Quantification of the contribution of cardiac and arterial remodeling to hypertension.

The study aim was to quantify the individual and combined contributions of both the arterial system and the heart to systolic blood pressure in hypertension. We assessed the parameters of a heart-arterial model for normotensive control subjects and hypertensive patients with left ventricular adaptation patterns classified as normal, concentric remodeling, concentric hypertrophy, or eccentric hypertrophy. The present simulations show that vascular stiffening alone increases the pulse pressure without increasing systolic blood pressure. It is only in combination with an increased peripheral resistance that arterial stiffening leads to systolic hypertension in concentric remodeling and concentric hypertrophy. The contribution of cardiac pump function to the increase in blood pressure depends on cardiac remodeling, hypertrophy, or both. In hypertensive patients with a normal left ventricle, the heart is responsible for 55% of the increase in systolic blood pressure. In concentric remodeling, concentric hypertrophy, and eccentric hypertrophy, the cardiac contribution to the increase in systolic blood pressure is 21%, 65%, and 108%, respectively. We conclude that along with arterial changes, cardiac remodeling and hypertrophy contribute to hypertension

Whole-blood sorting, enrichment and in situ immunolabeling of cellular subsets using acoustic microstreaming

Analyzing undiluted whole human blood is a challenge due to its complex composition of hematopoietic cellular populations, nucleic acids, metabolites, and proteins. We present a novel multi-functional microfluidic acoustic streaming platform that enables sorting, enrichment and in situ identification of cellular subsets from whole blood. This single device platform, based on lateral cavity acoustic transducers (LCAT), enables (1) the sorting of undiluted donor whole blood into its cellular subsets (platelets, RBCs, and WBCs), (2) the enrichment and retrieval of breast cancer cells (MCF-7) spiked in donor whole blood at rare cell relevant concentrations (10 mL− 1), and (3) on-chip immunofluorescent labeling for the detection of specific target cellular populations by their known marker expression patterns. Our approach thus demonstrates a compact system that integrates upstream sample processing with downstream separation/enrichment, to carry out multi-parametric cell analysis for blood-based diagnosis and liquid biopsy blood sampling

Dynamics of genetic rescue in inbred <i>Drosophila melanogaster</i> populations

Genetic rescue has been proposed as a management strategy to improve the fitness of genetically eroded populations by alleviating inbreeding depression. We studied the dynamics of genetic rescue in inbred populations of Drosophila. Using balancer chromosomes, we show that the force of heterosis that accompanies genetic rescue is large and allows even a recessive lethal to increase substantially in frequency in the rescued populations, particularly at stress temperatures. This indicates that deleterious alleles present in the immigrants can increase significantly in frequency in the recipient population when they are in linkage disequilibrium with genes responsible for the heterosis. In a second experiment we rescued eight inbred Drosophila populations with immigrants from two other inbred populations and observe: (i) there is a significant increase in viability both 5 and 10 generations after the rescue event, showing that the increase in fitness is not transient but persists long-term. (ii) The lower the fitness of the recipient population the larger the fitness increase. (iii) The increase in fitness depends significantly on the origin of the rescuers. The immigrants used were fixed for a conditional lethal that was mildly deleterious at 25A degrees C but lethal at 29A degrees C. By comparing fitness at 25A degrees C (the temperature during the rescue experiment) and 29A degrees C, we show that the lethal allele reached significant frequencies in most rescued populations, which upon renewed inbreeding became fixed in part of the inbred lines. In conclusion, in addition to the fitness increase genetic rescue can easily result in a substantial increase in the frequency of mildly deleterious alleles carried by the immigrants. This can endanger the rescued population greatly when it undergoes recurrent inbreeding. However, using a sufficient number of immigrants and to accompany the rescue event with the right demographic measures will overcome this problem. As such, genetic rescue still is a viable option to manage genetically eroded populations

From time-series to complex networks: Application to the cerebrovascular flow patterns in atrial fibrillation

A network-based approach is presented to investigate the cerebrovascular flow patterns during atrial fibrillation (AF) with respect to normal sinus rhythm (NSR). AF, the most common cardiac arrhythmia with faster and irregular beating, has been recently and independently associated with the increased risk of dementia. However, the underlying hemodynamic mechanisms relating the two pathologies remain mainly undetermined so far; thus the contribution of modeling and refined statistical tools is valuable. Pressure and flow rate temporal series in NSR and AF are here evaluated along representative cerebral sites (from carotid arteries to capillary brain circulation), exploiting reliable artificially built signals recently obtained from an in silico approach. The complex network analysis evidences, in a synthetic and original way, a dramatic signal variation towards the distal/capillary cerebral regions during AF, which has no counterpart in NSR conditions. At the large artery level, networks obtained from both AF and NSR hemodynamic signals exhibit elongated and chained features, which are typical of pseudo-periodic series. These aspects are almost completely lost towards the microcirculation during AF, where the networks are topologically more circular and present random-like characteristics. As a consequence, all the physiological phenomena at microcerebral level ruled by periodicity - such as regular perfusion, mean pressure per beat, and average nutrient supply at cellular level - can be strongly compromised, since the AF hemodynamic signals assume irregular behaviour and random-like features. Through a powerful approach which is complementary to the classical statistical tools, the present findings further strengthen the potential link between AF hemodynamic and cognitive decline.Comment: 12 pages, 10 figure

Emotional expression in oral history narratives: comparing results of automated verbal and nonverbal analyses

Audiovisual collections of narratives about war-traumas are rich in descriptions of personal and emotional experiences which can be expressed through verbal and nonverbal means. We complement a commonly used verbal analysis with a nonverbal one to study emotional developments in narratives. Using automatic text, vocal, and facial expression analysis we found that verbal emotional expressions do not correspond much to nonverbal ones. This observation may have important implications for the way narratives traditionally are being studied. We aim to understand how different modes of narrative expression relate to each other, and to enrich digital audiovisual interview collections with emotion-oriented tags

Sustaining Water Resources: Environmental and Economic Impact

Water is essential to human health and economic development due to its utilization in sanitation, agriculture, and energy. Supplying water to an expanding world population requires simultaneous consideration of multiple societal sectors competing for limited resources. Water conservation, supply augmentation, distribution, and treatment of contaminants must work in concert to ensure water sustainability. Water is linked to other sectors, and the quantity and quality of water resources are changing. The efficient use of water in agriculture, the largest user of water worldwide, via drip irrigation is described as is the use of energy-intensive reverse osmosis to supplement freshwater supplies. Efforts to manage watersheds and model their responses to severe weather events are discussed along with efforts to improve the predictability of their function. The regional competition for water resources impacts both energy and water supply reliability, which requires that nations balance both for sustainable economic development. The use of water and energy in the US is described which provides a lens through which to both rethink the interrelationship of water and energy as well as evaluate technological developments. Advances in nanotechnology are highlighted as one emerging technology. These results underscore the multifaceted nature of water sustainability, its interrelationship to energy and economic development, and the need to develop, manage and regulate water systems in a concerted manner

Simultaneous determination of wave speed and arrival time of reflected waves using the pressure-velocity loop

This is the post print version of the article. The official published version can be found at the link below.In a previous paper we demonstrated that the linear portion of the pressure–velocity loop (PU-loop) corresponding to early systole could be used to calculate the local wave speed. In this paper we extend this work to show that determination of the time at which the PU-loop first deviates from linearity provides a convenient way to determine the arrival time of reflected waves (Tr). We also present a new technique using the PU-loop that allows for the determination of wave speed and Tr simultaneously. We measured pressure and flow in elastic tubes of different diameters, where a strong reflection site existed at known distances away form the measurement site. We also measured pressure and flow in the ascending aorta of 11 anaesthetised dogs where a strong reflection site was produced through total arterial occlusion at four different sites. Wave speed was determined from the initial slope of the PU-loop and Tr was determined using a new algorithm that detects the sampling point at which the initial linear part of the PU-loop deviates from linearity. The results of the new technique for detecting Tr were comparable to those determined using the foot-to-foot and wave intensity analysis methods. In elastic tubes Tr detected using the new algorithm was almost identical to that detected using wave intensity analysis and foot-to-foot methods with a maximum difference of 2%. Tr detected using the PU-loop in vivo highly correlated with that detected using wave intensity analysis (r 2 = 0.83, P < 0.001). We conclude that the new technique described in this paper offers a convenient and objective method for detecting Tr, and allows for the dynamic determination of wave speed and Tr, simultaneously