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Laboratory Work (laboratory + work)
Selected AbstractsComputer-based management environment for an assembly language programming laboratoryCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 1 2007Santiago Rodríguez Abstract This article describes the environment used in the Computer Architecture Department of the Technical University of Madrid (UPM) for managing small laboratory work projects and a specific application for an Assembly Language Programming Laboratory. The approach is based on a chain of tools that a small team of teachers can use to efficiently manage a course with a large number of students (400 per year). Students use this tool chain to complete their assignments using an MC88110 CPU simulator also developed by the Department. Students use a Delivery Agent tool to send files containing their implementations. These files are stored in one of the Department servers. Every student laboratory assignment is tested by an Automatic Project Evaluator that executes a set of previously designed and configured tests. These tools are used by teachers to manage mass courses thereby avoiding restrictions on students working on the same assignment. This procedure may encourage students to copy others' laboratory work and we have therefore developed a complementary tool to help teachers find "replicated" laboratory assignment implementations. This tool is a plagiarism detection assistant that completes the tool-chain functionality. Jointly, these tools have demonstrated over the last decade that important benefits can be gained from the exploitation of a global laboratory work management system. Some of the benefits may be transferable to an area of growing importance that we have not directly explored, i.e. distance learning environments for technical subjects. © 2007 Wiley Periodicals, Inc. Comput Appl Eng Educ 15: 41,54, 2007; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20094 [source] Laboratory simulation of the salt weathering of schist: II.EARTH SURFACE PROCESSES AND LANDFORMS, Issue 5 2007Fragmentation of fine schist particles Abstract Recent developments in long term landform evolution modelling have created a new demand for quantitative salt weathering data, and in particular data describing the size distribution of the weathered rock fragments. To enable future development of rock breakdown models for use in landscape evolution and soil production models, laboratory work was undertaken to extend existing schist/salt weathering fragmentation studies to include an examination of the breakdown of sub-millimetre quartz chlorite schist particles in a seasonally wet tropical climate. Laser particle sizing was used to assess the impact of different experimental procedures on the resulting particle size distribution. The results reveal that salt weathering under a range of realistic simulated tropical wet season conditions produces a significant degree of schist particle breakdown. The fragmentation of the schist is characterized by splitting of the larger fragments into mid-sized product with finer material produced, possibly from the breakdown of mid-sized fragments when weathering is more advanced. Salinity, the salt addition method and temperature were all found to affect weathering rates. Subtle differences in mineralogy also produce variations in weathering patterns and rates. It is also shown that an increase in drying temperature leads to accelerated weathering rates, however, the geometry of the fracture process is not significantly affected. Copyright © 2006 John Wiley & Sons, Ltd. [source] REVIEW: Mechanisms driving change: altered species interactions and ecosystem function through global warmingJOURNAL OF ANIMAL ECOLOGY, Issue 5 2010Lochran W. Traill Summary 1.,We review the mechanisms behind ecosystem functions, the processes that facilitate energy transfer along food webs, and the major processes that allow the cycling of carbon, oxygen and nitrogen, and use case studies to show how these have already been, and will continue to be, altered by global warming. 2.,Increased temperatures will affect the interactions between heterotrophs and autotrophs (e.g. pollination and seed dispersal), and between heterotrophs (e.g. predators-prey, parasites/pathogens-hosts), with generally negative ramifications for important ecosystem services (functions that provide direct benefit to human society such as pollination) and potential for heightened species co-extinction rates. 3.,Mitigation of likely impacts of warming will require, in particular, the maintenance of species diversity as insurance for the provision of basic ecosystem services. Key to this will be long-term monitoring and focused research that seek to maintain ecosystem resilience in the face of global warming. 4.,We provide guidelines for pursuing research that quantifies the nexus between ecosystem function and global warming. These include documentation of key functional species groups within systems, and understanding the principal outcomes arising from direct and indirect effects of a rapidly warming environment. Localized and targeted research and monitoring, complemented with laboratory work, will determine outcomes for resilience and guide adaptive conservation responses and long-term planning. [source] Teaching crystallography to undergraduate physical chemistry studentsJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5-2 2010Virginia B. Pett Teaching goals, laboratory experiments and homework assignments are described for teaching crystallography as part of two undergraduate physical chemistry courses. A two-week teaching module is suggested for introductory physical chemistry, including six to eight classroom sessions, several laboratory experiences and a 3,h computer-based session, to acquaint undergraduate physical chemistry students with crystals, diffraction patterns, the mathematics of structure determination by X-ray diffraction, data collection, structure solution and the chemical insights available from crystal structure information. Student projects and laboratory work for three to four weeks of an advanced physical chemistry course are presented. Topics such as symmetry operators, space groups, systematic extinctions, methods of solving the phase problem, the Patterson map, anomalous scattering, synchrotron radiation, crystallographic refinement, hydrogen bonding and neutron diffraction all lead to the goal of understanding and evaluating a crystallographic journal article. Many of the ideas presented here could also be adapted for inorganic chemistry courses. [source] Sense of Coherence and Mood States: Exploring the Causal RelationshipsJOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 1 2009Rivka Berger The current study seeks to explore the effect of an academic course on sense of coherence (SOC) and transitory mood states. Moreover, the causal relationships between SOC and transitory mood states was evaluated. Second-year pharmacology students completed pencil-and-paper questionnaires at the beginning of the semester and 3-1/2 months later. The study group (n = 37) participated in an academic course developed to teach cognitive behavior concept and practice, whereas the control group (n = 43) had additional sessions of laboratory work. SOC increased significantly after the course while tension,anxiety and confusion decreased significantly. Structural equation analyses in the study group suggested that SOC was modified by confusion and perceived stress. No such pattern was observed in the control group. [source] Modified evolving window factor analysis for process monitoringJOURNAL OF CHEMOMETRICS, Issue 9 2004S. Kamaledin Setarehdan Abstract Reaction process monitoring and control are usually involved with direct measurement or indirect model-based prediction of concentration profiles of the constituents of interest in a chemical reaction at regular time intervals. These approaches are expensive, time-consuming and sometimes impossible. On the other hand, application of so-called ,calibration-free' techniques such as EFA and EWFA to spectral data usually provides important information regarding the structural variations in the chemical system without identification of the chemical components responsible for the variations. In this paper a novel spectral data pre-processing algorithm is presented which helps EWFA to extract the concentration trends of the components of interest within the reaction. The proposed algorithm uses the pure spectrum of the component of interest to develop a so-called ,weighting filter' which is applied to the input spectral information before EWFA. The algorithm was applied to a real Raman spectral data set obtained from a pre-treatment distillation column used for removing unwanted heavy/cyclic hydrocarbons from naphtha in an oil company. Comparison of the concentration trends resulting from the proposed algorithm with those obtained using conventional PLS1 models shows that the new calibration-free and on-line algorithm outperforms the calibration models obtained by difficult and expensive laboratory work. Copyright © 2005 John Wiley & Sons, Ltd. [source] Learning intravenous cannulation: a comparison of the conventional method and the CathSim Intravenous Training SystemJOURNAL OF CLINICAL NURSING, Issue 1 2002KATHERINE KA-PIK CHANG BHSc ,,Intravenous cannulation is a nursing procedure carried out in some clinical units that may induce trauma and discomfort. Nurses should be well prepared before practising the procedure with clients. ,,Conventionally, a plastic arm was used for practice but, with innovative developments in technology, a computer program called the CathSim Intravenous Training System (CathSim ITS) is available for this purpose. This study was conducted to compare the effectiveness of learning using a plastic arm with the CathSim ITS. ,,Twenty-eight nurses were divided into two groups and randomly assigned to the two different methods: plastic arm (control group) or CathSim ITS (experimental group). Both groups were provided with 1 hour of theory input and 2 hours of nursing laboratory work. ,,When the nurses felt ready to practise on clients, their performances were assessed by researchers with an intravenous cannulation qualification using a validated checklist. Prior to the assessment, trait and state anxiety levels were measured using the State-Trait Anxiety Inventory (Hong Kong Chinese adaptation) to check whether anxiety would affect the performance. Following the assessment, a semi-structured interview was conducted to reveal any knowledge acquired through using the selected method. ,,Both the control and CathSim ITS groups demonstrated a high success rate, scoring 100% and 92.86%, respectively, with their first client. ,,The semi-structured interviews revealed that the CathSim ITS group appreciated several features of their assigned method. However, there is room for further development. [source] Flow and pollution transport during Wagerup 2006: a case studyMETEOROLOGICAL APPLICATIONS, Issue 3 2010Charles Retallack Abstract As part of a broader field campaign dubbed Wagerup 2006, a case study was carried out to determine the overnight pollution transport mechanisms and flow characteristics near Wagerup, Western Australia. The ambient conditions were characterized by stable stratification with little synoptic influence in the lower boundary layer. An elevated jet intrusion originating on a nearby escarpment slope was found to induce sufficient mixing causing elevated pollution plumes to reach ground level. Onset of mixing was accurately predicted by non-linear critical Richardson number estimates obtained in previous laboratory work. The increase in ground level temperatures brought about by shear induced mixing later prompted a sea-breeze like gravity current that was completely blocked by the escarpment and as a result pollutants were trapped against the escarpment slope. A notable side effect of the topographic blocking was the subsequent steady 360° rotation of ground level winds within an area of influence described by the Rossby deformation radius. Copyright © 2009 Royal Meteorological Society [source] How to track and assess genotyping errors in population genetics studiesMOLECULAR ECOLOGY, Issue 11 2004A. BONIN Abstract Genotyping errors occur when the genotype determined after molecular analysis does not correspond to the real genotype of the individual under consideration. Virtually every genetic data set includes some erroneous genotypes, but genotyping errors remain a taboo subject in population genetics, even though they might greatly bias the final conclusions, especially for studies based on individual identification. Here, we consider four case studies representing a large variety of population genetics investigations differing in their sampling strategies (noninvasive or traditional), in the type of organism studied (plant or animal) and the molecular markers used [microsatellites or amplified fragment length polymorphisms (AFLPs)]. In these data sets, the estimated genotyping error rate ranges from 0.8% for microsatellite loci from bear tissues to 2.6% for AFLP loci from dwarf birch leaves. Main sources of errors were allelic dropouts for microsatellites and differences in peak intensities for AFLPs, but in both cases human factors were non-negligible error generators. Therefore, tracking genotyping errors and identifying their causes are necessary to clean up the data sets and validate the final results according to the precision required. In addition, we propose the outline of a protocol designed to limit and quantify genotyping errors at each step of the genotyping process. In particular, we recommend (i) several efficient precautions to prevent contaminations and technical artefacts; (ii) systematic use of blind samples and automation; (iii) experience and rigor for laboratory work and scoring; and (iv) systematic reporting of the error rate in population genetics studies. [source] OLFinder,a program which disentangles DNA sequences containing heterozygous indelsMOLECULAR ECOLOGY RESOURCES, Issue 2 2010C. J. DIXON Abstract The presence of heterozygous indels in a DNA sequence usually results in the sequence being discarded. If the sequence trace is of high enough quality, however, it will contain enough information to reconstruct the two constituent sequences with very little ambiguity. Solutions already exist using comparisons with a known reference sequence, but this is often unavailable for nonmodel organisms or novel DNA regions. I present a program which determines the sizes and positions of heterozygous indels in a DNA sequence and reconstructs the two constituent haploid sequences. No external data such as a reference sequence or other prior knowledge are required. Simulation suggests an accuracy of >99% from a single read, with errors being eliminable by the inclusion of a second sequencing read, such as one using a reverse primer. Diploid sequences can be fully reconstructed across any number of heterozygous indels, with two overlapping sequencing reads almost always sufficient to infer the entire DNA sequence. This eliminates the need for costly and laborious cloning, and allows data to be used which would otherwise be discarded. With no more laboratory work than is needed to produce two normal sequencing reads, two aligned haploid sequences can be produced quickly and accurately and with extensive phasing information. [source] Toward full restoration of synaptic and terminal function of the dopaminergic system in Parkinson's disease by stem cellsANNALS OF NEUROLOGY, Issue S3 2003Ole Isacson DrMedSci New therapeutic nonpharmacological methodology in Parkinson's disease (PD) involves cell and synaptic renewal or replacement to restore function of neuronal systems, including the dopaminergic (DA) system. Using fetal DA cell therapy in PD patients and laboratory models, it has been demonstrated that functional motor deficits associated with parkinsonism can be reduced. Similar results have been observed in animal models with stem cell-derived DA neurons. Evidence obtained from transplanted PD patients further shows that the underlying disease process does not destroy transplanted fetal DA cells, although degeneration of the host nigrostriatal system continues. The optimal DA cell regeneration system would reconstitute a normal neuronal network capable of restoring feedback-controlled release of DA in the nigrostriatal system. The success of cell therapy for PD is limited by access to preparation and development of highly specialized dopaminergic neurons found in the A9 and A10 region of the substantia nigra pars compacta as well as the technical and surgical steps associated with the transplantation procedure. Recent laboratory work has focused on using stem cells as a starting point for deriving the optimal DA cells to restore the nigrostriatal system. Ultimately, understanding the cell biological principles necessary for generating functional DA neurons can provide many new avenues for better treatment of patients with PD. Ann Neurol 2003;53 (suppl 3):S135,S148 [source] Assessment of the ecological status of north-eastern Adriatic coastal waters (Istria, Croatia) using macroalgal assemblages for the European Union Water Framework DirectiveAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2009Ljiljana Ive Abstract 1.Based on the inclusion of macroalgae in the European Union Water Framework Directive as quality elements for the evaluation of the ecological status of coastal waters, the suitability of one (Ecological Evaluation Index, EEI) of several previously proposed evaluation methods in the particular ecological conditions of the northern Adriatic Sea was tested. 2.The EEI was assessed for 10 locations (polluted and putatively pristine) scattered along 60,km of the western Istrian coast. The sampling was performed seasonally at 1 and 3,m depth by destructive (determination of species cover and biomass) and non-destructive (determination of species coverage using digital photography) methods. 3.When assessed at 1,m depth the spatial scale weighted EEI for the west Istrian coast was 8.1, corresponding to an ecological status class (ESC) value of high. However, data for 3,m depth gave a spatial EEI of 6.72 which corresponds to an ESC value of good. Regressions of the ratio of ecological state group I (ESG I, i.e. thick leathery, calcareous and crustose species) over total algal abundance with the pollution gradient (obtained using principal components analysis (PCA) ordination of environmental variables) were significant at 3,m but not at 1,m depth. This was due to the high abundance of ESG I macroalgae Corallina elongata and Cystoseira compressa at 1,m depth at polluted stations. Similar regressions were obtained using cover, biomass and coverage. 4.It is concluded that the EEI method may be suitable for the classification of coastal waters in the northern Adriatic only in certain cases. A better assessment of ecological status using this method would require more realistic estimations based on the inclusion of data from several sampling depths. As all three abundance measures (cover, biomass, coverage) gave similar results, coverage (using digital photography) is suggested as being a preferred measure owing to the rapidity of sampling at several depths and less time-consuming laboratory work. Copyright © 2008 John Wiley & Sons, Ltd. [source] Salt fractionation of plasma proteins: A procedure to teach principles of protein chemistryBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 4 2003A. C. C. Spadaro Abstract A two-step laboratory exercise in biochemistry is proposed, comprising salt fractionation of plasma proteins and protein quantification. This exercise targets mainly undergraduate students, namely in the second year of Pharmacy, who are up to this point more used to deal with physical and chemical properties of micromolecules than macromolecules. The exercise requires simple equipment usually available in basic laboratories. Students work in small teams or alone depending on the laboratory conditions. Questions are proposed to check and reinforce the essential concepts involved as a preparation for detailed comprehension of protein chemistry. After salt fractionation, protein samples can be stored before quantification, allowing a two-period schedule for the laboratory work. Exercises as proposed here are very useful to guide students to a detailed analysis of fundamental aspects determining structure and physicochemical properties of proteins. [source] Titrant standardizations: A research-oriented laboratory practiceBIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 2 2003Tânia M. F. Günther Abstract The quantitative character of biochemistry imposes some familiarization of the student with analytical practice in laboratory work and data analysis. This article describes the application of an inexpensive home-made precision titrator for titrant standardizations, introducing the students to amino acid and protein pH titrations and data analysis. [source] Extremely low frequency electric fields and cancer: Assessing the evidenceBIOELECTROMAGNETICS, Issue 2 2010Leeka Kheifets Abstract Much of the research and reviews on extremely low frequency (ELF) electric and magnetic fields (EMFs) have focused on magnetic rather than electric fields. Some have considered such focus to be inappropriate and have argued that electric fields should be part of both epidemiologic and laboratory work. This paper fills the gap by systematically and critically reviewing electric-fields literature and by comparing overall strength of evidence for electric versus magnetic fields. The review of possible mechanisms does not provide any specific basis for focusing on electric fields. While laboratory studies of electric fields are few, they do not indicate that electric fields should be the exposure of interest. The existing epidemiology on residential electric-field exposures and appliance use does not support the conclusion of adverse health effects from electric-field exposure. Workers in close proximity to high-voltage transmission lines or substation equipment can be exposed to high electric fields. While there are sporadic reports of increase in cancer in some occupational studies, these are inconsistent and fraught with methodologic problems. Overall, there seems little basis to suppose there might be a risk for electric fields, and, in contrast to magnetic fields, and with a possible exception of occupational epidemiology, there seems little basis for continued research into electric fields. Bioelectromagnetics 31:89,101, 2010. © 2009 Wiley-Liss, Inc. [source] Heparin-induced thrombocytopenia (HIT) causing pulmonary emboli during coronary intervention,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 6 2008Ronny S. Jiji MD Abstract Thrombotic complications of heparin-induced thrombocytopenia (HIT) can be devastating if not recognized and treated promptly. We describe an unusual case of rapid-onset HIT resulting in massive-bilateral pulmonary emboli in a 70 year-old man who developed chest pain during elective percutaneous coronary intervention (PCI). The diagnosis was made the following day after persistent chest pain and laboratory work demonstrating a new thrombocytopenia, a mildly elevated troponin, and positive DIC panel led to confirmatory imaging tests. HIT-related thrombosis should be considered in the differential diagnosis of chest pain in patients undergoing PCI. © 2008 Wiley-Liss, Inc. [source] Electrochemical Processing of Carbon DioxideCHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 5 2008Colin Oloman Prof. Abstract With respect to the negative role of carbon dioxide on our climate, it is clear that the time is ripe for the development of processes that convert CO2 into useful products. The electroreduction of CO2 is a prime candidate here, as the reaction at near-ambient conditions can yield organics such as formic acid, methanol, and methane. Recent laboratory work on the 100,A scale has shown that reduction of CO2 to formate (HCO2,) may be carried out in a trickle-bed continuous electrochemical reactor under industrially viable conditions. Presuming the problems of cathode stability and formate crossover can be overcome, this type of reactor is proposed as the basis for a commercial operation. The viability of corresponding processes for electrosynthesis of formate salts and/or formic acid from CO2 is examined here through conceptual flowsheets for two process options, each converting CO2 at the rate of 100,tonnes per day. [source] | |||||||||||||||||||