The effects of patch size and isolation on metapopulation dynamics have received wide empirical support and theoretical formalization. By contrast, the effects of patch quality seem largely ...underinvestigated, partly due to technical difficulties in properly assessing quality. Here we combine habitat-quality modeling with four years of demographic monitoring in a metapopulation of greater white-toothed shrews (Crocidura russula) to investigate the role of patch quality on metapopulation processes. Together, local patch quality and connectivity significantly enhanced local population sizes and occupancy rates (R2 = 14% and 19%, respectively). Accounting for the quality of patches connected to the focal one and acting as potential sources improved slightly the model explanatory power for local population sizes, pointing to significant source—sink dynamics. Local habitat quality, in interaction with connectivity, also increased colonization rate (R2 = 28%), suggesting the ability of immigrants to target high-quality patches. Overall, patterns were best explained when assuming a mean dispersal distance of 800 m, a realistic value for the species under study. Our results thus provide evidence that patch quality, in interaction with connectivity, may affect major demographic processes.
We use our new optical-imaging and spectrophotometric survey of key diagnostic emission lines in 30 Doradus, together with CLOUDY photoionization models, to study the physical conditions and ...ionization mechanisms along over 4000 individual lines of sight at points spread across the face of the extended nebula, out to a projected radius 75 pc from R136 at the center of the ionizing cluster NGC 2070. We focus on the physical conditions, geometry, and importance of radiation pressure on a point-by-point basis, with the aim of setting observational constraints on important feedback processes. We find that the dynamics and large-scale structure of 30 Dor are set by a confined system of X-ray bubbles in rough pressure equilibrium with each other and with the confining molecular gas. Although the warm (10,000 K) gas is photoionized by the massive young stars in NGC 2070, the radiation pressure does not currently play a major role in shaping the overall structure. The completeness of our survey also allows us to create a composite spectrum of 30 Doradus, simulating the observable spectrum of a spatially unresolved, distant giant extragalactic H II region. We find that the highly simplified models used in the 'strong line' abundance technique do in fact reproduce our observed line strengths and deduced chemical abundances, in spite of the more than one order of magnitude range in the ionization parameter and density of the actual gas in 30 Dor.
ABSTRACT
We present MUSE integral field data of two H ii region complexes in the Large Magellanic Cloud: N44 and N180. Both regions consist of a main superbubble and a number of smaller, more compact ...H ii regions that formed on the edge of the superbubble. For a total of 11 H ii regions, we systematically analyse the radiative and mechanical feedback from the massive O-type stars on the surrounding gas. We exploit the integral field property of the data and the coverage of the He ii λ5412 line to identify and classify the feedback-driving massive stars and from the estimated spectral types and luminosity classes we determine the stellar radiative output in terms of the ionizing photon flux Q0. We characterize the H ii regions in terms of their sizes, morphologies, ionization structure, luminosity and kinematics, and derive oxygen abundances via emission line ratios. We analyse the role of different stellar feedback mechanisms for each region by measuring the direct radiation pressure, the pressure of the ionized gas, and the pressure of the shock-heated winds. We find that stellar winds and ionized gas are the main drivers of H ii region expansion in our sample, while the direct radiation pressure is up to three orders of magnitude lower than the other terms. We relate the total pressure to the star formation rate per unit area, ΣSFR, for each region and find that stellar feedback has a negative effect on star formation, and sets an upper limit to ΣSFR as a function of increasing pressure.
We study the spectral energy distribution (SED) of the radio continuum (RC) emission from the Key Insight in Nearby Galaxies Emitting in Radio (KINGFISHER) sample of nearby galaxies to understand the ...energetics and origin of this emission. Effelsberg multi-wavelength observations at 1.4, 4.8, 8.4, and 10.5 GHz combined with archive data allow us, for the first time, to determine the mid-RC (1-10 GHz, MRC) bolometric luminosities and further present calibration relations versus the monochromatic radio luminosities. The 1-10 GHz radio SED is fitted using a Bayesian Markov Chain Monte Carlo technique leading to measurements for the nonthermal spectral index ( ) and the thermal fraction ( ) with mean values of for the total spectral index) and = (10 9)% at 1.4 GHz. The MRC luminosity changes over ∼3 orders of magnitude in the sample, MRC . The thermal emission is responsible for ∼23% of the MRC on average. We also compare the extinction-corrected diagnostics of the star-formation rate (SFR) with the thermal and nonthermal radio tracers and derive the first star-formation calibration relations using the MRC radio luminosity. The nonthermal spectral index flattens with increasing SFR surface density, indicating the effect of the star-formation feedback on the cosmic-ray electron population in galaxies. Comparing the radio and IR SEDs, we find that the FIR-to-MRC ratio could decrease with SFR, due to the amplification of the magnetic fields in star-forming regions. This particularly implies a decrease in the ratio at high redshifts, where mostly luminous/star-forming galaxies are detected.
The growing interest on the therapeutic potential against neurodegeneration of Cannabis sativa extracts, and of phytocannabinoids in particular, is paralleled by a limited understanding of the ...undergoing biochemical pathways in which these natural compounds may be involved. Computational tools are nowadays commonly enrolled in the drug discovery workflow and can guide the investigation of macromolecular targets for such molecules. In this contribution, in silico techniques have been applied to the study of C. sativa constituents at various extents, and a total of seven phytocannabinoids and four terpenes were considered. On the side of ligand‐based virtual screening, physico‐chemical descriptors were computed and evaluated, highlighting the phytocannabinoids possessing suitable drug‐like properties to potentially target the central nervous system. Our previous findings and literature data prompted us to investigate the interaction of these molecules with phosphodiesterases (PDEs), a family of enzymes being studied for the development of therapeutic agents against neurodegeneration. Among the compounds, structure‐based techniques such as docking and molecular dynamics (MD), highlighted cannabidiol (CBD) as a potential and selective PDE9 ligand, since a promising calculated binding energy value (−9.1 kcal/mol) and a stable interaction in the MD simulation timeframe were predicted.
Additionally, PDE9 inhibition assay confirmed the computational results, and showed that CBD inhibits the enzyme in the nanomolar range in vitro, paving the way for further development of this phytocannabinoid as a therapeutic option against neurodegeneration.
A multi‐level computational study, including ligand‐based and structure‐based screenings, together with in vitro tests, highlighted cannabidiol (CBD) as a central nervous system (CNS)‐targeting PDE9 inhibitor.
Trees are essential in the urban environment not only because of their aesthetic and social values, but also for their effects on air quality. Data of the present experiment show some of the ...integrated mechanisms that may confer sensitivity/tolerance in Tilia americana saplings exposed to ozone treatment (120ppb, 5hday−1 for 45 consecutive days) in order to improve the management of green spaces responding to oxidative stress. At the end of exposure, plants do not exhibit any foliar symptoms. Profiles related to membrane injury, photosynthetic gas exchange, chlorophyll a fluorescence, pigment content and enzymes/metabolites linked to the synthesis of phenylpropanoids show a vulnerability in terms of: (i) change in the ionic and solute reactions of the membrane cells (maximum value of +34%, 28 days after the beginning of fumigation, compared to controls); (ii) inhibition of the carbon assimilation (−41%), mostly as a consequence of non-stomatal limitation of assimilation rate; (iii) progressive inhibition of the Calvin cycle, as demonstrated by decreases in Rubisco carboxylation efficiency and regeneration capacity (−35 and −21%, respectively, at the end of exposure), quantum yield of electron transfer at PSII and in the fraction of energy passively dissipated as heat and fluorescence (−34% and −31%); (iv) senescence process (decline in demand for reducing power and energy at the end of treatment); (v) damage to the chlorophyll pigment system. However, the activation of xanthophylls cycle and phenylpropanoid metabolism, that can be considered a strategy in plants in order to regulate light absorbed energy and to scavenge reactive oxygen species does not preserve PSII photochemistry from impairment at the end of exposure.
Unveiling the processes driving exotic plant invasion represent a central issue in taking decisions aimed at constraining the loss of biodiversity and related ecosystem services. The invasion success ...is often linked to anthropogenic land uses and warming due to climate change. We studied the responses of native versus casual and naturalised exotic species richness to land uses and climate at the landscape level, relying on a large floristic survey undertaken in North - Eastern Italy. Both climate and land use drove exotic species richness. Our results suggest that the success of plant invasion at this scale is mainly due to warm climatic conditions and the extent of urban and agricultural land, but with different effects on casual and naturalized exotic species. The occurrence of non-linear trends showed that a small percentage of extensive agricultural land in the landscape may concurrently reduce the number of exotic plant while sustaining native plant diversity. Plant invasion could be potentially limited by land management, mainly focusing on areas with extensive agricultural land use. A more consciousness land management is more and more commonly required by local administrations. According to our results, a shift of intensive to extensive agricultural land, by implementing green infrastructures, seems to be a win-win solution favouring native species while controlling the oversimplification of the flora due to plant invasion.
The confinement and lockdown imposed by the COVID-19 pandemic have produced restrictions in the lifestyle of Italian citizens with variations in their psychological well-being. The aim of the study ...was to identify changes and relationship with socio-demographic parameters. An online survey was administered to 1383 subjects (1007 females and 307 males) working in the University of Florence, Italy. Three validated questionnaires were used for the survey: the Global Physical Activity Questionnaire, the Med Diet Score and the Psychological General Well-Being Index-A. All the subjects were asked to complete the questionnaires twice, in order to attain a picture of the habits before and a later time point during confinement. Our results show that work-related physical activity was decreased, along with an increase in sedentary behaviour (from 07:22±03:20 to 08:49±03:41 h:min; p<0.001, ES = 0.38), whereas recreational physical activity was increased (vigorous exercise varied from 568.5 ± 838.6 to 833.7 ± 1263.0 METs; p<0.002, ES = 0.25). Eating habits changed according to the place where meals were eaten, with an increased habit for breakfast and snacks and a slight increase in alcohol consumption. Psychological well-being decreased (Index from 21.4±3.9 to 18.0±5.3; p<0.001, ES = 0.723), especially in terms of vitality and positive thinking. The socio-demographic variables affecting these variations were mostly represented by age, gender and working conditions: young age and self-employment conditions can be considered factors for the changes in daily habits induced by confinement that may affect psychological well-being.
The C ii 158 m fine-structure line is the brightest emission line observed in local star-forming galaxies. As a major coolant of the gas-phase interstellar medium, C ii balances the heating, ...including that due to far-ultraviolet photons, which heat the gas via the photoelectric effect. However, the origin of C ii emission remains unclear because C+ can be found in multiple phases of the interstellar medium. Here we measure the fractions of C ii emission originating in the ionized and neutral gas phases of a sample of nearby galaxies. We use the N ii 205 m fine-structure line to trace the ionized medium, thereby eliminating the strong density dependence that exists in the ratio of C ii/N ii 122 m. Using the FIR C ii and N ii emission detected by the KINGFISH (Key Insights on Nearby Galaxies: a Far- Infrared Survey with Herschel) and Beyond the Peak Herschel programs, we show that 60%-80% of C ii emission originates from neutral gas. We find that the fraction of C ii originating in the neutral medium has a weak dependence on dust temperature and the surface density of star formation, and has a stronger dependence on the gas-phase metallicity. In metal-rich environments, the relatively cooler ionized gas makes substantially larger contributions to total C ii emission than at low abundance, contrary to prior expectations. Approximate calibrations of this metallicity trend are provided.
The MDANSE softwareMolecular Dynamics Analysis of Neutron Scattering Experimentsis presented. It is an interactive application for postprocessing molecular dynamics (MD) simulations. Given the ...widespread use of MD simulations in material and biomolecular sciences to get a better insight for experimental techniques such as thermal neutron scattering (TNS), the development of MDANSE has focused on providing a user-friendly, interactive, graphical user interface for analyzing many trajectories in the same session and running several analyses simultaneously independently of the interface. This first version of MDANSE already proposes a broad range of analyses, and the application has been designed to facilitate the introduction of new analyses in the framework. All this makes MDANSE a valuable tool for extracting useful information from trajectories resulting from a wide range of MD codes.
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