T-wave alternans: desempenho clínico, limitações, metodologias de análise

Reconhecer com precisão indivíduos com maior risco imediato de morte súbita cardíaca (MSC) ainda é uma questão em aberto. A natureza fortuita dos eventos cardiovasculares agudos não parece se adequar ao conhecido modelo de indução de taquicardia/fibrilação ventricular por um gatilho em sincronia a um substrato arritmogênico estático. Quanto ao mecanismo da MSC, uma instabilidade elétrica dinâmica explicaria melhor a raridade da associação simultânea de um gatilho certo a um substrato cardíaco apropriado. Diversos estudos tentaram medir essa instabilidade elétrica cardíaca (ou um equivalente válido) em uma sequência de batimentos cardíacos no ECG. Dentre os mecanismos possíveis podemos citar o prolongamento do QT, dispersão do QT, potenciais tardios, alternância de onda T ou T-wave alternans (TWA), e turbulência da frequência cardíaca. Este artigo se atém em particular ao papel da TWA no panorama atual da estratificação de risco cardíaco. Os achados sobre TWA ainda são heterogêneos, variando de um desempenho prognóstico muito bom até um quase nulo, dependendo da população clínica observada e protocolo clínico usado. Para preencher as atuais lacunas no conhecimento sobre TWA, profissionais médicos e pesquisadores devem explorar melhor as características técnicas das diversas tecnologias disponíveis para a avaliação de TWA e atentar ao fato de que os valores de TWA respondem a diversos outros fatores, além de medicamentos. Informações sobre mecanismos celulares e subcelulares da TWA estão fora do escopo deste artigo, mas são referenciados alguns dos principais trabalhos sobre este tópico, com o intuito de auxiliar no entendimento dos conceitos e fatos cobertos neste artigo.

Ray-wave correspondence and extended ray dynamics in optical microcavities

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2011

Full-wave field interactions of nonuniform transmission lines

Transmission-line supertheory, generalized transmission-line theory, radiation

Control of spiral wave dynamics by feedback mechanism via a triangular sensory domain

Spiral wave,feedback mechanism, photosensitive BZ reaction, excitable media, drift vetor field plot, planewave approximation, BZ, nonlinear

Theory and application of nonlinear wave propagation phenomena in combined reaction/separation processes

Reaction separation processes, reactive distillation, chromatographic reactor, equilibrium theory, nonlinear waves, process control, observer design, asymptoticaly exact input/output-linearization

Development of a new isogeometric finite element and its application for Lamb wave based structural health monitoring

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2012

Higher order finite elements and the fictitious domain concept for wave propagation analysis

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2014

Morphological development of Corydoras aff. paleatus (Siluriformes, Callichthyidae) and correlation with the emergence of motor and social behaviors

Here we examine major anatomical characteristics of Corydoras aff. paleatus (Jenyns, 1842) post-hatching development, in parallel with its neurobehavioral evolution. Eleutheroembryonic phase, 4.3-8.8 days post-fertilization (dpf); 4.3-6.4 mm standard length (SL) encompasses from hatching to transition to exogenous feeding. Protopterygiolarval phase (8.9-10.9 dpf; 6.5-6.7 mm SL) goes from feeding transition to the commencement of unpaired fin differentiation, which marks the start of pterygiolarval phase (11-33 dpf; 6.8-10.7 mm SL) defined by appearance of lepidotrichia in the dorsal part of the median finfold. This phase ends with the full detachment and differentiation of unpaired fins, events signaling the commencement of the juvenile period (34-60 dpf; 10.8-18.0 mm SL). Eleutheroembryonic phase focuses on hiding and differentiation of mechanosensory, chemosensory and central neural systems, crucial for supplying the larval period with efficient escape and nutrient detection-capture neurocircuits. Protopterygiolarval priorities include visual development and respiratory, digestive and hydrodynamic efficiencies. Pterygiolarval priorities change towards higher swimming efficacy, including carangiform and vertical swimming, necessary for the high social interaction typical of this species. At the end of the protopterygiolarval phase, simple resting and foraging aggregations are seen. Resting and foraging shoals grow in complexity and participant number during pterygiolarval phase, but particularly during juvenile period.

Black Wave

Combined media on photographic paper. 110" x 54" Los Angeles County Museum of Art (LACMA)

Europeanization and the Emergence of a European Society

This article examines the European integration process from a sociological perspective, where the main focus is the examination of the social consequences of the integration process. The European Union has advanced significantly in the economic, social, and political integration processes. This has resulted in a rapid Europeanization of behavior. There has hardly been any progress, however, toward the development of European social groups. This article examines the causes of this lag and concludes that it is highly unlikely that in the middle run there be significant progress toward the Europeanization of society.

Estudio de las diferentes alternativas para mejorar la respuesta de los filtros BAW (Bulk Acoustic Wave) con topología en escalera

Los requisitos de los dispositivos empleados en los nuevos sistemas de telecomunicaciones son: unas avanzadas prestaciones, reducido tamaño y bajo coste. Actualmente, se utilizan filtros basados en la tecnología SAW para trabajar a frecuencias de microondas. Dado los inconvenientes que presentan dicho tipo de filtros, se pretende substituirlos por filtros basados en tecnología BAW. La topología en escalera es hasta el momento la más extendida para diseñar estos filtros.

Long-term outcome after cognitive and behavioral regression in nonlesional epilepsy with continuous spike-waves during slow-wave sleep.

PURPOSE: To present the long-term follow-up of 10 adolescents and young adults with documented cognitive and behavioral regression as children due to nonlesional focal, mainly frontal, epilepsy with continuous spike-waves during slow wave sleep (CSWS). METHODS: Past medical and electroencephalography (EEG) data were reviewed and neuropsychological tests exploring main cognitive functions were administered. KEY FINDINGS: After a mean duration of follow-up of 15.6 years (range, 8-23 years), none of the 10 patients had recovered fully, but four regained borderline to normal intelligence and were almost independent. Patients with prolonged global intellectual regression had the worst outcome, whereas those with more specific and short-lived deficits recovered best. The marked behavioral disorders resolved in all but one patient. Executive functions were neither severely nor homogenously affected. Three patients with a frontal syndrome during the active phase (AP) disclosed only mild residual executive and social cognition deficits. The main cognitive gains occurred shortly after the AP, but qualitative improvements continued to occur. Long-term outcome correlated best with duration of CSWS. SIGNIFICANCE: Our findings emphasize that cognitive recovery after cessation of CSWS depends on the severity and duration of the initial regression. None of our patients had major executive and social cognition deficits with preserved intelligence, as reported in adults with early destructive lesions of the frontal lobes. Early recognition of epilepsy with CSWS and rapid introduction of effective therapy are crucial for a best possible outcome.

Threshold Effects of Dismissal Protection Regulation and the Emergence of Temporary Work Agencies

Labour market regulations aimed at enhancing job-security are dominant in several OECD countries. These regulations seek to reduce dismissals of workers and fluctuations in employment. The main theoretical contribution is to gauge the effects of such regulations on labour demand across establishment sizes. In order to achieve this, we investigate an optimising model of labour demand under uncertainty through the application of real option theory. We also consider other forms of employment which increase the flexibility of the labour market. In particular, we are modelling the contribution of temporary employment agencies (Zeitarbeit) allowing for quick personnel adjustments in client firms. The calibration results indicate that labour market rigidities may be crucial for understanding sluggishness in firms´ labour demand and the emergence and growth of temporary work.

Bilateral symmetry of radial pulse in high-level tennis players: implications for the validity of central aortic pulse wave analysis.

BACKGROUND: Reconstruction of the central aortic pressure wave from the noninvasive recording of the radial pulse with applanation tonometry has become a standard tool in the field of hypertension. It is not presently known whether recording the radial pulse on the dominant or the nondominant side has any effect on such reconstruction. METHOD: We carried out radial applanation tonometry on both forearms in young, healthy, male volunteers, who were either sedentary (n = 11) or high-level tennis players (n = 10). The purpose of including tennis players was to investigate individuals with extreme asymmetry between the dominant and nondominant upper limb. RESULTS: In the sedentary individuals, forearm circumference and handgrip strength were slightly larger on the dominant (mean +/- SD respectively 27.9 +/- 1.5 cm and 53.8 +/- 10 kg) than on nondominant side (27.3 +/- 1.6 cm, P < 0.001 vs. dominant, and 52.1 +/- 11 kg, P = NS). In the tennis players, differences between sides were more conspicuous (forearm circumference: dominant 28.0 +/- 1.7 cm nondominant 26.4 +/- 1.5 cm, P < 0.001; handgrip strength 61.4 +/- 10.8 vs. 53.4 +/- 9.7 kg, P < 0.001). We found that in both sedentary individuals and tennis players, the radial pulse had identical shape on both sides and, consequently, the reconstructed central aortic pressure waveforms, as well as derived indices of central pulsatility, were not dependent on the side where applanation tonometry was carried out. CONCLUSION: Evidence from individuals with maximal asymmetry of dominant vs. nondominant upper limb indicates that laterality of measurement is not a methodological issue for central pulse wave analysis carried out with radial applanation tonometry.