1,104 research outputs found
Critical behavior at Mott-Anderson transition: a TMT-DMFT perspective
We present a detailed analysis of the critical behavior close to the
Mott-Anderson transition. Our findings are based on a combination of numerical
and analytical results obtained within the framework of Typical-Medium Theory
(TMT-DMFT) - the simplest extension of dynamical mean field theory (DMFT)
capable of incorporating Anderson localization effects. By making use of
previous scaling studies of Anderson impurity models close to the
metal-insulator transition, we solve this problem analytically and reveal the
dependence of the critical behavior on the particle-hole symmetry. Our main
result is that, for sufficiently strong disorder, the Mott-Anderson transition
is characterized by a precisely defined two-fluid behavior, in which only a
fraction of the electrons undergo a "site selective" Mott localization; the
rest become Anderson-localized quasiparticles.Comment: 4+ pages, 4 figures, v2: minor changes, accepted for publication in
Phys. Rev. Let
Sodium fraction excretion rate in nocturnal enuresis correlates with nocturnal polyuria and osmolality
Abstract: Purpose: We verify the sodium fraction excretion rate (FE Na) and potassium fraction excretion WE K) rates in monosymptomatic nocturnal enuresis. We also correlate FE Na and FE K to urinary osmolality, nocturnal polyuria and vasopressin in the same population.
Materials and Methods: A total of 438 children 6 to 15 years old (mean age 9.7) presenting with monosymptomatic nocturnal enuresis were recruited from different centers. Inclusion criteria were 3 or greater wet nights a week, no daytime incontinence and no treatment in the previous 2 months. Exclusion criteria were cardiopathy, endocrinopathy, psychiatric problems and urinary tract abnormalities. Micturition chart, diurnal (8 am to 8 pm) and nocturnal (8 pm to 8 am) urine collection, including separate diuresis volumes, (Na, K and Ca) electrolytes and osmolality were evaluated, as well as serum electrolytes, creatinine and nocturnal (4 am) vasopressin. Diurnal and nocturnal FE K and FE Na were calculated. ANOVA test, chi-square test, Student's t test and Pearson correlation test were used for statistical analysis.
Results: Nocturnal polyuria (diurnal to nocturnal diuresis ratio less than 1) was found in 273 children (62.3%, group I and nocturnal urine volumes were normal in 165 with enuresis (37.7%, group 2). Nocturnal FE Na was abnormal in 179 children (40.8%), including 118 in group 1 (43.2%) and 61 in group 2 (36.9%) (chi-square not significant). FE Na was also increased in nocturnal versus daytime diuresis (Student's t test p < 0.001). In group 1 nocturnal FE Na correlated with nocturnal diuresis (Pearson correlation p = 0.003, r = +0.175), while daytime FE Na and nocturnal FE Na correlated with diurnal diuresis (Pearson correlation p = 0.001, r = +0.225 and Pearson correlation p = 0.001, r = +0.209, respectively). In group 2 nocturnal FE Na did not correlate with diuresis (Pearson correlation p = 0.103, r = +0.128) but correlated with vasopressin values (Pearson correlation p = 0.042, r = -0.205). Urine osmolality was reduced in 140 children (31.9%) and correlated with nocturnal diuresis (Pearson correlation p = 0.003, r = -0.321). Vasopressin was decreased in 332 children (75.8%, 62.6% in group 1 and 13.2% in group 2). No significant difference was found between sexes and age of enuretic subgroups.
Conclusions: Nocturnal FE Na correlates with nocturnal diuresis, whereas daytime FE Na does not. FE K in daytime and nighttime diuresis does not statistically differ in nocturnal polyuric and nonpolyuric enuretic groups. Osmolality correlates with nocturnal diuresis, and vasopressin at 4 am was lower in the nocturnal polyuric group. The hypothesis of a subset of enuretic patients presenting with nocturnal polyuria associated with high nocturnal natriuria and low vasopressin values has been confirmed
The Complexity of Codiagnosability for Discrete Event and Timed Systems
In this paper we study the fault codiagnosis problem for discrete event
systems given by finite automata (FA) and timed systems given by timed automata
(TA). We provide a uniform characterization of codiagnosability for FA and TA
which extends the necessary and sufficient condition that characterizes
diagnosability. We also settle the complexity of the codiagnosability problems
both for FA and TA and show that codiagnosability is PSPACE-complete in both
cases. For FA this improves on the previously known bound (EXPTIME) and for TA
it is a new result. Finally we address the codiagnosis problem for TA under
bounded resources and show it is 2EXPTIME-complete.Comment: 24 pages
Enuresis subtypes based on nocturnal hypercalciuria: A multicenter study
Purpose: Desmopressin may not be effective for nocturnal enuresis associated with polyuria and hypercalciuria. Nighttime hypercalciuria in an enuretic population from 5 centers and its correlation with nighttime polyuria were verified. Materials and Methods: A total of 450 enuretic patients (278 males, 172 females, mean age 9.7 years) were evaluated with 72-hour micturition charts, urinalysis, serum creatinine and osmolarity, diurnal and nocturnal electrolytes with fractional Na+ and K+ urinary excretion, and nocturnal (4 a.m.) plasma vasopressin. Creatinine electrolytes and osmolarity were measured in daytime (8 a.m. to 8 p.m.) and nighttime (8 p.m. to 8 a.m.) urine volumes. Patients were divided into group 1 with nocturnal polyuria and group 2 without nocturnal polyuria. Hypercalciuria was defined as urinary calcium-to-urinary creatinine ratio greater than 0.21. Statistic evaluation was performed using chi-square, Pearson correlation and ANOVA tests. Results: Nighttime polyuria was demonstrated in 292 bedwetters (65% group 1). Nocturnal hypercalciuria was present in 179 of the 450 children (39.7%), including 125 in group 1 (42.8%) and 54 in group 2 (34.2%), which was statistically significant (chi-square p = 0.008, Pearson correlation test r = 0.157). Daytime calciuria was not statistically modified in either group (group 1 p = 0.054, group 2 p = 0.56). Adrenocorticotropic hormone (ADH) was normal in 18.5% and low in 81.5% of enuretics with nocturnal hypercalciuria. ADH levels and nocturnal hypercalciuria significantly correlated (p = 0.003, r = 0.148). Conversely, the group 2 patients had normal ADH levels. Conclusions: Nocturnal hypercalciuria has a pivotal role in nocturnal enuresis, as it is significantly associated with low ADH levels and nocturnal polyuria. A new classification of nocturnal enuresis subtypes based on nighttime calciuria levels is mandatory to address treatment properly
A non-interleaving process calculus for multi-party synchronisation
We introduce the wire calculus. Its dynamic features are inspired by Milner's
CCS: a unary prefix operation, binary choice and a standard recursion
construct. Instead of an interleaving parallel composition operator there are
operators for synchronisation along a common boundary and non-communicating
parallel composition. The (operational) semantics is a labelled transition
system obtained with SOS rules. Bisimilarity is a congruence with respect to
the operators of the language. Quotienting terms by bisimilarity results in a
compact closed category
Parameterized Verification of Safety Properties in Ad Hoc Network Protocols
We summarize the main results proved in recent work on the parameterized
verification of safety properties for ad hoc network protocols. We consider a
model in which the communication topology of a network is represented as a
graph. Nodes represent states of individual processes. Adjacent nodes represent
single-hop neighbors. Processes are finite state automata that communicate via
selective broadcast messages. Reception of a broadcast is restricted to
single-hop neighbors. For this model we consider a decision problem that can be
expressed as the verification of the existence of an initial topology in which
the execution of the protocol can lead to a configuration with at least one
node in a certain state. The decision problem is parametric both on the size
and on the form of the communication topology of the initial configurations. We
draw a complete picture of the decidability and complexity boundaries of this
problem according to various assumptions on the possible topologies.Comment: In Proceedings PACO 2011, arXiv:1108.145
Acta Informatica manuscript No. (will be inserted by the editor) A Complete Classification of the Expressiveness of Interval Logics of Allen’s Relations The General and the Dense Cases
Abstract Interval temporal logics take time intervals, instead of time instants, as their primitive temporal entities. One of the most studied interval temporal logics is Halpern and Shoham’s modal logic of time intervals HS, which associates a modal operator with each binary relation between intervals over a linear order (the so-called Allen’s interval relations). In this paper, we compare and classify the expressiveness of all fragments of HS on the class of all linear orders and on the subclass of all dense linear orders. For each of these classes, we identify a complete set of definabilities between HS modalities, valid in that class, thus obtaining a complete classification of the family of all 4096 fragments of HS with respect to their expressiveness. We show that on the class of all linear orders there are exactly 1347 expressively different fragments of HS, while on the class of dense linear orders there are exactly 966 such expressively different fragments
High prevalence of BRCA1 deletions in BRCAPRO-positive patients with high carrier probability.
Mutation screening of the BRCA1 and BRCA2 genes in probands with familial breast/ovarian cancer has been
greatly improved by the multiplex ligation-dependent probe amplification (MLPA) assay able to evidence gene
rearrangements not detectable by standard screening methods. However, no criteria for selection of cases to
be submitted to the MLPA test have been reported yet. We used the BRCAPro software for the selection of
familial breast/ovarian cancer probands investigated with the MLPA approach after negative BRCA1/2
conventional mutation screening. One hundred and seventy-seven probands were investigated for germline
BRCA1/2 mutations after assessment of genetic risk using BRCAPro. Probands were classified as BRCAPro
positive (n = 67) when the carrier probability (CP) was >10% and as BRCAPro negative (n = 110), when the CP
was <10%. Conventional mutational analyses of the BRCA1/2 genes and, in one case, of p53 identified 22
pathogenetic germline mutations, 12 in BRCA1, 9 in BRCA2 and 1 in p53, in 22/177 (12.4%) probands. All the
mutations except one were detected in BRCAPro-positive patients. In the 46 BRCAPro-positive cases that
resulted negative by BRCA1/2 mutation, screening analysis of rearrangements within BRCA1/2 by MLPA was
carried out. Three patients with a very high CP showed BRCA1 deletions, consisting of deletions of exons 1–2 in
two probands and of exon 24 in the third proband. In one case, the exons 1–2 deletion was shown to
cosegregate with disease in the family. No BRCA2 rearrangements were detected, but one patient showed the
1100delC of the CHEK2 gene, whose probe is present in the BRCA2 kit. In our series, the highest carrier
detection rate of mutation screening plus MLPA analysis (52.3%) was in patients with a BRCAPro CP >50%
Analysis of extended genomic rearrangements in oncological research.
Screening for genomic rearrangements is a fundamental task in the genetic diagnosis of many inherited
disorders including cancer-predisposing syndromes. Several methods were developed for analysis of structural
genomic abnormalities, some are targeted to the analysis of one or few specific loci, others are designed to
scan the whole genome. Locus-specific methods are used when the candidate loci responsible for the specific
pathological condition are known. Whole-genome methods are used to discover loci bearing structural
abnormalities when the disease-associated locus is unknown. Three main approaches have been employed for
the analysis of locus-specific structural changes. The first two are based on probe hybridization and include
cytogenetics and DNA blotting. The third approach is based on PCR amplification and includes microsatellite or
single nucleotide polymorphism (SNP) genotyping, relative allele quantitation, real-time quantitative PCR, long
PCR and multiplex PCR-based methods such as multiplex ligation-dependent probe amplification and the
recently developed nonfluorescent multiplex PCR coupled to high-performance liquid chromatography analysis.
Whole-genome methods include cytogenetic methods, array-comparative genomic hybridization, SNP array
and other sequence-based methods. The goal of the present review is to provide an overview of the main
features and advantages and limitations of methods for the screening of structural genomic abnormalities
relevant to oncological research
Probiotic modulation of the microbiota-gut-brain axis and behaviour in zebrafish
The gut microbiota plays a crucial role in the bi-directional gut–brain axis, a communication that integrates the gut and central nervous system (CNS) activities. Animal studies reveal that gut bacteria influence behaviour, Brain-Derived Neurotrophic Factor (BDNF) levels and serotonin metabolism. In the present study, we report for the first time an analysis of the microbiota–gut–brain axis in zebrafish (Danio rerio). After 28 days of dietary administration with the probiotic Lactobacillus rhamnosus IMC 501, we found differences in shoaling behaviour, brain expression levels of bdnf and of genes involved in serotonin signalling/metabolism between control and treated zebrafish group. In addition, in microbiota we found a significant increase of Firmicutes and a trending reduction of Proteobacteria. This study demonstrates that selected microbes can be used to modulate endogenous neuroactive molecules in zebrafish
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