Control of conditional pattern with polarization entanglement

Conditional interference patterns can be obtained with twin photons from spontaneous parametric down-conversion and the phase of the pattern can be controlled by the relative transverse position of the signal and idler detectors. Using a configuration that produces entangled photons in both polarization and transverse momentum we report on the control of the conditional patterns by acting on the polarization degree of freedom.Comment: Submitted for publication in Optics Communication

Density results for Sobolev, Besov and Triebel--Lizorkin spaces on rough sets

We investigate two density questions for Sobolev, Besov and Triebel--Lizorkin spaces on rough sets. Our main results, stated in the simplest Sobolev space setting, are that: (i) for an open set $\Omega\subset\mathbb R^n$, $\mathcal{D}(\Omega)$ is dense in $\{u\in H^s(\mathbb R^n):{\rm supp}\, u\subset \overline{\Omega}\}$ whenever $\partial\Omega$ has zero Lebesgue measure and $\Omega$ is "thick" (in the sense of Triebel); and (ii) for a $d$-set $\Gamma\subset\mathbb R^n$ ($0<d<n$), $\{u\in H^{s_1}(\mathbb R^n):{\rm supp}\, u\subset \Gamma\}$ is dense in $\{u\in H^{s_2}(\mathbb R^n):{\rm supp}\, u\subset \Gamma\}$ whenever $-\frac{n-d}{2}-m-1<s_{2}\leq s_{1}<-\frac{n-d}{2}-m$ for some $m\in\mathbb N_0$. For (ii), we provide concrete examples, for any $m\in\mathbb N_0$, where density fails when $s_1$ and $s_2$ are on opposite sides of $-\frac{n-d}{2}-m$. The results (i) and (ii) are related in a number of ways, including via their connection to the question of whether $\{u\in H^s(\mathbb R^n):{\rm supp}\, u\subset \Gamma\}=\{0\}$ for a given closed set $\Gamma\subset\mathbb R^n$ and $s\in \mathbb R$. They also both arise naturally in the study of boundary integral equation formulations of acoustic wave scattering by fractal screens. We additionally provide analogous results in the more general setting of Besov and Triebel--Lizorkin spaces.Comment: 38 pages, 6 figure

Microcredentials

Describing Life Long Learning implementation at Universidade Aberta across the years and the recent implementation of Microcredentials.N/

Socialização Política na Escola Secundária Portuguesa: as composições entre o projeto estatal imaginado de Cidadania e as gramáticas políticas disponíveis

Com o propósito de compreender o renovado interesse pela socialização política nos contextos europeu e português, procurámos reconhecer os dispositivos e referências nos quais os actores sociais se suportam para perfazer as suas avaliações e julgamentos críticos quanto às formas de melhor educar as crianças em sociedade tendo em conta os interesses do bem comum. Estes julgamentos, não são arbitrários ou relativizantes, mas manifestam a observância de um determinado requisito de obrigações (convenções), para assim se poderem apresentar publicamente como legítimos. Como tal, eles organizam-se em gramáticas de socialização política, as quais são também o produto da elaboração teórica de filósofos e educadores

Confined Placental Mosaicism in Chorionic Vilus Sampling - Case Report

Objectives: Chorionic Vilus Sampling (CVS) has several advantages over amniocentesis: it may be performed at an earlier gestational age, the results are quicker to obtain and there’s a lower miscarriage risk – 1%. However, the higher prevalence of discrepant fetal and vilus sampling material’s karyotype findings is a disadvantage of this technique – 0.5%. This is caused, amongst other causes, by placental mosaicism which consists of two genetically different cell lines. There are three types of placental mosaicism according to the abnormal cell line location: Type I – in the cytotrophoblast; Type II – in the vilus’ stroma; Type III – in both the above locations. Material and Methods: We present a case report about a 36-year-old pregnant woman going through our Department’s 1st trimester combined screening program; a CVS was performed, which showed Confined Placental Mosaicism (CPM). Results and Conclusion: Although the pregnant woman was in the low-risk group for aneuploidy, the patient wanted the cytogenetic study to be performed in order to reduce maternal anxiety. CVS was performed at the gestational age of 12 weeks + 5 days and the karyotype was 47XY+2/46XY. For the correct interpretation of this data an amniocentesis was performed at the gestational age of 15 weeks + 6 days, which showed a 46XY karyotype. We therefore conclude that the cytogenetic analysis of the CVS was the result of a CPM. A careful follow-up including fetal echocardiogram and seriated ultrasonographic monitoring was used to safely exclude malformations and fetal growth restriction. We verified no occurences throughout pregnancy, delivery and perinatal period. CVS practice was recently implemented in our country and has many advantages over amniocentesis. Besides the fact that an earlier gestational age usually means less affective bonding to the fetus and therefore makes medical termination of pregnancy somewhat less difficult, one should consider specific situations like the one reported in which CPM may be diagnosed. This condition is associated with increased risk of fetal growth restriction, so the clinician should be aware of the need for a more careful follow-up, since perinatal complications, which should be anticipated and treated, can be expected in 16-21% of these cases

Stratigraphy and sequence correlations in the Lower Cretaceous around Lisbon

The cliffs along the Atlantic coast near Lisbon—between Cascais and Guincho Beach, near Ericeira, and north of Cape Espichel—exhibit perfectly preserved Lower Cretaceous formations, with a large variety of sedimentary deposits (siliciclastics and carbonates) and recorded environments (from open distal platform to fluvial systems and palaeosols). These exposures allow the stratal, sedimentological, palaeontological, mineralogical, and geochemical patterns of depositional sequences during the Valanginian–Albian to be analyzed. The series representing the deepest marine environments are found in the vicinity of Cascais, with deposits in more proximal positions being observed both northwards (the Ericeira area) and southwards (Cape Espichel). The cyclic variations in sea level at the second-order scale record the tectonic events linked to the initial episodes of the northward propagation of the opening of the Atlantic. The sea-level changes observed at the third-order scale are registered by transgressive and highstand systems tracts. Lowstand systems tracts are very scarce in these shallow environments.publishersversionpublishe