Comprehensive analysis of the simplest curvaton model

We carry out a comprehensive analysis of the simplest curvaton model, which is based on two non-interacting massive fields. Our analysis encompasses cases where the inflaton and curvaton both contribute to observable perturbations, and where the curvaton itself drives a second period of in inflation. We consider both power spectrum and non-Gaussianity observables, and focus on presenting constraints in model parameter space. The fully curvaton-dominated regime is in some tension with observational data, while an admixture of inflaton-generated perturbations improves the fit. The inflating curvaton regime mimics the predictions of Nflation. Some parts of parameter space permitted by power spectrum data are excluded by non-Gaussianity constraints. The recent BICEP2 results [1] require that the in inflaton perturbations provide a significant fraction of the total perturbation, ruling out the usual curvaton scenario in which the inflaton perturbations are negligible, though not the admixture regime where both inflaton and curvaton contribute to the spectrum

Non-coding RNAs in saliva: emerging biomarkers for molecular diagnostics.

Saliva is a complex body fluid that comprises secretions from the major and minor salivary glands, which are extensively supplied by blood. Therefore, molecules such as proteins, DNA, RNA, etc., present in plasma could be also present in saliva. Many studies have reported that saliva body fluid can be useful for discriminating several oral diseases, but also systemic diseases including cancer. Most of these studies revealed messenger RNA (mRNA) and proteomic biomarker signatures rather than specific non-coding RNA (ncRNA) profiles. NcRNAs are emerging as new regulators of diverse biological functions, playing an important role in oncogenesis and tumor progression. Indeed, the small size of these molecules makes them very stable in different body fluids and not as susceptible as mRNAs to degradation by ribonucleases (RNases). Therefore, the development of a non-invasive salivary test, based on ncRNAs profiles, could have a significant applicability to clinical practice, not only by reducing the cost of the health system, but also by benefitting the patient. Here, we summarize the current status and clinical implications of the ncRNAs present in human saliva as a source of biological information

Generalized Attractor Points in Gauged Supergravity

The attractor mechanism governs the near-horizon geometry of extremal black holes in ungauged 4D N=2 supergravity theories and in Calabi-Yau compactifications of string theory. In this paper, we study a natural generalization of this mechanism to solutions of arbitrary 4D N=2 gauged supergravities. We define generalized attractor points as solutions of an ansatz which reduces the Einstein, gauge field, and scalar equations of motion to algebraic equations. The simplest generalized attractor geometries are characterized by non-vanishing constant anholonomy coefficients in an orthonormal frame. Basic examples include Lifshitz and Schrodinger solutions, as well as AdS and dS vacua. There is a generalized attractor potential whose critical points are the attractor points, and its extremization explains the algebraic nature of the equations governing both supersymmetric and non-supersymmetric attractors.Comment: 31 pages, LaTeX; v2, references fixed; v3, minor changes, version to appear in Phys. Rev.

A Role for the Lipid Droplet Protein HIG2 in Promoting Lipid Deposition in Liver and Adipose Tissue: A Dissertation

Chronic exposure of humans or rodents to high calorie diets leads to hypertriglyceridemia and ectopic lipid deposition throughout the body, resulting in metabolic disease. Cellular lipids are stored in organelles termed lipid droplets (LDs) that are regulated by tissue-specific LD proteins. These proteins are critical for lipid homeostasis, as humans with LD protein mutations manifest metabolic dysfunction. Identification of novel components of the LD machinery could shed light on human disease mechanisms and suggest potential therapeutics for Type 2 Diabetes. Microarray analyses pinpointed the largely unstudied Hypoxia-Inducible Gene 2 (Hig2) as a gene that was highly expressed in obese human adipocytes. Imaging studies demonstrated that Hig2 localized to LDs in mouse hepatocytes and the human SGBS adipocyte cell line. Thus, this work examined the role of Hig2 as a LD protein in liver and adipose tissue. Hig2 deficiency reduced triglyceride deposition in hepatocytes; conversely, ectopic Hig2 expression promoted lipid deposition. Furthermore, liver-specific Hig2-deficient mice displayed improved glucose tolerance and reduced liver triglyceride content. Hig2 deficiency increased lipolysis and -oxidation, accounting for the reduced triglyceride accumulation. Similarly, adipocyte-specific Hig2-deficient mice displayed improved glucose tolerance, reduced adipose tissue weight and brown adipose tissue that was largely cleared of lipids. These improvements were abrogated when the animals were placed in thermoneutral housing and brown adipocyte-specific Hig2-deficient mice also displayed improved glucose tolerance, suggesting that active brown fat largely mediates the metabolic phenotype of Hig2 deletion. Thus, this work demonstrates that Hig2 localizes to LDs in liver and adipose tissue and promotes glucose intolerance

Detecting cells with low RNA content colonizing artworks non-invasively: RNA-FISH

Various non-invasive RNA-FISH methodologies were tested in this work. They seem to be good alternatives for analyzing the potential biodeteriogenic microorganisms thriving in CH objects.This work was co- financed by FCT Fundação para a Ciência e a Tecnologia through the project "MICROTECH-ART- Microorganisms Thriving on and Endamaging Cultural Heritage -an Analytical Rapid Tool-" (PTDC/BBB-IMG/0046/2014) and by European Union, European Regional Development Fund ALENTEJO 2020 through the project HIT3CH - HERCULES Interface for Technology Transfer and Teaming in Cultural Heritage (ALT20-03-0246-FEDER-000004). Marina González-Pérez acknowledges FCT for the economic support through the post-doctoral grant SFRH/BPD/100754/2014

Global Optimization: Software and Applications

Mathematical models are a gateway into both theoretical and experimental understand- ing. However, sometimes these models need certain parameters to be established in order to obtain the optimal behaviour or value. This is done by using an optimization method that obtains certain parameters for optimal behaviour, as described by an objective function that may be a minimum (or maximum) result. Global optimization is a branch of optimization that takes a model and determines the global minimum for a given domain. Global opti- mization can become extremely challenging when the domain yields multiple local minima. Moreover, the complexity of the mathematical model and the consequent lengths of calcu- lations tend to increase the amount of time required for the solver to find the solution. To address these challenges, two software packages were developed to aid a solver in optimizing a black box objective function. The first software package is called Computefarm, a distributed local-resource computing software package that parallelizes the iteration step of a solver by distributing objective function evaluations to idle computers. The second software package is an Optimization Database that is used to monitor the global optimization process by storing information on the objective function evaluation and any extra information on the objective function. The Optimization Database is also used to prevent data from being lost during a failure in the optimization process. In this thesis, both Computefarm and the Optimization Database are used in the context of two particular applications. The first application is quantum error correction gate design. Quantum computers cannot rely on software to correct errors because of the quantum me- chanical properties that allow non-deterministic behaviour in the quantum bit. This means the quantum bits can change states between (0, 1) at any point in time. There are various ways to stabilize the quantum bits; however, errors in the system of quantum bits and the sys- tem to measure the states can occur. Therefore, error correction gates are designed to correct for these different types of errors to ensure a high fidelity in the overall circuit. A simulation of a quantum error correction gate is used to determine the properties of components needed to correct for errors in the circuit of the qubit system. The gate designs for the three-qubit and four-qubit systems are obtained by solving a feasibility problem for the intrinsic fidelity ii(error-correction percentage) to be above the prescribed 99.99% threshold. The Optimization Database is used with the MATLAB ’s Global Search algorithm to obtain the results for the three-qubit and four-qubit systems. The approach used in this thesis yields a faster high- fidelity (≤ 99.99%) three-qubit gate time than obtained previously, and obtained a solution for a fast high-fidelity four-qubit gate time. The second application is Rational Design of Materials, in which global optimization is used to find stable crystal structures of chemical compositions. To predict crystal structures, the enthalpy that determines the stability of the structure is minimized. The Optimization Database is used to store information on the obtained structure that is later used for identification of the crystal structure and Compute- farm is used to speed up the global optimization process. Ten crystal structures for carbon and five crystal structures for silicon-dioxide are obtained by using Global Convergence Par- ticle Swarm Optimization. The stable structures, graphite (carbon) and cristobalite (silicon dioxide), are obtained by using Global Convergence Particle Swarm Optimization. Achieving these results allows for further research on the stable and meta-stable crystal structures to understand various properties like hardness and thermal conductivity