Loss of Extracellular Signal-Regulated Kinase 1/2 in the Retinal Pigment Epithelium Leads to RPE65 Decrease and Retinal Degeneration.

Recent work suggested that the activity of extracellular signal-regulated kinase 1/2 (ERK1/2) is increased in the retinal pigment epithelium (RPE) of age-related macular degeneration (ARMD) patients and therefore could be an attractive therapeutic target. Notably, ERK1/2 pathway inhibitors are used in cancer therapy, with severe and noncharacterized ocular side effects. To decipher the role of ERK1/2 in RPE cells, we conditionally disrupted the Erk1 and Erk2 genes in mouse RPE. The loss of ERK1/2 activity resulted in a significant decrease in the level of RPE65 expression, a decrease in ocular retinoid levels concomitant with low visual function, and a rapid disorganization of RPE cells, ultimately leading to retinal degeneration. Our results identify the ERK1/2 pathway as a direct regulator of the visual cycle and a critical component of the viability of RPE and photoreceptor cells. Moreover, our results caution about the need for a very fine adjustment of kinase inhibition in cancer or ARMD treatment in order to avoid ocular side effects

Curvature-bias corrections using a pseudomass method

Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using Z→μ + μ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z→μ + μ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass

Helium identification with LHCb

The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

Augmentation des aromes dans le vin et utilisation d'enzymes

National audienc

Varroa destructor changes its cuticular hydrocarbons to mimic new hosts

International audienceVarroa destructor (Vd) is a honeybee ectoparasite. Its original host is the Asianhoneybee, Apis cerana, but it has also become a severe, global threat to theEuropean honeybee, Apis mellifera. Previous studies have shown that Varroacan mimic a host’s cuticular hydrocarbons (HC), enabling the parasite toescape the hygienic behaviour of the host honeybees. By transferring mitesbetween the two honeybee species, we further demonstrate that Vd is able tomimic the cuticular HC of a novel host species when artificially transferredto this new host. Mites originally from A. cerana are more efficient thanmites from A. mellifera in mimicking HC of both A. cerana and A. mellifera.This remarkable adaptability may explain their relatively recent host-shiftfrom A. cerana to A. mellifera

Colour vision defects in schizophrenia spectrum disorders: a systematic review

This systematic review synthesized the existing literature to summarize colour vision disturbances experienced by patients with schizophrenia. A comprehensive literature search compliant with PRISMA-2020 was conducted in Medline and Embase from inception to February 28, 2023. Studies were included if they: (1) included people diagnosed with schizophrenia, (2) investigated colour vision, (3) had a comparator with or without schizophrenia. Study quality appraisal was performed using the NIH Study Quality Assessment Tool. Seven studies of fair quality with 695 patients were included, of whom, 46.5% (n = 323) patients were diagnosed with a schizophrenia-spectrum disorder. Compared to healthy controls, patients with schizophrenia either made more mistakes in discriminating between colours, or were delayed in recognizing colours. One study found that Positive and Negative Syndrome Scale for Schizophrenia (PANSS) scores correlated weakly with error scores related to colour vision impairments. The most common shortcomings were lack of sample size justification (k = 7, 100%), and lack of blinding (k = 7, 100%). Our review indicates early evidence of colour vision deficits among patients with schizophrenia, and an unclear relationship between severity of schizophrenia with colour vision deficits. Possible mechanisms may include alterations in retinal dopamine transmission or schizophrenia-related cognitive deficits interacting with colour vision outcomes. Future studies may benefit from large registry analyses of patients with various schizophrenia spectrum disorders, analyzing ocular parameters (e.g., OCT), collecting data on cognitive impairment, and pursuing multivariate analyses to elucidate mechanisms for schizophrenia-related colour vision changes

Colour vision impairments in bipolar disorder: a systematic review

Visual impairments are common in patients with bipolar disorder (BD), and the neuropathophysiology may suggest a potential influence on colour vision. This systematic review aimed to assess existing data of colour vision impairment, including chromatic discrimination and colour blindness in patients with BD. Comprehensive literature search compliant with PRISMA 2020 was conducted in Medline, Embase, and Google Scholar from inception to February 28th, 2023. Our inclusion criteria were: (1) patients with a diagnosis of bipolar I or II disorder based on DSM, ICD, or clinical diagnosis, and (2) study investigating colour vision (i.e., including colour blindness and discrimination), with (3) no restrictions on the condition of the comparator group. Study quality appraisal was performed using the NIH Study Quality Assessment Tool. Five studies from Brazil, Netherlands, and USA, with 338 patients were included. Three cross-sectional studies assessed chromatic discrimination and two case-series assessed colour blindness in patients with BD. The three cross-sectional studies support reduced chromatic discrimination during mild to moderate mania in BD when compared to healthy comparators. The latter two articles presented low evidence of an X-linked inheritance of BD. Our review indicates evidence of reduced chromatic discrimination in mild to moderate mania. However, further research is needed to validate these findings and to extend to other mood states in BD given current limitations. Future studies can benefit from further multi-institutional data, larger sample sizes, appropriate blinding, the use of biomarkers, and statistical adjustment to confounders to fully elucidate the role of chromatic discrimination in BD