bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of frontogenetic and frontolytic wind field effects during cyclonic development
Authors: Kurz Manfred 
Published: July 2002

AbstractWith the aid of a generalised frontogenesis vector and an expanded Q‐vector diagnosis, the frontogenetic and frontolytic effects in numerical model analysed winds are determined for the case of a typical cyclogenesis over the North Atlantic. These effects, when occurring in the geostrophic part of the flow, give rise to circulations transverse to the frontal zone and the resulting vertical motions are of importance for the dynamics of the cyclone. The forcing of the transverse circulatory motions, which is given by Q‐vector divergences across the isotherms, is computed and compared with the forcing resulting from divergences along the frontal zone. The analyses for 850 and 500 hPa show that frontogenesis dominates at the beginning of the cyclogenesis as well as at its final stage, whereas in the meantime different patterns result for both levels. A significant feature in this case was the development of a new frontal zone north of the deepening low through interaction with the parent low further north. Comparison of the different parts of the omega forcing reveals that the forcing through Q‐vector divergences along the isotherms is the stronger one during the mature stage, but that the transverse circulations contribute significantly to the total forcing. This is especially true for the cold front in the lower troposphere and for the newly developing frontal zone in both levels. At the final stage the influence of the transverse circulatory forcing is even more important and determines to a great extent the shape of the total forcing. The outcome of this study corresponds very well with the findings from other investigations and with the fields derived from a vortex model. Copyright © 1997 Royal Meteorological Society
Space in sound: sound of space
Authors: WORRALL DAVID 
Published: July 2002

At a time when our sense of physical space is
being radically challenged and modified by new global communication
technologies, it seems not unusual that composers are taking a renewed
interest in it. We have begun to experiment with using the new technologies
available to us to move sound in space and create surround-sound environments.For electroacoustic music and other soundscapes we have pan pots on our
mixing desks and in our synthesizers to radially position sounds between
loudspeakers, and reverberators to simulate the distance of sound sources
from the listener. Dolby Digital 5.1 (AC-3) and DTS were introduced as
competing standards for theatre sound recordings around 1992 and consumer
products are available in both formats. In addition, Digital Versatile Discs
(DVDs) are making sophisticated soundfield techniques such as Ambisonics
both practical and more accessible.This article traces some of my own explorations in the use of
3-space for musical composition, examines the limitations of
basing structuring methodologies primarily on functional psychoacoustic
studies of hearing, and suggests alternative approaches based on an
understanding of 3-space from the work of the perceptual psychologist James
Gibson.
Spermidine-Binding Proteins. Purification and Expression Analysis in Maize
Authors: Tassoni Annalisa , Napier Richard M. , Franceschetti Marina , Venis Michael A. , Bagni Nello 
Published: July 2002

Abstract
Polyamine-binding proteins have been identified in a wide range of organisms, including mammals, yeasts, and bacteria. In this work, we have investigated specific spermidine binding to plant membrane proteins purified from microsomes of etiolated maize (Zea mays) coleoptiles. In the final purification step, specific spermidine-binding activity (K d6.02 10−7 m) was eluted from a HiTrapQ fast-protein liquid chromatography column at about 0.25 mNaCl, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the most active fraction showed a major polypeptide of about 60 kD and another copurifying 18-kD protein. Competition experiments, performed on HiTrapQ active fractions, confirmed the specificity of the binding. Upon Sephadex G-100 gel filtration, spermidine binding was associated almost exclusively with the 18-kD protein. On the basis of the N-terminal sequences, degenerate oligonucleotide probes were designed and used to isolate, by reverse transcriptase-polymerase chain reaction and polymerase chain reaction, cDNA fragments of about 1 kb for the 60-kD protein, and 0.9 kb for the 18-kD protein. Northern-blot analysis performed on etiolated coleoptiles and different tissues from 10-d-old maize plants indicated the presence of two different mRNAs of 1.7 and 0.7 kb. Southern-blot analysis indicated that the genes encoding the 60- and 18-kD proteins are probably derived from differential processing of the same precursor mRNA. Using rabbit polyclonal antibodies raised against these proteins, affinity purification and dot-blot experiments detected analogous membrane proteins in monocot and dicot plants.
Fourier Transform Infrared Microspectroscopy Detects Changes in Protein Secondary Structure Associated with Desiccation Tolerance in Developing Maize Embryos1
Authors: Wolkers Willem F. , Bochicchio Adriana , Selvaggi Giuseppe , Hoekstra Folkert A. 
Published: July 2002

Abstract
Isolated immature maize (Zea mays L.) embryos have been shown to acquire tolerance to rapid drying between 22 and 25 d after pollination (DAP) and to slow drying from 18 DAP onward. To investigate adaptations in protein profile in association with the acquisition of desiccation tolerance in isolated, immature maize embryos, we applied in situ Fourier transform infrared microspectroscopy. In fresh, viable, 20- and 25-DAP embryo axes, the shapes of the different amide-I bands were identical, and this was maintained after flash drying. On rapid drying, the 20-DAP axes had a reduced relative proportion of α-helical protein structure and lost viability. Rapidly dried 25-DAP embryos germinated (74%) and had a protein profile similar to the fresh control axes. On slow drying, the α-helical contribution in both the 20- and 25-DAP embryo axes increased compared with that in the fresh control axes, and survival of desiccation was high. The protein profile in dry, mature axes resembled that after slow drying of the immature axes. Rapid drying resulted in an almost complete loss of membrane integrity in the 20-DAP embryo axes and much less so in the 25-DAP axes. After slow drying, low plasma membrane permeability ensued in both the 20- and 25-DAP axes. We conclude that slow drying of excised, immature embryos leads to an increased proportion of α-helical protein structures in their axes, which coincides with additional tolerance of desiccation stress.
Allele-Dependent Barley Grain β-Amylase Activity1
Authors: Erkkilä Maria J. , Leah Robert , Ahokas Hannu , Cameron-Mills Verena 
Published: July 2002

Abstract
The wild ancestor of cultivated barley, Hordeum vulgaresubsp. spontaneum (K. Koch) A. & Gr. (H. spontaneum), is a source of wide genetic diversity, including traits that are important for malting quality. A high β-amylase trait was previously identified in H. spontaneum strains from Israel, and transferred into the backcross progeny of a cross with the domesticated barley cv Adorra. We have used Southern-blot analysis andβ-amy1 gene characterization to demonstrate that the high β-amylase trait in the backcross line is co-inherited with theβ-amy1 gene from the H. spontaneumparent. We have analyzed the β-amy1 gene organization in various domesticated and wild-type barley strains and identified three distinct β-amy1 alleles. Two of theseβ-amy1 alleles were present in modern barley, one of which was specifically found in good malting barley cultivars. The third allele, linked with high grain β-amylase activity, was found only in a H.spontaneum strain from the Judean foothills in Israel. The sequences of three isolatedβ-amy1 alleles are compared. The involvement of specific intron III sequences, in particular a 126-bp palindromic insertion, in the allele-dependent expression of β-amylase activity in barley grain is proposed.
Adventitious Root Growth and Cell-Cycle Induction in Deepwater Rice1
Authors: Lorbiecke René , Sauter Margret 
Published: July 2002

Abstract
Deepwater rice (Oryza sativa) is adapted to survive conditions of severe flooding over extended periods of time. During such periods adventitious roots develop to provide water, nutrients, and anchorage. In the present study the growth of adventitious roots was induced by treatment with ethylene but not auxin, cytokinin, or gibberellin. Root elongation was enhanced between 8 and 10 h after submergence. The population of cells in the S phase and expression of the S-phase-specific histone H3 gene increased within 4 to 6 h. Within 6 to 8 h the G2-phase population increased. Cell-cycle activation was accompanied by sequential induction of a cdc2-activating kinase homolog, R2, of two cdc2 genes, cdc2Os-1and cdc2Os-2, and of three cyclin genes,cycA1;3, cycB2;1, andcycB2;2, but only induction of the R2 gene expression preceded the induction of the S phase, possibly contributing to cell-cycle regulation in the G1 phase. Both cdc2 genes were expressed at slightly higher levels during DNA replication. Transcripts of the A-type cyclin accumulated during the S and G2 phases, and transcripts of the B-type cyclins accumulated during the G2 phase. Cyclin expression was induced at all nodes with a similar time course, suggesting that ethylene acts systemically and that root primordia respond to ethylene at an early developmental stage.
Patterns of Starchy Endosperm Acidification and Protease Gene Expression in Wheat Grains following Germination1
Authors: Domı́nguez Fernando , Cejudo Francisco J. 
Published: July 2002

AbstractCereal aleurone responses to gibberellic acid (GA3) include activation of synthesis of hydrolytic enzymes and acidification of the external medium. We have studied the effect of the pH of the incubation medium on the response of wheat (Triticum aestivum) aleurone cells to GA3. De-embryonated half grains show the capacity for GA3-activated medium acidification when incubation is carried out at pH 6.0 to 7.0 but not at lower pHs. In addition, the activating effect of GA3 on the expression of carboxypeptidase III and thiol protease genes is more efficient when the hormone treatment is carried out at neutral pH. In situ pH staining showed that starchy endosperm acidification takes place upon imbibition and advances from the embryo to the distal part of the grain. In situ hybridization experiments showed a similar pattern of expression of a carboxypeptidase III gene, which is up-regulated by GA3 in aleurone cells. However, aleurone gene expression precedes starchy endosperm acidification. These findings imply that in vivo GA perception by the aleurone layer takes place at neutral pH and suggest that the acidification of the starchy endosperm is regulated by GA3 in germinated wheat grains.
Successive Use of Non-Host Plant Proteinase Inhibitors Required for Effective Inhibition of Helicoverpa armigera Gut Proteinases and Larval Growth
Authors: Harsulkar Abhay M. , Giri Ashok P. , Patankar Aparna G. , Gupta Vidya S. , Sainani Mohini N. , Ranjekar Prabhakar K. , Deshpande Vasanti V. 
Published: July 2002

Abstract
We report on the efficacy of proteinase inhibitors (PIs) from three host plants (chickpea [Cicer arietinum], pigeonpea [Cajanus cajan], and cotton [Gossypium arboreum]) and three non-host (groundnut [Arachis hypogea], winged bean [Psophocarpus tetragonolobus], and potato [Solanum tuberosum]) in retarding the growth ofHelicoverpa armigera larvae, a devastating pest of important crop plants. Enzyme assays and electrophoretic analysis of interaction of H. armigera gut proteinases (HGPs) with PIs revealed that non-host PIs inhibited HGP activity efficiently whereas host PIs were ineffective. In the electrophoretic assay, trypsin inhibitor activity bands were detected in all of the host and non-host plants, but HGP inhibitor activity bands were present only in non-host plants (except cotton in the host plant group). H. armigera larvae reared on a diet containing non-host PIs showed growth retardation, a reduction in total and trypsin-like proteinase activity, and the production of inhibitor-insensitive proteinases. Electrophoretic analysis of PI-induced HGP showed differential regulation of proteinase isoforms. Interestingly, HGP activity induced in response to dietary potato PI-II was inhibited by winged bean PIs. The optimized combination of potato PI-II and winged bean PIs identified in the present study and their proposed successive use has potential in developing H. armigera-resistant transgenic plants.
Salicylic Acid Mediated by the Oxidative Burst Is a Key Molecule in Local and Systemic Responses of Cotton Challenged by an Avirulent Race of Xanthomonas campestris pvmalvacearum
Authors: Martinez Christelle , Baccou Jean-Claude , Bresson Estelle , Baissac Yves , Daniel Jean-François , Jalloul Aı̈da , Montillet Jean-Luc , Geiger Jean-Paul , Assigbetsé Komi , Nicole Michel 
Published: July 2002

Abstract
We analyzed the production of reactive oxygen species, the accumulation of salicylic acid (SA), and peroxidase activity during the incompatible interaction between cotyledons of the cotton (Gossypium hirsutum) cv Reba B50/Xanthomonas campestris pvmalvacearum (Xcm) race 18. SA was detected in petioles of cotyledons 6 h after infection and 24 h post inoculation in cotyledons and untreated leaves. The first peak of SA occurred 3 h after generation of superoxide (O2 ·−), and was inhibited by infiltration of catalase. Peroxidase activity and accumulation of SA increased in petioles of cotyledons and leaves following H2O2 infiltration of cotyledons from 0.85 to 1 mm. Infiltration of 2 mm SA increased peroxidase activity in treated cotyledons and in the first leaves, but most of the infiltrated SA was rapidly conjugated within the cotyledons. When increasing concentrations of SA were infiltrated 2.5 h post inoculation at the beginning of the oxidative burst, the activity of the apoplastic cationic O2 ·−-generating peroxidase decreased in a dose-dependent manner. We have shown that during the cotton hypersensitive response to Xcm, H2O2 is required for local and systemic accumulation of SA, which may locally control the generation of O2 ·−. Detaching cotyledons at intervals after inoculation demonstrated that the signal leading to systemic accumulation of SA was emitted around 3 h post inoculation, and was associated with the oxidative burst. SA produced 6 h post infection at HR sites was not the primary mobile signal diffusing systemically from infected cotyledons.
Permeability and Channel-Mediated Transport of Boric Acid across Membrane Vesicles Isolated from Squash Roots
Authors: Dordas Christos , Chrispeels Maarten J. , Brown Patrick H. 
Published: July 2002

Abstract
Boron is an essential micronutrient for plant growth and the boron content of plants differs greatly, but the mechanism(s) of its uptake into cells is not known. Boron is present in the soil solution as boric acid and it is in this form that it enters the roots. We determined the boron permeability coefficient of purified plasma membrane vesicles obtained from squash (Cucurbita pepo) roots and found it to be 3 × 10−7 ±1.4 × 10−8 cm s−1, six times higher than the permeability of microsomal vesicles. Boric acid permeation of the plasma membrane vesicles was partially inhibited (30%–39%) by mercuric chloride and phloretin, a non-specific channel blocker. The inhibition by mercuric chloride was readily reversible by 2-mercaptoethanol. The energy of activation for boron transport into the plasma membrane vesicles was 10.2 kcal mol−1. Together these data indicate that boron enters plant cells in part by passive diffusion through the lipid bilayer of the plasma membrane and in part through proteinaceous channels. Expression of the major intrinsic protein (MIP) PIP1 in Xenopus laevis oocytes resulted in a 30% increase in the boron permeability of the oocytes. Other MIPs tested (PIP3, MLM1, and GlpF) did not have this effect. We postulate that certain MIPs, like those that have recently been shown to transport small neutral solutes, may also be the channels through which boron enters plant cells.
Release of Reactive Oxygen Intermediates (Superoxide Radicals, Hydrogen Peroxide, and Hydroxyl Radicals) and Peroxidase in Germinating Radish Seeds Controlled by Light, Gibberellin, and Abscisic Acid
Authors: Schopfer Peter , Plachy Claudia , Frahry Gitta 
Published: July 2002

AbstractGermination of radish (Raphanus sativus cv Eterna) seeds can be inhibited by far-red light (high-irradiance reaction of phytochrome) or abscisic acid (ABA). Gibberellic acid (GA3) restores full germination under far-red light. This experimental system was used to investigate the release of reactive oxygen intermediates (ROI) by seed coats and embryos during germination, utilizing the apoplastic oxidation of 2′,7′-dichlorofluorescin to fluorescent 2′,7′-dichlorofluorescein as an in vivo assay. Germination in darkness is accompanied by a steep rise in ROI release originating from the seed coat (living aleurone layer) as well as the embryo. At the same time as the inhibition of germination, far-red light and ABA inhibit ROI release in both seed parts and GA3 reverses this inhibition when initiating germination under far-red light. During the later stage of germination the seed coat also releases peroxidase with a time course affected by far-red light, ABA, and GA3. The participation of superoxide radicals, hydrogen peroxide, and hydroxyl radicals in ROI metabolism was demonstrated with specific in vivo assays. ROI production by germinating seeds represents an active, developmentally controlled physiological function, presumably for protecting the emerging seedling against attack by pathogens.
The Biological Functions of Glutathione Revisited in Arabidopsis Transgenic Plants with Altered Glutathione Levels
Authors: Xiang Chengbin , Werner Bonnie L. , Christensen E'Lise M. , Oliver David J. 
Published: July 2002

Abstract
A functional analysis of the role of glutathione in protecting plants from environmental stress was undertaken by studying Arabidopsis that had been genetically modified to have altered glutathione levels. The steady-state glutathione concentration in Arabidopsis plants was modified by expressing the cDNA for γ-glutamyl-cysteine synthetase (GSH1) in both the sense and antisense orientation. The resulting plants had glutathione levels that ranged between 3% and 200% of the level in wild-type plants. Arabidopsis plants with low glutathione levels were hypersensitive to Cd due to the limited capacity of these plants to make phytochelatins. Plants with the lowest levels of reduced glutathione (10% of wild type) were sensitive to as little as 5 μm Cd, whereas those with 50% wild-type levels required higher Cd concentrations to inhibit growth. Elevating glutathione levels did not increase metal resistance. It is interesting that the plants with low glutathione levels were also less able to accumulate anthocyanins supporting a role for glutathione S-transferases for anthocyanin formation or for the vacuolar localization and therefore accumulation of these compounds. Plants with less than 5% of wild-type glutathione levels were smaller and more sensitive to environmental stress but otherwise grew normally.
Thin Films of Niobium for Cryotron Ground Planes
Authors: Joynson R. E. , Neugebauer C. A. , Rairden J. R. 
Published: July 2002

A process is described for the vacuum deposition of thin films of superconductive niobium for use as electrical ground planes in cryoelectric circuitry. High-purity niobium films are deposited onto glass and aluminum substrates by evaporation from a focused electron-beam-heated source.
The deposition process is described in detail, and the influence of substrate temperature on film purities is discussed. A pinhole-free insulation between 1000–3000 Å is formed on the niobium films by anodization, and the surface roughness of the niobium is examined with an electron microscope as a function of oxide thickness. The superconducting properties of the niobium films are described in terms of their critical temperature, lattice parameter, resistance ratio, critical currents of shielded Sn films, and their ability to resist flux trapping.
Efficacies of Vesicular and Free Sodium Stibogluconate Formulations against Clinical Isolates of
Leishmania donovani
Authors: Carter K. C. , Mullen A. B. , Sundar S. , Kenney R. T. 
Published: July 2002

ABSTRACT

In this study, the in vitro and in vivo efficacies of free sodium stibogluconate (SSG) and a nonionic surfactant vesicular formulation of SSG (SSG-NIV) against a laboratory strain of
Leishmania donovani
(MHOM/ET/67:LV82) and different clinical isolates of
L. donovani
were determined. Treatment with SSG-NIV was more effective against intramacrophage amastigotes than treatment with SSG. In vivo murine studies showed that there was interstrain variability in the infectivity of the different
L. donovani
strains, with two of the strains (20001 and 20003) giving low parasite burdens. In addition, interstrain variability in the antileishmanial efficacy of SSG in a single dose containing 300 mg of Sb(V)/kg of body weight was observed. This dose of free drug either caused a >97% reduction in liver parasite burdens or had no significant effect on parasite burdens compared with the result with the respective control. In some instances, treatment with this free SSG dose also caused a significant reduction in spleen (strain 20006) or bone marrow (strains 20001 and 20009) parasite burdens. Treatment with SSG-NIV was more effective than that with SSG against all of the strains tested. In SSG-responsive strains, the reduction in liver parasite burdens by SSG-NIV treatment was similar to that caused by free SSG. In SSG-nonresponsive strains, SSG-NIV treatment caused at least a 95% reduction in liver parasite burdens. Overall, these results indicate that the use of a vesicular formulation of SSG is likely to increase its clinical efficacy against visceral leishmaniasis.
Multidrug Resistant
Mycobacterium leprae
from Patients with Leprosy
Authors: Maeda Shinji , Matsuoka Masanori , Nakata Noboru , Kai Masanori , Maeda Yumi , Hashimoto Ken , Kimura Hiroaki , Kobayashi Kazuo , Kashiwabara Yoshiko 
Published: July 2002

ABSTRACT

Sequences of the
folP1
,
rpoB
, and
gyrA
genes were analyzed for 88 isolates of
Mycobacterium leprae
from leprosy patients in Japan, Haiti, Indonesia, Pakistan, and the Philippines. Thirteen isolates (14.8%) showed representative mutations in more than two genes, suggesting the emergence of multidrug-resistant
M. leprae
.
Rapid Detection of Mutations in the Human-Derived
Pneumocystis carinii
Dihydropteroate Synthase Gene Associated with Sulfa Resistance
Authors: Ma Liang , Kovacs Joseph A. 
Published: July 2002

ABSTRACT

Recent studies have shown that point mutations in the dihydropteroate synthase (DHPS) gene of human-derived
Pneumocystis carinii
are related to exposure to sulfa drugs and possibly represent the emergence of sulfa resistance. We developed a simple single-strand conformation polymorphism (SSCP) method to permit rapid detection of these mutations. With plasmid constructs, SSCP was able to detect as little as 10% of a minority population. The SSCP assay was compared to direct sequencing for typing the DHPS gene by examining 37 clinical isolates with known DHPS sequences and 41 clinical isolates with unknown DHPS sequences. The typing results were consistent between these two methods for all isolates except 11 in which mutations were detected by SSCP but not by direct sequencing. Sequencing of individual clones after subcloning confirmed the presence of mutations in a minority population as determined by SSCP. SSCP is a very simple and sensitive method for rapid identification of
P. camii
DHPS mutations.