735 research outputs found
Quantum Quench in the Transverse Field Ising Chain
We consider the time evolution of observables in the transverse field Ising
chain (TFIC) after a sudden quench of the magnetic field. We provide exact
analytical results for the asymptotic time and distance dependence of one- and
two-point correlation functions of the order parameter. We employ two
complementary approaches based on asymptotic evaluations of determinants and
form-factor sums. We prove that the stationary value of the two-point
correlation function is not thermal, but can be described by a generalized
Gibbs ensemble (GGE). The approach to the stationary state can also be
understood in terms of a GGE. We present a conjecture on how these results
generalize to particular quenches in other integrable models.Comment: 4 pages, 1 figur
Multiple isoform recovery (MIR)-PCR: a simple method for the isolation of related mRNA isoforms
We present a rapid and efficient method for the detection of related transcripts with different expression levels. This approach combines the rapid amplification of cDNA ends (RACE) method with a cDNA subtractive technique. The strategy is based on successive subtractions of prevalent isoforms resulting in enrichment of less expressed transcripts. For each subtraction, a biotinylated primer specific for the prevalent isoform is hybridized on the total cDNA and the hybrid is retained on a streptavidin affinity column. The unbound cDNA serves as a template for subsequent isoform identification. To illustrate its application we describe the isolation of three new actin cDNA isoforms in the freshwater planarian Dugesia (S) polychro
Quantum Quench in the Transverse Field Ising chain I: Time evolution of order parameter correlators
We consider the time evolution of order parameter correlation functions after
a sudden quantum quench of the magnetic field in the transverse field Ising
chain. Using two novel methods based on determinants and form factor sums
respectively, we derive analytic expressions for the asymptotic behaviour of
one and two point correlators. We discuss quenches within the ordered and
disordered phases as well as quenches between the phases and to the quantum
critical point. We give detailed account of both methods.Comment: 65 pages, 21 figures, some typos correcte
Peritoneal carcinosis of ovarian origin
Epithelial ovarian cancer (EOC) is the second most common
genital malignancy in women and is the most lethal
gynecological malignancy, with an estimated five-year
survival rate of 39%. Despite efforts to develop an effective
ovarian cancer screening method, 60% of patients still
present with advanced disease. Comprehensive management
using surgical cytoreduction to decrease the tumor
load to a minimum, and intraperitoneal chemotherapy to
eliminate microscopic disease on peritoneal surface, has
the potential to greatly improve quality of life and to have
an impact on survival in ovarian cancer patients. Despite
achieving clinical remission after completion of initial treatment,
most patients (60%) with advanced EOC will ultimately
develop recurrent disease or show drug resistance;
the eventual rate of curability is less than 30%. Given the
poor outcome of women with advanced EOC, it is imperative
to continue to explore novel therapies.
Immunoradiometric and immunohistochemical analysis of Cathepsin D in ovarian cancer: lack of association with clinical outcome.
The aim of this study was to analyse the clinical significance of Cathepsin D (Cath D) content as determined by an immunoradiometric assay in a series of primary untreated ovarian cancers from 162 patients. In addition, immunohistochemical analysis of Cath D was also performed on a subset of 86 tumours. Cath D levels were distributed in an asymmetrical way and were skewed towards the lower values (median value 20.8 pmol mg(-1) protein, range 2.0-99.0 pmol mg(-1) protein). No correlation was found between Cath D levels and clinicopathological parameters. However, the percentage of Cath D positivity was significantly higher in oestrogen receptor-positive (57%) compared with oestrogen receptor-negative (36%) cases (P= 0.01). The percentage of Cath D-positive staining was not significantly different for both epithelial (27%) and stromal components (40%). Immunoradiometrically detected Cath D levels were not different according to Cath D stromal immunostaining (P= 0.18), while higher Cath D levels were measured in Cath D-positive than in Cath D-negative tumour epithelial cells (P = 0.027). Survival analysis was conducted on 161 primary untreated ovarian cancer patients. The 5-year overall survival rate was 57% and 55% in Cath D-positive and Cath D-negative patients respectively (P = 0.69). As far as time to progression was concerned, there was no significant difference in the survival rate of patients with either high or low Cath D content (P = 0.56). Similar results have been obtained in the subset of patients in which Cath D was analysed by immunohistochemistry. In conclusion, Cath D measurement in tumour extracts appears to have a limited usefulness in improving the prognostic characterization of ovarian cancer patients
Diversidade de bactérias diazotróficas endofíticas de milho em cultivos convencional e agroecológico.
Diferentes gêneros de bactérias diazotróficas, além de fixar N2 atmosférico, também promovem o crescimento de plantas pela produção de hormônios vegetais e disponibilização de outros nutrientes como o fósforo. O objetivo deste trabalho foi isolar e identificar bactérias diazotróficas endofíticas de milho (Zea mays L.) sob plantio direto e convencional, em sistema agroecológico e convencional. O isolamento foi realizado em meios de cultura livres de N (LGI, JNFb e JMV), totalizando 86 isolados. Por meio do sequenciamento do gene 16S DNAr foram identificadas bactérias dos gêneros Burkholderia spp., Agrobacterium spp., Enterobacter spp., Stenotrophomonas spp., Rhizobium spp., Pseudoxanthomonas sp., Microbacterium sp., Sphingomonas sp., Klebsiella spp., Bacillus sp., Xanthomonas sp., Leclercia sp., Pantoea sp., Dyella sp. e Pseudomonas spp. O gênero Burkholderia representou 30% dos isolados, seguido de Agrobacterium com 14%. O milho sob cultivo agroecológico apresentou mais isolados de bactérias endofíticas (24%). Assim, sistemas menos sujeitos a ações antrópicas parecem ser hotspots de diversidade para isolamento de microrganismos com potencial para promoção de crescimento vegetal.Fertbio
Entropy inequalities from reflection positivity
We investigate the question of whether the entropy and the Renyi entropies of
the vacuum state reduced to a region of the space can be represented in terms
of correlators in quantum field theory. In this case, the positivity relations
for the correlators are mapped into inequalities for the entropies. We write
them using a real time version of reflection positivity, which can be
generalized to general quantum systems. Using this generalization we can prove
an infinite sequence of inequalities which are obeyed by the Renyi entropies of
integer index. There is one independent inequality involving any number of
different subsystems. In quantum field theory the inequalities acquire a simple
geometrical form and are consistent with the integer index Renyi entropies
being given by vacuum expectation values of twisting operators in the Euclidean
formulation. Several possible generalizations and specific examples are
analyzed.Comment: Significantly enlarged and corrected version. Counterexamples found
for the most general form of the inequalities. V3: minor change
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