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    Evolution of costly signaling and partial cooperation

    , Article Scientific Reports ; Volume 9, Issue 1 , 2019 ; 20452322 (ISSN) Salahshour, M ; Sharif University of Technology
    Nature Publishing Group  2019
    Two seemingly unrelated, but fundamental challenges in evolutionary theory, are the evolution of costly signals and costly cooperative traits, both expected to reduce an individual’s fitness and diminish by natural selection. Here, by considering a well mixed population of individuals who produce signals and decide on their strategies in a game they play, based on the signals, we show that costly signals and costly cooperative strategies can co-evolve as a result of internal dynamics of the system. Costly signals evolve, despite their apparent cost, due to a favorable cooperative response they elicit. This favorable strategic response can be quantified in a fitness term which governs the... 

    Multivariate Curve Resolution Methods for Qualitative and Quantitative Analysis in Analytical Chemistry

    , Article Data Handling in Science and Technology ; Volume 29 , 2015 , Pages 393-345 ; 09223487 (ISSN) ; 9780444635273 (ISBN) Parastar, H ; Sharif University of Technology
    Owing to the fact that obtaining useful information from complex analytical systems is one of the keys to make correct decisions about the systems under study, in this chapter, the capabilities and versatility of multivariate curve resolution (MCR) methods are discussed in light of the nowadays issues in qualitative and quantitative analysis in analytical chemistry. In this regard, classification of MCR methods, data structures, data arrangement, bilinear model, and pros and cons of MCR methods is presented. Then, MCR scenarios for qualitative and quantitative purposes in analytical chemistry are discussed in the course of some of the recent applications of MCR methods. Furthermore,... 

    Alterations of the electroencephalogram sub-bands amplitude during focal seizures in the pilocarpine model of epilepsy

    , Article Physiology and Pharmacology ; Volume 16, Issue 1 , 2012 , Pages 11-20 ; 17350581 (ISSN) Motaghi, S ; Niknazar, M ; Sayyah, M ; babapour, V ; Vahdat, B. V ; Shamsollahi, M. B ; Sharif University of Technology
    Introduction: Temporal lobe epilepsy (TLE) is the most common and drug resistant epilepsy in adults. Due to behavioral, morphologic and electrographic similarities, pilocarpine model of epilepsy best resembles TLE. This study was aimed at determination of the changes in electroencephalogram (EEG) sub-bands amplitude during focal seizures in the pilocarpine model of epilepsy. Analysis of these changes might help detection of a pre-seizure state before an oncoming seizure. Methods: Rats were treated by scopolamine (1mg/kg, s.c) to prevent cholinergic effects. After 30 min, pilocarpine (380 mg/kg, i.p) was administered to induce status epilepticus (SE) and 2 hours after SE, diazepam (20 mg/kg,... 

    Mixed qualitative/quantitative dynamic simulation of processing systems

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 24, Issue 1 , 2005 , Pages 53-67 ; 10219986 (ISSN) Yadegar, S ; Pishvaie, M. R ; Sharif University of Technology
    In this article the methodology proposed by Li and Wang for mixed qualitative and quantitative modeling and simulation of temporal behavior of processing unit is reexamined and extended to more complex case. The main issue of their approach considers the multivariate statistics of principal component analysis (PCA), along with clustered fuzzy digraphs and reasoning. The PCA and fuzzy clustering provide tools to categorize the quantitative dynamic trends, describing the temporal behavior of joint human-process interactions qualitatively, and through the proposed neuro-fuzzy reasoning the system responses can be obtained when the system is exposed to uncertain disturbances. First, the method... 

    Quantifying how staining methods bias measurements of neuron morphologies

    , Article Frontiers in Neuroinformatics ; Volume 13 , 2019 ; 16625196 (ISSN) Farhoodi, R ; Lansdell, B. J ; Kording, K. P ; Sharif University of Technology
    Frontiers Media S.A  2019
    The process through which neurons are labeled is a key methodological choice in measuring neuron morphology. However, little is known about how this choice may bias measurements. To quantify this bias we compare the extracted morphology of neurons collected from the same rodent species, experimental condition, gender distribution, age distribution, brain region and putative cell type, but obtained with 19 distinct staining methods. We found strong biases on measured features of morphology. These were largest in features related to the coverage of the dendritic tree (e.g., the total dendritic tree length). Understanding measurement biases is crucial for interpreting morphological data  

    Alternative biomass fuels consideration exergy and power analysis for hybrid system includes PSOFC and GT integration

    , Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 37, Issue 18 , Sep , 2015 , Pages 1962-1970 ; 15567036 (ISSN) Ozgoli, H. A ; Ghadamian, H ; Roshandel, R ; Moghadasi, M ; Sharif University of Technology
    Taylor and Francis Inc  2015
    The present study aims to analyze a combined heat and power (CHP) system with an approach towards exergy analysis and employing biomass gasification. The cycle modeling was carried out using Cycle-Tempo and the main purpose was to achieve parametric analysis of the model. The systems function was studied by categorizing alternative biomass fuels, also qualitative and quantitative analyses of the biomass fuel samples were presented and considering the trade-off points, most appropriate biomass fuel with respect to exergy efficiency and delivered power were determined. The results indicated that the bagasse and wood chips had the total exergy efficiency of 54.5 and 57.1% in trade-off point,... 

    Field Scale Characterization of Geological Formations Using Percolation Theory

    , Article Transport in Porous Media ; Vol. 92, issue. 2 , March , 2012 , p. 357-372 ; ISSN: 1693913 Sadeghnejad, S ; Masihi, M ; Shojaei, A ; Pishvaie, M ; King, P. R ; Sharif University of Technology
    The connectivity of high conductivity pathways in geological formations depend on the spatial distribution of geological heterogeneities that may appear on various length scales. Appropriate modeling of this is crucial within in hydrology and petroleum systems. The approach taken in this study is to use percolation theory to quantify the connectivity, hydraulic conductivity, and breakthrough time behavior between an injector and a producer within such systems. In particular, a three-dimensional overlapping sandbody model is considered which assumes that the geological formation can be split into either conductive flow units (i. e., good sands) or non-conductive units (i. e., poor sands). The... 

    Fluorescent quantification of size and lamellarity of membrane nanotubes

    , Article European Biophysics Journal ; Vol. 43, Issue. 12 , 2014 , pp. 595-602 ; ISSN: 1432-1017 Baroji,Y. F ; Oddershede, L. B ; Reihani, S. N. S ; Bendix, P. M ; Sharif University of Technology
    Membrane nanotubes, ubiquitous in cellular systems, adopt a spectrum of curvatures and shapes that are dictated by their intrinsic physical characteristics as well as their interactions with the local cellular environment. A high bending flexibility is needed in the crowded cytoplasm where tubes often need to bend significantly in the axial direction at sub-micron length scales. We find the stiffness of spontaneously formed membrane nanotubes by measuring the persistence length of reconstituted membrane nanotubes freely suspended in solution and imaged by fluorescence microscopy. By quantifying the tube diameter we demonstrate for the first time that the persistence length scales linearly... 

    Tip and sample flexibility effects on tapping mode (amplitude modulation) AFM measurements

    , Article Micro and Nano Letters ; Volume 6, Issue 12 , December , 2011 , Pages 1023-1028 ; 17500443 (ISSN) Pishkenari, H. N ; Meghdari, A ; Sharif University of Technology
    This Letter is devoted to the investigation of the tip, substrate and particle flexibility effects on the elastic deformation, the maximum repulsive force and the topography images in tapping mode (amplitude modulation) atomic force microscopy (TM-AFM). Several quantitative comparisons among the different models are presented and the effects of the elastic deformations on TM-AFM measurement are investigated  

    An appropriate multiple criteria decision making method for solving electricity planning problems, addressing sustainability issue

    , Article International Journal of Environmental Science and Technology ; Volume 8, Issue 3 , June , 2011 , Pages 605-620 ; 17351472 (ISSN) Bagheri Moghaddam, N ; Nasiri, M ; Mousavi, S. M ; Sharif University of Technology
    In the past, decision making within the energy sector, especially in Iran, was limited to economic analysis. Lately, multiple criteria decision making has gained great popularity. However, this is not enough to make a right decision by considering sustainability. This paper deals with designing an appropriate multiple criteria decision making method to address the multifaceted nature of such problems. This task is the second precondition to make a decision which meets the sustainability criterion. This is done by revealing new facts about quantitative and qualitative data and the degree of compensation between the criteria. Moreover, this paper illustrates the capability of different methods... 

    Pore-Level Observation of Free Gravity Drainage of Oil in Fractured Porous Media

    , Article Transport in Porous Media ; Volume 87, Issue 2 , 2011 , Pages 561-584 ; 01693913 (ISSN) Mashayekhizadeh, V ; Ghazanfari, M. H ; Kharrat, R ; Dejam, M ; Sharif University of Technology
    This work presents results from two sets of experiments conducted to study, in pore level, the role of fracture aperture and tilt angle on the stability of liquid bridges and the shape of a front during free gravity drainage process. Glass micromodels of two different aperture sizes were used to monitor the mechanism of gravity drainage of air-crude oil system, rotating around a bottom corner to create different tilting angles. Oil content within the matrix blocks was determined as a function of time using a series of images obtained during the experiments, from which net drainage rate from the upper and lower matrix blocks is calculated. Liquid bridges are more frequent but less stable at... 

    A simple and efficient total synthesis of (±)-danshexinkun A, a bioactive diterpenoid from Salvia miltiorrhiza

    , Article Tetrahedron Letters ; Volume 51, Issue 3 , 2010 , Pages 540-542 ; 00404039 (ISSN) Matloubi Moghaddam, F ; Moridi Farimani, M ; Sharif University of Technology
    An efficient 12-step route for the synthesis of the diterpenoid quinone (±)-danshexinkun A in 23% overall yield from the corresponding highly substituted stilbene using a photocyclization strategy is described  

    Correlation between trunk-pelvis inter-segmental coordination parameters during walking and disability level in chronic low back pain patients

    , Article Journal of Biomedical Physics and Engineering ; Volume 8, Issue 2 , 2018 , Pages 193-202 ; 22517200 (ISSN) Ebrahimi, S ; Kamali, F ; Razeghi, M ; Haghpanah, A ; Sharif University of Technology
    Shiraz University of Medical Sciences  2018
    Background: Chronic low back pain (CLBP) disability has been particularly frustrating because its treatment has been a great therapeutic challenge. Disability has been suggested to depend on different factors that should be found and considered in the medical management. The inter-segmental coordination is often impaired in CLBP subjects; however, to the best of our knowledge, there is no evidence about the relationship between the existence of coordination problems and disability in CLBP patients. Objective: To evaluate the correlation between sagittal plane trunk-pelvis intersegmental coordination parameters during walking and disability level in CLBP patients. Methods: Kinematic data were... 

    Noninvasive fetal ECG extraction using doubly constrained block-term decomposition

    , Article Mathematical Biosciences and Engineering ; Volume 17, Issue 1 , 2020 , Pages 144-159 Mousavian, I ; Shamsollahi, M. B ; Fatemizadeh, E ; Sharif University of Technology
    American Institute of Mathematical Sciences  2020
    Fetal electrocardiogram (fECG) monitoring is a beneficial method for assessing fetal health and diagnosing the fetal cardiac condition during pregnancy. In this study, an algorithm is proposed to extract fECG from maternal abdominal signals based on doubly constrained block-term (DoCoBT) tensor decomposition. This tensor decomposition method is constrained by quasi-periodicity constraints of fetal and maternal ECG signals. Tensor decompositions are more powerful tools than matrix decomposition, due to employing more information for source separation. Tensorizing abdominal signals and using periodicity constraints of fetal and maternal ECG, appropriately separates subspaces of the mother, the... 

    Uncertainty quantification in seismic collapse assessment of the Iranian code-conforming RC buildings

    , Article Scientia Iranica ; Volume 27, Issue 4 , 2021 , Pages 1786-1802 ; 10263098 (ISSN) Hosseini, A ; Ghaemian, M ; Hariri Ardebili, M. A ; Sharif University of Technology
    Sharif University of Technology  2021
    Abstract. Structural collapse is the main concern for the existing structures which are built in the seismic-prone regions. Therefore, the primary goal of the seismic provisions in building codes is to prevent the global collapse. Iran is located in the Alpine-Himalayan belt, and has experienced some of the most destructive earthquakes in the past century. To evaluate the extent to which the Iranian building code provisions meet the abovementioned objective, the authors conducted a detailed assessment of collapse risk on a set of moderate moment resisting Reinforced Concrete (RC) buildings. While many features might affect the seismic performance of the RC structures, this study considers... 

    Use of second-order calibration for residue screening of some triazines in the presence of coeluting interferences by gas chromatography-selected ion mass spectrometry

    , Article Analytica Chimica Acta ; Volume 537, Issue 1-2 , 2005 , Pages 89-100 ; 00032670 (ISSN) Jalali Heravi, M ; Vosough, M ; Sharif University of Technology
    Elsevier  2005
    The quantities of residues of some triazines such as prometon, propazine, atrazine and simazine in complex matrices of apple samples were determined, using gas chromatography-selected ion mass (GC-SIM) spectrometry. Generalized rank annihilation method (GRAM) as a second-order calibration technique was used for screening, resolving and finally determining the amounts of the residues. Before the GRAM analysis, different steps of data preprocessing such as background correction, de-skewing and standardization for rank alignment was used for every target analyte. The de-skewing and rank alignment algorithms were used for bilinearity and trilinearity corrections, respectively. The two data... 

    On-line micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofibers

    , Article Chromatographia ; Vol. 77, issue. 9-10 , May , 2014 , p. 723-728 Bagheri, H ; Asgari, S ; Piri-Moghadam, H ; Sharif University of Technology
    An on-line extraction/determination set up was designed for micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofiber mats. The prepared mats were packed in a stainless steel tube which conveniently acted as a high-performance liquid chromatography injection loop. Influential parameters affecting the extraction efficiency were optimized using a distilled water sample fortified with 25 μg L-1 of clodinafop propargyl. An enrichment factor of 440 was achieved for clodinafop propargyl indicating the ability of the whole procedure. Under the optimum conditions, the linearity for the analyte was in the range of 6-700 μg L-1, while... 

    MRI-PET image fusion based on NSCT transform using local energy and local variance fusion rules

    , Article Journal of Medical Engineering and Technology ; Vol. 38, issue. 4 , 2014 , p. 211-219 Amini, N ; Fatemizadeh, E ; Behnam, H ; Sharif University of Technology
    Image fusion means to integrate information from one image to another image. Medical images according to the nature of the images are divided into structural (such as CT and MRI) and functional (such as SPECT, PET). This article fused MRI and PET images and the purpose is adding structural information from MRI to functional information of PET images. The images decomposed with Nonsubsampled Contourlet Transform and then two images were fused with applying fusion rules. The coefficients of the low frequency band are combined by a maximal energy rule and coefficients of the high frequency bands are combined by a maximal variance rule. Finally, visual and quantitative criteria were used to... 

    Two-compartment processing as a tool to boost recombinant protein production

    , Article Engineering in Life Sciences ; Vol. 14, issue. 2 , March , 2014 , p. 118-128 Jazini, M ; Herwig, C ; Sharif University of Technology
    Pichia pastoris is used extensively as a production platform for many recombinant proteins. The dissolved oxygen (DO) is one of the most important factors influencing protein production. The influence of the DO on productivity has not been studied independent from the feed rate. In this work, various DO levels were investigated independent from the feed rate. The model system was recombinant P. pastoris under the control of methanol-induced alcohol oxidase promoter, which expressed HRP as the target protein. No significant effect was observed in terms of titer and specific productivity, which is a confirmation of the fact that the DO in a one-compartment system cannot boost productivity for... 

    Metabonomics based NMR in Crohn's disease applying PLS-DA

    , Article Gastroenterology and Hepatology from Bed to Bench ; Volume 6, Issue SUPPL , 2013 , Pages S82-S86 ; 20082258 (ISSN) Fathi, F ; Oskouie, A. A ; Tafazzoli, M ; Naderi, N ; Sohrabzedeh, K ; Fathi, S ; Norouzinia, M ; Nejad, M. R ; Sharif University of Technology
    Aim: The aim of this study was to search for metabolic biomarkers of Crohn's disease (CD). Background: Crohn's disease (CD) is a type of inflammatory bowel disease that causes a wide variety of symptoms. CD can influence any part of the gastrointestinal tract from mouth to anus. CD is not easily diagnosed because monitoring tools are currently insufficient. Thus, the discovery of proper methods is needed for early diagnosis of CD. Patients and methods: We utilized metabolic profiling using proton nuclear magnetic resonance spectroscopy (1HNMR) to find the metabolites in serum. Classification of CD and healthy subject was done using partial least squares discriminant analysis (PLS-DA)....