AlmaLaurea - the italian experience in monitoring the fortunes of graduates

Celem niniejszego artykułu jest zaprezentowanie jednego z systemów badania karier osób, które ukończyły naukę na uczelniach wyższych. Autorka stara się przybliżyć polskiemu czytelnikowi działalność istniejącego od kilkunastu lat we Włoszech konsorcjum międzyuczelnianego AlmaLaurea oraz, na wybranych przykładach, pokazać, jakie korzyści może przynieść monitoring losów absolwentów.The purpose of this article is to explain one of the systems of monitoring the careers of people who finished their university studies. The author tries to bring closer to the Polish reader the activities of the existing in Italy sińce several years inter-university consortium, AlmaLaurea and to show on selected examples, what advantages can monitoring the fortunes of graduates bring about

Discrete charges on a two dimensional conductor

We investigate the electrostatic equilibria of N discrete charges of size 1/N on a two dimensional conductor (domain). We study the distribution of the charges on symmetric domains including the ellipse, the hypotrochoid and various regular polygons, with an emphasis on understanding the distributions of the charges, as the shape of the underlying conductor becomes singular. We find that there are two regimes of behavior, a symmetric regime for smooth conductors, and a symmetry broken regime for ``singular'' domains. For smooth conductors, the locations of the charges can be determined up to a certain order by an integral equation due to Pommerenke (1969). We present a derivation of a related (but different) integral equation, which has the same solutions. We also solve the equation to obtain (asymptotic) solutions which show universal behavior in the distribution of the charges in conductors with somewhat smooth cusps. Conductors with sharp cusps and singularities show qualitatively different behavior, where the symmetry of the problem is broken, and the distribution of the discrete charges does not respect the symmetry of the underlying domain. We investigate the symmetry breaking both theoretically, and numerically, and find good agreement between our theory and the numerics. We also find that the universality in the distribution of the charges near the cusps persists in the symmetry broken regime, although this distribution is very different from the one given by the integral equation.Comment: 46 pages, 46 figures, submitted to J. Stat. Phy

Antioxidant capacity of honey from the urban apiary: a comparison with honey from the rural apiary

Honey is a source of natural antioxidant compounds exerting several health-beneficial effects. Since urban beekeeping is quite common, the fear among potential consumers about the quality and the safety of honey produced exclusively in the cities is observed. However, the antioxidant properties of urban honey have not yet been tested. We described the antioxidant properties of linden honey from urban and rural areas. We analyzed the total phenolic content, DPPH• radical scavenging activity, Trolox equivalent antioxidant activity assay, the protein content, and catalase activity. The analysis showed that all tested parameters were significantly higher in honey from rural areas than in urban samples. The differences in the obtained results are certainly not the effect of the floral composition of honey, but rather due to the location of the honeybee colonies. It seems that the consumption of honey from urban areas for health purposes should be considered

Set of stress biomarkers as a practical tool in the assessment of multistress effect using honeybees from urban and rural areas as a model organism: a pilot study

A decrease among honey bee populations (Apis mellifera) in the traditional apiaries has been observed in recent years. In light of this negative phenomenon, urban beekeeping seems to be an appropriate alternative solution for the bee population in reducing the toxic effects of a large number of pesticides that are commonly used in agricultural ecosystems. Despite the rapid development of urban beekeeping, there is little information regarding the different aspects of the defense effectiveness of bees from the urban and rural areas. The study was aimed to show whether honey bees from these two locations differ in the level of the valuable biomarkers of stress exposure helpful in establishing which bees, from urban or rural areas, are under greater environmental pressure. For this purpose, foragers from an urban rooftop apiary and a traditional rural apiary were collected. The chosen biomarkers were measured in various tissues of bees. The activity of glutathione S-transferase and acetylcholinesterase, the level of total antioxidant capacity, heat shock protein 70 (Hsp70), and defensin were selected for the analyses. In our opinion, the Hsp70 and defensin levels seemed to be important in the indication of urban multistress factors. The higher level of heat shock proteins and defensins in tissues/organs of bees from the urban apiary—in the gut (an increase, respectively, 92% and 7.3%) and fat body (an increase, respectively, 130% and 7.8%), known as targets of environmental toxins, pointed out the urban environment as highly stressful at both the individual and colony levels. In turn, high total antioxidant capacity was measured in the guts of honey bees from rural area (an increase 107%). Such a situation suggests a different mechanism of defense and specificity of rural and urban environmental stressors and also honey bees foraging activity

The [1,2]-Brook rearrangement: novel carbon-carbon bond forming reactions and application to the total synthesis of zaragozic acid C

I. Catalytic Cyanation/Brook Rearrangement/C-Acylation Reactions of Acylsilanes A tandem nucleophile-catalyzed cyanation/Brook rearrangement/C-acylation has been developed. Phase transfer cocatalysts facilitate cyanide-catalyzed reactions between acylsilanes and cyanoformates to afford protected tertiary carbinol products. A catalytic cycle is proposed involving cyanation of an acylsilane, [1,2]-Brook rearrangement, and C-acylation of the derived carbanion by a cyanoformate ester. The reaction offers an efficient method for the preparation of functionalized, unsymmetrical malonic acid derivatives. II. Catalytic Enantioselective Acylation of (Silyloxy)nitrile Anions New catalytic enantioselective cyanation/[1,2]-Brook rearrangement/C-acylation reactions of acylsilanes with cyanoformate esters are described. Catalysts for this transformation were discovered via a directed candidate screen of 96 metal-ligand complexes. Optimization of a (salen)aluminum complex revealed significant remote electronic effects and concentration effects. The scope of the reaction was investigated by using a number of aryl acylsilanes and cyanoformate esters. Chemoselective reduction of the reaction products afforded new enantioenriched alpha-hydroxy-alpha-aryl-beta-amino acid derivatives and beta-lactams. This reaction provides a simple method for the construction of new nitrogen-containing enantioenriched chiral building blocks. III. Three Component Coupling Reactions of Silylglyoxylates, Alkynes, and Aldehydes: A Chemoselective One Step Glycolate Aldol Construction A single-pot three-component coupling reaction of silylglyoxylates, terminal alkynes, and aldehydes in the presence of ZnI2 and Et3N is presented. The products of the reaction, densely functionalized silyl-protected glycolate aldols, can be converted to the corresponding acetonides in a one-pot deprotection/ketalization sequence. Mechanistic experiments suggest that the zinc acetylide reacts with the silylgyloxylate in a chemoselective manner. Using an unoptimized (+)-N-methylephedrine and Zn(OTf)2 system, moderate levels of enantioselectivity for the title reaction was achieved. IV. Application of the Silylglyoxylate Glycolate Aldol Reaction: Progress Toward the Total Synthesis of Zaragozic Acid C A review of the literature concerning previous approaches to the zaragozic acids is presented. A highly diastereoselective single step double aldol reaction of vinylmagnesium bromide, tert-butyl tert-butyldimethylsilylglyoxylate, and tert-butyl glyoxylate to afford an advanced intermediate with the potential for further elaboration to zaragozic acid C was explored. Subsequent manipulations set the stage for an intramolecular aldol which constructed a key epsilon-lactone and supplied all of the required atoms of the zaragozic acid C core

Oxidation of alkyl benzenes by a flavin photooxidation catalyst on nanostructured metal-oxide films

There are significant advantages in organic, interfacial photooxidation catalysis. Surface-bound catalysts on oxide interfaces offer highly reactive assemblies that minimize both catalyst and solution volume. We demonstrate here the oxygenation of alkyl benzenes by a flavin mononucleotide on nanoporous ZrO2 or TiO2 surfaces

Anti-Markovnikov Hydroamination of Alkenes Catalyzed by an Organic Photoredox System

Herein we report a metal-free method for the direct anti-Markovnikov hydroamination of unsaturated amines. Irradiation of the amine substrates with visible light in the presence of catalytic quantities of easily synthesized 9-mesityl-10-methylacridinium tetrafluoroborate and thiophenol as a hydrogen atom donor furnished the nitrogen containing heterocycles with complete regio-control. Two examples of in termolecular anti-Markovnikov alkene hydroamination are also disclosed

Three-Component Coupling Reactions of Silylglyoxylates, Alkynes, and Aldehydes: A Chemoselective One-Step Glycolate Aldol Construction

A single-pot three-component coupling reaction of silylglyoxylates (1), terminal alkynes, and aldehydes in the presence of ZnI2 and Et3N is presented. The products of the reaction, densely functionalized silyl-protected glycolate aldols (2), can be converted to the corresponding acetonides (3) in a one-pot deprotection/ketalization sequence. A variety of terminal alkynes and aldehydes can be successfully employed to give a range of highly functionalized, fully protected 1,2-diols in good yields and moderate diastereoselectivities. Mechanistic experiments suggest that the zinc acetylide reacts with the silylgyloxylate (1) in a chemoselective manner. Using an unoptimized (+)-N-methylephedrine and Zn(OTf)2 system, silyl-deprotected adduct 2 was formed in 64% ee and 89:11 dr

Direct Catalytic Anti-Markovnikov Addition of Carboxylic Acids to Alkenes

A direct catalytic anti-Markovnikov addition of carboxylic acids to alkenes is reported. The catalyst system is comprised of the Fukuzumi acridinium photooxidant (1) and a substoichiometric quantity of a hydrogen atom donor. Oxidizable olefins such as styrenes, trisubstituted aliphatic alkenes, and enamides can be employed along with a variety of carboxylic acids to afford the anti-Markovnikov addition adducts exclusively. A deuterium-labeling experiment lends insight to the potential mechanism

Three-Component Coupling Reactions of Silyl Glyoxylates, Vinyl Grignard Reagent, and Nitroalkenes: An Efficient, Highly Diastereoselective Approach to Nitrocyclopentanols

The sequential vinylation/[1,2]-Brook rearrangement/vinylogous Michael reaction provides (Z)-silyl enol ethers