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

Vitellogenins in the spider Parasteatoda tepidariorum – expression profile and putative hormonal regulation of vitellogenesis

Background: Knowledge about vitellogenesis in spiders is rudimentary. Therefore, the aim of study was to check the vitellogenin (Vg) presence in various tissues of the female spider Parasteatoda tepidariorum, determine when and where vitellogenesis starts and takes place, and the putative role of selected hormones in the vitellogenesis. Results: Here we show two genes encoding Vg (PtVg4 and PtVg6) in the genome of the spider P. tepidariorum. One gene PtVg4 and three subunits of Vg (250 kDa, 47 kDa and 30 kDa) are expressed in the midgut glands, ovaries and hemolymph. Heterosynthesis of the Vg in the midgut glands and autosynthesis in the ovaries were observed. Vitellogenesis begins in the last nymphal stage in the midgut glands (heterosynthesis). However, after sexual maturity is reached, Vg is also synthesized in the ovaries (autosynthesis). Changes in the PtVg4 expression level and in the Vg concentration after treatment with 20-hydroxyecdysone, a juvenile hormone analog (fenoxycarb) and an antijuvenoid compound (precocene I) were observed. Therefore, we propose a hypothetical model for the hormonal regulation of vitellogenesis in P. tepidariorum. Conclusions: Our results are the first comprehensive study on spider vitellogenesis. In our opinion, this work will open discussion on the evolutionary context of possible similarities in the hormonal control of vitellogenesis between P. tepidariorum and other arthropods as well as their consequences

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

Synthesis of cyclobutane lignans via an organic single electron oxidant–electron relay system

A direct method to synthesize lignan cyclobutanes and analogs via photoinduced electron transfer is presented. A variety of oxygenated alkenes are employed to furnish terminal or substituted cyclobutane adducts with complete regiocontrol, yielding cycloadducts with trans stereochemistry. Key to minimizing competing cycloreversion is the inclusion of an aromatic electron relay (ER). This method has been adapted to the synthesis of the natural products magnosalin and pellucidin A

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