21,815 research outputs found
Polarized minimal families of rational curves and higher Fano manifolds
In this paper we investigate Fano manifolds whose Chern characters
satisfy some positivity conditions. Our approach is via the study of
polarized minimal families of rational curves through a general
point . First we translate positivity properties of the Chern
characters of into properties of the pair . This allows us to
classify polarized minimal families of rational curves associated to Fano
manifolds satisfying and . As a first
application, we provide sufficient conditions for these manifolds to be covered
by subvarieties isomorphic to and . Moreover, this
classification enables us to find new examples of Fano manifolds satisfying
.Comment: 17 page
A closed-form solution to predict short-range surface plasmons in thin films and its application to hole arrays
A theoretical study of surface plasmon polaritons (SPPs) in ultrathin lossy
metal films is presented. The dispersion relation of such films is well known
and can be solved numerically to obtain a combination of long-range (LR-) and
short-range (SR-) eigenmodes. In this contribution, a simple solution for the
SR-SPPs is derived. An approximation for the LR- eigenmodes can be found
elsewhere. To validate the approximation, a two dimensional (2D) periodic array
of small holes is studied subsequently. The spectral response of the array is
obtained by full-wave simulations and the results compared with those
calculated analytically, showing an excellent agreement for small holes
Guia de tutoria de área
O Guia de Tutoria de Área tem como foco central os profissionais que vão atuar como tutores de professores. A publicação apresenta as estratégias que devem nortear o trabalho desse profissional para que ele se prepare para fazer uma boa gestão da sala de aula, identificando as dificuldades de aprendizado da turma, ouvindo o aluno e refletindo, também, sobre a própria atuação
Prediction of percentage of ferrite as a function of heat input in robotic gas metal arc welding of duplex stainless steel SAF 2205 Welds
Skills that Pre-service Primary Teachers’ consider important in argumentation approach
Argumentation as a form of scientific discourse is a powerful tool that allows students questioning, justifying, and evaluating their and others’ claims. In science education, transmissive teaching predominates and this leads to difficulties in students’ construction of arguments and highlights limitations in teachers' pedagogical abilities in the management of this type of activities. Also, teachers' beliefs and perceptions have a big influence in the way they teach. Thus, the purpose has been to investigate pre-service primary teachers’ beliefs of what would be the skills they need as a core to support argumentation in science classrooms, and what skills students can develop when participate in science lessons based in argumentation. Results show that Pre-service Teachers of Primary pay little attention to the skills they will need in order to manage different methodological strategies as debate, pair work or pair discussion, that support the argumentation approach. Moreover, they lack of awareness about what is a good argument and its components, besides scientific knowledge. These results are significant because they indicate a need in designing specific training programs to support teachers in acquiring knowledge and skills about argumentation.Campus de Excelencia Internacional Andalucía Tech. This study is part of the project “La argumentacıón como estrategıa metodológıca para el desarrollo de competencıas profesıonales docentes.” [Argumentation as a methodological strategy for the development of professional teacher competences] (PIE15-74) funded by the University of Málaga in the assembly of 201
Membrane-associated proteins in giardia lamblia
The manner in which membrane-associated proteins interact with the membrane defines their subcellular fate and function. This interaction relies on the characteristics of the proteins, their journey after synthesis, and their interaction with other proteins or enzymes. Understanding these properties may help to define the function of a protein and also the role of an organelle. In the case of microorganisms like protozoa parasites, it may help to understand singular features that will eventually lead to the design of parasite-specific drugs. The protozoa parasite Giardia lamblia is an example of a widespread parasite that has been infecting humans and animals from ancestral times, adjusting itself to the changes of the environment inside and outside the host. Several membrane-associated proteins have been posted in the genome database GiardiaDB, although only a few of them have been characterized. This review discusses the data regarding membrane-associated proteins in relationship with lipids and specific organelles and their implication in the discovery of anti-giardial therapies.Fil: Touz, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Feliziani, Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Ropolo, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentin
Novel pathway for corrinoid compounds production in lactobacillus
Vitamin B12 or cobalamin is an essential metabolite for humans, which makes it an interesting compound for many research groups that focus in different producer-strains synthesis pathways. In this work, we report the influence of key intermediaries for cobalamin synthesis added to the culture medium in two Lactobacillus (L.) strains, L. reuteri CRL 1098 and L. coryniformis CRL 1001. Here, we report that addition of Co2+ and 5,6-dimethylbenzimidazole increased the corrinoid compounds production in both strains while addition of L-threonine increased only the corrinoid compounds production by CRL 1001 strain. Then, we purified and characterized by LC-MS the corrinoid compounds obtained. Physiological studies besides in silico analysis revealed that L. reuteri CRL 1098 and L. coryniformis CRL 1001 follow different pathways for the last steps of the corrinoid compounds synthesis.Fil: Torres, Andrea Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Vannini, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Font, Graciela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Saavedra, Maria Lucila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Taranto, Maria Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin
A Lucky Imaging search for stellar companions to transiting planet host stars
The presence of stellar companions around planet hosting stars influences the
architecture of their planetary systems. To find and characterise these
companions and determine their orbits is thus an important consideration to
understand planet formation and evolution. For transiting systems even unbound
field stars are of interest if they are within the photometric aperture of the
light curve measurement. Then they contribute a constant flux offset to the
transit light curve and bias the derivation of the stellar and planetary
parameters if their existence is unknown. Close stellar sources are, however,
easily overlooked by common planet surveys due to their limited spatial
resolution. We therefore performed high angular resolution imaging of 49
transiting exoplanet hosts to identify unresolved binaries, characterize their
spectral type, and determine their separation. The observations were carried
out with the Calar Alto 2.2m telescope using the Lucky Imaging camera AstraLux
Norte. All targets were imaged in i' and z' passbands. We found new companion
candidates to WASP-14 and WASP-58, and we re-observed the stellar companion
candidates to CoRoT-2, CoRoT-3, CoRoT-11, HAT-P-7, HAT-P-8, HAT-P-41, KIC
10905746, TrES-2, TrES-4, and WASP-2. We deduce from the stellar density around
all sources that two companion candidates out of the targets with the first
position measurement (CoRoT-11, HAT-P-41, KIC 10905746, WASP-14 and WASP-58)
are probably unbound. In addition, we re-analyse the influence of the sources
close to WASP-14 and WASP-58 on the planetary parameters given in the
literature and find no significant changes
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