1,407 research outputs found
On the Catalysis of the Electroweak Vacuum Decay by Black Holes at High Temperature
We study the effect of primordial black holes on the classical rate of
nucleation of AdS regions within the standard electroweak vacuum at high
temperature. We find that the energy barrier for transitions to the new vacuum,
which determines the exponential suppression of the nucleation rate, can be
reduced significantly, or even eliminated completely, in the black-hole
background if the Standard Model Higgs is coupled to gravity through the
renormalizable term .Comment: LaTeX file, 15 pages, 5 figure
The double well potential in quantum mechanics: a simple, numerically exact formulation
The double well potential is arguably one of the most important potentials in
quantum mechanics, because the solution contains the notion of a state as a
linear superposition of `classical' states, a concept which has become very
important in quantum information theory. It is therefore desirable to have
solutions to simple double well potentials that are accessible to the
undergraduate student. We describe a method for obtaining the numerically exact
eigenenergies and eigenstates for such a model, along with the energies
obtained through the Wentzel-Kramers-Brillouin (WKB) approximation. The exact
solution is accessible with elementary mathematics, though numerical solutions
are required. We also find that the WKB approximation is remarkably accurate,
not just for the ground state, but for the excited states as well.Comment: 10 pages, 4 figures; suitable for undergraduate courses in quantum
mechanic
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Review of experience of family medicine in Europe and Central Asia (Vol. 3): Bosnia and Herzegovina case study
This report summarizes the findings of four case studies that review the experience of family medicine in Europe and Central Asia (ECA) Region. It is part of a study comprising five volumes that review the experience of family medicine in four countries in ECA--Armenia, Bosnia and Herzegovina, Kyrgyz Republic and Moldova. The report reviews the experience, draws lessons, and establishes an evidence base for detailed analysis. The study presents best practices for policy dialogue and future investments by the World Bank and other financial institutions. The detailed case studies compare these countries and draw common themes and issues. Comparisons are made with best-developed or existing models in the OECD and other countries in the Europe and Central Asia Region that have already undertaken family medicine reform
Matrix metalloproteinase-2 (MMP-2) and-9 (MMP-9) gene variants and microvascular complications in type 2 diabetes patients
AbstractVascular complications are the leading cause of increased morbidity and mortality of diabetic patients. It has been postulated that matrix metalloproteinases MMP-2 and MMP-9, zinc-dependent endopeptidases through remodeling of the extracellular matrix, can contribute to the onset and progression of diabetic vascular complications. The aim of our study was to assess whether there is a major difference in single nucleotide polymorphisms in the MMP-2 (at position -1306C˃T) and MMP-9 (at position -1562C˃T) gene in type 2 diabetic patients and healthy controls and to determine whether there is an association of these gene variants with the presence of microvascular complications in diabetic patients. Our study included 102 type 2 diabetes patients and a control group which was comprised of 56 healthy controls. All diabetic patients were screened for microvascular diabetes complications. Genotypes were detected by polymerase chain reactions followed by restriction analyses with specific endonucleases and their frequencies were determined. The MMP-2 variant -1306C>T showed a negative correlation with type 2 diabetes (p=0.028). It was also shown that the presence of the -1306C allele increases the probability of developing type 2 diabetes. This was a 2.2 fold increase and that the -1306 T allele has a protective role in regards t
Bioaugmentation of sewage sludge with Trametes versicolor in solid-phase biopiles produces degradation of pharmaceuticals and affects microbial communities
The use of sludge (biosolids) in land
application may contribute to the spread of organic micropollutants
as wastewater treatments do not completely remove
these compounds. Therefore, the development of alternative
strategies for sludge treatment is a matter of recent concern.
The elimination of pharmaceuticals at pre-existent concentrations
from sewage sludge was assessed, for the first time, in
nonsterile biopiles by means of fungal bioaugmentation with
Trametes versicolor (BTV-systems) and compared with the
effect of autochthonous microbiota (NB-systems). The
competition between the autochthonous fungal/bacterial
communities and T. versicolor was studied using denaturing
gradient gel electrophoresis (DGGE) and the cloning/
sequencing approach. An inhibitory effect exerted by T.
versicolor over bacterial populations was suggested. However,
after 21 days, T. versicolor was no longer the main taxon in the
fungal communities. The elimination profiles revealed an enhanced removal of atorvastatin-diclofenac-hydrochlorothiazide
(during the whole treatment) and ranitidine-fenofibrate (at short periods) in the BTV biopiles in respect to NB biopiles,
coincident with the presence of the fungus. For ibuprofen-clarithromycin-furosemide, the elimination profiles were similar
irrespective of the system, and with carbamazepine no significant degradation was obtained. The results suggest that a fungal
treatment with T. versicolor could be a promising process for the remediation of some pharmaceuticals in complex matrices such
as biosolids.Portuguese-Spanish action E51/1
Uticaj mineralne ishrane na prinos ozime pšenice (Triticum aestivum L.)
Investigations were carried out during the 2006/2007 year on stationary field trial, the Center for Small Grains in Kragujevac. The objective of this study was to investigate the influence of mineral nutrition on the yield of winter wheat varieties (Lazarica, Takovčanka, Kg 56S, Kg 100 i Ana Morava). For these investigations were conducted two experiments (N1-80 kg ha-1 and N2-120 kg ha-1). Analysis of variance indicates very significant effects of cultivar on the grain yield, 1000-grain weight and test weight. Analysis of variance for the impact of nitrogen rates (N1 and N2) on investigated traits was found that doses of nitrogen in combination with NPK fertilizers significantly affected only on grain yield.Istraživanja su izvedena tokom 2006/2007. godine na stacionarnom poljskom ogledu, Centra za strna žita u Kragujevcu. Cilj ovog istraživanja je bio da se ispita uticaj mineralne ishrane na prinos ozime pšenice sorte (Lazarica, Takovčanka, Kg 56S, Kg 100 i Ana Morava). Za ova istraživanja su izvedena dva ogleda (N1-80 kg ha-1 i N2-120 kg ha-1). Analizaom varijanse je utvrđen vrlo visoko značajan uticaj sorte na prinos, masu 1000 zrna i hektolitarsku masu. Analizom varijanse za uticaj doze azota (N1 i N2) na ispitivane osobine utvrđeno je da su doze azota u kombinaciji sa NPK đubrivima značajno uticale samo na prinos zrna
Silent flocks: Constraints on signal propagation across biological groups
Experiments find coherent information transfer through biological groups on length and time scales distinctly below those on which asymptotically correct hydrodynamic theories apply. We present here a new continuum theory of collective motion coupling the velocity and density fields of Toner and Tu to the inertial spin field recently introduced to describe information propagation in natural flocks of birds. The long-wavelength limit of the new equations reproduces the Toner-Tu theory, while at shorter wavelengths (or, equivalently, smaller damping), spin fluctuations dominate over density fluctuations, and second-sound propagation of the kind observed in real flocks emerges. We study the dispersion relation of the new theory and find that when the speed of second sound is large, a gap in momentum space sharply separates first- from second-sound modes. This gap implies the existence of silent flocks, namely, of medium-sized systems across which information cannot propagate in a linear and underdamped way, either under the form of orientational fluctuations or under that of density fluctuations, making it hard for the group to achieve coordination.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta
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Review of experience of family medicine in Europe and Central Asia : Executive summary
This report summarizes the findings of four case studies that review the experience of family medicine in Europe and Central Asia (ECA) Region. It is part of a study comprising five volumes that review the experience of family medicine in four countries in ECA--Armenia, Bosnia and Herzegovina, Kyrgyz Republic and Moldova. The report reviews the experience, draws lessons, and establishes an evidence base for detailed analysis. The study presents best practices for policy dialogue and future investments by the World Bank and other financial institutions. The detailed case studies compare these countries and draw common themes and issues. Comparisons are made with best-developed or existing models in the OECD and other countries in the Europe and Central Asia Region that have already undertaken family medicine reform
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