1,941 research outputs found
The Desirable Organizational Structure for Evolutionary Firms in Static Landscapes
In addition to the common analysis of the Kauffman NK model where the value of K and the structure of interaction is given, the aim of this paper is to study what would be the values of these two parameters if they were endogenized. Thus, a model is proposed where firms and business schools coordinate to search for high peaks in their respective landscapes using evolutionary algorithms. The main result coming out from the analysis of the model is that agents, using evolutionary algorithms, attempt to simplify the problems of coordination and this, over time, produces the existence in the economy of agents using many different strategies. (JEL-code: C61, C63, D21, D23
Effect of impurities and sintering temperature on properties of MgO-CaZrO3 ceramic
CaZrO3 -MgO ceramics are useful as refractories in kilns for the cement production. One method of manufacture of such ceramics is by sintering from m-ZrO2 and dolomite MgCa(CO3 )2 mixtures. In this work electrofused m-ZrO2 grains (fraction <M325) and two Argentinean dolomites with different mineralogical compositions were used as raw materials. Ceramics were obtained by the conventional powder method of uniaxial pressing and subsequent sintering at 1400 to 1680 °C. The influence of the different mineralogy of the dolomites and sintering temperature on the properties of the composites was investigated. Ceramics had 20-30% porosity with representative SEM-EDX microstructure constituted by CaZrO3 agglomerates of variable size (~100µm) and MgO grains (size <50µm) containing some unreacted m-ZrO2 grains. The elastic modulus and flexural strength were correlated with the presence of impurities of the dolomite, porosity and microstructure of the ceramic.Fil: Booth, Raul Fernando Nicolas. Provincia de Buenos Aires. Gobernación. Comision de Invest.científicas. Centro de Tecnología de Recursos Minerales y Ceramica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Tecnología de Recursos Minerales y Ceramica; ArgentinaFil: Garrido, Liliana Beatriz. Provincia de Buenos Aires. Gobernación. Comision de Invest.científicas. Centro de Tecnología de Recursos Minerales y Ceramica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Tecnología de Recursos Minerales y Ceramica; ArgentinaFil: Aglietti, Esteban Fausto. Provincia de Buenos Aires. Gobernación. Comision de Invest.científicas. Centro de Tecnología de Recursos Minerales y Ceramica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Tecnología de Recursos Minerales y Ceramica; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentin
The implications of male human papilloma virus infection in couples seeking assisted reproduction technologies
Human papilloma virus (HPV) is one of the most common viral sexually-transmitted diseases worldwide. The prevalence of HPV is higher in infertile males when compared with fertile men and ranges between 10 and 35.7% in men affected by unexplained infertility. HPV can bind to spermatozoa and can potentially be transferred to fertilized oocytes. Viral detection in blastocysts and trophoblastic cells is associated with impaired embryo development and poor pregnancy outcomes. Nevertheless, attempts to eliminate HPV-DNA from sperm samples through routine washing techniques have failed. In assisted reproduction technologies (ART), intracytoplasmic sperm injection involves no natural selection of the sperm cell, which means that these procedures have a plausible risk of injecting sperm containing HPV. The possible detrimental effects of HPV on ART in couples with infected male partners are summarized in this review
On generalized definitions of ultradifferentiable classes
We show that the ultradifferentiable-like classes of smooth functions
introduced and studied by S. Pilipovi\'c, N. Teofanov and F. Tomi\'c are
special cases of the general framework of spaces of ultradifferentiable
functions defined in terms of weight matrices in the sense of A. Rainer and the
third author. We study classes "beyond geometric growth factors" defined in
terms of a weight sequence and an exponent sequence, prove that these new types
admit a weight matrix representation and transfer known results from the
matrix-type to such a non-standard ultradifferentiable setting.Comment: Some typos corrected; to appear in Journal of Mathematical Analysis
and Application
Multivariate Cepstral Feature Compensation on Band-limited Data for Robust Speech Recognition
Proceedings of the 16th Nordic Conference
of Computational Linguistics NODALIDA-2007.
Editors: Joakim Nivre, Heiki-Jaan Kaalep, Kadri Muischnek and Mare Koit.
University of Tartu, Tartu, 2007.
ISBN 978-9985-4-0513-0 (online)
ISBN 978-9985-4-0514-7 (CD-ROM)
pp. 144-151
Learning and Leveraging World Models in Visual Representation Learning
Joint-Embedding Predictive Architecture (JEPA) has emerged as a promising
self-supervised approach that learns by leveraging a world model. While
previously limited to predicting missing parts of an input, we explore how to
generalize the JEPA prediction task to a broader set of corruptions. We
introduce Image World Models, an approach that goes beyond masked image
modeling and learns to predict the effect of global photometric transformations
in latent space. We study the recipe of learning performant IWMs and show that
it relies on three key aspects: conditioning, prediction difficulty, and
capacity. Additionally, we show that the predictive world model learned by IWM
can be adapted through finetuning to solve diverse tasks; a fine-tuned IWM
world model matches or surpasses the performance of previous self-supervised
methods. Finally, we show that learning with an IWM allows one to control the
abstraction level of the learned representations, learning invariant
representations such as contrastive methods, or equivariant representations
such as masked image modelling.Comment: 23 pages, 16 figure
Wildfire spreading simulator using fast marching algorithm
Programs that can predict wildfire behavior are a very useful tool in terms of extinguishing these fires more effectively. State of the art wildfire simulators present some drawbacks such as not being sufficiently user-friendly, being expensive, requiring great computational power or having poor graphical representation. This paper presents a prototype wildfire simulation app that uses Fast Marching (FM) as its core algorithm. The wildfire app is developed as a Matlab GUI. Said application shows the shape of the fire front at a given moment in time in a 3D map of the terrain affected by the fire. Any real life maps can be loaded to the application for wildfire prediction. The user can choose to vary parameters such as starting (ignition) and ending points, wind direction and speed and propagation time, and see its effect on fire propagation. Interface response to each change in the input is very fast, therefore proving the effciency of the algorithm. Although a prototype, the wildfire basic app is superior to some state of the art simulators regarding certain important features. It can be concluded that Fast Marching is a valid core algorithm for a fire simulator. The way the app is programmed in Matlab confers it flexibility, enabling further specific changes that make it truly competitive against currently used wildfire simulators
HTLV-1 and -2 envelope SU subdomains and critical determinants in receptor binding
BACKGROUND: Human T-cell leukemia virus (HTLV) -1 and -2 are deltaretroviruses that infect a wide range of cells. Glut1, the major vertebrate glucose transporter, has been shown to be the HTLV Env receptor. While it is well established that the extracellular surface component (SU) of the HTLV envelope glycoprotein (Env) harbors all of the determinants of interaction with the receptor, identification of SU subdomains that are necessary and sufficient for interaction with the receptor, as well as critical amino acids therein, remain to be precisely defined. Although highly divergent in the rest of their genomes, HTLV and murine leukemia virus (MLV) Env appear to be related and based on homologous motifs between the HTLV and MLV SU, we derived chimeric HTLV/MLV Env and soluble HTLV-1 and -2 truncated amino terminal SU subdomains. RESULTS: Using these SU constructs, we found that the 183 and 178 amino terminal residues of the HTLV-1 and -2 Env, respectively, were sufficient to efficiently bind target cells of different species. Binding resulted from bona fide interaction with the HTLV receptor as isolated SU subdomains specifically interfered with HTLV Env-mediated binding, cell fusion, and cell-free as well as cell-to-cell infection. Therefore, the HTLV receptor-binding domain (RBD) lies in the amino terminus of the SU, immediately upstream of a central immunodominant proline rich region (Env residues 180 to 205), that we show to be dispensible for receptor-binding and interference. Moreover, we identified a highly conserved tyrosine residue at position 114 of HTLV-1 Env, Tyr(114), as critical for receptor-binding and subsequent interference to cell-to-cell fusion and infection. Finally, we observed that residues in the vicinity of Tyr(114 )have lesser impact on receptor binding and had various efficiency in interference to post-binding events. CONCLUSIONS: The first 160 residues of the HTLV-1 and -2 mature cleaved SU fold as autonomous domains that contain all the determinants required for binding the HTLV receptor
IMPLEMENTACIÓN DE SERVICIOS CON NETHSERVER
NethServer, una plataforma de servidor de código abierto basada en Linux simplifica la implementación y administración de servicios esenciales en redes. Se destaca por su capacidad para configurar diferentes servicios de manera modular y extensible por medio de la instalación integrada de servicios desde un centro de aplicaciones disponible por medio de su interfaz web. En el presente informe se implementan servicios como DNS y DHCP, gestionar servicios LDAP para usuarios y grupos, implementar un proxy para el control del tráfico web, facilitar la creación de conexiones VPN seguras y ofrecer un sólido módulo de firewall. Con una interfaz web intuitiva, NethServer se presenta como una solución completa y accesible, adaptada tanto para entornos empresariales como para pequeñas empresas.NethServer, an open source Linux-based server platform, simplifies the deployment and management of essential network services. It stands out for its ability to configure different services in a modular and extensible way through the integrated installation of services from an application center available through its web interface. This report implements services such as DNS and DHCP, manage LDAP services for users and groups, implement a proxy for web traffic control, facilitate the creation of secure VPN connections and offer a robust firewall module. With an intuitive web interface, NethServer is presented as a complete and accessible solution, adapted for both enterprise and small business environments
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