Hidden scaling in the quantum Hall metal-insulator transition

Scaling properties of the quantum Hall metal-insulator transition are severely affected by finite-size effects in small systems. Surprisingly, despite the narrow spatial range where probability structure functions exhibit multifractal scaling, we clearly verify the existence of extended self-similarity-a hidden infrared scaling phenomenon related to the peculiar form of the crossover at the onset of nonmultifractal behavior. As finite-size effects get stronger for structure functions with negative orders, the parabolic approximation for the multifractal spectrum loses accuracy. However, by means of an extended self-similarity analysis, an improved evaluation of the multifractal exponents is attained for negative orders too, rendering them consistent with previous results, which rely on computations performed for considerably larger systems.69

TAZ is required for metastatic activity and chemoresistance of breast cancer stem cells

Metastatic growth in breast cancer (BC) has been proposed as an exclusive property of cancer stem cells (CSCs). However, formal proof of their identity as cells of origin of recurrences at distant sites and the molecular events that may contribute to tumor cell dissemination and metastasis development are yet to be elucidated. In this study, we analyzed a set of patient-derived breast cancer stem cell (BCSC) lines. We found that in vitro BCSCs exhibit a higher chemoresistance and migratory potential when compared with differentiated, nontumorigenic, breast cancer cells (dBCCs). By developing an in vivo metastatic model simulating the disease of patients with early BC, we observed that BCSCs is the only cell population endowed with metastatic potential. Gene-expression profile studies comparing metastagenic and non-metastagenic cells identified TAZ, a transducer of the Hippo pathway and biomechanical cues, as a central mediator of BCSCs metastatic ability involved in their chemoresistance and tumorigenic potential. Overexpression of TAZ in low-expressing dBCCs induced cell transformation and conferred tumorigenicity and migratory activity. Conversely, loss of TAZ in BCSCs severely impaired metastatic colonization and chemoresistance. In clinical data from 99 BC patients, high expression levels of TAZ were associated with shorter disease-free survival in multivariate analysis, thus indicating that TAZ may represent a novel independent negative prognostic factor. Overall, this study designates TAZ as a novel biomarker and a possible therapeutic target for BC

Beyond the labour income tax wedge: the unemployment-reducing effect of tax progressivity

In this paper, we argue that, for a given overall level of labour income taxation, a more progressive tax schedule increases employment. From a theoretical point of view, higher progressivity increases overall employment through a wage moderating effect and also because employment of low-paid workers is more elastic to wages. We test these theoretical predictions on a panel of 21 OECD countries over 1998–2008. Controlling for the burden of taxation at the average wage, our estimates suggest that a more progressive tax schedule reduces the unemployment rate and increases the employment rate. These findings are confirmed when we account for the potential endogeneity of both average taxation and progressivity. Overall, our results suggest that policy-makers should not only focus on the detrimental effects of tax progressivity on in-work effort, but also consider the employment-enhancing effects