Abstract:
le of glutathione in immunity and inflammation in the lung Review (5064) Total Article Views Authors: Pietro Ghezzi Published Date January 2011 Volume 2011:4 Pages 105 - 113 DOI: http://dx.doi.org/10.2147/IJGM.S15618 Pietro Ghezzi Brighton and Sussex Medical School, Trafford Centre, Falmer, Brighton, UK Abstract: Reactive oxygen species and thiol antioxidants, including glutathione (GSH), regulate innate immunity at various levels. This review outlines the redox-sensitive steps of the cellular mechanisms implicated in inflammation and host defense against infection, and describes how GSH is not only important as an antioxidant but also as a signaling molecule. There is an extensive literature of the role of GSH in immunity. Most reviews are biased by an oversimplified picture where “bad” free radicals cause all sorts of diseases and “good” antioxidants protect from them and prevent oxidative stress. While this may be the case in certain fields (eg, toxicology), the role of thiols (the topic of this review) in immunity certainly requires wearing scientist’s goggles and being prepared to accept a more complex picture. This review aims at describing the role of GSH in the lung in the context of immunity and inflammation. The first part summarizes the history and basic concepts of this picture. The second part focuses on GSH metabolism/levels in pathology, the third on the role of GSH in innate immunity and inflammation, and the fourth gives 4 examples describing the importance of GSH in the response to infections.

Abstract:
Pietro GhezziBrighton and Sussex Medical School, Trafford Centre, Falmer, Brighton, UKAbstract: Reactive oxygen species and thiol antioxidants, including glutathione (GSH), regulate innate immunity at various levels. This review outlines the redox-sensitive steps of the cellular mechanisms implicated in inflammation and host defense against infection, and describes how GSH is not only important as an antioxidant but also as a signaling molecule. There is an extensive literature of the role of GSH in immunity. Most reviews are biased by an oversimplified picture where “bad” free radicals cause all sorts of diseases and “good” antioxidants protect from them and prevent oxidative stress. While this may be the case in certain fields (eg, toxicology), the role of thiols (the topic of this review) in immunity certainly requires wearing scientist’s goggles and being prepared to accept a more complex picture. This review aims at describing the role of GSH in the lung in the context of immunity and inflammation. The first part summarizes the history and basic concepts of this picture. The second part focuses on GSH metabolism/levels in pathology, the third on the role of GSH in innate immunity and inflammation, and the fourth gives 4 examples describing the importance of GSH in the response to infections.Keywords: antioxidants, oxidative stress, sepsis, infection, cysteine

Abstract:
We consider a set $X$ of distinct points in the $n$-dimensional projective space over an algebraically closed field $k$. Let $A$ denote the coordinate ring of $X$, and let $a_i(X)=\dim_k [{\rm Tor}_i^R(A,k)]_{i+1}$. Green's Strong Castelnuovo Lemma (SCL) shows that if the points are in general position, then $a_{n-1}(X)\neq 0$ if and only if the points are on a rational normal curve. Cavaliere, Rossi and Valla conjectured that if the points are not necessarily in general position the possible extension of the SCL should be the following: $a_{n-1}(X)\neq 0$ if and only if either the points are on a rational normal curve or in the union of two linear subspaces whose dimensions add up to $n$. In this work we prove the conjecture.

Abstract:
An almost-Riemannian structure on a surface is a generalized Riemannian structure whose local orthonormal frames are given by Lie bracket generating pairs of vector fields that can become collinear. The distribution generated locally by orthonormal frames has maximal rank at almost every point of the surface, but in general it has rank 1 on a nonempty set which is generically a smooth curve. In this paper we provide a short introduction to 2-dimensional almost-Riemannian geometry highlighting its novelties with respect to Riemannian geometry. We present some results that investigate topological, metric and geometric aspects of almost- Riemannian surfaces from a local and global point of view.

Abstract:
In a performance – and results – driven educational world the concept of formative assessment has inspired the educational community by its discourse and focus on learning and learners. However, a number of controversies have surfaced: primary among these are terminological opacities and disparities both within and across continents and sectors (TARAS 2007b, 2009). Among others, Perrenoud (1998) signals the importance of positioning theoretical and practical discourse on assessment within a wider pedagogic context and within theories of learning. Taras (2005) argues that concepts of assessment, including formative assessment, are best and more effectively understood firstly within the wider assessment framework and, secondly, within the relationships of summative, formative and self-assessment. This paper examines definitions of assessments. It begins with basic concepts of assessment, summative, formative, self-assessment and feedback and inter-relates these. The principles inherent in definitions set the parameters of both processes and practice as part of a logical sequence and framework.

Abstract:
An acute triangulation of a polygon is a triangulation whose triangles have all their angles less than . The number of triangles in a triangulation is called the size of it. In this paper, we investigate acute triangulations of trapezoids and convex pentagons and prove new results about such triangulations with minimum size. This completes and improves in some cases the results obtained in two papers of Yuan (2010). 1. Introduction and Preliminaries A triangulation of a planar polygon is a finite set of nonoverlapping triangles covering the polygon in such a way that any two distinct triangles are either disjoint or intersect in a single common vertex or edge. An acute (resp., nonobtuse) triangulation of a polygon is a triangulation whose triangles have all their angles less (resp., not larger) than . The number of triangles in a triangulation is called the size. Burago and Zalgaller [1] and, independently, Goldberg and Manheimer [2] proved that every obtuse triangle can be triangulated into seven acute triangles and this bound is the best possible. Cassidy and Lord [3] showed that every square can be triangulated into eight acute triangles and eight is the minimum number. This remains true for any rectangle as proved by Hangan et al. in [4]. Acute triangulations of trapezoids, quadrilaterals, and pentagons were investigated in [5–8]. Further information, historical notes, and problems about acute triangulations of polygons and surfaces can be found in the survey paper [9]. Let denote a family of planar polygons, and for , let be the minimum size of an acute triangulation of . Then, let denote the maximum value of for all . The following results are known. Theorem 1. (i) Reference [7]: let denote the family of all trapezoids, that is, quadrilaterals with at least one pair of parallel sides. Then, , where is the family of all rectangles (also including squares). (ii) Reference [6]: let be the family of all quadrilaterals. Then, . (iii) Reference [5]: let be the family of all convex quadrilaterals. Then, . (iv) Reference [8]: let denote the family of all planar pentagons. Then, . In this paper, we discuss acute triangulations of trapezoids and convex pentagons and prove new results of such triangulations with minimum size. For example, we get the following characterization of the right trapezoids: they are the only trapezoids needing exactly six triangles and one interior vertex for an acute triangulation of minimum size. For the family of convex pentagons, we show that the bound stated in Theorem 1(iv) can be improved under some additional conditions.

Climate
change is a living topic when dealing with modern natural sciences. The
increase in the average air temperature, as measured in the last decades, is
considered as the most relevant effect of climate change on the Earth system.
Since the air temperature has a key role in determining the partitioning
between liquid and solid precipitation events at a site, important changes in
rainfall dynamics are expected, especially in mountainous areas. Thus, an
important issue for modern hydrology is to determine how climate change would
affect the liquid-solid partitioning of precipitation and its statistical
properties. The main aim here is to determine, via statistical analysis and
goodness-of-fit tests, whether the duration of precipitation events under the
different forms (namely solid, liquid and mixed) may be characterized by the
same probability distribution. Similar issue is tested for the volume of
precipitation. For this aim, our study pays attention to hourly data collected
along an altitude gradient identified through six automatic weather stations in
Trentino region, northeast Italy. To distinguish the different types of events
from observed heated pluviometers’ data, a partitioning procedure has been used
and validated, through some disdrometer data. Sample data of duration and
volume, relatively to solid, liquid and mixed events, are extracted, and
univariate and bivariate statistics are calculated. Then, the two-sample
Kolmogorov-Smirnov test is used to test if the data distinguished by different
types of precipitation can be considered extracted from the same distribution.
The results showed that in most cases, durations, as well as volumes of the
different types of events, cannot be considered equally distributed. This
consideration is particularly clear at high elevations.