Detection of electronic nematicity using scanning tunneling microscopy

Electronic nematic phases have been proposed to occur in various correlated electron systems and were recently claimed to have been detected in scanning tunneling microscopy (STM) conductance maps of the pseudogap states of the cuprate high-temperature superconductor Bi2Sr2CaCu2O8+x (Bi-2212). We investigate the influence of anisotropic STM tip structures on such measurements and establish, with a model calculation, the presence of a tunneling interference effect within an STM junction that induces energy-dependent symmetry-breaking features in the conductance maps. We experimentally confirm this phenomenon on different correlated electron systems, including measurements in the pseudogap state of Bi-2212, showing that the apparent nematic behavior of the imaged crystal lattice is likely not due to nematic order but is related to how a realistic STM tip probes the band structure of a material. We further establish that this interference effect can be used as a sensitive probe of changes in the momentum structure of the sample's quasiparticles as a function of energy.Comment: Accepted for publication (PRB - Rapid Communications). Main text (5 pages, 4 figures) + Supplemental Material (4 pages, 4 figures

Comparative Evaluation of Action Recognition Methods via Riemannian Manifolds, Fisher Vectors and GMMs: Ideal and Challenging Conditions

We present a comparative evaluation of various techniques for action recognition while keeping as many variables as possible controlled. We employ two categories of Riemannian manifolds: symmetric positive definite matrices and linear subspaces. For both categories we use their corresponding nearest neighbour classifiers, kernels, and recent kernelised sparse representations. We compare against traditional action recognition techniques based on Gaussian mixture models and Fisher vectors (FVs). We evaluate these action recognition techniques under ideal conditions, as well as their sensitivity in more challenging conditions (variations in scale and translation). Despite recent advancements for handling manifolds, manifold based techniques obtain the lowest performance and their kernel representations are more unstable in the presence of challenging conditions. The FV approach obtains the highest accuracy under ideal conditions. Moreover, FV best deals with moderate scale and translation changes

Higgs for Graviton: Simple and Elegant Solution

A Higgs mechanism for gravity is presented, where four scalars with global Lorentz symmetry are employed. We show that in the broken symmetry phase a graviton absorbs all scalars and become massive spin 2 particle with five degrees of freedom. The resulting theory is unitary and free of ghosts.Comment: 8 pages, References added. The decoupling of ghost state is analyzed in detail

Global transcript and phenotypic analysis of yeast cells expressing Ssa1, Ssa2, Ssa3 or Ssa4 as sole source of cytosolic Hsp70-Ssa chaperone activity.

BACKGROUND: Cytosolic Hsp70 is a ubiquitous molecular chaperone that is involved in responding to a variety of cellular stresses. A major function of Hsp70 is to prevent the aggregation of denatured proteins by binding to exposed hydrophobic regions and preventing the accumulation of amorphous aggregates. To gain further insight into the functional redundancy and specialisation of the highly homologous yeast Hsp70-Ssa family we expressed each of the individual Ssa proteins as the sole source of Hsp70 in the cell and assessed phenotypic differences in prion propagation and stress resistance. Additionally we also analysed the global gene expression patterns in yeast strains expressing individual Ssa proteins, using microarray and RT-qPCR analysis. RESULTS: We confirm and extend previous studies demonstrating that cells expressing different Hsp70-Ssa isoforms vary in their ability to propagate the yeast [PSI+] prion, with Ssa3 being the most proficient. Of the four Ssa family members the heat inducible isoforms are more proficient in acquiring thermotolerance and we show a greater requirement than was previously thought, for cellular processes in addition to the traditional Hsp104 protein disaggregase machinery, in acquiring such thermotolerance. Cells expressing different Hsp70-Ssa isoforms also display differences in phenotypic response to exposure to cell wall damaging and oxidative stress agents, again with the heat inducible isoforms providing better protection than constitutive isoforms. We assessed global transcriptome profiles for cells expressing individual Hsp70-Ssa isoforms as the sole source of cytosolic Hsp70, and identified a significant difference in cellular gene expression between these strains. Differences in gene expression profiles provide a rationale for some phenotypic differences we observed in this study. We also demonstrate a high degree of correlation between microarray data and RT-qPCR analysis for a selection of genes. CONCLUSIONS: The Hsp70-Ssa family provide both redundant and variant-specific functions within the yeast cell. Yeast cells expressing individual members of the Hsp70-Ssa family as the sole source of Ssa protein display differences in global gene expression profiles. These changes in global gene expression may contribute significantly to the phenotypic differences observed between the Hsp70-Ssa family members

Evaluating the design and reporting of pragmatic trials in osteoarthritis research

Objectives. Among the challenges in health research is translating interventions from controlled experimental settings to clinical and community settings where chronic disease is managed daily. Pragmatic trials offer a method for testing interventions in real-world settings but are seldom used in OA research. The aim of this study was to evaluate the literature on pragmatic trials in OA research up to August 2016 in order to identify strengths and weaknesses in the design and reporting of these trials. Methods. We used established guidelines to assess the degree to which 61 OA studies complied with pragmatic trial design and reporting. We assessed design according to the pragmatic–explanatory continuum indicator summary and reporting according to the pragmatic trials extension of the CONsolidated Standards of Reporting Trials guidelines. Results. None of the pragmatic trials met all 11 criteria evaluated and most of the trials met between 5 and 8 of the criteria. Criteria most often unmet pertained to practitioner expertise (by requiring specialists) and criteria most often met pertained to primary outcome analysis (by using intention-to-treat analysis). Conclusion. Our results suggest a lack of highly pragmatic trials in OA research. We identify this as a point of opportunity to improve research translation, since optimizing the design and reporting of pragmatic trials can facilitate implementation of evidence-based interventions for OA care

Stationary Cylindrical Anisotropic Fluid

We present the whole set of equations with regularity and matching conditions required for the description of physically meaningful stationary cylindrically symmmetric distributions of matter, smoothly matched to Lewis vacuum spacetime. A specific example is given. The electric and magnetic parts of the Weyl tensor are calculated, and it is shown that purely electric solutions are necessarily static. Then, it is shown that no conformally flat stationary cylindrical fluid exits, satisfying regularity and matching conditions.Comment: 17 pages Latex. To appear in Gen.Rel.Gra

The effects of inspiratory muscle strengthening on MIP and quality of life of elderly nursing home patients. (Los efectos del beneficio de la fuerza del músculo inspiratorio en la PIM y la calidad de la vida de los pacientes mayores de la clínica de reposo.)

<b>Abstract</b><p align="justify">The objective of this study was to compare the effects of inspiratory muscle strengthening on maximal inspiratory pressure (MIP) and on quality of life among elderly nursing home patients. The study population was divided in two groups: experimental group- EG (n=21, 76.48 2.12 years) and control group- CG (n=13, 75.69 2.26 years). The World Health Organization Quality of Life Group (WHOQOL-100) questionnaire was used to evaluate the quality of life of the subjects. A Manovacuometer (analogical, with an operational interval of –150 to +150 cmH2O; Critical Med/USA-2002) was used to evaluate MIP. The study protocol consisted of a gradual increase in workload (50%-100%); the sessions lasted 20 minutes and were composed of 7 series of strengthening (2 minutes each) with a 1-minute interval between the series, 3 times a week for 10 weeks. Variance analysis of multivariate repeated measurements demonstrated significant differences only for MIP between CG (32,69±17,03 cmH2O versus 23,08±10,71 cmH2O) and EG (31,67±11,11 cmH2O versus 55,24±23,26 cmH2O), and the latter was higher than the former (p= 0,00000). Therefore, we concluded that inspiratory muscle strengthening led to an increase in MIP that did not improve quality of life. However, further studies should be done in this population to validate a quality of life questionnaire specific for the elderly.</p><b>Resumen</b><p align="justify">El objetivo de este estudio era comparar los efectos del músculo inspiratorio que consolidaban en la presión inspiratoria máxima (PIM) y en la calidad de la vida entre pacientes mayores de la clínica de reposo. Dividieron a la población del estudio en dos grupos: grupo experimental EG. (n=21,76.48 2.12 años) y grupo de control CG (n=13, 75.69 2.26 años). La calidad de la Organización Mundial de la Salud del cuestionario del grupo de la vida(WHOQOL-100) fue utilizada para evaluar la calidad de la vida de los temas. Un Manovacuometer (analógico, con un intervalo operacional - de 150 a +150 cmH2O; Med/USA-2002 crítico) fue utilizado para evaluar la MIP.El protocolo del estudio consistió en un aumento gradual en la carga de trabajo (50%-100%); las sesiones duraron 20 minutos y fueron compuestas de 7 series de consolidación (2 minutos cada uno) con un 1 intervalo minucioso entre la serie, 3 veces a la semana por 10 semanas. El análisis de variación de medidas repetidas multivariate demostró diferencias significativas solamente para la MIPS entre CG (32,69±17,03 cmH2O contra 23,08±10,71 cmH2O) y EG. (31,67±11,11 cmH2O contra 55,24±23,26 cmH2O), y el último era más alto que el anterior (p= 0.00000). Por lo tanto, concluimos que el músculo inspiratorio que consolidaba condujo a un aumento en la MIPS que no mejoró la calidad de la vida. Sin embargo, otros estudios se deben hacer en esta población para validar una calidad del específico del cuestionario de la vida para los ancianos.</p