Controllability of a viscoelastic plate using one boundary control in displacement or bending

In this paper we consider a viscoelastic plate (linear viscoelasticity of the Maxwell-Boltzmann type) and we compare its controllability properties with the (known) controllability of a purely elastic plate (the control acts on the boundary displacement or bending). By combining operator and moment methods, we prove that the viscoelastic plate inherits the controllability properties of the purely elastic plate

Boundary Controllability and Observability of a Viscoelastic String

In this paper we consider an integrodifferential system, which governs the vibration of a viscoelastic one-dimensional object. We assume that we can act on the system at the boundary and we prove that it is possible to control both the position and the velocity at every point of the body and at a certain time $T$, large enough. We shall prove this result using moment theory and we shall prove that the solution of this problem leads to identify a Riesz sequence which solves controllability and observability. So, the result as presented here are constructive and can lead to simple numerical algorithms

A case of intersex occurrence in Steindachneridion parahybae (Steindachner, 1877) (Siluriformes: Pimelodidae) under captivity condition: A cytogenetic and morphological study

Poco se sabe sobre la biología reproductiva de Steindachneridion parahybae , una especie de teleósteo gonocorístico en peligro de extinción que habita la cuenca del río Paraíba do Sul y en éste trabajo se describe por primera vez la aparición de individuo intersexo en juvenil de S. parahybae . También se describió el aspecto normal de los ovarios y de los testículos de individuos juveniles procedentes del mismo lote de cría para su comparación; se realizó además el análisis citogenético. Un espécimen fue clasificado a priori como hembra debido a las características macroscópicas de los ovarios, con pequeños oocitos amarillos, sin flecos (característica principal de los bagres macho) y más grande que los testículos; sin embargo el análisis microscópico reveló la presencia de un ovotestis, incluyendo una espermatogénesis completa. S. parahybae presentó un número diploide, 2n = 56 cromosomas, sin evidencia de cromosomas sexuales diferenciados o supernumerarios entre ellos. Estos hallazgos pueden deberse al resultado de la exposición de los individuos a desorganizadores endocrinos o estar influenciados por las condiciones ambientales. Sin embargo no se puede descartar la posibilidad de la presencia de intersexos de forma espontánea. Por lo tanto, la importancia funcional y las consecuencias reproductivas de estas anomalías permanecen aún sin ser determinadas, sugiriendo que esta especie puede ser susceptible a los disruptores endocrinos. Estos resultados contribuyen a ampliar el conocimiento de la biología reproductiva de esta especie en peligro de extinción en condiciones de cautiverio.Little is known about reproductive biology of endangered Steindachneridion parahybae , a gonochoristic teleost species inhabiting the Paraíba do Sul River Basin, and herein is the first description of intersex in S. parahybae juvenile. The normal appearance of ovaries and testes in juvenile from the same lot of breeding were also described for comparison, even as cytogenetic analysis was performed in these juveniles. One specimen was a priori classified as female due to the macroscopic characteristic of ovaries, with small yellow oocytes, without fringes (a main characteristic of catfish male), and larger than testes; however the microscopic analysis revealed the presence of ovotestes, including the complete spermatogenesis. S. parahybae had diploid number, 2n = 56 chromosomes with no evidence of differentiated sex chromosomes or supernumerary chromosomes among them. These findings may be due to the result of exposure to endocrine disrupting compounds or may also be influenced by environmental conditions. The possibility of intersexes might also happen spontaneously and it cannot be ruled out. Therefore, the functional significance and reproductive consequences of this anomaly remain to be determined, suggesting that this species may be susceptible to endocrine disruption. These results contribute to gain expertise about reproductive biology of an endangered species in captivity.Fil: Honji, Renato Massaaki. Universidade de Sao Paulo; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Caneppele, Danilo. Companhia Energética de São Paulo. Unidade de Hidrobiologia e Aquicultura; BrasilFil: Pandolfi, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Lo Nostro, Fabiana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Moreira, Renata G.. Universidade de Sao Paulo; Brasi

A nonlinear transport problem of monochromatic photons in resonance with a gas

A transport problem arising from the dynamics of a gas in a radiation field, recently modelled in kinetic theory, is formulated and the trend to equilibrium of the gas-photon system is studied. A computational technique matching relevant mathematical aspects of differential quadrature and spectral methods is applied. The numerical results are then compared with those of other models known in literatur

Networks of plants: How to measure similarity in vegetable species

Despite the common misconception of nearly static organisms, plants do interact continuously with the environment and with each other. It is fair to assume that during their evolution they developed particular features to overcome similar problems and to exploit possibilities from environment. In this paper we introduce various quantitative measures based on recent advancements in complex network theory that allow to measure the effective similarities of various species. By using this approach on the similarity in fruit-Typology ecological traits we obtain a clear plant classification in a way similar to traditional taxonomic classification. This result is not trivial, since a similar analysis done on the basis of diaspore morphological properties do not provide any clear parameter to classify plants species. Complex network theory can then be used in order to determine which feature amongst many can be used to distinguish scope and possibly evolution of plants. Future uses of this approach range from functional classification to quantitative determination of plant communities in nature

Intravital imaging reveals p53-dependent cancer cell death induced by phototherapy via calcium signaling.

One challenge in biology is signal transduction monitoring in a physiological context. Intravital imaging techniques are revolutionizing our understanding of tumor and host cell behaviors in the tumor environment. However, these deep tissue imaging techniques have not yet been adopted to investigate the second messenger calcium (Ca2+). In the present study, we established conditions that allow the in vivo detection of Ca2+ signaling in three-dimensional tumor masses in mouse models. By combining intravital imaging and a skinfold chamber technique, we determined the ability of photodynamic cancer therapy to induce an increase in intracellular Ca2+ concentrations and, consequently, an increase in cell death in a p53-dependent pathway

The External Ligurian units (Northern Apennine, Italy): from rifting to convergence of a fossil ocean-continent transition zone

The External Ligurian Units of the Northern Apennine are interpreted as derived from the continent-ocean transition domain at the northern thinned conti- nental margin of the Adria microplate, i.e. the External Ligurian domain. The evolution of this paleogeographic realm from pre-orogenic times to the Eo- alpine and Meso-alpine tectonics is presented here, through a review of stratigraphic, petrological and structural data. The tectono-metamorphic evolution started in the Late Carboniferous-Early Permian (about 290 Ma), with the emplacement at deep crustal levels of the gabbroic protholits of mafic granulites. These lower continental crust rocks subsequentely underwent Permo-Triassic tectonic exhumation and were finally exhumed at shallow crustal levels in mid- dle Jurassic. The latter period was characterized by extensive brittle faulting at shallow crustal levels, giving rise to extensional allochtons formed by stretched slices of upper continental crust (mainly granitoids). At deep structural levels high temperature shearing of ophiolitic gabbros took place. Opening of the Lig- urian Tethys is finally testified by the basalt emplacement and radiolarian chert sedimentation in the Late Jurassic. During Late Cretaceous, development of Alpine intraoceanic subduction led to the inversion of the External Ligurian domain: the Eo-alpine deformation is recorded by syn-tectonic sedimentation of the Complessi di Base Auct., by development of very low-grade metamorphism and deformation at about 80 Ma. Middle Eocene deformation related with collision and indentation of the Adria with the Alpine accretionary wedge can be subdivided in two main stages: the first one (Ligurian Phase 1) implies large-scale, westward displacement of the EL Units, whereas the second stage (Ligurian Phase 2) is characterized by east- verging structures probably driven by the thinning of the preexisting nappe pile associated with exumation of underplated HP/LT Alpine units

AlpStore Project: A Viable Model for Renewables Exploitation in the Alps

AbstractNowadays, the integration of intermittent and unpredictable Renewable Energy Sources (RESs) has led to new issues for the electrical system. The paper proposes a model, named Virtual Power System (VPS), which enables the management of generators and loads as a single (virtual) entity in order to achieve a “global” benefit, i.e. to improve the capability of the grid to host RESs. Moreover Energy Storage Systems (ESSs) could be integrated in the VPS in order to provide ancillary services: voltage regulation, primary frequency regulation and exchange profiles adjustment for a better RESs programmability. This work proposes a quantitative approach for ESSs design and integration in a VPS. Numerical results are reported with respect to an experimental application in the AlpStore project (Alpine Space Program 2007-2013)

Radiolarian biostratigraphic evidence for a Late Jurassic age of the El Tambor Group ophiolites (Guatemala)

We present a radiolarian biostratigraphic study of the metacherts of the El Tambor Group ophiolites (South Motagua Unit), Guatemala. The ophiolite sequence comprises MOR pillow metabasalts, massive metabasalts, metacherts and micaschists. The age of the studied metacherts is referable to the Late Jurassic (Oxfordian - Kimmeridgian). The radiolarian assemblage described in this paper is the first Jurassic finding in the ophiolitic MOR succession of the Motagua zone and represents a valuable tool to constrain the geodynamic evolution of the Caribbean area. A review of the ages of Jurassic rocks associated with the ophiolites from the Caribbean area is also reported