3,107 research outputs found
Seeking the Real Adam Smith and Milton Friedman
In this paper we will analyze the relationship between free market principles and ethics through an exploration of how too many business managers often approach the ideas of Adam Smith and Milton Friedman. In doing so, we aim to provide a thoughtful foundation for future discussions of how we ought to navigate this intersection. We briefly examine questions such as: What is the relationship between the “best” economy in terms of efficiency and the common good for society? Is pursuing one’s individual economic advantage the same as promoting the general interest? As we analyze and discuss these questions, specifically in the context of Smith and Friedman, we also make some alternative normative assertions, grounded in social welfare, about adopting a broader societal perspective for the purpose of business
Cerebral venous thrombosis: retrospective analysis of 49 cases
Introduction: Cerebral Venous Thrombosis (CVT) is a rare and potentially life-threatening disease, accounting for about 0.5% of stroke cases. However, it is believed to be an underdiagnosed condition. Early diagnosis requires a high degree of suspicion and appropriate use of imaging modalities. Objectives: Imagiological and clinical characterization of CVT cases diagnosed at our hospital from 2004 to 2007. Methods: This study was a retrospective, cross-sectional analysis from 2004 to 2007, using our institution database. We reviewed hospital discharge data to assess the incidence of CVT. The study population consisted of 49 patients. Retrospective review of the clinical data and imaging studies of these patients was then performed. Results: Of the 49 patients with confirmed CVT, 38 were female. Patient age varied between 16 and 75 years, with an average of 42.6 years. Thrombotic risk factors were found in 43 patients; the most frequent was dyslipidemia (n = 22) followed by oral contraceptive use (n = 18). Initial head Computerized Tomography (CT) was normal in six cases. Diagnosis was made by Magnetic Resonance (MR) in 38 cases, Cerebral CT-Venography in 10 cases and Digital Subtraction Angiography in one case. Average time from onset of symptoms to diagnosis was nine days; this was not significantly different when comparing the group diagnosed by MR with the group diagnosed by CT-Venography. Right transverse sinus was the most frequent location of thrombosis (n = 36). Only in four cases thrombosis did not involve the lateral sinuses. Conclusions: Lateral sinus thrombosis is a frequent variety of CVT, accounting for 91.8% of our cases. A negative Head CT scan does not exclude the presence of cerebral venous thrombosis; therefore appropriate imaging study should be performed whenever there's a high degree of clinical suspicion. Cerebral CT-Venography seems to be a good alternative to MR for the diagnosis of CVT
Manejo da adubação potássica e da irrigação no progresso de doenças fúngicas e produtividade da melancia
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Transparent and flexible polymerized graphite oxide thin film with frequency-dependent dielectric constant
Here we report on the preparation of transparent and flexible polymerized
graphite oxide, which is composed of carbons with sp3-hybridized orbitals and a
non-planar ring structure, and which demonstrates dispersion in its dielectric
constant at room temperature. This frequency dependence renders the material
suitable for creating miniaturized, flexible, and transparent variable
capacitors, allowing for smaller and simpler integrated electronic devices. We
discuss this polarizability in terms of space charge effects
Immunomodulatory properties of Musa paradisiaca L. inflorescence in Combined Allergic Rhinitis and Asthma Syndrome (CARAS) model towards NFκB pathway inhibition
Musa paradisiaca L. (Musaceae), a tropical plant named banana is used as food and as medicine in Brazil. Banana inflorescence, popularly known as mangará, presents several biological activities including anti-inflammatory effects. Here, we demonstrated the immunomodulatory activity of banana inflorescence extract (HEM) on a mice model of combined allergic rhinitis and asthma syndrome (CARAS) and in human macrophages. The HEM inhibited the eosinophil migration, production of cytokines as IL-4, IL-5, IL-13, and IL-17A dependent on IFN-¿ production in the airway. The mechanism of the extract was, in part, by the NF-¿B signaling pathway inhibition. Besides, the HEM decreased expression of the CD86 and HLA-DR receptors on human M1 macrophages independently of M2 modulation. Therefore, we infer that the inflorescence, a disposable material from the banana crops, has anti-allergic property in the CARAS model and modulates the human macrophages, characterizing it as biologically important material for the production of phytomedicine.This work was supported by Brazilian agencies National Council for Scientific and Technological Development (CNPq), Coordination for the Improvement of Higher Education Personnel (CAPES), Institute for Research and Innovation in Health (I3S) and National Institute of Biomedical Engineering (INEB). The authors would like to thank Serviço de Imunohemoterapia of Centro Hospitalar Universitário de São João (CHUSJ), Porto, Portugal, for kindly donating Buffy Coats. The authors are also grateful for the valuable assistance provided by agencies, institutes and collaborators.
This work was supported by Brazilian agencies National Council for Scientific and Technological Development (CNPq), Coordination for the Improvement of Higher Education Personnel (CAPES), Institute for Research and Innovation in Health (I3S) and National Institute of Biomedical Engineering (INEB). The authors would like to thank Serviço de Imunohemoterapia of Centro Hospitalar Universitário de São João (CHUSJ), Porto, Portugal, for kindly donating Buffy Coats. The authors are also grateful for the valuable assistance provided by agencies, institutes and collaborators
An in vivo tethered toxin approach for the cell-autonomous inactivation of voltage-gated sodium channel currents in nociceptors
Understanding information flow in sensory pathways requires cell-selective approaches to manipulate the activity of defined neurones. Primary afferent nociceptors, which detect painful stimuli, are enriched in specific voltage-gated sodium channel (VGSC) subtypes. Toxins derived from venomous animals can be used to dissect the contributions of particular ion currents to cell physiology. Here we have used a transgenic approach to target a membrane-tethered isoform of the conotoxin MrVIa (t-MrVIa) only to nociceptive neurones in mice. T-MrVIa transgenic mice show a 44 ± 7% reduction of tetrodotoxin-resistant (TTX-R) VGSC current densities. This inhibition is permanent, reversible and does not result in functional upregulation of TTX-sensitive (TTX-S) VGSCs, voltage-gated calcium channels (VGCCs) or transient receptor potential (TRP) channels present in nociceptive neurones. As a consequence of the reduction of TTX-R VGSC currents, t-MrVIa transgenic mice display decreased inflammatory mechanical hypersensitivity, cold pain insensitivity and reduced firing of cutaneous C-fibres sensitive to noxious cold temperatures. These data validate the use of genetically encoded t-toxins as a powerful tool to manipulate VGSCs in specific cell types within the mammalian nervous system. This novel genetic methodology can be used for circuit mapping and has the key advantage that it enables the dissection of the contribution of specific ionic currents to neuronal function and to behaviour.This work was supported by grants from the DFG to I.I.-T. and G.R.L. within the collaborative research centre (SFB 665) and from the Alexander von Humboldt Foundation to E.St.J.S
A comprehensive probabilistic analysis of SIR-type epidemiological models based on full randomized Discrete-Time Markov Chain formulation with applications
[EN] This paper provides a comprehensive probabilistic analysis of a full randomization of approximate SIR-type epidemiological models based on discrete-time Markov chain formulation. The randomization is performed by assuming that all input data (initial conditions, the contagion, and recovering rates involved in the transition matrix) are random variables instead of deterministic constants. In the first part of the paper, we determine explicit expressions for the so called first probability density function of each subpopulation identified as the corresponding states of the Markov chain (susceptible, infected, and recovered) in terms of the probability density function of each input random variable. Afterwards, we obtain the probability density functions of the times until a given proportion of the population remains susceptible, infected, and recovered, respectively. The theoretical analysis is completed by computing explicit expressions of important randomized epidemiological quantities, namely, the basic reproduction number, the effective reproduction number, and the herd immunity threshold. The study is conducted under very general assumptions and taking extensive advantage of the random variable transformation technique. The second part of the paper is devoted to apply our theoretical findings to describe the dynamics of the pandemic influenza in Egypt using simulated data excerpted from the literature. The simulations are complemented with valuable information, which is seldom displayed in epidemiological models. In spite of the nonlinear mathematical nature of SIR epidemiological model, our results show a strong agreement with the approximation via an appropriate randomized Markov chain. A justification in this regard is discussed.Spanish Ministerio de Economia y Competitividad, Grant/Award Number: MTM2017-89664-P; Generalitat Valenciana, Grant/Award Number: APOSTD/2019/128; Ministerio de Economia y Competitividad, Grant/Award Number: MTM2017-89664-PCortés, J.; El-Labany, S.; Navarro-Quiles, A.; Selim, MM.; Slama, H. (2020). A comprehensive probabilistic analysis of SIR-type epidemiological models based on full randomized Discrete-Time Markov Chain formulation with applications. Mathematical Methods in the Applied Sciences. 43(14):8204-8222. https://doi.org/10.1002/mma.6482S820482224314Hamra, G., MacLehose, R., & Richardson, D. (2013). Markov Chain Monte Carlo: an introduction for epidemiologists. International Journal of Epidemiology, 42(2), 627-634. doi:10.1093/ije/dyt043Becker, N. (1981). A General Chain Binomial Model for Infectious Diseases. Biometrics, 37(2), 251. doi:10.2307/2530415Allen, L. J. S. (2010). An Introduction to Stochastic Processes with Applications to Biology. doi:10.1201/b12537Hethcote, H. W. (2000). The Mathematics of Infectious Diseases. SIAM Review, 42(4), 599-653. doi:10.1137/s0036144500371907Brauer, F., & Castillo-Chávez, C. (2001). Mathematical Models in Population Biology and Epidemiology. Texts in Applied Mathematics. doi:10.1007/978-1-4757-3516-1Cortés, J.-C., Navarro-Quiles, A., Romero, J.-V., & Roselló, M.-D. (2018). Some results about randomized binary Markov chains: theory, computing and applications. International Journal of Computer Mathematics, 97(1-2), 141-156. doi:10.1080/00207160.2018.1440290Cortés, J.-C., Navarro-Quiles, A., Romero, J.-V., & Roselló, M.-D. (2017). Randomizing the parameters of a Markov chain to model the stroke disease: A technical generalization of established computational methodologies towards improving real applications. Journal of Computational and Applied Mathematics, 324, 225-240. doi:10.1016/j.cam.2017.04.040Casabán, M.-C., Cortés, J.-C., Romero, J.-V., & Roselló, M.-D. (2015). Probabilistic solution of random SI-type epidemiological models using the Random Variable Transformation technique. Communications in Nonlinear Science and Numerical Simulation, 24(1-3), 86-97. doi:10.1016/j.cnsns.2014.12.016Casabán, M.-C., Cortés, J.-C., Navarro-Quiles, A., Romero, J.-V., Roselló, M.-D., & Villanueva, R.-J. (2016). A comprehensive probabilistic solution of random SIS-type epidemiological models using the random variable transformation technique. Communications in Nonlinear Science and Numerical Simulation, 32, 199-210. doi:10.1016/j.cnsns.2015.08.009Slama, H., Hussein, A., El-Bedwhey, N. A., & Selim, M. M. (2019). An approximate probabilistic solution of a random SIR-type epidemiological model using RVT technique. Applied Mathematics and Computation, 361, 144-156. doi:10.1016/j.amc.2019.05.019Slama, H., El-Bedwhey, N. A., El-Depsy, A., & Selim, M. M. (2017). Solution of the finite Milne problem in stochastic media with RVT Technique. The European Physical Journal Plus, 132(12). doi:10.1140/epjp/i2017-11763-6Kegan, B., & West, R. W. (2005). Modeling the simple epidemic with deterministic differential equations and random initial conditions. Mathematical Biosciences, 195(2), 179-193. doi:10.1016/j.mbs.2005.02.004Dorini, F. A., Cecconello, M. S., & Dorini, L. B. (2016). On the logistic equation subject to uncertainties in the environmental carrying capacity and initial population density. Communications in Nonlinear Science and Numerical Simulation, 33, 160-173. doi:10.1016/j.cnsns.2015.09.009Van den Driessche, P. (2017). Reproduction numbers of infectious disease models. Infectious Disease Modelling, 2(3), 288-303. doi:10.1016/j.idm.2017.06.002Heffernan, J. ., Smith, R. ., & Wahl, L. . (2005). Perspectives on the basic reproductive ratio. Journal of The Royal Society Interface, 2(4), 281-293. doi:10.1098/rsif.2005.0042Khalil, K. M., Abdel-Aziz, M., Nazmy, T. T., & Salem, A.-B. M. (2012). An Agent-Based Modeling for Pandemic Influenza in Egypt. Intelligent Systems Reference Library, 205-218. doi:10.1007/978-3-642-25755-1_1
Physiological and enzymatic changes in rice seeds stored at low temperatures
This study aimed to evaluate the effect of low temperatures on the physiological and enzymatic changes of rice seeds. The seeds were packed in airtight chambers and maintained at temperatures of 8 and -50°C for periods of 15, 30 , 45, 60, 75 and 90 days. The same procedure was adopted for the control treatment with the seeds kept at a temperature of 25°C. The seeds were evaluated regarding germination test; seedling emergency; emergency speed index; length and dry weight of radicle; and seedling of shoot. The activity of amylase and total protein content were also evaluated. The temperatures of 8 and -50°C significantly influenced the physiological quality and the enzyme amylase activity of rice seeds, resulting in higher germination, seedling emergence and enzyme activity. The temperature is a promising alternative for the maintenance of physiological quality and enzymatic activity of rice seeds during storage. Key words: Oryza sativa L., enzymatic activity, physiological quality, storage.Abbreviation: ESI, Emergence speed index; PVP, polyvinylpyrrolidone
Clinical and genetic analysis of 29 Brazilian patients with Huntington’s disease-like phenotype
Huntington’s disease (HD) is a neurodegenerative disorder characterized by chorea,
behavioral disturbances and dementia, caused by a pathological expansion of the CAG
trinucleotide in the HTT gene. Several patients have been recognized with the typical HD
phenotype without the expected mutation. The objective of this study was to assess the
occurrence of diseases such as Huntington’s disease-like 2 (HDL2), spinocerebellar ataxia
(SCA) 1, SCA2, SCA3, SCA7, dentatorubral-pallidoluysian atrophy (DRPLA) and choreaacanthocytosis
(ChAc) among 29 Brazilian patients with a HD-like phenotype. In the group
analyzed, we found 3 patients with HDL2 and 2 patients with ChAc. The diagnosis was not
reached in 79.3% of the patients. HDL2 was the main cause of the HD-like phenotype in
the group analyzed, and is attributable to the African ancestry of this population. However,
the etiology of the disease remains undetermined in the majority of the HD negative
patients with HD-like phenotype.
Key words: Huntington’s disease, Huntington’s disease-like, chorea-acanthocytosis,
Huntington’s disease-like 2
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