Bitcoin as a Digital Commodity

The paper demonstrates that Bitcoin is not money but rather a digital commodity that has value but no value-added. We show that both the production of and the speculation with Bitcoin draw from the existing global pool of value-added. By extending the Classical Political Economy approach and the New Interpretation of the labour theory of value to the domain of digital commodities, the paper argues that Bitcoin mining is an automated reproduction process that requires no direct (living) labour and thus creates no new value. Bitcoin, in this regard, is not ‘digital gold’. Between sectors, Bitcoin mining redistributes wealth and value-added already in existence, while Bitcoin miners with more computational power compete to appropriate the mining profits within the blockchain. The Bitcoin blockchain then creates rivalry in both the ownership and the use of the digital commodity through non-legal means. Our approach can be further expanded to the larger domain of automated digital commodities that are reproducible without the expenditure of direct, living labour

Projeto HAPRONT – Módulos de Matemática Vol. 2

Esta foi localizada pelo professor Dr. Reginaldo Rodrigues da Costa.Esta fonte foi inserida por alunos da Iniciação Científica da PUC-PR coordenado pelo professor Dr. Reginaldo Rodrigues da Costa.Este volume contém vários módulos de matemática. Normalmente, em cada módulo é apresentado o título, assunto, matéria, pré-requisitos, objetivos, pré-teste, procedimentos e atividades, pós-teste, gabarito, bibliografia e glossário. Neste volume estão presentes os seguintes módulos: operando com conjuntos (módulo 10); produtos cartesiano (módulo 26); operando com números naturais (módulo 27); noções de geometria I (módulo 39); noções de geometria II (módulo 40); grandezas mensuráveis II (módulo 59); grandezas mensuráveis I (módulo 58); operando com números (módulo 60) de autoria de Clélia Tavares Martins

Occurrence and toxicity of Microcystis aeruginosa (Cyanobacteria) in the Paraná River, downstream of the Yacyretá dam (Argentina)

Cyanobacteria constitute the main toxin producers in inland water ecosystems and have extensive global distribution. The presence of hepatotoxins in aquatic environments is hazardous to human and animal health; even though the presence and identification of hepatotoxic microcystins in rivers and reservoirs of the world have been confirmed by several studies in the last few years. Herein, we studied the abundance and toxicity of Microcystis aeruginosa in the Argentine section of the Paraná River at the beginning of the Middle Paraná (Corrientes Hydrometer), near Corrientes city (27º28´ S - 58º51´ W) and approximately 220 km downstream of the Yacyretá dam (High Paraná). The Paraná River basin, with a drainage area of 3.1 x 106 km2 and 3 965 km in length, is the second largest catchment of South America, after that of the Amazon. The Paraná River is the main source of drinking water supply for the Northeastern Argentine region. Phytoplankton samples were collected and environmental variables were measured in a monthly basis (exceptionally fortnightly), from March 2004 to June 2008. Fifty-eight samples were analyzed for phytoplankton density and biomass. Five samples were used for toxicity testing; the latter were obtained during the cyanobacteria blooms from 2005 to 2008. Phytoplankton counts were performed with an inverted microscope, and biomass was expressed as biovolume. Bioassays with mice and high-performance liquid chromatography (HPLC) analysis were performed to evaluate the presence of cyanotoxins. Phytoplankton mainly consisted of Cryptophyta, Chlorophyta and Bacillariophyta. Microcystis aeruginosa was identified during the warmer months each year (November to March). Density varied between 189 and 25 027 cells/mL (1-10 colonies/mL) and biomass from 0.34 to 44 mm3/L. Taking into account the number of cells, the highest abundance occurred in April 2004 (25 027 cells/mL), coinciding with the largest biovolume (44 mm3/L). All mice subjected to intraperitoneal injections with samples obtained during bloom episodes showed positive results for the presence of hepatotoxins. Three microcystins variants: LR, RR and [D-Leu1] Mcyst-LR were detected by analysis with semi-preparative high-performance liquid chromatography with diode array detector system (HPLC-PDA). This constitutes the first report of microcystins recorded during M. aeruginosa blooms in the Argentine stretch of the Paraná River at the beginning of the Middle Paraná (Corrientes Hydrometer), approximately 220 km downstream of the Yacyretá dam (High Paraná).Fil: Forastier, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Zalocar, Yolanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Andrinolo, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Domitrovic, Hugo Alberto. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Variability of the chemical index of alteration (CIA) in the Paraná River suspended load

Variability of the chemical index of alteration (CIA) in the Paraná River suspended loa

Adorno, Habermas, Honneth:: uma genealogia da contradição capital-trabalho nas três gerações da Teoria Crítica

O trabalho apresenta uma breve revisão do desenvolvimento da tradição de pensamento da Teoria Crítica ao longo de suas três gerações (aqui representadas, respectivamente, por Theodor Adorno e Max Horkheimer, Jurgen Habermas e Axel Honneth) em relação ao modo de como tratam, aproximando ou afastando-se deste eixo, a contradição capital-trabalho na explicação da dominação na modernidade capitalista. Ao situá-lo a partir dessa categoria, objetiva traçar o referido panorama da trajetória intelectual dessa linhagem na perspectiva de seu projeto fundacional de crítica radical da realidade social ancorada nas formulações de Karl Marx, como núcleo teórico-conceitual. Feito esse apanhado, argumenta que as distintas formas de negação do imperativo de ruptura sistêmica pela via revolucionária frente ao modo produção capitalista, verificadas nas propostas de tais autores, estão diretamente relacionadas à secundarização teórica da contradição capital-trabalho que estes empreendem na construção de suas formulações

Impactos ENSO en cuencas atlánticas de Sudamérica

Interannual changes in precipitation cause significant effects on the Pacific watersheds of South America. Large rivers flowing to the Atlantic Ocean as the Paraná and Uruguay are also influenced by ENSO-triggered floods causing significant impacts on the economies of Argentina, Brazil and Uruguay. At the same time, the floodplains of small rivers are also sensitive to strong ENSOs. Floods occur approximately simultaneously in subtropical watersheds of Brazil and high-latitude watersheds of North Patagonia. ENSO-triggered floods were recorded during the years 1941-42, 1982-83 and 1997- 98. Several floods impacted along the Itajaí River affecting the higher (Blumenau city) and lower estuary (Itajaí city). The Guaiba River, at the headlands of Lagoa dos Patos, has repeatedly flooded Porto Alegre. At the Río de la Plata basin, significant increases in the discharges were assigned to the Paraná and the Uruguay rivers. The small basin of the Quequén Grande River without extended floodplains is subject to periodic failure of its margins. The Colorado River, the northern limit of Patagonia, is allochthonous and its watershed was artificial and progressively modified; the ENSO event of 1983 caused an increase in its salinity due to the sudden reactivation of the DesaguaderoCuracó system.Los cambios interanuales en las precipitaciones causan significativos efectos en las cuencas pacíficas de Sudamérica. Los grandes ríos que fluyen hacia el Océano Atlántico como el Paraná y el Uruguay también son influenciados por estas inundaciones originadas por estos eventos ENSO causando significativos impactos en las economías de Argentina, Brasil y Uruguay. Asimismo, las planicies aluviales de los pequeños ríos también son sensibles a los ENSOs fuertes. Las crecidas ocurren casi simultáneamente en las cuencas subtropicales de Brasil como en las cuencas de altas latitudes de Patagonia. Inundaciones gavilladas por eventos ENSO fueron registradas en los años 1941-42, 1982-83 y 1997-98. Varias inundaciones afectaron al río Itajaí afectando las porciones más altas (Blumenau) y bajas del estuario (Itajaí). El río Guaíba, en las cabeceras de la Lagoa dos Patos, ha repetidamente inundado Porto Alegre. En la cuenca del Río de la Plata, incrementos significativos de su descarga fueron originados por los ríos Paraná y Uruguay. La pequeña cuenca del río Quequén Grande sin grandes planicies aluviales está sujeta a periódicos derrumbes de sus albardones. El río Colorado, límite norte de la Patagonia, es alóctono y su cuenca fue progresiva y artificialmente modificada; el ENSO de 1983 causó un aumento de su salinidad debido a la súbita reactivación del sistema DesaguaderoCuracó.Fil: Isla, Federico Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Toldo Junior, Elirio Ernestino. Universidade Federal do Rio Grande do Sul; Brasi

Changes in Species Richness and Composition of Tiger Moths (Lepidoptera: Erebidae: Arctiinae) among Three Neotropical Ecoregions

Paraná, Yungas and Chaco Serrano ecoregions are among the most species-richterrestrial habitats at higher latitude. However, the information for tiger moths, one of the most speciose group of moths, is unknown in these ecoregion. In this study, we assess the species richness and composition on these three ecoregion. Also we investigated whether tiger moths species composition is influenced by climatic factors and altitude. Tiger moths species were obtained with samples from 71 sites using standardized protocols (21 sites were in Yungas, 19 in Paraná and 31 in Chaco Serrano). Rarefaction-extrapolation curves, non-parametric estimators for incidence and sample coverage indices were performed to assess species richness in the ecoregions studied. Non metric multidimensional scaling and adonis test were performed to compare the species composition of tiger moths among ecoregions. Permutest analysis and Pearson correlation were used to evaluate the relationship among species composition and annual mean temperature, annual temperature range, annual precipitation, precipitation seasonality and altitude. Among ecoregions Paraná was the richest with 125 species, followed by Yungas with 63 species and Chaco Serrano with 24 species. Species composition differed among these ecoregions, although Yungas and Chaco Serrano were more similar than Paraná. Species composition was significantly influenced by climatic factors and altitude. This study showed that species richness and species composition of tiger moths differed among the three ecoregions assessed. Furthermore, not only climatic factors and altitude influence the species composition of tiger moths among ecoregions, but also climatic seasonality at higher latitude in Neotropical South America region becomes an important factor.Fil: Beccacece, Hernán Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Zeballos, Sebastián Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Zapata, Adriana Inés. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Diversidad Animal I; Argentin

Parameter estimates for fishes of the upper Paraná river floodplain and Itaipu reservoir (Brazil)

Estimates of the growth (K), natural mortality (M), consumption/biomass (Q/B) rate and trophic level (TL) for 35 species in the upper Paraná river floodplain and the Itaipu reservoir (interconnected ecosystems) are presented. A compilation of these biological statistics is made for comparison purposes and some general trends are briefly discussed