Human ApoD, an apolipoprotein up-regulated in neurodegenerative diseases, extends lifespan and increases stress resistance in Drosophila

Apolipoprotein D (ApoD) expression increases in several neurological disorders and in spinal cord injury. We provide a report of a physiological role for human ApoD (hApoD): Flies overexpressing hApoD are long-lived and protected against stress conditions associated with aging and neurodegeneration, including hyperoxia, dietary paraquat, and heat stress. We show that the fly ortholog, Glial Lazarillo, is strongly up-regulated in response to these extrinsic stresses and also can protect in vitro-cultured cells in situations modeling Alzheimer's disease (AD) and Parkinson's disease (PD). In adult flies, hApoD overexpression reduces age-associated lipid peroxide accumulation, suggesting a proximal mechanism of action. Similar data obtained in the mouse [Ganfornina, M.D., et al., (2008) Apolipoprotein D is involved in the mechanisms regulating protection from oxidative stress. Aging Cell 10.1111/j.1474-9726.2008.00395.] as well as in plants (Charron et al., personal communication) suggest that ApoD and its orthologs play an evolutionarily conserved role in response to stress, possibly managing or preventing lipid peroxidation

Bazzoni-Glaz Conjecture

In their paper, Bazzoni and Glaz conjecture that the weak global dimension of a Gaussian ring is $0,1$ or $\infty$. In this paper, we prove their conjecture.Comment: arXiv admin note: substantial text overlap with arXiv:1107.044

Approximations for the boundary crossing probabilities of moving sums of normal random variables

In this paper we study approximations for boundary crossing probabilities for the moving sums of i.i.d. normal random variables. We propose approximating a discrete time problem with a continuous time problem allowing us to apply developed theory for stationary Gaussian processes and to consider a number of approximations (some well known and some not). We bring particular attention to the strong performance of a newly developed approximation that corrects the use of continuous time results in a discrete time setting. Results of extensive numerical comparisons are reported. These results show that the developed approximation is very accurate even for small window length

Approximations for two-dimensional discrete scan statistics in some block-factor type dependent models

We consider the two-dimensional discrete scan statistic generated by a block-factor type model obtained from i.i.d. sequence. We present an approximation for the distribution of the scan statistics and the corresponding error bounds. A simulation study illustrates our methodology.Comment: 17 pages, 9 figure

On Pr\"ufer-like conditions

This paper deals with five extensions of the Pr\"ufer domain concept to commutative rings with zero divisors. We investigate the stability of these Pr\"ufer-like conditions under localization and homomorphic image. Our results generate new and original examples of Pr\"ufer-like rings

Identification of activity peaks in time-tagged data with a scan-statistics driven clustering method and its application to gamma-ray data samples

The investigation of activity periods in time-tagged data-samples is a topic of large interest. Among Astrophysical samples, gamma-ray sources are widely studied, due to the huge quasi-continuum data set available today from the FERMI-LAT and AGILE-GRID gamma-ray telescopes. To reveal flaring episodes of a given gamma-ray source, researchers make use of binned light-curves. This method suffers several drawbacks: the results depends on time-binning, the identification of activity periods is difficult for bins with low signal to noise ratio. I developed a general temporal-unbinned method to identify flaring periods in time-tagged data and discriminate statistically-significant flares: I propose an event clustering method in one-dimension to identify flaring episodes, and Scan-statistics to evaluate the flare significance within the whole data sample. This is a photometric algorithm. The comparison of the photometric results (e.g., photometric flux, gamma-ray spatial distribution) for the identified peaks with the standard likelihood analysis for the same period is mandatory to establish if source-confusion is spoiling results. The procedure can be applied to reveal flares in any time-tagged data sample. The study of the gamma ray activity of 3C 454.3 and of the fast variability of the Crab Nebula are shown as examples. The result of the proposed method is similar to a photometric light curve, but peaks are resolved, they are statistically significant within the whole period of investigation, and peak detection capability does not suffer time-binning related issues. The method can be applied for gamma-ray sources of known celestial position. Furthermore the method can be used when it is necessary to assess the statistical significance within the whole period of investigation of a flare from an unknown gamma-ray source.Comment: 17 pages, 10 figures Accepted for publication in A&

Constructing two-sided simultaneous confidence intervals for multinomial proportions for small counts in a large number of cells

Confidence intervals for multinomial proportions are often constructed using large-sample methods that rely on expected cell counts of 5 or greater. In situations that give rise to a large number of categories, the cell counts may not be of adequate size to ensure the appropriate overall coverage probability and alternative methods of construction have been proposed. Sison and Glaz (1995) developed a method of constructing two-sided confidence intervals for multinomial proportions that is based on the doubly truncated Poisson distribution and their method performs well when the cell counts are fairly equally dispersed over a large number of categories. In fact, the Sison and Glaz (1995) intervals appear to outperform other methods of simultaneous construction in terms of coverage probabilities and interval length in these situations. To make the method available to researchers, we have developed a SAS macro to construct the intervals proposed by Sison and Glaz (1995).

On the notion of Cohen-Macaulayness for non Noetherian rings

There exist many characterizations of Noetherian Cohen-Macaulay rings in the literature. These characterizations do not remain equivalent if we drop the Noetherian assumption. The aim of this paper is to provide some comparisons between some of these characterizations in non Noetherian case. Toward solving a conjecture posed by Glaz, we give a generalization of the Hochster-Eagon result on Cohen-Macaulayness of invariant rings, in the context of non Noetherian rings.Comment: 2