Update and review of accuracy assessment techniques for remotely sensed data

Research performed in the accuracy assessment of remotely sensed data is updated and reviewed. The use of discrete multivariate analysis techniques for the assessment of error matrices, the use of computer simulation for assessing various sampling strategies, and an investigation of spatial autocorrelation techniques are examined

Performance and modeling of superconducting ring resonators at millimeter-wave frequencies

Microstrip ring resonators operating at 35 GHz were fabricated from laser ablated YBCO thin films deposited on lanthanum aluminate substrates. They were measured over a range of temperatures and their performance compared to identical resonators made of evaporated gold. Below 60 Kelvin the superconducting strip performed better than the gold, reaching an unloaded Q approximately 1.5 times that of gold at 25 K. A shift in the resonant frequency follows the form predicted by the London equations. The Phenomenological Loss Equivalence Method is applied to the ring resonator and the theoretically calculated Q values are compared to the experimental results

Suspended animation inducer hydrogen sulfide is protective in an in vivo model of ventilator-induced lung injury

Acute lung injury is characterized by an exaggerated inflammatory response and a high metabolic demand. Mechanical ventilation can contribute to lung injury, resulting in ventilator-induced lung injury (VILI). A suspended-animation-like state induced by hydrogen sulfide (H2S) protects against hypoxia-induced organ injury. We hypothesized that suspended animation is protective in VILI by reducing metabolism and thereby CO2 production, allowing for a lower respiratory rate while maintaining adequate gas exchange. Alternatively, H2S may reduce inflammation in VILI. In mechanically ventilated rats, VILI was created by application of 25 cmH(2)O positive inspiratory pressure (PIP) and zero positive end-expiratory pressure (PEEP). Controls were lung-protective mechanically ventilated (13 cmH(2)O PIP, 5 cmH(2)O PEEP). H2S donor NaHS was infused continuously; controls received saline. In separate control groups, hypothermia was induced to reproduce the H2S-induced fall in temperature. In VILI groups, respiratory rate was adjusted to maintain normo-pH. NaHS dose-dependently and reversibly reduced body temperature, heart rate, and exhaled amount of CO2. In VILI, NaHS reduced markers of pulmonary inflammation and improved oxygenation, an effect which was not observed after induction of deep hypothermia that paralleled the NaHS-induced fall in temperature. Both NaHS and hypothermia allowed for lower respiratory rates while maintaining gas exchange. NaHS reversibly induced a hypometabolic state in anesthetized rats and protected from VILI by reducing pulmonary inflammation, an effect that was in part independent of body temperatur

Microwave conductivity of laser ablated YBa2Cu3O(7-delta) superconducting films and its relation to microstrip transmission line performance

The discovery of high temperature superconductor oxides has raised the possibility of a new class of millimeter and microwave devices operating at temperatures considerably higher than liquid helium temperatures. Therefore, materials properties such as conductivity, current density, and sheet resistance as a function of temperature and frequency, possible anisotropies, moisture absorption, thermal expansion, and others, have to be well characterized and understood. The millimeter wave response of laser ablated YBa2Cu3O(7-delta)/LaAlO3 thin films was studied as a function of temperature and frequency. In particular, the evaluation of their microwave conductivity was emphasized, since knowledge of this parameter provides a basis for the derivation of other relevant properties of these superconducting oxides, and for using them in the fabrication of actual passive circuits. The microwave conductivity for these films was measured at frequencies from 26.5 to 40.0 GHz, in the temperature range from 20 to 300 K. The values of the conductivity are obtained from the millimeter wave power transmitted through the films, using a two fluid model

New highway development in the Netherlands: A residents’ perspective

This study investigates the impacts of new highway development from a residents’ perspective. Data were collected by questionnaire in two residential areas, Son and Uden, both situated along the new A50 highway in the Netherlands. The objectives of this study are: 1) to analyse the extent to which highway development has impacted the residents’ self-reported residential satisfaction through the use of Structural Equation Modeling, and 2) to explore residential self-selection, by comparing characteristics of the original population with those who have relocated into the area during and after highway development using Multinomial Logistic Regression. The results indicate that a small majority of the residents perceived an increase in residential satisfaction due to the highway development. Living in the sampled area in Son (compared to Uden), living on close proximity to the A50 highway, having a low preference for car accessibility, and a strong preference for environmental quality were negatively associated with the change in residential satisfaction, mostly via a negative association with the perceived change in liveability or accessibility. The findings of our second analysis show that residents who had relocated into the area after the highway development have a slightly more ‘highway-oriented’ profile than the original population, i.e. a marginally higher preference for car accessibility and lower preference for environmental quality. The study sheds light on the importance of accounting for the perceptions of the wider residential population and reveals how the impacts of new highway development differ between and within residential areas

Microwave Conductivity of Laser Ablated YBa2Cu3O7-delta Superconducting Films and Its Relation to Microstrip Transmission Line Performance

We report on the values of the microwave conductivity in the normal (sigma(subN)) and superconducting (sigma*=sigma(sub1)-j sigma(sub2)) states of two laser ablated YBa2CU3O7(sigma) thin films at 35 GHz, in the temperature range from 20 to 300 K. The films 0.7 and 0.4 micrometers) were deposited on LaA10(sub3) by laser ablation. The conductivity was obtained from the microwave power transmitted through the films and assuming a two-fluid model. Values of sigma(subN) approximately 2.3 X 10(exp5) S/m at room temperature for both films, and of sigma(sub1) approximately 6.3 X 10(exp5) and 4.6 X 10(exp5) S/m at temperatures around 80 K were obtained for the 0.7 and 0.4 micrometer films respectively. For sigma(sub2) values of 4.9 X 10(exp6) and 5.4 X 10(exp6) S/m were obtained for the 0.7 and 0.4 micrometer films at 80 K. The expected conductor losses and Q-factor of a superconducting ring resonator were calculated using these conductivity values. The theoretical values were then compared with the experimental results obtained for a resonator fabricated from one of these films

Nutritional Control of DNA Replication Initiation through the Proteolysis and Regulated Translation of DnaA

Bacteria can arrest their own growth and proliferation upon nutrient depletion and under various stressful conditions to ensure their survival. However, the molecular mechanisms responsible for suppressing growth and arresting the cell cycle under such conditions remain incompletely understood. Here, we identify post-transcriptional mechanisms that help enforce a cell-cycle arrest in Caulobacter crescentus following nutrient limitation and during entry into stationary phase by limiting the accumulation of DnaA, the conserved replication initiator protein. DnaA is rapidly degraded by the Lon protease following nutrient limitation. However, the rate of DnaA degradation is not significantly altered by changes in nutrient availability. Instead, we demonstrate that decreased nutrient availability downregulates dnaA translation by a mechanism involving the 5' untranslated leader region of the dnaA transcript; Lon-dependent proteolysis of DnaA then outpaces synthesis, leading to the elimination of DnaA and the arrest of DNA replication. Our results demonstrate how regulated translation and constitutive degradation provide cells a means of precisely and rapidly modulating the concentration of key regulatory proteins in response to environmental inputs.National Institutes of Health (U.S.) (Grant 5R01GM082899

Electrochemical behaviour of gamma hydroxybutyric acid at a platinum electrode in acidic medium

The electrooxidation of Gamma Hydroxybutyric Acid (GHB) on a polycrystalline platinum electrode is studied by cyclic voltammetry in acidic medium. Two oxidation peaks, A and B, are obtained in the positive scan within the potential range of the double layer region and of the platinum oxide region, respectively. In the negative going potential sweep an inverted oxidation peak with an onset partially overlapping with the tail of the cathodic peak for the reduction of the platinum oxide formed during the anodic scan is obtained (peak C). This inverted peak can be observed at a potential close to +0.2 V (vs Ag/AgCl at pH 2) and separated 0.4 and 0.8 V from the two other oxidation peaks obtained during the anodic scan and in such conditions that the surface is particularly activated to favour this electrochemical process. The response obtained in the electronic current for the different peaks when GHB concentration and scan rate were changed to allows inferring that these are the result of a potential dependent mechanism. The behaviour observed is according with the oxidation of the alcohol group to the corresponding aldehyde and carboxylic acid (succinic acid) as main products