Galaxy cluster mergers as triggers for the formation of jellyfish galaxies: case study of the A901/2 system

The A901/2 system is a rare case of galaxy cluster interaction, in which two galaxy clusters and two smaller groups are seen in route of collision with each other simultaneously. Within each of the four substructures, several galaxies with features indicative of jellyfish morphologies have been observed. In this paper, we propose a hydrodynamic model for the merger as a whole, compatible with its diffuse X-ray emission, and correlate the gas properties in this model with the locations of the jellyfish galaxy candidates in the real system. We find that jellyfish galaxies seem to be preferentially located near a boundary inside each subcluster where diffuse gas moving along with the subcluster and diffuse gas from the remainder of the system meet. The velocity change in those boundaries is such that a factor of up to $\sim$1000 increase in the ram pressure takes place within a few hundred kpc, which could trigger the high rate of gas loss necessary for a jellyfish morphology to emerge. A theoretical treatment of ram pressure stripping in the environment of galaxy cluster mergers has not been presented in the literature so far; we propose that this could be a common scenario for the formation of jellyfish morphologies in such systems.Comment: Accepted for publication in MNRAS. 10 pages, 9 figure

Dielectrophoretic manipulation of individual nickel nanowires for electrical transport measurements

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORNanowires (NW) have received much attention due to their high aspect ratio, shape anisotropy, relatively large surface area and particular electron transport properties. In addition, since NW present low current levels and high sensitivity, they can be used as sensor devices for several applications. One of the major challenges when dealing with transport measurements in NW is to trap them between electrodes, which allow electrical characterization and therefore fabrication of nanowire-based devices. Electrically neutral NW can be deposited by dielectrophoresis (DEP) method, which requires the application of an alternating electric field between electrodes. In this work, properly dispersed Ni nanowires (NiNW) (length = 4+/-1 mu m, diameter = 35+/-5 nm) were deposited on top of Pt electrodes using the DEP method. The effects of electrodes geometry and electric field frequency on DEP efficiency were evaluated. For optimized DEP parameters, the process efficiency is up to 85%. The deposited NiNW exhibit a Schottky-like current versus voltage behavior due to the high contact resistance between NiNW and electrode. Its reduction down to two orders of magnitude, reaching value less than the NiNW resistance (similar to 6k Omega), was achieved by depositing a 10 nm-thick Pt layer over the NW extremities. Therefore, this method presents a selection of adequate electrical DEP parameters and electrode geometry, making it a suitable process of NW deposition and electrical characterization. This can be used for investigation of electrical transport properties of individual NW and fabrication of NW-based devices, like sensors and field effect transistors. (C) 2015 American Vacuum Society.Nanowires (NW) have received much attention due to their high aspect ratio, shape anisotropy, relatively large surface area and particular electron transport properties. In addition, since NW present low current levels and high sensitivity, they can be used as sensor devices for several applications. One of the major challenges when dealing with transport measurements in NW is to trap them between electrodes, which allow electrical characterization and therefore fabrication of nanowire-based devices. Electrically neutral NW can be deposited by dielectrophoresis (DEP) method, which requires the application of an alternating electric field between electrodes. In this work, properly dispersed Ni nanowires (NiNW) (length = 4+/-1 mu m, diameter = 35+/-5 nm) were deposited on top of Pt electrodes using the DEP method. The effects of electrodes geometry and electric field frequency on DEP efficiency were evaluated. For optimized DEP parameters, the process efficiency is up to 85%. The deposited NiNW exhibit a Schottky-like current versus voltage behavior due to the high contact resistance between NiNW and electrode. Its reduction down to two orders of magnitude, reaching value less than the NiNW resistance (similar to 6k Omega), was achieved by depositing a 10 nm-thick Pt layer over the NW extremities. Therefore, this method presents a selection of adequate electrical DEP parameters and electrode geometry, making it a suitable process of NW deposition and electrical characterization. This can be used for investigation of electrical transport properties of individual NW and fabrication of NW-based devices, like sensors and field effect transistors.33318FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORSem informaçãoSem informaçãoSem informaçãoThe authors would like to thank CCS/UNICAMP and LMBT/IFGW/UNICAMP staff for device processing and characterization. The work was supported by the Brazilian funding agencies Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).Reference

(E)-1-Ethyl-4-oxo-N′-(4-pyridylmethyl­ene)-1,4-dihydroquinoline-3-carbo­hydrazide

In the title compound, C18H16N4O2, the plane defined by the ethyl C atoms and the attached N atom is inclined to the adjacent pyridine ring at an angle of 67.87 (16)°. The dihedral angle between the two heterocyclic rings is 3.33 (16)°. The mol­ecular conformation is stabilized by an intra­molecular N—H⋯O hydrogen bond and the crystal structure by inter­molecular C—H⋯O hydrogen bonds, forming a one-dimensional structure

immune activation of canine hepatic spheroids exposed to leishmania infantum

The application of innovative three-dimensional (3D) spheroids cell culture strategy to Parasitology offers the opportunity to closely explore host–parasite interactions. Here we present a first report on the application of 3D hepatic spheroids to unravel the immune response of canine hepatocytes exposed to Leishmania infantum. The liver, usually considered a major metabolic organ, also performs several important immunological functions and constitutes a target organ for L. infantum infection, the etiological agent of canine leishmaniasis (CanL), and a parasitic disease of major veterinary and public health concern. 3D hepatic spheroids were able to sense and immunologically react to L. infantum parasites, generating an innate immune response by increasing nitric oxide (NO) production and enhancing toll-like receptor (TLR) 2 and interleukin-10 gene expression. The immune response orchestrated by canine hepatocytes also lead to the impairment of several cytochrome P450 (CYP450) with possible implications for liver natural xenobiotic metabolization capacity. The application of meglumine antimoniate (MgA) increased the inflammatory response of 3D hepatic spheroids by inducing the expression of Nucleotide oligomerization domain (NOD)-like receptors 1 and NOD2 and TLR2, TLR4, and TLR9 and enhancing gene expression of tumour necrosis factor α. It is therefore suggested that hepatocytes are key effector cells and can activate and orchestrate the immune response to L. infantum parasites.publishersversionpublishe

Prototype Drop Tests of Cube and Cubipod Armor Units

In this paper, an experimental methodology is described to assess the structural strength of unreinforced concrete armor units (CAUs). The methodology is applied to measure the structural integrity under impact loads of the new Cubipod CAU compared with the conventional cube CAU. The casting systems and clamps are described for manufacturing and handling the 15-t conventional cubic block and 16-t Cubipod prototypes used for the drop tests. Two separate reinforced concrete platforms were used for overturning and for free-fall tests, respectively. Compared with conventional cubes of similar size and concrete strength, Cubipods withstand drops that are more than 50% higher. Two extreme free-fall tests confirmed the structural robustness of Cubipod armor units. Manufacturing cycle time, as well as storage and handling procedures, are similar for both Cubipods and conventional cubic blocks. © 2011 American Society of Civil Engineers.The writers are grateful for the logistic support provided by the Port Authority of Alicante and the consortium TMS. Financial support was received from CDTI (CUBIPOD Project). The writers also thank Roman Goumy for his assistance during the prototype drop tests and Debra Westall for revising the manuscript.Medina, JR.; Gómez-Martín, ME.; Corredor-Molguero, A.; Torres-Samper, R.; Miñana, JV.; Fernández, E.; Menéndez, CF.... (2011). Prototype Drop Tests of Cube and Cubipod Armor Units. Journal of Waterway, Port, Coastal, and Ocean Engineering. 137(2):54-63. doi:10.1061/(ASCE)WW.1943-5460.0000064S5463137

Method for Reading Sensors and Controlling Actuators Using Audio Interfaces of Mobile Devices

This article presents a novel closed loop control architecture based on audio channels of several types of computing devices, such as mobile phones and tablet computers, but not restricted to them. The communication is based on an audio interface that relies on the exchange of audio tones, allowing sensors to be read and actuators to be controlled. As an application example, the presented technique is used to build a low cost mobile robot, but the system can also be used in a variety of mechatronics applications and sensor networks, where smartphones are the basic building blocks