A rapid method for plasma ammonia estimation using an indigenously purified enzyme

Determination of ammonia level in blood is important, especially in the diagnosis of hepatic disorders. An indigenously purified enzyme was used in the standardisation of the assay. The assay is a two reagent system, requires five minutes for completion and can be performed at temperature between 25–27°C. Performance of the assay was assessed by linearity, imprecision, functional sensitivity and interference studies. Lyophilised reagent I and reagent II were found stable for at least one year. The plasma level of ammonia for the controls was 13.7±7.3 μMol/L, whereas for subjects of hepatic disorders, it was 69.1±32.4 μMol/L (P<0.001). The functional sensitivity was between 2–1000 μMol/L. Within-run coefficient of variation was between 1.1–2.0% and between-run coefficient of variation was between 1.9–3.7%. The mean recovery after dilution was 99.6%. The present method can estimate ammonia up to 1000 μMol/L without dilution of sample. Assay time of five minute may be shortened to one minute. This method is suited for routine clinical use in treatment of hepatic disorders.     

The Promise of the Transparency Culture

In 2013, with the introduction of the Transparency Law in Spain, a number of Spanish newsrooms started working with data journalism methods. In Sweden, which has one of the oldest Freedom of Information acts in the world, newsrooms invested in the skill development of data journalism at approximately the same time. Because previous research suggests that access to public data has been one of the key driving forces for the development of data journalism worldwide, it is important to understand how legislation is actually shaping the practice of data journalism. Based on a survey of 66 key informants in Spain and Sweden and ten in-depth interviews with data journalists from five media companies in each country, we conducted a comparative study, building on the frameworks of media systems to explore data journalism practices in these two countries. The differences found indicate that the national and EU legislation in both nations shape journalistic strategies for accessing data, turning journalists at times into activists fighting for the right to access public data. Beyond the law, data journalists advocate for a transparency culture among the civil servants, in order to secure public accountability.     

Salvador López Gómez: Apostle of Gymnastics in Spain

Abstract

Salvador López Gómez was a great exponent of gymnastics in Spain in the nineteenth and the twentieth century. His role as a teacher, a writer and even as a law developer who promoted gymnastics deserves a detailed study. For that reason, through primary sources of this era and, specially, papers from López Gómez himself, this paper depicts his long professional career, his conception of gymnastics and the constant efforts, not always properly rewarded, that he made for its social respect and acknowledgement during that time.     

Transforming communities through sport? critical pedagogy and sport for development

The value of sport as a vehicle for social development and progressive social change has been much debated, yet what tends to get missed in this debate is the way education may foster, enable or impede the transformative action that underpins the social outcomes to which the ‘sport for development and peace’ (SDP) sector aspires. This article draws on the critical pedagogy of Paulo Freire and his contemporaries to examine the nature of transformative action and how it may be fostered within SDP programs. Insights from critical pedagogy are applied to, and illustrated through, qualitative research undertaken with SDP programs located in Cameroon and Kenya. The findings show the complexities of designing and implementing critical pedagogy in a SDP context and, in particular, the challenges of creating and mobilizing for transformative action. Opportunities and lessons for embedding critical pedagogy within SDP programs are also presented.     

Circadian Rhythms in Cognitive Processes: Implications for School Learning

Circadian variations have been found in cognitive processes, such as attention, working memory, and executive functions, which may explain oscillations in the performance of many tasks. These cognitive processes improve during the day and decrease during the night and early hours of the morning. Sleep deprivation further decreases these cognitive processes during daytime hours. This review analyses the recent findings on circadian rhythms in cognitive processes, as well as the implications of these rhythms for school learning.     

Littlewood and number theory

J E Littlewood (1885–1977) was a British mathematician well known for his joint work with G H Hardy on Waring’s problem and the development of the circle method. In the first quarter of the 20th century, they created a school of analysis considered the best in the world. Littlewood firmly believed that research should be offset by a certain amount of teaching. In this exposition, we will highlight several notable results obtained by Littlewood in the area of number theory.     

Demonstration of a new biosensing concept for immunodiagnostic applications based on change in surface conductance of antibodies after biomolecular interactions

We report an important observation that the surface conductivity of antibody layer immobilized on polylysine-coated glass substrate decreases upon the formation of complex with their specific antigens. This change in conductivity has been observed for both monoclonal and polyclonal antibodies. The conductance of monoclonal mouse IgG immobilized on polylysine-coated glass substrate changed from 1.02×10⁻⁸ Ω⁻¹ to 1.41×10⁻¹¹ Ω⁻¹ at 10 V when complex is formed due to the specific biomolecular interactions with rabbit anti-mouse IgG F(ab′)₂. Similar behavior was observed when the same set up was tested in two clinical assays: (1) anti-Leishmania antigen polyclonal antibodies taken from Kala Azar positive patient serum interacting with Leishmania promastigote antigen, and (2) anti-p21 polyclonal antibodies interacting with p21 antigen. The proposed concept can represent a new immunodiagnostic technique and may have wide ranging applications in biosensors and nanobiotechnology too.     

Effect of the addition of hydroxyl-terminated polydimethylsiloxane to TEOS-based stone consolidants

Hybrid stone consolidants prepared from tetraethoxysilane (TEOS) and α,ω-hydroxyl-terminated polydimethylsiloxane (PDMS-OH) have been considered as one of the most promising approaches to improve the effectiveness of traditional alkoxysilane-based formulations. They have emerged as response to the negative reports commonly found in the literature: the resulting silica gel phase (SiO₂) tends to develop fractures and fissures inside the stone as the gel shrinks during the drying stage. In this work, we employed SEM, solid-state ²⁹Si NMR spectroscopy and compressive tests to characterize SiO₂-PDMS hybrid gels. We report the morphological characteristics exhibited by gels prepared in vitro and in situ. It was found an appreciable reduction of gel fracture for hybrids prepared from 5% w/w of PDMS. As TEOS polycondenses, PDMS-OH is chemically incorporated into the gel matrix via Si-O-Si bonds. The inclusion of these elastic chains provides the necessary flexibility to resist the stress imposed by capillary pressure. Additionally, an important hydrophobic character is imparted to the stone.