Change in Arctic Sea Ice Over the Past 50 years

Arctic sea ice plays a critical role in maintaining the earth’s water cycle, regulating the temperature of the planet, and providing habitat for a variety of wildlife species. Because of climate change and other human disturbances, this valuable resource has been declining at disturbing rates over the past few years. The hypothesis for this study is that Arctic sea ice has declined over the past over the past 50 years. For this study data was collected from Statista: the minimum arctic sea ice extent 2007- 2022 and the maximum arctic sea ice extent 1979-2022. Then a scatterplot was created for each data set and tested with a t-test of slope, specifically a linear regression. The results are that there was no significant decrease in the minimum amount of ice through 2007-2022. However, there was a significant decrease in the maximum amount of ice through 1979-2022. In summary the hypothesis was supported because the linear regression t-test for each graph show a significant change in the maximum amount of ice, over a longer period of time. Accordingly, this study has helped by showing how responsive and vulnerable the ice is to climate change effects

International Trade Patterns over the Last Four Decades: How does Portugal Compare with other Cohesion Countries?

This paper compares the international trade pattern of Portugal with the other three EU15 Cohesion countries - Spain, Greece and Ireland - over the last forty years. The paper adopts a fact-finding approach, investigating the degree of openness of these economies and making extensive use of the standard Balassa (1965) index to assess the technological content of these countries' manufacturing trade. In order to infer on international trade specialization and on the persistence of trade patterns, the paper provides empirical evidence on the shape of the cross-sector distribution of 120 manufacturing exports and examines the intra-distribution dynamics. The Balassa index is also computed using import data, which allows for an assessment on the similitude of relative import structures and a crude identification of major vertical specialization activities. The paper concludes that there was a significant increase in the degree of openness of all economies, particularly in Ireland. Over the last four decades, Portugal shows a tendency to reduce its overall extent of export specialization, but significant differences with the world average still remain. The same behaviour is found in Greece and, more strongly, in Spain, which is the least specialized country. Conversely, Ireland shows the strongest export specialization and there is evidence of an increase in the last twenty years. The overall degree of specialization is higher on the export than on the import side, as the four countries analyzed show an import structure very close to the world average in the 2000-04 period. In the Portuguese case, we also find evidence that the degree of persistence of export patterns is higher than that of imports, in particular over longer horizons.

Relative Export Structures and Vertical Specialization: A Simple Cross-Country Index

Relative export structures have changed substantially over the last forty years. We map these changes using a new cross-country specialization index - the B* -, defined as the export weight of a given product on total domestic exports, “normalized” by the average weight across all countries of the world. This indicator is close to the Revealed Comparative Advantage index suggested in Balassa (1965); it has been used as an intermediate calculation in some papers but it has never been highlighted or interpreted as an alternative index in its own right. We provide empirical evidence on the shape of the distribution of the B* for different technological sectors (high, medium-high, medium-low and low-technology sectors), how it has evolved through time and how its intra-distribution dynamics behave. The results indicate a relatively important degree of persistence, although the cross-country specialization distributions depict substantial differences as we move up the technology ladder. Special attention is given to the G5 countries and China. These economies are relatively more specialized in high-tech and medium high-tech products. China shows a striking increase in specialization in high-tech products and a substantial decrease in low-tech. Finally, by computing the B* for both exports and imports, we have identified countries with significant vertical specialization activities. These activities are predominant in high-tech industries and seem to be geographically concentrated in East-Asia.

Study of Confinement and Catalysis Effects of the Reaction of Methylation of Benzene by Methanol in H-Beta and H-ZSM-5 Zeolites by Topological Analysis of Electron Density

In this work we studied the host-guest interactions between confined molecules and zeolites and their relationship with the energies involved in the reaction of methylation of benzene by methanol in H-ZSM-5 and H-Beta zeolites employing density functional theory (DFT) methods and the quantum theory of atoms in molecules. Results show that the strength of the interactions related to adsorption and coadsorption processes is higher in the catalyst with the larger cavity; however, the confinement effects are higher in the smaller zeolite, explaining, from an electronic viewpoint, the reason why the stabilization energy is higher in H-ZSM-5 than in H-Beta. The confinement effects of the catalyst on the confined species for methanol adsorption, benzene coadsorption, and the formed intermediates dominate this stabilization. For the transition state (TS), the stability of the TS is achieved due to the stabilizing effect of the surrounding zeolite framework on the formed carbocationic species (CH3+) which is higher in H-ZSM-5 than in H-Beta. In both TSs the methyl cation is multicoordinated forming the following H2O···CH3+···CB concerted bonds. It is demonstrated that, through the electron density analysis, the criteria can be defined to discriminate between interactions related to the confinement effects and the reaction itself (adsorption, coadsorption, and bond-breaking and bond-forming processes) and, thus, to discriminate the relative contributions of the degree of confinement to the reaction energies for two zeolite catalysts with different topologies.Fil: Zalazar, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Paredes, Esteban Nadal. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Química. Laboratorio de Estructura Molecular y Propiedades; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Romero, Gonzalo David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Química. Laboratorio de Estructura Molecular y Propiedades; ArgentinaFil: Cabral, Néstor Damián. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Química. Laboratorio de Estructura Molecular y Propiedades; ArgentinaFil: Peruchena, Nelida Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin

Selective peace : decentralization of crime after the implementation of the UPP policy

El crimen es un problema complejo de naturaleza social, política y económica que resulta del desorden de las relaciones sociales en el territorio. Para reducir su impacto, el gobierno estatal de Río de Janeiro implementó la política de seguridad pública de la Unidad de Policía Pacificadora (UPP) en 2008. Las UPPs apuntan a resumir los territorios dominados por el tráfico de drogas, asegurando la proximidad entre Estado y población a través de la entrada de la policía y los programas sociales del estado de Río de Janeiro en estas áreas. Sin embargo, se argumenta que la política no tenía el alcance de todo el estado de Río de Janeiro, solo se implementaba en algunos territorios dominados por el narcotráfico. Por lo tanto, verificase, cuáles fueron los parámetros de decisión de los territorios que recibieron la política de las UPPs y si causó efectos secundarios o migraciones de delitos a otros territorios del estado. Para observar esto, se analizará la variación de las tasas de homicidios en las ciudades de Río de Janeiro después y antes del Programa UPP utilizando las herramientas de Análisis Espacial de Datos Exploratorios (ESDA). De hecho, hay evidencias de la existencia de migración criminal entre los municipios en el estado de Río de Janeiro.Crime is a complex social, political, and economic problem that results from the disorder of social relations in the territory. To reduce its impact, the state government of Río de Janeiro implemented the public security policy of the Pacifying Police Unit (UPP) in 2008. The UPP aims at reducing the territories dominated by drug trafficking and ensuring the proximity between State and population through the entrance of the police and state social programmes in these areas. However, it is argued that the policy did not reach the entire state of Rio de Janeiro, but it was implemented in some territories dominated by drug trafficking. Therefore, the parameters of decision of the territories in which the policy of the UPP was applied and possible side effects or migrations of crimes to other territories of the state have to be verified. To observe this, it will be analyzed the variation of homicide rates in the cities of Rio de Janeiro after and before the UPP Program using the Exploratory Spatial Data Analysis (ESDA) tools. In fact, there is evidence of the existence of criminal migration among municipalities in the state of Río de Janeiro.Fil: Cabral, Thayná Bitencourt . Brasil. Universidade Federal Rural do Rio de JaneiroFil: Cabral, Maria Viviana de Freitas. Brasil. Universidade Federal Rural do Rio de JaneiroFil: Cabral, Joilson de Assis. Brasil. Universidade Federal Rural do Rio de Janeir

Mysticism, Language and Silence in Plotinus's Philosophy

This article tries to highlight some important aspects of mystical experience in Plotinus, pointing out, above all, the problem of language that appears in the Plotinian Philosophy as a mediating term between the need to communicate the One and the impossibility of doing so