More Frequent, Intense, and Extensive Rainfall Events in a Strongly Warming Arctic

The changes in the Arctic precipitation profoundly impact the surface mass balance of ice sheet and sea ice, the extent of snow cover, as well as the land/ice surface runoff in the Arctic, particularly when it occurs in liquid form. Here, we use state-of-the-art models from the Coupled Model Intercomparison Project Phase 5 to project the number of days with rainfall, the intensities and onset dates of rainfall events in the Arctic under the strong emission scenario (RCP8.5). The multi-model mean shows that rainfall will occur more frequently in the Arctic at the end of this century (2091-2100), with larger increase in the rainy days over the Pacific and Atlantic sectors (up to 12 days/month) during the cold seasons (October-May) and over the Arctic Ocean (up to 14 days/month) during the warm seasons (June-September) as compared with the present day (2006-2015). Greater uncertainty is found in the cold seasons, which mainly comes from the high variability among different models in the Norwegian Sea. Sixty-seven to ninety-three percentage of the increases in rainy days is contributed by the local warming and the remainder by the increase in total precipitation. Moreover, at the end of this century, the rainfall in spring will occur much earlier than the present day by more than 1 month, and the extent of rainfall will further expand toward the center of the Arctic Ocean and the inland Greenland in the future. The changes of rainfall intensity on the Arctic land area to the climate warming are more sensitive than that on the Arctic Ocean in warm seasons (May-September). The rainfall will be further strengthened in most of the Arctic continents in summer, with the largest increase in the intensity of similar to 2 mm/day along the southwest coast of Greenland. The above results are confirmed by the latest projections from CMIP6 models

On the Ultraviolet Behaviour of Newton's constant

We clarify a point concerning the ultraviolet behaviour of the Quantum Field Theory of gravity, under the assumption of the existence of an ultraviolet Fixed Point. We explain why Newton's constant should to scale like the inverse of the square of the cutoff, even though it is technically inessential. As a consequence of this behaviour, the existence of an UV Fixed Point would seem to imply that gravity has a built-in UV cutoff when described in Planck units, but not necessarily in other units.Comment: 8 pages; CQG class; minor changes and rearrangement

A YOLOV8-based approach for steel plate surface defect detection

Hot-rolled steel strips are a commonly used product in both production and daily life. However, the manufacturing process inevitably leads to the occurrence of surface defects. To solve this problem, Our method uses YOLOV8 and squeeze-and-excitation (SE) attention mechanism to detect surface defects in hot-rolled steel strips. Our method balances accuracy and real-time performance, while detecting four common surface defects. The method has an average accuracy of 90,9 % and a maximum accuracy of 98,5 % for detecting a single category of surface defects. Experimental results confirm good performance of our proposed method in classifying and localizing surface defects in hot-rolled steel strips, and has the potential for broad application and promotion

A YOLOV8-based approach for steel plate surface defect detection

Hot-rolled steel strips are a commonly used product in both production and daily life. However, the manufacturing process inevitably leads to the occurrence of surface defects. To solve this problem, Our method uses YOLOV8 and squeeze-and-excitation (SE) attention mechanism to detect surface defects in hot-rolled steel strips. Our method balances accuracy and real-time performance, while detecting four common surface defects. The method has an average accuracy of 90,9 % and a maximum accuracy of 98,5 % for detecting a single category of surface defects. Experimental results confirm good performance of our proposed method in classifying and localizing surface defects in hot-rolled steel strips, and has the potential for broad application and promotion

Genotypic analysis of genes associated with transmission and drug resistance in the Beijing lineage of Mycobacterium tuberculosis

AbstractThe Beijing genotype of Mycobacterium tuberculosis is an endemic lineage in East Asia that has disseminated worldwide. It is a major health concern, as it is geographically widespread and is considered to be hypervirulent. To elucidate its genetic diversity in Taiwan, phylogenetic reconstruction was performed using 338 M. tuberculosis Beijing family clinical isolates. Region-of-difference analysis revealed the strains from Taiwan to be distributed among six subgroups of a phylogenetic tree. Synonymous single nucleotide polymorphisms at 10 chromosomal positions were also analysed. Among the 338 isolates analysed for single-nucleotide polymorphisms by using mass spectrometry, the most frequent strain found was ST10 (53.3%), followed by ST19 (14.8%) and ST22 (14.5%). Tests of drug resistance showed that the sublineages ST10, ST19 and ST26 were over-represented in the multidrug-resistant population. The presence of mutations in putative genes coding for DNA repair enzymes, which could confer a mutator phenotype to facilitate spreading of the pathogen, did not demonstrate an association with multidrug resistance. Therefore, the DNA repair genes may be involved in transmission but not in drug resistance

Enhancement of Critical Current Density in low level Al-doped MgB2

Two sets of MgB2 samples doped with up to 5 at. % of Al were prepared in different laboratories using different procedures. Decreases in the a and c lattice parameters were observed with Al doping confirming Al substitution onto the Mg site. The critical temperature (Tc) remained largely unchanged with Al doping. For 1 - 2.5 at.% doping, at 20K the in-field critical current densities (Jc's) were enhanced, particularly at lower fields. At 5K, in-field Jc was markedly improved, e.g. at 5T Jc was enhanced by a factor of 20 for a doping level of 1 at.% Al. The improved Jcs correlate with increased sample resistivity indicative of an increase in the upper critical field, Hc2, through alloying.Comment: 17 pages, 4 figures, to be published in Superconductor Science and Technolog

Renormalization Group Flow in Scalar-Tensor Theories. II

We study the UV behaviour of actions including integer powers of scalar curvature and even powers of scalar fields with Functional Renormalization Group techniques. We find UV fixed points where the gravitational couplings have non-trivial values while the matter ones are Gaussian. We prove several properties of the linearized flow at such a fixed point in arbitrary dimensions in the one-loop approximation and find recursive relations among the critical exponents. We illustrate these results in explicit calculations in $d=4$ for actions including up to four powers of scalar curvature and two powers of the scalar field. In this setting we notice that the same recursive properties among the critical exponents, which were proven at one-loop order, still hold, in such a way that the UV critical surface is found to be five dimensional. We then search for the same type of fixed point in a scalar theory with minimal coupling to gravity in $d=4$ including up to eight powers of scalar curvature. Assuming that the recursive properties of the critical exponents still hold, one would conclude that the UV critical surface of these theories is five dimensional.Comment: 14 pages. v.2: Minor changes, some references adde

Modified Dispersion Relations from the Renormalization Group of Gravity

We show that the running of gravitational couplings, together with a suitable identification of the renormalization group scale can give rise to modified dispersion relations for massive particles. This result seems to be compatible with both the frameworks of effective field theory with Lorentz invariance violation and deformed special relativity. The phenomenological consequences depend on which of the frameworks is assumed. We discuss the nature and strength of the available constraints for both cases and show that in the case of Lorentz invariance violation, the theory would be strongly constrained.Comment: revtex4, 9 pages, updated to match published versio