bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation and characterization of microsatellite DNA markers from the Lanyu scops owl (Otus elegans botelensis)
Authors: Hsu Yu‐Cheng , Severinghaus Lucia L. , Lin Yao‐Sung , Li Shou‐Hsien
Published: November 2003

From a genomic library enriched for GATA/CTAT and GAAA/CTTT repeats, 12 polymorphic microsatellite markers were developed for the Lanyu scops owl (Otus elegans botelensis). Polymorphism of these loci was evaluated in a sample of 58 adult individuals of unknown relationship. The allele numbers of each locus were from five to 25 and the observed heterozygosity of each locus ranges from 0.707 to 0.914. When using these loci in parentage assignment, the probability of false parent exclusion is greater than 0.999. All loci conformed to Hardy–Weinberg expectations.
Development of microsatellite markers for the European white elm (Ulmus laevis Pall.) and cross‐species amplification within the genus Ulmus
Authors: Whiteley R. E. , Black‐Samuelsson S. , Clapham D.
Published: November 2003

Ulmus laevis Pall. is a broad‐leaved deciduous tree with a central and eastern European distribution. We describe the development of six polymorphic microsatellite markers for this species. These markers were also tested for utility in U. americana, U. glabra, U. minor and U. pumila. One additional marker gave ambiguous results in U. laevis but amplified clearly in three other species. In U. laevis, the number of alleles observed per locus ranged from two to nine. Five loci showed polymorphism in at least one of the nontarget species tested.
Cooperation in the Budgeting Process
Authors: Chen Qi
Published: November 2003

In this article I analyze the role of cooperation between firm divisions in the budgeting process. I study a setting in which cooperation is a necessary condition for information sharing among division managers, which in turn benefits the principal. The results in this article can help reconcile the differing views between practitioners and academic researchers on the desirability of cooperation in the budgeting process. The results also have implications for some common budgeting processes observed in practice, including bundling budgeting and bottom‐up budgeting.
Does Greater Firm‐Specific Return Variation Mean More or Less Informed Stock Pricing?
Authors: Durnev Artyom , Morck Randall , Yeung Bernard , Zarowin Paul
Published: November 2003

Roll [1988] observes lowR2statistics for common asset pricing models due to vigorous firm‐specific return variation not associated with public information. He concludes that this implies “either private information or else occasional frenzy unrelated to concrete information”[p. 56]. We show that firms and industries with lower market modelR2statistics exhibit higher association between current returns and future earnings, indicating more information about future earnings in current stock returns. This supports Roll's first interpretation: higher firm‐specific return variation as a fraction of total variation signals more information‐laden stock prices and, therefore, more efficient stock markets.
Family influences on commitment: Examining the family of origin correlates of relationship commitment attitudes
Authors: Weigel Daniel J. , Bennett Kymberley K. , Ballard–Reisch Deborah S.
Published: November 2003

Two studies were conducted to investigate the lessons about relationship commitment that people gain from their families of origin. In the first study, participants identified a story from their families of origin that characterized a number of themes about commitment. In the second study, these themes were further refined to reveal eight factors underlying these themes: dedication to partner, constraints on relationships, relationships are impermanent, disillusionment, family and gender influences, approaching relationships with caution, relationships take work, and divorce has negative consequences. Ratings of the themes varied by the occurrence of parental divorce, perceived parental marital happiness, and gender. Commitment lessons remembered from families of origin also were associated with the participants’ reported level of commitment in their current relationships. Implications for current theory on commitment are discussed.
Helicobacter pylori and gastric malignancies
Authors: Nardone Gerardo , Morgner Andrea
Published: November 2003

ABSTRACT Despite decreasing incidence during the last 50 years, gastric cancer still ranks as one of the most frequent cancers. A multifactorial model of human gastric carcinogenesis is currently accepted in which different dietary and nondietary factors, including genetic susceptibility of the host and Helicobacter pylori infection are involved at different stages in the cancer process. On the molecular level, at least two phenotypes, associated with distinct pathways of genome destabilization, have been identified. However, applying new technologies such as cDNA microarrays a new era in the analysis of molecular markers has started. This molecular technology may open the path towards novel treatment modalities, i.e. gene therapy. Epidemiological, biological, and molecular genetic studies have also implicated the role of H. pylori in lymphomagenesis. Knowledge of pathogenesis and therapy is increasing while good epidemiological data are rare. Many studies have demonstrated that MALT‐type lymphomas develop along two different pathways: t(11;18)‐positive cases, and t(11;18)‐negative cases. Meanwhile, a third translocation could be detected, the t(14;18), opening the discussion of a possible third pathway of lymphoma development.
A Curvilinear Tool-Path Method for Pocket Machining
Authors: Bieterman Michael B. , Sandstrom Donald R.
Published: November 2003

A novel curvilinear tool-path generation method is described for planar milling of pockets. The method uses the solution of an elliptic partial differential equation boundary value problem defined on a pocket region. This mathematical function helps morph a smooth low-curvature spiral path in a pocket interior to one that conforms to the pocket boundary. This morphing leads to substantial reductions of tool wear in cutting hard metals and of machining time in cutting all metals, as experiments described here show. A variable feed-rate optimization procedure is also described. This procedure incorporates path, tool-engagement, and machine constraints and can be applied to maximize machine performance for any tool path.
New developments in passive radiation dosimetry: radiation‐induced thermally activated currents
Authors: Moran P. R. , Podgoršak E. B. , Fuller G. E. , Fullerton G. D.
Published: November 2003

Radiation‐induced thermally activated currents (RITAC) in ultra‐high‐purity dielectrics provide a radiation dosimetry technique which is practical for applications at room temperature and is much more sensitive than other more well known, solid state dosimetry effects. The essential requirement for producing high‐radiation‐sensitivity RITAC readout, either in polarization or conductance modes of operation, is selective purification of the dosimetry material. Simple methods exist for monitoring the active impurity levels for fabrication of highly sensitive reproducible RITAC effect devices.
Chemolithoorganotrophic Growth of
Nitrosomonas europaea
on Fructose
Authors: Hommes Norman G. , Sayavedra-Soto Luis A. , Arp Daniel J.
Published: November 2003

The nitrifying bacterium
Nitrosomonas europaea
can obtain all its carbon for growth from CO
2
and all its energy and reductant for growth from the oxidation of NH
3
and is considered an obligate chemolithoautotroph. Previous studies have shown that
N. europaea
can utilize limited amounts of certain organic compounds, including amino acids, pyruvate, and acetate, although no organic compound has been reported to support the growth of
N. europaea
. The recently completed genomic sequence of
N. europaea
revealed a potential permease for fructose. With this in mind, we tested if
N. europaea
could utilize fructose and other compounds as carbon sources to support growth. Cultures were incubated in the presence of fructose or other organic compounds in sealed bottles purged of CO
2
. In these cultures, addition of either fructose or pyruvate as the sole carbon source resulted in a two- to threefold increase in optical density and protein content in 3 to 4 days. Studies with [
14
C]fructose showed that >90% of the carbon incorporated by the cells during growth was derived from fructose. Cultures containing mannose, glucose, glycerol, mannitol, citrate, or acetate showed little or no growth.
N. europaea
was not able to grow with fructose as an energy source, although the presence of fructose did provide an energy benefit to the cells. These results show that
N. europaea
can be grown in CO
2
-free medium by using fructose and pyruvate as carbon sources and may now be considered a facultative chemolithoorganotroph.
The
Vibrio
Pathogenicity Island of Epidemic
Vibrio cholerae
Forms Precise Extrachromosomal Circular Excision Products
Authors: Rajanna C. , Wang J. , Zhang D. , Xu Zheng , Ali A. , Hou Y.-M. , Karaolis D. K. R.
Published: November 2003

The
Vibrio
pathogenicity island (VPI) in epidemic
Vibrio cholerae
is an essential virulence gene cluster. Like many pathogenicity islands, the VPI has at its termini a phage-like integrase gene (
int
), a transposase-like gene (
vpiT
), and phage-like attachment (
att
) sites, and is inserted at a tRNA-like locus (
ssrA
). We report that the VPI precisely excises from the chromosome and that its left and right ends join to form an extrachromosomal circular excision product (pVPI). Two-stage nested PCR analysis and DNA sequencing confirmed the
int-att-vpiT
junction and that the core
attP
of pVPI is identical to the chromosomal VPI
attR
site. Excision was independent of
toxR
and
toxT
. Excision was independent of
recA
, suggesting that it is mediated by site-specific recombination. Interestingly, while excision was detected in
int
and
vpiT
mutants, excision was abolished in a double (
int vpiT
) mutant and was restored by plasmids containing genes for either recombinase. Excision results in deletion of A361 in the
ssrA
locus, which flanks the right junction of the VPI. Since A361 encodes U70 in the critical G · U base pair in the acceptor stem of the
ssrA
RNA that is the determinant for aminoacylation with alanine, this deletion might have deleterious effects on
ssrA
function. Also,
vpiT
may have undergone interchromosomal translocation or may represent an independent integration event, as it was found downstream of
hutA
in some isolates. Our results provide new insight into the molecular biology of the VPI, and we propose that the process of excision and circularization is important in the emergence, pathogenesis, and persistence of epidemic
V. cholerae
.
Anabaena
sp. Strain PCC 7120
hetY
Gene Influences Heterocyst Development
Authors: Yoon Ho-Sung , Lee Martin H. , Xiong Jin , Golden James W.
Published: November 2003

The filamentous cyanobacterium
Anabaena
(
Nostoc
) sp. strain PCC 7120 responds to starvation for fixed nitrogen by producing a semiregular pattern of nitrogen-fixing cells called heterocysts. Overexpression of the
hetY
gene partially suppressed heterocyst formation, resulting in an abnormal heterocyst pattern. Inactivation of
hetY
increased the time required for heterocyst maturation and caused defects in heterocyst morphology. The 489-bp
hetY
gene (alr2300), which is adjacent to
patS
(asl2301), encodes a protein that belongs to a conserved family of bacterial hypothetical proteins that contain an ATP-binding motif.
The Quorum Sensing Negative Regulators EsaR and ExpR

Ecc

, Homologues within the LuxR Family, Retain the Ability To Function as Activators of Transcription
Authors: von Bodman Susanne B. , Ball Jessica K. , Faini Marie A. , Herrera Carmen M. , Minogue Timothy D. , Urbanowski Mark L. , Stevens Ann M.
Published: November 2003

Most LuxR homologues function as activators of transcription during the process of quorum sensing, but a few, including EsaR and ExpR

Ecc

, negatively impact gene expression. The LuxR-activated
luxI
promoter and LuxR binding site, the
lux
box, were used in artificial contexts to assess the potential for transcriptional activation and DNA binding by EsaR and ExpR

Ecc

. Although the acyl-homoserine lactone responsiveness of both proteins is the opposite of that shown by most LuxR family members, EsaR and ExpR

Ecc

have preserved the ability to interact with RNA polymerase and activate transcription despite their low affinity for the
lux
box DNA.
Change-in-ratio estimates of lobster exploitation rate using sampling concurrent with fishing
Authors: Claytor Ross , Allard Jacques
Published: November 2003

We present a continuous change-in-ratio (CIR) method for estimating lobster exploitation rate using data from monitoring traps continuously sampled during fishing. The exploitation rate is estimated by fitting a nonlinear model to ratios of exploited catch over total catch (exploited plus an unexploited reference class) as a function of the cumulative exploited catch. Confidence intervals are obtained by bootstrapping. The method is applied to data collected by nearly 100 lobster fishers who sampled monitoring traps in fishing areas of Nova Scotia, Canada, from 1999 to 2001, and to simulated data. Best estimates are obtained where the exploited and the reference length classes are adjacent and narrow. A method to predict the impact of season length restriction on exploitation rate is presented. Simulations demonstrate that the method displays some robustness relative to departures from the model's assumptions. Exploitation rate estimates decline for length classes in which the minimum legal carapace length has been increased. The continuous CIR method can provide daily, local, and length-specific estimates of exploitation rate. For similar sample sizes, continuous CIR estimates are better than CIR estimates based on pre- and post-season sampling. A continuous CIR method is cost efficient because the data can be collected during regular fishing activity.
Electrochemical Reduction of Monochlorinated Hydrocarbons at a Hydrophobic Zn/PTFE Composite‐Electroplated Zn Electrode in a Water‐Acetonitrile Mixture
Authors: Wiyaratn Wisitsree , Somasundrum Mithran , Surareungchai Werasak
Published: November 2003

Composite‐electroplating of zinc particles with polytetrafluoroethylene at a zinc substrate resulted in a working electrode which could be used at high negative potentials (to −2.5 V vs. Ag/AgCl) without significant hydrogen evolution. The electrodes were characterized by SEM and CV and were used to detect organochloride compounds in a water‐acetonitrile mixture, by potential step methods.
Fabrication of Covalently Attached Multilayer Film Electrode Containing Iron Porphyrin and Its Electrocatalysis Toward Sulfite
Authors: Li Xiaofang , Fu Yaqin , Sun Changqing
Published: November 2003

Construction of a highly stable covalently attached multilayer film electrode containing iron porphyrin was achieved by UV irradiation of ionic self‐assembled multilayer films of diazo‐resins (DAR) and anionic Fe(III)tetrakis(p‐sulfonatophenyl)porphyrin (FeTSPP). The multilayer films had been characterized by UV, IR spectra and cyclic valtammetry. The electrocatalytic transformation of sulfite to SO42− by the multilayer film electrode containing FeTSPP was investigated. In 0.1 M NH4OHNH4Cl buffer solution (pH 8.74) and 0.1 M borate buffer solution (pH 9.18) the electrocatalytic oxidation of sulfite through the multilayer film electrode can be performed. However, in acetate buffer solution (pH 4.0) the electrocatalytic reduction of sulfite by the multilayer film electrode had also good activity. The modified electrode also exhibited a fast response and good stability.
Sonoelectrochemistry in Acoustically Emulsified Media: The Detection of Lead
Authors: Tomčík Peter , Banks Craig E. , Compton Richard G.
Published: November 2003

The double extraction of target lead ions which are then voltammetrically quantified via acoustically assisted anodic stripping voltammetry is demonstrated. The technique involves first the extraction of lead from the aqueous volume into an organic phase containing the ligand dithizone (diphenylthiocarbazone). Second, the chelated lead is then stripped into a clean electrochemically clean aqueous solution where the lead from the original solution can be quantified. This method is shown to be applicable in electrochemically fouling media, providing a high sensitivity with a limit of detection for lead in the order of 10−7 mol dm−3. A theoretical extraction model is presented for the optimal conditions of extraction. The technique is applied to the analysis of lead in wine samples offering quantitative data, which is in good agreement with those obtained from an independent technique (AAS).
Identification of yeasts isolated from Nigerian sugar cane peels
Authors: Olasupo N. A. , Bakre S. , Teniola O. D. , James S. A.
Published: November 2003

A pilot study was carried out to determine the yeast species associated with sugar cane peels recovered from three separate dumping sites found in Ojo, a typical market town in Nigeria. Species identities were determined by 26S ribosomal DNA (rDNA) sequencing. By using this method, a total of 6 different yeasts were identified, with Candida tropicalis, a recognised human yeast pathogen, being the species most frequently isolated from these dumping sites. The implications of this and other findings of the study, the apparent first of its kind, are discussed in detail.
Increased solubility of (heavy) metals in soil during microbial transformations of sucrose and casein amendments
Authors: Gramss Gerhard , Voigt Klaus‐Dieter , Bublitz Friedemann , Bergmann Hans
Published: November 2003

Unsterile soil samples pH 6.8 were amended with 10% sucrose or 0.1% NH4NO3/2% casein to influence solubility of metal cations. Microbial formation of aliphatic carboxylic acids reduced pH of sucrose soil to 4.3 and increased the solubility of heavy metals by 60‐fold due to the increased presence of H+, and the metal‐chelating and humic‐molecule fragmenting properties of carboxylic acids. Soil pH increased finally to 7.8 upon the degradation of the carboxylic acids. In casein soil, ammonia production increased pH initially to 8.5 and promoted solubility of metal‐containing humic compounds. Subsequent nitrification reduced pH to 5.6 to increase concentations of Ca and Mg in the soil solution, which prevented a comparable increase in the solubility of heavy metals competitively. It is concluded that amendment with sugar and nitrogen occasionally increases the concentrations of (hazardous) elements in the soil solution to facilitate their uptake by metal hyperaccumulating plants.
Virulence of Photobacterium damselae subsp. piscicida in cultured cobia Rachycentron canadum
Authors: Liu Ping‐Chung , Lin Ji‐Yang , Lee Kuo‐Kau
Published: November 2003

An outbreak of serious mortality among the cultured cobia Rachycentron canadum (weighing 3 kg) characterized by the presence of whitish granulomatous deposits on the kidney, liver and spleen occurred in July of 2000 in Taiwan. A non‐motile strain CP1 was isolated from kidney and/or liver on tryptic soy agar and/or brain heart infusion agar plates (both supplemented with 1% NaCl, w/v). This strain was characterized and identified as Photobacterium damselae subsp. piscicida using biochemical characteristics and Bionor mono‐Pp tests. The bacterium and its extracellular products (ECP) were lethal to the cobia (weighing 10 g) with LD50 values of 1.03 × 104 colony forming units and 1.26 μg protein/g fish body weight, respectively. All the moribund/dead fish exhibited darkness in color with no gross or internal leasions. However, the bacteria could be reisolated from kidney and liver after bacterial challenge. The present results reveal that Ph. damselae subsp. piscicida is the causative agent of fish photobacteriosis in the cobia and the bacterium isolated from sub‐adult cobia (chronic form) is virulent to young cobia causing acute form of the disease.
Shock tube measurements of branched alkane ignition times and OH concentration time histories
Authors: Oehlschlaeger M. A. , Davidson D. F. , Herbon J. T. , Hanson R. K.
Published: November 2003

Ignition times and hydroxyl (OH) radical concentration time histories were measured behind reflected shock waves during the oxidation of three branched alkanes: iso‐butane (2‐methylpropane), iso‐pentane (2‐methylbutane), and iso‐octane (2,2,4‐trimethylpentane). Initial reflected shock conditions ranged from 1177 to 2009 K and 1.10 to 12.58 atm with dilute fuel/O2/Ar mixtures varying in fuel concentration from 100 ppm to 1.25% and in equivalence ratio from 0.25 to 2. Ignition times were measured using endwall CH emission and OH concentrations were measured using narrow‐linewidth ring‐dye laser absorption of the R1(5) line of the OH A‐X (0,0) band at 306.7 nm. The ignition times and OH concentration time histories were compared to modeled predictions of seven branched alkane oxidation mechanisms currently available in the literature and the implications of these comparisons are discussed. These data provide a unique database for the validation of detailed hydrocarbon oxidation mechanisms of propulsion related fuels. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 36: 67–78 2004
Comparison of PDQuest and Progenesis software packages in the analysis of two‐dimensional electrophoresis gels
Authors: Rosengren Arsi T. , Salmi Jussi M. , Aittokallio Tero , Westerholm Jan , Lahesmaa Riitta , Nyman Tuula A. , Nevalainen Olli S.
Published: November 2003

Efficient analysis of protein expression by using two‐dimensional electrophoresis (2‐DE) data relies on the use of automated image processing techniques. The overall success of this research depends critically on the accuracy and the reliability of the analysis software. In addition, the software has a profound effect on the interpretation of the results obtained, and the amount of user intervention demanded during the analysis. The choice of analysis software that best meets specific needs is therefore of interest to the research laboratory. In this paper we compare two advanced analysis software packages, PDQuest and Progenesis. Their evaluation is based on quantitative tests at three different levels of standard 2‐DE analysis: spot detection, gel matching and spot quantitation. As test materials we use three gel sets previously used in a similar comparison of Z3 and Melanie, and three sets of gels from our own research. It was observed that the quality of the test gels critically influences the spot detection and gel matching results. Both packages were sensitive to the parameter or filter settings with respect to the tendency of finding true positive and false positive spots. Quantitation results were very accurate for both analysis software packages.
Visible/near‐infrared spectra of experimentally shocked plagioclase feldspars
Authors: Johnson Jeffrey R. , Hörz Friedrich
Published: November 2003

High shock pressures cause structural changes in plagioclase feldspars such as mechanical fracturing and disaggregation of the crystal lattice at submicron scales, the formation of diaplectic glass (maskelynite), and genuine melting. Past studies of visible/near‐infrared spectra of shocked feldspars demonstrated few spectral variations with pressure except for a decrease in the depth of the absorption feature near 1250–1300 nm and an overall decrease in reflectance. New visible/near–infrared spectra (400–2500 nm) of experimentally shocked (17–56 GPa) albite‐ and anorthite‐rich rock powders demonstrate similar trends, including the loss of minor hydrated mineral bands near 1410, 1930, 2250, and 2350 nm. However, the most interesting new observations are increases in reflectance at intermediate pressures, followed by subsequent decreases in reflectance at higher pressures. The amount of internal scattering and overall sample reflectance is controlled by the relative proportions of micro‐fractures, submicron grains, diaplectic glass, and melts formed during shock metamorphism. We interpret the observed reflectance increases at intermediate pressures to result from progressively larger proportions of submicron feldspar grains and diaplectic glass. The ensuing decreases in reflectance occur after diaplectic glass formation is complete and the proportion of genuine melt inclusions increases. The pressure regimes over which these reflectance variations occur differ between albite and anorthite, consistent with thermal infrared spectra of these samples and previous studies of shocked feldspars. These types of spectral variations associated with different peak shock pressures should be considered during interpretation and modeling of visible/near‐infrared remotely sensed spectra of planetary and asteroidal surfaces.
Mapping, characterisation, and comparison of the spatio‐temporal distributions of cabbage stem flea beetle (Psylliodes chrysocephala), carabids, and Collembola in a crop of winter oilseed rape (Brassica napus)
Authors: Warner D. J. , Allen‐Williams L. J. , Warrington S. , Ferguson A. W. , Williams I. H.
Published: November 2003

The spatio‐temporal distribution of Psylliodes chrysocephala (L.) (Coleoptera: Chrysomelidae), a pest of oilseed rape (Brassica napus) (L.) (Cruciferae) and its potential predators, carabid beetles, within a crop of winter oilseed rape is described. The distribution of Collembola, a potential alternative food source for the predators, is also investigated. Insects were collected from spatially referenced sampling points across the crop and the counts mapped, analysed, and the degree of spatial association between the distributions determined using Spatial Analysis by Distance IndicEs (SADIE). Immigration into the crop by adult P. chrysocephala occurred from two edges and resulted in a non‐uniform distribution of the pest within the crop. Infestation of rape plants by P. chrysocephala larvae was greatest within the central area of the crop. Significant spatial association between adult female P. chrysocephala and the larval infestation of plants occurred throughout October. Three carabid species were active and abundant during peak pest immigration into the crop, viz., Trechus quadristriatus (Schrank) (Coleoptera: Carabidae), Pterostichus madidus (Fabricius) (Coleoptera: Carabidae), and Nebria brevicollis (Fabricius) (Coleoptera: Carabidae). Two of these species, T. quadristriatus and P. madidus, showed significant spatial association with the larvae of P. chrysocephala during October. All three carabid species showed a significant spatial association with Collembola during mid‐September, indicating that the latter may be an important food source for carabids during this period. In laboratory feeding experiments, only T. quadristriatus consumed the eggs of P. chrysocephala suggesting that, in the adult stage, this species may be the most important of the naturally occurring carabids as a predator of P. chrysocephala in the field. Adult T. quadristriatus may be a valuable component of an Integrated Pest Management strategy for winter oilseed rape, and the conservation of this species could be beneficial.
Interpopulation Variation in the Social Organization of Female Collared Lizards, Crotaphytus collaris
Authors: Baird Troy A. , Sloan Chris L.
Published: November 2003

We tested the hypotheses that levels of intrasexual aggression and the social structure among neighboring females differed in two central Oklahoma populations of collared lizards, Crotaphytus collaris, and examined the extent to which variation in aggression might be related to differences in the availability of arthropods, elevated perches used by females to scan for prey, and crawlspace refugia. Because both the costs of aggression and access to resources may influence female fitness, we also compared growth and survival rates and the number of clutches produced. At Morningside Farms Ranch (MS), lizards occupied naturally‐formed sandstone washes with naturally‐sculpted irregular topographies, whereas they inhabited homogenous fields of boulders used to construct flood control spillways at the Arcadia Lake Dam (AL). The frequency of intrasexual aggression was markedly higher at MS, and groups of MS females had social hierarchies structured by size and age with older females defending territories, whereas no such social structure was apparent at AL. Moreover, experimental removal of individuals from female groups resulted in more pronounced changes by the remaining females at MS than at AL. Elevated perches and crawlspace refugia were much less abundant at MS. Arthropod availability was similar at the two sites, but at AL arthropods were clustered near the edges of rock patches where elevated perches overlooking adjacent grassy areas were particularly abundant. MS females showed lower rates of survival, and growth during the first year (when growth is highest) than AL females, whereas the number of clutches produced by females at the two sites was similar. Our results suggest that variation in the availability of perch rocks may have resulted in differences in female social structure at the two sites, and relaxed intrasexual competition for perches may have resulted in higher female fitness at AL.
Effect of bioresorbable fibres (Polyfibre®) and a bioresorbable foam (Polyfoam®) on new bone formation
Authors: Wallkamm Beat , Schmid Jürg , Hämmerle Christoph H.F. , Gogolewski Sylwester , Lang Niklaus P.
Published: November 2003

The aim of the study was to evaluate two bioresorbable polylactic acid (PLA) filler materials in a guided bone regeneration (GBR) model system. The first was Polyfibre®, a fibrous PLA filler material. Polyfoam®, the second material tested, consisted of a spongy PLA filler material. In each group there were eight rabbits. In test rabbits a flap was raised uncovering the calvaria. A hemispherical PLA dome was filled with Polyfibre® or Polyfoam® material and periphereal blood and anchored onto the calvaria. Eight rabbits with the same domes, filled with blood alone, served as controls. The rabbits were sacrificed at 1 or 2 months. Histomorphometric measurements of regenerated total tissue volume, bone height and bone volume were carried out in undecalcified sections under a light microscope. At 1 month the totally filled volume attained 87% (range 82–91) in the fibre group, including 25% (23–27) fibres, 87% (85–95) in the foam group, including 15% (15–16) foam, and 55% (16–100) in the controls. The volume of mineralized bone was 12% (7–15) in the fibre group, 15% (12–18) in the foam group and 6% (1–11) in control domes. Bone height attained 48% (27–79) in the fibre group, 37% (31–58) in the foam group and 45% (14–67) in the control group. At 2 months, tissue volume attained 86% (85–87) including 26% (22–29) fibres, bone volume attained 13% (7–21) and bone height attained 56% (42–78) in the Polyfibre® group. In the Polyfoam® group, they were 83% (55–99) including 18% (15–19) foam, 13% (7–24) and 49% (29–74). In control domes, tissue volume was 82% (35–100), bone volume 20% (9–27) and bone height 86% (60–100). The Polyfibre® and Polyfoam® material was excellently integrated. No adverse reactions were found in the surrounding tissues. Direct bone apposition was observed onto the material. In conclusion, Polyfibre® and Polyfoam® material had a positive effect on initial bone and tissue formation but was a hindrance to increasing tissue volume, bone volume or bone height at 2 months compared to control specimens. The Polyfibre® and Polyfoam® material provoked no adverse reactions in the surrounding tissues and allowed for extensive angiogenesis.
Denaturation of demineralized bone matrix significantly reduces bone formation by guided tissue regeneration
Authors: Mardas N. , Kostopoulos L. , Stavropoulos A. , Karring T.
Published: November 2003

Abstract: Aim: To examine in a discriminating capsule model whether denaturation of demineralized bone matrix (DBM) by heating may influence bone formation.

Materials and methods: DBM was produced from the long bones of rats. Half the portion of DBM was denatured by heating in distilled water for 20 min at temperatures between 70°C and 90°C. Prior to the study, the destruction of the osteoinductive properties of the DBM was confirmed in three rats following intramuscular implantation. Thirty, 4‐month‐old, male albino rats of the Wistar strain were used in the study. Following surgical exposure of the mandibular ramus, a hemispherical Teflon capsule (internal diameter=5.0 mm) was placed, with its open part facing the lateral aspect of the ramus. On one side (test side), the capsule was loosely packed with denatured DBM, while on the contralateral side, serving as control, the capsule was loosely packed with the same amount of non‐denatured DBM. After healing periods of 30, 60, and 120 days, groups of 10 animals were killed and 40–70 μm thick undecalcified sections of the capsules were produced. Three sections from each specimen, representing the mid‐portion of the capsule, were subjected to histological analysis and computer‐assisted planimetric measurements.

Results: Increasing amounts of newly formed bone were observed in both test and control capsules during the experimental period. At 4 months, the new bone formed in the control capsules occupied 46.7% of the cross‐sectional area of the capsules, while it was only 19.1% in the test capsules (P<0.05).

Conclusion: Denaturation of DBM by heating significantly reduces bone formation by guided tissue regeneration.
Evaluation of a cell‐permeable barrier for guided tissue regeneration combined with demineralized bone matrix
Authors: Mardas N. , Kostopoulos L. , Stavropoulos A. , Karring T.
Published: November 2003

Abstract: Aim: To evaluate whether bone formation by guided tissue regeneration (GTR) and demineralized bone matrix (DBM) can be enhanced by the use of a cell‐permeable Teflon barrier allowing the penetration of undifferentiated mesenchymal cells from the surrounding soft tissues.

Material and methods: DBM was produced from the long bones of rats, and its bone‐inductive properties were tested in three rats prior to the study by intramuscular implantation. Thirty, 4‐month‐old, male albino rats of the Wistar strain were used. Following surgical exposure of the mandibular ramus, a cell‐permeable Teflon capsule, loosely packed with DBM, was placed with its opening facing the lateral surface of the ramus (test side). At the contralateral side, serving as control, a non‐perforated (cell‐occlusive) Teflon capsule, loosely packed with the same amount of DBM, was placed. After healing periods of 30, 60, and 120 days, groups of 10 animals were killed, and 40–70 μm thick undecalcified sections of the capsules were produced.

Results: Computer‐assisted planimetric measurements on the histological sections disclosed similar amounts of newly formed bone in both test and control capsules. After 4 months, the new bone in the control capsules occupied 45.0% of the cross‐sectional area of the capsule, while it was 50.5% in the test capsules. This difference was not statistically significant (P<0.05).

Conclusion: Similar amounts of bone formed in cell‐permeable and cell‐occlusive capsules grafted with DBM, suggesting that invasion of undifferentiated mesenchymal cells from the surrounding soft tissues into the barrier‐protected area is unnecessary for bone formation with GTR.
Evaluation of Cabergoline and Buserelin Efficacy for Oestrous Induction in the Bitch
Authors: Rota A , Mollo A , Marinelli L , Gabai G , Vincenti L
Published: November 2003

Contents

The purpose of this work was to compare two different protocols of oestrous induction, using either a dopamine agonist (cabergoline) or a GnRH agonist (buserelin) in anoestrus bitches. The clinical trial involved 22 Beagle bitches, randomly allotted to two treatment groups: group A (n = 12) was orally administered cabergoline (Galastop®; Centralvet‐Vetem, Milan, Italy; 5 μg/kg SID), until the onset of cytological oestrus or for a maximum of 30 days and group B (n = 10) was treated with buserelin acetate, (Suprefact®; Aventis Pharma, Milan, Italy), administered subcutaneously t.i.d., at 1.5 μg/kg for 11 days and 0.75 μg/kg for the following 3 days. Blood samples were collected twice a week to measure progesterone and prolactin concentration. Both cabergoline and buserelin produced a significant early decline in prolactin concentration (p < 0.01), but the effect of cabergoline lasted longer. Progesterone concentration was significantly affected by buserelin administration, showing a significant increase (p < 0.01) from day 3 to day 6 of treatment. Cabergoline confirmed its effectiveness in inducing oestrus as 10 of 12 bitches responded to the treatment, were mated and whelped. On the contrary, oestrus was observed in only three of 10 buserelin‐treated bitches and in two of them 7 and 13 days after the end of treatment. These same two bitches accepted mating and conceived. The results suggest that in a clinical setting, dopaminergic treatment is the treatment of choice as it yields more consistent results and involves a much easier administration protocol.
Efficient Production of Cloned Bovine Embryos Using cdc2 kinase Inhibitor
Authors: Yoo J‐G , Choe S‐Y , Rho G‐J
Published: November 2003

Contents

This study was carried out to compare the effects of the combination of ionomycin with a H1‐histone kinase inhibitor (dimethylaminopurine, DMAP) or cdc2 kinase inhibitor (sodium pyrophosphate, SPP) on the development of reconstituted bovine eggs. For this study, the enucleated bovine oocytes were injected with a presumptive primordial germ cell pre‐treated with 1% sodium citrate, and randomly allocated into three activation groups: Group 1 (ionomycin 5 μm, 5 min), Group 2 (ionomycin + DMAP 1.9 mm, 3 h), and Group 3 (ionomycin + SPP 2 mm, 3 h). The reconstituted eggs were compared on the rates of cleavage and development with the blastocyst stage and the ploidy of embryos at 96 h post‐activation. Cleavage rates and blastocyst development in Groups 1, 2 and 3 were 7 and 0%, 63 and 17%, and 53 and 14%, respectively. The chromosomal composition differed significantly (p < 0.05) among treatments. Although the embryos in Group 1 had significantly lower developments, 60% of embryos evaluated had diploid chromosomal sets. In contrast, ∼60% of embryos in Group 2 had abnormal ploidy (21% polyploid and 38% mixoploid). In Group 3, the appearance of abnormal chromosome sets was reduced with the proportion of diploid embryos being increased to 86% (19 of 22), significantly higher (p < 0.05) than in Group 2. It can be concluded that the use of SPP with ionomycin reduces greatly the incidence of chromosomal abnormalities, and may be applicable for the activation of nuclear transplant bovine embryos.
Ericoid mycorrhiza: a partnership that exploits harsh edaphic conditions
Authors: Cairney J. W. G. , Meharg A. A.
Published: November 2003

Plants that form ericoid mycorrhizal associations are widespread in harsh habitats. Ericoid mycorrhizal fungal endophytes are a genetically diverse group, and they appear to be able to alleviate certain environmental stresses and so facilitate the establishment and survival of Ericaceae. Some of the fungal taxa that form ericoid mycorrhizas, or at least closely related strains, also form associations with other plant hosts (trees and leafy liverworts). The functional significance of these associations and putative mycelial links between Ericaceae and other plant taxa, however, remain unclear. Evidence from environments that are contaminated by toxic metals indicates that ericoid mycorrhizal fungal endophytes, and in some instances their plant hosts, can evolve resistance to these metals. The apparent ability of these endophytes to develop resistance enables ericoid mycorrhizal plants to colonize polluted soil. This seems to be a major factor in the success of ericoid mycorrhizal taxa in a range of harsh environments.
Microbial diversity and soil functions
Authors: Nannipieri P. , Ascher J. , Ceccherini M. T. , Landi L. , Pietramellara G. , Renella G.
Published: November 2003

Soil is a complex and dynamic biological system, and still in 2003 it is difficult to determine the composition of microbial communities in soil. We are also limited in the determination of microbially mediated reactions because present assays for determining the overall rate of entire metabolic processes (such as respiration) or specific enzyme activities (such as urease, protease and phosphomonoesterase activity) do not allow any identification of the microbial species directly involved in the measured processes. The central problem posed by the link between microbial diversity and soil function is to understand the relations between genetic diversity and community structure and between community structure and function. A better understanding of the relations between microbial diversity and soil functions requires not only the use of more accurate assays for taxonomically and functionally characterizing DNA and RNA extracted from soil, but also high‐resolution techniques with which to detect inactive and active microbial cells in the soil matrix.

Soil seems to be characterized by a redundancy of functions; for example, no relationship has been shown to exist between microbial diversity and decomposition of organic matter. Generally, a reduction in any group of species has little effect on overall processes in soil because other microorganisms can take on its function.

The determination of the composition of microbial communities in soil is not necessary for a better quantification of nutrient transformations. The holistic approach, based on the division of the systems in pools and the measurement of fluxes linking these pools, is the most efficient. The determination of microbial C, N, P and S contents by fumigation techniques has allowed a better quantification of nutrient dynamics in soil. However, further advances require determining new pools, such as active microbial biomass, also with molecular techniques. Recently investigators have separated 13C‐ and 12C‐DNA, both extracted from soil treated with a 13C source, by density‐gradient centrifugation. This technique should allow us to calculate the active microbial C pool by multiplying the ratio between labelled and total DNA by the microbial biomass C content of soil. In addition, the taxonomic and functional characterization of 13C‐DNA allows us to understand more precisely the changes in the composition of microbial communities affected by the C‐substrate added to soil.
Ethyl glucuronide—the direct ethanol metabolite on the threshold from science to routine use
Authors: Wurst Friedrich Martin , Skipper Gregory E. , Weinmann Wolfgang
Published: November 2003

Aims  Current biological state markers remain suboptimal with regard to sensitivity and specificity for monitoring recent alcohol consumption in various settings. Furthermore, these biomarkers can be influenced by age, gender and a variety of substances and non‐alcohol‐associated diseases and do not cover fully the time axis for alcohol intake. Ethyl glucuronide (EtG) is a non‐volatile, water‐soluble, stable, direct metabolite of ethanol that can be detected in various body fluids, tissues and hair. Shortly after the consumption even of small amounts of ethanol, EtG becomes positive. It can detect ethanol intake up to 80 hours after the complete elimination of alcohol from the body, covering a unique and important time spectrum for recent alcohol use. EtG seems to meet the need for a sensitive and specific marker to elucidate alcohol use not detected by standard testing.

Design, setting, participants, methods and findings  The literature was re‐viewed with a focus on possible diagnostic and therapeutic applications, currently available methods and future perspectives. To date, more than 4000 samples of body fluids, tissues and hair from approximately 1500 individuals have been assessed.

Conclusions  The data suggest that EtG is a useful tool in numerous settings, including alcohol and drug treatment (to detect lapse/relapse and for motivational feedback), in safety sensitive work settings where use is dangerous or in other settings where alcohol use may be risky (e.g. such as driving, work‐place, pregnancy or monitoring physicians or other professionals who are in recovery and working) or for resolving forensic questions. If the question of recent alcohol consumption has to be answered in a binary way (yes/no), such as for determining lapses, the use of EtG in urine is among the preferred tests. The use of this marker alone and complementary with other biological state markers and self‐reports is expected to lead to significant improvement in treatment outcome, therapy efficacy and cost reduction.
Trust, collaboration, e‐learning and organisational transformation
Authors: Mason Jon , Lefrere Paul
Published: November 2003

While theoretically distinct, learning and knowing are meshed in practice. This paper builds on this observation and argues that organisational transformation and the development of best practices in e‐learning share some similar context. This is particularly evident when knowledge management perspectives are considered. Specifically, trust and collaboration are shown to be common enablers of both activities. A range of interrelated models is introduced with trust identified as prominent within a complex mix of processes and outputs that can be described in terms of interoperability. Collaboration and interoperability are identified as key organising principles in information‐based and knowledge‐based economies. Through collaboration common goals and mutual benefit are discerned and pursued; duplication of effort is minimised; innovation is stimulated. Achieving technical interoperability demands use of networks in ways that harness the aggregate capacity of disparate systems, applications and services. The resulting infrastructure matches requirements of both e‐learning and organisational transformation.
Liver transplantation
Authors: O'Grady J. G.
Published: November 2003

The economic assessment of liver transplantation is complex and involves the cost of the transplant procedure, the cost of alternative treatments and the positive economic contribution of successful outcomes. The one‐year survival rates are currently in the order of 80–90% for elective transplants and 60–75% for emergency transplantation. The average cost of a liver transplant operation in the UK is between £32 000 and £45 000. Factors which have a major influence on costs are aetiology, patient status at the time of transplantation, retransplantation and duration of hospital stay. Rejection episodes, renal impairment and surgical complications are of intermediate importance. The cost of transplantation must be balanced against the cost of alternative treatments that would be required if the patient were not transplanted and the positive economic benefit derived from excellent rehabilitation in the majority of recipients.
Low cure rate of Helicobacter pylori infection with omeprazole and furazolidone dual therapy for one week
Authors: Zwet A. A. van , Thijs J. C. , Wouden E. J. van der , Kooy A.
Published: November 2003

Background:

Furazolidone is an inexpensive antibiotic that has considerable anti‐Helicobacter pylori activity in vitro.

Methods:

Twenty‐three patients with culture‐proven H. pylori infection were treated for one week with a dual therapy containing omeprazole and furazolidone.

Results:

Eradication succeeded in 10 of the first 20 evaluable patients (50%; 95% CI: 27.2–72.8%). This percentage was regarded as too low, and the study was terminated. Side‐effects were mild.

Conclusion:

With the possible increase in resistance to metronidazole and clarithromycin world‐wide, furazolidone may be a useful alternative in the treatment of H. pylori infection. Dual therapy for one week, however, is not sufficient.