Estado, bloco no poder e acumulação capitalista: uma abordagem teórica

State, power block and capitalist accumulation: a theoretical approach. This article aims to elaborate a theory, based on Poulantzas, about the role of the State in a capitalist economy through a relational perspective that perceives the State as a field and a strategic process for the disputes of class fractions within the power bloc. In order to do so, it exposes the relation between State and accumulation at an abstract-formal level, emphasising the limitations of studies that use only this dimension. Next, it analyzes the role of the power bloc in mediating between the abstract and concrete levels of the State, observing that public policies are elaborated as a result of the clashes within the power bloc. Finally, it promotes a discussion on the external constraints (international system) that are affected and affect the State and, consequently, the dynamics of the power bloc.

Projeto de regularização fundiária no bairro da Terra Firme: reflexões sobre os limites da intervenção para a efetivação do direito à cidade

O processo de ocupação desigual da cidade de Belém possui uma relação direta com o aumento da ocupação informal nesse município. As intervenções urbanísticas de cunho elitista resultaram em poucas intervenções do Estado no sentido de garantir o direito à moradia digna as frações de classe popular, assim as áreas de ocupação se tornaram entre as décadas de 1980 e 1990 praticamente a única forma de provisão da habitação para os pobres. O Estado, por não apresentar alternativas para o problema da moradia, cede às pressões populares de forma limitada com ações pontuais para amenizar os possíveis conflitos. A regularização fundiária urbana, apesar do discurso oficial, que apresenta a política como garantia ao direito à cidade, não foge à regra de outras políticas estatais formal, pontual, fragmentada e descontínua. Que ao contrário de representar formas de legitimar a equidade urbana acabam por exacerbar às expressões da questão social produto da desigualdade social que no Brasil se mostra cada vez mais danosa no campo ou na cidade.

La configuración del modelo postconvertibilidad : Políticas y clases. Algunas claves para su caracterización, 2002-2007

El presente artículo se propone realizar un ejercicio de caracterización del modelo de acumulación postconvertibilidad en la Argentina, 2002-2007, analizando sus relaciones con las políticas económicas aplicadas y los cambios en la correlación de fuerzas entre fracciones de clase. En este sentido analizaremos sintéticamente distintas fracciones de clase, tanto dominantes como subalternas, identificando las principales políticas y condiciones estructurales del modelo que las afectan para ver cómo se distribuyen las 'cargas' y 'beneficios' del nuevo modelo. De este modo percibiremos el cambio en la correlación de fuerzas entre fracciones de clase al mismo tiempo que estudiaremos las acciones estatales tendientes a constituir condiciones de compensación y estabilización del modelo a través de un sistema de transferencias de ingresos, que encuentra en el Estado aun actor fundamental

Inflación, transferencias y distribución del ingreso en la Argentina post-convertibilidad : ¿Cómo se gestan y a quiénes benefician?

El trabajo analiza cómo se distribuyen las cargas y beneficios del modelo de acumulación post-convertibilidad, 2002-2007, entre las fracciones de clase. En este sentido exploramos la constitución de un sistema de transferencias de ingresos en el que convergen en un proceso dinámico la inflación, las políticas económicas y las estrategias de acumulación de los agentes económicos. Desde una perspectiva que amplía el modo de abordaje del debate sobre la distribución del ingreso, postulamos la conformación de un sistema de transferencias en base al análisis de dos núcleos vinculados: uno ligado a transferencias operadas a partir de la articulación de políticas económicas y transformaciones estructurales, y otro que es en sí mismo un mecanismo de transferencia de importante relevancia y alcance explicativo: la inflación. La evolución diferencial de los precios afecta la capacidad de apropiación, por los agentes económicos, del ingreso socialmente producido, expresando así cambios en las relaciones de fuerzas

La configuración del modelo postconvertibilidad : Políticas y clases. Algunas claves para su caracterización, 2002-2007

El presente artículo se propone realizar un ejercicio de caracterización del modelo de acumulación postconvertibilidad en la Argentina, 2002-2007, analizando sus relaciones con las políticas económicas aplicadas y los cambios en la correlación de fuerzas entre fracciones de clase. En este sentido analizaremos sintéticamente distintas fracciones de clase, tanto dominantes como subalternas, identificando las principales políticas y condiciones estructurales del modelo que las afectan para ver cómo se distribuyen las 'cargas' y 'beneficios' del nuevo modelo. De este modo percibiremos el cambio en la correlación de fuerzas entre fracciones de clase al mismo tiempo que estudiaremos las acciones estatales tendientes a constituir condiciones de compensación y estabilización del modelo a través de un sistema de transferencias de ingresos, que encuentra en el Estado aun actor fundamental

Inflación, transferencias y distribución del ingreso en la Argentina post-convertibilidad : ¿Cómo se gestan y a quiénes benefician?

El trabajo analiza cómo se distribuyen las cargas y beneficios del modelo de acumulación post-convertibilidad, 2002-2007, entre las fracciones de clase. En este sentido exploramos la constitución de un sistema de transferencias de ingresos en el que convergen en un proceso dinámico la inflación, las políticas económicas y las estrategias de acumulación de los agentes económicos. Desde una perspectiva que amplía el modo de abordaje del debate sobre la distribución del ingreso, postulamos la conformación de un sistema de transferencias en base al análisis de dos núcleos vinculados: uno ligado a transferencias operadas a partir de la articulación de políticas económicas y transformaciones estructurales, y otro que es en sí mismo un mecanismo de transferencia de importante relevancia y alcance explicativo: la inflación. La evolución diferencial de los precios afecta la capacidad de apropiación, por los agentes económicos, del ingreso socialmente producido, expresando así cambios en las relaciones de fuerzas

La configuración del modelo postconvertibilidad : Políticas y clases. Algunas claves para su caracterización, 2002-2007

El presente artículo se propone realizar un ejercicio de caracterización del modelo de acumulación postconvertibilidad en la Argentina, 2002-2007, analizando sus relaciones con las políticas económicas aplicadas y los cambios en la correlación de fuerzas entre fracciones de clase. En este sentido analizaremos sintéticamente distintas fracciones de clase, tanto dominantes como subalternas, identificando las principales políticas y condiciones estructurales del modelo que las afectan para ver cómo se distribuyen las 'cargas' y 'beneficios' del nuevo modelo. De este modo percibiremos el cambio en la correlación de fuerzas entre fracciones de clase al mismo tiempo que estudiaremos las acciones estatales tendientes a constituir condiciones de compensación y estabilización del modelo a través de un sistema de transferencias de ingresos, que encuentra en el Estado aun actor fundamental

Inflación, transferencias y distribución del ingreso en la Argentina post-convertibilidad : ¿Cómo se gestan y a quiénes benefician?

El trabajo analiza cómo se distribuyen las cargas y beneficios del modelo de acumulación post-convertibilidad, 2002-2007, entre las fracciones de clase. En este sentido exploramos la constitución de un sistema de transferencias de ingresos en el que convergen en un proceso dinámico la inflación, las políticas económicas y las estrategias de acumulación de los agentes económicos. Desde una perspectiva que amplía el modo de abordaje del debate sobre la distribución del ingreso, postulamos la conformación de un sistema de transferencias en base al análisis de dos núcleos vinculados: uno ligado a transferencias operadas a partir de la articulación de políticas económicas y transformaciones estructurales, y otro que es en sí mismo un mecanismo de transferencia de importante relevancia y alcance explicativo: la inflación. La evolución diferencial de los precios afecta la capacidad de apropiación, por los agentes económicos, del ingreso socialmente producido, expresando así cambios en las relaciones de fuerzas

The final N-terminal trimming of a subaminoterminal proline-containing HLA class I-restricted antigenic peptide in the cytosol is mediated by two peptidases.

The proteasome produces MHC class I-restricted antigenic peptides carrying N-terminal extensions, which are trimmed by other peptidases in the cytosol or within the endoplasmic reticulum. In this study, we show that the N-terminal editing of an antigenic peptide with a predicted low TAP affinity can occur in the cytosol. Using proteomics, we identified two cytosolic peptidases, tripeptidyl peptidase II and puromycin-sensitive aminopeptidase, that trimmed the N-terminal extensions of the precursors produced by the proteasome, and led to a transient enrichment of the final antigenic peptide. These peptidases acted either sequentially or redundantly, depending on the extension remaining at the N terminus of the peptides released from the proteasome. Inhibition of these peptidases abolished the CTL-mediated recognition of Ag-expressing cells. Although we observed some proteolytic activity in fractions enriched in endoplasmic reticulum, it could not compensate for the loss of tripeptidyl peptidase II/puromycin-sensitive aminopeptidase activities.

Labile and stable fractions of soil organic matter under management systems and native cerrado

Soil organic matter can be analyzed on the basis of the different fractions. Changes in the levels of organic matter, caused by land use, can be better understood by alterations in the different compartments. The aim of this study was to evaluate the effect of different management systems on the labile and stable organic matter of a dystrophic Red Latosol (Oxisol). The following properties were determined: total organic C and total N (TOC and TN), particulate organic C and particulate N (POC and PN), organic C and N mineral-associated (MOC and NM) and particulate organic C associated with aggregate classes (POCA). Eight treatments were used: seven with soil management systems and one with native Cerrado as a reference. The experiment was designed to study the dynamics of systems of tillage and crop rotation, alternating in time and space. The experimental design was a randomized block design with three replications. The soil samples were collected from five depths: 0-5, 5-10, 10-20, 20-30 and 30-40 cm. Changes in organic C by land use occurred mainly in the fraction of particulate organic matter (> 53 mm). Proper management of grazing promoted increased levels of particulate organic matter by association with larger aggregates (2-8 mm), demonstrating the importance of the formation of this aggregate class for C protection in pasture.

Composition and stability of organic matter fractions in soils under different land use regimes

Soil organic matter (SOM) vitally impacts all soil functions and plays a key role in the global carbon (C) cycle. More than 70% of the terrestric C stocks that participate in the active C cycle are stored in the soil. Therefore, quantitative knowledge of the rates of C incorporation into SOM fractions of different residence time is crucial to understand and predict the sequestration and stabilization of soil organic carbon (SOC). Consequently, there is a need of fractionation procedures that are capable of isolating functionally SOM fractions, i.e. fractions that are defined by their stability. The literature generally refers to three main mechanisms of SOM stabilization: protection of SOM from decomposition by (i) its structural composition, i.e. recalcitrance, (ii) spatial inaccessibility and/or (iii) interaction with soil minerals and metal ions. One of the difficulties in developing fractionation procedures for the isolation of functional SOM fractions is the marked heterogeneity of the soil environment with its various stabilization mechanisms – often several mechanisms operating simultaneously – in soils and soil horizons of different texture and mineralogy. The overall objective of the present thesis was to evaluate present fractionation techniques and to get a better understanding of the factors of SOM sequestration and stabilization. The first part of this study is attended to the structural composition of SOM. Using 13C cross-polarization magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy, (i) the effect of land use on SOM composition was investigated and (ii) examined whether SOM composition contributes to the different stability of SOM in density and aggregate fractions. The second part of the present work deals with the mineral-associated SOM fraction. The aim was (iii) to evaluate the suitability of chemical fractionation procedures used in the literature for the isolation of stable SOM pools (stepwise hydrolysis, treatments using oxidizing agents like Na2S2O8, H2O2, and NaOCl as well as demineralization of the residue obtained by the NaOCl treatment using HF (NaOCl+HF)) by pool sizes, 13C and 14C data. Further, (iv) the isolated SOM fractions were compared to the inert organic matter (IOM) pool obtained for the investigated soils using the Rothamsted Carbon Model and isotope data in order to see whether the tested chemical fractionation methods produce SOM fractions capable to represent this pool. Besides chemical fractionation, (v) the suitability of thermal oxidation at different temperatures for obtaining stable SOC pools was evaluated. Finally, (vi) the short-term aggregate dynamics and the factors that impact macroaggregate formation and C stabilization were investigated by means of an incubation study using treatments with and without application of 15N labeled maize straw of different degradability (leaves and coarse roots). All treatments were conducted with and without the addition of fungicide. Two study sites with different soil properties and land managements were chosen for these investigations. The first one, located at Rotthalmünster, is a Stagnic Luvisol (silty loam) under different land use regimes. The Ah horizons of a spruce forest and continuous grassland and the Ap and E horizons of two plots with arable crops (continuous maize and wheat cropping) were examined. The soil of the second study site, located at Halle, is a Haplic Phaeozem (loamy sand) where the Ap horizons of two plots with arable crops (continuous maize and rye cropping) were investigated. Both study sites had a C3-/C4-vegetational change on the maize plot for the purpose of tracing the incorporation of the younger, maize-derived C into different SOM fractions and the calculation of apparent C turnover times of these. The Halle site is located near a train station and industrial areas, which caused a contamination with high amounts of fossil C. The investigation of aggregate and density fractions by 13C CPMAS NMR spectroscopy revealed that density fractionation isolated SOM fractions of different composition. The consumption of a considerable part (10–20%) of the easily available O-alkyl-C and the selective preservation of the more recalcitrant alkyl-C when passing from litter to the different particulate organic matter (POM) fractions suggest that density fractionation was able to isolate SOM fractions with different degrees of decomposition. The spectra of the aggregate fractions resembled those of the mineral-associated SOM fraction obtained by density fractionation and no considerable differences were observed between aggregate size classes. Comparison of plant litter, density and aggregate size fractions from soil under different land use showed that the type of land use markedly influenced the composition of SOM. While SOM of the acid forest soil was characterized by a large content (> 50%) of POM, which contained high amounts of spruce-litter derived alkyl-C, the organic matter in the biologically more active grassland and arable soils was dominated by mineral-associated SOM (> 95%). This SOM fraction comprised greater proportions of aryl- and carbonyl-C and is considered to contain a higher amount of microbially-derived organic substances. Land use can alter both, structure and stability of SOM fractions. All applied chemical treatments induced considerable SOC losses (> 70–95% of mineral-associated SOM) in the investigated soils. The proportion of residual C after chemical fractionation was largest in the arable Ap and E horizons and increased with decreasing C content in the initial SOC after stepwise hydrolysis as well as after the oxidative treatments with H2O2 and Na2S2O8. This can be expected for a functional stable pool of SOM, because it is assumed that the more easily available part of SOC is consumed first if C inputs decrease. All chemical treatments led to a preferential loss of the younger, maize-derived SOC, but this was most pronounced after the treatments with Na2S2O8 and H2O2. After all chemical fractionations, the mean 14C ages of SOC were higher than in the mineral-associated SOM fraction for both study sites and increased in the order: NaOCl < NaOCl+HF ≤ stepwise hydrolysis << H2O2 ≈ Na2S2O8. The results suggest that all treatments were capable of isolating a more stable SOM fraction, but the treatments with H2O2 and Na2S2O8 were the most efficient ones. However, none of the chemical fractionation methods was able to fit the IOM pool calculated using the Rothamsted Carbon Model and isotope data. In the evaluation of thermal oxidation for obtaining stable C fractions, SOC losses increased with temperature from 24–48% (200°C) to 100% (500°C). In the Halle maize Ap horizon, losses of the young, maize-derived C were considerably higher than losses of the older C3-derived C, leading to an increase in the apparent C turnover time from 220 years in mineral-associated SOC to 1158 years after thermal oxidation at 300°C. Most likely, the preferential loss of maize-derived C in the Halle soil was caused by the presence of the high amounts of fossil C mentioned above, which make up a relatively large thermally stable C3-C pool in this soil. This agrees with lower overall SOC losses for the Halle Ap horizon compared to the Rotthalmünster Ap horizon. In the Rotthalmünster soil only slightly more maize-derived than C3-derived SOC was removed by thermal oxidation. Apparent C turnover times increased slightly from 58 years in mineral-associated SOC to 77 years after thermal oxidation at 300°C in the Rotthalmünster Ap and from 151 to 247 years in the Rotthalmünster E horizon. This led to the conclusion that thermal oxidation of SOM was not capable of isolating SOM fractions of considerably higher stability. The incubation experiment showed that macroaggregates develop rapidly after the addition of easily available plant residues. Within the first four weeks of incubation, the maximum aggregation was reached in all treatments without addition of fungicide. The formation of water-stable macroaggregates was related to the size of the microbial biomass pool and its activity. Furthermore, fungi were found to be crucial for the development of soil macroaggregates as the formation of water-stable macroaggregates was significantly delayed in the fungicide treated soils. The C concentration in the obtained aggregate fractions decreased with decreasing aggregate size class, which is in line with the aggregate hierarchy postulated by several authors for soils with SOM as the major binding agent. Macroaggregation involved incorporation of large amounts maize-derived organic matter, but macroaggregates did not play the most important role in the stabilization of maize-derived SOM, because of their relatively low amount (less than 10% of the soil mass). Furthermore, the maize-derived organic matter was quickly incorporated into all aggregate size classes. The microaggregate fraction stored the largest quantities of maize-derived C and N – up to 70% of the residual maize-C and -N were stored in this fraction.

Class-switzched B cells display response to therapeutic B-cell depletion in rheumatoid arthritis

Introduction Reconstitution of peripheral blood (PB) B cells after therapeutic depletion with the chimeric anti-CD20 antibody rituximab (RTX) mimics lymphatic ontogeny. In this situation, the repletion kinetics and migratory properties of distinct developmental B-cell stages and their correlation to disease activity might facilitate our understanding of innate and adaptive B-cell functions in rheumatoid arthritis (RA). Methods Thirty-five 'RTX-naïve' RA patients with active arthritis were treated after failure of tumour necrosis factor blockade in an open-label study with two infusions of 1,000 mg RTX. Prednisone dose was tapered according to clinical improvement from a median of 10 mg at baseline to 5 mg at 9 and 12 months. Conventional disease-modifying antirheumatic drugs were kept stable. Subsets of CD19+ B cells were assessed by flow cytometry according to their IgD and CD27 surface expression. Their absolute number and relative frequency in PB were followed every 3 months and were determined in parallel in synovial tissue (n = 3) or synovial fluid (n = 3) in the case of florid arthritis. Results Six of 35 patients fulfilled the European League Against Rheumatism criteria for moderate clinical response, and 19 others for good clinical response. All PB B-cell fractions decreased significantly in number (P < 0.001) after the first infusion. Disease activity developed independently of the total B-cell number. B-cell repopulation was dominated in quantity by CD27-IgD+ 'naïve' B cells. The low number of CD27+IgD- class-switched memory B cells (MemB) in the blood, together with sustained reduction of rheumatoid factor serum concentrations, correlated with good clinical response. Class-switched MemB were found accumulated in flaring joints. Conclusions The present data support the hypothesis that control of adaptive immune processes involving germinal centre-derived, antigen, and T-cell-dependently matured B cells is essential for successful RTX treatment.

The immunodominant major histocompatibility complex class I-restricted antigen of a murine colon tumor derives from an endogenous retroviral gene product.

Tumors express peptide antigens capable of being recognized by tumor-specific cytotoxic T lymphocytes (CTL). Immunization of mice with a carcinogen-induced colorectal tumor, CT26, engineered to secrete granulocyte/macrophage colony-stimulating factor, routinely generated both short-term and long-term CTL lines that not only lysed the parental tumor in vitro, but also cured mice of established tumor following adoptive transfer in vivo. When either short-term or long-term CTL lines were used to screen peptides isolated from CT26, one reverse-phase high performance liquid chromatography peptide fraction consistently sensitized a surrogate target for specific lysis. The bioactivity remained localized within one fraction following multiple purification procedures, indicating that virtually all of the CT26-specific CTL recognized a single peptide. This result contrasts with other tumor systems, where multiple bioactive peptide fractions have been detected. The bioactive peptide was identified as a nonmutated nonamer derived from the envelope protein (gp70) of an endogenous ecotropic murine leukemia provirus. Adoptive transfer with CTL lines specific for this antigen demonstrated that this epitope represents a potent tumor rejection antigen. The selective expression of this antigen in multiple non-viral-induced tumors provides evidence for a unique class of shared immunodominant tumor associated antigens as targets for antitumor immunity.

Class Number Two for Real Quadratic Fields of Richaud-Degert Type

2000 Mathematics Subject Classification: Primary: 11D09, 11A55, 11C08, 11R11, 11R29; Secondary: 11R65, 11S40; 11R09.

What Teaching Strategies Can I Employ to Improve Student Achievement in the Addition of Fractions with Different Denominators?

The purpose of this action research was to determine what instructional strategies could be used to improve student achievement in fraction addition. An eighth grade intensive math class practiced multiplication facts and hands-on applications of fractions concepts for 2 months. Pretests/posttests were used to measure improvement in computation and understanding.