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https://www.readbyqxmd.com/read/29141401/-simulation-of-an-outbreak-of-acinetobacter-baumannii-in-hospitals
#1
A Martín-Del Rey, M García-Moro, E García-Sánchez, E García-Merino, J E García-Sánchez
OBJECTIVE: Acinetobacter baumannii infections have increased over time becoming a significant issue. Consequently, those applications that allow to predict the evolution of an outbreak and the relevance of the different control methods, are very important. The design of mathematical models plays a central role in this topic. METHODS: Development of a deterministic mathematical model based on ordinary differential equations whose variables and parameters are defined upon the basis of knowledge of the epidemiology and characteristics of A...
November 13, 2017: Revista Española de Quimioterapia: Publicación Oficial de la Sociedad Española de Quimioterapia
https://www.readbyqxmd.com/read/29141102/statistically-optimized-ceftriaxone-sodium-biotransformation-through-achromobacter-xylosoxidans-strain-cef6-an-unusual-insight-for-bioremediation
#2
Ahmed Anan, Khaled M Ghanem, Amira M Embaby, Ahmed Hussein, Moustafa Y El-Naggar
The present study underlines a unique promising approach toward efficient biotransformation of ceftriaxone sodium (Ceftx), a highly frequent prescribed cephalosporin antibiotic, by a newly bacterium namely Achromobacter xylosoxidans strain Cef6 isolated from Ceftx contaminated raw materials in pharmaceutical industries. A three step sequential statistical-mathematical approach (Plackett-Burman design [PBD], Central Composite Design [CCD], and ridge-canonical analyses) was anticipated to optimize the biotransformation process...
November 15, 2017: Journal of Basic Microbiology
https://www.readbyqxmd.com/read/29141044/high-dimensional-linear-state-space-models-for-dynamic-microbial-interaction-networks
#3
Iris Chen, Yogeshwar D Kelkar, Yu Gu, Jie Zhou, Xing Qiu, Hulin Wu
Medical researchers are increasingly interested in knowing how the complex community of micro-organisms living on human body impacts human health. Key to this is to understand how the microbes interact with each other. Time-course studies on human microbiome indicate that the composition of microbiome changes over short time periods, primarily as a consequence of synergistic and antagonistic interactions of the members of the microbiome with each other and with the environment. Knowledge of the abundance of bacteria-which are the predominant members of the human microbiome-in such time-course studies along with appropriate mathematical models will allow us to identify key dynamic interaction networks within the microbiome...
2017: PloS One
https://www.readbyqxmd.com/read/29140499/simple-arithmetic-not-so-simple-for-highly-math-anxious-individuals
#4
Hyesang Chang, Lisa Sprute, Erin A Maloney, Sian L Beilock, Marc G Berman
Fluency with simple arithmetic, typically achieved in early elementary school, is thought to be one of the building blocks of mathematical competence. Behavioral studies with adults indicate that math anxiety (feelings of tension or apprehension about math) is associated with poor performance on cognitively demanding math problems. However, it remains unclear whether there are fundamental differences in how high and low math anxious individuals approach overlearned simple arithmetic problems that are less reliant on cognitive control...
November 11, 2017: Social Cognitive and Affective Neuroscience
https://www.readbyqxmd.com/read/29140341/gaussian-beams-diffracting-in-time
#5
Miguel A Porras
We show how to transform the mathematical expression of any monochromatic paraxial light beam into the expression of a pulsed beam whose diffraction is switched from the axial direction to its temporal structure. We exemplify this transformation with time-diffracting Gaussian beams. The conditions for the obtained diffraction-free wave to be physically meaningful are discussed.
November 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/29140313/a-new-low-complexity-angle-of-arrival-algorithm-for-1d-and-2d-direction-estimation-in-mimo-smart-antenna-systems
#6
Mohammed A G Al-Sadoon, Nazar T Ali, Yousf Dama, Abdulkareim Zuid, Stephen M R Jones, Raed A Abd-Alhameed, James M Noras
This paper proposes a new low complexity angle of arrival (AOA) method for signal direction estimation in multi-element smart wireless communication systems. The new method estimates the AOAs of the received signals directly from the received signals with significantly reduced complexity since it does not need to construct the correlation matrix, invert the matrix or apply eigen-decomposition, which are computationally expensive. A mathematical model of the proposed method is illustrated and then verified using extensive computer simulations...
November 15, 2017: Sensors
https://www.readbyqxmd.com/read/29138254/estimating-realized-heritability-in-panmictic-populations
#7
Milan Lstibůrek, Václav Bittner, Gary R Hodge, Jan Picek, Trudy F C Mackay
Narrow sense heritability (h(2) ) is a key concept in quantitative genetics, as it expresses the proportion of the observed phenotypic variation that is transmissible from parents to offspring. h(2) determines the resemblance among relatives and the rate of response to artificial and natural selection. Classical methods for estimating h(2) use random samples of individuals with known relatedness, as well as response to artificial selection, when it is called realized heritability. Here, we present a method for estimating realized h(2) based on a simple assessment of a random-mating population with no artificial manipulation of the population structure, and derive standard errors of the estimates...
November 14, 2017: Genetics
https://www.readbyqxmd.com/read/29138071/a-mathematical-network-of-seizure-activity-how-pre-surgical-simulation-can-predict-post-surgical-success
#8
Reid Hoshide, Zain Jandial, Michael Levy
No abstract text is available yet for this article.
November 11, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/29137991/spectrally-decomposed-dark-to-light-transitions-in-a-psi-deficient-mutant-of-synechocystis-sp-pcc-6803
#9
Alonso M Acuña, Pascal van Alphen, Filipe Branco Dos Santos, Rienk van Grondelle, Klaas J Hellingwerf, Ivo H M van Stokkum
Cyanobacterial thylakoid membranes are known to host photosynthetic and respiratory complexes. This hampers a straight forward interpretation of the highly dynamic fluorescence originating from photosynthetic units. The present study focuses on dark-to-light transitions in whole cells of a PSI-deficient mutant of the cyanobacterium Synechocystis sp. PCC 6803. The time-dependent cellular fluorescence spectrum has been measured, while having previously exposed the cells to different conditions that affect respiratory activity...
November 11, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29137728/a-computational-model-for-false-lumen-thrombosis-in-type-b-aortic-dissection-following-thoracic-endovascular-repair
#10
Claudia Menichini, Zhuo Cheng, Richard G J Gibbs, Xiao Yun Xu
Thoracic endovascular repair (TEVAR) has recently been established as the preferred treatment option for complicated type B dissection. This procedure involves covering the primary entry tear to stimulate aortic remodelling and promote false lumen thrombosis thereby restoring true lumen flow. However, complications associated with incomplete false lumen thrombosis, such as aortic dilatation and stent graft induced new entry tears, can arise after TEVAR. This study presents the application and validation of a recently developed mathematical model for patient-specific prediction of thrombus formation and growth under physiologically realistic flow conditions...
November 11, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/29137716/-a-phantasia-and-severely-deficient-autobiographical-memory-scientific-and-personal-perspectives
#11
Nicholas W Watkins
I address two interlinked aspects of the diversity in our experiences of memory and the mind's eye. I summarise the long-appreciated role of imagery in mathematics and the physical sciences, and contrast it with the evidence that some scientists have had limited or zero imagery. I then recount the story of how I became aware of my own lack of mental imagery, and the accompanying deficit in my episodic memory, how I have sought scientific understanding of these conditions, and how they have affected my life.
November 7, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/29137348/reverse-phase-protein-array-rppa-combined-with-computational-analysis-to-unravel-relevant-prognostic-factors-in-non-small-cell-lung-cancer-nsclc-a-pilot-study
#12
Vienna Ludovini, Rita Chiari, Lorenzo Tomassoni, Chiara Antonini, Elisa Baldelli, Sara Baglivo, Annamaria Siggillino, Francesca Romana Tofanetti, Guido Bellezza, K Alex Hodge, Emanuel Petricoin, Mariaelena Pierobon, Lucio Crinò, Fortunato Bianconi
In this work high throughput technology and computational analysis were used to study two stage IV lung adenocarcinoma patients treated with standard chemotherapy with markedly different survival (128 months vs 6 months, respectively) and whose tumor samples exhibit a dissimilar protein activation pattern of the signal transduction. Tumor samples of the two patients were subjected to Reverse Phase Protein Microarray (RPPA) analysis to explore the expression/activation levels of 51 signaling proteins. We selected the most divergent proteins based on the ratio of their RPPA values in the two patients with short (s-OS) and long (l-OS) overall survival (OS) and tested them against a EGFR-IGF1R mathematical model...
October 10, 2017: Oncotarget
https://www.readbyqxmd.com/read/29136815/quantitative-study-of-zinc-and-metallothioneins-in-the-human-retina-and-rpe-cells-by-mass-spectrometry-based-methodologies
#13
Sara Rodríguez-Menéndez, Beatriz Fernández, Montserrat García, Lydia Álvarez, Maria Luisa Fernández, Alfredo Sanz-Medel, Miguel Coca-Prados, Rosario Pereiro, Héctor González-Iglesias
The retina contains the highest concentration of zinc in the human eye and it is primarily associated with the retinal pigment epithelium (RPE). Metallothioneins (MTs) are the main cytosolic zinc-ion-binding proteins, exerting a tight control in the number of atoms of Zn-bound to the MTs related with their antioxidant and neuroprotective functions. In order to study the Zn-MT system in retina and RPE, we have implemented mass spectrometry (MS)-based technologies: two complementary element detection methodologies (HPLC- and laser ablation (LA)-ICP-MS) have been successfully employed to study metal content in the human eye as well as to perform speciation studies of Zn-MTs...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29135576/assisted-partner-notification-services-are-cost-effective-for-decreasing-hiv-burden-in-western-kenya-a-mathematical-modeling-analysis
#14
Monisha Sharma, Jennifer A Smith, Carey Farquhar, Roger Ying, Peter Cherutich, Matthew Golden, Beatrice Wamuti, David Bukusi, Hans Spiegel, Ruanne V Barnabas
BACKGROUND: Assisted partner services (aPS) or provider notification for sexual partners of persons diagnosed HIV-positive can increase HIV testing and linkage in sub-Saharan Africa (SSA) and is a high yield strategy to identify HIV-positive persons. However, its cost-effectiveness is not well-evaluated. METHODS: Using effectiveness and cost data from an aPS trial in Kenya, we parameterized an individual-based, dynamic HIV transmission model. We estimated costs for both a program scenario and a task-shifting scenario using community health workers to conduct the intervention...
November 10, 2017: AIDS
https://www.readbyqxmd.com/read/29135323/impact-assessment-of-the-rational-selection-of-training-and-test-sets-on-the-predictive-ability-of-qsar-models
#15
M F Andrada, E G Vega-Hissi, M R Estrada, J C Garro Martinez
This study performed an analysis of the influence of the training and test set rational selection on the quality and predictively of the quantitative structure-activity relationship (QSAR) model. The study was carried out on three different datasets of Influenza Neuraminidase (H1N1) inhibitors. The three datasets were divided into training and test sets using three rational selection methods: based on k-means, Kennard-Stone algorithm and Activity and the results were compared with Random selection. Then, a total of 31,490 mathematical models were developed and those models that presented a determination coefficient higher than: r(2)train > 0...
November 14, 2017: SAR and QSAR in Environmental Research
https://www.readbyqxmd.com/read/29135012/shrinking-microbubbles-with-microfluidics-mathematical-modelling-to-control-microbubble-sizes
#16
A Salari, V Gnyawali, I M Griffiths, R Karshafian, M C Kolios, S S H Tsai
Microbubbles have applications in industry and life-sciences. In medicine, small encapsulated bubbles (<10 μm) are desirable because of their utility in drug/oxygen delivery, sonoporation, and ultrasound diagnostics. While there are various techniques for generating microbubbles, microfluidic methods are distinguished due to their precise control and ease-of-fabrication. Nevertheless, sub-10 μm diameter bubble generation using microfluidics remains challenging, and typically requires expensive equipment and cumbersome setups...
November 14, 2017: Soft Matter
https://www.readbyqxmd.com/read/29134716/advances-in-computational-and-statistical-diffusion-mri
#17
Lauren J O'Donnell, Alessandro Daducci, Demian Wassermann, Christophe Lenglet
Computational methods are crucial for the analysis of diffusion magnetic resonance imaging (MRI) of the brain. Computational diffusion MRI can provide rich information at many size scales, including local microstructure measures such as diffusion anisotropies or apparent axon diameters, whole-brain connectivity information that describes the brain's wiring diagram and population-based studies in health and disease. Many of the diffusion MRI analyses performed today were not possible five, ten or twenty years ago, due to the requirements for large amounts of computer memory or processor time...
November 14, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/29134583/basic-phage-mathematics
#18
Stephen T Abedon, Tena I Katsaounis
Basic mathematical descriptions are useful in phage ecology, applied phage ecology such as in the course of phage therapy, and also toward keeping track of expected phage-bacterial interactions as seen during laboratory manipulation of phages. The most basic mathematical descriptor of phages is their titer, that is, their concentration within stocks, experimental vessels, or other environments. Various phenomena can serve to modify phage titers, and indeed phage titers can vary as a function of how they are measured...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29134101/aligning-evidence-concerns-regarding-multiple-sequence-alignments-in-estimating-the-phylogeny-of-the-nudibranchia-suborder-doridina
#19
Joshua M Hallas, Anton Chichvarkhin, Terrence M Gosliner
Molecular estimates of phylogenetic relationships rely heavily on multiple sequence alignment construction. There has been little consensus, however, on how to properly address issues pertaining to the alignment of variable regions. Here, we construct alignments from four commonly sequenced molecular markers (16S, 18S, 28S and cytochrome c oxidase subunit I) for the Nudibranchia using three different methodologies: (i) strict mathematical algorithm; (ii) exclusion of variable or divergent regions and (iii) manually curated, and examine how different alignment construction methods can affect phylogenetic signal and phylogenetic estimates for the suborder Doridina...
October 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/29134067/modelling-the-role-of-correctional-services-on-gangs-insights-through-a-mathematical-model
#20
F Nyabadza, C P Ogbogbo, J Mushanyu
Research has shown that gang membership increases the chances of offending, antisocial behaviour and drug use. Gang membership should be acknowledged as part of crime prevention and policy designs, and when developing interventions and preventative programmes. Correctional services are designed to rehabilitate convicted offenders. We formulate a deterministic mathematical model using nonlinear ordinary differential equations to investigate the role of correctional services on the dynamics of gangs. The recruitment into gang membership is assumed to happen through an imitation process...
October 2017: Royal Society Open Science
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