Quality improvement in ammonium nitrate production using Six Sigma methodology

Six sigma has been used in different industries to reach operational excellence. However, in the chemical industry, the application of this methodology is limited. This research presents an implementation of the six sigma method for ammonium nitrate (AN) content optimization in condensate production for a fertilizer company in Colombia. The paper aims to determine the levels for input variables in the process, to meet desirable standards for condensate quality in terms of ammonium nitrate content. Based on the DMAIC steps implementation, it was possible to establish the main variables affecting the condensate quality and their optimal levels to reach an ammonium nitrate content below 15,000 ppm. These results demonstrate the impact that a six sigma project may have on operational effectiveness and quality improvement for meeting the customer requirements

P300 amplitude is insensitive to working memory load in schizophrenia

<p>Abstract</p> <p>Background</p> <p>Working memory (WM) tasks usually elicit a P300 ERP component, whose amplitude decreases with increasing WM load. So far, this effect has not been studied in schizophrenics (SZs), a group that is considered to have an aberrant brain connectivity and impairments in WM capacity. The aim of this study was to determine the dependency of the P300 component on WM load in a sample of SZ subjects.</p> <p>Methods</p> <p>We recorded 26 subjects (13 SZ patients and their matched controls) with an 80-channel electroencephalogram. Subjects performed an N-back task, a WM paradigm that manipulates the number of items to be stored in memory.</p> <p>Results</p> <p>In healthy subjects, P300 amplitude was highest in the low WM load condition, and lowest in both the attentional control condition and the high WM load condition. In contrast, SZs evidenced low P300 amplitude in all conditions. A significant between group difference in P300 amplitude was evidenced only at the low WM load condition (1 -back), being smaller in SZs.</p> <p>Conclusions</p> <p>SZ subjects display a lower than normal P300 amplitude, which does not vary as a function of memory load. These results are consistent with a general impairment in WM capacity in these patients.</p

Homens e violência conjugal: uma análise de estudos brasileiros Men and conjugal violence: an analysis of Brazilian studies

O estudo analisou qualitativamente 54 textos brasileiros sobre homens e violência conjugal, relacionados a atividades de pesquisa ou de intervenção. Primeiramente caracterizou-se o material quanto aos temas abordados, ao foco principal e ao tipo de texto. A seguir fizeram-se sínteses e análises das principais considerações dos textos a partir dos eixos temáticos encontrados: diferentes inteligibilidades da problemática, magnitude da violência conjugal, sentidos de homens relacionados à violência e intervenções e/ou políticas junto a homens agressores. A análise teve como parâmetro o ramo de discussões nacionais e internacionais que se esforça por ultrapassar a polêmica em torno da definição do problema como "violência de gênero" ou "violência conjugal", cunhando sobretudo o pressuposto de que existem diversos estilos de conjugalidade violenta. Concluiu-se que a maior unanimidade dos estudos é pensar a problemática como questão relacional de gênero. Defendeu-se, por fim, a ideia de que a escolha da melhor abordagem articuladora entre os polos da polêmica ainda demanda mais investigações, com metodologias qualitativas junto a atores de diferentes camadas e grupos sociais. Quanto às intervenções, propõem-se investimentos no maior número possível de alternativas, valorizando a singularidade dos casos.<br>This study consisted of a qualitative analysis of 54 Brazilian texts about men and conjugal violence related to research or intervention activities. Initially, the material was divided up according to the topics under scrutiny, the main focus and the type of text. Analysis and synthesis of the main considerations of the texts, based on the thematic points revealed, was then carried out. This included the different approaches to the problem, the magnitude of conjugal violence, the attitudes of men vis-à-vis violence and interventions and/or policies towards male aggressors. The parameter for the analysis was the national and international debate seeking to overcome the controversy surrounding the definition of the problem as "gender violence" or conjugal violence," essentially fostering the hypothesis of various types of violent conjugal relationships. It was concluded that the unanimous outcome of the study was to view the problem as a gender relationship issue. Lastly, it was argued that the choice of the best approach between the poles of the controversy requires further investigation using qualitative methodologies together with players from different classes and social backgrounds. With respect to further intervention, it was considered necessary to examine a broad gamut of alternatives emphasizing the singular nature of the cases

HER-2 and EGFR mRNA Expression and Its Relationship with Versican in Malignant Matrix-Producing Tumors of the Canine Mammary Gland

Versican expression promotes tumor growth by destabilizing focal cell contacts, thus impeding cell adhesion and facilitating cell migration. It not only presents or recruits molecules to the cell surface, but also modulates gene expression levels and coordinates complex signal pathways. Previously, we suggested that the interaction between versican and human epidermal growth factor receptors may be directly associated with tumor aggressiveness. Thus, the expression of EGFR and HER-2 in these neoplasms may contribute to a better understanding of the progression mechanisms in malignant mammary tumors. The purpose of this study was to correlate the gene and protein expressions of EGFR and HER2 by RNA In Situ Hybridization (ISH) and immunohistochemistry (IHC), respectively, and their relationship with the versican expression in carcinomas in mixed tumors and carcinosarcomas of the canine mammary gland. The results revealed that EGFR mRNA expression showed a significant difference between in situ and invasive carcinomatous areas in low and high versican expression groups. Identical results were observed in HER-2 mRNA expression. In immunohistochemistry analysis, neoplasms with low versican expression showed greater EGFR immunostaining in the in situ areas than in invasive areas, even as the group presenting high versican expression displayed greater EGFR and HER-2 staining in in situ areas. Significant EGFR and HER-2 mRNA and protein expressions in in situ carcinomatous sites relative to invasive areas suggest that these molecules play a role during the early stages of tumor progression