Near the boundary between ordered and disordered quantum phases, several experiments have demonstrated metallic behaviour that defies the Landau Fermi paradigm.sup.1-5. In moiré heterostructures, ...gate-tuneable insulating phases driven by electronic correlations have been recently discovered.sup.6-23. Here, we use transport measurements to characterize metal-insulator transitions (MITs) in twisted WSe.sub.2 near half filling of the first moiré subband. We find that the MIT as a function of both density and displacement field is continuous. At the metal-insulator boundary, the resistivity displays strange metal behaviour at low temperatures, with dissipation comparable to that at the Planckian limit. Further into the metallic phase, Fermi liquid behaviour is recovered at low temperature, and this evolves into a quantum critical fan at intermediate temperatures, before eventually reaching an anomalous saturated regime near room temperature. An analysis of the residual resistivity indicates the presence of strong quantum fluctuations in the insulating phase. These results establish twisted WSe.sub.2 as a new platform to study doping and bandwidth-controlled metal-insulator quantum phase transitions on the triangular lattice.
Teleparallel gravity and its popular generalization gravity can be formulated as fully invariant (under both coordinate transformations and local Lorentz transformations) theories of gravity. Several ...misconceptions about teleparallel gravity and its generalizations can be found in the literature, especially regarding their local Lorentz invariance. We describe how these misunderstandings may have arisen and attempt to clarify the situation. In particular, the central point of confusion in the literature appears to be related to the inertial spin connection in teleparallel gravity models. While inertial spin connections are commonplace in special relativity, and not something inherent to teleparallel gravity, the role of the inertial spin connection in removing the spurious inertial effects within a given frame of reference is emphasized here. The careful consideration of the inertial spin connection leads to the construction of a fully invariant theory of teleparallel gravity and its generalizations. Indeed, it is the nature of the spin connection that differentiates the relationship between what have been called good tetrads and bad tetrads and clearly shows that, in principle, any tetrad can be utilized. The field equations for the fully invariant formulation of teleparallel gravity and its generalizations are presented and a number of examples using different assumptions on the frame and spin connection are displayed to illustrate the covariant procedure. Various modified teleparallel gravity models are also briefly reviewed.
The present study focuses on the dependence of the space–time permutation scan statistics (STPSS) (1) on the input database's characteristics and (2) on the use of this methodology to assess changes ...on the fire regime due to different type of climate and fire management activities. Based on the very strong relationship between weather and the fire incidence in Portugal, the detected clusters will be interpreted in terms of the atmospheric conditions. Apart from being the country most affected by the fires in the European context, Portugal meets all the conditions required to carry out this study, namely: (i) two long and comprehensive official datasets, i.e. the Portuguese Rural Fire Database (PRFD) and the National Mapping Burnt Areas (NMBA), respectively based on ground and satellite measurements; (ii) the two types of climate (Csb in the north and Csa in the south) that characterizes the Mediterranean basin regions most affected by the fires also divide the mainland Portuguese area; and, (iii) the national plan for the defence of forest against fires was approved a decade ago and it is now reasonable to assess its impacts. Results confirmed (1) the influence of the dataset's characteristics on the detected clusters, (2) the existence of two different fire regimes in the country promoted by the different types of climate, (3) the positive impacts of the fire prevention policy decisions and (4) the ability of the STPSS to correctly identify clusters, regarding their number, location, and space-time size in spite of eventual space and/or time splits of the datasets. Finally, the role of the weather on days when clustered fires were active was confirmed for the classes of small, medium and large fires.
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•Spatial-temporal scan statistics were applied to different Portuguese fire datasets.•Results depend on the dataset and discrepancies are bigger for small fires.•Two fire regimes were found (North vs South) due to different environmental factors.•Detected clusters were discussed in terms of fire weather and fire management.•Abnormal weather conditions were associated to clusters of all fire size classes.
In general relativity, inertia and gravitation are both included in the Levi–Civita connection. As a consequence, the gravitational action, as well as the corresponding energy–momentum density, are ...in general contaminated by spurious contributions coming from inertial effects. In teleparallel gravity, on the other hand, because the spin connection represents inertial effects only, it is possible to separate inertia from gravitation. Relying on this property, it is shown that to each tetrad there is naturally associated a spin connection that
locally removes the inertial effects
from the action. The use of the appropriate spin connection can be viewed as a renormalization process in the sense that the computation of energy and momentum naturally yields the physically relevant values. A self-consistent method for solving field equations and determining the appropriate spin connection is presented.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The microorganisms associated with sugary Brazilian kefir beverage were investigated using a combination of culture-dependent and -independent methods. A total of 289 bacteria and 129 yeasts were ...identified via phenotypic and genotypic methods. Lb. paracasei (23.8%) was the major bacterial isolate identified, followed by Acetobacter lovaniensis (16.31%), Lactobacillus parabuchneri (11.71%), Lactobacillus kefir (10.03%) and Lactococcus lactis (10.03%). Saccharomyces cerevisiae (54.26%) and Kluyveromyces lactis (20.15%) were the most common yeast species isolated. Scanning electron microscopy showed that the microbiota was dominated by lemon-shaped yeast cells growing in close association with Lactobacillus (long and curved). Some lactic acid bacteria detected by sequence analysis of DGGE (denaturing gradient gel electrophoresis) bands were not recovered at any time through fermentation by plating. Conversely, DGGE fingerprints did not reveal bands corresponding to some of the species isolated by culturing methods. The bacteria Acetobacter lovaniensis and the yeast Kazachstania aerobia are described for the first time in sugary kefir. During the 24 h of fermentation, the concentration of lactic acid ranged from 0.2 to 1.80 mg/ml, and that of acetic acid increased from 0.08 to 1.12 mg/ml. The production of ethanol was limited, reaching a final mean value of 1.24 mg/ml.
This study is focused in mapping the structural fire risk in the vegetated area of Portugal using a deterministic approach based on the concept of fire risk currently accepted by the scientific ...community which consists in the combination of the fire hazard and the potential economic damage. The fire susceptibility map of Verde and Zêzere (2010) was adopted and updated by the use of a higher resolution digital terrain model, longer burnt area perimeter dataset (1975–2013) and the entire set of Corine land cover inventories. The susceptibility was mapped with five classes to be in accordance with the Portuguese law and the results confirms the good performance of this model not only in the favourability scores but also in the predictive values. Three different scenarios of (maximum, mean, and minimum annual) burnt area were consider to estimate the fire hazard which allow to estimate the likelihood of a pixel to burn (ranging between 0% and 20%) depending on the class to which it belongs and on the future burnt area scenario. The potential economic damage was estimated with the vulnerability scores and monetary values of species defined in the literature and by law. The obtained fire risk map identifies the areas more prone to be affected by fires in the future and provides an estimate of the economic damage of the fire which will be a valuable tool for forest and fire managers and to minimize the economic and environmental consequences of vegetation fires in Portugal.
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•Verde and Zêzere susceptibility map was updated with longer and high resolution data.•Susceptibility model's performance and particularities were assessed and discussed.•Structural fire risk computed for updated potential damage and three hazard scenarios•Potential damage mapped with recent vulnerability and Horizon 3030 economic values•Higher fire risk in central, north and extreme south (Algarve) of Portugal
Highlights • LED light requirements may be related to the evolutionary history of endosymbiosis. • Red or blue LEDs are often the most effective artificial light sources for microalgae. • LED light ...quality influences the growth and biochemistry of microalgae. • LEDs are ideal for building tailored light sources.
Amyotrophic lateral sclerosis (ALS) is the most frequent adult-onset motor neuron disorder. The disease is characterized by degeneration of upper and lower motor neurons, leading to death usually ...within five years after the onset of symptoms. While most cases are sporadic, 5%-10% of cases can be associated with familial inheritance, including ALS type 6, which is associated with mutations in the Fused in Sarcoma (FUS) gene. This work aimed to evaluate how the most frequent ALS-related mutations in FUS, R521C, R521H, and P525L affect the protein structure and function. We used prediction algorithms to analyze the effects of the non-synonymous single nucleotide polymorphisms and performed evolutionary conservation analysis, protein frustration analysis, and molecular dynamics simulations. Most of the prediction algorithms classified the three mutations as deleterious. All three mutations were predicted to reduce protein stability, especially the mutation R521C, which was also predicted to increase chaperone binding tendency. The protein frustration analysis showed an increase in frustration in the interactions involving the mutated residue 521C. Evolutionary conservation analysis showed that residues 521 and 525 of human FUS are highly conserved sites. The molecular dynamics results indicate that protein stability could be compromised in all three mutations. They also affected the exposed surface area and protein compactness. The analyzed mutations also displayed high flexibility in most residues in all variants, most notably in the interaction site with the nuclear import protein of FUS.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The flow of two immiscible fluid components with large density and viscosity ratios is considered. Using the pseudo-potential lattice Boltzmann model with a non-ideal equation of state and a mixture ...viscosity formulation, we can develop a model that successfully passes a series of benchmark tests, most importantly co-current layered flows, with no discontinuities in the velocity profiles at interfaces. The model is then applied to applications of bubbles rising in denser fluids and shows good quantitative agreement with previous numerical and experimental results. The model is also applied to the flow of two immiscible fluids in a porous medium and shows characteristics that are physically consistent with established experimental observations.
Cardiac surgeries are complex procedures aiming to re-establish coronary flow and correct valvular defects. Oxidative stress, caused by inflammation and ischemia-reperfusion injury, is associated ...with these procedures, increasing the risk of adverse outcomes. N-acetylcysteine (NAC) acts as an antioxidant by replenishing the glutathione stores, and emerging evidence suggests that NAC may reduce the risk of adverse perioperative outcomes. We conducted a systematic review and meta-analysis to investigate the addition of NAC to a standard of care among adult patients undergoing cardiac surgery.
We searched four databases (PubMed, EMBASE, CENTRAL, LILACS) from inception to October 2018 and the grey literaure for randomized controlled trials (RCTs) investigating the effect of NAC on pre-defined outcomes including mortality, acute renal insufficiency (ARI), acute cardiac insufficiency (ACI), hospital length of stay (HLoS), intensive care unit length of stay (ICULoS), arrhythmia and acute myocardial infarction (AMI). Reviewers independently screened potentially eligible articles, extracted data and assessed the risk of bias among eligible articles. We used the GRADE approach to rate the overall certainty of evidence for each outcome.
Twenty-nine RCTs including 2,486 participants proved eligible. Low to moderate certainty evidence demonstrated that the addition of NAC resulted in a non-statistically significant reduction in mortality (Risk Ratio (RR) 0.71; 95% Confidence Interval (CI) 0.40 to 1.25), ARI (RR 0.92; 95% CI 0.79 to 1.09), ACI (RR 0.77; 95% CI 0.44 to 1.38), HLoS (Mean Difference (MD) 0.21; 95% CI -0.64 to 0.23), ICULoS (MD -0.04; 95% CI -0.29 to 0.20), arrhythmia (RR 0.79; 95% CI 0.52 to 1.20), and AMI (RR 0.84; 95% CI 0.48 to 1.48).
Among eligible trials, we observed heterogeneity in the population and interventions including patients with and without kidney dysfunction and interventions that differed in route of administration, dosage, and duration of treatment. This observed heterogeneity was not explained by our subgroup analyses.
The addition of NAC during cardiac surgery did not result in a statistically significant reduction in clinical outcomes. A large randomized placebo-controlled multi-centre trial is needed to determine whether NAC reduces mortality.
PROSPERO CRD42018091191.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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