Nutrient availability and yield formation.

Available macronutrients present in the immediate vicinity of plant roots contribute only to a small degree to the total nutrient uptake of the plant. An important factor in the availability of a nutrient is therefore its mobility in the soil. The rate of translocation of a nutrient by diffusion or mass flow depends on its concentration in the soil solution, hence the nutrient level of the soil solution is of greater importance than the amounts of exchangeable or easily soluble plant nutrients in determining nutrient availability. Soil moisture and the volume of the root system also have an important effect on nutrient availability. In general, soil test methods based on the nutrient concentration of the soil solution give better correlations with plant growth than methods based on the pool of soluble and/or exchangeable nutrients. 43 references. (Abstract retrieved from CAB Abstracts by CABI’s permission

A new era of spectroscopy: SINFONI, NIR integral field spectroscopy at the diffraction limit of an 8m telescope

SINFONI, the SINgle Faint Object Near-infrared Investigation, is an instrument for the Very Large Telescope (VLT), which will start its operation mid 2002 and allow for the first time near infrared (NIR) integral field spectroscopy at the diffraction limit of an 8-m telescope. SINFONI is the combination of two state-of-the art instruments, the integral field spectrometer SPIFFI, built by the Max-Planck-Institut fuer extraterrestrische Physik (MPE), and the adaptive optics (AO) system MACAO, built by the European Southern Observatory (ESO). It will allow a unique type of observations by delivering simultaneously high spatial resolution (pixel sizes 0.025arcsec to 0.25arcsec) and a moderate spectral resolution (R~2000 to R~4500), where the higher spectral resolution mode will allow for software OH suppression. This opens new prospects for astronomy.Comment: 9 pages, 4 figures, to appear in SPIE proceedings "Astronomical Telescopes and Instrumentation 2000". More recent sensitivity estimates are available at http://www.mpe.mpg.de/www_ir/ir_instruments/sinfoni/spiffi.ht

A Triarylamine-Triarylborane Dyad with a Photochromic Dithienylethene Bridge

A molecular triad composed of a triarylamine donor, a triarylborane acceptor, and a photoisomerizable dithienylethene bridge has been synthesized and explored by cyclic voltammetry, UV–vis, and luminescence spectroscopy. The effects of irradiation with UV light and fluoride addition on the electrochemical and optical spectroscopic properties of the donor–bridge–acceptor molecule were investigated. Photoisomerization of the dithienylethene bridge affects the triarylboron reduction potential, but not the triarylamine oxidation potential. UV–vis experiments reveal that the association constant for fluoride binding at the triarylborane site is independent of the isomerization state of the bridge. Irradiation of a THF solution of our donor–bridge–acceptor molecule with UV light, followed by F– addition, leads to a different color of the sample than UV irradiation alone or F– addition alone

Spectral properties and geology of bright and dark material on dwarf planet Ceres

Variations and spatial distributions of bright and dark material on dwarf planet Ceres play a key role in understanding the processes that have led to its present surface composition. We define limits for bright and dark material in order to distinguish them consistently, based on the reflectance of the average surface using Dawn Framing Camera data. A systematic classification of four types of bright material is presented based on their spectral properties, composition, spatial distribution, and association with specific geomorphological features. We found obvious correlations of reflectance with spectral shape (slopes) and age; however, this is not unique throughout the bright spots. Although impact features show generally more extreme reflectance variations, several areas can only be understood in terms of inhomogeneous distribution of composition as inferred from Dawn Visible and Infrared Spectrometer data. Additional material with anomalous composition and spectral properties are rare. The identification of the composition and origin of the dark, particularly the darkest material, remains to be explored. The spectral properties and the morphology of the dark sites suggest an endogenic origin, but it is not clear whether they are more or less primitive surficial exposures or excavated subsurface but localized material. The reflectance, spectral properties, inferred composition, and geologic context collectively suggest that the bright and dark material tends to gradually change toward the average surface over time. This could be because of multiple processes, i.e., impact gardening/space weathering, and lateral mixing, including thermal and aqueous alteration, accompanied by changes in composition and physical properties such as grain size, surface temperature, and porosity (compaction).Comment: Meteoritics and Planetary Science; Dawn at Ceres special issu

G301: The Flying Falcon geological remote sensing experiment

Get-Away Special (GAS) G-301, named the Flying Falcon and scheduled for launch on the STS-77 Space Shuttle in April, 1996, is being prepared to perform an experiment designed by the Department of Geology, Bowling Green State University (BGSU). The experiment will employ a new type of infrared imager designed and built by a consortium of Teltron Technologies Inc., Hudson Research Inc., and BGSU that is an uncooled, quantrum ferro-electric, infrared return beam vidicon (IRBV) camera capable of detecting thermal infrared radiation throughout the 2.0-50.0 micron wavelength region, and to which an integral, unable Fabry-Perot filter and a telescopic lens have been added. The primary objectives in the experiment include the mapping of methane plumes from solid waste landfills and wetlands in the midwestern U.S., the mapping of methane plumes offshore in the Gulf of Mexico and in the Middle East, brief monitoring for precursors of volcanoes or earthquakes in the South China sea and the East Pacific Rise (about 300 km west of Easter Island), and the mapping of silica content in exposed outcrops and residual soils of the southwestern U.S. and Middle East

Bicarbonat als auslösender Faktor der Eisenchlorose bei der Weinrebe (Vitis vinifera)

In einem Hydrokulturversuch und in einem Quarzsandversuch wurde der Einfluß von HCO3- auf das Auftreten von Fe-Chlorose bei der Weinrebe untersucht. HCO3- im Nährmedium induzierte bei beiden Versuchen typische Fe-Mangelsymptome an den jüngeren Blättern, obgleich im Nährmedium Fe vorhanden war. Demgegenüber traten im Quarzsandversuch bei Abwesenheit von Fe und HCO3- im Nährmedium keine Fe-Mangelsymptome auf. Im Hydrokulturversuch waren in der Variante „ohne Fe" die Fe-Mangelsymptome wesentlich schwächer ausgeprägt als in den Varianten, die in der Nährlösung Fe + HC03 - enthielten. Ernährung mit NO3- + HCO3- wirkte stärker Chlorose auslösend als Ernährung mit NH4+  + HCO3-.In den Varianten mit Carbonat + Einleitung von C02 in die Nährlösung traten HCO3-- Konzentrationen von mehr als 10 X 10 -3M auf. Sie wirkten toxisch auf die Pflanzen. Hier wurden keine Fe-Chlorosen beobachtet. Vielmehr starben die Pflanzen dieser Variante im Verlaufe der Versuchsperiode ab. Der Gehalt der Blätter an Fe stand in keiner Beziehung zum Auftreten der Fe-Chlorose.Bicarbonate as a factor inducing iron chlorosis in grapevine (Vitis vinifera)The effect of HCO3- on the occurrence of iron chlorosis in grapevine has been studied in a solution culture experiment and in a quartz sand experiment. In both experiments, HCO3- in the nutrient medium induced typical Fe chlorotic symptoms in the younger leaves, although Fe was present in the nutrient medium. In the quartz sand experiment, absence of Fe and HCO3- in the nutrient medium did not result in Fe deficiency symptoms. In the solution culture· experiment, the Fe deficiency symptoms were less marked in the treatment "without Fe" as compared with the treatments which contained Fe + HCO3- in the nutrient solution. Iron chlorosis was more heavily induced by nutrition with NO3- + HC03 - than with NH4+  + HCO3- . In the treatments with carbonate and an additional supply of C02 to the nutrient solution, HCO3- concentrations higher than 10 X 10-3M were measured, which were toxic to the plants. In these treatments no Fe chlorosis occurred, and the plants died before the end of the experiment. The Fe content of the leaves was not related to the occurrence of Fe chlorosis

Middle Atmosphere Dynamics with Gravity Wave Interactions in the Numerical Spectral Model: Tides and Planetary Waves

As Lindzen (1981) had shown, small-scale gravity waves (GW) produce the observed reversals of the zonal-mean circulation and temperature variations in the upper mesosphere. The waves also play a major role in modulating and amplifying the diurnal tides (DT) (e.g., Waltersheid, 1981; Fritts and Vincent, 1987; Fritts, 1995a). We summarize here the modeling studies with the mechanistic numerical spectral model (NSM) with Doppler spread parameterization for GW (Hines, 1997a, b), which describes in the middle atmosphere: (a) migrating and non-migrating DT, (b) planetary waves (PW), and (c) global-scale inertio gravity waves. Numerical experiments are discussed that illuminate the influence of GW filtering and nonlinear interactions between DT, PW, and zonal mean variations. Keywords: Theoretical modeling, Middle atmosphere dynamics, Gravity wave interactions, Migrating and non-migrating tides, Planetary waves, Global-scale inertio gravity waves

Impact of elosulfase alfa in patients with morquio A syndrome who have limited ambulation: An open-label, phase 2 study.

Efficacy and safety of elosulfase alfa enzyme replacement therapy (ERT) were assessed in an open-label, phase 2, multi-national study in Morquio A patients aged ≥5 years unable to walk ≥30 meters in the 6-min walk test. Patients received elosulfase alfa 2.0 mg/kg/week intravenously for 48 weeks. Efficacy measures were functional dexterity, pinch/grip strength, mobility in a modified timed 25-foot walk, pain, quality of life, respiratory function, and urine keratan sulfate (KS). Safety/tolerability was also assessed. Fifteen patients received elosulfase alfa, three patients discontinued ERT due to adverse events (two were grade 3 drug-related adverse events, the other was not drug-related), and two patients missed >20% of planned infusions; 10 completed treatment through 48 weeks and received ≥80% of planned infusions (Modified Per Protocol [MPP] population). The study population had more advanced disease than that enrolled in other trials. From baseline to week 48, MPP data showed biochemical efficacy (urine KS decreased 52.4%). The remaining efficacy results were highly variable due to challenges in test execution because of severe skeletal and joint abnormalities, small sample sizes, and clinical heterogeneity among patients. Eight patients showed improvements in one or more outcome measures; several patients indicated improvements not captured by the study assessments (e.g., increased energy, functional ability). The nature of adverse events was similar to other elosulfase alfa studies. This study illustrates the considerable challenges in objectively measuring impact of ERT in very disabled Morquio A patients and highlights the need to examine results on an individual basis. © 2016 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc

Imaging the Universe in 3D with the VLT: The Next Generation Field Spectrometer SPIFFI

We present SPIFFI, the integral field spectrometer for the VLT. This instrument allows simultaneous observation of infrared spectra in more than 1000 image points of a two dimensional field. With its set of four gratings and a pixel scale that can be varied by a factor of ten, SPIFFI provides high flexibility, and at the same time offers the unique possibility of diffraction limited imaging spectroscopy at an 8m-class telescope, when fed by the adaptive optics system MACAO. We outline the scientific drivers for building such an instrument, the concept of image slicing, the optical design, and the implementation of SPIFFI