Universality of transition temperatures in families of copper-oxide superconductors: interlayer tunneling redux

We revisit the interlayer tunneling theory of high temperature superconductors and formulate it as a mechanism by which the striking systematics of the transition temperature within a given homologous series can be understood. We pay attention not only to the enhancement of pairing, as was originally suggested, but also to the role of competing order parameters that tend to suppress superconductivity, and to the charge imbalance between inequivalent outer and inner CuO2 planes in a unit cell. Calculations based on a generalized Ginzburg-Landau theory yield results that bear robust and remarkable resemblance to experimental observations.Comment: 14 pages, 9 figures. Missing axes labels correcte

Universal and measurable entanglement entropy in the spin-boson model

We study the entanglement between a qubit and its environment from the spin-boson model with Ohmic dissipation. Through a mapping to the anisotropic Kondo model, we derive the entropy of entanglement of the spin $E(\alpha,\Delta,h)$, where $\alpha$ is the dissipation strength, $\Delta$ is the tunneling amplitude between qubit states, and $h$ is the level asymmetry. For $1-\alpha \gg \Delta/\omega_c$ and $(\Delta,h) \ll \omega_c$, we show that the Kondo energy scale $T_K$ controls the entanglement between the qubit and the bosonic environment ($\omega_c$ is a high-energy cutoff). For $h\ll T_K$, the disentanglement proceeds as $(h/T_K)^2$; for $h\gg T_K$, $E$ vanishes as $(T_K/h)^{2-2\alpha}$, up to a logarithmic correction. For a given $h$, the maximum entanglement occurs at a value of $\alpha$ which lies in the crossover regime $h\sim T_K$. We emphasize the possibility of measuring this entanglement using charge qubits subject to electromagnetic noise.Comment: 4 pages and 4 figures; updated version to appear in Physical Review Letter

Modulation of the local density of states within the dd-density wave theory in the underdoped cuprates

The low temperature scanning tunneling microscopy spectra in the underdoped regime is analyzed from the perspective of coexisting $d$-density wave and d-wave superconducting states. The calculations are carried out in the presence of a low concentration of unitary impurities and within the framework of the fully self-consistent Bogoliubov-de Gennes theory, which allows local modulations of the magnitude of the order parameters in response to the impurities. Our theory captures the essential aspects of the experiments in the underdoped BSCCO at very low temperatures.Comment: 4 pages, 4 eps figures, RevTex4. New added material as well as reference

Young people's trauma-related cognitions before and after cognitive processing therapy for post-traumatic stress disorder

Objectives: Cognitive processing therapy (CPT) is a psychotherapy for post‐traumatic stress disorder (PTSD) with a broad evidence base. Change in trauma‐related cognitions is considered its primary working mechanism. When trying to integrate a traumatic event into existing cognitive schemas, the adaptive mechanism is changing the schema (accommodation). However, PTSD patients frequently either change their schemas too much (over‐accommodation), or cognitively distort the event (assimilation). We aimed to test the hypothesized connections between the three types of cognition and symptom load. Design: This study adds to the literature using ‘impact statements’, essays on their trauma‐related thoughts written by patients at the beginning and end of CPT, to investigate cognitive change and its relationship to symptomatic outcome. Methods: We analysed statements written by 31 adolescents and young adults who received developmentally adapted CPT (a longer treatment where CPT is the core component) in a randomized controlled trial. Results: As expected, post‐CPT statements contained more accommodated and fewer over‐accommodated and assimilated clauses than pre‐CPT statements. Correlations between cognition frequencies and concurrent symptom load were as expected for assimilation, and, in part, over‐accommodation and accommodation. Decreased PTSD and depressive symptoms were correlated with increased accommodated thoughts. For over‐accommodation and assimilation, however, expected correlations could not be shown. Conclusions: Our results support the notion that cognitive change is an important mechanism of change in CPT in a sample of younger, non‐English‐speaking clients

Identifying Patients With Vesicovaginal Fistula at High Risk of Urinary Incontinence After Surgery:

To develop a risk score to identify women with vesicovaginal fistula at high risk of residual urinary incontinence after surgical repair

Replacing energy by von Neumann entropy in quantum phase transitions

In the thermodynamic limit two distinct states of matter cannot be analytic continuations of each other. Classical phase transitions are characterized by non-analyticities of the free energy. For quantum phase transitions (QPTs) the ground state energy often assumes the role of the free energy. But in a number of important cases this criterion fails to predict a QPT, such as the three-dimensional metal-insulator transition of non-interacting electrons in a random potential (Anderson localization). It is therefore essential that we find alternative criteria that can track fundamental changes in the internal correlations of the ground state wavefunction. Here we propose that QPTs are generally accompanied by non-analyticities of the von Neumann (entanglement) entropy. In particular, the entropy is non-analytic at the Anderson transition, where it exhibits unusual fractal scaling. We also examine two dissipative quantum systems of considerable interest to the study of decoherence and find that non-analyticities occur if and only if the system undergoes a QPT.Comment: 8 pages, 6 figures; Annals of Physics, in press (2006

Criticality in correlated quantum matter

At quantum critical points (QCP) \cite{Pfeuty:1971,Young:1975,Hertz:1976,Chakravarty:1989,Millis:1993,Chubukov:1 994,Coleman:2005} there are quantum fluctuations on all length scales, from microscopic to macroscopic lengths, which, remarkably, can be observed at finite temperatures, the regime to which all experiments are necessarily confined. A fundamental question is how high in temperature can the effects of quantum criticality persist? That is, can physical observables be described in terms of universal scaling functions originating from the QCPs? Here we answer these questions by examining exact solutions of models of correlated systems and find that the temperature can be surprisingly high. As a powerful illustration of quantum criticality, we predict that the zero temperature superfluid density, $\rho_{s}(0)$, and the transition temperature, $T_{c}$, of the cuprates are related by $T_{c}\propto\rho_{s}(0)^y$, where the exponent $y$ is different at the two edges of the superconducting dome, signifying the respective QCPs. This relationship can be tested in high quality crystals.Comment: Final accepted version not including minor stylistic correction

Fertility outcomes following obstetric fistula repair: a prospective cohort study

Abstract Background Obstetric fistula (OF) is a maternal morbidity associated with high rates of stillbirth, amenorrhea, and sexual dysfunction. Limited data exists on the reproductive outcomes of women in the years following a fistula repair. The objective of this study is to describe the fertility outcomes and family planning practices in a population of Malawian women 1–4 years after fistula repair. Methods Women who had enrolled into a clinical database of OF patients and undergone OF repair between January 1, 2012 and July 31, 2014 were recruited and enrolled to complete a home-based survey of their demographic and reproductive health data 1–4 years after their repair. Pregnancy, amenorrhea, and sexual function were described using frequency analysis, and we compared antimüllerian hormone (AMH) concentrations between women with menses or pregnancy with women with amenorrhea or no pregnancy using Wilcoxon rank sum tests. Results Of 297 women with a prior OF repair, 148 had reproductive potential and were included in this analysis. Overall 30 women of these women (21%) became pregnant since their fistula repair, with most pregnancies ending with cesarean delivery. Of the 32 women who were amenorrheic at the time of repair, 25 (78.1%) had resumption of menses. Only 11 (8.6%) of sexually active women reported dyspareunia, and among women who were not trying to conceive, 53.1% were currently using a method of family planning. No significant differences were found in AMH concentrations between those who were pregnant or had menses versus those without pregnancy or menses, respectively. Conclusions In this long-term follow-up study of women after OF repair, many women were able to achieve a pregnancy with a live birth, have normal menses, be sexually active, and access contraception. These achievements will further assist a population of women whose reintegration and restoration of dignity is closely tied to their ability to achieve their reproductive goals. Trial registration ClinicalTrials.gov Identifier: NCT02685878

Explanation as a Social Practice: Toward a Conceptual Framework for the Social Design of AI Systems

none20siThe recent surge of interest in explainability in artificial intelligence (XAI) is propelled by not only technological advancements in machine learning, but also by regulatory initiatives to foster transparency in algorithmic decision making. In this article, we revise the current concept of explainability and identify three limitations: passive explainee, narrow view on the social process, and undifferentiated assessment of understanding. In order to overcome these limitations, we present explanation as a social practice in which explainer and explainee co-construct understanding on the microlevel. We view the co-construction on a microlevel as embedded into a macrolevel, yielding expectations concerning, e.g., social roles or partner models: Typically, the role of the explainer is to provide an explanation and to adapt it to the current level of understanding of the explainee; the explainee, in turn, is expected to provide cues that guide the explainer. Building on explanations being a social practice, we present a conceptual framework that aims to guide future research in XAI. The framework relies on the key concepts of monitoring and scaffolding to capture the development of interaction. We relate our conceptual framework and our new perspective on explaining to transparency and autonomy as objectives considered for XAInoneKatharina J. Rohlfing; Philipp Cimiano; Ingrid Scharlau; Tobias Matzner; Heike M. Buhl; Hendrik Buschmeier; Elena Esposito; Angela Grimminger; Barbara Hammer; Reinhold Häb-Umbach; Ilona Horwath; Eyke Hüllermeier; Friederike Kern; Stefan Kopp; Kirsten Thommes; Axel-Cyrille Ngonga Ngomo; Carsten Schulte; Henning Wachsmuth; Petra Wagner; Britta WredeKatharina J. Rohlfing; Philipp Cimiano; Ingrid Scharlau; Tobias Matzner; Heike M. Buhl; Hendrik Buschmeier; Elena Esposito; Angela Grimminger; Barbara Hammer; Reinhold Häb-Umbach; Ilona Horwath; Eyke Hüllermeier; Friederike Kern; Stefan Kopp; Kirsten Thommes; Axel-Cyrille Ngonga Ngomo; Carsten Schulte; Henning Wachsmuth; Petra Wagner; Britta Wred