Leave-one-out prediction error of systolic arterial pressure time series under paced breathing

In this paper we show that different physiological states and pathological conditions may be characterized in terms of predictability of time series signals from the underlying biological system. In particular we consider systolic arterial pressure time series from healthy subjects and Chronic Heart Failure patients, undergoing paced respiration. We model time series by the regularized least squares approach and quantify predictability by the leave-one-out error. We find that the entrainment mechanism connected to paced breath, that renders the arterial blood pressure signal more regular, thus more predictable, is less effective in patients, and this effect correlates with the seriousness of the heart failure. The leave-one-out error separates controls from patients and, when all orders of nonlinearity are taken into account, alive patients from patients for which cardiac death occurred

Interação de genótipos de Pinus taeda L. com locais no sul-sudeste do Brasil.

A importância da resposta relativa diferenciada de progênies e de árvores por locais em Pinus taeda L. na perda de potencial genético pela seleção foi estudada no caráter volume de madeira total do tronco, em 46 progênies de meio-irmãos, em quatro locais no sul-sudeste do Brasil. As progê-nies foram dispostas em nove parcelas lineares, com seis plantas espaçadas em 3 m x 2 m. As análises de variância foram realizadas por local, em conjunto e por locais, dois a dois. As componentes de vari-ância foram estimadas a partir dessas análises e por máxima verossimilhança restrita (REML). Nesse método, foram ajustados modelos estatísticos mistos para a interação das progênies x locais e preditos os valores genéticos aditivos (VG's) pela “melhor predição linear não viciada” (BLUP). A interação foi significativa nas análises de variância conjunta e por locais, dois a dois. O ajuste de modelos mis-tos também foi significativo pelo teste da razão de verossimilhança. A perda do potencial genético na seleção de progênies com base nas estimativas por REML foi de 3,2%. Na seleção de genitores, a per-da na resposta média, pela seleção por VG’s médios, em vez de VG’s por locais, foi de 2,3%. Na sele-ção de árvores para pomares de sementes por mudas não ocorreu redução na resposta média. Para po-mar clonal de dez árvores, a interação superestimou a resposta média esperada em 2%. Nessa ação de melhoramento, a seleção pelo VG médio incrementou a resposta média em 3%. Esse valor foi conside-rado, como a perda de potencial genético, pela não seleção pelo VG médio, quando a interação progê-nies x locais e/ou, o ajuste de modelos são significativos. Sugere-se, o uso do valor genético médio na seleção individual, para maximizar a resposta média esperada

Migraine and cluster headache show impaired neurosteroids patterns

Background: Perturbation of neuronal excitability contributes to migraine. Neurosteroids modulate the activity of γ-aminobutyric acid A and N-methyl-d-aspartate receptors, and might be involved in the pathogenesis of migraine. Here, we measured plasma levels of four neurosteroids, i.e., allopregnanolone, epiallopregnanolone, dehydroepiandrosterone and deydroepiandrosterone sulfate, in patients affected by episodic migraine, chronic migraine, or cluster headache. Methods: Nineteen female patients affected by episodic migraine, 51 female patients affected by chronic migraine, and 18 male patients affected by cluster headache were recruited to the study. Sex- and age-matched healthy control subjects (31 females and 16 males) were also recruited. Patients were clinically characterized by using validated questionnaires. Plasma neurosteroid levels were measured by liquid chromatography-tandem mass spectrometry. Results: We found disease-specific changes in neurosteroid levels in our study groups. For example, allopregnanolone levels were significantly increased in episodic migraine and chronic migraine patients than in control subjects, whereas they were reduced in patients affected by cluster headache. Dehydroepiandrosterone and dehydroepiandrosterone sulfate levels were reduced in patients affected by chronic migraine, but did not change in patients affected by cluster headache. Conclusion: We have shown for the first time that large and disease-specific changes in circulating neurosteroid levels are associated with chronic headache disorders, raising the interesting possibility that fluctuations of neurosteroids at their site of action might shape the natural course of migraine and cluster headache. Whether the observed changes in neurosteroids are genetically determined or rather result from exposure to environmental or intrinsic stressors is unknown. This might also be matter for further investigation because stress is a known triggering factor for headache attacks in both migraineurs and cluster headache patients

Perception of Nigerian Dùndún talking drum performances as speech-like vs. music-like: The role of familiarity and acoustic cues

It seems trivial to identify sound sequences as music or speech, particularly when the sequences come from different sound sources, such as an orchestra and a human voice. Can we also easily distinguish these categories when the sequence comes from the same sound source? On the basis of which acoustic features? We investigated these questions by examining listeners’ classification of sound sequences performed by an instrument intertwining both speech and music: the dùndún talking drum. The dùndún is commonly used in south-west Nigeria as a musical instrument but is also perfectly fit for linguistic usage in what has been described as speech surrogates in Africa. One hundred seven participants from diverse geographical locations (15 different mother tongues represented) took part in an online experiment. Fifty-one participants reported being familiar with the dùndún talking drum, 55% of those being speakers of Yorùbá. During the experiment, participants listened to 30 dùndún samples of about 7s long, performed either as music or Yorùbá speech surrogate (n = 15 each) by a professional musician, and were asked to classify each sample as music or speech-like. The classification task revealed the ability of the listeners to identify the samples as intended by the performer, particularly when they were familiar with the dùndún, though even unfamiliar participants performed above chance. A logistic regression predicting participants’ classification of the samples from several acoustic features confirmed the perceptual relevance of intensity, pitch, timbre, and timing measures and their interaction with listener familiarity. In all, this study provides empirical evidence supporting the discriminating role of acoustic features and the modulatory role of familiarity in teasing apart speech and music

The Dùndún Drum helps us understand how we process speech and music

Every day, you hear many sounds in your environment, like speech, music, animal calls, or passing cars. How do you tease apart these unique categories of sounds? We aimed to understand more about how people distinguish speech and music by using an instrument that can both “speak” and play music: the dùndún talking drum. We were interested in whether people could tell if the sound produced by the drum was speech or music. People who were familiar with the dùndún were good at the task, but so were those who had never heard the dùndún, suggesting that there are general characteristics of sound that define speech and music categories. We observed that music is faster, more regular, and more variable in volume than “speech.” This research helps us understand the interesting instrument that is dùndún and provides insights about how humans distinguish two important types of sound: speech and music

One step minilaparotomy-assisted transmesenteric portal vein recanalization combined with transjugular intrahepatic portosystemic shunt placement: A novel surgical proposal in pediatrics

Transjugular intrahepatic portosystemic shunt (TIPS) placement is a standard procedure for the treatment of portal hypertension complications. When this conventional approach is not feasible, alternative procedures for systemic diversion of portal blood have been proposed. A one-step interventional approach, combining minilaparotomy-assisted transmesenteric (MAT) antegrade portal recanalization and TIPS, is described in an adolescent with recurrent esophageal varice bleeding and portal cavernoma (PC). A 16-year-old girl was admitted to our Unit because of repeated bleeding episodes over a short period of time due to esophageal varices in the context of a PC. A portal vein recanalization through an ileocolic vein isolation with the MAT approach followed by TIPS during the same session was performed. In the case of failed portal recanalization, this approach, would also be useful for varice endovascular embolization. Postoperative recovery was uneventful. Treatment consisting of propanolol, enoxaparin and a proton pump inhibitor was prescribed after the procedure. One month post-op, contrast enhanced computed tomography confirmed the patency of the portal and intrahepatic stent grafts. No residual peritoneal fluid was detected nor opacification of the large varices. Endoscopy showed good improvement of the varices. Doppler ultrasound confirmed the accelerated flow in the portal stent and hepatopetal flow inside the intrahepatic portal branches. Three months post-op, TIPS maintained its hourglass shape despite a slight expansion. Portal hypertension and life threatening conditions related to PC would benefit from one-step portal recanalization. MAT-TIPS is feasible and safe for the treatment of PC even in children. This minimally invasive procedure avoids or delays surgical treatment or re-transplantation when necessary in pediatric patients

Energetic potential of Sclerobium paniculatum vogel (taxi-branco) and its preferential top climatic condition in Eastern Amazonia, Brasil.

Tropentag 2009