Neutral and charged electron-hole complexes in artificial molecules: quantum transitions induced by the in-plane magnetic field

We theoretically investigate the properties of neutral and charged excitons and of the biexciton in vertically coupled quantum dots, as a function of the in-plane magnetic field B-parallel to. The main effect of the field consists in the suppression of the bonding-antibonding splitting, and in the resulting enhancement of the interdot correlations. As a consequence, the excitons form with the additional carrier a bound or an unbound complex depending on the sign of the charging, whereas the biexciton undergoes a transition between different quantum states with increasing B-parallel to. The discussed behaviors and transitions show up in the field dependence of experimentally accessible quantities, such as the charged-exciton and biexciton binding energies

Quantum phases of correlated electrons in artificial molecules under magnetic fields

We investigate the stability of few-electron quantum phases in vertically coupled quantum dots under a magnetic field of arbitrary strength and direction. The orbital and spin stability diagrams of realistic devices containing up to five electrons, from strong to weak interdot coupling, is determined. Correlation effects and realistic sample geometries are fully taken into account within the full configuration interaction method. In general, the magnetic field drives the system into a strongly correlated regime by modulating the single-particle gaps. In coupled quantum dots different components of the field, either parallel or perpendicular to the tunneling direction, affect single-dot orbitals and tunneling energy, respectively. Therefore the stability of the quantum phases is related to different correlation mechanisms, depending on the field direction. Comparison of exact diagonalization results with simple models allows one to identify the specific role of correlations

Spin-Spin Interaction In Artificial Molecules With In-Plane Magnetic Field

We investigate theoretically the spin-spin interaction of two-electrons in vertically coupled QDs as a function of the angle between magnetic field and growth axis. Our numerical approach is based on a real-space description of single-particle states in realistic samples and exact diagonalization of carrier-carrier Coulomb interaction. In particular, the effect of the in-plane field component on tunneling and, therefore, spin-spin interaction will be discussed; the singlet-triplet phase diagram as a function of the field strength and direction is drawn.Comment: Proc. of EP2DS-15, Nara, Japan - 6 pages, 4 figure

Synthesis of Amphiphilic Hydantoin-based Universal Peptidomimetics as Antibiotic Agents

Three model hydantoin-based universal peptidomimetics are designed and synthetized. Their preferred amphiphilic -turn conformation was assessed by molecular modeling and NMR experiments, and their antibacterial acivity tasted against Gram positive and Gram negative bacteria strains, demostrating that these compounds could be a captivating class of antibiotic to fight emergent drug resistanc

Unconventional Pathways of Protein Secretion: Mammals vs. Plants

none6noIn eukaryotes, many proteins contain an N-terminal signal peptide that allows their translocation into the endoplasmic reticulum followed by secretion outside the cell according to the classical secretory system. However, an increasing number of secreted proteins lacking the signal peptide sequence are emerging. These proteins, secreted in several alternative ways collectively known as unconventional protein secretion (UPS) pathways, exert extracellular functions including cell signaling, immune modulation, as well as moonlighting activities different from their well-described intracellular functions. Pathways for UPS include direct transfer across the plasma membrane, secretion from endosomal/multivesicular body-related components, release within plasma membrane-derived microvesicles, or use of elements of autophagy. In this review we describe the mammals and plants UPS pathways identified so far highlighting commonalities and differencesopenElisa Maricchiolo, Eleonora Panfili, Andrea Pompa, Francesca De Marchis, Michele Bellucci, Maria Teresa PallottaMaricchiolo, Elisa; Panfili, Eleonora; Pompa, Andrea; De Marchis, Francesca; Bellucci, Michele; Teresa Pallotta, Mari

Tagging the signatures of domestication in common bean (<i>Phaseolus vulgaris</i>) by means of pooled DNA samples

Background and Aims: The main aim of this study was to use an amplified fragment length polymorphism (AFLP)-based, large-scale screening of the whole genome of Phaseolus vulgaris to determine the effects of selection on the structure of the genetic diversity in wild and domesticated populations. Methods: Using pooled DNA samples, seven each of wild and domesticated populations of P. vulgaris were studied using 2506 AFLP markers (on average, one every 250 kb). About 10 % of the markers were also analysed on individual genotypes and were used to infer allelic frequencies empirically from bulk data. In both data sets, tests were made to determine the departure from neutral expectation for each marker using an FST-based method. Key Results: The most important outcome is that a large fraction of the genome of the common bean (16 %; P &lt;0·01) appears to have been subjected to effects of selection during domestication. Markers obtained in individual genotypes were also mapped and classified according to their proximities to known genes and quantitative trait loci (QTLs) of the domestication syndrome. Most of the markers that were found to be potentially under the effects of selection were located in the proximity of previously mapped genes and QTLs related to the domestication syndrome. Conclusions: Overall, the results indicate that in P. vulgaris a large portion of the genome appears to have been subjected to the effects of selection, probably because of linkage to the loci selected during domestication. As most of the markers that are under the effects of selection are linked to known loci related to the domestication syndrome, it is concluded that population genomics approaches are very efficient in detecting QTLs. A method based on bulk DNA samples is presented that is effective in pre-screening for a large number of markers to determine selection signatures

Climate variability and change in the Euro-Mediterranean Region: results from a global AOGCM coupled with an interactive high-resolution model of the Mediterranean Sea

In this work we present and discuss the results obtained from a set of present and future climate simulations performed with a high-resolution model able to represent the dynamics of the Mediterranean Sea. The ability of the model to reproduce the basic features of the observed climate in the Mediterranean region and the beneficial effects of both atmospheric improved resolution and interactive Mediterranean Sea are assessed. In particular, the major characteristics of the variability in the Mediterranean basin and its connection with the large-scale circulation are investigated. Furthermore, the mechanisms through which global warming might affect the regional features of the climate are explored, focusing especially on the characteristics of the hydrological cycle