bluuebunny/crossref_metadata_2025 huggingface dataset:
Requirement of transcription factor NFAT in developing atrial myocardium
Authors: Schubert William , Yang Xiao Yong , Yang Teddy T.C. , Factor Stephen M. , Lisanti Michael P. , Molkentin Jeffery D. , Rincón Mercedes , Chow Chi-Wing
Published: June 2003

Nuclear factor of activated T cell (NFAT) is a ubiquitous regulator involved in multiple biological processes. Here, we demonstrate that NFAT is temporally required in the developing atrial myocardium between embryonic day 14 and P0 (birth). Inhibition of NFAT activity by conditional expression of dominant-negative NFAT causes thinning of the atrial myocardium. The thin myocardium exhibits severe sarcomere disorganization and reduced expression of cardiac troponin-I (cTnI) and cardiac troponin-T (cTnT). Promoter analysis indicates that NFAT binds to and regulates transcription of the cTnI and the cTnT genes. Thus, regulation of cytoskeletal protein gene expression by NFAT may be important for the structural architecture of the developing atrial myocardium.
The liberation of CD44
Authors: Cichy Joanna , Puré Ellen
Published: June 2003

CD44 was once thought to simply be a transmembrane adhesion molecule that also played a role in the metabolism of its principal ligand hyaluronan. Investigations of CD44 over the past ∼20 yr have established additional functions for CD44, including its capacity to mediate inflammatory cell function and tumor growth and metastasis. It has also become evident that intricate posttranslational modifications of CD44 regulate the affinity of the receptor for its ligands. In this review, we focus on emerging evidence that functional fragments of the cytoplasmic and ectodomain of CD44 can be liberated by enzymatic modification of cell surfaces as well as of cell-associated matrix. Based on the evidence discussed, we propose that CD44 exists in three phases, as a transmembrane receptor, as an integral component of the matrix, and as a soluble protein found in body fluids, each with biologically significant functions of which some are shared and some distinct. Thus, CD44 represents a model for understanding posttranslational processing and its emerging role as a general mechanism for regulating cell behavior.
Extrusion, contraction: their discretization via Whitney forms
Authors: Bossavit Alain
Published: June 2003

The v×B term in eddy current equations for conducting fluids is an instance of contraction of a differential form by a vector field. We search for a natural way to discretize such contractions. Looking at the operation of extrusion of a manifold, which is dual to contraction, provides the main clue. Two example applications, Carpenter's gauge and Eulerian computations in MHD problems, are suggested.
Reconstruction of inhomogeneities in fluids by means of capacitance tomography
Authors: Brandstätter Bernhard , Holler Gert , Watzenig Daniel
Published: June 2003

Electrical capacitance tomography (ECT) is a technique for reconstructing information about the spatial distribution of the contents of closed pipes by measuring variations in the dielectric properties of the material inside the pipe. In this paper, we propose a method that solves the non‐linear reconstruction problem directly leading to less iterations and higher accuracy than linear back projection algorithms currently in use in most ECT systems.
Robust target functions in electromagnetic design
Authors: Alotto Piergiorgio , Magele Christian , Renhart Werner , Weber Andreas , Steiner Gerald
Published: June 2003

Uncertainties in the design variables of non‐linear engineering optimization problems are often neglected. That could result in considerable deterioration of the target function value of an implemented design compared with the computed optimal solution. This effect can be reduced with robust optimization, where it is tried to achieve robust designs by actively embedding the uncertainties and robustness measures in the optimization process. A methodology for robust optimization of non‐linear problems is presented, including practical methods for the solution of such programs. The benefits of the approach are discussed in a numerical field calculation example.
Adjustment with magnetic field
Authors: Szabó Zsolt , Iványi Amália
Published: June 2003

In this paper the kinetic behavior of a non‐magnetic cube, plated on two opposite sides with ferromagnetic coating, situated on a horizontal plane surface and immersed in a homogeneous magnetic field is investigated. The created magnetic torque is determined, the involved field quantities are computed applying the integral equation method taking into account the hysteresis of the ferromagnetic coating by a non‐linear iterative procedure based on the Piccard‐Banach fixed point technique. Considering the friction between the piece and the plane surface the equation of motion is solved. The magnetic field strength necessary to rotate the piece in a required direction is determined.
Robust design of high field magnets through Monte Carlo analysis
Authors: Cavaliere Vincenzo , Cioffi Marco , Formisano Alessandro , Martone Raffale
Published: June 2003

An effective approach to the optimal design of electromagnetic devices should take into account the effect of mechanical tolerances on the actual devices performance. A possible approach could be to match a Pareto optimality study with a Monte Carlo analysis by randomly varying the constructive parameters. In this paper it is shown how such an analysis can be used to allow an expert designer to select among different Pareto optimal designs.
Forward simulations for free boundary reconstruction in magnetic fluid dynamics
Authors: Brauer Hartmut , Ziolkowski Marek , Dannemann Matthias , Kuilekov Milko , Alexeevski Denis
Published: June 2003

In many industrial applications of magnetic fluid dynamics it is important to control the motion of the surface of liquids. In aluminium electrolysis cells, large surface deformations of the molten aluminium are undesired, and it would be useful to have the possibility to recognize the surface deviation. This includes the problem of reconstructing a free boundary between the conducting fluids. We have investigated how the interface between two fluids of different conductivity assumed in a highly simplified model of an aluminium electrolysis cell could be reconstructed by means of external magnetic field measurements. Forward simulations of the magnetic field generated by the impressed current are done by applying the FEM software code FEMLAB. Several interface shapes which can be realized in experiments are investigated and a strategy for identifying the main interface characteristics using magnetic field measurements as an initial guess to the solution of the inverse problem is proposed.
3D magneto‐thermal computations of electromagnetic induction phenomena
Authors: Paya Bernard , Fireteanu Virgiliu , Spahiu Alexandru , Guérin Christophe
Published: June 2003

This paper presents the results of a series of tests made in order to validate the magneto‐thermal module of the new FLUX3D v3.40. The tool was conceived to solve the coupled problems of electromagnetic and thermal phenomena. The solving method of the program considers a thermal‐transient problem during a certain period of time and it solves, at each time step, the thermal and electromagnetic equations (in quasi‐stationary magneto‐harmonic formulation), alternatively. We have modelled the inductive longitudinal welding of steel pipes. The results of 3D simulations are compared with measurements on a laboratory device.
Representation of Objects and Events
Authors: Keen Rachel
Published: June 2003

Research has demonstrated that very young infants can discriminate between visual events that are physically impossible versus possible. These findings suggest that infants have knowledge of physical laws concerning solidity and continuity. However, research with 2-year-olds has shown that they cannot solve simple problems involving search for a hidden object, even though these problems require the same knowledge. These apparently inconsistent findings raise questions about the interpretation of both data sets. This discrepancy may be resolved by examining differences in task demands.
Movies About Intelligence
Authors: Flynn James R.
Published: June 2003

There is a strong tendency for the same people to do better or worse on a wide variety of IQ tests. On this basis, some psychologists posit the concept of g, or a general intelligence factor. Does g show that performance on a wide range of cognitive tasks is influenced by individual differences in brain quality? It may, but if so, g lacks a sociological dimension and cannot explain cognitive trends over time or assess their significance. It also encourages a paradox about nature versus nurture and oversimplifies the causes of the Black-White IQ gap.
Was Mancur a Maoist? An Essay on Kleptocracy and Political Stability
Authors: Rose‐Ackerman Susan
Published: June 2003

Much of Mancur Olson's work explored the link between government structure and economic development. This paper provides a framework for thinking about this link that exposes both the powerful insights and the deep tensions in Olson's work. InThe Rise and Decline of NationsOlson argued that instability was good for democratic accountability because it upset entrenched interests. In contrast, after the fall of the socialist regimes in Europe and the Soviet Union, Olson argued that the stability of a single autocrat or “stationary bandit” was superior to the competitive rent seeking of competing “roving bandits.” I argue that there is a real inconsistency in Olson's thinking on the role of stability and change in political life; I do this by developing the connections between Olson's classicLogic of Collective Actionand his subsequent writing. The paper concludes by building on Olson's insights to point the way to a more complete analysis of democracy and transition.
Concessional Amnesty and the Politics of Immigration Reforms
Authors: Chau Nancy H.
Published: June 2003

This paper establishes a political support model of immigration reforms. The analysis highlights the distinction between border enforcement and employer sanction measures in that the former can be more aptly characterized as an income transfer from employer to native labor interests, whereas the latter generates deadweight losses that are borne entirely by producers. We show that while amnesty may appear to run contrary to the original intent of the immigration reform, it may nevertheless facilitate rent capture by the politician by “wiping the slate clean” and reducing the deadweight loss of employer sanction measures.
Calcineurin Is Essential for
Candida albicans
Survival in Serum and Virulence
Authors: Blankenship Jill R. , Wormley Floyd L. , Boyce Molly K. , Schell Wiley A. , Filler Scott G. , Perfect John R. , Heitman Joseph
Published: June 2003

Calcineurin is a calcium-activated protein phosphatase that is the target of the immunosuppressants cyclosporin A and FK506. In T cells, calcineurin controls nuclear import of the NF-AT transcription factor and gene activation. In plants and fungi, calcineurin functions in stress responses (e.g., temperature, cations, and pH) and is necessary for the virulence of the fungal pathogen
Cryptococcus neoformans
. Here we show that calcineurin is also required for the virulence of another major fungus that is pathogenic to humans,
Candida albicans. C. albicans
calcineurin mutants had significantly reduced virulence in a murine model of systemic infection. In contrast to its role in
C. neoformans
, calcineurin was not required for
C. albicans
survival at 37°C. Moreover,
C. albicans
calcineurin mutant strains exhibited no defects in known
Candida
virulence traits associated with host invasion, including filamentous growth, germ tube formation, and adherence to and injury of mammalian cells.
C. albicans
calcineurin mutant strains failed to colonize and grow in the kidneys of infected animals and were unable to survive when exposed to serum in vitro. Our studies illustrate that calcineurin has evolved to control aspects of the virulence of two divergent fungal pathogens via distinct mechanisms that can be targeted to achieve broad-spectrum antifungal action.
Ady4p and Spo74p Are Components of the Meiotic Spindle Pole Body That Promote Growth of the Prospore Membrane in
Saccharomyces cerevisiae
Authors: Nickas Mark E. , Schwartz Cindi , Neiman Aaron M.
Published: June 2003

Spore formation in
Saccharomyces cerevisiae
occurs via the de novo synthesis of the prospore membrane during the second meiotic division. Prospore membrane formation is triggered by assembly of a membrane-organizing center, the meiotic outer plaque (MOP), on the cytoplasmic face of the spindle pole body (SPB) during meiosis. We report here the identification of two new components of the MOP, Ady4p and Spo74p. Ady4p and Spo74p interact with known proteins of the MOP and are localized to the outer plaque of the SPB during meiosis II. MOP assembly and prospore membrane formation are abolished in
spo74
Δ/
spo74
Δ cells and occur aberrantly in
ady4
Δ/
ady4
Δ cells. Spo74p and the MOP component Mpc70p are mutually dependent for recruitment to SPBs during meiosis. In contrast, both Ady4p and Spo74p are present at SPBs, albeit at reduced levels, in cells that lack the MOP component Mpc54p. Our findings suggest a model for the assembled MOP in which Mpc54p, Mpc70p, and Spo74p make up a core structural unit of the scaffold that initiates synthesis of the prospore membrane, and Ady4p is an auxiliary component that stabilizes the plaque.
TmkA, a Mitogen-Activated Protein Kinase of
Trichoderma virens
, Is Involved in Biocontrol Properties and Repression of Conidiation in the Dark
Authors: Mukherjee Prasun K. , Latha Jagannathan , Hadar Ruthi , Horwitz Benjamin A.
Published: June 2003

Trichoderma virens
is a mycoparasitic fungus used in biocontrol of soilborne plant pathogens. It inhibits or kills plant-pathogenic fungi through production of antifungal antibiotics and parasitism of hyphae and sclerotia. Conidiation, or the production of asexual spores, an inducible process triggered by light or nutrient stress, is an important trait in survival and also development of formulation products. In many fungi, signaling pathways, including mitogen-activated protein kinase (MAPK) cascades, have been implicated in parasitism of host plants as well as in the production of asexual spores. Here, we have studied the role of a MAPK gene, that for TmkA, in conidiation and antagonistic properties of a biocontrol strain of
T. virens
. Through single- and double-crossover recombination, we obtained three
tmkA
loss-of-function mutants. The TmkA transcript was not detectable in these mutants. The mutants conidiated in the dark, although photoinduction was normal and the light sensitivities of the wild type and the mutant were the same. The mutants had, overall, normal colony morphology, but their radial growth rate was reduced by about 16%, with no decrease in biomass production. Against
Rhizoctonia solani
hyphae, the knockout mutants exhibited mycoparasitic coiling and lysis of host hyphae similar to that of the wild type. The mutants, however, were less effective in colonizing the sclerotia of
R. solani
. On
Sclerotium rolfsii
, the MAPK loss-of-function mutants had reduced antagonistic properties in confrontation assays and failed to parasitize the sclerotia. TmkA-dependent and -independent pathways are thus involved in antagonism against different hosts. Finally, in contrast to the case for other filamentous fungi studied so far, signaling through a MAPK represses, rather than induces, asexual sporulation.
Roles of Tyrosine-Rich Precursor Glycoproteins and Dityrosine- and 3,4-Dihydroxyphenylalanine-Mediated Protein Cross-Linking in Development of the Oocyst Wall in the Coccidian Parasite
Eimeria maxima
Authors: Belli Sabina I. , Wallach Michael G. , Luxford Catherine , Davies Michael J. , Smith Nicholas C.
Published: June 2003

The oocyst wall of apicomplexan parasites protects them from the harsh external environment, preserving their survival prior to transmission to the next host. If oocyst wall formation could be disrupted, then logically, the cycle of disease transmission could be stopped, and strategies to control infection by several organisms of medical and veterinary importance such as
Eimeria
,
Plasmodium
,
Toxoplasma
,
Cyclospora
, and
Neospora
could be developed. Here, we show that two tyrosine-rich precursor glycoproteins, gam56 and gam82, found in specialized organelles (wall-forming bodies) in the sexual stage (macrogamete) of
Eimeria maxima
are proteolytically processed into smaller glycoproteins, which are then incorporated into the developing oocyst wall. The identification of high concentrations of dityrosine and 3,4-dihydroxyphenylalanine (DOPA) in oocyst extracts by high-pressure liquid chromatography, together with the detection of a UV autofluorescence in intact oocysts, implicates dityrosine- and possibly DOPA-protein cross-links in oocyst wall hardening. In addition, the identification of peroxidase activity in the wall-forming bodies of macrogametes supports the hypothesis that dityrosine- and DOPA-mediated cross-linking might be an enzyme-catalyzed event. As such, the mechanism of oocyst wall formation in
Eimeria
, is analogous to the underlying mechanisms involved in the stabilization of extracellular matrices in a number of organisms, widely distributed in nature, including insect resilin, nematode cuticles, yeast cell walls, mussel byssal threads, and sea urchin fertilization membranes.
RacB Regulates Cytoskeletal Function in
Dictyostelium
spp
Authors: Lee Eunkyung , Seastone David J. , Harris Ed , Cardelli James A. , Knecht David A.
Published: June 2003

Thus far, 14 homologues of mammalian Rac proteins have been identified in
Dictyostelium.
It is unclear whether each of these genes has a unique function or to what extent they play redundant roles in actin cytoskeletal organization. To investigate the specific function of RacB, we have conditionally expressed wild-type (WT-RacB), dominant negative (N17-RacB), and constitutively activated (V12-RacB) versions of the protein. On induction, cells expressing V12-RacB stopped growing, detached from the surface, and formed numerous spherical surface protrusions while cells overexpressing WT-RacB became flattened on the surface. In contrast, cells overexpressing N17-RacB did not show any significant morphological abnormalities. The surface protrusions seen in V12-RacB cells appear to be actin-driven protrusions because they were enriched in F-actin and were inhibitable by cytochalasin A treatment. The protrusions in V12-RacB cells did not require myosin II activity, which distinguishes them from blebs formed by wild-type cells under stress. Finally, we examined the functional consequences of expression of wild-type and mutant RacB. Phagocytosis, endocytosis, and fluid phase efflux rates were reduced in all cell lines expressing RacB proteins but the greatest decrease was observed for cells expressing V12-RacB. From these results, we conclude that like other members of the Rho family, RacB induces polymerization of actin but the consequences of activation appear to be different from other
Dictyostelium
Rac proteins so far investigated, resulting in different morphological and functional changes in cells.
The Intestinal Protozoan ParasiteEntamoeba histolyticaContains 20 Cysteine Protease Genes, of Which Only a Small Subset Is Expressed during In Vitro Cultivation
Authors: Bruchhaus Iris , Loftus Brendan J. , Hall Neil , Tannich Egbert
Published: June 2003

Cysteine proteases are known to be important pathogenicity factors of the protozoan parasiteEntamoeba histolytica. So far, a total of eight genes coding for cysteine proteases have been identified inE. histolytica, two of which are absent in the closely related nonpathogenic speciesE. dispar.However, present knowledge is restricted to enzymes expressed during in vitro cultivation of the parasite, which might represent only a subset of the entire repertoire. Taking advantage of the currentE. histolyticagenome-sequencing efforts, we analyzed databases containing more than 99% of all ameba gene sequences for the presence of cysteine protease genes. A total of 20 full-length genes was identified (including all eight genes previously reported), which show 10 to 86% sequence identity. The various genes obviously originated from two separate ancestors since they form two distinct clades. Despite cathepsin B-like substrate specificities, all of the ameba polypeptides are structurally related to cathepsin L-like enzymes. None of the previously described enzymes but 7 of the 12 newly identified proteins are unique compared to cathepsins of higher eukaryotes in that they are predicted to have transmembrane or glycosylphosphatidylinositol anchor attachment domains. Southern blot analysis revealed that orthologous sequences for all of the newly identified proteases are present inE. dispar.Interestingly, the majority of the various cysteine protease genes are not expressed inE. histolyticaorE. dispartrophozoites during in vitro cultivation. Therefore, it is likely that at least some of these enzymes are required for infection of the human host and/or for completion of the parasite life cycle.
RNA Polymerase I Transcribes Procyclin Genes and Variant Surface Glycoprotein Gene Expression Sites in
Trypanosoma brucei
Authors: Günzl Arthur , Bruderer Thomas , Laufer Gabriele , Schimanski Bernd , Tu Lan-Chun , Chung Hui-Min , Lee Pei-Tseng , Lee Mary Gwo-Shu
Published: June 2003

In eukaryotes, RNA polymerase (pol) I exclusively transcribes the large rRNA gene unit (rDNA) and mRNA is synthesized by RNA pol II. The African trypanosome,
Trypanosoma brucei
, represents an exception to this rule. In this organism, transcription of genes encoding the variant surface glycoprotein (VSG) and the procyclins is resistant to α-amanitin, indicating that it is mediated by RNA pol I, while other protein-coding genes are transcribed by RNA pol II. To obtain firm proof for this concept, we generated a
T. brucei
cell line which exclusively expresses protein C epitope-tagged RNA pol I. Using an anti-protein C immunoaffinity matrix, we specifically depleted RNA pol I from transcriptionally active cell extracts. The depletion of RNA pol I impaired in vitro transcription initiated at the rDNA promoter, the GPEET procyclin gene promoter, and a VSG gene expression site promoter but did not affect transcription from the spliced leader (SL) RNA gene promoter. Fittingly, induction of RNA interference against the RNA pol I largest subunit in insect-form trypanosomes significantly reduced the relative transcriptional efficiency of rDNA, procyclin genes, and VSG expression sites in vivo whereas that of SL RNA, αβ-tubulin, and heat shock protein 70 genes was not affected. Our studies unequivocally show that
T. brucei
harbors a multifunctional RNA pol I which, in addition to transcribing rDNA, transcribes procyclin genes and VSG gene expression sites.
A Region within a Lumenal Loop of
Saccharomyces cerevisiae
Ycf1p Directs Proteolytic Processing and Substrate Specificity
Authors: Mason Deborah L. , Mallampalli Monica P. , Huyer Gregory , Michaelis Susan
Published: June 2003

Ycf1p, a member of the yeast multidrug resistance-associated protein (MRP) subfamily of ATP-binding cassette proteins, is a vacuolar membrane transporter that confers resistance to a variety of toxic substances such as cadmium and arsenite. Ycf1p undergoes a
PEP4
-dependent processing event to yield N- and C-terminal cleavage products that remain associated with one another. In the present study, we sought to determine whether proteolytic cleavage is required for Ycf1p activity. We have identified a unique region within lumenal loop 6 of Ycf1p, designated the loop 6 insertion (L6
ins
), which appears to be necessary and sufficient for proteolytic cleavage, since L6
ins
can promote processing when moved to new locations in Ycf1p or into a related transporter, Bpt1p. Surprisingly, mutational results indicate that proteolytic processing is not essential for Ycf1p transport activity. Instead, the L6
ins
appears to regulate substrate specificity of Ycf1p, since certain mutations in this region lower cellular cadmium resistance with a concomitant gain in arsenite resistance. Although some of these L6
ins
mutations block processing, there is no correlation between processing and substrate specificity. The activity profiles of the Ycf1p L6
ins
mutants are dramatically affected by the strain background in which they are expressed, raising the possibility that another cellular component may functionally impact Ycf1p activity. A candidate component may be a new full-length MRP-type transporter (
NFT1
), reported in the
Saccharomyces
Genome Database as two adjacent open reading frames,
YKR103w
and
YKR104w
, but which we show here is present in most
Saccharomyces
strains as a single open reading frame.
Identification of In Vivo Enzyme Activities in the Cometabolism of Glucose and Acetate by
Saccharomyces cerevisiae
by Using
13
C-Labeled Substrates
Authors: dos Santos Margarida Moreira , Gombert Andreas Karoly , Christensen Bjarke , Olsson Lisbeth , Nielsen Jens
Published: June 2003

A detailed characterization of the central metabolic network of
Saccharomyces cerevisiae
CEN.PK 113-7D was carried out during cometabolism of different mixtures of glucose and acetate, using aerobic C-limited chemostats in which one of these two substrates was labeled with
13
C. To confirm the role of malic enzyme, an isogenic strain with the corresponding gene deleted was grown under the same conditions. The labeling patterns of proteinogenic amino acids were analyzed and used to estimate metabolic fluxes and/or make inferences about the in vivo activities of enzymes of the central carbon metabolism and amino acid biosynthesis. Malic enzyme flux increased linearly with increasing acetate fraction. During growth on a very-high-acetate fraction, the activity of malic enzyme satisfied the biosynthetic needs of pyruvate in the mitochondria, while in the cytosol pyruvate was supplied via pyruvate kinase. In several cases enzyme activities were unexpectedly detected, e.g., the glyoxylate shunt for a very-low-acetate fraction, phosphoenolpyruvate carboxykinase for an acetate fraction of 0.46 C-mol of acetate/C-mol of substrate, and glucose catabolism to CO
2
via the tricarboxylic acid cycle for a very-high-acetate fraction. Cytoplasmic alanine aminotransferase activity was detected, and evidence was found that α-isopropylmalate synthase has two active forms in vivo, one mitochondrial and the other a short cytoplasmic form.
Histone-Like Proteins of the Dinoflagellate
Crypthecodinium cohnii
Have Homologies to Bacterial DNA-Binding Proteins
Authors: Wong J. T. Y. , New D. C. , Wong J. C. W. , Hung V. K. L.
Published: June 2003

The dinoflagellates have very large genomes encoded in permanently condensed and histoneless chromosomes. Sequence alignment identified significant similarity between the dinoflagellate chromosomal histone-like proteins of
Crypthecodinium cohnii
(HCCs) and the bacterial DNA-binding and the eukaryotic histone H1 proteins. Phylogenetic analysis also supports the origin of the HCCs from histone-like proteins of bacteria.
Do the sick have a right to cadaveric organs?
Authors: Glannon W
Published: June 2003

One way of increasing the supply of organs for transplantation is to adopt a policy giving the sick a right to cadaveric organs. Such a right would entail the coercive transfer of organs from the dead without their previous consent. Because this policy would violate individual autonomy and the special relation between humans and their bodies, it would be morally unjustifiable. Although a rights-based non-consensual model of salvaging cadaveric organs would be medically desirable, a communitarian-based consensual model would be a morally justifiable alternative way of addressing the problem of organ scarcity.
Defining death in non-heart beating organ donors
Authors: Zamperetti N , Bellomo R , Ronco C
Published: June 2003

Protocols for retrieving vital organs in consenting patients in cardiovascular arrest (non-heart beating donors, NHBD) rest on the assumptions that irreversible asystole a) identifies the instant of biological death, and b) is clinically assessable at the time when retrieval of vital organs is possible. Unfortunately both assumptions are flawed. We argue that traditional life/death definitions could be actually inadequate to represent the reality of dying under intensive support, and we suggest redefining NHBD protocols on moral, social, and antrhopological criteria, admitting that irreversible (however defined) asystole can only equate a clinically determinable point of no return in the process of dying, where organ retrieval can be morally and socially accepted in previously consenting patients.
Attitudes of Swedes to marginal donors and xenotransplantation
Authors: Lundin S , Idvall M
Published: June 2003

The aim of our survey was to capture the attitudes of Swedes to marginal donors and xenotransplantation. Modern biotechnology makes it possible to replace non-functioning organs, cells, and genes. Nonetheless, people may have reservations and fears about such treatments. With the survey,Attitudes of the General Public to Transplants, we have sought to expose the ambivalence that arises when medical possibilities are juxtaposed with ideas of risk. The design of the questionnaire originates from the interdisciplinary cooperation between ethnologists, medical scientists, and geneticists. By combining qualitative and quantitative methods, it is possible to illustrate the complexity that characterises people’s view of modern biomedicine. People’s reflections are based on a personal and situation bound morality, which does not necessarily coincide with what they generally consider as ethically justifiable.
A stronger policy of organ retrieval from cadaveric donors: some ethical considerations
Authors: Hamer C L , Rivlin M M
Published: June 2003

Taking organs from dead people seems, prima facie, to raise fewer ethical complications than taking organs from other sources. There are, however, serious ethical problems in taking organs from the dead unless there is premortem evidence that this is what the deceased would have wanted, or at least, not have objected to. In this paper we will look at a “strong” opting out policy as proposed by John Harris. We will argue that people can be harmed after their death and that the posthumous removal of organs against their expressed wishes is one form that such harm might take. We also argue that Harris’s claim that we show “equality of concern” between the donor and recipient requires too much.
Geographical pattern of brain cancer incidence in the Navarre and Basque Country regions of Spain
Authors: López-Abente G , Pollán M , Ardanaz E , Errezola M
Published: June 2003

Background:The study of the distribution of brain cancer mortality in Spain shows a grouping of highest risk provinces corresponding to the autonomous regions of Navarre and the Basque Country.

Aim:To explore the possible existence of geographical patterns in these areas.

Methods:Municipal maps of brain cancer incidence were drawn up and the influence of land use related variables on the distribution of the disease duly analysed. Autoregressive conditional models were used to plot smoothed municipal maps. The influence of explanatory land use variables, ascertained by remote sensing, was assessed.

Results:The maps revealed that certain towns situated in the “Media” and “Cantábrica-Baja Montaña” districts of Navarre were areas of highest risk. Among the towns in question, those in the “Media” district lie very close to the city of Pamplona. However, the pattern of brain cancer incidence in Navarre and the Basque Country could not be conclusively said to be determined by any specific type of land cover and/or crop.

Conclusions:Results suggest a possible increase of risk linked to areas devoted to a high percentage of non-irrigated arable land.
Evaluation of two commercial methods for the detection ofListeriasp. andListeria monocytogenesin a chicken nugget processing plant
Authors: Rodrigues D , Landgraf M , Destro M T
Published: June 2003

This study measures the detection performances of two rapid test systems (Listeria Rapid Test ClearviewTMand BaxTMsystem) for the screening of Listeria sp. and Listeria monocytogenes, respectively. A total of 413 samples from different sources (product from (i) different stages of processing, (ii) different environments, and (iii) different food handlers), collected from a chicken nugget processing plant, were analysed by both rapid methods and a cultural method consisting of pre-enrichment, enrichment, and isolation onto selective agars (PALCAM, LPM, and HCLA). Overall, results showed an excellent correlation between data obtained using ClearviewTMand the cultural method, with ClearviewTMpresenting an efficiency of 99%. BaxTMshowed a lower correlation using the cultural method, with an efficiency of 71.1%. The type of sample did not affect the efficiency of ClearviewTM, which varied from 98.1% for product samples to 100% for environmental and food handler samples, while for BaxTMit had a marked influence. Efficiency of BaxTMvaried from as high as 100% for food handlers to 37.9% for product samples.Key words: Listeria, Listeria monocytogenes, ClearviewTM, BaxTM.
Azotobacter chroococcumdoes not containsodAor its gene product Mn-superoxide dismutase
Authors: Caldwell Jane M , Hassan Hosni M
Published: June 2003

Azotobacter chroococcum and Azotobacter vinelandii grown in Burk medium with 1% mannitol (BM) or in BM supplemented with 2.2 mg/mL ammonium acetate (BM+N) were found to have only iron-containing and CuZn-containing superoxide dismutase. Furthermore, genomic DNA from A. chroococcum and A. vinelandii were subjected to polymerase chain reaction analysis using sodA- and sodB-specific primers and yielded only a sodB product. These results dispute the assertion by Buchanan and Lees (Can. J. Microbiol. 26: 441447, 1980) that A. chroococcum contains Mn-superoxide dismutase.Key words: FeSOD, Cu-ZnSOD, MnSOD, Azotobacter chroococcum, Azotobacter vinelandii.
Degradation of polycyclic aromatic hydrocarbons dissolved in Tween 80 surfactant solutions bySphingomonas paucimobilisEPA 505
Authors: Luning Prak Dianne J , Pritchard Parmely H
Published: June 2003

The degradation rates of mixtures of pyrene (PYR), fluoranthene (FLA), and phenanthrene (PHE) by Sphingomonas paucimobilis EPA 505 were measured in the presence of the nonionic surfactant Tween 80. For strain EPA 505, FLA and PHE are growth substrates, while PYR is not. Linear degradation rates ranging from 0.05 to 2.2 mg·L1·h1were observed for FLA, PYR, and PHE at approximately 107colony-forming units (CFU)/mL. At lower biomass, PYR degradation exhibited lognormal degradation. The degradation rates of PYR, FLA, and PHE increased with increasing biomass and substrate concentration. At high FLA concentrations, FLA degradation rates were faster in the presence of surfactant than in the absence of surfactant, suggesting that some of the FLA was transported directly into the cell from the micellar phase. In mixtures, PHE was the preferred substrate and was utilized first, followed by FLA and then PYR. Once the competing substrates were degraded, the remaining substrate was degraded at the same rate or faster than the rate found in the single-substrate system. Based on the results with Tween 80, it appears that PHE, PYR, and FLA are competing for the same enzymatic sites.Key words: PAH mixtures, microbial degradation, surfactant, solubilization, EPA 505.
Larvicidal toxins fromBacillusthuringiensissubspp.kurstaki,morrisoni(straintenebrionis), andisraelensishave no microbicidal or microbiostatic activity against selected bacteria, fungi, and algae in vitro
Authors: Koskella J , Stotzky G
Published: June 2003

The insecticidal toxins from Bacillus thuringiensis subspp. kurstaki (antilepidopteran), morrisoni strain tenebrionis (anticoleopteran), and israelensis (antidipteran) did not affect the growth of a variety of bacteria (8 gram-negative, 5 gram-positive, and a cyanobacterium), fungi (2 Zygomycetes, 1 Ascomycete, 2 Deuteromycetes, and 2 yeasts), and algae (primarily green and diatoms) in pure and mixed culture, as determined by dilution, disk-diffusion, and sporulation assays with purified free and clay-bound toxins. The insecticidal crystal proteins from B. thuringiensis subspp. kurstaki and israelensis had no antibiotic effect on various gram-positive bacteria.Key words: insecticidal toxins, Bacillus thuringiensis, microbiostatic, microbicidal.
Detecting structural and functional differences in activated sludge bacterial communities originating from laboratory treatment of elementally and totally chlorine-free bleaching effluents
Authors: Mounteer Ann H , Passos Flávia ML , Borges Arnaldo Chaer , Silva Daison Olzany
Published: June 2003

The ability to differentiate functional and structural diversity of bacterial communities present in activated sludges adapted to elementally (ECF) and totally (TCF) chlorine-free bleaching effluents was evaluated. Community function was evaluated through substrate utilization patterns in BiologGN®microplates, and taxonomic structure was evaluated by fluorescent in situ hybridization using probes targeting the Eubacteria; the alpha, beta, and gamma subclasses of the Proteobacteria; and gram-positive bacteria with high GC content. Over 6-week sampling periods, ECF- and TCF-adapted sludge bacterial communities presented reproducible substrate utilization patterns that through principal components (PCs) analysis, separated the ECF samples from the TCF samples. Application of the fluorescent in situ hybridization technique was complicated by the intense autofluorescence of the bleaching effluent sludge samples that interfered with detection of specific hybridization signals. The most notable difference in community structure detected using the chosen set of probes was the relatively greater proportion of cells of the alpha subclass in TCF sludge (27%) than in ECF sludge (6%). Nonspecific hybridization with beta and gamma probes was relatively high, but both sludges appeared to have similar proportions of cells of the beta (2022%) and gamma (1112%) subclasses. The two sludges presented relatively few gram-positive cells with high GC content (<0.2% of eubacterial counts). Differences in both metabolic potential and taxonomic structure of the microbial communities in the ECF- and TCF-activated sludges were detected. The kinetics of the development of these differences in treatment plants and their relationships with treatment efficiency and production process conditions should now be evaluated.Key words: activated sludge, bleaching effluents, Biolog, in situ hybridization.
Response of spring rape (Brassica napus var. oleifera L.) to inoculation with plant growth promoting rhizobacteria containing 1-aminocyclopropane-1-carboxylate deaminase depends on nutrient status of the plant
Authors: Belimov Andrei A , Safronova Vera I , Mimura Tetsuro
Published: June 2003

Responses of rape (Brassica napus var. oleifera L.) to inoculation with plant growth promoting rhizobacteria, Pseudomonas putida Am2, Pseudomonas putida Bm3, Alcaligenes xylosoxidans Cm4, and Pseudomonas sp. Dp2, containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase were studied using growth pouch and soil cultures. In growth pouch culture, the bacteria significantly increased root elongation of phosphorus-sufficient seedlings, whereas root elongation of phosphorus-deficient seedlings was not affected or was even inhibited by the bacteria. Bacterial stimulation of root elongation of phosphorus-sufficient seedlings was eliminated in the presence of a high ammonia concentration (1 mM) in the nutrient solution. Bacterial effects on root elongation of potassium-deficient and potassium-sufficient seedlings were similar. The bacteria also decreased inorganic phosphate content in shoots of potassium- and phosphorus-sufficient seedlings, reduced ethylene production by phosphorus-sufficient seedlings, and inhibited development of root hairs. The effects of treatment with Ag+, a chemical inhibitor of plant ethylene production, on root elongation, ethylene evolution, and root hair formation were similar to bacterial treatments. The number of bacteria on the roots of phosphorus-deficient seedlings was not limited by phosphorus deficiency. In pot experiments with soil culture, inoculation of seeds with bacteria and treatment with aminoethoxyvinylglycine, an inhibitor of ethylene biosynthesis in plants, increased root and (or) shoot biomass of rape plants. Stimulation of plant growth caused by the bacteria was often associated with a decrease in the content of nutrients, such as P, K, S, Mo, and Ba, in shoots, depending on the strain used. The results obtained show that the growth-promoting effects of ACC-utilizing rhizobacteria depend significantly on the nutrient status of the plant.Key words: 1-aminocyclopropane-1-carboxylate deaminase, Brassica napus, PGPR, phosphorus uptake, plant-bacteria interaction, ethylene, Pseudomonas.
Long-term survival and germination of Bacillus thuringiensis var. kurstaki in a field trial
Authors: Hendriksen Niels Bohse , Hansen Bjarne Munk
Published: June 2003

Long-term survival, dispersal, and germination of Bacillus thuringiensis var. kurstaki DMU67R has been investigated in a field trial. An experimental cabbage plot was sprayed with DMU67R in 1993 and allowed to lie fallow since. The investigations reported here were carried out from 1997 to 2000 in this plot. High persistence of DMU67R for 7 years in the bulk soil of the plot has been demonstrated. The numbers have not significantly reduced since 1994, stabilizing around 6.6 × 102 cfu/g from 1996 to 2000. Horizontal dispersal of DMU67R in the 19941999 period was limited. Vertical dispersal occurred from 1994 to 1999, as 77% of the population of DMU67R occurred in the 02 cm layer in 1994, while only 22% of the population was found there in 1999. Most of the population in 1999 was present homogeneously in the upper 6 cm of the soil profile. Germination, as evidenced by the ratio of DMU67R cfu before and after heat treatment, was not observed in the bulk soil. However, in the rhizospheres of dandelion (Taraxacum officinalis) and quackgrass (Agropyron repens), 40 and 50% of DMU67R was present as vegetative germinated cells, respectively. No germination occurred in the rhizosphere of red fescue (Festuca rubra). The material from the gut of the earthworm species Lumbricus rubellus, Lumbricus terrestris, and Apporrectodea caliginosa and from a tipulid larvae from the plot also contained vegetative cells of DMU67R. Further investigations of A. caliginosa showed that germination seemed to be restricted to the gut and that sporulation occurred after defecation. The germination of DMU67R in rhizospheres and in the gut of nontarget invertebrates suggests that survival in the soil of B. thuringiensis is a dynamic process involving germination, cell divisions, and sporulation in specific microhabitats.Key words: Bacillus thuringiensis, survival, germination, dispersal, rhizosphere, earthworm.
Biotransformation of waste lignin products by the soil-inhabiting yeastTrichosporon pullulans
Authors: Sláviková Elena , Košíková Božena , Mikulášová Mária
Published: June 2003

In this study the biotransformation of lignin by-products of beechwood pulping with a soil-inhabiting yeast strain of Trichosporon pullulans was examined. The structural and molecular changes in the lignin during a cultivation process were determined by13C NMR spectroscopy and gel permeation chromatography analysis, which confirmed the ability of the yeast strain tested to biodegrade lignin. Enzymatic analysis showed the presence of lignin peroxidase and Mn(II) peroxidase in the culture supernatant. The ligninolytic activity of both enzymes increased under carbon-depleted conditions. This observation is particularly important in the biodegradation of recalcitrant lignins in soil.Key words: lignin, Trichosporon pullulans, biotransformation, manganese and lignin peroxidase.
Clostridium perfringenstoxin types from wild-caught Atlantic cod (Gadus morhuaL.), determined by PCR and ELISA
Authors: Aschfalk A , Müller W
Published: June 2003

Ninety-five fecal samples from Atlantic cod (Gadus morhua L.), caught along the northern Norwegian coast, were examined bacteriologically for occurrence of C. perfringens. Isolates were examined by polymerase chain reaction (PCR) for genes encoding the four lethal toxins (α, β, ε, and ι) for classification into toxin types and for genes encoding enterotoxin and the novel β2 toxin for further subclassification. In addition, a commercial enzyme-linked immunosorbent assay (ELISA) kit for detection of C. perfringens α, β, and ε toxin was used. Clostridium perfringens could be isolated in 37 fecal samples (38.9%) from cod. All isolates were C. perfringens toxin type A (α toxin positive) as determined by PCR and also ELISA. In addition, in isolates from two cod (2.1%) the gene encoding for β2 toxin was found (A, β2) by PCR. Genes encoding for β, ε, and ι toxins and enterotoxin were not found. This is the first detection of C. perfringens alpha and β2 toxin in cod and of β2 toxin in fish in general. The origin of this bacterium in cod is discussed.Key words: Clostridium perfringens, cod, Gadus morhua L.
1,8-Dihydroxynaphthalene monoglucoside, a new metabolite of Sclerotinia sclerotiorum, and the effect of tricyclazole on its production
Authors: Starratt A N , Ross L M , Lazarovits G
Published: June 2003

Isolate SS7 of Sclerotinia sclerotiorum was previously shown to produce and excrete into agar medium copious amounts of the melanin precursor 1,8-dihydroxynaphthalene. Much reduced quantities of this product were produced in the presence of tricyclazole, an inhibitor of pentaketide melanin biosynthesis. In this study, we demonstrate that young cultures of isolate SS7 produce 1,8-dihydroxynaphthalene monoglucoside, a new natural product not previously reported from fungi. When cultured in the presence of tricyclazole, such young cultures also accumulated two new monoglucosides of 1,3,8-trihydroxynaphthalene, which, as well as 1,8-dihydroxynaphthalene monoglucoside, were also obtained from cultures of two other isolates of S. sclerotiorum. It is proposed that rapid glucosylation of 1,3,8-trihydroxynaphthalene in young tricyclazole-inhibited S. sclerotiorum cultures accounts for the failure to observe 2-hydroxyjuglone or other metabolites usually associated with blockage of the pentaketide pathway to melanin in fungi.Key words: Sclerotinia sclerotiorum, melanin production, tricyclazole, phenol glucosylation.
Enzymes of malate metabolism inMesorhizobium ciceriCC 1192
Authors: Tabrett Catherine Ann , Copeland Les
Published: June 2003

Electrophoretic studies were performed on enzymes concerned with the oxidation of malate in free-living and bacteroid cells of Mesorhizobium ciceri CC 1192, which forms nitrogen-fixing symbioses with chickpea (Cicer arietinum L.) plants. Two malate dehydrogenases were detected in extracts from both types of cells in native polyacrylamide electrophoresis gels that were stained for enzyme activity. One band of malate dehydrogenase activity was stained only in the presence of NADP+, whereas the other band was revealed with NAD+but not NADP+. Further evidence for the occurrence of separate NAD- and NADP-dependent malate dehydrogenases was obtained from preliminary enzyme kinetic studies with crude extracts from free-living M. ciceri CC 1192 cells. Activity staining of electrophoretic gels also indicated the presence of two malic enzymes in free-living and bacteroid cells of M. ciceri CC 1192. One malic enzyme was active with both NAD+and NADP+, whereas the other was specific for NADP+. Possible roles of the multiple forms of malate dehydrogenase and malic enzyme in nitrogen-fixing symbioses are discussed.Key words: Mesorhizobium ciceri, malate dehydrogenase, malic enzyme, chickpea bacteroids, symbiotic nitrogen fixation.