Atlantic Water warming increases melt below Northeast Greenland's last floating ice tongue.

The 79 North Glacier (79NG) features Greenland's largest floating ice tongue. Even though its extent has not changed significantly in recent years, observations have indicated a major thinning of the ice tongue from below. Both ocean warming and an increase in subglacial discharge from the ice sheet induced by atmospheric warming could increase the basal melt; however, available observations alone cannot tell which of these is the main driver. Here, we employ a global simulation which explicitly resolves the ocean circulation in the cavity with 700 m resolution to disentangle the impact of the ocean and atmosphere. We find that the interannual variability of basal melt below 79NG over the past 50 years is mainly associated with changes in the temperature of the Atlantic Intermediate Water inflow, which can be traced back across the Northeast Greenland continental shelf to the eastern Fram Strait with a lag of 3 years.

A Prospective Comparison of Transrectal Standard, Cognitive, Transperineal Fusion, and Mapping Prostate Biopsy for Cancer Detection.

Purpose: The aim of this research was to compare the clinically significant prostate cancer (csPCa) detection rate (International Society of Urological Pathology [ISUP] ≥2) for the four biopsy methods: transrectal ultrasound-guided biopsy (TRUS-GB), cognitive transrectal biopsy (COG-TB), fusion transperineal biopsy (FUS-TB), and transperineal template mapping biopsy (TPMB). Materials and Methods: The inclusion criteria were as follows: prostate-specific antigen (PSA) >2 ng/mL, and/or positive digital rectal examination (DRE), and/or suspicious lesion on transrectal ultrasound (TRUS) and Prostate Imaging Reporting and Data System (Pi-RADS) v2.1 ≥ 3 score. In total, 102 patients were enrolled in the study. Biopsies were performed by two urologists. In a single procedure, the first urologist performed a FUS-TB and TPMB followed by second urologist who performed TRUS-GB and COG-TB. All specimens were obtained within a single procedure. Results: The csPCa detection rate and overall cancer detection rate (CDR) per patient were comparable among the respective biopsy methods (p > 0.05). Compared with other biopsy methods, a lower clinically insignificant prostate cancer (cisPCa) was detected using COG-TB (p = 0.004). The positive cores percentage ratio (p < 0.001) as well as positive cores containing csPCa percentage ratio (p < 0.001) significantly increased for the targeted biopsy methods. The median maximum cancer core length (MCCL; p = 0.52) as well the median for the MCCL of csPCa (p = 0.47) did not differ significantly among the respective biopsy methods. Concordance of the Gleason scores between biopsy and postprostatectomy pathology did not differ significantly among biopsy methods (p = 0.87). For TRUS-GB, FUS-TB, and TPMB, the common predictive factors for csPCa were positive DRE, suspicious lesion on ultrasound and Pi-RADS 5. As for COG-TB, the only predictor was Pi-RADS 5. Conclusion: The targeted methods did not show an increase in detection of csPCa and overall CDR over systematic ones in patients with Pi-RADS ≥3. A lower cisPCa was detected using COG-TB in comparison with the other methods. The sampling efficiency increased for the targeted biopsy methods, which used only a proportion of positive cores and cores containing csPCa. There was no statistical difference in histology concordance among the biopsies. One common predictive factor of increased csPCa detection for all biopsy methods was Pi-RADS 5.

Regulation of the Concentration Heterogeneity and Thermal Expansion Coefficient in the Metastable Invar FeNi31.1 Alloy.

Mössbauer spectroscopy and electron microscopy study of the active redistribution of Ni atoms during the process of polymorphous transformation α→γ in the metastable FeNi31.1 alloy revealed that slow heating (at the rate of 0.2 K/min) results in the depletion of the initial α-phase with a beneficiation of developing disperse γ-phase plates according to the equilibrium diagram. A regulation possibility of the concentration heterogeneity and austenite thermal expansion coefficient resulted from the polymorphous transformation α→γ was shown. Comparison with data of FeNi35 alloy irradiation by high-energy electrons responsible for the variation of atomic distribution and thermal expansion coefficient (owing to the spinodal decomposition) was performed.

Delayed Antarctic sea-ice decline in high-resolution climate change simulations.

Despite global warming and Arctic sea-ice loss, on average the Antarctic sea-ice extent has not declined since 1979 when satellite data became available. In contrast, climate model simulations tend to exhibit strong negative sea-ice trends for the same period. This Antarctic sea-ice paradox leads to low confidence in 21st-century sea-ice projections. Here we present multi-resolution climate change projections that account for Southern Ocean mesoscale eddies. The high-resolution configuration simulates stable September Antarctic sea-ice extent that is not projected to decline until the mid-21st century. We argue that one reason for this finding is a more realistic ocean circulation that increases the equatorward heat transport response to global warming. As a result, the ocean becomes more efficient at moderating the anthropogenic warming around Antarctica and hence at delaying sea-ice decline. Our study suggests that explicitly simulating Southern Ocean eddies is necessary for providing Antarctic sea-ice projections with higher confidence.

Tensile Deformation and Fracture Behavior of API-5L X70 Line Pipe Steel.

Thermo-mechanical controlled processing (TMCP) is employed to obtain the required level of mechanical properties of contemporary HSLA steel plates utilized for gas and oil pipeline production. The strength and crack resistance of pipeline steels are mainly determined by its microstructure and crystallographic texture. In this study, the influence of the structural and textural states of industrially produced API-5L X70-X80 pipeline steels on tensile mechanical properties was analyzed. TMCP routes with different hot rolling temperatures and cooling rates were employed. The texture of steel was assessed using the Taylor factor, which was calculated based on electron backscatter diffraction (EBSD). The decrease in rolling temperature resulted in the sharper texture characterized by {001} planes banding (cleavage planes in the bcc lattice) parallel to rolling direction. The tensile deformation behavior at the stage of necking was determined by the crystallographic and morphological texture of the material and demonstrated significant anisotropy. Rupture of all investigated samples was accompanied by the development of splitting on the fracture surface. The splitting was localized in the rolling plane similar to the splitting in standard Charpy tests of pipeline steels.

Photoelectromagnetic Effect Induced by Terahertz Laser Radiation in Topological Crystalline Insulators Pb1-xSnxTe.

Topological crystalline insulators form a class of semiconductors for which surface electron states with the Dirac dispersion relation are formed on surfaces with a certain crystallographic orientation. Pb1-xSnxTe alloys belong to the topological crystalline phase when the SnTe content x exceeds 0.35, while they are in the trivial phase at x < 0.35. For the surface crystallographic orientation (111), the appearance of topologically nontrivial surface states is expected. We studied the photoelectromagnetic (PEM) effect induced by laser terahertz radiation in Pb1-xSnxTe films in the composition range x = (0.11-0.44), with the (111) surface crystallographic orientation. It was found that in the trivial phase, the amplitude of the PEM effect is determined by the power of the incident radiation, while in the topological phase, the amplitude is proportional to the flux of laser radiation quanta. A possible mechanism responsible for the effect observed presumes damping of the thermalization rate of photoexcited electrons in the topological phase and, consequently, prevailing of electron diffusion, compared with energy relaxation.

Helicity-Sensitive Plasmonic Terahertz Interferometer.

Plasmonic interferometry is a rapidly growing area of research with a huge potential for applications in the terahertz frequency range. In this Letter, we explore a plasmonic interferometer based on graphene field effect transistor connected to specially designed antennas. As a key result, we observe helicity- and phase-sensitive conversion of circularly polarized radiation into dc photovoltage caused by the plasmon-interference mechanism: two plasma waves, excited at the source and drain part of the transistor, interfere inside the channel. The helicity-sensitive phase shift between these waves is achieved by using an asymmetric antenna configuration. The dc signal changes sign with inversion of the helicity. A suggested plasmonic interferometer is capable of measuring the phase difference between two arbitrary phase-shifted optical signals. The observed effect opens a wide avenue for phase-sensitive probing of plasma wave excitations in two-dimensional materials.

Non-equilibrium electron transport induced by terahertz radiation in the topological and trivial phases of Hg1-x Cd x Te.

Terahertz photoconductivity in heterostructures based on n-type Hg1-x Cd x Te epitaxial films both in the topological phase (x < 0.16, inverted band structure, zero band gap) and the trivial state (x > 0.16, normal band structure) has been studied. We show that both the positive photoresponse in films with x < 0.16 and the negative photoconductivity in samples with x > 0.16 have no low-energy threshold. The observed non-threshold positive photoconductivity is discussed in terms of a qualitative model that takes into account a 3D potential well and 2D topological Dirac states coexisting in a smooth topological heterojunction.

Electron energy relaxation under terahertz excitation in (Cd1-x Zn x )3As2 Dirac semimetals.

We demonstrate that measurements of the photo-electromagnetic effect using terahertz laser radiation provide an argument for the existence of highly conductive surface electron states with a spin texture in Dirac semimetals (Cd1-x Zn x )3As2. We performed a study on a range of (Cd1-x Zn x )3As2 mixed crystals undergoing a transition from the Dirac semimetal phase with an inverse electron energy spectrum to trivial a semiconductor with a direct spectrum in the crystal bulk by varying the composition x. We show that for the Dirac semimetal phase, the photo-electromagnetic effect amplitude is defined by the number of incident radiation quanta, whereas for the trivial semiconductor phase, it depends on the laser pulse power, irrespective of wavelength. We assume that such behavior is attributed to a strong damping of the interelectron interaction in the Dirac semimetal phase compared to the trivial semiconductor, which may be due to the formation of surface electron states with a spin texture in Dirac semimetals.

Terahertz polarization conversion with quartz waveplate sets.

We present the results of calculation and experimental testing of an achromatic polarization converter and a composite terahertz waveplate (WP), which are represented by sets of plane-parallel birefringent plates with in-plane birefringence axis. The calculations took into account the effect of interference, which was especially prominent when plates were separated by an air gap. The possibility of development of a spectrum analyzer design based on a set of WPs is also discussed.

Rhines scale and spectra of the beta-plane turbulence with bottom drag.

We study two-dimensional incompressible turbulence on the beta plane and propose a modification to the Rhines scale that takes into account the bottom friction. The modified Rhines scale is studied numerically, and found to predict accurately the jet number and the energy peak of the beta-plane turbulence for strong beta. The intermediate cases show a transition from the (isotropic) friction scale to the Rhines one, as the proper halting scale for the inverse cascade.