Search results for "Variability"

Towards understanding the complexity of cardiovascular oscillations: Insights from information theory.

2018

Abstract Cardiovascular complexity is a feature of healthy physiological regulation, which stems from the simultaneous activity of several cardiovascular reflexes and other non-reflex physiological mechanisms. It is manifested in the rich dynamics characterizing the spontaneous heart rate and blood pressure variability (HRV and BPV). The present study faces the challenge of disclosing the origin of short-term HRV and BPV from the statistical perspective offered by information theory. To dissect the physiological mechanisms giving rise to cardiovascular complexity in different conditions, measures of predictive information, information storage, information transfer and information modificati…

RELATIONSHIPS BETWEEN SHORT-TERM BLOOD PRESSURE VARIABILITY AND EARLY RENAL DYSFUNCTION IN ESSENTIAL HYPERTENSIVE PATIENTS

2014

RELATIONSHIPS BETWEEN SHORT-TERM BLOOD PRESSURE VARIABILITY AND EARLY RENAL DYSFUNCTION IN HYPERTENSION

2014

The prognostic significance of short–term blood pressure (BP) variability (STBPV), expressed as standard deviation (SD) of blood pressures (BP) intermittently recorded over 24 hours, is debated. Recently, indices of STBPV other than SD have been proposed. Among these, the 24-h BP Average Real Variability (ARV) seems to be associated more consistently than SD with an enhanced cardiovascular risk. The relationship between mild-to-moderate renal dysfunction (MMRD) and ARV was not investigated. Our study was aimed to analyse, in a large group of untreated essential hypertensives, the relationships between ARV, and other STBV indices, with MMRD. We enrolled 329 essential hypertensive patients, w…

Should reduction of increased short‐term blood pressure variability be a target of antihypertensive therapy?

2021

Abstract It has long been known that blood pressure (BP) is characterized by marked short‐term fluctuations occurring within a 24‐h period and also by long‐term oscillations occurring over more prolonged periods of time. An increased short‐term blood pressure variability (BPV) appears to importantly contribute to target organ damage and to the enhanced cardiovascular risk of hypertensive patients, over and above the effect of an increase in mean BP levels. Reducing 24‐h mean BP is the main aim of antihypertensive therapy, but initial data are available that additional cardiovascular protection can be achieved by reducing BPV. However, to definitively prove the prognostic role of short‐term …

ABSENCE OF RELATIONSHIPS BETWEEN SHORT-TERM BLOOD PRESSURE VARIABILITY AND EARLY RENAL DYSFUNCTION IN HYPERTENSION

2014

Blood pressure variability

Phylogeography and genetic divergence of some lymnaeid snails, intermediate hosts of human and animal fascioliasis with special reference to lymnaeid…

1997

Abstract A population genetic study using starch gel electrophoresis was performed on populations of several species of lymnaeid snails acting as intermediate hosts for Fasciola hepatica (Trematoda, Plathyhelminth). Lymnaea viatrix was collected in 16 sites from the Bolivian Northern Altiplano. L. cubensis were obtained in one site from Venezuela, one site from Guadeloupe, three sites from Cuba and one site from the Dominican Republic. L. truncatula were collected in one site from France, one from Portugal and one from Morocco. Multilocus enzyme electrophoresis (MEE) were determined for 282 snails at 18 loci. A complete monomorphism was encountered at each geographic site. However, among th…

Comparative analysis of variation and selection in the HCV genome

2016

AbstractGenotype 1 of the hepatitis C virus (HCV) is the most prevalent of the variants of this virus. Its two main subtypes, HCV-1a and HCV-1b, are associated to differences in epidemic features and risk groups, despite sharing similar features in most biological properties. We have analyzed the impact of positive selection on the evolution of these variants using complete genome coding regions, and compared the levels of genetic variability and the distribution of positively selected sites. We have also compared the distributions of positively selected and conserved sites considering different factors such as RNA secondary structure, the presence of different epitopes (antibody, CD4 and C…

The gait is less stable in children with cerebral palsy in normal and dual-task gait compared to typically developed peers

2021

There is limited evidence about gait stability and its alteration by concurrent motor and cognitive tasks in children with cerebral palsy (CP). We examined gait stability and how it is altered by constrained cognitive or motor task in CP and their typically developed (TD) controls. Gait kinematics were recorded using inertial-measurement units (IMU) from 18 patients with hemiplegia (13.5 +/- 2.4 years), 12 with diplegia (13.0 +/- 2.1 years), and 31 TD controls (13.5 +/- 2.2 years) during unconstrained gait, and motor (carrying a tray) and cognitive (word naming) task constrained gait at preferred speed (similar to 400 steps/task). Step duration, its standard deviation and refined-compound-m…

P 042 - Gait complexity quantified using inertial measurement units in children with cerebral palsy

2018

Abstract Children with cerebral palsy (CP) have gait impairments, and their gait is affected by concurrent tasks. We used inertial measurement units (IMU) to quantify CP-related gait complexity alterations, and identify effects of dual tasks on gait variability from 12 children with CP and 23 typically developed (TD) controls. The data were collected for normal and dual-tasks (motor; carrying a tray, cognitive; word naming) during walking. Step duration and adjusted multiscale entropy (MSE) index were computed. In overall, children with CP had shorter step duration and greater gait complexity than TD. Gait complexity was higher in vertical direction during the cognitive than normal and moto…

Spatial variability of 2,4-dichlorophenoxyacetic acid (2,4-D) mineralisation potential at a millimetre scale in soil

2003

Abstract We analysed the ability of soil units of millimetre size to mineralise a herbicide, 2,4-D, using incubations of individual aggregates (2–7 mm diameter) and 6×6×6 mm 3 cubes dissected from soil cores, under standard conditions. Mineralisation of 14 C-ring labelled 2,4-D was measured using a barite paper trap and a Phosphorimager to record the evolved 14 C-CO 2 from these very small soil samples. We found a large variability of 2,4-D mineralisation potential between aggregate size classes, between individual aggregates of the same size and between the different dissected cubes from a given core. We explained this variability by an uneven distribution of the degrading microorganisms a…