Evolutionary and demographic correlates of Pleistocene coastline changes in the Sicilian wall lizard Podarcis wagleriana

Aim Emergence of coastal lowlands during Pleistocene ice ages might have provided conditions for glacial expansions (demographic and spatial), rather than contraction, of coastal populations of temperate species. Here, we tested these predictions in the insular endemic Sicilian wall lizard Podarcis wagleriana. Location Sicily and neighbouring islands. Methods We sampled 179 individuals from 45 localities across the whole range of P. wagleriana. We investigated demographic and spatial variations through time using Bayesian coalescent models (Bayesian phylogeographic reconstruction, Extended Bayesian Skyline plots, Isolation‐with‐migration models) based on multilocus DNA sequence data. We used species distribution modelling to reconstruct present and past habitat suitability. Results We found two main lineages distributed in the east and west portions of the current species range and a third lineage restricted to a small area in the north of Sicily. Multiple lines of evidence from palaeogeographic (shorelines), palaeoclimatic (species distribution models), and multilocus genetic data (demographic and spatial Bayesian reconstructions) indicate that these lineages originated in distinct refugia, located in the north‐western and south‐eastern coastal lowlands, during Middle Pleistocene interglacial phases, and came into secondary contact following demographic and spatial expansions during the last glacial phase. Main conclusions This scenario of interglacial contraction and glacial expansion is in sharp contrast with patterns commonly observed in temperate species on the continent but parallels recent findings on other Mediterranean island endemics. Such a reverse expansion–contraction (EC) dynamic has been likely associated with glacial increases of climatically suitable coastal lowlands, suggesting this might be a general pattern in Mediterranean island species and also in other coastal regions strongly affected by glacial marine regressions during glacial episodes. This study provides explicit predictions and some methodological recommendations for testing the reverse EC model in other region and taxa

Nanorings driven by a laser field

We present the dynamics of an electron constrained over an 1D ring with radius of 0.142 nm driven by a laser field. The temporal evolution of the system is evaluated by a semi-analytical solution of the full quantum time dependent Schr¨odinger equation. In our calculation the gap energy between the ground and the first excited state of the nanoring is three times the photon energy laser (0.63 eV) and the laser intensity is 4·1014 W/cm2 . Our analysis is performed by considering different polarization states of the incident laser. Our attention is mainly focused on the study of the High Harmonic Generation (HHG), the energy and the angular momentum absorbed by the driven system. We observe 1) that the harmonic yield is strongly dependent upon the pump polarization field and almost vanishes for circular polarization and 2) that the ring can be left in a state with average angular momentum different than zero. In figure we show the time average of the absorbed angular momentum (in atomic units) versus polarization angle (θ = 0◦ and θ = 90◦ correspond to linear polarization along x and y axes respectively; θ = 45◦ corresponds to circular polarization)

Angular harmonic dependence from a 3D-H2+ Molecular Ion

The time-dependent Schroedinger equation of a H2+ molecular ion in the presence of a linearly polarized laser field is numerically solved by means of a split-operator parallel code. The electron, driven by the laser electric field, emits electromagnetic radiation whose HHG spectrum (shown in Figure 1) can be finely controlled by changing the angle between the laser electric field and the molecular axis. The numerical results confirm that the structure of the spectra strongly depends on this angle. In particular the correlation between the laser orientation (with respect to the molecular axis) and the intensity of various harmonic peaks are displayed in Figure 2

Laser induced ultrafast H2+ dinamic and attosecond generation

We examine the possibility that a H2+ molecular ion driven by a linearly polarized laser field can be considered as a source of attosecond pulses. The emisseion is investigated taking into account the role of the internuclear distance and by changing the angle between the laser field and the molecular axis. We find that the attosecond pulses emission happens when the electron cloud is over one nucleus; on the contrary, when the elctron is travelling between the two nuclei the attosecond emission do not take place

Ichthyosis Linearis Circumflexa as the Only Clinical Manifestation of Netherton Syndrome.

Ichthyosis linearis circumflexa (ILC) presents as serpiginous and migratory erythematous patches with double-edged scales. ILC is rarely an isolated skin manifestation, but most commonly a part of Netherton syndrome (NS). NS is caused by SPINK5 mutations, which lead to absent or sometimes reduced expression of the serine protease inhibitor LEKTI. NS is characterised by congenital ichthyosiform erytroderma, trichorrhexis invaginata (TI) and atopy. We report 2 children who presented since the first months of life cheek erythema followed by the appearance of sparse ILC lesions on the face, trunk and proximal extremities. Erythroderma at birth, TI and atopy were absent. LEKTI immunoreactivity was reduced in patient epidermis, and serine protease activity was modestly increased, while desmoglein-1 expression remained unaffected. SPINK5 mutation and expression analysis in patient keratinocytes revealed compound heterozygous splicing variants, which allowed residual LEKTI secretion. Our results show that ILC can be the only clinical manifestation of NS

Hypoxia and Human Genome Stability: Downregulation of BRCA2 Expression in Breast Cancer Cell Lines

Previously, it has been reported that hypoxia causes increased mutagenesis and alteration in DNA repair mechanisms. In 2005, an interesting study showed that hypoxia-induced decreases in BRCA1 expression and the consequent suppression of homologous recombination may lead to genetic instability. However, nothing is yet known about the involvement of BRCA2 in hypoxic conditions in breast cancer. Initially, a cell proliferation assay allowed us to hypothesize that hypoxia could negatively regulate the breast cancer cell growth in short term in vitro studies. Subsequently, we analyzed gene expression in breast cancer cell lines exposed to hypoxic condition by microarray analysis. Interestingly, genes involved in DNA damage repair pathways such as mismatch repair, nucleotide excision repair, nonhomologous end-joining and homologous recombination repair were downregulated. In particular, we focused on the BRCA2 downregulation which was confirmed at mRNA and protein level. In addition, breast cancer cells were treated with dimethyloxalylglycine (DMOG), a cell-permeable inhibitor of both proline and asparaginyl hydroxylases able to induce HIF-1α stabilization in normoxia, providing results comparable to those previously described. These findings may provide new insights into the mechanisms underlying genetic instability mediated by hypoxia and BRCA involvement in sporadic breast cancers

Family Burden in Epidermolysis Bullosa is High Independent of Disease Type/Subtype

Epidermolysis bullosa is a rare, inherited group of disorders characterized by blistering of the skin following friction or mechanical trauma. The aim of this study was to assess the family burden of epidermolysis bullosa in children aged 0-7 years. A postal survey was conducted. The perceived severity of the disease was evaluated by the caregivers, using the Patient Global Assessment 5-point scale. The caregiver received the Family Strain Questionnaire and the 12-item General Health Questionnaire to assess the probable presence of depression/anxiety. A single-item analysis was also performed for questions related to the burden of disease. Forty-two families were invited to participate. Data from 28 young patients and their caregivers were analysed (response rate 66.7%). The family burden increased with increasing caregiver's perceived disease severity, with increasing patient's body surface involved, and if parents had depression/anxiety, reaching statistical significance in several Family Strain Questionnaire scales. The family burden due to epidermolysis bullosa is very high independent of disease type/subtype

Compound Heterozygosity for a Recessive Glycine Substitution and a Splice Site Mutation in the COL7A1 Gene Causes an Unusually Mild Form of Localized Recessive Dystrophic Epidermolysis Bullosa

Type VII collagen is the major component of anchoring fibrils, adhesion structures of stratified epithelia that span the basement membrane region and papillary dermis. Mutations in the gene COL7A1 encoding type VII collagen cause dystrophic epidermolysis bullosa, a clinically heterogeneous autosomal dominant or recessive blistering disorder of the skin and mucous membranes. In this report, we investigate three siblings affected by an unusually mild form of localized recessive dystrophic epidermolysis bullosa who were shown to be compound heterozygotes for novel mutations affecting COL7A1. The maternally inherited mutation is a G→C transversion that converts a codon for glycine to a codon for arginine (G1347R). The paternal mutation is a neutral G→A transition at the last base of exon 70 (5820G→A) that alters the correct splicing of COL7A1 pre-mRNA, giving rise to an aberrant mRNA carrying the in-frame skipping of exon 70 in addition to the full-length RNA transcript carrying the G→A substitution. Consistent with the normal levels of COL7A1 mRNA transcripts detected by northern analysis, immunoblotting and immunofluorescence studies evidenced that the patient keratinocytes synthesize and secrete normal amounts of stable type VII collagen, which is correctly deposited at the dermal–epidermal junction. In addition, mutated type VII collagen molecules assemble to form numerous, normally shaped anchoring fibrils, as shown by electron microscopic examination. The combination of a recessive glycine substitution with a splice site mutation that permits partially correct splicing therefore leads to a normal expression of mutated type VII collagen molecules with marginally altered biologic activity, and to the extremely mild phenotype observed in our patients

Lipoid Proteinosis: A Previously Unrecognized Mutation and Therapeutic Response to Acitretin.

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