Synthèse en espace et temps du rayonnement acoustique d'une paroi sous excitation turbulente par synthèse spectrale 2D+T et formulation vibro-acoustique directe

6 Pages, 20 RefsNational audienceUne méthode directe pour simuler les vibrations et le rayonnement acoustique d'une paroi soumise à un écoulement subsonique est proposée. Tout d'abord, en adoptant l'hypothèse d'un écoulement homogène et stationnaire, on montre qu'une méthode de synthèse spectrale en espace et temps (2D+t) est suffisante pour obtenir explicitement une réalisation d'un champ de pression pariétale excitatrice p(x,y,t) dont les propriétés inter-spectrales sont prescrites par un modèle empirique de Chase. Cette pression turbulente p(x,y,t) est obtenue explicitement et permet de résoudre le problème vibro-acoustique de la paroi dans une formulation directe. La méthode proposée fournit ainsi une solution complète du problème dans le domaine spatio-temporel : pression excitatrice, déplacement en flexion et pression acoustique rayonnée par la paroi. Une caractéristique de la méthode proposée est un cout de calcul qui s'avère similaire aux formulations inter-spectrales majoritairement utilisées dans la littérature. En particulier, la synthèse permet de prendre en compte l'intégralité des échelles spatio-temporelles du problème : échelles turbulentes, vibratoires et acoustiques. A titre d'exemple, la pression aux oreilles d'un auditeur suite à l'excitation turbulente de la paroi est synthétisée

Expression profiling of the RPE in zebrafish smarca4 mutant revealed altered signals that potentially affect RPE and retinal differentiation

Purpose The purpose of this study was to develop a framework for analyzing retinal pigment epithelium (RPE) expression profiles from zebrafish eye mutants. Methods: The fish model we used was SWI/SNF-related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4 (smarca4), a retinal dystrophic mutant with a previously described retinal phenotype and expression profiles. Histological and Affymetrix GeneChip analyses were conducted to characterize the RPE defects and underlying differential expression, respectively. Results: Histological analysis revealed that smarca4 RPE was formed, but its differentiation was abnormal. In particular, ultrastructural analysis of smarca4 RPE by transmission electron microscopy demonstrated several defects in melanogenesis. The nature of these defects also suggests that the cytoskeletal dynamics, which are tightly linked with melanogenesis, were impaired in smarca4 RPE. To compare the expression profile of normal wild-type (WT) and smarca4 RPE, the gene expression profiles of microdissected retinas and RPE-attached retinas were measured with Affymetrix GeneChip analysis. The RPE expression values were then estimated from these samples by subtracting the retinal expression values from the expression values of the RPE-attached retinas. A factorial analysis was conducted using the expression values of the RPE, retinal, and whole-embryo samples. Specific rules (contrasts) were built using the coefficients of the resulting fitted models to select for three groups of genes: 1) smarca4-regulated RPE genes, 2) smarca4-regulated retinal genes, and 3) smarca4-regulated RPE genes that are not differentially expressed in the retina. Interestingly, the third group consists of 39 genes that are highly related to cytoskeletal dynamics, melanogenesis, and paracrine and intracellular signal transduction. Conclusions: Our analytical framework provides an experimental approach to identify differentially-regulated genes in the retina and the RPE of zebrafish mutants in which both of these tissues are affected by the underlying mutation. Specifically, we have used the method to identify a group of 39 genes that can potentially explain the melanogenesis defect in the smarca4 RPE. In addition, several genes in this group are secreted signaling molecules. Thus, this observation further implicates that the smarca4 RPE might play a role in the retinal dystrophic phenotype in smarca4

Care home staff's experiences and views of supporting the dietary management and choices of older residents with obesity

BackgroundRising numbers of older people with obesity living in care homes is an international phenomenon. Addressing dietary management of residents with obesity is a cause of debate and controversy. On one hand, the ‘obesity paradox’ suggests obesity protects against morbidity in frail older people. On the other hand, obesity reduces functional status and restricts activity for this group. This paper considers care home staff’s experience and views of supporting dietary management and choice for residents with obesity within the context of this controversy. DesignIn this qualitative study, 33 staff from seven care homes in the North East of England participated in focus groups, and data were analysed using Braun and Clarkes’s (2006) six phase thematic analysis approach. FindingsFindings indicate that participants’ support of dietary management and choice for residents with obesity may be strongly influenced by the care home environment. Care priorities, dietary management approaches, care home life, and family involvement in residents’ dietary intake facilitate and encourage weight gain, and as such, pose challenges for staff attempting to support weight management of residents with obesity.ConclusionFindings suggest that in the care home setting, nutrition policy, guidelines and service commissioning processes, and staff nutrition education, should include management of obesity. Furthermore, families should be supported to understand the implications of their own caring behaviours on residents’ nutritional status

Rule Learning from Time-Dependent Data Applied to Fraud Detection

International audienceIn financial environment, fraud detection is a challenging problem with tremendous financial impacts where data is highly unbalanced, sequential and timestamped. An additional constraint comes from the fact that common machine learning methods cannot be used alone for fraud detection, as every decision made in order to label a transaction as fraudulent needs to be explainable and the complete model understandable.The use of a symbolic language, such as understandable classification rules, is therefore preferred or even required

Characterisation of expression patterns and functional role of Cactin in early zebrafish development

The immune system of teleost zebrafish (Danio rerio) shows high similarity to mammalian counterparts sharing many innate immune components including Toll-Like Receptors (TLRs), cytokines, chemokines and complement molecules. As in mammals, zebrafish also contains the transcription factor NF-jB that plays dualist roles in innate immunity and early development. Indeed NF-jB members are expressed in different temporal patterns during the early stages of zebrafish embryogenesis indicating that each molecule is involved in specific developmental events. In the present study we employ zebrafish as a model to characterise the expression pattern and role of a novel NF-jB regulator, termed Cactin, in early development. Cactin was first characterised in Drosophila as a new member of the Rel pathway that could affect the generation of dorsal–ventral polarity. To explore the potential developmental role of Cactin in zebrafish, we initially investigated its expression pattern and functional role during early embryonic developmental stages. We detect Cactin expression at all stages of early development and knockdown of Cactin by specific morpholino antisense oligonucleotides causes developmental abnormalities manifested by an overall dysmorphic cellular organisation. These results indicate that Cactin has been highly conserved during evolution and plays a key role in early embryonic development

Characterisation of expression patterns and functional role of Cactin in early zebrafish development

The immune system of teleost zebrafish (Danio rerio) shows high similarity to mammalian counterparts sharing many innate immune components including Toll-Like Receptors (TLRs), cytokines, chemokines and complement molecules. As in mammals, zebrafish also contains the transcription factor NF-jB that plays dualist roles in innate immunity and early development. Indeed NF-jB members are expressed in different temporal patterns during the early stages of zebrafish embryogenesis indicating that each molecule is involved in specific developmental events. In the present study we employ zebrafish as a model to characterise the expression pattern and role of a novel NF-jB regulator, termed Cactin, in early development. Cactin was first characterised in Drosophila as a new member of the Rel pathway that could affect the generation of dorsal–ventral polarity. To explore the potential developmental role of Cactin in zebrafish, we initially investigated its expression pattern and functional role during early embryonic developmental stages. We detect Cactin expression at all stages of early development and knockdown of Cactin by specific morpholino antisense oligonucleotides causes developmental abnormalities manifested by an overall dysmorphic cellular organisation. These results indicate that Cactin has been highly conserved during evolution and plays a key role in early embryonic development

Climate change worry and the association with future depression and anxiety: cross-national analysis of 11 European countries

Background: Climate change affects people’s mental health directly and indirectly. Climate anxiety, characterised by persistent worry and distress about environmental changes, is increasingly recognised as a factor affecting mental well-being. This study focused on potential implications of climate change worry for mental health. Objective To assess whether climate change worry is associated with an increased risk of depression, anxiety and sleep disturbance across European countries. Methods: The study used longitudinal data from the European Social Survey-10 (2020–2022) and the followup CROss-National Online Survey 2 wave 4 (2022). A total of 5155 participants across 11 European countries were included in the analysis. Logistic regression models were used to examine the relationship between climate change worry and mental health outcomes (anxiety, depression and sleep), adjusting for potential confounding factors. Stratified analyses were conducted to assess variations between countries. Findings: Climate change worry was associated with increased risk of anxiety (OR: 1.38, 95%CI: 1.13 to 1.68), but not depression (OR: 1.10, 95%CI: 0.94 to 1.29), or sleep disturbance (OR: 1.08, 95%CI: 0.92 to 1.27), in pooled analyses across countries. Country specific analyses revealed notable differences, with the strongest associations between climate worry and anxiety observed in Slovenia and Italy. Conclusions: These findings suggest that the psychological impact of climate change worry is not uniform across Europe and may be influenced by national policies, environmental risks and sociocultural factors. Given the varying effects across countries, policy-makers should consider contextual factors when designing strategies to address climate anxiety. Integrating mental health considerations into climate policies may enhance public engagement and resilience in the face of environmental challenges. Clinical implications: Traditional therapeutic approaches may not fully capture the unique distress associated with environmental worries, necessitating the development of specialised interventions that validate individuals’ concerns while equipping them with coping mechanisms

Automated Estimation of the Spinal Curvature via Spine Centerline Extraction with Ensembles of Cascaded Neural Networks

Scoliosis is a condition defined by an abnormal spinal curvature. For diagnosis and treatment planning of scoliosis, spinal curvature can be estimated using Cobb angles. We propose an automated method for the estimation of Cobb angles from X-ray scans. First, the centerline of the spine was segmented using a cascade of two convolutional neural networks. After smoothing the centerline, Cobb angles were automatically estimated using the derivative of the centerline. We evaluated the results using the mean absolute error and the average symmetric mean absolute percentage error between the manual assessment by experts and the automated predictions. For optimization, we used 609 X-ray scans from the London Health Sciences Center, and for evaluation, we participated in the international challenge "Accurate Automated Spinal Curvature Estimation, MICCAI 2019" (100 scans). On the challenge's test set, we obtained an average symmetric mean absolute percentage error of 22.96

Maternal topoisomerase II alpha, not topoisomerase II beta, enables embryonic development of zebrafish top2a-/- mutants

Background Genetic alterations in human topoisomerase II alpha (TOP2A) are linked to cancer susceptibility. TOP2A decatenates chromosomes and thus is necessary for multiple aspects of cell division including DNA replication, chromosome condensation and segregation. Topoisomerase II alpha is also required for embryonic development in mammals, as mouse Top2a knockouts result in embryonic lethality as early as the 4-8 cell stage. The purpose of this study was to determine whether the extended developmental capability of zebrafish top2a mutants arises from maternal expression of top2a or compensation from its top2b paralogue. Results Here, we describe bloody minded (blm), a novel mutant of zebrafish top2a. In contrast to mouse Top2a nulls, zebrafish top2a mutants survive to larval stages (4-5 day post fertilization). Developmental analyses demonstrate abundant expression of maternal top2a but not top2b. Inhibition or poisoning of maternal topoisomerase II delays embryonic development by extending the cell cycle M-phase. Zygotic top2a and top2b are co-expressed in the zebrafish CNS, but endogenous or ectopic top2b RNA appear unable to prevent the blm phenotype. Conclusions We conclude that maternal top2a enables zebrafish development before the mid-zygotic transition (MZT) and that zebrafish top2a and top2b are not functionally redundant during development after activation of the zygotic genome