Effect of collection, transport, processing and storage of blood specimens on the activity of lysosomal enzymes in plasma and leukocytes

This study was designed to evaluate the effect of different conditions of collection, transport and storage on the quality of blood samples from normal individuals in terms of the activity of the enzymes ß-glucuronidase, total hexosaminidase, hexosaminidase A, arylsulfatase A and ß-galactosidase. The enzyme activities were not affected by the different materials used for collection (plastic syringes or vacuum glass tubes). In the evaluation of different heparin concentrations (10% heparin, 5% heparin, and heparinized syringe) in the syringes, it was observed that higher doses resulted in an increase of at least 1-fold in the activities of ß-galactosidase, total hexosaminidase and hexosaminidase A in leukocytes, and ß-glucuronidase in plasma. When the effects of time and means of transportation were studied, samples that had been kept at room temperature showed higher deterioration with time (72 and 96 h) before processing, and in this case it was impossible to isolate leukocytes from most samples. Comparison of heparin and acid citrate-dextrose (ACD) as anticoagulants revealed that ß-glucuronidase and hexosaminidase activities in plasma reached levels near the lower normal limits when ACD was used. In conclusion, we observed that heparin should be used as the preferable anticoagulant when measuring these lysosomal enzyme activities, and we recommend that, when transport time is more than 24 h, samples should be shipped by air in a styrofoam box containing wet ice.

STUDIES ON THE QUALITY AND PROCESS CONTROL FACTORS DURING THE PRODUCTION AND STORAGE OF SALTED DRIED FISH PRODUCTS

In this study the quality and process control factors during the production and storage of salted dried fish products. The study reveals that quantity of dry fish production in the state is decreasing and dry fish processing industry should be encouraged by central and state governments. The dry and wet salting may be carried out to a period of 4 to 8 hours respectively and time may depend on temperature, size, and concentration of medium. Demand is an unavoidable factor for sale of fish. The packed dry salted lots kept at room temperature are useful only for 20 days. The refrigerator- stored lots had more storage life and nutritional content are good up to 3 months. The cold storage stored dry salted lot had more storage life than the wet salted lot. The use of preservatives in salting is encouraged to reduce pH. The low temperature preservation maintains the nutritional value and quality for long period. It further encourages the labeling of nutritional value of dry fish as in tinned products.

Creation and Annihilation of Fluxons in ac‐driven Semi-annular Josephson Junction

A new geometry (semiannular) for Josephson junction has been proposed and theoretical studies have shown that the new geometry is useful for electronic applications [1, 2]. In this work we study the voltage‐current response of the junction with a periodic modulation. The fluxon experiences an oscillating potential in the presence of the ac‐bias which increases the depinning current value. We show that in a system with periodic boundary conditions, average progressive motion of fluxon commences after the amplitude of the ac drive exceeds a certain threshold value. The analytic studies are justified by simulating the equation using finite‐difference method. We observe creation and annihilation of fluxons in semiannular Josephson junction with an ac‐bias in the presence of an external magnetic field.

Una aproximación documental para la creación e integración de juegos digitales en entornos virtuales de enseñanza. A documental approach to the creation and integration of digital videogames in virtual learning environments

Desde el campo de la informática educativa, varios autores exponen el posible efecto positivo de incorporar videojuegos y simulaciones con elementos de juego en los procesos educativos. Esta postura continúa siendo objeto de debate y sus detractores identifican, dos problemas fundamentales, por un lado el excesivo coste de estas iniciativas y, por otro, su carácter limitado que obliga a que formen parte de variados procesos educativos.. En este trabajo se estudia cómo abordar estos dos problemas desde un punto de vista tecnológico. Se propone una plataforma menor que e-adventure, un entorno de desarrollo para juegos educativos. Esta plataforma aborda el primer problema planteando, un modelo de proceso de desarrollo inspirado en la aproximación documental al desarrollo de software. El modelo de proceso incluye la propuesta de un lenguaje de marcado extendido, XML, específico del dominio de las aventuras gráficas educativas. Este lenguaje es sencillo de utilizar y facilita la creación de este tipo de juegos e incluye construcciones específicamente educativas que dan soporte a la evaluación de la actividad del alumno y a patrones de aprendizaje adaptativo. El segundo problema se aborda proponiendo la integración de dichos juegos con plataformas de tele-enseñanza, LMS, que se emplean tanto en la enseñanza a través de internet como en aproximaciones del aprendizaje electrónico, e-learning, combinadas con la enseñanza tradicional.. Se incluye la implementación de un prototipo de la plataforma propuesta y varios juegos educativos desarrollados con ella, en colaboración con investigadores e instructores de otros campos..

Issues in design, creation and production of distance-learning resources. 'Cuestiones en el diseño, creación y producción de recursos para la enseñanza a distancia'.

Resumen basado en el de la publicación

Strategy clusters and sources of knowledge in French L2 listening comprehension

This article reports on an exploratory investigation into the listening strategies of lower-intermediate learners of French as an L2, including the sources of knowledge they employed in order to comprehend spoken French. Data from 14 learners were analysed to investigate whether employment of strategies in general and sources of knowledge in particular varied according to the underlying linguistic knowledge of the student. While low linguistic knowledge learners were less likely to deploy effectively certain strategies or strategy clusters, high linguistic knowledge levels were not always associated with effective strategy use. Similarly, while there was an association between linguistic knowledge and learners’ ability to draw on more than one source of knowledge in a facilitative manner, there was also evidence that learners tended to over-rely on linguistic knowledge where other sources, such as world knowledge, would have proved facilitative. We conclude by arguing for a fresh approach to listening pedagogy and research, including strategy instruction, bottom-up skill development and a consideration of the role of linguistic knowledge in strategy use.

Generation, description and storage of dendritic morphology data

It is generally assumed that the variability of neuronal morphology has an important effect on both the connectivity and the activity of the nervous system, but this effect has not been thoroughly investigated. Neuroanatomical archives represent a crucial tool to explore structure–function relationships in the brain. We are developing computational tools to describe, generate, store and render large sets of three–dimensional neuronal structures in a format that is compact, quantitative, accurate and readily accessible to the neuroscientist. Single–cell neuroanatomy can be characterized quantitatively at several levels. In computer–aided neuronal tracing files, a dendritic tree is described as a series of cylinders, each represented by diameter, spatial coordinates and the connectivity to other cylinders in the tree. This ‘Cartesian’ description constitutes a completely accurate mapping of dendritic morphology but it bears little intuitive information for the neuroscientist. In contrast, a classical neuroanatomical analysis characterizes neuronal dendrites on the basis of the statistical distributions of morphological parameters, e.g. maximum branching order or bifurcation asymmetry. This description is intuitively more accessible, but it only yields information on the collective anatomy of a group of dendrites, i.e. it is not complete enough to provide a precise ‘blueprint’ of the original data. We are adopting a third, intermediate level of description, which consists of the algorithmic generation of neuronal structures within a certain morphological class based on a set of ‘fundamental’, measured parameters. This description is as intuitive as a classical neuroanatomical analysis (parameters have an intuitive interpretation), and as complete as a Cartesian file (the algorithms generate and display complete neurons). The advantages of the algorithmic description of neuronal structure are immense. If an algorithm can measure the values of a handful of parameters from an experimental database and generate virtual neurons whose anatomy is statistically indistinguishable from that of their real counterparts, a great deal of data compression and amplification can be achieved. Data compression results from the quantitative and complete description of thousands of neurons with a handful of statistical distributions of parameters. Data amplification is possible because, from a set of experimental neurons, many more virtual analogues can be generated. This approach could allow one, in principle, to create and store a neuroanatomical database containing data for an entire human brain in a personal computer. We are using two programs, L–NEURON and ARBORVITAE, to investigate systematically the potential of several different algorithms for the generation of virtual neurons. Using these programs, we have generated anatomically plausible virtual neurons for several morphological classes, including guinea pig cerebellar Purkinje cells and cat spinal cord motor neurons. These virtual neurons are stored in an online electronic archive of dendritic morphology. This process highlights the potential and the limitations of the ‘computational neuroanatomy’ strategy for neuroscience databases.

‘These changes and accessions of knowledge’: translation, scientific travel writing and modernity - Alexander von Humboldt's Personal Narrative

A second English translation of Alexander von Humboldt's account of travel to South America, the Relation historique (1814–25), was published between 1852 and 1853. Appearing some 30 years after the first seven-volume translation (1814–29) by Helen Maria Williams, this second rendering of the Personal Narrative by Thomasina Ross was an abridged version that aimed to make Humboldt's travelogue more relevant to the mid-century reader. This translation has largely been overlooked by Humboldt scholars, despite it being a far more affordable, accessible and popular edition. I discuss here how Ross's revisions can be understood within a larger process of rereading and revision that responded to critics’ assessments of the first translation. Emphasising the status of the Personal Narrative as a text in flux, I assess how Ross modernised it to meet the demands of a new readership, recasting the image that Humboldt had constructed of himself as a travelling scientist, scientific writer and member of the international scientific community.

The creation and diffusion of innovation in developing countries: a systematic literature review

In this study, we review the literature on the creation and diffusion of innovation in the private sectors (industry and services) in developing countries. In particular, we collect evidence on what are the barriers to innovation creation and diffusion and the channels of innovation diffusion to and within developing countries. We find that innovation in developing countries is about creation or adoption of new ideas and technologies; but the capacity for innovation is embedded in and constituted by dynamics between geographical, socio-economic, political and legal subsystems. We contextualize the findings from the review in the current theoretical framework of diffusion of innovations, and we emphasize how the institutional context typical of developing countries impacts the diffusion itself.

Morphological Aspects and Storage of Dypsis leptocheilos (Hodel) Beentje & J. Dransf. (Arecaceae) Seeds

Dypsis leptocheilos (Hodel) Beentje & J. Dransf. palms are widely used in landscaping, however there is a lack of studies about its biology, especially on the morphology of its seedling disseminules and the ideal seed storage time without loss of viability. The objectives of this work were to describe the morphological aspects and to study the storage effect on the germination of D. leptocheilos seeds. The experiments were performed at FCAV/UNESP, Jaboticabal Campus, São Paulo State, Brazil. In order to obtain a morphology description 100 disseminules were sowed in vermiculite. The external and internal sides of the disseminules as well as the representative phases of the germination process were sketched with the help of a light chamber attached to a stereomicroscope. Five treatments were arranged in order to study the storage effects on the seeds (four months of storage and straight after harvest), with four replicates with 25 disseminules each (seeds with attached endocarp) in a completely randomized design. The germination test was conducted over a 140 days period and noted every two days. In order to calculate the germination percentage (% G) and the Germination Speed Index (GSI), the seeds were considered germinated when the germinative button appeared. The data were submitted to a polynomial regression analysis to verify the behavior of the variables over the storage period. The D. leptocheilos seeds have rounded shape, ruminate endosperm and hard consistency. The embryo is lateral, peripheral and relatively undifferentiated, with approximately 3 mm long and conical shape. The germination percentage increased from 17% for seeds sowed straight after harvest to 73% for those stored over a three-month period. For the GSI the increase was about 0.85%. It was concluded that the germination of D. leptocheilos is of an adjacent ligulate type. Furthermore, the seeds stored for 3 months at 14 degrees C showed both higher percentage and germination speed.

Beta-carotene stability during drying and storage of cassava and sweet potato

The effect of blanching on the β-carotene stability during drying and storage of cassava and sweet potato was evaluated. The orange-fleshed sweet potato showed good retention of β-carotene during the blanching and drying (100% and 96%, respectively), but lower retention (84% and 91%) was observed in cassava. Cassava also showed lower β-carotene stability than sweet potato during the storage of unblanched dried samples. β-Carotene content of dried cassava was reduced from 8.6 μg/g to traces in 20 days of storage while the initial amount of dried sweet potato (463 μg/g) was reduced by about 45% (210 μg/g). Blanching did not affect the β-carotene retention during the drying, but enhanced the stability of this carotenoid during the storage of dried samples at room temperature, especially in cassava. The initial levels of blanched-dried cassava and sweet potato (7.8 and 513 μg/g, respectively) took 70 days to fall by around 50%.

Influence of the combination of probiotic cultures during fermentation and storage of fermented milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distribution and stability of aflatoxin M-1 during processing and storage of Minas Frescal cheese

Aflatoxin M-1 (AFM(1)) is a hepatocarcinogen found in milk of animals that have consumed feeds with aflatoxin B-1. The carry-over of AFM(1) from milk to Minas Frescal cheese produced with or without starter cultures was determined. 40 L of milk were divided into 10 L each and assigned to the following treatments for cheese manufacture: 0.250 rig AFM(1) mL(-1), 0.500 rig AFM(1) mL(-1), 0.250 ng AFM(1) mL(-1) + starter, 0.500 ng AFM(1) mL(-1) + starter. Quantification of AFM(1) was achieved by high performance liquid chromatography. The carry-over of AFM(1) from milk to cheese ranged from 30.64% to 42.26%. There was no effect of storage time on AFM(1). Milk with AFM(1) in levels studied may concentrate the toxin in Minas Frescal cheese, but at concentrations below the Brazilian tolerance limit. The addition of starter cultures did not influence concentration or stability of the AFM(1) in cheese over 30 days storage. (C) 2011 Elsevier Ltd. All rights reserved.

Improvements in production and storage of HP-129 Xe

Seit seiner Entdeckung im Jahre 1978 wurden für hyperpolarisiertes (HP) 129Xe zahlreiche Anwendungen gefunden. Aufgrund seiner hohen Verstärkung von NMR-Signalen wird es dabei typischerweise für Tracer- und Oberflächenstudien verwendet. Im gasförmigen Zustand ist es ein interessantes, klinisches Kontrastmittel, welches für dynamische Lungen MRT genutzt oder auch in Blut oder lipophilen Flüssigkeiten gelöst werden kann. Weiterhin findet HP-Xe auch in der Grundlagenphysik in He-Xe Co-Magnetometern Verwendung, mit welchen z. B. das elektrische Dipolmoment von Xe bestimmt werden soll, oder es dient zur Überprüfung auf Lorentz-Invarianzen. Alle diese Anwendungen profitieren von einem hohen Polarisationsgrad (PXe), um hohe Signalstärken und lange Lagerzeiten zu erreichen. rnIn dieser Arbeit wurden zwei mobile Xe-Polarisatoren konstruiert: einer für Experimente in der Grundlagenphysik mit einer Produktionsrate von 400 mbar·l/h mit PXe ≈ 5%. Der zweite Xe-Polarisator wurde für medizinische Anwendungen entwickelt und soll 1 bar l/h mit PXe > 20% erzeugen. Der letztere wurde noch nicht getestet. Die Arbeitsbedingungen des Xe-Polarisators für Grundlagenphysik (Strömung des Gasgemischs, Temperatur, Druck und Konzentration von Xe) wurden variiert, um einen höchstmöglichen Polarisationsgrad zu erzielen. Die maximale Polarisation von 5,6 % wurde bei Verwendung eine Gasmischung von 1% Xe bei einem Durchfluss von 200 ml/min, einer Temperatur von 150°C und einem Gesamtdruck von 4 bar erreicht. rnWeiterhin muss HP-Xe auch effizient gelagert werden, um Polarisationsverluste zu minimieren. Das ist besonders für solche Anwendungen notwendig, welche an einem entfernten Standort durchgeführt werden sollen oder auch wenn lange Spinkohärenzeiten gefordert sind, z.B. bei He-Xe Co-Magnetometern. rnHierbei bestand bisher die größte Schwierigkeit darin, die Reproduzierbarkeit der gemessenen Lagerzeiten sicherzustellen. In dieser Arbeit konnte die Spin-Gitter-Relaxationszeit (T1) von HP-129Xe in unbeschichteten, Rb-freien, sphärischen Zellen aus Aluminiumsilikatglas (GE-180) signifikant verbessert werden. Die T1–Zeit wurde in einem selbstgebauten Niederfeld-NMR-System (2 mT) sowohl für reines HP-Xe als auch für HP-Xe in Mischungen mit N2, SF6 und CO2 bestimmt. Bei diesen Experimenten wurde die maximale Relaxationszeit für reines Xe (85% 129 Xe) bei (4,6 ± 0,1) h festgestellt. Dabei lagen die typischen Wand-Relaxationszeiten bei ca. 18 h für Glaszellen mit einem Durchmesser von 10 cm. Des Weiteren wurde herausgefunden, dass CO2 eine unerwartet hohe Effizienz bei der Verkürzung der Lebensdauer der Xe-Xe Moleküle zeigte und somit zu einer deutlichen Verlängerung der gesamten T1-Zeit genutzt werden kann. rnIm Verlauf vieler Experimente wurde durch wiederholte Messungen mit der gleichen Zelle, ein "Alterungsprozess“ bei der Wandrelaxation identifiziert und untersucht. Dieser Effekt könnte leicht rückgängig gemacht werden, indem die anfängliche Reinigungsprozedur wiederholt wurde. Auf diese Weise kann eine konstante Wandrelaxation sichergestellt werden, durch die sehr reproduzierbare T1-Messungen möglich werden. rnSchließlich wurde die maximale Relaxationszeit für HP-Xe mit natürlicher Häufigkeit in Mischungen mit SF6 bestimmt. Überraschenderweise war dieser Wert um ca. 75% niedriger als der Wert für Xenon, das zu 85% mit 129Xe angereichert war. Dieser Effekt wurde durch drei unabhängige Experimente bestätigt, da er nicht von der bestehenden Theorie der Xe-Relaxation ableitbar ist. rnDie Polarisation von HP-Xe, PXe, wird normalerweise durch den Vergleich der NMR-Signale des HP-Xe mit einer thermischen polarisierten Probe (z. B. 1H2O oder Xe) bestimmt. Dabei beinhaltet der Vergleich unterschiedlicher Messungen an verschiedenen Proben (unterschiedlicher Druck, Signalintensität und Messverfahren) viele experimentelle Unsicherheiten, welche sich oft nicht leicht bestimmen lassen. Eine einfache, genaue und kostengünstige Methode zur Bestimmung von PXe durch eine direkte Messung der makroskopischen Magnetisierung in einem statischen Magnetfeld vermeidet alle diese Unsicherheiten. Dieses Verfahren kann Polarisationen von > 2 % mit einer Genauigkeit von maximal 10% fast ohne Polarisationsverlust bestimmen. Zusätzlich kann diese Methode ohne weitere Änderungen auch für Bestimmungen des Polarisationsgrades anderer HP-Gase verwendet werden.rn