Discrete Formulation for the dynamics of rods deforming in space

We describe the main ingredients needed to create, from the smooth lagrangian density, a variational principle for discrete motions of a discrete rod, with corresponding conserved Noether currents. We describe all geometrical objects in terms of elements on the linear Atiyah bundle, using a reduced forward difference operator. We show how this introduces a discrete lagrangian density that models the discrete dynamics of a discrete rod. The presented tools are general enough to represent a discretization of any variational theory in principal bundles, and its simplicity allows to perform an iterative integration algorithm to compute the discrete rod evolution in time, starting from any predefined configurations of all discrete rod elements at initial times

Time-dependent prediction degradation assessment of neural-networks-based TEC forecasting models

An estimation of the difference in TEC prediction accuracy achieved when the prediction varies from 1 h to 7 days in advance is described using classical neural networks. Hourly-daily Faraday-rotation derived TEC measurements from Florence are used. It is shown that the prediction accuracy for the examined dataset, though degrading when time span increases, is always high. In fact, when a relative prediction error margin of +/-10% is considered, the population percentage included therein is almost always well above the 55%. It is found that the results are highly dependent on season and the dataset wealth, whereas they highly depend on the f(0)F2 - TEC variability difference and on hysteresis-like effect between these two ionospheric characteristics.info:eu-repo/semantics/publishedVersio

Stability of Affine G-varieties and Irreducibility in Reductive Groups

Let $G$ be a reductive affine algebraic group, and let $X$ be an affine algebraic $G$-variety. We establish a (poly)stability criterion for points $x\in X$ in terms of intrinsically defined closed subgroups $H_{x}$ of $G$, and relate it with the numerical criterion of Mumford, and with Richardson and Bate-Martin-R\"ohrle criteria, in the case $X=G^{N}$. Our criterion builds on a close analogue of a theorem of Mundet and Schmitt on polystability and allows the generalization to the algebraic group setting of results of Johnson-Millson and Sikora about complex representation varieties of finitely presented groups. By well established results, it also provides a restatement of the non-abelian Hodge theorem in terms of stability notions.Comment: 29 pages. To appear in Int. J. Math. Note: this version 4 is identical with version 2 (version 3 is empty

Contraste fiel de la critica y juicio del pronostico de Don Diego de Torres de este año de 1728

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-2010Fecha tomada de la AprobaciónSign.. A-D4, E2Port. con orla tip

Historical Archaeology in the Iberian Peninsula

UID/HIS/04209/2019 DL 57/2016/CP1453/CT0084authorsversionpublishe

Effect of antibodies on the expression of Plasmodium falciparum circumsporozoite protein gene

Antibodies are known to play an important role in the control of malaria infection. However, they can modulate parasite development enhancing infection. The effect of anti-Plasmodium antibodies on the expression of circumsporozoite protein gene (csp) was investigated. Plasmodium falciparum 3D7 in vitro cultures were submitted to: i) anti- circumsporozoite protein monoclonal antibody (anti-CSP-mAb) [1μg/ml, 0.1μg/ml, 0.01μg/ml and 0.001μg/ml] and ii) purified IgG Fab fragment from a pool of malaria patients [1mg/ml and 1μg/ml]; and compared to control cultures. After 24h the number of ring infected erythrocytes was determined in order to calculate invasion efficacy. At 48h culture supernatant was collected, and the amount of circumsporozoite protein determined by ELISA, parasitaemia was calculated and cells were processed for RNA preparation. Expression of csp gene was quantified using Real time RT-PCR. There was an increase in parasite growth when treated with lower anti-CSP-mAb concentration, which was associated with lower csp expression, while 1μg/ml anti-CSP-mAb treatment presented a growth inhibitory effect accompanied by high csp expression

The Safe-Port project: an approach to port surveillance and protection

SAFE-PORT is a recently started project addressing the complex issue of determining the best configurations of resources for harbour and port surveillance and protection. More specifically, the main goal is to find, for any given scenario, an adequate set of configuration solutions — i.e., number and type of sensors and equipments, their locations and operating modes, the corresponding personnel and other support resources — that maximize protection over a specific area. The project includes research and development of sensors models, novel algorithms for optimization and decision support, and a computer-based decision support system (DSS) to assist decision makers in that task. It includes also the development of a simulation environment for modelling relevant aspects of the scenario (including sensors used for surveillance, platforms, threats and the environment), capable to incorporate data from field-trials, used to test and validate solutions proposed by the DSS. Test cases will consider the use of intelligent agents to model the behaviour of threats and of NATO forces in a realistic way, following experts’ definitions and parameters

Performance of the freshwater shrimp <i>Atyaephyra desmarestii</i> as indicator of stress imposed by textile effluents

Textile plants consume large volumes of water and produce a great amount of wastewaters, which can be important sources of toxic discharges in receiving environments. The objective of this study was to evaluate the acute toxicity of textile effluents on the freshwater shrimp A. desmarestii. A whole effluent toxicity test procedure was used to determine the aggregate toxicity of three samples taken before and after wastewater treatment in a textile mill. The following LC50 &minus; 48 h values (%, v/v) were calculated: Untreated effluent &minus;29% effluent (sample 1), 22% effluent (sample 2), and 47% (sample 3); Treated effluent &minus;73% effluent (sample 1), 74% effluent (sample 2), and &gt; 100% (sample 3). Based upon acute toxicity units (TUa = 100/LC50), untreated effluent varied from toxic in samples 1 and 3 (2.00 &le; TUa &le; 4.00) to very toxic in sample 2 (TUa &gt; 4.0), whereas treated effluent varied from no toxic in sample 3 to moderately toxic in samples 1 and 2 (1.33 &le; TUa &le; 1.99). Despite some limitations and constraints related to innate variability of industrial effluents, our results suggested that A. desmarestii can be a promising and potential test organism for assessing toxicity of complex chemical mixtures