Strong light-matter coupling: from traditional to cavity-free polaritons

Polaritons are formed when light and matter interact strongly. For this to occur, photons and transitions in a material must exchange energy faster than the dissipation rate of the interacting components. Polaritons have shown the ability to change such material properties as photophysics, chemical reaction rates, transport, etc. Most of the studies on strong coupling use an external cavity. These sort of platforms form what here are called traditional polaritons. Moreover, such a cavity is often made of two metallic mirrors, which restrict access to the material. The first part of the thesis is devoted to traditional polaritons in a microcavity-plasmon coupling platform. The versatility of the platform allows to achieve strong and ultrastrong coupling at room temperature. The second part is dedicated to cavity-free or self-hybridized polaritons. Here it is shown that polaritons can be sustained by the material with the transition resonance itself, by reshaping it into simple structures as slabs, cylinders, and spheres. The structures reveal a minimal critical size for polaritons to exist. Moreover, the coupling strength seems to be limited only by the macroscopic optical properties of the material. These results can guide the community to quickly realize which materials can be used to form polaritons and to find them in simpler structures. Since the structures are not restricted by an external cavity, a window of opportunity is open for applications and further studies on the impact of polaritons on material properties

The Political Incorporation of Latino Immigrants in California

This paper explores and analyzes the political incorporation of Latino immigrants in California over the last several decades. Political incorporation refers to the process through which immigrants and their descendants claim their political rights and exercise their voice in politics. In order to understand the impact of Latino immigration on California state politics, the paper first examines the demographic changes in the state. This paper then provides an overview of all of the major immigration legislation in California, beginning from the anti-immigration initiatives to the California Dream Act and immigration-friendly legislation that Governor Jerry Brown signed into law in 2013

Laccase-based technologies to remove organic pollutants from soils and wastewaters

Pollution of soil and water is an environmental issue worldwide. Thereby, the development and implementation of low-cost and eco-friendly treatments for the decontamination of polluted sites and wastewater is a priority. In this regard, the use of biological agents, as white rot fungi, to degrade and detoxify environmental contaminants has emerged as a potential alternative. These microorganisms have been reported to remove a wide range of xenobiotics by the action of the extracellular lignin-modifying enzymes, such as peroxidases and laccases. Laccases (copper-containing oxidases, EC 1.10.3.2) are promising biocatalysts due to their oxidative versatility and low catalytic requirements. Laccases, as well as laccase-mediator systems, have been successfully used to oxidatively detoxify and remove a great number of contaminants. The potential of laccase is explored in the current research aiming to develop continuous or semicontinuous technologies to remove pollutants of concern, such as Polycyclic Aromatic Hydrocarbons (PAHs) and Emerging Organic Contaminants (EOCs), from real environmental matrices. In the first section of the Thesis, the use of laccase is investigated to degrade PAHs. The natural biodegradation of these toxic pollutants is restricted by two major factors: low water solubility and high hydrophobicity, which make PAHs persistent pollutants in soil. Extraction with solvents or surfactants is an alternative to remove PAHs from soils. However, this technique by itself does not degrade the pollutants, but only attains their transfer to another phase. Enzymatic remediation with laccase may be a feasible alternative, but requires the addition of surfactants or solvents to increase the pollutant bioavailability for the enzymatic action. Initially, different reactor configurations (micellar, biphasic and the combination of both) were evaluated to perform the laccase-catalyzed degradation of anthracene, the model PAH. The use of a Two Phase Partitioning Bioreactor (TPPB) with silicone oil and the addition of surfactant in the aqueous phase allowed the enzymatic treatment of high loads of anthracene at fast conversion rate. Subsequently, the use of vegetable oils (sunflower or pomace olive oil) as organic phase in the TPPB was proposed to dissolve high concentrations of the target pollutant. Pomace olive oil led to the best results and after optimizing the operational conditions in the TPPB, a novel remediation process to remove anthracene from polluted soils was proposed. The process consisted of the extraction of anthracene from the soil by the oil followed by its degradation in a surfactant-assisted TPPB, operated with a laccase-mediator system. The main outcomes of this study showed high extraction efficiency for pomace olive oil and high removal rate of anthracene in the TPPB. Moreover, the feasibility of reusing both the aqueous and organic phases of the TPPB in successive batches of anthracene degradation in the reactor was also demonstrated. The second section of the Thesis focuses on the enzymatic removal of EOCs from aqueous systems. The industrial chemical bisphenol A and pharmaceuticals active compounds are examples of EOCs frequently detected in wastewaters, considered as the main source of EOCs entering the environment. The application of laccases in tertiary wastewater treatment requires the retention of the biocatalyst in the reactor. In the current research, two main approaches were considered to fulfill such requirement. On one hand, the use of an enzymatic membrane reactor with a ceramic membrane was considered to perform the continuous removal of BPA from secondary effluent by free laccase. The second approach consisted of the immobilization of laccase onto nanoparticles or magnetic microparticles, prior to its application to remove micropollutants from secondary effluents. Immobilization not only facilitated the retention of the biocatalyst in the system by a high pore size membrane or by applying an external magnetic field, but also increased laccase stability

Value-at-Risk and Tsallis statistics: risk analysis of the aerospace sector

In this study, we analyze the aerospace stocks prices in order to characterize the sector behavior. The data analyzed cover the period from January 1987 to April 1999. We present a new index for the aerospace sector and we investigate the statistical characteristics of this index. Our results show that this index is well described by Tsallis distribution. We explore this result and modify the standard Value-at-Risk (VaR), financial risk assessment methodology in order to reflect an asset which obeys Tsallis non-extensive statistics.Comment: 10 pages, 4 figures, 1 table, to appear in Physica

La probabilidad y la estadística en la construcción del pensamiento matemático del niño preescolar

Esta investigación, en curso y cualitativa, trata la introducción de nociones de probabilidad y de estadística en la educación preescolar mexicana, la comprensión de los niños de esas nociones resultante de su enseñanza y a qué otras de sus nociones matemáticas favorece el proceso. Sus referentes teóricos consideran las ideas fundamentales de estocásticos para el curriculum y el origen de la idea de azar en el niño; el cognitivo, el rol de la intuición en la adquisición de nociones de estocásticos; el social, el rol de la interacción en el aula en esa adquisición. Su primera fase examina la propuesta institucional para preescolar; la segunda, la docencia y su formación y, la tercera, la enseñanza de estocásticos en un aula con 25 niños de 3 a 4 años de edad y otra con 30 niños de 5 años. Los resultados indican que para la educación preescolar no se considera el valor formativo de su estudio, no obstante que los niños son sensibles a las ideas de azar y de probabilidad y que la docencia requiere formación en estocásticos

La formación docente de preescolar en estocásticos

Esta investigación se orienta, epistemológicamente, por las ideas fundamentales de estocásticos para el currículum (Heitele, 1975) y el origen de la idea de azar en el niño (Piaget e Inhelder, 1951); cognitivamente, por el rol de la intuición en las ideas de estocásticos (Fischbein, 1975); y socialmente por el papel de la interacción en el aula en la adquisición de nociones de probabilidad y de estadística (Steinbring, 1991). De forma cualitativa se caracterizó la comprensión de ideas de estocásticos de dos docentes en ejercicio y 25 en formación y su enseñanza en el aula real de preescolar, durante la impartición de un estudio dirigido a estocásticos para su enseñanza. De la experienciación desarrollada, de las bitácoras y de la aplicación de cuestionarios, resultó la necesidad de formar a la docencia en probabilidad y en estadística para desarraigar la prevalencia del determinismo en su enseñanza y posibilitar así la introducción de nociones de estocásticos como vía hacia la construcción del pensamiento matemático del niño preescolar

Cooperative approach to a location problem with agglomeration economies

This paper considers agglomeration economies. A new firm is planning to open a plant in a country divided into several regions. Each firm receives a positive externality if the new plant is located in its region. In a decentralized mechanism, the plant would be opened in the region where the new firm maximizes its individual benefit. Due to the externalities, it could be the case that the aggregated utility of all firms is maximized in a different region. Thus, the firms in the optimal region could transfer something to the new firm in order to incentivize it to open the plant in that region. We propose two rules that provide two different schemes for transfers between firms already located in the country and the newcomer. The first is based on cooperative game theory. This rule coincides with the nucleolus and the t-value of the associated cooperative game. The second is defined directly. We provide axiomatic characterizations for both rules. We characterize the core of the cooperative game. We prove that both rules belong to the core

The perspectives of men in Mexico City about vasectomy—Brief

On November 17, 2017, Mexico City took part in the global World Vasectomy Day campaign promoting men’s participation in family planning, especially through no-scalpel vasectomy (NSV). During the event the Population Council Mexico conducted an exploratory study to better understand the reasons men chose NSV, as well as their concerns before and after the procedure. The study found that the principal reason for seeking NSV among men surveyed was their achievement of a desired family size, for themselves and their partners. The study further reveals the need to disseminate information through mass media, social networks, and all levels of the health system about NSV as a permanent, simple, and cost-effective procedure with low rates of complications and minimal pain. The report recommends that health institutions integrate NSV information, counseling, referrals, and services, for expanded family planning options and perspectives, within the National Family Planning Program, and facilitate the monitoring and evaluation of men who undergo NSV at least six months after the procedure

Decisiones robustas en la producción agrícola para dos períodos : Primera aproximación a las estrategias adaptativas

La presentación se basará en el desarrollo y análisis de una Metodología de Decisiones Robustas con el propósito de ayudar a los productores agrícolas a decidir qué cultivos implantar para dos campañas de producción. El objetivo principal del trabajo es hacer una primera aproximación para agregar al planteo de Decisiones Robustas la posibilidad de evaluar y modificar las decisiones en escenarios que duren más de un período, logrando de esta manera elaborar planes a largo plazo. Asimismo, trabajar con estas Estrategias Adaptativas da la posibilidad de hacer correcciones en las decisiones de cultivo en base a los resultados obtenidos en períodos anteriores. Se presentará una primera aproximación del enfoque, con sus resultados preliminares.The presentation will review the development and analysis of a Robust Decisions Methodology in order to help farmers decide which crops introduce in two production campaigns. The main objective of this work is to make a first step to apply Adaptive Strategies into a Robust Decision Methodology. This will permit decision maker to assess and change decisions in scenarios that last more than one period in order to achieve long term planning goals. In addition, working with these adaptive strategies gives the opportunity to make corrections in planting decisions based on the results obtained in previous periods. We will present a first approach with its preliminary results.Sociedad Argentina de Informática e Investigación Operativa (SADIO