Ideal Family Size and Fertility in Egypt: An Overview of Recent Trends

Egypt is already the most populous Arab country in the world with 93 million citizens in 2016 which may grow to about 120 million by 2030 if the same level of fertility continues. This paper aims to offer an overview of the evolution over time of the ideal number of children in Egypt, assessing previous researches and giving a particular emphasis on most recent data on such topic. In a context of raising fertility, whose causes are still unknown, we test the persistence of a high ideal number of children among younger cohorts

Failure of conductance quantization in two-dimensional topological insulators due to non-magnetic impurities

Despite topological protection and the absence of magnetic impurities, two-dimensional topological insulators display quantized conductance only in surprisingly short channels, which can be as short as 100 nm for atomically thin materials. We show that the combined action of short-range nonmagnetic impurities located near the edges and on site electron-electron interactions effectively creates noncollinear magnetic scatterers, and, hence, results in strong backscattering. The mechanism causes deviations from quantization even at zero temperature and for a modest strength of electron-electron interactions. Our theory provides a straightforward conceptual framework to explain experimental results, especially those in atomically thin crystals, plagued with short-range edge disorder.Comment: 8 pages, 9 figures, 5 appendice

Studies and projects for the archaeological park of the Nuraghe s’Urachi (Sardinia, Italy). From knowledge for heritage conservation to project for the community

This piece of research regards the archaeological area of the Nuraghe s'Urachi in San Vero Milis (OR- Sardinia, Italy). The site is probably one of the most significant and complex testimonies of the so-called "Nuragic civilization" in Sardinia (18th–11th century BC). Among the approximately eight thou-sand currently surviving "nuraghi”, the s'Urachi complex stands out for its pivotal role in the vast and important network of territorial relations that characterized central-western Sardinia during the Archaic period. Its crucial role in terms of its political, economic, social, and military importance is displayed by its considerable size. Today only seven of the ten perimetral towers are still visible, and of the cen-tral tower — originally over twenty-five meters high — only the base remains. However, from an ar-chaeological point of view, the Nuraghe still constitutes one of the most interesting artifacts of the re-gion. As part of a renewed collective interest in Nuragic sites, the area of the excavations of s'Urachi is a candidate to host a new archaeological park whose formal and organizational characters are still to be defined (section 1.1). In August 2021, a workshop was organized and promoted as part of Accademia Adrianea in Rome Master's degree program on Architecture and Archaeology. The workshop focused on the site to envision four possible scenarios (section 2.1) for implementing and stimulating the preserva-tion and conservation processes, as well as to enhance the archaeological area in accord with the munic-ipal administration and the local community. The process of rediscovery, participation, sharing, and fi-nal "reappropriation" of this heritage's tangible and intangible value represents one of the fundamental objectives this article intends to outline

Studies and projects for the archaeological park of the Nuraghe s’Urachi (Sardinia, Italy). From knowledge for heritage conservation to project for the community

[EN] This piece of research regards the archaeological area of ​​the Nuraghe s'Urachi in San Vero Milis (OR- Sardinia, Italy). The site is probably one of the most significant and complex testimonies of the so-called "Nuragic civilization" in Sardinia (18th–11th century BC). Among the approximately eight thousand currently surviving "nuraghi”, the s'Urachi complex stands out for its pivotal role in the vast and important network of territorial relations that characterized central-western Sardinia during the Archaic period. Its crucial role in terms of its political, economic, social, and military importance is displayed by its considerable size. Today only seven of the ten perimetral towers are still visible, and of the central tower — originally over twenty-five meters high — only the base remains. However, from an archaeological point of view, the Nuraghe still constitutes one of the most interesting artifacts of the region. As part of a renewed collective interest in Nuragic sites, the area of ​​the excavations of s'Urachi is a candidate to host a new archaeological park whose formal and organizational characters are still to be defined (section 1.1). In August 2021, a workshop was organized and promoted as part of Accademia Adrianea in Rome Master's degree program on Architecture and Archaeology. The workshop focused on the site to envision four possible scenarios (section 2.1) for implementing and stimulating the preservation and conservation processes, as well as to enhance the archaeological area in accord with the municipal administration and the local community. The process of rediscovery, participation, sharing, and final "reappropriation" of this heritage's tangible and intangible value represents one of the fundamental objectives this article intends to outline.Chiri, GM.; Novelli, F. (2022). Studies and projects for the archaeological park of the Nuraghe s’Urachi (Sardinia, Italy). From knowledge for heritage conservation to project for the community. Editorial Universitat Politècnica de València. 823-830. https://doi.org/10.4995/HERITAGE2022.2022.1567482383

Optical and plasmonic properties of twisted bilayer graphene: Impact of interlayer tunneling asymmetry and ground-state charge inhomogeneity

We present a theoretical study of the local optical conductivity, plasmon spectra, and thermoelectric properties of twisted bilayer graphene (TBG) at different filling factors and twist angles $\theta$. Our calculations are based on the electronic band structures obtained from a continuum model that has two tunable parameters, $u_0$ and $u_1$, which parametrize the intra-sublattice inter-layer and inter-sublattice inter-layer tunneling rate, respectively. In this Article we focus on two key aspects: i) we study the dependence of our results on the value of $u_0$, exploring the whole range $0\leq u_0\leq u_1$; ii) we take into account effects arising from the intrinsic charge density inhomogeneity present in TBG, by calculating the band structures within the self-consistent Hartree approximation. At zero filling factor, i.e. at the charge neutrality point, the optical conductivity is quite sensitive to the value of $u_0$ and twist angle, whereas the charge inhomogeneity brings about only modest corrections. On the other hand, away from zero filling, static screening dominates and the optical conductivity is appreciably affected by the charge inhomogeneity, the largest effects being seen on the intra-band contribution to it. These findings are also reflected by the plasmonic spectra. We compare our results with existing ones in the literature, where effects i) and ii) above have not been studied systematically. As natural byproducts of our calculations, we obtain the Drude weight and Seebeck coefficient. The former displays an enhanced particle-hole asymmetry stemming from the inhomogeneous ground-state charge distribution. The latter is shown to display a broad sign-changing feature even at low temperatures ($\approx 5~{\rm K}$) due to the reduced slope of the bands, as compared to those of single-layer graphene.Comment: 28 pages, 16 figures, 6 appendice

A simple solution to the inadequacy of asymptotic likelihood-based inference for response-adaptive clinical trials

The present paper discusses drawbacks and limitations of likelihood-based inference in sequential clinical trials for treatment comparisons managed viaResponse-Adaptive Randomization. Taking into account the most common statistical models for the primary outcome—namely binary, Poisson, exponential and normal data—we derive the conditions under which (i) the classical confidence intervals degenerate and (ii) the Wald test becomes inconsistent and strongly affected by the nuisance parameters, also displaying a non monotonic power. To overcome these drawbacks, we provide a very simple solution that could preserve the fundamental properties of likelihood-based inference. Several illustrative examples and simulation studies are presented in order to confirm the relevance of our results and provide some practical recommendations

Simulated annealing for balancing covariates

Covariate balance is one of the fundamental issues in designing experiments for treatment comparisons, especially in randomized clinical trials. In this article, we introduce a new class of covariate-adaptive procedures based on the Simulated Annealing algorithm aimed at balancing the allocations of two competing treatments across a set of pre-specified covariates. Due to the nature of the simulated annealing, these designs are intrinsically randomized, thus completely unpredictable, and very flexible: they can manage both quantitative and qualitative factors and be implemented in a static version as well as sequentially. The properties of the suggested proposal are described, showing a significant improvement in terms of covariate balance and inferential accuracy with respect to all the other procedures proposed in the literature. An illustrative example based on real data is also discussed

Statistical Inference in Open Quantum Systems

This thesis concerns the statistical analysis of open quantum systems subject to an external and non-stationary perturbation. In the first paper, a generalization of the explicit-duration hidden Markov models (EDHMM) which takes into account the presence of sparse data is presented. Introducing a kernel estimator in the estimation procedure increases the accuracy of the estimates, and thus allows one to obtain a more reliable information about the evolution of the unobservable system. A generalization of the Viterbi algorithm to EDHMM is developed. In the second paper, we develop a Markov Chain Monte Carlo (MCMC) procedure for estimating the EDHMM. We improve the flexibility of our formulation by adopting a Bayesian model selection procedure which allows one to avoid a direct specification of the number of states of the hidden chain. Motivated by the presence of sparsity, we make use of a non-parametric estimator to obtain more accurate estimates of the model parameters. The formulation presented turns out to be straightforward to implement, robust against the underflow problem and provides accurate estimates of the parameters. In the third paper, an extension of the Cramér-Rao inequality for quantum discrete parameter models is derived. The latter are models in which the parameter space is restricted to a finite set of points. In some estimation problems indeed, theory provides us with additional information that allow us to restrict the parameter space to a finite set of points. The extension presented sets the ultimate accuracy of an estimator, and determines a discrete counterpart of the quantum Fisher information. This is particularly useful in many experiments in which the parameters can assume only few different values: for example, the direction which the magnetic field points to. We also provide an illustration related to a quantum optics problem