bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vitro Antimycobacterial Activities of Capuramycin Analogues
Authors: Reddy Venkata M. , Einck Leo , Nacy Carol A.
Published: December 2007

Translocase I inhibitor compounds derived from capuramycin demonstrated rapid bactericidal activity against several different mycobacterial species. SQ641 was the most active of the compounds, with a MIC of 0.12 to 8 μg/ml, a postantibiotic effect of 55 h, and interesting synergistic effects with other antitubercular drugs.
FcγRIII Mediates Immunoglobulin G-Induced Interleukin-10 and Is Required for ChronicLeishmania mexicanaLesions
Authors: Thomas Bolaji N. , Buxbaum Laurence U.
Published: December 2007

FcRγ and interleukin-10 (IL-10) are both required for chronic disease in C57BL/6 mice withLeishmania mexicanaparasite infection. FcRγ is a component of several different FcRs and may be a component of some T-cell receptors. The initial antibody response toL. mexicanais an immunoglobulin G1 (IgG1) response, and IgG1 preferentially binds to FcγRIII in other systems. To begin to dissect the mechanisms by which FcγRs contribute to chronic disease, we infected FcγRIII knockout (KO) mice withL.mexicana. We show that FcγRIII KO mice are resistant toL. mexicanainfection, resolving lesions in association with a stronger gamma interferon response, similar to IL-10 KO mice, with parasite control by 12 weeks. We found that theLeishmania-specific IgG response is unaltered in FcγRIII KO mice compared with that in wild-type controls. The frequencies of IL-10 production from lymph node CD25+CD4+T cells are the same in KO and wild-type mice, and depletion of CD25+cells did not alter the course of infection, implying that Tregcells may not be the mechanism for susceptibility toL. mexicanainfection, unlike forL. majorinfection. However, IL-10 mRNA was greatly diminished in the lesions of FcγRIII KO mice compared to that of B6 controls. Furthermore, macrophages from FcγRIII KO and FcRγ KO mice have the same profound defect in IL-10 production induced by IgG-opsonized amastigotes. We also found IL-10-dependent (major) and -independent (minor) inhibition of IL-12 mediated by FcγRIII, as well as parasite-mediated inhibition of IL-12 and induction of IL-10, independent of FcγR. Our data demonstrate a specific role for FcγRIII in suppressing protective immunity inL. mexicanainfection, likely through macrophage IL-10 production in the lesion.
Subunit Vaccine against the Seven Serotypes of Botulism
Authors: Baldwin Michael R. , Tepp William H. , Przedpelski Amanda , Pier Christina L. , Bradshaw Marite , Johnson Eric A. , Barbieri Joseph T.
Published: December 2007

Botulinum neurotoxins (BoNTs) are the most toxic proteins for humans and are classified as category A toxins. There are seven serotypes of BoNTs defined by the lack of cross-serotype toxin neutralization. Thus, an effective vaccine must neutralize each BoNT serotype. BoNTs are organized as dichain A-B toxins, where the N-terminal domain (light chain) is a zinc metalloprotease targeting soluble NSF attachment receptor proteins that is linked to the C-terminal domain (heavy chain [HC]) by a disulfide bond. The HC comprises a translocation domain and a C-terminal receptor binding domain (HCR). HCRs of the seven serotypes of BoNTs (hepta-HCR) were engineered for expression inEscherichia coli, and each HCR was purified fromE. colilysates. Immunization of mice with theE. coli-derived hepta-serotype HCR vaccine elicited an antibody response to each of the seven BoNT HCRs and neutralized challenge by 10,000 50% lethal doses of each of the seven BoNT serotypes. A solid-phase assay showed that the anti-hepta-serotype HCR sera inhibited the binding of HCR serotypes A and B to the ganglioside GT1b, the first step in BoNT intoxication of neurons. This is the firstE. coli-derived vaccine that effectively neutralizes each of the seven BoNT serotypes.
Sequence Diversity of theTrypanosoma cruziComplement Regulatory Protein Family
Authors: Beucher M. , Norris K. A.
Published: December 2007

As a central component of innate immunity, complement activation is a critical mechanism of containment and clearance of microbial pathogens in advance of the development of acquired immunity. Several pathogens restrict complement activation through the acquisition of host proteins that regulate complement activation or through the production of their own complement regulatory molecules (M. K. Liszewski, M. K. Leung, R. Hauhart, R. M. Buller, P. Bertram, X. Wang, A. M. Rosengard, G. J. Kotwal, and J. P. Atkinson, J. Immunol. 176:3725-3734, 2006; J. Lubinski, L. Wang, D. Mastellos, A. Sahu, J. D. Lambris, and H. M. Friedman, J. Exp. Med. 190:1637-1646, 1999). The infectious stage of the protozoan parasiteTrypanosoma cruziproduces a surface-anchored complement regulatory protein (CRP) that functions to inhibit alternative and classical pathway complement activation (K. A. Norris, B. Bradt, N. R. Cooper, and M. So, J. Immunol. 147:2240-2247, 1991). This study addresses the genomic complexity of theT. cruziCRP and its relationship to theT. cruzisupergene family comprising activetrans-sialidase (TS) and TS-like proteins. The TS superfamily consists of several functionally distinct subfamilies that share a characteristic sialidase domain at their amino termini. These TS families include active TS, adhesions, CRPs, and proteins of unknown functions (G. A. Cross and G. B. Takle, Annu. Rev. Microbiol. 47:385-411, 1993). A sequence comparison search of GenBank using BLASTP revealed several full-length paralogs of CRP. These proteins share significant homology at their amino termini and a strong spatial conservation of cysteine residues. Alternative pathway complement regulation was confirmed for CRP paralogs with 58% (low) and 83% (high) identity to AAB49414. CRPs are functionally similar to the microbial and mammalian proteins that regulate complement activation. Sequence alignment of mammalian complement control proteins to CRP showed that these sequences are distinct, supporting a convergent evolutionary pathway. Finally, we show that a clonal line ofT. cruziexpresses multiple unique copies of CRP that are differentially recognized by patient sera.
A SacB Mutagenesis Strategy Reveals that the
Bartonella quintana
Variably Expressed Outer Membrane Proteins Are Required for Bloodstream Infection of the Host
Authors: MacKichan Joanna K. , Gerns Helen L. , Chen Yu-Ting , Zhang Peng , Koehler Jane E.
Published: December 2007

Bartonella
bacteria adhere to erythrocytes and persistently infect the mammalian bloodstream. We previously identified four highly conserved
Bartonella quintana
adhesin genes that undergo phase variation during prolonged bloodstream infection. The
v
ariably expressed
o
uter
m
embrane
p
roteins (Vomp) encoded by these genes are members of the trimeric autotransporter adhesin family. Each
B. quintana
Vomp appears to contribute a different adhesion phenotype, likely mediated by the major variable region at the adhesive tip of each Vomp. Although studies document that the Vomp adhesins confer virulence phenotypes in vitro, little is known about in vivo virulence strategies of
Bartonella
. We sought to determine whether the
B. quintana
Vomp adhesins are necessary for infection in vivo by using a
vomp
null mutant. It first was necessary to develop a system to generate in-frame deletions of defined genes by allelic exchange in a wild-type
Bartonella
background, which had not been achieved previously. We utilized
sacB
negative selection to generate a targeted, in-frame, markerless deletion of the entire
vomp
locus in
B. quintana
. We also recently developed the first animal model for
B. quintana
infection, and using this model, we demonstrate here that the deletion of the entire
vomp
locus, but not the deletion of two
vomp
genes, results in a null mutant strain that is incapable of establishing bloodstream infection in vivo. The Vomp adhesins therefore represent critical virulence factors in vivo, warranting further study. Finally, our allelic exchange strategy provides an important advance in the genetic manipulation of all
Bartonella
species and, combined with the animal model that recapitulates human disease, will facilitate pathogenesis studies of
B. quintana
.
Characterization of the Fine Specificity of Bovine CD8 T-Cell Responses to Defined Antigens from the Protozoan ParasiteTheileria parva
Authors: Graham Simon P. , Pellé Roger , Yamage Mat , Mwangi Duncan M. , Honda Yoshikazu , Mwakubambanya Ramadhan S. , de Villiers Etienne P. , Abuya Evelyne , Awino Elias , Gachanja James , Mbwika Ferdinand , Muthiani Anthony M. , Muriuki Cecelia , Nyanjui John K. , Onono Fredrick O. , Osaso Julius , Riitho Victor , Saya Rosemary M. , Ellis Shirley A. , McKeever Declan J. , MacHugh Niall D. , Gilbert Sarah C. , Audonnet Jean-Christophe , Morrison W. Ivan , van der Bruggen Pierre , Taracha Evans L. N.
Published: December 2007

Immunity against the bovine intracellular protozoan parasiteTheileria parvahas been shown to be mediated by CD8 T cells. Six antigens targeted by CD8 T cells fromT. parva-immune cattle of different major histocompatibility complex (MHC) genotypes have been identified, raising the prospect of developing a subunit vaccine. To facilitate further dissection of the specificity of protective CD8 T-cell responses and to assist in the assessment of responses to vaccination, we set out to identify the epitopes recognized in theseT. parvaantigens and their MHC restriction elements. Nine epitopes in sixT. parvaantigens, together with their respective MHC restriction elements, were successfully identified. Five of the cytotoxic-T-lymphocyte epitopes were found to be restricted by products of previously described alleles, and four were restricted by four novel restriction elements. Analyses of CD8 T-cell responses to five of the epitopes in groups of cattle carrying the defined restriction elements and immunized with live parasites demonstrated that, with one exception, the epitopes were consistently recognized by animals of the respective genotypes. The analysis of responses was extended to animals immunized with multiple antigens delivered in separate vaccine constructs. Specific CD8 T-cell responses were detected in 19 of 24 immunized cattle. All responder cattle mounted responses specific for antigens for which they carried an identified restriction element. By contrast, only 8 of 19 responder cattle displayed a response to antigens for which they did not carry an identified restriction element. These data demonstrate that the identified antigens are inherently dominant in animals with the corresponding MHC genotypes.
Streptococcus pneumoniaeCholine-Binding Protein E Interaction with Plasminogen/Plasmin Stimulates Migration across the Extracellular Matrix
Authors: Attali Cécile , Frolet Cécile , Durmort Claire , Offant Julien , Vernet Thierry , Di Guilmi Anne Marie
Published: December 2007

The virulence mechanisms leadingStreptococcus pneumoniaeto convert from nasopharyngeal colonization to a tissue-invasive phenotype are still largely unknown. Proliferation of infection requires penetration of the extracellular matrix, which occurs by recruitment of host proteases to the bacterial cell surface. We present evidence supporting the role of choline-binding protein E (CBPE) (a member of the surface-exposed choline-binding protein family) as an important receptor for human plasminogen, the precursor of plasmin. The results of ligand overlay blot analyses, solid-phase binding assays, and surface plasmon resonance experiments support the idea of an interaction between CBPE and plasminogen. We have shown that the phosphorylcholine esterase (Pce) domain of CBPE interacts with the plasminogen kringle domains. Analysis of the crystal structure of the Pce domain, followed by site-directed mutagenesis, allowed the identification of the plasminogen-binding region composed in part by lysine residues, some of which map in a linear fashion on the surface of the Pce domain. The biological relevance of the CBPE-plasminogen interaction is supported by the fact that, compared to the wild-type strain, a mutant of pneumococcus with thecbpEgene deleted (i) displays a reduced level of plasminogen binding and plasmin activation and (ii) shows reduced ability to cross the extracellular matrix in an in vitro model. These results support the idea of a physiological role for the CBPE-plasminogen interaction in pneumococcal dissemination into human tissue.
Transcriptome Changes in
Mycoplasma hyopneumoniae
during Infection
Authors: Madsen Melissa L. , Puttamreddy Supraja , Thacker Eileen L. , Carruthers Michael D. , Minion F. Chris
Published: December 2007

Mycoplasma hyopneumoniae
causes swine pneumonia and contributes significantly to the porcine respiratory disease complex. The mechanisms of pathogenesis are difficult to address, since there is a lack of genetic tools, but microarrays are available and can be used to study transcriptional changes that occur during disease as a way to identify important virulence-related genes. Mycoplasmas were collected from bronchial alveolar lavage samples and compared to broth-grown cells using microarrays. Bronchial alveolar lavage was performed on pigs 28 days postinfection, and mycoplasmas were isolated by differential centrifugation. Mycoplasma RNA-enriched preparations were then obtained from total RNA by subtracting eucaryotic ribosomal and messenger RNAs. Labeled cDNAs were generated with mycoplasma open reading frame-specific primers. Nine biological replicates were analyzed. During lung infection, our analysis indicated that 79
M. hyopneumoniae
genes were differentially expressed (
P
< 0.01), at a false-discovery rate of <2.7%. Of the down-regulated genes, 28 of 46 (61%) lacked an assigned function, in comparison to 21 of 33 (63%) of up-regulated genes. Four down-regulated genes and two up-regulated genes encoded putative lipoproteins.
secA
(mhp295) (
P
= 0.003) and two glycerol transport permease genes (
potA
[mhp380;
P
= 0.006] and
ugpA
[mhp381;
P
= 0.003]) were up-regulated in vivo. Elongation factor EF-G (
fusA
[mhp083]) (
P
= 0.002), RNA polymerase beta chain (
rpoC
[mhp635]) (
P
= 0.003), adenylate kinase (
adk
[mhp208]) (
P
= 0.001), prolyl aminoacyl tRNA synthetase (
proS
[mhp397]) (
P
= 0.009), and cysteinyl-tRNA synthetase (
cysS
[mhp661]) (
P
< 0.001) were down-regulated in vivo.
Internal impingement in the tennis player: rehabilitation guidelines
Authors: Cools A M , Declercq G , Cagnie B , Cambier D , Witvrouw E
Published: December 2007

Internal impingement is a commonly described cause of shoulder pain in the overhead athlete, particularly in tennis players. Three shoulder dysfunctions, often correlated with internal impingement symptoms, require attention in the rehabilitation strategy of internal impingement in the tennis player: (1) acquired glenohumeral anterior instability, (2) loss of internal rotation range of motion, and (3) lack of retraction strength.

Based on recent literature, the following guidelines are proposed in the rehabilitation of the tennis player with internal impingement symptoms: (1) shoulder rehabilitation should be integrated into kinetic chain training, not only in the advanced phases of the athlete’s rehabilitation, but from the initial phases; (2) both angular and translational mobilisations can be used in the treatment of acquired loss of glenohumeral internal rotation range of motion to stretch the posterior structures of the glenohumeral joint; and 3) in the rehabilitation of scapular dyskinesis, the therapist should focus on restoration of intramuscular trapezius muscle balance in the scapular exercises, with special attention to strength training of the retractors.
Sports medicine clinical trial research publications in academic medical journals between 1996 and 2005: an audit of the PubMed MEDLINE database
Authors: Nichols A W
Published: December 2007

Objective:

To identify sports medicine-related clinical trial research articles in the PubMed MEDLINE database published between 1996 and 2005 and conduct a review and analysis of topics of research, experimental designs, journals of publication and the internationality of authorships.

Hypothesis:

Sports medicine research is international in scope with improving study methodology and an evolution of topics.

Design:

Structured review of articles identified in a search of a large electronic medical database.

Setting:

PubMed MEDLINE database.

Participants:

Sports medicine-related clinical research trials published between 1996 and 2005.

Interventions:

Review and analysis of articles that meet inclusion criteria.

Main outcome measurements:

Articles were examined for study topics, research methods, experimental subject characteristics, journal of publication, lead authors and journal countries of origin and language of publication.

Results:

The search retrieved 414 articles, of which 379 (345 English language and 34 non-English language) met the inclusion criteria. The number of publications increased steadily during the study period. Randomised clinical trials were the most common study type and the “diagnosis, management and treatment of sports-related injuries and conditions” was the most popular study topic. The knee, ankle/foot and shoulder were the most frequent anatomical sites of study. Soccer players and runners were the favourite study subjects. TheAmerican Journal of Sports Medicinehad the highest number of publications and shared the greatest international diversity of authorships with theBritish Journal of Sports Medicine. The USA, Australia, Germany and the UK produced a good number of the lead authorships. In all, 91% of articles and 88% of journals were published in English.

Conclusions:

Sports medicine-related research is internationally diverse, clinical trial publications are increasing and the sophistication of research design may be improving.
Cervical muscle strength measurement is dependent on the location of thoracic support
Authors: Rezasoltani A , Ylinen J , Bakhtiary A-H , Norozi M , Montazeri M
Published: December 2007

Background:

In all studies in which the strength of the neck extensor muscles has been measured, the level of thoracic support has been adjusted differently so direct comparison of the results is not possible.

Objective:

To measure and compare the isometric force and isometric torque of neck extensor muscles at different levels of thoracic support.

Methods:

Twenty healthy women volunteered for the study. The maximum isometric force of the neck extensor muscles was measured with the thoracic support located at five different levels. The highest level was set at the level of the spine of the scapula (level I) and the other levels were located 2.5 cm lower than the previous one, with the lowest level set 10 cm below the highest level. The maximum isometric torque for each level was calculated by multiplying the isometric force by the length of the lever arm measured from the upper tip of the thoracic support to the centre point of the cell load at the occiput.

Results:

The maximum isometric force and maximum isometric torque of the neck extensor muscles were increased step by step from 130.5 N to 138.9 N, 141.9 N, 147.9 N and 155.4 N and from 33.7 Nm to 38.7 Nm, 42.5 Nm, 47.2 Nm and 52.7 Nm, respectively. Except for the isometric force of the cervical extensor muscles measured at levels II and III, the differences between the other levels were significant (p<0.05). There was a significant correlation between isometric force and isometric torque measurements of the neck extensor muscles at different levels (0.81<r<0.96).

Conclusion:

Maximum isometric force and maximum isometric torque measurements of the neck extensor muscles vary with the length of the lever arm. It is recommended that a specific level of thoracic support should be used in follow-up and intervention studies. Setting the level of thoracic support at a specific level will make it possible to compare the strength of the neck extensor muscles in different studies. Measurements at the level of the spine of the scapula were easier and less time consuming.
The clinical utility of screening of biochemical parameters in elite athletes: analysis of 100 cases
Authors: Fallon K E
Published: December 2007

Objective:

To determine the clinical utility of screening for biochemical parameters in elite athletes.

Design:

A prospective sequential case series.

Setting:

The Department of Sports Medicine at the Australian Institute of Sport.

Participants:

100 elite athletes from 11 sports (56 male and 44 female athletes, mean age 19 years, range 16–27), undergoing routine medical screening.

Intervention:

Initial and follow-up assessment of the following biochemical parameters in association with clinical assessment; serum iron, ferritin, transferrin, percent transferrin saturation, sodium, potassium, chloride, calcium, magnesium, phosphate, urate, urea and creatinine, total protein, albumin, creatine kinase (CK), lactate dehydrogenase, aspartate aminotransaminase (AST), alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, total bilirubin, cholesterol and triglycerides (non-fasting), and random glucose.

Results:

18 athletes showed no abnormalities on biochemical screening. 194 abnormal results were found in 82 athletes. 115 abnormalities were noted in 46 male and 79 in 36 female athletes. In 43 individual tests, the results did not return to normal on repeat testing. The most common abnormalities were increases in AST (27%), phosphate (13%), CK (13%), urea (12%) and bilirubin (12%). Three cases of hypercholesterolaemia and one case of haemochromatosis were identified, and one athlete, who was asymptomatic, was diagnosed with Epstein–Barr virus infection, which was suspected because of an abnormal liver function test. The other abnormalities found appeared not to be of clinical significance.

Conclusion:

Most abnormalities found on routine biochemical screening in elite athletes are of no clinical significance, therefore such testing should, if used only for clinical purposes, be abandoned. When athletes are tested for iron status it would be prudent to include assessment of serum cholesterol in those with a family history of hyperlipidaemia.
Left atrial myocardial function in either physiological or pathological left ventricular hypertrophy: a two-dimensional speckle strain study
Authors: D’Andrea A , De Corato G , Scarafile R , Romano S , Reigler L , Mita C , Allocca F , Limongelli G , Gigantino G , Liccardo B , Cuomo S , Tagliamonte G , Caso P , Calbrò R
Published: December 2007

Background:

Atrial function is an integral part of cardiac function that is often neglected. The presence of left ventricule hypertrophy (LVH) due to arterial hypertension may impair atrial function. However, it has also been suggested that physical training attenuates the age-associated impairment of diastolic filling. This study investigated whether mechanical dysfunction in the left atrium (LA) is present in patients with either physiological or pathological LVH, using two-dimensional strain rate imaging (2D strain echocardiography; 2DSE).

Methods:

Standard echocardiography, exercise stress echo and 2DSE of the left atrium were performed in 40 patients with arterial hypertension, 45 age-matched elite athletes (>40 years) and 25 healthy sedentary controls. Atrial longitudinal strain was performed from the apical views for the basal segments of the LA septum, lateral wall and roof.

Results:

LV mass index and ejection fraction were comparable between patients with either physiological or pathological LVH. Elite athletes showed increased LV end-diastolic diameter, end-diastolic volume and stroke volume, whereas circumferential end-systolic stress was higher in patients with hypertension. LA diameter and maximum volume were increased but similar between the two groups of patients with LVH. LA active emptying volume and fraction were both higher in patients with hypertension. Conversely, peak systolic myocardial atrial strain was significantly reduced in patients with pathological LVH compared with controls and athletes for all the analysed atrial segments (p<0.0001). Using multivariate analysis, LV end-diastolic volume/body surface area (BSA) (β coefficient 0.52; p<0.0001) and LV mass (β = 0.48; p<0.001) in athletes emerged as the only independent determinants of LA lateral wall peak systolic strain. In contrast, in patients with hypertension, an independent negative association of LA lateral wall peak systolic strain with both LV mass (β = −0.42; p<0.001) and circumferential end-systolic stress (β = −0.43; p<0.001) was found. In addition, in the overall population of patients with LVH, LA lateral wall systolic strain (β = 0.49; p<0.0001) was a powerful independent predictor of maximum workload during exercise testing.

Conclusions:

2DSE represents a promising, non-invasive, simple and reproducible technique to assess LA myocardial function in patients with either physiological or pathological LVH. LA myocardial deformation is impaired in patients with hypertension compared with age-matched sedentary controls and elite athletes, and is closely associated with functional capacity during effort.
Short intensive exercise increases the migratory activity of mesenchymal stem cells
Authors: Schmidt A , Bierwirth S , Weber S , Platen P , Schinköthe T , Bloch W
Published: December 2007

Background:

It is known that exercise increases the number of stem cells within the circulation; however, it has not been clear which cellular processes are responsible for this increase. To answer this question, we analysed the influence of athletes’ blood sera on human mesenchymal stem cells (MSC).

Methods:

Sera were taken before and after short intensive exercise. As cellular parameters of MSC proliferation, apoptosis and migratory activity were analysed.

Results:

A change in stimulation of proliferation or apoptosis was not seen after exercise. In contrast, the migratory activity of MSC was significantly increased after exercise. To identify potential factors that could be responsible for this effect, we also analysed the semiquantitative serum concentration of 120 cytokines. Of these factors brain-derived neurotrophic factor, cutaneous T-cell-attracting chemokine, epidermal growth factor receptor, glucocorticoid-induced tumour necrosis factor receptor ligand, growth-regulated oncogene-α, interleukin (IL)1a, IL6, IL8, IL15, pulmonary and activation-regulated chemokine and soluble tumour necrosis factor receptor II showed a significant increase whereas migration inhibitory factor howed a decrease in concentration after exercise.

Conclusions:

IL6 is known to stimulate migration in MSC. It is recognised that contracting skeletal muscles synthesise and release IL6 into the systemic circulation in response to exercise. We therefore hypothesise that there is a direct relationship between exercise, IL6 release and stem cell recruitment.
Extent and pattern of genetic differentiation within and between phenotypic populations ofLeymus chinensis(Poaceae) revealed by AFLP analysis
Authors: Gong Lei , Song Xinxin , Li Mu , Guo Wanli , Hu Lanjuan , Tian Qin , Yang Yunfei , Zhang Yufei , Zhong Xiaofang , Wang Deli , Liu Bao
Published: December 2007

The extent and pattern of genetic differentiation between two naturally occurring phenotypes, grey–green leaf (GGL) and yellow–green leaf (YGL), of Leymus chinensis (Trin.) Tzvel., which colonize distinct habitats in the Songnen Prairie in northeast China, were investigated by amplified fragment length polymorphism (AFLP) analysis. Twelve selected AFLP primer pairs amplified 593 reproducible bands, of which 148 (24.96%) were polymorphic among 69 individuals taken from three populations: two natural ones (YGL and GGL1) and one transplanted (GGL2). Cluster analysis based on the AFLP data categorized the plants into distinct groups that are in line with their phenotypes and population origins, thus denoting clear genetic differentiation between the two phenotypes. This, together with their adaptation to contrasting natural habitats, suggests that the two phenotypes probably represent stabilized ecotypes. The grouping was supported by multiple statistical analyses including Mantel’s test, principal coordinate analysis (PCOORDA), and analysis of molecular variance (AMOVA). The GGL phenotype harbors a higher level of within-population genetic diversity than YGL, possibly reflecting selection by habitat heterogeneity. Although GGL2 is largely similar to its original population (GGL1), further diversification since transplantation was evident. Sequence analysis of a subset of phenotype-specific or phenotype-enriched AFLP bands implicated diverse biological functions being involved in ecological adaptation and formation of the two phenotypes.
Morphological and anatomical development in the Vitaceae. X. Comparative ontogeny and phylogenetic implications ofCissus quadrangularisL.
Authors: Timmons Susan A. , Posluszny Usher , Gerrath Jean M.
Published: December 2007

Although the grape family, Vitaceae, is of great economic importance, there is little understanding of the relationships between and within the genera. Recent DNA-based phylogenies of the Vitaceae have disagreed with traditional classifications by grouping some Cissus species (e.g., Cissus antarctica Vent.) in a clade with Vitis species, while placing other Cissus species (e.g., Cissus quadrangularis L.) in a monophyletic clade. This study investigates Cissus phylogeny using epi-illumination light microscopy and histological ontogenetic comparisons of vegetative and reproductive characters of Vitis rotundifolia (Forssk.) Vahl, Vitis ‘Ventura’, Vitis riparia Michx., C. antarctica, and C. quadrangularis. Ten characters limited to the Cissus species (connection of stipules, precocious axillary bud initiation, prophyll growth not obviously unequal, timing of mature shoot architecture on axillary buds, lack of spiral inflorescence branching, absence of calyptra, petals closely enveloping anthers, large gynoecial disk, ovary buried in the disk, and production of copious amounts of nectar) support the traditional phylogenies: the monophyly of Vitis and the exclusion of Cissus species from Vitis. The comparison of C. antarctica (Vitis–Cissus clade) and C. quadrangularis (monophyletic Cissus clade) supports the division of Cissus into two clades based on supernumerary buds, stipule connectivity, uncommitted primordium shape, and inflorescence branching patterns.
Phylogenetic relationships among taxa in the Jahnulales inferred from 18S and 28S nuclear ribosomal DNA sequences
Authors: Campbell Jinx , Ferrer Astrid , Raja Huzefa A. , Sivichai Somsak , Shearer Carol A.
Published: December 2007

Jahnulales is an order of freshwater, lignicolous, bitunicate ascomycetes characterized by wide (10–40 μm), brown, septate hyphae, stalked and (or) sessile ascomata, ascomal walls of 2–6 layers of large cells, and 1-septate ascospores. A variety of ascospore modifications are represented among the species in the order, including wall roughening, gelatinous sheaths, appendages and (or) pads, and apical caps or spines. To clarify generic boundaries and phylogenetic relationships within the Jahnulales and to assess the taxonomic significance of various morphological characters, a molecular study was carried out using 18S and 28S rDNA sequence data from 15 species representing the four genera in the order. In addition, Brachiosphaera tropicalis Nawawi and Xylomyces chlamydosporus Goos, R.D. Brooks & Lamore, two mitosporic species that co-occur with Jahnula Kirschst., species and have wide (>10 μm), brown, septate hyphae were included in the study to determine whether these species are members of this order. Maximum likelihood analyses confirmed the monophyly of the Jahnulales and resolved four clades. Two robustly supported clades comprise the genera Aliquandostipite Inderb. and Megalohypha A. Ferrer & Shearer. A third well-supported clade encompassed species of Brachiosphaera , Jahnula , and Xylomyces . The fourth clade contained isolates of the type species of the genus Jahnula, Jahnula aquatica (Plöttn. & Kirschst.) Kirschst., and two other members of this genus, but this clade was weakly supported. Our data suggest that the presence of very wide, brown, septate hyphae is an important character defining the Jahnulales. Based on molecular and morphological data, we propose the transfer of Jahnula siamensiae Sivichai & E.B.G. Jones and Patescospora separans Abdel-Wahab & El-Shar. to Aliquandostipite and emend the description of the Jahnulales.
Characteristics of anArabidopsisglyoxylate reductase: general biochemical properties and substrate specificity for the recombinant protein, and developmental expression and implications for glyoxylate and succinic semialdehyde metabolism in planta
Authors: Hoover Gordon J. , Van Cauwenberghe Owen R. , Breitkreuz Kevin E. , Clark Shawn M. , Merrill A. Rod , Shelp Barry J.
Published: December 2007

Constitutive expression of an Arabidopsis thaliana (L.) Heynh cDNA (GenBank accession No. AY044183 ) in a succinic semialdehyde (SSA) dehydrogenase-deficient yeast ( Saccharomyces cerevisiae Hansen) mutant enables growth on γ-aminobutyrate and significantly enhances the accumulation of γ-hydroxybutyrate. In this report, the cDNA (designated hereinafter as AtGR1) was functionally expressed in Escherichia coli , and the recombinant protein purified to homogeneity. Kinetic analysis of substrate specificity revealed that the enzyme catalyzed the conversion of glyoxylate to glycolate (Km,glyoxylate= 4.5 μmol·L–1) as well as SSA to γ-hydroxybutyrate (Km, SSA= 0.87 mmol·L–1) via an essentially irreversible, NADPH-based mechanism. The enzyme had a 250-fold higher preference for glyoxylate than SSA based on the performance constants (kcat/Km), and with the exception of 4-carboxybenzaldehyde, at least a 100-fold higher preference for SSA than all other substrates tested (formaldehyde, acetaldehyde, butyraldehyde, 2-carboxybenzaldehyde, glyoxal, methylglyoxal, phenylglyoxal, phenylglyoxylate). In vitro assays of SSA reductase activity in cell-free extracts from Arabidopisis revealed its presence throughout the plant, although its specific activity was considerably higher in leaves at all developmental stages and in reproductive parts than in roots. It is proposed that the enzyme functions in redox homeostasis and the detoxification of both glyoxylate and SSA, in planta, resulting in the production of glycolate and γ-hydroxybutyrate, respectively.
Kinetic mechanism of a recombinantArabidopsisglyoxylate reductase: studies of initial velocity, dead-end inhibition and product inhibition
Authors: Hoover Gordon J. , Prentice Gerald A. , Merrill A. Rod , Shelp Barry J.
Published: December 2007

Kinetic analysis of substrate specificity revealed that a recombinant Arabidopsis protein catalyzes the conversion of glyoxylate to glycolate (Km,glyoxylate= 4.5 μmol·L–1) and succinic semialdehyde (SSA) to γ-hydroxybutyrate (Km, SSA= 0.87 mmol·L–1) via an essentially irreversible, NADPH-based mechanism. In this report, the enzyme was further characterized via initial-velocity, dead-end inhibition and product inhibition studies. The kinetic mechanism was ordered Bi Bi, involving the complexation of NADPH to the enzyme before glyoxylate or SSA, and the release of NADP+before glycolate or γ-hydroxybutyrate, respectively. It can be concluded that the enzyme functions as a NADPH-dependent glyoxylate reductase (EC 1.1.1.79) or possibly an aldehyde reductase (EC 1.1.1.2), and the kinetic mechanism involved is consistent with that found in members of both the aldo-keto reductase and 3-hydroxyisobutyrate dehydrogenase-related superfamilies of enzymes. Since NADP+was an effective competitive inhibitor with respect to NADPH (Ki= 1–3 µmol·L–1), it is proposed that the ratio of NADPH/NADP+regulates enzymatic activity in planta.
The 2003 Canadian Geotechnical Colloquium: Mechanistic interpretation and practical application of damage and spalling prediction criteria for deep tunnelling
Authors: Diederichs Mark S.
Published: December 2007

Spalling and strain bursting has long been recognized as a mechanism of failure in deep underground mines in hard rock and in deep infrastructure tunnels. The latter is a significant growth industry, particularly in Europe where subalpine base tunnels in excess of 10 m wide and dozens of kilometres long are being driven by tunnel boring machine (TBM) through alpine terrain at depths greater than 2 km. In more massive granitoid or gneissic ground, these tunnels have experienced significant spalling damage. En route to a practical predictive technique for this condition, the author utilizes a number of analytical and micromechanical tools to validate a simple empirical predictive model for tunnel spall initiation. The true nature of damage and of yield, as the result of extensile damage accumulation, in hard rocks is examined using these tools. Based on the resultant conceptual model, the author expands on the empirical damage threshold, using a spalling limit to differentiate stress paths that lead to crack propagation and spalling from those that incur stable microdamage prior to conventional shear failure at higher relative confinements. Finally, the composite and robust in situ yield model is applied to nonlinear modelling for support design.
Long-term investigation of a deep-seated creeping landslide in crystalline rock. Part I. Geological and hydromechanical factors controlling the Campo Vallemaggia landslide
Authors: Bonzanigo L. , Eberhardt E. , Loew S.
Published: December 2007

Slope movements of the deep-seated Campo Vallemaggia landslide in the southern Swiss Alps have been reported for over 200 years. Surface and borehole investigations of the unstable mass reveal an up to 300 m deep complex structure incorporating 800 million cubic metres of disturbed metamorphic rocks divided into blocks along primary fault zones. An average slide velocity of approximately 5 cm/year can be calculated from various monitoring data recorded between 1892 and 1995. Block movements primarily involve mechanisms relating to multiple shear surfaces, but in cases where slide blocks are constrained by other blocks, creep deformations are observed. Borehole investigations revealed the presence of artesian water pressures, which when integrated with inclinometer and surface geodetic data, helped to provide key insights into the underlying instability mechanisms. This paper reports the findings of an extensive mapping, geophysical, and monitoring investigation carried out over a 20 year period. Results from the analysis are presented with respect to the hydromechanical factors controlling the unstable mass, the significance of which were instrumental in resolving conflicts with regards to the slope mitigation measures required to stabilize the slope. In Part II (see companion paper, this issue), the stabilization works performed at Campo Vallemaggia and their effectiveness are presented.
Base load – displacement response of piles in sand
Authors: Gavin Kenneth , Lehane Barry
Published: December 2007

The paper presents the results of a series of laboratory and field model pile tests performed to study the factors controlling the base pressure – settlement reponse of piles in sand. One series of tests involved the installation and load testing of steel open- and closed-ended piles in loose sand contained in a large pile testing chamber. A second series involved tests on open- and closed-ended steel piles and a concrete bored pile at a dense sand test bed site. The experiments were designed to investigate the effects of pile type, sand consistency, and installation resistance on a pile’s base response during static loading. The tests revealed that both the base capacity and stiffness of piles in sand are controlled by the degree of prestress imposed on the soil below the pile tip. Simple expressions, which require the small strain stiffness and cone penetration test data as the input parameters, are developed to predict the base pressure – settlement response. The final part of the paper employs other field tests on full-scale displacement piles and bored piles to verify the validity of the proposed approach.
Indirect methods to assess the solid particle thermal conductivity of Quebec marine clays
Authors: Côté Jean , Konrad Jean-Marie
Published: December 2007

Thermal and frost action analyses in soils require the knowledge of the thermal conductivity of soil solid particles. This parameter was obtained using reverse modeling applied to thermal conductivity data of Quebec marine clays. Values ranged from 2.2 to 3.2 W/mK mostly due to variation of the quartz fraction. The mean thermal conductivity of forming minerals other than quartz was equal to 2.15 W/mK. A modified geometric mean model was thus proposed to estimate the thermal conductivity of clay solid particles based on the thermal conductivity of quartz and the mean thermal conductivity of the other minerals. Several data for soils in the literature were also analyzed to confirm the experimental results of this study and to further clarify the quartz fraction influence on the thermal conductivity of clay particles. Finally, analyses of basic geotechnical data from the literature helped establish empirical relationships for the estimation of the quartz fraction of a soil as a function of either the clay-size particle fraction or the liquid limit.
Assessment of the self-desiccation process in cemented mine backfills
Authors: Helinski Matthew , Fourie Andy , Fahey Martin , Ismail Mostafa
Published: December 2007

During the placement of fine-grained cemented mine backfill, the high placement rates and low permeability often result in undrained self-weight loading conditions, when assessed in the conventional manner. However, hydration of the cement in the backfill results in a net volume reduction—the volume of the hydrated cement is less than the combined volume of the cement and water prior to hydration. Though the volume change is small, it occurs in conjunction with the increasing stiffness of the cementing soil matrix, and the result in certain circumstances can be a significant reduction in pore-water pressure as hydration proceeds. In this paper, the implications of this phenomenon in the area of cemented mine backfill are explored. An analytical model is developed to quantify this behaviour under undrained boundary conditions. This model illustrates that the pore-water pressure change is dependent on the amount of volume change associated with the cement hydration, the incremental stiffness change of the soil, and the porosity of the material. Experimental techniques for estimating key characteristics associated with this mechanism are presented. Testing undertaken on two different cement–minefill combinations indicated that the rate of hydration and volumes of water consumed during hydration were unique for each cement–tailings combination, regardless of mix proportions.
Chemical vapor deposition of nickel-group metals on multiwall carbon nanotubes
Authors: Feng Maoqi , Puddephatt Richard J
Published: December 2007

Chemical vapor deposition (CVD) of Ni, Pd, and Pt films and of Ni/Pd and Pd/Pt bimetallic films on multiwall carbon nanotubes (MWCNTs) can be effected at low temperature if the nanotubes are pretreated by CVD of titanium carbide. In the absence of the pretreatment, the CVD leads to formation of isolated nanoparticles of the nickel-group metals. The metallized MWCNTs are curved or kinked, as a result of the interaction with the metal. Preliminary oxidation of the carbon nanotubes allows easier metallization, and the bending of the metallated nanotubes is not observed in this case.Key words: Chemical vapor deposition, platinum, palladium, nickel, carbon, nanotube.
Synthesis and characterization of fluorinated phosphonium ionic liquids
Authors: Tindale Jocelyn J , Na Chris , Jennings Michael C , Ragogna Paul J
Published: December 2007

A wide variety of phosphonium ionic liquids containing fluorous ponytails Rfn (Rfn = –(CF2)n–1CF3; n = 4, 6, 10) are synthesized by the reaction of Rfn-(CH2)2-I with trialkylphosphines (R3P; R = Me, nBu, nOct). The efficacy of multiple metathetical routes to anion exchange have been investigated, thus the corresponding BF4–, PF6–, tosylate (OTs–) and triflate (OTf–) derivatives have also been prepared. All compounds have been comprehensively characterized by multinuclear NMR spectroscopy, ESI-MS, DSC, and TGA/SDTA, and in the case of [Me3PCH2CH2Rf4][I] by single crystal X-ray diffraction. These materials range from high melting solids (e.g., [Me3P(CH2)2Rf4][I] Tm = 195 °C) to very low melting liquids (e.g., [nOct3P(CH2)2Rf4][OTf] Tg = –64 °C), and they all have high thermal decomposition points (295 to 394 °C). Incorporation of the more weakly coordinating BF4– and PF6– yielded a significant increase in the melting point of the materials, in contrast to OTf– and OTs– derivatives, which all exhibited significantly depressed melting points.Key words: phosphonium ionic liquids, alternative solvents, fluorine, phosphorus, fluorous ponytails.
The chemical characterization of tribofilms using XANES — Interaction of nanosize calcium-containing detergents with zinc dialkyldithiophosphate
Authors: Yu L G , Yamaguchi E S , Kasrai M , Bancroft G M
Published: December 2007

A Plint friction and wear tester was used to investigate the effect of several calcium-containing detergents on the tribological and tribochemical performance of a zinc dialkyldithiophosphate (ZDDP) lubricating oil additive in a low-sulfur base stock, 100N. Thus, the friction and wear behavior of a steel-on-steel contact lubricated by 100N oil containing ZDDP alone and ZDDP–detergent mixtures at 100 °C was evaluated in a pin-on-disc configuration. The wear scar width of the upper steel pins was determined using an optical microscope, while the tribofilms formed on the lower steel discs were analyzed using X-ray absorption near edge structure (XANES) spectroscopy and X-ray photoelectron spectroscopy (XPS). At the same time, the thermal-oxidation films of the oil blends containing different additives were also prepared on the same steel discs and analyzed using XANES spectroscopy for comparative studies. It was found that in simple formulations the three kinds of calcium-containing detergents improved the friction-reducing and antiwear abilities of the 100N base stock. This was related to the individual tribochemical reactions and the deposition (in one case) of nanosized CaCO3 on the rubbing steel surface, indicating that the calcium-containing detergent had a synergistic antiwear performance with the ZDDP tested in the present work. Moreover, the calcium-containing detergents contributed to retarding the thermo-oxidation and friction-induced decomposition of ZDDP in 100N oil and influenced the composition and thickness of the tribofilms, which could be dependent on the molecular structures of the detergents and directly related to the tribochemistry of ZDDPs in mineral oil. The rubbing of the steel–steel pair at 100 °C was more beneficial for the deposition of nanosized calcium carbonate on the steel surface than heating at 150 °C. The calcium-containing detergents alone in the base stock also experienced tribochemical reactions, leading to obvious changes in the oxidation state of S in the corresponding tribofilms. Therefore, it was supposed that the tribochemical reactions of the ZDDP and detergents together with the deposition of nanosized CaCO3 on the rubbing steel surfaces accounted for the good antiwear performance of the blended oils.Key words: ZDDP, detergent, thermal film, tribofilm, tribochemistry, XANES, XPS.