A FAK conundrum is solved: activation and organization of focal adhesion kinase at the plasma membrane

Focal adhesion kinase (FAK) is a central mediator of cell adhesion, acting both as a scaffold and as catalytically active kinase. Acebronet al(2020) use cryo-electron microscopy (cryo-EM) to visualize the dramatic structural changes that occur uponFAKrecruitment to the plasma membrane, which releasesFAKautoinhibition and induces its oligomerization. Since activity control via autoinhibition and protein clustering are features also utilized by other focal adhesion (FA) proteins, they have moved center stage in the endeavor to understand the complex process of cell adhesion regulation

Geometries for universal quantum computation with matchgates

Matchgates are a group of two-qubit gates associated with free fermions. They are classically simulatable if restricted to act between nearest neighbors on a one-dimensional chain, but become universal for quantum computation with longer-range interactions. We describe various alternative geometries with nearest-neighbor interactions that result in universal quantum computation with matchgates only, including subtle departures from the chain. Our results pave the way for new quantum computer architectures that rely solely on the simple interactions associated with matchgates.Comment: 6 pages, 4 figures. Updated version includes an appendix extending one of the result

General rules for bosonic bunching in multimode interferometers

We perform a comprehensive set of experiments that characterize bosonic bunching of up to 3 photons in interferometers of up to 16 modes. Our experiments verify two rules that govern bosonic bunching. The first rule, obtained recently in [1,2], predicts the average behavior of the bunching probability and is known as the bosonic birthday paradox. The second rule is new, and establishes a n!-factor quantum enhancement for the probability that all n bosons bunch in a single output mode, with respect to the case of distinguishable bosons. Besides its fundamental importance in phenomena such as Bose-Einstein condensation, bosonic bunching can be exploited in applications such as linear optical quantum computing and quantum-enhanced metrology.Comment: 6 pages, 4 figures, and supplementary material (4 pages, 1 figure

Gauged flavour symmetry for the light generations

We study the phenomenology of a model where an SU(2)^3 flavour symmetry acting on the first two generation quarks is gauged and Yukawa couplings for the light generations are generated by a see-saw mechanism involving heavy fermions needed to cancel flavour-gauge anomalies. We find that, in constrast to the SU(3)^3 case studied in the literature, most of the constraints related to the third generation, like electroweak precision bounds or B physics observables, can be evaded, while characteristic collider signatures are predicted.Comment: 16 pages, 3 figure

Retinal pigment epithelial tears after intravitreal bevacizumab injection for exudative age-related macular degeneration.

PURPOSE: To determine the incidence of and the risk factors for the development of retinal pigment epithelial (RPE) tears after intravitreal bevacizumab (Avastin) injection for the treatment of exudative age-related macular degeneration (AMD). METHODS: A retrospective, multicentre, consecutive interventional case series of all patients with subfoveal exudative AMD treated with intravitreal bevacizumab between August 2005 and April 2007. The main outcome measures were pre- and post-RPE tear visual acuity and choroidal neovascular membrane lesion types, incidence of tears and time from first injection until development of the tear. RESULTS: A total of 920 eyes with exudative AMD were treated with intravitreal bevacizumab. Fifteen eyes from 15 patients developed a RPE tear for an incidence of 1.6%. The average patient age was 79 years. Fourteen of the fifteen eyes (93%) had an occult subfoveal choroidal neovascular membrane. Forty-seven per cent (7/15) of the RPE tears occurred within the first 6 weeks of treatment, and all tears occurred within the first 18 weeks of treatment initiation. The mean pre-injection visual acuity was 20/100 with a mean post-tear visual acuity of 20/200. In all 10 eyes in which the tear involved the fovea, the final visual acuity was poor. Six of the 15 eyes continued with bevacizumab/ranibizumab (Lucentis) injections after tear development, and four of these six eyes continued to have visual improvement. CONCLUSION: RPE tears occur after intravitreal bevacizumab injections for exudative AMD in approximately 1.6% of eyes and can cause severe vision loss. Maintenance of therapy may help preserve vision after RPE tear development

Initiating Insulin as Part of the Treating To Target in Type 2 Diabetes (4-T) Trial: An interview study of patients' and health professionals' experiences

OBJECTIVE: To explore patients' and health professionals' experiences of initiating insulin as part of the Treating To Target in Type 2 Diabetes (4-T) randomized controlled trial. RESEARCH DESIGN AND METHODS: Interviews were conducted with 45 trial participants and 21 health professionals and thematically analyzed. RESULTS: Patients were generally psychologically insulin receptive when approached to participate in the 4-T trial. Their receptiveness arose largely from their personal experiences observing intensifying prior treatments and deteriorating blood glucose control over time, which led them to engage with and accept the idea that their diabetes was progressive. Health professionals also fostered receptiveness by drawing on their clinical experience to manage patients' anxieties about initiating insulin. CONCLUSIONS: Previous studies may have overemphasized the problem of psychological insulin resistance and overlooked factors and treatment experiences that may promote insulin receptiveness among type 2 patients

Flavour physics from an approximate U(2)^3 symmetry

The quark sector of the Standard Model exhibits an approximate U(2)^3 flavour symmetry. This symmetry, broken in specific directions dictated by minimality, can explain the success of the Cabibbo-Kobayashi-Maskawa picture of flavour mixing and CP violation, confirmed by the data so far, while allowing for observable deviations from it, as expected in most models of ElectroWeak Symmetry Breaking. Building on previous work in the specific context of supersymmetry, we analyze the expected effects and we quantify the current bounds in a general Effective Field Theory framework. As a further relevant example we then show how the U(2)^3 symmetry and its breaking can be implemented in a generic composite Higgs model and we make a first analysis of its peculiar consequences. We also discuss how some partial extension of U(2)^3 to the lepton sector can arise, both in general and in composite Higgs models. An optimistic though conceivable interpretation of the considerations developed in this paper gives reasons to think that new physics searches in the flavour sector may be about to explore an interesting realm of phenomena.Comment: 29 pages, 5 figure