Publications by authors named "Ana Amador"

In this work, we used a dynamical system derived from an avian vocal production model to generate synthetic songs that mimic the Zonotrichia capensis songs. We confirmed that these synthetic renditions elicited behavioral responses similar to those evoked by real songs in wild songbirds of the same species. Specifically, we observed an increase in the singing rate of individual birds when a playback device was introduced into their territories.

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During sleep, sporadically, it is possible to find neural patterns of activity in areas of the avian brain that are activated during the generation of the song. It has recently been found that in the vocal muscles of a sleeping bird, it is possible to detect activity patterns during these silent replays. In this work, we employ a dynamical systems model for song production in suboscine birds in order to translate the vocal muscles activity during sleep into synthetic songs.

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Multicentric Castleman disease (MCD) is a poorly understood, heterogeneous lymphoproliferative disorder with benign hyperplastic lymph nodes and systemic inflammatory symptoms. Human herpesvirus-8 (HHV-8) may be associated with MCD, whether or not the patient is infected with the human immunodeficiency virus (HIV). A 74-year-old man presented with anaemia, thrombocytopenia and bilateral axillary adenomegaly of unknown origin.

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Percutaneous mitral valve commissurotomy (PMC) is a viable alternative to mitral valve (MV) surgery in the treatment of patients with rheumatic mitral stenosis (RMS). In this single-center retrospective study of consecutive patients with RMS submitted to PMC from 1991 to 2008, we analyzed clinical, echocardiographic, and hemodynamic data and events during follow-up (FUP) until December 2021. Major adverse cardiovascular events (MACE) were a combined endpoint of all-cause death, cardiovascular hospitalization, and MV re-intervention.

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Article Synopsis
  • Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease, with a recent study examining the link between first-degree atrioventricular block (FDAVB) and cardiovascular outcomes in patients.
  • In a study involving 97 patients, FDAVB was present in 14.4% of cases, and various cardiovascular events were tracked over an average follow-up period of about 4.3 years, but no significant association between FDAVB and these outcomes was found.
  • The study did discover that patients with FDAVB were generally older and had distinct echocardiographic measures, particularly a higher E/e' ratio, indicating a potential area for further research on FDAVB as a progn
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Although coronary angiography (CA) is the gold standard for coronary allograft vasculopathy (CAV) screening, non-invasive modalities have arisen as potential alternatives, such as coronary computed tomography angiography (CCTA). CCTA also quantifies plaque burden, which may influence medical treatment. From January 2021 to April 2022, we prospectively included heart transplant recipients who performed CCTA as a first-line method for CAV detection in a single center.

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Article Synopsis
  • The study investigates how pregnancy, particularly its associated volume overload, affects the heart's ability to adapt to additional pressure and volume changes, focusing on Stretch-Induced Compliance (SIC).
  • It compares cardiac responses in first and third trimester pregnant women, examining factors like Left Ventricular End-Diastolic Volume (LVEDV) and NT-proBNP levels before and after Acute Volume Overload (AVO) induced by leg elevation.
  • Results showed that while both groups experienced initial increases in cardiac volume, SIC adaptation significantly decreased in the third trimester, revealing that cardiovascular risk factors notably influenced heart performance during pregnancy.
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Percutaneous closure of the patent foramen ovale (PFO) is increasingly performed in specific patients with cryptogenic stroke or clinical evidence of a paradoxical embolism. This study was performed to determine the safety of same-day discharge (SDD) following such procedures. This is a prospective, observational study of patients undergoing elective percutaneous PFO closure in a single tertiary center in Portugal between January 2020 and July 2023.

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Cardiac magnetic resonance (CMR) is an established tool for risk stratification in several cardiomyopathies, and its role in muscular dystrophies (MuD) looks promising. We sought to assess how CMR performs in predicting cardiac events in a real cohort of MuD patients. A prospective single-center study with the enrollment of consecutive adult MuD patients referred to cardiac screening from 2012 to 2018 with the collection of clinical and CMR data.

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Background: The gold standard for diagnosis of cardiac tumours is histopathological examination. Cardiovascular magnetic resonance (CMR) is a valuable non-invasive, radiation-free tool for identifying and characterizing cardiac tumours. Our aim is to understand CMR diagnosis of cardiac tumours by distinguishing benign vs.

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Vocal behavior plays a crucial evolutionary role. In the case of birds, song is critically important in courtship, male-male competition and other key behaviors linked to reproduction. However, under natural conditions, a variety of avian species live in close proximity and share an 'acoustic landscape'.

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Introduction And Objectives: Acute total occlusion of the unprotected left main coronary artery (LMCA) is a dramatic event. There are limited data regarding this population. We aimed to describe the clinical presentation and outcomes of patients and to determine predictors of in-hospital mortality.

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Hereditary transthyretin amyloidosis caused by the (ATTRv) p. Val142Ile variant is a common cause of cardiac amyloidosis among Western African countries and Afro-Americans populations. However, in recent years, Caucasian patients have been identified in greater numbers, raising the question of whether this variant has been undeappreciated in this population.

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COVID-19 pandemic has unquestionably influenced care of acute myocardial infarction (AMI). Still, its impact on patients (pts) characteristics, presentation, treatment, and outcomes remains not well established in late pandemic times. To address this issue, we performed a prospective study of type-1 AMI patients admitted in a tertiary care hospital.

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We present a dynamical model for the avian respiratory system and report the measurement of its variables in normal breathing canaries (Serinus canaria). Fitting the parameters of the model, we are able to show that the birds in our study breathe at an aerodynamic resonance of their respiratory system. For different respiratory regimes, such as singing, where rapid respiratory gestures are used, the nonlinearities of the model lead to a shift in its resonances toward higher frequency values.

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How vocal communication signals are represented in the cortex is a major challenge for behavioural neuroscience. Beyond a descriptive code, it is relevant to unveil the dynamical mechanism responsible for the neural representation of auditory stimuli. In this work, we report evidence of synchronous neural activity in nucleus HVC, a telencephalic area of canaries (Serinus canaria), in response to auditory playback of the bird's own song.

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Birdsong is a complex vocal behavior, which emerges out of the interaction between a nervous system and a highly nonlinear vocal device, the syrinx. In this work we discuss how low dimensional dynamical systems, interpretable in terms of the biomechanics involved, are capable of synthesizing realistic songs. We review the experimental and conceptual steps that lead to the formulation of low dimensional dynamical systems for the song system and describe the tests that quantify their success.

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Activation of forebrain circuitry during sleep has been variably characterized as 'pre- or replay' and has been linked to memory consolidation. The evolutionary origins of this mechanism, however, are unknown. Sleep activation of the sensorimotor pathways of learned birdsong is a particularly useful model system because the muscles controlling the vocal organ are activated, revealing syringeal activity patterns for direct comparison with those of daytime vocal activity.

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Introduction And Objectives: The coronavirus SARS-CoV-2 (COVID-19) pandemic has been an unmatched challenge to global healthcare. Although the majority of patients admitted with acute coronary syndrome (ACS) may not be infected with COVID-19, the quarantine and public health emergency measures may have affected this particular high risk group. The objective of this study is to assess the impact of the early period of the COVID-19 pandemic on ACS admissions and clinical course in a tertiary care hospital in Portugal's most affected region.

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The complex vocalizations found in different bird species emerge from the interplay between morphological specializations and neuromuscular control mechanisms. In this work we study the dynamical mechanisms used by a nonlearner bird from the Americas, the suboscine Pitangus sulphuratus, in order to achieve a characteristic timbre of some of its vocalizations. By measuring syringeal muscle activity, air sac pressure, and sound as the bird sings, we are able to show that the birds of this species manage to lock the frequency difference between two sound sources.

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Vocal production in songbirds is a key topic regarding the motor control of a complex, learned behavior. Birdsong is the result of the interaction between the activity of an intricate set of neural nuclei specifically dedicated to song production and learning (known as the "song system"), the respiratory system and the vocal organ. These systems interact and give rise to precise biomechanical motor gestures which result in song production.

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Birdsong production involves the simultaneous and precise control of a set of muscles that change the configuration and dynamics of the vocal organ. Although it has been reported that each one of the different muscles is primarily involved in the control of one acoustic feature, recent advances have shown that they act synergistically to achieve the dynamical state necessary for phonation. In this work, we present a set of criteria that allow the extraction of gating-related information from the electromyographic activity of the syringealis ventralis muscle, a muscle that has been shown to be involved in frequency modulation.

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Neural coding of sound envelope structure in songbirds.

J Comp Physiol A Neuroethol Sens Neural Behav Physiol

March 2018

Songbirds are a well-established animal model to study the neural basis of learning, perception and production of complex vocalizations. In this system, telencephalic neurons in HVC present a state-dependent, highly selective response to auditory presentations of the bird's own song (BOS). This property provides an opportunity to study the neural code behind a complex motor behavior.

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