Multiplying unitary random matrices - universality and spectral properties

In this paper we calculate, in the large N limit, the eigenvalue density of an infinite product of random unitary matrices, each of them generated by a random hermitian matrix. This is equivalent to solving unitary diffusion generated by a hamiltonian random in time. We find that the result is universal and depends only on the second moment of the generator of the stochastic evolution. We find indications of critical behavior (eigenvalue spacing scaling like $1/N^{3/4}$) close to $\theta=\pi$ for a specific critical evolution time $t_c$.Comment: 12 pages, 2 figure

Fermion Zero Modes in the Presence of Fluxes and a Non-perturbative Superpotential

We study the effect of background fluxes of general Hodge type on the supersymmetry conditions and on the fermionic zero modes on the world-volume of a Euclidean M5/D3-brane in M-theory/type IIB string theory. Using the naive susy variation of the modulino fields to determine the number of zero modes in the presence of a flux of general Hodge type, an inconsistency appears. This inconsistency is resolved by a modification of the supersymmetry variation of the modulinos, which captures the back-reaction of the non-perturbative effects on the background flux and the geometry.Comment: 21 pages, revised version contains a new appendix on dimensional reduction of spinors and some changes in the spinor equation

Radial Velocity Studies of Close Binary Stars. IX

Radial-velocity measurements and sine-curve fits to the orbital velocity variations are presented for the eighth set of ten close binary systems: AB And, V402 Aur, V445 Cep, V2082 Cyg, BX Dra, V918 Her, V502 Oph, V1363 Ori, KP Peg, V335 Peg. Half of the systems (V445 Cep, V2082 Cyg, V918 Her, V1363 Ori, V335 Peg) were discovered photometrically by the Hipparcos mission and all systems are double-lined (SB2) contact binaries. The broadening function method permitted improvement of the orbital elements for AB And and V502 Oph. The other systems have been observed for radial velocity variations for the first time; in this group are five bright (V<7.5) binaries: V445 Cep, V2082 Cyg, V918 Her, KP Peg and V335 Peg. Several of the studied systems are prime candidates for combined light and radial-velocity synthesis solutions.Comment: 17+ pages, 2 tables, 4 figure

Acute pancreatitis following medical abortion: Case report

BACKGROUND: Acute pancreatitis rarely complicates pregnancy. Although most pregnant women with acute pancreatitis have associated gallstones, less common causes such as drugs have been reported. CASE PRESENTATION: We report the case of a 34-year-old woman who underwent medical abortion with mifepristone and gemeprost and received codeine as pain-relief during the induction of abortion. She developed a severe acute necrotizing pancreatitis which required 14 days of intensive care. Other possible etiological factors, i.e. gallstone, alcohol intake and hyperlipidemia, were excluded. CONCLUSIONS: The reported case of acute pancreatitis was most likely drug-induced

Association between the c.*229C>T polymorphism of the topoisomerase IIb binding protein 1 (TopBP1) gene and breast cancer

Topoisomerase IIb binding protein 1 (TopBP1) is involved in cell survival, DNA replication, DNA damage repair and cell cycle checkpoint control. The biological function of TopBP1 and its close relation with BRCA1 prompted us to investigate whether alterations in the TopBP1 gene can influence the risk of breast cancer. The aim of this study was to examine the association between five polymorphisms (rs185903567, rs116645643, rs115160714, rs116195487, and rs112843513) located in the 30UTR region of the TopBP1 gene and breast cancer risk as well as allele-specific gene expression. Five hundred thirty-four breast cancer patients and 556 population controls were genotyped for these SNPs. Allele-specific Top- BP1 mRNA and protein expressions were determined by using real time PCR and western blotting methods, respectively. Only one SNP (rs115160714) showed an association with breast cancer. Compared to homozygous common allele carriers, heterozygous and homozygous for the T variant had significantly increased risk of breast cancer (adjusted odds ratio = 3.81, 95 % confidence interval: 1.63–8.34, p = 0.001). Mean TopBP1 mRNA and protein expression were higher in the individuals with the CT or TT genotype. There was a significant association between the rs115160714 and tumor grade and stage. Most carriers of minor allele had a high grade (G3) tumors classified as T2-T4N1M0. Our study raises a possibility that a genetic variation of TopBP1 may be implicated in the etiology of breast cancer

Winter Bird Assemblages in Rural and Urban Environments: A National Survey

Urban development has a marked effect on the ecological and behavioural traits of many living organisms, including birds. In this paper, we analysed differences in the numbers of wintering birds between rural and urban areas in Poland. We also analysed species richness and abundance in relation to longitude, latitude, human population size, and landscape structure. All these parameters were analysed using modern statistical techniques incorporating species detectability. We counted birds in 156 squares (0.25 km2 each) in December 2012 and again in January 2013 in locations in and around 26 urban areas across Poland (in each urban area we surveyed 3 squares and 3 squares in nearby rural areas). The influence of twelve potential environmental variables on species abundance and richness was assessed with Generalized Linear Mixed Models, Principal Components and Detrended Correspondence Analyses. Totals of 72 bird species and 89,710 individual birds were recorded in this study. On average (±SE) 13.3 ± 0.3 species and 288 ± 14 individuals were recorded in each square in each survey. A formal comparison of rural and urban areas revealed that 27 species had a significant preference; 17 to rural areas and 10 to urban areas. Moreover, overall abundance in urban areas was more than double that of rural areas. There was almost a complete separation of rural and urban bird communities. Significantly more birds and more bird species were recorded in January compared to December. We conclude that differences between rural and urban areas in terms of winter conditions and the availability of resources are reflected in different bird communities in the two environments

A European Academy of Neurology guideline on medical management issues in dementia

BACKGROUND AND PURPOSE: Dementia is one of the most common disorders and is associated with increased morbidity, mortality and decreased quality of life. The present guideline addresses important medical management issues including systematic medical follow‐up, vascular risk factors in dementia, pain in dementia, use of antipsychotics in dementia and epilepsy in dementia. METHODS: A systematic review of the literature was carried out. Based on the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework, we developed a guideline. Where recommendations based on GRADE were not possible, a good practice statement was formulated. RESULTS: Systematic management of vascular risk factors should be performed in patients with mild to moderate dementia as prevention of cerebrovascular pathology may impact on the progression of dementia (Good Practice statement). Individuals with dementia (without previous stroke) and atrial fibrillation should be treated with anticoagulants (weak recommendation). Discontinuation of opioids should be considered in certain individuals with dementia (e.g. for whom there are no signs or symptoms of pain or no clear indication, or suspicion of side effects; Good Practice statement). Behavioral symptoms in persons with dementia should not be treated with mild analgesics (weak recommendation). In all patients with dementia treated with opioids, assessment of the individual risk–benefit ratio should be performed at regular intervals. Regular, preplanned medical follow‐up should be offered to all patients with dementia. The setting will depend on the organization of local health services and should, as a minimum, include general practitioners with easy access to dementia specialists (Good Practice statement). Individuals with dementia and agitation and/or aggression should be treated with atypical antipsychotics only after all non‐pharmacological measures have been proven to be without benefit or in the case of severe self‐harm or harm to others (weak recommendation). Antipsychotics should be discontinued after cessation of behavioral disturbances and in patients in whom there are side effects (Good Practice statement). For treatment of epilepsy in individuals with dementia, newer anticonvulsants should be considered as first‐line therapy (Good Practice statement). CONCLUSION: This GRADE‐based guideline offers recommendations on several important medical issues in patients with dementia, and thus adds important guidance for clinicians. For some issues, very little or no evidence was identified, highlighting the importance of further studies within these areas

The Pseudomonas aeruginosa T6SS Delivers a Periplasmic Toxin that Disrupts Bacterial Cell Morphology.

The type VI secretion system (T6SS) is crucial in interbacterial competition and is a virulence determinant of many Gram-negative bacteria. Several T6SS effectors are covalently fused to secreted T6SS structural components such as the VgrG spike for delivery into target cells. In Pseudomonas aeruginosa, the VgrG2b effector was previously proposed to mediate bacterial internalization into eukaryotic cells. In this work, we find that the VgrG2b C-terminal domain (VgrG2bC-ter) elicits toxicity in the bacterial periplasm, counteracted by a cognate immunity protein. We resolve the structure of VgrG2bC-ter and confirm it is a member of the zinc-metallopeptidase family of enzymes. We show that this effector causes membrane blebbing at midcell, which suggests a distinct type of T6SS-mediated growth inhibition through interference with cell division, mimicking the impact of β-lactam antibiotics. Our study introduces a further effector family to the T6SS arsenal and demonstrates that VgrG2b can target both prokaryotic and eukaryotic cells

White Matter Lesion Progression in LADIS Frequency, Clinical Effects, and Sample Size Calculations

BACKGROUND AND PURPOSE: White matter lesion (WML) progression has been advocated as a surrogate marker in intervention trials on cerebral small vessel disease. We assessed the rate of visually rated WML progression, studied correlations between lesion progression and cognition, and estimated sample sizes for clinical trials with pure WML progression vs combined WML progression-cognitive outcomes. METHODS: Those 394 participants of the Leukoaraiosis and Disability Study (LADIS) study with magnetic resonance imaging scanning at baseline and 3-year follow-up were analyzed. WML progression rating relied on the modified Rotterdam Progression Scale. The Vascular Dementia Assessment Scale global score and a composite score of specific executive function tests assessed longitudinal change in cognition. Sample size calculations were based on the assumption that treatment reduces WML progression by 1 grade on the Rotterdam Progression Scale. RESULTS: WML progression related to deterioration in cognitive functioning. This relationship was less pronounced in subjects with early confluent and confluent lesions. Consequently, studies in which the outcome is cognitive change resulting from treatment effects on lesion progression will need between 1809 subjects per treatment arm when using executive tests and up to 18 853 subjects when using the Vascular Dementia Assessment Scale score. Studies having WML progression as the sole outcome will need only 58 or 70 individuals per treatment arm. CONCLUSIONS: WML progression is an interesting outcome for proof-of-concept studies in cerebral small vessel disease. If cognitive outcome measures are added to protocols, then sample size estimates increase substantially. Our data support the use of an executive test battery rather than the Vascular Dementia Assessment Scale as the primary cognitive outcome measure

Confirmatory factor analysis of the Neuropsychological Assessment Battery of the LADIS study: a longitudinal analysis

WOS:000315985900004Age-related white matter changes have been associated with cognitive functioning, even though their role is not fully understood. This work aimed to test a 3-factor model of the neuropsychological assessment battery and evaluate how the model fit the data longitudinally. Confirmatory factor analysis (CFA) was used to investigate the dimensions of a structured set of neuropsychological tests administered to a multicenter, international sample of independent older adults (LADIS study). Six hundred and thirty-eight older adults completed baseline neuropsychological, clinical, functional and motor assessments, which were repeated each year for a 3-year follow-up. CFA provided support for a 3-factor model. These factors involve the dimensions of executive functions, memory functions, and speed and motor control abilities. Performance decreased in most neuropsychological measures. Results showed that executive functioning, memory and speed of motor abilities are valid latent variables of neuropsychological performance among older adults, and that this structure is relatively consistent longitudinally, even though performance decreases with time.info:eu-repo/semantics/acceptedVersio