1,775 research outputs found
Planning coastal Mediterranean stone pine (Pinus pinea L.) reforestations as a green infrastructure: combining GIS techniques and statistical analysis to identify management options
Mediterranean stone pine reforestations are common characteristics of the Italian Tyrrhenian coast, which mostly maintain uniform and monolayered stand structures. However, improving structural diversity is an effective climate change adaptation strategy in forest management. The aim of this study was to implement a methodology which allows distinct reforested areas such as a single green infrastructure to be managed according to the surrounding land use and the characteristics of the forest stands. 240 hectares of Mediterranean stone pine forests located along a 16 km strip of the Lazio coast (Central Italy) were mapped. Twelve attributes describing the pine stands and showing possible constraints for future management decisions were associated to each forest patch. A hierarchical cluster analysis was performed to group the pinewood patches according to their similarity level and five different groups were identified. For each group, different silvicultural methods were proposed to guide the compositional and structural evolution of the stands, in order to make them suitable for providing services required locally and increasing overall diversity at landscape scale. The results of the study highlight how coastal land uses can offer effective inputs to differentiate the management of forest systems and therefore achieve greater variety and resilience in the landscape over time. This approach is particularly useful in the case of very homogeneous stands such as the stone pine reforestations under study
Permutation centralizer algebras and multimatrix invariants
45 pages, 5 figures45 pages, 5 figure
A new approach to analyzing solar coronal spectra and updated collisional ionization equilibrium calculations. II. Additional ionization rate coefficients
We have reanalyzed SUMER observations of a parcel of coronal gas using new
collisional ionization equilibrium (CIE) calculations. These improved CIE
fractional abundances were calculated using state-of-the-art electron-ion
recombination data for K-shell, L-shell, Na-like, and Mg-like ions of all
elements from H through Zn and, additionally, Al- through Ar-like ions of Fe.
They also incorporate the latest recommended electron impact ionization data
for all ions of H through Zn. Improved CIE calculations based on these
recombination and ionization data are presented here. We have also developed a
new systematic method for determining the average emission measure () and
electron temperature () of an isothermal plasma. With our new CIE data and
our new approach for determining average and , we have reanalyzed
SUMER observations of the solar corona. We have compared our results with those
of previous studies and found some significant differences for the derived
and . We have also calculated the enhancement of coronal elemental
abundances compared to their photospheric abundances, using the SUMER
observations themselves to determine the abundance enhancement factor for each
of the emitting elements. Our observationally derived first ionization
potential (FIP) factors are in reasonable agreement with the theoretical model
of Laming (2008).Comment: 147 pages (102 of which are online only tables and figures).
Submitted to ApJ. Version 2 is updated addressing the referee's repor
The role of tyrosine M210 in the initial charge separation in the reaction center of Rhodobacter sphaeroides
Non-equilibrium fluctuations and metastability arising from non-additive interactions in dissipative multi-component Rydberg gases
We study the out-of-equilibrium dynamics of dissipative gases of atoms excited to two or more high-lying Rydberg states. This situation bears interesting similarities to classical binary (in general p-ary) mixtures of particles. The effective forces between the components are determined by the inter-level and intra-level interactions of Rydberg atoms. These systems permit to explore new parameter regimes which are physically inaccessible in a classical setting, for example one in which the mixtures exhibit non-additive interactions. In this situation the out-of-equilibrium evolution is characterized by the formation of metastable domains that reach partial equilibration long before the attainment of stationarity. In experimental settings with mesoscopic sizes, this collective behavior may in fact take the appearance of dynamic symmetry breaking
Dielectronic Recombination of Argon-Like Ions
We present a theoretical investigation of dielectronic recombination (DR) of
Ar-like ions that sheds new light on the behavior of the rate coefficient at
low-temperatures where these ions form in photoionized plasmas. We provide
results for the total and partial Maxwellian-averaged DR rate coefficients from
the initial ground level of K II -- Zn XIII ions. It is expected that these new
results will advance the accuracy of the ionization balance for Ar-like M-shell
ions and pave the way towards a detailed modeling of astrophysically relevant
X-ray absorption features. We utilize the AUTOSTRUCTURE computer code to obtain
the accurate core-excitation thresholds in target ions and carry out
multiconfiguration Breit-Pauli (MCBP) calculations of the DR cross section in
the independent-processes, isolated-resonance, distorted-wave (IPIRDW)
approximation. Our results mediate the complete absence of direct DR
calculations for certain Ar-like ions and question the reliability of the
existing empirical rate formulas, often inferred from renormalized data within
this isoelectronic sequence
The PLASMONX Project for advanced beam physics experiments
The Project PLASMONX is well progressing into its
design phase and has entered as well its second phase of
procurements for main components. The project foresees
the installation at LNF of a Ti:Sa laser system (peak
power > 170 TW), synchronized to the high brightness
electron beam produced by the SPARC photo-injector.
The advancement of the procurement of such a laser
system is reported, as well as the construction plans of a
new building at LNF to host a dedicated laboratory for
high intensity photon beam experiments (High Intensity
Laser Laboratory). Several experiments are foreseen
using this complex facility, mainly in the high gradient
plasma acceleration field and in the field of mono-
chromatic ultra-fast X-ray pulse generation via Thomson
back-scattering. Detailed numerical simulations have
been carried out to study the generation of tightly focused
electron bunches to collide with laser pulses in the
Thomson source: results on the emitted spectra of X-rays
are presented
Resolving mechanisms of immune-mediated disease in primary CD4 T cells
ABSTRACT Deriving mechanisms of immune-mediated disease from GWAS data remains a formidable challenge, with attempts to identify causal variants being frequently hampered by linkage disequilibrium. To determine whether causal variants could be identified via their functional effects, we adapted a massively-parallel reporter assay for use in primary CD4 T-cells, key effectors of many immune-mediated diseases. Using the results to guide further study, we provide a generalisable framework for resolving disease mechanisms from non-coding associations – illustrated by a locus linked to 6 immune-mediated diseases, where the lead functional variant causally disrupts a super-enhancer within an NF-κB-driven regulatory circuit, triggering unrestrained T-cell activation
A corridors and power-oriented perspective on energy-service demand and needs satisfaction
In this article, we explore the concept of consumption corridors as it might apply to energy use, with specific attention to both wellbeing and power relations. We employ the distinction between energy provisioning and human-need satisfaction to explore different configurations of energy use, as well as their possible dynamics. Specifically, we draw on past research documenting the benefits of decoupling our thinking about energy services and needs satisfaction and use it as a basis to identify scenarios characterized by different degrees of access to energy services and levels of resource demand. We then translate this perspective to the logic of sustainable consumption corridors. We delineate how minimum and maximum consumption standards would relate to combinations of energy-service demand and needs-satisfier access. Finally, we explore how power dynamics, specifically exercises of discursive power, might move societal trajectories toward sustainable combinations of energy provisioning and needs satisfaction or away from them
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