Search results for "ASYM"
showing 10 items of 2151 documents
Hybridization, developmental stability, and functionality of morphological traits in the ground beetle Carabus solieri (Coleoptera, Carabidae).
2006
Correspondance.: stephane.garnier@u-bourgogne.fr; International audience; The assessment of developmental stability in hybrids can provide valuable information in the study of species formation because it allows an evaluation of the degree of incompatibility of genetic systems that control developmental processes. The present study assessed the impact of two hybridization events, assumed to have occurred at different times, on developmental instability in the ground beetle Carabus solieri . Developmental instability was estimated in 678 individuals from 27 populations from the fluctuating asymmetry (FA) levels of four morphological traits: the tibia length of middle and hind legs, which are…
Nanopore charge inversion and current-voltage curves in mixtures of asymmetric electrolytes
2018
[EN] We consider the screening of the negative charges (carboxylic acid groups) fixed on the surface of a conical-shaped track-etched nanopore by divalent magnesium (Mg2+) and trivalent lanthanum (La3+). The experimental current (I)-voltage (V) curves and current rectification ratios allow discussing fundamental questions about the overcompensation of spatially-fixed charges by multivalent ions over nanoscale volumes. The effects of charge inversion or reversal on nanopore transport are discussed in mixtures of asymmetric electrolytes (LaCl3 and MgCl2 with KCl). In particular, pore charge inversion is demonstrated for La3+ as well as for mixtures of this trivalent ion at low concentrations …
Advances towards highly active and stereoselective simple and cheap proline-based organocatalysts
2010
Ten 4-acyloxy-L-prolines were screened as catalysts at loadings of 2–0.1 mol-% for the direct asymmetric aldol reaction in water by using variable amounts of water. Among them, a new catalyst, the L-proline carrying a trans-4-(2,2-diphenylacetoxy) group, and a catalyst previously synthesized by us, the L-proline carrying a trans-4-(4-phenylbutanoyloxy) group, were found to be excellent catalysts for the aldol reaction between cyclohexanone or cyclopentanone and substituted benzaldehydes when employed in only 1 and 0.5 mol-%,respectively, at room temperature without additives. For such catalysts, high turnover numbers were obtained, which are among the highest values obtained for enamine org…
Asymmetric Synthesis of Chiral Bimetallic [Ag28Cu12(SR)24]4- Nanoclusters via Ion Pairing
2016
In this work, a facile ion-pairing strategy for asymmetric synthesis of optically active negatively charged chiral metal nanoparticles using chiral ammonium cations is demonstrated. A new thiolated chiral three-concentric-shell cluster, [Ag28Cu12(SR)24] 4- was first synthesized as a racemic mixture and characterized by single-crystal X-ray structure determination. Mass spectrometric measurements revealed relatively strong ion-pairing interactions between the anionic nanocluster and ammonium cations. Inspired by this observation, the as-prepared racemic mixture was separated into enantiomers by employing chiral quaternary ammonium salts as chiral resolution agents. Subsequently, direct asymm…
Luottamus ja itsestäkertominen psykoterapeutin ja potilaan välisessä vuorovaikutussuhteessa
2016
Tämän tutkielman tarkoituksena oli kuvata luottamuksen ja itsestäkertomisen merkitystä ja ilmenemistä psykoterapeutin ja potilaan välisessä vuorovaikutussuhteessa. Tavoitteena oli tarkastella potilaiden sekä psykoterapeuttien kokemuksia luottamuksesta ja itsestäkertomisesta sekä näiden ilmiöiden suhteesta toisiinsa. Tutkimus toteutettiin laadullisin menetelmin ja aineisto kerättiin puolistrukturoidulla teemahaastattelulla. Tutkimukseen haastateltiin viittä psykoterapiassa käyvää henkilöä ja kuutta psykoterapeuttia, jotka edustavat erilaisia psykoterapiasuuntauksia. Haastatellut potilaat erosivat toisistaan psykoterapian keston suhteen, mutta he kaikki olivat aineistonkeruun aikana edelleen …
Endogenous firm asymmetry and cooperative R&D in linear duopoly with spillovers
2005
In a linear model ofcost reducing R&D/Cournot competition, firm asymmetry is shown to be sustainable as subgame perfect Nash equilibrium with R&D competition only ifthe productivity of research is sufficiently large relative to the benefits from imitation. In such a case, industry-wide cost reduction and firms asymmetry are increasing and decreasing functions of the spillover rate, respectively. In the absence of spillovers, a symmetric joint lab generates higher consumer surplus and social welfare than a pair ofasymmetric competitors. If spillovers are not too small, asymmetric R&D competition is advantageous toconsumers, but not to firms.
Taylorism on steroids or enabling autonomy? A systematic review of algorithmic management
2023
AbstractThe use of algorithmic management systems is rapidly changing organizational models and practices, as millions of workers in multiple sectors worldwide are managed by computer software. Despite receiving increasing academic interest, little summarizing literature exist on the ways algorithmic systems are used in management. This article aims to fill this gap by systematically reviewing and qualitatively analyzing 172 articles on the topic. Our research contributes to the existent algorithmic management literature in three ways. First, we provide a descriptive overview of algorithmic management as a field of research. Second, we identify and synthesize the discussion on the key conce…
Asymptotic theory of resonant tunneling in quantum waveguides of variable cross-section
2008
Halkaisijaltaan muunnellun kvanttiaaltojohtimen kapenemat toimivat tehokkaina potentiaalivalleina elektronin pitkittäissuuntaiselle liikkeelle. Kaksi kapenemaa muodostaa kvanttiresonaattorin, jossa resonoiva tunnelointi voi tapahtua. Tämä tarkoittaa sitä, että elektronit, joiden energia on lähellä resonanssia, läpäisevät resonaattorin todennäköisyydellä lähellä yhtä.Sarafanov kuvailee väitöskirjassaan asymptoottisesti elektroniaallon etenemistä kvanttiaaltojohtimessa, jossa on kaksi kapenemaa. Aaltoluvun k oletetaan olevan ensimmäisen ja toisen kynnysluvun välissä, jolloin vain sisään tuleva ja poismenevä aalto voivat edetä jokaisessa aaltojohtimen päässä äärettömyydessä. Väitöskirjassa esi…
Operācijas rezultātu korelācija ar miega artērijas revaskularizācijas metodēm
2014
Anotācija Miega artēriju stenozes ķirurģiskai korekcijai karotīdu endarterectomijai ir būtiska nozīme insulta profilaksē. Promocijas darba mērķis: Izvērtēt miega artērijas endarterektomiju operāciju rezultātus, ņemot vērā intima-media slāņa biezumu un pacienta dzīves kvalitāti. Promocijas darbā autore veikusi pētījumu, kas atspoguļo karotīdu endarterektomijas operāciju rezultātus (komplikācijas, dzīves kvalitātes izmaiņas) un intīmas hiperplāzijas attīstību postoperatīvā periodā. Izveidota speciāla dzīves kvalitātes novērtēšanas anketa pacientiem ar miega artērijas sašaurinājumu. Pētījuma materiālu veido 104 pacienti, kuriem veiktas karotīdu endarterektomijas. Darbs veikts Latvijas Universi…
Stereoselective Synthesis of Spiro-Decalin Oxindole Derivatives via Sequential Organocatalytic Michael-Domino Michael/Aldol Reaction.
2022
A highly stereoselective procedure for the synthesis of spiro-polycyclic oxindoles bearing five contiguous stereogenic centers including two tetrasubstituted carbons has been developed. Under sequential organocatalysis performed by a pyrrolidine-based organocatalyst and DBU, a highly atom-economical Michael–domino Michael/aldol reaction sequence was optimized, yielding variously functionalized spiro-decalin oxindoles with excellent stereoselectivity (>99:1 dr, up to 92% ee). peerReviewed