for a certain morally objectionable action and the fact that she is an appropriate target of blame for it relate to each other? Many authors inspired by Peter Strawson say that they necessarily co‐occur. Standard answers to the question of why they co‐occur say that the occurrence of one of the facts explains that the other obtains. This article presents a third option: that they are one and the same fact. There is no difference between the fact that a person is an appropriate target of blame for an objectionable action and the fact that she is morally responsible for it. This view has the advantage of being metaphysically more parsimonious and of answering, in an elegant and plausible way, an interesting question about which many standard theories of responsibility keep silent: what is it to be morally responsible simpliciter