A novel digital cognitive biomarker for mild cognitive impairment and Alzheimer disease

Recent evidence suggests that oculomotor behaviours linked to cognitive performance can be a biomarker of Alzheimer?s disease (AD). Short-Term Memory Binding (STMB) declines in patients with AD dementia and in those at risk of dementia. STMB relies on brain regions relevant to visual processing which are known to support oculomotor behaviours. Viewmind is proposed as a novel ?cognitive digital biomarker? with the potential of revealing phenotypic features of AD in the pre-dementia stage of the pathology. Viewmind applies artificial intelligence to analyse eye movements and pupil responses during the performance of STMBT.Fil: Fernández Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; ArgentinaFil: Schumacher, Marcela Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages". Universidad Nacional del Sur. Departamento de Ingeniería Eléctrica y de Computadoras. Instituto de Investigaciones en Ingeniería Eléctrica "Alfredo Desages"; ArgentinaFil: Orozco, David. Clínica Privada Bahiense; ArgentinaFil: Sgrilli Gustavo. Clinica Privada Bahiense; ArgentinaFil: Echeverria Gustavo. Clinica privada Bahiense; ArgentinaFil: Linares Ramiro. Clinica Privada Bahiense; ArgentinaFil: Parra, Mario A. University of Strathclyde; Reino UnidoAlzheimer´s Association International ConferenceDenver, ColoradoEstados UnidosAlzheimer Associatio

Distributed event-triggered communication for angular speed synchronization of networked BLDC motors

[EN] This work presents the design and implementation of a collaborative and decentralized control for synchronizing the angular velocity of a group of spatially distributed brushless direct current (BLDC) motors. Via an Active Disturbance Rejection Control (ADRC), acting as an internal-loop, the dynamics of the BLDC can be assimilated to that of a first-order integrator, which is considered an agent. Then, a decentralized collaborative control strategy with event-triggered communication is proposed, which solves the problem of leader-follower consensus for the multi-agent system and thus speed synchronization. The communication topology between agents is modeled using an undirected and connected graph. The decentralized control law incorporates an event function, which indicates the instant at which the i-th agent transmits the angular velocity information to its neighbor. An experimental platform using two BLDC and a virtual leader was developed to validate the proposed approach. The experimental results show excellent performance for angular velocity consensus for regulation tasks, while the bandwidth usage is only 1.25 % regarding a periodic communication implementation.[ES] Este trabajo presenta el diseño e implementación de un control colaborativo descentralizado para la sincronización de velocidad angular de un conjunto de motores de corriente continua sin escobillas (BLDC) distribuidos espacialmente. Apoyándose de un control por rechazo activo de perturbaciones, actuando como un bucle interno, la dinámica del BLDC puede asimilarse a la de un integrador de primer orden y el cual será considerado un agente. Se propone entonces una estrategia de control colaborativo descentralizado con una comunicación activada por eventos, que resuelve el problema del consenso líder-seguidor del sistema multi-agente y, con ello, la sincronización de velocidades entre motores. La topología de comunicación entre agentes se modela usando un grafo conectado y no dirigido. La ley de control descentralizado incorpora una función de evento, que indica el instante en el que $i$-ésimo agente transmite la información de velocidad angular a su vecino. El intercambio asíncrono de información permite reducir el tráfico de datos en la red de comunicaciones, lo que permite aprovechar el ancho de banda. Al analizar la dinámica de la trayectoria del error del sistema, se establece que el vector de error del sistema multi-agente tiende de forma exponencial y permanece confinado a una vecindad del origen del espacio de estados de error. Aunque la estrategia está diseñada para n-agentes, se desarrolló una plataforma experimental compuesta por dos motores y un líder virtual, permitiendo validar la estrategia. Los resultados experimentales muestran un excelente desempeño del consenso de velocidad angular de ambos motores BLDC para tareas de regulación, mientras que el uso del ancho de banda es de solamente 1.25 % con respecto a una implementación de comunicación periódica.Hernández-Méndez, A.; Guerrero-Castellanos, J.; Orozco-Urbieta, T.; Linares-Flores, J.; Mino-Aguilar, G.; Curiel, G. (2021). Comunicación distribuida activada por eventos para la sincronización de velocidad angular de motores BLDC en red. Revista Iberoamericana de Automática e Informática industrial. 18(4):360-370. https://doi.org/10.4995/riai.2021.14989OJS360370184Ahmed, N., Cortes, J., Martinez, S., 2016. Distributed control and estimation of robotic vehicle networks: Overview of the special issue-part II. IEEE Control Systems 36 (4), 18-21. https://doi.org/10.1109/MCS.2016.2558398Aranda-Escolástico, E., Guinaldo, M., Heradio, R., Chacon, J., Vargas, H., Sánchez, J., Dormido, S., 2020. 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A backstepping approach to decentralized active disturbance rejection control of interacting boost converters. Transactions on Industry Applications 53 (4), 4063-4072. https://doi.org/10.1109/TIA.2017.2683441Lee, J., Bagheri, B., Kao, H.-A., 2015. A cyber-physical systems architecture for industry 4.0-based manufacturing systems. Manufacturing Letters 3, 18- 23. https://doi.org/10.1016/j.mfglet.2014.12.001Lewis, F. L., Zhang, H., Hengster-Movric, K., Das, A., 2013. Cooperative control of multi-agent systems: optimal and adaptive design approaches. Springer Science & Business Media. https://doi.org/10.1007/978-1-4471-5574-4Marchand, N., Durand, S., Guerrero-Castellanos, J. F., 2013. A general formula for event-based stabilization of nonlinear systems. Automatic Control, IEEE Transactions on 58 (5), 1332-1337. https://doi.org/10.1109/TAC.2012.2225493Miskowicz, M., 2015. Event-Based Control and Signal Processing. CRC Press.Neenu, T., Poongodi, P., 07 2009. Position control of dc motor using genetic algorithm based pid controller. Lecture Notes in Engineering and Computer Science 2177.Olfati-Saber, R., Murray, R. M., 2004a. Consensus problems in networks of agents with switching topology and time-delays. Automatic Control, IEEE Transactions on 49 (9), 1520-1533. https://doi.org/10.1109/TAC.2004.834113Olfati-Saber, R., Murray, R. M., Sep. 2004b. Consensus problems in networks of agents with switching topology and time-delays. IEEE Transactions on Automatic Control 49 (9), 1520-1533. https://doi.org/10.1109/TAC.2004.834113Ren, W., Beard, R. W., 2008. Distributed consensus in multi-vehicle cooperative control. Springer. https://doi.org/10.1007/978-1-84800-015-5Sánchez-Santana, J., Guerrero-Castellanos, J., Villarreal-Cervantes, M., Ramırez-Martınez, S., 2018. Control distribuido y disparado por eventos para la formación de robots m'oviles tipo (3, 0)?. In: Congreso Nacional de Control Automático.Seyboth, G. S., Dimarogonas, D. 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On the sensitivity of the HAWC observatory to gamma-ray bursts

We present the sensitivity of HAWC to Gamma Ray Bursts (GRBs). HAWC is a very high-energy gamma-ray observatory currently under construction in Mexico at an altitude of 4100 m. It will observe atmospheric air showers via the water Cherenkov method. HAWC will consist of 300 large water tanks instrumented with 4 photomultipliers each. HAWC has two data acquisition (DAQ) systems. The main DAQ system reads out coincident signals in the tanks and reconstructs the direction and energy of individual atmospheric showers. The scaler DAQ counts the hits in each photomultiplier tube (PMT) in the detector and searches for a statistical excess over the noise of all PMTs. We show that HAWC has a realistic opportunity to observe the high-energy power law components of GRBs that extend at least up to 30 GeV, as it has been observed by Fermi LAT. The two DAQ systems have an energy threshold that is low enough to observe events similar to GRB 090510 and GRB 090902b with the characteristics observed by Fermi LAT. HAWC will provide information about the high-energy spectra of GRBs which in turn could help to understanding about e-pair attenuation in GRB jets, extragalactic background light absorption, as well as establishing the highest energy to which GRBs accelerate particles

Ancestral diversity improves discovery and fine-mapping of genetic loci for anthropometric traits — The Hispanic/Latino Anthropometry Consortium

Hispanic/Latinos have been underrepresented in genome-wide association studies (GWAS) for anthropometric traits despite their notable anthropometric variability, ancestry proportions, and high burden of growth stunting and overweight/obesity. To address this knowledge gap, we analyzed densely imputed genetic data in a sample of Hispanic/Latino adults to identify and fine-map genetic variants associated with body mass index (BMI), height, and BMI-adjusted waist-to-hip ratio (WHRadjBMI). We conducted a GWAS of 18 studies/consortia as part of the Hispanic/Latino Anthropometry (HISLA) Consortium (stage 1, n = 59,771) and generalized our findings in 9 additional studies (stage 2, n = 10,538). We conducted a trans-ancestral GWAS with summary statistics from HISLA stage 1 and existing consortia of European and African ancestries. In our HISLA stage 1 + 2 analyses, we discovered one BMI locus, as well as two BMI signals and another height signal each within established anthropometric loci. In our trans-ancestral meta-analysis, we discovered three BMI loci, one height locus, and one WHRadjBMI locus. We also identified 3 secondary signals for BMI, 28 for height, and 2 for WHRadjBMI in established loci. We show that 336 known BMI, 1,177 known height, and 143 known WHRadjBMI (combined) SNPs demonstrated suggestive transferability (nominal significance and effect estimate directional consistency) in Hispanic/Latino adults. Of these, 36 BMI, 124 height, and 11 WHRadjBMI SNPs were significant after trait-specific Bonferroni correction. Trans-ancestral meta-analysis of the three ancestries showed a small-to-moderate impact of uncorrected population stratification on the resulting effect size estimates. Our findings demonstrate that future studies may also benefit from leveraging diverse ancestries and differences in linkage disequilibrium patterns to discover novel loci and additional signals with less residual population stratification

Complement component C4 structural variation and quantitative traits contribute to sex-biased vulnerability in systemic sclerosis

Altres ajuts: Fondo Europeo de Desarrollo Regional (FEDER), "A way of making Europe".Copy number (CN) polymorphisms of complement C4 play distinct roles in many conditions, including immune-mediated diseases. We investigated the association of C4 CN with systemic sclerosis (SSc) risk. Imputed total C4, C4A, C4B, and HERV-K CN were analyzed in 26,633 individuals and validated in an independent cohort. Our results showed that higher C4 CN confers protection to SSc, and deviations from CN parity of C4A and C4B augmented risk. The protection contributed per copy of C4A and C4B differed by sex. Stronger protection was afforded by C4A in men and by C4B in women. C4 CN correlated well with its gene expression and serum protein levels, and less C4 was detected for both in SSc patients. Conditioned analysis suggests that C4 genetics strongly contributes to the SSc association within the major histocompatibility complex locus and highlights classical alleles and amino acid variants of HLA-DRB1 and HLA-DPB1 as C4-independent signals

Ancestral diversity improves discovery and fine-mapping of genetic loci for anthropometric traits - the Hispanic/Latino Anthropometry Consortium

Hispanic/Latinos have been underrepresented in genome-wide association studies (GWAS) for anthropometric traits despite their notable anthropometric variability, ancestry proportions, and high burden of growth stunting and overweight/obesity. To address this knowledge gap, we analyzed densely-imputed genetic data in a sample of Hispanic/Latino adults to identify and fine-map genetic variants associated with body mass index (BMI), height, and BMI-adjusted waist-to-hip ratio (WHRadjBMI). We conducted a GWAS of 18 studies/consortia as part of the Hispanic/Latino Anthropometry (HISLA) Consortium (Stage 1, n=59,771) and generalized our findings in 9 additional studies (HISLA Stage 2, n=10,538). We conducted a trans-ancestral GWAS with summary statistics from HISLA Stage 1 and existing consortia of European and African ancestries. In our HISLA Stage 1+2 analyses, we discovered one BMI locus, as well as two BMI signals and another height signal each within established anthropometric loci. In our trans-ancestral meta-analysis, we discovered three BMI loci, one height locus, and one WHRadjBMI locus. We also identified three secondary signals for BMI, 28 for height, and two for WHRadjBMI in established loci. We show that 336 known BMI, 1,177 known height, and 143 known WHRadjBMI (combined) SNPs demonstrated suggestive transferability (nominal significance and effect estimate directional consistency) in Hispanic/Latino adults. Of these, 36 BMI, 124 height, and 11 WHRadjBMI SNPs were significant after trait-specific Bonferroni correction. Trans-ancestral meta-analysis of the three ancestries showed a small-to-moderate impact of uncorrected population stratification on the resulting effect size estimates. Our findings demonstrate that future studies may also benefit from leveraging diverse ancestries and differences in linkage disequilibrium patterns to discover novel loci and additional signals with less residual population stratification

Effects of Once-Weekly Exenatide on Cardiovascular Outcomes in Type 2 Diabetes.

Abstract BACKGROUND: The cardiovascular effects of adding once-weekly treatment with exenatide to usual care in patients with type 2 diabetes are unknown. METHODS: We randomly assigned patients with type 2 diabetes, with or without previous cardiovascular disease, to receive subcutaneous injections of extended-release exenatide at a dose of 2 mg or matching placebo once weekly. The primary composite outcome was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The coprimary hypotheses were that exenatide, administered once weekly, would be noninferior to placebo with respect to safety and superior to placebo with respect to efficacy. RESULTS: In all, 14,752 patients (of whom 10,782 [73.1%] had previous cardiovascular disease) were followed for a median of 3.2 years (interquartile range, 2.2 to 4.4). A primary composite outcome event occurred in 839 of 7356 patients (11.4%; 3.7 events per 100 person-years) in the exenatide group and in 905 of 7396 patients (12.2%; 4.0 events per 100 person-years) in the placebo group (hazard ratio, 0.91; 95% confidence interval [CI], 0.83 to 1.00), with the intention-to-treat analysis indicating that exenatide, administered once weekly, was noninferior to placebo with respect to safety (P<0.001 for noninferiority) but was not superior to placebo with respect to efficacy (P=0.06 for superiority). The rates of death from cardiovascular causes, fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, hospitalization for heart failure, and hospitalization for acute coronary syndrome, and the incidence of acute pancreatitis, pancreatic cancer, medullary thyroid carcinoma, and serious adverse events did not differ significantly between the two groups. CONCLUSIONS: Among patients with type 2 diabetes with or without previous cardiovascular disease, the incidence of major adverse cardiovascular events did not differ significantly between patients who received exenatide and those who received placebo. (Funded by Amylin Pharmaceuticals; EXSCEL ClinicalTrials.gov number, NCT01144338 .)

A novel digital cognitive biomarker for mild cognitive impairment and Alzheimer's disease

Background -- Recent evidence suggests that oculomotor behaviours linked to cognitive performance can be a biomarker of Alzheimer’s disease (AD). Short-Term Memory Binding (STMB) declines in patients with AD dementia and in those at risk of dementia. STMB relies on brain regions relevant to visual processing which are known to support oculomotor behaviours. Viewmind is proposed as a novel “cognitive digital biomarker” with the potential of revealing phenotypic features of AD in the pre-dementia stage of the pathology. Viewmind applies artificial intelligence to analyse eye movements and pupil responses during the performance of STMBT. Method -- STMBT assesses the ability to temporarily hold bicoloured objects whose colours had to be remembered either as individual features (baseline) or integrated within unified representations (binding). Viewmind’s technology powered by Artificial Intelligence improved STMBT for identifying MCI patients and their potential conversion to AD. Result -- The 3 years Longitudinal Study involved 42 healthy older adults and 61 patients with Mild Cognitive Impairment (MCI). Viewmind retrospectively classified 91% of the MCI patients who later converted to AD as AD patients. From those MCI patients that Viewmind predicted as no AD, none later converted to AD but they progressed to Fronto-temporal or Parkinson’s Disease. Conclusion -- Taken together, the results above suggest that Viewmind can (1) unveil novel features of AD dementia unknown to date, and (2) provide a more sensitive tool which can detect and trace aspects of such phenotype in people at risk, thus helping to ascertain the presence of the prodromal stages of the disease

Neurofibromatosis tipo 1 (NF1) revisión y presentación de un caso clínico con manifestaciones bucofaciles

La neurofibromatosis es una enfermedad hereditaria de transmisión autosómica dominante que compromete el desarrollo de las células de la cresta neural. Las manifestaciones bucofaciales de la neurofibromatosis tipo 1 (NF1) son muy escasas, presentando una prevalencia de 1:16.000. El caso que se presenta es de un paciente varón de 10 años de edad, de raza negra, que acudió al Servicio de Cirugía Oral y Maxilofacial del Hospital Universitario de Cartagena de Indias (Colombia) por presentar un nódulo en el suelo de la boca y una ligera asimetría facial provocada por una hipertrofia fibrosa que comprometía el maxilar superior y el cuerpo mandibular izquierdo. En el examen físico se encontraron, a nivel cutáneo, numerosas manchas café con leche dispersas por todo el cuerpo, mientras que la exploración oftalmológica reveló múltiples nódulos de Usch (hamartomas del iris). Las imágenes radiográficas mostraron una compresión extraósea y la tomografía computadorizada (TC) descartó la presencia de glioma de los nervios ópticos. Como antecedentes familiares, el padre, una hermana y una tía del paciente presentaban una NF1 confirmada clínicamente. De acuerdo con la determinación de los criterios diagnósticos de la NF1 establecidos en 1987 por el "National institut of health concensus development conference on neurofibromatosis", esos tres hallazgos permitieron hacer un diagnóstico de NF1 y orientar la impresión clínica de las lesiones bucofaciales hacia neurofibromas, lo que fue confirmado histológicamente. El manejo de los pacientes con NF1 es difícil, como también lo es el tratamiento de las complicaciones que pueden producir las lesiones tales como deformidades (con el consiguiente problema psicológico), gliomas de los nervios ópticos (ceguera) o un alto riesgo de malignización. La ayuda del consejo genético, el aislamiento del gen implicado y los últimos avances en el campo de la genética, son muy esperanzadoras en cuanto al diagnóstico prenatal