Gravity is controlled by cosmological constant

We discuss a Randall-Sundrum-type two D-braneworld model in which D-branes possess different values of the tensions from those of the charges, and derive an effective gravitational equation on the branes. As a consequence, the Einstein-Maxwell theory is realized together with the non-zero cosmological constant. Here an interesting point is that the effective gravitational constant is proportional to the cosmological constant. If the distance between two D-branes is appropriately tuned, the cosmological constant can have a consistent value with the current observations. From this result we see that, in our model, the presence of the cosmological constant is naturally explained by the presence of the effective gravitational coupling of the Maxwell field on the D-brane.Comment: 10 page

Variable Permanent Magnet Quadrupole

A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments

Band-theoretical prediction of magnetic anisotropy in uranium monochalcogenides

Magnetic anisotropy of uranium monochalcogenides, US, USe and UTe, is studied by means of fully-relativistic spin-polarized band structure calculations within the local spin-density approximation. It is found that the size of the magnetic anisotropy is fairly large (about 10 meV/unit formula), which is comparable with experiment. This strong anisotropy is discussed in view of a pseudo-gap formation, of which crucial ingredients are the exchange splitting of U 5f states and their hybridization with chalcogen p states (f-p hybridization). An anomalous trend in the anisotropy is found in the series (US>>USe<UTe) and interpreted in terms of competition between localization of the U 5f states and the f-p hybridization. It is the spin-orbit interaction on the chalcogen p states that plays an essential role in enlarging the strength of the f-p hybridization in UTe, leading to an anomalous systematic trend in the magnetic anisotropy.Comment: 4 pages, 5 figure

Microbiological quality of fresh local fish: coagulase-positive Staphylococci analysis.

The aim of this research was to evaluate and quantify the presence of Staphylococci in fresh local fish at a fish processing plant monitored by the Brazilian Federal Inspection Service (Serviço de Inspeção Federal - SIF) located in the North Region of Brazil

Myeloid progenitors with PTPN11 and nonRAS pathway gene mutations are refractory to treatment with 6-mercaptopurine in juvenile myelomonocytic leukemia

advance online publication, February 25, 2014Juvenile myelomonocytic leukemia (JMML) is a fatal, mixed myeloproliferative and myelodysplastic disorder occurring in infancy and early childhood. Children with JMML have mutually exclusive genetic abnormalities in granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling pathways, inactivation of the NF1 or mutations in PTPN11, NRAS, KRAS and CBL. A whole-exome sequencing study, performed by Sakaguchi et al.,3 has recently demonstrated that in addition to the high frequency of RAS pathway mutations, mutations in SETBP1 and JAK3 are common recurrent secondary events, and that these events may be involved in tumor progression, and are associated with poor clinical outcomes.ArticleLEUKEMIA. 28(7):1545-1548 (2014)journal articl

Procedimentos analíticos para avaliação de doenças de peixes.

bitstream/item/142632/1/Doc-204.pd

Restructuring of colloidal aggregates in shear flow: Coupling interparticle contact models with Stokesian dynamics

A method to couple interparticle contact models with Stokesian dynamics (SD) is introduced to simulate colloidal aggregates under flow conditions. The contact model mimics both the elastic and plastic behavior of the cohesive connections between particles within clusters. Owing to this, clusters can maintain their structures under low stress while restructuring or even breakage may occur under sufficiently high stress conditions. SD is an efficient method to deal with the long-ranged and many-body nature of hydrodynamic interactions for low Reynolds number flows. By using such a coupled model, the restructuring of colloidal aggregates under stepwise increasing shear flows was studied. Irreversible compaction occurs due to the increase of hydrodynamic stress on clusters. Results show that the greater part of the fractal clusters are compacted to rod-shaped packed structures, while the others show isotropic compaction.Comment: A simulation movie be found at http://www-levich.engr.ccny.cuny.edu/~seto/sites/colloidal_aggregates_shearflow.htm

Low-Lying Excited States and Low-Temperature Properties of an Alternating Spin-1 / Spin-1/2 Chain : A DMRG study

We report spin wave and DMRG studies of the ground and low-lying excited states of uniform and dimerized alternating spin chains. The DMRG procedure is also employed to obtain low-temperature thermodynamic properties of the system. The ground state of a 2N spin system with spin-1 and spin-1/2 alternating from site to site and interacting via an antiferromagnetic exchange is found to be ferrimagnetic with total spin $s_G=N/2$ from both DMRG and spin wave analysis. Both the studies also show that there is a gapless excitation to a state with spin $s_G-1$ and a gapped excitation to a state with spin $s_G+1$. Surprisingly, the correlation length in the ground state is found to be very small from both the studies for this gapless system. For this very reason, we show that the ground state can be described by a variational ``ansatz'' of the product type. DMRG analysis shows that the chain is susceptible to a conditional spin-Peierls' instability. The DMRG studies of magnetization, magnetic susceptibility ($\chi$) and specific heat show strong magnetic-field dependence. The product $\chi T$ shows a minimum as a function of temperature($T$) at low-magnetic fields and the minimum vanishes at high-magnetic fields. This low-field behaviour is in agreement with earlier experimental observations. The specific heat shows a maximum as a function of temperature and the height of the maximum increases sharply at high magnetic fields. It is hoped that these studies will motivate experimental studies at high-magnetic fields.Comment: 22 pages in latex; 16 eps figures available upon reques

Initial Results from the Nobeyama Molecular Gas Observations of Distant Bright Galaxies

We present initial results from the CO survey toward high redshift galaxies using the Nobeyama 45m telescope. Using the new wide bandwidth spectrometer equipped with a two-beam SIS receiver, we have robust new detections of three high redshift (z=1.6-3.4) submillimeter galaxies (SXDF 1100.001, SDP9, and SDP17), one tentative detection (SDSS J160705+533558), and one non-detection (COSMOS-AzTEC1). The galaxies observed during the commissioning phase are sources with known spectroscopic redshifts from previous optical or from wide-band submm spectroscopy. The derived molecular gas mass and line widths from Gaussian fits are ~10^11 Msun and 430-530 km/s, which are consistent with previous CO observations of distant submm galaxies and quasars. The spectrometer that allows a maximum of 32 GHz instantaneous bandwidth will provide new science capabilities at the Nobeyama 45m telescope, allowing us to determine redshifts of bright submm selected galaxies without any prior redshift information.Comment: 4 pages, 1 figure, PASJ Letter Accepte