Biorefining of wheat straw:accounting for the distribution of mineral elements in pretreated biomass by an extended pretreatment–severity equation

BACKGROUND: Mineral elements present in lignocellulosic biomass feedstocks may accumulate in biorefinery process streams and cause technological problems, or alternatively can be reaped for value addition. A better understanding of the distribution of minerals in biomass in response to pretreatment factors is therefore important in relation to development of new biorefinery processes. The objective of the present study was to examine the levels of mineral elements in pretreated wheat straw in response to systematic variations in the hydrothermal pretreatment parameters (pH, temperature, and treatment time), and to assess whether it is possible to model mineral levels in the pretreated fiber fraction. RESULTS: Principal component analysis of the wheat straw biomass constituents, including mineral elements, showed that the recovered levels of wheat straw constituents after different hydrothermal pretreatments could be divided into two groups: 1) Phosphorus, magnesium, potassium, manganese, zinc, and calcium correlated with xylose and arabinose (that is, hemicellulose), and levels of these constituents present in the fiber fraction after pretreatment varied depending on the pretreatment-severity; and 2) Silicon, iron, copper, aluminum correlated with lignin and cellulose levels, but the levels of these constituents showed no severity-dependent trends. For the first group, an expanded pretreatment-severity equation, containing a specific factor for each constituent, accounting for variability due to pretreatment pH, was developed. Using this equation, the mineral levels could be predicted with R(2) > 0.75; for some with R(2) up to 0.96. CONCLUSION: Pretreatment conditions, especially pH, significantly influenced the levels of phosphorus, magnesium, potassium, manganese, zinc, and calcium in the resulting fiber fractions. A new expanded pretreatment-severity equation is proposed to model and predict mineral composition in pretreated wheat straw biomass

MDL28170, a Calpain Inhibitor, Affects Trypanosoma cruzi Metacyclogenesis, Ultrastructure and Attachment to Rhodnius prolixus Midgut

BACKGROUND: Trypanosoma cruzi is the etiological agent of Chagas' disease. During the parasite life cycle, many molecules are involved in the differentiation process and infectivity. Peptidases are relevant for crucial steps of T. cruzi life cycle; as such, it is conceivable that they may participate in the metacyclogenesis and interaction with the invertebrate host. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we have investigated the effect of the calpain inhibitor MDL28170 on the attachment of T. cruzi epimastigotes to the luminal midgut surface of Rhodnius prolixus, as well as on the metacyclogenesis process and ultrastructure. MDL28170 treatment was capable of significantly reducing the number of bound epimastigotes to the luminal surface midgut of the insect. Once the cross-reactivity of the anti-Dm-calpain was assessed, it was possible to block calpain molecules by the antibody, leading to a significant reduction in the capacity of adhesion to the insect guts by T. cruzi. However, the antibodies were unable to interfere in metacyclogenesis, which was impaired by the calpain inhibitor presenting a significant reduction in the number of metacyclic trypomastigotes. The calpain inhibitor also promoted a direct effect against bloodstream trypomastigotes. Ultrastructural analysis of epimastigotes treated with the calpain inhibitor revealed disorganization in the reservosomes, Golgi and plasma membrane disruption. CONCLUSIONS/SIGNIFICANCE: The presence of calpain and calpain-like molecules in a wide range of organisms suggests that these proteins could be necessary for basic cellular functions. Herein, we demonstrated the effects of MDL28170 in crucial steps of the T. cruzi life cycle, such as attachment to the insect midgut and metacyclogenesis, as well as in parasite viability and morphology. Together with our previous findings, these results help to shed some light on the functions of T. cruzi calpains. Considering the potential roles of these molecules on the interaction with both invertebrate and vertebrate hosts, it is interesting to improve knowledge on these molecules in T. cruzi

Democracia y gobernabilidad en la región latinoamericana

The concept of social cohesion has been extensively discussed over by social sciences. Cohesion is largely the result of historical, and political, and socioeconomics processes. Therefore, its measurement is quite complex. To contribute to the debate, this article is about social cohesion measurement and its impact on governance in Latin America. The thesis developed in this article is that three elements are necessary for social cohesion: individuals, potentially shared objectives and an incentives� system with institutions able to unite and reach those objectives. In this context, it is not only important to count with social groups but to ensure they are communicating with each other. The institutional environment, the context and collective history are attraction or distraction streams from the community�s expectations, which means that they can foster or hinder social cohesion. Social cohesion is part of the collective dynamics that play a central role in economical, institutional and civil society development. The major challenge for the region is to move from a type of society divided by poverty and inequality to a type of society grounded on rights and opportunities.O conceito de coesão social foi amplamente discutido nas ciências sociais. A coesão é, em boa medida, o resultado de processos históricos, políticos e socioeconomicos. É, portanto, complicada sua medição. Com o objetivo de fazer uma contribuição neste debate, o seguinte artigo discute o conceito e a medição da coesão social, assim como suas implicações para a governabilidade na América Latina. A perspectiva aqui desenvolvida coloca que a coesão social requer de três elementos: indivíduos, objetivos potencialmente compartilhados e um sistema de incentivos e instituições que permitam unir e alcançar ditos objetivos. Neste contexto, não só é importante a existência de grupos sociais, mas também que existam pontes de comunicação entre eles. O ambiente institucional, o contexto e a história coletiva se constituem em forças de atração ou �distração� com relação aos anelos da coletividade, isto é, podem facilitar ou obstruir a coesão social. A coesão social é um aspecto da dinâmica coletiva que joga um papel central para o desempenho econômico, da institucionalidade e a cidadania. O grande desafio da região é passar de ser sociedades divididas pela pobreza e a iniqüidade, a sociedades integradas pelos direitos e as oportunidades.El concepto de cohesión social ha sido ampliamente discutido en las ciencias sociales. La cohesión es, en buena medida, el resultado de procesos históricos, políticos y socioeconómicos. Es, por lo tanto, complicada su medición. Con el objeto de hacer un aporte en este debate, el siguiente artículo discute el concepto y la medición de la cohesión social, así como sus impliciones para la gobernabilidad en América Latina. La perspectiva aquí desarrollada plantea que la cohesión social requiere de tres elementos: individuos, objetivos potencialmente compartidos y un sistema de incentivos e instituciones que permitan unir y alcanzar dichos objetivos. En este contexto, no sólo es importante la existencia de grupos sociales sino que también existan puentes de comunicación entre ellos. El entorno institucional, el contexto y la historia colectiva se constituyen en fuerzas de atracción o �distracción� con respecto a los anhelos de la colectividad, es decir, pueden facilitar u obstruir la cohesión social. La cohesión social es un aspecto de la dinámica colectiva que juega un papel central para el desempeño económico, de la institucionalidad y la ciudadanía. El gran reto de la región es pasar de ser sociedades divididas por la pobreza y la inequidad, a sociedades integradas por los derechos y las oportunidades