3,585 research outputs found
Critical Steps of Plasmodium falciparum Ookinete Maturation
The egress and fertilization of Plasmodium gametes and development of a motile ookinete are the first crucial steps that mediate the successful transmission of the malaria parasites from humans to the Anopheles vector. However, limited information exists about the cell biology and regulation of this process. Technical impediments in the establishment of in vitro conditions for ookinete maturation in Plasmodium falciparum and other human malaria parasites further constrain a detailed characterization of ookinete maturation. Here, using fluorescence microscopy and immunolabeling, we compared P. falciparum ookinete maturation in Anopheles coluzzii mosquitoes in vivo and in cell culture in vitro. Our results identified two critical steps in ookinete maturation that are regulated by distinct mosquito factors, thereby highlighting the role of the mosquito environment in the transmission efficiency of malaria parasites
Radiative decay Z_H-> \gamma A_H in the little Higgs model with T-parity
In the little Higgs model with T-parity (LHTM), the only tree-level
kinematically allowed two-body decay of the Z_H boson is Z_H-> A_H H and thus
one-loop induced two-body decays may have a significant rate. We study the
Z_H-> \gamma A_H decay, which is induced at the one-loop level by a fermion
triangle and is interesting as it depends on the mechanism of anomaly
cancellation of the model. All the relevant two- and three-body decays of the
Z_H gauge boson arising at the tree-level are also calculated. We consider a
small region of the parameter space where the scale of the symmetry breaking f
is still allowed to be as low as 500 GeV by electroweak precision data. We
first analyze the scenario of a Higgs boson with a mass of 120 GeV. We found
that the Z_H->\gamma A_H branching ratio can be of the order of a tree-level
three-body decay and may be at the reach of detection at the LHC for f close to
500 GeV, but it may be difficult to detect for f=1 TeV. There is also an
scenario where the Higgs boson has an intermediate mass such that the Z_H-> A_H
H decay is closed, the Z_H-> \gamma A_H gets considerably enhanced and the
chances of detection get a large boost.Comment: 19 pages, 9 figures, 2 table
Random Hermite differential equations: Mean square power series solutions and statistical properties
This paper deals with the construction of random power series solution of second order linear differential equations of Hermite containing uncertainty through its coefficients and initial conditions. Under appropriate hypotheses on the data, we establish that the constructed random power series solution is mean square convergent. We provide conditions in order to obtain random polynomial solutions and, as a consequence, random Hermite polynomial are introduced. Also, the main statistical functions of the approximate stochastic process solution generated by truncation of the exact power series solution are given. Finally, we apply the proposed technique to several illustrative examples comparing the numerical results with respect to those provided by other available approaches including Monte Carlo simulation. © 2011 Elsevier Inc. All rights reserved.This work has been partially supported by the Spanish M.C.Y.T. and FEDER grants MTM2009-08587, DPI2010-20891-C02-01 as well as the Universitat Politecnica de Valencia grant PAID-06-09 (Ref. 2588).Calbo Sanjuán, G.; Cortés López, JC.; Jódar Sánchez, LA. (2011). Random Hermite differential equations: Mean square power series solutions and statistical properties. Applied Mathematics and Computation. 218(7):3654-3666. https://doi.org/10.1016/j.amc.2011.09.008S36543666218
Conectividad tridimensional durante el verano en el norte del Golfo de California
Connectivity studies in the Gulf of California are an important tool for improving the use and management of the gulf’s natural resources. The goal of this work was to study the three-dimensional connectivity in the northern Gulf of California during two representative months of summer when most local marine species spawn. Passive particles were advected for eight weeks in a three-dimensional current field generated by a three-dimensional baroclinic numerical model. The results indicate that the locations of greatest particle retention were the Upper Gulf and the Seasonal Eddy. The Seasonal Eddy corresponded to the area of largest particle catchment because the continental coastal current carries most particles released in the Midriff Archipelago region; subsequently these particles were entrained in the seasonal cyclonic eddy, causing most of them to remain within it. We conclude that the continental coastal current and the Seasonal Eddy control the connectivity patterns in the northern Gulf of California.Los estudios de conectividad en el Golfo de California (GC) son una herramienta importante para mejorar el uso y la gestión de los recursos naturales del golfo. El objetivo de este trabajo fue estudiar la conectividad tridimensional en el norte del Golfo de California (NGC) durante dos meses representativos de verano, ya que es la temporada con mayor desove de especies marinas. Se advectaron partículas pasivas durante ocho semanas en un campo de corrientes tridimensional generado por un modelo numérico baroclínico tridimensional. Los resultados indicaron que los lugares con mayor retención de las partículas fueron el Alto Golfo (UG) y el Remolino Estacional (SE). A su vez, SE fue el área de máxima captación de partículas debido a que la corriente costera continental transporta la mayoría de las partículas liberadas en las localidades ubicadas en la zona de las Grandes Islas, posteriormente estas partículas son atrapadas por el remolino ciclónico estacional lo que provocó que la mayoría de las partículas liberadas se queden dentro de éste. Por último, concluimos que la corriente costera continental y el remolino estacional controlan los patrones de conectividad en el NGC
Special Geometry of Euclidean Supersymmetry III: the local r-map, instantons and black holes
We define and study projective special para-Kahler manifolds and show that
they appear as target manifolds when reducing five-dimensional vector
multiplets coupled to supergravity with respect to time. The dimensional
reductions with respect to time and space are carried out in a uniform way
using an epsilon-complex notation. We explain the relation of our formalism to
other formalisms of special geometry used in the literature. In the second part
of the paper we investigate instanton solutions and their dimensional lifting
to black holes. We show that the instanton action, which can be defined after
dualising axions into tensor fields, agrees with the ADM mass of the
corresponding black hole. The relation between actions via Wick rotation, Hodge
dualisation and analytic continuation of axions is discussed.Comment: 72 pages, 2 figure
Silicon-based three-dimensional microstructures for radiation dosimetry in hadrontherapy
In this work, we propose a solid-state-detector for use in radiation microdosimetry. This device improves the performance of existing dosimeters using customized 3D-cylindrical microstructures etched inside silicon. The microdosimeter consists of an array of micro-sensors that have 3D-cylindrical electrodes of 15 μm diameter and a depth of 5 μm within a silicon membrane, resulting in a well-defined micrometric radiation sensitive volume. These microdetectors have been characterized using an 241Am source to assess their performance as radiation detectors in a high-LET environment. This letter demonstrates the capability of this microdetector to be used to measure dose and LET in hadrontherapy centers for treatment plan verification as part of their patient-specific quality control program
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