bluuebunny/crossref_metadata_2025 huggingface dataset:
Muscle‐derived stem cells used to treat skin defects prevent wound contraction and expedite reepithelialization
Authors: Buján Julia , Pascual Gemma , Corrales Celia , Gómez‐Gil Verónica , Garcia‐Honduvilla Natalio , Bellón Juan M.
Published: April 2006

Stem cells derived from adult tissues may serve as cell therapy to enhance the healing process in skin wounds. This study was designed to evaluate the use of autologous muscle‐derived stem cells in an experimental skin wound model in terms of their efficiency at promoting tissue repair/regeneration. Muscle‐derived cells obtained from the dorsal muscle of New Zealand rabbits were cultured in vitro for 2 weeks. The cell population was identified using the satellite markers CD34, m‐cadherin and Myf5, and the proliferative capacity of the adult stem cells was determined. The population was then fluorescently labeled with PKH26 and seeded onto a circular 2 cm diameter defect created on the dorsal side of the ear of the rabbit from which the cells had been harvested. Similar defects on the contra lateral ears were left untreated to form the control group. Fourteen days later, specimens were taken for light, transmission, and scanning electron microscopy, as well as for immunolabeling with antibodies against vimentin, α‐actin, desmin, myosin, fibronectin, and cytokeratin 14. Areas of wound contraction and reepithelialization were determined by image analysis. Wound contraction was significantly greater in the control than the treatment group (p<0.05); control specimens also showed more myosin expression. Reepithelialized areas were significantly greater in the treatment group (p<0.05). Control wounds showed nonepithelialized areas and inflammatory granulation tissue. Reepithelialization occurred as epidermal tongues of fusiform cells. Our findings indicate that the use of autologous stem cells on skin wounds expedites and improves the organism's natural healing process.
Embryo production in a parthenogenetic snail (Potamopyrgus antipodarum) is negatively affected by the presence of other parthenogenetic females
Authors: Neiman Maurine
Published: April 2006

Abstract. Stimuli associated with copulatory behavior are often needed to maximize reproductive output in internally fertilized sexual taxa. Although non‐pseudogamous parthenogenetic females have no need for sperm, parthenogens descended from sexual ancestors may still require copulatory stimuli to reach their full reproductive potential. Retention of physiological dependence on copulation in parthenogens could facilitate the maintenance of sexual reproduction in species where sexual and parthenogenetic individuals coexist if parthenogens do not receive enough copulatory stimuli to achieve maximal daughter production. A laboratory experiment was conducted to determine whether embryo production in parthenogenetic female snails (Potamopyrgus antipodarum) is dependent on male presence. Rather than male presence, this experiment showed that embryo production is affected by the number of coexisting parthenogens. Specifically, parthenogens housed with fewer other parthenogens produced significantly more embryos than parthenogens housed with a greater number of other parthenogens, regardless of male presence and total population size. This result indicates that copulatory dependence is not likely to contribute to the maintenance of sex in P. antipodarum. Instead, it demonstrates that females of P. antipodarum negatively affect each other's reproduction, and suggests that females of P. antipodarum may exert a larger competitive influence than males of P. antipodarum. Moreover, this finding raises the possibility that highly parthenogenetic and consequently female‐dense populations of P. antipodarum may experience decreased reproductive output when population size is large and resources are limiting.
THERMAL PROCESS CALCULATION USING ARTIFICIAL NEURAL NETWORKS AND OTHER TRADITIONAL METHODS
Authors: GONÇALVES ELIANE CALOMINO , MINIM LUIS ANTONIO , COIMBRA JANE SÉLIA DOS REIS , MINIM VALÉRIA PAULA RODRIGUES
Published: April 2006

This work aimed to develop a method of thermal process calculation of canned food based on an artificial neural network and to compare it to the traditional Ball and Stumbo methods. A back‐propagation through time network was used as a model of heat conduction occurring in canned food, in order to predict the cold point temperature as a function of the autoclave and the initial product temperature. For training the network, a dataset of the cold point and retort temperature along time was obtained by processing a paste‐based product in autoclave. The network architecture (5‐8‐9‐1) was selected, presenting an excellent generalization capacity, with a mean relative error of 2.2% between the calculated F‐values of the observed and predicted time–temperature data. The Ball and Stumbo methods presented higher errors as the retort temperature was not constant. Neural network showed a great potential for online process calculation by having advantages such as precision and simplicity.
Signalling during hypoxia in human T lymphocytes – critical role of the src protein tyrosine kinase p56Lck in the O2 sensitivity of Kv1.3 channels
Authors: Szigligeti Peter , Neumeier Lisa , Duke Eugene , Chougnet Claire , Takimoto Koichi , Lee Susan Molleran , Filipovich Alexandra H. , Conforti Laura
Published: April 2006

T lymphocytes encounter hypoxia when they migrate to pathological sites such as tumours and wounds. The inability of T cells to provide an efficient defence at these sites can in part be explained by the hypoxic environment. Kv1.3 channels, important components of the T cell activation process are inhibited by hypoxia and their inhibition accounts for a hypoxia‐induced decrease in T cell proliferation. Although Kv1.3 channels play a key role in T cell O2 sensing, the signalling mechanisms mediating their response to hypoxia are still not understood. In this study, we show that the src‐protein tyrosine kinase p56Lck (Lck) is required for Kv1.3 channel response to hypoxia. Pre‐exposure to the src inhibitor PP2 abolished the hypoxia‐induced inhibition of Kv1.3 channels in primary human T lymphocytes. Moreover, Kv1.3 channel sensitivity to hypoxia was lost in Lck‐deficient Jurkat T cells. Further studies with recombinant Kv1.3 channels showed that Kv1.3 channels lack intrinsic O2 sensitivity, but delivery of Lck into the cells and transfection of a constitutively active Lck (Y505FLck) restored their sensitivity to hypoxia. Although Lck is necessary for the Kv1.3 channel response to hypoxia, it does not directly inhibit Kv1.3 channels. Indeed, under normal oxygen tension, delivery of active Lck into L929 cells and overexpression of Y505FLck did not decrease recombinant Kv1.3 currents. On the contrary, activation of endogenous src kinases increased wild‐type Kv1.3 currents in T lymphocytes. Our findings indicate that Lck is required for the acute response to hypoxia of human T lymphocytes as it is necessary to confer O2 sensitivity on Kv1.3 channels.
Hot-wire chemical-vapor-deposited nanometer range a-SiC:H diffusion barrier films for ultralarge-scale-integrated application
Authors: Singh S. K. , Kumbhar A. A. , Dusane R. O. , Bock W.
Published: April 2006

Hydrogenated amorphous silicon-carbon alloy thin films (a-SiC:H) deposited from C2H2 and SiH4 by the hot-wire chemical-vapor deposition (HWCVD) technique on low-k hydrogen silsesquioxane (HSQ) layers show effective barrier properties against Cu diffusion. These a-SiC:H films with different thicknesses were deposited on HSQ films and the leakage current in a metal-insulator-semiconductor device structure such as Cu∕a-SiC:H∕HSQ∕Si∕Al was determined. It was observed that HWCVD a-SiC:H acts as a very efficient diffusion barrier layer on HSQ with an effective dielectric constant of the combined stack much lower than that of SiO2. Secondary-ion-mass spectroscopy analysis indicates that an a-SiC:H film of less than 10 nm would provide the desired barrier effect.
Impact of supercritical CO2 drying on roughness of hydrogen silsesquioxane e-beam resist
Authors: Küpper Daniel , Küpper David , Wahlbrink Thorsten , Henschel Wolfgang , Bolten Jens , Lemme Max C. , Georgiev Yordan M. , Kurz Heinrich
Published: April 2006

Surface roughness (SR) and, especially, the closely related line-edge roughness (LER) of nanostructures are important issues in advanced lithography. In this study, the origin of surface roughness in the negative tone electron resist hydrogen silsesquioxane is shown to be associated with polymer aggregate extraction not only during resist development but also during resist drying. In addition, the impact of exposure dose and resist development time on SR is clarified. Possibilities to reduce SR and LER of nanostructures by optimizing resist rinsing and drying are evaluated. A process of supercritical CO2 resist drying that delivers remarkable reduction of roughness is presented.
Study of two-dimensional B doping profile in Si fin field-effect transistor structures by high angle annular dark field in scanning transmission electron microscopy mode
Authors: Garcia-Gutierrez D. I. , Jose-Yacaman M. , Khajetoorians A. A. , Shih C. K. , Wang X.-D. , Pham D. , Celio H. , Diebold A.
Published: April 2006

High angle annular dark field in scanning transmission electron microscopy mode is used to characterize the two-dimensional B dopant profile of Si fin field-effect transistor nanostructures. We attribute the enhanced intensity in the images to the strain fields produced by the substitutional B atoms in the Si lattice. Two different doping cases were studied, with an increment in the ion dose level. The observed doping profiles were compared with scanning capacitance microscopy images and with computer simulations of the same structures. All results show excellent qualitative agreement. High resolution transmission electron microscopy, electron energy-loss spectroscopy, and energy-dispersive spectroscopy analyses were also performed on these samples and were instrumental in identifying Cu nanoparticle contamination in the prepared transmission electron microscopy samples.
Comparison of electrical and reliability performances of TiB2-, CrB2-, and W2B5-based Ohmic contacts on n-GaN
Authors: Khanna Rohit , Pearton S. J. , Ren F. , Kravchenko I. I.
Published: April 2006

Three different metal borides (TiB2, CrB2, and W2B5) were examined for the use in Ti∕Al∕boride∕Ti∕Au Ohmic contacts on n-type GaN and the reliability compared to the more usual Ti∕Al∕Ni∕Au metal scheme. The minimum specific contact resistance obtained was in the range of 10−5Ωcm2 with CrB2 and W2B5 and approximately an order of magnitude lower with TiB2. In all cases, the minimum contact resistance is achieved after annealing in the range of 700–900°C. The main current transport mechanism in the contacts after this annealing is tunneling as determined by the absence of any significant measurement temperature dependence to the contact resistance. The TiB2 and CrB2 contacts retain smooth morphology even after annealing at 1000°C. Auger electron spectroscopy depth profiling indicated that the formation of an interfacial TiNX layer is likely responsible for the Ohmic nature of the contact after annealing. All three boride-based contacts show lower contact resistance than Ti∕Al∕Ni∕Au after extended aging at 350°C.
Field-enhanced photoemission from metals and coated materials
Authors: Jensen Kevin L. , Feldman Donald W. , Moody Nathan A. , O’Shea Patrick G.
Published: April 2006

A model of photoemission from the surface of a metal coated with a submonolayer covering of an alkali or alkali earth coating and subjected to an applied field is developed and compared to experimental data of the quantum efficiency (QE) of cesium on tungsten and cesium on silver at various wavelengths. A method to determine the parameters needed in a Gyftopoulos-Levine model of work function for submonolayer coverage as well as an estimate of temperature rise as a function of laser intensity and pulse length for long pulses are given. The qualitative agreement is found to be good: significant differences in the quantitative comparison are found to be due to, first, the relaxation time in the QE model, evaluated from thermal conductivity data, which neglects the contribution of electron-electron scattering at higher energies, and, second, the quantum mechanical reflection for electrons with energies near the barrier maximum. The latter effect is investigated using a quantum distribution function approach to determine the potential barrier with and without a coating and, from it, the changes in the reflection probability.
Development of microfocused x-ray source by using carbon nanotube field emitter
Authors: Kawakita Kunihiko , Hata Koichi , Sato Hideki , Saito Yahachi
Published: April 2006

To develop a microfocused x-ray source, field emission properties of a bundle of multiwalled carbon nanotubes were investigated under an ordinary vacuum pressure of 5×10−7Torr for a practical use. Total emission current reached up to 1.3mA at an applied voltage of −7kV. An emitted electron beam was focused on a Cu anode by using a simple electrostatic lens and excited an x ray with the source size of less than 30μm. X-ray transmission images were taken as a preliminary demonstration for a microfocused x-ray source and clear images whose resolutions were nearly equal to the source size of x ray were easily obtained.
Microcathodoluminescence and electrical properties of GaN epitaxial layers grown on thick freestanding GaN substrates
Authors: Govorkov A. V. , Smirnov N. B. , Polyakov A. Y. , Markov A. V. , Voss Lars , Pearton S. J.
Published: April 2006

Microcathodoluminescence (MCL) spectra, MCL imaging, electron beam induced current imaging, capacitance-voltage (C-V) profiling, and deep level transient spectrum measurements with optical injection (ODLTS) were performed on 3-μm-thick GaN epilayers prepared by metal organic chemical vapor deposition on top of thick freestanding GaN crystals grown by hydride vapor phase epitaxy. The GaN substrates showed a dislocation density of around 5×106cm−2 near the back surface and ∼106cm−2 near the Ga surface on which the epitaxy was performed. Dislocations are revealed as broad dark spots in MCL spectra taken on (0001) surface and as dark broad lines on the cleaved surface. The structure of the GaN film is more complicated, showing a pattern of arrowheadlike features of alternating dark-bright contrast. MCL spectra taken in the dark and bright regions indicate that the shallow donors in the dark region are more heavily compensated. The carrier lifetime near defects is greatly reduced. ODLTS spectra of the films show the presence of well known hole traps with activation energy of 0.85eV often associated with the yellow luminescence band in GaN.
Quantum-Dot Spin-State Preparation with Near-Unity Fidelity
Authors: Atatüre Mete , Dreiser Jan , Badolato Antonio , Högele Alexander , Karrai Khaled , Imamoglu Atac
Published: April 2006

We have demonstrated laser cooling of a single electron spin trapped in a semiconductor quantum dot. Optical coupling of electronic spin states was achieved using resonant excitation of the charged quantum dot (trion) transitions along with the heavy-light hole mixing, which leads to weak yet finite rates for spin-flip Raman scattering. With this mechanism, the electron spin can be cooled from 4.2 to 0.020 kelvin, as confirmed by the strength of the induced Pauli blockade of the trion absorption. Within the framework of quantum information processing, this corresponds to a spin-state preparation with a fidelity exceeding 99.8%.
True Giants on Earth
Authors: Norman David
Published: April 2006

The Sauropods
. Evolution and Paleobiology.
Kristina A. Curry Rogers and Jeffrey A. Wilson, Eds.
. University of California Press, Berkeley, CA, 2005. 359 pp. $65, £41.95. ISBN 0-520-24623-3.

The contributors offer a scholarly overview of the biology and evolutionary history of the clade that contains the largest terrestrial vertebrates in Earth's history.
Male-Specific Coliphages as Indicators of Thermal Inactivation of Pathogens in Biosolids
Authors: Nappier Sharon P. , Aitken Michael D. , Sobsey Mark D.
Published: April 2006

Male-specific (F
+
) coliphages have been proposed as a candidate indicator of fecal contamination and of virus reduction in waste treatment. However, in this and earlier work with a laboratory thermophilic anaerobic digester, a heat-resistant fraction of F
+
coliphage populations indigenous to municipal wastewater and sludge was evident. We therefore isolated coliphages from municipal wastewater sludge and from biosolid samples after thermophilic anaerobic digestion to evaluate the susceptibility of specific groups to thermal inactivation. Similar numbers of F
+
DNA and F
+
RNA coliphages were found in untreated sludge, but the majority of isolates in digested biosolids were group I F
+
RNA phages. Separate experiments on individual isolates at 53°C confirmed the apparent heat resistance of group I F
+
RNA coliphages as well as the susceptibility of group III F
+
RNA coliphages. Although few F
+
DNA coliphages were recovered from the treated biosolid samples, thermal inactivation experiments indicated heat resistance similar to that of group I F
+
RNA phages. Hence, F
+
DNA coliphage reductions during thermophilic anaerobic digestion are probably related to mechanisms other than thermal inactivation. Further studies should focus on the group III F
+
RNA coliphages as potential indicators of reductions of heat-resistant pathogens in thermal processes for sludge treatment.
Abundance and Distribution of
Ostreococcus
sp. in the San Pedro Channel, California, as Revealed by Quantitative PCR
Authors: Countway Peter D. , Caron David A.
Published: April 2006

Ostreococcus
is a genus of widely distributed marine phytoplankton which are picoplanktonic in size (<2 μm) and capable of rapid growth. Although
Ostreococcus
has been detected around the world, little quantitative information exists on its contribution to planktonic communities. We designed and implemented a genus-specific TaqMan-based quantitative PCR (qPCR) assay to investigate the dynamics and ecology of
Ostreococcus
at the USC Microbial Observatory (eastern North Pacific). Samples were collected from 5 m and the deep chlorophyll maximum (DCM) between September 2000 and August 2002.
Ostreococcus
abundance at 5 m was generally <5.0 × 10
3
cells ml
−1
, with a maximum of 8.2 × 10
4
cells ml
−1
.
Ostreococcus
abundance was typically higher at the DCM, with a maximum of 3.2 × 10
5
cells ml
−1
. The vertical distribution of
Ostreococcus
was examined in March 2005 and compared to the distribution of phototrophic picoeukaryotes (PPE) measured by flow cytometry. The largest contribution to PPE abundance by
Ostreococcus
was ∼70% and occurred at 30 m, near the DCM. Despite its relatively low abundance, the depth-integrated standing stock of
Ostreococcus
in March 2005 was ∼30 mg C m
−2
. Our work provides a new technique for quantifying the abundance of
Ostreococcus
and demonstrates the seasonal dynamics of this genus and its contribution to picoeukaryote biomass at our coastal sampling station.
Development of a Quantitative Assay for Mycobacterial Endogenous Arabinase and Ensuing Studies of Arabinase Levels and Arabinan Metabolism in
Mycobacterium smegmatis
Authors: Dong Xu , Bhamidi Suresh , Scherman Michael , Xin Yi , McNeil Michael R.
Published: April 2006

Treatment of either
Mycobacterium tuberculosis
or
M. smegmatis
with ethambutol results both in inhibition of arabinan synthesis and in copious loss of previously formed arabinan from the cell wall. The loss of arabinan has been shown to be due to the action of an endogenous arabinase. To better understand this phenomenon, a quantitative assay for endogenous arabinase was developed. Using the assay it was determined that various subcellular fractions of
M. smegmatis
showed significant amounts of endogenous arabinase activity. Surprisingly, treatment with ethambutol yielded only minor changes in the amounts of endogenous arabinase activities. Endogenous arabinase was present in the cell wall, and consistently, incubation of the
M. smegmatis
cell wall in only buffer resulted in the release of arabinan, mimicking the effect of ethambutol on whole cells. To determine if cell wall arabinan is rapidly turned over, the arabinan was labeled in the early log phase of culture by feeding [
14
C]glucose, followed by a “chase” with nonradioactive glucose. Most of the labeled arabinan remained in the cell wall after the culture was grown to late log phase. Thus, there is active arabinase in the cell wall, but arabinan is not rapidly removed unless ethambutol is present. Purification of the endogenous arabinase, using the assay described, is ongoing to help further discern its biological function.
Fluorescence In Situ Hybridization and Spectral Imaging of Coral-Associated Bacterial Communities
Authors: Ainsworth T. D. , Fine M. , Blackall L. L. , Hoegh-Guldberg O.
Published: April 2006

Microbial communities play important roles in the functioning of coral reef communities. However, extensive autofluorescence of coral tissues and endosymbionts limits the application of standard fluorescence in situ hybridization (FISH) techniques for the identification of the coral-associated bacterial communities. This study overcomes these limitations by combining FISH and spectral imaging.
Diversity and Distribution of
Planctomycetes
and Related Bacteria in the Suboxic Zone of the Black Sea
Authors: Kirkpatrick John , Oakley Brian , Fuchsman Clara , Srinivasan Sujatha , Staley James T. , Murray James W.
Published: April 2006

Samples from six depths of the Black Sea's suboxic zone were analyzed for 16S rRNA gene sequence information. A gradient in phylotype diversity was found. The distributions of known
an
aerobic
amm
onium
ox
idation (anammox) bacteria, many unknown
Planctomycetes
, and other phylotypes were examined in relation to the local nutrient and redox conditions.
Rapid, Field-Adapted Indirect Enzyme-Linked Immunosorbent Assay for Detection of Antibodies in Bovine Whole Blood and Serum to
Brucella abortus
Authors: Gall D. , Nielsen K. , Yu W. , Smith P.
Published: April 2006

A simple, rapid, field-adapted indirect enzyme-linked immunoassay (FldELISA) for the detection of antibodies to
Brucella abortus
in whole blood and serum has been developed. This assay detects antibodies to
B. abortus
in approximately 15 min or less. Over a 3-month period, this assay has consistently identified immunized and nonimmunized animals, while the percent coefficient of variation for each immunized animal has been less than 20%. As with any indirect enzyme-linked immunoassay, quality control can be established and maintained. Using defined positive and negative sera, the sensitivity and specificity of the FldELISA was 100% and 94.2%, respectively. As a model, this test can be readily extended to other disease applications that use lipopolysaccharide or other stable antigens for the detection of antibodies, such as those to
Salmonella
spp.,
Escherichia coli
, or
Yersinia
spp.
Immunoglobulin G Subclass Response to a Meningococcal Quadrivalent Polysaccharide-Diphtheria Toxoid Conjugate Vaccine
Authors: Findlow Helen , Southern Jo , Mabey Lesley , Balmer Paul , Heyderman Robert S. , Auckland Cressida , Morris Rhonwen , Miller Elizabeth , Borrow Ray
Published: April 2006

Changes in the immunoglobulin G1 (IgG1)/IgG2 ratio following vaccination can indicate the activation of cellular control mechanisms typical of a T-cell-dependent response. We examined IgG subclass ratios in 17 healthy adults (26 to 55 years of age) before and 4 to 6 weeks following immunization with a quadrivalent meningococcal-polysaccharide diphtheria toxoid conjugate vaccine against serogroups A, C, Y, and W135. Serologic responses were determined by serum bactericidal antibody assay and serogroup-specific IgG, IgG1, and IgG2 enzyme-linked immunosorbent assay. Prevaccination serogroup A-specific IgG1/IgG2 ratios were <1 for all subjects and differed by subject for C, Y, and W-135. Postvaccination, significant increases in IgG, IgG1, and IgG2, were observed for all serogroups. Serogroup-specific IgG1/IgG2 ratios increased for group A (14/17 subjects, 88%), decreased in more than half of subjects for groups C (9/17, 53%) and W135 (12/17, 71%) and decreased for serogroup Y (16/17, 94%). IgG1/IgG2 ratios differed between individual vaccinees and were similar to the responses of adults who received pneumococcal conjugate vaccines or a monovalent C conjugate vaccine. Further studies on IgG subclasses following meningococcal polysaccharide and conjugate vaccination are needed.
Serological Detection of Human Papillomavirus Type 16 Infection in Human Immunodeficiency Virus (HIV)-Positive and High-Risk HIV-Negative Women
Authors: Silverberg Michael J. , Schneider Michael F. , Silver Barbara , Anastos Kathryn M. , Burk Robert D. , Minkoff Howard , Palefsky Joel , Levine Alexandra M. , Viscidi Raphael P.
Published: April 2006

Serial measurement of antibodies has not been used to provide evidence of active viral replication of human papillomavirus (HPV). Serum specimens from sequential study visits contributed by 642 human immunodeficiency virus (HIV)-positive and 116 HIV-negative participants enrolled in the Women's Interagency HIV Study were used to detect significant rises in HPV type 16 (HPV-16) antibody levels. Factors associated with a significant rise were identified using multivariable logistic regression models with generalized estimating equations. Among HIV-positive women, 8.3% of 1,997 pairs showed antibody rises, compared to 6.1% of 361 pairs among HIV-negative women (P= 0.191). For HIV-positive women, rises were associated with current (odds ratio [OR], 23.4;P< 0.001) or past (OR, 8.9;P< 0.001) HPV-16 infection relative to never being HPV-16 infected and with CD4+cell counts (OR per 100-cell increase, 0.8;P< 0.001) but not with sexual behavior. For HIV-negative women, rises were associated with past (OR, 10.9;P= 0.033) HPV-16 infection relative to no HPV-16, current cigarette smoking (OR, 5.0;P= 0.029) relative to no smoking history, and having 6 to 10 lifetime sexual partners compared to 0 to 5 partners (OR, 9.9;P= 0.036). Serial measurement of HPV-16 serum antibodies is a useful tool for identifying active HPV-16 viral replication. Rises among HIV-positive women may more often result from reactivation of a latent HPV infection in the context of HIV-induced immunosuppression, while rises among HIV-negative women may more often result from reinfection with HPV.
A Decrease in the Immunoglobulin G Antibody Response against the VlsE Protein of
Borrelia burgdorferi
Sensu Lato Correlates with the Resolution of Clinical Signs in Antibiotic-Treated Patients with Early Lyme Disease
Authors: Marangoni Antonella , Sambri Vittorio , Accardo Silvia , Cavrini Francesca , Mondardini Valeria , Moroni Alessandra , Storni Elisa , Cevenini Roberto
Published: April 2006

The purpose of this study was to evaluate the diagnostic performance of the LIAISON Borrelia Screen (Diasorin, Saluggia, Italy), a new automated immunoassay based on the chemiluminescent technology (chemiluminescence immunoassay). To assess whether a decrease in a negative value in the anti-VlsE immunoglobulin G (IgG) antibody titer was correlated with a positive response to treatment, a group of serially collected serum samples from 67 patients with culture-confirmed erythema migrans was retrospectively studied. All the patients had been treated with antibiotics and were free of disease within 3 to 6 months of follow-up. All the 15 patients who were found to be IgG positive at the time of enrollment and who were bled at least four times during the follow-up became IgG seronegative at 2 to 6 months posttreatment. These results indicate that a decline in the anti-VlsE antibody titer coincides with effective antimicrobial therapy in patients with early localized Lyme disease.
Phylogenetic Lineages of Invasive and Colonizing Strains of Serotype III Group B Streptococci from Neonates: a Multicenter Prospective Study
Authors: Lin Feng-Ying C. , Whiting April , Adderson Elisabeth , Takahashi Shinji , Dunn Diane Marie , Weiss Robert , Azimi Parvin H. , Philips Joseph B. , Weisman Leonard E. , Regan Joan , Clark Penny , Rhoads George G. , Frasch Carl E. , Troendle James , Moyer Patricia , Bohnsack John F.
Published: April 2006

This study compares the phylogenetic lineages of invasive serotype III group B streptococci (GBS) to those of colonizing strains in order to determine lineages associated with invasive disease. Isolates from 29 infants with early-onset disease (EOD) and from 196 colonized infants, collected in a prospective, multicenter study, were assigned a sequence type (ST) by multilocus sequence typing. Overall, 54.5% of the isolates were in the ST-19 complex, and 40.4% were in the ST-17 complex. Invasive strains were more likely to be in the ST-17 complex than were colonizing strains (59% versus 38%,
P
= 0.03). After we adjusted for potential confounders, the ST-17 complex was more likely to be associated with EOD than were other lineages (odds ratio = 2.51, 95% confidence interval = 1.02 to 6.20). These data support the hypothesis that ST-17 complex GBS are more virulent than other serotype III GBS.
Evaluation of the COBAS AmpliPrep-Total Nucleic Acid Isolation-COBAS TaqMan Hepatitis B Virus (HBV) Quantitative Test and Comparison to the VERSANT HBV DNA 3.0 Assay
Authors: Ronsin Christophe , Pillet Anne , Bali Corinne , Denoyel Gérard-Antoine
Published: April 2006

Quantitative detection of hepatitis B virus (HBV) in serum or plasma has become the most direct and reliable method for monitoring chronic hepatitis B. Here, we report the performance characteristics of a real-time PCR hepatitis B DNA quantitative assay, the COBAS TaqMan (CTM) HBV test (Roche Diagnostics, Meylan, France), in combination with an automated DNA extraction on the COBAS AmpliPrep (CAP) instrument using the total nucleic acid isolation kit (TNAI kit), a generic reagent for nucleic acid isolation (both from Roche Diagnostics). The linearity, accuracy, and specificity of the CAP-TNAI-CTM HBV test were evaluated using various reference panels and standards (HBV panel 2004 from Quality Control for Molecular Diagnostics, OptiQuant HBV panel from AcroMetrix, WHO International Standard for HBV, and Teragenix hepatitis B genotype panel). Quantitative results show that the CAP-TNAI-CTM HBV test performed well with respect to linearity, accuracy, and reproducibility from at least 100 to 500,000 HBV DNA IU/ml. Based on the log
10
IU of HBV DNA/ml measured, the intra-assay variation ranged from 2.49% to 8.46% and the interassay variation ranged from 1.88% to 7.83%. The test was extremely sensitive and could detect samples containing HBV DNA below the reported quantification threshold (<30 IU/ml). All HBV genotypes were correctly amplified, and no cross-contamination occurred during the automated sample preparation. In addition, 402 human serum samples were tested comparatively to the VERSANT HBV DNA 3.0 assay (bDNA; Bayer Diagnostics, Puteaux, France). The viral load results of the CAP-TNAI-CTM test and bDNA were significantly correlated, but the agreement between the two tests was poor, with large differences between results for individual samples. The hands-on time was estimated to be reduced from 2.30 h with bDNA to 45 min with the CAP-TNAI-CTM test, and up to 84 samples were completely processed within a working day. Overall, the performance characteristics of the CAP-TNAI-CTM test demonstrated that it provides a high-throughput sensitive and reliable method for quantitation of HBV DNA levels in the routine molecular laboratory.
Preparation and Conformational Study of 19β,28-Epoxy-18α-olean-5-ene Derivatives
Authors: Dračínský Martin , Richtr Václav , Křeček Václav , Sejbal Jan , Klinot Jiří , Buděšínský Miloš
Published: April 2006

New oleanane type triterpenoids with the 5(6) double bond were prepared using partial demethylation on carbon C-4. The starting compound was 23-hydroxybetulin (1b) and the key reaction was the methylation of 19β,28-epoxy-24-nor-18α-olean-4-en-3-one (3b). The 5(6) double bond was used in preparation of new derivatives with an epoxy or oxo substituent in ring B. The conformation of ring A of new type 3-oxo oleanane derivatives with a double bond or a substituent on ring B was elucidated from vicinal coupling constants of hydrogen atoms in positions 1 and 2.
AFluvioviridavis-like bird from the Middle Eocene of Messel, Germany
Authors: Mayr Gerald
Published: April 2006

A new avian taxon is described from the Middle Eocene of Messel in Germany. This bird closely resembles the Lower Eocene North American Fluvioviridavis platyrhamphus Mayr and Daniels, 2001. Eurofluvioviridavis robustipes n. gen. et sp. and F. platyrhamphus are classified in the new taxon Fluvioviridavidae. These birds exhibit a bauplan that is unknown among modern birds in combining a flycatcher-like beak with greatly abbreviated legs. Eurofluvioviridavis is distinguished from Fluvioviridavis by its much stronger toes, indicating that the new Messel species occupied a different ecological niche from its North American relative and that the Fluvioviridavidae were an ecologically diversified group in the Eocene. Despite their morphological distinctness, however, the phylogenetic affinities of the Fluvioviridavidae are still uncertain. Their phylogenetic affinities are evaluated in a cladistic analysis of 96 morphological characters, but the resulting position basal to a cluster of several modern higher level taxa is only weakly supported.
An expanded record of Early Cambrian carbon cycling from the Anti-Atlas Margin, Morocco
Authors: Maloof Adam C , Schrag Daniel P , Crowley James L , Bowring Samuel A
Published: April 2006

We present a δ13C record from the Anti-Atlas mountains of Morocco and place it in the context of a detailed regional tectonostratigraphy. We place the litho- and chemostratigraphic record in a temporal framework using precision UPb zircon geochronology of ashes interbedded with the same carbonate units that provide δ13C data. The variations in δ13C of carbonate occur on a wide range of time scales, suggesting that different mechanisms are involved, including non-steady state release of isotopically depleted carbon reservoirs on short (<100 000 years) time scales and changes in nutrient recycling and organic carbon burial on longer (≥1 Ma) time scales. Through a correlation with more fossiliferous, albeit condensed, sections in Siberia, we examine the pattern of cyclic δ13C variation in the context of the reappearance and diversification of skeletonized metazoa during the Early Cambrian.
Mapping lithology in Canada's Arctic: application of hyperspectral data using the minimum noise fraction transformation and matched filtering
Authors: Harris J R , Rogge D , Hitchcock R , Ijewliw O , Wright D
Published: April 2006

A test site in southern Baffin Island, Canada has been established to study the applications of hyperspectral data to lithological mapping. Good bedrock exposure and minimal vegetation cover provide an ideal environment for the evaluation of hyperspectral remote sensing. Airborne PROBE hyperspectral data were collected over the study site during the summer of 2000. Processing methods involved (1) applying a minimum noise fraction (MNF) transformation to the data and visual interpretation of a ternary colour MNF image to produce a lithologicalcompositional map, and (2) selection of end members from the MNF image followed by matched filtering based on the selected end members to produce a lithologicalcompositional map. Both methods have produced a lithological map that compares favourably with the existing geological map. Although lichen imparts a similarity to the spectra throughout the visible and near infrared and short-wave infrared ranges, this study has shown that enough variability in the spectra as a function of different mineralogy was present to successfully discriminate one major lithological group (metatonalites) and three compositional units (psammites, quartzites, and monzogranites). Vegetation could be clearly distinguished, which in this area only is a good proxy for mapping metagabbroic rocks. Furthermore, discrimination of slightly different compositional units within the psammites and the metatonalites was also possible. The results from this study indicate that hyperspectral remotely sensed imagery holds promise for lithological mapping in Canada's North, although further analysis is required in different geologic environments in Canada's North to validate hyperspectral remote sensing as a useful aid to litho logical mapping.
A Late Cretaceous (TuronianConiacian) high-latitude turtle assemblage from the Canadian Arctic
Authors: Brinkman Donald B , Tarduno John A
Published: April 2006

Three turtles are present in a TuronianConiacian age high-latitude vertebrate assemblage from Axel Heiberg Island: Borealochelys axelheibergensis gen. et sp. nov., a generically indeterminate eucryptodire, and a trionychid. The assemblage differs from most Late Cretaceous turtle assemblages from North America in that members of the Paracryptodira are absent. The absence of this group is interpreted as a result of latitudinal differentiation of turtle assemblages in North America during the Late Cretaceous. The level of diversity of turtles in the Axel Heiberg assemblage is comparable to that of mid-latitude assemblages associated with a mean annual paleotemperature of 14 °C, adding to the evidence for high mean annual temperatures at high latitudes during TuronianConiacian times.
Rostral structure in Thalattosauria (Reptilia, Diapsida)
Authors: Rieppel Olivier , Müller Johannes , Liu Jun
Published: April 2006

The rostral structure of thalattosaurs is reviewed on the basis of a re-investigation of the holotype of Nectosaurus halius and Thalattosaurus alexandrae. The askeptosaurid genera Askeptosaurus and Anshunsaurus share an elongated, parallel-sided rostrum that terminates in a blunt tip. A diastema separating the premaxillary from the maxillary teeth is absent. The claraziid genera Clarazia and Thalattosaurus share a relatively shorter rostrum that has convergent lateral margins and that terminates in a pointed tip. A diastema separating the premaxillary from the maxillary teeth is present. The well-preserved holotype of Nectosaurus halius shows a highly derived rostral structure. The maxilla is short with an anteriorly truncated (vertical) margin, a narrow but high ascending process, and a dorsally curving medial flange that is in natural articulation with the ventrally deflected vomer. These findings corroborate Peyer's original reconstruction of Hescheleria with a nearly vertically placed premaxilla.
Cretaceous fossil birds from Hornby Island (British Columbia)
Authors: Morrison Kurt , Dyke Gareth J , Chiappe Luis M
Published: April 2006

We present the first records of Mesozoic fossil birds to be described from British Columbia. New fossil avians from the Campanian Northumberland Formation on Hornby Island (Strait of Georgia) add to the known distributions of two groups of fossil birds during the latter stage of the Mesozoic. New specimens referred to the clades Ornithurae and Enantiornithes demonstrate the presence of a diverse marine avifauna in Canadian Pacific marine sediments prior to the CretaceousTertiary (KT) boundary. These new fossil bird remains from coastal rocks on the west coast of British Columbia lend further support to suggestions that ocean-going birds were important constituents of marine ecosystems in the terminal stages of the Mesozoic.
40Ar/39Ar dates on hornblende, muscovite, and biotite from the Mica Creek area, British Columbia: regional metamorphic and tectonic implications
Authors: Ghent Edward , Villeneuve Michael
Published: April 2006

A metamorphic high, the SelkirkMonasheeCariboo complex (SMC) is a 200 km × 60 km area cored by K-feldsparsillimanite rocks. In the Mica Creek area, there appear to be no discontinuities in metamorphic isograds, structural trends, or the Late Precambrian stratigraphic units. UPb dates suggested that the continuities may only be apparent. In this paper, we report 40Ar/39Ar dates on muscovite, biotite, and hornblende from some of the same samples dated by UPb and samples that crop out very close to the dated samples. The goal was to set constraints on the alternative interpretations of the metamorphicstructural history. These interpretations are as follows: (1) UPb ages record different times of metamorphic crystallization and deformation, and there are significant tectonic displacements; the mappable continuities are only apparent. (2) The structural and stratigraphic continuity is real, and the range is due to localized heating and deformation events spanning ~100 Ma; the relative uniformity of the 40Ar/39Ar dates over a distance of ~45 km suggests that the area behaved as a coherent cooling unit.
Genome size variation in the Artemisia arborescens complex (Asteraceae, Anthemideae) and its cultivars
Authors: Garcia Sònia , Garnatje Teresa , Twibell John D , Vallès Joan
Published: April 2006

Different wild Mediterranean populations of Artemisia arborescens from diverse locations representing its geographical distribution, as well as some of its well-known cultivars and some specimens cultivated as ornamentals in gardens, streets, roads and nurseries, were analysed for genome size. Other closely related species endemic to Macaronesia, Artemisia canariensis, Artemisia argentea, and Artemisia gorgonum, were also analysed, and their nuclear DNA amount has been related to the biogeography of this group of species. Additionally, 5 populations of the closely related Artemisia absinthium were analysed to establish comparisons. Measurements acquired by flow cytometry ranged from 8.29 to 11.61 pg for 2C values. Statistically significant differences of 2C nuclear DNA amounts with respect to factors such as insularity or domestication have been detected. However, quite a low intraspecific genome size variation has been found in these species. Furthermore, the study also addressed the possible hybrid origins and possible misidentifications of some of the supposed cultivars of A. arborescens.Key words: Artemisia arborescens, Artemisia absinthium, Artemisia argentea, Artemisia canariensis, Artemisia gorgonum, C value, Compositae, cultivar, domestication, flow cytometry, genome size, hybridization, interspecific variation, intraspecific variation, speciation.
Objective and subjective analysis of the training content in young cyclists
Authors: Delattre Emmanuelle , Garcin Murielle , Mille-Hamard Laurence , Billat Véronique
Published: April 2006

The purpose of this study was to analyse the objective and subjective training for young cyclists that is prescribed by their coaches. Seven cyclists performed an incremental exercise to exhaustion before and after 14 weeks of training using an incremental test to determine their maximal oxygen uptake (VO2 max), the velocity associated with VO2 max (vVO2max), and the velocity associated with the ventilatory threshold (vVT). Cyclists completed a training record with the actual content and the perceived exertion of each training session during these 14 weeks. We have focused on the actual content of the training prescribed by the coaches. Analysis of the content of each session allowed us to calculate the objective training load (volume at different intensities) and to determine the subjective training load from perceived exertion ratings (training load, monotony, strain, and fitness-fatigue). The results showed that cyclists were training at a relatively low intensity and that training rating of perceived exhaustion was weak. Moreover, after 14 weeks of training, VO2 max did not change whereas vVO2max and vVT increased significantly. Therefore, a discrepancy may exist between what is perceived during training and the effects of training. Consequently, objective and subjective indices collected from training books provided useful information supplementary to that recorded from the physiological indices alone.Key words: training load, training book, perceived exertion, performance.
The effect of a competitive season and environmental factors on pulmonary function and aerobic power in varsity hockey players
Authors: Game Alex B , Bell Gordon J
Published: April 2006

This study examined the effect of a competitive season and environmental factors on pulmonary function and aerobic power in varsity hockey players. Fourteen male subjects completed testing before and after a 7-month varsity hockey season within ice arena conditions. All subjects completed an aerobic power [Formula: see text]O2 max test on a cycle ergometer. Pulmonary function tests were performed at rest and 1, 10, 15, and 25 min after the [Formula: see text]O2 max test. The arena environment was monitored during testing and throughout the season for temperature, relative humidity, gaseous chemicals, moulds, and fungi. There was no change in [Formula: see text]O2 max during the season. The percent change in forced expiratory flow in 1 s (FEV1) post-exercise compared to resting FEV1 and forced vital capacity (FVC) after the [Formula: see text]O2 max test were significantly lower after the season. The arena temperature and relative humidity ranged between 13 and 16 °C and between 30% and 45% over the course of the season. Sulfur dioxide (0.7-4.5 ppm) was found in the arena and no airborne moulds unique to the dressing room environment were found to exceed Health Canada's guideline of 50 CFU/m3 for indoor air quality. It was concluded that some hockey players experience limitations to pulmonary function over the course of a competitive season. Key words: exercise-induced bronchospasm, exercise-induced hypoxaemia, air quality, mould, asthma.
Computational fluid dynamics application in modeling and improving the performance of a storage reservoir used as a contact chamber for microorganism inactivation
Authors: Baawain Mahad S , El-Din Mohamed Gamal , Smith Daniel W
Published: April 2006

This study explored the use of computational fluid dynamics (CFD) modeling approach to simulate two tracer studies conducted, in scaled-down physical models of an existing storage tank, to investigate the effect of tank configuration on the effective contact time (t10). One of the scaled-down physical models, of the storage tank, was equipped with one baffle wall at the middle length and the other was equipped with nine baffle walls distributed evenly along the reservoir length. A comparison between the experimental and modeled tracer concentration profiles showed an excellent agreement. The developed CFD model was then applied to different reservoir configurations for further investigation towards achieving t10 improvement. The use of seven small inlets and nine baffle walls resulted in extending the t10 from about 8 min to about 30 min (for a theoretical detention time, τ , of 32 min). Furthermore, using fewer baffle walls with different inlet arrangements enhanced the t10. Key words: microorganism inactivation, disinfection, computational fluid dynamics (CFD), modeling, effective contact time, storage reservoir hydraulics.