bluuebunny/crossref_metadata_2025 huggingface dataset:
3D MRI-Based Anisotropic FSI Models With Cyclic Bending for Human Coronary Atherosclerotic Plaque Mechanical Analysis
Authors: Tang Dalin , Yang Chun , Kobayashi Shunichi , Zheng Jie , Woodard Pamela K. , Teng Zhongzhao , Billiar Kristen , Bach Richard , Ku David N.
Published: May 2009

Heart attack and stroke are often caused by atherosclerotic plaque rupture, which happens without warning most of the time. Magnetic resonance imaging (MRI)-based atherosclerotic plaque models with fluid-structure interactions (FSIs) have been introduced to perform flow and stress/strain analysis and identify possible mechanical and morphological indices for accurate plaque vulnerability assessment. For coronary arteries, cyclic bending associated with heart motion and anisotropy of the vessel walls may have significant influence on flow and stress/strain distributions in the plaque. FSI models with cyclic bending and anisotropic vessel properties for coronary plaques are lacking in the current literature. In this paper, cyclic bending and anisotropic vessel properties were added to 3D FSI coronary plaque models so that the models would be more realistic for more accurate computational flow and stress/strain predictions. Six computational models using one ex vivo MRI human coronary plaque specimen data were constructed to assess the effects of cyclic bending, anisotropic vessel properties, pulsating pressure, plaque structure, and axial stretch on plaque stress/strain distributions. Our results indicate that cyclic bending and anisotropic properties may cause 50–800% increase in maximum principal stress (Stress-P1) values at selected locations. The stress increase varies with location and is higher when bending is coupled with axial stretch, nonsmooth plaque structure, and resonant pressure conditions (zero phase angle shift). Effects of cyclic bending on flow behaviors are more modest (9.8% decrease in maximum velocity, 2.5% decrease in flow rate, 15% increase in maximum flow shear stress). Inclusion of cyclic bending, anisotropic vessel material properties, accurate plaque structure, and axial stretch in computational FSI models should lead to a considerable improvement of accuracy of computational stress/strain predictions for coronary plaque vulnerability assessment. Further studies incorporating additional mechanical property data and in vivo MRI data are needed to obtain more complete and accurate knowledge about flow and stress/strain behaviors in coronary plaques and to identify critical indicators for better plaque assessment and possible rupture predictions.
Parametric Finite Element Analysis of Physical Stimuli Resulting From Mechanical Stimulation of Tissue Engineered Cartilage
Authors: Babalola Omotunde M. , Bonassar Lawrence J.
Published: May 2009

While mechanical stimulation of cells seeded within scaffolds is widely thought to be beneficial, the amount of benefit observed is highly variable between experimental systems. Although studies have investigated specific experimental loading protocols thought to be advantageous for cartilage growth, less is known about the physical stimuli (e.g., pressures, velocities, and local strains) cells experience during these experiments. This study used results of a literature survey, which looked for patterns in the efficacy of mechanical stimulation of chondrocyte seeded scaffolds, to inform the modeling of spatial patterns of physical stimuli present in mechanically stimulated constructs. The literature survey revealed a large variation in conditions used in mechanical loading studies, with a peak to peak strain of 10% (i.e., the maximum amount of deformation experienced by the scaffold) at 1 Hz on agarose scaffolds being the most frequently studied parameters and scaffold. This loading frequency was then used as the basis for simulation in the finite element analyses. 2D axisymmetric finite element models of 2×4 mm2 scaffolds with 360 modulus/permeability combinations were constructed using COMSOLMULTIPHYSICS software. A time dependent coupled pore pressure/effective stress analysis was used to model fluid/solid interactions in the scaffolds upon loading. Loading was simulated using an impermeable frictionless loader on the top boundary with fluid and solid displacement confined to the radial axis. As expected, all scaffold materials exhibited classic poro-elastic behavior having pressurized cores with low fluid flow and edges with high radial fluid velocities. Under the simulation parameters of this study, PEG scaffolds had the highest pressure and radial fluid velocity but also the lowest shear stress and radial strain. Chitosan and KLD-12 simulated scaffold materials had the lowest radial strains and fluid velocities, with collagen scaffolds having the lowest pressures. Parametric analysis showed maximum peak pressures within the scaffold to be more dependent on scaffold modulus than on permeability and velocities to depend on both scaffold properties similarly. The dependence of radial strain on permeability or modulus was more complex; maximum strains occurred at lower permeabilities and moduli, and the lowest strain occurred at the stiffest most permeable scaffold. Shear stresses within all scaffolds were negligible. These results give insight into the large variations in metabolic response seen in studies involving mechanical stimulation of cell-seeded constructs, where the same loading conditions produce very different results due to the differences in material properties.
Some Unwelcome Questions About Big Dams
Authors: Stone Richard
Published: May 2009

Soon after the magnitude-7.9 Wenchuan earthquake struck last May, geologist Fan Xiao asked: Could a large dam near the fault have triggered the devastating quake?
Science
spoke with Fan about his views.
Resistance Selection Studies Comparing the Activity of Razupenem (PTZ601) to Vancomycin and Linezolid against Eight Methicillin-Resistant and Two Methicillin-Susceptible
Staphylococcus aureus
Strains
Authors: Clark Catherine , Kosowska-Shick Klaudia , McGhee Pamela , Dewasse Bonifacio , Beachel Linda , Appelbaum Peter C.
Published: May 2009

Multistep and single-step resistance selection studies were performed with razupenem, linezolid, and vancomycin against 10 methicillin (meticillin)-resistant and -susceptible
Staphylococcus aureus
strains. After 20 daily subcultures, razupenem yielded only clones with MICs of >4 μg/ml in one strain (8 μg/ml) whose parent's MIC was already 4 μg/ml. After 18 to 49 passages in 6/10 strains, razupenem MICs rose from 0.016 to 2 μg/ml (parents) to 0.125 to 8 μg/ml (with clones stable after 10 drug-free subcultures). Single-step mutant selection frequencies were similarly low for razupenem and comparators.
NB-002, a Novel Nanoemulsion with Broad Antifungal Activity against Dermatophytes, Other Filamentous Fungi, and
Candida albicans
Authors: Pannu J. , McCarthy A. , Martin A. , Hamouda T. , Ciotti S. , Fothergill A. , Sutcliffe J.
Published: May 2009

NB-002 is an oil-in-water emulsion designed for use for the treatment of skin, hair, and nail infections. The activity of NB-002 was compared to the activities of the available antifungal drugs against the major dermatophytes responsible for cutaneous infections,
Trichophyton rubrum
,
Trichophyton mentagrophytes
,
Epidermophyton floccosum
, and
Microsporum
spp., as well as 12 other genera of filamentous fungi. NB-002 consistently displayed fungicidal activity against all dermatophytes. The comparator compounds were either fungistatic or fungicidal, and for some strain-drug combinations, tolerance was observed. Assessment of the development of spontaneous resistance to NB-002 in different dermatophyte species yielded few stably resistant mutants. For filamentous nondermatophyte fungi, the MIC range varied from 0.06 to 0.5 μg/ml for
Alternaria
spp. to 2 to 8 μg/ml for
Paecilomyes
spp. NB-002 had activity against both azole-susceptible and -resistant
Candida albicans
yeast isolates, with MIC
90
s of 2 μg/ml, respectively, and minimum fungicidal concentrations at which 90% of isolates are inhibited of 4 and 8 μg/ml, respectively. The kinetics of the fungicidal activity of NB-002 against
T. rubrum
isolates were compared to those of the other antifungal drugs. NB-002 killed both mycelia and microconidia even when the fungal forms were dormant or not actively growing. Electron micrographs of mycelia and spores treated with NB-002 showed the significant disruption of the fungal structure. The in vitro broad coverage of NB-002 against filamentous fungi, dermatophytes, and
C. albicans
, as well as its rapid fungicidal activity, warrants further investigations to ascertain if NB-002 would be useful for the treatment of cutaneous mycoses.
Population Pharmacokinetic Analysis of Colistin Methanesulfonate and Colistin after Intravenous Administration in Critically Ill Patients with Infections Caused by Gram-Negative Bacteria
Authors: Plachouras D. , Karvanen M. , Friberg L. E. , Papadomichelakis E. , Antoniadou A. , Tsangaris I. , Karaiskos I. , Poulakou G. , Kontopidou F. , Armaganidis A. , Cars O. , Giamarellou H.
Published: May 2009

Colistin is used to treat infections caused by multidrug-resistant gram-negative bacteria (MDR-GNB). It is administered intravenously in the form of colistin methanesulfonate (CMS), which is hydrolyzed in vivo to the active drug. However, pharmacokinetic data are limited. The aim of the present study was to characterize the pharmacokinetics of CMS and colistin in a population of critically ill patients. Patients receiving colistin for the treatment of infections caused by MDR-GNB were enrolled in the study; however, patients receiving a renal replacement therapy were excluded. CMS was administered at a dose of 3 million units (240 mg) every 8 h. Venous blood was collected immediately before and at multiple occasions after the first and the fourth infusions. Plasma CMS and colistin concentrations were determined by a novel liquid chromatography-tandem mass spectrometry method after a rapid precipitation step that avoids the significant degradation of CMS and colistin. Population pharmacokinetic analysis was performed with the NONMEM program. Eighteen patients (6 females; mean age, 63.6 years; mean creatinine clearance, 82.3 ml/min) were included in the study. For CMS, a two-compartment model best described the pharmacokinetics, and the half-lives of the two phases were estimated to be 0.046 h and 2.3 h, respectively. The clearance of CMS was 13.7 liters/h. For colistin, a one-compartment model was sufficient to describe the data, and the estimated half-life was 14.4 h. The predicted maximum concentrations of drug in plasma were 0.60 mg/liter and 2.3 mg/liter for the first dose and at steady state, respectively. Colistin displayed a half-life that was significantly long in relation to the dosing interval. The implications of these findings are that the plasma colistin concentrations are insufficient before steady state and raise the question of whether the administration of a loading dose would benefit critically ill patients.
Use of
l
-Proline and ATP Production by
Trypanosoma cruzi
Metacyclic Forms as Requirements for Host Cell Invasion
Authors: Martins Rafael Miyazawa , Covarrubias Charles , Rojas Robert Galvez , Silber Ariel Mariano , Yoshida Nobuko
Published: May 2009

The process of host cell invasion by
Trypanosoma cruzi
depends on parasite energy. What source of energy is used for that event is not known. To address this and other questions related to
T. cruzi
energy requirements and cell invasion, we analyzed metacyclic trypomastigote forms of the phylogenetically distant CL and G strains. For both strains, the nutritional stress experienced by cells starved for 24, 36, or 48 h in phosphate-buffered saline reduced the ATP content and the ability of the parasite to invade HeLa cells proportionally to the starvation time. Inhibition of ATP production by treating parasites with rotenone plus antimycin A also diminished the infectivity. Nutrient depletion did not alter the expression of gp82, the surface molecule that mediates CL strain internalization, but increased the expression of gp90, the negative regulator of cell invasion, in the G strain. When
l
-proline was given to metacyclic forms starved for 36 h, the ATP levels were restored to those of nonstarved controls for both strains. Glucose had no such effect, although this carbohydrate and
l
-proline were transported in similar fashions. Recovery of infectivity promoted by
l
-proline treatment of starved parasites was restricted to the CL strain. The profile of restoration of ATP content and gp82-mediated invasion capacity by
l
-proline treatment of starved Y-strain parasites was similar to that of the CL strain, whereas the Dm28 and Dm30 strains, whose infectivity is downregulated by gp90, behaved like the G strain.
l
-Proline was also found to increase the ability of the CL strain to traverse a gastric mucin layer, a property important for the establishment of
T. cruzi
infection by the oral route. Efficient translocation of parasites through gastric mucin toward the target epithelial cells in the stomach mucosa is an essential requirement for subsequent cell invasion. By relying on these closely associated ATP-driven processes, the metacyclic trypomastigotes effectively accomplish their internalization.
Overexpression of the Natural Inhibitor of Cysteine Peptidases inLeishmania mexicanaLeads to Reduced Virulence and a Th1 Response
Authors: Bryson Karen , Besteiro Sébastien , McGachy H. Adrienne , Coombs Graham H. , Mottram Jeremy C. , Alexander James
Published: May 2009

Leishmania mexicanacysteine peptidases (CPs) have been identified as important parasite virulence factors. More recently, a natural inhibitor of CPs (ICP) fromL. mexicanahas been characterized, and ICP mutants have been created. Infection of BALB/c mice with ICP null mutants or ICP reexpressing mutants resulted in nonhealing, progressively growing lesions albeit slightly attenuated compared with the growth of lesions produced by wild-type parasites. In contrast, BALB/c mice infected with mutants overexpressing ICP were able to significantly control lesion growth or heal. While BALB/c mice infected with wild-type parasites, ICP null mutants, or ICP reexpressing mutants produced significant antibody responses, including immunoglobulin E (IgE), no Th1 response, as indicated by antigen-induced splenocyte gamma interferon (IFN-γ) production, could be demonstrated. In contrast, BALB/c mice infected with mutants overexpressing ICP produced significantly less antibody, particularly IgE, as well as significantly reduced splenocyte interleukin-4 and enhanced IFN-γ production. BALB/c mice were able to resolve infection following infection with one ICP overexpressing clone, which was subsequently used for vaccination studies with BALB/c mice. However, no protection was afforded these mice when they were challenged with wild-type parasites. Nevertheless, two other mouse strains susceptible toL. mexicana, C3H and C57BL/6, vaccinated with overexpressing ICP mutants were able to control challenge infection associated with an enhanced Th1 response. This study confirms thatL. mexicanaCPs are virulence factors and that ICPs have therapeutic potential.
Role of Teichoic Acid Choline Moieties in the Virulence of
Streptococcus pneumoniae
Authors: Gehre Florian , Spisek Radek , Kharat Arun S. , Matthews Phillip , Kukreja Anjli , Anthony Robert M. , Dhodapkar Madhav V. , Vollmer Waldemar , Tomasz Alexander
Published: May 2009

In recent reports it was shown that genetically modified choline-free strains of
Streptococcus pneumoniae
(D39Cho
−
licA64 and D39ChiplicB31) expressing the type II capsular polysaccharide were virtually avirulent in the murine sepsis model, in sharp contrast to the isogenic and highly virulent strains D39Cho
−
and D39Chip, which have retained the choline residues at their surface. We now demonstrate that this choline-associated virulence is independent of Toll-like receptor 2 recognition. Also, despite the lack of virulence, choline-free strains of
S. pneumoniae
were able to activate splenic dendritic cells, induce secretion of proinflammatory cytokines, and produce specific protective immunity against subsequent challenge. However, after this transient engagement of the immune system the choline-free bacteria were rapidly cleared from the blood, while the isogenic virulent strain D39Cho
−
continued to grow, accompanied by prolonged expression of cytokines, eventually killing the experimental animals. The critical contribution of choline residues to the virulence potential of pneumococci appears to be the role that these amino alcohol residues play in a pneumococcal immune evasion strategy, the mechanism of which is unknown at the present time.
Sortase A Confers Protection against
Streptococcus pneumoniae
in Mice
Authors: Gianfaldoni Claudia , Maccari Silvia , Pancotto Laura , Rossi Giacomo , Hilleringmann Markus , Pansegrau Werner , Sinisi Antonia , Moschioni Monica , Masignani Vega , Rappuoli Rino , Del Giudice Giuseppe , Ruggiero Paolo
Published: May 2009

Streptococcus pneumoniae
sortase A (SrtA) is a transpeptidase that is highly conserved among pneumococcal strains, whose involvement in adhesion/colonization has been reported. We found that intraperitoneal immunization with recombinant SrtA conferred to mice protection against
S. pneumoniae
intraperitoneal challenge and that the passive transfer of immune serum before intraperitoneal challenge was also protective. Moreover, by using the intranasal challenge model, we observed a significant reduction of bacteremia when mice were intraperitoneally immunized with SrtA, while a moderate decrease of lung infection was achieved by intranasal immunization, even though no influence on nasopharynx colonization was seen. Taken together, our results suggest that SrtA is a good candidate for inclusion in a multicomponent, protein-based, pneumococcal vaccine.
Perturbation of the Small Intestine Microbial Ecology by Streptomycin Alters Pathology in a
Salmonella enterica
Serovar Typhimurium Murine Model of Infection
Authors: Garner Cherilyn D. , Antonopoulos Dionysios A. , Wagner Bettina , Duhamel Gerald E. , Keresztes Ivan , Ross Deborah A. , Young Vincent B. , Altier Craig
Published: May 2009

The small intestine is an important site of infection for many enteric bacterial pathogens, and murine models, including the streptomycin-treated mouse model of infection, are frequently used to study these infections. The environment of the mouse small intestine and the microbiota with which enteric pathogens are likely to interact, however, have not been well described. Therefore, we compared the microbiota and the concentrations of short-chain fatty acids (SCFAs) present in the ileum and cecum of streptomycin-treated mice and untreated controls. We found that the microbiota in the ileum of untreated mice differed greatly from that of the cecum of the same mice, primarily among families of the phylum
Firmicutes
. Upon treatment with streptomycin, substantial changes in the microbial composition occurred, with a marked loss of population complexity. Characterization of the metabolic products of the microbiota, the SCFAs, showed that formate was present in the ileum but low or not detectable in the cecum while butyrate was present in the cecum but not the ileum. Treatment with streptomycin altered the SCFAs in the cecum, significantly decreasing the concentration of acetate, propionate, and butyrate. In this work, we also characterized the pathology of
Salmonella
infection in the ileum. Infection of streptomycin-treated mice with
Salmonella
was characterized by a significant increase in the relative and absolute levels of the pathogen and was associated with more severe ileal inflammation and pathology. Together these results provide a better understanding of the ileal environment in the mouse and the changes that occur upon streptomycin treatment.
Anomalous Quantitation Standard Growth Curves in a Laboratory-Developed Hepatitis C Virus (HCV) RNA Quantification Assay Using the TaqMan HCV Analyte-Specific Reagent
Authors: Germer Jeffrey J. , Kathrotiya Jemee D. , Bouse Carrie F. , Mitchell P. Shawn , Yao Joseph D. C.
Published: May 2009

A retrospective examination of quantitation standard growth curves associated with 1,000 unique clinical serum specimens tested by a laboratory-developed TaqMan hepatitis C virus analyte-specific reagent-based assay revealed anomalous growth curves associated with 0.40% (95% confidence interval, 0.11% to 1.00%) of these specimens.
Delivery of Human Immunodeficiency Virus Vaccine Vectors to the Intestine Induces Enhanced Mucosal Cellular Immunity
Authors: Wang Lingshu , Cheng Cheng , Ko Sung-Youl , Kong Wing-Pui , Kanekiyo Masaru , Einfeld David , Schwartz Richard M. , King C. Richter , Gall Jason G. D. , Nabel Gary J.
Published: May 2009

Effective vaccines for human immunodeficiency virus type 1 (HIV-1) will likely need to stimulate protective immunity in the intestinal mucosa, where HIV-1 infection causes severe CD4+T-cell depletion. While replication-competent recombinant adenovirus (rAd) vectors can stimulate adenovirus-specific mucosal immunity after replication, oral delivery of replication-defective rAd vectors encoding specific immunogens has proven challenging. In this study, we have systematically identified barriers to effective gut delivery of rAd vectors and identified sites and strategies to induce potent cellular and humoral immunity. Vector-mediated gene transfer by rAd5 was susceptible to low-pH buffer, gastric and pancreatic proteases, and extracellular mucins. Using ex vivo organ explants, we found that transduction with rAd5 was highest in the ileum and colon among all intestinal segments. Transgene expression was 100-fold higher after direct surgical introduction into the ileum than after oral gavage, with rAd5 showing greater potency than the rAd35 or the rAd41 vector. A single immunization of rAd5 encoding HIV-1 gp140B to the ileum stimulated potent CD8+T-cell responses in the intestinal and systemic compartments, and these responses were further enhanced by intramuscular rAd5 boosting. These studies suggest that induction of primary immune responses by rAd5 gut immunization and subsequent systemic boosting elicits potent antigen-specific gut mucosal responses.
On the role of photosynthesis in the nitrate-dependent induction of the alternative oxidase inChlamydomonas reinhardtii
Authors: Pakkiriswami Shanmugasundaram , Beall Benjamin F.N. , Maxwell Denis P.
Published: May 2009

In the green alga Chlamydomonas reinhardtii Dangeard a shift in nitrogen source from ammonium to nitrate results in the rapid induction of the mitochondrial alternative oxidase (AOX). It has been hypothesized that this induction compensates for the increased generation of ATP in the chloroplast. Based upon light response curves of oxygen evolution, a shift from ammonium to nitrate resulted in a significant increase in both apparent quantum yield of oxygen evolution and photosynthetic capacity. Changes in chlorophyll a fluorescence including a decrease in both excitation pressure and nonphotochemical quenching were also observed over a 12 h nitrate shift. To investigate whether changes in chloroplast ATP generation were behind the nitrate-dependent induction of AOX, transcript and protein accumulation were monitored in cells grown under high, moderate and low irradiances. No major differences in Aox1 gene expression or AOX accumulation were found among the different light regimes. These data do not support the hypothesis that an increase in AOX within the mitochondrion in response to nitrate is tied to changes in photosynthesis occurring within the chloroplast.
Latitudinal decrease in acorn size in bur oak (Quercus macrocarpa) is due to environmental constraints, not avian dispersal
Authors: Koenig Walter D. , Knops Johannes M. H. , Dickinson Janis L. , Zuckerberg Benjamin
Published: May 2009

The size of acorns produced by several species of eastern North American oaks decreases with latitude. We investigated three hypotheses for this pattern in the bur oak ( Quercus macrocarpa Michx.) using samples collected over 2 years throughout the species’ range. We found strong support for the hypothesis that abiotic factors, including both temperature and rainfall, constrain acorn size. There was also a smaller but important difference in acorn size related to whether sites were glaciated or not, providing support for the hypothesis that some factor associated with the history of glaciation affects acorn mass. In contrast, although blue jays ( Cyanocitta cristata  L.) prefer smaller acorns and are an important dispersal agent, the latitudinal patterns of acorn size and variability were not consistent with predictions of the hypothesis that they are the product of blue jay dispersal during bur oak’s postglacial Holocene expansion. Assuming that there is a lower limit to the size that acorns can be and still be successful, the strong role of environmental constraints on acorn size may be important in explaining the apparently contradictory interspecific pattern that North American oaks successfully colonizing areas further north during the Holocene are those that produce relatively larger acorns.
Climatic determinants of berry crops in the boreal forest of the southwestern Yukon
Authors: Krebs C. J. , Boonstra R. , Cowcill K. , Kenney A. J.
Published: May 2009

Berry crops in the southwestern Yukon were quantified from 1997 to 2008 at 10 locations along 210 km of the Alaska and Haines highways. We tested the hypothesis that the size of berry crops could be predicted from spring and summer temperature and rainfall of years t, t–1 (1 year prior), and t–2 (2 years prior). Six common species were studied in the boreal forest of the Kluane region: Arctostaphylos rubra (Rehd. & Wils.) Fern., Arctostaphylos uva-ursi (L.) Spreng. s.l., Empetrum nigrum  L., Vaccinium vitis-idaea  L., Geocaulon lividum (Richards) Fern, and Shepherdia canadensis (L.) Nutt.. For the first five species we counted berries on fixed 40 cm × 40 cm quadrats to obtain an index of berry production for the Kluane region for each of the 12 years, and for S. canadensis we counted berries on two tagged branches of 10 bushes at each location. Stepwise multiple regressions were utilized to predict the size of berry crops for each species. For all species, predictive equations could explain statistically 80%–96% of the variation in berry crops. Different weather variables characterized each plant species, and there was no common weather regression that could explain the variation in berry crops in all species. Rainfall and temperature from years t–1 and t–2 were typically the significant predictors. There was no indication of a periodicity in berry production, and 43%–60% of the quadrats counted had large berry crops at one year intervals, while other quadrats never had a high crop during the study interval.
New species of freshwater diatoms from acidic localities along the Atlantic Coastal Plain of the United States
Authors: Siver Peter A. , Hamilton Paul B. , Pelczar Jeffery
Published: May 2009

During our investigations of freshwater sites along the Atlantic Coastal Plain of North America we had the opportunity to critically study five interesting diatoms with light (LM) and scanning electron microscopy (SEM), each of which is described here as a new species. Two of the organisms are in the genus Eunotia , Eunotia lewisii Siver & Hamilton sp. nov. and Eunotia quadra Siver & Hamilton sp. nov.; two in Frustulia , Frustulia crispula Siver, Pelczar, & Hamilton sp. nov. and Frustulia inculta Siver, Pelczar, & Hamilton sp. nov.; and the last is Neidium trainori Siver & Hamilton sp. nov. All five species are reported from acidic, poorly buffered, dilute waterbodies high in dissolved humic substances. Two of the taxa are found in suites of waterbodies in close geographic proximity, two in somewhat disjunct regions, and the fifth is only known from the type locality. The relationships of each taxon to similar species are discussed.
Calculated and observed behaviour of clayey soil under cyclic loading beneath preloading embankments for oil tanks
Authors: Gajo A. , Colleselli F.
Published: May 2009

Two accurately monitored preloading embankments built to reduce the settlement of two oil tanks for a thermoelectric power plant near Mantova, Italy, were analysed using the finite element method and different constitutive assumptions. The most prominent feature of the proposed case study is that it involved two major loading cycles (preloading embankment construction–removal and oil tank filling–emptying) of different amplitudes (embankment heights of 8.60 and 12.50 m and a tank level of 14.00 m). Further minor loading cycles were also applied due to changes (of up to 6–7 m) in the hydrometric levels of the Po River. Because of the cyclic nature of the loading and the detailed measurements (of pore pressures and horizontal and vertical movements on the ground surface and in depth), this case study proves very useful for validating advanced features of modern constitutive models. The effects of elastic anisotropy, plastic anisotropy, and destructuration are considered in two different bounding-surface, kinematic-hardening plasticity models specific to clays and sands. The effects of permeability and Poisson’s ratio are also analysed. The conclusions have a general applicability and are not specific to the selected constitutive models.
BODE-TYPE EQUALIZERS USING CURRENT CONVEYORS
Authors: SOLIMAN AHMED M.
Published: May 2009

New voltage mode and current mode active RC Bode-type variable equalizers using current conveyors are introduced. The proposed equalizers can operate at much higher frequencies than the classical operational amplifier-based variable equalizers. Spice simulation results are included to confirm the practicality of the proposed circuits.
BLIND PARALIND SPACE-TIME MULTIUSER DETECTION FOR ASYNCHRONOUS CDMA SYSTEM
Authors: ZHANG XIAOFEI , FENG GAOPENG , XU DAZHUAN , GAO XIN
Published: May 2009

This paper links the asynchronous CDMA system signal detection problem to the parallel profiles with linear dependencies (PARALIND), and derives a deterministic blind PARALIND algorithm whose performance is close to nonblind space-time minimum mean square error method. The proposed algorithm has the better performance than space-time matched filter, supports small sample sizes, and even works well in array error condition. Most notably, it does not require knowledge of the direction of arrival and channel fading information.
DECONFINEMENT AND QUARK–GLUON PLASMA
Authors: NEFEDIEV A. V. , SIMONOV YU. A. , TRUSOV M. A.
Published: May 2009

The theory of confinement and deconfinement is discussed as based on the properties of the QCD vacuum. The latter are described by field correlators of color-electric and color-magnetic fields in the vacuum, which can be calculated analytically and on the lattice. As a result one obtains a self-consistent theory of the confined region in the (μ, T) plane with realistic hadron properties. At the boundary of the confining region, the color-electric confining correlator vanishes, and the remaining correlators describe strong nonperturbative dynamics in the deconfined region with (weakly) bound states. Resulting equation of state for μ = 0, p(T), [Formula: see text] are in good agreement with lattice data. Phase transition occurs due to evaporation of a part of the color-electric gluon condensate, and the resulting critical temperatures Tc(μ) for different nf are in good correspondence with available data.
STUDIES FOR THE EQUATION OF STATE IN THE ISOSPIN ASYMMETRICAL NUCLEAR INTERACTIONS
Authors: LIU JIAN YE , GUO WEN-JUN , ZUO WEI , LEE XI GUO
Published: May 2009

In order to determine the equation of state in the isospin asymmetrical nuclear interactions, we have found the observables for extracting the information of them within the isospin-dependent quantum molecular dynamics in recent years. The several sensitive probes for extracting the information of the in-medium nucleon–nucleon cross section and the symmetry potential have found; meanwhile, their mechanisms are investigated in more details. The main point in this paper gives the summary for above probes and their outlook in the future.
WAITING TIMES IN SIMULATED STOCK MARKETS
Authors: CAPPELLINI ALESSANDRO N. , FERRARIS GIANLUIGI
Published: May 2009

Exploiting a precise reproduction of a stock exchange, the robustness of the continuous double auction (CDA) mechanism, evaluated by means of the waiting time distributions, has been proved versus 36 different setups made by varying both the operators' behavior and the market micro structure. The obtained results demonstrate that the CDA remains able to clear strongly different order flows, although the Milan stock exchange seemed to be a little more efficient than the NYSE under the allocative point of view, evidencing the intrinsic complexity of the stock market. The simulation has been built as an agent-based model in order to obtain a plausible order flow. The decisions of single agents and their interaction through the market book are realistic and reproduce some empirical analysis results. The mentioned results have been obtained either by the analysis of the complete pending time series or the same computation of the asks and bids series alone.
ON APPROXIMATING THE DISTRIBUTIONS OF GOODNESS-OF-FIT TEST STATISTICS BASED ON THE EMPIRICAL DISTRIBUTION FUNCTION: THE CASE OF UNKNOWN PARAMETERS
Authors: CAPASSO MARCO , ALESSI LUCIA , BARIGOZZI MATTEO , FAGIOLO GIORGIO
Published: May 2009

This paper discusses some problems possibly arising when approximating via Monte-Carlo simulations the distributions of goodness-of-fit test statistics based on the empirical distribution function. We argue that failing to re-estimate unknown parameters on each simulated Monte-Carlo sample — and thus avoiding to employ this information to build the test statistic — may lead to wrong, overly-conservative. Furthermore, we present some simple examples suggesting that the impact of this possible mistake may turn out to be dramatic and does not vanish as the sample size increases.
INCREASING INFRASTRUCTURE RESILIENCE THROUGH COMPETITIVE COEVOLUTION
Authors: SERVICE TRAVIS , TAURITZ DANIEL
Published: May 2009

The world is increasingly dependent on critical infrastructures such as the electric power grid, water, gas and oil transport systems. Due to this increasing dependence and inadequate infrastructure expansion, these systems are becoming increasingly stressed. These additional stresses leave these systems less resilient to external faults, both accidental and malicious than ever before. As a result of this increased vulnerability, many critical infrastructures are becoming susceptible to cascading failures, where an initial fault caused by an external force may induce a domino-effect of further component failures. An important implication is that traditional infrastructure risk analysis methods, often relying on Monte Carlo sampling of fault scenarios, are no longer sufficient. Instead, systematic analysis based on worst-case attacks by intelligent adversaries is essential. This paper describes a coevolutionary methodology to simultaneously discover low-effort high-impact faults and corresponding means of hardening infrastructures against them. We empirically validate our methodology through an electric power transmission system case study.
ANALYSIS OF MUTATION OPERATORS ON QUANTUM-BEHAVED PARTICLE SWARM OPTIMIZATION ALGORITHM
Authors: FANG WEI , SUN JUN , XU WENBO
Published: May 2009

Mutation operator is one of the mechanisms of evolutionary algorithms (EAs) and it can provide diversity in the search and help to explore the undiscovered search place. Quantum-behaved particle swarm optimization (QPSO), which is inspired by fundamental theory of PSO algorithm and quantum mechanics, is a novel stochastic searching technique and it may encounter local minima problem when solving multi-modal problems just as that in PSO. A novel mutation mechanism is proposed in this paper to enhance the global search ability of QPSO and a set of different mutation operators is introduced and implemented on the QPSO. Experiments are conducted on several well-known benchmark functions. Experimental results show that QPSO with some of the mutation operators is proven to be statistically significant better than the original QPSO.
MODULAR SOFT COMPUTING APPROACH FOR AIRCRAFT CARRIER LANDING TRAJECTORY PREDICTION
Authors: TSENG CHRIS , EPSHTEYN ARKADY
Published: May 2009

A modular learning design for classifying aircraft flight data in time-series prediction is proposed in this paper. This is part of the decision support system to assist landing signal officers in guiding aircraft to land on aircraft carriers. NeuroFuzzy systems are used to emulate the flight patterns for future real-time flight prediction. To improve the learning efficiency, a two stage modular learning design is proposed. The data to be learned is first decomposed into categories in accordance to their physical structure. Each module of data is presented to a different NeuroFuzzy system for learning purpose. Individually trained modules are modeled as genetic chromosomes. Genetic algorithm is used to produce a chromosome module that represents a generalization of all the trained modules. As compared with the non-modular approach, the modular approach offers comparable prediction performance with significantly lower overall computation time. We show that the reduction in computation time with the modular approach is exponential as the problem size increases. Navy aircraft data were used to validate the effectiveness of the modular design and the result is consistent and promising.
EMOTION RECOGNITION BASED ON THE ANALYSIS OF FACIAL EXPRESIONS: A SURVEY
Authors: BERISTAIN ANDONI , GRAÑA MANUEL
Published: May 2009

Face expression recognition is an active area of research with several fields of applications, ranging from emotion recognition for advanced human computer interaction to avatar animation for the movie industry. This paper presents a review of the state-of-the-art emotion recognition based on the visual analysis of facial expressions. We cover the main technical approaches and discuss the issues related to the gathering of data for the validation of the proposed systems.
An early 'ostrich dinosaur' (Theropoda: Ornithomimosauria) from the Early Cretaceous Sao Khua Formation of NE Thailand
Authors: Buffetaut Eric , Suteethorn Varavudh , Tong Haiyan
Published: May 2009

Postcranial remains of a small theropod dinosaur, including vertebrae, incomplete pubes, tibiae, an incomplete fibula, metatarsals and phalanges, from the Early Cretaceous Sao Khua Formation of Phu Wiang, Khon Kaen Province, NE Thailand, are described as a new taxon of ornithomimosaur,
Kinnareemimus khonkaenensis
, gen. et sp. nov. This early ‘ostrich dinosaur’ is characterized by a fairly advanced metatarsus, in which metatarsal III, although still visible proximally between metatarsals II and IV in cranial view, is markedly ‘pinched’ more distally and becomes triangular in cross-section. The condition of its metatarsus shows that
Kinnareemimus khonkaenensis
is more derived than the geologically younger primitive ornithomimosaurs
Harpymimus
and
Garudimimus
, but less derived than
Archaeornithomimus
. Its occurrence in the Early Cretaceous of Thailand suggests that advanced ornithomimosaurs may have originated in Asia.
Mesozoic vertebrate footprints of Thailand and Laos
Authors: Le Loeuff Jean , Saenyamoon Tida , Souillat Christel , Suteethorn Varavudh , Buffetaut Eric
Published: May 2009

Vertebrate footprints have been discovered in recent years from seven Mesozoic formations of Thailand and Laos dating from the Late Triassic (Kuchinari Group) and the Early Cretaceous (Khorat Group). The sites are reviewed here in chronological order. The ichnological record reflects fairly well the broad picture of the evolution of continental vertebrates in Asia known from the skeletal record. Norian basal archosaurs are replaced by Rhaetian dinosaurs although both footprint morphotypes look different from the contemporaneous European and North American forms. Two successive ornithopod radiations can be observed in the Early Cretaceous, with primitive small tetradactyl
Hypsilophodon
-like dinosaurs in the Earliest Cretaceous followed by advanced iguanodontoids with tridactyl fleshy footprints in the Aptian. Late Early Cretaceous dinosaur footprints from NE Thailand, however, do not validate previous hypotheses on the geographical distribution of Cretaceous ornithopod tracks in Asia. The ichnological record also reveals a hitherto unsuspected high diversity of theropods in the early Cretaceous with many different morphotypes.
Biogeographical affinities of Jurassic and Cretaceous continental vertebrate assemblages from SE Asia
Authors: Fernandez Vincent , Claude Julien , Escarguel Gilles , Buffetaut Eric , Suteethorn Varavudh
Published: May 2009

Over the last 25 years, rich vertebrate assemblages have been discovered in three distinct formations of the Late Jurassic and Early Cretaceous of Thailand. This work aims to compare the taxonomic assemblages of SE Asia within their palaeogeographical context in Asia. Occurrences of 477 taxa in 94 Regional Faunal Assemblages (RFA) have provided the raw material for producing a dissimilarity matrix based on the Raup & Crick index. These distances have been investigated statistically to infer relationships between the diverse faunal assemblages in space and time. Our results show that the Thai formations are more similar to each other than to any other formations, suggesting a strong provincialism. The relationship of SE Asian RFAs with other Asian RFAs is more influenced by the presence of freshwater or near-shore taxa than by strictly terrestrial ones. Our analysis shows that the faunal interchange between RFAs was rather low from the Late Jurassic to the end of the Early Cretaceous. However, faunal dispersals dramatically decreased during the mid-Early Cretaceous in Asia. The faunas show an overall stronger provincialism during the mid-Early Cretaceous, indicating the role of possible geographical barriers. This event is characterized by the absence of ornithischian dinosaurs in the Sao Khua Formation although they are present in the under- and overlying formations. Taxonomic diversity and exchanges between faunal assemblages recovered rapidly as early as the Aptian in Asia, but the fauna of SE Asia still retained a strong biogeographical signature.
Late Permian dicynodont fauna from Laos
Authors: Battail Bernard
Published: May 2009

In Laos, dicynodonts have long been known only from one specimen, now lost, a partial skull discovered by Counillon in the purple beds of the area of Luang Prabang, and initially described by Repelin as
Dicynodon incisivum
. Subsequent researchers attributed the specimen either to the Late Permian genus
Dicynodon
or to the Early Triassic genus
Lystrosaurus.
Recent Franco-Laotian expeditions have gathered, from the same purple beds, a collection of tetrapods composed mainly of dicynodonts. They can all be ascribed to
Dicynodon
, and the available evidence suggests that the purple beds are Late Permian in age. The genus
Lystrosaurus
remains unknown in Laos.
Mesozoic red bed sequences from SE Asia and the significance of the Khorat Group of NE Thailand
Authors: Racey Andrew
Published: May 2009

New geological data are presented and previously published information is reviewed to demonstrate that much of the Khorat Group (Phu Kradung to Khok Kruat Formations) of NE Thailand is Early Cretaceous in age. It is suggested that the Mesozoic red bed sequences of neighbouring Indochina are likely to be of similar age rather than spanning the entire Late Triassic to Early Cretaceous as previously assumed. Moreover, the Lower Nam Phong Formation dated as Late Triassic and previously included as the basal formation of the Khorat Group is now removed from this group, thus creating a hiatus within the Jurassic. There is therefore no clear relationship between the Indosinian Orogeny and the Triassic collision of the Sibumasu (also referred to as Shan-Thai) and Indochina Blocks and the subsequent deposition of the Khorat Group in a Late Triassic–Early Cretaceous thermal sag basin. It is now proposed that much of the sequence was deposited during the Late Jurassic–Early Cretaceous. Jurassic sediments may be absent across much of the Khorat Plateau whereas marine Jurassic sediments to the west and east show no sediments younger than Bajocian. Because sea levels were generally rising in the Middle and Late Jurassic it is likely that the Khorat region was uplifted at this time. It is suggested that the Khorat Group was originally deposited in a foreland basin setting rather than a thermal sag basin following Late Triassic rifting. Moreover, the original site of deposition was to the north in southern China, with the present-day location being the result of movement along the Red River Fault coupled with a clockwise rotation of the Indochina Block (on which the Khorat Group sits) with respect to the South China Block.
Silhouette and palaeoecology of Mesozoic trees in Thailand
Authors: Philippe Marc , Daviero-Gomez Véronique , Suteethorn Varavudh
Published: May 2009

Trees are an obvious component of most landscapes. Artists' views of Mesozoic landscapes regularly feature modern trees such as firs (
Abies
and
Picea
) and monkey-puzzle trees (
Araucaria araucana
). However, these reconstructions are highly hypothetical and, in reality, very little is known about the silhouettes of Mesozoic trees. In Mesozoic (Middle Jurassic to Early Cretaceous) strata of Thailand, large conifer logs with different types of architecture are evident, a rare opportunity for architectural studies. Various methods to estimate the original diameter and height of the trees are assessed. Among our material some trees have the classical Christmas-tree shape, whereas others are more oak-like in silhouette. All these trees lived in forest environments. Tree shape is strongly related to environment, and is still under-used as a palaeoecological tool. Reconstructing trees and vegetation has wide implications, from evaluating dinosaur herbivory to calculating elements of the carbon cycle.
A new elasmobranch fauna from the Middle Jurassic of southern Thailand
Authors: Cuny Gilles , Srisuk Paladej , Khamha Suchada , Suteethorn Varavudh , Tong Haiyan
Published: May 2009

We describe a new elasmobranch fauna from the lower part of the Khlong Min Formation in Thailand. The fauna includes
Hybodus
sp.,
Asteracanthus
sp.,
Lonchidion reesunderwoodi
sp. nov.,
Belemnobatis aominensis
sp. nov., and possibly a second species of
Belemnobatis.
This fauna supports a Bathonian–Callovian age for the Khlong Min Formation, and suggests a close taxonomic relationship between the Middle Jurassic elasmobranch faunas of Europe and Thailand. The presence of a monolayered enameloid in
Belemnobatis aominensis
sp. nov. and other primitive batoids is interpreted as the retention of a primitive character for neoselachians, which would suggest a divergence time between the batoids and the rest of the neoselachian sharks as early as the Carboniferous–Permian boundary.