Direct sampling from muscle cross sections for electrophoretic analysis of individual mitochondria

Muscle is a highly heterogeneous tissue. Practical approaches to sample selectively small regions of muscle cross sections would help to effectively utilize analytical techniques on muscle studies while taking into account tissue heterogeneity. In this report, semimembranosus muscle tissue cross sections were directly sampled and analyzed by capillary electrophoresis (CE) with laser-induced fluorescence detection (LIF). Prior to CE-LIF analysis, a small region in the muscle cross section was stained with 10-nonyl acridine orange (NAO) which is a mitochondrion-selective fluorescent probe known to form a stable complex with cardiolipin, a phospholipid found only in mitochondria. By micromanipulation, the injection end of the capillary was brought into contact with the tissue exhibiting fluorescently labeled mitochondria. Sampling from a region similar in size to the cross section of a single fiber was carried out by applying 11 kPa of negative pressure for 3 s. When an electric field of -200V/cm was applied, fluorescently labeled mitochondria electromigrated and were individually detected by postcolumn LIF detection. For each sample, the electropherogram displays a migration time window with a collection of narrow peaks. The collection of individual peak measurements is represented as a distribution of individual intensities related to cardiolipin content of mitochondria and a distribution of individual electrophoretic mobilities. Positioning the capillary injection end was sufficiently spatially accurate to deplete mitochondria in the sampled region upon repetitive injections. Treatment of a muscle cross section with a protease (trypsin) prior to mitochondria sampling resulted in a higher number of detected mitochondria, suggesting that one of the effects of this enzyme is a partial digestion of the muscles myofibrils, which eases the release of interfibrillar mitochondria entangled within these fibers. The protease treatment also resulted in changes to the electrophoretic mobility distribution of individual mitochondria, which may imply that partial digestion of proteins bound to the mitochondria contributes to the alteration in the electrophoretic mobility of mitochondria. The ability to sample a region as small as a single muscle fiber cross section and its direct CE-LIF analysis opens exciting possibilities for the direct analysis of muscle biopsies and mapping the mitochondrial electrophoretic properties in highly heterogeneous tissues.     

Glucose quantification in dried-down nanoliter samples using mid-infrared attenuated total reflection spectroscopy

The aim of this study was to determine the feasibility of minimally invasive glucose concentration measurement of a body fluid within the physiologically important range below 100 nL with a number of samples such as interstitial fluid, plasma, or whole blood using mid-infrared spectroscopy, but starting with preliminary measurements on samples of simple aqueous glucose solutions. The Fourier transform infrared spectrometer was equipped with a Golden Gate single reflection diamond attenuated total reflection (ATR) accessory and a room-temperature pyroelectric detector. As the necessary detection limits can be achieved only for dried samples within the spectrometric conditions realized by a commercial instrument, the work focused on the optimization of such ATR measurements. We achieved quantification of samples with volumes as low as 7 nL between 10 and 600 mg/dL. The standard error of prediction (SEP) for the concentration range 10-100 mg/dL is 3.2 mg/dL with full interval data between 1180 and 940 cm(-1). The performance of the prediction is given by a coefficient of variation of prediction (CV(pred) ) of 6.2%. When all samples within the whole concentration range are included, the SEP increases to 20.2 mg/dL, and hence the CV(pred) to 10.6% due to a nonlinear signal dependence on glucose concentration. A detection limit for glucose of 0.7 ng with a signal-to-noise ratio of 10 was obtained.     

Review of A Triune Concept of the Brain and Behaviour.

Reviews the book, A Triune Concept of the Brain and Behaviour by Paul D. MacLean, edited by T. J. Boag and D. Campbell. This volume contains the three Hincks Memorial Lectures given by Paul D. MacLean at Queen's University, Kingston, Ontario together with a number of supporting papers. The lectures were given in 1969 but not published until four years later. MacLean first presents an evolutionary view of the brain as having developed in three stages with each stage being superimposed upon the previous one. The scope of MacLean's discourse is very wide and, as is common in lectures of this type, rather speculative. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incorporation of a venturi device in electrospray ionization

Electrospray ionization has grown to be one of the most commonly used ionization techniques for mass spectrometry, and efforts continue to improve its performance. Typically, the sprayer tip must be very close to the entrance orifice of the mass spectrometer in order to maximize the conduction of ions from the sprayer into the mass spectrometer. However, because of space-charge repulsion, most ions never reach the sampling orifice. In this work, an industrial air amplifier, for which the working mechanism is based on venturi and coanda effects, was added between an electrospray ionization source and a time-of-flight mass spectrometer. When a series of reserpine solutions (0.5, 1.0, 5.0, and 10.0 microM) were monitored using mass spectrometry, an over 5-fold increase in m/z 609.3 ion intensity was measured for a separation distance of 14 mm between the electrospray tip and interface capillary inlet, as compared to when the electrospray tip was in its normal position 1 mm in front of the inlet without the amplifier. When a voltage was applied to the air amplifier to further assist in focusing the electrosprayed ions, an approximately 18-fold increase in m/z 609.3 ion intensity was obtained. In addition, a 34-fold reduction in method detection limit was observed.     

V2O5 nanofibre sheet actuators

Vanadium oxides, such as V2O5, are promising for lithium-ion batteries, catalysis, electrochromic devices and sensors. Vanadium oxides were proposed more than a decade ago for another redox-dependent application: the direct conversion of electrical energy to mechanical energy in actuators (artificial muscles). Although related conducting polymer and carbon nanotube actuators have been demonstrated, electromechanical actuators based on vanadium oxides have not be realized. V2O5 nanofibres and nanotubes provide the potential advantages of low-cost synthesis by sol-gel routes and high charging capacity and long cycle life. Here, we demonstrate electromechanical actuation for obtained high modulus V2O5 sheets comprising entangled V2O5 nanofibres. The high surface area of these V2O5 sheets facilitates electrochemical charge injection and intercalation that causes the electromechanical actuation. We show that the V2O5 sheets provide high Young's modulus, high actuator-generated stress, and high actuator stroke at low applied voltage.     

The abstract selection task: New data and an almost comprehensive model.

A complete quantitative account of P. Wason's (1966) abstract selection task is proposed. The account takes the form of a mathematical model. It is assumed that some response patterns are caused by inferential reasoning, whereas other responses reflect cognitive processes that affect each card selection separately and independently of other card selections. The model parameters assess the contributions of different interpretational, inferential, and heuristic factors that jointly determine performance in the selection task. The interpretation of most of the model parameters in terms of these different factors is validated experimentally. This model of the selection task is the first to account for the observed frequencies of all 16 possible response patterns that can arise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

<Emphasis Type="Italic">Vive les differences?</Emphasis> Developing a profile of European information systems research as a basis for international comparisons

The information systems (IS) community is truly international, yet there is often a sense that different elements of the community have different profiles in terms of their research and publication expectations. This paper contributes to this discussion by developing a profile of European IS research that can be used as a basis for international comparisons. It reflects on European research on IS as presented during the first 10 years of the European Conference on Information Systems (ECIS). Based on an analysis of all papers published in the ECIS proceedings during the period 1993–2002, the paper presents the key characteristics of the ECIS conferences, together with a profile of European IS research activity as presented at ECIS. In particular, it highlights the key references and sources used by researchers presenting papers at ECIS. It articulates the research areas presented at ECIS and explores the claim that European IS draws more on social theories than elsewhere. Its contribution in presenting a profile of European research in the IS field lies in identifying particular characteristics of the European style of research that can be compared to that undertaken in other parts of the world.     

CULTURE: A STRESSED SYSTEM

As for fuzzy closed loop control systems composed of fuzzy relation de scribed process and controller this paper proposes an analytical method for the stability of fuzzy closed loop control systems using fuzzy relations and a design method for constructing a stable fuzzy controller As a result the paper develops the theory of fuzzy control systems Examples are given to illustrate how to use the method for the analysis and design of fuzzycontrol systems     

Confusion,social knowledge and the design of intelligent machines

This paper explores the notion of confusion as it applies to the design of intelligent machines and suggests that it arises from the social nature of knowledge. It provides a framework for analysing the causes of confusion and shows how confusion normally reveals itself after the cause of the confusion has occurred. This places practical limitations on how intelligent machines can react to confusion when it is noticed. The paper also describes a prototype system that aims to minimize the effects of confusion by allowing the users to explore the design rationale of the system.     

An Overview of Synergistic Data Tools for Biological Scrutiny

A network of biological databases is reviewed, supplying a framework for studies of human genes and the association of their genomic variations with human phenotypes. The network is composed of GeneCards, the human gene compendium, which provides comprehensive information on all known and predicted human genes, along with its suite members GeneDecks and GeneLoc. Two databases are shown that address genes and variations focusing on olfactory reception (HORDE) and transduction (GOSdb). In the realm of disease scrutiny, we portray MalaCards, a novel comprehensive database of human diseases and their annotations. Also shown is GeneKid, a tool aimed at generating novel kidney disease biomarkers using systems biology, as well as Xome, a database for whole-exome next-generation DNA sequences for human diseases in the Israeli population. Finally, we show LifeMap Discovery, a database of embryonic development, stem cell research and regenerative medicine, which links to both GeneCards and MalaCards.