Forecasting virus outbreaks with social media data via neural ordinary differential equations.

During the Covid-19 pandemic, real-time social media data could in principle be used as an early predictor of a new epidemic wave. This possibility is examined here by employing a neural ordinary differential equation (neural ODE) trained to forecast viral outbreaks in a specific geographic region. It learns from multivariate time series of signals derived from a novel set of large online polls regarding COVID-19 symptoms. Once trained, the neural ODE can capture the dynamics of interconnected local signals and effectively estimate the number of new infections up to two months in advance. In addition, it may predict the future consequences of changes in the number of infected at a certain period, which might be related with the flow of individuals entering or exiting a region. This study provides persuasive evidence for the predictive ability of widely disseminated social media surveys for public health applications.

Anti-bat ultrasound production in moths is globally and phylogenetically widespread.

Warning signals are well known in the visual system, but rare in other modalities. Some moths produce ultrasonic sounds to warn bats of noxious taste or to mimic unpalatable models. Here, we report results from a long-term study across the globe, assaying moth response to playback of bat echolocation. We tested 252 genera, spanning most families of large-bodied moths, and document anti-bat ultrasound production in 52 genera, with eight subfamily origins described. Based on acoustic analysis of ultrasonic emissions and palatability experiments with bats, it seems that acoustic warning and mimicry are the raison d'être for sound production in most moths. However, some moths use high-duty-cycle ultrasound capable of jamming bat sonar. In fact, we find preliminary evidence of independent origins of sonar jamming in at least six subfamilies. Palatability data indicate that jamming and warning are not mutually exclusive strategies. To explore the possible organization of anti-bat warning sounds into acoustic mimicry rings, we intensively studied a community of moths in Ecuador and, using machine-learning approaches, found five distinct acoustic clusters. While these data represent an early understanding of acoustic aposematism and mimicry across this megadiverse insect order, it is likely that ultrasonically signaling moths comprise one of the largest mimicry complexes on earth.

Concordancia entre pruebas de estabilidad unipodal estática para riesgo de caída en adultos mayores chilenos / Concordance between Static Unipodal Stability Tests concerning Risk of Falling in Chilean Aged Adults

Introducción: El equilibrio postural conforma parte de la evaluación funcional para riesgo de caída en adultos mayores. El Ministerio de Salud Chileno aplica el Test Estación Unipodal para valora la estabilidad unipodal estática como herramienta de prevención en salud. Objetivo: Determinar la concordancia o equivalencia diagnóstica entre el Test Estación Unipodal y el Test unipodal para estabilidad corporal estática, en modalidad ojos abiertos. Métodos: Estudio de concordancia diagnóstica, de tipo transversal; aplicado en 60 adultos mayores autovalentes pertenecientes a talleres deportivos del Gimnasio Olímpico de San Miguel, Región Metropolitana, Chile, quienes voluntariamente ejecutaron dos pruebas de estabilidad unipodal estática y respondieron un instrumento de consulta al final de la evaluación referida al Test unipodal para estabilidad corporal estática. Resultados: Entre las dos pruebas de estabilidad unipodal, en modalidad ojos abiertos, se presentó una concordancia significativa al evaluar buena o deficiente estabilidad (p = 0,0005). Los adultos mayores evaluados percibieron el Test unipodal para estabilidad corporal estática como prueba de fácil aplicación, bajo nivel de riesgo físico y cansancio, declarando intención de volver a realizarla si se requiere valorar nuevamente su estabilidad. Conclusión: Ambos métodos, Test Estación Unipodal y Test unipodal para estabilidad corporal estática, en modalidad ojos abiertos, fueron capaces de clasificar correctamente buena estabilidad o estabilidad deficiente en los adultos mayores evaluados. Por lo tanto, resultan equivalentes y concordantes para el diagnóstico de la estabilidad estática con apoyo unipodal(AU)

Introduction: Postural balance is part of the functional assessment for risk of falling in aged adults. The Chilean Ministry of Health applies the Unipodal Station Test to assess static unipodal stability as a health prevention tool. Objective: To determine concordance or diagnostic equivalence between the Unipodal Station Test and the Unipodal Test for static body stability, in the open eyes modality. Methods: Cross-sectional study of diagnostic concordance applied in sixty self-supporting aged adults belonging to sports workshops of the Olympic Gymnasium of San Miguel, in the Metropolitan Region of Chile, who voluntarily completed two static unipodal stability tests and answered a consultation instrument at the end of the assessment concerning the Unipodal Test for static body stability. Results: Between the two unipodal stability tests, in the open eyes modality, a significant concordance was present upon assessing good or poor stability (p = 0.0005). The aged adults who underwent assessment perceived the Unipodal Test for static body stability as a test of easy application and low level of physical risk and fatigue, as well as declared their intention to complete it again if their stability needed to be reassessed. Conclusion: Both the Unipodal Station Test and the Unipodal Test for static body stability, in the open eyes modality, were effective methods to classify good stability or poor stability correctly in the aged adults who underwent assessment. Therefore, they are equivalent and concordant for the diagnosis of static stability with unipodal support(AU)

Onset of ferrielectricity and the hidden nature of nanoscale polarization in ferroelectric thin films.

Using calculations from first principles and the concept of layer polarization, we have elucidated the nanoscale organization and local polarization in ferroelectric thin films between metallic contacts. The profile of the local polarization for different film thicknesses unveils a peculiar spatial pattern of atomic layers with uncompensated dipoles in what was originally thought to be a ferroelectric domain. This effectively ferrielectric behavior is induced by the dominant roles of the interfaces at such reduced dimensionality and can be interpreted using a simple classical model where the latter are explicitly taken into account.