Sun-view angle effects on reflectance factors of corn canopies

The bidirectional reflectance characteristics of vegetation canopies vary with time of day and through the growing season. In this study the effects of sun and view angles on bidirectional reflectance factors from corn (Zea mays L.) canopies ranging in development from the six leaf stage to harvest maturity were examined. For nadir-acquired reflectance factors there was a strong solar angle dependence in all spectral bands for canopies with low leaf area index (LAI). A decrease in contrast between bare soil and vegetation due to shadows at larger solar zenith angles appeared to be the cause of this dependence. Sun angle dependence was least for well-developed canopies with higher LAI. However, for higher LAI canopies a moderate increase in reflectance factor was observed at larger solar zenith angles and was attributed to the presence of specular reflectance. Trends of off-nadir reflectance factors with respect to sun angle at different view azimuth angles indicated that the position of the sensor relative to the sun was an important factor for determining the angular reflectance characteristics of corn canopies. Reflectance factors were maximized for coincident sun and view angles and minimized when the sensor view direction was towards the sun. View direction relative to row orientation also contributed to the variation in reflectance factors.     

Ein Beitrag zur Eingrenzung der elektrostatischen Kapazität ungeschirmter Streifenleitungen

Übersicht Mit Hilfe von Paaren sogenannten dualer oder auch komplementärer Extremalproblem können unter Verwendung der Methoden der Variationsrechnung obere und untere Schranken für die elektrostatische Kapazität von beliebigen Leiteranordnungen ermittelt werden. In dieser Arbeit werden für ungeschirmte Streifenleiter Lösungsansätze in Gestalt einer modifizierten Finite-Elemente-Methode zur praktischen Anwendung der Extremalprinzipe vorgestellt. Anhand einiger numerischer Beispiele wird die Eignung der behandelten Methode aufgezeigt.

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Capacity calculation with error bounds of unshielded microstrips

Contents By means of pairs of socalled dual or complementary extremum principles upper and lower bounds for the electrostatical capacity of arbitrary conductors can be determined with variational methods. In this paper proposals for solution making use of a modified Finite-Element-Method for unshielded microstrips are presented for the practical application of the extremum principles. Based on some numerical examples the suitibility of the considered approach is demonstrated.

     

Coherence and Specificity of Information-Processing Biases in Depression and Social Phobia.

Research has not resolved whether depression is associated with a distinct information-processing bias, whether the content of the information-processing bias in depression is specific to themes of loss and sadness, or whether biases are consistent across the tasks most commonly used to assess attention and memory processing. In the present study, participants diagnosed with major depression, social phobia, or no Axis I disorder, completed several information-processing tasks assessing attention and memory for sad, socially threatening, physically threatening, and positive stimuli. As predicted, depressed participants exhibited specific biases for stimuli connoting sadness; social phobic participants did not evidence such specificity for threat stimuli. It is important to note that the different measures of bias in memory and attention were not systematically intercorrelated. Implications for the study of cognitive bias in depression, and for cognitive theory more broadly, are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Field trial to evaluate the immunogenicity of pseudorabies virus vaccines with deletions for glycoproteins G and E

This study is a geographically systematic genetic survey of the easternmost subspecies of chimpanzee, Pan troglodytes schweinfurthii. DNA was noninvasively collected in the form of shed hair from chimpanzees of known origin in Uganda, Rwanda, Tanzania, and Za?re. Two hundred sixty-two DNA sequences from hypervariable region 1 of which of the mitochondrial control region were generated. Eastern chimpanzees display levels of mitochondrial genetic variation which are low and which are similar to levels observed in humans (Homo sapiens). Also like humans, between 80% and 90% of the genetic variability within the eastern chimpanzees is apportioned within populations. Spatial autocorrelation analysis shows that genetic similarity between eastern chimpanzees decreases clinically with distance, in a pattern remarkably similar to one seen for humans separated by equivalent geographic distances. Eastern chimpanzee mismatch distributions (frequency distributions of pairwise genetic differences between individuals) are similar in shape to those for humans, implying similar population histories of recent demographic expansion. The overall pattern of genetic variability in eastern chimpanzees is consistent with the hypothesis that the subject has responded demographically to paleoclimatically driven changes in the distribution of eastern African forests during the recent Pleistocene.     

Coiled‐Coil‐Mediated Activation of Oligoarginine Cell‐Penetrating Peptides

A supramolecular approach was undertaken to create functionally activatable cell‐penetrating peptides. Two tetra‐arginines were assembled into an active cell‐penetrating peptide by heterodimerizing leucine zippers. Three different leucine‐zipper pairs were evaluated: activation was found to depend on the association constant of the coiled‐coil peptides. The weaker‐binding peptides required an additional disulfide linkage to induce cell‐penetrating capability, whereas for the most‐stable coiled‐coil no additional stabilization was needed. The latter zipper pair was used to show that the induced formation of the coiled coils allows control over the uptake of an oligoarginine CPP‐conjugated cargo protein.     

Development of a novel piezoresistive thin film sensor system based on hydrogenated carbon

Thin film sensor systems based on hydrogenated carbon have the advantage to combine two very important characteristics in order to be used in measurement engineering: Firstly, the sensory layer demonstrates piezoresistive behavior and secondly its good properties related to hardness and wear resistance lead in a tribologically stable system. Therefore, the thin film sensor systems can be applied into the main distribution of force within machine parts or used for universal interchangeable sensor systems, e.g. sensory washers. In this article the deposition of a self-contained thin film sensor system on a large technical component (spindle shaft) is shown. The spindle shaft with a length of 480 mm and an outer diameter of 90 mm is part of a belt driven machining spindle for planing machines in woodworking industries. In order to establish a measurement system, which allows monitoring the clamping force of the tool holder and the imbalance of the mounted tool, the thin film sensor system was directly applied to the front surface of the spindle shaft. For this application a novel self-contained thin film sensor system was developed, which consists of an alumina layer for electrical isolation, a chromium layer to establish internal sensor electrodes, a piezoresistive hydrogenated carbon layer (1 μm) and a second covering wear resistance and insulation layer (silicon and oxygen modified carbon layer). The piezoresistive sensor layer and the top layer are part of the diamond like carbon layer family (Robertson, Diam Relat Mater 12:79–84, 2003; Bewilogua et al. DLC based coatings for tribological applications, pp. 67–75, 2006; Biehl et al. Thin Solid Films 515(3):1171–1175, 2006, Novel measurement and monitoring system for forming processes based on piezoresistive thin film systems. Springer Verlag, pp. 879–883, 2010).     

Catalytic reduction of NOx with H2/CO/CH4 over PdMOR catalysts

Conversion of NO_x with reducing agents H₂, CO and CH₄, with and without O₂, H₂O, and CO₂ were studied with catalysts based on MOR zeolite loaded with palladium and cerium. The catalysts reached high NO_x to N₂ conversion with H₂ and CO (>90% conversion and N₂ selectivity) range under lean conditions. The formation of N₂O is absent in the presence of both H₂ and CO together with oxygen in the feed, which will be the case in lean engine exhaust. PdMOR shows synergic co-operation between H₂ and CO at 450–500 K. The positive effect of cerium is significant in the case of H₂ and CH₄ reducing agent but is less obvious with H₂/CO mixture and under lean conditions. Cerium lowers the reducibility of Pd species in the zeolite micropores. The catalysts showed excellent stability at temperatures up to 673 K in a feed with 2500 ppm CH₄, 500 ppm NO, 5% O₂, 10% H₂O (0–1% H₂), N₂ balance but deactivation is noticed at higher temperatures. Combining results of the present study with those of previous studies it shows that the PdMOR-based catalysts are good catalysts for NO_x reduction with H₂, CO, hydrocarbons, alcohols and aldehydes under lean conditions at temperatures up to 673 K.     

Toward a persuasive mobile application to reduce sedentary behavior

Prolonged sitting is a potential health risk, not only for people with an inactive lifestyle but also for those who meet the daily physical activity recommendations. Mobile applications that trigger people to take regular breaks from sitting seem promising. In this paper, we present the results of our quest to create effective persuasive mobile applications aimed at reducing sedentary behavior. First, we developed SitCoach, a mobile application to nudge office workers from their seats. SitCoach monitors physical activity and sedentary behavior and provides timely persuasive messages suggesting active breaks. A user test showed that users had little awareness of the risks of prolonged sitting and considered their ability to take active breaks to be highly dependent on external factors. The results from this study formed the basis for a second experiment, which was more extensive in duration and number of participants. In this 6-week experiment, office workers received timely persuasive messages on their smart phones, advising them to take an active break whenever they were sitting behind their computer for too long. Compared to a Control group who did not receive these messages, a significant decrease in computer activity was achieved. The studies show the potential and limitations of using a smart phone as a platform for reducing sedentary behavior. We conclude with recommendations to create effective mobile applications that motivate people to take regular breaks from sitting.