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https://www.readbyqxmd.com/read/28437535/clinical-aspects-of-glucose-transporter-type-1-deficiency-information-from-a-global-registry
#1
Jian Hao, Dorothy I Kelly, Jianzhong Su, Juan M Pascual
Importance: Case reports regularly document unique or unusual aspects of glucose transporter type 1 deficiency (G1D). In contrast, population studies from which to draw global inferences are lacking. Twenty-five years after the earliest case reports, this deficiency still particularly affects treatment and prognostic counseling. Objective: To examine the most common features of G1D. Design, Setting, and Participants: In this study, data were collected electronically from 181 patients with G1D through a web-based, worldwide patient registry from December 1, 2013, through December 1, 2016...
April 24, 2017: JAMA Neurology
https://www.readbyqxmd.com/read/28437460/an-aggregation-removal-model-for-the-formation-and-size-determination-of-post-synaptic-scaffold-domains
#2
Jonas Ranft, Leandro G Almeida, Pamela C Rodriguez, Antoine Triller, Vincent Hakim
The formation and stability of synapses are key questions in neuroscience. Post-synaptic domains have been classically conceived as resulting from local insertion and turnover of proteins at the synapse. However, insertion is likely to occur outside the post-synaptic domains and advances in single-molecule imaging have shown that proteins diffuse in the plane of the membrane prior to their accumulation at synapses. We quantitatively investigated this scenario using computer simulations and mathematical analysis, taking for definiteness the specific case of inhibitory synapse components, i...
April 24, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28437426/representational-models-a-common-framework-for-understanding-encoding-pattern-component-and-representational-similarity-analysis
#3
Jörn Diedrichsen, Nikolaus Kriegeskorte
Representational models specify how activity patterns in populations of neurons (or, more generally, in multivariate brain-activity measurements) relate to sensory stimuli, motor responses, or cognitive processes. In an experimental context, representational models can be defined as hypotheses about the distribution of activity profiles across experimental conditions. Currently, three different methods are being used to test such hypotheses: encoding analysis, pattern component modeling (PCM), and representational similarity analysis (RSA)...
April 24, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28436450/definition-of-fractal-topography-to-essential-understanding-of-scale-invariance
#4
Yi Jin, Ying Wu, Hui Li, Mengyu Zhao, Jienan Pan
Fractal behavior is scale-invariant and widely characterized by fractal dimension. However, the cor-respondence between them is that fractal behavior uniquely determines a fractal dimension while a fractal dimension can be related to many possible fractal behaviors. Therefore, fractal behavior is independent of the fractal generator and its geometries, spatial pattern, and statistical properties in addition to scale. To mathematically describe fractal behavior, we propose a novel concept of fractal topography defined by two scale-invariant parameters, scaling lacunarity (P) and scaling coverage (F)...
April 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28436171/sex-and-regional-differences-in-rabbit-right-ventricular-l-type-calcium-current-levels-and-mathematical-modeling-of-arrhythmia-vulnerability
#5
Zane M Kalik, Joshua L Mike, Cassandra Slipski, Moriah Wright, Jozsi Z Jalics, Mark D Womble
Previous studies have shown that adult rabbit left ventricular myocytes exhibit sex and regional differences in L-type calcium current (ICa-L ) levels that contribute to increased susceptibility to arrhythmogenic early afterdepolarizations (EADs). We used patch clamp recordings from isolated adult male and female rabbit right ventricular myocytes to determine apex-base differences in ICa-L density, and mathematical modeling to examine ICa-L contribution to EAD formation. Current density measured at 0 mV in female base myocytes was 67% higher than male base myocytes and 55% higher than female apex myocytes...
April 24, 2017: Experimental Physiology
https://www.readbyqxmd.com/read/28436072/real-time-individualization-of-the-unified-model-of-performance
#6
Jianbo Liu, Sridhar Ramakrishnan, Srinivas Laxminarayan, Thomas J Balkin, Jaques Reifman
Existing mathematical models for predicting neurobehavioural performance are not suited for mobile computing platforms because they cannot adapt model parameters automatically in real time to reflect individual differences in the effects of sleep loss. We used an extended Kalman filter to develop a computationally efficient algorithm that continually adapts the parameters of the recently developed Unified Model of Performance (UMP) to an individual. The algorithm accomplishes this in real time as new performance data for the individual become available...
April 24, 2017: Journal of Sleep Research
https://www.readbyqxmd.com/read/28434906/the-evolution-of-parasitic-and-mutualistic-plant-virus-symbioses-through-transmission-virulence-trade-offs
#7
Frédéric M Hamelin, Frank M Hilker, T Anthony Sun, Michael J Jeger, M Reza Hajimorad, Linda J S Allen, Holly R Prendeville
Virus-plant interactions range from parasitism to mutualism. Viruses have been shown to increase fecundity of infected plants in comparison with uninfected plants under certain environmental conditions. Increased fecundity of infected plants may benefit both the plant and the virus as seed transmission is one of the main virus transmission pathways, in addition to vector transmission. Trade-offs between vertical (seed) and horizontal (vector) transmission pathways may involve virulence, defined here as decreased fecundity in infected plants...
April 20, 2017: Virus Research
https://www.readbyqxmd.com/read/28434531/surface-properties-of-magnetite-in-high-temperature-aqueous-electrolyte-solutions-a-review
#8
REVIEW
Sonja M Vidojkovic, Marko P Rakin
Deposits and scales formed on heat transfer surfaces in power plant water/steam circuits have a significant negative impact on plant reliability, availability and performance, causing tremendous economic consequences and subsequent increases in electricity cost. Consequently, the improvement of the understanding of deposition mechanisms on power generating surfaces is defined as a high priority in the power industry. The deposits consist principally of iron oxides, which are steel corrosion products and usually present in colloidal form...
August 18, 2016: Advances in Colloid and Interface Science
https://www.readbyqxmd.com/read/28434057/predictive-control-of-intersegmental-tarsal-movements-in-an-insect
#9
Alicia Costalago-Meruelo, David M Simpson, Sandor M Veres, Philip L Newland
In many animals intersegmental reflexes are important for postural and movement control but are still poorly undesrtood. Mathematical methods can be used to model the responses to stimulation, and thus go beyond a simple description of responses to specific inputs. Here we analyse an intersegmental reflex of the foot (tarsus) of the locust hind leg, which raises the tarsus when the tibia is flexed and depresses it when the tibia is extended. A novel method is described to measure and quantify the intersegmental responses of the tarsus to a stimulus to the femoro-tibial chordotonal organ...
April 22, 2017: Journal of Computational Neuroscience
https://www.readbyqxmd.com/read/28434023/developing-a-statistically-powerful-measure-for-quartet-tree-inference-using-phylogenetic-identities-and-markov-invariants
#10
Jeremy G Sumner, Amelia Taylor, Barbara R Holland, Peter D Jarvis
Recently there has been renewed interest in phylogenetic inference methods based on phylogenetic invariants, alongside the related Markov invariants. Broadly speaking, both these approaches give rise to polynomial functions of sequence site patterns that, in expectation value, either vanish for particular evolutionary trees (in the case of phylogenetic invariants) or have well understood transformation properties (in the case of Markov invariants). While both approaches have been valued for their intrinsic mathematical interest, it is not clear how they relate to each other, and to what extent they can be used as practical tools for inference of phylogenetic trees...
April 22, 2017: Journal of Mathematical Biology
https://www.readbyqxmd.com/read/28433947/maximum-likelihood-estimation-of-cardiac-fiber-bundle-orientation-from-arbitrarily-spaced-diffusion-weighted-images
#11
Andreas Nagler, Cristóbal Bertoglio, Christian T Stoeck, Sebastian Kozerke, Wolfgang A Wall
We propose an estimation scheme for local fiber bundle direction in the left ventricle directly from gray values of arbitrarily spaced cardiac diffusion weighted images (DWI). The approach is based on a parametric and space-dependent mathematical representation of the myocardial fiber bundle orientation and hence the diffusion tensor (DT) for the ventricular geometry. By solving a nonlinear inverse problem derived from a maximum likelihood estimator, the degrees of freedom of the fiber and DT model can be estimated from the measured gray values of the DWIs...
April 4, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28433148/mechanics-and-transport-phenomena-in-agarose-based-hydrogels-studied-by-compression-relaxation-tests
#12
Diego Caccavo, Sara Cascone, Serena Poto, Gaetano Lamberti, Anna Angela Barba
Hydrogels are widespread materials, used in several frontier fields, due to their peculiar behavior: they couple solvent mass transport to system mechanics, exhibiting viscoelastic and poroelastic characteristics. The full understanding of this behavior is crucial to correctly design such complex systems. In this study agarose gels has been investigated through experimental stress-relaxation tests and with the aid of a 3D poroviscoelastic model. At the investigated experimental conditions, the agarose gels samples show a prevalent viscoelastic behavior, revealing limited water transport and an increase of the stiffness as well as of the relaxation time along with the polymer concentration...
July 1, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28432953/new-and-practical-mathematical-model-of-membrane-fouling-in-an-aerobic-submerged-membrane-bioreactor
#13
Mst Fazana Rahman Zuthi, Wenshan Guo, Huu Hao Ngo, Duc Long Nghiem, Faisal I Hai, Siqing Xia, Jianxin Li, Jixiang Li, Yi Liu
This study aimed to develop a practical semi-empirical mathematical model of membrane fouling that accounts for cake formation on the membrane and its pore blocking as the major processes of membrane fouling. In the developed model, the concentration of mixed liquor suspended solid is used as a lumped parameter to describe the formation of cake layer including the biofilm. The new model considers the combined effect of aeration and backwash on the foulants' detachment from the membrane. New exponential coefficients are also included in the model to describe the exponential increase of transmembrane pressure that typically occurs after the initial stage of an MBR operation...
April 4, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28432906/hydrophobic-and-hydrophilic-properties-of-pollutants-as-a-factor-influencing-their-redistribution-during-snowpack-melt
#14
Krystyna Kozioł, Katarzyna Kozak, Żaneta Polkowska
Glaciers accumulate organic pollutants delivered by snow. However, our understanding of the exact dynamics of organic pollutants in the snowpack relies primarily on laboratory experiments and mathematical models. To fill the gap related to the detailed field data, we have conducted observations of melting snow profiles in two locations and three different stages of melting on one High Arctic glacier, as well as in superimposed ice. We monitored the chemical concentrations of formaldehyde, phenols, short-chain carboxylic acids, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) and snow water equivalents to derive chemical loads...
April 19, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28432579/hcv-cure-and-reinfection-among-people-with-hiv-hcv-coinfection-and-people-who-inject-drugs
#15
REVIEW
Marianne Martinello, Behzad Hajarizadeh, Jason Grebely, Gregory J Dore, Gail V Matthews
PURPOSE OF REVIEW: Highly effective, well-tolerated interferon-free direct-acting antivirals (DAA) have revolutionised hepatitis C virus (HCV) therapeutics, with the opportunity for broad treatment scale-up among marginalised or "high-risk" populations, including people who inject drugs (PWID) and people with HIV/HCV coinfection. RECENT FINDINGS: Concern that HCV reinfection may compromise HCV treatment outcomes is sometimes cited as a reason for not offering treatment to current and former PWID...
April 21, 2017: Current HIV/AIDS Reports
https://www.readbyqxmd.com/read/28432448/resistance-to-radial-expansion-limits-muscle-strain-and-work
#16
E Azizi, A R Deslauriers, N C Holt, C E Eaton
The collagenous extracellular matrix (ECM) of skeletal muscle functions to transmit force, protect sensitive structures, and generate passive tension to resist stretch. The mechanical properties of the ECM change with age, atrophy, and neuromuscular pathologies, resulting in an increase in the relative amount of collagen and an increase in stiffness. Although numerous studies have focused on the effect of muscle fibrosis on passive muscle stiffness, few have examined how these structural changes may compromise contractile performance...
April 21, 2017: Biomechanics and Modeling in Mechanobiology
https://www.readbyqxmd.com/read/28432057/imaging-and-modeling-of-acute-pressure-induced-changes-of-collagen-and-elastin-microarchitectures-in-pig-and-human-resistance-arteries
#17
Maria Bloksgaard, Thomas M Leurgans, Bart Spronck, Maarten Hg Heusinkveld, Bjarne Thorsted, Kristoffer Rosenstand, Inger Nissen, Ulla Melchior Hansen, Jonathan R Brewer, Luis A Bagatolli, Lars M Rasmussen, Akhmadjon Irmukhamedov, Koen D Reesink, Jo G R De Mey
The impact of disease related changes in the extracellular matrix (ECM) on the mechanical properties of human resistance arteries largely remains to be established. Resistance arteries from both pig and human parietal pericardium (PRA) display a different ECM microarchitecture compared to frequently used rodent mesenteric arteries. We hypothesized that the biaxial mechanics of PRA mirror pressure induced changes in the ECM microarchitecture. This was tested using isolated pig PRA as model system, integrating vital imaging, pressure myography and mathematical modeling...
April 21, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28431843/on-the-complex-interaction-between-mathematics-and-the-sciences-of-living-systems-comment-on-move-me-astonish-me-delight-my-eyes-and-brain-the-vienna-integrated-model-of-top-down-and-bottom-up-processes-in-art-perception-vimap-and-corresponding-affective-evaluative
#18
https://www.readbyqxmd.com/read/28431573/a-highly-pathogenic-simian-human-immunodeficiency-virus-effectively-produces-infectious-virions-compared-with-a-less-pathogenic-virus-in-cell-culture
#19
Shoya Iwanami, Yusuke Kakizoe, Satoru Morita, Tomoyuki Miura, Shinji Nakaoka, Shingo Iwami
BACKGROUND: The host range of human immunodeficiency virus (HIV) is quite narrow. Therefore, analyzing HIV-1 pathogenesis in vivo has been limited owing to lack of appropriate animal model systems. To overcome this, chimeric simian and human immunodeficiency viruses (SHIVs) that encode HIV-1 Env and are infectious to macaques have been developed and used to investigate the pathogenicity of HIV-1 in vivo. So far, we have many SHIV strains that show different pathogenesis in macaque experiments...
April 21, 2017: Theoretical Biology & Medical Modelling
https://www.readbyqxmd.com/read/28431517/sharp-bounds-on-sufficient-cause-interactions-under-the-assumption-of-no-redundancy
#20
Wen-Chung Lee
BACKGROUND: Sufficient-cause interaction is a type of interaction that has received much attention recently. The sufficient component cause model on which the sufficient-cause interaction is based is however a non-identifiable model. Estimating the interaction parameters from the model is mathematically impossible. METHODS: In this paper, I derive bounding formulae for sufficient-cause interactions under the assumption of no redundancy. RESULTS: Two real data sets are used to demonstrate the method (R codes provided)...
April 21, 2017: BMC Medical Research Methodology
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