77 research outputs found
Direct entropy determination and application to artificial spin ice
From thermodynamic origins, the concept of entropy has expanded to a range of
statistical measures of uncertainty, which may still be thermodynamically
significant. However, laboratory measurements of entropy continue to rely on
direct measurements of heat. New technologies that can map out myriads of
microscopic degrees of freedom suggest direct determination of configurational
entropy by counting in systems where it is thermodynamically inaccessible, such
as granular and colloidal materials, proteins and lithographically fabricated
nanometre-scale arrays. Here, we demonstrate a conditional-probability
technique to calculate entropy densities of translation-invariant states on
lattices using limited configuration data on small clusters, and apply it to
arrays of interacting nanometre-scale magnetic islands (artificial spin ice).
Models for statistically disordered systems can be assessed by applying the
method to relative entropy densities. For artificial spin ice, this analysis
shows that nearest-neighbour correlations drive longer-range ones.Comment: 10 page
The influence of adolescents essential and non-essential use of technology and Internet addiction on their physical and mental fatigues
This study explores the impact of Internet addiction (IA), age, and essential and non-essential technology usage time on the physical and mental fatigue of adolescents. The research surveyed 477 adolescents from Qatar and employed the Internet Addiction Diagnostic Questionnaire (IADQ) and Chalder's Fatigue Scale for data collection. Multiple linear regression and Mann–Whitney U tests were utilized for analysis. The findings indicate that IA, non-essential usage time, and age are positively associated with overall fatigue among adolescents. IA and non-essential usage time are positively linked to physical fatigue, while IA, non-essential usage time, and age are positive predictors of mental fatigue. However, essential usage time is negatively associated with mental fatigue. These results highlight the importance of distinguishing technology usage based on intent and necessity, as well as differentiating between physical and mental fatigue when examining problematic technology usage. This study is among the few conducted in the Middle Eastern context.Open Access funding provided by the Qatar National Library. This publication was supported by NPRP 14 Cluster grant # NPRP 14C-0916–210015 from the Qatar National Research Fund (a member of Qatar Foundation)
Over-prescription of short-acting β2-agonists is associated with poor asthma outcomes: results from the African cohort of the SABINA III study
Background
The extent of short-acting β2-agonist (SABA) overuse in Africa remains poorly documented. As part of the SABA use IN Asthma (SABINA) III study, we assessed SABA prescriptions/clinical outcomes in 3 African countries.
Methods
Data on disease characteristics/asthma treatments were collected from patients (≥12 years) using electronic case report forms. Patients were classified by investigator-defined asthma severity (guided by the 2017 Global Initiative for Asthma) and practice type (primary/specialist care). Multivariable regression models analyzed associations between SABA prescriptions and outcomes.
Results
Data from 1778 patients (mean age, 43.7 years) were analyzed. Most patients were female (62.4%) and had moderate-to-severe asthma (63.3%), with 57.1 and 42.9% of patients treated in specialist and primary care, respectively. Asthma was partly controlled/uncontrolled in 66.2% of patients, with 57.9% experiencing ≥1 severe exacerbation in the previous 12 months. Overall, 46.5% of patients were prescribed ≥3 SABA canisters in the preceding 12 months (over-prescription); 26.2% were prescribed ≥10 canisters. SABAs were purchased over-the-counter by 32.6% of patients, of whom 79.3% had received SABA prescriptions; 71.9% and 40.1% for ≥3 and ≥10 canisters, respectively. Higher SABA prescriptions (vs. 1–2 canisters) were associated with increased incidence rate of severe exacerbations and lower odds of having at least partly controlled asthma (except 3–5 canisters).
Conclusions
Findings from this African cohort of the SABINA III study indicate that SABA over-prescription and SABA over-the-counter purchase are common and associated with poor asthma-related outcomes. This highlights the need for healthcare providers/policymakers to align clinical practices with the latest treatment recommendations
Real-world evidence in achondroplasia: considerations for a standardized data set
BackgroundCollection of real-world evidence (RWE) is important in achondroplasia. Development of a prospective, shared, international resource that follows the principles of findability, accessibility, interoperability, and reuse of digital assets, and that captures long-term, high-quality data, would improve understanding of the natural history of achondroplasia, quality of life, and related outcomes.MethodsThe Europe, Middle East, and Africa (EMEA) Achondroplasia Steering Committee comprises a multidisciplinary team of 17 clinical experts and 3 advocacy organization representatives. The committee undertook an exercise to identify essential data elements for a standardized prospective registry to study the natural history of achondroplasia and related outcomes.ResultsA range of RWE on achondroplasia is being collected at EMEA centres. Whereas commonalities exist, the data elements, methods used to collect and store them, and frequency of collection vary. The topics considered most important for collection were auxological measures, sleep studies, quality of life, and neurological manifestations. Data considered essential for a prospective registry were grouped into six categories: demographics; diagnosis and patient measurements; medical issues; investigations and surgical events; medications; and outcomes possibly associated with achondroplasia treatments.ConclusionsLong-term, high-quality data are needed for this rare, multifaceted condition. Establishing registries that collect predefined data elements across age spans will provide contemporaneous prospective and longitudinal information and will be useful to improve clinical decision-making and management. It should be feasible to collect a minimum dataset with the flexibility to include country-specific criteria and pool data across countries to examine clinical outcomes associated with achondroplasia and different therapeutic approaches.Metabolic health: pathophysiological trajectories and therap
Loss-of-function mutations in UDP-Glucose 6-Dehydrogenase cause recessive developmental epileptic encephalopathy
AbstractDevelopmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids. Consistent with being loss-of-function alleles, we show using patients’ primary fibroblasts and biochemical assays, that these mutations either impair UGDH stability, oligomerization, or enzymatic activity. In vitro, patient-derived cerebral organoids are smaller with a reduced number of proliferating neuronal progenitors while mutant ugdh zebrafish do not phenocopy the human disease. Our study defines UGDH as a key player for the production of extracellular matrix components that are essential for human brain development. Based on the incidence of variants observed, UGDH mutations are likely to be a frequent cause of recessive epileptic encephalopathy.</jats:p
Loss-of-function mutations in UDP-Glucose 6-Dehydrogenase cause recessive developmental epileptic encephalopathy
Developmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids. Consistent with being loss-of-function alleles, we show using patients’ primary fibroblasts and biochemical assays, that these mutations either impair UGDH stability, oligomerization, or enzymatic activity. In vitro, patient-derived cerebral organoids are smaller with a reduced number of proliferating neuronal progenitors while mutant ugdh zebrafish do not phenocopy the human disease. Our study defines UGDH as a key player for the production of extracellular matrix components that are essential for human brain development. Based on the incidence of variants observed, UGDH mutations are likely to be a frequent cause of recessive epileptic encephalopathy
Recommended from our members
Epstein-Barr virus: clinical and epidemiological revisits and genetic basis of oncogenesis
Epstein-Barr virus (EBV) is classified as a member in the order herpesvirales, family herpesviridae, subfamily gammaherpesvirinae and the genus lymphocytovirus. The virus is an exclusively human pathogen and thus also termed as human herpesvirus 4 (HHV4). It was the first oncogenic virus recognized and has been incriminated in the causation of tumors of both lymphatic and epithelial nature. It was reported in some previous studies that 95% of the population worldwide are serologically positive to the virus. Clinically, EBV primary infection is almost silent, persisting as a life-long asymptomatic latent infection in B cells although it may be responsible for a transient clinical syndrome called infectious mononucleosis. Following reactivation of the virus from latency due to immunocompromised status, EBV was found to be associated with several tumors. EBV linked to oncogenesis as detected in lymphoid tumors such as Burkitt's lymphoma (BL), Hodgkin's disease (HD), post-transplant lymphoproliferative disorders (PTLD) and T-cell lymphomas (e.g. Peripheral T-cell lymphomas; PTCL and Anaplastic large cell lymphomas; ALCL). It is also linked to epithelial tumors such as nasopharyngeal carcinoma (NPC), gastric carcinomas and oral hairy leukoplakia (OHL). In vitro, EBV many studies have demonstrated its ability to transform B cells into lymphoblastoid cell lines (LCLs). Despite these malignancies showing different clinical and epidemiological patterns when studied, genetic studies have suggested that these EBV- associated transformations were characterized generally by low level of virus gene expression with only the latent virus proteins (LVPs) upregulated in both tumors and LCLs. In this review, we summarize some clinical and epidemiological features of EBV- associated tumors. We also discuss how EBV latent genes may lead to oncogenesis in the different clinical malignancie
- …