bluuebunny/crossref_metadata_2025 huggingface dataset:
The two‐component response regulator PprB modulates quorum‐sensing signal production and global gene expression in Pseudomonas aeruginosa
Authors: Dong Yi‐Hu , Zhang Xi‐Fen , Soo Hui‐Meng Linda , Greenberg Everett P. , Zhang Lian‐Hui
Published: May 2005

The response regulator PprB and its cognate sensor PprA were recently reported as a two‐component regulatory system that controls membrane permeability and antibiotic sensitivity of Pseudomonas aeruginosa. We found that a Tn5 insertion mutation in pprB caused a drastic reduction in virulence factor production and cell motility. A transcriptome analysis revealed that 175 genes were regulated by PprB. Among the 113 PprB‐activated genes, 85.5% are known to be activated by N‐3‐oxo‐dodecanoyl‐homoserine lactone (OdDHL) and N‐butanoyl‐homoserine lactone (BHL). In particular, the expression of lasI, rhlI and rhlR, which encode key components of the las and rhl quorum‐sensing (QS) systems, were significantly decreased in the pprB mutant. These data suggest that PprB might regulate QS signal production. Measurement of OdDHL and BHL in cultures of the mutant sustained this hypothesis. By using various OdDHL‐ or BHL‐responsive QS reporter systems, including lasB–lacZ, lasI–lacZ and rsaL–lacZ, we found that the mutation in pprB resulted in a large decrease in the sensitivity of P. aeruginosa to exogenous OdDHL. However, there was no difference in sensitivity to BHL. Further analysis showed that the OdDHL influx was significantly reduced in the pprB mutant. We conclude that PprB is a novel QS modulator that positively regulates N‐acylhomoserine lactone production probably by affecting the OdDHL signal influx and thereby influences global expression of the QS‐dependent genes.
Modulating factors for the Pkn4 kinase cascade in regulating 6‐phosphofructokinase in Myxococcus xanthus
Authors: Nariya Hirofumi , Inouye Sumiko
Published: May 2005

Myxococcus xanthus, a Gram‐negative developmental bacterium, contains a large number of protein Ser/Thr kinases (PSTKs). Among these PSTKs, Pkn4 has been shown to be 6‐phosphofructokinase (PFK) kinase. PFK associates with the regulatory domain of Pkn4 (Pkn4RD) and is activated by Pkn4‐mediated phosphorylation. The activation of PFK is required to consume glycogen accumulated during early development and is essential for efficient sporulation. Using the yeast two‐hybrid screen, we identified three new factors, MkapA, MkapB and MkapC, that interact with Pkn4 and each contains well‐known protein–protein interaction domains. MkapB contains eight tandem repeats of the TPR (tetratrico peptide repeat) domain and its interaction with Pkn4RD was phosphorylation‐dependent. MkapB remained associated with Pkn4RD. As a result, Pkn4 did not interact with PFK and its activation was inhibited. While deletion of the pfk‐pkn4 operon did not inhibit fruiting body formation, the spore yield was low. In contrast, a mkapB deletion mutant exhibited a 24 h delay in fruiting body formation, accumulated less glycogen in the stationary phase and gave rise to 3.2% spore formation as opposed to 100% attained with DZF1. In addition to Pkn4, MkapA associated with other membrane‐associated PSTKs, Pkn1, Pkn2, Pkn8 and Pkn9, while MkapB associated with Pkn8 and Pkn9, and MkapC with Pkn8. These results indicate that there are complex PSTK networks in M. xanthus that share common modulating factors.
CPCR1, but not its interacting transcription factor AcFKH1, controls fungal arthrospore formation in Acremonium chrysogenum
Authors: Hoff Birgit , Schmitt Esther K. , Kück Ulrich
Published: May 2005

Fungal morphogenesis and secondary metabolism are frequently associated; however, the molecular determinants connecting both processes remain largely undefined. Here we demonstrate that CPCR1 (cephalosporin C regulator 1 from Acremonium chrysogenum), a member of the winged helix/regulator factor X (RFX) transcription factor family that regulates cephalosporin C biosynthesis, also controls morphological development in the β‐lactam producer A. chrysogenum. The use of a disruption strain, multicopy strains as well as several recombinant control strains revealed that CPCR1 is required for hyphal fragmentation, and thus the formation of arthrospores. In a ΔcpcR1 disruption strain that exhibits only hyphal growth, the wild‐type cpcR1 gene was able to restore arthrospore formation; a phenomenon not observed for ΔcpcR1 derivatives or non‐related genes. The intracellular expression of cpcR1, and control genes (pcbC, egfp) was determined by in vivo monitoring of fluorescent protein fusions. Further, the role of the forkhead transcription factor AcFKH1, which directly interacts with CPCR1, was studied by generating an Acfkh1 knockout strain. In contrast to CPCR1, AcFKH1 is not directly involved in the fragmentation of hyphae. Instead, the presence of AcFKH1 seems to be necessary for CPCR1 function in A. chrysogenum morphogenesis, as overexpression of a functional cpcR1 gene in a ΔAcfkh1 background has no effect on arthrospore formation. Moreover, strains lacking Acfkh1 exhibit defects in cell separation, indicating an involvement of the forkhead transcription factor in mycelial growth of A. chrysogenum. Our data offer the potential to control fungal growth in biotechnical processes that require defined morphological stages for optimal production yields.
Anaerobic regulation by an atypical Arc system in Shewanella oneidensis
Authors: Gralnick Jeffrey A. , Brown C. Titus , Newman Dianne K.
Published: May 2005

Shewanella oneidensis strain MR‐1 is well known for its respiratory versatility, yet little is understood about how it regulates genes involved in anaerobic respiration. The Arc two‐component system plays an important role in this process in Escherichia coli; therefore, we determined its function in S. oneidensis. arcA from S. oneidensis complements an E. coli arcA mutant, but the Arc regulon in S. oneidensis constitutes a different suite of genes. For example, one of the strongest ArcA‐regulated gene clusters in E. coli, sdh, is not regulated by the Arc system in S. oneidensis, and the cyd locus, which is induced by ArcA in E. coli under microaerobic conditions, is repressed by ArcA in S. oneidensis under anaerobic conditions. One locus that we identified as being potentially regulated by ArcA in S. oneidensis contains genes predicted to encode subunits of a dimethyl sulphoxide (DMSO) reductase. We demonstrate that these genes encode a functional DMSO reductase, and that an arcA mutant cannot fully induce their expression and is defective in growing on DMSO under anaerobic conditions. While S. oneidensis lacks a highly conserved full‐length ArcB homologue, ArcA is partially activated by a small protein homologous to the histidine phosphotransfer domain of ArcB from E. coli, HptA. This protein alone is unable to compensate for the lack of arcB in E. coli, indicating that another protein is required in addition to HptA to activate ArcA in S. oneidensis.
Coupling of multicellular morphogenesis and cellular differentiation by an unusual hybrid histidine protein kinase in Myxococcus xanthus
Authors: Rasmussen Anders Aa. , Porter Steven L. , Armitage Judith P. , Søgaard‐Andersen Lotte
Published: May 2005

We describe an unusual hybrid histidine protein kinase, which is important for spatially coupling cell aggregation and sporulation during fruiting body formation in Myxococcus xanthus. A rodK mutant makes abnormal fruiting bodies and spores develop outside the fruiting bodies. RodK is a soluble, cytoplasmic protein, which contains an N‐terminal sensor domain, a histidine protein kinase domain and three receiver domains. In vitro phosphorylation assays showed that RodK possesses kinase activity. Kinase activity is essential for RodK function in vivo. RodK is present in vegetative cells and remains present until the late aggregation stage, after which the level decreases in a manner that depends on the intercellular A‐signal. Genetic evidence suggests that RodK may regulate multiple temporally separated events during fruiting body formation including stimulation of early developmental gene expression, inhibition of A‐signal production and inhibition of the intercellular C‐signal transduction pathway. We speculate that RodK undergoes a change in activity during development, which is reflected in changes in phosphotransfer to the receiver domains.
A glutamate‐alanine‐leucine (EAL) domain protein of Salmonella controls bacterial survival in mice, antioxidant defence and killing of macrophages: role of cyclic diGMP
Authors: Hisert Katherine B. , MacCoss Michael , Shiloh Michael U. , Darwin K. Heran , Singh Shaneen , Jones Roger A. , Ehrt Sabine , Zhang Zhaoying , Gaffney Barbara L. , Gandotra Sheetal , Holden David W. , Murray Diana , Nathan Carl
Published: May 2005

Signature‐tagged transposon mutagenesis of Salmonella with differential recovery from wild‐type and immunodeficient mice revealed that the gene here named cdgR[for c‐diguanylate (c‐diGMP) regulator] is required for the bacterium to resist host phagocyte oxidase in vivo. CdgR consists solely of a glutamate‐alanine‐leucine (EAL) domain, a predicted cyclic diGMP (c‐diGMP) phosphodiesterase. Disruption of cdgR decreased bacterial resistance to hydrogen peroxide and accelerated bacterial killing of macrophages. An ultrasensitive assay revealed c‐diGMP in wild‐type Salmonella with increased levels in the CdgR‐deficient mutant. Thus, besides its known role in regulating cellulose synthesis and biofilm formation, bacterial c‐diGMP also regulates host–pathogen interactions involving antioxidant defence and cytotoxicity.
The pyruvate kinase of Stigmatella aurantiaca is an indole binding protein and essential for development
Authors: Stamm Irmela , Lottspeich Friedrich , Plaga Wulf
Published: May 2005

Myxospore formation of the myxobacterium Stigmatella aurantiaca can be uncoupled from the cooperative development i.e. fruiting body formation, by low concentrations of indole. Two putative indole receptor proteins were isolated by their capacity to bind indole and identified as pyruvate kinase (PK) and aldehyde dehydrogenase. The PK activity of Stigmatella crude extracts was stimulated by indole. Cloning of the PK gene (pykA) and the construction of a pykA disruption mutant strikingly revealed that PK is essential for multicellular development: Fruiting body formation was abolished in the mutant strain and indole‐induced spore formation was delayed. The developmental defects could be complemented by insertion of the pykA gene at the mtaB locus of the Stigmatella genome excluding any polar effects of the pykA disruption.
Nitric oxide generation during the interaction with Phytophthora capsici of two Capsicum annuum varieties showing different degrees of sensitivity
Authors: Requena María‐Emilia , Egea‐Gilabert Catalina , Candela María‐Emilia
Published: May 2005

The response to the pathogenic oomycete, Phytophthora capsici, in plants of two varieties of pepper (Capsicum annuum L.), Serrano Criollo de Morelos (SCM) and Americano (AM), was studied. Both varieties developed a hypersensitive reaction and generated nitric oxide (NO) as a defence, but only SCM was able to overcome the infection by inhibiting the pathogen's growth, while AM succumbed to the disease. Bio‐imaging of NO in vivo was carried out using diaminofluorescein diacetate (DAF‐2DA) in conjunction with confocal laser scanning microscopy. NO‐induced fluorescence was always higher in SCM than in AM tissues, and was also detected at trace level in decapitated non‐infected control plants as a result of wounding. In var. SCM, the highest intensity was detected 3 days after infection in the first four sections following the necrosis zone, which corresponded to the mould invasion zone. In AM, extensive necrosis was followed by general invasion of the hyphae, accompanied by minimal NO production. These findings suggest that NO is involved in the resistance reaction against this water mould and that it is induced by the isoenzyme, nitric oxide synthase (iNOS), whose activity is qualitatively greater in the tissues of SCM. This is the first time that the involvement of NO and NOS has been reported in the defensive signalling reaction between pepper plants and P. capsici.
Fast phototransformation of the 636 nm‐emitting protochlorophyllide form in epicotyls of dark‐grown pea (Pisum sativum)
Authors: Kósa Annamária , Márton Zsuzsanna , Böddi Béla
Published: May 2005

The phototransformation of protochlorophyllide forms was studied in epicotyls of dark‐germinated pea (Pisum sativumL. cv. Zsuzsi) seedlings. Middle segments were illuminated with white or 632.8 nm laser flash or continuous light at room temperature and at −15°C. At low light intensities, photoreduction could be distinguished from bleaching. 77 K fluorescence emission spectra were measured, difference spectra of illuminated and non‐illuminated samples were calculated and/or the spectra were deconvoluted into Gaussian components. The 629 nm‐emitting protochlorophyllide form, P629 (Pxxxwherexxxis the fluorescence emission maximum), was inactive. For short‐period (2–100 ms) and/or low‐intensity (0.75–1.5 µmol m−2 s−1) illumination, particularly with laser light, the transformation of P636 into the 678 nm‐emitting chlorophyllide form, C678 (Cxxxwherexxxis the fluorescence emission maximum), was characteristic. This process was also found when the samples were cooled to −15°C. The transformation of P644 into C684 usually proceeded in parallel with the process above as a result of the strong overlap of the excitation bands of P636 and P644. The Shibata shift of C684 into a short‐wavelength form, C675–676, was observed. Long‐period (20–600 s) and/or high‐intensity (above 10 µmol m−2 s−1) illumination resulted in the parallel transformation of P655 into C692. These results demonstrate that three flash‐photoactive protochlorophyllide forms function in pea epicotyls. As a part of P636 is flash photoactive, its protochlorophyllide molecule must be bound to the active site of a monomer protein unit [Böddi B, Kis‐Petik K, Kaposi AD, Fidy J, Sundqvist C (1998) The two short wavelength protochlorophyllide forms in pea epicotyls are both monomeric. Biochim Biophys Acta 1365: 531–540] of the NADPH:protochlorophyllide oxidoreductase (EC 1.3.1.33). Dynamic interconversions of the protochlorophyllide forms into each other, and their regeneration, were also found, which are summarized in a scheme.
Identification of stress‐induced mitochondrial proteins in cultured tobacco cells
Authors: Hájek Tomáš , Honys David , Witters Erwin , Čapková Věra
Published: May 2005

Under stress conditions, small and large heat‐shock proteins cooperatively fulfil molecular chaperone activities within many cellular compartments, including mitochondria. Here, we report the identification and characterization of 10 newly synthesized low‐molecular‐weight heat stress‐induced proteins (SIPs) found solely in the mitochondrial fraction of suspension‐cultured cells of tobacco (Nicotiana tabacum L., strain Virginia Bright Italia‐0). These SIPs were shown to be encoded by the nuclear genome and none was detected in non‐stressed cells. Mass spectroscopy analysis revealed that eight SIPs belonged to the group of small heat‐shock proteins, whilst one protein shared significant homology with transcription factors. De novo synthesis of all SIPs was detected within 10 min of the commencement of heat stress and continued for the whole 12 h stress interval. Moreover, nine of the SIPs were stable for 24 h following stress termination. SIP1, which showed the most intense synthesis profile, was found to be phosphorylated. The most intense stress response was observed mainly during the exponential growth phase of the cell culture. Native electrophoresis of mitochondrial protein complexes revealed an association of all the SIPs in high‐molecular‐weight complexes with no free SIPs left in mitochondria. These complexes were localized to the mitochondrial membrane fraction.
Developmental regulation of 1‐aminocyclopropane‐1‐carboxylate synthase gene expression during leaf ontogeny in white clover
Authors: Murray Trish A. , McManus Michael T.
Published: May 2005

Reverse‐transcriptase‐dependent polymerase chain reaction (RT‐PCR) was used to identify three distinct DNA sequences (designated TR‐ACS1, TR‐ACS2 and TR‐ACS3), each with identity to 1‐aminocyclopropane‐1‐carboxylate synthase (ACS). Southern analysis confirmed that these sequences represented three distinct genes, and phylogenetic analysis showed that each gene was more closely related to homologues from other plant species than to each other. The expression of these three ACS genes during leaf ontogeny in white clover was examined. Northern analysis revealed that TR‐ACS1 was expressed in the apical structure of the stolon in mature‐green leaf tissue and in leaf tissue at the onset of senescence; RT‐PCR analysis showed that TR‐ACS2 was expressed in the apical structure of the stolon and in newly initiated leaf tissue. Furthermore, the expression of TR‐ACS1 was regulated by the exogenous application of auxin. The third gene, TR‐ACS3, was expressed in senescent leaf tissue, but translation of the nucleotide sequence provided an enzyme with a deleted binding site for pyridoxal‐phosphate and S‐adenosyl methionine (AdoMet), suggesting that this was a pseudogene. Antibodies, raised to the protein product of TR‐ACS1 expressed in Escherichia coli, recognized a protein of 55 kDa in leaf extracts of white clover using Western analysis, with the pattern of protein accumulation corresponding to the pattern of gene expression determined using Northern analysis. The significance of these results is discussed with respect to the developmental expression of ACS genes during leaf ontogeny.
Molecular cloning and characterization of S‐adenosyl‐methionine decarboxylase genes from mustard (Brassica juncea)
Authors: Hu Wen‐Wei , Gong Haibiao , Pua Eng‐Chong
Published: May 2005

S‐Adenosylmethionine decarboxylase (SAMDC, E.C. 4.1.4.50) is a key enzyme involved in the polyamine (PA) biosynthetic pathway. An understanding of how SAMDC genes are regulated is important for elucidating the molecular basis of PA biosynthesis and the role of PAs in plant growth and development. However, information regarding transcriptional regulation of SAMDC has been limited. In an attempt to address this question, we isolated four cDNAs from mustard (Brassica juncea), designated BJSAMDC1, BJSAMDC2, BJSAMDC3 and BJSAMDC4, encoding predicted SAMDC. A comparison of deduced amino acid sequence revealed that they are highly homologous to other plant SAMDCs. These proenzymes also possess the conserved cleavage domain and putative PEST sequence for SAMDC. Northern analysis showed that the SAMDC transcripts were most abundant in reproductive organs and roots but that the level was low in young leaves and petioles. Meanwhile, SAMDC expression in the leaf was up‐regulated differentially in response to stress such as chilling and exogenous ACC. The effect of exogenous PAs on SAMDC expression appears to be divergent. While putrescine up‐regulated the expression of BJSAMDC1, spermidine and spermine down‐regulated its expression. Furthermore, mannitol was also shown to up‐regulate SAMDC expression in a gene‐specific manner, in which the BJSAMDC1 transcript increases but other SAMDC transcripts are not affected.
Leukapheresis for the extraction of monocytes and various lymphocyte subpopulations from peripheral blood: product quality and prediction of the yield using different harvest procedures
Authors: Wolf C. E. , Meyer M. , Riggert J.
Published: May 2005

Background and Objectives  Leukapheresis of non‐mobilized healthy donors is performed to harvest monocytes and lymphocyte subpopulations for use in various therapeutic regimens. In this methodological study, we compared two different leukapheresis programs, using equivalent volumes of processed blood over similar processing periods, to determine the influence of the procedures on the donor peripheral blood count and to establish the procedure that yields the highest quality product.

Materials and Methods  The target variables obtained in 41 healthy blood donors who underwent short‐term leukapheresis (80–105 min) were retrospectively compared. Twenty‐one volunteers were processed on a COBE Spectra™ machine at the MNC setting and 20 volunteers were processed at the AutoPBSC setting. Data were collected on pre‐ and postleukapheresis samples and on the product.

Results  AutoPBSC and MNC procedures resulted in a decrease of haemoglobin (5–7%), platelets (17–20%), monocytes (22%) and lymphocytes (23–27%), but not of granulocytes in peripheral blood. Both procedures produced nearly identical leucocyte and lymphocyte yields. AutoPBSC products contained a greater number of granulocytes, monocytes and red cells, but fewer platelets. The preleukapheresis values correlated with the yields for monocytes, T‐helper and T‐suppressor cells, B‐lymphocytes and natural killer cells, but not for granulocytes or platelets.

Conclusions Leukapheresis  is a safe and efficient procedure for collecting large numbers of peripheral blood monocytes and different lymphocyte populations from non‐mobilized donors. The two programs yield comparable leucocyte harvests. Based on our results, yields can be predicted from the peripheral cell counts.
Economic values for resistance to gastrointestinal helminths in meat sheep in Kenya
Authors: Gicheha M.G. , Kosgey I.S. , Bebe B.O. , Kahi A.K.
Published: May 2005

Economic values for resistance to gastrointestinal (GI) helminths in meat sheep were estimated based on previously published genetic and phenotypic parameters in a selection index objectively optimizing gains on yearling weight (YW). A two‐trait index of YW and faecal egg count (FEC) were considered when accounting only for tangible roles of sheep production using individual records for index calculation (scheme 1) or including individual, sire, dam and male paternal half‐sib information (scheme 2). Schemes 3 and 4 were similar to schemes 1 and 2, respectively, but accounted for both tangible and intangible roles of sheep production. Economic values within each scheme were estimated for five breeding objectives as follows: (i) index response in YW equals response from single trait selection, (ii) index response in YW is maximum, (iii) the level of FEC was held constant, (iv) A predetermined response of −0.22 (×1000) eggs per gram was assumed and (v) Monetary value of response in FEC is minimum. All estimated economic values were negative, and were Kenya Shillings (KSh) −34.90 (US$−0.50), 0.00, −92.20 (US$−1.32), −153.31 (US$−2.19) and −47.90 (US$−0.68), respectively, for options 1–5 in scheme 1. In all schemes the breeding options ranked 4, 3, 5 and 1 in descending order; however, options 1 and 5 exchanged positions in schemes 2 and 4. Economic values were responsive to changes in heritability of FEC and genetic correlation between the two traits. The magnitude of the economic values reflects the importance of including resistance to GI helminths in the breeding objectives for meat sheep in different production systems.
The FUT1 and ESR genes – their variability and associations with reproduction in Přeštice Black‐Pied sows
Authors: Horák P. , Urban T. , Dvořák J.
Published: May 2005

The determination of genetic variability by means of molecular genetic markers FUT1 and ESR2, and the evaluation of their associations with reproduction traits in population of Přeštice Black‐Pied sows have been implemented. A lower frequency of the allele FUT1A than the frequency of the allele FUT1G in the FUT1 gene was ascertained. In the ESR2 polymorphism, a higher frequency of the allele ESR2A compared with the allele ESR2B was determined. In the second to sixth litters as well as in the first to sixth litters, a significantly lower number of piglets born alive and number of weaned piglets from sows of the FUT1A/FUT1A genotype was found. Moreover, the homozygotes FUT1G/FUT1G significantly exceeded sows of the FUT1A/FUT1A genotype in the total number of born piglets in the first to sixth litters. No significant effect of the ESR2 polymorphism on reproduction was observed.
Using expected allele number as objective function to design between and within breed conservation of farm animal biodiversity
Authors: Simianer H.
Published: May 2005

Conservation of genetic diversity in farm animal species can be achieved by preventing extinction of breeds and by reducing genetic drift within breeds. It is suggested to use the expected number of alleles segregating in the species after a given time period as objective function in the design of conservation strategies. A formal approach is presented to predict this quantity based on marker information, accounting for extinction probability of breeds and effective population size within breeds as the major component of genetic drift. Based on this model, relative efficiency of different strategies of diversity conservation can be quantified. Formulas are given to derive the marginal expected number of alleles with respect to genetic drift within population and extinction probability, respectively. The suggested approach is illustrated with an example of 13 European cattle breeds. With the assumed parameters, drift is shown to be the major force leading to loss of alleles, and different breeds are prioritized for activities to reduce risk of extinction and for measures to reduce genetic drift, respectively. Although different aspects of the model need to be further refined, the suggested methodology provides a general and flexible tool to derive the optimum conservation strategy in various scenarios.
Long‐term responses, changes in genetic variances and inbreeding depression from 122 generations of selection on increased litter size in mice
Authors: Holt M. , Meuwissen T. , Vangen O.
Published: May 2005

Data on mice selected for litter size over 122 generations have been analysed in order to reveal the effect of long‐term selection on responses and changes in variances over a long selection period. Originally, three lines were established from the same base population, namely an H line selected for large litter size, an L line selected for small litter size and a K line without selection. In generation 122, the mean number of pups born alive (NBA) was 22 for the H line and 11 for the K line. Phenotypic response to selection is reduced over generations, but crossing of plateaued lines increased responses and realized heritabilities. Both realized heritabilities and heritabilities from residual maximal likelihood (REML) analyses were, in general, calculated from generation (−1)–44 (period 1), 45–70 (period 2) and 71–122 (period 3) separately. Realized heritabilities were in general smaller than heritabilities estimated from mixed model analysis. An overall estimate of heritability for NBA was found to be 0.19 (±0.01) by REML analysis. Additive variance is constant over all periods in the high line and the control line, but is reduced over periods in the low line. The reduction of additive variance in the low line could probably be explained by changes in gene frequencies. In all lines, environmental variances increased over periods. Inbreeding reduced the mean litter size by 0.72 (±0.10) pups per 10% increase in inbreeding, with substantial variance between periods and lines.
Prediction of random effects in finite mixture models with Gaussian components
Authors: Gianola D.
Published: May 2005

Prediction of random effects in finite mixture models with Gaussian distributions is discussed from a non‐Bayesian perspective, assuming that location and dispersion parameters are known. The focus is on calculating the best predictor, that is, the statistic with minimum expected squared prediction error, for several models. Coverage includes mixture sampling models, as well as mixtures for the distribution of the random effects. Longitudinal and cross‐sectional specifications with correlated random effects, such as those arising in animal breeding and genetics, are examined. The best linear predictor and the best linear unbiased predictor are derived for these models as well.
Transcriptional profiling of the hyperthermophilic methanarchaeon Methanococcus jannaschii in response to lethal heat and non‐lethal cold shock
Authors: Boonyaratanakornkit Boonchai B. , Simpson Anjana J. , Whitehead Timothy A. , Fraser Claire M. , El‐Sayed Najib M. A. , Clark Douglas S.
Published: May 2005

Temperature shock of the hyperthermophilic methanarchaeon Methanococcus jannaschii from its optimal growth temperature of 85°C to 65°C and 95°C resulted in different transcriptional responses characteristic of both the direction of shock (heat or cold shock) and whether the shock was lethal. Specific outcomes of lethal heat shock to 95°C included upregulation of genes encoding chaperones, and downregulation of genes encoding subunits of the H+ transporting ATP synthase. A gene encoding an α subunit of a putative prefoldin was also upregulated, which may comprise a novel element in the protein processing pathway in M. jannaschii. Very different responses were observed upon cold shock to 65°C. These included upregulation of a gene encoding an RNA helicase and other genes involved in transcription and translation, and upregulation of genes coding for proteases and transport proteins. Also upregulated was a gene that codes for an 18 kDa FKBP‐type PPIase, which may facilitate protein folding at low temperatures. Transcriptional profiling also revealed several hypothetical proteins that respond to temperature stress conditions.
Changes in sleep problems, parents distress and impact of sleep problems from infancy to preschool age for referred and unreferred children
Authors: Thome Marga , Skuladottir Arna
Published: May 2005

This article compares and describes changes in sleep problems in 3‐ to 5‐year‐old Icelandic children referred and unreferred for sleep problems in infancy and explores changes in parents’ distress and the impact of children's sleep problems on families over time. The sample consisted of a clinical group (n = 31) that had been referred to a sleep‐disorder clinic in infancy, and a comparative group (n = 150) of age‐matched unreferred community children. Self‐report scales assessed infant/child sleep pattern, the impact of the sleep problem on family life and parents’ distress. Results showed that about half the children in the community group have had a sleep problem in infancy. Nightwakings improved in both the referred and unreferred group over time but remained more frequent in the unreferred group. The referred group had significantly more settling problems in infancy than the other group but settling improved markedly over time. Parents of referred children were more fatigued compared with others despite improvement of children's sleep problems over time. Mothers of referred children were however, less likely to perceive the sleep problem as troublesome for family life than the others. It is concluded that parents of referred children are more fatigued than parents of unreferred children and nightwakings are more likely to persist in children who had sleep problems in infancy than in those with no such problems.
Stroke Specific Quality of Life Scale: Danish adaptation and a pilot study for testing psychometric properties
Authors: Muus Ingrid , Ringsberg Karin C.
Published: May 2005

Background and purpose:  Stroke has an effect on many aspects of quality of life (QoL) and therefore it is important to measure the magnitude of the impact. Items in the American version of the Stroke Specific Quality of Life (SS‐QoL) Scale are developed with help from patients with stroke and include even language impairments.

Aims:  To translate and culturally adapt the American SS‐QoL Scale, version 2.0, a stroke‐specific instrument measuring health‐related QoL, into a Danish version, and to perform a pilot testing of the psychometric properties of the instrument.

Methods:  The guidelines recommended by Guillemin et al. (J Clin Epidemiol, 46, 1993, 1417) were followed including two independent forward and one back translation, inclusion of laymen, here patients with stroke and their spouses, pretest, and examining selected items with a probing technique. Four couples were included in the pretest, 14 in the pilot study. The patients for pretest and pilot study were selected strategically with regard to interest for participation, experience as stroke survivors, sufficient capacity of language perception and cohabitant status.

Results:  In the Danish version instructions were made more distinct and formal than in the original American version. Explanatory examples within the items were excluded. One new item adjusted for Danish conditions replaced one in the original version, and the response categories concerning personality were adjusted for cultural differences. The pilot study resulted in a more explicit formulation of the instructions to mark each item only once and on the same line as the item.

Conclusions:  A Danish version of SS‐QoL version 2.0 has been developed and content as well as format has proved relevant and acceptable to patients with stroke including those with impaired language production. The next step is testing the psychometric properties of the instrument.
Adolescents’ perception of the quality of orthodontic treatment
Authors: Larsson Bodil Wilde , Bergström Kurt
Published: May 2005

The aim was to describe quality of care from a patient perspective among adolescents receiving orthodontic treatment and to assess the relationship between quality of care and outcome‐related aspects. The research design was cross‐sectional. The sample consisted of 151 young people (mean age 17.1 years, SD: 2.2; 53% girls and 47% boys) receiving orthodontic treatment in the Stockholm region in Sweden (response rate 75%). Data were collected using the Quality from the Patient's Perspective questionnaire. The highest quality of care perceptions were noted on items dealing with receiving the best possible orthodontic treatment and being treated with respect. Less favourable perceptions of the quality of care were found regarding the opportunity to participate in the decisions related to the orthodontic treatment. In order to improve the quality of care a more active involvement of these patients in the decision‐making process is suggested. The item ‘I received the best possible orthodontic treatment’ noted the highest subjective importance rating. The youngest participants reported the most favourable scores and the oldest the least. The majority (74%) reported that they were ‘completely satisfied’ with the result of the orthodontic treatment. However, 52% claimed that they had not followed all of the advice obtained during the treatment period, and 29% indicated some or more hesitation about attending the same dentist for future treatment.
Recognition of client values as a basis for tailored care: the view of Dutch expert patients and family caregivers
Authors: Schoot Tineke , Proot Ireen , Meulen Ruud ter , de Witte Luc
Published: May 2005

In the Netherlands confusion is signalled about the introduction of new care concepts like demand‐oriented care. The aim of this article is to explore the phenomenon ‘interaction aimed at care tailored to the client demand’ as seen by expert clients: patients and their family caregivers. Focus interviews were held with expert patients and expert family caregivers of the ‘Dutch Council of the Chronically ill and the Disabled’. Grounded theory methodology was used to analyse the results.

Recognition by the professional of client values underlying their demand (uniqueness, comprehensiveness, continuity of life, fairness and autonomy) and underlying the care‐relationship (equality, partnership and interdependence) emerged as central element within the interaction. Feelings of recognition with the client seem to reinforce autonomy, self‐esteem and participation. Recognition was optimally felt in a dialogue. Four professional competencies could be identified related to recognition: attentiveness (ongoing actions to know and understand the patient); responsiveness (active, committed and responsible care guided by respect of patient identity); being a critical partner in care (giving and grounding professional opinion and discuss boundaries); being a developer of client competencies (facilitating and developing client participation within care). The findings offer possibilities to operationalize care concepts aimed at tailored care. Further research aimed at refining and testing the hypothesis developed is recommended.
Curtailing: handling the complexity of body care in people hospitalized with severe COPD
Authors: Lomborg Kirsten , Kirkevold Marit
Published: May 2005

Assisted personal body care (APBC) tends to be regarded as an unproblematic nursing activity with little professional challenge. For severely ill patient diagnosed with chronic obstructive pulmonary disease (COPD) daily bathing and washing is, however, a significant self‐preserving activity that requires substantial efforts on the part of both patients and nurses. The aim of this study was to report on the complex pattern of APBC in hospitalized patients with severe COPD and highlight significant characteristics that should be considered in clinical practice in order to support patients’ comfort and well‐being. The study used a grounded theory design with a generative and constant comparative approach. The sample consisted of 12 cases of nurse–patient interaction, based on data from participant observation of sessions of APBC, measures of patient's perceived degree of breathlessness and individual interviews with patients and nurses after the sessions. Findings show that APBC in hospitalized patients with severe COPD is a complex integrated pattern of body care activities that can proceed with a greater or lesser degree of success. The main problem is how to keep the patient's breathing under control while optimizing comfort and well‐being. Curtailing addresses this problem. Curtailing is a subtle, purposeful balancing of protection from breathlessness and promotion of patients’ present and future functional capacity in order to preserve their integrity. The idea that body care is a simple task belonging to patients’ private daily lives may obscure the importance of determining a mutual nurse–patient agenda and the professional nurse responsibility may consequently be nebulous. Finding in this study will contribute to the development of a comprehensive and detailed understanding of the APBC and suggest the need for further investigation of the interaction perspective.
Characterization of microsatellite loci in the endemic mound spring snail Fonscochlea accepta and cross species amplification in four other hydrobiid snails
Authors: WILMER JESSICA WORTHINGTON , HUGHES JANE M. , MA JING , WILCOX CHRIS
Published: May 2005

We identified and characterized nine microsatellite primer pairs from Fonscochlea accepta, a species of hydrobiid snail endemic to artesian mound springs associated with the Great Artesian Basin in arid South Australia. The loci were highly polymorphic, with five to 30 alleles per locus. Gene diversity, estimated as expected heterozygosity ranged from 0.364 to 0.851, and was generally matched by levels of observed heterozygosity (0.373–0.829). Cross‐species amplification trials with four other hydrobiid species associated with these southern mound springs showed that these primers will be useful for genetic analyses of these other endemic snails.
Isolation of microsatellite loci from the common buzzard, Buteo buteo (Aves: Accipitridae)
Authors: JOHNSON PAUL C. D. , FOWLIE MARTIN K. , AMOS WILLIAM
Published: May 2005

We isolated 56 common buzzard (Buteo buteo) microsatellite loci from (AC)n‐ and (AAAG)n‐enriched genomic libraries. Eleven loci were tested on 90 individuals from Eastern Westphalia in Germany, yielding two to 17 alleles per locus (average 5.7) and expected heterozygosities ranging from 0.11 to 0.93 (average 0.53). These highly variable microsatellite markers provide a powerful means for investigating population genetic diversity in the common buzzard, a little‐understood aspect of this widespread species.
Isolation of polymorphic microsatellite loci in Crossosoma californicum (Crossosomataceae)
Authors: WALLACE LISA E. , HELENURM KAIUS
Published: May 2005

Crossosoma californicum (Crossosomataceae) is a rare shrub species endemic to the California Channel Islands. Previous studies based on allozymes revealed little genetic variability in this plant species. We have isolated 13 polymorphic microsatellite loci from C. californicum. These loci show intermediate levels of variability, averaging 4.2 alleles per locus and expected heterozygosity of 0.376. Two loci did not fit Hardy–Weinberg expectations with significant deficits of heterozygous genotypes consistent with the presence of null alleles or population subdivision.
Isolation and characterization of microsatellites loci in the lemon (Citrus limon)
Authors: GOLEIN B. , KOLTUNOW A. M. , TALAIE A. , ZAMANI Z. , EBADI A.
Published: May 2005

This study reports the isolation and characterization of seven polymorphic microsatellite loci in Citrus. The loci were isolated from two libraries constructed from genomic DNA nonenriched for TC and AC repeats and enriched for AC repeats. These markers yielded four to nine alleles per locus (mean 6.14) in a survey of 32 Citrus cultivars. Average observed heterozygosity ranged from 0.43 to 0.72. The levels of polymorphism found in this study suggest that these microsatellite loci can become an important tool for genetic studies in Citrus.
Isolation of polymorphic tetranucleotide microsatellite markers in the satin bowerbird, Ptilonorhynchus violaceus
Authors: BARDELEBEN CAROLYNE , MOORE RACHAEL L. , NICHOLLS JAMES A. , AUSTIN JEREMY J. , ROBSON TIMOTHY E.
Published: May 2005

We isolated 13 polymorphic microsatellite markers from the satin bowerbird, Ptilonorhynchus violaceus from a genomic library enriched in (AAGG)n repetitive elements and characterized them in 20 individuals. The number of alleles ranged from two to 18 per locus with the observed heterozygosity ranging from 0.15 to 1.00. These markers will be useful for analysing questions concerning parentage, population genetic structure and models of speciation.
Polymorphic microsatellite loci in pheasant coucal (Centropus phasianinus)
Authors: MAURER G. , HALE M. L. , VERDUIJN M. H. , WOLFF K.
Published: May 2005

Little is known about the effect of male parental care and behavioural sex‐role reversal on the mating system of birds because genetic markers for species with these characteristics are lacking. We developed primers for nine polymorphic microsatellite loci in pheasant coucals (Centropus phasianinus). Eight of the primers were also polymorphic in African black coucals (Centropus grillii). Pheasant coucals are of particular interest in the study of evolutionary and behavioural ecology, because their sex‐role reversal and extensive male parental care suggests low levels of extra‐pair fertilizations, yet they have large testes indicating sperm competition.
Isolation and characterization of 11 polymorphic microsatellite loci in the giant white‐tailed rat (Uromys caudimaculatus)
Authors: CHAND V. , STREATFEILD C. A. , WILSON J. C. , MATHER P. B.
Published: May 2005

Microsatellite loci were developed for the giant white‐tailed rat (Uromys caudimaculatus) to aid in assigning paternity and to subsequently investigate their mating system and sex‐biased dispersal characteristics. Twenty‐two primer sets were originally developed and of these, 11 were polymorphic with between five and 10 alleles per locus. In addition, two primer sets designed for Hydromys chyrsogaster also amplified in this species despite an evolutionary divergence of 15 million years (Myr).
Isolation and characterization of 10 microsatellite loci from Iris hexagona (Iridaceae)
Authors: MEEROW ALAN W. , GIDEON MICHAEL , KUHN DAVID N. , SCHNELL RAYMOND J.
Published: May 2005

Ten microsatellite loci isolated from Iris hexagona are described. All these loci are polymorphic, with three to 13 alleles across 24 individuals from a single natural population. Heterozygosity ranged from 0.125 to 0.870. Three loci depart significantly from Hardy–Weinberg equilibrium in our test population. The test population shows significant heterozygote deficiency in these and two other loci. Three loci exhibit significant linkage disequilibrium. These loci will be utilized to investigate patterns of genetic variation in the species throughout the Florida peninsula.
Isolation and characterization of polymorphic microsatellite loci for parentage analysis in a rhacophorid tree frog (Chirixalus eiffingeri) with unusual parental care
Authors: CHEN YI‐HUEY , KAM YEONG‐CHOY , YU HON‐TSEN
Published: May 2005

Chirixalus eiffingeri is an arboreal breeding rhacophorid frog with unique parental care behaviours. We developed 11 polymorphic microsatellites as genetic makers for parentage analysis to resolve the ecology of parental care. The numbers of alleles per locus ranged from two to 17. The observed and expected heterozygosities averaged 0.433 and 0.656, respectively. Total exclusionary probability of these loci is 0.984 when no parental genotypes are known, and is 0.999 when one of the parental genotypes is known. The results indicate that the 11 markers should provide sufficient resolution for inferring genetic parentage in C. eiffingeri.
Novel polymorphic microsatellites for the red‐legged partridge (Alectoris rufa) and cross‐species amplification in Alectoris graeca
Authors: GONZALEZ E. G. , CASTILLA A. M. , ZARDOYA R.
Published: May 2005

The red‐legged partridge, Alectoris rufa, is an endemic species of the southwestern Mediterranean, and the most popular game bird in the Iberian Peninsula. A total of 27 microsatellite loci was isolated from an enriched genomic library of A. rufa. Six perfect GT microsatellites were characterized and optimized in 45 individuals of A. rufa. All loci revealed high levels of polymorphism with a number of alleles that ranged from three to 13. Observed heterozygosity ranged from 0.2 to 0.6. Cross‐species amplification showed that all loci were also polymorphic in rock partridge, Alectoris graeca. The new markers will be useful in determining hybridization between both species of Alectoris.
The Long‐Run Performance of REIT Stock Repurchases
Authors: Giambona Erasmo , Giaccotto Carmelo , Sirmans C.F.
Published: May 2005

This study investigates the long‐horizon performance of open‐market stock repurchases for real estate investment trusts (REITs). We develop a new methodology to model the autocorrelation of monthly returns into long‐horizon buy‐and‐hold abnormal return estimators. Serial correlation can introduce bias (autocorrelation bias) because the bid‐ask bounce may affect monthly returns for sample firms and non‐sample firms in a different fashion. Previous long‐horizon event studies have overlooked this source of bias. There is compelling evidence that the market underreacts to the stock repurchase announcements. The evidence holds for different measures of the variance and the effects of cross‐correlation of abnormal returns. Results are also robust to the traditional buy‐and‐hold abnormal return and the wealth relative estimators. We investigate the nature of the underreaction and find strong support for the undervaluation hypothesis.
What Moves the Mortgage‐Backed Securities Market?
Authors: Xu Xiaoqing Eleanor , Fung Hung‐Gay
Published: May 2005

Using a vector autoregressive model with monthly data from 1988 through 2001, this study investigates the factors that drive the excess returns on a widely followed mortgage‐backed securities (MBS) index. We find that eight important economic variables (industrial productions, new home sales, bond horizon premium, bond quality premium, mortgage rate, refinancing proxy, general stock market index and world bond market index) appear to move the excess returns on MBS. Impulse response analysis and variance decomposition further indicate a strong dynamic relationship between MBS excess returns and changes in these economic variables. Additional analysis of Freddie Mac and Fannie Mae MBS also indicates that the risk of the MBS guarantor is an important determinant of the MBS return dynamics after the creation of the Office of Federal Housing Enterprise Oversight.