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31.
Coupled gas chromatography with electroantennographic detection (GC-EAD) using antennae of adult female Manduca sexta was employed to screen for olfactory stimulants present in headspace collections from four species of larval host plants belonging to two families: Solanaceae—Lycopersicon esculentum (tomato), Capiscum annuum (bell pepper), and Datura wrightii; and Martyniaceae—Proboscidea parviflora. Headspace volatiles were collected from undamaged foliage of potted, living plants. GC–EAD revealed 23 EAD-active compounds, of which 15 were identified by GC-mass spectrometry. Identified compounds included aliphatic, aromatic, and terpenoid compounds bearing a range of functional groups. Nine EAD-active compounds were common to all four host plant species: (Z)-3-hexenyl acetate, nonanal, decanal, phenylacetaldehyde, methyl salicylate, benzyl alcohol, geranyl acetone, (E)-nerolidol, and one unidentified compound. Behavioral responses of female moths to an eight-component synthetic blend of selected tomato headspace volatiles were tested in a laboratory wind tunnel. Females were attracted to the blend. A comparison of responses from antennae of males and females to bell pepper headspace volatiles revealed that males responded to the same suite of volatiles as females, except for (Z)-3-hexenyl benzoate. EAD responses of males also were lower for (Z)- and (E)-nerolidol and one unidentified compound. Electroantennogram EAG dose–response curves for the 15 identified EAD-active volatiles were recorded. At the higher test doses (10–100 g), female antennae yielded larger EAG responses to terpenoids and to aliphatic and aromatic esters. Male antennae did respond to the higher doses of (Z)-3-hexenyl benzoate, indicating that they can detect this compound. On the basis of ubiquity of the EAD-active volatiles identified to date in host plant headspace collections, we suggest that M. sexta uses a suite of volatiles to locate and identify appropriate host plants. 相似文献
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Many software engineering problems have been addressed with search algorithms. Search algorithms usually depend on several parameters (e.g., population size and crossover rate in genetic algorithms), and the choice of these parameters can have an impact on the performance of the algorithm. It has been formally proven in the No Free Lunch theorem that it is impossible to tune a search algorithm such that it will have optimal settings for all possible problems. So, how to properly set the parameters of a search algorithm for a given software engineering problem? In this paper, we carry out the largest empirical analysis so far on parameter tuning in search-based software engineering. More than one million experiments were carried out and statistically analyzed in the context of test data generation for object-oriented software using the EvoSuite tool. Results show that tuning does indeed have impact on the performance of a search algorithm. But, at least in the context of test data generation, it does not seem easy to find good settings that significantly outperform the “default” values suggested in the literature. This has very practical value for both researchers (e.g., when different techniques are compared) and practitioners. Using “default” values is a reasonable and justified choice, whereas parameter tuning is a long and expensive process that might or might not pay off in the end. 相似文献
34.
BACKGROUND: Do-not-resuscitate (DNR) orders for critically ill patients are frequently miscommunicated between attending physicians, house staff, and nurses. A computer-based system was developed to improve the communication of a procedure-specific DNR order form. METHODS: Concordance of understanding of patients' DNR status was measured with the use of unstructured DNR orders (period 1), procedure-specific DNR order forms (period 2), and procedure-specific DNR order forms administered with a computer-based communication system (period 3). The 3 components of the DNR order assessed were (1) the clinical events to which the DNR order applied, (2) whether the DNR order withheld all elements of cardiopulmonary resuscitation, and (3) whether other treatments were to be withheld. RESULTS: For the 147 patients, the computer-based system in period 3 (n = 71) improved concordance for attending physicians and nurses or residents for all 3 of the DNR components compared with period 1 (n = 40) and some of the DNR components compared with period 2 (n = 36). Concordance was "substantial" or "almost perfect" as measured by the K statistic during period 3. The proportion of agreement for the composite of all 3 components of the DNR order increased during each period (P<.001, period 3 vs period 1). Overall agreement between all caregivers for the composite DNR order also improved from period 1 (22.2%) to period 2 (47.8%) and period 3 (61.9%; P<.001 vs period 1). Errors in order entry were detected by physicians because of the computer system and corrected in 9.9% of DNR orders in period 3. Progress note documentation of DNR status did not improve during period 3. The procedures of period 3 were considered acceptable by the physician and nursing staff. CONCLUSION: A computer-based system combined with a procedure-specific DNR order form improves communication of patients' DNR status in a critical care setting. 相似文献
35.
LK Friedman 《Canadian Metallurgical Quarterly》1998,8(5):511-525
Kainic acid (KA) induces status epilepticus and delayed neurodegeneration of CA3 hippocampal neurons. Downregulation of glutamate receptor 2 (GluR2) subunit mRNA [the alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) subunit that limits Ca2+ permeability] is thought to a play role in this neurodegeneration, possibly by increased formation of Ca2+ permeable AMPA receptors. The present study examined early hippocampal decreases in GluR2 mRNA and protein following kainate-induced status epilepticus and correlated expression changes with the appearance of dead or dying cells by several histological procedures. At 12 h, in situ hybridization followed by emulsion dipping showed nonuniform decreases in GluR2 mRNA hybridization grains overlying morphologically healthy-appearing CA3 neurons. GluR1 and N-methyl-D-aspartate receptor mRNAs were unchanged. At 12-16 h, when little argyrophilia or cells with some features of apoptosis were detected by silver impregnation or electron microscopy, single immunohistochemistry with GluR2 and GluR2/3 subunit-specific antibodies demonstrated a pattern of decreased GluR2 receptor protein within CA3 neurons that appeared to predict a pattern of damage, similar to the mRNA observations. Double immunolabeling showed that GluR2 immunofluorescence was depleted and that GluR1 immunofluorescence was sustained in clusters of the same CA3 neurons. Quantitation of Western blots showed increased GluR1:GluR2 ratios in CA3 but not in CA1 or dentate gyrus subfields. Findings indicate that the GluR1:GluR2 protein ratio is increased in a population of CA3 neurons prior to significant cell loss. Data are consistent with the "GluR2 hypothesis" that reduced expression of GluR2 subunits will increase formation of AMPA receptors permeable to Ca2+ and predict vulnerability to a particular subset of pyramidal neurons following status epilepticus. 相似文献
36.
GW Gao SH Lin YF Lin LK Diang KC Lu FC Yu SD Shieh 《Canadian Metallurgical Quarterly》1996,57(6):438-442
Despite a general national decline in criminal activities in the 1990s, juvenile criminal offenses continue to increase, (including violent, property, and delinquency acts). In addition increased numbers of children are being held in juvenile jails. It is all but impossible for pediatric health providers to think that "their patients" and "their practices" are immune from the epidemic of crime that affects and is caused by "just kids." 相似文献
37.
Martin Weiglhofer Gordon Fraser Franz Wotawa 《Information and Software Technology》2009,51(11):1601-1617
Test purposes have been presented as a solution to avoid the state space explosion when selecting test cases from formal models. Although such techniques work very well with regard to the speed of the test derivation, they leave the tester with one important task that influences the quality of the overall testing process: test purposes have to be formulated manually. In this paper, we present an approach that assists a test engineer with test purpose design in two ways: it allows automatic generation of coverage based test suites and can be used to automatically exercise those aspects of the system that are missed by hand-crafted test purposes. We consider coverage of Lotos specifications, and show how labeled transition systems derived from such specifications have to be extended in order to allow the application of logical coverage criteria to Lotos specifications. We then show how existing tools can be used to efficiently derive test cases and suggest how to use the coverage information to minimize test suites while generating them. 相似文献
38.
Karel Domansky Josiah D. Sliz Norman Wen Christopher Hinojosa Guy ThompsonII Jacob P. Fraser Tiama Hamkins-Indik Geraldine A. Hamilton Daniel Levner Donald E. Ingber 《Microfluidics and nanofluidics》2017,21(6):107
The majority of microfluidic devices used for cell culture, including Organ-on-a-Chips (Organ Chips), are fabricated using polydimethylsiloxane (PDMS) polymer because it is flexible, optically clear, and easy to mold. However, PDMS possesses significant challenges for high volume manufacturing and its tendency to absorb small hydrophobic compounds limits its usefulness as a material in devices used for drug evaluation studies. Here, we demonstrate that a subset of optically clear, elastomeric, styrenic block copolymers based on styrene-ethylene-butylene-styrene exhibit reduced absorption of small hydrophobic molecules and drug compounds compared to PDMS and that they can be fabricated into microfluidic devices with fine features and the flexibility required for Organ Chips using mass production techniques of injection molding and extrusion. 相似文献
39.
Eiman Kanjo Steve Benford Mark Paxton Alan Chamberlain Danae Stanton Fraser Dawn Woodgate David Crellin Adrain Woolard 《Personal and Ubiquitous Computing》2008,12(8):599-607
Mobile sensing and mapping applications are becoming more prevalent because sensing hardware is becoming more portable and
more affordable. However, most of the hardware uses small numbers of fixed sensors that report and share multiple sets of
environmental data which raises privacy concerns. Instead, these systems can be decentralized and managed by individuals in
their public and private spaces. This paper describes a robust system called MobGeoSens which enables individuals to monitor
their local environment (e.g. pollution and temperature) and their private spaces (e.g. activities and health) by using mobile
phones in their day to day life. The MobGeoSen is a combination of software components that facilitates the phone’s internal
sensing devices (e.g. microphone and camera) and external wireless sensors (e.g. data loggers and GPS receivers) for data
collection. It also adds a new dimension of spatial localization to the data collection process and provides the user with
both textual and spatial cartographic displays. While collecting the data, individuals can interactively add annotations and
photos which are automatically added and integrated in the visualization file/log. This makes it easy to visualize the data,
photos and annotations on a spatial and temporal visualization tool. In addition, the paper will present ways in which mobile
phones can be used as noise sensors using an on-device microphone. Finally, we present our experiences with school children
using the above mentioned system to measure their exposure to environmental pollution.
相似文献
Adrain WoolardEmail: |
40.