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https://www.readbyqxmd.com/read/27922181/evaluation-of-gas-and-carbon-transport-in-a-methanogenic-bioelectrochemical-system-bes
#1
Christy M Dykstra, Spyros G Pavlostathis
Bioelectrochemical systems (BESs) may be used to upgrade anaerobic digester biogas by directly converting CO2 to CH4 .The objective of this study was to evaluate gas (N2 , CO2 , CH4 , and H2 ) and carbon transport within a methanogenic BES. Four BES configurations were evaluated: abiotic anode with abiotic cathode (AAn-ACa), bioanode with abiotic cathode (BAn-ACa), abiotic anode with biocathode (AAn-BCa), and bioanode with biocathode (BAn-BCa). Transport of N2 , a gas commonly used for flushing anoxic systems, out of the anode headspace ranged from 3...
December 6, 2016: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/27921334/synacton-and-individual-activity-of-synthetic-and-natural-corticotropins
#2
T V Vyunova, L A Andreeva, K V Shevchenko, N F Myasoedov
Short endogenous peptides represent one of the most important constituents of the mammalian body's general regulatory system. Some synthesized analogs and modified natural peptides (eg, corticotropins) also show high biological activity. Nevertheless, the mechanism of action of regulatory peptides remains unclear. To explain the effects of peptides of intermolecular processes, the hypothesis that a synactonal mechanism underlies the action of regulatory peptides, exemplified by the heptapeptide Semax, has been proposed...
December 6, 2016: Journal of Molecular Recognition: JMR
https://www.readbyqxmd.com/read/27921305/early-math-trajectories-low-income-children-s-mathematics-knowledge-from-ages-4-to-11
#3
Bethany Rittle-Johnson, Emily R Fyfe, Kerry G Hofer, Dale C Farran
Early mathematics knowledge is a strong predictor of later academic achievement, but children from low-income families enter school with weak mathematics knowledge. An early math trajectories model is proposed and evaluated within a longitudinal study of 517 low-income American children from ages 4 to 11. This model includes a broad range of math topics, as well as potential pathways from preschool to middle grades mathematics achievement. In preschool, nonsymbolic quantity, counting, and patterning knowledge predicted fifth-grade mathematics achievement...
December 6, 2016: Child Development
https://www.readbyqxmd.com/read/27921285/spatiotemporal-distribution-modeling-of-pet-tracer-uptake-in-solid-tumors
#4
Madjid Soltani, Mostafa Sefidgar, Hossein Bazmara, Michael E Casey, Rathan M Subramaniam, Richard L Wahl, Arman Rahmim
OBJECTIVE: Distribution of PET tracer uptake is elaborately modeled via a general equation used for solute transport modeling. This model can be used to incorporate various transport parameters of a solid tumor such as hydraulic conductivity of the microvessel wall, transvascular permeability as well as interstitial space parameters. This is especially significant because tracer delivery and drug delivery to solid tumors are determined by similar underlying tumor transport phenomena, and quantifying the former can enable enhanced prediction of the latter...
December 5, 2016: Annals of Nuclear Medicine
https://www.readbyqxmd.com/read/27920389/resistance-in-persisting-bat-populations-after-white-nose-syndrome-invasion
#5
Kate E Langwig, Joseph R Hoyt, Katy L Parise, Winifred F Frick, Jeffrey T Foster, A Marm Kilpatrick
Increases in anthropogenic movement have led to a rise in pathogen introductions and the emergence of infectious diseases in naive host communities worldwide. We combined empirical data and mathematical models to examine changes in disease dynamics in little brown bat (Myotis lucifugus) populations following the introduction of the emerging fungal pathogen Pseudogymnoascus destructans, which causes the disease white-nose syndrome. We found that infection intensity was much lower in persisting populations than in declining populations where the fungus has recently invaded...
January 19, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/27920175/bridging-the-gap-between-experimental-data-and-model-parameterization-for-chikungunya-virus-transmission-predictions
#6
Rebecca C Christofferson, Christopher N Mores, Helen J Wearing
Chikungunya virus (CHIKV) has experienced 2 major expansion events in the last decade. The most recently emerged sublineage (ECSA-V) was shown to have increased efficiency in a historically secondary vector, Aedes albopictus, leading to speculation that this was a major factor in expansion. Subsequently, a number of experimental studies focused on the vector competence of CHIKV, as well as transmission modeling efforts. Mathematical models have used these data to inform their own investigations, but some have incorrectly parameterized the extrinsic incubation period (EIP) of the mosquitoes, using vector competence data...
December 15, 2016: Journal of Infectious Diseases
https://www.readbyqxmd.com/read/27919850/detection-and-differentiation-of-early-hepatocellular-carcinoma-from-cirrhosis-using-ct-perfusion-in-a-rat-liver-model
#7
Jin-Ping Li, Guang-Long Feng, Da-Qing Li, Hai-Bo Wang, De-Li Zhao, Yong Wan, Hui-Jie Jiang
BACKGROUND: Functional imaging such as CT perfusion can detect morphological and hemodynamic changes in hepatocellular carcinoma (HCC). Pre-carcinoma and early HCC nodules are difficult to differentiate by observing only their hemodynamics changes. The present study aimed to investigate hemodynamic parameters and evaluate their differential diagnostic cut-off between pre-carcinoma and early HCC nodules using CT perfusion and receiver operating characteristic (ROC) curves. METHODS: Male Wistar rats were randomly divided into control (n=20) and experimental (n=70) groups...
December 2016: Hepatobiliary & Pancreatic Diseases International: HBPD INT
https://www.readbyqxmd.com/read/27919524/demystifying-the-cytokine-network-mathematical-models-point-the-way
#8
REVIEW
Penelope A Morel, Robin E C Lee, James R Faeder
Cytokines provide the means by which immune cells communicate with each other and with parenchymal cells. There are over one hundred cytokines and many exist in families that share receptor components and signal transduction pathways, creating complex networks. Reductionist approaches to understanding the role of specific cytokines, through the use of gene-targeted mice, have revealed further complexity in the form of redundancy and pleiotropy in cytokine function. Creating an understanding of the complex interactions between cytokines and their target cells is challenging experimentally...
December 2, 2016: Cytokine
https://www.readbyqxmd.com/read/27918797/going-nuclear-evidence-implicating-the-cell-nucleus-in-mechanotransduction
#9
Spencer E Szczesny, Robert L Mauck
Biophysical stimuli presented to cells via micro-environmental properties (e.g., alignment, stiffness) or external forces have a significant impact on their function and behavior. Recently, the cell nucleus has been identified as a mechano-responsive organelle that contributes to the perception and response to mechanical stimuli. However, the specific mechanotransduction mechanisms that mediate these effects have not been clearly defined. Here, we review the evidence supporting (and refuting) three hypothetical nuclear mechanotransduction mechanisms: physical reorganization of chromatin, signaling at the nuclear envelope, and altered cytoskeletal structure/tension due to nuclear remodeling...
December 3, 2016: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/27918656/aerobic-evaluation-in-elite-slalom-kayakers-using-tethered-canoe-system-a-new-proposal
#10
Homero Gustavo Ferrari, Leonardo H D Messias, Ivan G M Reis, Claudio A Gobatto, Filipe A B Sousa, Camila C S Serra, Fúlvia B Manchado-Gobatto
BACKGROUND: Among other aspects, aerobic fitness is indispensable for performance in slalom canoe. PURPOSE: The aims of the study were to propose the maximal lactate steady state (MLSS) and critical force (CF) tests using a tethered canoe system as new strategies for aerobic evaluation in elite slalom kayakers. Also, we studied the relationship between the aerobic parameters from these tests and the kayakers' performances. METHODS: Twelve male elite slalom kayakers from the Brazilian National Team participated in this study...
December 5, 2016: International Journal of Sports Physiology and Performance
https://www.readbyqxmd.com/read/27918588/optimization-of-a-multi-product-intra-supply-chain-system-with-failure-in-rework
#11
Singa Wang Chiu, Shin-Wei Chen, Chih-Kai Chang, Yuan-Shyi Peter Chiu
Globalization has created tremendous opportunities, but also made business environment highly competitive and turbulent. To gain competitive advantage, management of present-day transnational firms always seeks options to trim down various transaction and coordination costs, especially in the area of controllable intra-supply chain system. This study investigates a multi-product intra-supply chain system with failure in rework. To achieve maximum machine utilization, multiple products are fabricated in succession on a single machine...
2016: PloS One
https://www.readbyqxmd.com/read/27918434/mass-transport-through-nanostructured-membranes-towards-a-predictive-tool
#12
Siavash Darvishmanesh, Bart Van der Bruggen
This study proposes a new mechanism to understand the transport of solvents through nanostructured membranes from a fundamental point of view. The findings are used to develop readily applicable mathematical models to predict solvent fluxes and solute rejections through solvent resistant membranes used for nanofiltration. The new model was developed based on a pore-flow type of transport. New parameters found to be of fundamental importance were introduced to the equation, i.e., the affinity of the solute and the solvent for the membrane expressed as the hydrogen-bonding contribution of the solubility parameter for the solute, solvent and membrane...
December 2, 2016: Membranes
https://www.readbyqxmd.com/read/27917492/predictors-of-developing-mathematics-anxiety-among-middle-school-students-a-2-year-prospective-study
#13
Nir Madjar, Gil Zalsman, Abraham Weizman, Shaul Lev-Ran, Gal Shoval
While there is an abundance of research pertaining to the development of anxiety disorders, there is still a dearth of knowledge regarding the development of anxiety in the general population. The objective of this study was to longitudinally explore the development of mathematics anxiety among normative middle-school students, and to identify the moderating role of gender, school transition and scholastic achievements on these trajectories. Subjects included 413 sixth grade students (53.3% females, mean age 11...
December 4, 2016: International Journal of Psychology: Journal International de Psychologie
https://www.readbyqxmd.com/read/27917265/novel-non-invasive-biological-predictive-index-for-liver-fibrosis-in-hepatitis-c-virus-genotype-4-patients
#14
Mahmoud Khattab, Mohamed Amin Sakr, Mohamed Abdel Fattah, Youssef Mousa, Elwy Soliman, Ashraf Breedy, Mona Fathi, Salwa Gaber, Ahmed Altaweil, Ashraf Osman, Ahmed Hassouna, Ibrahim Motawea
AIM: To investigate the diagnostic ability of a non-invasive biological marker to predict liver fibrosis in hepatitis C genotype 4 patients with high accuracy. METHODS: A cohort of 332 patients infected with hepatitis C genotype 4 was included in this cross-sectional study. Fasting plasma glucose, insulin, C-peptide, and angiotensin-converting enzyme serum levels were measured. Insulin resistance was mathematically calculated using the homeostasis model of insulin resistance (HOMA-IR)...
November 18, 2016: World Journal of Hepatology
https://www.readbyqxmd.com/read/27917139/the-source-of-the-symbolic-numerical-distance-and-size-effects
#15
Attila Krajcsi, Gábor Lengyel, Petia Kojouharova
Human number understanding is thought to rely on the analog number system (ANS), working according to Weber's law. We propose an alternative account, suggesting that symbolic mathematical knowledge is based on a discrete semantic system (DSS), a representation that stores values in a semantic network, similar to the mental lexicon or to a conceptual network. Here, focusing on the phenomena of numerical distance and size effects in comparison tasks, first we discuss how a DSS model could explain these numerical effects...
2016: Frontiers in Psychology
https://www.readbyqxmd.com/read/27916634/lateral-heterogeneity-of-the-proton-potential-along-the-thylakoid-membranes-of-chloroplasts
#16
Alexey V Vershubskii, Boris V Trubitsin, Vladimir I Priklonskii, Alexander N Tikhonov
This work is devoted to critical analysis and reexamination of the problem of lateral heterogeneity of the trans-thylakoid pH difference (ΔpH=pHout-pHin) in thylakoid membranes of chloroplasts. Correct measurements of ΔpH may be complicated by nonuniform partitioning of the protons pumped into the lumen of granal (stacked) and stroma-exposed thylakoids. We have compared results of ΔpH estimations in isolated bean chloroplasts by two different methods. One of the methods is based on the use of pH-sensitive spin-probes...
December 1, 2016: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27915211/impact-of-waning-acquired-immunity-and-asymptomatic-infections-on-case-control-studies-for-enteric-pathogens
#17
Arie H Havelaar, Arno Swart
Case-control studies of outbreaks and of sporadic cases of infectious diseases may provide a biased estimate of the infection rate ratio, due to selecting controls that are not at risk of disease. We use a dynamic mathematical model to explore biases introduced in results drawn from case-control studies of enteric pathogens by waning and boosting of immunity, and by asymptomatic infections, using Campylobacter jejuni as an example. Individuals in the population are either susceptible (at risk of infection and disease), fully protected (not at risk of either) or partially protected (at risk of infection but not of disease)...
November 28, 2016: Epidemics
https://www.readbyqxmd.com/read/27915073/a-mathematical-model-of-reward-and-executive-circuitry-in-obsessive-compulsive-disorder
#18
Anca Raˇdulescu, Rachel Marra
The neuronal circuit that controls obsessive and compulsive behaviors involves a complex network of brain regions (some with known involvement in reward processing). Among these are cortical regions, the striatum and the thalamus (which compose the CSTC pathway), limbic areas such as the amygdala and the hippocampus, and well as dopamine pathways. Abnormal dynamic behavior in this brain network is a hallmark feature of patients with increased anxiety and motor activity, like the ones affected by OCD. There is currently no clear understanding of precisely what mechanisms generate these behaviors...
November 30, 2016: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/27915061/modelling-the-consequences-of-targeted-selective-treatment-strategies-on-performance-and-emergence-of-anthelmintic-resistance-amongst-grazing-calves
#19
Zoe Berk, Yan C S M Laurenson, Andrew B Forbes, Ilias Kyriazakis
The development of anthelmintic resistance by helminths can be slowed by maintaining refugia on pasture or in untreated hosts. Targeted selective treatments (TST) may achieve this through the treatment only of individuals that would benefit most from anthelmintic, according to certain criteria. However TST consequences on cattle are uncertain, mainly due to difficulties of comparison between alternative strategies. We developed a mathematical model to compare: 1) the most 'beneficial' indicator for treatment selection and 2) the method of selection of calves exposed to Ostertagia ostertagi, i...
November 16, 2016: International Journal for Parasitology, Drugs and Drug Resistance
https://www.readbyqxmd.com/read/27915008/sensitivity-analysis-of-a-pharmaceutical-tablet-production-process-from-the-control-engineering-perspective
#20
Jakob Rehrl, Arlin Gruber, Johannes G Khinast, Martin Horn
This paper presents a sensitivity analysis of a pharmaceutical direct compaction process. Sensitivity analysis is an important tool for gaining valuable process insights and designing a process control concept. Examining its results in a systematic manner makes it possible to assign actuating signals to controlled variables. This paper presents mathematical models for individual unit operations, on which the sensitivity analysis is based. Two sensitivity analysis methods are outlined: (i) based on the so-called Sobol indices and (ii) based on the steady-state gains and the frequency response of the proposed plant model...
November 30, 2016: International Journal of Pharmaceutics
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