bluuebunny/crossref_metadata_2025_split huggingface dataset:
Different Pathways Are Involved in Phosphate and Iron Stress-Induced Alterations of Root Epidermal Cell Development
Authors: Schmidt Wolfgang , Schikora Adam 
Published: July 2002

Abstract
Low bioavailability of phosphorus (P) and iron (Fe) induces morphogenetic changes in roots that lead to a higher surface-to-volume ratio. In Arabidopsis, an enlargement in the absorptive surface area is achieved by an increase in the length and frequency of hairs in roots of Fe- and P-deficient plants. The extra root hairs are often located in positions that are occupied with non-hair cells under normal conditions, i.e. over a tangential wall of underlying cortical cells. An involvement of auxin and ethylene in root epidermis cell development of Fe- and P-deficient plants was inferred from phenotypical analysis of hormone-related Arabidopsis mutants and from the application of substances that interfere with either synthesis, transport, or perception of the hormones. Application of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid or the auxin analog 2,4-D caused a marked increase in root hair density in plants of all growth types and confers a phenotype characteristic of ethylene-overproducing mutants. Hormone insensitivity and application of hormone antagonists inhibited the initiation of extranumerary root hairs induced by Fe deficiency, but did not counteract the formation of extra hairs in response to P deprivation. A model is presented summarizing putative pathways for alterations in root epidermal cell patterning induced by environmental stress.
Mobilization of Ca2+ by Cyclic ADP-Ribose from the Endoplasmic Reticulum of Cauliflower Florets
Authors: Navazio Lorella , Mariani Paola , Sanders Dale 
Published: July 2002

Abstract
The NAD+ metabolite cADP-Rib (cADPR) elevates cytosolic free Ca2+ in plants and thereby plays a central role in signal transduction pathways evoked by the drought and stress hormone abscisic acid. cADPR is known to mobilize Ca2+ from the large vacuole of mature cells. To determine whether additional sites for cADPR-gated Ca2+ release reside in plant cells, microsomes from cauliflower (Brassica oleracea) inflorescences were subfractionated on sucrose density gradients, and the distribution of cADPR-elicited Ca2+ release was monitored. cADPR-gated Ca2+ release was detected in the heavy-density fractions associated with rough endoplasmic reticulum (ER). cADPR-dependent Ca2+ release co-migrated with two ER markers, calnexin and antimycin A-insensitive NADH-cytochromec reductase activity. To investigate the possibility that contaminating plasma membrane in the ER-rich fractions was responsible for the observed release, plasma membrane vesicles were purified by aqueous two-phase partitioning, everted with Brij-58, and loaded with Ca2+: These vesicles failed to respond to cADPR. Ca2+ release evoked by cADPR at the ER was fully inhibited by ruthenium red and 8-NH2-cADPR, a specific antagonist of cADPR-gated Ca2+ release in animal cells. The presence of a Ca2+ release pathway activated by cADPR at higher plant ER reinforces the notion that, alongside the vacuole, the ER participates in Ca2+ signaling.
Regulation of Flowering in Arabidopsis by anFLCHomologue
Authors: Ratcliffe Oliver J. , Nadzan Greg C. , Reuber T. Lynne , Riechmann José Luis 
Published: July 2002

AbstractThe Arabidopsis FLC gene encodes a MADS domain protein that acts as a repressor of flowering. Late-flowering vernalization-responsive ecotypes and mutants have high steady-state levels of FLC transcript, which decrease during the promotion of flowering by vernalization. Therefore, FLC has a central role in regulating the response to vernalization. We have isolated an Arabidopsis gene, MAF1, which encodes a protein that is closely related to FLC. Overexpression studies demonstrate thatMAF1 produces comparable effects to FLC, and likely has a similar function in the regulation of flowering. In contrast to FLC, however, MAF1 expression shows a less clear correlation with the vernalization response. In addition, MAF1 overexpression does not influenceFLC transcript levels. Thus, MAF1 likely acts downstream or independently of FLC transcription. We further report identification of a cluster of four additionalFLC-like genes in the Arabidopsis genome.
Characterization of Two HKT1 Homologues from Eucalyptus camaldulensis That Display Intrinsic Osmosensing Capability
Authors: Liu Weihong , Fairbairn David J. , Reid Rob J. , Schachtman Daniel P. 
Published: July 2002

Abstract
Plants have multiple potassium (K+) uptake and efflux mechanisms that are expressed throughout plant tissues to fulfill different physiological functions. Several different classes of K+ channels and carriers have been identified at the molecular level in plants. K+ transporters of the HKT1 superfamily have been cloned from wheat (Triticum aestivum), Arabidopsis, and Eucalyptus camaldulensis. The functional characteristics as well as the primary structure of these transporters are diverse with orthologues found in bacterial and fungal genomes. In this report, we provide a detailed characterization of the functional characteristics, as expressed in Xenopus laevis oocytes, of two cDNAs isolated from E. camaldulensis that encode proteins belonging to the HKT1 superfamily of K+/Na+transporters. The transport of K+ inEcHKT-expressing oocytes is enhanced by Na+, but K+ was also transported in the absence of Na+. Na+ is transported in the absence of K+ as has been demonstrated for HKT1 and AtHKT1. Overall, the E. camaldulensis transporters show some similarities and differences in ionic selectivity to HKT1 and AtHKT1. One striking difference between HKT1 and EcHKT is the sensitivity to changes in the external osmolarity of the solution. Hypotonic solutions increased EcHKT induced currents in oocytes by 100% as compared with no increased current in HKT1 expressing or uninjected oocytes. These osmotically sensitive currents were not enhanced by voltage and may mediate water flux. The physiological function of these osmotically induced increases in currents may be related to the ecological niches that E. camaldulensis inhabits, which are periodically flooded. Therefore, the osmosensing function of EcHKT may provide this species with a competitive advantage in maintaining K+ homeostasis under certain conditions.
Designed heterodimerizing leucine zippers with a ranger of pIs and stabilities up to 10−15 M
Authors: Moll Jonathan R. , Ruvinov Sergei B. , Pastan Ira , Vinson Charles 
Published: July 2002

AbstractWe have designed a heterodimerizing leucine zipper system to target a radionuclide to prelocalized noninternalizing tumor‐specific antibodies. The modular nature of the leucine zipper allows us to iteratively use design rules to achieve specific homodimer and heterodimer affinities. We present circular‐dichroism thermal denaturation measurements on four pairs of heterodimerizing leucine zippers. These peptides are 47 amino acids long and contain four or five pairs of electrostatically attractive g ↔ e′ (i, i′ +5) interhelical heterodimeric interactions. The most stable heterodimer consists of an acidic leucine zipper and a basic leucine zipper that melt as homodimers in the micro (Tm = 28°C) or nanomolar (Tm = 40°C) range, respectively, but heterodimerize with a Tm >90°C, calculated to represent femtamolar affinities. Modifications to this pair of acidic and basic zippers, designed to destabilize homodimerization, resulted in peptides that are unstructured monomers at 4 μM and 6°C but that heterodimerize with a Tm = 74°C or Kd(37) = 1.1 × 10−11 M. A third heterodimerizing pair was designed to have a more neutral isoelectric focusing point (pI) and formed a heterodimer with Tm = 73°C. We can tailor this heterodimerizing system to achieve pharmacokinetics aimed at optimizing targeted killing of cancer cells.
Epitope mapping of a monoclonal antibody against human thrombin by H/D‐exchange mass spectrometry reveals selection of a diverse sequence in a highly conserved protein
Authors: Baerga‐Ortiz Abel , Hughes Carrie A. , Mandell Jeffrey G. , Komives Elizabeth A. 
Published: July 2002

AbstractThe epitope of a monoclonal antibody raised against human thrombin has been determined by hydrogen/deuterium exchange coupled to MALDI mass spectrometry. The antibody epitope was identified as the surface of thrombin that retained deuterium in the presence of the monoclonal antibody compared to control experiments in its absence. Covalent attachment of the antibody to protein G beads and efficient elution of the antigen after deuterium exchange afforded the analysis of all possible epitopes in a single MALDI mass spectrum. The epitope, which was discontinuous, consisting of two peptides close to anion‐binding exosite I, was readily identified. The epitope overlapped with, but was not identical to, the thrombomodulin binding site, consistent with inhibition studies. The antibody bound specifically to human thrombin and not to murine or bovine thrombin, although these proteins share 86% identity with the human protein. Interestingly, the epitope turned out to be the more structured of two surface regions in which higher sequence variation between the three species is seen.
Wake Recovery Performance Benefit in a High-Speed Axial Compressor
Authors: Van Zante Dale E. , Adamczyk John J. , Strazisar Anthony J. , Okiishi Theodore H. 
Published: July 2002

Abstract
Rotor wakes are an important source of loss in axial compressors. The decay rate of a rotor wake is largely due to both mixing (results in loss) and stretching (no loss accrual). Thus, the actual loss associated with rotor wake decay will vary in proportion to the amounts of mixing and stretching involved. This wake stretching process, referred to by Smith (1996) as recovery, is reversible and for a 2-D rotor wake leads to an inviscid reduction of the velocity deficit of the wake. It will be shown that for the rotor/stator spacing typical of core compressors, wake stretching is the dominant wake decay process within the stator with viscous mixing playing only a secondary role. A model for the rotor wake decay process is developed and used to quantify the viscous dissipation effects relative to those of inviscid wake stretching. The model is verified using laser anemometer measurements acquired in the wake of a transonic rotor operated alone and in a stage configuration at near peak efficiency and near stall operating conditions. Results from the wake decay model exhibit good agreement with the experimental data. Data from the model and laser anemometer measurements indicate that rotor wake straining (stretching) is the primary decay process in the stator passage. Some implications of these results on compressor stage design are discussed.
Analysis of Damage of Ball Bearings of Aeronautical Transmissions by
Auto-Power Spectrum and Cross-Power Spectrum
Authors: Cavacece Massimo , Introini Alberto 
Published: July 2002

Abstract
Fourier analysis is used as a framework in which to obtain spectral estimates for nonstationary discrete time signals. Analysis of the auto-power spectrum and the cross-power spectrum makes it possible to distinguish between false alarms and real risk situations and, in the latter case, to determine the propagation of any possible damage in its earliest phases. This analysis then allows corrective actions to be taken, such as parts replacement, in order to limit damage and contamination of component parts in fatigue tests and thus shorten machine stoppage times.
Time-Domain Analysis of Floating Bodies with Forward Speed
Authors: Clauss Günther F. , Stutz Katja 
Published: July 2002

Abstract
Broaching, surf-riding, and capsizing of ships and offshore structures are transient wave-structure interactions which imply high risks for crew, vessel and cargo. As nonlinear effects are of great importance, time-domain investigations are indispensable. For unveiling the associated driving mechanism of these critical motions, it is desirable to analyze the cause-reaction chains in detail: Depending on the transient wave elevation, we obtain an instationary pressure distribution on the wetted surface of the cruising vessel. Resulting forces and moments excite vessel motions in six degrees of freedom. Based on the linear panel-method program for transient wave-body interactions, TiMIT [Korsmeyer et al. (1999)], this paper investigates seakeeping characteristics of offshore structures with forward speed. Results are presented in frequency and time domain. The procedure allows to identify critical seaways, and to analyze cause-reaction chains in deterministic wave sequences where critical and steep wave packets are embedded in random seas. The detailed evaluation reveals that large roll and pitch motions are easily reduced by variation of course and speed. For investigating the mechanism of wave/structure interactions, this paper introduces the relevant time-domain methodology, and indicates how nonlinear wave characteristics can be introduced in the time-stepping analysis. In subsequent steps nonlinear wave/structure interactions will also be considered.
Green Water Loading on a FPSO
Authors: Faltinsen O. M. , Greco M. , Landrini M. 
Published: July 2002

Abstract
Green Water Loading in the bow region of a Floating Production Storage and Offloading unit (FPSO) in head sea waves is studied by numerical means. A 2-D method satisfying the exact nonlinear free-surface conditions within potential-flow theory has been developed as a step towards a fully 3-D method. The flow is assumed 2-D in a plane containing the ship’s centerplane. The method is partly validated by model tests. The importance of environmental conditions, 3-D flow effects, ship motions, and hull parameters are summarized. The wave steepness of the incident waves causes important nonlinear effects. The local flow at the bow is, in general, important to account for. It has become popular to use a dam-breaking model to study the propagation of water on the deck. However, the numerical studies show the importance of accounting for the coupled flow between the deck and outside the ship. When the water is propagating on the deck, a suitable distance from the bow can be found from where shallow-water equations can be used. Impact between green water on deck and a vertical deck-house side in the bow area is studied in details. A similarity solution for impact between a wedge-formed water front and a vertical rigid wall is used. Simplified solutions for an impacting fluid wedge with small and large interior angles are developed, both to support the numerical computations and to provide simpler formulas of practical use. It is demonstrated how the local design of the deck house can reduce the slamming loads. The importance of hydroelasticity during the impact is discussed by using realistic structural dimensions of a deck house. This indicates that hydroelasticity is insignificant. On the contrary, first results from an ongoing experimental investigation document blunt impacts against the deck during the initial stage of water shipping, which deserve a dedicated hydroelastic analysis.
Oblique Wave-Scattering by Thick Horizontal Barriers
Authors: Mandal B. N. , Kanoria Mridula 
Published: July 2002

Abstract
This paper is concerned with scattering of an obliquely incident surface water wave train by an obstacle in the form of a thick horizontal barrier of rectangular cross section present in finite depth water. Four different geometrical configurations of the obstacle are considered. It may be surface-piercing or bottom-standing, or in the form of a submerged block not extending down to the bottom, or in the form of a thick wall with a submerged gap. Multi-term Galerkin approximations involving ultraspherical Gegenbauer polynomials for solving first-kind integral equations are utilized in the mathematical analysis to obtain very accurate numerical estimates for the reflection coefficient, which are depicted graphically against the wave number for each configurations of the thick barrier. [S0892-7219(00)00701-9]
HAARP Facility in Alaska
Authors: Gordon William E. 
Published: July 2002

With respect to the News & Comment article “Ionosphere research lab sparks fears in Alaska” by Lisa Busch (
21 Feb., p. 1060
), I would like to make two points.

First, the anti-HAARP (High-Frequency Active Auroral Research Program) activists overestimated the power of the Gakona, Alaska, facility by a factor of more than a million and then used statements in patents (
1
) to fuel speculations on the part of the public about possible effects such as weather manipulations, mind warping, and communication disruptions. This incorrect information has been refuted in hearings in the Alaska legislature, in a video prepared by Senator Frank H. Murkowski (R-AK) for airing in Alaska, and at open-house sessions at the site for interested visitors.

Second, the Gakona site is now intended to be a world-class facility for studying the upper atmosphere, although the function has evolved from an over-the-horizon radar (never constructed), to a high-frequency facility (under construction) to generate ELF (Extremely Low Frequency) radio waves in the ionosphere, to a major center for upper atmosphere studies using a variety of diagnostics (some in place) with a powerful incoherent scatter radar (ISR) as the core instrument (to be constructed). The core instrument will join with existing ISRs at Svalbard and Tromsø in Norway; Sondrestrom, Greenland; and Boston, Massachusetts, and with the proposed ISR at Resolute Bay, Canada, to form an Arctic network of radars to observe virtually the whole Polar Cap and to track disturbances produced by solar inputs in the form of waves and particles. The network will be a remarkable additon to the tools available to the atmospheric science community with applications to space weather, Arctic and satellite communications, and electric power-grid problems.
In the early days of the Arecibo Observatory in Puerto Rico there were concerns expressed about the facility, but these have long since been replaced by satisfaction with the scientific outcomes and the benefits to the local economy. The residents of Alaska will find similar benefits.
International Support for Natural History Museums
Authors: Budiman Arie , Burley John , Peake John , West Judy 
Published: July 2002

An article by Nigel Williams (News & Comment,
27 Sept., p. 1792
) and a Policy Forum by Stephen Blackmore (
4 Oct., p. 63
) raise three issues: (i) How can the biodiversity information associated with natural history museum collections be made available to a wider range of users? (ii) How can international support and funding for this activity be increased? and (iii) Do we need a new international organization, responsible for coordination and strategic planning, to facilitate these two objectives?

Multilateral and bilateral international funding agencies have already demonstrated a willingness to fund systematic collections and biodiversity information systems, in the context of “demand driven” projects that have close links to users, lead to clearly identifiable outputs, and can be achieved in discrete time-frames. Present examples include the Indonesian Biodiversity Collections Project, a 5-year international program to strengthen the institutional capacity of the national herbarium (Herbarium Bogoriense) and the national zoological museum (Museum Zoologicum Bogoriense), under the Research and Development Center for Biology of the Indonesian Institute of Sciences. This project is funded in part by a $7.2-million grant from the Global Environment Facility Trust Fund under the supervision of the World Bank. Closely associated with this project is the Indonesian Biodiversity Conservation Project, which includes $14 million in grant aid from the government of Japan to construct a new, custom-built museum to rehouse the zoology collections.
The urgent need for these projects was first identified in the Biodiversity Action Plan for Indonesia. The Government of Indonesia has since reaffirmed this goal as a national priority and provided substantial counterpart funding.
Careful consideration should be given to how these and other projects are being implemented before the systematics community develops proposals to create new international organizations for the promotion of natural history collections or new financial instruments to facilitate access to information held in these collections.
Bactericidal Activities of HMR 3647, Moxifloxacin, and Rifapentine against
Mycobacterium leprae
in Mice
Authors: Consigny Sophie , Bentoucha Abdelhalim , Bonnafous Pascale , Grosset Jacques , Ji Baohong 
Published: July 2002

ABSTRACT

Bactericidal activities of HMR 3647 (HMR), moxifloxacin (MXFX), and rifapentine (RPT) against
Mycobacterium leprae
, measured by the proportional bactericidal technique in the mouse footpad system, were compared with those of the established antileprosy drugs clarithromycin (CLARI), ofloxacin (OFLO), and rifampin (RMP). Administered in five daily doses of 100 mg/kg of body weight, HMR appeared slightly more bactericidal than CLARI. In a single dose, MXFX at 150 mg/kg was more active than the same dose of OFLO and displayed exactly the same level of activity as RMP at 10 mg/kg; the combination MXFX-minocycline (MINO) (MM) was more bactericidal than the combination OFLO-MINO (OM); RPT at 10 mg/kg was more bactericidal than the same dose of RMP and even more active than the combination RMP-OFLO-MINO (ROM); the combination RPT-MXFX-MINO (PMM) killed 99.9% of viable
M. leprae
and was slightly more bactericidal than RPT alone, indicating that the combination PMM showed an additive effect against
M. leprae
.
Thrombin-Induced Platelet Microbicidal Protein Susceptibility Phenotype Influences the Outcome of Oxacillin Prophylaxis and Therapy of Experimental
Staphylococcus aureus
Endocarditis
Authors: Dhawan V. K. , Bayer A. S. , Yeaman M. R. 
Published: July 2002

ABSTRACT

We previously showed that in vitro susceptibility profiles of
Staphylococcus aureus
to thrombin-induced platelet microbicidal protein 1 (tPMP-1) impacted the outcome of vancomycin treatment in experimental infective endocarditis. In this same model, treatment with oxacillin (a more rapid staphylocidal agent than vancomycin) enhanced the clearance of both tPMP-1-susceptible and -resistant cells from vegetations. The extent of clearance was greater for tPMP-1-susceptible cells.
Anti-Epstein-Barr Virus (EBV) Activity of β-
l
-5-Iododioxolane Uracil Is Dependent on EBV Thymidine Kinase
Authors: Kira Toshihiko , Grill Susan P. , Dutschman Ginger E. , Lin Ju-Sheng , Qu Fucheng , Choi Yongseok , Chu Chung K. , Cheng Yung-Chi 
Published: July 2002

ABSTRACT

β-
l
-5-Iododioxolane uracil was shown to have potent anti-Epstein-Barr virus (EBV) activity (50% effective concentration = 0.03 μM) with low cytotoxicity (50% cytotoxic concentration = 1,000 μM). It exerts its antiviral activity by suppressing replicative EBV DNA and viral protein synthesis. This compound is phosphorylated in cells where the EBV is replicating but not in cells where the EBV is latent. EBV-specific thymidine kinase could phosphorylate β-
l
-5-iododioxolane uracil to the monophosphate metabolite. The

K
m

of β-
l
-5-iododioxolane uracil with EBV thymidine kinase was estimated to be 5.5 μM, which is similar to that obtained with thymidine but about fivefold higher than that obtained with 2′ fluoro-5-methyl-β-
l
-arabinofuranosyl uracil, the first
l
-nucleoside analogue discovered to have anti-EBV activity. The relative
V
max
is seven times higher than that of thymidine. The anti-EBV activity of β-
l
-5-iododioxolane uracil and its intracellular phosphorylation could be inhibited by 5′-ethynylthymidine, a potent EBV thymidine kinase inhibitor. The present study suggests that β-
l
-5-iododioxolane uracil exerts its action after phosphorylation; therefore, EBV thymidine kinase is critical for the antiviral action of this drug.