bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term accumulation of uranium in bones of Wistar rats as a function of intake dosages
Authors: Arruda-Neto J. D. T. , Manso Guevara M. V. , Nogueira G. P. , Saiki M. , Cestari A. C. , Shtejer K. , Deppman A. , Pereira Filho J. W. , Garcia F. , Geraldo L. P. , Gouveia A. N. , Guzmán F. , Mesa J. , Rodriguez O. , Semmler R. , Vanin V. R.
Published: October 2004

Groups of Wistar rats were fed with ration doped with uranyl nitrate at concentration A ranging from 0.5 to 100 ppm, starting after the weaning period and lasting until the postpuberty period when the animals were sacrificed. Uranium in the ashes of bones was determined by neutron activation analysis. It was found that the uranium concentration in the bones, as a function of A, exhibits a change in its slope at ∼20 ppm—a probable consequence of the malfunctioning of kidneys. The uranium transfer coefficient was obtained and an analytical expression was fitted into the data, thus allowing extrapolation down to low doses. Internal and localized doses were calculated. Absorbed doses exceeded the critical dose, even for the lowest uranium dosage.
1-Chloro-1,3,3,5,5-pentaphenoxycyclotriphosphazene: a precursor of functionalized cyclophosphazene derivatives
Authors: Sopková-de Oliveira Santos Jana , Bauchart Diane , Besset Celine , Dez Isabelle
Published: October 2004

The crystal structure of the title compound, C30H25ClN3O5P3, shows that the direct bonding between P and Cl does not modify the structural parameters in the vicinity of this P atom. It also confirms the structural difference between the two P atoms which are each bonded to two phenoxy groups, observed in the 31P NMR spectrum. The crystal packing consists principally of complex stacking interactions.
2-Pyridone–tartronic acid (1/1), 3-hydroxypyridinium hydrogen tartronate and 4-hydroxypyridinium hydrogen tartronate
Authors: Fukunaga Takeo , Kashino Setsuo , Ishida Hiroyuki
Published: October 2004

Tartronic acid forms a hydrogen-bonded complex, C5H5NO·C3H4O5, (I), with 2-pyridone, while it forms acid salts, namely 3-hydroxypyridinium hydrogen tartronate, (II), and 4-hydroxypyridinium hydrogen tartronate, (III), both C5H6NO+·C3H3O5
−, with 3-hydroxypyridine and 4-hydroxypyridine, respectively. In (I), the pyridone molecules and the acid molecules form R{_2^2}(8) and R{_2^2}(10) hydrogen-bonded rings, respectively, around the inversion centres. In (II) and (III), the cations and anions are linked by N—H...O and O—H...O hydrogen bonds to form a hydrogen-bonded chain. In each of (I), (II) and (III), an intermolecular hydrogen bond is formed between a carboxyl group and the hydroxyl group attached to the central C atom, and in (I), the hydroxyl group participates in an intramolecular hydrogen bond with a carbonyl group. No intermolecular hydrogen bond is formed between the carboxyl groups in (I), or between the carboxyl and carboxylate groups in (II) and (III).
6-(3,4-Difluorobenzoyl)-3-[2-(4-pyridyl)ethyl]-1,3-benzothiazol-2(3H)-one
Authors: Özbey Süheyla , Gökhan Nesrin
Published: October 2004

A new type of benzothiazolinone derivative with potential pharmacological activity, viz. 6-(3,4-difluorobenzoyl)-3-[2-(4-pyridyl)ethyl]-1,3-benzothiazol-2(3H)-one, C21H14F2N2O2S, has been prepared and studied by NMR, IR and single-crystal X-ray diffraction techniques. The molecule is not planar, the pyridine and difluorobenzene moieties being located above and below the benzothiazole ring system. The carbonyl O atoms are involved in an intramolecular hydrogen-bond-type interaction.
Poly[[copper(II)-di-μ-5-aminoisophthalato(1–)-κ4
N:O] monohydrate]
Authors: Liao Qiu-Xia , Li Zhao-Ji , Zhang Jian , Kang Yao , Dai Yu-Mei , Yao Yuan-Gen
Published: October 2004

The title compound, {[Cu(C8H6NO4)2]·H2O}
n
, was prepared by the hydrothermal assembly of 5-aminoisophthalic acid with copper nitrate. Single-crystal X-ray analysis shows that it has a two-dimensional layer coordination framework, in which the unique Cu atom lies on an inversion centre and adopts a square-planar geometry, coordinated to two N and two O atoms from symmetry-related ligands. The water molecule lies on a twofold axis and there are hydrogen-bonding interactions between the layers.
(R,R)-Tricarbonyl{η6-1-(diphenylphosphino)-2-[1-(diphenylphosphino)ethyl]benzene}chromium(0), (R,R)-tricarbonyl-1κ3
C-{μ-1(η6):2κ2
P,P′-1-(diphenylphosphino)-2-[1-(diphenylphosphino)ethyl]benzene}[2(η4)-norbornadiene]chromium(0)rhodium(I) tetrafluoroborate methanol 0.75-solvate and (R,R)-tricarbonyl-1κ3
C-{μ-1(η6):2κ2
P,P′-1-(diphenylphosphino)-2-[1-(diphenylphosphino)ethyl]benzene}[2(η4)-(Z,Z)-cycloocta-1,5-diene]chromium(0)rhodium(I) tetrafluoroborate methanol 1.5-solvate
Authors: Braun Wolfgang , Calmuschi Beatrice , Drexler Hans-Joachim , Englert Ulli , Heller Detlef , Salzer Albrecht
Published: October 2004

The title mononuclear chromium compound, [Cr(C32H28P2)(CO)3], (I), and its rhodium complexes [CrRh(C7H8)(C32H28P2)(CO)3]BF4·0.75CH4O, (II), and [CrRh(C8H12)(C32H28P2)(CO)3]BF4·1.5CH4O, (III), prepared as a ligand and precatalysts, respectively, for application in asymmetric homogeneous hydrogenation, have been studied by single-crystal X-ray diffraction. The structures of the free and complexed ligand are compared. It was found that the backbone of the ligand remains rigid on coordination, while only minor conformational changes of its side chains are observed. Both elements of central and planar chirality seem to build a well defined chiral environment for stereoselective catalysis.
Poverty and Neo‐Liberal Bias in the Middle East and North Africa
Authors: Bush Ray
Published: October 2004

This article examines the definition of poverty and the evidential base for the claims that the region of the Middle East and North Africa (MENA) has historically low levels of poverty and relatively good levels of income distribution. It argues that the dominant trend in the literature on poverty in the global south in general, and in MENA in particular, has a neo‐classical bias. Amongst other things, that bias fails to understand that poverty does not emerge because of exclusion but because of poor people's ‘differential incorporation’ into economic and political processes. It also raises the question: if the MENA has indeed had relatively low levels of poverty and good income distribution, does this complicate the issue of autocracy and the western drive to remove political ‘backwardness’ in the region? In particular, the characterization of autocracy and the west's attempt to promote political liberalization is likely to impact adversely on the social contract that autocratic rulers have enforced regarding the delivery of basic services.
The Transmigration of Rights: Women, Movement and the Grassroots in Latin American and Caribbean Communities
Authors: Burton Barbara
Published: October 2004

In order to better understand both the global and local contours and impact of transnationalism as a political and cultural force, this article suggests the need for an exploration of shifting gender roles and expectations as they are becoming manifest in situated arenas. The awkwardness of transposing an international rights discourse into local communities and settings deeply infused with tradition, or onto grassroots nationalist movements that work to resist foreign impositions is a widely recognized concern. At the same time, the influence of diaspora populations is seen to leaven and situate global discourse for local movements in a sending country and translates more local interests into global concerns in important and effective ways. Transnational feminist discourse now often concerns itself with the different strategies employed by diasporas, the strategic uses of global discourse, and the meaningful efforts to resist it. Through illustrations drawn from a study of women refugees in El Salvador, the Haitian democracy movement, and a rural Brazilian women's organization, this article links the experience of transmigration to women's mobilizing efforts and the proliferation of rights discourses.
Phylogeny of the true water bugs (Nepomorpha: Hemiptera–Heteroptera) based on 16S and 28S rDNA and morphology
Authors: Hebsgaard Martin B. , Andersen Nils M. , Damgaard Jakob
Published: October 2004

Abstract.  Morphological characters and molecular sequence data were for the first time analysed separately and combined for the true water bugs (Hemiptera–Heteroptera, infraorder Nepomorpha). Data from forty species representing all families were included, together with two outgroup species representing the infraorders Gerromorpha and Leptopodomorpha. The morphological data matrix consisted of sixty‐five characters obtained from literature sources. Molecular data included approximately 960 bp from the mitochondrial gene 16S and the nuclear gene 28S for all forty‐two terminal taxa. The morphological dataset was analysed using maximum parsimony and the combined morphological and molecular (16S + 28S rDNA) dataset was analysed using direct optimization. A sensitivity analysis of sixteen different sets of parameters (various combinations of insertion–deletion cost and transversion costs) was undertaken. Character congruence was used as an optimality criterion to choose among competing phylogenetic hypotheses. The final hypothesis was obtained from the analysis of the combined molecular and mor phological dataset with the most congruent parameter set. This hypothesis supports the monophyly of all currently recognized families of Nepomorpha, and of the superfamilies Nepoidea (Nepidae + Belostomatidae), Corixoidea (Corixidae), Ochteroidea Ochteridae + Gelastocoridae), Notonectoidea (Notonectidae), and Pleoidea (Pleidae + Helotrephidae), but not the monophyly of the Naucoroidea (Naucoridae + Aphelocheiridae + Potamocoridae). The close relationship between the Notonectidae and Pleoidea is also supported. Our hypothesis concurs with Mahner in the placement of the Corixidae as a sister group to the remaining nepomorphan superfamilies except the Nepoidea, but differs in the placement of the Ochteroidea as a sister group to the Notonectoidea + Pleoidea. The superfamily Naucoroidea should be limited to only including the family Naucoridae and not the families Aphelocheiridae and Potamocoridae. The present analysis strongly supports a sister group relationship between the families Aphelocheiridae and Potamocoridae, a monophylum for which we propose a new superfamily, Aphelocheiroidea.
Larvae of Ceratocanthidae and Hybosoridae (Coleoptera: Scarabaeoidea): study of morphology, phylogenetic analysis and evidence of paraphyly of Hybosoridae
Authors: Grebennikov Vasily V. , Ballerio Alberto , Ocampo Federico C. , Scholtz Clarke H.
Published: October 2004

Abstract.  Larvae of the scarabaeoid genera Germarostes Paulian, Cyphopisthes Gestro, Paulianostes Ballerio, Ceratocanthus White, Pterorthochaetes Gestro, Madrasostes Paulian, Astaenomoechus Martínez & Pereira (Ceratocanthidae) and Hybosorus Macleay, Phaeochrous Castelnau, and Anaides Westwood (Hybosoridae) are described, keyed and illustrated with fifty‐seven drawings. A phylogenetic analysis of these two families based on larval morphology is presented. Fifty‐four larval morphological and three biological characters from twenty‐seven taxa revealed nineteen equally parsimonious cladograms. The monophyly of (Ceratocanthidae + Hybosoridae) is supported by four unambiguous unique synapomorphies: dorsal medial endocarina on cranium extended anteriorly into frontal sclerite; presence of large membranous spot on apical antennomere; labium dorsally with four pores in centre (secondarily reduced to two pores in some groups); and presence of stridulatory organ on fore‐ and middle legs (secondarily reduced in some groups). Our analysis suggests that the family Hybosoridae is paraphyletic with respect to Ceratocanthidae. The clade comprising the hybosorid genera Hybosorus and Phaeochrous is the sister group of the remaining Hybosoridae plus Ceratocanthidae. It is supported by two unambiguous synapomorphies: two apical antennomeres completely joined and the stridulatory organ represented by seven to nine large teeth anteriorly on the middle leg. The hybosorid genus Anaides is a sister group to the remaining Hybosoridae plus Ceratocanthidae (without Hybosorus and Phaeochrous) and the ceratocanthid genus Germarostes is a sister group to the remaining Hybosoridae plus Ceratocanthidae (without Hybosorus, Phaeochrous and Anaides). The ceratocanthid genera Cyphopisthes, Astaenomoechus, Paulianostes, Pterorthochaetes, and Madrasostes constitute a sister group to the hybosorid genus Cryptogenius and are supported by the presence of two reversions: two dorsal pores on labium and completely reduced stridulatory organs on fore‐ and middle legs.
The phylogenetic position of early hexapod lineages: morphological data contradict molecular data
Authors: Bitsch Jacques , Bitsch Colette , Bourgoin Thierry , D'Haese Cyrille
Published: October 2004

Abstract. A review of different studies on the phylogenetic relationships of the early Hexapoda lineages shows that analyses based on molecular sequence data have led to labile and sometimes incongruous results, introducing doubt as to the reliability of the cladograms as a whole. In a recent analysis using molecular data, the Collembola, usually considered as early branching hexapods, appear to occupy a position outside the assemblage of Crustacea and Insecta, leading to the rejection of the traditional view of hexapod monophyly. However, many morphological features, as well as the results of cladistic analyses based on morphological and developmental information, contradict these conclusions. More generally, it appears that in the present state of the analytical strategies, hypotheses concerning arthropod phylogenies obtained from morphological and developmental criteria and combined analyses involving molecular and morphological data provide more reliable results than those generated by molecular information alone.
Phylogeny and behaviour of the Gollumiellinae, a new subfamily of the ant‐parasitic Eucharitidae (Hymenoptera: Chalcidoidea)
Authors: Heraty John , Hawks David , Kostecki Jan S. , Carmichael Andrew
Published: October 2004

Abstract.  Gollumiellinae is proposed as a new subfamily for the Indo‐Pacific genera Gollumiella Hedqvist and Anorasema Bouc̆ek based on analyses of three ribosomal transcript gene regions (28S‐D2 and ‐D3, and 18S‐E23; 1262 aligned base pairs) sequenced for twenty‐eight genera and fifty‐four species of Eucharitidae, and twelve genera and nineteen species of Pteromalidae (Pteromalinae) and Perilampidae (Chrysolampinae and Perilampinae). Gollumiella and Anorasema have been treated as either a monophyletic or paraphyletic group within the Eucharitini (Hymenoptera: Eucharitidae). The monophyly of the Eucharitidae and a sister‐group relationship between Gollumiellinae and Oraseminae +  Eucharitinae are supported strongly in parsimony and Bayesian analyses. The molecular phylogeny contradicts previous morphological hypotheses, in which Gollumiella and Anorasema are within Eucharitini. The strength of the molecular hypothesis is explored through evaluations of data alignments that are eye optimized, clustal‐x aligned, eye optimized but with gaps coded as a fifth base, and eye optimized and combined with morphological data. The oviposition behaviour and host associations of G. longipetiolata on tree ferns (Cyathea latebrosa, Cyatheaceae), and the morphology of the planidium and pupa are newly described. Eggs are deposited vertically, with the base anchored into the leaf or petiolar surface. Unlike other Eucharitidae, the eggs are not stalked, but rather tipped with a secretion that may act as an attractant for their ant host, Paratrechina sp. (Formicidae: Formicinae). Various morphological character state optimizations and their implications for convergent morphology, behaviour and host associations are discussed. All results using gene regions treated separately or combined with the morphological data reach the same conclusion: Anorasema + Gollumiella form the sister group of Oraseminae + Eucharitinae, and thus deserve subfamily status. This suggests that very distinct traits such as the fusion of the pronotum and prepectus in adults and the fusion of the first two tergites of the planidia are convergent apomorphies. Molecular data, when strongly supported, can provide new information to unravel convergent from synapomorphic changes, resulting in more robust hypotheses of relationship.
Prejunctional Muscarinic Receptor Modulation of Noradrenaline Release from Sympathetic Neurones in Rabbit Aorta *
Authors: Lomholt Mads , Nedergaard Ove A.
Published: October 2004

The prejunctional muscarinic modulation of stimulation‐evoked release of 3H‐noradrenaline from sympathetic neurones in rabbit aorta was examined. The role of transmitter uptake, α‐adrenoceptor blockade, stimulation frequency and endothelium on the modulation was investigated. Rings of aorta were incubated with (‐)‐3H‐noradrenaline and subsequently subjected to electrical‐field stimulation. Fractional 3H‐overflow was determined by liquid scintillation counting. Acetylcholine (10−8–3×10−6 M) added cumulatively, reduced the stimulation‐evoked 3H‐overflow up to 80%. The effect of acetylcholine was the same in intact and endothelium‐free aorta. The inhibitory effect of acetylcholine was inversely related to the frequency of stimulation (1–10 Hz). The maximal inhibition (%) was 80 (1 Hz), 53 (3 Hz) and 14 (10 Hz). The inhibitory effect of acetylcholine (10−6 M) and carbachol (10−5 M) reached a maximum 15 min. after addition and then remained almost constant. Cocaine (3×10−5 M) did not alter the effect of acetylcholine. Desipramine (10−6 M) and corticosterone (4×10−5 M) attenuated the inhibition seen with low concentrations (10−8–10−7 M) of acetylcholine. The acetylcholine‐induced inhibition was antagonized by desipramine. Cocaine plus corticosterone attenuated the inhibition seen with high concentrations (10−6–3×10−6 M) of acetylcholine. Rauwolscine (10−6 M) enhanced the maximal inhibitory effect of acetylcholine. We conclude that the inhibitory effect of acetylcholine on 3H‐overflow from rabbit aorta preloaded with 3H‐noradrenaline is (1) inversely related to stimulation frequency; (2) independent of endothelium; (3) unaffected by neuronal and extraneuronal transmitter uptake; (4) that cocaine is not a prejunctional muscarinic antagonist; (5) that cocaine, but not desipramine, is suited as a neuronal uptake inhibitor in studies of prejunctional muscarinic receptor subtypes; and (6) and that there is an inverse interaction between prejunctional α2‐adrenoceptors and muscarinic receptors.
Asset Pricing of Insurance Loss Liabilities: Some Examples
Authors: O'Brien Thomas J.
Published: October 2004

I construct examples of valuing insurance loss liabilities with asset pricing models, comparing the Rubinstein‐Leland model with the better‐known CAPM. The two models give different values only if the loss payment is asymmetric and correlated with the market portfolio, conditions which can result from the nature of the underlying loss or from the impact of insolvency on the insurer's payment.

In examples where insolvency is not possible and there is no liquidity cost of raising new equity on short notice, the value of a loss liability is equal to the value of the underlying loss, i.e., of the promised coverage, and depends neither on (1) the size of the loss pool; nor on (2) the unsystematic risk of the insurer's liabilities; nor on (3) the composition of an insurer's investment portfolio; nor on (4) the amount of insurer equity.

These factors do affect the value of a loss liability in examples where insolvency and liquidity costs are considered. Other things equal, if a factor increases the likelihood of insolvency, the fair value of a loss liability is lower because the insured is partially self‐insuring; but the liquidity cost of maintaining solvency by raising new equity on short notice is higher, implying a higher fair value of the loss liability.
Retracted: In vivo potentiation of human oestrogen receptor α by Cdk7‐mediated phosphorylation
Authors: Ito Saya , Takeyama Ken‐ichi , Yamamoto Ayako , Sawatsubashi Shun , Shirode Yuko , Kouzmenko Alexander , Tabata Tetsuya , Kato Shigeaki
Published: October 2004

Phosphorylation of the Ser118 residue in the N‐terminal A/B domain of the human oestrogen receptor α (hERα) by mitogen‐activated protein kinase (MAPK), stimulated via growth factor signalling pathways, is known to potentiate ERα ligand‐induced transactivation function. Besides MAPK, cyclin dependent kinase 7 (Cdk7) in the TFIIH complex has also been found to potentiate hERα transactivation in vitro through Ser118 phosphorylation. To investigate an impact of Cdk7 on hERα transactivation in vivo, we assessed activity of hERα in a wild‐type and cdk7 inactive mutant Drosophila that ectopically expressed hERα in the eye disc. Ectopic expression of the wild‐type or mutant receptors, together with a green fluorescent protein (GFP) reporter gene, allowed us to demonstrate that hERα expressed in the fly tissues was transcriptionally functional and adequately responded to hERα ligands in the patterns similar to those observed in mammalian cells. Replacement of Ser118 with alanine in hERα (S118A mutant) significantly reduced the ligand‐induced hERα transactivation function. Importantly, while in cdk7 inactive mutant Drosophila the wild‐type hERα exhibited reduced response to the ligand; levels of transactivation by the hERα S118A mutant were not affected in these inactive cdk7 mutant flies. Furthermore, phosphorylation of hERα at Ser118 has been observed in vitro by both human and Drosophila Cdk7. Our findings demonstrate that Cdk7 is involved in regulation of the ligand‐induced transactivation function of hERαin vivo via Ser118 phosphorylation.
Propagation of γPKC translocation along the dendrites of Purkinje cell in γPKC‐GFP transgenic mice
Authors: Sakai Norio , Tsubokawa Hiroshi , Matsuzaki Masanori , Kajimoto Taketoshi , Takahashi Eri , Ren Yi , Ohmori Shiho , Shirai Yasuhito , Matsubayashi Hiroaki , Chen Jingshan , Duman Ronald S. , Kasai Haruo , Saito Naoaki
Published: October 2004

To elucidate spatial and temporal profiles of the protein kinase C (PKC) activation in relation to neuronal functions including synaptic plasticity, we tried to detect PKC translocation in living brain slices. We first developed brain region‐specific and inducible γPKC‐GFP transgenic mice using a tetracycline (tet)‐regulated system. In the transgenic mice, the expression of γPKC‐GFP was region‐specifically regulated by the promoter and abolished by the administration of doxycycline. Cerebellar slices from the mice were utilized for intracellular recording and fluorescence imaging of γPKC‐GFP in Purkinje cells. GFP fluorescence was uniformly distributed from soma to dendritic arbor. When mGluR agonists were applied, the intensity was transiently increased at the edge of the dendrite and concomitantly decreased in the cytoplasm, indicating that γPKC translocated to the plasma membrane. This transient change in the pattern of GFP fluorescence simultaneously occurred throughout the Purkinje cell dendrites by agonist stimulation. Translocation of γPKC‐GFP was also induced by electrical stimulation of parallel fibres. However, the event was not restricted at the distal dendrites, propagated forwardly along the dendritic tree and reached to the proximal trunk close to the soma. Time course of the propagation was slower than the electrical signal and Ca2+ waves and faster than conveying molecules through microtubules. The present results indicate that PKC signals activated locally by parallel fibre input could propagate to the soma through dendrites in living Purkinje neurones. The findings may provide us with a new insight for understanding molecular mechanisms of the synaptic plasticity including cerebellar long‐term depression.
Local exposure of phosphatidylethanolamine on the yeast plasma membrane is implicated in cell polarity
Authors: Iwamoto Kunihiko , Kobayashi Shingo , Fukuda Ryouichi , Umeda Masato , Kobayashi Toshihide , Ohta Akinori
Published: October 2004

Cell surface phosphatidylethanolamine (PE) of the yeast cell was probed by biotinylated Ro09‐0198 (Bio‐Ro), which specifically binds to PE and was visualized with fluorescein‐labelled streptavidin. In Saccharomyces cerevisiae, the signals were observed at the presumptive bud site, the emerging small bud cortex, the bud neck of the late mitotic large‐budded cells and the tip of the mating projection. In Schizosaccharomyces pombe, the signals were observed at one end or both ends of mono‐nucleated cells and the division plane of the late mitotic cells. These sites were polarized ends in the yeast cells, implying that PE is exposed on the cell surface at cellular polarized ends. Treatment of S. cerevisiae cells with Ro09‐0198 resulted in aberrant F‐actin accumulation at the above sites, implying that limited surface exposure of PE is involved in the polarized organization of the actin cytoskeleton. Furthermore, S. cerevisiae ros3, dnf1 and dnf2 null mutants, which were known to be defective in the internalization of fluorescence‐labelled PE, as well as the combinatorial mutants, were stained with Bio‐Ro at the enlarging bud cortex, in addition to the Bio‐Ro‐staining sites of wild‐type cells, suggesting that Ros3p, Dnf1p and Dnf2p are involved in the retrieval of exposed PE at the bud cortex.
Quantitative and qualitative evaluation of selected wheat varieties released since 1903 to increasing atmospheric carbon dioxide: can yield sensitivity to carbon dioxide be a factor in wheat performance?
Authors: Ziska L. H. , Morris C. F. , Goins E. W.
Published: October 2004

The sensitivity of yield and quality parameters to carbon dioxide concentration [CO2] was determined for individual lines of hard‐red spring wheat released in 1903, 1921, 1965 and 1996. All cultivars were evaluated with respect to growth and vegetative characteristics, grain yield and nutritional quality in response to [CO2] increases that corresponded roughly to the CO2 concentrations at the beginning of the 20th century, the current [CO2], and the future projected [CO2] for the end of the 21st century, respectively. Leaf area ratio (cm2 g−1) declined and net assimilation rate (g m2 day−1) increased in response to increasing [CO2] for all cultivars during early vegetative growth. By maturity, vegetative growth of all cultivars significantly increased with the increase in [CO2]. Seed yield increased significantly as [CO2] increased, with yield sensitivity to rising [CO2] inversely proportional to the year of cultivar release. Greater [CO2] yield sensitivity in older cultivars was associated with whole‐plant characteristics such as increased tillering and panicle formation. Grain and flour protein, however, declined significantly with increasing [CO2] and with year of release for all cultivars, although absolute values were higher for the older cultivars. Overall, these data indicate that yield response at the whole‐plant level to recent and projected increases in [CO2] has declined with the release of newer cultivars, as has protein content of grain and flour. However, if agronomic practice can be adapted to maximize individual plant performance, [CO2] responsive characteristics of older cultivars could, potentially, be incorporated as factors in future wheat selection.
Long‐term carbon exchange in a sparse, seasonally dry tussock grassland
Authors: Hunt John E. , Kelliher Francis M. , McSeveny Tony M. , Ross Des J. , Whitehead David
Published: October 2004

Rainfall and its seasonal distribution can alter carbon dioxide (CO2) exchange and the sustainability of grassland ecosystems. Using eddy covariance, CO2 exchange between the atmosphere and a sparse grassland was measured for 2 years at Twizel, New Zealand. The years had contrasting distributions of rain and falls (446 mm followed by 933 mm; long‐term mean=646 mm). The vegetation was sparse with total above‐ground biomass of only 1410 g m−2. During the dry year, leaf area index peaked in spring (November) at 0.7, but it was <0.2 by early summer.

The maximum daily net CO2 uptake rate was only 1.5 g C m−2 day−1, and it occurred before mid‐summer in both years. On an annual basis, for the dry year, 9 g C m−2 was lost to the atmosphere. During the wet year, 41 g C m−2 was sequestered from the atmosphere. The net exchange rates were determined mostly by the timing and intensity of spring rainfall.

The components of ecosystem respiration were measured using chambers. Combining scaled‐up measurements with the eddy CO2 effluxes, it was estimated that 85% of ecosystem respiration emanated from the soil surface. Under well‐watered conditions, 26% of the soil surface CO2 efflux came from soil microbial activity. Rates of soil microbial CO2 production and net mineral‐N production were low and indicative of substrate limitation. Soil respiration declined by a factor of four as the soil water content declined from field capacity (0.21 m3 m−3) to the driest value obtained (0.04 m3 m−3). Rainfall after periods of drought resulted in large, but short‐lived, respiration pulses that were curvilinearly related to the increase in root‐zone water content. Coupled with the low leaf area and high root : shoot ratio, this sparse grassland had a limited capacity to sequester and store carbon. Assuming a proportionality between carbon gain and rainfall during the summer, rainfall distribution statistics suggest that the ecosystem is sustainable in the long term.
A large carbon pool and small sink in boreal Holocene lake sediments
Authors: Kortelainen Pirkko , Pajunen Hannu , Rantakari Miitta , Saarnisto Matti
Published: October 2004

Model‐based estimates suggest that lake sediments may be a significant, long‐term sink for organic carbon (C) at regional to global scales. These models have used various approaches to predict sediment storage at broad scales from very limited data sets. Here, we report a large‐scale direct assessment of the standing stock and sedimentation rate of C for a representative set of lakes in Finland. The 122 lakes were selected from the statistically selected Nordic Lake Survey database, they cover the entire country and the water quality represents the average lake water quality in Finland. Unlike all prior estimates, these data use sediment cores that comprise the entire sediment record. The data show that within Finland, aquatic ecosystems contain the second largest areal C stocks (19 kg C m−2) after peatlands (72 kg C m−2), and exceed by significant amounts stocks in the forest soil (uppermost 75cm; 7.2 kg C m−2) and woody biomass (3.4 kg C m−2). Kauppi et al. (1997). The Finnish estimate extrapolated over the boreal region gives a total C pool in lakes 19–27 Pg C, significantly lower than the previous model‐based estimates.
Decomposition of Betula papyrifera leaf litter under the independent and interactive effects of elevated CO2 and O3
Authors: Parsons William F. J. , Lindroth Richard L. , Bockheim James G.
Published: October 2004

Litter decay dynamics of paper birch (Betula papyrifera) were assessed at the Aspen free‐air CO2 enrichment (FACE) facility in northern Wisconsin, USA. Leaf litter was decomposed for 12 months under factorial combinations of 360 vs. 560 μL CO2 L−1, crossed with 36 vs. 55 nL O3 L−1. To differentiate between substrate quality and environment effects, litterbags were placed in their Native Plots of origin or transplanted into the other treatments. CO2 enrichment, regardless of O3 concentration, produced poorer quality litter (high C/N, lignin/N and condensed tannins) than did ambient CO2 (low C/N, lignin/N and condensed tannins). Substrate quality differences were reflected in the mass loss rates (k‐values), which were high for litter generated under ambient CO2 (0.887 year−1) and low for litter generated under elevated CO2 (0.674 year−1). The rate‐retarding effects of CO2 enrichment were neither alleviated nor exacerbated by O3 exposure. Decay rates varied, however, depending on whether litter was placed back into its plot of origin or transplanted to Common Gardens. The results of this study are species specific, but they have important implications for understanding the processes regulating storage of fixed C and the release of CO2 from northern forest ecosystems.
Caring as worrying: the experience of spousal carers
Authors: Cheung Jenny , Hocking Peta
Published: October 2004

Background. With the emerging focus on home‐based care, there is an increasing demand on spouses to look after their chronically ill partners at home. The theoretical aspects of caring have been much discussed in the literature, but the pragmatic aspects have received less attention. Carer stress has been explored, but little has been written about the meaning of caring to informal carers.

Aim. The aim of this paper is to report one of the major themes that emerged from a study conducted between 1998 and 1999 to explicate the meaning of caring from the perspective of spousal carers for people with multiple sclerosis in order to shed light on and understand the challenges and demands these carers encountered.

Methodology. An interpretive phenomenological approach was used to describe spousal carers’ experiences of caring for their partner. Ten spousal carers of people with multiple sclerosis participated. Data were collected through unstructured in‐depth interviews and analysed by the method of hermeneutic analysis.

Findings. This paper presents one of the major themes identified: ‘caring as worrying’. While the meaning of caring that emerged from this theme supports many of the philosophical understandings of caring as discussed in the literature, worrying as a care responsibility provides a further insight. Caring as worrying describes caring as a complex emotional relationship of responsibility in these participants. They worried about their partners, their relationships with their partners and their future. They also worried about their own health, institutional care, and lack of government support.

Conclusion. Spousal carers’ worries have significant implications for health care professionals. The findings provide insight into the concerns and worries the carers of people with multiple sclerosis face when caring for their chronically ill partners at home.
Coronary artery bypass graft surgery: discharge planning for successful recovery
Authors: Theobald Karen , McMurray Anne
Published: October 2004

Background.  Coronary artery bypass graft (CABG) surgery is a lifesaving intervention, but the early recovery period presents a number of challenges for patients, carers and nurses. Early and adequate discharge planning based on in‐depth knowledge of the postdischarge experience can help to ensure optimal recovery.

Aim.  This paper reports a study to examine the range of postdischarge issues, concerns and needs of patients and their family carers after discharge after CABG surgery, and explore their perceptions of unmet needs 1 year later.

Methods.  A two‐phase naturalistic inquiry was undertaken. Interviews were conducted with 30 patients and their carers 4–5 weeks after coronary artery bypass grafting (phase 1) and 1 year after the initial interview (phase 2). Thematic analysis was used to identify the major concerns of participants.

Findings.  Almost half the patients experienced heart surgery as a huge personal shock. Adjusting to life afterwards was difficult, and they experienced a variety of changes, including pain. An unexpected finding was a heightened sense of body awareness and the need for postoperative physical adjustments. The financial implications of surgery were a major burden. Lifestyle adjustments were important and led to suggestions for support services, using telephone support and/or community patient networks. All participants recommended strengthening discharge planning with more accurate information about what to expect during recovery, to help them anticipate fluctuations in health and wellbeing. Carers experienced a wide range of unanticipated feelings during early recovery and had to deal with a number of personal changes.

Conclusions.  The findings suggest a need to improve discharge preparation and provide enhanced home support services. Further research should evaluate models of periodic follow‐up and mechanisms for mutual support, and compare the experiences of cardiac patients and their carers with those of other surgical cohorts.
Physicians and nurses with substance use disorders
Authors: Shaw Matthew F. , McGovern Mark P. , Angres Daniel H. , Rawal Purva
Published: October 2004

Background.  The literature addressing substance use patterns among medical professionals suggests that specialty, gender, age, familial substance abuse, and access/familiarity with prescription drugs are associated with particular chemical dependencies. These studies have rarely compared nurses and physicians directly, thereby making if difficult to tailor interventions to the potentially unique needs of each group.

Aim.  This paper reports a study to compare the initial clinical presentations, service utilization patterns, and post‐treatment functioning of nurses and physicians who received services in an addiction treatment programme.

Method.  This exploratory study combined data collected through retrospective record reviews and prospective questionnaires. There were three types of dependent variables: initial clinical characteristics, treatment utilization patterns, and post‐treatment functioning. The independent variable was membership of either professional group. Time both in treatment and between discharge and follow‐up were covariates.

Results.  Nurses and physicians showed comparable results in most domains. Among the statistically significant differences between groups, a subset was particularly noteworthy. Prior to participating in the programme nurses showed significantly less personality disturbance than physicians, although they tended to work and live in environments with more triggers to relapse, such as other substance users. After the index hospitalization, nurses received less primary treatment, worked longer hours, and were more symptomatic than physicians. Furthermore, nurses reported more frequent and severe work‐related sanctions as a consequence of their behavioural disorders.

Conclusion.  In most areas of study, nurses and physicians demonstrated comparable results; however, a series of statistically significant differences suggest that these groups may have unique clinical needs. The policy implications of these findings are discussed.
Co‐ordinate single‐cell expression of LEE4‐ and LEE5‐encoded proteins of Escherichia coli O157:H7
Authors: Roe Andrew J. , Naylor Stuart W. , Spears Kevin J. , Yull Helen M. , Dransfield Tracy A. , Oxford Matthew , McKendrick Iain J. , Porter Megan , Woodward Martin J. , Smith David G. E. , Gally David L.
Published: October 2004

Escherichia coli O157:H7 is a zoonotic pathogen that can express a type III secretion system (TTSS) considered important for colonization and persistence in ruminants. E. coli O157:H7 strains have been shown to vary markedly in levels of protein secreted using the TTSS and this study has confirmed that a high secretion phenotype is more prevalent among isolates associated with human disease than isolates shed by healthy cattle. The variation in secretion levels is a consequence of heterogeneous expression, being dependent on the proportion of bacteria in a population that are actively engaged in protein secretion. This was demonstrated by indirect immunofluorescence and eGFP fusions that examined the expression of locus of enterocyte effacement (LEE)‐encoded factors in individual bacteria. In liquid media, the expression of EspA, tir::egfp, intimin, but not map::egfp were co‐ordinated in a subpopulation of bacteria. In contrast to E. coli O157:H7, expression of tir::egfp in EPEC E2348/69 was equivalent in all bacteria although the same fusion exhibited variable expression when transformed into an E. coli O157:H7 background. An E. coli O157:H7 strain deleted for the LEE demonstrated weak but variable expression of tir::egfp indicating that the elements controlling the heterogeneous expression lie outside the LEE. The research also demonstrated the rapid induction of tir::egfp and map::egfp on contact with bovine epithelial cells. This control in E. coli O157:H7 may be required to limit exposure of key surface antigens, EspA, Tir and intimin during colonization of cattle but allow their rapid production on contact with bovine gastrointestinal epithelium at the terminal rectum.
Multiple variants of the archaeal DNA rudivirus SIRV1 in a single host and a novel mechanism of genomic variation
Authors: Peng Xu , Kessler Alexandra , Phan Hien , Garrett Roger A. , Prangishvili David
Published: October 2004

The DNA rudivirus SIRV1 of the hyperthermophilic archaeon Sulfolobus shows exceptional properties. Viral isolates invariably contain a population of variants with different but closely related genomes. Upon propagation in a given host strain, one or more genomes dominate in the viral population. However, upon passage into a new host strain the viral population undergoes changes and other dominant variants are selected. Sequencing and analysis of the variant genomes revealed that major differences occur in gene order, gene size and gene content at localized genomic sites. A previously unknown mechanism of genomic rearrangement involving putative 12 bp archaeal introns appears to facilitate alteration of the variant genomes. Inter‐genomic recombination between the different variants also occurs. The variant genomes exhibit signature tetranucleotide sequences near their putative sites for replication initiation.
Cladosporium fulvum circumvents the second functional resistance gene homologue at the Cf‐4 locus (Hcr9‐4E ) by secretion of a stable avr4E isoform
Authors: Westerink Nienke , Brandwagt Bas F. , De Wit Pierre J. G. M. , Joosten Matthieu H. A. J.
Published: October 2004

Introgression of resistance trait Cf‐4 from wild tomato species into tomato cultivar MoneyMaker (MM‐Cf0) has resulted in the near‐isogenic line MM‐Cf4 that confers resistance to the fungal tomato pathogen Cladosporium fulvum. At the Cf‐4 locus, five homologues of Cladosporium resistance gene Cf‐9 (Hcr9s) are present. While Hcr9‐4D represents the functional Cf‐4 resistance gene matching Avr4, Hcr9‐4E confers resistance towards C. fulvum by mediating recognition of the novel avirulence determinant Avr4E. Here, we report the isolation of the Avr4E gene, which encodes a cysteine‐rich protein of 101 amino acids that is secreted by C. fulvum during colonization of the apoplastic space of tomato leaves. By complementation we show that Avr4E confers avirulence to strains of C. fulvum that are normally virulent on Hcr9‐4E‐transgenic plants, indicating that Avr4E is a genuine, race‐specific avirulence determinant. Strains of C. fulvum evade Hcr9‐4E‐mediated resistance either by a deletion of the Avr4E gene or by production of a stable Avr4E mutant protein that carries two amino acid substitutions, Phe82Leu and Met93Thr. Moreover, we demonstrate by site‐directed mutagenesis that the single amino acid substitution Phe82Leu in Avr4E is sufficient to evade Hcr9‐4E‐mediated resistance.
Peptide‐mediated macrolide resistance reveals possible specific interactions in the nascent peptide exit tunnel
Authors: Vimberg Vladimir , Xiong Liqun , Bailey Marne , Tenson Tanel , Mankin Alexander
Published: October 2004

Expression of specific short peptides can render cells resistant to macrolide antibiotics. Peptides conferring resistance to structurally different macrolides including oleandomycin, azithromycin, azaerythromycin, josamycin and a ketolide cethromycin were selected from a random pentapeptide expression library. Analysis of the entire collection of the resistance peptides allowed their classification into five distinct groups according to their sequence similarity and the type of resistance they confer. A strong correlation was observed between the structures of macrolide antibiotics and sequences of the peptides conferring resistance. Such a correlation indicates that sequence‐specific interactions between the nascent peptide and the macrolide antibiotic and/or the ribosome can occur in the ribosomal exit tunnel.
Activation of the RcsC/YojN/RcsB phosphorelay system attenuates Salmonella virulence
Authors: Mouslim Chakib , Delgado Mónica , Groisman Eduardo A.
Published: October 2004

Bacterial pathogens have the ability to sense their presence in host tissues and to promote expression of their virulence factors in a time‐ and location‐dependent manner. However, little is known about those genes whose expression is detrimental and thus suppressed during infection. Here we report that constitutive activation of the RcsC/YojN/RcsB system resulting from a mutation in the rcsC sensor gene dramatically attenuates Salmonella virulence. Mutation of the cognate response regulator gene rcsB restored full virulence to the rcsC constitutive mutant, indicating that virulence attenuation results from aberrant expression of RcsB‐regulated genes. The virulence attenuation phenotype was partially dependent on the regulatory gene rcsA, which is necessary for transcription of certain RcsB‐regulated genes, and on the RcsB‐ and RcsA‐dependent colanic acid capsule synthesis cps operon. The rcsC constitutive mutant was phagocytized less efficiently by macrophages and it was defective for invasion of non‐phagocytic cells and survival within macrophages; but it could protect mice upon challenge with wild‐type Salmonella. Our results suggest that a successful infection demands that pathogens turn off expression of products that might interfere with virulence functions.
Modulation of AraC family member activity by protein ligands
Authors: Plano Gregory V.
Published: October 2004

A number of AraC family transcriptional activators bind low‐molecular‐weight ligands that modulate the activity of these proteins. Recently, it has become clear that the activity of several virulence‐related AraC family members is regulated through the direct interaction of protein ligands. These interactions, in general, function to activate or repress the transcription of virulence genes in response to specific extracellular stimuli. The identification and characterization of several protein ligands that modify the activity of AraC family members in Pseudomonas aeruginosa and Salmonella enterica are discussed herein.
Cryptococcus neoformans Kin1 protein kinase homologue, identified through a Caenorhabditis elegans screen, promotes virulence in mammals
Authors: Mylonakis Eleftherios , Idnurm Alexander , Moreno Roberto , El Khoury Joseph , Rottman James B. , Ausubel Frederick M. , Heitman Joseph , Calderwood Stephen B.
Published: October 2004

Cryptococcal infections are a global cause of significant morbidity and mortality. Recent studies support the hypothesis that virulence of Cryptococcus neoformans may have evolved via survival selection in environmental hosts, such as amoebae and free‐living nematodes. We used killing of the nematode Caenorhabditis elegans by C. neoformans as an assay to screen a library of random C. neoformans insertion mutants. Of 350 mutants tested, seven were identified with attenuated virulence that persisted after crossing the mutation back into a wild‐type strain. Genetic analysis of one strain revealed an insertion in a gene homologous to Saccharomyces cerevisiae KIN1, which encodes a serine/threonine protein kinase. C. neoformans kin1 mutants exhibited significant defects in virulence in murine inhalation and haematogenous infection models and displayed increased binding to alveolar and peritoneal macrophages. The kin1 mutant phenotypes were complemented by the wild‐type KIN1 gene. These findings show that the C. neoformans Kin1 kinase homologue is required for full virulence in disparate hosts and that C. elegans can be used as a substitute host to identify novel factors involved in fungal pathogenesis in mammals.