142 research outputs found
Quantum dynamics in canonical and micro-canonical ensembles. Part I. Anderson localization of electrons
The new numerical approach for consideration of quantum dynamics and
calculations of the average values of quantum operators and time correlation
functions in the Wigner representation of quantum statistical mechanics has
been developed. The time correlation functions have been presented in the form
of the integral of the Weyl's symbol of considered operators and the Fourier
transform of the product of matrix elements of the dynamic propagators. For the
last function the integral Wigner- Liouville's type equation has been derived.
The numerical procedure for solving this equation combining both molecular
dynamics and Monte Carlo methods has been developed. For electrons in
disordered systems of scatterers the numerical results have been obtained for
series of the average values of the quantum operators including position and
momentum dispersions, average energy, energy distribution function as well as
for the frequency dependencies of tensor of electron conductivity and
permittivity according to quantum Kubo formula. Zero or very small value of
static conductivity have been considered as the manifestation of Anderson
localization of electrons in 1D case. Independent evidence of Anderson
localization comes from the behaviour of the calculated time dependence of
position dispersion.Comment: 8 pages, 10 figure
Wave activity in the neighborhood of the bowshock of Mars
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95091/1/grl4815.pd
Strongly Interacting Vector Bosons at the LHC: Quartic Anomalous Couplings
We analyze the potential of the CERN Large Hadron Collider to study anomalous
quartic vector--boson interactions through the production of vector--boson
pairs accompanied by jets. In the framework of chiral
Lagrangians, we examine all effective operators of order that lead to new
four--gauge--boson interactions but do not alter trilinear vertices. In our
analyses, we perform the full tree level calculation of the processes leading
to two jets plus vector--boson pairs, , , , or
, taking properly into account the interference between the standard model
and the anomalous contributions. We obtain the bounds that can be placed on the
anomalous quartic interactions and we study the strategies to distinguish the
possible new couplings.Comment: 12 pages, ReVTeX, 5 figure
Bacterial Community Profiling of Milk Samples as a Means to Understand Culture-Negative Bovine Clinical Mastitis
Inflammation and infection of bovine mammary glands, commonly known as mastitis, imposes significant losses each year in the dairy industry worldwide. While several different bacterial species have been identified as causative agents of mastitis, many clinical mastitis cases remain culture negative, even after enrichment for bacterial growth. To understand the basis for this increasingly common phenomenon, the composition of bacterial communities from milk samples was analyzed using culture independent pyrosequencing of amplicons of 16S ribosomal RNA genes (16S rDNA). Comparisons were made of the microbial community composition of culture negative milk samples from mastitic quarters with that of non-mastitic quarters from the same animals. Genomic DNA from culture-negative clinical and healthy quarter sample pairs was isolated, and amplicon libraries were prepared using indexed primers specific to the V1–V2 region of bacterial 16S rRNA genes and sequenced using the Roche 454 GS FLX with titanium chemistry. Evaluation of the taxonomic composition of these samples revealed significant differences in the microbiota in milk from mastitic and healthy quarters. Statistical analysis identified seven bacterial genera that may be mainly responsible for the observed microbial community differences between mastitic and healthy quarters. Collectively, these results provide evidence that cases of culture negative mastitis can be associated with bacterial species that may be present below culture detection thresholds used here. The application of culture-independent bacterial community profiling represents a powerful approach to understand long-standing questions in animal health and disease
From Laboratory to Road. A 2015 update of official and real-world fuel concumption and CO2 values for passenger cars in Europe
Official average carbon dioxide (CO 2) emissions of new passenger cars in the European Union declined from 170 grams per kilometer (g/km) in 2001 to 123 g/km in 2014. During the period 2001–2014, the rate of reduction in CO 2 emissions per kilometer increased from approximately one percent per year to approximately four percent per year. A direct cause of that improvement was the introduction of mandatory CO 2 fleet targets, in place of voluntary commitments, in 2009. Despite concerns expressed then about the feasibility of the mandate, Europe’s automakers met the 2015 target of 130 g/km two years ahead of schedule. Today, in 2015, manufacturers are on track to meet the 2020/21 target of 95 g/km. However, that simple summary of vital progress in transportation and climate policy, while accurate, leaves out some crucial details. As our series From Laboratory to Road has made clear over the past three years, in reality, CO 2 emissions from passenger cars in everyday operation have not declined as much as these official statistics would seem to indicate, which has become a subject of rising concern. This study, which updates the From Laboratory to Road series for 2015, demonstrates that the trend has not improved — on the contrary, the gap between real-world and official values continues to increase
and Experimental Effect of Aprindine on Transmembrane Currents and Contractile Force in Frog Atria1
ASSESSMENT OF THE RESIDUAL TUMOR IN PATIENTS WITH MULTIPLE MYELOMA BASED ON THE ANALYSIS OF THE FREE LIGHT CHAINS OF IMMUNOGLOBULINS IN BLOOD SERUM
Efficiency of the multiple myeloma treatment with chemotherapy including bortezomib was assessed based on determination of the level of immunoglobulin free light chains in blood serum. The method enables estimation of changes in kinetic parameters of the residual tumor, detection of the disease course prognosis, and the choice of the optimal approach to the disease therapy
Quantum Dynamics in Canonical and Micro-canonical Ensembles. Part II. Tunneling in Double Well Potential
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