WorldWideScience

Sample records for activity rational biophysical

  1. Biophysics of protein evolution and evolutionary protein biophysics

    Science.gov (United States)

    Sikosek, Tobias; Chan, Hue Sun

    2014-01-01

    The study of molecular evolution at the level of protein-coding genes often entails comparing large datasets of sequences to infer their evolutionary relationships. Despite the importance of a protein's structure and conformational dynamics to its function and thus its fitness, common phylogenetic methods embody minimal biophysical knowledge of proteins. To underscore the biophysical constraints on natural selection, we survey effects of protein mutations, highlighting the physical basis for marginal stability of natural globular proteins and how requirement for kinetic stability and avoidance of misfolding and misinteractions might have affected protein evolution. The biophysical underpinnings of these effects have been addressed by models with an explicit coarse-grained spatial representation of the polypeptide chain. Sequence–structure mappings based on such models are powerful conceptual tools that rationalize mutational robustness, evolvability, epistasis, promiscuous function performed by ‘hidden’ conformational states, resolution of adaptive conflicts and conformational switches in the evolution from one protein fold to another. Recently, protein biophysics has been applied to derive more accurate evolutionary accounts of sequence data. Methods have also been developed to exploit sequence-based evolutionary information to predict biophysical behaviours of proteins. The success of these approaches demonstrates a deep synergy between the fields of protein biophysics and protein evolution. PMID:25165599

  2. A Biophysical Model of CRISPR/Cas9 Activity for Rational Design of Genome Editing and Gene Regulation

    Science.gov (United States)

    Farasat, Iman; Salis, Howard M.

    2016-01-01

    The ability to precisely modify genomes and regulate specific genes will greatly accelerate several medical and engineering applications. The CRISPR/Cas9 (Type II) system binds and cuts DNA using guide RNAs, though the variables that control its on-target and off-target activity remain poorly characterized. Here, we develop and parameterize a system-wide biophysical model of Cas9-based genome editing and gene regulation to predict how changing guide RNA sequences, DNA superhelical densities, Cas9 and crRNA expression levels, organisms and growth conditions, and experimental conditions collectively control the dynamics of dCas9-based binding and Cas9-based cleavage at all DNA sites with both canonical and non-canonical PAMs. We combine statistical thermodynamics and kinetics to model Cas9:crRNA complex formation, diffusion, site selection, reversible R-loop formation, and cleavage, using large amounts of structural, biochemical, expression, and next-generation sequencing data to determine kinetic parameters and develop free energy models. Our results identify DNA supercoiling as a novel mechanism controlling Cas9 binding. Using the model, we predict Cas9 off-target binding frequencies across the lambdaphage and human genomes, and explain why Cas9’s off-target activity can be so high. With this improved understanding, we propose several rules for designing experiments for minimizing off-target activity. We also discuss the implications for engineering dCas9-based genetic circuits. PMID:26824432

  3. Biophysically inspired rational design of structured chimeric substrates for DNAzyme cascade engineering.

    Directory of Open Access Journals (Sweden)

    Matthew R Lakin

    Full Text Available The development of large-scale molecular computational networks is a promising approach to implementing logical decision making at the nanoscale, analogous to cellular signaling and regulatory cascades. DNA strands with catalytic activity (DNAzymes are one means of systematically constructing molecular computation networks with inherent signal amplification. Linking multiple DNAzymes into a computational circuit requires the design of substrate molecules that allow a signal to be passed from one DNAzyme to another through programmed biochemical interactions. In this paper, we chronicle an iterative design process guided by biophysical and kinetic constraints on the desired reaction pathways and use the resulting substrate design to implement heterogeneous DNAzyme signaling cascades. A key aspect of our design process is the use of secondary structure in the substrate molecule to sequester a downstream effector sequence prior to cleavage by an upstream DNAzyme. Our goal was to develop a concrete substrate molecule design to achieve efficient signal propagation with maximal activation and minimal leakage. We have previously employed the resulting design to develop high-performance DNAzyme-based signaling systems with applications in pathogen detection and autonomous theranostics.

  4. Mathematical biophysics

    CERN Document Server

    Rubin, Andrew

    2014-01-01

    This book presents concise descriptions and analysis of the classical and modern models used in mathematical biophysics. The authors ask the question "what new information can be provided by the models that cannot be obtained directly from experimental data?" Actively developing fields such as regulatory mechanisms in cells and subcellular systems and electron transport and energy transport in membranes are addressed together with more classical topics such as metabolic processes, nerve conduction and heart activity, chemical kinetics, population dynamics, and photosynthesis. The main approach is to describe biological processes using different mathematical approaches necessary to reveal characteristic features and properties of simulated systems. With the emergence of powerful mathematics software packages such as MAPLE, Mathematica, Mathcad, and MatLab, these methodologies are now accessible to a wide audience. Provides succinct but authoritative coverage of a broad array of biophysical topics and models Wr...

  5. Biophysical aspects of using liposomes as delivery vehicles.

    Science.gov (United States)

    Ulrich, Anne S

    2002-04-01

    Liposomes are used as biocompatible carriers of drugs, peptides, proteins, plasmic DNA, antisense oligonucleotides or ribozymes, for pharmaceutical, cosmetic, and biochemical purposes. The enormous versatility in particle size and in the physical parameters of the lipids affords an attractive potential for constructing tailor-made vehicles for a wide range of applications. Some of the recent literature will be reviewed here and presented from a biophysical point of view, thus providing a background for the more specialized articles in this special issue on liposome technology. Different properties (size, colloidal behavior, phase transitions, and polymorphism) of diverse lipid formulations (liposomes, lipoplexes, cubic phases, emulsions, and solid lipid nanoparticles) for distinct applications (parenteral, transdermal, pulmonary, and oral administration) will be rationalized in terms of common structural, thermodynamic and kinetic parameters of the lipids. This general biophysical basis helps to understand pharmaceutically relevant aspects such as liposome stability during storage and towards serum, the biodistribution and specific targeting of cargo, and how to trigger drug release and membrane fusion. Methods for the preparation and characterization of liposomal formulations in vitro will be outlined, too.

  6. Biophysical Screening of a Focused Library for the Discovery of CYP121 Inhibitors as Novel Antimycobacterials.

    Science.gov (United States)

    Brengel, Christian; Thomann, Andreas; Schifrin, Alexander; Allegretta, Giuseppe; Kamal, Ahmed A M; Haupenthal, Jörg; Schnorr, Isabell; Cho, Sang Hyun; Franzblau, Scott G; Empting, Martin; Eberhard, Jens; Hartmann, Rolf W

    2017-10-09

    The development of novel antimycobacterial agents against Mycobacterium tuberculosis (Mtb) is urgently required due to the appearance of multidrug resistance (MDR) combined with complicated long-term treatment. CYP121 was shown to be a promising novel target for inhibition of mycobacterial growth. In this study, we describe the rational discovery of new CYP121 inhibitors by a systematic screening based on biophysical and microbiological methods. The best hits originating from only one structural class gave initial information about molecular motifs required for binding and activity. The initial screening procedure was followed by mode-of-action studies and further biological characterizations. The results demonstrate superior antimycobacterial efficacy and a decreased toxicity profile of our frontrunner compound relative to the reference compound econazole. Due to its low molecular weight, promising biological profile, and physicochemical properties, this compound is an excellent starting point for further rational optimization. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Anti-pulmonary fibrotic activity of salvianolic acid B was screened by a novel method based on the cyto-biophysical properties

    International Nuclear Information System (INIS)

    Liu, Miao; Zheng, Mingjing; Xu, Hanying; Liu, Lianqing; Li, Yanchun; Xiao, Wei; Li, Jianchun; Ma, Enlong

    2015-01-01

    Various methods have been used to evaluate anti-fibrotic activity of drugs. However, most of them are complicated, labor-intensive and lack of efficiency. This study was intended to develop a rapid method for anti-fibrotic drugs screening based on biophysical properties. A549 cells in vitro were stimulated with transforming growth factor-β1 (TGF-β1), and fibrogenesis was confirmed by conventional immunological assays. Meanwhile, the alterations of cyto-biophysical properties including morphology, roughness and stiffness were measured utilizing atomic force microscopy (AFM). It was found that fibrogenesis was accompanied with changes of cellular biophysical properties. TGF-β1-stimulated A549 cells became remarkably longer, rougher and stiffer than the control. Then, the effect of N-acetyl-L-cysteine (NAC) as a positive drug on ameliorating fibrogenesis in TGF-β1-stimulated A549 cells was verified respectively by immunological and biophysical markers. The result of Principal Component Analysis showed that stiffness was a leading index among all biophysical markers during fibrogenesis. Salvianolic acid B (SalB), a natural anti-oxidant, was detected by AFM to protect TGF-β1-stimulated A549 cells against stiffening. Then, SalB treatment was provided in preventive mode on a rat model of bleomycin (BLM) -induced pulmonary fibrosis. The results showed that SalB treatment significantly ameliorated BLM-induced histological alterations, blocked collagen accumulations and reduced α-SMA expression in lung tissues. All these results revealed the anti-pulmonary fibrotic activity of SalB. Detection of cyto-biophysical properties were therefore recommended as a rapid method for anti-pulmonary fibrotic drugs screening. - Highlights: • Fibrogenesis was accompanied with the changes of cyto-biophysical properties. • Cyto-biophysical properties could be markers for anti-fibrotic drugs screening. • Stiffness is a leading index among all biophysical markers. • SalB was

  8. Anti-pulmonary fibrotic activity of salvianolic acid B was screened by a novel method based on the cyto-biophysical properties

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Miao; Zheng, Mingjing; Xu, Hanying [Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016 (China); Liu, Lianqing [Shenyang Institute of Automation China Academy of Sciences, Shenyang, 110016 (China); Li, Yanchun [Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016 (China); Xiao, Wei [Jiangsu Kanion Pharmaceutical Co., Ltd., Nanjing, 222001 (China); Li, Jianchun, E-mail: lijianchun0317@sina.com.cn [Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016 (China); Ma, Enlong, E-mail: enlong_ma2014@hotmail.com [Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016 (China); Jiangsu Kanion Pharmaceutical Co., Ltd., Nanjing, 222001 (China)

    2015-12-04

    Various methods have been used to evaluate anti-fibrotic activity of drugs. However, most of them are complicated, labor-intensive and lack of efficiency. This study was intended to develop a rapid method for anti-fibrotic drugs screening based on biophysical properties. A549 cells in vitro were stimulated with transforming growth factor-β1 (TGF-β1), and fibrogenesis was confirmed by conventional immunological assays. Meanwhile, the alterations of cyto-biophysical properties including morphology, roughness and stiffness were measured utilizing atomic force microscopy (AFM). It was found that fibrogenesis was accompanied with changes of cellular biophysical properties. TGF-β1-stimulated A549 cells became remarkably longer, rougher and stiffer than the control. Then, the effect of N-acetyl-L-cysteine (NAC) as a positive drug on ameliorating fibrogenesis in TGF-β1-stimulated A549 cells was verified respectively by immunological and biophysical markers. The result of Principal Component Analysis showed that stiffness was a leading index among all biophysical markers during fibrogenesis. Salvianolic acid B (SalB), a natural anti-oxidant, was detected by AFM to protect TGF-β1-stimulated A549 cells against stiffening. Then, SalB treatment was provided in preventive mode on a rat model of bleomycin (BLM) -induced pulmonary fibrosis. The results showed that SalB treatment significantly ameliorated BLM-induced histological alterations, blocked collagen accumulations and reduced α-SMA expression in lung tissues. All these results revealed the anti-pulmonary fibrotic activity of SalB. Detection of cyto-biophysical properties were therefore recommended as a rapid method for anti-pulmonary fibrotic drugs screening. - Highlights: • Fibrogenesis was accompanied with the changes of cyto-biophysical properties. • Cyto-biophysical properties could be markers for anti-fibrotic drugs screening. • Stiffness is a leading index among all biophysical markers. • SalB was

  9. Biophysics conference 1978

    International Nuclear Information System (INIS)

    1978-01-01

    The main subject on the biophysics meeting was the biophysics of membranes with practical subjects from photosynthesis and the transfer processes on membranes. In radiation biophysics, problems of radiation sensitisation, immunological problems after radiation exposure, the oxygen effect and inhibitory processes in RNS synthesis after radiation exposure were discussed with a view to tumour therapy. (AJ) [de

  10. Biophysics An Introduction

    CERN Document Server

    Glaser, Roland

    2012-01-01

    Biophysics is the science of physical principles underlying all processes of life, including the dynamics and kinetics of biological systems. This fully revised 2nd English edition is an introductory text that spans all steps of biological organization, from the molecular, to the organism level, as well as influences of environmental factors. In response to the enormous progress recently made, especially in theoretical and molecular biophysics, the author has updated the text, integrating new results and developments concerning protein folding and dynamics, molecular aspects of membrane assembly and transport, noise-enhanced processes, and photo-biophysics. The advances made in theoretical biology in the last decade call for a fully new conception of the corresponding sections. Thus, the book provides the background needed for fundamental training in biophysics and, in addition, offers a great deal of advanced biophysical knowledge.

  11. Integrated Molecular and Cellular Biophysics

    CERN Document Server

    Raicu, Valerica

    2008-01-01

    This book integrates concepts and methods from physics, biology, biochemistry and physical chemistry into a standalone, unitary text of biophysics that aims to provide a quantitative description of structures and processes occurring in living matter. The book introduces graduate physics students and physicists interested in biophysics research to 'classical' as well as emerging areas of biophysics. The advanced undergraduate physics students and the life scientists are also invited to join in, by building on their knowledge of basic physics. Essential notions of biochemistry and biology are introduced, as necessary, throughout the book, while the reader's familiarity with basic knowledge of physics is assumed. Topics covered include interactions between biological molecules, physical chemistry of phospholipids association into bilayer membranes, DNA and protein structure and folding, passive and active electrical properties of the cell membrane, classical as well as fractal aspects of reaction kinetics and di...

  12. Fab-based bispecific antibody formats with robust biophysical properties and biological activity.

    Science.gov (United States)

    Wu, Xiufeng; Sereno, Arlene J; Huang, Flora; Lewis, Steven M; Lieu, Ricky L; Weldon, Caroline; Torres, Carina; Fine, Cody; Batt, Micheal A; Fitchett, Jonathan R; Glasebrook, Andrew L; Kuhlman, Brian; Demarest, Stephen J

    2015-01-01

    A myriad of innovative bispecific antibody (BsAb) platforms have been reported. Most require significant protein engineering to be viable from a development and manufacturing perspective. Single-chain variable fragments (scFvs) and diabodies that consist only of antibody variable domains have been used as building blocks for making BsAbs for decades. The drawback with Fv-only moieties is that they lack the native-like interactions with CH1/CL domains that make antibody Fab regions stable and soluble. Here, we utilize a redesigned Fab interface to explore 2 novel Fab-based BsAbs platforms. The redesigned Fab interface designs limit heavy and light chain mixing when 2 Fabs are co-expressed simultaneously, thus allowing the use of 2 different Fabs within a BsAb construct without the requirement of one or more scFvs. We describe the stability and activity of a HER2×HER2 IgG-Fab BsAb, and compare its biophysical and activity properties with those of an IgG-scFv that utilizes the variable domains of the same parental antibodies. We also generated an EGFR × CD3 tandem Fab protein with a similar format to a tandem scFv (otherwise known as a bispecific T cell engager or BiTE). We show that the Fab-based BsAbs have superior biophysical properties compared to the scFv-based BsAbs. Additionally, the Fab-based BsAbs do not simply recapitulate the activity of their scFv counterparts, but are shown to possess unique biological activity.

  13. Biophysics

    CERN Document Server

    Glaser, Roland

    1999-01-01

    The message of this book is that biophysics is the science of physical principles underlying the "phenomenon life" on all levels of organization. Rather than teaching "physics for biologists" or "physical methods applied to biology", it regards its subject as a defined discipline with its own network of ideas and approaches. The book starts by explaining molecular structures of biological systems, various kinds of atomic, molecular and ionic interactions, movements, energy transfer, self organization of supramolecular structures and dynamic properties of biological membranes. It then goes on to introduce the biological organism as a non-equilibrium system, before treating thermodynamic concepts of osmotic and electrolyte equilibria as well as currents and potential profiles. It continues with topics of environmental biophysics and such medical aspects as the influence of electromagnetic fields or radiation on living systems and the biophysics of hearing and noice protection. The book concludes with a discussi...

  14. Methods in Modern Biophysics

    CERN Document Server

    Nölting, Bengt

    2006-01-01

    Incorporating recent dramatic advances, this textbook presents a fresh and timely introduction to modern biophysical methods. An array of new, faster and higher-power biophysical methods now enables scientists to examine the mysteries of life at a molecular level. This innovative text surveys and explains the ten key biophysical methods, including those related to biophysical nanotechnology, scanning probe microscopy, X-ray crystallography, ion mobility spectrometry, mass spectrometry, proteomics, and protein folding and structure. Incorporating much information previously unavailable in tutorial form, Nölting employs worked examples and 267 illustrations to fully detail the techniques and their underlying mechanisms. Methods in Modern Biophysics is written for advanced undergraduate and graduate students, postdocs, researchers, lecturers and professors in biophysics, biochemistry and related fields. Special features in the 2nd edition: • Illustrates the high-resolution methods for ultrashort-living protei...

  15. Methods in Modern Biophysics

    CERN Document Server

    Nölting, Bengt

    2010-01-01

    Incorporating recent dramatic advances, this textbook presents a fresh and timely introduction to modern biophysical methods. An array of new, faster and higher-power biophysical methods now enables scientists to examine the mysteries of life at a molecular level. This innovative text surveys and explains the ten key biophysical methods, including those related to biophysical nanotechnology, scanning probe microscopy, X-ray crystallography, ion mobility spectrometry, mass spectrometry, proteomics, and protein folding and structure. Incorporating much information previously unavailable in tutorial form, Nölting employs worked examples and about 270 illustrations to fully detail the techniques and their underlying mechanisms. Methods in Modern Biophysics is written for advanced undergraduate and graduate students, postdocs, researchers, lecturers, and professors in biophysics, biochemistry and related fields. Special features in the 3rd edition: Introduces rapid partial protein ladder sequencing - an important...

  16. Anti-pulmonary fibrotic activity of salvianolic acid B was screened by a novel method based on the cyto-biophysical properties.

    Science.gov (United States)

    Liu, Miao; Zheng, Mingjing; Xu, Hanying; Liu, Lianqing; Li, Yanchun; Xiao, Wei; Li, Jianchun; Ma, Enlong

    Various methods have been used to evaluate anti-fibrotic activity of drugs. However, most of them are complicated, labor-intensive and lack of efficiency. This study was intended to develop a rapid method for anti-fibrotic drugs screening based on biophysical properties. A549 cells in vitro were stimulated with transforming growth factor-β1 (TGF-β1), and fibrogenesis was confirmed by conventional immunological assays. Meanwhile, the alterations of cyto-biophysical properties including morphology, roughness and stiffness were measured utilizing atomic force microscopy (AFM). It was found that fibrogenesis was accompanied with changes of cellular biophysical properties. TGF-β1-stimulated A549 cells became remarkably longer, rougher and stiffer than the control. Then, the effect of N-acetyl-L-cysteine (NAC) as a positive drug on ameliorating fibrogenesis in TGF-β1-stimulated A549 cells was verified respectively by immunological and biophysical markers. The result of Principal Component Analysis showed that stiffness was a leading index among all biophysical markers during fibrogenesis. Salvianolic acid B (SalB), a natural anti-oxidant, was detected by AFM to protect TGF-β1-stimulated A549 cells against stiffening. Then, SalB treatment was provided in preventive mode on a rat model of bleomycin (BLM) -induced pulmonary fibrosis. The results showed that SalB treatment significantly ameliorated BLM-induced histological alterations, blocked collagen accumulations and reduced α-SMA expression in lung tissues. All these results revealed the anti-pulmonary fibrotic activity of SalB. Detection of cyto-biophysical properties were therefore recommended as a rapid method for anti-pulmonary fibrotic drugs screening. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Delineating Biophysical Environments of the Sunda Banda Seascape, Indonesia

    Directory of Open Access Journals (Sweden)

    Mingshu Wang

    2015-01-01

    Full Text Available The Sunda Banda Seascape (SBS, located in the center of the Coral Triangle, is a global center of marine biodiversity and a conservation priority. We proposed the first biophysical environmental delineation of the SBS using globally available satellite remote sensing and model-assimilated data to categorize this area into unique and meaningful biophysical classes. Specifically, the SBS was partitioned into eight biophysical classes characterized by similar sea surface temperature, chlorophyll a concentration, currents, and salinity patterns. Areas within each class were expected to have similar habitat types and ecosystem functions. Our work supplemented prevailing global marine management schemes by focusing in on a regional scale with finer spatial resolution. It also provided a baseline for academic research, ecological assessments and will facilitate marine spatial planning and conservation activities in the area. In addition, the framework and methods of delineating biophysical environments we presented can be expanded throughout the whole Coral Triangle to support research and conservation activities in this important region.

  18. 2. biophysical work meeting

    International Nuclear Information System (INIS)

    1992-11-01

    The report comprises 18 papers held at the 2nd Biophysical Work Meeting, 11 - 13 September 1991 in Schlema, Germany. The history of biophysics in Germany particularly of radiation biophysics and radon research, measurements of the radiation effects of radon and the derivation of limits, radon balneotherapy and consequences of uranium ore mining are dealt with. (orig.) [de

  19. Standby Gasoline Rationing Plan. Contingency gasoline rationing regulations

    Energy Technology Data Exchange (ETDEWEB)

    1979-02-01

    The Economic Regulatory Administration issues final rules with respect to standby gasoline rationing. The plan is designed for and would be used only in the event of a severe gasoline shortage. The plan provides that eligibility for ration allotments will be primarily on the basis of motor vehicle registrations. DOE will mail government ration checks to the parties named in a national vehicle registration file to be maintained by DOE. Ration recipients may cash these checks for ration coupons at various designated coupon issuance points. Retail outlets and other suppliers will be required to redeem the ration coupons received in exchange for gasoline sold. Supplemental gas will be given to high-priority activities. A ration banking system will be established with two separate and distinct of ration accounts: retail outlets and other suppliers will open redemption accounts for the deposit of redeemed ration rights; and individuals or firms may open ration rights accounts, which will operate in much the same manner as monetary checking accounts. A white market will be permitted for the sale of transfer of ration rights. A percentage of the total ration rights to be issued will be reserved for distribution to the states as a State Ration Reserve, to be used by the states primarily for the relief of hardship. A National Ration Reserave will also be established. All sections of the Standby Gasoline Rationing Regulations are analyzed. (MCW)

  20. Structural biophysics

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Summaries of research projects conducted during 1978 and 1979 are presented. The structural biophysics group explores the high-resolution structure of biological macromolecules and cell organelles. Specific subject areas include: the basic characteristics of photosynthesis in plants; the chemical composition of individual fly ash particles at the site of their damaging action in tissues; direct analysis of frozen-hydrated biological samples by scanning electron microscopy; yeast genetics; the optical activity of DNA aggregates; measurement and characterization of lipoproteins; function of lipoproteins; and the effect of radiation and pollutants on mammalian cells

  1. New horizons in Biophysics

    Science.gov (United States)

    2011-01-01

    This editorial celebrates the re-launch of PMC Biophysics previously published by PhysMath Central, in its new format as BMC Biophysics published by BioMed Central with an expanded scope and Editorial Board. BMC Biophysics will fill its own niche in the BMC series alongside complementary companion journals including BMC Bioinformatics, BMC Medical Physics, BMC Structural Biology and BMC Systems Biology. PMID:21595996

  2. Fundamental Concepts in Biophysics Volume 1

    CERN Document Server

    Jue, Thomas

    2009-01-01

    HANDBOOK OF MODERN BIOPHYSICS Series Editor Thomas Jue, PhD Handbook of Modern Biophysics brings current biophysics topics into focus, so that biology, medical, engineering, mathematics, and physical-science students or researchers can learn fundamental concepts and the application of new techniques in addressing biomedical challenges. Chapters explicate the conceptual framework of the physics formalism and illustrate the biomedical applications. With the addition of problem sets, guides to further study, and references, the interested reader can continue to explore independently the ideas presented. Volume I: Fundamental Concepts in Biophysics Editor Thomas Jue, PhD In Fundamental Concepts in Biophysics, prominent professors have established a foundation for the study of biophysics related to the following topics: Mathematical Methods in Biophysics Quantum Mechanics Basic to Biophysical Methods Computational Modeling of Receptor–Ligand Binding and Cellular Signaling Processes Fluorescence Spectroscopy Elec...

  3. Encyclopedia of biophysics

    CERN Document Server

    2013-01-01

    The Encyclopedia of Biophysics is envisioned both as an easily accessible source of information and as an introductory guide to the scientific literature. It includes entries describing both Techniques and Systems.  In the Techniques entries, each of the wide range of methods which fall under the heading of Biophysics are explained in detail, together with the value and the limitations of the information each provides. Techniques covered range from diffraction (X-ray, electron and neutron) through a wide range of spectroscopic methods (X-ray, optical, EPR, NMR) to imaging (from electron microscopy to live cell imaging and MRI), as well as computational and simulation approaches. In the Systems entries, biophysical approaches to specific biological systems or problems – from protein and nucleic acid structure to membranes, ion channels and receptors – are described. These sections, which place emphasis on the integration of the different techniques, therefore provide an inroad into Biophysics from a biolo...

  4. [Fluctuations in biophysical measurements as a result of variations in solar activity].

    Science.gov (United States)

    Peterson, T F

    1995-01-01

    A theory is proposed to explain variations in the net electrical charge of biological substances at the Earth's surface. These are shown to occur in association with changes in the solar wind and geomagnetic field. It is suggested that a liquid dielectric's net volume charge will imitate pH effects, influence chemical reaction rates, and alter ion transfer mechanisms in biophysical systems. An experiment is described which measures dielectric volume charge, or non-neutrality, to allow correlation of this property with daily, 28-day, and 11-year fluctuation patterns in geophysical and satellite data associated with solar activity and the interplanetary magnetic field.

  5. Research Institute for Medical Biophysics

    International Nuclear Information System (INIS)

    Wynchank, S.

    1989-01-01

    The effects of ionising and non-ionising radiation on rodent tumours and normal tissue were studied in terms of cellular repair and the relevant biochemical and biophysical changes following radiation. Rodent tumours investigated in vivo were the CaNT adenocarcinoma and a chemically induced transplantable rhabdomyosarcoma. Radiations used were 100KVp of X-Rays, neutron beams, various magnetic fields, and microwave radiation of 2450MHz. The biochemical parameters measured were, inter alia, levels of adenosine-5'-triphoshate (ATP) and the specific activity of hexokinase (HK). Metabolic changes in ATP levels and the activity of HK were observed in tumour and normal tissues following ionising and non-ionising radiation in normoxia and hypoxia. The observation that the effect of radiation and chemotherapeutic treatment of some tumours may be size dependent can possibly now be explained by the variation of ATP content with tumour size. The enhanced tumour HK specific activity implies increased metabolism, possibly a consequence of cellular requirements to maintain homeostasis during repair processes. Other research projects of the Research Institute for Medical Biophysics involved, inter alia, gastroesophageal scintigraphies to evaluate the results of new forms of therapy. 1 ill

  6. Role of Membrane Biophysics in Alzheimer's - related cell pathways

    Directory of Open Access Journals (Sweden)

    Donghui eZhu

    2015-05-01

    Full Text Available Cellular membrane alterations are commonly observed in many diseases, including Alzheimer’s disease (AD. Membrane biophysical properties, such as membrane molecular order, membrane fluidity, organization of lipid rafts, and adhesion between membrane and cytoskeleton, play an important role in various cellular activities and functions. While membrane biophysics impacts a broad range of cellular pathways, this review addresses the role of membrane biophysics in amyloid-β peptide aggregation, Aβ-induced oxidative pathways, amyloid precursor protein processing, and cerebral endothelial functions in AD. Understanding the mechanism(s underlying the effects of cell membrane properties on cellular processes should shed light on the development of new preventive and therapeutic strategies for this devastating disease.

  7. The relationship between fetal biophysical profile and cord blood PH

    Directory of Open Access Journals (Sweden)

    Valadan M

    2009-02-01

    Full Text Available "nBackground: The Biophysical Profile (BPP is a noninvasive test that predicts the presence or absence of fetal asphyxia and, ultimately, the risk of fetal death in the antenatal period. Intervention on the basis of an abnormal biophysical profile result has been reported to yield a significant reduction in prenatal mortality, and an association exists between biophysical profile scoring and a decreased cerebral palsy rate in a given population. The BPP evaluates five characteristics: fetal movement, tone, breathing, heart reactivity, and amniotic fluid (AF volume estimation. The purpose of study was to determine whether there are different degree of acidosis at which the biophysical activity (acute marker are affected. "nMethods: In a prospective study of 140 patients undergoing cesarean section before onset of labor, the fetal biophysical profile was performed 24h before the time of cesarean and was matched with cord arterial PH that was obtained from a cord segment (10-20cm that was double clamped after delivery of newborn. (using cord arterial PH less than 7.20 for the diagnosis of acidosis. "nResults: The fetal biophysical profile was found to have a significant relationship with umbilical blood PH. The sensitivity, specificity, positive predictive value, negative predictive value of fetal biophysical profile score were: 88.9%, 88.6%, 50%, 98.1%. "nConclusion: The first manifestations of fetal acidosis are nonreactive nonstress testing and fetal breathing loss; in advanced acidemia fetal movements and fetal tone are compromised. A protocol of antepartum fetal evaluation is suggested based upon the individual biophysical components rather than the score alone.

  8. Handbook of Single-Molecule Biophysics

    CERN Document Server

    Hinterdorfer, Peter

    2009-01-01

    The last decade has seen the development of a number of novel biophysical methods that allow the manipulation and study of individual biomolecules. The ability to monitor biological processes at this fundamental level of sensitivity has given rise to an improved understanding of the underlying molecular mechanisms. Through the removal of ensemble averaging, distributions and fluctuations of molecular properties can be characterized, transient intermediates identified, and catalytic mechanisms elucidated. By applying forces on biomolecules while monitoring their activity, important information can be obtained on how proteins couple function to structure. The Handbook of Single-Molecule Biophysics provides an introduction to these techniques and presents an extensive discussion of the new biological insights obtained from them. Coverage includes: Experimental techniques to monitor and manipulate individual biomolecules The use of single-molecule techniques in super-resolution and functional imaging Single-molec...

  9. Advanced Techniques in Biophysics

    CERN Document Server

    Arrondo, José Luis R

    2006-01-01

    Technical advancements are basic elements in our life. In biophysical studies, new applications and improvements in well-established techniques are being implemented every day. This book deals with advancements produced not only from a technical point of view, but also from new approaches that are being taken in the study of biophysical samples, such as nanotechniques or single-cell measurements. This book constitutes a privileged observatory for reviewing novel applications of biophysical techniques that can help the reader enter an area where the technology is progressing quickly and where a comprehensive explanation is not always to be found.

  10. Biophysics of Hair Cell Sensory Systems

    NARCIS (Netherlands)

    Duifhuis, Hendrikus; Horst, Johannes; van Dijk, Pim; van Netten, Sietse

    1993-01-01

    The last decade revealed to auditory researchers that hair cells can not only detect and process mechanical energy, but are also able to produce it. Thanks to the active hair cell, ears can produce otoacoustic emissions. This book gives the newest insights into the biophysics and physiology of

  11. Interactive Biophysics with Microswimmers: Education, Cloud Experimentation, Programmed Swarms, and Biotic Games

    Science.gov (United States)

    Riedel-Kruse, Ingmar

    Modern biotechnology gets increasingly powerful to manipulate and measure microscopic biophysical processes. Nevertheless, no platform exists to truly interact with these processes, certainly not with the convenience that we are accustomed to from our electronic smart devices. In my talk I will provide the rational for such Interactive Biotechnology and conceptualize its core component, the BPU (biotic processing unit), which is then connected to an according user interface. The biophysical phenomena currently featured on these platforms utilize the phototactic response of motile microorganisms, e.g., Euglena gracilis, resulting in spatio-temporal dynamics from the single cell to the self-organized multi-cellular scale. I will demonstrate multiple platforms, such as scalable biology cloud experimentation labs, tangible museum exhibits, biotic video games, low-cost interactive DIY kits using smartphones, and programming languages for swarm robotics. I will discuss applications for education as well as for professional and citizen science. Hence, we turn traditionally observational microscopy into an interactive experience. I was told that presenting in the educational section does not count against the ''one author - one talk policy'' - so I submit two abstracts. In case of conflict - please contact me: ingmar@stanford.edu.

  12. Molecular, biophysical, and pharmacological properties of calcium-activated chloride channels.

    Science.gov (United States)

    Kamaleddin, Mohammad Amin

    2018-02-01

    Calcium-activated chloride channels (CaCCs) are a family of anionic transmembrane ion channels. They are mainly responsible for the movement of Cl - and other anions across the biological membranes, and they are widely expressed in different tissues. Since the Cl - flow into or out of the cell plays a crucial role in hyperpolarizing or depolarizing the cells, respectively, the impact of intracellular Ca 2+ concentration on these channels is attracting a lot of attentions. After summarizing the molecular, biophysical, and pharmacological properties of CaCCs, the role of CaCCs in normal cellular functions will be discussed, and I will emphasize how dysregulation of CaCCs in pathological conditions can account for different diseases. A better understanding of CaCCs and a pivotal regulatory role of Ca 2+ can shed more light on the therapeutic strategies for different neurological disorders that arise from chloride dysregulation, such as asthma, cystic fibrosis, and neuropathic pain. © 2017 Wiley Periodicals, Inc.

  13. [Rationalization and rationing at the bedside. A normative and empirical status quo analysis].

    Science.gov (United States)

    Strech, D

    2014-02-01

    The topic of bedside rationing is increasingly discussed in Germany. Further need for clarification exists for the question how bedside rationing (e.g., in the area of overcare) can be justified despite coexistent inefficiencies. This paper outlines and analyses the relationship of waste avoidance and rationing from an ethical perspective. Empirical findings regarding the status quo of bedside rationing and rationalization are presented. These normative and empirical explorations will then be further specified regarding opportunities for future physician-driven activities to tackle overuse. The self-government partners in Germany should communicate more explicitly within their communities and to the public how and with which benchmarks they aim to reduce inefficient health care (overuse) in an appropriate manner. Physician-driven activities such as the "Choosing Wisely®" initiative in the USA could provide a first step to raise the awareness for overuse among physicians as well as in the public.

  14. Argumentation, rationality, and psychology of reasoning

    Directory of Open Access Journals (Sweden)

    David Godden

    2015-05-01

    Full Text Available This paper explicates an account of argumentative rationality by articulating the common, basic idea of its nature, and then identifying a collection of assumptions inherent in it. Argumentative rationality is then contrasted with dual-process theories of reasoning and rationality prevalent in the psychology of reasoning. It is argued that argumentative rationality properly corresponds only with system-2 reasoning in dual-process theories. This result challenges the prescriptive force of argumentative norms derives if they derive at all from their descriptive accuracy of our cognitive capacities. In response, I propose an activity-based account of reasoning which retains the assumptions of argumentative rationality while recontextualizing the relationship between reasoning as a justificatory activity and the psychological states and processes underlying that activity.

  15. Biophysical pathology in cancer transformation

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Jiří; Pokorný, Jan

    S1, Nov (2013), s. 1-9 ISSN 2324-9110 R&D Projects: GA ČR(CZ) GAP102/11/0649 Institutional support: RVO:68378271 ; RVO:67985882 Keywords : cancer biophysics * Warburg effect * reverse Warburg effect * biological electrodynamics * coherent states Subject RIV: BO - Biophysics

  16. New generation non-stationary portable neutron generators for biophysical applications of Neutron Activation Analysis.

    Science.gov (United States)

    Marchese, N; Cannuli, A; Caccamo, M T; Pace, C

    2017-01-01

    Neutron sources are increasingly employed in a wide range of research fields. For some specific purposes an alternative to existing large-scale neutron scattering facilities, can be offered by the new generation of portable neutron devices. This review reports an overview for such recently available neutron generators mainly addressed to biophysics applications with specific reference to portable non-stationary neutron generators applied in Neutron Activation Analysis (NAA). The review reports a description of a typical portable neutron generator set-up addressed to biophysics applications. New generation portable neutron devices, for some specific applications, can constitute an alternative to existing large-scale neutron scattering facilities. Deuterium-Deuterium pulsed neutron sources able to generate 2.5MeV neutrons, with a neutron yield of 1.0×10 6 n/s, a pulse rate of 250Hz to 20kHz and a duty factor varying from 5% to 100%, when combined with solid-state photon detectors, show that this kind of compact devices allow rapid and user-friendly elemental analysis. "This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo". Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Multimodal Imaging of Human Brain Activity: Rational, Biophysical Aspects and Modes of Integration

    Science.gov (United States)

    Blinowska, Katarzyna; Müller-Putz, Gernot; Kaiser, Vera; Astolfi, Laura; Vanderperren, Katrien; Van Huffel, Sabine; Lemieux, Louis

    2009-01-01

    Until relatively recently the vast majority of imaging and electrophysiological studies of human brain activity have relied on single-modality measurements usually correlated with readily observable or experimentally modified behavioural or brain state patterns. Multi-modal imaging is the concept of bringing together observations or measurements from different instruments. We discuss the aims of multi-modal imaging and the ways in which it can be accomplished using representative applications. Given the importance of haemodynamic and electrophysiological signals in current multi-modal imaging applications, we also review some of the basic physiology relevant to understanding their relationship. PMID:19547657

  18. Activation of Hsp90 Enzymatic Activity and Conformational Dynamics through Rationally Designed Allosteric Ligands.

    Science.gov (United States)

    Sattin, Sara; Tao, Jiahui; Vettoretti, Gerolamo; Moroni, Elisabetta; Pennati, Marzia; Lopergolo, Alessia; Morelli, Laura; Bugatti, Antonella; Zuehlke, Abbey; Moses, Mike; Prince, Thomas; Kijima, Toshiki; Beebe, Kristin; Rusnati, Marco; Neckers, Len; Zaffaroni, Nadia; Agard, David A; Bernardi, Anna; Colombo, Giorgio

    2015-09-21

    Hsp90 is a molecular chaperone of pivotal importance for multiple cell pathways. ATP-regulated internal dynamics are critical for its function and current pharmacological approaches block the chaperone with ATP-competitive inhibitors. Herein, a general approach to perturb Hsp90 through design of new allosteric ligands aimed at modulating its functional dynamics is proposed. Based on the characterization of a first set of 2-phenylbenzofurans showing stimulatory effects on Hsp90 ATPase and conformational dynamics, new ligands were developed that activate Hsp90 by targeting an allosteric site, located 65 Å from the active site. Specifically, analysis of protein responses to first-generation activators was exploited to guide the design of novel derivatives with improved ability to stimulate ATP hydrolysis. The molecules' effects on Hsp90 enzymatic, conformational, co-chaperone and client-binding properties were characterized through biochemical, biophysical and cellular approaches. These designed probes act as allosteric activators of the chaperone and affect the viability of cancer cell lines for which proper functioning of Hsp90 is necessary. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Biophysical applications of satellite remote sensing

    CERN Document Server

    Hanes, Jonathan

    2014-01-01

    Including an introduction and historical overview of the field, this comprehensive synthesis of the major biophysical applications of satellite remote sensing includes in-depth discussion of satellite-sourced biophysical metrics such as leaf area index.

  20. Historical and Critical Review on Biophysical Economics

    Science.gov (United States)

    Adigüzel, Yekbun

    2016-07-01

    Biophysical economics is initiated with the long history of the relation of economics with ecological basis and biophysical perspectives of the physiocrats. It inherently has social, economic, biological, environmental, natural, physical, and scientific grounds. Biological entities in economy like the resources, consumers, populations, and parts of production systems, etc. could all be dealt by biophysical economics. Considering this wide scope, current work is a “biophysical economics at a glance” rather than a comprehensive review of the full range of topics that may just be adequately covered in a book-length work. However, the sense of its wide range of applications is aimed to be provided to the reader in this work. Here, modern approaches and biophysical growth theory are presented after the long history and an overview of the concepts in biophysical economics. Examples of the recent studies are provided at the end with discussions. This review is also related to the work by Cleveland, “Biophysical Economics: From Physiocracy to Ecological Economics and Industrial Ecology” [C. J. Cleveland, in Advances in Bioeconomics and Sustainability: Essay in Honor of Nicholas Gerogescu-Roegen, eds. J. Gowdy and K. Mayumi (Edward Elgar Publishing, Cheltenham, England, 1999), pp. 125-154.]. Relevant parts include critics and comments on the presented concepts in a parallelized fashion with the Cleveland’s work.

  1. A quantitative overview of biophysical forces impinging on neural function

    International Nuclear Information System (INIS)

    Mueller, Jerel K; Tyler, William J

    2014-01-01

    The fundamentals of neuronal membrane excitability are globally described using the Hodgkin-Huxley (HH) model. The HH model, however, does not account for a number of biophysical phenomena associated with action potentials or propagating nerve impulses. Physical mechanisms underlying these processes, such as reversible heat transfer and axonal swelling, have been compartmentalized and separately investigated to reveal neuronal activity is not solely influenced by electrical or biochemical factors. Instead, mechanical forces and thermodynamics also govern neuronal excitability and signaling. To advance our understanding of neuronal function and dysfunction, compartmentalized analyses of electrical, chemical, and mechanical processes need to be revaluated and integrated into more comprehensive theories. The present perspective is intended to provide a broad overview of biophysical forces that can influence neural function, but which have been traditionally underappreciated in neuroscience. Further, several examples where mechanical forces have been shown to exert their actions on nervous system development, signaling, and plasticity are highlighted to underscore their importance in sculpting neural function. By considering the collective actions of biophysical forces influencing neuronal activity, our working models can be expanded and new paradigms can be applied to the investigation and characterization of brain function and dysfunction. (topical review)

  2. The biophysics of renal sympathetic denervation using radiofrequency energy.

    Science.gov (United States)

    Patel, Hitesh C; Dhillon, Paramdeep S; Mahfoud, Felix; Lindsay, Alistair C; Hayward, Carl; Ernst, Sabine; Lyon, Alexander R; Rosen, Stuart D; di Mario, Carlo

    2014-05-01

    Renal sympathetic denervation is currently performed in the treatment of resistant hypertension by interventionists who otherwise do not typically use radiofrequency (RF) energy ablation in their clinical practice. Adequate RF lesion formation is dependent upon good electrode-tissue contact, power delivery, electrode-tissue interface temperature, target-tissue impedance and the size of the catheter's active electrode. There is significant interplay between these variables and hence an appreciation of the biophysical determinants of RF lesion formation is required to provide effective and safe clinical care to our patients. In this review article, we summarize the biophysics of RF ablation and explain why and how complications of renal sympathetic denervation may occur and discuss methods to minimise them.

  3. Biophysics and cancer

    CERN Document Server

    Nicolini, Claudio

    1986-01-01

    Since the early times of the Greek philosophers Leucippus and Democritus, and later of the Roman philosopher Lucretius, a simple, fundamental idea emerged that brought the life sciences into the realm of the physical sciences. Atoms, after various interactions, were assumed to acquire stable configurations that corresponded either to the living or to the inanimate world. This simple and unitary theory, which has evolved in successive steps to our present time, remarkably maintained its validity despite several centuries of alternative vicissitudes, and is the foundation of modern biophysics. Some of the recent developments of this ancient idea are the discovery of the direct relationship between spatial structures and chemical activity of such molecules as methane and benzene, and the later discovery of the three-dimensional structure of double-helical DNA, and of its relationship with biological activity. The relationship between the structure of various macromolecules and the function of living cells was on...

  4. Theoretical Molecular Biophysics

    CERN Document Server

    Scherer, Philipp

    2010-01-01

    "Theoretical Molecular Biophysics" is an advanced study book for students, shortly before or after completing undergraduate studies, in physics, chemistry or biology. It provides the tools for an understanding of elementary processes in biology, such as photosynthesis on a molecular level. A basic knowledge in mechanics, electrostatics, quantum theory and statistical physics is desirable. The reader will be exposed to basic concepts in modern biophysics such as entropic forces, phase separation, potentials of mean force, proton and electron transfer, heterogeneous reactions coherent and incoherent energy transfer as well as molecular motors. Basic concepts such as phase transitions of biopolymers, electrostatics, protonation equilibria, ion transport, radiationless transitions as well as energy- and electron transfer are discussed within the frame of simple models.

  5. Biophysics an introduction

    CERN Document Server

    Cotteril, Rodney

    2002-01-01

    Biophysics: An Introduction, is a concise balanced introduction to this subject. Written in an accessible and readable style, the book takes a fresh, modern approach with the author successfully combining key concepts and theory with relevant applications and examples drawn from the field as a whole. Beginning with a brief introduction to the origins of biophysics, the book takes the reader through successive levels of complexity, from atoms to molecules, structures, systems and ultimately to the behaviour of organisms. The book also includes extensive coverage of biopolymers, biomembranes, biological energy, and nervous systems. The text not only explores basic ideas, but also discusses recent developments, such as protein folding, DNA/RNA conformations, molecular motors, optical tweezers and the biological origins of consciousness and intelligence.

  6. Simplifications of rational matrices by using UML

    OpenAIRE

    Tasić, Milan B.; Stanimirović, Ivan P.

    2013-01-01

    The simplification process on rational matrices consists of simplifying each entry represented by a rational function. We follow the classic approach of dividing the numerator and denominator polynomials by their common GCD polynomial, and provide the activity diagram in UML for this process. A rational matrix representation as the quotient of a polynomial matrix and a polynomial is also discussed here and illustrated via activity diagrams. Also, a class diagram giving the links between the c...

  7. Biophysical radiosensitization

    International Nuclear Information System (INIS)

    Vladescu, C.; Apetroae, M.

    1983-01-01

    Experimental studies on normal and tumor-bearing rats revealed that chronic treatment with hydroquinone (5 mg/kg/day) inhibited catalase activity in liver, spleen, blood, and H 18R tumor. 3 H-hydroquinone (1.5 μCi/g body weight) showed tumor specificity, with maximum radioactivity in the tumor at 1 h after administration. The biological half-time of 3 H-hydroquinone in the tumor was 2 h, but there seems to exist a longer component, since 24 h after administration, some 30% of the maximum radioactivity could be detected in the tumor. Hydroquinone treatment produces a specific inhibition of catalase in the tumor and a higher degree of oxygenation at this level. These findings support the assumption that the mechanism of action of hydroquinone as an anticancer agent is achieved mainly via peroxide production. The oxygenation of the hypoxic tumoral tissue is done at non-toxic levels of hydroquinone, through a natural and specific biophysical pathway, recommanding hydroquinone for combined anticancer treatment (radiotherapy and chemotherapy). (orig.)

  8. Cognitive Rationality and Its Logic-Mathematical Language

    Science.gov (United States)

    Masalova, Svetlana

    2012-01-01

    The article deals with the cognitive (flexible) rationality, combining rational and irrational moments of the scientific search of the cognizing subject. Linguo-cognitive model of the concept as the flexible regulative rationality reveals the activity of the cognitive processes and the mentality of the epistemological-ontic subject, its leading…

  9. Rationality of limited rationality : some aggregate implications

    OpenAIRE

    Uri M. Possen; Mikko Puhakka

    1994-01-01

    In this paper we let economic agents choose whether to become fully rational or stay boundedly rational. Boundedly rational agents are less sophisticated in their information processing abilities. It is costly to acquire information needed to become fully rational, and thus not all agents are willing to incur those costs. We then explore the aggregate effects of endogenizing the decision whether the agent should or should not become fully rational in handling information. Since fully and boun...

  10. Smoothing of, and parameter estimation from, noisy biophysical recordings.

    Directory of Open Access Journals (Sweden)

    Quentin J M Huys

    2009-05-01

    Full Text Available Biophysically detailed models of single cells are difficult to fit to real data. Recent advances in imaging techniques allow simultaneous access to various intracellular variables, and these data can be used to significantly facilitate the modelling task. These data, however, are noisy, and current approaches to building biophysically detailed models are not designed to deal with this. We extend previous techniques to take the noisy nature of the measurements into account. Sequential Monte Carlo ("particle filtering" methods, in combination with a detailed biophysical description of a cell, are used for principled, model-based smoothing of noisy recording data. We also provide an alternative formulation of smoothing where the neural nonlinearities are estimated in a non-parametric manner. Biophysically important parameters of detailed models (such as channel densities, intercompartmental conductances, input resistances, and observation noise are inferred automatically from noisy data via expectation-maximization. Overall, we find that model-based smoothing is a powerful, robust technique for smoothing of noisy biophysical data and for inference of biophysical parameters in the face of recording noise.

  11. Structure and biophysics

    CERN Document Server

    Puglisi, Joseph D

    2007-01-01

    This volume is a collection of articles from the proceedings of the ISSBMR 7th Course: Structure and Biophysics - New Technologies for Current Challenges in Biology and Beyond. This NATO Advanced Institute (ASI) was held in Erice at the Ettore Majorana Foundation and Centre for Scientific Culture on 22 June through 3 July 2005. The ASI brought together a diverse group of experts in the fields of Structural Biology, Biophysics and Physics. Prominent lecturers, from seven different countries, and students from around the world participated in the NATO ASI organized by Professors Joseph Puglisi (Stanford University, USA) and Alexander Arseniev (Moscow, RU). Advances in nuclear magnetic resonance spectroscopy (NMR) and x-ray crystallography have allowed the three-dimensional structures of many biological macromolecules and their complexes, including the ribosome and RNA polymerase to be solved. Fundamental principles of NMR spectroscopy and dynamics, x-ray crystallography, computation and experimental dynamics we...

  12. The application of multiple biophysical cues to engineer functional neocartilage for treatment of osteoarthritis. Part II: signal transduction.

    Science.gov (United States)

    Brady, Mariea A; Waldman, Stephen D; Ethier, C Ross

    2015-02-01

    The unique mechanoelectrochemical environment of cartilage has motivated researchers to investigate the effect of multiple biophysical cues, including mechanical, magnetic, and electrical stimulation, on chondrocyte biology. It is well established that biophysical stimuli promote chondrocyte proliferation, differentiation, and maturation within "biological windows" of defined dose parameters, including mode, frequency, magnitude, and duration of stimuli (see companion review Part I: Cellular Response). However, the underlying molecular mechanisms and signal transduction pathways activated in response to multiple biophysical stimuli remain to be elucidated. Understanding the mechanisms of biophysical signal transduction will deepen knowledge of tissue organogenesis, remodeling, and regeneration and aiding in the treatment of pathologies such as osteoarthritis. Further, this knowledge will provide the tissue engineer with a potent toolset to manipulate and control cell fate and subsequently develop functional replacement cartilage. The aim of this article is to review chondrocyte signal transduction pathways in response to mechanical, magnetic, and electrical cues. Signal transduction does not occur along a single pathway; rather a number of parallel pathways appear to be activated, with calcium signaling apparently common to all three types of stimuli, though there are different modes of activation. Current tissue engineering strategies, such as the development of "smart" functionalized biomaterials that enable the delivery of growth factors or integration of conjugated nanoparticles, may further benefit from targeting known signal transduction pathways in combination with external biophysical cues.

  13. Ultrasound assessment of the fetal biophysical profile: What does an radiologist need to know?

    International Nuclear Information System (INIS)

    Guimaraes Filho, Helio Antonio; Araujo Junior, Edward; Marcondes Machado Nardozza, Luciano; Linhares Dias da Costa, Lavoisier; Fernandes Moron, Antonio; Mattar, Rosiane

    2008-01-01

    Proposed by Frank Manning about 26 years ago, fetal biophysical profile has been incorporated to the propaedeutics of non-invasive fetal well being assessment in high-risk gestations. Despite the existence of other methods for assessing fetal vitality, as Doppler flowmetry, the biophysical profile continues to be important in estimating the risk of hypoxia and perinatal morbimortality for those fetuses. In the present article, the authors review the regulatory mechanisms of fetal biophysical activities, as well as physiological and pathological factors that interfere with them. The main objective of the study is to discuss the present and important aspects of the method, and the practical applications and interpretation of its findings, in order to help radiologists improve their knowledge in this specific area of fetal ultrasonography

  14. Engineered biomaterial and biophysical stimulation as combinatorial strategies to address prosthetic infection by pathogenic bacteria.

    Science.gov (United States)

    Boda, Sunil Kumar; Basu, Bikramjit

    2017-10-01

    A plethora of antimicrobial strategies are being developed to address prosthetic infection. The currently available methods for implant infection treatment include the use of antibiotics and revision surgery. Among the bacterial strains, Staphylococcus species pose significant challenges particularly, with regard to hospital acquired infections. In order to combat such life threatening infectious diseases, researchers have developed implantable biomaterials incorporating nanoparticles, antimicrobial reinforcements, surface coatings, slippery/non-adhesive and contact killing surfaces. This review discusses a few of the biomaterial and biophysical antimicrobial strategies, which are in the developmental stage and actively being pursued by several research groups. The clinical efficacy of biophysical stimulation methods such as ultrasound, electric and magnetic field treatments against prosthetic infection depends critically on the stimulation protocol and parameters of the treatment modality. A common thread among the three biophysical stimulation methods is the mechanism of bactericidal action, which is centered on biophysical rupture of bacterial membranes, the generation of reactive oxygen species (ROS) and bacterial membrane depolarization evoked by the interference of essential ion-transport. Although the extent of antimicrobial effect, normally achieved through biophysical stimulation protocol is insufficient to warrant therapeutic application, a combination of antibiotic/ROS inducing agents and biophysical stimulation methods can elicit a clinically relevant reduction in viable bacterial numbers. In this review, we present a detailed account of both the biomaterial and biophysical approaches for achieving maximum bacterial inactivation. Summarizing, the biophysical stimulation methods in a combinatorial manner with material based strategies can be a more potent solution to control bacterial infections. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B

  15. Biophysics: for HTS hit validation, chemical lead optimization, and beyond.

    Science.gov (United States)

    Genick, Christine C; Wright, S Kirk

    2017-09-01

    There are many challenges to the drug discovery process, including the complexity of the target, its interactions, and how these factors play a role in causing the disease. Traditionally, biophysics has been used for hit validation and chemical lead optimization. With its increased throughput and sensitivity, biophysics is now being applied earlier in this process to empower target characterization and hit finding. Areas covered: In this article, the authors provide an overview of how biophysics can be utilized to assess the quality of the reagents used in screening assays, to validate potential tool compounds, to test the integrity of screening assays, and to create follow-up strategies for compound characterization. They also briefly discuss the utilization of different biophysical methods in hit validation to help avoid the resource consuming pitfalls caused by the lack of hit overlap between biophysical methods. Expert opinion: The use of biophysics early on in the drug discovery process has proven crucial to identifying and characterizing targets of complex nature. It also has enabled the identification and classification of small molecules which interact in an allosteric or covalent manner with the target. By applying biophysics in this manner and at the early stages of this process, the chances of finding chemical leads with novel mechanisms of action are increased. In the future, focused screens with biophysics as a primary readout will become increasingly common.

  16. Radiation dosimetry and radiation biophysics

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with the design and measurement of physical parameters used in theory or to support biological experiments. The radiation biophysics program tests and uses the theoretical developments for experimental design, and provides information for further theoretical development through experiments on cellular systems

  17. Radiation dosimetry and radiation biophysics

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with design and measurement of those physical parameters used in the theory or to support biological experiments. The radiation biophysics program tests and makes use of the theoretical developments for experimental design. Also, this program provides information for further theoretical development through experiments on cellular systems

  18. Synchrotron radiation applications in biophysics and medicine

    International Nuclear Information System (INIS)

    Burattini, E.

    1985-01-01

    The peculiar properties of synchrotron radiation are briefly summarized. A short review on the possible applications of synchrotron radiation in two important fields like Biophysics and Medicine is presented. Details are given on experiments both in progress and carried out in many synchrotron radiation facilities, all over the world, using different techniques like X-ray absorption and fluorescence spectroscopy, X-ray fluorescence microanalysis, X-ray microscopy and digital subtraction angiography. Some news about the photon-activation therapy are briefly reported too

  19. Improving specific activity and thermostability of Escherichia coli phytase by structure-based rational design.

    Science.gov (United States)

    Wu, Tzu-Hui; Chen, Chun-Chi; Cheng, Ya-Shan; Ko, Tzu-Ping; Lin, Cheng-Yen; Lai, Hui-Lin; Huang, Ting-Yung; Liu, Je-Ruei; Guo, Rey-Ting

    2014-04-10

    Escherichia coli phytase (EcAppA) which hydrolyzes phytate has been widely applied in the feed industry, but the need to improve the enzyme activity and thermostability remains. Here, we conduct rational design with two strategies to enhance the EcAppA performance. First, residues near the substrate binding pocket of EcAppA were modified according to the consensus sequence of two highly active Citrobacter phytases. One out of the eleven mutants, V89T, exhibited 17.5% increase in catalytic activity, which might be a result of stabilized protein folding. Second, the EcAppA glycosylation pattern was modified in accordance with the Citrobacter phytases. An N-glycosylation motif near the substrate binding site was disrupted to remove spatial hindrance for phytate entry and product departure. The de-glycosylated mutants showed 9.6% increase in specific activity. On the other hand, the EcAppA mutants that adopt N-glycosylation motifs from CbAppA showed improved thermostability that three mutants carrying single N-glycosylation motif exhibited 5.6-9.5% residual activity after treatment at 80°C (1.8% for wild type). Furthermore, the mutant carrying all three glycosylation motifs exhibited 27% residual activity. In conclusion, a successful rational design was performed to obtain several useful EcAppA mutants with better properties for further applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. RATIONAL-IRRATIONAL ELECTORAL PREFERENCES, ALTRUISM AND EXPRESSIVE BEHAVIOR

    Directory of Open Access Journals (Sweden)

    Mihai Ungureanu

    2015-01-01

    Full Text Available Caplan (2000, 2001, 2006 proposed the rational-irrationality model arguing that irrationality is a good as any other, whose consumption is maximized in relation to its costs and benefits. Applying this model to the problem of electoral behavior Caplan implies that voters ‘afford’ many irrational beliefs, because the lack of individual decisiveness renders vote as a consequenceless act. This paper contributes to the development of knowledge by analyzing the compatibility of rational irrationality with active electoral behavior. Two important arguments are being proposed: First, Wittman’s (2008 intuition that rational irrationality is incompatible with voting could be supported only about a particular type of altruism, which Caplan actually seems to reject. Second, rational irrationality seems to be compatible with expressive motivations, reinforcing the conclusion that rational-irrational individuals are active voters in mass elections.

  1. Rational Design of Semiconductor Nanostructures for Functional Subcellular Interfaces.

    Science.gov (United States)

    Parameswaran, Ramya; Tian, Bozhi

    2018-05-15

    One of the fundamental questions guiding research in the biological sciences is how cellular systems process complex physical and environmental cues and communicate with each other across multiple length scales. Importantly, aberrant signal processing in these systems can lead to diseases that can have devastating impacts on human lives. Biophysical studies in the past several decades have demonstrated that cells can respond to not only biochemical cues but also mechanical and electrical ones. Thus, the development of new materials that can both sense and modulate all of these pathways is necessary. Semiconducting nanostructures are an emerging class of discovery platforms and tools that can push the limits of our ability to modulate and sense biological behaviors for both fundamental research and clinical applications. These materials are of particular interest for interfacing with cellular systems due to their matched dimension with subcellular components (e.g., cytoskeletal filaments), and easily tunable properties in the electrical, optical and mechanical regimes. Rational design via traditional or new approaches, such as nanocasting and mesoscale chemical lithography, can allow us to control micro- and nanoscale features in nanowires to achieve new biointerfaces. Both processes endogenous to the target cell and properties of the material surface dictate the character of these interfaces. In this Account, we focus on (1) approaches for the rational design of semiconducting nanowires that exhibit unique structures for biointerfaces, (2) recent fundamental discoveries that yield robust biointerfaces at the subcellular level, (3) intracellular electrical and mechanical sensing, and (4) modulation of cellular behaviors through material topography and remote physical stimuli. In the first section, we discuss new approaches for the synthetic control of micro- and nanoscale features of these materials. In the second section, we focus on achieving biointerfaces with

  2. The biophysics of neuronal growth

    International Nuclear Information System (INIS)

    Franze, Kristian; Guck, Jochen

    2010-01-01

    For a long time, neuroscience has focused on biochemical, molecular biological and electrophysiological aspects of neuronal physiology and pathology. However, there is a growing body of evidence indicating the importance of physical stimuli for neuronal growth and development. In this review we briefly summarize the historical background of neurobiophysics and give an overview over the current understanding of neuronal growth from a physics perspective. We show how biophysics has so far contributed to a better understanding of neuronal growth and discuss current inconsistencies. Finally, we speculate how biophysics may contribute to the successful treatment of lesions to the central nervous system, which have been considered incurable until very recently.

  3. Biophysical regulation of stem cell differentiation.

    Science.gov (United States)

    Govey, Peter M; Loiselle, Alayna E; Donahue, Henry J

    2013-06-01

    Bone adaptation to its mechanical environment, from embryonic through adult life, is thought to be the product of increased osteoblastic differentiation from mesenchymal stem cells. In parallel with tissue-scale loading, these heterogeneous populations of multipotent stem cells are subject to a variety of biophysical cues within their native microenvironments. Bone marrow-derived mesenchymal stem cells-the most broadly studied source of osteoblastic progenitors-undergo osteoblastic differentiation in vitro in response to biophysical signals, including hydrostatic pressure, fluid flow and accompanying shear stress, substrate strain and stiffness, substrate topography, and electromagnetic fields. Furthermore, stem cells may be subject to indirect regulation by mechano-sensing osteocytes positioned to more readily detect these same loading-induced signals within the bone matrix. Such paracrine and juxtacrine regulation of differentiation by osteocytes occurs in vitro. Further studies are needed to confirm both direct and indirect mechanisms of biophysical regulation within the in vivo stem cell niche.

  4. Satellite mapping of surface biophysical parameters at the biome scale over the North American grasslands: A case study

    Science.gov (United States)

    Wylie, B.K.; Meyer, D.J.; Tieszen, L.L.; Mannel, S.

    2002-01-01

    Quantification of biophysical parameters is needed by terrestrial process modeling and other applications. A study testing the role of multispectral data for monitoring biophysical parameters was conducted over a network of grassland field sites in the Great Plains of North America. Grassland biophysical parameters [leaf area index (LAI), fraction of absorbed photosynthetically active radiation (fPAR), and biomass] and their relationships with ground radiometer normalized difference vegetation index (NDVI) were established in this study (r2=.66–.85) from data collected across the central and northern Great Plains in 1995. These spectral/biophysical relationships were compared to 1996 field data from the Tallgrass Prairie Preserve in northeastern Oklahoma and showed no consistent biases, with most regression estimates falling within the respective 95% confidence intervals. Biophysical parameters were estimated for 21 “ground pixels” (grids) at the Tallgrass Prairie Preserve in 1996, representing three grazing/burning treatments. Each grid was 30×30 m in size and was systematically sampled with ground radiometer readings. The radiometric measurements were then converted to biophysical parameters and spatially interpolated using geostatistical kriging. Grid-based biophysical parameters were monitored through the growing season and regressed against Landsat Thematic Mapper (TM) NDVI (r2=.92–.94). These regression equations were used to estimate biophysical parameters for grassland TM pixels over the Tallgrass Prairie Preserve in 1996. This method maintained consistent regression development and prediction scales and attempted to minimize scaling problems associated with mixed land cover pixels. A method for scaling Landsat biophysical parameters to coarser resolution satellite data sets (1 km2) was also investigated.

  5. Biophysical Evaluation of SonoSteam®:

    DEFF Research Database (Denmark)

    Andersen, Ann Zahle; Duelund, Lars; Brewer, Jonathan R.

    and safety evaluations. Our results show that there are no contradictions between data obtained by either approach. However, the biophysical methods draw a much more nuanced picture of the effects and efficiency of the investigated decontamination method, revealing e.g. an exponential dose/response...... relationship between SonoSteam treatment time and changes in collagen I, and a depth dependency in bacterial reduction, which points toward CFU counts overestimating total bacterial reduction. In conclusion the biophysical methods provide a less biased, reproducible and highly detailed system description...

  6. Biophysical Cancer Transformation Pathway

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Jiří

    2009-01-01

    Roč. 28, č. 2 (2009), s. 105-123 ISSN 1536-8378 Institutional research plan: CEZ:AV0Z20670512 Keywords : Biophysics * Cancer * Electromagnetic fields Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.729, year: 2009

  7. Radiobiology, biochemistry and radiation biophysics at CYLAB

    International Nuclear Information System (INIS)

    Ftacnikova, S.

    1998-01-01

    The Cyclotron Laboratory (CYLAB) should fill the gap in the field of nuclear medicine, radiotherapy, basic research, metrology of ionizing radiation, education and implications of accelerator technology existing today in Slovak Republic. The main planned activities of this facility are in the fields of nuclear medicine (production of radioisotopes for Positron Emission Tomography - PET and for oncology) and radiotherapy (neutron capture therapy, fast neutron therapy and proton therapy). The radiobiological and biophysical research will be closely connected with medical applications, particularly with radiotherapy. Problems to be addressed include the determination of the values of Relative Biological Effectiveness (RBE) for different types of ionizing radiation involved in the therapy, microdosimetric measurements and calculations, which are indispensable in the calculation of the absorbed dose (lineal and specific energy spectra) at the cellular and macromolecular level. Radiation biophysics and medical physics help in creating therapeutic plans for radiotherapy (NCT and fast neutron therapy). In nuclear medicine, in diagnostic and therapeutical procedures it is necessary to assess the biodistribution of radiopharmaceuticals and to calculate doses in target and critical organs and to determine whole body burden - effective equivalent dose for newly developed radiopharmaceuticals

  8. Assaying Auxin Receptor Activity Using SPR Assays with F-Box Proteins and Aux/IAA Degrons.

    Science.gov (United States)

    Quareshy, Mussa; Uzunova, Veselina; Prusinska, Justyna M; Napier, Richard M

    2017-01-01

    The identification of TIR1 as an auxin receptor combined with advanced biophysical instrumentation has led to the development of real-time activity assays for auxins. Traditionally, molecules have been assessed for auxinic activity using bioassays, and agrochemical compound discovery continues to be based on "spray and pray" technologies. Here, we describe the methodology behind an SPR-based assay that uses TIR1 and related F-box proteins with surface plasmon resonance spectrometry for rapid compound screening. In addition, methods for collecting kinetic binding data and data processing are given so that they may support programs for rational design of novel auxin ligands.

  9. Rationalization: A Bibliography.

    Science.gov (United States)

    Pedrini, D. T.; Pedrini, Bonnie C.

    Rationalization was studied by Sigmund Freud and was specifically labeled by Ernest Jones. Rationalization ought to be differentiated from rational, rationality, logical analysis, etc. On the one hand, rationalization is considered a defense mechanism, on the other hand, rationality is not. Haan has done much work with self-report inventories and…

  10. A biotic video game smart phone kit for formal and informal biophysics education

    Science.gov (United States)

    Kim, Honesty; Lee, Seung Ah; Riedel-Kruse, Ingmar

    2015-03-01

    Novel ways for formal and informal biophysics education are important. We present a low-cost biotic game design kit that incorporates microbial organisms into an interactive gaming experience: A 3D-printable microscope containing four LEDs controlled by a joystick enable human players to provide directional light stimuli to the motile single-celled organism Euglena gracilis. These cellular behaviors are displayed on the integrated smart phone. Real time cell-tracking couples these cells into interactive biotic video game play, i.e., the human player steers Euglena to play soccer with virtual balls and goals. The player's learning curve in mastering this fun game is intrinsically coupled to develop a deeper knowledge about Euglena's cell morphology and the biophysics of its phototactic behavior. This kit is dual educational - via construction and via play - and it provides an engaging theme for a formal biophysics devices class as well as to be presented in informal outreach activities; its low cost and open soft- and hardware should enable wide adoption.

  11. Biophysical EPR Studies Applied to Membrane Proteins

    Science.gov (United States)

    Sahu, Indra D; Lorigan, Gary A

    2015-01-01

    Membrane proteins are very important in controlling bioenergetics, functional activity, and initializing signal pathways in a wide variety of complicated biological systems. They also represent approximately 50% of the potential drug targets. EPR spectroscopy is a very popular and powerful biophysical tool that is used to study the structural and dynamic properties of membrane proteins. In this article, a basic overview of the most commonly used EPR techniques and examples of recent applications to answer pertinent structural and dynamic related questions on membrane protein systems will be presented. PMID:26855825

  12. Rational Decision Making as Performative Praxis: Explaining Rationality's Éternel Retour

    OpenAIRE

    Cabantous, L.; Gond, J-P.

    2011-01-01

    Organizational theorists built their knowledge of decision making through a progressive critique of rational choice theory. Their positioning towards rationality, however, is at odds with the observation of rationality persistence in organizational life. This paper addresses this paradox. It proposes a new perspective on rationality that allows the theorizing of the production of rational decisions by organizations. To account for rationality's éternel retour, we approach rational decision ma...

  13. The physical basis of biochemistry the foundations of molecular biophysics

    CERN Document Server

    Bergethon, Peter R

    1998-01-01

    The objective of this book is to provide a unifying approach to the study of biophysical chemistry for the advanced undergraduate who has had a year of physics, organic chem­ istry, calculus, and biology. This book began as a revised edition of Biophysical Chemistry: Molecules to Membranes, which Elizabeth Simons and I coauthored. That short volume was written in an attempt to provide a concise text for a one-semester course in biophysical chemistry at the graduate level. The experience of teaching biophysical chemistry to bi­ ologically oriented students over the last decade has made it clear that the subject requires a more fundamental text that unifies the many threads of modem science: physics, chem­ istry, biology, mathematics, and statistics. This book represents that effort. This volume is not a treatment of modem biophysical chemistry with its rich history and many contro­ versies, although a book on that topic is also needed. The Physical Basis of Biochemistry is an introduction to the philosophy...

  14. Rational Emotive Education

    Science.gov (United States)

    Knaus, William

    1977-01-01

    Rational Emotive Education--an outgrowth of theories developed by Albert Ellis--is a teaching design of mental health concepts and problem-solving activities designed to help students to approach and cope with their problems through experiential learning, via a structured, thematic sequence of emotive education lessons. (MJB)

  15. Quantify the Biophysical and Socioeconomic Drivers of Changes in Forest and Agricultural Land in South and Southeast Asia

    Science.gov (United States)

    Xu, X.; Jain, A. K.; Calvin, K. V.

    2017-12-01

    Due to the rapid socioeconomic development and biophysical factors, South and Southeast Asia (SSEA) has become a hotspot region of land use and land cover changes (LULCCs) in past few decades. Uncovering the drivers of LULCC is crucial for improving the understanding of LULCC processes. Due to the differences from spatiotemporal scales, methods and data sources in previous studies, the quantitative relationships between the LULCC activities and biophysical and socioeconomic drivers at the regional scale of SSEA have not been established. Here we present a comprehensive estimation of the biophysical and socioeconomic drivers of the major LULCC activities in SSEA: changes in forest and agricultural land. We used the Climate Change Initiative land cover data developed by European Space Agency to reveal the dynamics of forest and agricultural land from 1992 to 2015. Then we synthesized 200 publications about LULCC drivers at different spatial scales in SSEA to identify the major drivers of these LULCC activities. Corresponding representative variables of the major drivers were collected. The geographically weighted regression was employed to assess the spatiotemporally heterogeneous drivers of LULCC. Moreover, we validated our results with some national level case studies in SSEA. The results showed that both biophysical conditions such as terrain, soil, and climate, and socioeconomic factors such as migration, poverty, and economy played important roles in driving the changes of forest and agricultural land. The major drivers varied in different locations and periods. Our study integrated the bottom-up knowledge from local scale case studies with the top-down estimation of LULCC drivers, therefore generated more accurate and credible results. The identified biophysical and socioeconomic components could be used to improve the LULCC modelling and projection.

  16. Global energy modeling - A biophysical approach

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Michael

    2010-09-15

    This paper contrasts the standard economic approach to energy modelling with energy models using a biophysical approach. Neither of these approaches includes changing energy-returns-on-investment (EROI) due to declining resource quality or the capital intensive nature of renewable energy sources. Both of these factors will become increasingly important in the future. An extension to the biophysical approach is outlined which encompasses a dynamic EROI function that explicitly incorporates technological learning. The model is used to explore several scenarios of long-term future energy supply especially concerning the global transition to renewable energy sources in the quest for a sustainable energy system.

  17. Biophysical Regulation of Vascular Differentiation and Assembly

    CERN Document Server

    Gerecht, Sharon

    2011-01-01

    The ability to grow stem cells in the laboratory and to guide their maturation to functional cells allows us to study the underlying mechanisms that govern vasculature differentiation and assembly in health and disease. Accumulating evidence suggests that early stages of vascular growth are exquisitely tuned by biophysical cues from the microenvironment, yet the scientific understanding of such cellular environments is still in its infancy. Comprehending these processes sufficiently to manipulate them would pave the way to controlling blood vessel growth in therapeutic applications. This book assembles the works and views of experts from various disciplines to provide a unique perspective on how different aspects of its microenvironment regulate the differentiation and assembly of the vasculature. In particular, it describes recent efforts to exploit modern engineering techniques to study and manipulate various biophysical cues. Biophysical Regulation of Vascular Differentiation and Assembly provides an inter...

  18. Biophysics and systems biology.

    Science.gov (United States)

    Noble, Denis

    2010-03-13

    Biophysics at the systems level, as distinct from molecular biophysics, acquired its most famous paradigm in the work of Hodgkin and Huxley, who integrated their equations for the nerve impulse in 1952. Their approach has since been extended to other organs of the body, notably including the heart. The modern field of computational biology has expanded rapidly during the first decade of the twenty-first century and, through its contribution to what is now called systems biology, it is set to revise many of the fundamental principles of biology, including the relations between genotypes and phenotypes. Evolutionary theory, in particular, will require re-assessment. To succeed in this, computational and systems biology will need to develop the theoretical framework required to deal with multilevel interactions. While computational power is necessary, and is forthcoming, it is not sufficient. We will also require mathematical insight, perhaps of a nature we have not yet identified. This article is therefore also a challenge to mathematicians to develop such insights.

  19. Large-scale biophysical evaluation of protein PEGylation effects

    DEFF Research Database (Denmark)

    Vernet, Erik; Popa, Gina; Pozdnyakova, Irina

    2016-01-01

    PEGylation is the most widely used method to chemically modify protein biopharmaceuticals, but surprisingly limited public data is available on the biophysical effects of protein PEGylation. Here we report the first large-scale study, with site-specific mono-PEGylation of 15 different proteins...... of PEGylation on the thermal stability of a protein based on data generated by circular dichroism (CD), differential scanning calorimetry (DSC), or differential scanning fluorimetry (DSF). In addition, DSF was validated as a fast and inexpensive screening method for thermal unfolding studies of PEGylated...... proteins. Multivariate data analysis revealed clear trends in biophysical properties upon PEGylation for a subset of proteins, although no universal trends were found. Taken together, these findings are important in the consideration of biophysical methods and evaluation of second...

  20. Biophysical and lipofection studies of DOTAP analogs.

    Science.gov (United States)

    Regelin, A E; Fankhaenel, S; Gürtesch, L; Prinz, C; von Kiedrowski, G; Massing, U

    2000-03-15

    In order to investigate the relationship between lipid structure and liposome-mediated gene transfer, we have studied biophysical parameters and transfection properties of monocationic DOTAP analogs, systematically modified in their non-polar hydrocarbon chains. Stability, size and (by means of anisotropy profiles) membrane fluidity of liposomes and lipoplexes were determined, and lipofection efficiency was tested in a luciferase reporter gene assay. DOTAP analogs were used as single components or combined with a helper lipid, either DOPE or cholesterol. Stability of liposomes was a precondition for formation of temporarily stable lipoplexes. Addition of DOPE or cholesterol improved liposome and lipoplex stability. Transfection efficiencies of lipoplexes based on pure DOTAP analogs could be correlated with stability data and membrane fluidity at transfection temperature. Inclusion of DOPE led to rather uniform transfection and anisotropy profiles, corresponding to lipoplex stability. Cholesterol-containing lipoplexes were generally stable, showing high transfection efficiency at low relative fluidity. Our results demonstrate that the efficiency of gene transfer mediated by monocationic lipids is greatly influenced by lipoplex biophysics due to lipid composition. The measurement of fluorescence anisotropy is an appropriate method to characterize membrane fluidity within a defined system of liposomes or lipoplexes and may be helpful to elucidate structure-activity relationships.

  1. Biophysics of radiation action

    International Nuclear Information System (INIS)

    Dertinger, H.

    1984-01-01

    Understanding the cellular response to ionizing radiation is not only necessary to meet the requirements of radioprotection, but also for medical application of radiation in cancer treatment. In terms of radiobiology, cancer therapy means the selective inactivation of malignant cells without affecting the normal healthy tissue. However, for several physical and biological reasons, this ideal situation is normally not attained. The elaboration of biophysical parameters that could be used to improve the selective sterilization of tumor cells has become one of the main activities of cellular radiobiology during the last two decades. Progress in this field has been facilitated by the development of tissue culture techniques allowing to grow and analyze cells in a synthetic nutrient medium. This chapter describes the physical and biological factors which determine cellular radiosensitivity and which are important to know for better understanding the cellular radiation action, in particular with reference to cancer treatment

  2. Biophysical models of larval dispersal in the Benguela Current ...

    African Journals Online (AJOL)

    We synthesise and update results from the suite of biophysical, larval-dispersal models developed in the Benguela Current ecosystem. Biophysical models of larval dispersal use outputs of physical hydrodynamic models as inputs to individual-based models in which biological processes acting during the larval life are ...

  3. Recent progress in Biophysics

    International Nuclear Information System (INIS)

    Bemski, G.

    1980-03-01

    Recent progress in biophysics is reviewed, and three examples of the use of physical techniques and ideas in biological research are given. The first one deals with the oxygen transporting protein-hemoglobin, the second one with photosynthesis, and the third one with image formation, using nuclear magnetic resonance. (Author) [pt

  4. Rationality in Society

    NARCIS (Netherlands)

    Flache, Andreas; Dijkstra, Jacob; Wright, James D.

    2015-01-01

    Contemporary theories of rational behavior in human society augment the orthodox model of rationality both by adding various forms of bounded rationality and relaxing the assumptions of self-interest and materialistic preferences. This entry discusses how these extensions of the theory of rational

  5. Intergroup conflict and rational decision making.

    Science.gov (United States)

    Martínez-Tur, Vicente; Peñarroja, Vicente; Serrano, Miguel A; Hidalgo, Vanesa; Moliner, Carolina; Salvador, Alicia; Alacreu-Crespo, Adrián; Gracia, Esther; Molina, Agustín

    2014-01-01

    The literature has been relatively silent about post-conflict processes. However, understanding the way humans deal with post-conflict situations is a challenge in our societies. With this in mind, we focus the present study on the rationality of cooperative decision making after an intergroup conflict, i.e., the extent to which groups take advantage of post-conflict situations to obtain benefits from collaborating with the other group involved in the conflict. Based on dual-process theories of thinking and affect heuristic, we propose that intergroup conflict hinders the rationality of cooperative decision making. We also hypothesize that this rationality improves when groups are involved in an in-group deliberative discussion. Results of a laboratory experiment support the idea that intergroup conflict -associated with indicators of the activation of negative feelings (negative affect state and heart rate)- has a negative effect on the aforementioned rationality over time and on both group and individual decision making. Although intergroup conflict leads to sub-optimal decision making, rationality improves when groups and individuals subjected to intergroup conflict make decisions after an in-group deliberative discussion. Additionally, the increased rationality of the group decision making after the deliberative discussion is transferred to subsequent individual decision making.

  6. Intergroup Conflict and Rational Decision Making

    Science.gov (United States)

    Martínez-Tur, Vicente; Peñarroja, Vicente; Serrano, Miguel A.; Hidalgo, Vanesa; Moliner, Carolina; Salvador, Alicia; Alacreu-Crespo, Adrián; Gracia, Esther; Molina, Agustín

    2014-01-01

    The literature has been relatively silent about post-conflict processes. However, understanding the way humans deal with post-conflict situations is a challenge in our societies. With this in mind, we focus the present study on the rationality of cooperative decision making after an intergroup conflict, i.e., the extent to which groups take advantage of post-conflict situations to obtain benefits from collaborating with the other group involved in the conflict. Based on dual-process theories of thinking and affect heuristic, we propose that intergroup conflict hinders the rationality of cooperative decision making. We also hypothesize that this rationality improves when groups are involved in an in-group deliberative discussion. Results of a laboratory experiment support the idea that intergroup conflict –associated with indicators of the activation of negative feelings (negative affect state and heart rate)– has a negative effect on the aforementioned rationality over time and on both group and individual decision making. Although intergroup conflict leads to sub-optimal decision making, rationality improves when groups and individuals subjected to intergroup conflict make decisions after an in-group deliberative discussion. Additionally, the increased rationality of the group decision making after the deliberative discussion is transferred to subsequent individual decision making. PMID:25461384

  7. Intergroup conflict and rational decision making.

    Directory of Open Access Journals (Sweden)

    Vicente Martínez-Tur

    Full Text Available The literature has been relatively silent about post-conflict processes. However, understanding the way humans deal with post-conflict situations is a challenge in our societies. With this in mind, we focus the present study on the rationality of cooperative decision making after an intergroup conflict, i.e., the extent to which groups take advantage of post-conflict situations to obtain benefits from collaborating with the other group involved in the conflict. Based on dual-process theories of thinking and affect heuristic, we propose that intergroup conflict hinders the rationality of cooperative decision making. We also hypothesize that this rationality improves when groups are involved in an in-group deliberative discussion. Results of a laboratory experiment support the idea that intergroup conflict -associated with indicators of the activation of negative feelings (negative affect state and heart rate- has a negative effect on the aforementioned rationality over time and on both group and individual decision making. Although intergroup conflict leads to sub-optimal decision making, rationality improves when groups and individuals subjected to intergroup conflict make decisions after an in-group deliberative discussion. Additionally, the increased rationality of the group decision making after the deliberative discussion is transferred to subsequent individual decision making.

  8. The case for biophysics super-groups in physics departments.

    Science.gov (United States)

    Hoogenboom, Bart W; Leake, Mark

    2018-06-04

    Increasing numbers of physicists engage in research activities that address biological questions from physics perspectives or strive to develop physics insights from active biological processes. The on-going development and success of such activities morph our ways of thinking about what it is to 'do biophysics' and add to our understanding of the physics of life. Many scientists in this research and teaching landscape are homed in physics departments. A challenge for a hosting department is how to group, name and structure such biophysicists to best add value to their emerging research and teaching but also to the portfolio of the whole department. Here we discuss these issues and speculate on strategies. Creative Commons Attribution license.

  9. A Rational Approach to Rational Suicide.

    Science.gov (United States)

    Richman, Joseph

    1992-01-01

    Describes suicide as reaction to internal and external sources of stress and the impact of life events. Notes that, in the elderly, these situations are prevalent in many who are not suicidal. Contends that much more is written about rational suicide than its alternative (rational nonsuicide). Reviews reasons for this and suggests rational…

  10. MODELLING BIOPHYSICAL PARAMETERS OF MAIZE USING LANDSAT 8 TIME SERIES

    Directory of Open Access Journals (Sweden)

    T. Dahms

    2016-06-01

    Full Text Available Open and free access to multi-frequent high-resolution data (e.g. Sentinel – 2 will fortify agricultural applications based on satellite data. The temporal and spatial resolution of these remote sensing datasets directly affects the applicability of remote sensing methods, for instance a robust retrieving of biophysical parameters over the entire growing season with very high geometric resolution. In this study we use machine learning methods to predict biophysical parameters, namely the fraction of absorbed photosynthetic radiation (FPAR, the leaf area index (LAI and the chlorophyll content, from high resolution remote sensing. 30 Landsat 8 OLI scenes were available in our study region in Mecklenburg-Western Pomerania, Germany. In-situ data were weekly to bi-weekly collected on 18 maize plots throughout the summer season 2015. The study aims at an optimized prediction of biophysical parameters and the identification of the best explaining spectral bands and vegetation indices. For this purpose, we used the entire in-situ dataset from 24.03.2015 to 15.10.2015. Random forest and conditional inference forests were used because of their explicit strong exploratory and predictive character. Variable importance measures allowed for analysing the relation between the biophysical parameters with respect to the spectral response, and the performance of the two approaches over the plant stock evolvement. Classical random forest regression outreached the performance of conditional inference forests, in particular when modelling the biophysical parameters over the entire growing period. For example, modelling biophysical parameters of maize for the entire vegetation period using random forests yielded: FPAR: R² = 0.85; RMSE = 0.11; LAI: R² = 0.64; RMSE = 0.9 and chlorophyll content (SPAD: R² = 0.80; RMSE=4.9. Our results demonstrate the great potential in using machine-learning methods for the interpretation of long-term multi-frequent remote sensing

  11. Modelling Biophysical Parameters of Maize Using Landsat 8 Time Series

    Science.gov (United States)

    Dahms, Thorsten; Seissiger, Sylvia; Conrad, Christopher; Borg, Erik

    2016-06-01

    Open and free access to multi-frequent high-resolution data (e.g. Sentinel - 2) will fortify agricultural applications based on satellite data. The temporal and spatial resolution of these remote sensing datasets directly affects the applicability of remote sensing methods, for instance a robust retrieving of biophysical parameters over the entire growing season with very high geometric resolution. In this study we use machine learning methods to predict biophysical parameters, namely the fraction of absorbed photosynthetic radiation (FPAR), the leaf area index (LAI) and the chlorophyll content, from high resolution remote sensing. 30 Landsat 8 OLI scenes were available in our study region in Mecklenburg-Western Pomerania, Germany. In-situ data were weekly to bi-weekly collected on 18 maize plots throughout the summer season 2015. The study aims at an optimized prediction of biophysical parameters and the identification of the best explaining spectral bands and vegetation indices. For this purpose, we used the entire in-situ dataset from 24.03.2015 to 15.10.2015. Random forest and conditional inference forests were used because of their explicit strong exploratory and predictive character. Variable importance measures allowed for analysing the relation between the biophysical parameters with respect to the spectral response, and the performance of the two approaches over the plant stock evolvement. Classical random forest regression outreached the performance of conditional inference forests, in particular when modelling the biophysical parameters over the entire growing period. For example, modelling biophysical parameters of maize for the entire vegetation period using random forests yielded: FPAR: R² = 0.85; RMSE = 0.11; LAI: R² = 0.64; RMSE = 0.9 and chlorophyll content (SPAD): R² = 0.80; RMSE=4.9. Our results demonstrate the great potential in using machine-learning methods for the interpretation of long-term multi-frequent remote sensing datasets to model

  12. Epigenetic modulation of the biophysical properties of drug-resistant cell lipids to restore drug transport and endocytic functions.

    Science.gov (United States)

    Vijayaraghavalu, Sivakumar; Peetla, Chiranjeevi; Lu, Shan; Labhasetwar, Vinod

    2012-09-04

    In our recent studies exploring the biophysical characteristics of resistant cell lipids, and the role they play in drug transport, we demonstrated the difference of drug-resistant breast cancer cells from drug-sensitive cells in lipid composition and biophysical properties, suggesting that cancer cells acquire a drug-resistant phenotype through the alteration of lipid synthesis to inhibit intracellular drug transport to protect from cytotoxic effect. In cancer cells, epigenetic changes (e.g., DNA hypermethylation) are essential to maintain this drug-resistant phenotype. Thus, altered lipid synthesis may be linked to epigenetic mechanisms of drug resistance. We hypothesize that reversing DNA hypermethylation in resistant cells with an epigenetic drug could alter lipid synthesis, changing the cell membrane's biophysical properties to facilitate drug delivery to overcome drug resistance. Herein we show that treating drug-resistant breast cancer cells (MCF-7/ADR) with the epigenetic drug 5-aza-2'-deoxycytidine (decitabine) significantly alters cell lipid composition and biophysical properties, causing the resistant cells to acquire biophysical characteristics similar to those of sensitive cell (MCF-7) lipids. Following decitabine treatment, resistant cells demonstrated increased sphingomyelinase activity, resulting in a decreased sphingomyelin level that influenced lipid domain structures, increased membrane fluidity, and reduced P-glycoprotein expression. Changes in the biophysical characteristics of resistant cell lipids facilitated doxorubicin transport and restored endocytic function for drug delivery with a lipid-encapsulated form of doxorubicin, enhancing the drug efficacy. In conclusion, we have established a new mechanism for efficacy of an epigenetic drug, mediated through changes in lipid composition and biophysical properties, in reversing cancer drug resistance.

  13. Biophysical impacts of climate-smart agriculture in the Midwest United States.

    Science.gov (United States)

    Bagley, Justin E; Miller, Jesse; Bernacchi, Carl J

    2015-09-01

    The potential impacts of climate change in the Midwest United States present unprecedented challenges to regional agriculture. In response to these challenges, a variety of climate-smart agricultural methodologies have been proposed to retain or improve crop yields, reduce agricultural greenhouse gas emissions, retain soil quality and increase climate resilience of agricultural systems. One component that is commonly neglected when assessing the environmental impacts of climate-smart agriculture is the biophysical impacts, where changes in ecosystem fluxes and storage of moisture and energy lead to perturbations in local climate and water availability. Using a combination of observational data and an agroecosystem model, a series of climate-smart agricultural scenarios were assessed to determine the biophysical impacts these techniques have in the Midwest United States. The first scenario extended the growing season for existing crops using future temperature and CO2 concentrations. The second scenario examined the biophysical impacts of no-till agriculture and the impacts of annually retaining crop debris. Finally, the third scenario evaluated the potential impacts that the adoption of perennial cultivars had on biophysical quantities. Each of these scenarios was found to have significant biophysical impacts. However, the timing and magnitude of the biophysical impacts differed between scenarios. © 2014 John Wiley & Sons Ltd.

  14. Modelling benthic biophysical drivers of ecosystem structure and biogeochemical response

    Science.gov (United States)

    Stephens, Nicholas; Bruggeman, Jorn; Lessin, Gennadi; Allen, Icarus

    2016-04-01

    The fate of carbon deposited at the sea floor is ultimately decided by biophysical drivers that control the efficiency of remineralisation and timescale of carbon burial in sediments. Specifically, these drivers include bioturbation through ingestion and movement, burrow-flushing and sediment reworking, which enhance vertical particulate transport and solute diffusion. Unfortunately, these processes are rarely satisfactorily resolved in models. To address this, a benthic model that explicitly describes the vertical position of biology (e.g., habitats) and biogeochemical processes is presented that includes biological functionality and biogeochemical response capturing changes in ecosystem structure, benthic-pelagic fluxes and biodiversity on inter-annual timescales. This is demonstrated by the model's ability to reproduce temporal variability in benthic infauna, vertical pore water nutrients and pelagic-benthic solute fluxes compared to in-situ data. A key advance is the replacement of bulk parameterisation of bioturbation by explicit description of the bio-physical processes responsible. This permits direct comparison with observations and determination of key parameters in experiments. Crucially, the model resolves the two-way interaction between sediment biogeochemistry and ecology, allowing exploration of the benthic response to changing environmental conditions, the importance of infaunal functional traits in shaping benthic ecological structure and the feedback the resulting bio-physical processes exert on pore water nutrient profiles. The model is actively being used to understand shelf sea carbon cycling, the response of the benthos to climatic change, food provision and other societal benefits.

  15. Biophysics of molecular gastronomy.

    Science.gov (United States)

    Brenner, Michael P; Sörensen, Pia M

    2015-03-26

    Chefs and scientists exploring biophysical processes have given rise to molecular gastronomy. In this Commentary, we describe how a scientific understanding of recipes and techniques facilitates the development of new textures and expands the flavor palette. The new dishes that result engage our senses in unexpected ways. PAPERCLIP. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Structural, mutational and biophysical studies reveal a canonical mode of molecular recognition between immune receptor TIGIT and nectin-2

    Energy Technology Data Exchange (ETDEWEB)

    Samanta, Dibyendu; Guo, Haisu; Rubinstein, Rotem; Ramagopal, Udupi A.; Almo, Steven C.

    2017-01-01

    In addition to antigen-specific stimulation of T cell receptor (TCR) by a peptide-MHC complex, the functional outcome of TCR engagement is regulated by antigen-independent costimulatory signals. Costimulatory signals are provided by an array of interactions involving activating and inhibitory receptors expressed on T cells and their cognate ligands on antigen presenting cells. T cell immunoglobulin and ITIM domain (TIGIT), a recently identified immune receptor expressed on T and NK cells, upon interaction with either of its two ligands, nectin-2 or poliovirus receptor (PVR), inhibits activation of T and NK cells. Here we report the crystal structure of the human TIGIT ectodomain, which exhibits the classic two-layer β-sandwich topology observed in other immunoglobulin super family (IgSF) members. Biophysical studies indicate that TIGIT is monomeric in solution but can form a dimer at high concentrations, consistent with the observation of a canonical immunoglobulin-like dimer interface in the crystalline state. Based on existing structural data, we present a model of the TIGIT:nectin-2 complex and utilized complementary biochemical studies to map the nectin-binding interface on TIGIT. Our data provide important structural and biochemical determinants responsible for the recognition of nectin-2 by TIGIT. Defining the TIGIT:nectin-2 binding interface provides the basis for rational manipulation of this molecular interaction for the development of immunotherapeutic reagents in autoimmunity and cancer.

  17. Biotic games and cloud experimentation as novel media for biophysics education

    Science.gov (United States)

    Riedel-Kruse, Ingmar; Blikstein, Paulo

    2014-03-01

    First-hand, open-ended experimentation is key for effective formal and informal biophysics education. We developed, tested and assessed multiple new platforms that enable students and children to directly interact with and learn about microscopic biophysical processes: (1) Biotic games that enable local and online play using galvano- and photo-tactic stimulation of micro-swimmers, illustrating concepts such as biased random walks, Low Reynolds number hydrodynamics, and Brownian motion; (2) an undergraduate course where students learn optics, electronics, micro-fluidics, real time image analysis, and instrument control by building biotic games; and (3) a graduate class on the biophysics of multi-cellular systems that contains a cloud experimentation lab enabling students to execute open-ended chemotaxis experiments on slimemolds online, analyze their data, and build biophysical models. Our work aims to generate the equivalent excitement and educational impact for biophysics as robotics and video games have had for mechatronics and computer science, respectively. We also discuss how scaled-up cloud experimentation systems can support MOOCs with true lab components and life-science research in general.

  18. An allosteric gating model recapitulates the biophysical properties of IK,L expressed in mouse vestibular type I hair cells.

    Science.gov (United States)

    Spaiardi, Paolo; Tavazzani, Elisa; Manca, Marco; Milesi, Veronica; Russo, Giancarlo; Prigioni, Ivo; Marcotti, Walter; Magistretti, Jacopo; Masetto, Sergio

    2017-11-01

    Vestibular type I and type II hair cells and their afferent fibres send information to the brain regarding the position and movement of the head. The characteristic feature of type I hair cells is the expression of a low-voltage-activated outward rectifying K + current, I K,L , whose biophysical properties and molecular identity are still largely unknown. In vitro, the afferent nerve calyx surrounding type I hair cells causes unstable intercellular K + concentrations, altering the biophysical properties of I K,L . We found that in the absence of the calyx, I K,L in type I hair cells exhibited unique biophysical activation properties, which were faithfully reproduced by an allosteric channel gating scheme. These results form the basis for a molecular and pharmacological identification of I K,L . Type I and type II hair cells are the sensory receptors of the mammalian vestibular epithelia. Type I hair cells are characterized by their basolateral membrane being enveloped in a single large afferent nerve terminal, named the calyx, and by the expression of a low-voltage-activated outward rectifying K + current, I K,L . The biophysical properties and molecular profile of I K,L are still largely unknown. By using the patch-clamp whole-cell technique, we examined the voltage- and time-dependent properties of I K,L in type I hair cells of the mouse semicircular canal. We found that the biophysical properties of I K,L were affected by an unstable K + equilibrium potential (V eq K + ). Both the outward and inward K + currents shifted V eq K + consistent with K + accumulation or depletion, respectively, in the extracellular space, which we attributed to a residual calyx attached to the basolateral membrane of the hair cells. We therefore optimized the hair cell dissociation protocol in order to isolate mature type I hair cells without their calyx. In these cells, the uncontaminated I K,L showed a half-activation at -79.6 mV and a steep voltage dependence (2.8 mV). I K,L also

  19. Preface: Special Topic on Single-Molecule Biophysics.

    Science.gov (United States)

    Makarov, Dmitrii E; Schuler, Benjamin

    2018-03-28

    Single-molecule measurements are now almost routinely used to study biological systems and processes. The scope of this special topic emphasizes the physics side of single-molecule observations, with the goal of highlighting new developments in physical techniques as well as conceptual insights that single-molecule measurements bring to biophysics. This issue also comprises recent advances in theoretical physical models of single-molecule phenomena, interpretation of single-molecule signals, and fundamental areas of statistical mechanics that are related to single-molecule observations. A particular goal is to illustrate the increasing synergy between theory, simulation, and experiment in single-molecule biophysics.

  20. Biophysical shunt theory for neuropsychopathology: Part I.

    Science.gov (United States)

    Naisberg, Y; Avnon, M; Weizman, A

    1995-11-01

    We present a new model of the origin of schizophrenia based on biophysical ionic shunts in neuronal (electrical) pathways. Microstructural and molecular evidence is presented for the way in which changes in the neuronal membrane ionic channels may facilitate membrane property rearrangement, leading to a change in the density and composition of the ion channel charge which in turn causes a change in ionic flow orientation and distribution. We suggest that, under abnormal conditions, ionic flow shunts are created which redirect the biophysical collateral neuronal (electrical) pathways, resulting in psychiatric signs and symptoms. This model is complementary to the biological basis of schizophrenia.

  1. On rationally supported surfaces

    DEFF Research Database (Denmark)

    Gravesen, Jens; Juttler, B.; Sir, Z.

    2008-01-01

    We analyze the class of surfaces which are equipped with rational support functions. Any rational support function can be decomposed into a symmetric (even) and an antisymmetric (odd) part. We analyze certain geometric properties of surfaces with odd and even rational support functions....... In particular it is shown that odd rational support functions correspond to those rational surfaces which can be equipped with a linear field of normal vectors, which were discussed by Sampoli et al. (Sampoli, M.L., Peternell, M., Juttler, B., 2006. Rational surfaces with linear normals and their convolutions...... with rational surfaces. Comput. Aided Geom. Design 23, 179-192). As shown recently, this class of surfaces includes non-developable quadratic triangular Bezier surface patches (Lavicka, M., Bastl, B., 2007. Rational hypersurfaces with rational convolutions. Comput. Aided Geom. Design 24, 410426; Peternell, M...

  2. 2. biophysical work meeting. Papers; 2. Biophysikalische Arbeitstagung; Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    The report comprises 18 papers held at the 2nd Biophysical Work Meeting, 11 - 13 September 1991 in Schlema, Germany. The history of biophysics in Germany particularly of radiation biophysics and radon research, measurements of the radiation effects of radon and the derivation of limits, radon balneotherapy and consequences of uranium ore mining are dealt with. (orig.) [Deutsch] Der Report enthaelt 18 Vortraege, die auf der 2. Biophysikalischen Arbeitstagung in Schlema vom 11. bis 13. September 1991 gehalten wurden. Es werden die Geschichte der Biophysik in Deutschland, speziell der Strahlenbiophysik und Radonforschung, Messungen von Radon und seinen Folgeprodukten, Epidemiologie und Strahlenbiologie zur Bestimmung der Strahlenwirkung des Radons und die Ableitung entsprechender Grenzwerte, Radon-Balneotherapie und Folgen des Uranerzbergbaus behandelt. (orig.)

  3. Remote sensing of the Canadian Arctic: Modelling biophysical variables

    Science.gov (United States)

    Liu, Nanfeng

    It is anticipated that Arctic vegetation will respond in a variety of ways to altered temperature and precipitation patterns expected with climate change, including changes in phenology, productivity, biomass, cover and net ecosystem exchange. Remote sensing provides data and data processing methodologies for monitoring and assessing Arctic vegetation over large areas. The goal of this research was to explore the potential of hyperspectral and high spatial resolution multispectral remote sensing data for modelling two important Arctic biophysical variables: Percent Vegetation Cover (PVC) and the fraction of Absorbed Photosynthetically Active Radiation (fAPAR). A series of field experiments were conducted to collect PVC and fAPAR at three Canadian Arctic sites: (1) Sabine Peninsula, Melville Island, NU; (2) Cape Bounty Arctic Watershed Observatory (CBAWO), Melville Island, NU; and (3) Apex River Watershed (ARW), Baffin Island, NU. Linear relationships between biophysical variables and Vegetation Indices (VIs) were examined at different spatial scales using field spectra (for the Sabine Peninsula site) and high spatial resolution satellite data (for the CBAWO and ARW sites). At the Sabine Peninsula site, hyperspectral VIs exhibited a better performance for modelling PVC than multispectral VIs due to their capacity for sampling fine spectral features. The optimal hyperspectral bands were located at important spectral features observed in Arctic vegetation spectra, including leaf pigment absorption in the red wavelengths and at the red-edge, leaf water absorption in the near infrared, and leaf cellulose and lignin absorption in the shortwave infrared. At the CBAWO and ARW sites, field PVC and fAPAR exhibited strong correlations (R2 > 0.70) with the NDVI (Normalized Difference Vegetation Index) derived from high-resolution WorldView-2 data. Similarly, high spatial resolution satellite-derived fAPAR was correlated to MODIS fAPAR (R2 = 0.68), with a systematic

  4. Mass spectrometry in structural biology and biophysics architecture, dynamics, and interaction of biomolecules

    CERN Document Server

    Kaltashov, Igor A; Desiderio, Dominic M; Nibbering, Nico M

    2012-01-01

    The definitive guide to mass spectrometry techniques in biology and biophysics The use of mass spectrometry (MS) to study the architecture and dynamics of proteins is increasingly common within the biophysical community, and Mass Spectrometry in Structural Biology and Biophysics: Architecture, Dynamics, and Interaction of Biomolecules, Second Edition provides readers with detailed, systematic coverage of the current state of the art. Offering an unrivalled overview of modern MS-based armamentarium that can be used to solve the most challenging problems in biophysics, structural biol

  5. Comparison of biophysical factors influencing on emphysema quantification with low-dose CT

    Science.gov (United States)

    Heo, Chang Yong; Kim, Jong Hyo

    2014-03-01

    Emphysema Index(EI) measurements in MDCT is known to be influenced by various biophysical factors such as total lung volume, and body size. We investigated the association of the four biophysical factors with emphysema index in low-dose MDCT. In particular, we attempted to identify a potentially stronger biophysical factor than total lung volume. A total of 400 low-dose MDCT volumes taken at 120kVp, 40mAs, 1mm thickness, and B30f reconstruction kernel were used. The lungs, airways, and pulmonary vessels were automatically segmented, and two Emphysema Indices, relative area below -950HU(RA950) and 15th percentile(Perc15), were extracted from the segmented lungs. The biophysical factors such as total lung volume(TLV), mode of lung attenuation(ModLA), effective body diameter(EBD), and the water equivalent body diameter(WBD) were estimated from the segmented lung and body area. The association of biophysical factors with emphysema indices were evaluated by correlation coefficients. The mean emphysema indices were 8.3±5.5(%) in RA950, and -930±18(HU) in Perc15. The estimates of biophysical factors were 4.7±1.0(L) in TLV, -901±21(HU) in ModLA, 26.9±2.2(cm) in EBD, and 25.9±2.6(cm) in WBD. The correlation coefficients of biophysical factors with RA950 were 0.73 in TLV, 0.94 in ModLA, 0.31 in EBD, and 0.18 WBD, the ones with Perc15 were 0.74 in TLV, 0.98 in ModLA, 0.29 in EBD, and 0.15 WBD. Study results revealed that two biophysical factors, TLV and ModLA, mostly affects the emphysema indices. In particular, the ModLA exhibited strongest correlation of 0.98 with Perc15, which indicating the ModLA is the most significant confounding biophysical factor in emphysema indices measurement.

  6. Radiation biophysics

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Summaries of research projects conducted during 1978 and 1979 are presented. The overall thrust of the research is aimed at understanding the effects of radiation on organisms. Specific subject areas include: the effects of heavy-particle beam nuclear interactions in tissue on dosimetry; tracer studies with radioactive fragments of heavy-ion beams; the effects of heavy/ions on human kidney cells and Chinese hamster cells; the response of a rhabdomyosarcoma tumor system in rats to heavy-ion beams; the use of heavy charged particles in radiotherapy of human cancer; heavy-ion radiography; the biological effects of high magnetic fields; central nervous system neurotoxicity; and biophysical studies on cell membranes

  7. Pragmatics & rationality.

    OpenAIRE

    Allott, N. E.

    2007-01-01

    This thesis is about the reconciliation of realistic views of rationality with inferential-intentional theories of communication. Grice (1957 1975) argued that working out what a speaker meant by an utterance is a matter of inferring the speaker's intentions on the presumption that she is acting rationally. This is abductive inference: inference to the best explanation for the utterance. Thus an utterance both rationalises and causes the interpretation the hearer constructs. Human rationality...

  8. Rational design and validation of an anti-protein kinase C active-state specific antibody based on conformational changes.

    Science.gov (United States)

    Pena, Darlene Aparecida; Andrade, Victor Piana de; Silva, Gabriela Ávila Fernandes; Neves, José Ivanildo; Oliveira, Paulo Sergio Lopes de; Alves, Maria Julia Manso; Devi, Lakshmi A; Schechtman, Deborah

    2016-02-25

    Protein kinase C (PKC) plays a regulatory role in key pathways in cancer. However, since phosphorylation is a step for classical PKC (cPKC) maturation and does not correlate with activation, there is a lack of tools to detect active PKC in tissue samples. Here, a structure-based rational approach was used to select a peptide to generate an antibody that distinguishes active from inactive cPKC. A peptide conserved in all cPKCs, C2Cat, was chosen since modeling studies based on a crystal structure of PKCβ showed that it is localized at the interface between the C2 and catalytic domains of cPKCs in an inactive kinase. Anti-C2Cat recognizes active cPKCs at least two-fold better than inactive kinase in ELISA and immunoprecipitation assays, and detects the temporal dynamics of cPKC activation upon receptor or phorbol stimulation. Furthermore, the antibody is able to detect active PKC in human tissue. Higher levels of active cPKC were observed in the more aggressive triple negative breast cancer tumors as compared to the less aggressive estrogen receptor positive tumors. Thus, this antibody represents a reliable, hitherto unavailable and a valuable tool to study PKC activation in cells and tissues. Similar structure-based rational design strategies can be broadly applied to obtain active-state specific antibodies for other signal transduction molecules.

  9. Baseline rationing

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moreno-Ternero, Juan D.; Østerdal, Lars Peter Raahave

    The standard problem of adjudicating conflicting claims describes a situation in which a given amount of a divisible good has to be allocated among agents who hold claims against it exceeding the available amount. This paper considers more general rationing problems in which, in addition to claims...... to international protocols for the reduction of greenhouse emissions, or water distribution in drought periods. We define a family of allocation methods for such general rationing problems - called baseline rationing rules - and provide an axiomatic characterization for it. Any baseline rationing rule within...... the family is associated with a standard rule and we show that if the latter obeys some properties reflecting principles of impartiality, priority and solidarity, the former obeys them too....

  10. Bounded Rationality, Retaliation, and the Spread of Urban Violence

    Science.gov (United States)

    Jacobs, Bruce A.; Wright, Richard

    2010-01-01

    Drawing from in-depth interviews with 52 active street criminals, this article examines the grounded theoretic implications of bounded rationality for retaliatory street violence. The bounds on rationality that this article explores are anger, uncertainty, and time pressure. These bounds create imperfections in the retaliatory decision-making…

  11. Rationing with baselines

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moreno-Ternero, Juan D.; Østerdal, Lars Peter Raahave

    2013-01-01

    We introduce a new operator for general rationing problems in which, besides conflicting claims, individual baselines play an important role in the rationing process. The operator builds onto ideas of composition, which are not only frequent in rationing, but also in related problems...... such as bargaining, choice, and queuing. We characterize the operator and show how it preserves some standard axioms in the literature on rationing. We also relate it to recent contributions in such literature....

  12. Biophysics of Human Hair Structural, Nanomechanical, and Nanotribological Studies

    CERN Document Server

    Bhushan, Bharat

    2010-01-01

    This book presents the biophysics of hair. It deals with the structure of hair, its mechanical properties, the nanomechanical characterization, tensile deformation, tribological characterization, the thickness distribution and binding interactions on hair surface. Another important topic of the book is the health of hair, human hair and skin, hair care, cleaning and conditioning treatments and damaging processes. It is the first book on the biophysical properties of hair.

  13. Applications of synchrotron radiation in Biophysics

    International Nuclear Information System (INIS)

    Bemski, G.

    1983-01-01

    A short introduction to the generation of the synchrotron radiation is made. Following, the applications of such a radiation in biophysics with emphasis to the study of the hemoglobin molecule are presented. (L.C.) [pt

  14. Materials science and biophysics applications at the ISOLDE radioactive ion beam facility

    Energy Technology Data Exchange (ETDEWEB)

    Wahl, U., E-mail: uwahl@itn.pt [Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavem (Portugal); Centro de Fisica Nuclear da Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal)

    2011-12-15

    The ISOLDE isotope separator facility at CERN provides a variety of radioactive ion beams, currently more than 800 different isotopes from {approx}70 chemical elements. The radioisotopes are produced on-line by nuclear reactions from a 1.4 GeV proton beam with various types of targets, outdiffusion of the reaction products and, if possible, chemically selective ionisation, followed by 60 kV acceleration and mass separation. While ISOLDE is mainly used for nuclear and atomic physics studies, applications in materials science and biophysics account for a significant part (currently {approx}15%) of the delivered beam time, requested by 18 different experiments. The ISOLDE materials science and biophysics community currently consists of {approx}80 scientists from more than 40 participating institutes and 21 countries. In the field of materials science, investigations focus on the study of semiconductors and oxides, with the recent additions of nanoparticles and metals, while the biophysics studies address the toxicity of metal ions in biological systems. The characterisation methods used are typical radioactive probe techniques such as Moessbauer spectroscopy, perturbed angular correlation, emission channeling, and tracer diffusion studies. In addition to these 'classic' methods of nuclear solid state physics, also standard semiconductor analysis techniques such as photoluminescence or deep level transient spectroscopy profit from the application of radioactive isotopes, which helps them to overcome their chemical 'blindness' since the nuclear half life of radioisotopes provides a signal that changes in time with characteristic exponential decay or saturation curves. In this presentation an overview will be given on the recent research activities in materials science and biophysics at ISOLDE, presenting some of the highlights during the last five years, together with a short outlook on the new developments under way.

  15. Rational choice in field archaelology

    Directory of Open Access Journals (Sweden)

    Cătălin Pavel

    2011-11-01

    Full Text Available In the present article I attempt to apply advances in the study of instrumental and epistemic rationality to field archaeology in order to gain insights into the ways archaeologists reason. The cognitive processes, particularly processes of decision making, that enable archaeologists to conduct the excavation in the trench have not been adequately studied so far. I take my cues from two different bodies of theory. I first inquire into the potential that rational choice theory (RCT may have in modeling archaeological behaviour, and I define subjective expected utility, which archaeologists attempt to maximize, in terms of knowledge acquisition and social gain. Following Elster’s criticism of RCT, I conclude that RCT’s standards for rational action do not correspond with those ostensibly used in field archaeology, but that instrumental rationality has a prominent role in the “archaeological experiment”. I further explore if models proposed as reaction to RCT may account for archaeological decision making. I focus on fast and frugal heuristics, and search for archaeological illustrations for some of the cognitive biases that are better documented in psychological literature. I document confirmation and congruence biases, the endowment effect, observer-expectancy bias, illusory correlation, clustering illusion, sunk cost bias, and anchoring, among others and I propose that some of these biases are used as cognitive tools by archaeologists at work and retain epistemic value. However, I find formal logic to be secondary in the development of archaeological reasoning, with default logic and defeasible logic being used instead. I emphasize scientific knowledge as an actively negotiated social product of human inquiry, and conclude that to describe rationality in field archaeology a bounded rationality model is the most promising avenue of investigation.

  16. Inaugurating Rationalization: Three Field Studies Find Increased Rationalization When Anticipated Realities Become Current.

    Science.gov (United States)

    Laurin, Kristin

    2018-04-01

    People will often rationalize the status quo, reconstruing it in an exaggeratedly positive light. They will even rationalize the status quo they anticipate, emphasizing the upsides and minimizing the downsides of sociopolitical realities they expect to take effect. Drawing on recent findings on the psychological triggers of rationalization, I present results from three field studies, one of which was preregistered, testing the hypothesis that an anticipated reality becoming current triggers an observable boost in people's rationalizations. San Franciscans rationalized a ban on plastic water bottles, Ontarians rationalized a targeted smoking ban, and Americans rationalized the presidency of Donald Trump, more in the days immediately after these realities became current compared with the days immediately before. Additional findings show evidence for a mechanism underlying these behaviors and rule out alternative accounts. These findings carry implications for scholarship on rationalization, for understanding protest behavior, and for policymakers.

  17. Molecular dynamics simulations and docking enable to explore the biophysical factors controlling the yields of engineered nanobodies

    Science.gov (United States)

    Soler, Miguel A.; De Marco, Ario; Fortuna, Sara

    2016-10-01

    Nanobodies (VHHs) have proved to be valuable substitutes of conventional antibodies for molecular recognition. Their small size represents a precious advantage for rational mutagenesis based on modelling. Here we address the problem of predicting how Camelidae nanobody sequences can tolerate mutations by developing a simulation protocol based on all-atom molecular dynamics and whole-molecule docking. The method was tested on two sets of nanobodies characterized experimentally for their biophysical features. One set contained point mutations introduced to humanize a wild type sequence, in the second the CDRs were swapped between single-domain frameworks with Camelidae and human hallmarks. The method resulted in accurate scoring approaches to predict experimental yields and enabled to identify the structural modifications induced by mutations. This work is a promising tool for the in silico development of single-domain antibodies and opens the opportunity to customize single functional domains of larger macromolecules.

  18. Realization theory for rational systems: Minimal rational realizations

    NARCIS (Netherlands)

    J. Nemcová (Jana); J.H. van Schuppen (Jan)

    2010-01-01

    htmlabstractThe study of realizations of response maps is a topic of control and system theory. Realization theory is used in system identification and control synthesis. A minimal rational realization of a given response map p is a rational realization of p such that the dimension of its state

  19. Many faces of rationality: Implications of the great rationality debate for clinical decision‐making

    Science.gov (United States)

    Elqayam, Shira

    2017-01-01

    Abstract Given that more than 30% of healthcare costs are wasted on inappropriate care, suboptimal care is increasingly connected to the quality of medical decisions. It has been argued that personal decisions are the leading cause of death, and 80% of healthcare expenditures result from physicians' decisions. Therefore, improving healthcare necessitates improving medical decisions, ie, making decisions (more) rational. Drawing on writings from The Great Rationality Debate from the fields of philosophy, economics, and psychology, we identify core ingredients of rationality commonly encountered across various theoretical models. Rationality is typically classified under umbrella of normative (addressing the question how people “should” or “ought to” make their decisions) and descriptive theories of decision‐making (which portray how people actually make their decisions). Normative theories of rational thought of relevance to medicine include epistemic theories that direct practice of evidence‐based medicine and expected utility theory, which provides the basis for widely used clinical decision analyses. Descriptive theories of rationality of direct relevance to medical decision‐making include bounded rationality, argumentative theory of reasoning, adaptive rationality, dual processing model of rationality, regret‐based rationality, pragmatic/substantive rationality, and meta‐rationality. For the first time, we provide a review of wide range of theories and models of rationality. We showed that what is “rational” behaviour under one rationality theory may be irrational under the other theory. We also showed that context is of paramount importance to rationality and that no one model of rationality can possibly fit all contexts. We suggest that in context‐poor situations, such as policy decision‐making, normative theories based on expected utility informed by best research evidence may provide the optimal approach to medical decision

  20. Many faces of rationality: Implications of the great rationality debate for clinical decision-making.

    Science.gov (United States)

    Djulbegovic, Benjamin; Elqayam, Shira

    2017-10-01

    Given that more than 30% of healthcare costs are wasted on inappropriate care, suboptimal care is increasingly connected to the quality of medical decisions. It has been argued that personal decisions are the leading cause of death, and 80% of healthcare expenditures result from physicians' decisions. Therefore, improving healthcare necessitates improving medical decisions, ie, making decisions (more) rational. Drawing on writings from The Great Rationality Debate from the fields of philosophy, economics, and psychology, we identify core ingredients of rationality commonly encountered across various theoretical models. Rationality is typically classified under umbrella of normative (addressing the question how people "should" or "ought to" make their decisions) and descriptive theories of decision-making (which portray how people actually make their decisions). Normative theories of rational thought of relevance to medicine include epistemic theories that direct practice of evidence-based medicine and expected utility theory, which provides the basis for widely used clinical decision analyses. Descriptive theories of rationality of direct relevance to medical decision-making include bounded rationality, argumentative theory of reasoning, adaptive rationality, dual processing model of rationality, regret-based rationality, pragmatic/substantive rationality, and meta-rationality. For the first time, we provide a review of wide range of theories and models of rationality. We showed that what is "rational" behaviour under one rationality theory may be irrational under the other theory. We also showed that context is of paramount importance to rationality and that no one model of rationality can possibly fit all contexts. We suggest that in context-poor situations, such as policy decision-making, normative theories based on expected utility informed by best research evidence may provide the optimal approach to medical decision-making, whereas in the context

  1. Past and Present Biophysical Redundancy of Countries as a Buffer to Changes in Food Supply

    Science.gov (United States)

    Fader, Marianela; Rulli, Maria Cristina; Carr, Joel; Dell' Angelo, Jampel; D' Odorico, Paolo; Gephart, Jessica A.; Kummu, Matti; Magliocca, Nicholas; Porkka, Miina; Prell, Christina; hide

    2016-01-01

    Spatially diverse trends in population growth, climate change, industrialization, urbanization and economic development are expected to change future food supply and demand. These changes may affect the suitability of land for food production, implying elevated risks especially for resource constrained, food-importing countries. We present the evolution of biophysical redundancy for agricultural production at country level, from 1992 to 2012. Biophysical redundancy, defined as unused biotic and abiotic environmental resources, is represented by the potential food production of 'spare land', available water resources (i.e., not already used for human activities), as well as production increases through yield gap closure on cultivated areas and potential agricultural areas. In 2012, the biophysical redundancy of 75 (48) countries, mainly in North Africa, Western Europe, the Middle East and Asia, was insufficient to produce the caloric nutritional needs for at least 50% (25%) of their population during a year. Biophysical redundancy has decreased in the last two decades in 102 out of 155 countries, 11 of these went from high to limited redundancy, and nine of these from limited to very low redundancy. Although the variability of the drivers of change across different countries is high, improvements in yield and population growth have a clear impact on the decreases of redundancy towards the very low redundancy category. We took a more detailed look at countries classified as 'Low Income Economies (LIEs)' since they are particularly vulnerable to domestic or external food supply changes, due to their limited capacity to offset for food supply decreases with higher purchasing power on the international market. Currently, nine LIEs have limited or very low biophysical redundancy. Many of these showed a decrease in redundancy over the last two decades, which is not always linked with improvements in per capita food availability.

  2. Past and present biophysical redundancy of countries as a buffer to changes in food supply

    Science.gov (United States)

    Fader, Marianela; Rulli, Maria Cristina; Carr, Joel; Dell'Angelo, Jampel; D'Odorico, Paolo; Gephart, Jessica A.; Kummu, Matti; Magliocca, Nicholas; Porkka, Miina; Prell, Christina; Puma, Michael J.; Ratajczak, Zak; Seekell, David A.; Suweis, Samir; Tavoni, Alessandro

    2016-05-01

    Spatially diverse trends in population growth, climate change, industrialization, urbanization and economic development are expected to change future food supply and demand. These changes may affect the suitability of land for food production, implying elevated risks especially for resource-constrained, food-importing countries. We present the evolution of biophysical redundancy for agricultural production at country level, from 1992 to 2012. Biophysical redundancy, defined as unused biotic and abiotic environmental resources, is represented by the potential food production of ‘spare land’, available water resources (i.e., not already used for human activities), as well as production increases through yield gap closure on cultivated areas and potential agricultural areas. In 2012, the biophysical redundancy of 75 (48) countries, mainly in North Africa, Western Europe, the Middle East and Asia, was insufficient to produce the caloric nutritional needs for at least 50% (25%) of their population during a year. Biophysical redundancy has decreased in the last two decades in 102 out of 155 countries, 11 of these went from high to limited redundancy, and nine of these from limited to very low redundancy. Although the variability of the drivers of change across different countries is high, improvements in yield and population growth have a clear impact on the decreases of redundancy towards the very low redundancy category. We took a more detailed look at countries classified as ‘Low Income Economies (LIEs)’ since they are particularly vulnerable to domestic or external food supply changes, due to their limited capacity to offset for food supply decreases with higher purchasing power on the international market. Currently, nine LIEs have limited or very low biophysical redundancy. Many of these showed a decrease in redundancy over the last two decades, which is not always linked with improvements in per capita food availability.

  3. Biophysical aspects of photodynamic therapy.

    Science.gov (United States)

    Juzeniene, Asta; Nielsen, Kristian Pagh; Moan, Johan

    2006-01-01

    Over the last three decades photodynamic therapy (PDT) has been developed to a useful clinical tool, a viable alternative in the treatment of cancer and other diseases. Several disciplines have contributed to this development: chemistry in the development of new photosensitizing agents, biology in the elucidation of cellular processes involved in PDT, pharmacology and physiology in identifying the mechanisms of distribution of photosensitizers in an organism, and, last but not least, physics in the development of better light sources, dosimetric concepts and construction of imaging devices, optical sensors and spectroscopic methods for determining sensitizer concentrations in different tissues. Physics and biophysics have also helped to focus on the role of pH for sensitizer accumulation, dose rate effects, oxygen depletion, temperature, and optical penetration of light of different wavelengths into various types of tissue. These are all important parameters for optimally effective PDT. The present review will give a brief, physically based, overview of PDT and then discuss some of the main biophysical aspects of this therapeutic modality.

  4. Standby Gasoline Rationing Plan

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-06-01

    The final rules adopted by the President for a Standby Gasoline Rationing Plan are presented. The plan provides that eligibility for ration allotments will be determined primarily on the basis of motor vehicle registrations, taking into account historical differences in the use of gasoline among states. The regulations also provide authority for supplemental allotments to firms so that their allotment will equal a specified percentage of gasoline use during a base period. Priority classifications, i.e., agriculture, defense, etc., are established to assure adequate gasoline supplies for designated essential services. Ration rights must be provided by end-users to their suppliers for each gallon sold. DOE will regulate the distribution of gasoline at the wholesale level according to the transfer by suppliers of redeemed ration rights and the gasoline allocation regulations. Ration rights are transferable. A ration banking system is created to facilitate transfers of ration rights. Each state will be provided with a reserve of ration rights to provide for hardship needs and to alleviate inequities. (DC)

  5. Rationalization of work of leaders of physical-sports organizations

    Directory of Open Access Journals (Sweden)

    Galina Putiatina

    2016-02-01

    Full Text Available Purpose: to create the main ways of rationalization of the work of heads of physical-sports organizations in the structure of their scientific organization of the work. Material & Methods: the content of the administrative activity of representatives of the system of the regional government of the sphere of physical culture and sport of the Kharkov area, and also directors of sports schools of Kharkov (57 respondents are generalized. Methods – the analysis of references, the organizational analysis, the organizational diagnosis, the poll (questioning, the methods of mathematical statistics. Results: the essence and the content of rationalization of the administrative work in the sphere of physical culture and sport are considered. The integrated approach to certain objects of rationalization of the administrative work is established in physical-sports organizations. Conclusions: the main ways of rationalization of the work of heads of physical-sports organizations are: the organization of work concerning the development of motivational mechanisms of the activity of heads; the increase of the economic appeal of work; the formation of ideology of a healthy lifestyle.

  6. Building biophysics in mid-century China: the University of Science and Technology of China.

    Science.gov (United States)

    Luk, Yi Lai Christine

    2015-01-01

    Biophysics has been either an independent discipline or an element of another discipline in the United States, but it has always been recognized as a stand-alone discipline in the People's Republic of China (PRC) since 1949. To inquire into this apparent divergence, this paper investigates the formational history of biophysics in China by examining the early institutional history of one of the best-known and prestigious science and technology universities in the PRC, the University of Science and Technology of China (USTC). By showing how the university and its biophysics program co-evolved with national priorities from the school's founding in 1958 to the eve of the Cultural Revolution in 1966, the purpose of this paper is to assess the development of a scientific discipline in the context of national demands and institutional politics. Specific materials for analysis include the school's admission policies, curricula, students' dissertations, and research program. To further contextualize the institutional setting of Chinese biophysics, this paper begins with a general history of proto-biophysical institutions in China during the Nationalist-Communist transitional years. This paper could be of interest to historians wanting to know more about the origin of the biophysics profession in China, and in particular how research areas that constitute biophysics changed in tandem with socio-political contingencies.

  7. Biophysical aspects of cancer - Electromagnetic mechanism

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Jiří; Hašek, Jiří; Vaniš, Jan; Jelínek, František

    2008-01-01

    Roč. 46, č. 5 (2008), s. 310-321 ISSN 0019-5189 Institutional research plan: CEZ:AV0Z20670512; CEZ:AV0Z50200510 Keywords : Electromagnetic Fields * Biophysics * Cancer Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.599, year: 2008

  8. Biophysical Neural Spiking, Bursting, and Excitability Dynamics in Reconfigurable Analog VLSI.

    Science.gov (United States)

    Yu, T; Sejnowski, T J; Cauwenberghs, G

    2011-10-01

    We study a range of neural dynamics under variations in biophysical parameters underlying extended Morris-Lecar and Hodgkin-Huxley models in three gating variables. The extended models are implemented in NeuroDyn, a four neuron, twelve synapse continuous-time analog VLSI programmable neural emulation platform with generalized channel kinetics and biophysical membrane dynamics. The dynamics exhibit a wide range of time scales extending beyond 100 ms neglected in typical silicon models of tonic spiking neurons. Circuit simulations and measurements show transition from tonic spiking to tonic bursting dynamics through variation of a single conductance parameter governing calcium recovery. We similarly demonstrate transition from graded to all-or-none neural excitability in the onset of spiking dynamics through the variation of channel kinetic parameters governing the speed of potassium activation. Other combinations of variations in conductance and channel kinetic parameters give rise to phasic spiking and spike frequency adaptation dynamics. The NeuroDyn chip consumes 1.29 mW and occupies 3 mm × 3 mm in 0.5 μm CMOS, supporting emerging developments in neuromorphic silicon-neuron interfaces.

  9. Adolescent rationality.

    Science.gov (United States)

    Moshman, David

    2013-01-01

    Adolescents are commonly seen as irrational, a position supported to varying degrees by many developmentalists, who often appeal to recent research on adolescent brains. Careful review of relevant evidence, however, shows that (1) adults are less rational than is generally assumed, (2) adolescents (and adults) are categorically different from children with respect to the attainment of advanced levels of rationality and psychological functioning, and (3) adolescents and adults do not differ categorically from each other with respect to any rational competencies, irrational tendencies, brain structures, or neurological functioning. Development often continues in adolescence and beyond but categorical claims about adolescents as distinct from adults cannot be justified. A review of U.S. Supreme Court decisions concerning intellectual freedom, reproductive freedom, and criminal responsibility shows ongoing ambivalence and confusion about the rationality of adolescents. Developmental theory and research suggest that adolescents should be conceptualized as young adults, not immature brains, with important implications for their roles, rights, and responsibilities.

  10. Love and rationality: on some possible rational effects of love

    Directory of Open Access Journals (Sweden)

    Gustavo Ortiz-Millán

    Full Text Available In this paper I defend the idea that rather than disrupting rationality, as the common-sense conception has done it, love may actually help us to develop rational ways of thinking and acting. I make the case for romantic or erotic love, since this is the kind of love that is more frequently associated with irrationality in acting and thinking. I argue that this kind of love may make us develop epistemic and practical forms of rationality. Based on an analysis of its characteristic action tendencies, I argue that love may help us to develop an instrumental form of rationality in determining the best means to achieve the object of love. It may also narrow down the number of practical considerations that may help us to achieve our goals. Finally, love may generate rational ways of belief-formation by framing the parameters taken into account in perception and attention, and by bringing into light only a small portion of the epistemic information available. Love may make us perceive reality more acutely.

  11. A dataset mapping the potential biophysical effects of vegetation cover change

    Science.gov (United States)

    Duveiller, Gregory; Hooker, Josh; Cescatti, Alessandro

    2018-02-01

    Changing the vegetation cover of the Earth has impacts on the biophysical properties of the surface and ultimately on the local climate. Depending on the specific type of vegetation change and on the background climate, the resulting competing biophysical processes can have a net warming or cooling effect, which can further vary both spatially and seasonally. Due to uncertain climate impacts and the lack of robust observations, biophysical effects are not yet considered in land-based climate policies. Here we present a dataset based on satellite remote sensing observations that provides the potential changes i) of the full surface energy balance, ii) at global scale, and iii) for multiple vegetation transitions, as would now be required for the comprehensive evaluation of land based mitigation plans. We anticipate that this dataset will provide valuable information to benchmark Earth system models, to assess future scenarios of land cover change and to develop the monitoring, reporting and verification guidelines required for the implementation of mitigation plans that account for biophysical land processes.

  12. CONTRIBUTIONS TO RATIONAL APPROXIMATION,

    Science.gov (United States)

    Some of the key results of linear Chebyshev approximation theory are extended to generalized rational functions. Prominent among these is Haar’s...linear theorem which yields necessary and sufficient conditions for uniqueness. Some new results in the classic field of rational function Chebyshev...Furthermore a Weierstrass type theorem is proven for rational Chebyshev approximation. A characterization theorem for rational trigonometric Chebyshev approximation in terms of sign alternation is developed. (Author)

  13. The role of bio-physical cohesive substrates on sediment winnowing and bedform development

    Science.gov (United States)

    Ye, Leiping; Parsons, Daniel; Manning, Andrew

    2017-04-01

    Existing sediment transport and bedform size predictions for natural open-channel flows in many environments are seriously impeded by a lack of process-based knowledge concerning the dynamics of complex bed sediment mixtures comprising cohesionless sand and biologically-active cohesive muds. A series of flume experiments (14 experimental runs) with different substrate mixtures of sand-clay-EPS (Extracellular Polymeric Substance) are combined with a detailed estuarine field survey (Dee estuary, NW England) to investigate the development of bedform morphologies and characteristics of suspended sediment over bio-physical cohesive substrates. The experimental results indicate that winnowing and sediment sorting can occur pervasively in bio-physical cohesive sediment - flow systems. Importantly however, the evolution of the bed and bedform dynamics, and hence turbulence production, is significantly reduced as bed substrate cohesivity increases. The estuarine subtidal zone survey also revealed that the bio-physical cohesion provided by both the clay and microorganism fractions in the bed plays a significant role in controlling the interactions between bed substrate and sediment suspension, deposition and bedform generation. The work will be presented here concludes by outlining the need to extend and revisit the effects of cohesivity in morphodynamic systems and the sets of parameters presently used in numerical modelling, particularly in the context of the impact of climate change on estuarine and coastal systems.

  14. Rational points, rational curves, and entire holomorphic curves on projective varieties

    CERN Document Server

    Gasbarri, Carlo; Roth, Mike; Tschinkel, Yuri

    2015-01-01

    This volume contains papers from the Short Thematic Program on Rational Points, Rational Curves, and Entire Holomorphic Curves and Algebraic Varieties, held from June 3-28, 2013, at the Centre de Recherches Mathématiques, Université de Montréal, Québec, Canada. The program was dedicated to the study of subtle interconnections between geometric and arithmetic properties of higher-dimensional algebraic varieties. The main areas of the program were, among others, proving density of rational points in Zariski or analytic topology on special varieties, understanding global geometric properties of rationally connected varieties, as well as connections between geometry and algebraic dynamics exploring new geometric techniques in Diophantine approximation.

  15. The necessity to rationalize library procedures and activities

    OpenAIRE

    Matjaž Žaucer

    2007-01-01

    The necessity of the rationalization of work and procedures in libraries due to the altered requirements and needs of users and due to the expected aggravated demands of the environment are displayed in the article. The causes for the changes in the librarianship and the causes for the changes in the environment are stated. The article analyzes the searching procedure in the Slovenian union bibliographic and catalogue database using the UDC. Upon a practical experiment it was established that...

  16. Rational Multiparty Computation

    OpenAIRE

    Wallrabenstein, John Ross

    2014-01-01

    The field of rational cryptography considers the design of cryptographic protocols in the presence of rational agents seeking to maximize local utility functions. This departs from the standard secure multiparty computation setting, where players are assumed to be either honest or malicious. ^ We detail the construction of both a two-party and a multiparty game theoretic framework for constructing rational cryptographic protocols. Our framework specifies the utility function assumptions neces...

  17. A highly rationalized procedure of neutron activation analysis for routine applications in dairy science

    International Nuclear Information System (INIS)

    Heine, K.; Wiechen, A.

    1976-01-01

    A rational procedure was developed for the multi-element analysis by neutron activation for applications in dairy science. The preparation of samples prior to irradiation consists of drying, weighing, and welding in quartz ampoules. The neutron flux, samples are exposed to during reactor irradiation , is determined by the mono-comparator technique for which the Co-content of a commercial aluminium foil was chosen as the flux monitor. Constancy of the Co-content and uncomplicated handling of the foil essentially simplify the determination of flux. The samples are irradiated for 72 h, dissolved in HNO 3 /H 2 SO 4 and measured in the liquid state after waiting times of 1-2, 4 and 8 weeks by a Ge(Li)-detector and a 4,096 channel spectrometer. The procedure was confirmed by investigations of the biological KALE standard and by participation in inter-comparisons of biological substances of the Analytical Quality Control Service of the IAEA for the analysis of the elements Na, Ca, Cr, Fe, Co, Zn, Se, Rb, and Cs. So a procedure was developed suitable for routine multi-element analysis of biologic samples by optimizing and rationalizing all analytical steps. (orig./MG) [de

  18. Identity construction and British Muslims' political activity: beyond rational actor theory.

    Science.gov (United States)

    Hopkins, Nick; Kahani-Hopkins, Vered

    2004-09-01

    Political activity is often addressed in terms of rational actor theory (RAT). We review RAT's psychological assumptions and highlight the neglect of collective identity. In turn, we view the perception of 'interest' as contingent upon constructions of identity and explore how different characterizations of collective identity are organized strategically so as to shape people's understandings of their interests and how they should act to realize them. Using examples taken from a study of British Muslims' political activity we emphasize the contested and strategic dimension to identity construction and analyse how activists addressing the same constituency construe Muslim identity in different ways so as to promote different conceptions of collective interest. Specifically, we explore the contested invocations of Prophetic example in the definition of Muslim identity. The broader thrust behind this work is a critique of the sharp dichotomization of Muslim and non-Muslim political activity. We maintain that essentially similar processes of identity construction underlie all attempts to organize collective sentiment and political action (including that comprising so-called 'conventional' electoralist politics in the West), and that conceiving of identity as a site of political struggle underscores the inadequacy of Orientalist characterizations of Muslim identity in terms of a singular, transhistorical essence.

  19. A mathematical approach to protein biophysics

    CERN Document Server

    Scott, L Ridgway

    2017-01-01

    This book explores quantitative aspects of protein biophysics and attempts to delineate certain rules of molecular behavior that make atomic scale objects behave in a digital way.  This book will help readers to understand how certain biological systems involving proteins function as digital information systems despite the fact that underlying processes are analog in nature. The in-depth explanation of proteins from a quantitative point of view and the variety of level of exercises (including physical experiments) at the end of each chapter will appeal to graduate and senior undergraduate students in mathematics, computer science, mechanical engineering, and physics, wanting to learn about the biophysics of proteins.  L. Ridgway Scott has been Professor of Computer Science and of Mathematics at the University of Chicago since 1998, and the Louis Block Professor since 2001.  He obtained a B.S. degree (Magna Cum Laude) from Tulane University in 1969 and a PhD degree in Mathematics from the Massachusetts Ins...

  20. Institute of Biochemistry and Biophysics. Research Report 1996-1997

    International Nuclear Information System (INIS)

    1998-01-01

    Scientific interests of the Institute of Biochemistry and Biophysics of the Polish Academy of Sciences have evolved from classical biochemistry, biophysics and physiological chemistry to up-to-date molecular biology. Research interests are focussed on replication, mutagenesis and repair of DNA; regulation of gene expression at various levels; biosynthesis and post-translational modifications of proteins; gene sequencing and functional analysis of open reading frames; structure, function and regulation of enzymes; conformation of proteins and peptides; modelling of structures and prediction of functions of proteins; mechanisms of electron transfer in polypeptides

  1. Institute of Biochemistry and Biophysics. Research Report 1996-1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    Scientific interests of the Institute of Biochemistry and Biophysics of the Polish Academy of Sciences have evolved from classical biochemistry, biophysics and physiological chemistry to up-to-date molecular biology. Research interests are focussed on replication, mutagenesis and repair of DNA; regulation of gene expression at various levels; biosynthesis and post-translational modifications of proteins; gene sequencing and functional analysis of open reading frames; structure, function and regulation of enzymes; conformation of proteins and peptides; modelling of structures and prediction of functions of proteins; mechanisms of electron transfer in polypeptides.

  2. Polish Academy of Sciences. Institute of Biochemistry and Biophysics. Research Report 1998-1999

    International Nuclear Information System (INIS)

    2000-01-01

    The report presented research activities of the Institute of Biochemistry and Biophysics, Polish Academy of Sciences, in 1998-1999. Research interests focus on: replication, mutagenesis and repair of DNA, regulation of gene expression, biosynthesis and post-translational modifications of proteins, gene sequencing and functional gene analysis, structure and function of enzymes, conformation of proteins and peptides, modeling of structures and prediction of function of proteins

  3. Polish Academy of Sciences. Institute of Biochemistry and Biophysics. Research Report 1998-1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The report presented research activities of the Institute of Biochemistry and Biophysics, Polish Academy of Sciences, in 1998-1999. Research interests focus on: replication, mutagenesis and repair of DNA, regulation of gene expression, biosynthesis and post-translational modifications of proteins, gene sequencing and functional gene analysis, structure and function of enzymes, conformation of proteins and peptides, modeling of structures and prediction of function of proteins.

  4. Biophysical Influence of Airborne Carbon Nanomaterials on Natural Pulmonary Surfactant

    OpenAIRE

    Valle, Russell P.; Wu, Tony; Zuo, Yi Y.

    2015-01-01

    Inhalation of nanoparticles (NP), including lightweight airborne carbonaceous nanomaterials (CNM), poses a direct and systemic health threat to those who handle them. Inhaled NP penetrate deep pulmonary structures in which they first interact with the pulmonary surfactant (PS) lining at the alveolar air–water interface. In spite of many research efforts, there is a gap of knowledge between in vitro biophysical study and in vivo inhalation toxicology since all existing biophysical models handl...

  5. Irrational Rationality of Terrorism

    Directory of Open Access Journals (Sweden)

    Robert Nalbandov

    2013-12-01

    Full Text Available The present article deals with the ontological problem of applying the rational choice frameworks to the study of terrorism. It testing the application of the rational choice to the “old” (before the end of the Cold War and the “new” (after the end of the Cold War terrorisms. It starts with analyzing the fundamentals of rationality and applies it at two levels: the individual (actors and group (collective via two outlooks: tactical (short-term and strategic (long-term. The main argument of the article is that while the “old” terrorism can be explained by the rational choice theory its “new” version represents a substantial departure from rationality.

  6. Replacing natural wetlands with stormwater management facilities: Biophysical and perceived social values.

    Science.gov (United States)

    Rooney, R C; Foote, L; Krogman, N; Pattison, J K; Wilson, M J; Bayley, S E

    2015-04-15

    Urban expansion replaces wetlands of natural origin with artificial stormwater management facilities. The literature suggests that efforts to mimic natural wetlands in the design of stormwater facilities can expand the provision of ecosystem services. Policy developments seek to capitalize on these improvements, encouraging developers to build stormwater wetlands in place of stormwater ponds; however, few have compared the biophysical values and social perceptions of these created wetlands to those of the natural wetlands they are replacing. We compared four types of wetlands: natural references sites, natural wetlands impacted by agriculture, created stormwater wetlands, and created stormwater ponds. We anticipated that they would exhibit a gradient in biodiversity, ecological integrity, chemical and hydrologic stress. We further anticipated that perceived values would mirror measured biophysical values. We found higher biophysical values associated with wetlands of natural origin (both reference and agriculturally impacted). The biophysical values of stormwater wetlands and stormwater ponds were lower and indistinguishable from one another. The perceived wetland values assessed by the public differed from the observed biophysical values. This has important policy implications, as the public are not likely to perceive the loss of values associated with the replacement of natural wetlands with created stormwater management facilities. We conclude that 1) agriculturally impacted wetlands provide biophysical values equivalent to those of natural wetlands, meaning that land use alone is not a great predictor of wetland value; 2) stormwater wetlands are not a substantive improvement over stormwater ponds, relative to wetlands of natural origin; 3) stormwater wetlands are poor mimics of natural wetlands, likely due to fundamental distinctions in terms of basin morphology, temporal variation in hydrology, ground water connectivity, and landscape position; 4) these

  7. Lying for Strategic Advantage: Rational and Boundedly Rational Misrepresentation of Intentions

    OpenAIRE

    Crawford, Vincent P.

    2001-01-01

    Starting from Hendricks and McAfee's (2000) example of the Allies' decision to feint at Calais and attack at Normandy on D-Day, this paper models misrepresentation of intentions to competitors or enemies. Allowing for the possibility of bounded strategic rationality and rational players' responses to it yields a sensible account of lying via costless, noiseless messages. In many cases the model has generically unique pure-strategy sequential equilibria, in which rational players exploit bound...

  8. Polish Academy of Sciences Institute of Biochemistry and Biophysics research report 1994-1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    Scientific interests of Institute of Biochemistry and Biophysics Polish Academy of Sciences are focused on DNA replication and repair, gene expression, gene sequencing and molecular biophysics. The work reviews research projects of the Institute in 1994-1995.

  9. Polish Academy of Sciences Institute of Biochemistry and Biophysics research report 1994-1995

    International Nuclear Information System (INIS)

    1996-01-01

    Scientific interests of Institute of Biochemistry and Biophysics Polish Academy of Sciences are focused on DNA replication and repair, gene expression, gene sequencing and molecular biophysics. The work reviews research projects of the Institute in 1994-1995

  10. Polish Academy of Sciences Institute of Biochemistry and Biophysics research report 1994-1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    Scientific interests of Institute of Biochemistry and Biophysics Polish Academy of Sciences are focused on DNA replication and repair, gene expression, gene sequencing and molecular biophysics. The work reviews research projects of the Institute in 1994-1995.

  11. Surface-enhanced Raman scattering: a new optical probe in molecular biophysics and biomedicine

    DEFF Research Database (Denmark)

    Kneipp, J.; Wittig, B.; Bohr, Henrik

    2010-01-01

    Sensitive and detailed molecular structural information plays an increasing role in molecular biophysics and molecular medicine. Therefore, vibrational spectroscopic techniques, such as Raman scattering, which provide high structural information content are of growing interest in biophysical and ...

  12. Determinants of Actor Rationality

    DEFF Research Database (Denmark)

    Ellegaard, Chris

    Industrial companies must exercise influence on their suppliers (or supplier actors). Actor rationality is a central theme connected to this management task. In this article, relevant literature is studied with the purpose of shedding light on determinants of actor rationality. Two buyer-supplier...... relations are investigated in a multiple case study, leading to the proposal of various additional factors that determine and shape actor rationality. Moreover a conceptual model of rationality determinants in the buyer-supplier relation is proposed, a model that may help supply managers analyse...

  13. Two Concepts of Rationality

    Directory of Open Access Journals (Sweden)

    Danny Frederick

    2010-02-01

    Full Text Available The dominant tradition in Western philosophy sees rationality as dictating. Thus rationality may require that we believe the best explanation and simple conceptual truths and that we infer in accordance with evident rules of inference. I argue that, given what we know about the growth of knowledge, this authoritarian concept of rationality leads to absurdities and should be abandoned. I then outline a libertarian concept of rationality, derived from Popper, which eschews the dictates and which sees a rational agent as one who questions, criticises, conjectures and experiments. I argue that, while the libertarian approach escapes the absurdities of the authoritarian, it requires two significant developments and an important clarification to be made fully consistent with itself.

  14. Rationality and institutions : an inquiry into the normative implications of rational choice theory

    OpenAIRE

    Engelen, Bart

    2007-01-01

    I aim to analyze in this dissertation what a desirable basic institutional structure looks like from the perspective of rationality. While the main topic is thus normative in nature, I start by clarifying in the first part what the notion of rationality exactly entails. I do so by focusing explicitly on the economic conception of rationality, according to which a rational individual is motivated to serve his self-interest on the basis of cost-benefit calculations. Such a Homo Economicus is ch...

  15. [Biophysical methods in assessment of the skin microcirculation system].

    Science.gov (United States)

    Dynnik, O B; Mostovoĭ, S E; Berezovskiĭ, V A

    2008-01-01

    In this work has been analyzed the potential of biophysics methods in estimations of the microcirculatory system. Capillaroresistometry, Computer capillaroscopy and Laser Doppler Flowmetry can to detect of the endothelial dysfunction in the patients with chronic hepatic diseases. This instrumentals biophysics methods may be used in clinical investigations for screening early pathological conditions with dysfunction of the microcirculatory system. The methods Laser Doppler Flowmetry is important for investigations the patients with others diseases and for dynamical monitoring by quality of the treatment. The purpose of these methods an objective estimation of disorders in the microcirculatory system.

  16. Rationing medical education.

    African Journals Online (AJOL)

    This paper discussed the pros and cons of the application of rationing to medical education and the different ... Different types of rationing exist in healthcare professional education. ... state-of-the-art resources, technology and tutors con-.

  17. Rationalization of activity cliffs of a sulfonamide inhibitor of DNA methyltransferases with induced-fit docking.

    Science.gov (United States)

    Medina-Franco, José L; Méndez-Lucio, Oscar; Yoo, Jakyung

    2014-02-21

    Inhibitors of human DNA methyltransferases (DNMT) are of increasing interest to develop novel epi-drugs for the treatment of cancer and other diseases. As the number of compounds with reported DNMT inhibition is increasing, molecular docking is shedding light to elucidate their mechanism of action and further interpret structure-activity relationships. Herein, we present a structure-based rationalization of the activity of SW155246, a distinct sulfonamide compound recently reported as an inhibitor of human DNMT1 obtained from high-throughput screening. We used flexible and induce-fit docking to develop a binding model of SW155246 with a crystallographic structure of human DNMT1. Results were in excellent agreement with experimental information providing a three-dimensional structural interpretation of 'activity cliffs', e.g., analogues of SW155246 with a high structural similarity to the sulfonamide compound, but with no activity in the enzymatic assay.

  18. Rationalization of Activity Cliffs of a Sulfonamide Inhibitor of DNA Methyltransferases with Induced-Fit Docking

    Directory of Open Access Journals (Sweden)

    José L. Medina-Franco

    2014-02-01

    Full Text Available Inhibitors of human DNA methyltransferases (DNMT are of increasing interest to develop novel epi-drugs for the treatment of cancer and other diseases. As the number of compounds with reported DNMT inhibition is increasing, molecular docking is shedding light to elucidate their mechanism of action and further interpret structure–activity relationships. Herein, we present a structure-based rationalization of the activity of SW155246, a distinct sulfonamide compound recently reported as an inhibitor of human DNMT1 obtained from high-throughput screening. We used flexible and induce-fit docking to develop a binding model of SW155246 with a crystallographic structure of human DNMT1. Results were in excellent agreement with experimental information providing a three-dimensional structural interpretation of ‘activity cliffs’, e.g., analogues of SW155246 with a high structural similarity to the sulfonamide compound, but with no activity in the enzymatic assay.

  19. Rationality problem for algebraic tori

    CERN Document Server

    Hoshi, Akinari

    2017-01-01

    The authors give the complete stably rational classification of algebraic tori of dimensions 4 and 5 over a field k. In particular, the stably rational classification of norm one tori whose Chevalley modules are of rank 4 and 5 is given. The authors show that there exist exactly 487 (resp. 7, resp. 216) stably rational (resp. not stably but retract rational, resp. not retract rational) algebraic tori of dimension 4, and there exist exactly 3051 (resp. 25, resp. 3003) stably rational (resp. not stably but retract rational, resp. not retract rational) algebraic tori of dimension 5. The authors make a procedure to compute a flabby resolution of a G-lattice effectively by using the computer algebra system GAP. Some algorithms may determine whether the flabby class of a G-lattice is invertible (resp. zero) or not. Using the algorithms, the suthors determine all the flabby and coflabby G-lattices of rank up to 6 and verify that they are stably permutation. The authors also show that the Krull-Schmidt theorem for G-...

  20. Rational Approximations to Rational Models: Alternative Algorithms for Category Learning

    Science.gov (United States)

    Sanborn, Adam N.; Griffiths, Thomas L.; Navarro, Daniel J.

    2010-01-01

    Rational models of cognition typically consider the abstract computational problems posed by the environment, assuming that people are capable of optimally solving those problems. This differs from more traditional formal models of cognition, which focus on the psychological processes responsible for behavior. A basic challenge for rational models…

  1. Cellular normoxic biophysical markers of hydroxyurea treatment in sickle cell disease

    OpenAIRE

    Hosseini, Poorya; Abidi, Sabia Z.; Du, E; Papageorgiou, Dimitrios P.; Choi, Youngwoon; Park, YongKeun; Higgins, John M.; Kato, Gregory J.; Suresh, Subra; Dao, Ming; Yaqoob, Zahid; So, Peter T. C.

    2016-01-01

    There exists a critical need for developing biomarkers reflecting clinical outcomes and for evaluating the effectiveness of treatments for sickle cell disease patients. Prior attempts to find such patient-specific markers have mostly relied upon chemical biomarkers or biophysical properties at hypoxia with limited success. We introduce unique biomarkers based on characterization of cellular biophysical properties at normoxia and show that these markers correlate sensitively with treatment usi...

  2. Toward Biophysical Probes for the 5-HT3 Receptor: Structure−Activity Relationship Study of Granisetron Derivatives

    Science.gov (United States)

    2010-01-01

    This report describes the synthesis and biological characterization of novel granisetron derivatives that are antagonists of the human serotonin (5-HT3A) receptor. Some of these substituted granisetron derivatives showed low nanomolar binding affinity and allowed the identification of positions on the granisetron core that might be used as attachment points for biophysical tags. A BODIPY fluorophore was appended to one such position and specifically bound to 5-HT3A receptors in mammalian cells. PMID:20146481

  3. Toward biophysical probes for the 5-HT3 receptor: structure-activity relationship study of granisetron derivatives.

    Science.gov (United States)

    Vernekar, Sanjeev Kumar V; Hallaq, Hasan Y; Clarkson, Guy; Thompson, Andrew J; Silvestri, Linda; Lummis, Sarah C R; Lochner, Martin

    2010-03-11

    This report describes the synthesis and biological characterization of novel granisetron derivatives that are antagonists of the human serotonin (5-HT(3)A) receptor. Some of these substituted granisetron derivatives showed low nanomolar binding affinity and allowed the identification of positions on the granisetron core that might be used as attachment points for biophysical tags. A BODIPY fluorophore was appended to one such position and specifically bound to 5-HT(3)A receptors in mammalian cells.

  4. Biophysical behavior of Scomberoides commersonianus skin collagen.

    Science.gov (United States)

    Kolli, Nagamalleswari; Joseph, K Thomas; Ramasami, T

    2002-06-01

    Some biophysical characteristics of the skin collagen from Scomberoides commersonianus were measured and compared to those of rat tail tendon. Stress-strain data indicate that the strain at break as well as the tensile strength of the fish skin without scales increased significantly. The maximum tension in case of rat skin is at least a factor of two higher than that observed in fish skin. The much lower hydrothermal isometric tension measurements observed in fish skin are attributable to a lesser number of heat stable crosslinks. Stress relaxation measurements in the fish skin indicate that more than one relaxation process may be involved in the stabilization of collagenous matrix. The observed differences in the biophysical behavior of fish skin may well arise from combination of changes in extent of hydroxylation of proline in collagen synthesis, hydrogen bond network and fibril orientation as compared to rat tail tendon.

  5. Optimal public rationing and price response.

    Science.gov (United States)

    Grassi, Simona; Ma, Ching-To Albert

    2011-12-01

    We study optimal public health care rationing and private sector price responses. Consumers differ in their wealth and illness severity (defined as treatment cost). Due to a limited budget, some consumers must be rationed. Rationed consumers may purchase from a monopolistic private market. We consider two information regimes. In the first, the public supplier rations consumers according to their wealth information (means testing). In equilibrium, the public supplier must ration both rich and poor consumers. Rationing some poor consumers implements price reduction in the private market. In the second information regime, the public supplier rations consumers according to consumers' wealth and cost information. In equilibrium, consumers are allocated the good if and only if their costs are below a threshold (cost effectiveness). Rationing based on cost results in higher equilibrium consumer surplus than rationing based on wealth. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Exploring rationality in schizophrenia

    DEFF Research Database (Denmark)

    Revsbech, Rasmus; Mortensen, Erik Lykke; Owen, Gareth

    2015-01-01

    Background Empirical studies of rationality (syllogisms) in patients with schizophrenia have obtained different results. One study found that patients reason more logically if the syllogism is presented through an unusual content. Aims To explore syllogism-based rationality in schizophrenia. Meth...... differences became non-significant. Conclusions When taking intelligence and neuropsychological performance into account, patients with schizophrenia and controls perform similarly on syllogism tests of rationality.......Background Empirical studies of rationality (syllogisms) in patients with schizophrenia have obtained different results. One study found that patients reason more logically if the syllogism is presented through an unusual content. Aims To explore syllogism-based rationality in schizophrenia. Method...... Thirty-eight first-admitted patients with schizophrenia and 38 healthy controls solved 29 syllogisms that varied in presentation content (ordinary v. unusual) and validity (valid v. invalid). Statistical tests were made of unadjusted and adjusted group differences in models adjusting for intelligence...

  7. Respect for rational autonomy.

    Science.gov (United States)

    Walker, Rebecca L

    2009-12-01

    The standard notion of autonomy in medical ethics does not require that autonomous choices not be irrational. The paper gives three examples of seemingly irrational patient choices and discusses how a rational autonomy analysis differs from the standard view. It then considers whether a switch to the rational autonomy view would lead to overriding more patient decisions but concludes that this should not be the case. Rather, a determination of whether individual patient decisions are autonomous is much less relevant than usually considered in determining whether health care providers must abide by these decisions. Furthermore, respect for rational autonomy entails strong positive requirements of respect for the autonomy of the person as a rational decision maker. The rationality view of autonomy is conceptually stronger than the standard view, allows for a more nuanced understanding of the practical moral calculus involved in respecting patient autonomy, and promotes positive respect for patient autonomy.

  8. Cell biology, biophysics, and mechanobiology: From the basics to Clinics.

    Science.gov (United States)

    Zeng, Y

    2017-04-29

    Cell biology, biomechanics and biophysics are the key subjects that guide our understanding in diverse areas of tissue growth, development, remodeling and homeostasis. Novel discoveries such as molecular mechanism, and mechanobiological mechanism in cell biology, biomechanics and biophysics play essential roles in our understanding of the pathogenesis of various human diseases, as well as in designing the treatment of these diseases. In addition, studies in these areas will also facilitate early diagnostics of human diseases, such as cardiovascular diseases and cancer. In this special issue, we collected 10 original research articles and 1 review...

  9. Embodying rationality

    OpenAIRE

    Mastrogiorgio, Antonio; Petracca, Enrico

    2016-01-01

    The current notions of bounded rationality in economics share distinctive features with Simon’s original notion, which still influences the theoretical and experimental research in the fields of choice, judgment, decision making, problem solving, and social cognition. All these notions of bounded rationality are in fact equally rooted in the information-processing approach to human cognition, expressing the view that reasoning is disembodied and that it can be reduced to the processing of abs...

  10. Sonographic biophysical profile in detection of foetal hypoxia in 100 cases of suspected high risk pregnancy

    International Nuclear Information System (INIS)

    Ullah, N.; Khan, A.R.; Usman, M.

    2010-01-01

    Background: The foetus has become increasingly accessible and visible as a patient over the last two decades. Ultrasound imaging has broadened the scope of foetal assessment. Dynamic real time B-Mode ultrasound is used to monitor cluster of biophysical variables, both dynamic and static collectively termed as biophysical profile. The purpose of this study was to determine the effect of sonographic biophysical profile score on perinatal outcome in terms of mortality and morbidity. Methods: This descriptive study was carried on 100 randomly select ed high risk pregnant patients in Radiology Department PGMI, Government Lady Reading Hospital, Peshawar from December 2007 to June 2008. Manning biophysical profile including non-stress was employed for foetal screening, using Toshiba ultrasound machine model Nemio SSA-550A and 7.5 MHZ probe. Results: Out of 100 cases 79 (79%) had a normal biophysical profile in the last scan of 10/10 and had a normal perinatal outcome with 5 minutes Apgar score >7/10. In 13 (13%) cases Apgar score at 5 minute was < 7/10 and babies were shifted to nursery. There were 2 (2%) false positive cases that showed abnormal biophysical profile scores of 6/10 but babies were born with an Apgar score of 8/10 at 5 minutes. There were 2 (2%) neonatal deaths in this study group. The sensitivity of biophysical profile was 79.1%, specificity 92.9%. Predictive value for a positive test was 98.55%; predictive value for a negative test was 41.93%. Conclusion: Biophysical profile is highly accurate and reliable test of diagnosing foetal hypoxia. (author)

  11. Procedural Rationality in the Decision-Making of Internationalizing SMEs

    DEFF Research Database (Denmark)

    Hsieh, Linda; Elbanna, Said; Narooz, Rose

    This paper contributes to the growing body of empirical work on how SME decision-makers decide to internationalize in two ways: first, it responds to recent calls for incorporating strategic decision-making literature into understanding SME internationalization decisions. Second, it provides a be...... a more rational decision-making procedure when they perceive a high level of international risk. The evidence also suggest that internationalization performance, planned internationalization, credit check, and decision team size are positively related to procedural rationality....... a better understanding of under what circumstances, SME decision-makers tend to follow a more rational approach toward internationalization decisions. Specifically, this paper examines a set of contextual variables (the level of perceived international risk, internationalization performance, planned versus...... ad hoc internationalization, credit check, distribution adaptation, and decision team size) and their influence on the extent of procedural rationality in SME internationalization decision-making process. The findings from a sample of 176 export-active SMEs show that decision-makers tend to follow...

  12. Capital Requirements and Credit Rationing

    OpenAIRE

    Itai Agur

    2010-01-01

    This paper analyzes the trade-off between financial stability and credit rationing that arises when increasing capital requirements. It extends the Stiglitz-Weiss model of credit rationing to allow for bank default. Bank capital structure then matters for lending incentives. With default and rationing endogenous, optimal capital requirements can be analyzed. Introducing bank financiers, the paper also shows that uninsured funding raises the sensitivity of rationing to capital requirements. In...

  13. Effect of ambient light on the time needed to complete a fetal biophysical profile: A randomized controlled trial.

    Science.gov (United States)

    Said, Heather M; Gupta, Shweta; Vricella, Laura K; Wand, Katy; Nguyen, Thinh; Gross, Gilad

    2017-10-01

    The objective of this study is to determine whether ambient light serves as a fetal stimulus to decrease the amount of time needed to complete a biophysical profile. This is a randomized controlled trial of singleton gestations undergoing a biophysical profile. Patients were randomized to either ambient light or a darkened room. The primary outcome was the time needed to complete the biophysical profile. Secondary outcomes included total and individual component biophysical profile scores and scores less than 8. A subgroup analysis of different maternal body mass indices was also performed. 357 biophysical profile studies were analyzed. 182 studies were performed with ambient light and 175 were performed in a darkened room. There was no difference in the median time needed to complete the biophysical profile based on exposure to ambient light (6.1min in darkened room versus 6.6min with ambient light; P=0.73). No difference was found in total or individual component biophysical profile scores. Subgroup analysis by maternal body mass index did not demonstrate shorter study times with ambient light exposure in women who were normal weight, overweight or obese. Ambient light exposure did not decrease the time needed to complete the biophysical profile. There was no evidence that ambient light altered fetal behavior observed during the biophysical profile. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. From autopoiesis to neurophenomenology: Francisco Varela's exploration of the biophysics of being

    Directory of Open Access Journals (Sweden)

    DAVID RUDRAUF

    2003-01-01

    Full Text Available This paper reviews in detail Francisco Varela's work on subjectivity and consciousness in the biological sciences. His original approach to this "hard problem" presents a subjectivity that is radically intertwined with its biological and physical roots. It must be understood within the framework of his theory of a concrete, embodied dynamics, grounded in his general theory of autonomous systems. Through concepts and paradigms such as biological autonomy, embodiment and neurophenomenology, the article explores the multiple levels of circular causality assumed by Varela to play a fundamental role in the emergence of human experience. The concept of biological autonomy provides the necessary and sufficient conditions for characterizing biological life and identity as an emergent and circular self-producing process. Embodiment provides a systemic and dynamical framework for understanding how a cognitive -a mind- can arise in an organism in the midst of its operational cycles of internal regulation and ongoing sensorimotor coupling. Global subjective properties can emerge at different levels from the interactions of components and can reciprocally constrain local processes through an ongoing, recursive morphodynamics. Neurophenomenology is a supplementary step in the study of consciousness. Through a rigorous method, it advocates the careful examination of experience with first-person methodologies. It attempts to create heuristic mutual constraints between biophysical data and data produced by accounts of subjective experience. The aim is to explicitly ground the active and disciplined insight the subject has about his/her experience in a biophysical emergent process. Finally, we discuss Varela's essential contribution to our understanding of the generation of consciousness in the framework of what we call his "biophysics of being."

  15. Synthetic Biology: Engineering Living Systems from Biophysical Principles.

    Science.gov (United States)

    Bartley, Bryan A; Kim, Kyung; Medley, J Kyle; Sauro, Herbert M

    2017-03-28

    Synthetic biology was founded as a biophysical discipline that sought explanations for the origins of life from chemical and physical first principles. Modern synthetic biology has been reinvented as an engineering discipline to design new organisms as well as to better understand fundamental biological mechanisms. However, success is still largely limited to the laboratory and transformative applications of synthetic biology are still in their infancy. Here, we review six principles of living systems and how they compare and contrast with engineered systems. We cite specific examples from the synthetic biology literature that illustrate these principles and speculate on their implications for further study. To fully realize the promise of synthetic biology, we must be aware of life's unique properties. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. Biophysics and the Challenges of Emerging Threats

    CERN Document Server

    Puglisi, Joseph D

    2009-01-01

    This volume is a collection of articles from the proceedings of the International School of Structural Biology and Magnetic Resonance 8th Course: Biophysics and the Challenges of Emerging Threats. This NATO Advance Study Institute (ASI) was held in Erice at the Ettore Majorana Foundation and Centre for Scientific Culture on 19 through 30 June 2007. The ASI brought together a diverse group of experts who bridged the fields of virology and biology, biophysics, chemistry and physics. Prominent lecturers and students from around the world representant a total of 24 countries participated in the NATO ASI organized by Professors Joseph Puglisi (Stanford University, USA) and Alexander Arseniev (Moscow, RU). The central hypothesis underlying this ASI was that interdisciplinary research, merging principles of physics, chemistry and biology, can drive new discovery in detecting and fighting bioterrorism agents, lead to cleaner environments, and help propel development in NATO partner countries. The ASI merged the relat...

  17. Rational BRDF.

    Science.gov (United States)

    Pacanowski, Romain; Salazar Celis, Oliver; Schlick, Christophe; Granier, Xavier; Poulin, Pierre; Cuyt, Annie

    2012-11-01

    Over the last two decades, much effort has been devoted to accurately measuring Bidirectional Reflectance Distribution Functions (BRDFs) of real-world materials and to use efficiently the resulting data for rendering. Because of their large size, it is difficult to use directly measured BRDFs for real-time applications, and fitting the most sophisticated analytical BRDF models is still a complex task. In this paper, we introduce Rational BRDF, a general-purpose and efficient representation for arbitrary BRDFs, based on Rational Functions (RFs). Using an adapted parametrization, we demonstrate how Rational BRDFs offer 1) a more compact and efficient representation using low-degree RFs, 2) an accurate fitting of measured materials with guaranteed control of the residual error, and 3) efficient importance sampling by applying the same fitting process to determine the inverse of the Cumulative Distribution Function (CDF) generated from the BRDF for use in Monte-Carlo rendering.

  18. Cellular normoxic biophysical markers of hydroxyurea treatment in sickle cell disease.

    Science.gov (United States)

    Hosseini, Poorya; Abidi, Sabia Z; Du, E; Papageorgiou, Dimitrios P; Choi, Youngwoon; Park, YongKeun; Higgins, John M; Kato, Gregory J; Suresh, Subra; Dao, Ming; Yaqoob, Zahid; So, Peter T C

    2016-08-23

    Hydroxyurea (HU) has been used clinically to reduce the frequency of painful crisis and the need for blood transfusion in sickle cell disease (SCD) patients. However, the mechanisms underlying such beneficial effects of HU treatment are still not fully understood. Studies have indicated a weak correlation between clinical outcome and molecular markers, and the scientific quest to develop companion biophysical markers have mostly targeted studies of blood properties under hypoxia. Using a common-path interferometric technique, we measure biomechanical and morphological properties of individual red blood cells in SCD patients as a function of cell density, and investigate the correlation of these biophysical properties with drug intake as well as other clinically measured parameters. Our results show that patient-specific HU effects on the cellular biophysical properties are detectable at normoxia, and that these properties are strongly correlated with the clinically measured mean cellular volume rather than fetal hemoglobin level.

  19. Coexistence between silent and bursting states in a biophysical Hodgkin-Huxley-type of model

    DEFF Research Database (Denmark)

    Stankevich, Nataliya; Mosekilde, Erik

    2017-01-01

    in a slightly modified, biophysical model that describe the dynamics of pancreatic beta-cells. To realize this form of coexistence, we have introduced an additional voltage-dependent potassium current that is activated in the region around the original, unstable equilibrium point. It is interesting to note...... that this modification also leads the model to display a blue-sky catastrophe in the transition region between chaotic and bursting states....

  20. A synthesized biophysical and social vulnerability assessment for Taiwan

    Science.gov (United States)

    Lee, Yung-Jaan

    2017-11-01

    Taiwan, located in the Western Pacific, is a country that is one of the most vulnerable to disasters that are associated with the changing climate; it is located within the Ring of Fire, which is the most geologically active region in the world. The environmental and geological conditions in Taiwan are sensitive and vulnerable to such disasters. Owing to increasing urbanization in Taiwan, floods and climate-related disasters have taken an increasing toll on human lives. As global warming accelerates the rising of sea levels and increasing of the frequency of extreme weather events, disasters will continue to affect socioeconomic development and human conditions. Under such circumstances, researchers and policymakers alike must recognize the importance of providing useful knowledge concerning vulnerability, disaster recovery and resilience. Strategies for reducing vulnerability and climate-related disaster risks and for increasing resilience involve preparedness, mitigation and adaptation. In the last two decades, extreme climate events have caused severe flash floods, debris flows, landslides, and other disasters and have had negative effects of many sectors, including agriculture, infrastructure and health. Since climate change is expected to have a continued impact on socio-economic development, this work develops a vulnerability assessment framework that integrates both biophysical and social vulnerability and supports synthesized vulnerability analyses to identify vulnerable areas in Taiwan. Owing to its geographical, geological and climatic features, Taiwan is susceptible to earthquakes, typhoons, droughts and various induced disasters. Therefore, Taiwan has the urgent task of establishing a framework for assessing vulnerability as a planning and policy tool that can be used to identify not only the regions that require special attention but also hotspots in which efforts should be made to reduce vulnerability and the risk of climate-related disaster. To

  1. Is It Rational to Assume that Infants Imitate Rationally? A Theoretical Analysis and Critique

    Science.gov (United States)

    Paulus, Markus

    2012-01-01

    It has been suggested that preverbal infants evaluate the efficiency of others' actions (by applying a "principle of rational action") and that they imitate others' actions rationally. The present contribution presents a conceptual analysis of the claim that preverbal infants imitate rationally. It shows that this ability rests on at least three…

  2. The biophysical link between climate, water, and vegetation in bioenergy agro-ecosystems

    International Nuclear Information System (INIS)

    Bagley, Justin E.; Davis, Sarah C.; Georgescu, Matei; Hussain, Mir Zaman; Miller, Jesse; Nesbitt, Stephen W.; VanLoocke, Andy; Bernacchi, Carl J.

    2014-01-01

    Land use change for bioenergy feedstocks is likely to intensify as energy demand rises simultaneously with increased pressure to minimize greenhouse gas emissions. Initial assessments of the impact of adopting bioenergy crops as a significant energy source have largely focused on the potential for bioenergy agroecosystems to provide global-scale climate regulating ecosystem services via biogeochemical processes. Such as those processes associated with carbon uptake, conversion, and storage that have the potential to reduce global greenhouse gas emissions (GHG). However, the expansion of bioenergy crops can also lead to direct biophysical impacts on climate through water regulating services. Perturbations of processes influencing terrestrial energy fluxes can result in impacts on climate and water across a spectrum of spatial and temporal scales. Here, we review the current state of knowledge about biophysical feedbacks between vegetation, water, and climate that would be affected by bioenergy-related land use change. The physical mechanisms involved in biophysical feedbacks are detailed, and interactions at leaf, field, regional, and global spatial scales are described. Locally, impacts on climate of biophysical changes associated with land use change for bioenergy crops can meet or exceed the biogeochemical changes in climate associated with rising GHG's, but these impacts have received far less attention. Realization of the importance of ecosystems in providing services that extend beyond biogeochemical GHG regulation and harvestable yields has led to significant debate regarding the viability of various feedstocks in many locations. The lack of data, and in some cases gaps in knowledge associated with biophysical and biochemical influences on land–atmosphere interactions, can lead to premature policy decisions. - Highlights: • The physical basis for biophysical impacts of expanding bioenergy agroecosystems on climate and water is described. • We

  3. Bounded Rationality and Budgeting

    OpenAIRE

    Ibrahim, Mukdad

    2016-01-01

    This article discusses the theory of bounded rationality which had been introduced by Herbert Simon in the 1950s. Simon introduced the notion of bounded rationality stating that while decision-makers strive for rationality, they are limited by the effect of the environment, their information process capacity and by the constraints on their information storage and retrieval capabilities. Moreover, this article tries to specifically blend this notion into budgeting, using the foundations of inc...

  4. Raman spectroscopy reveals biophysical markers in skin cancer surgical margins

    Science.gov (United States)

    Feng, Xu; Moy, Austin J.; Nguyen, Hieu T. M.; Zhang, Yao; Fox, Matthew C.; Sebastian, Katherine R.; Reichenberg, Jason S.; Markey, Mia K.; Tunnell, James W.

    2018-02-01

    The recurrence rate of nonmelanoma skin cancer is highly related to the residual tumor after surgery. Although tissueconserving surgery, such as Mohs surgery, is a standard method for the treatment of nonmelanoma skin cancer, they are limited by lengthy and costly frozen-section histopathology. Raman spectroscopy (RS) is proving to be an objective, sensitive, and non-destructive tool for detecting skin cancer. Previous studies demonstrated the high sensitivity of RS in detecting tumor margins of basal cell carcinoma (BCC). However, those studies rely on statistical classification models and do not elucidate the skin biophysical composition. As a result, we aim to discover the biophysical differences between BCC and primary normal skin structures (including epidermis, dermis, hair follicle, sebaceous gland and fat). We obtained freshly resected ex vivo skin samples from fresh resection specimens from 14 patients undergoing Mohs surgery. Raman images were acquired from regions containing one or more structures using a custom built 830nm confocal Raman microscope. The spectra were grouped using K-means clustering analysis and annotated as either BCC or each of the five normal structures by comparing with the histopathology image of the serial section. The spectral data were then fit by a previously established biophysical model with eight primary skin constituents. Our results show that BCC has significant differences in the fit coefficients of nucleus, collagen, triolein, keratin and elastin compared with normal structures. Our study reveals RS has the potential to detect biophysical changes in resection margins, and supports the development of diagnostic algorithms for future intraoperative implementation of RS during Mohs surgery.

  5. The necessity to rationalize library procedures and activities

    Directory of Open Access Journals (Sweden)

    Matjaž Žaucer

    2007-01-01

    Full Text Available The necessity of the rationalization of work and procedures in libraries due to the altered requirements and needs of users and due to the expected aggravated demands of the environment are displayed in the article. The causes for the changes in the librarianship and the causes for the changes in the environment are stated. The article analyzes the searching procedure in the Slovenian union bibliographic and catalogue database using the UDC. Upon a practical experiment it was established that the users can not make a successful use of the UDC because neither on the web nor in the database there are freely accessible UDC tables; there are also no exact usage instructions available. The outcomes of some tests in public and academic libraries reveal that the assistance of librarians with retrievals by the UDC is unpractical, timeconsuming and does not always lead to the correct result. Based on an international comparison of foreign academic libraries and one Slovenian library, the latter shows a substantial ineffectiveness in cataloging which leads to the assumption of the highdemanding or incomplete cataloguing rules. The case of the digital patent documents in one of the libraries reveals the incapability of processing of a large amount of documents according to the existing rules. The conclusion of the article is the appeal for more rational cataloging rules, for the accessibility of cataloging records directly via web search engines and for an optional indication of the UDC in the records. However, as the conditions in Slovenian libraries are not critical yet, the author has doubts about a quick response to those appeals.

  6. Natural Radioactivity In Poultry Rations And DCP For Bovine Nutrition

    International Nuclear Information System (INIS)

    Luz-Filho, Isaias V.; Scheibel, Viviane; Appoloni, Carlos R.

    2011-01-01

    The aim of this study is to determine the level of radioactivity present in samples of poultry rations and dicalcium phosphate (DCP) used for cattle feed. Knowledge of these levels is of fundamental importance, because part of this radioactivity will possibly be transferred to humans. The radiation found in such samples is due to the presence of radioactive series of 238 U and 232 Th and 40 K. Measurements were performed with a 66% HPGe detector at the Laboratory of Applied Nuclear Physics, State University of Londrina. The measured samples were commercialized in Londrina, Brazil, in the second half of 2007. The accommodation recipient of the samples was a 1 L Marinelli beaker. Poultry rations were divided into two types: for young chickens and adult chickens. Among these, the ration for adult chickens showed the highest values for the activities of 226 Ra and 228 Ra, 0.23±0.17 and 0.493±0.091 Bq/kg respectively. But the ration for young chickens showed the highest activity for the 40 K, 304±15 Bq/kg. The DCP sample showed a much higher value for the series of 238 U and 232 Th, 83±26 and 7.79±0.70 Bq/kg, respectively. However, the 40 K activity in this sample was about 5 or 6 times lower than samples for poultry feed, reaching 46.6±2.8 Bq/kg.

  7. X-Ray structure and biophysical properties of rabbit fibroblast growth factor 1

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jihun; Blaber, Sachiko I.; Irsigler, Andre; Aspinwall, Eric; Blaber, Michael; (FSU)

    2010-01-14

    The rabbit is an important and de facto animal model in the study of ischemic disease and angiogenic therapy. Additionally, fibroblast growth factor 1 (FGF-1) is emerging as one of the most important growth factors for novel pro-angiogenic and pro-arteriogenic therapy. However, despite its significance, the fundamental biophysical properties of rabbit FGF-1, including its X-ray structure, have never been reported. Here, the cloning, crystallization, X-ray structure and determination of the biophysical properties of rabbit FGF-1 are described. The X-ray structure shows that the amino-acid differences between human and rabbit FGF-1 are solvent-exposed and therefore potentially immunogenic, while the biophysical studies identify differences in thermostability and receptor-binding affinity that distinguish rabbit FGF-1 from human FGF-1.

  8. CREB Overexpression Ameliorates Age-related Behavioral and Biophysical Deficits

    Science.gov (United States)

    Yu, Xiao-Wen

    Age-related cognitive deficits are observed in both humans and animals. Yet, the molecular mechanisms underlying these deficits are not yet fully elucidated. In aged animals, a decrease in intrinsic excitability of pyramidal neurons from the CA1 sub-region of hippocampus is believed to contribute to age-related cognitive impairments, but the molecular mechanism(s) that modulate both these factors has yet to be identified. Increasing activity of the transcription factor cAMP response element-binding protein (CREB) in young adult rodents has been shown to facilitate cognition, and increase intrinsic excitability of their neurons. However, how CREB changes with age, and how that impacts cognition in aged animals, is not clear. Therefore, we first systematically characterized age- and training-related changes in CREB levels in dorsal hippocampus. At a remote time point after undergoing behavioral training, levels of total CREB and activated CREB (phosphorylated at S133, pCREB) were measured in both young and aged rats. We found that pCREB, but not total CREB was significantly reduced in dorsal CA1 of aged rats. Importantly, levels of pCREB were found to be positively correlated with short-term spatial memory in both young and aged rats i.e. higher pCREB in dorsal CA1 was associated with better spatial memory. These findings indicate that an age-related deficit in CREB activity may contribute to the development of age-related cognitive deficits. However, it was still unclear if increasing CREB activity would be sufficient to ameliorate age-related cognitive, and biophysical deficits. To address this question, we virally overexpressed CREB in CA1, where we found the age-related deficit. Young and aged rats received control or CREB virus, and underwent water maze training. While control aged animals exhibited deficits in long-term spatial memory, aged animals with CREB overexpression performed at levels comparable to young animals. Concurrently, aged neurons

  9. Rational valuations

    Directory of Open Access Journals (Sweden)

    Georg Spielthenner

    2007-01-01

    Full Text Available Valuations are ubiquitous. We may be for or against genetically modified food; we find some politicians irresponsible; we prefer Beethoven to rock ‘n’ roll or vice versa; some enjoy bird-watching while others find it boring; and we may think that we have to tighten up on green-house gas emissions. Valuing is pervasive and often we are not even aware that we are valuing. However, many of ourvaluations are ill grounded and rationally defective. They are frequently based on misinformation, sloppy thinking, prejudice, and are biased in many ways as psychological research shows. For this reason there is widespread agreement among phi-losophers that we need an account of substantive valuational rationality, both for the theory of practical reasoning and for ethics as well. My main objectin this paper is to outline such an account and to present a principle that allows a non-technical rational criticism of valuations

  10. Rational emotions.

    Science.gov (United States)

    Meshulam, Meir; Winter, Eyal; Ben-Shakhar, Gershon; Aharon, Itzhak

    2012-01-01

    We present here the concept of rational emotions: Emotions may be directly controlled and utilized in a conscious, analytic fashion, enabling an individual to size up a situation, to determine that a certain "mental state" is strategically advantageous and adjust accordingly. Building on the growing body of literature recognizing the vital role of emotions in determining decisions, we explore the complementary role of rational choice in choosing emotional states. Participants played the role of "recipient" in the dictator game, in which an anonymous "dictator" decides how to split an amount of money between himself and the recipient. A subset of recipients was given a monetary incentive to be angry at low-split offers. That subset demonstrated increased physiological arousal at low offers relative to high offers as well as more anger than other participants. These results provide a fresh outlook on human decision-making and contribute to the continuing effort to build more complete models of rational behavior.

  11. Models for Rational Number Bases

    Science.gov (United States)

    Pedersen, Jean J.; Armbruster, Frank O.

    1975-01-01

    This article extends number bases to negative integers, then to positive rationals and finally to negative rationals. Methods and rules for operations in positive and negative rational bases greater than one or less than negative one are summarized in tables. Sample problems are explained and illustrated. (KM)

  12. Contribution to researches in biophysics and biology

    International Nuclear Information System (INIS)

    Luccioni, Catherine

    2000-01-01

    In this accreditation to supervise research, the author indicates its curriculum and scientific works which mainly dealt with the different agents used in chemotherapy. Scientific works addressed anti-carcinogenic pharmacology, applied biophysics, and researches in oncology and radiobiology. Current research projects deal with mechanisms of cellular transformation and the implication of the anti-oxidising metabolism and of nucleotide metabolism in cell radio-sensitivity. Teaching and research supervising activities are also indicated. Several articles are proposed in appendix: Average quality factor and dose equivalent meter based on microdosimetry techniques; Activity of thymidylate synthetase, thymidine kinase and galactokinase in primary and xenografted human colorectal cancers in relation to their chromosomal patterns; Nucleotide metabolism in human gliomas, relation to the chromosomal profile; Pyrimidine nucleotide metabolism in human colon carcinomas: comparison of normal tissues, primary tumors and xenografts; Modifications of the antioxidant metabolism during proliferation and differentiation of colon tumours cell lines; Modulation of the antioxidant enzymes, p21 and p53 expression during proliferation and differentiation of human melanoma cell lines; Purine metabolism in 2 human melanoma cell lines, relation with proliferation and differentiation; Radiation-induced changes in nucleotide metabolism of 2 colon cancer cell lines with different radio-sensitivities

  13. Chief, Structural Biophysics Laboratory | Center for Cancer Research

    Science.gov (United States)

    The SBL Chief is expected to establish a strong research program in structural biology/biophysics in addition to providing leadership of the SBL and the structural biology community in the NCI Intramural Program.  Applicants should hold a Ph.D., M.D./Ph.D., or equivalent doctoral degree in a relevant discipline, and should possess outstanding communication skills and documented leadership experience.  Tenured faculty or industrial scientists of equivalent rank with a demonstrated commitment to structural biophysics should apply.  Salary will be commensurate with experience and accomplishments.  This position is not restricted to U.S. citizens. A full civil service package of benefits (including health insurance, life insurance, and retirement) is available. This position is subject to a background investigation.  The NIH is dedicated to building a diverse community in its training and employment programs.

  14. Are security analysts rational? a literature review

    OpenAIRE

    Peixinho, Rúben; Coelho, Luís; Taffler, Richard J.

    2005-01-01

    Rational choice theory and bounded rationality constitute the basis for the discussion in several areas regarding human rationality. In finance, this discussion has been made between traditional finance and behavioural finance approach, which have different perspectives concerning market agents’ rationality. This paper reviews several studies addressing rationality among security analysts. The analysis shows that analysts’systematic optimism seems to be inconsistent with rationality....

  15. Developing spatial biophysical accounting for multiple ecosystem services

    NARCIS (Netherlands)

    Remme, R.P.; Schroter, M.; Hein, L.G.

    2014-01-01

    Ecosystem accounting is receiving increasing interest as a way to systematically monitor the conditions of ecosystems and the ecosystem services they provide. A critical element of ecosystem accounting is understanding spatially explicit flows of ecosystem services. We developed spatial biophysical

  16. Quality Saving Mechanisms of Mitochondria during Aging in a Fully Time-Dependent Computational Biophysical Model.

    Directory of Open Access Journals (Sweden)

    Daniel Mellem

    Full Text Available Mitochondria are essential for the energy production of eukaryotic cells. During aging mitochondria run through various processes which change their quality in terms of activity, health and metabolic supply. In recent years, many of these processes such as fission and fusion of mitochondria, mitophagy, mitochondrial biogenesis and energy consumption have been subject of research. Based on numerous experimental insights, it was possible to qualify mitochondrial behaviour in computational simulations. Here, we present a new biophysical model based on the approach of Figge et al. in 2012. We introduce exponential decay and growth laws for each mitochondrial process to derive its time-dependent probability during the aging of cells. All mitochondrial processes of the original model are mathematically and biophysically redefined and additional processes are implemented: Mitochondrial fission and fusion is separated into a metabolic outer-membrane part and a protein-related inner-membrane part, a quality-dependent threshold for mitophagy and mitochondrial biogenesis is introduced and processes for activity-dependent internal oxidative stress as well as mitochondrial repair mechanisms are newly included. Our findings reveal a decrease of mitochondrial quality and a fragmentation of the mitochondrial network during aging. Additionally, the model discloses a quality increasing mechanism due to the interplay of the mitophagy and biogenesis cycle and the fission and fusion cycle of mitochondria. It is revealed that decreased mitochondrial repair can be a quality saving process in aged cells. Furthermore, the model finds strategies to sustain the quality of the mitochondrial network in cells with high production rates of reactive oxygen species due to large energy demands. Hence, the model adds new insights to biophysical mechanisms of mitochondrial aging and provides novel understandings of the interdependency of mitochondrial processes.

  17. Frames, biases, and rational decision-making in the human brain.

    Science.gov (United States)

    De Martino, Benedetto; Kumaran, Dharshan; Seymour, Ben; Dolan, Raymond J

    2006-08-04

    Human choices are remarkably susceptible to the manner in which options are presented. This so-called "framing effect" represents a striking violation of standard economic accounts of human rationality, although its underlying neurobiology is not understood. We found that the framing effect was specifically associated with amygdala activity, suggesting a key role for an emotional system in mediating decision biases. Moreover, across individuals, orbital and medial prefrontal cortex activity predicted a reduced susceptibility to the framing effect. This finding highlights the importance of incorporating emotional processes within models of human choice and suggests how the brain may modulate the effect of these biasing influences to approximate rationality.

  18. Achievements and challenges in structural bioinformatics and computational biophysics.

    Science.gov (United States)

    Samish, Ilan; Bourne, Philip E; Najmanovich, Rafael J

    2015-01-01

    The field of structural bioinformatics and computational biophysics has undergone a revolution in the last 10 years. Developments that are captured annually through the 3DSIG meeting, upon which this article reflects. An increase in the accessible data, computational resources and methodology has resulted in an increase in the size and resolution of studied systems and the complexity of the questions amenable to research. Concomitantly, the parameterization and efficiency of the methods have markedly improved along with their cross-validation with other computational and experimental results. The field exhibits an ever-increasing integration with biochemistry, biophysics and other disciplines. In this article, we discuss recent achievements along with current challenges within the field. © The Author 2014. Published by Oxford University Press.

  19. Evolution and Biophysics of the Escherichia coli lac Operon

    Science.gov (United States)

    Ray, J. Christian; Igoshin, Oleg; Quan, Selwyn; Monds, Russell; Cooper, Tim; Balázsi, Gábor

    2011-03-01

    To understand, predict, and control the evolution of living organisms, we consider biophysical effects and molecular network architectures. The lactose utilization system of E. coli is among the most well-studied molecular networks in biology, making it an ideal candidate for such studies. Simulations show how the genetic architecture of the wild-type operon attenuates large metabolic intermediate fluctuations that are predicted to occur in an equivalent system with the component genes on separate operons. Quantification of gene expression in the lac operon evolved in growth conditions containing constant lactose, alternating with glucose, or constant glucose, shows characteristic gene expression patterns depending on conditions. We are simulating these conditions to show context-dependent biophysical sources and costs of different lac operon architectures.

  20. Limited rationality and strategic interaction

    DEFF Research Database (Denmark)

    Fehr, Ernst; Tyran, Jean-Robert

    2008-01-01

    Much evidence suggests that people are heterogeneous with regard to their abilities to make rational, forward-looking decisions. This raises the question as to when the rational types are decisive for aggregate outcomes and when the boundedly rational types shape aggregate results. We examine...... this question in the context of a long-standing and important economic problem: the adjustment of nominal prices after an anticipated monetary shock. Our experiments suggest that two types of bounded rationality-money illusion and anchoring-are important behavioral forces behind nominal inertia. However......, depending on the strategic environment, bounded rationality has vastly different effects on aggregate price adjustment. If agents' actions are strategic substitutes, adjustment to the new equilibrium is extremely quick, whereas under strategic complementarity, adjustment is both very slow and associated...

  1. Direct Scaling of Leaf-Resolving Biophysical Models from Leaves to Canopies

    Science.gov (United States)

    Bailey, B.; Mahaffee, W.; Hernandez Ochoa, M.

    2017-12-01

    Recent advances in the development of biophysical models and high-performance computing have enabled rapid increases in the level of detail that can be represented by simulations of plant systems. However, increasingly detailed models typically require increasingly detailed inputs, which can be a challenge to accurately specify. In this work, we explore the use of terrestrial LiDAR scanning data to accurately specify geometric inputs for high-resolution biophysical models that enables direct up-scaling of leaf-level biophysical processes. Terrestrial LiDAR scans generate "clouds" of millions of points that map out the geometric structure of the area of interest. However, points alone are often not particularly useful in generating geometric model inputs, as additional data processing techniques are required to provide necessary information regarding vegetation structure. A new method was developed that directly reconstructs as many leaves as possible that are in view of the LiDAR instrument, and uses a statistical backfilling technique to ensure that the overall leaf area and orientation distribution matches that of the actual vegetation being measured. This detailed structural data is used to provide inputs for leaf-resolving models of radiation, microclimate, evapotranspiration, and photosynthesis. Model complexity is afforded by utilizing graphics processing units (GPUs), which allows for simulations that resolve scales ranging from leaves to canopies. The model system was used to explore how heterogeneity in canopy architecture at various scales affects scaling of biophysical processes from leaves to canopies.

  2. The physics, biophysics and technology of photodynamic therapy

    International Nuclear Information System (INIS)

    Wilson, Brian C; Patterson, Michael S

    2008-01-01

    Photodynamic therapy (PDT) uses light-activated drugs to treat diseases ranging from cancer to age-related macular degeneration and antibiotic-resistant infections. This paper reviews the current status of PDT with an emphasis on the contributions of physics, biophysics and technology, and the challenges remaining in the optimization and adoption of this treatment modality. A theme of the review is the complexity of PDT dosimetry due to the dynamic nature of the three essential components-light, photosensitizer and oxygen. Considerable progress has been made in understanding the problem and in developing instruments to measure all three, so that optimization of individual PDT treatments is becoming a feasible target. The final section of the review introduces some new frontiers of research including low dose rate (metronomic) PDT, two-photon PDT, activatable PDT molecular beacons and nanoparticle-based PDT. (topical review)

  3. The physics, biophysics and technology of photodynamic therapy.

    Science.gov (United States)

    Wilson, Brian C; Patterson, Michael S

    2008-05-07

    Photodynamic therapy (PDT) uses light-activated drugs to treat diseases ranging from cancer to age-related macular degeneration and antibiotic-resistant infections. This paper reviews the current status of PDT with an emphasis on the contributions of physics, biophysics and technology, and the challenges remaining in the optimization and adoption of this treatment modality. A theme of the review is the complexity of PDT dosimetry due to the dynamic nature of the three essential components -- light, photosensitizer and oxygen. Considerable progress has been made in understanding the problem and in developing instruments to measure all three, so that optimization of individual PDT treatments is becoming a feasible target. The final section of the review introduces some new frontiers of research including low dose rate (metronomic) PDT, two-photon PDT, activatable PDT molecular beacons and nanoparticle-based PDT.

  4. The physics, biophysics and technology of photodynamic therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Brian C [Division of Biophysics and Bioimaging, Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, 610 University Avenue, Toronto, ON M5G 2M9 (Canada); Patterson, Michael S [Department of Medical Physics, Juravinski Cancer Centre and Department of Medical Physics and Applied Radiation Sciences, McMaster University, 699 Concession Street, Hamilton, ON L8V 5C2 (Canada)], E-mail: wilson@uhnres.utoronto.ca, E-mail: mike.patterson@jcc.hhsc.ca

    2008-05-07

    Photodynamic therapy (PDT) uses light-activated drugs to treat diseases ranging from cancer to age-related macular degeneration and antibiotic-resistant infections. This paper reviews the current status of PDT with an emphasis on the contributions of physics, biophysics and technology, and the challenges remaining in the optimization and adoption of this treatment modality. A theme of the review is the complexity of PDT dosimetry due to the dynamic nature of the three essential components-light, photosensitizer and oxygen. Considerable progress has been made in understanding the problem and in developing instruments to measure all three, so that optimization of individual PDT treatments is becoming a feasible target. The final section of the review introduces some new frontiers of research including low dose rate (metronomic) PDT, two-photon PDT, activatable PDT molecular beacons and nanoparticle-based PDT. (topical review)

  5. Interpolation of rational matrix functions

    CERN Document Server

    Ball, Joseph A; Rodman, Leiba

    1990-01-01

    This book aims to present the theory of interpolation for rational matrix functions as a recently matured independent mathematical subject with its own problems, methods and applications. The authors decided to start working on this book during the regional CBMS conference in Lincoln, Nebraska organized by F. Gilfeather and D. Larson. The principal lecturer, J. William Helton, presented ten lectures on operator and systems theory and the interplay between them. The conference was very stimulating and helped us to decide that the time was ripe for a book on interpolation for matrix valued functions (both rational and non-rational). When the work started and the first partial draft of the book was ready it became clear that the topic is vast and that the rational case by itself with its applications is already enough material for an interesting book. In the process of writing the book, methods for the rational case were developed and refined. As a result we are now able to present the rational case as an indepe...

  6. Introducing "biophysical redundancy": the global status and past evolution of unused water, land and productivity resources for food production

    Science.gov (United States)

    Fader, Marianela

    2017-04-01

    Countries have different resilience to sudden and long-term changes in food demand and supply. An important part of this resilience is the degree of biophysical redundancy, defined as the potential food production of 'spare land', available water resources (i.e., not already used for human activities), as well as production increases through yield gap closure on cultivated areas and potential agricultural areas. The presentation will show the results of a recently published paper1 on the evolution of biophysical redundancy for agricultural production at country level, from 1992 to 2012. Results indicate that in 2012, the biophysical redundancy of 75 (48) countries, mainly in North Africa, Western Europe, the Middle East and Asia, was insufficient to produce the caloric nutritional needs for at least 50% (25%) of their population during a year. Biophysical redundancy has decreased in the last two decades in 102 out of 155 countries, 11 of these went from high to limited redundancy, and nine of these from limited to very low redundancy. Although the variability of the drivers of change across different countries is high, improvements in yield and population growth have a clear impact on the decreases of redundancy towards the very low redundancy category. We took a more detailed look at countries classified as 'Low Income Economies (LIEs)' since they are particularly vulnerable to domestic or external food supply changes, due to their limited capacity to offset for food supply decreases with higher purchasing power on the international market. Currently, nine LIEs have limited or very low biophysical redundancy. Many of these showed a decrease in redundancy over the last two decades, which is not always linked with improvements in per capita food availability.

  7. Mutual Fund Flows and Performance in Rational Markets

    OpenAIRE

    Jonathan B. Berk; Richard C. Green

    2004-01-01

    We develop a simple rational model of active portfolio management that provides a natural benchmark against which to evaluate observed relationship between returns and fund flows. Many effects widely regarded as anomalous are consistent with this simple explanation. In the model, investments with active managers do not outperform passive benchmarks because of the competitive market for capital provision, combined with decreasing returns to scale in active portfolio management. Consequently, p...

  8. Separation of transient and oscillatory cerebral activities using over-complete rational dilation wavelet transforms

    International Nuclear Information System (INIS)

    Chaibi, S.; Lajnef, T.; Samet, M.; Kachouri, A.

    2011-01-01

    Many natural signals EEG are comprised frequency overlapping of oscillatory and transient components. In our study the intracranial EEG signals of epilepsy are composed of the superposition of oscillatory signals (HFOs: High Frequency oscillations) and a transient signals (spikes and sharp waves, etc.). The oscillatory components (HFOs) exist in the frequency band 80-500Hz. The transient components comes from nonrhythmic brain activities (spikes, sharp waves and vertex waves of varying amplitude, shape and duration) and cover a continuous wide bandwidth from low to high frequencies and resemble an HFOs events when filtered using a band pass classical filter. The classical filtering methods based on FIR filters, Wavelet transforms and the Matching Pursuit cannot separate the oscillatory from transient activities. This paper describes an approach for decomposing an iEEG signals of epilepsy into the sum of oscillatory components and a transient components based on overcomplete rational dilation wavelet transforms (overcomplete RADWT) in conjunction with morphological component analysis (MCA).

  9. History of Economic Rationalities

    DEFF Research Database (Denmark)

    This book concentrates upon how economic rationalities have been embedded into particular historical practices, cultures, and moral systems. Through multiple case-studies, situated in different historical contexts of the modern West, the book shows that the development of economic rationalities...... takes place in the meeting with other regimes of thought, values, and moral discourses. The book offers new and refreshing insights, ranging from the development of early economic thinking to economic aspects and concepts in the works of classical thinkers such as Thomas Hobbes, John Locke and Karl Marx......, to the role of economic reasoning in contemporary policies of art and health care. With economic rationalities as the read thread, the reader is offered a unique chance of historical self-awareness and recollection of how economic rationality became the powerful ideological and moral force that it is today....

  10. Biophysical characteristics reveal neural stem cell differentiation potential.

    Directory of Open Access Journals (Sweden)

    Fatima H Labeed

    Full Text Available Distinguishing human neural stem/progenitor cell (huNSPC populations that will predominantly generate neurons from those that produce glia is currently hampered by a lack of sufficient cell type-specific surface markers predictive of fate potential. This limits investigation of lineage-biased progenitors and their potential use as therapeutic agents. A live-cell biophysical and label-free measure of fate potential would solve this problem by obviating the need for specific cell surface markers.We used dielectrophoresis (DEP to analyze the biophysical, specifically electrophysiological, properties of cortical human and mouse NSPCs that vary in differentiation potential. Our data demonstrate that the electrophysiological property membrane capacitance inversely correlates with the neurogenic potential of NSPCs. Furthermore, as huNSPCs are continually passaged they decrease neuron generation and increase membrane capacitance, confirming that this parameter dynamically predicts and negatively correlates with neurogenic potential. In contrast, differences in membrane conductance between NSPCs do not consistently correlate with the ability of the cells to generate neurons. DEP crossover frequency, which is a quantitative measure of cell behavior in DEP, directly correlates with neuron generation of NSPCs, indicating a potential mechanism to separate stem cells biased to particular differentiated cell fates.We show here that whole cell membrane capacitance, but not membrane conductance, reflects and predicts the neurogenic potential of human and mouse NSPCs. Stem cell biophysical characteristics therefore provide a completely novel and quantitative measure of stem cell fate potential and a label-free means to identify neuron- or glial-biased progenitors.

  11. Biochemical and Biophysical Cues in Matrix Design for Chronic and Diabetic Wound Treatment.

    Science.gov (United States)

    Xiao, Yun; Ahadian, Samad; Radisic, Milica

    2017-02-01

    Progress in biomaterial science and engineering and increasing knowledge in cell biology have enabled us to develop functional biomaterials providing appropriate biochemical and biophysical cues for tissue regeneration applications. Tissue regeneration is particularly important to treat chronic wounds of people with diabetes. Understanding and controlling the cellular microenvironment of the wound tissue are important to improve the wound healing process. In this study, we review different biochemical (e.g., growth factors, peptides, DNA, and RNA) and biophysical (e.g., topographical guidance, pressure, electrical stimulation, and pulsed electromagnetic field) cues providing a functional and instructive acellular matrix to heal diabetic chronic wounds. The biochemical and biophysical signals generally regulate cell-matrix interactions and cell behavior and function inducing the tissue regeneration for chronic wounds. Some technologies and devices have already been developed and used in the clinic employing biochemical and biophysical cues for wound healing applications. These technologies can be integrated with smart biomaterials to deliver therapeutic agents to the wound tissue in a precise and controllable manner. This review provides useful guidance in understanding molecular mechanisms and signals in the healing of diabetic chronic wounds and in designing instructive biomaterials to treat them.

  12. Biophysical models of radiobiological effects

    International Nuclear Information System (INIS)

    Obaturov, G.M.

    1987-01-01

    Radiobiological effect models at different organization levels, developed by the author, are presented. Classification and analysis of concepts and biophysical models at molecular, genetic and cellular levels, developed by Soviet and foreign authors in comparison to inherent models, are conducted from the viewpoint of system approach to radiobiological processes and of modelling principles. Models are compared with each other, limits of their applicability and drawbacks are determined. Evaluation of the model truthfulness is conducted according to a number of criteria, ways of further investigations and experimental examination of some models are proposed

  13. Psychology and the Rationality of Emotion.

    Science.gov (United States)

    Clore, Gerald L

    2011-04-01

    Questions addressed by recent psychological research on emotion include questions about how thought shapes emotion and how emotion, in turn, shapes thought. Research on emotion and cognition paints a somewhat different picture than that seen in traditional discussions of passion and reason. This article reviews several aspects of this research, concentrating specifically on three views of rationality: Rationality as Process, Rationality as Product, and Rationality as Outcome.

  14. Psychology and the Rationality of Emotion*

    OpenAIRE

    Clore, Gerald L.

    2011-01-01

    Questions addressed by recent psychological research on emotion include questions about how thought shapes emotion and how emotion, in turn, shapes thought. Research on emotion and cognition paints a somewhat different picture than that seen in traditional discussions of passion and reason. This article reviews several aspects of this research, concentrating specifically on three views of rationality: Rationality as Process, Rationality as Product, and Rationality as Outcome.

  15. Mechanoresponsive stem cells to target cancer metastases through biophysical cues.

    Science.gov (United States)

    Liu, Linan; Zhang, Shirley X; Liao, Wenbin; Farhoodi, Henry P; Wong, Chi W; Chen, Claire C; Ségaliny, Aude I; Chacko, Jenu V; Nguyen, Lily P; Lu, Mengrou; Polovin, George; Pone, Egest J; Downing, Timothy L; Lawson, Devon A; Digman, Michelle A; Zhao, Weian

    2017-07-26

    Despite decades of effort, little progress has been made to improve the treatment of cancer metastases. To leverage the central role of the mechanoenvironment in cancer metastasis, we present a mechanoresponsive cell system (MRCS) to selectively identify and treat cancer metastases by targeting the specific biophysical cues in the tumor niche in vivo. Our MRCS uses mechanosensitive promoter-driven mesenchymal stem cell (MSC)-based vectors, which selectively home to and target cancer metastases in response to specific mechanical cues to deliver therapeutics to effectively kill cancer cells, as demonstrated in a metastatic breast cancer mouse model. Our data suggest a strong correlation between collagen cross-linking and increased tissue stiffness at the metastatic sites, where our MRCS is specifically activated by the specific cancer-associated mechano-cues. MRCS has markedly reduced deleterious effects compared to MSCs constitutively expressing therapeutics. MRCS indicates that biophysical cues, specifically matrix stiffness, are appealing targets for cancer treatment due to their long persistence in the body (measured in years), making them refractory to the development of resistance to treatment. Our MRCS can serve as a platform for future diagnostics and therapies targeting aberrant tissue stiffness in conditions such as cancer and fibrotic diseases, and it should help to elucidate mechanobiology and reveal what cells "feel" in the microenvironment in vivo. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  16. Testing bounded rationality against full rationality in job changing behavior

    OpenAIRE

    Contini, Bruno; Morini, Matteo

    2007-01-01

    In this paper we question the hypothesis of full rationality in the context of job changing behaviour, via simple econometric explorations on microdata drawn from WHIP (Worker Histories Italian Panel). Workers' performance is compared at the end of a three-year time window that starts when choices are expressed, under the accepted notion that the main driving forces of job change are future real wages and expected job quality. Bounded rationality suggests that individuals will search for new ...

  17. Testing Bounded Rationality Against Full Rationality in Job Changing Behavior

    OpenAIRE

    Bruno Contini

    2008-01-01

    In this paper I question the hypothesis of full rationality in the context of job changing behaviour, via simple econometric explorations on microdata drawn from WHIP (Worker Histories Italian Panel). Workers’ performance is compared at the end of a three-year time window that starts when choices are expressed, under the accepted notion that the main driving forces of job change are future real wages and expected job quality. Bounded rationality suggests that individuals will search for new o...

  18. Biophysics of DNA

    CERN Document Server

    Vologodskii, Alexander

    2015-01-01

    Surveying the last sixty years of research, this book describes the physical properties of DNA in the context of its biological functioning. It is designed to enable both students and researchers of molecular biology, biochemistry and physics to better understand the biophysics of DNA, addressing key questions and facilitating further research. The chapters integrate theoretical and experimental approaches, emphasising throughout the importance of a quantitative knowledge of physical properties in building and analysing models of DNA functioning. For example, the book shows how the relationship between DNA mechanical properties and the sequence specificity of DNA-protein binding can be analyzed quantitatively by using our current knowledge of the physical and structural properties of DNA. Theoretical models and experimental methods in the field are critically considered to enable the reader to engage effectively with the current scientific literature on the physical properties of DNA.

  19. Biophysics at the Boundaries: The Next Problem Sets

    Science.gov (United States)

    Skolnick, Malcolm

    2009-03-01

    The interface between physics and biology is one of the fastest growing subfields of physics. As knowledge of such topics as cellular processes and complex ecological systems advances, researchers have found that progress in understanding these and other systems requires application of more quantitative approaches. Today, there is a growing demand for quantitative and computational skills in biological research and the commercialization of that research. The fragmented teaching of science in our universities still leaves biology outside the quantitative and mathematical culture that is the foundation of physics. This is particularly inopportune at a time when the needs for quantitative thinking about biological systems are exploding. More physicists should be encouraged to become active in research and development in the growing application fields of biophysics including molecular genetics, biomedical imaging, tissue generation and regeneration, drug development, prosthetics, neural and brain function, kinetics of nonequilibrium open biological systems, metabolic networks, biological transport processes, large-scale biochemical networks and stochastic processes in biochemical systems to name a few. In addition to moving into basic research in these areas, there is increasing opportunity for physicists in industry beginning with entrepreneurial roles in taking research results out of the laboratory and in the industries who perfect and market the inventions and developments that physicists produce. In this talk we will identify and discuss emerging opportunities for physicists in biophysical and biotechnological pursuits ranging from basic research through development of applications and commercialization of results. This will include discussion of the roles of physicists in non-traditional areas apart from academia such as patent law, financial analysis and regulatory science and the problem sets assigned in education and training that will enable future

  20. Psychology and the Rationality of Emotion*

    Science.gov (United States)

    Clore, Gerald L.

    2014-01-01

    Questions addressed by recent psychological research on emotion include questions about how thought shapes emotion and how emotion, in turn, shapes thought. Research on emotion and cognition paints a somewhat different picture than that seen in traditional discussions of passion and reason. This article reviews several aspects of this research, concentrating specifically on three views of rationality: Rationality as Process, Rationality as Product, and Rationality as Outcome. PMID:25125770

  1. Radiation levels in samples of dicalcium phosphate (DCP) and bovine and poultry rations by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Luz Filho, Isaias Venancio da; Scheibel, Viviane; Appoloni, Carlos Roberto

    2009-01-01

    The objective of the present work is to determine the radiation levels found in bovine rations and in the dicalcium phosphate (DCP) feed supplement. Knowledge of the radiation levels in samples of rations and DCP for cattle is important, because they are directly and indirectly-part of the human diet. In order to obtain this data, gamma-ray spectrometry technique was used, employing a HPGe detector of 66% of relative efficiency, with an energy resolution of 2.03 KeV for the 60 Co 1332.46 KeV line. The radioactive activity of the radionuclides 40 K, 137 Cs, 238 U, 232 Th and its respective decay series was measured. The accommodation recipient of the samples was a Marinelli beaker of 1 L. The 238 U series activities were calculated through 214 Pb and 214 Bi activities, and the 232 Th series' activity was calculated through the 228 Ac, 212 Pb, 212 Bi and 208 Tl values. The DCP samples and the rations measured in this work were produced in Londrina city, Brazil, in the second semester of 2007. Among the rations, the largest 40 K and 228 Ra activities were found in the ration sample for milk cattle, 402 ± 14 and 1.71 ± 0.10 Bq/kg, respectively. The ration for beef cattle yielded the largest activity for 226 Ra, 1.51 + 0.93 Bq/kg. In the DCP sample, the activities for the 238 U, 40 K and 232 Th were respectively 83 ± 26; 46.6 ± 2.8 and 7.79 ± 0.70 Bq/kg. The MDA values for 137 Cs varied from 0.037 to 0.29 Bq/kg. (author)

  2. DISTRIBUTED RC NETWORKS WITH RATIONAL TRANSFER FUNCTIONS,

    Science.gov (United States)

    A distributed RC circuit analogous to a continuously tapped transmission line can be made to have a rational short-circuit transfer admittance and...one rational shortcircuit driving-point admittance. A subcircuit of the same structure has a rational open circuit transfer impedance and one rational ...open circuit driving-point impedance. Hence, rational transfer functions may be obtained while considering either generator impedance or load

  3. Biophysical approach to low back pain: a pilot report

    Czech Academy of Sciences Publication Activity Database

    Foletti, A.; Pokorný, Jiří

    2015-01-01

    Roč. 34, č. 2 (2015), s. 156-159 ISSN 1536-8378 Institutional support: RVO:67985882 Keywords : Bioelectromagnetic medicine * Biophysical therapy * Coherence domains Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.208, year: 2015

  4. Max Weber's Types of Rationality: Cornerstones for the Analysis of Rationalization Processes in History.

    Science.gov (United States)

    Kalberg, Stephen

    1980-01-01

    Explores rationality in Max Weber's works and identifies four types of rationality which play major roles in his writing--practical, theoretical, substantive, and formal. Implications for society and education are discussed. (DB)

  5. The concept of rational suicide.

    Science.gov (United States)

    Mayo, D J

    1986-05-01

    Suicide has been condemned in our culture in one way or another since Augustine offered theological arguments against it in the sixth century. More recently, theological condemnation has given way to the view that suicidal behavior must always be symptomatic of emotional disturbance and mental illness. However, suicide has not always been viewed so negatively. In other times and cultures, it has been held that circumstances might befall a person in which suicide would be a perfectly rational course of action, in the same sense that any other course of action could be rational: that it could be sensible, i.e., defensible by good reasons, or that it could be in keeping with the agent's fundamental interests. Indiscriminate use of modern life-sustaining technologies has renewed interest in the possibility of rational suicide. Today proponents of rational suicide tend to equate the rationality of suicide with the competence of the decision to commit suicide.

  6. RATGRAPH: Computer Graphing of Rational Functions.

    Science.gov (United States)

    Minch, Bradley A.

    1987-01-01

    Presents an easy-to-use Applesoft BASIC program that graphs rational functions and any asymptotes that the functions might have. Discusses the nature of rational functions, graphing them manually, employing a computer to graph rational functions, and describes how the program works. (TW)

  7. F-theory and all things rational: surveying U(1) symmetries with rational sections

    International Nuclear Information System (INIS)

    Lawrie, Craig; Schäfer-Nameki, Sakura; Wong, Jin-Mann

    2015-01-01

    We study elliptic fibrations for F-theory compactifications realizing 4d and 6d supersymmetric gauge theories with abelian gauge factors. In the fibration these U(1) symmetries are realized in terms of additional rational section. We obtain a universal characterization of all the possible U(1) charges of matter fields by determining the corresponding codimension two fibers with rational sections. In view of modelling supersymmetric Grand Unified Theories, one of the main examples that we analyze are U(1) symmetries for SU(5) gauge theories with 5̄ and 10 matter. We use a combination of constraints on the normal bundle of rational curves in Calabi-Yau three- and four-folds, as well as the splitting of rational curves in the fibers in codimension two, to determine the possible configurations of smooth rational sections. This analysis straightforwardly generalizes to multiple U(1)s. We study the flops of such fibers, as well as some of the Yukawa couplings in codimension three. Furthermore, we carry out a universal study of the U(1)-charged GUT singlets, including their KK-charges, and determine all realizations of singlet fibers. By giving vacuum expectation values to these singlets, we propose a systematic way to analyze the Higgsing of U(1)s to discrete gauge symmetries in F-theory.

  8. "Leaky" Rationality: How Research on Behavioral Decision Making Challenges Normative Standards of Rationality.

    Science.gov (United States)

    Keys, Daniel J; Schwartz, Barry

    2007-06-01

    For more than 30 years, decision-making research has documented that people often violate various principles of rationality, some of which are so fundamental that theorists of rationality rarely bother to state them. We take these characteristics of decision making as a given but argue that it is problematic to conclude that they typically represent departures from rationality. The very psychological processes that lead to "irrational" decisions (e.g., framing, mental accounting) continue to exert their influence when one experiences the results of the decisions. That is, psychological processes that affect decisions may be said also to "leak" into one's experience. The implication is that formal principles of rationality do not provide a good enough normative standard against which to assess decision making. Instead, what is needed is a substantive theory of rationality-one that takes subjective experience seriously, considers both direct and indirect consequences of particular decisions, considers how particular decisions fit into life as a whole, and considers the effects of decisions on others. Formal principles may play a role as approximations of the substantive theory that can be used by theorists and decision makers in cases in which the formal principles can capture most of the relevant considerations and leakage into experience is negligible. © 2007 Association for Psychological Science.

  9. Popper, Rationality and the Possibility of Social Science

    Directory of Open Access Journals (Sweden)

    Danny Frederick

    2013-02-01

    Full Text Available Social science employs teleological explanations which depend upon the rationality principle, according to which people exhibit instrumental rationality. Popper points out that people also exhibit critical rationality, the tendency to stand back from, and to question or criticise, their views. I explain how our critical rationality impugns the explanatory value of the rationality principle and thereby threatens the very possibility of social science. I discuss the relationship between instrumental and critical rationality and show how we can reconcile our critical rationality with the possibility of social science if we invoke Popper’s conception of limited rationality and his indeterminism.

  10. Ethics of rationing of nursing care.

    Science.gov (United States)

    Rooddehghan, Zahra; Yekta, Zohreh Parsa; Nasrabadi, Alireza N

    2016-09-21

    Rationing of various needed services, for example, nursing care, is inevitable due to unlimited needs and limited resources. Rationing of nursing care is considered an ethical issue since it requires judgment about potential conflicts between personal and professional values. The present research sought to explore aspects of rationing nursing care in Iran. This study applied qualitative content analysis, a method to explore people's perceptions of everyday life phenomena and interpret the subjective content of text data. Data collection was performed through in-depth, unstructured, face-to-face interviews with open-ended questions. The study population included Iranian nurses of all nursing positions, from clinical nurses to nurse managers. Purposive sampling was employed to select 15 female and 3 male nurses (11 clinical nurses, 3 supervisors, 1 matron, 1 nurse, and 2 members of the Nursing Council) working in hospitals of three cities in Iran. The study protocol was approved by Tehran University of Medical Sciences (91D1302870). Written informed consent was also obtained from all participants. According to the participants, rationing of nursing care consisted of two categories, that is, causes of rationing and consequences of rationing. The first category comprised three subcategories, namely, patient needs and demands, routinism, and VIP patients. The three subcategories forming the second category were missed nursing care, patient dissatisfaction, and nurses' feeling of guilt. Levels at which healthcare practices are rationed and clarity of the rationing are important structural considerations in the development of an equal, appropriate, and ethical healthcare system. Moreover, the procedure of rationing is critical as it not only influences people's lives but also reflects the values that dominate in the society. Therefore, in order to minimize the negative consequences of rationing of nursing care, further studies on the ethical dimensions of this phenomenon

  11. Casebook on rationalization of power use

    International Nuclear Information System (INIS)

    1986-06-01

    This book introduces the cases on rationalization of power use, which is divided into four parts. The first part refers the goal of rational use of energy and the result. The second part deals with the excellent cases on rationalization of domestic power use, which list the name of the company, hotel and factory according to the field such as building, textile and food. The third part contains the outstanding cases on rationalization of foreign power use, which were listed by the specific way to reduce electricity use each section. The fourth part is comprised of two chapters, which deals with the cases of domestic technical data and foreign technical data for rational use of energy.

  12. Probabilistic approach to rationalization of plants maintenance

    International Nuclear Information System (INIS)

    Kasai, Masao; Notoya, Junichi; Uchimoto, Tetsuya; Miya, Kenzo

    2001-01-01

    Since there are a lot of equipments in large plants, their safety and reliability cannot be kept as high level as designed without maintenance activities. Then preventive maintenance is intensively executed in some large plants. However, it will be inefficient to perform the preventive maintenance blindly. To make maintenance activities effective, it is essential to identify the critical equipments influencing plant safety and/or reliability and carry out the maintenance by focusing attentions on these equipments. It needs quantitative analyses to identify the critical equipments based on the data of failure rates. However, complete data set of failure rates cannot necessarily be available for some plants such as nuclear power plants. In this study, we carry out the reliability analysis for generic LNG plant and calculate various quantitative risk importance measures for each equipment. We propose rather qualitative representations for some quantitative measures, considering the situation without complete data set and conclude that it is possible to rationalize maintenance procedure by using these rather qualitative measures, though the level of rationalization is of course limited. (author)

  13. Theoretical molecular biophysics

    CERN Document Server

    Scherer, Philipp O J

    2017-01-01

    This book gives an introduction to molecular biophysics. It starts from material properties at equilibrium related to polymers, dielectrics and membranes. Electronic spectra are developed for the understanding of elementary dynamic processes in photosynthesis including proton transfer and dynamics of molecular motors. Since the molecular structures of functional groups of bio-systems were resolved, it has become feasible to develop a theory based on the quantum theory and statistical physics with emphasis on the specifics of the high complexity of bio-systems. This introduction to molecular aspects of the field focuses on solvable models. Elementary biological processes provide as special challenge the presence of partial disorder in the structure which does not destroy the basic reproducibility of the processes. Apparently the elementary molecular processes are organized in a way to optimize the efficiency. Learning from nature by means exploring the relation between structure and function may even help to b...

  14. Biophysical dosimetry using electron paramagnetic resonance in human tooth

    International Nuclear Information System (INIS)

    Khan, R.F.H.; Boreham, D.R.; Rink, W.J.

    2002-01-01

    Accidental dosimetry utilizing radiation induced paramagnetic species in biophysical tissues like teeth is a technique; that can measure the amount of radiation exposure to an individual. The major problem in implementing this technique at low doses is the presence of native organic signal, and various other artifacts produced as a result of sample processing. After a series of experimental trials, we developed an optimum set of rules, which uses high temperature ultrasonic treatment of enamel in KOH, multiple sample rotation during in-cavity measurement of natural and calibrated added irradiations, and dose construction using a backward extrapolation method. By using this we report the successful dose reconstruction in a few of our laboratory samples in 100 mGy range (76.29 ± 30.14) mGy with reasonably low uncertainty. Keywords: biophysical dosimetry, human tooth enamel, low dose measurements, accidental dosimetry (author)

  15. Radiation levels in samples of dicalcium phosphate (DCP) and bovine and poultry rations by gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Luz Filho, Isaias Venancio da; Scheibel, Viviane; Appoloni, Carlos Roberto, E-mail: isaiasfilhojr@yahoo.com.b [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. de Fisica

    2009-07-01

    The objective of the present work is to determine the radiation levels found in bovine rations and in the dicalcium phosphate (DCP) feed supplement. Knowledge of the radiation levels in samples of rations and DCP for cattle is important, because they are directly and indirectly-part of the human diet. In order to obtain this data, gamma-ray spectrometry technique was used, employing a HPGe detector of 66% of relative efficiency, with an energy resolution of 2.03 KeV for the {sup 60}Co 1332.46 KeV line. The radioactive activity of the radionuclides {sup 40}K, {sup 137}Cs, {sup 238}U, {sup 232}Th and its respective decay series was measured. The accommodation recipient of the samples was a Marinelli beaker of 1 L. The {sup 238}U series activities were calculated through {sup 214}Pb and {sup 214}Bi activities, and the {sup 232}Th series' activity was calculated through the {sup 228}Ac, {sup 212}Pb, {sup 212}Bi and {sup 208}Tl values. The DCP samples and the rations measured in this work were produced in Londrina city, Brazil, in the second semester of 2007. Among the rations, the largest {sup 40}K and {sup 228}Ra activities were found in the ration sample for milk cattle, 402 +- 14 and 1.71 +- 0.10 Bq/kg, respectively. The ration for beef cattle yielded the largest activity for {sup 226}Ra, 1.51 + 0.93 Bq/kg. In the DCP sample, the activities for the {sup 238}U, {sup 40}K and {sup 232}Th were respectively 83 +- 26; 46.6 +- 2.8 and 7.79 +- 0.70 Bq/kg. The MDA values for {sup 137}Cs varied from 0.037 to 0.29 Bq/kg. (author)

  16. From rational creatures to the rational Creator: ancient and patristic analogies of the “fine-tuning” argument

    Directory of Open Access Journals (Sweden)

    Alexey Fokin

    2017-12-01

    Full Text Available In this article the author deals with the proofs of the existence of God, based on the fact of the presence of rational beings in the world. These proofs can be found in Greek and Roman Classical philosophy and early Patristics, and can be viewed as an analogue of the modern “fine-tuning argument”. The author considers the origins and development of this argument in the Greek and Roman philosophy: in Socrates, Plato, Cicero, Sextus Empiricus, and especially the Stoics, who gave to the argument a logical form, based on the relationship between “the parts and the whole”: if the world as a whole produces and contains rational beings as its parts, it should also be rational or contain a rational principle that generates all its parts and governs them, just as human soul governs human body. The correction of this argument was proposed by Sextus Empiricus, who introduced the concept of "spermatic logoi", or rational principles, to explain the generation of the rational beings by the world, so that if the world contains the spermatic logoi of rational and living beings, then the world as a whole is also rational. The author also investigates the reception of the argument based on the existence of rational beings in the world in Latin Patristics: in Minucius Felix, Tertullian and especially Lactantius, in whom this argument has reached the climax of its development. At the same time it was shown, that the ancient argument has undergone a transformation from the postulation of the rationality of the world as a whole or its equation with God himself to a genuine proof of the existence of the one God who is the Creator both of the world and human beings, superior to the both as the all-powerful and transcendent Mind.

  17. Rationing medical education | Walsh | African Health Sciences

    African Journals Online (AJOL)

    Even though some stakeholders in medical education might be taken aback at the prospect of rationing, the truth is that rationing has always occurred in one form or another in medical education and in healthcare more broadly. Different types of rationing exist in healthcare professional education. For example rationing may ...

  18. Effects of Rational-Emotive Therapy, Rational Role Reversal, and Rational-Emotive Imagery on the Emotional Adjustment of Community Mental Health Center Patients.

    Science.gov (United States)

    Lipsky, Marc J.; And Others

    1980-01-01

    Results showed that rational-emotive therapy (RET), with the addition of rational role reversal, produced significantly better results than did relaxation training and support or no contact. This was the first study to demonstrate the efficacy of RET with multisymptomatic applicants to a community mental health center. (Author/BEF)

  19. A biophysical approach to the optimisation of dendritic-tumour cell electrofusion

    International Nuclear Information System (INIS)

    Sukhorukov, Vladimir L.; Reuss, Randolph; Endter, Joerg M.; Fehrmann, Steffen; Katsen-Globa, Alisa; Gessner, Petra; Steinbach, Andrea; Mueller, Kilian J.; Karpas, Abraham; Zimmermann, Ulrich; Zimmermann, Heiko

    2006-01-01

    Electrofusion of tumour and dendritic cells (DCs) is a promising approach for production of DC-based anti-tumour vaccines. Although human DCs are well characterised immunologically, little is known about their biophysical properties, including dielectric and osmotic parameters, both of which are essential for the development of efficient electrofusion protocols. In the present study, human DCs from the peripheral blood along with a tumour cell line used as a model fusion partner were examined by means of time-resolved cell volumetry and electrorotation. Based on the biophysical cell data, the electrofusion protocol could be rapidly optimised with respect to the sugar composition of the fusion medium, duration of hypotonic treatment, frequency range for stable cell alignment, and field strengths of breakdown pulses triggering membrane fusion. The hypotonic electrofusion consistently gave a tumour-DC hybrid rate of up to 19%, as determined by counting dually labelled fluorescent hybrids in a microscope. This fusion rate is nearly twice as high as that usually reported in the literature for isotonic media. The experimental findings and biophysical approach presented here are generally useful for the development of efficient electrofusion protocols, especially for rare and valuable human cells

  20. Rational Thinking in School-Based Practice

    Science.gov (United States)

    Clark, Mary Kristen; Flynn, Perry

    2011-01-01

    Purpose: We reflect on Alan Kamhi's (2011) prologue on balancing certainty and uncertainty as it pertains to school-based practice. Method: In schools, rational thinking depends on effective team processes, much like professional learning communities. We consider the conditions that are required for rational thinking and how rational team dialogue…

  1. Seminal Fluid Analysis And Biophysical Profile: Findings And ...

    African Journals Online (AJOL)

    Seminal Fluid Analysis And Biophysical Profile: Findings And Relevance In Infertile Males In Ilorin, Nigeria. EK Oghagbon, AAG Jimoh, SA Adebisi. Abstract. To determine if there was a bearing of body mass index (BMI) on male infertility, a cross-sectional study of males of infertile couples, attending our infertility clinic was ...

  2. Climate Change Effects on Agriculture: Economic Responses to Biophysical Shocks

    Science.gov (United States)

    Nelson, Gerald C.; Valin, Hugo; Sands, Ronald D.; Havlik, Petr; Ahammad, Helal; Deryng, Delphine; Elliott, Joshua; Fujimori, Shinichiro; Hasegawa, Tomoko; Heyhoe, Edwina

    2014-01-01

    Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change's representative concentration pathway with end-of-century radiative forcing of 8.5 W/m(sup 2). The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change.

  3. Rationality in Machiavelli and in Kant

    Directory of Open Access Journals (Sweden)

    Vadim Chaly

    2016-11-01

    Full Text Available The paper contains interpretation and comparative analysis of Machiavelli’s and Kant’s conceptions on rationality as two prime examples of “realist” and “idealist” modes of agency. Kantian model of rationality is viewed as an augmentation of the Machiavellian one, not an opposition to it. To elaborate the point, Robert Aumann’s model of act-rationality and rulerationality is applied to the two philosophical models. Kantian practical reason is interpreted as an addition to Aumann’s instrumental rationality, providing rules for rules, or “rule-rule-rationality”.

  4. An ethnographic study: Becoming a physics expert in a biophysics research group

    Science.gov (United States)

    Rodriguez, Idaykis

    Expertise in physics has been traditionally studied in cognitive science, where physics expertise is understood through the difference between novice and expert problem solving skills. The cognitive perspective of physics experts only create a partial model of physics expertise and does not take into account the development of physics experts in the natural context of research. This dissertation takes a social and cultural perspective of learning through apprenticeship to model the development of physics expertise of physics graduate students in a research group. I use a qualitative methodological approach of an ethnographic case study to observe and video record the common practices of graduate students in their biophysics weekly research group meetings. I recorded notes on observations and conduct interviews with all participants of the biophysics research group for a period of eight months. I apply the theoretical framework of Communities of Practice to distinguish the cultural norms of the group that cultivate physics expert practices. Results indicate that physics expertise is specific to a topic or subfield and it is established through effectively publishing research in the larger biophysics research community. The participant biophysics research group follows a learning trajectory for its students to contribute to research and learn to communicate their research in the larger biophysics community. In this learning trajectory students develop expert member competencies to learn to communicate their research and to learn the standards and trends of research in the larger research community. Findings from this dissertation expand the model of physics expertise beyond the cognitive realm and add the social and cultural nature of physics expertise development. This research also addresses ways to increase physics graduate student success towards their PhD. and decrease the 48% attrition rate of physics graduate students. Cultivating effective research

  5. Representing biophysical landscape interactions in soil models by bridging disciplines and scales.

    Science.gov (United States)

    van der Ploeg, M. J.; Carranza, C.; Teixeira da Silva, R.; te Brake, B.; Baartman, J.; Robinson, D.

    2017-12-01

    The combination of climate change, population growth and soil threats including carbon loss, biodiversity decline and erosion, increasingly confront the global community (Schwilch et al., 2016). One major challenge in studying processes involved in soil threats, landscape resilience, ecosystem stability, sustainable land management and resulting economic consequences, is that it is an interdisciplinary field (Pelletier et al., 2012). Less stringent scientific disciplinary boundaries are therefore important (Liu et al., 2007), because as a result of disciplinary focus, ambiguity may arise on the understanding of landscape interactions. This is especially true in the interaction between a landscape's physical and biological processes (van der Ploeg et al. 2012). Biophysical landscape interactions are those biotic and abiotic processes in a landscape that have an influence on the developments within and evolution of a landscape. An important aspect in biophysical landscape interactions is the differences in scale related to the various processes that play a role in these systems. Moreover, the interplay between the physical landscape and the occurring vegetation, which often co-evolve, and the resulting heterogeneity and emerging patterns are the reason why it is so challenging to establish a theoretical basis to describe biophysical processes in landscapes (e.g. te Brake et al. 2013, Robinson et al. 2016). Another complicating factor is the response of vegetation to changing environmental conditions, including a possible, and often unknown, time-lag (e.g. Metzger et al., 2009). An integrative description for modelling biophysical interactions has been a long standing goal in soil science (Vereecken et al., 2016). We need the development of soil models that are more focused on networks, connectivity and feedbacks incorporating the most important aspects of our detailed mechanistic modelling (Paola & Leeder, 2011). Additionally, remote sensing measurement techniques

  6. Effective Entrepreneurial Choice: The Role of Rationality and Non-Rationality in Three Entrepreneurs Success Stories

    OpenAIRE

    Chong, Anne Michele, Siang Yoon

    2007-01-01

    Good entrepreneurship is important for economic growth and productivity in any modern economy. The purpose of this dissertation is to research how good entrepreneurial decisions are made. In theory, optimal or rational decision making means choosing the best alternative in response to the problem. However, in reality, people do not act rationally because they often cannot make rational choices. The reason is that people do not have enough brain power, time or resources to process the compl...

  7. Adolescents' AIDS Risk Taking: A Rational Choice Perspective.

    Science.gov (United States)

    Gardner, William; Herman, Janna

    1990-01-01

    Discounts the belief in adolescents' irrational behavior, and proposes a rational choice decision-making theory of adolescent risk-taking behavior. Suggests that social ecology affects risk-taking choices. Proposals for AIDS education concern delayed initiation of sexual activity, promotion of condom use, and counseling of high-risk adolescents.…

  8. Biophysical characterization of the Lactobacillus delbrueckii subsp. bulgaricus membrane during cold and osmotic stress and its relevance for cryopreservation.

    Science.gov (United States)

    Meneghel, Julie; Passot, Stéphanie; Dupont, Sébastien; Fonseca, Fernanda

    2017-02-01

    Freezing lactic acid bacteria often leads to cell death and loss of technological properties. Our objective was to provide an in-depth characterization of the biophysical properties of the Lactobacillus delbrueckii subsp. bulgaricus membrane in relation to its freeze resistance. Freezing was represented as a combination of cold and osmotic stress. This work investigated the relative incidence of increasing sucrose concentrations coupled or not with subzero temperatures without ice nucleation on the biological and biophysical responses of two strains with different membrane fatty acid compositions and freeze resistances. Following exposure of bacterial cells to the highest sucrose concentration, the sensitive strain exhibited a survival rate of less than 10 % and 5 h of acidifying activity loss. Similar biological activity losses were observed upon freeze-thawing and after osmotic treatment for each strain thus highlighting osmotic stress as the main source of cryoinjury. The direct measurement of membrane fluidity by fluorescence anisotropy was linked to membrane lipid organization characterized by FTIR spectroscopy. Both approaches made it possible to investigate the specific contributions of the membrane core and the bilayer external surface to cell degradation caused by cold and osmotic stress. Cold-induced membrane rigidification had no significant implication on bacterial freeze-thaw resistance. Interactions between extracellular sucrose and membrane phospholipid headgroups under osmotic stress were also observed. Such interactions were more evident in the sensitive strain and when increasing sucrose concentration, thus suggesting membrane permeabilization. The relevance of biophysical properties for elucidating mechanisms of cryoinjury and cryoprotection is discussed.

  9. Biophysical constraints on leaf expansion in a tall conifer.

    Science.gov (United States)

    Fredrick C. Meinzer; Barbara J. Bond; Jennifer A. Karanian

    2008-01-01

    The physiological mechanisms responsible for reduced extension growth as trees increase in height remain elusive. We evaluated biophysical constraints on leaf expansion in old-growth Douglas-fir (Psuedotsuga menziesii (Mirb.) Franco) trees. Needle elongation rates, plastic and elastic extensibility, bulk leaf water, (L...

  10. Cellular biophysics during freezing of rat and mouse sperm predicts post-thaw motility.

    Science.gov (United States)

    Hagiwara, Mie; Choi, Jeung Hwan; Devireddy, Ramachandra V; Roberts, Kenneth P; Wolkers, Willem F; Makhlouf, Antoine; Bischof, John C

    2009-10-01

    Though cryopreservation of mouse sperm yields good survival and motility after thawing, cryopreservation of rat sperm remains a challenge. This study was designed to evaluate the biophysics (membrane permeability) of rat in comparison to mouse to better understand the cooling rate response that contributes to cryopreservation success or failure in these two sperm types. In order to extract subzero membrane hydraulic permeability in the presence of ice, a differential scanning calorimeter (DSC) method was used. By analyzing rat and mouse sperm frozen at 5 degrees C/min and 20 degrees C/min, heat release signatures characteristic of each sperm type were obtained and correlated to cellular dehydration. The dehydration response was then fit to a model of cellular water transport (dehydration) by adjusting cell-specific biophysical (membrane hydraulic permeability) parameters L(pg) and E(Lp). A "combined fit" (to 5 degrees C/min and 20 degrees C/min data) for rat sperm in Biggers-Whitten-Whittingham media yielded L(pg) = 0.007 microm min(-1) atm(-1) and E(Lp) = 17.8 kcal/mol, and in egg yolk cryopreservation media yielded L(pg) = 0.005 microm min(-1) atm(-1) and E(Lp) = 14.3 kcal/mol. These parameters, especially the activation energy, were found to be lower than previously published parameters for mouse sperm. In addition, the biophysical responses in mouse and rat sperm were shown to depend on the constituents of the cryopreservation media, in particular egg yolk and glycerol. Using these parameters, optimal cooling rates for cryopreservation were predicted for each sperm based on a criteria of 5%-15% normalized cell water at -30 degrees C during freezing in cryopreservation media. These predicted rates range from 53 degrees C/min to 70 degrees C/min and from 28 degrees C/min to 36 degrees C/min in rat and mouse, respectively. These predictions were validated by comparison to experimentally determined cryopreservation outcomes, in this case based on motility. Maximum

  11. Communicative versus strategic rationality: Habermas theory of communicative action and the social brain.

    Science.gov (United States)

    Schaefer, Michael; Heinze, Hans-Jochen; Rotte, Michael; Denke, Claudia

    2013-01-01

    In the philosophical theory of communicative action, rationality refers to interpersonal communication rather than to a knowing subject. Thus, a social view of rationality is suggested. The theory differentiates between two kinds of rationality, the emancipative communicative and the strategic or instrumental reasoning. Using experimental designs in an fMRI setting, recent studies explored similar questions of reasoning in the social world and linked them with a neural network including prefrontal and parietal brain regions. Here, we employed an fMRI approach to highlight brain areas associated with strategic and communicative reasoning according to the theory of communicative action. Participants were asked to assess different social scenarios with respect to communicative or strategic rationality. We found a network of brain areas including temporal pole, precuneus, and STS more activated when participants performed communicative reasoning compared with strategic thinking and a control condition. These brain regions have been previously linked to moral sensitivity. In contrast, strategic rationality compared with communicative reasoning and control was associated with less activation in areas known to be related to moral sensitivity, emotional processing, and language control. The results suggest that strategic reasoning is associated with reduced social and emotional cognitions and may use different language related networks. Thus, the results demonstrate experimental support for the assumptions of the theory of communicative action.

  12. Guidance for Large-scale Implementation of Alternate Wetting and Drying: A Biophysical Suitability Assessment

    Science.gov (United States)

    Sander, B. O.; Wassmann, R.; Nelson, A.; Palao, L.; Wollenberg, E.; Ishitani, M.

    2014-12-01

    The alternate wetting and drying (AWD) technology for rice production does not only save 15-30% of irrigation water, it also reduces methane emissions by up to 70%. AWD is defined by periodic drying and re-flooding of a rice field. Due to its high mitigation potential and its simplicity to execute this practice AWD has gained a lot of attention in recent years. The Climate and Clean Air Coalition (CCAC) has put AWD high on its agenda and funds a project to guide implementation of this technology in Vietnam, Bangladesh and Colombia. One crucial activity is a biophysical suitability assessment for AWD in the three countries. For this, we analyzed rainfall and soil data as well as potential evapotranspiration to assess if the water balance allows practicing AWD or if precipitation is too high for rice fields to fall dry. In my talk I will outline key factors for a successful large-scale implementation of AWD with a focus on the biophysical suitability assessment. The seasonal suitability maps that we generated highlight priority areas for AWD implementation and guide policy makers to informed decisions about meaningful investments in infrastructure and extension work.

  13. Neurobiological and psychosocial conditionings of rationality of criminal behaviour – review

    Directory of Open Access Journals (Sweden)

    Przemysław Piotrowski

    2011-12-01

    Full Text Available The term “rationality” has been mentioned for ages in philosophical discourse, and later in science. No wonder that considerations regarding the reasons behind committing crimes involve the question of rationality of culprits. The article comprises a review of contemporary research on factors which, on a neurobiological, psychological or social level, modify the level of rationality of criminals. In case of the juveniles, factors such as not fully developed brain structures, the influence of hormonal changes resulting in emotional instability and peer pressure, should also be taken into account. Adult criminals often manifest a deficit of activity in the prefrontal cortex of the brain, combined with increased activity in the subcortex, resulting in an increased propensity for violence. Neurophysiologic disorders may be accompanied by factors reducing the rationality, such as: errors in thinking, habitual use of neutralisation techniques or being lead by the, typical for street culture, perception of justice. All of the above should be taken into account as a part of a multi-aspect analyses of the causes of crime.

  14. Discrete Choice and Rational Inattention

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Melo, Emerson; de Palma, André

    2017-01-01

    This paper establishes a general equivalence between discrete choice and rational inattention models. Matejka and McKay (2015, AER) showed that when information costs are modelled using the Shannon entropy, the result- ing choice probabilities in the rational inattention model take the multinomial...... logit form. We show that when information costs are modelled using a class of generalized entropies, then the choice probabilities in any rational inattention model are observationally equivalent to some additive random utility discrete choice model and vice versa. This equivalence arises from convex...

  15. Rational top and its classical r-matrix

    International Nuclear Information System (INIS)

    Aminov, G; Arthamonov, S; Smirnov, A; Zotov, A

    2014-01-01

    We construct a rational integrable system (the rational top) on a co-adjoint orbit of SL N Lie group. It is described by the Lax operator with spectral parameter and classical non-dynamical skew-symmetric r-matrix. In the case of the orbit of minimal dimension the model is gauge equivalent to the rational Calogero–Moser (CM) system. To obtain the results we represent the Lax operator of the CM model in two different factorized forms—without spectral parameter (related to the spinless case) and another one with the spectral parameter. The latter gives rise to the rational top while the first one is related to generalized Cremmer–Gervais r-matrices. The gauge transformation relating the rational top and CM model provides the classical rational version of the IRF-Vertex correspondence. From the geometrical point of view it describes the modification of SL(N,C)-bundles over degenerated elliptic curve. In view of the Symplectic Hecke Correspondence the rational top is related to the rational spin CM model. Possible applications and generalizations of the suggested construction are discussed. In particular, the obtained r-matrix defines a class of KZB equations. (paper)

  16. Fiber sources for complete calf starter rations.

    Science.gov (United States)

    Murdock, F R; Wallenius, R W

    1980-11-01

    Complete calf starter rations containing either 1) alfalfa hay, 2) cottonseed hulls, or 3) alfalfa-beet pulp as sources of fiber were fed to Holstein heifer calves at two locations on a limited milk program from 3 days to 12 wk of age. Rations were isonitrogenous and similar in content of crude fiber and acid detergent fiber. Although growth and development were normal on all rations, calves fed the cottonseed hull ration consumed more starter and gained more body weight than calves fed the other sources of fiber. The similarity of feed efficiencies, rumen pH, and molar ratios of volatile fatty acids between rations indicated no appreciable differences in rumen development or function. The growth response of calves fed the cottonseed hull ration appeared to be a result of better ration acceptability for which no reason was evident. Calves raised at Puyallup gained more body weight than calves at Pullman, and these gains were made more efficiently. These location effects may be related to seasonal differences and greater demands for production of body heat. Although the incidence of scours was less for calves fed alfalfa hay starter, the incidence and severity of bloat were higher for that ration.

  17. Lessons from Learning to Have Rational Expectations

    OpenAIRE

    Lindh, Thomas

    1989-01-01

    This paper reviews a growing literature investigating how economic agents may learn rational expectations. Fully rational learning requires implausible initial information assumptions, therefore some form of bounded rationality has come into focus. Such learning models often converge to rational expectations equilibria within certain bounds. Convergence analysis has been much simplified by methods from adaptive control theory. Learning stability as a correspondence principle show some promise...

  18. Echinocandins for candidemia: a rational choice

    Directory of Open Access Journals (Sweden)

    Francesco Menichetti

    2013-08-01

    Full Text Available Among antifungal drugs, echinocandins (micafungin, caspofungin and anidulafungin represent a rational choice for the first-line therapy of candidemia/invasive candidiasis in critically ill patients. Among other properties characterizing echinocandins, it’s important to emphasize the broad spectrum of activity, the fungicidal activity against the majority of Candida spp., and the activity against the biofilm. Furthermore, echinocandins show greater efficacy than conventional amphotericin B and fluconazole, and similar efficacy to liposomal amphotericin B (but they are less toxic. Finally, echinocandins are recommended at the highest level of evidence (AI for the treatment of invasive candidiasis by IDSA and ESCMID guidelines.http://dx.doi.org/10.7175/rhc.v4i2s.872

  19. Plasma membrane--cortical cytoskeleton interactions: a cell biology approach with biophysical considerations.

    Science.gov (United States)

    Kapus, András; Janmey, Paul

    2013-07-01

    From a biophysical standpoint, the interface between the cell membrane and the cytoskeleton is an intriguing site where a "two-dimensional fluid" interacts with an exceedingly complex three-dimensional protein meshwork. The membrane is a key regulator of the cytoskeleton, which not only provides docking sites for cytoskeletal elements through transmembrane proteins, lipid binding-based, and electrostatic interactions, but also serves as the source of the signaling events and molecules that control cytoskeletal organization and remolding. Conversely, the cytoskeleton is a key determinant of the biophysical and biochemical properties of the membrane, including its shape, tension, movement, composition, as well as the mobility, partitioning, and recycling of its constituents. From a cell biological standpoint, the membrane-cytoskeleton interplay underlies--as a central executor and/or regulator--a multitude of complex processes including chemical and mechanical signal transduction, motility/migration, endo-/exo-/phagocytosis, and other forms of membrane traffic, cell-cell, and cell-matrix adhesion. The aim of this article is to provide an overview of the tight structural and functional coupling between the membrane and the cytoskeleton. As biophysical approaches, both theoretical and experimental, proved to be instrumental for our understanding of the membrane/cytoskeleton interplay, this review will "oscillate" between the cell biological phenomena and the corresponding biophysical principles and considerations. After describing the types of connections between the membrane and the cytoskeleton, we will focus on a few key physical parameters and processes (force generation, curvature, tension, and surface charge) and will discuss how these contribute to a variety of fundamental cell biological functions. © 2013 American Physiological Society.

  20. Strategy selection as rational metareasoning.

    Science.gov (United States)

    Lieder, Falk; Griffiths, Thomas L

    2017-11-01

    Many contemporary accounts of human reasoning assume that the mind is equipped with multiple heuristics that could be deployed to perform a given task. This raises the question of how the mind determines when to use which heuristic. To answer this question, we developed a rational model of strategy selection, based on the theory of rational metareasoning developed in the artificial intelligence literature. According to our model people learn to efficiently choose the strategy with the best cost-benefit tradeoff by learning a predictive model of each strategy's performance. We found that our model can provide a unifying explanation for classic findings from domains ranging from decision-making to arithmetic by capturing the variability of people's strategy choices, their dependence on task and context, and their development over time. Systematic model comparisons supported our theory, and 4 new experiments confirmed its distinctive predictions. Our findings suggest that people gradually learn to make increasingly more rational use of fallible heuristics. This perspective reconciles the 2 poles of the debate about human rationality by integrating heuristics and biases with learning and rationality. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  1. Biophysical Evaluation of Food Decontamination Effects on Tissue and Bacteria

    DEFF Research Database (Denmark)

    Andersen, Ann Zahle; Duelund, Lars; Brewer, Jonathan

    2011-01-01

    Traditionally, the effects and efficiency of food surface decontamination processes, such as chlorine washing, radiation, or heating, have been evaluated by sensoric analysis and colony-forming unit (CFU) counts of surface swabs or carcass rinses. These methods suffice when determining probable...... consumer responses or meeting legislative contamination limits. However, in the often very costly, optimization process of a new method, more quantitative and unbiased results are invaluable. In this study, we employed a biophysical approach for the investigation of qualitative and quantitative changes...... that there are no contradictions between data obtained by either approach. However, the biophysical methods draw a much more nuanced picture of the effects and efficiency of the investigated decontamination method, revealing, e.g., an exponential dose/response relationship between SonoSteam® treatment time and changes in collagen...

  2. Enhancing Irreversible Electroporation by Manipulating Cellular Biophysics with a Molecular Adjuvant.

    Science.gov (United States)

    Ivey, Jill W; Latouche, Eduardo L; Richards, Megan L; Lesser, Glenn J; Debinski, Waldemar; Davalos, Rafael V; Verbridge, Scott S

    2017-07-25

    Pulsed electric fields applied to cells have been used as an invaluable research tool to enhance delivery of genes or other intracellular cargo, as well as for tumor treatment via electrochemotherapy or tissue ablation. These processes involve the buildup of charge across the cell membrane, with subsequent alteration of transmembrane potential that is a function of cell biophysics and geometry. For traditional electroporation parameters, larger cells experience a greater degree of membrane potential alteration. However, we have recently demonstrated that the nuclear/cytoplasm ratio (NCR), rather than cell size, is a key predictor of response for cells treated with high-frequency irreversible electroporation (IRE). In this study, we leverage a targeted molecular therapy, ephrinA1, known to markedly collapse the cytoplasm of cells expressing the EphA2 receptor, to investigate how biophysical cellular changes resulting from NCR manipulation affect the response to IRE at varying frequencies. We present evidence that the increase in the NCR mitigates the cell death response to conventional electroporation pulsed-electric fields (∼100 μs), consistent with the previously noted size dependence. However, this same molecular treatment enhanced the cell death response to high-frequency electric fields (∼1 μs). This finding demonstrates the importance of considering cellular biophysics and frequency-dependent effects in developing electroporation protocols, and our approach provides, to our knowledge, a novel and direct experimental methodology to quantify the relationship between cell morphology, pulse frequency, and electroporation response. Finally, this novel, to our knowledge, combinatorial approach may provide a paradigm to enhance in vivo tumor ablation through a molecular manipulation of cellular morphology before IRE application. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  3. Should informed consent be based on rational beliefs?

    Science.gov (United States)

    Savulescu, J; Momeyer, R W

    1997-10-01

    Our aim is to expand the regulative ideal governing consent. We argue that consent should not only be informed but also based on rational beliefs. We argue that holding true beliefs promotes autonomy. Information is important insofar as it helps a person to hold the relevant true beliefs. But in order to hold the relevant true beliefs, competent people must also think rationally. Insofar as information is important, rational deliberation is important. Just as physicians should aim to provide relevant information regarding the medical procedures prior to patients consenting to have those procedures, they should also assist patients to think more rationally. We distinguish between rational choice/action and rational belief. While autonomous choice need not necessarily be rational, it should be based on rational belief. The implication for the doctrine of informed consent and the practice of medicine is that, if physicians are to respect patient autonomy and help patients to choose and act more rationally, not only must they provide information, but they should care more about the theoretical rationality of their patients. They should not abandon their patients to irrationality. They should help their patients to deliberate more effectively and to care more about thinking rationally. We illustrate these arguments in the context of Jehovah's Witnesses refusing life-saving blood transfusions. Insofar as Jehovah's Witnesses should be informed of the consequences of their actions, they should also deliberate rationally about these consequences.

  4. Using Biophysical Models to Understand the Effect of tDCS on Neurorehabilitation: Searching for Optimal Covariates to Enhance Poststroke Recovery.

    Science.gov (United States)

    Malerba, Paola; Straudi, Sofia; Fregni, Felipe; Bazhenov, Maxim; Basaglia, Nino

    2017-01-01

    Stroke is a leading cause of worldwide disability, and up to 75% of survivors suffer from some degree of arm paresis. Recently, rehabilitation of stroke patients has focused on recovering motor skills by taking advantage of use-dependent neuroplasticity, where high-repetition of goal-oriented movement is at times combined with non-invasive brain stimulation, such as transcranial direct current stimulation (tDCS). Merging the two approaches is thought to provide outlasting clinical gains, by enhancing synaptic plasticity and motor relearning in the motor cortex primary area. However, this general approach has shown mixed results across the stroke population. In particular, stroke location has been found to correlate with the likelihood of success, which suggests that different patients might require different protocols. Understanding how motor rehabilitation and stimulation interact with ongoing neural dynamics is crucial to optimize rehabilitation strategies, but it requires theoretical and computational models to consider the multiple levels at which this complex phenomenon operate. In this work, we argue that biophysical models of cortical dynamics are uniquely suited to address this problem. Specifically, biophysical models can predict treatment efficacy by introducing explicit variables and dynamics for damaged connections, changes in neural excitability, neurotransmitters, neuromodulators, plasticity mechanisms, and repetitive movement, which together can represent brain state, effect of incoming stimulus, and movement-induced activity. In this work, we hypothesize that effects of tDCS depend on ongoing neural activity and that tDCS effects on plasticity may be also related to enhancing inhibitory processes. We propose a model design for each step of this complex system, and highlight strengths and limitations of the different modeling choices within our approach. Our theoretical framework proposes a change in paradigm, where biophysical models can contribute

  5. Entrepreneurial orientation and international performance: the moderating effect of decision-making rationality

    OpenAIRE

    Deligianni, I.; Dimitratos, P.; Petrou, A.; Aharoni, Y.

    2016-01-01

    This research examines how entrepreneurial orientation (EO) influences international performance (IP) of the firm taking into account the moderating effect of decision-making rationality (DR) on the EO–IP association. Such an investigation is significant because it considers the interplay of strategic decision-making processes supported by the bounded rationality concept in the entrepreneurship field. Drawing from a study on activities of 216 firms in the United States and United Kingdom, the...

  6. Biophysical Insights into the Inhibitory Mechanism of Non-Nucleoside HIV-1 Reverse Transcriptase Inhibitors

    Directory of Open Access Journals (Sweden)

    Nicolas Sluis-Cremer

    2013-11-01

    Full Text Available HIV-1 reverse transcriptase (RT plays a central role in HIV infection. Current United States Federal Drug Administration (USFDA-approved antiretroviral therapies can include one of five approved non-nucleoside RT inhibitors (NNRTIs, which are potent inhibitors of RT activity. Despite their crucial clinical role in treating and preventing HIV-1 infection, their mechanism of action remains elusive. In this review, we introduce RT and highlight major advances from experimental and computational biophysical experiments toward an understanding of RT function and the inhibitory mechanism(s of NNRTIs.

  7. Product differentiation under bounded rationality

    NARCIS (Netherlands)

    Vermeulen, B.; Poutré, La J.A.; Kok, de A.G.; Pyka, A.; Handa, H.; Ishibuchi, H.; Ong, Y.-S.; Tan, K.-C.

    2015-01-01

    We study product differentiation equilibria and dynamics on the Salop circle under bounded rationality. Due to bounded rationality, firms tend to agglomerate in pairs. Upon adding a second tier of component suppliers, downstream assemblers may escape pairwise horizontal agglomeration. Moreover, we

  8. Comparison of Cold Weather Clothing Biophysical Properties: US Army, Canadian Department of National Defence, and Norwegian Military

    Science.gov (United States)

    2018-03-01

    Natick, MA 2 Rutgers University, School of Biomedical and Health Sciences, Newark, NJ 3 Research Support Division, USARIEM, Natick, MA 4 Toronto...issue for the U.S. military, as they routinely travel and conduct a range of physical activities around the world within the full spectrum of extreme...level of physical analysis (level 1), for example, clothing can be weighed and inspected for physical attributes. Biophysical analysis (level 2

  9. An evaluation of rational-emotive imagery as a component of rational-emotive therapy in the treatment of test anxiety.

    Science.gov (United States)

    Hymen, S P; Warren, R

    1978-06-01

    This study evaluated the efficacy of rational-emotive imagery as a component of rational-emotive therapy in reduction of college students' test anxiety. 11 volunteers met for 6 1-hr. group treatment sessions over a 3-wk. period. After 2 initial treatment sessions subjects were randomly assigned to groups given either rational-emotive therapy with rational-emotive imagery or rational-emotive therapy without imagery. Contrary to predictions, improvement between groups on self-report and performance measures was nonsignificant. Failure to obtain differences was attributed to similarities in content of treatment sessions and short treatment time. Combined groups reported significant improvement on all dependent measures. Although the study did not yield the predicted benefits of the imagery, results lend further support to the efficacy of rational-emotive therapy procedures in the reduction of test anxiety.

  10. Rationing in health systems: A critical review.

    Science.gov (United States)

    Keliddar, Iman; Mosadeghrad, Ali Mohammad; Jafari-Sirizi, Mehdi

    2017-01-01

    Background: It is difficult to provide health care services to all those in need of such services due to limited resources and unlimited demands. Thus, priority setting and rationing have to be applied. This study aimed at critically examining the concept of rationing in health sector and identifying its purposes, influencing factors, mechanisms, and outcomes. Methods: The critical interpretive synthesis methodology was used in this study. PubMed, Cochrane, and Proquest databases were searched using the related key words to find related documents published between 1970 and 2015. In total, 161 published reports were reviewed and included in the study. Thematic content analysis was applied for data analysis. Results: Health services rationing means restricting the access of some people to useful or potentially useful health services due to budgetary limitation. The inherent features of the health market and health services, limited resources, and unlimited needs necessitate health services rationing. Rationing can be applied in 4 levels: health care policy- makers, health care managers, health care providers, and patients. Health care rationing can be accomplished through fixed budget, benefit package, payment mechanisms, queuing, copayments, and deductibles. Conclusion: This paper enriched our understanding of health services rationing and its mechanisms at various levels and contributed to the literature by broadly conceptualizing health services rationing.

  11. Biophysical Insights into How Spike Threshold Depends on the Rate of Membrane Potential Depolarization in Type I and Type II Neurons.

    Directory of Open Access Journals (Sweden)

    Guo-Sheng Yi

    Full Text Available Dynamic spike threshold plays a critical role in neuronal input-output relations. In many neurons, the threshold potential depends on the rate of membrane potential depolarization (dV/dt preceding a spike. There are two basic classes of neural excitability, i.e., Type I and Type II, according to input-output properties. Although the dynamical and biophysical basis of their spike initiation has been established, the spike threshold dynamic for each cell type has not been well described. Here, we use a biophysical model to investigate how spike threshold depends on dV/dt in two types of neuron. It is observed that Type II spike threshold is more depolarized and more sensitive to dV/dt than Type I. With phase plane analysis, we show that each threshold dynamic arises from the different separatrix and K+ current kinetics. By analyzing subthreshold properties of membrane currents, we find the activation of hyperpolarizing current prior to spike initiation is a major factor that regulates the threshold dynamics. The outward K+ current in Type I neuron does not activate at the perithresholds, which makes its spike threshold insensitive to dV/dt. The Type II K+ current activates prior to spike initiation and there is a large net hyperpolarizing current at the perithresholds, which results in a depolarized threshold as well as a pronounced threshold dynamic. These predictions are further attested in several other functionally equivalent cases of neural excitability. Our study provides a fundamental description about how intrinsic biophysical properties contribute to the threshold dynamics in Type I and Type II neurons, which could decipher their significant functions in neural coding.

  12. Biophysical approach to low back pain: a pilot report.

    Science.gov (United States)

    Foletti, Alberto; Pokorný, Jiry

    2015-01-01

    Since biophysical treatment has been reported to be effective in the general management of pain, we decided to assess the specific effect and treatment duration of this therapeutic strategy in low back pain. We were interested in verifying the possibility that a single clinical procedure could reduce pain and improve patients' quality of life within a period of three months. An Electromagnetic Information Transfer Through Aqueous System was employed to record endogenous therapeutic signals from each individual using an electromagnetic recording device (Med Select 729). A highly significant reduction in the Roland Morris low back pain and disability questionnaire score was observed after 3 months following a single biophysical intervention (11.83 ± 6 at baseline versus 2.3 ± 3.25 at 3 months, p < 0.0001). This preliminary report provides further evidence of the theoretical implications and clinical applications of Quantum Electro Dynamic concepts in biology and medicine.

  13. Quantum-Sequencing: Biophysics of quantum tunneling through nucleic acids

    Science.gov (United States)

    Casamada Ribot, Josep; Chatterjee, Anushree; Nagpal, Prashant

    2014-03-01

    Tunneling microscopy and spectroscopy has extensively been used in physical surface sciences to study quantum tunneling to measure electronic local density of states of nanomaterials and to characterize adsorbed species. Quantum-Sequencing (Q-Seq) is a new method based on tunneling microscopy for electronic sequencing of single molecule of nucleic acids. A major goal of third-generation sequencing technologies is to develop a fast, reliable, enzyme-free single-molecule sequencing method. Here, we present the unique ``electronic fingerprints'' for all nucleotides on DNA and RNA using Q-Seq along their intrinsic biophysical parameters. We have analyzed tunneling spectra for the nucleotides at different pH conditions and analyzed the HOMO, LUMO and energy gap for all of them. In addition we show a number of biophysical parameters to further characterize all nucleobases (electron and hole transition voltage and energy barriers). These results highlight the robustness of Q-Seq as a technique for next-generation sequencing.

  14. Evaluation of urban river landscape design rationality based on AHP

    Directory of Open Access Journals (Sweden)

    Qiao Lifang

    2008-12-01

    Full Text Available An evaluation model for the rationality of the landscape design of urban rivers was established with the analytic hierarchy process (AHP method so as to provide a foundation for updating the landscape design of urban rivers. The evaluation system was divided into four layers, including the target layer, the comprehensive layer, the element layer, and the index layer. Each layer was made of different indices. The evaluation standards for each index were also given in this paper. This evaluation model was proved tenable through its application to the landscape design rationality evaluation of the Weihe River in Xinxiang City of Henan Province. The results show that the water quality, space, activity, facility, community, width of vegetation, sense of beauty and water content are among the most influential factors and should be considered the main basis for evaluating the rationality of the landscape design of urban rivers.

  15. A note on the roles of quantum and mechanical models in social biophysics.

    Science.gov (United States)

    Takahashi, Taiki; Kim, Song-Ju; Naruse, Makoto

    2017-11-01

    Recent advances in the applications of quantum models into various disciplines such as cognitive science, social sciences, economics, and biology witnessed enormous achievements and possible future progress. In this paper, we propose one of the most promising directions in the applications of quantum models: the combination of quantum and mechanical models in social biophysics. The possible resulting discipline may be called as experimental quantum social biophysics and could foster our understandings of the relationships between the society and individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Biophysical processes in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Mc; Murtugudde, R.; Vialard, J.; Vinayachandran, P.N.; Wiggert, J.D.; Hood, R.R.; Shankar, D.; Shetye, S.R.

    Ocean Biogeochemical Processes and Ecological Variability Geophysical Monograph Series 185 Copyright 200� by the American Geophysical Union. 10.102�/2008GM000768 Biophysical Processes in the Indian Ocean J. P. McCreary, 1 R. Murtugudde, 2 J. Vialard, 3...) also plots the upper-layer thickness, h 1 , from the model of McCreary et al. [1��3] (hereinafter referred to as MKM); h 1 simulates the structure of the top of the actual thermocline reasonably well, except that it is somewhat too thin from 5...

  17. Research on Bounded Rationality of Fuzzy Choice Functions

    Directory of Open Access Journals (Sweden)

    Xinlin Wu

    2014-01-01

    Full Text Available The rationality of a fuzzy choice function is a hot research topic in the study of fuzzy choice functions. In this paper, two common fuzzy sets are studied and analyzed in the framework of the Banerjee choice function. The complete rationality and bounded rationality of fuzzy choice functions are defined based on the two fuzzy sets. An assumption is presented to study the fuzzy choice function, and especially the fuzzy choice function with bounded rationality is studied combined with some rationality conditions. Results show that the fuzzy choice function with bounded rationality also satisfies some important rationality conditions, but not vice versa. The research gives supplements to the investigation in the framework of the Banerjee choice function.

  18. Hierarchy and Interactions in Environmental Interfaces Regarded as Biophysical Complex Systems

    Science.gov (United States)

    Mihailovic, Dragutin T.; Balaz, Igor

    The field of environmental sciences is abundant with various interfaces and is the right place for the application of new fundamental approaches leading towards a better understanding of environmental phenomena. For example, following the definition of environmental interface by Mihailovic and Balaž [23], such interface can be placed between: human or animal bodies and surrounding air, aquatic species and water and air around them, and natural or artificially built surfaces (vegetation, ice, snow, barren soil, water, urban communities) and the atmosphere. Complex environmental interface systems are open and hierarchically organised, interactions between their constituent parts are nonlinear, and the interaction with the surrounding environment is noisy. These systems are therefore very sensitive to initial conditions, deterministic external perturbations and random fluctuations always present in nature. The study of noisy non-equilibrium processes is fundamental for modelling the dynamics of environmental interface systems and for understanding the mechanisms of spatio-temporal pattern formation in contemporary environmental sciences, particularly in environmental fluid mechanics. In modelling complex biophysical systems one of the main tasks is to successfully create an operative interface with the external environment. It should provide a robust and prompt translation of the vast diversity of external physical and/or chemical changes into a set of signals, which are "understandable" for an organism. Although the establishment of organisation in any system is of crucial importance for its functioning, it should not be forgotten that in biophysical systems we deal with real-life problems where a number of other conditions should be reached in order to put the system to work. One of them is the proper supply of the system by the energy. Therefore, we will investigate an aspect of dynamics of energy flow based on the energy balance equation. The energy as well as

  19. Linking biophysical models and public preferences for ecosystem service assessments: a case study for the Southern Rocky Mountains

    Science.gov (United States)

    Bagstad, Kenneth J.; Reed, James; Semmens, Darius J.; Sherrouse, Ben C.; Troy, Austin

    2016-01-01

    Through extensive research, ecosystem services have been mapped using both survey-based and biophysical approaches, but comparative mapping of public values and those quantified using models has been lacking. In this paper, we mapped hot and cold spots for perceived and modeled ecosystem services by synthesizing results from a social-values mapping study of residents living near the Pike–San Isabel National Forest (PSI), located in the Southern Rocky Mountains, with corresponding biophysically modeled ecosystem services. Social-value maps for the PSI were developed using the Social Values for Ecosystem Services tool, providing statistically modeled continuous value surfaces for 12 value types, including aesthetic, biodiversity, and life-sustaining values. Biophysically modeled maps of carbon sequestration and storage, scenic viewsheds, sediment regulation, and water yield were generated using the Artificial Intelligence for Ecosystem Services tool. Hotspots for both perceived and modeled services were disproportionately located within the PSI’s wilderness areas. Additionally, we used regression analysis to evaluate spatial relationships between perceived biodiversity and cultural ecosystem services and corresponding biophysical model outputs. Our goal was to determine whether publicly valued locations for aesthetic, biodiversity, and life-sustaining values relate meaningfully to results from corresponding biophysical ecosystem service models. We found weak relationships between perceived and biophysically modeled services, indicating that public perception of ecosystem service provisioning regions is limited. We believe that biophysical and social approaches to ecosystem service mapping can serve as methodological complements that can advance ecosystem services-based resource management, benefitting resource managers by showing potential locations of synergy or conflict between areas supplying ecosystem services and those valued by the public.

  20. Effects of LiDAR point density, sampling size and height threshold on estimation accuracy of crop biophysical parameters.

    Science.gov (United States)

    Luo, Shezhou; Chen, Jing M; Wang, Cheng; Xi, Xiaohuan; Zeng, Hongcheng; Peng, Dailiang; Li, Dong

    2016-05-30

    Vegetation leaf area index (LAI), height, and aboveground biomass are key biophysical parameters. Corn is an important and globally distributed crop, and reliable estimations of these parameters are essential for corn yield forecasting, health monitoring and ecosystem modeling. Light Detection and Ranging (LiDAR) is considered an effective technology for estimating vegetation biophysical parameters. However, the estimation accuracies of these parameters are affected by multiple factors. In this study, we first estimated corn LAI, height and biomass (R2 = 0.80, 0.874 and 0.838, respectively) using the original LiDAR data (7.32 points/m2), and the results showed that LiDAR data could accurately estimate these biophysical parameters. Second, comprehensive research was conducted on the effects of LiDAR point density, sampling size and height threshold on the estimation accuracy of LAI, height and biomass. Our findings indicated that LiDAR point density had an important effect on the estimation accuracy for vegetation biophysical parameters, however, high point density did not always produce highly accurate estimates, and reduced point density could deliver reasonable estimation results. Furthermore, the results showed that sampling size and height threshold were additional key factors that affect the estimation accuracy of biophysical parameters. Therefore, the optimal sampling size and the height threshold should be determined to improve the estimation accuracy of biophysical parameters. Our results also implied that a higher LiDAR point density, larger sampling size and height threshold were required to obtain accurate corn LAI estimation when compared with height and biomass estimations. In general, our results provide valuable guidance for LiDAR data acquisition and estimation of vegetation biophysical parameters using LiDAR data.

  1. Theoretical Insights into the Biophysics of Protein Bi-stability and Evolutionary Switches.

    Directory of Open Access Journals (Sweden)

    Tobias Sikosek

    2016-06-01

    Full Text Available Deciphering the effects of nonsynonymous mutations on protein structure is central to many areas of biomedical research and is of fundamental importance to the study of molecular evolution. Much of the investigation of protein evolution has focused on mutations that leave a protein's folded structure essentially unchanged. However, to evolve novel folds of proteins, mutations that lead to large conformational modifications have to be involved. Unraveling the basic biophysics of such mutations is a challenge to theory, especially when only one or two amino acid substitutions cause a large-scale conformational switch. Among the few such mutational switches identified experimentally, the one between the GA all-α and GB α+β folds is extensively characterized; but all-atom simulations using fully transferrable potentials have not been able to account for this striking switching behavior. Here we introduce an explicit-chain model that combines structure-based native biases for multiple alternative structures with a general physical atomic force field, and apply this construct to twelve mutants spanning the sequence variation between GA and GB. In agreement with experiment, we observe conformational switching from GA to GB upon a single L45Y substitution in the GA98 mutant. In line with the latent evolutionary potential concept, our model shows a gradual sequence-dependent change in fold preference in the mutants before this switch. Our analysis also indicates that a sharp GA/GB switch may arise from the orientation dependence of aromatic π-interactions. These findings provide physical insights toward rationalizing, predicting and designing evolutionary conformational switches.

  2. Developing a protocol for managing the biophysical condition of a ...

    African Journals Online (AJOL)

    Their function will focus on the overall management of water resources on a ... for the integrated management of the biophysical component of a catchment, with ... and implement a protocol which will combine and integrate the knowledge of ...

  3. Using Rational-Emotive Therapy to Prevent Classroom Problems.

    Science.gov (United States)

    Webber, Jo; Coleman, Maggie

    1988-01-01

    Teachers are encouraged to utilize rational-emotive therapy to prevent and deal with classroom behavior problems. Rational-emotive therapy is defined, the ABC model of rational thinking briefly explained, types of irrational thinking identified, and suggestions for becoming a rational thinker are offered. Classroom examples are given. (DB)

  4. [Rationalization, rationing, prioritization: terminology and ethical approaches to the allocation of limited resources in hematology/oncology].

    Science.gov (United States)

    Winkler, Eva

    2011-01-01

    The field of oncology with its numerous high-priced innovations contributes considerably to the fact that medical progress is expensive. Additionally, due to the demographic changes and the increasing life expectancy, a growing number of cancer patients want to profit from this progress. Since resources are limited also in the health system, the fair distribution of the available resources urgently needs to be addressed. Dealing with scarcity is a typical problem in the domain of justice theory; therefore, this article first discusses different strategies to manage limited resources: rationalization, rationing, and prioritization. It then presents substantive as well as procedural criteria that assist in the just distribution of effective health benefits. There are various strategies to reduce the utilization of limited resources: Rationalization means that efficiency reserves are being exhausted; by means of rationing, effective health benefits are withheld due to cost considerations. Rationing can occur implicitly and thus covertly, e.g. through budgeting or the implementation of waiting periods, or explicitly, through transparent rules or policies about healthcare coverage. Ranking medical treatments according to their importance (prioritization) is often a prerequisite for rationing decisions. In terms of requirements of justice, both procedural and substantive criteria (e.g. equality, urgency, benefit) are relevant for the acceptance and quality of a decision to limit access to effective health benefits. Copyright © 2011 S. Karger AG, Basel.

  5. Differential Rationality and Personal Development.

    Science.gov (United States)

    Fincher, Cameron

    This publication discusses differential rationality; it asserts that the development of institutions, professions, and individuals involves the differentiation of forms and styles of thinking and knowing that are, in various ways, idiosyncratic. Based on this understanding, differential rationality can be seen as a developmental construct that…

  6. Biophysical properties of the normal-sized aorta in patients with Marfan syndrome: evaluation with MR flow mapping

    NARCIS (Netherlands)

    Groenink, M.; de Roos, A.; Mulder, B. J.; Verbeeten, B.; Timmermans, J.; Zwinderman, A. H.; Spaan, J. A.; van der Wall, E. E.

    2001-01-01

    PURPOSE: To investigate the feasibility of magnetic resonance (MR) flow mapping in the assessment of aortic biophysical properties in patients with Marfan syndrome and to detect differences in biophysical properties in the normal-sized aorta distal to the aortic root between these patients and

  7. Laser dynamics of asynchronous rational harmonic mode-locked fiber soliton lasers

    International Nuclear Information System (INIS)

    Jyu, Siao-Shan; Jiang, Guo-Hao; Lai, Yinchieh

    2013-01-01

    Laser dynamics of asynchronous rational harmonic mode-locked (ARHM) fiber soliton lasers are investigated in detail. In particular, based on the unique laser dynamics of asynchronous mode-locking, we have developed a new method for determining the effective active modulation strength in situ for ARHM lasers. By measuring the magnitudes of the slowly oscillating pulse timing position and central frequency, the effective phase modulation strength at the multiplication frequency of rational harmonic mode-locking can be accurately inferred. The method can be a very useful tool for developing ARHM fiber lasers. (paper)

  8. Rational reconstructions of modern physics

    CERN Document Server

    Mittelstaedt, Peter

    2013-01-01

    Newton’s classical physics and its underlying ontology are loaded with several metaphysical hypotheses that cannot be justified by rational reasoning nor by experimental evidence. Furthermore, it is well known that some of these hypotheses are not contained in the great theories of Modern Physics, such as the theory of Special Relativity and Quantum Mechanics. This book shows that, on the basis of Newton’s classical physics and by rational reconstruction, the theory of Special Relativity as well as Quantum Mechanics can be obtained by partly eliminating or attenuating the metaphysical hypotheses. Moreover, it is shown that these reconstructions do not require additional hypotheses or new experimental results. In the second edition the rational reconstructions are completed with respect to General Relativity and Cosmology. In addition, the statistics of quantum objects is elaborated in more detail with respect to the rational reconstruction of quantum mechanics. The new material completes the approach of t...

  9. Rational Choice and the Framing of Decisions.

    Science.gov (United States)

    1986-05-29

    survival in a competitive environment , and a minority of rational individuals can sometimes impose rationality on the whole market. Third, the...intuitive appeal of the axioms of rational choice makes it plausible that the theory derived from these axioms should provide an acceptable account of choice...rn-use U? RATIONAL CHOICE AMD THE FINNING OF KCISIOUS(U mi/ STANFORD UNIV CR A TYERSEY ET AL. 29 NAYN4-S4-K-S61SWICLASS IF lED FO 5/10S IL EEEEEEEE

  10. A Method Sustaining the Bioelectric, Biophysical, and Bioenergetic Function of Cultured Rabbit Atrial Cells

    OpenAIRE

    Noa Kirschner Peretz; Sofia Segal; Limor Arbel-Ganon; Ronen Ben Jehuda; Ronen Ben Jehuda; Yuval Shemer; Yuval Shemer; Binyamin Eisen; Binyamin Eisen; Moran Davoodi; Ofer Binah; Ofer Binah; Yael Yaniv

    2017-01-01

    Culturing atrial cells leads to a loss in their ability to be externally paced at physiological rates and to maintain their shape. We aim to develop a culture method that sustains the shape of atrial cells along with their biophysical and bioenergetic properties in response to physiological pacing. We hypothesize that adding 2,3-Butanedione 2-monoxime (BDM), which inhibits contraction during the culture period, will preserve these biophysical and bioenergetic properties. Rabbit atrial cells w...

  11. Nanoscale biophysics of the cell

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2018-01-01

    Macroscopic cellular structures and functions are generally investigated using biological and biochemical approaches. But these methods are no longer adequate when one needs to penetrate deep into the small-scale structures and understand their functions. The cell is found to hold various physical structures, molecular machines, and processes that require physical and mathematical approaches to understand and indeed manipulate them. Disorders in general cellular compartments, perturbations in single molecular structures, drug distribution therein, and target specific drug-binding, etc. are mostly physical phenomena. This book will show how biophysics has revolutionized our way of addressing the science and technology of nanoscale structures of cells, and also describes the potential for manipulating the events that occur in them.

  12. Cellular Biophysics During Freezing of Rat and Mouse Sperm Predicts Post-thaw Motility1

    Science.gov (United States)

    Hagiwara, Mie; Choi, Jeung Hwan; Devireddy, Ramachandra V.; Roberts, Kenneth P.; Wolkers, Willem F.; Makhlouf, Antoine; Bischof, John C.

    2009-01-01

    Though cryopreservation of mouse sperm yields good survival and motility after thawing, cryopreservation of rat sperm remains a challenge. This study was designed to evaluate the biophysics (membrane permeability) of rat in comparison to mouse to better understand the cooling rate response that contributes to cryopreservation success or failure in these two sperm types. In order to extract subzero membrane hydraulic permeability in the presence of ice, a differential scanning calorimeter (DSC) method was used. By analyzing rat and mouse sperm frozen at 5°C/min and 20°C/min, heat release signatures characteristic of each sperm type were obtained and correlated to cellular dehydration. The dehydration response was then fit to a model of cellular water transport (dehydration) by adjusting cell-specific biophysical (membrane hydraulic permeability) parameters Lpg and ELp. A “combined fit” (to 5°C/min and 20°C/min data) for rat sperm in Biggers-Whitten-Whittingham media yielded Lpg = 0.007 μm min−1 atm−1 and ELp = 17.8 kcal/mol, and in egg yolk cryopreservation media yielded Lpg = 0.005 μm min−1 atm−1 and ELp = 14.3 kcal/mol. These parameters, especially the activation energy, were found to be lower than previously published parameters for mouse sperm. In addition, the biophysical responses in mouse and rat sperm were shown to depend on the constituents of the cryopreservation media, in particular egg yolk and glycerol. Using these parameters, optimal cooling rates for cryopreservation were predicted for each sperm based on a criteria of 5%–15% normalized cell water at −30°C during freezing in cryopreservation media. These predicted rates range from 53°C/min to 70°C/min and from 28°C/min to 36°C/min in rat and mouse, respectively. These predictions were validated by comparison to experimentally determined cryopreservation outcomes, in this case based on motility. Maximum motility was obtained with freezing rates between 50°C/min and 80

  13. Rational customs clearance technology choice

    OpenAIRE

    Shramenko, N.; Andriets, V.

    2008-01-01

    Issues concerning cargo delivery efficiencyincrease by choice of rational customs clearance technology have been considered. Three possible variants of customs clearance andmethods which allow to define the most rational version of cargo delivery in international road communication based on main efficiency criteria for definite distance have been presented.

  14. The relationship of staffing and work environment with implicit rationing of nursing care in Swiss nursing homes--A cross-sectional study.

    Science.gov (United States)

    Zúñiga, Franziska; Ausserhofer, Dietmar; Hamers, Jan P H; Engberg, Sandra; Simon, Michael; Schwendimann, René

    2015-09-01

    Implicit rationing of nursing care refers to the withdrawal of or failure to carry out necessary nursing care activities due to lack of resources, in the literature also described as missed care, omitted care, or nursing care left undone. Under time constraints, nurses give priority to activities related to vital medical needs and the safety of the patient, leaving out documentation, rehabilitation, or emotional support of patients. In nursing homes, little is known about the occurrence of implicit rationing of nursing care and possible contributing factors. The purpose of this study was (1) to describe levels and patterns of self-reported implicit rationing of nursing care in Swiss nursing homes and (2) to explore the relationship between staffing level, turnover, and work environment factors and implicit rationing of nursing care. Cross-sectional, multi-center sub-study of the Swiss Nursing Home Human Resources Project (SHURP). Nursing homes from all three language regions of Switzerland. A random selection of 156 facilities with 402 units and 4307 direct care workers from all educational levels (including 25% registered nurses). We utilized data from established scales to measure implicit rationing of nursing care (Basel Extent of Rationing of Nursing Care), perceptions of leadership ability and staffing resources (Practice Environment Scale of the Nursing Work Index), teamwork and safety climate (Safety Attitudes Questionnaire), and work stressors (Health Professions Stress Inventory). Staffing level and turnover at the unit level were measured with self-developed questions. Multilevel linear regression models were used to explore the proposed relationships. Implicit rationing of nursing care does not occur frequently in Swiss nursing homes. Care workers ration support in activities of daily living, such as eating, drinking, elimination and mobilization less often than documentation of care and the social care of nursing homes residents. Statistically

  15. Coupling Biophysical and Socioeconomic Models for Coral Reef Systems in Quintana Roo, Mexican Caribbean

    Directory of Open Access Journals (Sweden)

    Jessica Melbourne-Thomas

    2011-09-01

    Full Text Available Transdisciplinary approaches that consider both socioeconomic and biophysical processes are central to understanding and managing rapid change in coral reef systems worldwide. To date, there have been limited attempts to couple the two sets of processes in dynamic models for coral reefs, and these attempts are confined to reef systems in developed countries. We present an approach to coupling existing biophysical and socioeconomic models for coral reef systems in the Mexican state of Quintana Roo. The biophysical model is multiscale, using dynamic equations to capture local-scale ecological processes on individual reefs, with reefs connected at regional scales by the ocean transport of larval propagules. The agent-based socioeconomic model simulates changes in tourism, fisheries, and urbanization in the Quintana Roo region. Despite differences in the formulation and currencies of the two models, we were able to successfully modify and integrate them to synchronize and define information flows and feedbacks between them. A preliminary evaluation of the coupled model system indicates that the model gives reasonable predictions for fisheries and ecological variables and can be used to examine scenarios for future social-ecological change in Quintana Roo. We provide recommendations for where efforts might usefully be focused in future attempts to integrate models of biophysical and socioeconomic processes, based on the limitations of our coupled system.

  16. Winnowing and Flocculation in Bio-physical Cohesive Substrate: A Flume Experimental and Estuarine Study

    Science.gov (United States)

    Ye, L.; Parsons, D. R.; Manning, A. J.

    2016-12-01

    Cohesive sediment, or mud, is ubiquitously found in most aqueous environments, such as coasts and estuaries. The study of cohesive sediment behaviors requires the synchronous description of mutual interactions of grains (e.g., winnowing and flocculation), their physical properties (e.g., grain size) and also the ambient water. Herein, a series of flume experiments (14 runs) with different substrate mixtures of sand-clay-EPS (Extracellular Polymeric Substrates: secreted by aquatic microorganisms) are combined with an estuarine field survey (Dee estuary, NW England) to investigate the behavior of suspensions over bio-physical cohesive substrates. The experimental results indicate that winnowing and flocculation occur pervasively in bio-physical cohesive flow systems. Importantly however, the evolution of the bed and bedform dynamics and hence turbulence production can be lower when cohesivity is high. The estuarine survey also revealed that the bio-physical cohesion provided by both the clay and microorganism fractions in the bed, that pervasively exists in many natural estuarine systems, plays a significant role in controlling the interactions between bed substrate and sediment suspension and deposition, including controlling processes such as sediment winnowing, flocculation and re-deposition. Full understanding of these processes are essential in advancing sediment transport modelling and prediction studies across natural estuarine systems and the work will report on an improved conceptual model for sediment sorting deposition in bio-physical cohesive substrates.

  17. Review of FEWS NET Biophysical Monitoring Requirements

    Science.gov (United States)

    Ross, K. W.; Brown, Molly E.; Verdin, J.; Underwood, L. W.

    2009-01-01

    The Famine Early Warning System Network (FEWS NET) provides monitoring and early warning support to decision makers responsible for responding to famine and food insecurity. FEWS NET transforms satellite remote sensing data into rainfall and vegetation information that can be used by these decision makers. The National Aeronautics and Space Administration has recently funded activities to enhance remote sensing inputs to FEWS NET. To elicit Earth observation requirements, a professional review questionnaire was disseminated to FEWS NET expert end-users: it focused upon operational requirements to determine additional useful remote sensing data and; subsequently, beneficial FEWS NET biophysical supplementary inputs. The review was completed by over 40 experts from around the world, enabling a robust set of professional perspectives to be gathered and analyzed rapidly. Reviewers were asked to evaluate the relative importance of environmental variables and spatio-temporal requirements for Earth science data products, in particular for rainfall and vegetation products. The results showed that spatio-temporal resolution requirements are complex and need to vary according to place, time, and hazard: that high resolution remote sensing products continue to be in demand, and that rainfall and vegetation products were valued as data that provide actionable food security information.

  18. Biophysically realistic minimal model of dopamine neuron

    Science.gov (United States)

    Oprisan, Sorinel

    2008-03-01

    We proposed and studied a new biophysically relevant computational model of dopaminergic neurons. Midbrain dopamine neurons are involved in motivation and the control of movement, and have been implicated in various pathologies such as Parkinson's disease, schizophrenia, and drug abuse. The model we developed is a single-compartment Hodgkin-Huxley (HH)-type parallel conductance membrane model. The model captures the essential mechanisms underlying the slow oscillatory potentials and plateau potential oscillations. The main currents involved are: 1) a voltage-dependent fast calcium current, 2) a small conductance potassium current that is modulated by the cytosolic concentration of calcium, and 3) a slow voltage-activated potassium current. We developed multidimensional bifurcation diagrams and extracted the effective domains of sustained oscillations. The model includes a calcium balance due to the fundamental importance of calcium influx as proved by simultaneous electrophysiological and calcium imaging procedure. Although there are significant evidences to suggest a partially electrogenic calcium pump, all previous models considered only elecrtogenic pumps. We investigated the effect of the electrogenic calcium pump on the bifurcation diagram of the model and compared our findings against the experimental results.

  19. ViSAPy: a Python tool for biophysics-based generation of virtual spiking activity for evaluation of spike-sorting algorithms.

    Science.gov (United States)

    Hagen, Espen; Ness, Torbjørn V; Khosrowshahi, Amir; Sørensen, Christina; Fyhn, Marianne; Hafting, Torkel; Franke, Felix; Einevoll, Gaute T

    2015-04-30

    New, silicon-based multielectrodes comprising hundreds or more electrode contacts offer the possibility to record spike trains from thousands of neurons simultaneously. This potential cannot be realized unless accurate, reliable automated methods for spike sorting are developed, in turn requiring benchmarking data sets with known ground-truth spike times. We here present a general simulation tool for computing benchmarking data for evaluation of spike-sorting algorithms entitled ViSAPy (Virtual Spiking Activity in Python). The tool is based on a well-established biophysical forward-modeling scheme and is implemented as a Python package built on top of the neuronal simulator NEURON and the Python tool LFPy. ViSAPy allows for arbitrary combinations of multicompartmental neuron models and geometries of recording multielectrodes. Three example benchmarking data sets are generated, i.e., tetrode and polytrode data mimicking in vivo cortical recordings and microelectrode array (MEA) recordings of in vitro activity in salamander retinas. The synthesized example benchmarking data mimics salient features of typical experimental recordings, for example, spike waveforms depending on interspike interval. ViSAPy goes beyond existing methods as it includes biologically realistic model noise, synaptic activation by recurrent spiking networks, finite-sized electrode contacts, and allows for inhomogeneous electrical conductivities. ViSAPy is optimized to allow for generation of long time series of benchmarking data, spanning minutes of biological time, by parallel execution on multi-core computers. ViSAPy is an open-ended tool as it can be generalized to produce benchmarking data or arbitrary recording-electrode geometries and with various levels of complexity. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Technique on rationalization of using electricity and cases

    International Nuclear Information System (INIS)

    1988-04-01

    This book deals with rationalization of using electric and cases. It is divided into four parts. The first part introduces necessity and of progression rationalization of using electric. The second part describes the technique on rationalization of using electric with management of electric energy. The third part depicts domestic cases of rationalization on using of electric such as substation and motor. The last part also introduces foreign cases of rationalization on using of electric with measure of generator circuit, design of motor, design of lighting and design of other equipment.

  1. Book Selection, Collection Development, and Bounded Rationality.

    Science.gov (United States)

    Schwartz, Charles A.

    1989-01-01

    Reviews previously proposed schemes of classical rationality in book selection, describes new approaches to rational choice behavior, and presents a model of book selection based on bounded rationality in a garbage can decision process. The role of tacit knowledge and symbolic content in the selection process are also discussed. (102 references)…

  2. Antimicrobial and biophysical properties of surfactant supplemented with an antimicrobial peptide for treatment of bacterial pneumonia.

    Science.gov (United States)

    Banaschewski, Brandon J H; Veldhuizen, Edwin J A; Keating, Eleonora; Haagsman, Henk P; Zuo, Yi Y; Yamashita, Cory M; Veldhuizen, Ruud A W

    2015-01-01

    Antibiotic-resistant bacterial infections represent an emerging health concern in clinical settings, and a lack of novel developments in the pharmaceutical pipeline is creating a "perfect storm" for multidrug-resistant bacterial infections. Antimicrobial peptides (AMPs) have been suggested as future therapeutics for these drug-resistant bacteria, since they have potent broad-spectrum activity, with little development of resistance. Due to the unique structure of the lung, bacterial pneumonia has the additional problem of delivering antimicrobials to the site of infection. One potential solution is coadministration of AMPs with exogenous surfactant, allowing for distribution of the peptides to distal airways and opening of collapsed lung regions. The objective of this study was to test various surfactant-AMP mixtures with regard to maintaining pulmonary surfactant biophysical properties and bactericidal functions. We compared the properties of four AMPs (CATH-1, CATH-2, CRAMP, and LL-37) suspended in bovine lipid-extract surfactant (BLES) by assessing surfactant-AMP mixture biophysical and antimicrobial functions. Antimicrobial activity was tested against methillicin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. All AMP/surfactant mixtures exhibited an increase of spreading compared to a BLES control. BLES+CATH-2 mixtures had no significantly different minimum surface tension versus the BLES control. Compared to the other cathelicidins, CATH-2 retained the most bactericidal activity in the presence of BLES. The BLES+CATH-2 mixture appears to be an optimal surfactant-AMP mixture based on in vitro assays. Future directions involve investigating the potential of this mixture in animal models of bacterial pneumonia. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  3. Love and rationality: on some possible rational effects of love

    Directory of Open Access Journals (Sweden)

    Gustavo Ortiz-Millán

    2007-01-01

    Full Text Available In this paper I defend the idea that rather than disrupting rationality, as the common-sense conception has done it, love may actually help us to develop rational ways of thinking and acting. I make the case for romantic or erotic love, since this is the kind of love that is more frequently associated with irrationality in acting and thinking. I argue that this kind of love may make us develop epistemic and practical forms of rationality. Based on an analysis of its characteristic action tendencies, I argue that love may help us to develop an instrumental form of rationality in determining the best means to achieve the object of love. It may also narrow down the number of practical considerations that may help us to achieve our goals. Finally, love may generate rational ways of belief-formation by framing the parameters taken into account in perception and attention, and by bringing into light only a small portion of the epistemic information available. Love may make us perceive reality more acutely.Neste artigo defendo a idéia de que, em vez de perturbar a racionalidade, como a concepção do senso comum o faz, o amor pode, na verdade, ajudar-nos a desenvolver modos racionais de pensar e agir. Dou bons argumentos para o amor romântico ou erótico, uma vez que esse é o tipo de amor que é mais freqüentemente associado à irracionalidade no agir e no pensar. Argumento que esse tipo de amor pode fazer-nos desenvolver formas epistêmicas e práticas de racionalidade. Com base em uma análise de suas tendências características para a ação, argumento que o amor pode ajudar-nos a desenvolver uma forma instrumental de racionalidade para se determinar o melhor meio de atingir o objeto de amor. Ele também pode limitar o número de considerações práticas que podem ajudar-nos a atingir os nossos objetivos. Finalmente, o amor pode gerar modos racionais de formação de crenças ao estruturar os parâmetros considerados na percepção e na aten

  4. A discussion of theoretical and practical rationality

    Energy Technology Data Exchange (ETDEWEB)

    Wahlstroem, B. [Technical Research Centre of Finland, Espoo (Finland). VTT Automation

    1999-12-01

    Theoretical rationality as defined in Expected Utility Theory and amended with other considerations gives a good basis for decision making. One should however always keep in mind that practical rationality often is far more complicated. People use their everyday experience when placed before new problems and this may lead to apparently irrational choices which on a closer scrutiny may be completely rational. Theories in human decision making unfortunately becomes untestable, firstly because a theory taking all considerations into account would be to complex to be practical and secondly because the data needed to test the theory cannot be collected. The benefit of EUT is that it is simple and straightforward as compared with competing theories. In the natural sciences rationality is often seen simply as a problem of optimisation. This view is practical, but it has to include also psychological and sociological considerations. The apparent controversy between natural and behavioural sciences could at least in principle be resolved by a better understanding of the complexity of human rationality. The human mind does not work in isolation, but it is adapted to a social community and a continuously changing environment. Understanding all components of human rationality is a challenge which cannot be solved on a short term basis. An important part of human rationality is connected to the intricate balance between individual and societal utility. The human mind has over thousands of years learnt to resolve that balance, but in the modern society there are decisions which may not be solvable with an intuitive approach and a strategy of trial and error. For these decisions more solid theories of rationality will be needed. EUT can in spite of its dismerits be used as the backbone for such a theory, but it has to be extended with better explanations of both individual and social rationality. If this understanding of the practical aspects of human rationality can be reached

  5. A discussion of theoretical and practical rationality

    International Nuclear Information System (INIS)

    Wahlstroem, B.

    1999-01-01

    Theoretical rationality as defined in Expected Utility Theory and amended with other considerations gives a good basis for decision making. One should however always keep in mind that practical rationality often is far more complicated. People use their everyday experience when placed before new problems and this may lead to apparently irrational choices which on a closer scrutiny may be completely rational. Theories in human decision making unfortunately becomes untestable, firstly because a theory taking all considerations into account would be to complex to be practical and secondly because the data needed to test the theory cannot be collected. The benefit of EUT is that it is simple and straightforward as compared with competing theories. In the natural sciences rationality is often seen simply as a problem of optimisation. This view is practical, but it has to include also psychological and sociological considerations. The apparent controversy between natural and behavioural sciences could at least in principle be resolved by a better understanding of the complexity of human rationality. The human mind does not work in isolation, but it is adapted to a social community and a continuously changing environment. Understanding all components of human rationality is a challenge which cannot be solved on a short term basis. An important part of human rationality is connected to the intricate balance between individual and societal utility. The human mind has over thousands of years learnt to resolve that balance, but in the modern society there are decisions which may not be solvable with an intuitive approach and a strategy of trial and error. For these decisions more solid theories of rationality will be needed. EUT can in spite of its dismerits be used as the backbone for such a theory, but it has to be extended with better explanations of both individual and social rationality. If this understanding of the practical aspects of human rationality can be reached

  6. Mass spectrometry for the biophysical characterization of therapeutic monoclonal antibodies.

    Science.gov (United States)

    Zhang, Hao; Cui, Weidong; Gross, Michael L

    2014-01-21

    Monoclonal antibodies (mAbs) are powerful therapeutics, and their characterization has drawn considerable attention and urgency. Unlike small-molecule drugs (150-600 Da) that have rigid structures, mAbs (∼150 kDa) are engineered proteins that undergo complicated folding and can exist in a number of low-energy structures, posing a challenge for traditional methods in structural biology. Mass spectrometry (MS)-based biophysical characterization approaches can provide structural information, bringing high sensitivity, fast turnaround, and small sample consumption. This review outlines various MS-based strategies for protein biophysical characterization and then reviews how these strategies provide structural information of mAbs at the protein level (intact or top-down approaches), peptide, and residue level (bottom-up approaches), affording information on higher order structure, aggregation, and the nature of antibody complexes. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  7. THE HICKSIAN RATIONAL CONSUMER

    OpenAIRE

    Manuel FERNÁNDEZ-GRELA

    2005-01-01

    The aim of this paper is to trace the evolution of the concept of ''rational consumer'' in Hicks's writings. After being one of the pioneers in the introduction of rationality assumptions about consumer behaviour in economic models, Hicks gradually developed a sceptical view about some of the uses to which those assumptions were put into. The focus of the paper is on continuity in Hicksian views, providing a picture of gradual changes in the long series of Hicks's works

  8. Short-Term Memory and Its Biophysical Model

    Science.gov (United States)

    Wang, Wei; Zhang, Kai; Tang, Xiao-wei

    1996-12-01

    The capacity of short-term memory has been studied using an integrate-and-fire neuronal network model. It is found that the storage of events depend on the manner of the correlation between the events, and the capacity is dominated by the value of after-depolarization potential. There is a monotonic increasing relationship between the value of after-depolarization potential and the memory numbers. The biophysics relevance of the network model is discussed and different kinds of the information processes are studied too.

  9. On the Other Hand Am I Rational? Hemispheric Activation and the Framing Effect

    Science.gov (United States)

    McElroy, Todd; Seta, John J.

    2004-01-01

    In recent decades the investigation of framing effects has become the foremost studied phenomenon of rational/irrational decision making. Two experiments were conducted to determine whether the functional specializations of the left and the right hemispheres would produce different responses to a traditional framing task. In Experiment 1, a…

  10. Coping More Effectively Through Rational Self-Counseling.

    Science.gov (United States)

    Rogers, George W., Jr.

    1981-01-01

    Rational Self-Counseling, a variation of rational-emotive therapy, is a self-help therapeutic technique in which students are encouraged to be responsible for their own behavior and emotions. The primary function of self-counseling is to evaluate whether thoughts are rational. A list of questions which students might ask themselves is presented.…

  11. Freedom and Rationality : Rousseau on Citizenship

    OpenAIRE

    Salvat, Christophe

    2008-01-01

    This paper deals with Rousseau's idea of freedom in terms of rationality and deliberation. It gives support to Berlin's interpretation of the general will as a rational and objective will but dismisses the idea that Rousseau's theory necessarily leads to authoritarianism. The general will, publicly expressed by the law, may be defined as the rational and self-regarding will agents would have if put in an independent and objective state, i.e. the state of nature. The general and the particular...

  12. Enhancing the biophysical properties of mRFP1 through incorporation of fluoroproline

    Energy Technology Data Exchange (ETDEWEB)

    Deepankumar, Kanagavel; Nadarajan, Saravanan Prabhu; Ayyadurai, Niraikulam; Yun, Hyungdon, E-mail: hyungdon@ynu.ac.kr

    2013-11-01

    Graphical abstract: Enhancing the biophysical properties of mRFP1 through incorporation of (2S, 4R)-4-fluoroproline at proline residues after mutating non-permissive site Pro63 into Ala. -- Highlights: •We incorporate (4S)-FP into mRFP1 led to insoluble protein. •Whereas, incorporation of (4R)-FP resulted in soluble but lost its fluorescence. •mRFP1-P63A mutant accommodate (4R)-FP and gave soluble protein with fluorescence. •Moreover mRFP1-P63A[(4R)-FP] showed enhanced biophysical properties of protein. -- Abstract: Here we enhanced the stability and biophysical properties of mRFP1 through a combination of canonical and non-canonical amino acid mutagenesis. The global replacement of proline residue with (2S, 4R)-4-fluoroproline [(4R)-FP] into mRFP1 led to soluble protein but lost its fluorescence, whereas (2S, 4S)-4-fluoroproline [(4S)-FP] incorporation resulted in insoluble protein. The bioinformatics analysis revealed that (4R)-FP incorporation at Pro63 caused fluorescence loss due to the steric hindrance of fluorine atom of (4R)-FP with the chromophore. Therefore, Pro63 residue was mutated with the smallest amino acid Ala to maintain non coplanar conformation of the chromophore and helps to retain its fluorescence with (4R)-FP incorporation. The incorporation of (4R)-FP into mRFP1-P63A showed about 2–3-fold enhancement in thermal and chemical stability. The rate of maturation is also greatly accelerated over the presence of (4R)-FP into mRFP1-P63A. Our study showed that a successful enhancement in the biophysical property of mRFP1-P63A[(4R)-FP] using non-canonical amino acid mutagenesis after mutating non-permissive site Pro63 into Ala.

  13. Enhancing the biophysical properties of mRFP1 through incorporation of fluoroproline

    International Nuclear Information System (INIS)

    Deepankumar, Kanagavel; Nadarajan, Saravanan Prabhu; Ayyadurai, Niraikulam; Yun, Hyungdon

    2013-01-01

    Graphical abstract: Enhancing the biophysical properties of mRFP1 through incorporation of (2S, 4R)-4-fluoroproline at proline residues after mutating non-permissive site Pro63 into Ala. -- Highlights: •We incorporate (4S)-FP into mRFP1 led to insoluble protein. •Whereas, incorporation of (4R)-FP resulted in soluble but lost its fluorescence. •mRFP1-P63A mutant accommodate (4R)-FP and gave soluble protein with fluorescence. •Moreover mRFP1-P63A[(4R)-FP] showed enhanced biophysical properties of protein. -- Abstract: Here we enhanced the stability and biophysical properties of mRFP1 through a combination of canonical and non-canonical amino acid mutagenesis. The global replacement of proline residue with (2S, 4R)-4-fluoroproline [(4R)-FP] into mRFP1 led to soluble protein but lost its fluorescence, whereas (2S, 4S)-4-fluoroproline [(4S)-FP] incorporation resulted in insoluble protein. The bioinformatics analysis revealed that (4R)-FP incorporation at Pro63 caused fluorescence loss due to the steric hindrance of fluorine atom of (4R)-FP with the chromophore. Therefore, Pro63 residue was mutated with the smallest amino acid Ala to maintain non coplanar conformation of the chromophore and helps to retain its fluorescence with (4R)-FP incorporation. The incorporation of (4R)-FP into mRFP1-P63A showed about 2–3-fold enhancement in thermal and chemical stability. The rate of maturation is also greatly accelerated over the presence of (4R)-FP into mRFP1-P63A. Our study showed that a successful enhancement in the biophysical property of mRFP1-P63A[(4R)-FP] using non-canonical amino acid mutagenesis after mutating non-permissive site Pro63 into Ala

  14. The rational maps Fλ(z)

    Indian Academy of Sciences (India)

    It is proved that the rational maps in the family {z → zm +λ/zd : λ ∈ C\\{0}} for integers m, d ≥ 2 ... The problem of the existence of Herman rings of a rational map has been studied by. Lyubich in [9] ..... Surveys 41(4) (1986) 35–95. [10] Milnor J ...

  15. Heterogeneity and the (de)stabilizing role of rationality

    International Nuclear Information System (INIS)

    Cavalli, Fausto; Naimzada, Ahmad; Pireddu, Marina

    2015-01-01

    Highlights: • We analyze Cournot oligopolies with heterogeneous firms of generic size. • Rational and naive players are considered. • Stability with respect to oligopoly composition is studied. • In some settings, increasing the rational firms fraction introduces instability. - Abstract: In this paper we study oligopolies of generic size consisting of heterogeneous firms, which adopt best response adjustment mechanisms with either perfect foresight (rational firms) or static expectations (naive firms). Assuming an isoelastic demand function and possibly different marginal costs for the two groups of firms, we focus on the local stability of the Nash equilibrium. We show that, with respect to the oligopoly composition, described in terms of the fraction of rational firms, different scenarios are possible. We find that a high rationality degree may not always guarantee stability, in particular when rational firms have sufficiently larger marginal costs. In fact, in this situation, increasing the fraction of rational firms can even introduce instability. Besides the usual scenarios in which replacing some naive firms with rational ones leads to a stabilization of (or at least keeps unchanged) the dynamics, we provide a family of situations, characterized by costs ratio favorable to naive firms, in which equilibrium loses its stability when naive firms are replaced by rational ones. The results we present are both analytical and simulative.

  16. Chiropractic biophysics technique: a linear algebra approach to posture in chiropractic.

    Science.gov (United States)

    Harrison, D D; Janik, T J; Harrison, G R; Troyanovich, S; Harrison, D E; Harrison, S O

    1996-10-01

    This paper discusses linear algebra as applied to human posture in chiropractic, specifically chiropractic biophysics technique (CBP). Rotations, reflections and translations are geometric functions studied in vector spaces in linear algebra. These mathematical functions are termed rigid body transformations and are applied to segmental spinal movement in the literature. Review of the literature indicates that these linear algebra concepts have been used to describe vertebral motion. However, these rigid body movers are presented here as applying to the global postural movements of the head, thoracic cage and pelvis. The unique inverse functions of rotations, reflections and translations provide a theoretical basis for making postural corrections in neutral static resting posture. Chiropractic biophysics technique (CBP) uses these concepts in examination procedures, manual spinal manipulation, instrument assisted spinal manipulation, postural exercises, extension traction and clinical outcome measures.

  17. Rationality and the Logic of Good Reasons.

    Science.gov (United States)

    Fisher, Walter R.

    This paper contends that the rationality of the logic of good reasons is constituted in its use. To support this claim, the paper presents an analysis of the relationship between being reasonable and being rational. It then considers how following the logic of good reasons leads to rationality in the behavior of individuals and groups; the latter…

  18. Rationality, mental causation and social sciences

    OpenAIRE

    Mladenović Ivan

    2009-01-01

    The aim of this paper is to investigate the role of mental causation in the context of rational choice theory. The author defends psychological aspect of rational explanation against the challenge of contemporary reductive materialism.

  19. Radiation biophysics in space

    International Nuclear Information System (INIS)

    Buecker, H.; Horneck, G.

    1983-01-01

    In a demonstration experiment bacterium sporules have been exposed to the space vacuum and to the solar radiation field at 254 nm, with the following results: 1) a short vacuum exposition of 1.3 h does not affect the vitality of the sporules, 2) the survival rate of humid sporules after UV-irradiation is consistent with terrestrial control samples, 3) after a simultaneous exposition to vacuum and solar UV-radiation the effect on the sporules is enhanced by a factor of ten as compared to the situation without vaccum exposition. Additional studies in biophysical simulation systems revealed, that the enhanced UV sensitivity is caused by the dehydration of the sporules. By this process the structure of the essential macromolecules in cell, such as DNA and proteins, is modified such that new photo-products can be formed. For these products the cells have no effective repair systems. (AJ) [de

  20. Physiological responses to rational-emotive self-verbalizations.

    Science.gov (United States)

    Master, S; Gershman, L

    1983-12-01

    This study tested Albert Ellis' Rational Emotive Therapy (RET) theory which predicts that cognitive beliefs, not the stimulus situation, generate human emotions. According to RET, emotions created by rational beliefs are adaptive, while irrational beliefs result in an unadaptive anxiety level. Results demonstrated that at high levels of problem relevance there was (1) a significantly greater GSR in direct response to the stimulus situation, and also to irrational statements, than to rational and control statements, and (2) no significant difference between rational and neutral control statements. The authors argue that these results are more parsimoniously explained by conditioning theory than by RET theory.

  1. Internal transport barrier triggering by rational magnetic flux surfaces in tokamaks

    International Nuclear Information System (INIS)

    Joffrin, E.; Challis, C.D.; Conway, G.D.

    2003-01-01

    The formation of Internal Transport Barriers (ITBs) has been experimentally associated with the presence of rational q-surfaces in both JET and ASDEX Upgrade. The triggering mechanisms are related to the occurrence of magneto-hydrodynamic (MHD) instabilities such as mode coupling or fishbone activity. These events could locally modify the poloidal velocity and increase transiently the shearing rate to values comparable to the linear growth rate of ITG modes. For JET reversed magnetic shear scenarios, ITB emergence occurs preferentially when the minimum q reaches an integer value. In this case, transport effects localised in the vicinity of zero magnetic shear and close to rational q values may also contribute to the formation of ITBs.The role of rational q surfaces on ITB triggering stresses the importance of q profile control for advanced tokamak scenario and could contribute to lower substantially the access power to these scenarios in next step facilities. (author)

  2. Internal Transport Barrier triggering by rational magnetic flux surfaces in tokamaks

    International Nuclear Information System (INIS)

    Joffrin, E.H.

    2002-01-01

    The formation of Internal Transport Barriers (ITBs) has been experimentally associated with the presence of rational q-surfaces in both JET and ASDEX Upgrade. The triggering mechanisms are related to the occurrence of magneto-hydrodynamic (MHD) instabilities such as mode coupling or fishbone activity. These events could locally modify the poloidal velocity and increase transiently the shearing rate to values comparable to the linear growth rate of ITG modes. For reversed magnetic shear scenario, ITB emergence occurs preferentially when the minimum q reaches an integer value. In this case, transport effects localised in the vicinity of zero magnetic shear and close to rational q values may also contribute to the formation of ITBs. The role of rational q surfaces on ITB triggering stresses the importance of q profile control for advanced tokamak scenario and could contribute to lower substantially the access power to these scenarios in next step facilities. (author)

  3. Group rational-emotive and cognitive-behavioral therapy.

    Science.gov (United States)

    Ellis, A

    1992-01-01

    The theory of rational-emotive therapy (RET) and of cognitive-behavioral therapy (CBT) is briefly explained and is applied to group therapy. It is shown how RET and CBT therapy groups deal with transference, countertransference, levels of group intervention, process versus content orientation, identifying underlying group process themes, here-and-now activation, working with difficult group members, activity levels of therapist and group members, and other group problems. Although they particularly concentrate on people's tendencies to construct and create their own "emotional" difficulties, RET and CBT group procedures fully acknowledge the interactions of human thoughts, feelings, and actions and active-directively employ a variety of cognitive, emotive, and behavioral group therapy techniques.

  4. Influence of different doses of octenidine hexafluorosilicate on parodontotium state of rat, which received cariesogenic ration

    Directory of Open Access Journals (Sweden)

    V. Yu. Anisimov

    2017-06-01

    Full Text Available Aim: To determine of parodontium state of rat, which received cariesogenic ration and different doses of octenidine hexafluorosilicate (O-HFS. Methods: The octenidine hexafluorosilicate was synthesized by us and was used into mucoso-adgesive gels (Na-CMC in next concentrations: 1 mg/ml, 2 mg/ml and 4 mg/ml. The rats received high-sugar cariesogenic ration and oral applications of gels with O-HFS in doses of 0,3 ml (daily doses of O-HFS were 1,4 mg/kg, 2,8 mg/kg and 5,6 mg/kg. The duration of experiment was 35 days. The activities of urease, lysozyme and elastase were determined into gum. The activities of urease, lysozyme, ALT and alkaline phosphatase (APh were determined into serum. The degree of dysbiosis calculated by ration urease and lysozyme. The degree of atrophy of parodontale bone was determined by Nicolaeva method. Results: The activities of elastase and urease, the degree of atrophy and dysbiosis were raised into gum of rat, which received cariesogenic ration. The activities of ALT and APh, the degree of dysbiosis were raised into serum. The oral application of O-HFS-gels decreased the all these indices. The maximal action made O-HFS-gel in dose 2,8 mg/kg. Conclusion: The oral application of O-HFS-gel make parodontoprotective action.

  5. Astronomy in the training of teachers and the role of practical rationality in sky observation

    Science.gov (United States)

    Bretones, P. S.; Compiani, M.

    2006-08-01

    This work analyses a program in the training of teachers that departs from the courses based on the technical rationality. An Astronomy course was offered to Science and Geography teachers of the four last years of high school education, comprising 46 hours, and organized in 2002 by the Instituto Superior de Ciências Aplicadas in Limeira, Brazil. Following the course a study group was established and held five meetings. The data was obtained through assessments, interviews, and accounts by the teachers and records from the classes and meetings. The actions and conceptual changes and the role of the Practical Rationality were then investigated. It was verified that for sky observation, the model of Practical Rationality within the reflective teacher theoretical framework and tutorial actions leads to knowledge acquisition, conceptual changes and extracurricular activities. Examples are: suggestions, personal actions of the teachers without their students, accounts of extracurricular activities and development of astronomical contents in class, actions in the pedagogical practices and reflections of the teachers with the teacher/ researcher towards the assessment of such changes are shown. It is important to stress that sky observation has specific features that lead to an equally specific school practice, in which the contents and procedures based on observations and their representation point towards a more practical rationality. Even in a training course for teachers based on technical rationality, the introduction of sky observation deepens the practical rationality and the development of principles that guide the acquisition and the teaching of knowledge about sky observation.

  6. Towards a Characterization of Rational Expectations

    OpenAIRE

    Itai Arieli

    2008-01-01

    R. J. Aumann and J. H. Drèze (2008) define a rational expectation of a player i in a game G as the expected payo of some type of i in some belief system for G in which common knowledge of rationality and common priors obtain. Our goal is to characterize the set of rational expectations in terms of the game's payoff matrix. We provide such a characterization for a specific class of strategic games, called semi-elementary, which includes Myerson's "elementary" games.

  7. Perspectives and Plans for Graduate Studies. 16. Biophysics 1974.

    Science.gov (United States)

    Ontario Council on Graduate Studies, Toronto. Advisory Committee on Academic Planning.

    In March, 1973, after a review of the Ontario universities' three-year plans, a provisional embargo was placed on doctoral work in biophysics. A full-scale assessment with outside consultants was not necessary in the case of a provisional embargo. Instead, the method used to remove the embargo was self-study by the discipline group leading to a…

  8. Southwest Ecological Restoration Institutes (SWERI) Biophysical Monitoring Workshop Report

    Science.gov (United States)

    Joseph Seidenberg; Judy Springer; Tessa Nicolet; Mike Battaglia; Christina Vothja

    2009-01-01

    On October 15-16, 2009, the Southwest Ecological Restoration Institutes (SWERI) hosted a workshop in which the participants would 1) build a common understanding of the types of monitoring that are occurring in forested ecosystems of the Southwest; 2) analyze and agree on an efficient, yet robust set of biophysical variables that can be used by land mangers and...

  9. Biophysical and electrochemical studies of protein-nucleic acid interactions

    Czech Academy of Sciences Publication Activity Database

    Bowater, R. P.; Cobb, A:M.; Pivoňková, Hana; Havran, Luděk; Fojta, Miroslav

    2015-01-01

    Roč. 146, č. 5 (2015), s. 723-739 ISSN 0026-9247 R&D Projects: GA ČR(CZ) GBP206/12/G151; GA ČR(CZ) GAP301/11/2076 Institutional support: RVO:68081707 Keywords : ISOTHERMAL TITRATION CALORIMETRY * OSMIUM-TETROXIDE COMPLEXES * SURFACE-PLASMON RESONANCE Subject RIV: BO - Biophysics Impact factor: 1.131, year: 2015

  10. Formation of an internal transport barrier and magnetohydrodynamic activity in experiments with the controlled density of rational magnetic surfaces in the T-10 Tokamak

    International Nuclear Information System (INIS)

    Razumova, K. A.; Andreev, V. F.; Bel’bas, I. S.; Gorshkov, A. V.; Dnestrovskij, A. Yu.; Dyabilin, K. S.; Kislov, A. Ya.; Lysenko, S. E.; Notkin, G. E.; Timchenko, N. N.; Chudnovskiy, A. N.; Shelukhin, D. A.

    2013-01-01

    Results are presented from experiments on the formation of an internal electron transport barrier near the q = 1.5 rational surface in the T-10 tokamak. The experiments were carried out in the regime with off-axis electron cyclotron resonance (ECR) heating followed by a fast plasma current ramp-up. After suppressing sawtooth oscillations by off-axis ECR heating, an internal transport barrier began to form near the q = 1.5 rational surface. In the phase of the current ramp-up, the quality of the transport barrier improved; as a result, the plasma energy confinement time increased 2–2.5 times. The intentionally produced flattening of the profile of the safety factor q(r) insignificantly affected magnetohydrodynamic activity in the plasma column in spite of the theoretical possibility of formation of substantial m/n = 3/2 and 2/1 magnetic islands. Conditions are discussed under which the flattening of the profile of the safety factor q near low-order rational surfaces leads to the formation of either an internal transport barrier or the development of an island magnetic structure induced by tearing modes

  11. Rational inattention or rational overreaction?

    DEFF Research Database (Denmark)

    Browning, Martin; Hansen, Lars Gårn; Smed, Sinne

    We investigate differences in how consumers of fish react to health information in the mass media. We specify a dynamic empirical model that allows for heterogeneity in all basic parameters of consumer behavior as well as in how consumers react to information. We estimate the model using a unique...... houshold panel tracking consumption, prices, news stories and media habits over 24 quarters. We fi nd that the consumers most likely to be ’rationally ignorant’ of health effects react more dramatically to health news than the consumers who most likely are well informed....

  12. Carcass percentage and quality of broilers given a ration containing probiotics and prebiotics

    Directory of Open Access Journals (Sweden)

    Muhammad Daud

    2007-10-01

    Full Text Available Probiotics is a feed additive in the form of life microorganisms that balance microorganism population in the digestive tract. While prebiotics is a feed substance which is not digested, and selectively improves growth and activity of useful microbes in large intestine. The objectives of this research were to study the carcass percentage and carcass quality of broilers given a ration containing probiotics and prebiotics. Four hundred eighty day-old chicks of broiler Arbor Acres strain were divided into four dietary treatments and three replications (40 birds / replicate. Ration used was consisted of: R1 = basal ration + 0.01% antibiotics (Zinc bacitracin, R2 = basal ration + 0.2% probiotics (Bacillus spp, R3 = basal ration + 0.2% probiotics + 0.5% prebiotics and R4 = basal ration + 0.5% prebiotics (katuk leaves. The variables observed were: carcass percentage, fat content in the abdomen, liver and carcass, cholesterol content in the liver, carcass and blood serum. The results showed that the carcass quality of broiler received probiotics and prebiotics either independently or the combination was significantly (P<0.05 different. The fat content of liver and thigh, and breast cholesterol of R3 was significantly (P<0.05 lower than that of the control (R1. It is concluded that combination of probiotics and prebiotics were able to decrease the carcass fat and cholesterol content at six week of age.

  13. Aspects regarding the analysis of the rationality of the buying decision of the Romanian consumer

    Directory of Open Access Journals (Sweden)

    Corina PELĂU

    2012-12-01

    Full Text Available One of the biggest challenges of economic theory is to determine the effectiveness and efficiency of economic activities and processes. In terms of consumer behavior this can be defined by the rationality of the buying decision. In this article there are presented several theories that have defined over time and still influence the rationality of the consumer. There are also presented the results of a research which aims to analyze the rationality of the consumer. In particular there are analyzed the relations between different quantitative aspects of the buying decision and the impulsive buying reactions of the consumer.

  14. Interoception drives increased rational decision-making in meditators playing the ultimatum game.

    Science.gov (United States)

    Kirk, Ulrich; Downar, Jonathan; Montague, P Read

    2011-01-01

    Human decision-making is often conceptualized as a competition between cognitive and emotional processes in the brain. Deviations from rational processes are believed to derive from inclusion of emotional factors in decision-making. Here, we investigate whether experienced Buddhist meditators are better equipped to regulate emotional processes compared with controls during economic decision-making in the Ultimatum Game. We show that meditators accept unfair offers on more than half of the trials, whereas controls only accept unfair offers on one-quarter of the trials. By applying fMRI we show that controls recruit the anterior insula during unfair offers. Such responses are powerful predictors of rejecting offers in social interaction. By contrast, meditators display attenuated activity in high-level emotional representations of the anterior insula and increased activity in the low-level interoceptive representations of the posterior insula. In addition we show that a subset of control participants who play rationally (i.e., accepts >85% unfair offers) recruits the dorsolateral prefrontal cortex presumably reflecting increased cognitive demands, whereas rational meditators by contrast display elevated activity in the somatosensory cortex and posterior superior temporal cortex. In summary, when assessing unfairness in the Ultimatum Game, meditators activate a different network of brain areas compared with controls enabling them to uncouple negative emotional reactions from their behavior. These findings highlight the clinically and socially important possibility that sustained training in mindfulness meditation may impact distinct domains of human decision-making.

  15. Interoception drives increased rational decision-making in meditators playing the Ultimatum Game.

    Directory of Open Access Journals (Sweden)

    Ulrich eKirk

    2011-04-01

    Full Text Available Human decision-making is often framed as a competition between cognitive and emotional processes in the brain. Deviations from rational processes are believed to derive from inclusion of emotional factors in decision-making. Here, we investigate whether a group of experienced Buddhist meditators are better equipped to regulate emotional processes compared with controls during economic decision-making in the Ultimatum Game. We show that meditators accept unfair offers on more than half of the trials, whereas controls only accept unfair offers on one-quarter of the trials. By applying fMRI we show that controls recruit the anterior insula during unfair offers. Such responses are powerful predictors of rejecting offers in social interaction. By contrast, meditators display attenuated activity in high-level emotional representations of the anterior insula and increased activity in the lower-level interoceptive representations of the posterior insula. In addition we show that a subset of control participants who play rationally (i.e. accepts >85% unfair offers recruits the DLPFC reflecting increased cognitive demands to accept unfairness, whereas rational meditators by contrast activates the somatosensory cortex and posterior superior temporal cortex (pSTC. In summary, when assessing unfairness, meditators activate a different network of brain areas compared with controls enabling them to uncouple negative emotional reactions from their behavior. These findings highlight the clinically and socially important possibility that sustained training in mindfulness meditation may impact distinct domains of human decision-making.

  16. Rationality, mental causation and social sciences

    Directory of Open Access Journals (Sweden)

    Mladenović Ivan

    2009-01-01

    Full Text Available The aim of this paper is to investigate the role of mental causation in the context of rational choice theory. The author defends psychological aspect of rational explanation against the challenge of contemporary reductive materialism.

  17. Pandemic ventilator rationing and appeals processes.

    Science.gov (United States)

    Patrone, Daniel; Resnik, David

    2011-06-01

    In a severe influenza pandemic, hospitals will likely experience serious and widespread shortages of patient pulmonary ventilators and of staff qualified to operate them. Deciding who will receive access to mechanical ventilation will often determine who lives and who dies. This prospect raises an important question whether pandemic preparedness plans should include some process by which individuals affected by ventilator rationing would have the opportunity to appeal adverse decisions. However, the issue of appeals processes to ventilator rationing decisions has been largely neglected in state pandemic planning efforts. If we are to devise just and effective plans for coping with a severe influenza pandemic, more attention to the issue of appeals processes for pandemic ventilator rationing decisions is needed. Arguments for and against appeals processes are considered, and some suggestions are offered to help efforts at devising more rational pandemic preparedness plans.

  18. The moderating role of rational beliefs in the relationship between irrational beliefs and posttraumatic stress symptomology.

    Science.gov (United States)

    Hyland, Philip; Shevlin, Mark; Adamson, Gary; Boduszek, Daniel

    2014-05-01

    Rational Emotive Behaviour Therapy (REBT) assumes that rational beliefs act as cognitive protective factors against the development of psychopathology; however little empirical evidence exists regarding the nature of the possible protective effects that they offer. The current study investigates whether rational beliefs moderate the impact of irrational beliefs on posttraumatic stress symptomology (PTS). Three hundred and thirteen active law enforcement, military, and related emergency service personnel took part in the current study. Sequential moderated multiple regression analysis was employed to investigate: (i) the direct impact of irrational beliefs on PTS; (ii) the direct impact of rational beliefs on PTS; (iii) the moderating effects of rational beliefs in the relationship between irrational beliefs and PTS. The irrational beliefs predicted by REBT theory emerged as critical predictors of PTS symptomology, in particular Depreciation beliefs. Rational beliefs (Preferences, and Acceptance beliefs) had a direct, negative impact on levels of PTS, and Acceptance beliefs moderated the impact of Catastrophizing beliefs on PTS. Irrational beliefs are important cognitive vulnerability factors in symptoms of PTS, while rational beliefs (Acceptance) appear to have a protective role in the emergence of PTS symptoms, both directly and by moderating the impact of Catastrophizing beliefs.

  19. From hadron therapy to cosmic rays: a life in biophysics

    CERN Multimedia

    Christine Sutton

    2014-01-01

    In 1954 – the year CERN was founded – another scientific journey began at what is now the Lawrence Berkeley National Laboratory. Beams of protons from a particle accelerator were used for the first time by John Lawrence – a doctor and the brother of Ernest Lawrence, the physicist after whom the Berkeley lab is named – to treat patients with cancer. For many years, Eleanor Blakely has been one of the leaders of that journey. She visited CERN last week and spoke with the Bulletin about her life in biophysics.   Use of the cylcotron beam to mimic "shooting stars" seen by astronauts. Black hood on subject Cornelius Tobias keeps out light during neutron irradiation experiment at the 184-inch accelerator. Helping to position Tobias in the beam line are (left to right) John Lyman of Biomedical Division, and Ralph Thomas of Health Physics. (Photo courtesy of Lawrence Berkeley National Laboratory.) Interested in biophysics, which was still a new...

  20. RATIONAL APPROXIMATIONS TO GENERALIZED HYPERGEOMETRIC FUNCTIONS.

    Science.gov (United States)

    Under weak restrictions on the various free parameters, general theorems for rational representations of the generalized hypergeometric functions...and certain Meijer G-functions are developed. Upon specialization, these theorems yield a sequency of rational approximations which converge to the

  1. Rational Choice, Consumer Vulnerability and Empowerment: Diverging Economic Perspectives and Issues for Debate

    Directory of Open Access Journals (Sweden)

    Mădălina Bălău-Ariton

    2013-05-01

    Full Text Available This paper discusses the issue of consumer choice seen from two quite diverging perspectives: rational choice theory and consumer empowerment as it is currently measured by available research at European Union level. The question we try to answer is: In what manner do the assumptions on consumer rational choice influence the actual understanding of choice and the improvement of the fairness of the choice? To this aim we review the basic theoretical ideas on rational choice and consumer empowerment, as well as the conclusions of previous research on Romanian consumers’ empowerment current situation. The main finding of this analysis is that Romanian consumer choice needs more awareness, an increase of consumer skills and more active individual involvement in discussing these issues.

  2. Racionalizam u arhitekturi: nekoliko modela instrumentalizacije / Rationalism in Architecture: Several Models of Instrumentalization

    Directory of Open Access Journals (Sweden)

    Vladimir Stevanović

    2014-10-01

    Full Text Available Rationalism in architecture is a European concept which, from Enlightment to postmodern era, advocates values of order, clarity and logic, represented through primary geometrism, functionalism, profitability and absence of ornament. The text connects and analyzes (1 formal-stilistic manifestations of rationalism in architecture: French neoclassicism; Soviet constructivism, German new objectivity, Italian rationalism; postmodern Italian neorationalism in the context of (2 dominant paradigms which directs them: divine nature; technological-utilitarian; autonomus-selfreferent, and (3 social, economic, ideological and cultural activities around which they are organized, such as: French bourgeois revolution; proleterian-communist, socialdemocratic and faschist ideas beteween two World wars; critical procession of populist values in mass consumer society and global capitalist economy at the threshold of postmodern era.

  3. Many faces of rationality: Implications of the great rationality debate for clinical decision-making

    OpenAIRE

    Djulbegovic, B.; Elqayam, Shira

    2017-01-01

    open access article Given that more than 30% of healthcare costs are wasted on inappropriate care, suboptimal care is increasingly connected to the quality of medical decisions. It has been argued that personal decisions are the leading cause of death, and 80% of healthcare expenditures result from physicians' decisions. Therefore, improving healthcare necessitates improving medical decisions, ie, making decisions (more) rational. Drawing on writings fromThe Great Rationality Debate from t...

  4. Biophysical mechanisms complementing "classical" cell biology.

    Science.gov (United States)

    Funk, Richard H W

    2018-01-01

    This overview addresses phenomena in cell- and molecular biology which are puzzling by their fast and highly coordinated way of organization. Generally, it appears that informative processes probably involved are more on the biophysical than on the classical biochemical side. The coordination problem is explained within the first part of the review by the topic of endogenous electrical phenomena. These are found e.g. in fast tissue organization and reorganization processes like development, wound healing and regeneration. Here, coupling into classical biochemical signaling and reactions can be shown by modern microscopy, electronics and bioinformatics. Further, one can follow the triggered reactions seamlessly via molecular biology till into genetics. Direct observation of intracellular electric processes is very difficult because of e.g. shielding through the cell membrane and damping by other structures. Therefore, we have to rely on photonic and photon - phonon coupling phenomena like molecular vibrations, which are addressed within the second part. Molecules normally possess different charge moieties and thus small electromagnetic (EMF) patterns arise during molecular vibration. These patterns can now be measured best within the optical part of the spectrum - much less in the lower terahertz till kHz and lower Hz part (third part of this review). Finally, EMFs facilitate quantum informative processes in coherent domains of molecular, charge and electron spin motion. This helps to coordinate such manifold and intertwined processes going on within cells, tissues and organs (part 4). Because the phenomena described in part 3 and 4 of the review still await really hard proofs we need concerted efforts and a combination of biophysics, molecular biology and informatics to unravel the described mysteries in "physics of life".

  5. Rationalizing the Promotion of Non-Rational Behaviors in Organizations.

    Science.gov (United States)

    Smith, Peter A. C.; Sharma, Meenakshi

    2002-01-01

    Organizations must balance rational/technical efficiency and emotions. Action learning has been proven to be effective for developing emotional openness in the workplace. Facilitators of action learning should draw upon the disciplines of counseling, Gestalt, psychodynamics, and Eastern philosophies. (Contains 23 references.) (SK)

  6. Generalized NLS hierarchies from rational W algebras

    International Nuclear Information System (INIS)

    Toppan, F.

    1993-11-01

    Finite rational W algebras are very natural structures appearing in coset constructions when a Kac-Moody subalgebra is factored out. The problem of relating these algebras to integrable hierarchies of equations is studied by showing how to associate to a rational W algebra its corresponding hierarchy. Two examples are worked out, the sl(2)/U(1) coset, leading to the Non-Linear Schroedinger hierarchy, and the U(1) coset of the Polyakov-Bershadsky W algebra, leading to a 3-field representation of the KP hierarchy already encountered in the literature. In such examples a rational algebra appears as algebra of constraints when reducing a KP hierarchy to a finite field representation. This fact arises the natural question whether rational algebras are always associated to such reductions and whether a classification of rational algebras can lead to a classification of the integrable hierarchies. (author). 19 refs

  7. Social and Biophysical Predictors of Public Perceptions of Extreme Fires

    Science.gov (United States)

    Hall, T. E.; Kooistra, C. M.; Paveglio, T.; Gress, S.; Smith, A. M.

    2013-12-01

    To date, what constitutes an 'extreme' fire has been approached separately by biophysical and social scientists. Research on the biophysical characteristics of fires has identified potential dimensions of extremity, including fire size and vegetation mortality. On the social side, factors such as the degree of immediate impact to one's life and property or the extent of social disruption in the community contribute to a perception of extremity. However, some biophysical characteristics may also contribute to perceptions of extremity, including number of simultaneous ignitions, rapidity of fire spread, atypical fire behavior, and intensity of smoke. Perceptions of these impacts can vary within and across communities, but no studies to date have investigated such perceptions in a comprehensive way. In this study, we address the question, to what extent is the magnitude of impact of fires on WUI residents' well-being explained by measurable biophysical characteristics of the fire and subjective evaluations of the personal and community-level impacts of the fire? We bring together diverse strands of psychological theory, including landscape perception, mental models, risk perception, and community studies. The majority of social science research on fires has been in the form of qualitative case studies, and our study is methodologically unique by using a nested design (hierarchical modeling) to enable generalizable conclusions across a wide range of fires and human communities. We identified fires that burned in 2011 or 2012 in the northern Rocky Mountain region that were at least 1,000 acres and that intersected (within 15 km) urban clusters or identified Census places. For fires where an adequately large number of households was located in proximity to the fire, we drew random samples of approximately 150 individuals for each fire. We used a hybrid internet (Qualtrics) and mail survey, following the Dillman method, to measure individual perceptions. We developed two

  8. Rationalizing fragment based drug discovery for BACE1: insights from FB-QSAR, FB-QSSR, multi objective (MO-QSPR) and MIF studies.

    Science.gov (United States)

    Manoharan, Prabu; Vijayan, R S K; Ghoshal, Nanda

    2010-10-01

    The ability to identify fragments that interact with a biological target is a key step in FBDD. To date, the concept of fragment based drug design (FBDD) is increasingly driven by bio-physical methods. To expand the boundaries of QSAR paradigm, and to rationalize FBDD using In silico approach, we propose a fragment based QSAR methodology referred here in as FB-QSAR. The FB-QSAR methodology was validated on a dataset consisting of 52 Hydroxy ethylamine (HEA) inhibitors, disclosed by GlaxoSmithKline Pharmaceuticals as potential anti-Alzheimer agents. To address the issue of target selectivity, a major confounding factor in the development of selective BACE1 inhibitors, FB-QSSR models were developed using the reported off target activity values. A heat map constructed, based on the activity and selectivity profile of the individual R-group fragments, and was in turn used to identify superior R-group fragments. Further, simultaneous optimization of multiple properties, an issue encountered in real-world drug discovery scenario, and often overlooked in QSAR approaches, was addressed using a Multi Objective (MO-QSPR) method that balances properties, based on the defined objectives. MO-QSPR was implemented using Derringer and Suich desirability algorithm to identify the optimal level of independent variables (X) that could confer a trade-off between selectivity and activity. The results obtained from FB-QSAR were further substantiated using MIF (Molecular Interaction Fields) studies. To exemplify the potentials of FB-QSAR and MO-QSPR in a pragmatic fashion, the insights gleaned from the MO-QSPR study was reverse engineered using Inverse-QSAR in a combinatorial fashion to enumerate some prospective novel, potent and selective BACE1 inhibitors.

  9. Rationalizing fragment based drug discovery for BACE1: insights from FB-QSAR, FB-QSSR, multi objective (MO-QSPR) and MIF studies

    Science.gov (United States)

    Manoharan, Prabu; Vijayan, R. S. K.; Ghoshal, Nanda

    2010-10-01

    The ability to identify fragments that interact with a biological target is a key step in FBDD. To date, the concept of fragment based drug design (FBDD) is increasingly driven by bio-physical methods. To expand the boundaries of QSAR paradigm, and to rationalize FBDD using In silico approach, we propose a fragment based QSAR methodology referred here in as FB-QSAR. The FB-QSAR methodology was validated on a dataset consisting of 52 Hydroxy ethylamine (HEA) inhibitors, disclosed by GlaxoSmithKline Pharmaceuticals as potential anti-Alzheimer agents. To address the issue of target selectivity, a major confounding factor in the development of selective BACE1 inhibitors, FB-QSSR models were developed using the reported off target activity values. A heat map constructed, based on the activity and selectivity profile of the individual R-group fragments, and was in turn used to identify superior R-group fragments. Further, simultaneous optimization of multiple properties, an issue encountered in real-world drug discovery scenario, and often overlooked in QSAR approaches, was addressed using a Multi Objective (MO-QSPR) method that balances properties, based on the defined objectives. MO-QSPR was implemented using Derringer and Suich desirability algorithm to identify the optimal level of independent variables ( X) that could confer a trade-off between selectivity and activity. The results obtained from FB-QSAR were further substantiated using MIF (Molecular Interaction Fields) studies. To exemplify the potentials of FB-QSAR and MO-QSPR in a pragmatic fashion, the insights gleaned from the MO-QSPR study was reverse engineered using Inverse-QSAR in a combinatorial fashion to enumerate some prospective novel, potent and selective BACE1 inhibitors.

  10. BIOPHYSICAL PROPERTIES OF NUCLEIC ACIDS AT SURFACES RELEVANT TO MICROARRAY PERFORMANCE.

    Science.gov (United States)

    Rao, Archana N; Grainger, David W

    2014-04-01

    Both clinical and analytical metrics produced by microarray-based assay technology have recognized problems in reproducibility, reliability and analytical sensitivity. These issues are often attributed to poor understanding and control of nucleic acid behaviors and properties at solid-liquid interfaces. Nucleic acid hybridization, central to DNA and RNA microarray formats, depends on the properties and behaviors of single strand (ss) nucleic acids (e.g., probe oligomeric DNA) bound to surfaces. ssDNA's persistence length, radius of gyration, electrostatics, conformations on different surfaces and under various assay conditions, its chain flexibility and curvature, charging effects in ionic solutions, and fluorescent labeling all influence its physical chemistry and hybridization under assay conditions. Nucleic acid (e.g., both RNA and DNA) target interactions with immobilized ssDNA strands are highly impacted by these biophysical states. Furthermore, the kinetics, thermodynamics, and enthalpic and entropic contributions to DNA hybridization reflect global probe/target structures and interaction dynamics. Here we review several biophysical issues relevant to oligomeric nucleic acid molecular behaviors at surfaces and their influences on duplex formation that influence microarray assay performance. Correlation of biophysical aspects of single and double-stranded nucleic acids with their complexes in bulk solution is common. Such analysis at surfaces is not commonly reported, despite its importance to microarray assays. We seek to provide further insight into nucleic acid-surface challenges facing microarray diagnostic formats that have hindered their clinical adoption and compromise their research quality and value as genomics tools.

  11. BIOPHYSICAL PROPERTIES OF NUCLEIC ACIDS AT SURFACES RELEVANT TO MICROARRAY PERFORMANCE

    Science.gov (United States)

    Rao, Archana N.; Grainger, David W.

    2014-01-01

    Both clinical and analytical metrics produced by microarray-based assay technology have recognized problems in reproducibility, reliability and analytical sensitivity. These issues are often attributed to poor understanding and control of nucleic acid behaviors and properties at solid-liquid interfaces. Nucleic acid hybridization, central to DNA and RNA microarray formats, depends on the properties and behaviors of single strand (ss) nucleic acids (e.g., probe oligomeric DNA) bound to surfaces. ssDNA’s persistence length, radius of gyration, electrostatics, conformations on different surfaces and under various assay conditions, its chain flexibility and curvature, charging effects in ionic solutions, and fluorescent labeling all influence its physical chemistry and hybridization under assay conditions. Nucleic acid (e.g., both RNA and DNA) target interactions with immobilized ssDNA strands are highly impacted by these biophysical states. Furthermore, the kinetics, thermodynamics, and enthalpic and entropic contributions to DNA hybridization reflect global probe/target structures and interaction dynamics. Here we review several biophysical issues relevant to oligomeric nucleic acid molecular behaviors at surfaces and their influences on duplex formation that influence microarray assay performance. Correlation of biophysical aspects of single and double-stranded nucleic acids with their complexes in bulk solution is common. Such analysis at surfaces is not commonly reported, despite its importance to microarray assays. We seek to provide further insight into nucleic acid-surface challenges facing microarray diagnostic formats that have hindered their clinical adoption and compromise their research quality and value as genomics tools. PMID:24765522

  12. Active Site Flexibility as a Hallmark for Efficient PET Degradation by I. sakaiensis PETase.

    Science.gov (United States)

    Fecker, Tobias; Galaz-Davison, Pablo; Engelberger, Felipe; Narui, Yoshie; Sotomayor, Marcos; Parra, Loreto P; Ramírez-Sarmiento, César A

    2018-03-27

    Polyethylene terephthalate (PET) is one of the most-consumed synthetic polymers, with an annual production of 50 million tons. Unfortunately, PET accumulates as waste and is highly resistant to biodegradation. Recently, fungal and bacterial thermophilic hydrolases were found to catalyze PET hydrolysis with optimal activities at high temperatures. Strikingly, an enzyme from Ideonella sakaiensis, termed PETase, was described to efficiently degrade PET at room temperature, but the molecular basis of its activity is not currently understood. Here, a crystal structure of PETase was determined at 2.02 Å resolution and employed in molecular dynamics simulations showing that the active site of PETase has higher flexibility at room temperature than its thermophilic counterparts. This flexibility is controlled by a novel disulfide bond in its active site, with its removal leading to destabilization of the catalytic triad and reduction of the hydrolase activity. Molecular docking of a model substrate predicts that PET binds to PETase in a unique and energetically favorable conformation facilitated by several residue substitutions within its active site when compared to other enzymes. These computational predictions are in excellent agreement with recent mutagenesis and PET film degradation analyses. Finally, we rationalize the increased catalytic activity of PETase at room temperature through molecular dynamics simulations of enzyme-ligand complexes for PETase and other thermophilic PET-degrading enzymes at 298, 323, and 353 K. Our results reveal that both the binding pose and residue substitutions within PETase favor proximity between the catalytic residues and the labile carbonyl of the substrate at room temperature, suggesting a more favorable hydrolytic reaction. These results are valuable for enabling detailed evolutionary analysis of PET-degrading enzymes and for rational design endeavors aiming at increasing the efficiency of PETase and similar enzymes toward plastic

  13. Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins.

    Science.gov (United States)

    Suganuma, Masami; Takahashi, Atsushi; Watanabe, Tatsuro; Iida, Keisuke; Matsuzaki, Takahisa; Yoshikawa, Hiroshi Y; Fujiki, Hirota

    2016-11-18

    Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (-)-epigallocatechin gallate (EGCG) in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AFM) and microfluidic optical stretcher. Specifically, determination of biophysical properties of cancer cells, low cell stiffness, and high deformability in relation to migration, along with biophysical effects, were studied by treatment with green tea catechins. The study with AFM revealed that low average values of Young's moduli, indicating low cell stiffness, are closely associated with strong potential of cell migration and metastasis for various cancer cells. It is important to note that treatments with EGCG and green tea extract elevated the average values of Young's moduli resulting in increased stiffness (large elasticity) of melanomas and various cancer cells. We discuss here the biophysical basis of multifunctions of green tea catechins and green tea extract leading to beneficial effects for cancer prevention and treatment.

  14. Lying for the Greater Good: Bounded Rationality in a Team

    Directory of Open Access Journals (Sweden)

    Oktay Sürücü

    2014-10-01

    Full Text Available This paper is concerned with the interaction between fully and boundedly rational agents in situations where their interests are perfectly aligned. The cognitive limitations of the boundedly rational agent do not allow him to fully understand the market conditions and lead him to take non-optimal decisions in some situations. Using categorization to model bounded rationality, we show that the fully rational agent can nudge, i.e., he can manipulate the information he sends and decrease the expected loss caused by the boundedly rational agent. Assuming different types for the boundedly rational agent, who differ only in the categories used, we show that the fully rational agent may learn the type of the boundedly rational agent along their interaction. Using this additional information, the outcome can be improved and the amount of manipulated information can be decreased. Furthermore, as the length of the interaction increases the probability that the fully rational agent learns the type of the boundedly rational agent grows

  15. Structural and biophysical characteristics of human skin in maintaining proper epidermal barrier function

    Directory of Open Access Journals (Sweden)

    Magdalena Boer

    2016-02-01

    Full Text Available The complex structure of human skin and its physicochemical properties turn it into an efficient outermost defence line against exogenous factors, and help maintain homeostasis of the human body. This role is played by the epidermal barrier with its major part – stratum corneum. The condition of the epidermal barrier depends on individual and environmental factors. The most important biophysical parameters characterizing the status of this barrier are the skin pH, epidermal hydration, transepidermal water loss and sebum excretion. The knowledge of biophysical skin processes may be useful for the implementation of prophylactic actions whose aim is to restore the barrier function.

  16. Nanoscale quantification of the biophysical characterization of combretastatin A-4-treated tumor cells using atomic force microscopy.

    Science.gov (United States)

    Li, Yanchun; Chen, Jv; Liu, Yutong; Zhang, Weige; He, Wenhui; Xu, Hanying; Liu, Lianqing; Ma, Enlong

    2017-01-01

    As an inhibitor of microtubule assembly, combretastatin A-4 (CA-4)-induced biological responses in tumor cells have been well known, but the corresponding changes in nano-biophysical properties were not investigated given the lack of an ideal tool. Using AFM technique, we investigated the alteration of nano-biophysical properties when CA-4-treated tumor cells underwent the different biological processes, including cell cycle arrest, apoptosis and autophagy. We found that CA-4-resistant cells were rougher with the presence of characteristic "ridges", indicating that the development of "ridge" structure may be a determinant of the sensitivity of cells to CA-4 compounds. CA-4 induced G2/M arrest and apoptosis in sensitive cells but triggered anti-apoptotic autophagy in resistant cells. CA-4 treatment caused an increase in stiffness in both sensitive and resistant cells. However, these cells exhibited different changes in cell surface roughness. CA-4 decreased Ra and Rq values in sensitive cells but increased these values in resistant cells. The reorganization of F-actin might contribute to the different changes of nano-biophysical properties in CA-4-sensitive and-resistant cells. Our results suggest that cellular nano-biophysical properties, such as "ridges", roughness and stiffness, could be applied as potential biomarkers for evaluating CA-4 compounds, and knowledge regarding how biological alterations cause changes in cellular nano-biophysical properties is helpful to develop a new high-resolution screening tool for anti-tumor agents.

  17. Biophysical approach to chronic kidney disease management in older patients

    Directory of Open Access Journals (Sweden)

    Alberto Foletti

    2016-06-01

    Full Text Available Chronic kidney disease (CKD and its clinical progression are a critical issue in an aging population. Therefore, strategies aimed at preventing and managing the decline of renal function are warranted. Recent evidence has provided encouraging results for the improvement of renal function achieved through an integrated biophysical approach, but prospective studies on the clinical efficacy of this strategy are still lacking. This was an open-label prospective pilot study to investigate the effect of electromagnetic information transfer through the aqueous system on kidney function of older patients affected by stage 1 or 2 CKD. Patients received biophysical therapy every 3 months over a 1-year period. Estimated glomerular filtration rate (eGFR values were calculated using the CKD–Epidemiology Collaboration formula, and were recorded at baseline and at the end of treatment. Overall, 58 patients (mean age 74.8 ± 3.7 years were included in the study. At baseline, mean eGFR was 64.6 ± 15.5 mL/min, and it significantly increased to 69.9 ± 15.8 mL/min after 1 year (+5.2 ± 10 mL/min, p<0.0002. The same trend was observed among men (+5.7 ± 10.2 mL/min, p<0.0064 and women (+4.7 ± 9.9 mL/min, p<0.014. When results were analyzed by sex, no difference was found between the 2 groups. Although further and larger prospective studies are needed, our findings suggest that an integrated biophysical approach may be feasible in the management of older patients with early-stage CKD, to reduce and prevent the decline of renal function due to aging or comorbidities.

  18. Photobiology of Symbiodinium revisited: bio-physical and bio-optical signatures

    Science.gov (United States)

    Hennige, S. J.; Suggett, D. J.; Warner, M. E.; McDougall, K. E.; Smith, D. J.

    2009-03-01

    Light is often the most abundant resource within the nutrient-poor waters surrounding coral reefs. Consequently, zooxanthellae ( Symbiodinium spp.) must continually photoacclimate to optimise productivity and ensure coral success. In situ coral photobiology is becoming dominated by routine assessments using state-of-the-art non-invasive bio-optical or chlorophyll a fluorescence (bio-physical) techniques. Multiple genetic types of Symbiodinium are now known to exist; however, little focus has been given as to how these types differ in terms of characteristics that are observable using these techniques. Therefore, this investigation aimed to revisit and expand upon a pivotal study by Iglesias-Prieto and Trench (1994) by comparing the photoacclimation characteristics of different Symbiodinium types based on their bio-physical (chlorophyll a fluorescence, reaction centre counts) and bio-optical (optical absorption, pigment concentrations) ‘signatures’. Signatures described here are unique to Symbiodinium type and describe phenotypic responses to set conditions, and hence are not suitable to describe taxonomic structure of in hospite Symbiodinium communities. In this study, eight Symbiodinium types from clades and sub-clades (A-B, F) were grown under two PFDs (Photon Flux Density) and examined. The photoacclimation response by Symbiodinium was highly variable between algal types for all bio-physical and for many bio-optical measurements; however, a general preference to modifying reaction centre content over effective antennae-absorption was observed. Certain bio-optically derived patterns, such as light absorption, were independent of algal type and, when considered per photosystem, were matched by reaction centre stoichiometry. Only by better understanding genotypic and phenotypic variability between Symbiodinium types can future studies account for the relative taxonomic and physiological contribution by Symbiodinium to coral acclimation.

  19. Internal transport barrier triggering by rational magnetic flux surfaces in tokamaks

    International Nuclear Information System (INIS)

    Joffrin, E.; Challis, C.D.; Conway, G.D.

    2003-01-01

    The formation of internal transport barriers (ITBs) has been experimentally associated with the presence of rational q surfaces in both JET and ASDEX Upgrade. The triggering mechanisms are related to the occurrence of magneto-hydrodynamic (MHD) instabilities such as mode coupling and fishbone activity. These events could locally modify the poloidal velocity and increase transiently the shearing rate to values comparable with the linear growth rate of ion temperature gradient modes. For JET reversed magnetic shear scenarios, ITB emergence occurs preferentially when the minimum q reaches an integral value. In this case, transport effects localized in the vicinity of zero magnetic shear and close to rational q values may be at the origin of ITB formation. The role of rational q surfaces in ITB triggering stresses the importance of q profile control for an advanced tokamak scenario and could assist in substantially lowering the access power to these scenarios in next step facilities. (author)

  20. Normative and descriptive rationality: from nature to artifice and back

    Science.gov (United States)

    Besold, T. R.; Uckelman, S. L.

    2018-03-01

    Rationality plays a key role in both the study of human reasoning and Artificial Intelligence (AI). Certain notions of rationality have been adopted in AI as guides for the development of intelligent machines and these notions have been given a normative function. The notions of rationality in AI are often taken to be closely related to conceptions of rationality in human contexts. In this paper, we argue that the normative role of rationality differs in the human and artificial contexts. While rationality in human-focused fields of study is normative, prescribing how humans ought to reason, the normative conception in AI is built on a notion of human rationality which is descriptive, not normative, in the human context, as AI aims at building agents which reason as humans do. In order to make this point, we review prominent notions of rationality used in psychology, cognitive science, and (the history of) philosophy, as well as in AI, and discuss some factors that contributed to rationality being assigned the differing normative statuses in the differing fields of study. We argue that while 'rationality' is a normative notion in both AI and in human reasoning, the normativity of the AI conception of 'rationality' is grounded in a descriptive account of human rationality.

  1. LFPy: A tool for biophysical simulation of extracellular potentials generated by detailed model neurons

    Directory of Open Access Journals (Sweden)

    Henrik eLindén

    2014-01-01

    Full Text Available Electrical extracellular recordings, i.e., recordings of the electrical potentials in the extracellular medium between cells, have been a main work-horse in electrophysiology for almost a century. The high-frequency part of the signal (>=500 Hz, i.e., themulti-unit activity (MUA, contains information about the firing of action potentials in surrounding neurons, while the low-frequency part, the local field potential (LFP, contains information about how these neurons integrate synaptic inputs. As the recorded extracellular signals arise from multiple neural processes, their interpretation is typically ambiguous and difficult. Fortunately, a precise biophysical modeling scheme linking activity at the cellular level and the recorded signal has been established: the extracellular potential can be calculated as a weighted sum of all transmembrane currents in all cells located in the vicinity of the electrode. This computational scheme can considerably aid the modeling and analysis of MUA and LFP signals.Here, we describe LFPy, an open source Python package for numerical simulations of extracellular potentials. LFPy consists of a set of easy-to-use classes for defining cells, synapses and recording electrodes as Python objects, implementing this biophysical modeling scheme. It runs on top of the widely used NEURON simulation environment, which allows for flexible usage of both new and existing cell models.Further, calculation of extracellular potentials using the line-source-method is efficiently implemented.We describe the theoretical framework underlying the extracellular potential calculations and illustrate by examples how LFPy can be used both for simulating LFPs, i.e., synaptic contributions from single cells as well a populations of cells, and MUAs, i.e., extracellular signatures of action potentials.

  2. LFPy: a tool for biophysical simulation of extracellular potentials generated by detailed model neurons.

    Science.gov (United States)

    Lindén, Henrik; Hagen, Espen; Lęski, Szymon; Norheim, Eivind S; Pettersen, Klas H; Einevoll, Gaute T

    2013-01-01

    Electrical extracellular recordings, i.e., recordings of the electrical potentials in the extracellular medium between cells, have been a main work-horse in electrophysiology for almost a century. The high-frequency part of the signal (≳500 Hz), i.e., the multi-unit activity (MUA), contains information about the firing of action potentials in surrounding neurons, while the low-frequency part, the local field potential (LFP), contains information about how these neurons integrate synaptic inputs. As the recorded extracellular signals arise from multiple neural processes, their interpretation is typically ambiguous and difficult. Fortunately, a precise biophysical modeling scheme linking activity at the cellular level and the recorded signal has been established: the extracellular potential can be calculated as a weighted sum of all transmembrane currents in all cells located in the vicinity of the electrode. This computational scheme can considerably aid the modeling and analysis of MUA and LFP signals. Here, we describe LFPy, an open source Python package for numerical simulations of extracellular potentials. LFPy consists of a set of easy-to-use classes for defining cells, synapses and recording electrodes as Python objects, implementing this biophysical modeling scheme. It runs on top of the widely used NEURON simulation environment, which allows for flexible usage of both new and existing cell models. Further, calculation of extracellular potentials using the line-source-method is efficiently implemented. We describe the theoretical framework underlying the extracellular potential calculations and illustrate by examples how LFPy can be used both for simulating LFPs, i.e., synaptic contributions from single cells as well a populations of cells, and MUAs, i.e., extracellular signatures of action potentials.

  3. Momentum effect in stocks’ returns between the rational and the behavioural financial theories: Proposition of the progressive rationality

    Directory of Open Access Journals (Sweden)

    Faten Zoghlami

    2013-01-01

    Full Text Available     The puzzling momentum strategies’ payoffs defied the rational financial theory asserting the stocks returns’ unpredictability. Moreover, the momentum effect persist the main stocks returns’ anomaly escaping any risk-based explanation. The resilience of this phenomenon had favoured the development of behavioural financial field, which breaks with the investor’ full rationality hypothesis. This paper attempts to reconcile between the rational and behavioural financial theories, through the introduction of the progressive rationality concept. Especially, we argue that recognizing the temporary inappropriate investors’ reactions; can resolve the puzzling momentum anomaly. To fulfil our objective, we identify the appropriate autoregressive level that captures the significant autocorrelations involved by the investors’ over and under reactions. Then, we explore the profitability of the 6/6 momentum strategy implemented on the adjusted stocks’ returns. The adjusted momentum strategy is still profitable but no longer puzzling, since the related excess return is henceforth fully captured by a β and a size effect.Key words: Tunisian momentum effect, the rational finance theory, the behavioural finance theory, the three-factorial model and the autoregressive process.

  4. Frames, Biases, and Rational Decision-Making in the Human Brain

    OpenAIRE

    De Martino, Benedetto; Kumaran, Dharshan; Seymour, Ben; Dolan, Raymond J.

    2006-01-01

    Human choices are remarkably susceptible to the manner in which options are presented. This so-called “framing effect” represents a striking violation of standard economic accounts of human rationality, although its underlying neurobiology is not understood. We found that the framing effect was specifically associated with amygdala activity, suggesting a key role for an emotional system in mediating decision biases. Moreover, across individuals, orbital and medial prefrontal cortex activity p...

  5. Frames, biases, and rational decision-making in the human brain

    OpenAIRE

    De Martino, B.; Kumaran, D.; Seymour, B.; Dolan, R. J.

    2006-01-01

    Human choices are remarkably susceptible to the manner in which options are presented. This so-called "framing effect" represents a striking violation of standard economic accounts of human rationality, although its underlying neurobiology is not understood. We found that the framing effect was specifically associated with amygdala activity, suggesting a key role for an emotional system in mediating decision biases. Moreover, across individuals, orbital and medial prefrontal cortex activity p...

  6. Progress and challenges of engineering a biophysical CO2-concentrating mechanism into higher plants.

    Science.gov (United States)

    Rae, Benjamin D; Long, Benedict M; Förster, Britta; Nguyen, Nghiem D; Velanis, Christos N; Atkinson, Nicky; Hee, Wei Yih; Mukherjee, Bratati; Price, G Dean; McCormick, Alistair J

    2017-06-01

    Growth and productivity in important crop plants is limited by the inefficiencies of the C3 photosynthetic pathway. Introducing CO2-concentrating mechanisms (CCMs) into C3 plants could overcome these limitations and lead to increased yields. Many unicellular microautotrophs, such as cyanobacteria and green algae, possess highly efficient biophysical CCMs that increase CO2 concentrations around the primary carboxylase enzyme, Rubisco, to enhance CO2 assimilation rates. Algal and cyanobacterial CCMs utilize distinct molecular components, but share several functional commonalities. Here we outline the recent progress and current challenges of engineering biophysical CCMs into C3 plants. We review the predicted requirements for a functional biophysical CCM based on current knowledge of cyanobacterial and algal CCMs, the molecular engineering tools and research pipelines required to translate our theoretical knowledge into practice, and the current challenges to achieving these goals. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Neurophysiology and Rationality in Political Thinking.

    Science.gov (United States)

    Peterson, Steven A.

    Research both in cognitive psychology and psychobiology suggests that political behavior is often less rational than individuals believe it to be. Information processing, memory, and decision making are interlinked processes. Studies in cognitive psychology reveal that even though decision making requires rationality, individuals often adopt…

  8. Positroids Induced by Rational Dyck Paths

    OpenAIRE

    Gotti, Felix

    2017-01-01

    A rational Dyck path of type $(m,d)$ is an increasing unit-step lattice path from $(0,0)$ to $(m,d) \\in \\mathbb{Z}^2$ that never goes above the diagonal line $y = (d/m)x$. On the other hand, a positroid of rank $d$ on the ground set $[d+m]$ is a special type of matroid coming from the totally nonnegative Grassmannian. In this paper we describe how to naturally assign a rank $d$ positroid on the ground set $[d+m]$, which we name rational Dyck positroid, to each rational Dyck path of type $(m,d...

  9. Rationalization and the Role of the School Counselor.

    Science.gov (United States)

    Clark, Arthur J.

    1995-01-01

    Examines rationalization in counselors' interactions with students, parents, and teachers--provides examples of each kind of interaction. Describes the dynamics of rationalization in the schools and outlines interventions that may be used with students, parents, and teachers. Also explores counselors' use of rationalization and gives examples of…

  10. Biophysical characterization of the proton-coupled oligopeptide transporter YjdL

    DEFF Research Database (Denmark)

    Jensen, Johanne Mørch; Simonsen, Fie C.; Mastali, Amir

    2012-01-01

    significantly different from prototypical POTs such as the human hPepT1. Nonetheless YjdL contains several highly conserved POT residues, which include Glu388 that is located in the putative substrate binding cavity. Here we present biophysical characterization of WT-YjdL and Glu388Gln. Isothermal titration...

  11. Biophysical characterization of inwardly rectifying potassium currents (I(K1) I(K,ACh), I(K,Ca)) using sinus rhythm or atrial fibrillation action potential waveforms

    DEFF Research Database (Denmark)

    Tang, Chuyi; Skibsbye, Lasse; Yuan, Lei

    2015-01-01

    Although several physiological, pathophysiological and regulatory properties of classical inward rectifier K+ current I(K1), G-protein coupled inwardly-rectifying K+ current I(K,ACh) and the small-conductance Ca2+ activated K+ current I(K,Ca) have been identified, quantitative biophysical details...

  12. Rationality in the Cryptographic Model

    DEFF Research Database (Denmark)

    Hubacek, Pavel

    This thesis presents results in the field of rational cryptography. In the first part we study the use of cryptographic protocols to avoid mediation and binding commitment when implementing game theoretic equilibrium concepts. First, we concentrate on the limits of cryptographic cheap talk...... to implement correlated equilibria of two-player strategic games in a sequentially rational way. We show that there exist two-player games for which no cryptographic protocol can implement the mediator in a sequentially rational way; that is, without introducing empty threats. In the context of computational...... with appealing economic applications. Our implementation puts forward a notion of cryptographically blinded games that exploits the power of encryption to selectively restrict the information available to players about sampled action profiles, such that these desirable equilibria can be stably achieved...

  13. Proposed standby gasoline rationing plan: public comments

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    Under the proposed plan, DOE would allocate ration rights (rights to purchase gasoline) to owners of registered vehicles. All vehicles in a given class would receive the same entitlement. Essential services would receive supplemental allotments of ration rights as pririty firms. Once every 3 months, ration checks would be mailed out to all vehicle registrants, allotting them a certain amount of ration rights. These checks would then be cashed at Coupon Issuance Points, where the bearer would receive ration coupons to be used at gasoline stations. Large users of gasoline could deposit their allotment checks in accounts at ration banks. Coupons or checks would be freely exchangeable in a white market. A certain percentage of the gasoline supply would be set aside in reserve for use in national emergencies. When the plan was published in the Federal Register, public comments were requested. DOE also solicited comments from private citizens, public interest groups, business and industry, state and local governments. A total of 1126 responses were reveived and these are analyzed in this paper. The second part of the report describes how the comments were classified, and gives a statistical breakdown of the major responses. The last section is a discussion and analysis of theissue raised by commenting agencies, firms, associations, and individuals. (MCW)

  14. The application of multiple biophysical cues to engineer functional neocartilage for treatment of osteoarthritis. Part I: cellular response.

    Science.gov (United States)

    Brady, Mariea A; Waldman, Stephen D; Ethier, C Ross

    2015-02-01

    Osteoarthritis (OA) is a complex disease of the joint for which current treatments are unsatisfactory, thus motivating development of tissue engineering (TE)-based therapies. To date, TE strategies have had some success, developing replacement tissue constructs with biochemical properties approaching that of native cartilage. However, poor biomechanical properties and limited postimplantation integration with surrounding tissue are major shortcomings that need to be addressed. Functional tissue engineering strategies that apply physiologically relevant biophysical cues provide a platform to improve TE constructs before implantation. In the previous decade, new experimental and theoretical findings in cartilage biomechanics and electromechanics have emerged, resulting in an increased understanding of the complex interplay of multiple biophysical cues in the extracellular matrix of the tissue. The effect of biophysical stimulation on cartilage, and the resulting chondrocyte-mediated biosynthesis, remodeling, degradation, and repair, has, therefore, been extensively explored by the TE community. This article compares and contrasts the cellular response of chondrocytes to multiple biophysical stimuli, and may be read in conjunction with its companion paper that compares and contrasts the subsequent intracellular signal transduction cascades. Mechanical, magnetic, and electrical stimuli promote proliferation, differentiation, and maturation of chondrocytes within established dose parameters or "biological windows." This knowledge will provide a framework for ongoing studies incorporating multiple biophysical cues in TE functional neocartilage for treatment of OA.

  15. Predictive biophysical modeling and understanding of the dynamics of mRNA translation and its evolution

    Science.gov (United States)

    Zur, Hadas; Tuller, Tamir

    2016-01-01

    mRNA translation is the fundamental process of decoding the information encoded in mRNA molecules by the ribosome for the synthesis of proteins. The centrality of this process in various biomedical disciplines such as cell biology, evolution and biotechnology, encouraged the development of dozens of mathematical and computational models of translation in recent years. These models aimed at capturing various biophysical aspects of the process. The objective of this review is to survey these models, focusing on those based and/or validated on real large-scale genomic data. We consider aspects such as the complexity of the models, the biophysical aspects they regard and the predictions they may provide. Furthermore, we survey the central systems biology discoveries reported on their basis. This review demonstrates the fundamental advantages of employing computational biophysical translation models in general, and discusses the relative advantages of the different approaches and the challenges in the field. PMID:27591251

  16. Biophysical and sociocultural factors underlying spatial trade-offs of ecosystem services in semiarid watersheds

    Directory of Open Access Journals (Sweden)

    Marina García-Llorente

    2015-09-01

    Full Text Available Biophysical and social systems are linked to form social-ecological systems whose sustainability depends on their capacity to absorb uncertainty and cope with disturbances. In this study, we explored the key biophysical and socio-cultural factors underlying ecosystem service supply in two semiarid watersheds of southern Spain. These included variables associated with the role that freshwater flows and biodiversity play in securing the system's capacity to sustain essential ecosystem services and their relationship with social demand for services, local water governance, and land-use intensification. Our results reveal the importance of considering the invisible dimensions of water and biodiversity, i.e. green freshwater flows and trait-based indicators, because of their relevance to the supply of ecosystem services. Furthermore, they uncover the importance of traditional irrigation canals, a local water governance system, in maintaining the ecosystems' capacity to supply services. The study also highlights the complex trade-offs that occur because of the spatial mismatch between ecosystem service supply (upstream and ecosystem service demand (downstream in watersheds. Finally, we found that land-use intensification generally resulted in losses of the biophysical factors that underpin the supply of some ecosystem services, increases in social demand for less diversified services, and the abandonment of local governance practices. Attempts to manage social-ecological systems toward sustainability at the local scale should identify the key biophysical and socio-cultural factors that are essential for maintaining ecosystem services and should recognize existing interrelationships between them. Land-use management should also take into account ecosystem service trade-offs and the consequences resulting from land-use intensification.

  17. Privacy-Enhancing Auctions Using Rational Cryptography

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro; Nielsen, Jesper Buus; Triandopoulos, Nikolaos

    2009-01-01

    show how to use rational cryptography to approximately implement any given ex interim individually strictly rational equilibrium of such an auction without a trusted mediator through a cryptographic protocol that uses only point-to-point authenticated channels between the players. By “ex interim...

  18. Principles of Economic Rationality in Mice.

    Science.gov (United States)

    Rivalan, Marion; Winter, York; Nachev, Vladislav

    2017-12-12

    Humans and non-human animals frequently violate principles of economic rationality, such as transitivity, independence of irrelevant alternatives, and regularity. The conditions that lead to these violations are not completely understood. Here we report a study on mice tested in automated home-cage setups using rewards of drinking water. Rewards differed in one of two dimensions, volume or probability. Our results suggest that mouse choice conforms to the principles of economic rationality for options that differ along a single reward dimension. A psychometric analysis of mouse choices further revealed that mice responded more strongly to differences in probability than to differences in volume, despite equivalence in return rates. This study also demonstrates the synergistic effect between the principles of economic rationality and psychophysics in making quantitative predictions about choices of healthy laboratory mice. This opens up new possibilities for the analyses of multi-dimensional choice and the use of mice with cognitive impairments that may violate economic rationality.

  19. Lessons from the biophysics of interfaces: Lung surfactant and tear fluid

    DEFF Research Database (Denmark)

    Rantamaki, A.; Telenius, J.; Koivuniemi, A.

    2011-01-01

    The purpose of this review is to provide insight into the biophysical properties and functions of tear fluid and lung surfactant - two similar fluids covering the epithelium of two distinctive organs. Both fluids form a layer-like structure that essentially comprise of an aqueous layer next......-active function of the fluid film. The lipid layer of lung surfactant comprises mainly of phospholipids, especially phosphatidylcholines, and only small amounts of non-polar lipids, mainly cholesterol. In contrast, tear fluid lipid layer comprises of a mixture of polar and non-polar lipids. However, the relative...... proportion and the spectrum of different polar and non-polar lipids seem to be more extensive in tear fluid than in lung surfactant. The differing lipid compositions generate distinctive lipid layer structures. Despite the structural differences, these lipid layers decrease the surface tension of the air...

  20. LBA-ECO ND-01 Reflectance and Biophysical Measures, Grass Pastures: Rondonia, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides the results of spectral reflectance (350 to 2,500 nm at 1-nm increments) and biophysical measurements on grass pastures in eight...

  1. The neural basis of rationalization: cognitive dissonance reduction during decision-making.

    Science.gov (United States)

    Jarcho, Johanna M; Berkman, Elliot T; Lieberman, Matthew D

    2011-09-01

    People rationalize the choices they make when confronted with difficult decisions by claiming they never wanted the option they did not choose. Behavioral studies on cognitive dissonance provide evidence for decision-induced attitude change, but these studies cannot fully uncover the mechanisms driving the attitude change because only pre- and post-decision attitudes are measured, rather than the process of change itself. In the first fMRI study to examine the decision phase in a decision-based cognitive dissonance paradigm, we observed that increased activity in right-inferior frontal gyrus, medial fronto-parietal regions and ventral striatum, and decreased activity in anterior insula were associated with subsequent decision-related attitude change. These findings suggest the characteristic rationalization processes that are associated with decision-making may be engaged very quickly at the moment of the decision, without extended deliberation and may involve reappraisal-like emotion regulation processes.

  2. Decision Making: Rational, Nonrational, and Irrational.

    Science.gov (United States)

    Simon, Herbert A.

    1993-01-01

    Describes the current state of knowledge about human decision-making and problem-solving processes, explaining recent developments and their implications for management and management training. Rational goal-setting is the key to effective decision making and accomplishment. Bounded rationality is a realistic orientation, because the world is too…

  3. Estimation efficiency of usage satellite derived and modelled biophysical products for yield forecasting

    Science.gov (United States)

    Kolotii, Andrii; Kussul, Nataliia; Skakun, Sergii; Shelestov, Andrii; Ostapenko, Vadim; Oliinyk, Tamara

    2015-04-01

    Efficient and timely crop monitoring and yield forecasting are important tasks for ensuring of stability and sustainable economic development [1]. As winter crops pay prominent role in agriculture of Ukraine - the main focus of this study is concentrated on winter wheat. In our previous research [2, 3] it was shown that usage of biophysical parameters of crops such as FAPAR (derived from Geoland-2 portal as for SPOT Vegetation data) is far more efficient for crop yield forecasting to NDVI derived from MODIS data - for available data. In our current work efficiency of usage such biophysical parameters as LAI, FAPAR, FCOVER (derived from SPOT Vegetation and PROBA-V data at resolution of 1 km and simulated within WOFOST model) and NDVI product (derived from MODIS) for winter wheat monitoring and yield forecasting is estimated. As the part of crop monitoring workflow (vegetation anomaly detection, vegetation indexes and products analysis) and yield forecasting SPIRITS tool developed by JRC is used. Statistics extraction is done for landcover maps created in SRI within FP-7 SIGMA project. Efficiency of usage satellite based and modelled with WOFOST model biophysical products is estimated. [1] N. Kussul, S. Skakun, A. Shelestov, O. Kussul, "Sensor Web approach to Flood Monitoring and Risk Assessment", in: IGARSS 2013, 21-26 July 2013, Melbourne, Australia, pp. 815-818. [2] F. Kogan, N. Kussul, T. Adamenko, S. Skakun, O. Kravchenko, O. Kryvobok, A. Shelestov, A. Kolotii, O. Kussul, and A. Lavrenyuk, "Winter wheat yield forecasting in Ukraine based on Earth observation, meteorological data and biophysical models," International Journal of Applied Earth Observation and Geoinformation, vol. 23, pp. 192-203, 2013. [3] Kussul O., Kussul N., Skakun S., Kravchenko O., Shelestov A., Kolotii A, "Assessment of relative efficiency of using MODIS data to winter wheat yield forecasting in Ukraine", in: IGARSS 2013, 21-26 July 2013, Melbourne, Australia, pp. 3235 - 3238.

  4. Local Choices: Rationality and the Contextuality of Decision-Making

    Science.gov (United States)

    Vlaev, Ivo

    2018-01-01

    Rational explanation is ubiquitous in psychology and social sciences, ranging from rational analysis, expectancy-value theories, ideal observer models, mental logic to probabilistic frameworks, rational choice theory, and informal “folk psychological” explanation. However, rational explanation appears to be challenged by apparently systematic irrationality observed in psychological experiments, especially in the field of judgement and decision-making (JDM). Here, it is proposed that the experimental results require not that rational explanation should be rejected, but that rational explanation is local, i.e., within a context. Thus, rational models need to be supplemented with a theory of contextual shifts. We review evidence in JDM that patterns of choices are often consistent within contexts, but unstable between contexts. We also demonstrate that for a limited, though reasonably broad, class of decision-making domains, recent theoretical models can be viewed as providing theories of contextual shifts. It is argued that one particular significant source of global inconsistency arises from a cognitive inability to represent absolute magnitudes, whether for perceptual variables, utilities, payoffs, or probabilities. This overall argument provides a fresh perspective on the scope and limits of human rationality. PMID:29301289

  5. Local Choices: Rationality and the Contextuality of Decision-Making.

    Science.gov (United States)

    Vlaev, Ivo

    2018-01-02

    Rational explanation is ubiquitous in psychology and social sciences, ranging from rational analysis, expectancy-value theories, ideal observer models, mental logic to probabilistic frameworks, rational choice theory, and informal "folk psychological" explanation. However, rational explanation appears to be challenged by apparently systematic irrationality observed in psychological experiments, especially in the field of judgement and decision-making (JDM). Here, it is proposed that the experimental results require not that rational explanation should be rejected, but that rational explanation is local , i.e., within a context. Thus, rational models need to be supplemented with a theory of contextual shifts. We review evidence in JDM that patterns of choices are often consistent within contexts, but unstable between contexts. We also demonstrate that for a limited, though reasonably broad, class of decision-making domains, recent theoretical models can be viewed as providing theories of contextual shifts. It is argued that one particular significant source of global inconsistency arises from a cognitive inability to represent absolute magnitudes, whether for perceptual variables, utilities, payoffs, or probabilities. This overall argument provides a fresh perspective on the scope and limits of human rationality.

  6. Techno-Optimism and Rational Superstition

    DEFF Research Database (Denmark)

    Wilson, Alexander

    2017-01-01

    our common understanding of reason and rationality? To adopt rational expectations about the world, after all, should we not attempt to avoid the emotional over-determination of our assessments? I show that applied reason is conceptually entangled with this superstitious optimism in the continued...... of retro-causation, where the future is held to somehow have a retroactive effect on the past. This suggests, I argue, that the underlying mechanism by which techno-optimism is supposed to be instrumental in bringing about the future is fundamentally superstitious. But does this superstition not go against...... successes of technology. The article thus reveals a curious sense in which reason is intrinsically superstitious. I offer an evolutionary explanation for this, showing that the biological origins of reason will by nature tend to produce rational agents which are superstitiously bound to realism...

  7. [What did bachelard mean by "applied rationalism" ?].

    Science.gov (United States)

    Tiles, Mary

    2013-01-01

    Bachelard was concerned with the processes whereby scientific knowledge is acquired, including the activity of knowing subjects. He did not equate reasoning with logic but rather argued that reasoning resulted from the use of mathematics in organizing both thought and experimental practices, which is why he conceived science as applied mathematics. This had material and technical implications, for Bachelard was concerned with the element of reason inherent in technical materialism as well as the concrete reality inherent in applied rationalism.

  8. Information-Theoretic Bounded Rationality and ε-Optimality

    Directory of Open Access Journals (Sweden)

    Daniel A. Braun

    2014-08-01

    Full Text Available Bounded rationality concerns the study of decision makers with limited information processing resources. Previously, the free energy difference functional has been suggested to model bounded rational decision making, as it provides a natural trade-off between an energy or utility function that is to be optimized and information processing costs that are measured by entropic search costs. The main question of this article is how the information-theoretic free energy model relates to simple ε-optimality models of bounded rational decision making, where the decision maker is satisfied with any action in an ε-neighborhood of the optimal utility. We find that the stochastic policies that optimize the free energy trade-off comply with the notion of ε-optimality. Moreover, this optimality criterion even holds when the environment is adversarial. We conclude that the study of bounded rationality based on ε-optimality criteria that abstract away from the particulars of the information processing constraints is compatible with the information-theoretic free energy model of bounded rationality.

  9. Rationing critical care medicine: recent studies and current trends.

    Science.gov (United States)

    Ward, Nicholas S

    2005-12-01

    This paper reviews the literature on the rationing of critical care resources. Although much has been written about the concept of rationing, there have been few scientific studies as to its prevalence. A recent meta-analysis reviewed all previously published studies on rationing access to intensive care units but little is known about practices within the intensive care unit. Much literature in the past few years has focused on the growing use of critical care resources and projections for the future. Several authors suggest there may be a crisis in financial or personnel resources if some rationing does not take place. Other papers have argued that the methods of rationing critical care previously proposed, such as limiting the care of dying patients or using cost-effectiveness analysis to determine care, may not be effective or viewed as ethical by some. Finally, several recent papers review how critical care is practiced and allocated in India and Asian countries that already practice open rationing in their health care systems. There is currently no published evidence that overt rationing is taking place in critical care medicine. There is growing evidence that in the future, the need for critical care may outstrip financial resources unless some form of rationing takes place. It is also clear from the literature that choosing how to ration critical care will be a difficult task.

  10. Decision rules and group rationality: cognitive gain or standstill?

    Directory of Open Access Journals (Sweden)

    Petru Lucian Curşeu

    Full Text Available Recent research in group cognition points towards the existence of collective cognitive competencies that transcend individual group members' cognitive competencies. Since rationality is a key cognitive competence for group decision making, and group cognition emerges from the coordination of individual cognition during social interactions, this study tests the extent to which collaborative and consultative decision rules impact the emergence of group rationality. Using a set of decision tasks adapted from the heuristics and biases literature, we evaluate rationality as the extent to which individual choices are aligned with a normative ideal. We further operationalize group rationality as cognitive synergy (the extent to which collective rationality exceeds average or best individual rationality in the group, and we test the effect of collaborative and consultative decision rules in a sample of 176 groups. Our results show that the collaborative decision rule has superior synergic effects as compared to the consultative decision rule. The ninety one groups working in a collaborative fashion made more rational choices (above and beyond the average rationality of their members than the eighty five groups working in a consultative fashion. Moreover, the groups using a collaborative decision rule were closer to the rationality of their best member than groups using consultative decision rules. Nevertheless, on average groups did not outperformed their best member. Therefore, our results reveal how decision rules prescribing interpersonal interactions impact on the emergence of collective cognitive competencies. They also open potential venues for further research on the emergence of collective rationality in human decision-making groups.

  11. Decision rules and group rationality: cognitive gain or standstill?

    Science.gov (United States)

    Curşeu, Petru Lucian; Jansen, Rob J G; Chappin, Maryse M H

    2013-01-01

    Recent research in group cognition points towards the existence of collective cognitive competencies that transcend individual group members' cognitive competencies. Since rationality is a key cognitive competence for group decision making, and group cognition emerges from the coordination of individual cognition during social interactions, this study tests the extent to which collaborative and consultative decision rules impact the emergence of group rationality. Using a set of decision tasks adapted from the heuristics and biases literature, we evaluate rationality as the extent to which individual choices are aligned with a normative ideal. We further operationalize group rationality as cognitive synergy (the extent to which collective rationality exceeds average or best individual rationality in the group), and we test the effect of collaborative and consultative decision rules in a sample of 176 groups. Our results show that the collaborative decision rule has superior synergic effects as compared to the consultative decision rule. The ninety one groups working in a collaborative fashion made more rational choices (above and beyond the average rationality of their members) than the eighty five groups working in a consultative fashion. Moreover, the groups using a collaborative decision rule were closer to the rationality of their best member than groups using consultative decision rules. Nevertheless, on average groups did not outperformed their best member. Therefore, our results reveal how decision rules prescribing interpersonal interactions impact on the emergence of collective cognitive competencies. They also open potential venues for further research on the emergence of collective rationality in human decision-making groups.

  12. Low temperature experiments in radiation biophysics

    International Nuclear Information System (INIS)

    Moan, J.

    1977-01-01

    The reasons for performing experiments in radiation biophysics at low temperatures, whereby electron spectra may be studied, are explained. The phenomenon of phosphorescence spectra observed in frozen aqueous solutions of tryptophan and adenosine is also described. Free radicals play an important part in biological radiation effects and may be studied by ESR spectroscopy. An ESR spectrum of T 1 bacteriophages irradiated dry at 130K is illustrated and discussed. Hydrogen atoms, which give lines on the spectrum, are believed to be those radiation products causing most biological damage in a dry system. Low temperature experiments are of great help in explaining the significance of direct and indirect effects. This is illustrated for the case of trypsin. (JIW)

  13. Anxiety reduction through group instruction in rational therapy.

    Science.gov (United States)

    Maxwell, J W; Wilkerson, J

    1982-09-01

    This study investigated the effects of group Rational Therapy in promoting rational thinking and self-enhancing emotions among 24 college students. Each subject was administered the Sixteen Personality Factor Questionnaire as a pre- and post-test measurement. Results reveal that some aspects of personality are affected by Rational Therapy group programs while others are not.

  14. Thinking about acting logical foundations for rational decision making

    CERN Document Server

    Pollock, John L

    2006-01-01

    John Pollock aims to construct a theory of rational decision making for real agents--not ideal agents. Real agents have limited cognitive powers, but traditional theories of rationality have applied only to idealized agents that lack such constraints. Pollock argues that theories of ideal rationality are largely irrelevant to the decision making of real agents. Thinking about Acting aims to provide a theory of ""real rationality.""

  15. Choice, internal consistency, and rationality

    OpenAIRE

    Aditi Bhattacharyya; Prasanta K. Pattanaik; Yongsheng Xu

    2010-01-01

    The classical theory of rational choice is built on several important internal consistency conditions. In recent years, the reasonableness of those internal consistency conditions has been questioned and criticized, and several responses to accommodate such criticisms have been proposed in the literature. This paper develops a general framework to accommodate the issues raised by the criticisms of classical rational choice theory, and examines the broad impact of these criticisms from both no...

  16. Management between Rationality and Irrationality

    OpenAIRE

    Cene Bavec

    2012-01-01

    In the paper, we discuss theoretical and practical aspects of management and its rational and irrational behavior in the light of traditional management theories and contemporary social theories and theories of complexity. We exposed differences between middle and top management, where rationality is ascribed mainly to middle management, while top management often acts on seemingly irrational way. For the part of this irrationality, we cannot blame management because it originates from the na...

  17. Assimilation of Biophysical Neuronal Dynamics in Neuromorphic VLSI.

    Science.gov (United States)

    Wang, Jun; Breen, Daniel; Akinin, Abraham; Broccard, Frederic; Abarbanel, Henry D I; Cauwenberghs, Gert

    2017-12-01

    Representing the biophysics of neuronal dynamics and behavior offers a principled analysis-by-synthesis approach toward understanding mechanisms of nervous system functions. We report on a set of procedures assimilating and emulating neurobiological data on a neuromorphic very large scale integrated (VLSI) circuit. The analog VLSI chip, NeuroDyn, features 384 digitally programmable parameters specifying for 4 generalized Hodgkin-Huxley neurons coupled through 12 conductance-based chemical synapses. The parameters also describe reversal potentials, maximal conductances, and spline regressed kinetic functions for ion channel gating variables. In one set of experiments, we assimilated membrane potential recorded from one of the neurons on the chip to the model structure upon which NeuroDyn was designed using the known current input sequence. We arrived at the programmed parameters except for model errors due to analog imperfections in the chip fabrication. In a related set of experiments, we replicated songbird individual neuron dynamics on NeuroDyn by estimating and configuring parameters extracted using data assimilation from intracellular neural recordings. Faithful emulation of detailed biophysical neural dynamics will enable the use of NeuroDyn as a tool to probe electrical and molecular properties of functional neural circuits. Neuroscience applications include studying the relationship between molecular properties of neurons and the emergence of different spike patterns or different brain behaviors. Clinical applications include studying and predicting effects of neuromodulators or neurodegenerative diseases on ion channel kinetics.

  18. Biophysical basis for the geometry of conical stromatolites.

    Science.gov (United States)

    Petroff, Alexander P; Sim, Min Sub; Maslov, Andrey; Krupenin, Mikhail; Rothman, Daniel H; Bosak, Tanja

    2010-06-01

    Stromatolites may be Earth's oldest macroscopic fossils; however, it remains controversial what, if any, biological processes are recorded in their morphology. Although the biological interpretation of many stromatolite morphologies is confounded by the influence of sedimentation, conical stromatolites form in the absence of sedimentation and are, therefore, considered to be the most robust records of biophysical processes. A qualitative similarity between conical stromatolites and some modern microbial mats suggests a photosynthetic origin for ancient stromatolites. To better understand and interpret ancient fossils, we seek a quantitative relationship between the geometry of conical stromatolites and the biophysical processes that control their growth. We note that all modern conical stromatolites and many that formed in the last 2.8 billion years display a characteristic centimeter-scale spacing between neighboring structures. To understand this prominent-but hitherto uninterpreted-organization, we consider the role of diffusion in mediating competition between stromatolites. Having confirmed this model through laboratory experiments and field observation, we find that organization of a field of stromatolites is set by a diffusive time scale over which individual structures compete for nutrients, thus linking form to physiology. The centimeter-scale spacing between modern and ancient stromatolites corresponds to a rhythmically fluctuating metabolism with a period of approximately 20 hr. The correspondence between the observed spacing and the day length provides quantitative support for the photosynthetic origin of conical stromatolites throughout geologic time.

  19. Biophysics of filament length regulation by molecular motors

    International Nuclear Information System (INIS)

    Kuan, Hui-Shun; Betterton, M D

    2013-01-01

    Regulating physical size is an essential problem that biological organisms must solve from the subcellular to the organismal scales, but it is not well understood what physical principles and mechanisms organisms use to sense and regulate their size. Any biophysical size-regulation scheme operates in a noisy environment and must be robust to other cellular dynamics and fluctuations. This work develops theory of filament length regulation inspired by recent experiments on kinesin-8 motor proteins, which move with directional bias on microtubule filaments and alter microtubule dynamics. Purified kinesin-8 motors can depolymerize chemically-stabilized microtubules. In the length-dependent depolymerization model, the rate of depolymerization tends to increase with filament length, because long filaments accumulate more motors at their tips and therefore shorten more quickly. When balanced with a constant filament growth rate, this mechanism can lead to a fixed polymer length. However, the mechanism by which kinesin-8 motors affect the length of dynamic microtubules in cells is less clear. We study the more biologically realistic problem of microtubule dynamic instability modulated by a motor-dependent increase in the filament catastrophe frequency. This leads to a significant decrease in the mean filament length and a narrowing of the filament length distribution. The results improve our understanding of the biophysics of length regulation in cells. (paper)

  20. Self-Reported Rationing Behavior Among US Physicians: A National Survey.

    Science.gov (United States)

    Sheeler, Robert D; Mundell, Tim; Hurst, Samia A; Goold, Susan Dorr; Thorsteinsdottir, Bjorg; Tilburt, Jon C; Danis, Marion

    2016-12-01

    Rationing is a controversial topic among US physicians. Understanding their attitudes and behaviors around rationing may be essential to a more open and sensible professional discourse on this important but controversial topic. To describe rationing behavior and associated factors among US physicians. Survey mailed to US physicians in 2012 to evaluate self-reported rationing behavior and variables related to this behavior. US physicians across a full spectrum of practice settings. A total of 2541 respondents, representing 65.6 % of the original mailing list of 3872 US addresses. The study was a cross-sectional analysis of physician attitudes and self-reported behaviors, with neutral language representations of the behaviors as well as an embedded experiment to test the influence of the word "ration" on perceived responsibility. Overall percentage of respondents reporting rationing behavior in various contexts and assessment of attitudes toward rationing. In total, 1348 respondents (53.1 %) reported having personally refrained within the past 6 months from using specific clinical services that would have provided the best patient care, because of health system cost. Prescription drugs (n = 1073 [48.3 %]) and magnetic resonance imaging (n = 922 [44.5 %]) were most frequently rationed. Surgical and procedural specialists were less likely to report rationing behavior (adjusted odds ratio [OR] [95 % CI], 0.8 [0.9-0.9] and 0.5 [0.4-0.6], respectively) compared to primary care. Compared with small or solo practices, those in medical school settings reported less rationing (adjusted OR [95 % CI], 0.4 [0.2-0.7]). Physicians who self-identified as very or somewhat liberal were significantly less likely to report rationing (adjusted OR [95 % CI], 0.7 [0.6-0.9]) than those self-reporting being very or somewhat conservative. A more positive opinion about rationing tended to align with greater odds of rationing. More than one-half of respondents engaged in

  1. Rational-driver approximation in car-following theory

    Science.gov (United States)

    Lubashevsky, Ihor; Wagner, Peter; Mahnke, Reinhard

    2003-11-01

    The problem of a car following a lead car driven with constant velocity is considered. To derive the governing equations for the following car dynamics a cost functional is constructed. This functional ranks the outcomes of different driving strategies, which applies to fairly general properties of the driver behavior. Assuming rational-driver behavior, the existence of the Nash equilibrium is proved. Rational driving is defined by supposing that a driver corrects continuously the car motion to follow the optimal path minimizing the cost functional. The corresponding car-following dynamics is described quite generally by a boundary value problem based on the obtained extremal equations. Linearization of these equations around the stationary state results in a generalization of the widely used optimal velocity model. Under certain conditions (the “dense traffic” limit) the rational car dynamics comprises two stages, fast and slow. During the fast stage a driver eliminates the velocity difference between the cars, the subsequent slow stage optimizes the headway. In the dense traffic limit an effective Hamiltonian description is constructed. This allows a more detailed nonlinear analysis. Finally, the differences between rational and bounded rational driver behavior are discussed. The latter, in particular, justifies some basic assumptions used recently by the authors to construct a car-following model lying beyond the frameworks of rationality.

  2. Rationality and ritual

    International Nuclear Information System (INIS)

    Wynne, B.

    1982-01-01

    The book concerns the Windscale Public Inquiry, held to investigate the application by British Nuclear Fuels to build a 1200 tonne per year thermal oxide reprocessing plant (THORP) for spent nuclear fuels from Britain and overseas. The subject is discussed under the headings: introduction (international dimensions; the Windscale Inquiry; conflict resolution and social drama; public debate and the sociology of knowledge); the decision-making legacy; oxide reprocessing - the background; the public inquiry tradition - a comparative perspective; the emergence of THORP from a private to a public issue (local and national planning politics); the process and impact of the Inquiry (opposition groups); judicial rationality, expert conflict, and political authority); the rationality and politics of analysis (proliferation; radiation risks; relative risks; the Ravenglass issue; discharge targets; general radiation protection arrangements); conclusion. (U.K.)

  3. Rational accountability and rational autonomy in academic practice: An extended case study of the communicative ethic of interdisciplinary science

    Science.gov (United States)

    Robertson, Susan Margaret

    The dissertation investigates the interaction of rational accountability and rational autonomy in interdisciplinary science within the lifeworld of the university. It focuses on the cultural, social and motivational forces that university researchers draw on, and develop, to constitute and regulate interdisciplinary science. Findings are analyzed within an applied critical social theory framework that attends to the interaction of instrumental and communicative rational action within the public spaces that constitute the lifeworld of the university as a public sphere in society. The research raises questions of how academics practice interdisciplinary science and how these practices relate to the reproduction of the regulative ideal of the university as a community that practices public reason. The conceptual framework informing the research is Habermas' (1984) theory of communicative action. Using Burawoy's (1991) extended case study method as an operational strategy, two modes of constituting and regulating interdisciplinary science were found. Instrumental rational modes dominated in social contexts of interdisciplinary science where consensus on the normative goals and purposes of rational academic action were pre-existing and pre-supposed by participants. Communicative rational modes dominated in social contexts of interdisciplinary science where the normative goals and purposes of rational academic action entered a contested domain. Endorsements for interdisciplinary science policies are coinciding with demands for increased accountability and relevance of Canada's university system. At the same time that the university system must respond to external demands, it must reproduce itself as a public institution open to the discursive redemption of factual and normative validity claims. The study found that academics participate in, but also contest the instrumental regulation of academic inquiry and conduct by using their constitutional autonomy and freedom to

  4. THE PROBLEM OF RATIONAL CHOICE OF OPTIONS OF TRANSPORT COMPANY DIVERSIFICATION

    Directory of Open Access Journals (Sweden)

    G. A. Kryzhanovskii

    2014-01-01

    Full Text Available The necessity of using of heuristic methods take account of uncertainties in each of the transport company activities when choosing a rational variant of the vector control of dynamic processes related to performance indicators, built on the basis of poly-criteria evaluation.

  5. Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins

    Directory of Open Access Journals (Sweden)

    Masami Suganuma

    2016-11-01

    Full Text Available Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (−-epigallocatechin gallate (EGCG in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AFM and microfluidic optical stretcher. Specifically, determination of biophysical properties of cancer cells, low cell stiffness, and high deformability in relation to migration, along with biophysical effects, were studied by treatment with green tea catechins. The study with AFM revealed that low average values of Young’s moduli, indicating low cell stiffness, are closely associated with strong potential of cell migration and metastasis for various cancer cells. It is important to note that treatments with EGCG and green tea extract elevated the average values of Young’s moduli resulting in increased stiffness (large elasticity of melanomas and various cancer cells. We discuss here the biophysical basis of multifunctions of green tea catechins and green tea extract leading to beneficial effects for cancer prevention and treatment.

  6. Variation of Biophysical Parameters of the Skin with Age, Gender, and Body Region

    Science.gov (United States)

    Firooz, Alireza; Sadr, Bardia; Babakoohi, Shahab; Sarraf-Yazdy, Maryam; Fanian, Ferial; Kazerouni-Timsar, Ali; Nassiri-Kashani, Mansour; Naghizadeh, Mohammad Mehdi; Dowlati, Yahya

    2012-01-01

    Background. Understanding the physiological, chemical, and biophysical characteristics of the skin helps us to arrange a proper approach to the management of skin diseases. Objective. The aim of this study was to measure 6 biophysical characteristics of normal skin (sebum content, hydration, transepidermal water loss (TEWL), erythema index, melanin index, and elasticity) in a normal population and assess the effect of sex, age, and body location on them. Methods. Fifty healthy volunteers in 5 age groups (5 males and females in each) were enrolled in this study. A multifunctional skin physiology monitor (Courage & Khazaka electronic GmbH, Germany) was used to measure skin sebum content, hydration, TEWL, erythema index, melanin index, and elasticity in 8 different locations of the body. Results. There were significant differences between the hydration, melanin index, and elasticity of different age groups. Regarding the locations, forehead had the highest melanin index, where as palm had the lowest value. The mean values of erythema index and melanin index and TEWL were significantly higher in males and anatomic location was a significant independent factor for all of 6 measured parameters. Conclusion. Several biophysical properties of the skin vary among different gender, age groups, and body locations. PMID:22536139

  7. Magic vs. Science in the Historiography of Science: The Social-Historical Construction of Rationality

    Directory of Open Access Journals (Sweden)

    Carlos Alvarez Maia

    2017-12-01

    Full Text Available The historiography of scientific studies has suffered from a great impact, that is rarely referred to, from anthropological analyses of magic in so-called primitive societies. The emphasis brought by criticism during the 1950/1960’s of Evans-Pritchard’s 1937 classic, Witchcraft, Oracles and Magic among the Azande, brought a fresh look at certainties already consolidated in Western thought, especially those relating to rational human characteristics and science. For the history, these criticisms were interesting because they were presented science as a historically situated activity, in the same way as magic. It favours, therefore, the proximity of historians tout court with the history of the sciences that resists its absences even today. This renewal helped to create a scenario that would enable David Bloor to develop the strong program of Sociology of Knowledge in the 1970s. Such a program indicates the analogous process that involves both the social production of beliefs and that of scientific truths. The comparison between magic and science usually presents them in a hierarchy. As if there were an evolutionary process in which magical thinking necessarily preceded scientific thought. The one, more precarious, would belong to the prehistory of the scientific thought, which would be the climax of modern rational action. In this paper I evaluate the proximity of magic-science from the point of view of contemporary studies about scientific activity, questioning the concepts of rationality and logic as if they were exclusive qualities of scientific activity. A kind of metaphysical gift that would show the superiority of individuals over others, as much as of science over magic. I give special emphasis to the exposition of how rationality and logic are socio-historical characteristics acquired throughout history by human subjects in their experiential practices, and which are present both in magic and technical activities; these, an embryo of

  8. Laccase engineering: from rational design to directed evolution.

    Science.gov (United States)

    Mate, Diana M; Alcalde, Miguel

    2015-01-01

    Laccases are multicopper oxidoreductases considered by many in the biotechonology field as the ultimate "green catalysts". This is mainly due to their broad substrate specificity and relative autonomy (they use molecular oxygen from air as an electron acceptor and they only produce water as by-product), making them suitable for a wide array of applications: biofuel production, bioremediation, organic synthesis, pulp biobleaching, textiles, the beverage and food industries, biosensor and biofuel cell development. Since the beginning of the 21st century, specific features of bacterial and fungal laccases have been exhaustively adapted in order to reach the industrial demands for high catalytic activity and stability in conjunction with reduced production cost. Among the goals established for laccase engineering, heterologous functional expression, improved activity and thermostability, tolerance to non-natural media (organic solvents, ionic liquids, physiological fluids) and resistance to different types of inhibitors are all challenges that have been met, while obtaining a more comprehensive understanding of laccase structure-function relationships. In this review we examine the most significant advances in this exciting research area in which rational, semi-rational and directed evolution approaches have been employed to ultimately convert laccases into high value-added biocatalysts. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Quantum Nanobiology and Biophysical Chemistry

    DEFF Research Database (Denmark)

    2013-01-01

    An introduction was provided in the first issue by way of an Editorial to this special two issue volume of Current Physical Chemistry – “Quantum Nanobiology and Biophysical Chemistry” [1]. The Guest Editors would like to thank all the authors and referees who have contributed to this second issue....... Wu et al. use density functional theory to explore the use of Ni/Fe bimetallic nanotechnology in the bioremediation of decabromo-diphenyl esters. Araújo-Chaves et al. explore the binding and reactivity of Mn(III) porphyrins in the membrane mimetic setting of model liposomal systems. Claussen et al....... demonstrate extremely low detection performance of acyl-homoserine lactone in a biologically relevant system using surface enhanced Raman spectroscopy. Sugihara and Bondar evaluate the influence of methyl-groups and the protein environment on retinal geometries in rhodopsin and bacteriorhodopsin, two...

  10. The Problem of Rational Moral Enlistment

    Science.gov (United States)

    Tillson, John

    2017-01-01

    How can one bring children to recognize the requirements of morality without resorting only to non-rational means of persuasion (i.e. what rational ground can be offered to children for their moral enlistment)? Michael Hand has recently defended a foundationalist approach to answering this question and John White has responded by (a) criticizing…

  11. CASE STUDY OF A SUPPLIER WAREHOUSING PROCESS RATIONALIZATION

    OpenAIRE

    Richárd Ladányi; Norbert Tóth

    2010-01-01

    Accomplishment of customer orders from the viewpoints of required lead time and quality is important factor in successful operation of a multinational company. Logistics plays key role in meeting customer requirements and also it has great influence on operation costs. Rationalization efforts often mean the reduction of inbound and outbound stocks and the minimization of the material handling activities in a production factory accordingly customers require more and more complex services from ...

  12. Confucian Rationalism

    Science.gov (United States)

    Lam, Chi-Ming

    2014-01-01

    Nowadays, there is still a widely held view that the Chinese and Western modes of thought are quite distinct from each other. In particular, the Chinese mode of thought derived from Confucianism is considered as comparatively less rational than the Western one. In this article, I first argue that although the analogical mode of argumentation,…

  13. Changes in Rational Economic Behavior Model, Caused By the Development of E-Commerce

    Directory of Open Access Journals (Sweden)

    Menzeleev Ilya, A.

    2016-03-01

    Full Text Available In the paper the author examines the origins of rationality concept and its transformation within the framework of economic science. According to the author, rationality is a fundamental concept both for philosophy and for economics. Changes in rational economic behavior model significantly effect on informal institutes (in short-term perspective and on formal institutes (in long-term period. In the paper it is said about significant changes taking place with humanity right now. Today it becomes more and more difficult to describe human behavior by uniform concept of rationality. Now people live in a world that is developing unprecedentedly fast, with the usage of incredible amount of information, countless tasks and social contacts. The development of the Internet and IT tools facilitate this process. Already since the midtwentieth century advertising and marketing has been influencing people’s lifestyle like politics or news. Media resources brands today are comparable to the resources of some political parties or even TV channels what means that advertising today is one of the main factors affecting consumers ' minds and their behavioral model, main feature of which is the premise of rationality or justification of actions. The author analyzes the changes of models of rationality over time and, above all, the changes caused by the development of Internet marketing and its tools for monitoring user activity and the impact on decision making in the Network. In conclusion a number of recommendations is given, which can help consumers to save an independence in making decisions in the Internet environment.

  14. Cognitive distance, absorptive capacity and group rationality: a simulation study.

    Directory of Open Access Journals (Sweden)

    Petru Lucian Curşeu

    Full Text Available We report the results of a simulation study in which we explore the joint effect of group absorptive capacity (as the average individual rationality of the group members and cognitive distance (as the distance between the most rational group member and the rest of the group on the emergence of collective rationality in groups. We start from empirical results reported in the literature on group rationality as collective group level competence and use data on real-life groups of four and five to validate a mathematical model. We then use this mathematical model to predict group level scores from a variety of possible group configurations (varying both in cognitive distance and average individual rationality. Our results show that both group competence and cognitive distance are necessary conditions for emergent group rationality. Group configurations, in which the groups become more rational than the most rational group member, are groups scoring low on cognitive distance and scoring high on absorptive capacity.

  15. Cognitive distance, absorptive capacity and group rationality: a simulation study.

    Science.gov (United States)

    Curşeu, Petru Lucian; Krehel, Oleh; Evers, Joep H M; Muntean, Adrian

    2014-01-01

    We report the results of a simulation study in which we explore the joint effect of group absorptive capacity (as the average individual rationality of the group members) and cognitive distance (as the distance between the most rational group member and the rest of the group) on the emergence of collective rationality in groups. We start from empirical results reported in the literature on group rationality as collective group level competence and use data on real-life groups of four and five to validate a mathematical model. We then use this mathematical model to predict group level scores from a variety of possible group configurations (varying both in cognitive distance and average individual rationality). Our results show that both group competence and cognitive distance are necessary conditions for emergent group rationality. Group configurations, in which the groups become more rational than the most rational group member, are groups scoring low on cognitive distance and scoring high on absorptive capacity.

  16. Emotions as a Vehicle for Rationality: Rational Decision Making Models Based on Emotion-Related Valuing and Hebbian Learning

    NARCIS (Netherlands)

    Treur, J.; Umair, M.

    2015-01-01

    In this paper an adaptive decision model based on predictive loops through feeling states is analysed from the perspective of rationality. Hebbian learning is considered for different types of connections in the decision model. To assess the extent of rationality, a measure is introduced reflecting

  17. Re-visions of rationality?

    Science.gov (United States)

    Newell, Ben R

    2005-01-01

    The appeal of simple algorithms that take account of both the constraints of human cognitive capacity and the structure of environments has been an enduring theme in cognitive science. A novel version of such a boundedly rational perspective views the mind as containing an 'adaptive toolbox' of specialized cognitive heuristics suited to different problems. Although intuitively appealing, when this version was proposed, empirical evidence for the use of such heuristics was scant. I argue that in the light of empirical studies carried out since then, it is time this 'vision of rationality' was revised. An alternative view based on integrative models rather than collections of heuristics is proposed.

  18. Rationing medical education.

    African Journals Online (AJOL)

    This paper discussed the pros and cons of the application of rationing to medical education and the different ... Even though some stakeholders in medical education might be taken aback at .... Walsh K. Online educational tools to improve the.

  19. Rationality, perception, and the all-seeing eye.

    Science.gov (United States)

    Felin, Teppo; Koenderink, Jan; Krueger, Joachim I

    2017-08-01

    Seeing-perception and vision-is implicitly the fundamental building block of the literature on rationality and cognition. Herbert Simon and Daniel Kahneman's arguments against the omniscience of economic agents-and the concept of bounded rationality-depend critically on a particular view of the nature of perception and vision. We propose that this framework of rationality merely replaces economic omniscience with perceptual omniscience. We show how the cognitive and social sciences feature a pervasive but problematic meta-assumption that is characterized by an "all-seeing eye." We raise concerns about this assumption and discuss different ways in which the all-seeing eye manifests itself in existing research on (bounded) rationality. We first consider the centrality of vision and perception in Simon's pioneering work. We then point to Kahneman's work-particularly his article "Maps of Bounded Rationality"-to illustrate the pervasiveness of an all-seeing view of perception, as manifested in the extensive use of visual examples and illusions. Similar assumptions about perception can be found across a large literature in the cognitive sciences. The central problem is the present emphasis on inverse optics-the objective nature of objects and environments, e.g., size, contrast, and color. This framework ignores the nature of the organism and perceiver. We argue instead that reality is constructed and expressed, and we discuss the species-specificity of perception, as well as perception as a user interface. We draw on vision science as well as the arts to develop an alternative understanding of rationality in the cognitive and social sciences. We conclude with a discussion of the implications of our arguments for the rationality and decision-making literature in cognitive psychology and behavioral economics, along with suggesting some ways forward.

  20. The Biophysics Microgravity Initiative

    Science.gov (United States)

    Gorti, S.

    2016-01-01

    Biophysical microgravity research on the International Space Station using biological materials has been ongoing for several decades. The well-documented substantive effects of long duration microgravity include the facilitation of the assembly of biological macromolecules into large structures, e.g., formation of large protein crystals under micro-gravity. NASA is invested not only in understanding the possible physical mechanisms of crystal growth, but also promoting two flight investigations to determine the influence of µ-gravity on protein crystal quality. In addition to crystal growth, flight investigations to determine the effects of shear on nucleation and subsequent formation of complex structures (e.g., crystals, fibrils, etc.) are also supported. It is now considered that long duration microgravity research aboard the ISS could also make possible the formation of large complex biological and biomimetic materials. Investigations of various materials undergoing complex structure formation in microgravity will not only strengthen NASA science programs, but may also provide invaluable insight towards the construction of large complex tissues, organs, or biomimetic materials on Earth.

  1. Integrating socio-economic and biophysical data to enhance watershed management and planning

    Science.gov (United States)

    Pirani, Farshad Jalili; Mousavi, Seyed Alireza

    2016-09-01

    Sustainability has always been considered as one of the main aspects of watershed management plans. In many developing countries, watershed management practices and planning are usually performed by integrating biophysical layers, and other existing layers which cannot be identified as geographic layers are ignored. We introduce an approach to consider some socioeconomic parameters which are important for watershed management decisions. Ganj basin in Chaharmahal-Bakhtiari Province was selected as the case study area, which includes three traditional sanctums: Ganj, Shiremard and Gerdabe Olya. Socioeconomic data including net agricultural income, net ranching income, population and household number, literacy rate, unemployment rate, population growth rate and active population were mapped within traditional sanctums and then were integrated into other biophysical layers. After overlaying and processing these data to determine management units, different quantitative and qualitative approaches were adopted to achieve a practical framework for watershed management planning and relevant plans for homogeneous units were afterwards proposed. Comparing the results with current plans, the area of allocated lands to different proposed operations considering both qualitative and quantitative approaches were the same in many cases and there was a meaningful difference with current plans; e.g., 3820 ha of lands are currently managed under an enclosure plan, while qualitative and quantitative approaches in this study suggest 1388 and 1428 ha to be allocated to this operation type, respectively. Findings show that despite the ambiguities and complexities, different techniques could be adopted to incorporate socioeconomic conditions in watershed management plans. This introductory approach will help to enhance watershed management decisions with more attention to societal background and economic conditions, which will presumably motivate local communities to participate in

  2. Predicting the Presence of Scyphozoan Jellyfish in the Gulf of Mexico Using a Biophysical Model

    Science.gov (United States)

    Aleksa, K. T.; Nero, R. W.; Wiggert, J. D.; Graham, W. M.

    2016-02-01

    The study and quantification of jellyfish (cnidarian medusae and ctenophores) is difficult due to their fragile body plan and a composition similar to their environment. The development of a predictive biophysical jellyfish model would be the first of its kind for the Gulf of Mexico and could provide assistance in ecological research and human interactions. In this study, the collection data of two scyphozoan medusae, Chrysaora quinquecirrha and Aurelia spp., were extracted from SEAMAP trawling surveys and were used to determine biophysical predictors for the presence of large jellyfish medusae in the Gulf of Mexico. Both in situ and remote sensing measurements from 2003 to 2013 were obtained. Logistic regressions were then applied to 27 biophysical parameters derived from these data to explore and determine significant predictors for the presence of medusae. Significant predictors identified by this analysis included water temperature, chlorophyll a, turbidity, distance from shore, and salinity. Future application for this model include foraging assessment of gelatinous predators as well as possible near real time monitoring of the distribution and movement of these medusae in the Gulf of Mexico.

  3. Preclinical Activity of the Rational Combination of Selumetinib (AZD6244) in Combination with Vorinostat in KRAS-Mutant Colorectal Cancer Models

    Science.gov (United States)

    Morelli, M. Pia; Tentler, John J.; Kulikowski, Gillian N.; Tan, Aik-Choon; Bradshaw-Pierce, Erica L.; Pitts, Todd M.; Brown, Amy M.; Nallapareddy, Sujatha; Arcaroli, John J.; Serkova, Natalie J.; Hidalgo, Manuel; Ciardiello, Fortunato; Eckhardt, S. Gail

    2013-01-01

    Purpose Despite the availability of several active combination regimens for advanced colorectal cancer (CRC), the 5-year survival rate remains poor at less than 10%,supporting the development of novel therapeutic approaches. In this study, we focused on the preclinical assessment of a rationally based combination against KRAS-mutated CRC by testing the combination of the MEK inhibitor, selumetinib, and vorinostat, a histone deacetylase (HDAC) inhibitor. Experimental Design Transcriptional profiling and gene set enrichment analysis (baseline and post-treatment) of CRC cell lines provided the rationale for the combination. The activity of selumetinib and vorinostat against the KRAS-mutant SW620 and SW480 CRC cell lines was studied in vitro and in vivo. The effects of this combination on tumor phenotype were assessed using monolayer and 3-dimensional cultures, flow cytometry, apoptosis, and cell migration. In vivo, tumor growth inhibition, 18F-fluoro-deoxy-glucose positron emission tomography (FDG-PET), and proton nuclear magnetic resonance were carried out to evaluate the growth inhibitory and metabolic responses, respectively, in CRC xenografts. Results In vitro, treatment with selumetinib and vorinostat resulted in a synergistic inhibition of proliferation and spheroid formation in both CRC cell lines. This inhibition was associated with an increase in apoptosis, cell-cycle arrest in G1, and reduced cellular migration and VEGF-A secretion. In vivo, the combination resulted in additive tumor growth inhibition. The metabolic response to selumetinib and vorinostat consisted of significant inhibition of membrane phospholipids; no significant changes in glucose uptake or metabolism were observed in any of the treatment groups. Conclusion These data indicate that the rationally based combination of the mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitor, selumetinib, with the HDAC inhibitor vorinostat results in synergistic antiproliferative

  4. Towards a classification of rational Hopf algebras

    International Nuclear Information System (INIS)

    Fuchs, J.; Ganchev, A.; Vecsernyes, P.

    1994-02-01

    Rational Hopf algebras, i.e. certain quasitriangular weak quasi-Hopf *-algebras, are expected to describe the quantum symmetry of rational field theories. In this paper methods are developed which allow for a classification of all rational Hopf algebras that are compatible with some prescribed set of fusion rules. The algebras are parametrized by the solutions of the square, pentagon and hexagon identities. As examples, we classify all solutions for fusion rules with not more than three sectors, as well as for the level three affine A 1 (1) fusion rules. We also establish several general properties of rational Hopf algebras and present a graphical description of the coassociator in terms of labelled tetrahedra. The latter construction allows to make contact with conformal field theory fusing matrices and with invariants of three-manifolds and topological lattice field theory. (orig.)

  5. Bounded rational choice behaviour: applications in transport

    DEFF Research Database (Denmark)

    Jensen, Anders Fjendbo

    2016-01-01

    Even though the theory of rational behaviour has been challenged for almost 100 years, the dominant approach within the field of transport has been based upon the assumptions of neoclassical economics that we live in a world of rational decision makers who always have perfect knowledge and aim...... rational choice behaviour focuses on how the latter approach can be seriously taken into account within transport applications. As the editors discuss in the introduction, a true optimal choice can only be made if an individual has full and perfect information of all relevant attributes in his/her choice...... set. An individual is said to demonstrate bounded rational behaviour if he/she does not systematically consider all attributes deemed relevant for the decision problem at hand, does not consider all choice options and/or does not choose the best choice alternative. Such simplified representation...

  6. Economic Rationality in the Ultimatum Game

    Directory of Open Access Journals (Sweden)

    Jan Fiala

    2017-03-01

    Full Text Available Rigorous application of experimental methodology to the interdisciplinary research of economic decision making is the main purpose of our work. In this paper, we introduce the main decisionmaking theories and outline economic rationality. We explain why we find it useful to discriminate between the “irrational” and “non-rational” components of decision making. We offer an oriented interdisciplinary point of view on economic rationality. In the applied section, we describe the main features of the Ultimatum game and summarize the up-to-date theories explaining the non-rational course of the game. We discuss in detail the reported relations between the nominal value of the stakes and the distribution of the offers and responses. We introduce the blinded, randomized Ultimatum game experiment that we conducted in our laboratory. We stress the importance of anonymity of the study subjects and the difference in salience of a factual reward against a  hypothetical reward. We present the results of our study, showing that a  duly chosen non-monetary reward, directly inconvertible into money, leads to a different offer distribution in the Ultimatum game without the necessity to invest excessive sums of money in the rewards. We compare our results to research published by other authors. According to our theory, the rational, non-rational and irrational components contribute to the decision making in Ultimatum differently depending on the different reward stakes.

  7. Chemical and Biophysical Modulation of Cas9 for Tunable Genome Engineering.

    Science.gov (United States)

    Nuñez, James K; Harrington, Lucas B; Doudna, Jennifer A

    2016-03-18

    The application of the CRISPR-Cas9 system for genome engineering has revolutionized the ability to interrogate genomes of mammalian cells. Programming the Cas9 endonuclease to induce DNA breaks at specified sites is achieved by simply modifying the sequence of its cognate guide RNA. Although Cas9-mediated genome editing has been shown to be highly specific, cleavage events at off-target sites have also been reported. Minimizing, and eventually abolishing, unwanted off-target cleavage remains a major goal of the CRISPR-Cas9 technology before its implementation for therapeutic use. Recent efforts have turned to chemical biology and biophysical approaches to engineer inducible genome editing systems for controlling Cas9 activity at the transcriptional and protein levels. Here, we review recent advancements to modulate Cas9-mediated genome editing by engineering split-Cas9 constructs, inteins, small molecules, protein-based dimerizing domains, and light-inducible systems.

  8. submitter Next generation multi-scale biophysical characterization of high precision cancer particle radiotherapy using clinical proton, helium-, carbon- and oxygen ion beams

    CERN Document Server

    Dokic, Ivana; Niklas, Martin; Zimmermann, Ferdinand; Chaudhri, Naved; Krunic, Damir; Tessonnier, Thomas; Ferrari, Alfredo; Parodi, Katia; Jäkel, Oliver; Debus, Jürgen; Haberer, Thomas; Abdollahi, Amir

    2016-01-01

    The growing number of particle therapy facilities worldwide landmarks a novel era of precision oncology. Implementation of robust biophysical readouts is urgently needed to assess the efficacy of different radiation qualities. This is the first report on biophysical evaluation of Monte Carlo simulated predictive models of prescribed dose for four particle qualities i.e., proton, helium-, carbon- or oxygen ions using raster-scanning technology and clinical therapy settings at HIT. A high level of agreement was found between the in silico simulations, the physical dosimetry and the clonogenic tumor cell survival. The cell fluorescence ion track hybrid detector (Cell-Fit-HD) technology was employed to detect particle traverse per cell nucleus. Across a panel of radiobiological surrogates studied such as late ROS accumulation and apoptosis (caspase 3/7 activation), the relative biological effectiveness (RBE) chiefly correlated with the radiation species-specific spatio-temporal pattern of DNA double strand break ...

  9. The anchoring bias reflects rational use of cognitive resources

    OpenAIRE

    Goodman, Noah; Huys, Quentin; Griffiths, Tom; Lieder, Falk

    2017-01-01

    © 2017, Psychonomic Society, Inc. Cognitive biases, such as the anchoring bias, pose a serious challenge to rational accounts of human cognition. We investigate whether rational theories can meet this challenge by taking into account the mind’s bounded cognitive resources. We asked what reasoning under uncertainty would look like if people made rational use of their finite time and limited cognitive resources. To answer this question, we applied a mathematical theory of bounded rationality to...

  10. Human Pluripotent Stem Cell Mechanobiology: Manipulating the Biophysical Microenvironment for Regenerative Medicine and Tissue Engineering Applications.

    Science.gov (United States)

    Ireland, Ronald G; Simmons, Craig A

    2015-11-01

    A stem cell in its microenvironment is subjected to a myriad of soluble chemical cues and mechanical forces that act in concert to orchestrate cell fate. Intuitively, many of these soluble and biophysical factors have been the focus of intense study to successfully influence and direct cell differentiation in vitro. Human pluripotent stem cells (hPSCs) have been of considerable interest in these studies due to their great promise for regenerative medicine. Culturing and directing differentiation of hPSCs, however, is currently extremely labor-intensive and lacks the efficiency required to generate large populations of clinical-grade cells. Improved efficiency may come from efforts to understand how the cell biophysical signals can complement biochemical signals to regulate cell pluripotency and direct differentiation. In this concise review, we explore hPSC mechanobiology and how the hPSC biophysical microenvironment can be manipulated to maintain and differentiate hPSCs into functional cell types for regenerative medicine and tissue engineering applications. © 2015 AlphaMed Press.

  11. Riparian influences on the biophysical characteristics of seston in headwater streams.

    Science.gov (United States)

    Scott R. Elliott; Robert J. Naiman; Peter A. Bisson

    2004-01-01

    Suspended particles (seston) in streams are an important source of nutrition for many invertebrates, forming a strong trophic link between plant and animal production. In forested regions the management of riparian corridors may alter alloehthonous and autochthonous contributions to streams, ultimately changing the biophysical characteristics of seston. This article...

  12. Biophysical studies of irradiated thymocytes. 1. Surface changes

    Energy Technology Data Exchange (ETDEWEB)

    Sungurov, A Yu; Tokalov, S V; Petrov, Yu P; Sharlaeva, T M

    1985-08-15

    In order to study postirradiation changes in thymus lymphocyte surface, a number of biophysical analytical methods was used: the cell two-partition method, the physical adhesion method, fluorescence intensity and binding parameters of negatively charged ANS probe. Reduction of cell distribution factor in two-phase system and adhesion of thymocytes to cotton 1 hour after irradiation, as well as abrupt change in parameters of binding the probe in the interval of 3-4 hours after X-ray irradiation at the dose of 4 Gy are demonstrated.

  13. Similar Biophysical Abnormalities in Glomeruli and Podocytes from Two Distinct Models.

    Science.gov (United States)

    Embry, Addie E; Liu, Zhenan; Henderson, Joel M; Byfield, F Jefferson; Liu, Liping; Yoon, Joonho; Wu, Zhenzhen; Cruz, Katrina; Moradi, Sara; Gillombardo, C Barton; Hussain, Rihanna Z; Doelger, Richard; Stuve, Olaf; Chang, Audrey N; Janmey, Paul A; Bruggeman, Leslie A; Miller, R Tyler

    2018-03-23

    Background FSGS is a pattern of podocyte injury that leads to loss of glomerular function. Podocytes support other podocytes and glomerular capillary structure, oppose hemodynamic forces, form the slit diaphragm, and have mechanical properties that permit these functions. However, the biophysical characteristics of glomeruli and podocytes in disease remain unclear. Methods Using microindentation, atomic force microscopy, immunofluorescence microscopy, quantitative RT-PCR, and a three-dimensional collagen gel contraction assay, we studied the biophysical and structural properties of glomeruli and podocytes in chronic (Tg26 mice [HIV protein expression]) and acute (protamine administration [cytoskeletal rearrangement]) models of podocyte injury. Results Compared with wild-type glomeruli, Tg26 glomeruli became progressively more deformable with disease progression, despite increased collagen content. Tg26 podocytes had disordered cytoskeletons, markedly abnormal focal adhesions, and weaker adhesion; they failed to respond to mechanical signals and exerted minimal traction force in three-dimensional collagen gels. Protamine treatment had similar but milder effects on glomeruli and podocytes. Conclusions Reduced structural integrity of Tg26 podocytes causes increased deformability of glomerular capillaries and limits the ability of capillaries to counter hemodynamic force, possibly leading to further podocyte injury. Loss of normal podocyte mechanical integrity could injure neighboring podocytes due to the absence of normal biophysical signals required for podocyte maintenance. The severe defects in podocyte mechanical behavior in the Tg26 model may explain why Tg26 glomeruli soften progressively, despite increased collagen deposition, and may be the basis for the rapid course of glomerular diseases associated with severe podocyte injury. In milder injury (protamine), similar processes occur but over a longer time. Copyright © 2018 by the American Society of Nephrology.

  14. Rational points on elliptic curves

    CERN Document Server

    Silverman, Joseph H

    2015-01-01

    The theory of elliptic curves involves a pleasing blend of algebra, geometry, analysis, and number theory. This book stresses this interplay as it develops the basic theory, thereby providing an opportunity for advanced undergraduates to appreciate the unity of modern mathematics. At the same time, every effort has been made to use only methods and results commonly included in the undergraduate curriculum. This accessibility, the informal writing style, and a wealth of exercises make Rational Points on Elliptic Curves an ideal introduction for students at all levels who are interested in learning about Diophantine equations and arithmetic geometry. Most concretely, an elliptic curve is the set of zeroes of a cubic polynomial in two variables. If the polynomial has rational coefficients, then one can ask for a description of those zeroes whose coordinates are either integers or rational numbers. It is this number theoretic question that is the main subject of this book. Topics covered include the geometry and ...

  15. Nurses' work environments, care rationing, job outcomes, and quality of care on neonatal units.

    Science.gov (United States)

    Rochefort, Christian M; Clarke, Sean P

    2010-10-01

    This paper is a report of a study of the relationship between work environment characteristics and neonatal intensive care unit nurses' perceptions of care rationing, job outcomes, and quality of care. International evidence suggests that attention to work environments might improve nurse recruitment and retention, and the quality of care. However, comparatively little attention has been given to neonatal care, a specialty where patient and nurse outcomes are potentially quite sensitive to problems with staffing and work environments. Over a 6-month period in 2007-2008, a questionnaire containing measures of work environment characteristics, nursing care rationing, job satisfaction, burnout and quality of care was distributed to 553 nurses in all neonatal intensive care units in the province of Quebec (Canada). A total of 339 nurses (61.3%) completed questionnaires. Overall, 18.6% were dissatisfied with their job, 35.7% showed high emotional exhaustion, and 19.2% rated the quality of care on their unit as fair or poor. Care activities most frequently rationed because of insufficient time were discharge planning, parental support and teaching, and comfort care. In multivariate analyses, higher work environment ratings were related to lower likelihood of reporting rationing and burnout, and better ratings of quality of care and job satisfaction. Additional research on the determinants of nurse outcomes, the quality of patient care, and the impact of rationing of nursing care on patient outcomes in neonatal intensive care units is required. The Neonatal Extent of Work Rationing Instrument appears to be a useful tool for monitoring the extent of rationing of nursing care in neonatal units. © 2010 Blackwell Publishing Ltd.

  16. Correction: Towards the rationalization of catalytic activity values by means of local hyper-softness on the catalytic site: a criticism about the use of net electric charges.

    Science.gov (United States)

    Martínez-Araya, Jorge Ignacio; Grand, André; Glossman-Mitnik, Daniel

    2016-01-28

    Correction for 'Towards the rationalization of catalytic activity values by means of local hyper-softness on the catalytic site: a criticism about the use of net electric charges' by Jorge Ignacio Martínez-Araya et al., Phys. Chem. Chem. Phys., 2015, DOI: 10.1039/c5cp03822g.

  17. Rationality, perception, and the all-seeing eye

    NARCIS (Netherlands)

    Felin, Teppo; Koenderink, Jan|info:eu-repo/dai/nl/070864543; Krueger, Joachim I

    Seeing-perception and vision-is implicitly the fundamental building block of the literature on rationality and cognition. Herbert Simon and Daniel Kahneman's arguments against the omniscience of economic agents-and the concept of bounded rationality-depend critically on a particular view of the

  18. Dimension counts for singular rational curves via semigroups

    OpenAIRE

    Cotterill, Ethan; Feital, Lia; Martins, Renato Vidal

    2015-01-01

    We study singular rational curves in projective space, deducing conditions on their parametrizations from the value semigroups $\\sss$ of their singularities. In particular, we prove that a natural heuristic for the codimension of the space of nondegenerate rational curves of arithmetic genus $g>0$ and degree $d$ in $\\mb{P}^n$, viewed as a subspace of all degree-$d$ rational curves in $\\mb{P}^n$, holds whenever $g$ is small.

  19. The anchoring bias reflects rational use of cognitive resources.

    Science.gov (United States)

    Lieder, Falk; Griffiths, Thomas L; M Huys, Quentin J; Goodman, Noah D

    2018-02-01

    Cognitive biases, such as the anchoring bias, pose a serious challenge to rational accounts of human cognition. We investigate whether rational theories can meet this challenge by taking into account the mind's bounded cognitive resources. We asked what reasoning under uncertainty would look like if people made rational use of their finite time and limited cognitive resources. To answer this question, we applied a mathematical theory of bounded rationality to the problem of numerical estimation. Our analysis led to a rational process model that can be interpreted in terms of anchoring-and-adjustment. This model provided a unifying explanation for ten anchoring phenomena including the differential effect of accuracy motivation on the bias towards provided versus self-generated anchors. Our results illustrate the potential of resource-rational analysis to provide formal theories that can unify a wide range of empirical results and reconcile the impressive capacities of the human mind with its apparently irrational cognitive biases.

  20. Rational Design of Cancer-Targeted Benzoselenadiazole by RGD Peptide Functionalization for Cancer Theranostics.

    Science.gov (United States)

    Yang, Liye; Li, Wenying; Huang, Yanyu; Zhou, Yangliang; Chen, Tianfeng

    2015-09-01

    A cancer-targeted conjugate of the selenadiazole derivative BSeC (benzo[1,2,5] selenadiazole-5-carboxylic acid) with RGD peptide as targeting molecule and PEI (polyethylenimine) as a linker is rationally designed and synthesized in the present study. The results show that RGD-PEI-BSeC forms nanoparticles in aqueous solution with a core-shell nanostructure and high stability under physiological conditions. This rational design effectively enhances the selective cellular uptake and cellular retention of BSeC in human glioma cells, and increases its selectivity between cancer and normal cells. The nanoparticles enter the cells through receptor-mediated endocytosis via clathrin-mediated and nystatin-dependent lipid raft-mediated pathways. Internalized nanoparticles trigger glioma cell apoptosis by activation of ROS-mediated p53 phosphorylation. Therefore, this study provides a strategy for the rational design of selenium-containing cancer-targeted theranostics. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A Conjecture on Institutional Rationalities and Property Rights in Public Procurement of Innovation

    DEFF Research Database (Denmark)

    Ågren, Robert; Rolfstam, Max

    2013-01-01

    The increased interest in using public procurement as a policy tool for innovation has renewed a need for understanding the procurement process. A conjecture on institutional rationalities and property rights is offered to explain the hurdles present for conducting successful procurement projects....... If an efficient negotiation solution is to be achieved participants in procurement projects need to be aware of the other participants’ institutional rationalities and actively consider these while concluding the terms of procurement projects. Consequently, future policy efforts towards increased innovation have...... to be targeting the process of public procurement of innovation, rather than focusing on regulatory issues....

  2. Adaptive Rationality, Adaptive Behavior and Institutions

    Directory of Open Access Journals (Sweden)

    Volchik Vyacheslav, V.

    2015-12-01

    Full Text Available The economic literature focused on understanding decision-making and choice processes reveals a vast collection of approaches to human rationality. Theorists’ attention has moved from absolutely rational, utility-maximizing individuals to boundedly rational and adaptive ones. A number of economists have criticized the concepts of adaptive rationality and adaptive behavior. One of the recent trends in the economic literature is to consider humans irrational. This paper offers an approach which examines adaptive behavior in the context of existing institutions and constantly changing institutional environment. It is assumed that adaptive behavior is a process of evolutionary adjustment to fundamental uncertainty. We emphasize the importance of actors’ engagement in trial and error learning, since if they are involved in this process, they obtain experience and are able to adapt to existing and new institutions. The paper aims at identifying relevant institutions, adaptive mechanisms, informal working rules and practices that influence actors’ behavior in the field of Higher Education in Russia (Rostov Region education services market has been taken as an example. The paper emphasizes the application of qualitative interpretative methods (interviews and discourse analysis in examining actors’ behavior.

  3. The effectiveness of rational emotive therapy on achievement ...

    African Journals Online (AJOL)

    The effectiveness of rational emotive therapy on achievement motivation of students. ... PROMOTING ACCESS TO AFRICAN RESEARCH ... the effectiveness of Rational Emotive Behaviour Therapy on Students Achievement Motivation.

  4. Cognitive rationalizations for tanning-bed use: a preliminary exploration.

    Science.gov (United States)

    Banerjee, Smita C; Hay, Jennifer L; Greene, Kathryn

    2013-09-01

    To examine construct and predictive utility of an adapted cognitive rationalization scale for tanning-bed use. Current/former tanning-bedusing undergraduate students (N = 216; 87.6% females; 78.4% white) at a large northeastern university participated in a survey. A cognitive rationalization for tanning-bed use scale was adapted. Standardized self-report measures of past tanning-bed use, advantages of tanning, perceived vulnerability to photoaging, tanning-bed use dependence, and tanning-bed use intention were also administered. The cognitive rationalization scale exhibited strong construct and predictive validity. Current tanners and tanning-bed-use-dependent participants endorsed rationalizations more strongly than did former tanners and not-tanning-bed-use-dependent participants respectively. Findings indicate that cognitive rationalizations help explain discrepancy between inconsistent cognitions.

  5. Multivariate rational data fitting

    Science.gov (United States)

    Cuyt, Annie; Verdonk, Brigitte

    1992-12-01

    Sections 1 and 2 discuss the advantages of an object-oriented implementation combined with higher floating-point arithmetic, of the algorithms available for multivariate data fitting using rational functions. Section 1 will in particular explain what we mean by "higher arithmetic". Section 2 will concentrate on the concepts of "object orientation". In sections 3 and 4 we shall describe the generality of the data structure that can be dealt with: due to some new results virtually every data set is acceptable right now, with possible coalescence of coordinates or points. In order to solve the multivariate rational interpolation problem the data sets are fed to different algorithms depending on the structure of the interpolation points in then-variate space.

  6. Positivity Preserving Interpolation Using Rational Bicubic Spline

    Directory of Open Access Journals (Sweden)

    Samsul Ariffin Abdul Karim

    2015-01-01

    Full Text Available This paper discusses the positivity preserving interpolation for positive surfaces data by extending the C1 rational cubic spline interpolant of Karim and Kong to the bivariate cases. The partially blended rational bicubic spline has 12 parameters in the descriptions where 8 of them are free parameters. The sufficient conditions for the positivity are derived on every four boundary curves network on the rectangular patch. Numerical comparison with existing schemes also has been done in detail. Based on Root Mean Square Error (RMSE, our partially blended rational bicubic spline is on a par with the established methods.

  7. Probability and rational choice

    Directory of Open Access Journals (Sweden)

    David Botting

    2014-05-01

    Full Text Available http://dx.doi.org/10.5007/1808-1711.2014v18n1p1 In this paper I will discuss the rationality of reasoning about the future. There are two things that we might like to know about the future: which hypotheses are true and what will happen next. To put it in philosophical language, I aim to show that there are methods by which inferring to a generalization (selecting a hypothesis and inferring to the next instance (singular predictive inference can be shown to be normative and the method itself shown to be rational, where this is due in part to being based on evidence (although not in the same way and in part on a prior rational choice. I will also argue that these two inferences have been confused, being distinct not only conceptually (as nobody disputes but also in their results (the value given to the probability of the hypothesis being not in general that given to the next instance and that methods that are adequate for one are not by themselves adequate for the other. A number of debates over method founder on this confusion and do not show what the debaters think they show.

  8. Competition Law and the Bounded Rationality of Firms

    OpenAIRE

    Bhattacharya, Shilpi

    2016-01-01

    Firm rationality plays a role in several aspects of competition law. Yet, the conception of the firm as a rational, profit maximizing entity has been disputed in different disciplines. This literature shows that neoclassical economic assumptions on which competition law is based can fall short of explaining the full range of observed firm behaviour. Accordingly, an alternative conception of the firm as boundedly rational can impact the understanding of firm conduct in competition law. Be...

  9. Research of rheological characteristics and determination of rational parameters of drying process of activated ferment for bakery products

    Directory of Open Access Journals (Sweden)

    D. M. Borodulin

    2017-01-01

    Full Text Available The work is aimed at investigating the rheological properties of the ferment in the process of maturation and storage with subsequent determination of the rational parameters of its drying in various drying plants with the analysing of microflora of dried samples. We studied the rheological properties of the ferment using the strain of the lactobacilli L. Acidothilus 146A (activator and without it, which showed that the ferment for the production of special purpose bakery products to non-Newtonian or anomalously viscous liquids described by the Osthald-de-Vale rheological equation. We found that the introduction the strain of the lactobacilli L. Acidothilus 146A helps to reduce the viscosity during maturation by almost 3 times, and when storing the samples – in 2 times, this is indicated by the value of the consistency coefficient. The activator reduces the influence of temperature, so the structure of the ferment becomes more stable. It is easier to further process in this state. Consequently, the energy consumption for production is significantly reduced and the increases expiration date after the strain of the lactobacilli L. Acidothilus 146A is added to the starter for the production of special purpose bakery products. We detected kinetic patterns of drying of the activated ferment in thermoradiation, convective and sublimation dryers under different temperature operating conditions. We have determined the rational parameters of drying the ferment for the production of bakery products of specialized purpose. We analyzed the useful microflora of the dried samples. It has been revealed that microorganisms undergoing convective and sublimation (freeze drying are subjected to the smallest destructive effect. We found that microorganisms are less destroyed by convective and freeze drying. The microbial titer in these samples is at least 1(105CFU/g. While drying by the method of infrared irradiation, this titer is lower by a factor of ten

  10. 6th international conference on biophysics and synchrotron radiation. Program/Abstracts

    International Nuclear Information System (INIS)

    Pittroff, Connie; Strasser, Susan Barr

    1999-01-01

    This STI product consists of the Program/Abstracts book that was prepared for the participants in the Sixth International Conference on Biophysics and Synchrotron Radiation that was held August 4-8, 1998, at the Advanced Photon Source, Argonne National Laboratory. This book contains the full conference program and abstracts of the scientific presentations

  11. 6th international conference on biophysics and synchrotron radiation. Program/Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Pittroff, Connie; Strasser, Susan Barr [lead editors

    1999-08-03

    This STI product consists of the Program/Abstracts book that was prepared for the participants in the Sixth International Conference on Biophysics and Synchrotron Radiation that was held August 4-8, 1998, at the Advanced Photon Source, Argonne National Laboratory. This book contains the full conference program and abstracts of the scientific presentations.

  12. Public policy, rationality and reason

    Directory of Open Access Journals (Sweden)

    Rodolfo Canto Sáenz

    2015-07-01

    Full Text Available This work suggests the incorporation of practical reason in the design, implementation and evaluation of public policies, alongside instrumental rationality. It takes two proposals that today point in this direction: Rawls distinction between reasonable (practical reason and rational (instrumental reason and what this author calls the CI Procedure (categorical imperative procedure and Habermas model of deliberative democracy. The main conclusion is that the analysis of public policies can not be limited to rather narrow limits of science, but requires the contribution of political and moral philosophy.

  13. MARSI: metabolite analogues for rational strain improvement

    DEFF Research Database (Denmark)

    Cardoso, João G. R.; Zeidan, Ahmad A; Jensen, Kristian

    2018-01-01

    reactions in an organism can be used to predict effects of MAs on cellular phenotypes. Here, we present the Metabolite Analogues for Rational Strain Improvement (MARSI) framework. MARSI provides a rational approach to strain improvement by searching for metabolites as targets instead of genes or reactions...

  14. Simple market equilibria with rationally inattentive consumers

    Czech Academy of Sciences Publication Activity Database

    Matějka, Filip; McKay, A.

    2012-01-01

    Roč. 102, č. 3 (2012), s. 24-29 ISSN 0002-8282 R&D Projects: GA ČR(CZ) GPP402/11/P236 Institutional support: RVO:67985998 Keywords : rational choice theory * bounded rationality * consumer research Subject RIV: AH - Economics Impact factor: 2.792, year: 2012

  15. Comparative analysis of field ration for military personnel of the ukrainian army and armies of other countries worldwide

    Directory of Open Access Journals (Sweden)

    M. Mardar

    2017-04-01

    Full Text Available For the purpose of improvement of the Ukrainian nutritional standards this Article provides comparative analysis of field rations of different countries worldwide to make a proposal on improvement of food-stuff assortment in food ration for military personnel in the Armed Forces of Ukraine, Army of USA, the British Army, Army of Germany, Army of Italy, Army of Canada, Army of France, Army of Belarus, Army of Armenia. In accordance with the comparative analysis it was established that ration composition used for the Armed Forces of Ukraine military personnel lags behind developed countries of the world both in nutrition arrangement and in nutrient composition, especially in relation to assortment and variety of ration food-stuff. Moreover, a field ration is strictly unified and doesn’t consider individual needs of military personnel in calories, proteins, fats, carbohydrates, food fibers. Selection of individual field ration takes to account only age of military personnel, i. e. individual needs related to nutrition composition such as physical abilities, level of physical activity, gender, type of occupation before military conscription and etc. are not consideredThe obtained results confirms practicability of assortment products assortment included to field rations for the purpose to correct nutrition rations towards optimal balance for military efficiency of army, adaptation of military personnel to physical and psychological loads.

  16. Rational Choice theory and prison chaplaincy: the chaplain's dilemma.

    Science.gov (United States)

    Beckford, J A

    1999-12-01

    Critical responses to the application of Rational Choice theories to the study of religious phenomena tend to be polarized between outright denial that the theories have any relevance to religion and equally outspoken claims that the theories are the only hope for progress in the sociology of religion. This article aims to avoid both of these extreme positions by raising a question, instead, about one of Rational Choice's central propositions about religion. This proposition holds that levels of religious vitality vary positively with the degree to which agencies of the state are prevented from regulating religious activity. The findings of recent research into prison chaplaincy in the UK and the USA will be used to test this claim. The main argument will be that the existence of an established church has facilitated a higher level of religious activity, especially for minority faiths, in prisons in England and Wales than is possible in American prisons. This difference in religious vitality is explained in terms of the Church of England's privileged position as a 'broker' between the state and minority faith communities. There is greater equality of opportunity for religious activity in American prisons, but the level of the activity is necessarily lower. In neither country is there anything truly resembling a 'free' market for religion in prisons, but the established Church of England is able to use its quasi-monopoly powers to broker advantageous conditions for minority faith communities. This brokerage function may be advantageous to all religious organizations in the highly regulated 'economy' of prisons.

  17. Fields of rational constants of cyclic factorizable derivations

    Directory of Open Access Journals (Sweden)

    Janusz Zielinski

    2015-12-01

    Full Text Available We describe all rational constants of a large family of four-variable cyclic factorizable derivations. Thus, we determine all rational first integrals of their corresponding systems of differential equations. Moreover, we give a characteristic of all four-variable Lotka-Volterra derivations with a nontrivial rational constant. All considerations are over an arbitrary field of characteristic zero. Our main tool is the investigation of the cofactors of strict Darboux polynomials. Factorizable derivations are important in derivation theory. Namely, we may associate the factorizable derivation with any given derivation of a polynomial ring and that construction helps to determine rational constants of arbitrary derivations. Besides, Lotka-Volterra systems play a significant role in population biology, laser physics and plasma physics.

  18. Crab Rationalization Permit Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Crab Rationalization Program (Program) allocates BSAI crab resources among harvesters, processors, and coastal communities. The North Pacific Fishery Management...

  19. Should informed consent be based on rational beliefs?

    OpenAIRE

    Savulescu, J; Momeyer, R W

    1997-01-01

    Our aim is to expand the regulative ideal governing consent. We argue that consent should not only be informed but also based on rational beliefs. We argue that holding true beliefs promotes autonomy. Information is important insofar as it helps a person to hold the relevant true beliefs. But in order to hold the relevant true beliefs, competent people must also think rationally. Insofar as information is important, rational deliberation is important. Just as physicians should aim to provide ...

  20. Positive Feedback Investment Strategies and Destabilizing Rational Speculation

    OpenAIRE

    J. Bradford De Long; Andrei Shleifer; Lawrence H. Summers; Robert J. Waldmann

    1989-01-01

    Analyses of the role of rational speculators in financial markets usually presume that such investors dampen price fluctuations by trading against liquidity or noise traders. This conclusion does not necessarily hold when noise traders follow positive-feedback investment strategies buy when prices rise and sell when prices fall. In such cases, it may pay rational speculators to try to jump on the bandwagon early and to purchase ahead of noise trader demand. If rational speculators' attempts t...

  1. Brief Report: Risk-Aversion and Rationality in Autism Spectrum Disorders.

    Science.gov (United States)

    Gosling, Corentin J; Moutier, Sylvain

    2018-05-30

    Risk-aversion and rationality have both been highlighted as core features of decision making in individuals with Autism Spectrum Disorders (ASD). This study tested whether risk-aversion is related to rational decision-making in ASD individuals. ASD and matched control adults completed a decision-making task that discriminated between the use of risk-averse and rational strategies. Results showed that overall, ASD participants were more risk-averse than control participants. Specifically, both groups made similar choices when risk-aversion was the less rational strategy but ASD participants chose more rational options than control participants when risk-aversion was the most rational strategy. This study confirmed that risk-aversion is a core feature of ASD and revealed that ASD individuals can switch their decision-making strategy adaptively to avoid negative consequences.

  2. A rational inference approach to group and individual-level sentence comprehension performance in aphasia.

    Science.gov (United States)

    Warren, Tessa; Dickey, Michael Walsh; Liburd, Teljer L

    2017-07-01

    The rational inference, or noisy channel, account of language comprehension predicts that comprehenders are sensitive to the probabilities of different interpretations for a given sentence and adapt as these probabilities change (Gibson, Bergen & Piantadosi, 2013). This account provides an important new perspective on aphasic sentence comprehension: aphasia may increase the likelihood of sentence distortion, leading people with aphasia (PWA) to rely more on the prior probability of an interpretation and less on the form or structure of the sentence (Gibson, Sandberg, Fedorenko, Bergen & Kiran, 2015). We report the results of a sentence-picture matching experiment that tested the predictions of the rational inference account and other current models of aphasic sentence comprehension across a variety of sentence structures. Consistent with the rational inference account, PWA showed similar sensitivity to the probability of particular kinds of form distortions as age-matched controls, yet overall their interpretations relied more on prior probability and less on sentence form. As predicted by rational inference, but not by other models of sentence comprehension in aphasia, PWA's interpretations were more faithful to the form for active and passive sentences than for direct object and prepositional object sentences. However contra rational inference, there was no evidence that individual PWA's severity of syntactic or semantic impairment predicted their sensitivity to form versus the prior probability of a sentence, as cued by semantics. These findings confirm and extend previous findings that suggest the rational inference account holds promise for explaining aphasic and neurotypical comprehension, but they also raise new challenges for the account. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Structure-based, rational design of T cell receptors

    Directory of Open Access Journals (Sweden)

    Vincent eZoete

    2013-09-01

    Full Text Available Adoptive cell transfer using engineered T cells is emerging as a promising treatment for metastatic melanoma. Such an approach allows one to introduce TCR modifications that, while maintaining the specificity for the targeted antigen, can enhance the binding and kinetic parameters for the interaction pMHC. Using the well-characterized 2C TCR/SIYR/H-2K(b structure as a model system, we demonstrated that a binding free energy decomposition based on the MM-GBSA approach provides a detailed and reliable description of the TCR/pMHC interactions at the structural and thermodynamic levels. Starting from this result, we developed a new structure-based approach, to rationally design new TCR sequences, and applied it to the BC1 TCR targeting the HLA-A2 restricted NY-ESO-1157-165 cancer-testis epitope. 54% of the designed sequence replacements exhibited improved pMHC-binding as compared to the native TCR, with up to 150 fold increase in affinity, while preserving specificity. Genetically-engineered CD8+ T cells expressing these modified TCRs showed an improved functional activity compared to those expressing BC1 TCR. We measured maximum levels of activities for TCRs within the upper limit of natural affinity. Beyond the affinity threshold at KD < 1 μM we observed an attenuation in cellular function. We have also developed a homology modeling-based approach, TCRep 3D, to obtain accurate structural models of any TCR-pMHC complexes. We have complemented the approach with a simplified rigid method to predict the TCR orientation over pMHC. These methods potentially extend the use of our TCR engineering method to entire TCR repertoires for which no X-ray structure is available. We have also performed a steered molecular dynamics study of the unbinding of the TCR-pMHC complex to get a better understanding of how TCRs interact with pMHCs. This entire rational TCR design pipeline is now being used to produce rationally optimized TCRs for adoptive cell therapies of

  4. Interplay of mycolic acids, antimycobacterial compounds and pulmonary surfactant membrane: a biophysical approach to disease.

    Science.gov (United States)

    Pinheiro, Marina; Giner-Casares, Juan J; Lúcio, Marlene; Caio, João M; Moiteiro, Cristina; Lima, José L F C; Reis, Salette; Camacho, Luis

    2013-02-01

    This work focuses on the interaction of mycolic acids (MAs) and two antimycobacterial compounds (Rifabutin and N'-acetyl-Rifabutin) at the pulmonary membrane level to convey a biophysical perspective of their role in disease. For this purpose, accurate biophysical techniques (Langmuir isotherms, Brewster angle microscopy, and polarization-modulation infrared reflection spectroscopy) and lipid model systems were used to mimic biomembranes: MAs mimic bacterial lipids of the Mycobacterium tuberculosis (MTb) membrane, whereas Curosurf® was used as the human pulmonary surfactant (PS) membrane model. The results obtained show that high quantities of MAs are responsible for significant changes on PS biophysical properties. At the dynamic inspiratory surface tension, high amounts of MAs decrease the order of the lipid monolayer, which appears to be a concentration dependent effect. These results suggest that the amount of MAs might play a critical role in the initial access of the bacteria to their targets. Both molecules also interact with the PS monolayer at the dynamic inspiratory surface. However, in the presence of higher amounts of MAs, both compounds improve the phospholipid packing and, therefore, the order of the lipid surfactant monolayer. In summary, this work discloses the putative protective effects of antimycobacterial compounds against the MAs induced biophysical impairment of PS lipid monolayers. These protective effects are most of the times overlooked, but can constitute an additional therapeutic value in the treatment of pulmonary tuberculosis (Tb) and may provide significant insights for the design of new and more efficient anti-Tb drugs based on their behavior as membrane ordering agents. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. The impact of economic rationalization, prioritization and rationing on job satisfaction, motivation and team cohesion in hospitals: a survey among retired physician executives in Germany.

    Science.gov (United States)

    Schnoor, Joerg; Braehler, Elmar; Ghanem, Mohamed; Heyde, Christoph E

    2017-01-01

    The growing economization of the health care system and implication of market principles in the medical field have risen new and serious questions on the meaning of the medical profession, the doctor-patient relationship and the orientation of medicine itself. The impact of the dynamic clinical structures on the doctor-doctor and the doctor-patient interaction appear even unpredictable. Therefore, the impact of market-based methods, i.e. rationalization, prioritization and rationing, on job satisfaction, motivation and team cohesion should be quantified. The experiences of former and now retired physician executives in numerous hospitals in Saxony were determined. For this purpose, an anonymously written survey using a standardized questionnaire was conducted in the first quarter of 2016. Rationalization measures were confirmed by 88% of respondents. In more than a third of cases, former executives also experienced prioritization and rationing. The impact of these management techniques on job satisfaction, motivation and team cohesion was carried out in a differentiated manner. There was a tendency to regard rationalization and prioritization measures indifferently to rather disadvantageous, while rationing was predominantly rated negatively. In addition to rationalization, prioritization and rationing measures have now been part of working strategy at the hospitals. On one hand, the conceptual distinction between the terms still seems imprecise; on the other hand, a creeping and imperceptible medico-ethical transgression of the prioritization to rationing seems to have already taken place.

  6. Self-deception as pseudo-rational regulation of belief.

    Science.gov (United States)

    Michel, Christoph; Newen, Albert

    2010-09-01

    Self-deception is a special kind of motivational dominance in belief-formation. We develop criteria which set paradigmatic self-deception apart from related phenomena of auto-manipulation such as pretense and motivational bias. In self-deception rational subjects defend or develop beliefs of high subjective importance in response to strong counter-evidence. Self-deceivers make or keep these beliefs tenable by putting prima-facie rational defense-strategies to work against their established standards of rational evaluation. In paradigmatic self-deception, target-beliefs are made tenable via reorganizations of those belief-sets that relate relevant data to target-beliefs. This manipulation of the evidential value of relevant data goes beyond phenomena of motivated perception of data. In self-deception belief-defense is pseudo-rational. Self-deceivers will typically apply a dual standard of evaluation that remains intransparent to the subject. The developed model of self-deception as pseudo-rational belief-defense is empirically anchored. So, we hope to put forward a promising candidate. Copyright © 2010 Elsevier Inc. All rights reserved.

  7. Rational-Emotive Staff Development.

    Science.gov (United States)

    Forman, Susan G.; Forman, Bruce D.

    1980-01-01

    The application of Rational-Emotive Therapy principles and techniques in in-service education for school personnel is discussed. Teacher and counselor participation in a staff development program is described. (Author)

  8. Adaptive information-theoretic bounded rational decision-making with parametric priors

    OpenAIRE

    Grau-Moya, Jordi; Braun, Daniel A.

    2015-01-01

    Deviations from rational decision-making due to limited computational resources have been studied in the field of bounded rationality, originally proposed by Herbert Simon. There have been a number of different approaches to model bounded rationality ranging from optimality principles to heuristics. Here we take an information-theoretic approach to bounded rationality, where information-processing costs are measured by the relative entropy between a posterior decision strategy and a given fix...

  9. Biophysical and biochemical constraints imposed by salt stress:Learning from halophyte

    Directory of Open Access Journals (Sweden)

    Bernardo eDuarte

    2014-12-01

    Full Text Available Soil salinization is one of the most important factors impacting plant productivity. About 3.6 billion of the world’s 5.2 billion ha of agricultural dryland have already suffered erosion, degradation and salinization. Halophytes typically are considered as plants able to complete their life cycle in environments where the salt concentration is 200 mM NaCl or higher. Different strategies are known to overcome salt stress, as adaptation mechanisms from this type of plants. Salinity adjustment is a complex phenomenon characterized by both biochemical and biophysical adaptations. As photosynthesis is a prerequisite for biomass production, halophytes adapted their electronic transduction pathways and the entire energetic metabolism to overcome the salt excess. The maintenance of ionic homeostasis is in the basis of all cellular stress in particular in terms of redox potential and energy transduction. In the present work the biophysical mechanisms underlying energy capture and transduction in halophytes are discussed alongside with their relation to biochemical mechanisms, integrating data from photosystem light harvesting complexes, electronic transport chains to the quinone pools, carbon harvesting and energy dissipation metabolism.

  10. Rational Verification in Iterated Electric Boolean Games

    Directory of Open Access Journals (Sweden)

    Youssouf Oualhadj

    2016-07-01

    Full Text Available Electric boolean games are compact representations of games where the players have qualitative objectives described by LTL formulae and have limited resources. We study the complexity of several decision problems related to the analysis of rationality in electric boolean games with LTL objectives. In particular, we report that the problem of deciding whether a profile is a Nash equilibrium in an iterated electric boolean game is no harder than in iterated boolean games without resource bounds. We show that it is a PSPACE-complete problem. As a corollary, we obtain that both rational elimination and rational construction of Nash equilibria by a supervising authority are PSPACE-complete problems.

  11. A Biophysical Neural Model To Describe Spatial Visual Attention

    International Nuclear Information System (INIS)

    Hugues, Etienne; Jose, Jorge V.

    2008-01-01

    Visual scenes have enormous spatial and temporal information that are transduced into neural spike trains. Psychophysical experiments indicate that only a small portion of a spatial image is consciously accessible. Electrophysiological experiments in behaving monkeys have revealed a number of modulations of the neural activity in special visual area known as V4, when the animal is paying attention directly towards a particular stimulus location. The nature of the attentional input to V4, however, remains unknown as well as to the mechanisms responsible for these modulations. We use a biophysical neural network model of V4 to address these issues. We first constrain our model to reproduce the experimental results obtained for different external stimulus configurations and without paying attention. To reproduce the known neuronal response variability, we found that the neurons should receive about equal, or balanced, levels of excitatory and inhibitory inputs and whose levels are high as they are in in vivo conditions. Next we consider attentional inputs that can induce and reproduce the observed spiking modulations. We also elucidate the role played by the neural network to generate these modulations

  12. Does knowing that a suicide was "rational" influence grief?

    Science.gov (United States)

    Brazda, Geoffrey F; Range, Lillian M; Remley, Theodore P; White, Carolyn C

    2018-03-15

    Counseling professionals and graduate students (N = 117) recruited online read a randomly assigned one-paragraph vignette about either a non-rational or rational suicide involving an imaginary loved one. Then, they completed the Grief Experiences Questionnaire (GEQ) about how they would feel. The non-rational suicide group expected significantly more search for explanation than the rational suicide group, but were not significantly different on the other six GEQ subscales. All participants expected few distressing reactions to either vignette, suggesting a one-paragraph vignette may not be sufficient to induce the kind of grief many experience when a loved one dies by suicide.

  13. Indoor Fast Neutron Generator for Biophysical and Electronic Applications

    Science.gov (United States)

    Cannuli, A.; Caccamo, M. T.; Marchese, N.; Tomarchio, E. A.; Pace, C.; Magazù, S.

    2018-05-01

    This study focuses the attention on an indoor fast neutron generator for biophysical and electronic applications. More specifically, the findings obtained by several simulations with the MCNP Monte Carlo code, necessary for the realization of a shield for indoor measurements, are presented. Furthermore, an evaluation of the neutron spectrum modification caused by the shielding is reported. Fast neutron generators are a valid and interesting available source of neutrons, increasingly employed in a wide range of research fields, such as science and engineering. The employed portable pulsed neutron source is a MP320 Thermo Scientific neutron generator, able to generate 2.5 MeV neutrons with a neutron yield of 2.0 x 106 n/s, a pulse rate of 250 Hz to 20 KHz and a duty factor varying from 5% to 100%. The neutron generator, based on Deuterium-Deuterium nuclear fusion reactions, is employed in conjunction with a solid-state photon detector, made of n-type high-purity germanium (PINS-GMX by ORTEC) and it is mainly addressed to biophysical and electronic studies. The present study showed a proposal for the realization of a shield necessary for indoor applications for MP320 neutron generator, with a particular analysis of the transport of neutrons simulated with Monte Carlo code and described the two main lines of research in which the source will be used.

  14. Mate choice in fruit flies is rational and adaptive.

    Science.gov (United States)

    Arbuthnott, Devin; Fedina, Tatyana Y; Pletcher, Scott D; Promislow, Daniel E L

    2017-01-17

    According to rational choice theory, beneficial preferences should lead individuals to sort available options into linear, transitive hierarchies, although the extent to which non-human animals behave rationally is unclear. Here we demonstrate that mate choice in the fruit fly Drosophila melanogaster results in the linear sorting of a set of diverse isogenic female lines, unambiguously demonstrating the hallmark of rational behaviour, transitivity. These rational choices are associated with direct benefits, enabling males to maximize offspring production. Furthermore, we demonstrate that female behaviours and cues act redundantly in mate detection and assessment, as rational mate choice largely persists when visual or chemical sensory modalities are impaired, but not when both are impaired. Transitivity in mate choice demonstrates that the quality of potential mates varies significantly among genotypes, and that males and females behave in such a way as to facilitate adaptive mate choice.

  15. Epigenetic Modulation of the Biophysical Properties of Drug-Resistant Cell Lipids to Restore Drug Transport and Endocytic Functions

    OpenAIRE

    Vijayaraghavalu, Sivakumar; Peetla, Chiranjeevi; Lu, Shan; Labhasetwar, Vinod

    2012-01-01

    In our recent studies exploring the biophysical characteristics of resistant cell lipids, and the role they play in drug transport, we demonstrated the difference of drug-resistant breast cancer cells from drug-sensitive cells in lipid composition and biophysical properties, suggesting that cancer cells acquire a drug-resistant phenotype through the alteration of lipid synthesis to inhibit intracellular drug transport to protect from cytotoxic effect. In cancer cells, epigenetic changes (e.g....

  16. Rational speculative bubbles: A critical view

    Directory of Open Access Journals (Sweden)

    Radonjić Ognjen

    2007-01-01

    Full Text Available According to the theory of rational bubbles, the bubble is present whenever asset prices progressively diverge from their fundamental value, which occurs because agents expect that asset prices will continue to grow exponentially (self-fulfilling prophecies far in the future and consistently, which promises the realization of ever larger capital gains. In our opinion, the basic shortcoming of this theory refers to the assumption that all market agents are perfectly informed and rational and, accordingly, form homogeneous expectations. The model does not explain decision-making processes or expectation formation, nor does it detect potential psychological and institutional factors that might significantly influence decision making processes and market participants’ reactions to news. Since assumptions of the model critically determine its validity, we conclude that comprehensiveness of the rational bubble model is, to put it mildly, limited.

  17. Neuroethics transformation of economic rationality: implications for decision making in business

    Directory of Open Access Journals (Sweden)

    José-Félix Lozano

    2017-02-01

    Full Text Available The economy and business field has traditionally been dominated by a conception of calculator, strategic and profit-maximizing individual rationality. This model of rationality has important theoretical limitations and practical consequences. In recent decades the results of neuroethics´ research seems open new ways for understanding the practical rationality. These new routes, representing a revaluation of emotional and intuitive dimension in cognitive ability and have great relevance for business and economic decision making. The aim of this paper is to analyse the implications of a rational dialogic-friendly (cor-cordis concept for economic and business decision-making. Our work proposes a version of the dialogic-friendly practical rationality that integrate advances in neuroethics with the discursive rationality perspective in order to overcome the strategic rationality and emotivist intuitionism.

  18. [Maintenance ration and conversion efficiency of Hyporhamphus sajori].

    Science.gov (United States)

    Guo, X; Tang, Q

    2001-04-01

    The maintenance ration and conversion efficiency of Japanese halfbeak, Hyporhamphus sajori were tested with enclosures installed in a shrimp raising pond. The results showed that there existed an evident relationship between daily ration(DR) and growth rate(GR) of the fish, GR = 140.37 DR - 24.03. The conversion efficiency was 13.96% in biomass or 16.12% in energy. The maintenance ration was 17.12% and 20.39% of body weight in terms of growth rate and specific growth rate, respectively, indicating that it could be deduced from growth rate quite differently from that from specific growth rate in the same experiment. The abnormal growth rate appeared when daily ration was below 3.30% of body weight, implied that Japanese halfbeak may get other food resources besides supplied net zooplankton.

  19. Rational and moral action : a critical survey of rational choice theory

    NARCIS (Netherlands)

    de Jonge, J.P.R.

    2009-01-01

    This book is about rational choice theory from a different point of view. It is different for three reasons. First, it pays attention to the unintended consequences of intended actions. Second, it employs a non-instrumental approach to moral actions. And third, it argues that choice opportunities

  20. Quantifying Vegetation Biophysical Variables from Imaging Spectroscopy Data: A Review on Retrieval Methods

    Science.gov (United States)

    Verrelst, Jochem; Malenovský, Zbyněk; Van der Tol, Christiaan; Camps-Valls, Gustau; Gastellu-Etchegorry, Jean-Philippe; Lewis, Philip; North, Peter; Moreno, Jose

    2018-06-01

    An unprecedented spectroscopic data stream will soon become available with forthcoming Earth-observing satellite missions equipped with imaging spectroradiometers. This data stream will open up a vast array of opportunities to quantify a diversity of biochemical and structural vegetation properties. The processing requirements for such large data streams require reliable retrieval techniques enabling the spatiotemporally explicit quantification of biophysical variables. With the aim of preparing for this new era of Earth observation, this review summarizes the state-of-the-art retrieval methods that have been applied in experimental imaging spectroscopy studies inferring all kinds of vegetation biophysical variables. Identified retrieval methods are categorized into: (1) parametric regression, including vegetation indices, shape indices and spectral transformations; (2) nonparametric regression, including linear and nonlinear machine learning regression algorithms; (3) physically based, including inversion of radiative transfer models (RTMs) using numerical optimization and look-up table approaches; and (4) hybrid regression methods, which combine RTM simulations with machine learning regression methods. For each of these categories, an overview of widely applied methods with application to mapping vegetation properties is given. In view of processing imaging spectroscopy data, a critical aspect involves the challenge of dealing with spectral multicollinearity. The ability to provide robust estimates, retrieval uncertainties and acceptable retrieval processing speed are other important aspects in view of operational processing. Recommendations towards new-generation spectroscopy-based processing chains for operational production of biophysical variables are given.

  1. Assessment of the biophysical impacts of utility-scale photovoltaics through observations and modelling

    Science.gov (United States)

    Broadbent, A. M.; Georgescu, M.; Krayenhoff, E. S.; Sailor, D.

    2017-12-01

    Utility-scale solar power plants are a rapidly growing component of the solar energy sector. Utility-scale photovoltaic (PV) solar power generation in the United States has increased by 867% since 2012 (EIA, 2016). This expansion is likely to continue as the cost PV technologies decrease. While most agree that solar power can decrease greenhouse gas emissions, the biophysical effects of PV systems on surface energy balance (SEB), and implications for surface climate, are not well understood. To our knowledge, there has never been a detailed observational study of SEB at a utility-scale solar array. This study presents data from an eddy covariance observational tower, temporarily placed above a utility-scale PV array in Southern Arizona. Comparison of PV SEB with a reference (unmodified) site, shows that solar panels can alter the SEB and near surface climate. SEB observations are used to develop and validate a new and more complete SEB PV model. In addition, the PV model is compared to simpler PV modelling methods. The simpler PV models produce differing results to our newly developed model and cannot capture the more complex processes that influence PV SEB. Finally, hypothetical scenarios of PV expansion across the continental United States (CONUS) were developed using various spatial mapping criteria. CONUS simulations of PV expansion reveal regional variability in biophysical effects of PV expansion. The study presents the first rigorous and validated simulations of the biophysical effects of utility-scale PV arrays.

  2. Economic rationality and health and lifestyle choices for people with diabetes.

    Science.gov (United States)

    Baker, Rachel Mairi

    2006-11-01

    Economic rationality is traditionally represented by goal-oriented, maximising behaviour, or 'instrumental rationality'. Such a consequentialist, instrumental model of choice is often implicit in a biomedical approach to health promotion and education. The research reported here assesses the relevance of a broader conceptual framework of rationality, which includes 'procedural' and 'expressive' rationality as complements to an instrumental model of rationality, in a health context. Q methodology was used to derive 'factors' underlying health and lifestyle choices, based on a factor analysis of the results of a card sorting procedure undertaken by 27 adult respondents with type 2 diabetes in Newcastle upon Tyne, UK. These factors were then compared with the rationality framework and the appropriateness of an extended model of economic rationality as a means of better understanding health and lifestyle choices was assessed. Taking a wider rational choice perspective, choices which are rendered irrational within a narrow-biomedical or strictly instrumental model, can be understood in terms of a coherent rationale, grounded in the accounts of respondents. The implications of these findings are discussed in terms of rational choice theory and diabetes management and research.

  3. The Role of Rationality in University Budgeting.

    Science.gov (United States)

    Chaffee, Ellen Earle

    1983-01-01

    Although empirical accounts of organizational decision making often show that the process is not a rational one, a study of budgeting at Stanford University during the 1970s, while not conclusive or comprehensive, supported the claim that the institution's process was rational and provided a procedure for testing a decision-making model. (MSE)

  4. Should Teachers Be Taught to Be Rational?

    Science.gov (United States)

    Floden, Robert E.; Feiman, Sharon

    1981-01-01

    Teacher education programs have long attempted to teach students to follow a rational mode of thinking. Recent research on teacher thinking has shown that a gap exists between how teachers think and the rational model. Such research should be used to give teacher educators insight into how their students think and learn. (JN)

  5. Contributions of computational chemistry and biophysical techniques to fragment-based drug discovery.

    Science.gov (United States)

    Gozalbes, Rafael; Carbajo, Rodrigo J; Pineda-Lucena, Antonio

    2010-01-01

    In the last decade, fragment-based drug discovery (FBDD) has evolved from a novel approach in the search of new hits to a valuable alternative to the high-throughput screening (HTS) campaigns of many pharmaceutical companies. The increasing relevance of FBDD in the drug discovery universe has been concomitant with an implementation of the biophysical techniques used for the detection of weak inhibitors, e.g. NMR, X-ray crystallography or surface plasmon resonance (SPR). At the same time, computational approaches have also been progressively incorporated into the FBDD process and nowadays several computational tools are available. These stretch from the filtering of huge chemical databases in order to build fragment-focused libraries comprising compounds with adequate physicochemical properties, to more evolved models based on different in silico methods such as docking, pharmacophore modelling, QSAR and virtual screening. In this paper we will review the parallel evolution and complementarities of biophysical techniques and computational methods, providing some representative examples of drug discovery success stories by using FBDD.

  6. Heterogeneity, Bounded Rationality and Market Dysfunctionality

    OpenAIRE

    Xue-Zhong He; Lei Shi

    2008-01-01

    As the main building blocks of the modern finance theory, homogeneity and rational expectation have faced difficulty in explaining many market anomalies, stylized factors, and market inefficiency in empirical studies. As a result, heterogeneity and bounded rationality have been used as an alterative paradigm of asset price dynamics and this paradigm has been widely recognized recently in both academic and financial market practitioners. Within the framework of Chiarella, Dieci and He (2006a, ...

  7. Consumers' evaluations of ecological packaging - rational and emotional approaches

    OpenAIRE

    Koenig-Lewis, Nicole; Palmer, Adrian; Dermody, Janine; Urbye, Andreas

    2014-01-01

    Ecological marketing claims have been criticized for confusing or misleading buyers, leading to calls for more rationality in promoting and evaluating ‘green’ products. However, emotions are important drivers influencing pro-environmental purchase decisions. This study investigates consumers' emotional and rational evaluations of pro-environmental packaging. A conceptual model incorporates individuals' general environmental concerns, their rational beliefs about environmental effects of produ...

  8. Biophysical and structural considerations for protein sequence evolution

    Directory of Open Access Journals (Sweden)

    Grahnen Johan A

    2011-12-01

    Full Text Available Abstract Background Protein sequence evolution is constrained by the biophysics of folding and function, causing interdependence between interacting sites in the sequence. However, current site-independent models of sequence evolutions do not take this into account. Recent attempts to integrate the influence of structure and biophysics into phylogenetic models via statistical/informational approaches have not resulted in expected improvements in model performance. This suggests that further innovations are needed for progress in this field. Results Here we develop a coarse-grained physics-based model of protein folding and binding function, and compare it to a popular informational model. We find that both models violate the assumption of the native sequence being close to a thermodynamic optimum, causing directional selection away from the native state. Sampling and simulation show that the physics-based model is more specific for fold-defining interactions that vary less among residue type. The informational model diffuses further in sequence space with fewer barriers and tends to provide less support for an invariant sites model, although amino acid substitutions are generally conservative. Both approaches produce sequences with natural features like dN/dS Conclusions Simple coarse-grained models of protein folding can describe some natural features of evolving proteins but are currently not accurate enough to use in evolutionary inference. This is partly due to improper packing of the hydrophobic core. We suggest possible improvements on the representation of structure, folding energy, and binding function, as regards both native and non-native conformations, and describe a large number of possible applications for such a model.

  9. Génération Y : much ado about nothing ? Le talent des jeunes

    OpenAIRE

    Wilkin, Luc

    2015-01-01

    Introduction Baby Boomers, Génération X, Génération Y, Génération du Millénaire, Génération Z, Génération Nintendo, Génération Wii, Génération Internet, Génération C, Génération Google, Génération Mobile, Génération Powerpoint, Génération couper/coller, natifs et immigrants digitaux, Homo sapiens digital ou Homo-zappiens, les vocables ne manquent pas pour désigner, séparer, opposer et segmenter les générations. Celles-ci évoluent, dans les discours, au gré des révolutions proclamées qui survi...

  10. [Establishment of knowledge, attitudes and opinions of general population about rational use of medicines].

    Science.gov (United States)

    Puig Soler, Rita; Perramon Colet, Meritxell; Yahni, Corinne Zara; Garcia Puig, Anna M

    2015-01-01

    Identify the level of knowledge, opinions and attitudes of medicines in general population. Descriptive transversal study realised in a sample of≥18 years old public health users from primary health centres in the city of Barcelona. Sample has been chosen using a two phases sampling, stratified by district, gender and age. Questionnaire administered face-to-face. SPSSv15 used for the analysis. December 2011. 484 surveys has been done (IC 95%, α=5%). 53% were women and 21,3% had university studies. Medicine use: 81% had taken medicines in the last 3 months; average of 2,34. 80% of medicated people know what they take and its indication. 55,6% don't know active ingredient concept. Only 35% recognise the active ingredient showed in the box of the medicine (3 cases shown) and 44,5% not one. 22,7% know the meaning of security concepts contraindication, adverse effect and drug interaction. 20% ignore. This fact grows with age and reduces with high study levels. Global rational use of medicines indicator obtains 5,03 from 10: 3,42 opinion and 6,51 attitude. 70% of people think there is no rational use of medicines in general and 21,3% would promote raising awareness. Low level of knowledge and poor attitude and opinion in rational use of medicines have been shown in this study. It is necessary involve citizens and improve their basic knowledge to promote rational use of medicines. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  11. Microwave Tissue Ablation: Biophysics, Technology and Applications

    Science.gov (United States)

    2010-01-01

    Microwave ablation is an emerging treatment option for many cancers, cardiac arrhythmias and other medical conditions. During treatment, microwaves are applied directly to tissues to produce rapid temperature elevations sufficient to produce immediate coagulative necrosis. The engineering design criteria for each application differ, with individual consideration for factors such as desired ablation zone size, treatment duration, and procedural invasiveness. Recent technological developments in applicator cooling, power control and system optimization for specific applications promise to increase the utilization of microwave ablation in the future. This article will review the basic biophysics of microwave tissue heating, provide an overview of the design and operation of current equipment, and outline areas for future research for microwave ablation. PMID:21175404

  12. Substantiation of the active ingredients rational concentration of ointment for treatment of allergic dermatitis complicated by fungal infection

    Directory of Open Access Journals (Sweden)

    O. A. Rukhmakova

    2015-08-01

    Full Text Available Aim. Due to the rapid growth of number of allergic skin diseases complicated by secondary fungal infection, creation of new drugs with an integrated anti-allergic and anti-fungal action for their local treatment is especially important. Methods and results. In the process of developing an ointment under conventional name “Allergolik” microbiological studies have been conducted to determine its rational composition. Concentrations of licorice root extract, terbinafine hydrochloride and lavender essential oil have been substantiated as parts of the studied medication. Study of acute toxicity of the developed dosage form has set that it belongs to the IV class of low-toxic substances due to the standard classification of K.K. Sidorova. Conclusion. This testifies the correctness of the choice of drug active ingredients and their concentrations.

  13. Lying for the Greater Good: Bounded Rationality in a Team

    OpenAIRE

    Oktay Sürücü

    2014-01-01

    This paper is concerned with the interaction between fully and boundedly rational agents in situations where their interests are perfectly aligned. The cognitive limitations of the boundedly rational agent do not allow him to fully understand the market conditions and lead him to take non-optimal decisions in some situations. Using categorization to model bounded rationality, we show that the fully rational agent can nudge, i.e., he can manipulate the information he sends and decrease the exp...

  14. Bounded rationality alters the dynamics of paediatric immunization acceptance.

    Science.gov (United States)

    Oraby, Tamer; Bauch, Chris T

    2015-06-02

    Interactions between disease dynamics and vaccinating behavior have been explored in many coupled behavior-disease models. Cognitive effects such as risk perception, framing, and subjective probabilities of adverse events can be important determinants of the vaccinating behaviour, and represent departures from the pure "rational" decision model that are often described as "bounded rationality". However, the impact of such cognitive effects in the context of paediatric infectious disease vaccines has received relatively little attention. Here, we develop a disease-behavior model that accounts for bounded rationality through prospect theory. We analyze the model and compare its predictions to a reduced model that lacks bounded rationality. We find that, in general, introducing bounded rationality increases the dynamical richness of the model and makes it harder to eliminate a paediatric infectious disease. In contrast, in other cases, a low cost, highly efficacious vaccine can be refused, even when the rational decision model predicts acceptance. Injunctive social norms can prevent vaccine refusal, if vaccine acceptance is sufficiently high in the beginning of the vaccination campaign. Cognitive processes can have major impacts on the predictions of behaviour-disease models, and further study of such processes in the context of vaccination is thus warranted.

  15. Rational desires and the limitation of life-sustaining treatment.

    Science.gov (United States)

    Savulescu, Julian

    1994-07-01

    It is accepted that treatment of previously competent, now incompetent patients can be limited if that is what the patient would desire, if she were now competent. Expressed past preferences or an advance directive are often taken to constitute sufficient evidence of what a patient would now desire. I distinguish between desires and rational desires. I argue that for a desire to be an expression of a person's autonomy, it must be or satisfy that person's rational desires. A person rationally desires a course of action if that person desires it while being in possession of all available relevant facts, without committing relevant error of logic, and "vividly imagining" what its consequences would be like for her. I argue that some competent, expressed desires obstruct autonomy. I show that several psychological mechanisms operate to prevent a person rationally evaluating what future life in a disabled state would be like. Rational evaluation is difficult. However, treatment limitation, if it is to respect autonomy, must be in accord with a patient's rational desires, and not merely her expressed desires. I illustrate the implications of these arguments for the use of advance directives and for the treatment of competent patients.

  16. Development of rations for the enhanced survival of salmon

    International Nuclear Information System (INIS)

    Ewing, R.D.; Lagasse, J.P.

    1990-12-01

    The nutritional quality of feed plays an important role in determining the health and ''fitness'' of smolts. Commercial fish meal, the major source of protein in salmon rations, may be reduced in quality from poor drying techniques during manufacture. Dietary stress in the hatchery may result. This investigation tests the hypothesis that protein quality of fish rations can influence the survival of smolts and the ultimate return of adults. The test involves a comparison between performances of coho (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) reared on rations containing very high quality protein derived from vacuum dried meals and those of fish reared on commercial rations, with commercial fish meal as a source of protein. Survival and return of several brood years of test and control fish are used to measure the influence of ration on survival. This report includes recovery data from these marked fish collected 1982 through September 1990

  17. The University – a Rational-Biologic Model

    Directory of Open Access Journals (Sweden)

    Ion Gh. Rosca

    2008-05-01

    Full Text Available The article advances the extension of the biologic rational model for the organizations, which are reprocessing and living in a turbulent environment. The current “tree” type organizations are not able to satisfy the requirements of the socio-economical environment and are not able to provide the organizational perpetuation and development. Thus, an innovative performing model for both the top and down management areas is presented, with the following recommendations: dividing the organization into departments using neuronal connections, focusing on the formatting processes and not on the activities, rethinking the system of a new organizational culture.

  18. Abstracts of the 9. Brazilian Congress of Biophysics, 2. Brazilian Congress of Pharmacology and Experimental Therapeutics and 19. Brazilian Congress of Physiology

    International Nuclear Information System (INIS)

    1984-01-01

    Abstracts about biophysics, pharmacology, experimental therapeutics and physiology are presented. The use of radioisotopes in radioassays involve topics like biophysics and renal physiology; central nervous system; endocrinology; animal and comparative physiology; general physiology, digestion and nutrition; general pharmacology. (M.A.C.) [pt

  19. Canopy-scale biophysical controls on transpiration and evaporation in the Amazon Basin

    DEFF Research Database (Denmark)

    Mallick, Kaniska; Trebs, Ivonne; Bøgh, Eva

    2016-01-01

    to directly quantify the canopy-scale biophysical controls on λET and λEE over multiple plant functional types (PFTs) in the Amazon Basin. Combining data from six LBA (Large-scale Biosphere-Atmosphere Experiment in Amazonia) eddy covariance tower sites and a TR-driven physically based modeling approach, we...

  20. Boosting antibody developability through rational sequence optimization.

    Science.gov (United States)

    Seeliger, Daniel; Schulz, Patrick; Litzenburger, Tobias; Spitz, Julia; Hoerer, Stefan; Blech, Michaela; Enenkel, Barbara; Studts, Joey M; Garidel, Patrick; Karow, Anne R

    2015-01-01

    The application of monoclonal antibodies as commercial therapeutics poses substantial demands on stability and properties of an antibody. Therapeutic molecules that exhibit favorable properties increase the success rate in development. However, it is not yet fully understood how the protein sequences of an antibody translates into favorable in vitro molecule properties. In this work, computational design strategies based on heuristic sequence analysis were used to systematically modify an antibody that exhibited a tendency to precipitation in vitro. The resulting series of closely related antibodies showed improved stability as assessed by biophysical methods and long-term stability experiments. As a notable observation, expression levels also improved in comparison with the wild-type candidate. The methods employed to optimize the protein sequences, as well as the biophysical data used to determine the effect on stability under conditions commonly used in the formulation of therapeutic proteins, are described. Together, the experimental and computational data led to consistent conclusions regarding the effect of the introduced mutations. Our approach exemplifies how computational methods can be used to guide antibody optimization for increased stability.