Teleology, Causation and the Atlas Motif in Plato's Phaedo

In this paper, I propose a new reading of Phaedo 99b6-d2. My main thesis is that in 99c6-9, Socrates does not refer to the teleological αἰτία but to the αἰτία that will be provided by a stronger ‘Atlas’ (99c4-5). This means that the passage offers no evidence that Socrates abandons teleology or modifies his views about it. He acknowledges, instead, that he could not find or learn any αἰτία stronger than the teleological one. This, I suggest, allows an interpretation of the Phaedo in which Socrates offers a consistent account of the αἰτία of generation and destruction

Process optimization for semi-continuous virus production at high cell densities

Background. Unlike production of recombinant proteins, continuous production of viral vaccines at high cell densities (HCD) is still constrained by host cell lysis during virus propagation and limited virus recovery from culture broth. Nevertheless, advanced fed-batch [1] and perfusion strategies can be applied to achieve a high-yield virus production processes. In this study, the development of a high-yield semi-continuous process for the production and purification of the modified vaccinia Ankara virus isolate MVA-CR19 and influenza A/PR/8 in HCD cultivations of the suspension cell line AGE1.CR.pIX (ProBioGen AG, Berlin) is presented. Methods. Depending on the required scale, high cell concentrations (~ 50×106 cell mL-1) were achieved either through medium renewal by periodic centrifugation (semi-perfusion) in 50 mL cultivations or using an alternating tangential flow (ATF) perfusion system for 1 L bioreactors. Process development and optimization comprised three phases: 1) assessment of different fed-batch and medium exchange strategies for the propagation of MVA-CR19 or influenza A/PR/8 viruses in 50 mL cultivations; 2) scale-up and process optimization of the high-yield process strategy to a 1 L bioreactor with the ATF system, and 3) integration of a purification process step using magnetic sulfated cellulose particles (MSCP). For both viruses, conventional batch cultivation (no addition/medium exchange after infection) was compared with processes applying fed-batch, periodic medium exchange and the combination of both during virus propagation. Results. Perfusion and semi-perfusion at a feeding rate of 0.05 nL/cell×d was suitable to propagate AGE1.CR.pIX cells above 60×106 cells/mL with neither limitation nor overload of nutrients. For infections in 50 mL, the application of a combined strategy comprising an initial fed-batch phase followed by a periodic virus harvest phase resulted in the highest product yield with a more than 10-fold increase, compared to the conventional batch processes at 4 to 8×106 cell/mL [2]. Additionally, a 3-fold increase in both cell-specific yield (virus/cell) and volumetric productivity (virus/L×d) could be obtained. Although product harvesting was suboptimal when up-scaling to a 1 L bioreactor with ATF-system, comparable increases in virus yields and productivity with respect to the conventional batch process were observed. In all cases, cell-specific yields and volumetric productivities reached their peak values at the peak virus concentrations, indicating that the process should be stopped at that time point. Eventually, selection of the optimal pore size of the membrane of the ATF-system allowed semi-continuous harvesting of the produced viruses and its purification with MSCPs with a recovery of about 50%. Conclusion. Compared to conventional batch processes, the developed HCD process offers significantly higher productivities including the option to integrate a purification step in a semi-continuous mode. Overall, the results show that there is a great potential for semi-continuous HCD processes for the production of viral vaccines in larger scales, which could intensify the discussion towards the establishment of true continuous production process

Extranjerización de la tierra rural y protección del dominio nacional : Análisis espacial en la Patagonia argentina

Ante la profundización del declive ganadero ovino extensivo y en el marco de un proceso de revalorización de las tierras para diferentes usos, funciona en la región un mercado que tiene como características salientes el gran número de establecimientos ofertados y la demanda de actores de origen urbano y/o externo con adquisiciones que responden a intencionalidades situadas en algún punto del continuum rentabilidad - recreación y en otros casos a la conservación. Los discursos inmobiliarios asociados a la oferta de establecimientos, enaltecen posibilidades de uso que son el reflejo de nuevas modalidades y se dirigen a esos actores que en el contexto de compresión espacio-temporal (Harvey, 1998) tienen mayores posibilidades de experimentar/controlar territorios lejanos (Vazquez, 2015).Fil: Vazquez, Alberto Daniel. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Humanidades y Ciencias Sociales Sede Comodoro. Instituto de Investigaciones Geográficas de la Patagonia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Territorial logics and real estate speeches in rural areas of semiarid Patagonian Social: confusion and geographical uncertainty

En un contexto de transformaciones de alcance global y contando con las singularidades regionales, los ámbitos rurales de la Patagonia esteparia se enfrentan tanto al declive del sector ganadero en sus modalidades tradicionales como a nuevas valoraciones perceptivas de sus espacios. En este cuadro de indefinición funciona de forma activa un mercado de tierras que alterna entre las lógicas productivas, contemplativas y la especulación. El análisis de los discursos inmobiliarios nos aproxima a la (idea de) Patagonia ante el cruce de lógicas territoriales y ofrece elementos en relación a los recursos que se ponen en valor, a los atributos medulares de ese valor y a las características de oferentes y demandantes. Los avances que aquí se presentan forman parte de una investigación que se desarrolla en el marco del proyecto “Implicancias territoriales por nuevas formas de ausentismo dominial. “Casos rurales patagónicos como referentes”.In a context of transformations of global reach and with singularities regional, rural areas of Patagonia steppe face both the decline of sheep far ming in their traditional ways as new value perceptual of their spaces. In this situation of un certainty works actively a land market that alternates between productive and contemplative logics, and speculation. Analysis of the real estate speeches brings us to the image of Patagonia in the context of coexistence of different territorial logics and provides information relative to resources that give value a the rural space and characteristics of supply and demand. The advances presented here are part of a research carried out under the project entitled "Territorial consequences as result of new absent land lord forms. Patagonian rural examples a s references"Fil: Vazquez, Alberto Daniel. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Humanidades y Ciencias Sociales - Sede Comodoro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Competition Law And Professional Practice

Professional practice has traditionally distinguished itself for being subject to strong regulation, characterized by containing severe restrictions on competition between professionals

Optimal Carbon Taxes for Emissions Targets in the Electricity Sector

The most dangerous effects of anthropogenic climate change can be mitigated by using emissions taxes or other regulatory interventions to reduce greenhouse gas (GHG) emissions. This paper takes a regulatory viewpoint and describes the Weighted Sum Bisection method to determine the lowest emission tax rate that can reduce the anticipated emissions of the power sector below a prescribed, regulatorily-defined target. This bi-level method accounts for a variety of operating conditions via stochastic programming and remains computationally tractable for realistically large planning test systems, even when binary commitment decisions and multi-period constraints on conventional generators are considered. Case studies on a modified ISO New England test system demonstrate that this method reliably finds the minimum tax rate that meets emissions targets. In addition, it investigates the relationship between system investments and the tax-setting process. Introducing GHG emissions taxes increases the value proposition for investment in new cleaner generation, transmission, and energy efficiency; conversely, investing in these technologies reduces the tax rate required to reach a given emissions target

Field trials of an improved cost-effective device for detecting peridomestic populations of Triatoma infestans (Hemiptera: Reduviidae) in rural Argentina

An improved device for detecting peridomestic Triatoma infestans consisting of one-liter recycled Tetra Brik milk boxes with a central structure was tested using a matched-pair study design in two rural areas in Argentina. In Olta (La Rioja), the boxes were installed beneath the thatched roofs and on the vertical wooden posts of each peridomestic structure. After a 5-month exposure, at least one of the recovered boxes detected 88% of the 24 T. infestans-positive sites, and 86% of the 7 negative sites by timed manual collections at baseline. In Amamá (Santiago del Estero), the boxes were paired with the best performing prototype tested before (shelter unit). After 3 months, some evidence of infestation was detected in 89% (boxes) and 79% (shelters) of 18-19 sites positive by timed collections, whereas 19% and 16% of 32 negative sites were positive, respectively. Neither device differed significantly in the qualitative or quantitative collection of every sign of infestation. The installation site did not modify significantly the boxes' sampling efficiency in both study areas. As the total cost of each box was half as expensive as each shelter unit, the boxes are thus the most cost-effective and easy-to-use tool for detecting peridomestic T. infestans currently available.Fil: Vazquez Prokopec, Gonzalo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Ceballos, Leonardo A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Salomón, Oscar Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Centro Nacional de Diagnóstico e Investigaciones Endemo-epidémicas; ArgentinaFil: Gurtler, Ricardo Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentin

A Novel Control Architecture for Hybrid Power Plants to Provide Coordinated Frequency Reserves

The inertia reduction suffered by worldwide power grids, along with the upcoming necessity of providing frequency regulation with renewable sources, motivates the present work. This paper focuses on developing a control architecture aimed to perform frequency regulation with renewable hybrid power plants comprised of a wind farm, solar photovoltaic, and a battery storage system. The proposed control architecture considers the latest regulations and recommendations published by ENTSO-E when implementing the first two stages of frequency control, namely the fast frequency response and the frequency containment reserve. Additionally, special attention is paid to the coordination among sub-plants inside the hybrid plant and also between different plants in the grid. The system’s performance is tested after the sudden disconnection of a large generation unit (N-1 contingency rules). Thus, the outcome of this study is a control strategy that enables a hybrid power plant to provide frequency support in a system with reduced inertia, a large share of renewable energy, and power electronics-interfaced generation. Finally, it is worth mentioning that the model has been developed in discrete time, using relevant sampling times according to industrial practice