Publications by authors named "Falkenberg J"

This study examined the metrics of the macroparasite community in fishes from the Jaguaribe River basin, state of Ceará, before and after receiving water from the São Francisco River in Northeastern Brazil. This research assessed the association of environmental factors (water parameters) and the traits of 30 fish species on the parasite richness and abundance across space (river course) and time (seasons, pre- and post-transposition periods). Generalized linear models reveal associations between parasite metrics and host traits, water parameters, and river sub-basin.

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Mugil curema is a pelagic fish species and it is considered the most common species of the Mugilidae family on the Brazilian coast. The objective of this study was to compile the existing information on the metazoan parasites of this host, as well as including new records from specimens captured in the Cabedelo city, state of Paraíba, Brazil. In the present study, we listed 81 taxa belonging to ten groups previously recorded for the host M.

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Different groups parasitize the gills of fishes, and the organisms can interact in positive, negative, or neutral ways, depending on parasitic abundance, environmental conditions, and the availability of resources. Here, we studied the distribution of ectoparasites on the gills of the mullet Mugil curema in the Cabedelo port region (Brazil), asking if (1) the gill parasites of M. curema fix on specific host gill arches and/or (2) co-occur in the same gill arches within a host individual; (3) if the abundance of one parasite taxon affects the abundance of another on the same gill arches; and (4) considering distinct major groups, if parasites present patterns of co-occurrence on hosts and gill arches different from the expected at random.

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Parasites are important components of communities and constitute great part of the biological diversity found in ecosystems, providing valuable information about their hosts and the environment in which they live. However, despite its importance, parasitic diversity is still not well known in some regions of Brazil, especially with respect to fish parasites in the Northeast Region. The present study aims to perform the survey of gill parasites of fish from two tropical estuaries located in northeastern Brazil: Paraíba and Mamanguape rivers.

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The transmissions as functions of energy are central for electron or phonon transport in the Landauer transport picture. We suggest a simple and computationally "cheap" post-processing scheme to interpolate transmission functions over k-points to get smooth well-converged average transmission functions. This is relevant for data obtained using typical "expensive" first principles calculations where the leads/electrodes are described by periodic boundary conditions.

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Background: Approximately 30% of ischemic strokes have an unknown cause. Increased atrial ectopy (AE) increases the risk of atrial fibrillation (AF), but the risk of stroke in patients with increased AE is unknown.

Objectives: This study aimed to examine whether increased AE and short atrial runs increase the risk of stroke beyond incident AF.

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Objectives: This study sought to develop and validate a method for the integrated analysis of systolic and diastolic ventricular function.

Background: An integrated approach to assess ventricular pump function, myocontractility (end-systolic pressure-volume relationship [ESPVR]), and diastolic compliance (end-diastolic pressure-volume relation [EDPVR]) is of high clinical value. Cardiac magnetic resonance (CMR) is well established for measuring global pump function, and catheterization-combined CMR was previously shown to accurately measure ESPVR, but not yet the EDPVR.

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Several observations suggest that the transmission of myocardial forces is influenced in part by the spatial arrangement of the myocytes aggregated together within ventricular mass. Our aim was to assess, using diffusion tensor magnetic resonance imaging (DT-MRI), any differences in the three-dimensional arrangement of these myocytes in the normal heart compared with the hypertrophic murine myocardium. We induced ventricular hypertrophy in seven mice by infusion of angiotensin II through a subcutaneous pump, with seven other mice serving as controls.

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In cardiology, B-type natriuretic peptide and the amino terminal segment of its prohormone (NT-proBNP) are important biomarkers. The importance of these peptides as markers for heart disease in pediatric cardiology is reviewed. The peptide levels are dependent on age, assay, and possibly gender.

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The vascular NAD(P)H oxidase contributes to endothelial dysfunction and high blood pressure in the spontaneously hypertensive rat by enhancing superoxide production. We investigated the effects of apocynin, a NAD(P)H oxidase inhibitor, on blood pressure and vascular radical and nitric oxide formation in SHR and compared its effects to the calcium channel blocker nifedipine. Apocynin (over four weeks) lowered systolic blood pressure significantly and as effectively as nifedipine.

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Objective: To investigate the effect of carvedilol on electrocardiographic parameters in children with congestive heart failure.

Patients And Methods: 18 children with heart failure (aged 2 months-17 years) were treated with carvedilol (initially 0.09 mg/kg/day, slowly increased up to 0.

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High frequency deep brain stimulation (HFS) used to treat the symptoms of Parkinson's disease (PD) was first assumed to act by reducing an excessive tonic GABAergic inhibitory output from the internal globus pallidus (GPi). Stimulation in GPi might produce this directly by mechanisms such as depolarization block or activation of presynaptic inhibitory fibers, and the same mechanisms evoked by HFS in the subthalamic nucleus (STN) could reduce the excitatory action of STN on GPi neurons. Although somatic recordings from neurons near the stimulation site may appear to support this potential mechanism, the action downstream from the site of stimulation often is not consistent with this interpretation.

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Extracellular microelectrode recordings (MER) often contain artifact from a variety of sources that confound traditional signal-processing techniques that require stationary signal segments. We designed an algorithm to locate the longest stationary segment of MER signals. In this paper we provide a description of the segmentation algorithm and its performance assessment.

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Although microelectrode recordings (MER) are commonly used to confirm stereotactic targets during surgery for movement disorders, there is no consensus on whether the additional risks and cost of MER are worth the benefits. This may be due, in part, to the inconsistency and inefficiency of subjective interpretation of MER data that is currently used in practice. We describe several fully automatic visualization methods for MER that efficiently and clearly indicate segments of the microelectrode trajectories with homogeneous neural activity that correspond to expected deep brain nuclei.

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Locating deep brain neuronal structures is required to accurately place deep brain stimulation (DBS) electrodes during stereotactic surgery in patients with Parkinson's disease and other movement disorders. This study investigates the efficacy of automatic microelectrode visualization and analysis methods to help neurosurgeons locate target structures more objectively, consistently, and easily during surgery. Ten patients (4 males and 6 females) who underwent bilateral implantation of DBS electrodes in the globus pallidus interna (Gpi), from 2001 to 2003, at the Oregon Health and Science University and the Portland Veterans Administration Medical Center were included.

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Children with congenital heart disease need adequate diagnostic classification regarding their cardiovascular status (CVS). N-terminal brain natriuretic peptide (N-BNP) plasma concentration indicates dysfunction of the cardiovascular system and guides decisions concerning treatment and prognosis. Reference values are established for adults, with age-dependent increasing values and higher values in women.

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Objective: To evaluate the role of the concentration of brain natriuretic peptide in the plasma, and its correlation with haemodynamic right ventricular parameters, in children with overload of the right ventricle due to congenital cardiac disease.

Methods: We studied 31 children, with a mean age of 4.8 years, with volume or pressure overload of the right ventricle caused by congenital cardiac disease.

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The aim of this study was to configure a force assessment device and determine potential testing protocols for quantitative evaluation of human neck muscles. The study design consisted of non-randomized control trials, with repeated measures; data from 12 normal subjects were obtained. Several apparatuses were designed, constructed and tested, i.

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Direct intramuscular injection of doxorubicin results in permanent myofiber loss. A previous phase I trial demonstrated that such injections could successfully treat blepharospasm and hemifacial spasm. Our previous in vitro study demonstrated that doxorubicin resulted in a dose-dependent reduction in isometric force generation in sternocleidomastoid muscle in rabbits.

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Electromyographic (EMG) analysis has been used successfully to identify back muscle impairment in patients with low back pain. EMG signals from normal subjects during axial spinal unloading using an LTX 3000 device were obtained and spectral parameters of the electromyographic (EMG) signal were analyzed. The purpose of the study was to determine the optimal time for effective traction using the LTX 3000 rehabilitation device.

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Doxorubicin chemomyectomy is a potent method for the permanent removal of a muscle or group of muscles after direct local injection, and has been used successfully to treat blepharospasm and hemifacial spasm patients. The efficacy of doxorubicin chemomyectomy on reducing muscle strength after direct injection of doxorubicin into rabbit sternocleidomastoid muscle was tested. One- and 6-month postinjection force assessment was performed in vitro to measure alterations in peak twitch and tetanic force generation, as well as fatigue responses for the treated muscles compared to control.

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The sternocleidomastoid muscle (SCM) is one of the major muscles involved in producing abnormal head position in cervical dystonia patients. This study tested whether doxorubicin chemomyectomy, direct injection of doxorubicin into the SCM to permanently remove muscle fibers, has the potential to be a nonsurgical, permanent treatment for cervical dystonia. The right SCM of rabbits was injected with either 1 or 2 mg doxorubicin.

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