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Great Sensitivity (great + sensitivity)
Selected AbstractsLaser-induced breakdown spectroscopy for soil diagnosticsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2001J. Bublitz Summary Laser-optical measurements and fibre optics are potentially attractive tools for applications in soil science because of their great sensitivity and selectivity and their capabilities for on-line and in situ analysis. We have investigated laser-induced breakdown spectroscopy (LIBS) for the quantitative detection of metal ions on the surface of natural soil samples from two sites (Hohenschulen and Oderbruch, Germany). The LIBS technique allows the spatially resolved investigation of adsorption and desorption effects of ions in soil. A frequency doubled (532 nm) and Q-switched Nd:YAG laser with a pulse duration of 8 ns is focused on the soil surface and induces a plasma. Typical power densities are 150 mJ mm,2. The plasma emission is recorded in time and spectrally resolved by a gateable optical multichannel analyser (OMA). A delay time of about 500 ns between laser pulse and OMA gate was used to resolve single atomic and ionic spectral lines from the intense and spectrally broad light that is emitted by the plasma itself. The dependency of the LIBS signal of a single spectral line on the amount of water in the sample is investigated in detail. The results indicate that quenching of water in the plasma plume reduces the line intensities, while the interaction with aquatic colloids increases the intensity. The two processes compete with each other, and a non-linear correlation between measured line intensities and the amount of water in the sample is obtained. This is verified by a simple computer simulation and has to be taken into account for the quantitative interpretation of LIBS signals, e.g. when absolute concentrations are estimated. In the present investigation natural calcium concentrations <,2 ,g kg,1 were measured with the LIBS technique in the samples for the two test sites. In addition, measurements were made with dry and water-saturated BaCl2 mixed soil samples, and no significant difference in the detection limit for barium was obtained. [source] Parental behaviour of a precocial species: implications for juvenile survivalJOURNAL OF APPLIED ECOLOGY, Issue 4 2009Victoria J. Dreitz Summary 1., Parents determine habitat selection for precocial young by leading their young to foraging areas until the chicks attain full independence. There are potential benefits and costs to reproductive success associated with changing habitats while caring for young. This study investigated the relationship between different types of habitats and their quality on chick survival and brood movements of a declining upland shorebird, the mountain plover Charadrius montanus. 2., From 2004 to 2006, a total of 153 mountain plover broods were monitored on the primary breeding habitats in eastern Colorado, USA; two shortgrass prairie habitats that were either occupied or unoccupied by black-tailed prairie dogs Cynomys ludovicianus and agricultural lands. Habitat quality hypotheses were tested using newly developed statistical applications to estimate survival of chicks and brood movement patterns. 3., Chick survival and brood movements were influenced by habitat. Chick survival over the 30-day brood-rearing period was substantially higher on nesting habitat of shortgrass occupied by prairie dogs compared with agricultural land and shortgrass unoccupied by prairie dogs. The rate of brood movement away from shortgrass with prairie dogs was lower than shortgrass without prairie dogs, but higher than agricultural lands for each year of the study. 4., This study suggests that complex processes influence how different habitats affect brood-rearing activity of mountain plovers. Even though broods moved off nesting habitat of shortgrass occupied by prairie dogs, this habitat had the highest survival rate and is highly important to mountain plover reproductive success. 5.,Synthesis and applications. In order to develop effective conservation strategies, the provision of adequate breeding habitat should include information on patterns of habitat selection for all stages of the breeding cycle, including the nesting and dependent young periods. From a conservation perspective, understanding the habitat use of young birds is critical when population dynamics show great sensitivity to survival of young. Previous studies on mountain plovers have suggested that nest success is similar among shortgrass prairie habitats and agricultural lands. Thus, conservation measures that increase nest success may be ineffective for mountain plovers unless they are accompanied by measures promoting chick survival. [source] Nonclassical forces: Seemingly insignificant but a powerful tool to control macromolecular structuresJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 14 2008Michiya Fujiki Abstract Strong chemical forces such as covalent and ionic bonds are responsible for building discrete molecules, nature dwells on noncovalent forces weaker by three orders in magnitude, like the hydrophobic effect, hydrogen bonding, and van der Waals forces. Despite being weak, they possess the potential to drive spontaneous folding or unfolding of proteins and nucleic acids and the recognition between complimentary molecular surfaces. The power of these forces lies in the cooperativity with which they act, thereby generating a cumulative effect of many bonding interactions occurring together. Many ongoing research aims to translate the potential of these forces to the synthetic world to create desired structures with specific chemical functions. Achieving this offers unlimited opportunities for designing and synthesizing the most complex structures with specific applications. This highlight aims to reflect the critical role these noncovalent forces play in controlling macromolecular structures, which hold immense untapped potential for applications defying conventions, and briefly touches on the concept of homochirality in nature based on chiral and weak noncovalent interactions in synthetic nonpolar Si-catenated polymers. It sheds some light on the discovery and characterization of Si/F-C interactions in fluoroalkylated polysilanes in chemosensing of fluoride ions and nitroaromatics with a great sensitivity and selectivity. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4637,4650, 2008 [source] Isolation and characterization of microsatellite loci in the aphid species, Rhopalosiphum padiMOLECULAR ECOLOGY RESOURCES, Issue 1-2 2001Jean-Christophe Simon Abstract Due to their properties for resolving patterns of population genetic structure, microsatellites are increasingly used in studies of breeding systems. Here, eight polymorphic microsatellite loci were isolated and characterized in the aphid Rhopalosiphum padi, in which populations show a mixture of cyclically and obligatory parthenogenetic lines. These loci were then applied to distinguish between 55 parthenogenetic lines of R. padi collected across France. Interestingly, they allowed to detect several copies of the same genotypes among the sample, confirming the great sensitivity of microsatellites and their usefulness in population genetic studies of parthenogenetic organisms. [source] The Hippocratic Bargain and Health Information TechnologyTHE JOURNAL OF LAW, MEDICINE & ETHICS, Issue 1 2010Mark A. Rothstein The shift to longitudinal, comprehensive electronic health records (EHRs) means that any health care provider (e.g., dentist, pharmacist, physical therapist) or third-party user of the EHR (e.g., employer, life insurer) will be able to access much health information of questionable clinical utility and possibly of great sensitivity. Genetic test results, reproductive health, mental health, substance abuse, and domestic violence are examples of sensitive information that many patients would not want routinely available. The likely policy response is to give patients the ability to segment information in their EHRs and to sequester certain types of sensitive information, thereby limiting routine access to the totality of a patient's health record. This article explores the likely effect on the physician-patient relationship of patient-directed sequestration of sensitive health information, including the ethical and legal consequences. [source] Development of a New Pharmacophore Model That Discriminates Active Compstatin AnalogsCHEMICAL BIOLOGY & DRUG DESIGN, Issue 4 2008Ting-Lan Chiu Compstatin and its active peptide analogs can potentially be used for therapeutic purposes because their binding to the third component of complement prohibits its conversion into the proteolytically activated form of the third component of complement, thus inhibiting complement cascades in all three complement pathways. Mallik and Morikis built three quasi-dynamic pharmacophore models for compstatin peptide analogs before, but only nine compstatin peptide analogs were incorporated in their study and the most active compstatin analog had only medium inhibitory activity. Since then, many more compstatin analogs have been synthesized and their inhibitory activities tested. Furthermore, the X-ray structure of AcCompNH2-V4W-H9A bound to the third component of complement has become available (PDB ID: 2QKI). In this paper, we utilized all the new information and built a new pharmacophore model using a distinct approach. Our model demonstrated good performance in a separate test set of 82 compstatin analogs: it accurately identified 70% of the analogs of medium or high inhibitory activities and misclassified only 8.5% of the analogs of low or no inhibitory activities. The results proved our pharmacophore model to be a filter of great sensitivity and specificity. [source] | ||||||||||