Blocking Temperature Engineering in Exchange-Biased CoFeB/IrMn Bilayer

In this paper, we report on the magnetic and chemical characterization of the exchange-biased CoFeB/IrMn bilayers, grown by magnetron sputtering on a Si-based platform and capped by either a Ru or MgO/Ru overlayer. For Ru capping, the locking temperature monotonously increases with the IrMn thickness within the investigated range (3.5–8 nm). On the contrary, for MgO/Ru capping, the exchange bias is inhibited below 6 nm, whereas above 6 nm, the magnetic behavior is the same of Ru-capped films. The chemical analysis reveals a significant dependence of the Mn content from the capping layer for thin IrMn films (2.5 nm), whereas the difference disappears when IrMn becomes thick (7 nm). Our work suggests that a non-uniform composition of the IrMn films directly affects the exchange coupling at the IrMn/CoFeB interface

Ferroelectric control of the spin texture in germanium telluride

The electrical manipulation of spins in semiconductors, without magnetic fields or auxiliary ferromagnetic materials, represents the holy grail for spintronics. The use of Rashba effect is very attractive because the k-dependent spin-splitting is originated by an electric field. So far only tiny effects in two-dimensional electron gases (2DEG) have been exploited. Recently, GeTe has been predicted to have bulk bands with giant Rashba-like splitting, originated by the inversion symmetry breaking due to ferroelectric polarization. In this work, we show that GeTe(111) surfaces with inwards or outwards ferroelectric polarizations display opposite sense of circulation of spin in bulk Rashba bands, as seen by spin and angular resolved photoemission experiments. Our results represent the first experimental demonstration of ferroelectric control of the spin texture in a semiconductor, a fundamental milestone towards the exploitation of the non-volatile electrically switchable spin texture of GeTe in spintronic devices.Comment: 18 pages, 4 figure

Mechanisms of recovery after neck‐specific or general exercises in patients with cervical radiculopathy

Background The mechanisms of action that facilitate improved outcomes after conservative rehabilitation are unclear in individuals with cervical radiculopathy (CR). This study aims to determine the pathways of recovery of disability with different exercise programs in individuals with CR. Methods We analysed a dataset of 144 individuals with CR undergoing conservative rehabilitation. Eleven variables collected at baseline, 3, 6 and 12 months follow‐up were used to build a Bayesian Network (BN) model: treatment group (neck‐specific vs. general exercises), age, sex, self‐efficacy, catastrophizing, kinesiophobia, anxiety, neck–arm pain intensity, headache pain intensity and disability. The model was used to quantify the contribution of different mediating pathways on the outcome of disability at 12th months. Results All modelled variables were conditionally independent from treatment groups. A one‐point increase in anxiety at 3rd month was associated with a 2.45‐point increase in 12th month disability (p <.001). A one‐point increase in head pain at 3rd month was associated with a 0.08‐point increase in 12th month disability (p <.001). Approximately 83% of the effect of anxiety on disability was attributable to self‐efficacy. Approximately 88% of the effect of head pain on disability was attributable to neck–arm pain. Conclusions No psychological or pain‐related variables mediated the different treatment programs with respect to the outcome of disability. Thus, the specific characteristics investigated in this study did not explain the differences in mechanisms of effect between neck‐specific training and prescribed physical activity. The present study provides candidate modifiable mediators that could be the target of future intervention trials. Significance Psychological and pain characteristics did not differentially explain the mechanism of effect that two exercise regimes had on disability in individuals with cervical radiculopathy. In addition, we found that improvements in self‐efficacy was approximately five times more important than that of neck–arm pain intensity in mediating the anxiety‐disability relationship. A mechanistic understanding of recovery provides candidate modifiable mediators that could be the target of future intervention trials. Trials registration ClinicalTrials.gov identifier: NCT01547611

Stromal Hedgehog signalling is downregulated in colon cancer and its restoration restrains tumour growth

A role for Hedgehog (Hh) signalling in the development of colorectal cancer (CRC) has been proposed. In CRC and other solid tumours, Hh ligands are upregulated; however, a specific Hh antagonist provided no benefit in a clinical trial. Here we use Hh reporter mice to show that downstream Hh activity is unexpectedly diminished in a mouse model of colitis-associated colon cancer, and that downstream Hh signalling is restricted to the stroma. Functionally, stroma-specific Hh activation in mice markedly reduces the tumour load and blocks progression of advanced neoplasms, partly via the modulation of BMP signalling and restriction of the colonic stem cell signature. By contrast, attenuated Hh signalling accelerates colonic tumourigenesis. In human CRC, downstream Hh activity is similarly reduced and canonical Hh signalling remains predominantly paracrine. Our results suggest that diminished downstream Hh signalling enhances CRC development, and that stromal Hh activation can act as a colonic tumour suppressor

Direct Measurements of Meltwater Runoff on the Greenland Ice Sheet Surface

Meltwater runoff from the Greenland Ice Sheet surface influences surface mass balance (SMB), ice dynamics and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-hour trial for a 63.1 square kilometer moulin-terminating internally drained catchment (IDC) on Greenland's mid-elevation (1207-1381 meters above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6.1 (Modele Atmospherique Regionale 3.6.1), RACMO2.3 (Regional Atmospheric Climate Model 2.3), MERRA-2 (Modern Era Retrospective-analysis for Research and Applications-2) and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins, but are improved using synthetic unit hydrograph theory (SUH). Retroactive SUH applications to two older field studies reproduces their findings, signifying that remotely sensed IDC area, shape, and river-length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6.1, RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment models overestimated runoff by plus 21 percent to plus 58 percent, linked to overestimated ablation and possible meltwater retention in bare, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of surface mass balance with ice dynamics and subglacial systems

Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas

Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN