bluuebunny/crossref_metadata_2025 huggingface dataset:
A Dynamic Stiffness and Damping Model for Rail Car Center Plate Polymer Liners
Authors: Katta Raja R. , Conry Thomas F.
Published: November 2008

The center plate interface is made up of the body plate attached to the car body bolster, the polymer liner, and the bolster bowl, which is a part of the truck bolster. Roll motion of the rail car leads to the car body bolster rolling over the polymer liner on the truck bolster, which may result in partial loss of contact of the body plate with the polymer liner. This nonlinear phenomenon has a deleterious impact on the rail car dynamics. A technique for creating a center plate dynamic model accounting for the polymer liner and the loss of contact condition is presented here. Material tests were performed to model the stress-relaxation of the liner. A stiffness/damping model of the center plate accounting for the nonlinear effects of the lift-off was developed based on a nonlinear Winkler foundation model and was tested for a one-degree-of-freedom dynamic model. This continuous model was adapted into a 16 stiffness-damping element model to enable its usage in a NUCARS™ rail-car dynamic model.
Fullscale Two-Car Impact Test: A Comparison of Measured and Model Results
Authors: Rancatore Robert , Mayville Ronald , Baldwin Mark
Published: November 2008

The Volpe National Transportation Systems Center is conducting research into the crashworthiness of rail vehicles in support of the Federal Railroad Administration’s Office of Research and Development. The approach taken has focused on the review of accidents, development of analytical tools and performing full-scale testing. A series of inline full-scale impact tests have been performed using conventional passenger cars. Recent full-scale testing included two instrumented coupled conventional passenger cars impacting a fixed barrier at 26 mph. The cars were instrumented with accelerometers, strain gages and string potentiometers. From these measurements, car translations, rotations, relative displacements and coupler forces were calculated. A rigid body dynamics model of the two-car configuration was developed and used to design the test. In order to improve the collision dynamics models of passenger cars, the results from this test are being used to refine that model. This paper describes the two-car impact test, the reduction of data collected during the test and the refined collision dynamics model. Post-test refinements allow the model to more accurately simulate the vertical and lateral motions of the cars, including the timing of the lateral buckling of the cars. The post-test model also more accurately simulates the climbing of the impact car as it crushes. Comparisons between the refined model results with the measured data are presented for the motion of the center of gravity of the cars, coupled car interactions and forces, and lateral buckling.
Impact Test of a Crash-Energy Management Passenger Rail Car
Authors: Jacobsen Karina , Tyrell David , Perlman Benjamin
Published: November 2008

On December 3, 2003, a single-car impact test was conducted to assess the crashworthiness performance of a modified passenger rail car. A coach car retrofitted with a Crash Energy Management (CEM) end structure impacted a fixed barrier at approximately 35 mph. This speed is just beyond the capabilities of current equipment to protect the occupants. The test vehicle was instrumented with accelerometers, string potentiometers, and strain gages to measure the gross motions of the car body in three dimensions, the deformation of specific structural components, and the force/crush characteristic of the impacted end of the vehicle. The CEM crush zone is characterized by three structural components: a pushback coupler, a sliding sill (triggering the primary energy absorbers), and roof absorbers. These structural mechanisms guide the impact load and consequent crush through the end structure in a prescribed sequence. Pre-test activities included quasi-static and dynamic component testing, development of finite element and collision dynamics models and quasi-static strength tests of the end frame. These tests helped verify the predicted structural deformation of each component, estimate a force-crush curve for the crush zone, predict the gross motions of the car body, and determine instrumentation and test conditions for the impact test. During the test, the passenger car sustained approximately three feet of crush. In contrast to the test of the conventional passenger equipment, the crush imparted on the CEM vehicle did not intrude into the passenger compartment. However, as anticipated the car experienced higher accelerations than the conventional passenger car. Overall, the test results for the gross motions of the car are in close agreement. The measurements made from both tests show that the CEM design has improved crashworthiness performance over the conventional design. A two-car test will be performed to study the coupled interaction of CEM vehicles as well as the occupant environment. The train-to-train test results are expected to show that the crush is passed sequentially down the interfaces of the cars, consequently preserving occupant volume.
Intrapulmonary Pharmacokinetics and Pharmacodynamics of Posaconazole at Steady State in Healthy Subjects
Authors: Conte John E. , Golden Jeffrey A. , Krishna Gopal , McIver Marina , Little Emily , Zurlinden Elisabeth
Published: November 2008

We evaluated the pharmacokinetics (PK) and pharmacodynamics (PD) of posaconazole (POS) in a prospective, open-label study. Twenty-five healthy adults received 14 doses of POS oral suspension (400 mg twice daily) with a high-fat meal over 8 days. Pulmonary epithelial lining fluid (ELF) and alveolar cell (AC) samples were obtained via bronchoalveolar lavage, and blood samples were collected during the 24 h after the last dose. POS concentrations were determined using liquid chromatography with tandem mass spectrometry parameters. The maximum concentrations (
C
max
) (mean ± standard deviation) in plasma, ELF, and ACs were 2.08 ± 0.93, 1.86 ± 1.30, and 87.7 ± 65.0 μg/ml. The POS concentrations in plasma, ELF, and ACs did not decrease significantly, indicating slow elimination after multiple dosing. The mean concentrations of POS in plasma, ELF, and ACs were above the MIC
90
(0.5 μg/ml) for
Aspergillus
spp. over the 12-h dosing interval and for 24 h following the last dose. Area under the curve from 0 to 12 h (AUC
0-12
) ratios for ELF/plasma and AC/plasma were 0.84 and 33. AUC
0-24
/MIC
90
ratios in plasma, ELF, and AC were 87.6, 73.2, and 2,860. Nine (36%) of 25 subjects had treatment-related adverse events during the course of the study, which were all mild or moderate. We conclude that a dose of 400 mg twice daily resulted in sustained plasma, ELF, and AC concentrations above the MIC
90
for
Aspergillus
spp. during the dosing interval. The intrapulmonary PK/PD of POS are favorable for treatment or prevention of aspergillosis, and oral POS was well tolerated in healthy adults.
Molecular Evidence for Spread of Two Major Methicillin-Resistant
Staphylococcus aureus
Clones with a Unique Geographic Distribution in Chinese Hospitals
Authors: Liu Yudong , Wang Hui , Du Na , Shen Enhua , Chen Hongbin , Niu Junqi , Ye Huifen , Chen Minjun
Published: November 2008

Methicillin (meticillin)-resistant
Staphylococcus aureus
(MRSA) is a serious problem worldwide. To investigate the molecular epidemiology of MRSA isolates in China, a total of 702 MRSA isolates collected from 18 teaching hospitals in 14 cities between 2005 and 2006 were characterized by antibiogram analysis, pulsed-field gel electrophoresis (PFGE), staphylococcal cassette chromosome
mec
(SCC
mec
) typing, and
spa
typing; and 102 isolates were selected for multilocus sequence typing (MLST). Overall, SCC
mec
type III was the most popular type and was found in 541 isolates (77.1%), followed by SCC
mec
type II (109/702; 15.5%). Twenty-four PFGE types were obtained among 395 isolates collected in 2005, and 18
spa
types were obtained among 702 isolates.
spa
type t030, which corresponded to PFEG types A to E, constituted 52.0% (365/702) of all isolates, and isolates of this type were present in all 14 cities;
spa
type t037, which corresponded to PFGE types F and G, accounted for 25.5% (179/702) of all isolates, and isolates of this type were identified in 12 cities. The two
spa
genotypes belonged to sequence type 239 (ST239) and carried SCC
mec
type III.
spa
type t002, which included isolates of PFGE types L to T, made up 16.0% (112/702) of the isolates that belonged to ST5 and SCC
mec
type II, and isolates of this type were distributed in 12 cities. The distribution of
spa
types varied among the regions.
spa
type t002 was the most common in Dalian (53.4%) and Shenyang (44.4%);
spa
type t037 was predominant in Shanghai (74.8%), whereas
spa
type t030 was the most common in the other cities. Two isolates from Guangzhou that harbored SCC
mec
type IVa with ST59 and ST88 were identified as community-associated MRSA. The prevalence of the Panton-Valentine leukocidin gene was 2.3%. The data documented two major epidemic MRSA clones, ST239-MRSA-SCC
mec
type III and ST5-MRSA-SCC
mec
type II, with unique geographic distributions across China.
First Report on a Hyperepidemic Clone of KPC-3-Producing
Klebsiella pneumoniae
in Israel Genetically Related to a Strain Causing Outbreaks in the United States
Authors: Navon-Venezia Shiri , Leavitt Azita , Schwaber Mitchell J. , Rasheed J. Kamile , Srinivasan Arjun , Patel Jean B. , Carmeli Yehuda
Published: November 2008

A highly epidemic carbapenem-resistant clone of KPC-3-producing
Klebsiella pneumoniae
emerged in Israel in 2006, causing a nationwide outbreak. This clone was genetically related to outbreak strains from the United States isolated in 2000 but differed in KPC-carrying plasmids. The threat of the global spread of hyperepidemic, extensively drug-resistant bacterial strains should be recognized and confronted.
qnrD
, a Novel Gene Conferring Transferable Quinolone Resistance in
Salmonella enterica
Serovar Kentucky and Bovismorbificans Strains of Human Origin
Authors: Cavaco L. M. , Hasman H. , Xia S. , Aarestrup F. M.
Published: November 2008

In a previous study, four
Salmonella
isolates from humans in the Henan province of China showed reduced susceptibility to ciprofloxacin (MIC, 0.125 to 0.25 μg/ml) but were susceptible to nalidixic acid (MIC, 4 to 8 μg/ml). All isolates were negative for known
qnr
genes (A, B, and S),
aac(6′)Ib-cr
, and mutations in
gyrA
and
parC
. Plasmid DNA was extracted from all four isolates and transformed into
Escherichia coli
TG1 and DH10B cells by electroporation, and transformants were selected on 0.06 μg/ml ciprofloxacin containing brain heart infusion agar plates. Resistance to ciprofloxacin could be transferred by electroporation, and a similar 4,270-bp plasmid was found in all transformants. By sequence analysis, the plasmid was found to carry an open reading frame that had similarities to other
qnr
genes and that encoded a 214-amino-acid pentapeptide repeat protein. This gene, designated
qnrD
, showed 48% similarity to
qnrA1
, 61% similarity to
qnrB1
, and 41% similarity to
qnrS1
. Further subcloning of the
qnrD
coding region into the constitutively expressed
tetA
gene of vector pBR322 showed that the gene conferred an increase in the MIC of ciprofloxacin by a factor of 32 (from an MIC of 0.002 to an MIC of 0.06 μg/ml). For comparison,
qnrA1
and
qnrS1
were also subcloned into pBR322 and transformed into DH10B cells, conferring MICs of 0.125 and 0.5 μg/ml, respectively. A phylogenetic analysis of all known
qnr
sequences was performed and showed that
qnrD
was more closely related to the
qnrB
variants but formed an independent cluster. To our knowledge, this is the first description of this
qnrD
gene.
Comprehensive In Vitro Analysis of Voriconazole Inhibition of Eight Cytochrome P450 (CYP) Enzymes: Major Effect on CYPs 2B6, 2C9, 2C19, and 3A
Authors: Jeong Seongwook , Nguyen Phuong D. , Desta Zeruesenay
Published: November 2008

Voriconazole is an effective antifungal drug, but adverse drug-drug interactions associated with its use are of major clinical concern. To identify the mechanisms of these interactions, we tested the inhibitory potency of voriconazole with eight human cytochrome P450 (CYP) enzymes. Isoform-specific probes were incubated with human liver microsomes (HLMs) (or expressed CYPs) and cofactors in the absence and the presence of voriconazole. Preincubation experiments were performed to test mechanism-based inactivation. In pilot experiments, voriconazole showed inhibition of CYP2B6, CYP2C9, CYP2C19, and CYP3A (half-maximal [50%] inhibitory concentrations, <6 μM); its effect on CYP1A2, CYP2A6, CYP2C8, and CYP2D6 was marginal (<25% inhibition at 100 μM voriconazole). Further detailed experiments with HLMs showed that voriconazole is a potent competitive inhibitor of CYP2B6 (Ki< 0.5), CYP2C9 (Ki= 2.79 μM), and CYP2C19 (Ki= 5.1 μM). The inhibition of CYP3A by voriconazole was explained by noncompetitive (Ki= 2.97 μM) and competitive (Ki= 0.66 μM) modes of inhibition. Prediction of the in vivo interaction of voriconazole from these in vitro data suggests that voriconazole would substantially increase the exposure of drugs metabolized by CYP2B6, CYP2C9, CYP2C19, and CYP3A. Clinicians should be aware of these interactions and monitor patients for adverse effects or failure of therapy.
In Vitro and In Vivo Studies To Characterize the Clearance Mechanism and Potential Cytochrome P450 Interactions of Anidulafungin
Authors: Damle Bharat D. , Dowell James A. , Walsky Robert L. , Weber Gregory L. , Stogniew Martin , Inskeep Philip B.
Published: November 2008

Anidulafungin is a novel semisynthetic echinocandin with potent activity againstCandida(including azole-resistant isolates) andAspergillusspp. and is used for serious systemic fungal infections. The purpose of these studies was to characterize the clearance mechanism and potential for drug interactions of anidulafungin. Experiments included in vitro degradation of anidulafungin in buffer and human plasma, a bioassay for antifungal activity, in vitro human cytochrome P450 inhibition studies, in vitro incubation with rat and human hepatocytes, and mass balance studies in rats and humans. Clearance of anidulafungin appeared to be primarily due to slow chemical degradation, with no evidence of hepatic-mediated metabolism (phase 1 or 2). Under physiological conditions, further degradation of the primary degradant appears to take place. The primary degradation product does not retain antifungal activity. Anidulafungin was not an inhibitor of cytochrome P450 enzymes commonly involved in drug metabolism. Mass balance studies showed that anidulafungin was eliminated in the feces predominantly as degradation products, with only a small fraction (10%) eliminated as unchanged drug; fecal elimination likely occurred via biliary excretion. Only negligible renal involvement in the drug's elimination was observed. In conclusion, the primary biotransformation of anidulafungin is mediated by slow chemical degradation, with no evidence for hepatic enzymatic metabolism or renal elimination.
Local and Systemic Responses in Matrix Metalloproteinase 8-Deficient Mice duringPorphyromonas gingivalis-Induced Periodontitis
Authors: Kuula Heidi , Salo Tuula , Pirilä Emma , Tuomainen Anita M. , Jauhiainen Matti , Uitto Veli-Jukka , Tjäderhane Leo , Pussinen Pirkko J. , Sorsa Timo
Published: November 2008

Periodontitis is a bacterium-induced chronic inflammation that destroys tissues that attach teeth to jaw bone. Pathologically excessive matrix metalloproteinase 8 (MMP-8) is among the key players in periodontal destruction by initiating type I collagen degradation. We studied MMP-8 inPorphyromonas gingivalis-induced periodontitis by using MMP-8-deficient (MMP8−/−) and wild-type (WT) mice. Alveolar bone loss, inflammatory mediator expression, serum immunoglobulin, and lipoprotein responses were investigated to clarify the role of MMP-8 in periodontitis and systemic inflammatory responses.P. gingivalisinfection induced accelerated site-specific alveolar bone loss in bothMMP8−/−and WT mice relative to uninfected mice. The most extensive bone degradation took place in theP. gingivalis-infectedMMP8−/−group. Surprisingly, MMP-8 significantly attenuated (P< 0.05)P. gingivalis-induced site-specific alveolar bone loss. Increased alveolar bone loss inP. gingivalis-infectedMMP8−/−and WT mice was associated with increase in gingival neutrophil elastase production. Serum lipoprotein analysis demonstrated changes in the distribution of high-density lipoprotein (HDL) and very-low-density lipoprotein (VLDL) particles; unlike the WT mice, theMMP8−/−mice underwent a shift toward a smaller HDL/VLDL particle sizes.P. gingivalisinfection increased the HDL/VLDL particle size in theMMP8−/−mice, which is an indicator of lipoprotein responses during systemic inflammation. Serum total lipopolysaccharide activity and the immunoglobulin G-class antibody level in response toP. gingivaliswere significantly elevated in both infected mice groups. Thus, MMP-8 appears to act in a protective manner inhibiting the development of bacterium-induced periodontal tissue destruction, possibly through the processing anti-inflammatory cytokines and chemokines. Bacterium-induced periodontitis, especially inMMP8−/−mice, is associated with systemic inflammatory and lipoprotein changes that are likely involved in early atherosclerosis.
How Do Bottlenose Dolphins, Tursiops truncatus, React to Oil Films under Different Light Conditions?
Authors: St. Aubin D. J. , Geraci J. R. , Smith T. G. , Friesen T. G.
Published: November 2008

In daylight, and again at night under a shading canopy, we observed the behavior of bottlenose dolphins (Tursiops truncatus) allowed to swim freely in a pool with three surface divisions, one of which contained either clear mineral oil, dark-tinted mineral oil, or a thin sheen of refined motor oil. Overall, they avoided oil both during the day and at night. The response broke down when we presented them with a thin sheen, especially at night; we suggest that such conditions represent the threshold for their ability to detect oil or their desire to avoid it. Irrespective of light conditions, the dolphins' tactile sense played a more important role than vision in perceiving, and ultimately avoiding, oil. The strength of their basic reaction dampens our fear that they might be unknowingly subjected to prolonged or repeated exposure to oil at sea.
Importance of the Variation in Life History Parameters of Atlantic Salmon (Salmo salar)
Authors: Saunders Richard L. , Schom Charles B.
Published: November 2008

Atlantic salmon (Salmo salar) demonstrate great variability in their life history; individuals from a given year-class can spawn during several years and can, therefore, breed with salmon from other year-classes. Atlantic salmon can mature after 1–4 sea-winters and some males mature as parr, during the second through fifth years, before going to sea. Salmon may survive to spawn more than once; some spawn several times. This variability in life history may be a safeguard against loss of small stocks through several successive years of reproductive failure, since nonspawning individuals in the river or at sea could spawn in subsequent years. Spawning populations are frequently quite small. The effective spawning population size may be potentially much larger, however, since members of several year-classes, including sexually mature male parr and anadromous adults of various ages, contribute to spawning. The level of inbreeding may be relatively low, since a number of year-classes, each with different sets of parents, are represented during spawning.
Distribution of the Stonefly Nymph Paragnetina media (Plecoptera:Perlidae): Influence of Prey, Predators, Current Speed, and Substrate Composition
Authors: Feltmate Blair W. , Baker Robert L. , Pointing Philip J.
Published: November 2008

Effects of prey distribution, presence of a predator, current speed, and substrate composition on distribution of the predaceous stonefly nymph Paragnetina media (Walker) were examined in a large laboratory stream. Distribution of prey (Hydropsyche sparna, H. bronta) did not affect distribution of well-fed or non-fed (48 h) nymphs. However, P. media distribution was significantly influenced by independent and interactive effects of current speed (0.33–0.41 m∙s−1) and substrate composition (53.0–110.0 mm in diameter). In the presence of rainbow trout (Salmo gairdneri), P. media selected more specifically for larger substrate on which risk of predation was less than on smaller size classes. Lighting condition had no effect on substrate selection. Laboratory findings were consistent with distribution of P. media observed in the Credit River, Ontario, during midsummer, late fall, and early spring.
Quantitative measurement of the scour resistance of natural solid clays
Authors: Chapuis Robert P.
Published: November 2008

The erosion of clayey soils is a complex phenomenon that includes various types of erosive actions. A tentative classification of erosion processes is proposed. This paper concentrates on the scour resistance of solid clays. Available prediction methods are reviewed. Generally they propose relationships between physical or mechanical parameters and the critical hydraulic shear stress, [Formula: see text]c, that defines a boundary between "no erosion" and "erosion". It became apparent that the physicochemical parameters of both the clay and the eroding water control the erosion process. However, subsequent studies on these parameters have yet to yield reliable predictions of natural clay erodibility from indirect measurements. An erosion testing program was therefore performed on three Quebec clays with the improved rotating cylinder technique. In this test, intact or remolded samples can be tested, physicochemical parameters can be controlled, and the hydraulic shear stress [Formula: see text] and the erosion rate ė can be adequately determined. A relatively complete and accurate graph of ė versus [Formula: see text], including ė values for [Formula: see text] values lower than critical can be established. Previous and present research underline the need to exert a strict control of all clay and water parameters, including that of sample preparation, in order to adequately simulate a field problem. Key words: erosion, clay, scour resistance, physicochemical properties, rotating cylinder test.
Formulation of backfill material for a nuclear fuel waste disposal vault
Authors: Yong Raymond N. , Boonsinsuk Prapote , Wong Gary
Published: November 2008

The Canadian concept for disposing of nuclear fuel waste, currently being studied by Atomic Energy of Canada Limited (AECL) and Ontario Hydro, is to permanently place the waste in an underground vault located in plutonic rock of the Canadian Shield at a depth of 500–1000 m. The waste will be in containers surrounded by a buffer material. Following waste emplacement, the vault will be backfilled. The quantity of backfill material required will be between 5 and 10 million cubic metres.The development of backfill material for a nuclear fuel waste vault is directed at determining the appropriate composition of backfill material that will meet the stringent criteria to be set by AECL to ensure its successful performance. The criteria, with respect to engineering behaviour, include low hydraulic conductivity, sufficient swelling capacity upon wetting, low shrinkage upon drying, and low segregation tendency. The methodology adopted and the results obtained are described in this paper. Using a mixture of crushed granite aggregate and glacial Lake Agassiz clay, a potential candidate for backfill material would have a maximum grain size of 19.1 mm and a clay content of at least 25% by weight. Such a backfill material will yield low hydraulic conductivity (close to that of the pure clay) and other properties well within the acceptable range. Key words: aggregate–clay mixture, swelling clay, hydraulic conductivity, backfill, waste management.
CFD Code Validation against Stratified Air-Water Flow Experimental Data
Authors: Terzuoli F. , Galassi M. C. , Mazzini D. , D'Auria F.
Published: November 2008

Pressurized thermal shock (PTS) modelling has been identified as one of the most important industrial needs related to nuclear reactor safety. A severe PTS scenario limiting the reactor pressure vessel (RPV) lifetime is the cold water emergency core cooling (ECC) injection into the cold leg during a loss of coolant accident (LOCA). Since it represents a big challenge for numerical simulations, this scenario was selected within the European Platform for Nuclear Reactor Simulations (NURESIM) Integrated Project as a reference two-phase problem for computational fluid dynamics (CFDs) code validation. This paper presents a CFD analysis of a stratified air-water flow experimental investigation performed at the Institut de Mécanique des Fluides de Toulouse in 1985, which shares some common physical features with the ECC injection in PWR cold leg. Numerical simulations have been carried out with two commercial codes (Fluent and Ansys CFX), and a research code (NEPTUNE CFD). The aim of this work, carried out at the University of Pisa within the NURESIM IP, is to validate the free surface flow model implemented in the codes against experimental data, and to perform code-to-code benchmarking. Obtained results suggest the relevance of three-dimensional effects and stress the importance of a suitable interface drag modelling.
Photosensitivity of the Er/Yb-Codoped Schott IOG1 Phosphate Glass Using 248 nm, Femtosecond, and Picosecond Laser Radiation
Authors: Pissadakis Stavros , Michelakaki Irini
Published: November 2008

The effect of 248 nm laser radiation, with pulse duration
of 5 picoseconds, 500 femtoseconds, and 120 femtoseconds, on the optical properties and the Knoop hardness of a commercial Er/Yb-codoped phosphate glass is presented here. Refractive index changes of the order of few parts of 10-4 are correlated with optical absorption centers induced in the glass volume, using Kramers-Kroning relationship. Accordingly, substantially lower refractive index changes are measured in volume Bragg gratings inscribed in the glass, indicating that, in addition to the optical density changes, volume dilation changes of negative sign may also be associated with the 248 nm ultrafast irradiation. The Knoop hardness experimental results reveal that the glass matrix undergoes an observable initial hardening and then a reversing softening and volume dilation process for modest accumulated energy doses, where the Knoop hardness follows a nonmonotonic trend. Comparative results on the Knoop hardness trend are also presented for the case of 193 nm excimer laser radiation. The above findings denote that the positive or negative evolution of refractive index changes induced by the 248 nm ultrafast radiation in the glass is dominated by the counteraction of the color center formation and the volume modification effects.
The Role of PPARs in the Endothelium: Implications for Cancer Therapy
Authors: Bishop-Bailey David , Swales Karen E.
Published: November 2008

The growth and metastasis of cancers intimately involve the vasculature and in particular the endothelial cell layer. Tumours require new blood vessel formation via angiogenesis to support growth. In addition, inflammation, coagulation, and platelet activation are common signals in the growth and metastasis of tumour cells. The endothelium plays a central role in the homeostatic control of inflammatory cell recruitment, regulating platelet activation and coagulation pathways. PPARα, ‐β/δ, and ‐γ are all expressed in endothelial cells. This review will discuss the roles of PPARs in endothelial cells in relation to angiogenesis, inflammation, coagulation, and platelet control pathways. In particular, we will discuss the recent evidence that supports the hypothesis that PPARα and PPARγ are antiangiogenic receptors, while PPARβ/δ is proangiogenic.
Lactobacillus rhamnosusGG Suppresses MeningiticE. coliK1 Penetration across Human Intestinal Epithelial Cells In Vitro and Protects Neonatal Rats against Experimental Hematogenous Meningitis
Authors: Huang Sheng-He , He Lina , Zhou Yanhong , Wu Chun-Hua , Jong Ambrose
Published: November 2008

The purpose of this study was to examine prophylactic efficacy of probiotics in neonatal sepsis and meningitis caused byE. coliK1. The potential inhibitory effect ofLactobacillus rhamnosusGG (LGG) on meningiticE. coliK1 infection was examined by using (i) in vitro inhibition assays with E44 (a CSF isolate from a newborn baby withE. colimeningitis), and (ii) the neonatal rat model ofE. colisepsis and meningitis. The in vitro studies demonstrated that LGG blocked E44 adhesion, invasion, and transcytosis in a dose-dependent manner. A significant reduction in the levels of pathogen colonization,E. colibacteremia, and meningitis was observed in the LGG-treated neonatal rats, as assessed by viable cultures, compared to the levels in the control group. In conclusion, probiotic LGG strongly suppresses meningiticE. colipathogens in vitro and in vivo. The results support the use of probiotic strains such as LGG for prophylaxis of neonatal sepsis and meningitis.
Predominance of Heart Failure in the Heart of Soweto Study Cohort
Authors: Stewart Simon , Wilkinson David , Hansen Craig , Vaghela Vinesh , Mvungi Robert , McMurray John , Sliwa Karen
Published: November 2008

Background—

There is a paucity of data to describe the clinical characteristics of heart failure (HF) in urban African communities in epidemiological transition.

Methods and Results—

Chris Hani Baragwanath Hospital services the 1.1 million black African community of Soweto, South Africa. Of 1960 cases of HF and related cardiomyopathies in 2006, we prospectively collected detailed demographic and clinical data from all 844 de novo presentations (43%). Mean age was 55±16 years, and women (479 [57%]) and black Africans (739 [88%]) predominated. Most (761 [90%]) had ≥1 cardiovascular risk. Mean left ventricular ejection fraction was 45±18%. Overall, 180 patients (23%) had isolated diastolic dysfunction, 234 (28%) tricuspid regurgitation, 121 (14%) isolated right HF, and 100 (12%) mitral regurgitation. The most common diagnoses were hypertensive HF (281 [33%]), idiopathic dilated cardiomyopathy (237 [28%]), and, surprisingly, right HF (225 [27%]). Black Africans had less ischemic cardiomyopathy (adjusted odds ratio, 0.12; 95% CI, 0.07 to 0.20) but more idiopathic and other causes of cardiomyopathy (adjusted odds ratio, 4.80; 95% CI, 2.57 to 8.93). Concurrent renal dysfunction, anemia, and atrial fibrillation were found in 172 (25%), 72 (10%), and 53 (6.3%) cases, respectively.

Conclusions—

These contemporary data highlight the multiple challenges of preventing and managing an increasing and complex burden of HF in urban Africa. In addition to tackling antecedent hypertension, a predominance of young women and a large component of right HF predicate the development of tailored therapeutic strategies.
Cholesteryl Ester Transfer Protein Inhibition, High-Density Lipoprotein Raising, and Progression of Coronary Atherosclerosis
Authors: Nicholls Stephen J. , Tuzcu E. Murat , Brennan Danielle M. , Tardif Jean-Claude , Nissen Steven E.
Published: November 2008

Background—

Despite favorable effects on high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol, the cholesteryl ester transfer protein inhibitor torcetrapib failed to slow atherosclerosis progression and increased mortality. We investigated the relationship between lipid changes and progression of coronary atherosclerosis.

Methods and Results—

Intravascular ultrasound was performed at baseline and follow-up in 910 participants randomized to torcetrapib/atorvastatin or atorvastatin monotherapy. The relationship between changes in lipoprotein levels and the primary intravascular ultrasound end point, change in percent atheroma volume, was investigated. Compared with atorvastatin monotherapy, torcetrapib raised HDL-C by 61%, lowered low-density lipoprotein cholesterol by 20%, raised serum sodium (0.44±0.14 mmol/L,
P
=0.02), and lowered serum potassium (0.11±0.02 mmol/L,
P
<0.0001). Despite substantial increases in HDL-C, no effect was found of torcetrapib on percent atheroma volume. In torcetrapib-treated patients, an inverse relationship was observed between changes in HDL-C and percentage atheroma volume (
r
=−0.17,
P
<0.001). Participants with regression had greater increases in HDL-C (mean±SE, 62.9±37.4% versus 54.0±39.1%,
P
=0.002). Compared with the lowest quartile, torcetrapib-treated patients in the highest quartile of HDL-C change showed the least progression (−0.31±0.27 versus 0.88±0.27%,
P
=0.001). The highest on-treatment HDL-C quartile showed significant regression of percent atheroma volume (−0.69±0.27%,
P
=0.01). In multivariable analysis, changes in HDL-C levels independently predicted the effect on atherosclerosis progression (
P
=0.001).

Conclusions—

The majority of torcetrapib-treated patients demonstrated no regression of coronary atherosclerosis. Regression was only observed at the highest HDL-C levels. Torcetrapib raised serum sodium and lowered potassium, consistent with an aldosterone-like effect, which may explain the lack of favorable effects in the full study cohort. Accordingly, other cholesteryl ester transfer protein inhibitors, if they lack this off-target toxicity, may successfully slow atherosclerosis progression.
Effects of Habitual Alcohol Intake on Ambulatory Blood Pressure, Heart Rate, and Its Variability Among Japanese Men
Authors: Ohira Tetsuya , Tanigawa Takeshi , Tabata Minako , Imano Hironori , Kitamura Akihiko , Kiyama Masahiko , Sato Shinichi , Okamura Tomonori , Cui Renzhe , Koike Kazuko A. , Shimamoto Takashi , Iso Hiroyasu
Published: November 2008

We sought to examine effects of habitual alcohol intake on ambulatory blood pressure (BP), heart rate (HR), and HR variability among Japanese men. Subjects were 539 men aged 35 to 65 years from rural and urban communities. Ambulatory BP and HR were monitored with an automated, portable, noninvasive multibiomedical recorder. Power spectral analysis of the RR intervals on the ECG was performed every 5 minutes. Compared with nondrinkers, moderate drinkers (alcohol intake 23 to 45 g/d) and heavy drinkers (alcohol intake ≥46 g/d) showed higher age- and field-adjusted mean values of systolic and diastolic BPs during the morning and while awake, but there were no differences in BPs over 24-hour periods and while asleep among the alcohol intake categories. Alcohol intake was positively associated with mean values of sleep-morning differences and daytime variability in BPs, HRs while awake and asleep, and low frequency:high frequency ratio while asleep. The results were virtually unchanged after adjustment for body mass index, smoking, and diabetes mellitus. Compared with the nondrinkers, age- and field-adjusted odds ratios of the morning BP surge (excess elevation of BP in the morning: morning systolic BP minus sleep systolic BP ≥37 mm Hg) for light (alcohol intake 0 to 22 g/d), moderate, and heavy drinkers were 0.96 (95% CI: 0.34 to 2.78), 1.68 (95% CI: 0.64 to 4.38), and 2.73 (95% CI: 1.12 to 6.67), respectively. Habitual alcohol intake was associated with increased BP in the morning, HR while awake and asleep, and sympathetic activity while asleep, which may explain some of the mechanisms of the relationship between heavy alcohol intake and risk of cardiovascular diseases.
Association Between the Dietary Approaches to Hypertension Diet and Hypertension in Youth With Diabetes Mellitus
Authors: Günther Anke L.B. , Liese Angela D. , Bell Ronny A. , Dabelea Dana , Lawrence Jean M. , Rodriguez Beatriz L. , Standiford Debra A. , Mayer-Davis Elizabeth J.
Published: November 2008

Among youth with diabetes mellitus, elevated blood pressure represents one of the most common comorbidities. Hence, exploring dietary factors that may help prevent or control hypertension in this population is of paramount importance. We investigated whether adherence to the Dietary Approaches to Stop Hypertension (DASH) diet is associated with hypertension in youth with diabetes mellitus from the SEARCH for Diabetes in Youth Study. Between 2001 and 2005, 2830 youth aged 10 to 22 years (2440 with type 1 and 390 with type 2 diabetes mellitus) completed a study visit. For each of the 8 DASH food groups, a score of 10 was assigned when the DASH recommendation was met. Lower intakes were scored proportionately, and the 8 individual scores were summed. The association between the overall DASH score and hypertension was evaluated using multiple logistic regression. The crude prevalence of hypertension was 6.8% for youth with type 1 and 28.2% for youth with type 2 diabetes mellitus. In youth with type 1, a higher adherence to DASH was inversely related to hypertension, independent of demographic, clinical, and behavioral characteristics (tertile 2 versus 1: odds ratio: 0.7, 95% CI: 0.5 to 1.0; 3 versus 1: odds ratio: 0.6, 95% CI: 0.4 to 0.9;
P
trend
=0.007). For type 2 diabetes mellitus, the DASH diet was not associated with hypertension (tertile 2 versus 1: odds ratio: 0.8, 95% CI: 0.5 to 1.4; 3 versus 1: odds ratio: 0.9, 95% CI: 0.5 to 1.5;
P
trend
=0.6). Prospective observational studies or clinical trials are needed to investigate whether adherence to the DASH guidelines may help prevent hypertension in youth with type 1 diabetes mellitus. In type 2 diabetes mellitus, more research with a larger sample is necessary.
Discontinuities due to Joining Precipitation Station Observations in Canada
Authors: Vincent Lucie A. , Mekis Eva
Published: November 2008

When a climatological station is relocated or is closing, it is often possible to join the climate observations of a nearby site to create a longer time series. However, joining climate observations can sometimes introduce artificial discontinuity that affects the trend. A procedure to detect discontinuities at the joining dates for precipitation station observations is described. It is based on standardized ratios between a tested station and a neighbor, and the t test is used to determine whether the means before and after the joining dates are statistically significantly different. The procedure is applied to 234 climatological stations across Canada to identify steps in rainfall and snowfall. The results indicate that joining precipitation station observations creates steps of different magnitude for rain and snow. It is concluded that about 35% of the stations need adjustment for rain whereas 58% of the stations need adjustment for snow. The magnitude of the adjustments varies from 0.75 to 1.25 for rain and from 0.65 to 1.60 for snow. The annual and seasonal trends before and after adjustments are also examined for 1930–2007. The results show that the trends computed from the adjusted data present a more consistent regional pattern than do trends computed from the unadjusted observations.
On the Analysis of a Cloud Seeding Dataset over Tasmania
Authors: Morrison Anthony E. , Siems Steven T. , Manton Michael J. , Nazarov Alex
Published: November 2008

An analysis of cloud seeding activity for the period 1960–2005 over a hydroelectric catchment (target) area located in central Tasmania, Australia, is presented. The analysis is performed using a double ratio on monthly area-averaged rainfall for the months of May–October. Results indicate that increases in monthly precipitation are observed within the target area relative to nearby controls during periods of cloud seeding activity. Ten independent tests were performed and all double ratios found are above unity with values that range from 5% to 14%. Nine out of 10 confidence intervals are entirely above unity and overlap in the range of 6%–11%. Nine tests obtain levels of significance >0.05 level. If the Bonferroni adjustment is made to account for multiple comparisons, six tests are found to be significant at the adjusted alpha level. Further field measurements of the cloud microphysics over this region are needed to provide a physical basis for these statistical results.
Evolution of the Vertical Thermodynamic Profile during the Transition from Shallow to Deep Convection during CuPIDO 2006*
Authors: Zehnder Joseph A. , Hu Jiuxiang , Radzan Anshuman
Published: November 2008

The evolution of the vertical thermodynamic profile associated with two cases of deep orographic convection were studied with data from an instrumented aircraft, mobile surface based radiosondes, and stereo photogrammetric analyses. The data were collected during a field experiment [i.e., the Cumulus Photogrammetric, In Situ, and Doppler Observations (CuPIDO) experiment in 2006] performed over the Santa Catalina Mountains in southern Arizona. In both cases the vertical thermodynamic profile was modified in a way that supported subsequent deep convection. In one case, a midtropospheric stable layer was eroded through low-level warming and cooling at the cloud-top level that was likely due to an adiabatic adjustment of the profile through the action of gravity waves. In the second case, dry air aloft was moistened through the action of the shallow convection thus preventing the erosion of the convective turrets through entrainment of dry air. These cases illustrate mechanisms for convective conditioning of the atmosphere that may organize deep convection in general.
“I Write to Know What I Think”: a Four-Year Writing Curriculum
Authors: Lister Elena , Kravis Nathan , Sandberg Larry , Halpern Jeffrey K. , Cabaniss Deborah L. , Singer Meriamne B.
Published: November 2008

The four-year writing curriculum of the Columbia Center for Psychoanalytic Training and Research has as its main objective to teach candidates to learn about analysis through writing. Learning to write about analyses ultimately entails learning to clarify and then express how one thinks and functions as an analyst. Since its inception ten years ago, the program has evolved into its current structure, a stepwise approach through the years of candidate training based on a didactic method called “layering.” For each level of the course, candidates' typical writing difficulties are examined, and examples given of write-ups and how they were used in teaching. The essential role of the faculty experience is also described.
Democracy under the Gun Understanding Postconflict Economic Recovery
Authors: Edward Flores Thomas , Nooruddin Irfan
Published: November 2008

Increasingly, scholars studying civil conflicts believe that the pace of postconflict economic recovery is crucial to a return to peaceful politics. But why do some countries' economies recover more quickly than others'? The authors argue that the inability of politicians to commit credibly to postconflict peace inhibits investment and, hence, slows recovery. In turn, the ability of political actors to eschew further violence credibly depends on postconflict political institutions. The authors test this framework with duration analysis of an original data set of economic recovery, with two key results. First, they find that postconflict democratization retards recovery. Second, outright military victory sets the stage for a longer peace than negotiated settlements do. This research deepens the understanding of the bases of economic recovery and conflict recidivism in postconflict countries and points to future research that can augment this knowledge further still.
Use of Web and In-Person Survey Modes to Gather Data From Young Adults on Sex and Drug Use
Authors: McMorris Barbara J. , Petrie Renee S. , Catalano Richard F. , Fleming Charles B. , Haggerty Kevin P. , Abbott Robert D.
Published: November 2008

In a randomized test of mixed-mode data collection strategies, 386 participants in the Raising Healthy Children (RHC) Project were either (a) asked to complete a survey via the Internet and later offered the opportunity to complete the survey in person or (b) first offered an in-person survey, with the Web follow-up. The Web-first condition resulted in cost savings although the overall completion rates for the 2 conditions were similar. On average, in-person-first condition participants completed surveys earlier in the field period than Web-first condition participants. Based on intent-to-treat analyses, little evidence of condition effects on response bias, with respect to rates or levels of reported behavior, was found.
Public Ethnic Regard and Perceived Socioeconomic Stratification: Associations With Well-Being Among Dominican and Black American Youth
Authors: Rivas-Drake Deborah , Hughes Diane , Way Niobe
Published: November 2008

As the U.S. Latino population continues to diversify, it is necessary to understand their experiences of minority status and its implications for well-being. The present cross-sectional study investigates early adolescents' perceptions of public regard for their ethnic group and perceptions of the extent to which opportunity is differentiated by their socioeconomic background (perceived socioeconomic stratification). A comparative approach is taken to examine the extent to which the experiences of Dominican American youth ( n = 103) mirrored those of their Black American peers ( n = 129). For all youth, more positive public ethnic regard is associated with fewer somatic symptoms, whereas more perceived socioeconomic stratification is associated with more somatic symptoms. For Black youth, in contrast to Dominican youth, lower public regard is associated with higher self-esteem among those who perceives more socioeconomic stratification. Implications for Dominican and Black American youths' experiences of minority status are discussed.
The Development of Children’s Ethnic Identity in Immigrant Chinese Families in Canada
Authors: Su Tina F. , Costigan Catherine L.
Published: November 2008

Parents’ role in children’s ethnic identity development was examined among 95 immigrant Chinese families with young adolescents living in Canada. Children reported their feelings of ethnic identity and perceptions of parental family obligation expectations. Parents reported their family obligation expectations; parents and children reported on parenting practices. Mothers’ expectations, but not fathers’, were positively associated with children’s feelings of ethnic identity. This relation was mediated by children’s perceptions of parental expectations, suggesting that children must first perceive their parents’ expectations for these expectations to influence their ethnic identity. More positive parenting practices were related to stronger feelings of ethnic identity. Mothers’ parenting practices moderated the relations between mothers’ expectations and children’s ethnic affirmation and belonging. The results suggest immigrant mothers’ family obligation expectations provide an avenue for positive family identification and ethnic culture learning opportunities that may encourage children’s ethnic identity development.