Robust non-fragile LQ controllers: the static state feedback case

This paper describes the synthesis of non-fragile or resilient regulators for linear systems. The general framework for fragility is described using state-space methodologies, and the LQ/H2 static state-feedback case is examined in detail. We discuss the multiplicative structured uncertainties case, and propose remedies of the fragility problem using a convex programming framework as a possible solution scheme. The benchmark problem is taken as an example to show how controller gain variations can affect the performance of the closed-loop system

Bottlenose dolphin mothers modify signature whistles in the presence of their own calves

PLT received support from ONR grants N00014-18-1-2062 and N00014-20-1-2709. Financial support for the whistle database project has come from the Protect Wild Dolphins fund at Harbor Branch Oceanographic Institute, Vulcan Machine Learning Center for Impact, Allen Institute for Artificial Intelligence, Adelaide M. & Charles B. Link Foundation, and Dolphin Quest, Inc.Human caregivers interacting with children typically modify their speech in ways that promote attention, bonding, and language acquisition. Although this “motherese,” or child-directed communication (CDC), occurs in a variety of human cultures, evidence among nonhuman species is very rare. We looked for its occurrence in a nonhuman mammalian species with long-term mother–offspring bonds that is capable of vocal production learning, the bottlenose dolphin (Tursiops truncatus). Dolphin signature whistles provide a unique opportunity to test for CDC in nonhuman animals, because we are able to quantify changes in the same vocalizations produced in the presence or absence of calves. We analyzed recordings made during brief catch-and-release events of wild bottlenose dolphins in waters near Sarasota Bay, Florida, United States, and found that females produced signature whistles with significantly higher maximum frequencies and wider frequency ranges when they were recorded with their own dependent calves vs. not with them. These differences align with the higher fundamental frequencies and wider pitch ranges seen in human CDC. Our results provide evidence in a nonhuman mammal for changes in the same vocalizations when produced in the presence vs. absence of offspring, and thus strongly support convergent evolution of motherese, or CDC, in bottlenose dolphins. CDC may function to enhance attention, bonding, and vocal learning in dolphin calves, as it does in human children. Our data add to the growing body of evidence that dolphins provide a powerful animal model for studying the evolution of vocal learning and language.Publisher PDFPeer reviewe

Trends in prevalence of depression and anxiety symptoms and effects of sociodemographic variables before and after the first wave of COVID-19 in Qatar

Background Prevalence trends from Arabic speaking countries on psychiatric symptoms before and after the first wave of the COVID-19 pandemic are lacking. We estimated the point prevalence and change in depression and anxiety symptoms scores in relation to sociodemographic variables following the resolution of the first wave in Qatar compared with before the pandemic. Methods We conducted a trend analysis using repeated nationally representative cross-sectional surveys spanning 2017, 2018, 2020/2021 and using the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) to assess depressive and anxiety symptoms. Negative binomial regression was used to model changes in these symptoms in relation sociodemographics and survey year. Results The two-week prevalence of depressive symptoms (≥10 on the PHQ-9) was 6.6% in 2017 and 6.5% in 2020/2021 (p = 0.986). The two-week prevalence of anxiety symptoms (≥10 on the GAD-7) was 3.6% in 2018 and 5.1% in 2020/2021 (p = 0.062). The data for 2020/21 showed a 35.1% and 29.2% decrease in depression and anxiety symptoms scores compared to pre-pandemic years (2017/2018) after adjusting for sociodemographic factors. Limitations Screening tools rather than structured interviews were used to assess depressive and anxiety symptoms Conclusions The prevalence of depression and anxiety after the first COVID wave did not differ significantly to pre-pandemic estimates. The end of the first wave of the pandemic weakened the associations of these symptoms with traditional sociodemographic risk factors. The 2020/21 depression and anxiety symptoms scores remained high for Qataris and Arabs, suggesting that these cultural groups may benefit most from public mental health interventions.This research received an Emergency Response Grant Fund from Qatar University ( QUERGCAS-2020-1 ). The Funding agency had no input in the study design, data analysis or writing of this manuscript. The statements made herein are solely the responsibility of the authors.Scopu

The size, burden and cost of disorders of the brain in the UK

Aim: The aim of this paper is to increase awareness of the prevalence and cost of psychiatric and neurological disorders (brain disorders) in the UK. Method: UK data for 18 brain disorders were extracted from a systematic review of European epidemiological data and prevalence rates and the costs of each disorder were summarized (2010 values). Results: There were approximately 45 million cases of brain disorders in the UK, with a cost of €134 billion per annum. The most prevalent were headache, anxiety disorders, sleep disorders, mood disorders and somatoform disorders. However, the five most costly disorders (€ million) were: dementia: €22,164; psychotic disorders: €16,717; mood disorders: €19,238; addiction: €11,719; anxiety disorders: €11,687. Apart from psychosis, these five disorders ranked amongst those with the lowest direct medical expenditure per subject (Peer reviewe

Nonconvulsive Status Epilepticus in Patients with Altered Mental Status Admitted to Hamad General Hospital, Doha, Qatar

This is a prospective, hospital-based study reporting an update and the prevalence of nonconvulsive status epilepticus (NCSE) in patients with altered mental status (AMS) in Qatar. Patients presenting with NCSE are compared to controls. Two-hundred and fifty patients with AMS are involved. Patients with NCSE are: 65 (12–79 years, m, 37, f, 28); controls: 185 (12–80 years, m, 101, f, 84). Occurrence of NCSE in patients with AMS was 26%. NCSE patients were younger than controls (p < 0.001). Deaths in the NCSE group occurred in 31% and 19% in controls (p < 0.0007). Hospitalization length was longer in NCSE proper and in comatose NCSE compared to controls (p < 0.02, p < 0.03). Recovery occurred in 40% of NCSE patients and 53% of controls (p < 0.08). About 31% of patients (n = 21) had refractory NCSE and 9 died. This is the first study reporting the prevalence of NCSE in Qatar. This prevalence (26%) is in the middle range. NCSE did not do better than the controls, result being disappointing regarding comatose NCSE. NCSE is an emerging condition requiring rapid diagnosis and rapid treatment. Regarding the optimal duration of continuous EGG (cEEG) monitoring to diagnose the majority of NCSE cases, 3 days of cEEG monitoring could accomplish this task

Global analyses revealed age-related alterations in innate immune responses after stimulation of pathogen recognition receptors

Aging leads to dysregulation of multiple components of the immune system that results in increased susceptibility to infections and poor response to vaccines in the aging population. The dysfunctions of adaptive B and T cells are well documented, but the effect of aging on innate immunity remains incompletely understood. Using a heterogeneous population of peripheral blood mononuclear cells (PBMCs), we first undertook transcriptional profiling and found that PBMCs isolated from old individuals (≥ 65 years) exhibited a delayed and altered response to stimulation with TLR4, TLR7/8, and RIG-I agonists compared to cells obtained from adults (≤ 40 years). This delayed response to innate immune agonists resulted in the reduced production of pro-inflammatory and antiviral cytokines and chemokines including TNFα, IL-6, IL-1β, IFNα, IFNγ, CCL2, and CCL7. While the major monocyte and dendritic cell subsets did not change numerically with aging, activation of specific cell types was altered. PBMCs from old subjects also had a lower frequency of CD40+ monocytes, impaired up-regulation of PD-L1 on monocytes and T cells, and increased expression of PD-L2 and B7-H4 on B cells. The defective immune response to innate agonists adversely affected adaptive immunity as TLR-stimulated PBMCs (minus CD3 T cells) from old subjects elicited significantly lower levels of adult T-cell proliferation than those from adult subjects in an allogeneic mixed lymphocyte reaction (MLR). Collectively, these age-associated changes in cytokine, chemokine and interferon production, as well as co-stimulatory protein expression could contribute to the blunted memory B- and T-cell immune responses to vaccines and infections

Early prehabilitation reduces admissions and time in hospital in patients with newly diagnosed lung cancer

Objectives Lung cancer is the leading cause of cancer death in the UK. Prehabilitation aims to maximise patient fitness and minimise the negative impact of anticancer treatment. What constitutes prehabilitation before non-surgical anticancer treatment is not well established. We present data from a pilot project of Early prehabilitation In lung Cancer.Methods All new patients with likely advanced lung cancer were offered prehabilitation at respiratory clinic, if fit for further investigation. Prehabilitation included assessment and appropriate intervention from a consultant in palliative medicine, registered dietitian and rehabilitation physiotherapist. Four objective endpoints were identified, namely admissions to hospital, time spent in the hospital, treatment rates and overall survival. Outcomes were to be compared with 178 prehab eligible historical controls diagnosed from 2019 to 2021.Results From July 2021 to June 2023, 65 patients underwent prehabilitation and 72% of patients underwent all 3 interventions. 54 patients had a stage 3 or 4 lung cancer. In the prehab group, fewer patients attended Accident and Emergency (31.5 vs 37.4 attendances per 100 patients) and fewer were admitted (51.9 vs 67.9) when compared with historical controls. Those receiving prehab spent a lot less time in the hospital (129.7 vs 543.5 days per 100 patients) with shorter admissions (2.5 vs 8 days). Systemic anticancer treatment rates increased in the short term but were broadly similar overall. Median survival was higher in the prehabilitation group (0.73 vs 0.41 years, p=0.046).Conclusions Early prehabilitation appears to reduce time spent in the hospital. It may improve survival. Further work is required to understand its full effect on treatment rates.<br/

Implementation of U.K. Earth system models for CMIP6

We describe the scientific and technical implementation of two models for a core set of experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The models used are the physical atmosphere-land-ocean-sea ice model HadGEM3-GC3.1 and the Earth system model UKESM1 which adds a carbon-nitrogen cycle and atmospheric chemistry to HadGEM3-GC3.1. The model results are constrained by the external boundary conditions (forcing data) and initial conditions.We outline the scientific rationale and assumptions made in specifying these. Notable details of the implementation include an ozone redistribution scheme for prescribed ozone simulations (HadGEM3-GC3.1) to avoid inconsistencies with the model's thermal tropopause, and land use change in dynamic vegetation simulations (UKESM1) whose influence will be subject to potential biases in the simulation of background natural vegetation.We discuss the implications of these decisions for interpretation of the simulation results. These simulations are expensive in terms of human and CPU resources and will underpin many further experiments; we describe some of the technical steps taken to ensure their scientific robustness and reproducibility