Instrumentation Library Research Articles

CHEMICAL COMPOSITION OF ESSENTIAL OIL OF BACCHARIS SALICIFOLIA (RUIZ & PAVON) PERS. AND ANTIBACTERIAL ACTIVITY

The essential oil of the aerial parts of Baccharis salicifolia was examined by GC and GC-MS and the major components were identified as α-pinene, camphene, β-pinene, α-phellandrene, α-cubebene, β-cariophyllene, 6,9-guaiadiene, germacrene D and germacrone. The essential oil was tested against eight Gram positive and Gram negative bacteria. The essential oil was found to exhibit moderate antibacterial activity against Gram positive bacteria tested with MIC values from 0.47 to 0.94 (µg/ml). . Raw and/or processed food is open to contamination during the production, sale and distribution steps. Food preservation is a relevant and complex problem. Food products require a longer shelf life and greater assurance of being free from food-borne pathogenic and spoilage organism. The excessive use of synthetic preservatives has resulted in an increasing pressure on food manufacturers either to completely remove chemical preservatives or by the use of new alternatives that consumers conceive as natural or safe 5 . The distillated oil (0.56 g / Kg) was dried over anhydrous sodium sulfate and stored in tightly closed darks vials at 4 oC until analysis. The oil has a golden color with an herbal odor. Identification of components. The B. salicifolia EO composition was determined by GC-MS through comparison of the major signals with previously published spectra. Retention times and mass spectral data were checked with those obtained from authentic samples and/or from the MS instrument library. Relative percentages of the major components were calculated by integrating the registered peaks. GC-MS experiments were performed on a ion trap GCQ-Plus (Finnigan, ThermoQuest, Austin, TX, USA) instrument with MS-MS program using a silica capillary column Rtx® -5MS (30 m x 0.25 mm ID, 0.25 µm). The carrier gas was helium (40 cm.s -1 ). The port temperature was 200 oC in the splitless mode with 1.0 ml injection volume. The initial GC temperature was maintained at 40 oC for 2 min, then increased to 210 oC at 2 oC min -1 , and maintained at this temperature up to 120 min. For the analysis of low resolution MS, the ion trap mass detector was set in full scan mode from m/z 50 to m/z 450. For the analysis of product, the collision inducted detection (CID) method was used. The precursor was selected using tandem mass spectrometry (MS/MS) scan standard function, with 0.5 daltons peak-widths for the parent ion and dynamically programmed scans, as described previously 9 . The main components detected in the samples here analyzed were: α-pinene (6.6x10-4 %), camphene (8.2x10-4 %), β-pinene (4.06x 10-3 %), α-phellandrene (0.0272 %), α-cubebene (5.176 %), β-cariophyllene (65.16 %), 6,9-guaiadiene (5.18 %), germacrene-D (6.6 %) and germacrone (17.85 %) which represent a 99.99 % of the total area. In order to find some correlations between the identified compounds (GC- MS) and the 1 H NMR spectral data, a sample of the whole essential oil was analyzed by this technique. A series of multiplets at δ 0.70-1.20 was consistent with several methyl groups on sp 3

The ruby intermediate language

Ruby is a popular, dynamic scripting language that aims to "feel natural to programmers" and give users the "freedom to choose" among many different ways of doing the same thing. While this arguably makes programming in Ruby easier, it makes it hard to build analysis and transformation tools that operate on Ruby source code. In this paper, we present the Ruby Intermediate Language (RIL), a Ruby front-end and intermediate representation that addresses these. RIL includes an extensible GLR parser for Ruby, and an automatic translation into an easy-to-analyze intermediate form. This translation eliminates redundant language constructs, unravels the often subtle ordering among side effecting operations, and makes implicit interpreter operations explicit. We also describe several additional useful features of RIL, such as a dynamic instrumentation library for profiling source code and a dataflow analysis engine. We demonstrate the usefulness of RIL by presenting a static and dynamic analysis to eliminate null pointer errors in Ruby programs. We hope that RIL's features will enable others to more easily build analysis tools for Ruby, and that our design will inspire the of similar frameworks for other dynamic languages.

The case for a coordinating centre for birth cohort studies

Designing, piloting and proceeding with a longitudinal birth cohort is a major exercise. Here we outline ways in which a resource centre could be initiated to provide advice and training, a library of appropriate instruments and publications, provision for cross-cohort comparisons and a biobanking facility. The resource should be available for cohorts planned in the developed and developing world, as well as those countries in transition. We discuss possible strategies for funding such a centre.

Visualizing the runtime behavior of embedded network systems: A toolkit for TinyOS

TinyOS is an effective platform for developing lightweight embedded network applications. But the platform’s lean programming model and power-efficient operation come at a price: TinyOS applications are notoriously difficult to construct, debug, and maintain. The development difficulties stem largely from a programming model founded on events and deferred execution. In short, the model introduces non-determinism in the execution ordering of primitive actions — an issue exacerbated by the fact that embedded network systems are inherently distributed and reactive. The resulting set of possible execution sequences for a given system is typically large and can swamp developers’ unaided ability to reason about program behavior. In this paper, we present a visualization toolkit for TinyOS 2.0 to aid in program comprehension. The goal is to assist developers in reasoning about the computation forest underlying a system under test and the particular branches chosen during each run. The toolkit supports comprehension activities involving both local and distributed runtime behavior. The constituent components include (i) a full-featured static analysis and instrumentation library, (ii) a selection-based probe insertion system, (iii) a lightweight event recording service, (iv) a trace extraction and reconstruction tool, and (v) three visualization front-ends. We demonstrate the utility of the toolkit using both standard and custom system examples and present an analysis of the toolkit’s resource usage and performance characteristics.

Dynamic Binary Instrumentation and Data Aggregation on Large Scale Systems

Dynamic binary instrumentation for performance analysis on large scale architectures such as the IBM Blue Gene/L system (BG/L) poses unique challenges. Their unprecedented scale and often limited OS support require new mechanisms to organize binary instrumentation, to interact with the target application, and to collect the resulting data. We describe the design and current status of a new implementation of the Dynamic Probe Class Library (DPCL) API for large scale systems. DPCL provides an easy to use layer for dynamic instrumentation on parallel MPI applications based on the DynInst dynamic instrumentation library for sequential platforms. Our work includes modifying DynInst to control instrumentation from remote I/O nodes and porting DPCL's communication for performance data collection to use MRNet, a tree-based overlay network that (TBON) supports scalable multicast and data reduction. We describe extensions to the DPCL API that support instrumentation of task subsets and aggregation of collected performance data.

Integration of Web-based and PC-based Clinical Research Databases

We have created a Web-based repository or data library of information about measurement instruments used in studies of multi-factorial geriatric health conditions (the Geriatrics Research Instrument Library - GRIL) based upon existing features of two separate clinical study data management systems. GRIL allows browsing, searching, and selecting measurement instruments based upon criteria such as keywords and areas of applicability. Measurement instruments selected can be printed and/or included in an automatically generated standalone microcomputer database application, which can be downloaded by investigators for use in data collection and data management. Integration of database applications requires the creation of a common semantic model, and mapping from each system to this model. Various database schema conflicts at the table and attribute level must be identified and resolved prior to integration. Using a conflict taxonomy and a mapping schema facilitates this process. Critical conflicts at the table level that required resolution included name and relationship differences. A major benefit of integration efforts is the sharing of features and cross-fertilization of applications created for similar purposes in different operating environments. Integration of applications mandates some degree of metadata model unification.

Assessing health status and quality-of-life instruments: attributes and review criteria.

The field of health status and quality of life (QoL) measurement - as a formal discipline with a cohesive theoretical framework, accepted methods, and diverse applications--has been evolving for the better part of 30 years. To identify health status and QoL instruments and review them against rigorous criteria as a precursor to creating an instrument library for later dissemination, the Medical Outcomes Trust in 1994 created an independently functioning Scientific Advisory Committee (SAC). In the mid-1990s, the SAC defined a set of attributes and criteria to carry out instrument assessments; 5 years later, it updated and revised these materials to take account of the expanding theories and technologies upon which such instruments were being developed. This paper offers the SAC's current conceptualization of eight key attributes of health status and QoL instruments (i.e., conceptual and measurement model; reliability; validity; responsiveness; interpretability; respondent and administrative burden; alternate forms; and cultural and language adaptations) and the criteria by which instruments would be reviewed on each of those attributes. These are suggested guidelines for the field to consider and debate; as measurement techniques become both more familiar and more sophisticated, we expect that experts will wish to update and refine these criteria accordingly.