bluuebunny/crossref_metadata_2025 huggingface dataset:
Polymorphic microsatellite loci for the sand pocket mouseChaetodipus arenarius, an endemic from the Baja California Peninsula
Authors: MUNGUIA‐VEGA A. , RODRIGUEZ‐ESTRELLA R. , NACHMAN M. , CULVER M.
Published: November 2008

Fifteen polymorphic microsatellite loci were isolated from an enriched genomic library of the sand pocket mouseChaetodipus arenarius. The mean number of alleles per locus was 11.53 (range five to 19) and the average observed heterozygosity was 0.764 (range 0.121 to 1.0). The markers will be used for detecting the impact of human‐induced habitat fragmentation on patterns of gene flow, genetic structure, and extinction risk. In addition, these markers will be useful across the genus because most of the loci cross‐amplified and were polymorphic in three other species ofChaetodipus.
Fully informative microsatellite markers for the tetraploid plant Eritrichium nanum (Boraginaceae)
Authors: WIRTH L. R. , GRAF R. , BRODBECK S. , REBER‐FUNK C. , HOLDEREGGER R. , LANDERGOTT U.
Published: November 2008

We characterized eight polymorphic, codominant nuclear microsatellite loci in the tetraploid plant Eritrichium nanum. The different allelic configurations occurring under tetrasomic inheritance were fully resolved at all loci. Two natural populations showed high observed heterozygosities, which were in agreement with Hardy–Weinberg expectations. There was no evidence of genetic linkage disequilibrium for any pair of loci. The results suggest that these microsatellite markers are useful for mating system and population genetic analyses in high‐alpine E. nanum.
Niacin for Stroke Prevention: Evidence and Rationale
Authors: Keener Adrienne , Sanossian Nerses
Published: November 2008

Low levels of high‐density lipoprotein (HDL) cholesterol are associated with increased atherothrombotic events, including stroke. Niacin is a safe and effective means of raising HDL, yet its role in stroke prevention is not well characterized. The purpose of the study is to determine the role of niacin in stroke prevention. A search of the PUBMED database using the keywords niacin, stroke, atherosclerosis, and/or carotid artery was undertaken to identify studies for review. National guidelines from the American Heart Asssociation and National Cholesterol Education Program were reviewed. Treatment of low serum HDL (<40 mg/dL) is an identified goal of dyslipidemic therapy. Niacin is effective in raising HDL levels and reducing cardiovascular events in individuals with high vascular risk and can be used for treatment of stroke patients with low serum HDL. Niacin can be used safely in combination with statins, the first‐line dyslipidemic treatment for secondary stroke risk reduction, with increased efficacy. Studies are needed to better define the role for niacin in secondary stroke prevention. Treatment of stroke patients with extended‐release (ER) of niacin, alone or in combination with statins, should be considered in stroke patients with atherosclerotic mechanisms with low serum HDL‐C levels.
Simultaneous Manipulation of Multiple Brain Targets by Green Tea Catechins: A Potential Neuroprotective Strategy for Alzheimer and Parkinson Diseases
Authors: Mandel Silvia A. , Amit Tamar , Weinreb Orly , Reznichenko Lydia , Youdim Moussa B. H.
Published: November 2008

Current therapeutic approaches for Alzheimer and Parkinson disease (AD and PD, respectively) are merely symptomatic, intended for the treatment of symptoms, but offer only partial benefit, without any disease‐modifying activity. Novel promising strategies suggest the use of antiinflammatory drugs, antioxidants, iron‐complexing molecules, neurotrophic factor delivery, inhibitors of the amyloid precursor protein (APP)‐processing secretases, gamma and beta (that generate the amyloid‐beta peptides, Aβ), anti‐Aβ aggregation molecules, the interference with lipid cholesterol metabolism and naturally occurring plant flavonoids to potentially reverse the course of the diseases. Human epidemiological and new animal data suggest that tea drinking may decrease the incidence of dementia, AD, and PD. In particular, its main catechin polyphenol constituent (‐)‐epigallocatechin‐3‐gallate (EGCG) has been shown to exert neuroprotective/neurorescue activities in a wide array of cellular and animal models of neurological disorders. In the current article, we review the literature on the impact of the multimodal activities of green tea polyphenols and their neuroprotective effect on AD and PD.
Racial differences in bone density and fracture risk in the United States
Authors: WALKER Marcella D. , BILEZIKIAN John P.
Published: November 2008

Many studies indicate racial differences in areal bone mineral density (aBMD). African‐Americans tend to have the greatest aBMD, followed by Caucasian, Hispanic and Native Americans. Asian Americans, on average, have the lowest aBMD. Differences in aBMD are attenuated when adjustments are made for bone size, weight and lifestyle factors. While many studies have focused on racial differences in bone density, it is important to consider fracture risk since it is the clinically meaningful outcome and is determined by many factors other than bone density. African‐ and Asian‐Americans have a relatively low risk of fracture compared to other groups, despite drastically different bone density, as measured by dual X‐ray absorptiometry (DXA). Factors that cannot be completely evaluated by DXA, such as bone size, volumetric density, bone microarchitecture and turnover may be important in explaining disparate fracture rates. Newer technologies such as central quantitative computed tomography (CT) and high‐resolution peripheral CT promise to contribute important knowledge in this regard. Despite recent advances, more fracture risk data is needed for non‐Caucasian groups to assist in the development of relevant screening and treatment guidelines.
Mapping translational research into individualized prognosis of fracture risk
Authors: NGUYEN Tuan V.
Published: November 2008

The assessment of fracture risk has until now been based on the measurement of bone mineral density (BMD) and/or a prior fracture. Individuals with BMD T‐scores < –2.5 (e.g. osteoporosis) or with prior fractures are indicated for treatment. However, recent data have suggested that 55% of women and 74% of men who sustained a fracture did not have osteoporosis. Therefore, the current strategy reduces a small number of fractures in the general population, and new thinking is required for that majority of individuals whose BMD measurements are at or near (both sides) the current threshold of osteoporosis. An individual's absolute risk of fracture can be estimated from the individual risk profile, which includes age, BMD, weight or body mass index, prior fracture, comorbidities, corticosteroid use, lifestyle factors, and falls. Therefore, risk assessment must simultaneously consider all risk factors to which the individual is exposed. A number of prognostic models and predictive nomograms have been developed to estimate an individual's absolute risk of fracture, but they have not been externally validated. Nevertheless, these prognostic models can be effective tools for individualizing short‐term and long‐term risks of fracture, which can help patient counseling and selecting appropriate patients for intervention to maximize the benefit of fracture reduction in the general population.
Trends in calcium and vitamin D usage among older people in nursing care facilities in Australia: still falling short of the guidelines
Authors: SÀNCHEZ RIERA Lídia , WILSON Nicholas M. , SAMBROOK Philip N. , KOK Cindy , CUMMING Robert G. , CAMERON Ian D. , CHEN Jian Sheng , SIMPSON Judy , MASON Rebecca S. , SEIBEL Markus J. , MARCH Lynn M.
Published: November 2008

Objective:  To determine the impact of awareness‐raising strategies of calcium and vitamin D supplements in the active management of bone health of older people living in nursing care facilities in Australia.

Design:  We compared data drawn from two prospective cohort studies that have evaluated falls and fractures in older people living in hostels (intermediate care facilities): the FREE study (conducted from 1996–2002, n = 1107) and the ongoing FREEDOM study (commenced in 2006, n = 1284 screened individuals). Both studies recruited older people living in a large number of nursing care facilities in northern Sydney (Australia).

Results:  We found a small but significant increase in both calcium and vitamin D supplementation in the FREEDOM study participants compared to those in the FREE study. Calcium alone increased from 6.2% to 10.5% (P = 0.0002), vitamin D alone from 5.8% to 7.9% (P = 0.04) and the combined use of calcium and vitamin D increased from 1.6% to 11.9% (P < 0.0001).

Conclusion:  There appears to be increasing awareness of the need for calcium and vitamin D supplementation in older people in nursing care facilities. However, given the high prevalence of osteoporosis and vitamin D deficiency among this population, the levels of supplementation achieved must still be considered suboptimal for treatment and prevention of osteoporosis and falls.
Validation of the English version of the quality of life questionnaire of the European Foundation for Osteoporosis (QUALEFFO) in Malaysia
Authors: LAI Pauline Siew Mei , CHUA Siew Siang , CHAN Siew Pheng , LOW Wah Yun
Published: November 2008

Background:  Osteoporotic fractures will soon become a common problem in Asian countries including Malaysia, as the growth in the elderly population will be more marked in this region. This leads to loss of independence and reduced quality of life (QOL). QOL is used as an outcome measure in clinical trials to focus the management of diseases on the patient rather than the disease. To date, no such instrument for measuring QOL of osteoporosis patients has been validated in Malaysia.

Aim:  To investigate the reliability and validity of the English version of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO) in Malaysia.

Methods:  QUALEFFO was administered twice to postmenopausal osteoporotic women on alendronate. The patient group consisted of 46 women with back pain while the control group consisted of 42 women without back pain.

Results:  High internal consistency was seen in all domains in the QUALEFFO with Cronbach α of 0.74–0.95 and 0.53–0.89 in the patient and control group, respectively. Factor analysis also showed that each domain consisted of one component except for the social domain. The test‐retest reliability showed high correlation coefficient in all domains (0.50–0.90, P < 0.001). Patients with back pain showed significantly worse QOL in the overall total QUALEFFO score compared to the control group (P < 0.0001).

Conclusions:  The English version of QUALEFFO was found to be reliable and valid for the evaluation of patients with osteoporosis and who understand English in Malaysia. This study also indicates that patients with back pain have poorer QOL.
Spatial and temporal variation in species‐area relationships in the Fynbos biological hotspot
Authors: Manne Lisa L. , Williams Paul H. , Midgley Guy F. , Thuiller Wilfried , Rebelo Tony , Hannah Lee
Published: November 2008

Species‐area relations (SARs) are among the few recognized general patterns of ecology, are empirical relations giving the number of species found within an area of a given size and were initially formulated for island environments. The use of SARs has been extended to mainland environments, and to give baseline estimates of extinction rates attending habitat loss. Using current species distributions based on atlas data, we examined the spatial variation of rates of species accumulation and species‐area curves for Proteaceae species for all one‐minute by one‐minute areas within the Cape Floristic Region, South Africa. We compared SARs for current distributions to those generated from modeled future Protea distributions following climate change. Within one biome and for two different scales, there exists a very large spatial variation in turnover rates for current Proteaceae distributions, and we show that these rates will not remain constant as climate warming progresses. As climate changes in coming years, some areas will gain species due to migration, as other areas lose species, and still other areas maintain current rates of species accumulation/turnover. Both current and future distributions show highly variable rates of species accumulation across the landscape. This means that an average species‐area relationship will hide a very large interval of variation among SARs, for both current and future Proteaceae distributions. The use of species‐area relations to estimate species extinctions following loss of current habitat, or loss of future climatically‐suitable area is likely to result in erroneous predictions.
Agent‐based model approach to optimal foraging in heterogeneous landscapes: effects of patch clumpiness
Authors: Nonaka Etsuko , Holme Petter
Published: November 2008

Optimal foraging theory concerns animal behavior in landscapes where food is concentrated in patches. The efficiency of foraging is an effect of both the animal behavior and the geometry of the landscape; furthermore, the landscape is itself affected by the foraging of animals. We investigated the effect of landscape heterogeneity on the efficiency of an optimal forager. The particular aspect of heterogeneity we considered was “clumpiness”– the degree to which food resource patches are clustered together. The starting point for our study was the framework of the Mean Value Theorem (MVT) by Charnov. Since MVT is not spatially explicit, and thus not apt to investigate effects of clumpiness, we built an agent‐based (or individual‐based) model for animal movement in discrete landscapes extending the MVT. We also constructed a model for generating landscapes where the clumpiness of patches can be easily controlled, or “tuned”, by an input parameter. We evaluated the agent based model by comparing the results with what the MTV would give, i.e. if the spatial effects were removed. The MVT matched the simulations best on landscapes with random patch configuration and high food recovery rates. As for our main question about the effects of clumpiness, we found that, when landscapes were highly productive (rapid food replenishment), foraging efficiency was greatest in clumped landscapes. In less productive landscapes, however, foraging efficiency was lowest in landscapes with a clumped patch distribution.
Analysis of Flow Disturbance in a Stenosed Carotid Artery Bifurcation Using Two-Equation Transitional and Turbulence Models
Authors: Tan F. P. P. , Soloperto G. , Bashford S. , Wood N. B. , Thom S. , Hughes A. , Xu X. Y.
Published: November 2008

In this study, newly developed two-equation turbulence models and transitional variants are employed for the prediction of blood flow patterns in a diseased carotid artery where the growth, progression, and structure of the plaque at rupture are closely linked to low and oscillating wall shear stresses. Moreover, the laminar-turbulent transition in the poststenotic zone can alter the separation zone length, wall shear stress, and pressure distribution over the plaque, with potential implications for stresses within the plaque. Following the validation with well established experimental measurements and numerical studies, a magnetic-resonance (MR) image-based model of the carotid bifurcation with 70% stenosis was reconstructed and simulated using realistic patient-specific conditions. Laminar flow, a correlation-based transitional version of Menter’s hybrid k‐ϵ∕k‐ω shear stress transport (SST) model and its “scale adaptive simulation” (SAS) variant were implemented in pulsatile simulations from which analyses of velocity profiles, wall shear stress, and turbulence intensity were conducted. In general, the transitional version of SST and its SAS variant are shown to give a better overall agreement than their standard counterparts with experimental data for pulsatile flow in an axisymmetric stenosed tube. For the patient-specific case reported, the wall shear stress analysis showed discernable differences between the laminar flow and SST transitional models but virtually no difference between the SST transitional model and its SAS variant.
A Finite Element Prediction of Strain on Cells in a Highly Porous Collagen-Glycosaminoglycan Scaffold
Authors: Stops A. J. F. , McMahon L. A. , O’Mahoney D. , Prendergast P. J. , McHugh P. E.
Published: November 2008

Tissue engineering often involves seeding cells into porous scaffolds and subjecting the scaffold to mechanical stimulation. Current experimental techniques have provided a plethora of data regarding cell responses within scaffolds, but the quantitative understanding of the load transfer process within a cell-seeded scaffold is still relatively unknown. The objective of this work was to develop a finite element representation of the transient and heterogeneous nature of a cell-seeded collagen-GAG-scaffold. By undertaking experimental investigation, characteristics such as scaffold architecture and shrinkage, cellular attachment patterns, and cellular dimensions were used to create a finite element model of a cell-seeded porous scaffold. The results demonstrate that a very wide range of microscopic strains act at the cellular level when a sample value of macroscopic (apparent) strain is applied to the collagen-GAG-scaffold. An external uniaxial strain of 10% generated a cellular strain as high as 49%, although the majority experienced less than ∼5% strain. The finding that the strain on some cells could be higher than the macroscopic strain was unexpected and proves contrary to previous in vitro investigations. These findings indicate a complex system of biophysical stimuli created within the scaffolds and the difficulty of inducing the desired cellular responses from artificial environments. Future in vitro studies could also corroborate the results from this computational prediction to further explore mechanoregulatory mechanisms in tissue engineering.
Three-Dimensional Modeling and Computational Analysis of the Human Cornea Considering Distributed Collagen Fibril Orientations
Authors: Pandolfi Anna , Holzapfel Gerhard A.
Published: November 2008

Experimental tests on human corneas reveal distinguished reinforcing collagen lamellar structures that may be well described by a structural constitutive model considering distributed collagen fibril orientations along the superior-inferior and the nasal-temporal meridians. A proper interplay between the material structure and the geometry guarantees the refractive function and defines the refractive properties of the cornea. We propose a three-dimensional computational model for the human cornea that is able to provide the refractive power by analyzing the structural mechanical response with the nonlinear regime and the effect the intraocular pressure has. For an assigned unloaded geometry we show how the distribution of the von Mises stress at the top surface of the cornea and through the corneal thickness and the refractive power depend on the material properties and the fibril dispersion. We conclude that a model for the human cornea must not disregard the peculiar collagen fibrillar structure, which equips the cornea with the unique biophysical, mechanical, and optical properties.
Validation of a Numerical Model of Skeletal Muscle Compression With MR Tagging: A Contribution to Pressure Ulcer Research
Authors: Ceelen K. K. , Stekelenburg A. , Mulders J. L. J. , Strijkers G. J. , Baaijens F. P. T. , Nicolay K. , Oomens C. W. J.
Published: November 2008

Sustained tissue compression can lead to pressure ulcers, which can either start superficially or within deeper tissue layers. The latter type includes deep tissue injury, starting in skeletal muscle underneath an intact skin. Since the underlying damage mechanisms are poorly understood, prevention and early detection are difficult. Recent in vitro studies and in vivo animal studies have suggested that tissue deformation per se can lead to damage. In order to conclusively couple damage to deformation, experiments are required in which internal tissue deformation and damage are both known. Magnetic resonance (MR) tagging and T2-weighted MR imaging can be used to measure tissue deformation and damage, respectively, but they cannot be combined in a protocol for measuring damage after prolonged loading. Therefore, a dedicated finite element model was developed to calculate strains in damage experiments. In the present study, this model, which describes the compression of rat skeletal muscles, was validated with MR tagging. Displacements from both the tagging experiments and the model were interpolated on a grid and subsequently processed to obtain maximum shear strains. A correlation analysis revealed a linear correlation between experimental and numerical strains. It was further found that the accuracy of the numerical prediction decreased for increasing strains, but the positive predictive value remained reasonable. It was concluded that the model was suitable for calculating strains in skeletal muscle tissues in which damage is measured due to compression.
Constitutive Modeling of Skeletal Muscle Tissue With an Explicit Strain-Energy Function
Authors: Odegard G. M. , Haut Donahue T. L. , Morrow D. A. , Kaufman K. R.
Published: November 2008

While much work has previously been done in the modeling of skeletal muscle, no model has, to date, been developed that describes the mechanical behavior with an explicit strain-energy function associated with the active response of skeletal muscle tissue. A model is presented herein that has been developed to accommodate this design consideration using a robust dynamical approach. The model shows excellent agreement with a previously published model of both the active and passive length-tension properties of skeletal muscle.
Teaching Universal Gravitation with Vector Games
Authors: Lowry Matthew
Published: November 2008

Like many high school and college physics teachers, I have found playing vector games to be a useful way of illustrating the concepts of inertia, velocity, and acceleration. Like many, I have also had difficulty in trying to get students to understand Newton's law of universal gravitation, specifically the inverse-square law and its application to motion. In this paper, I'll outline a way to address this problem through use of a vector game. The inspiration for this idea came from a January 1998 article in The Physics Teacher by Michael Vinson entitled “Space Race: A Game of Physics Adventure.”1
Biological Half-Life of Cardiolite®
Authors: Jesse Kenneth
Published: November 2008

I recently had a cardiac stress test. It was my fourth. Its purpose was to determine whether my heart is pumping an adequate quantity of blood during exercise. Additionally, is there a partial arterial blockage or damaged heart muscle? The test involves the patient receiving an injection of Cardiolite®, a substance containing a molecule to which Technetium-99m (Tc-99m)1 is attached, and then lying under a camera that detects gamma rays emanating from the interior heart wall and forms an image indicative of blood flow in the resting heart. This is followed by treadmill exercise, another injection of Cardiolite® during peak exercise, and then another image obtained with the camera indicating maximum blood flow. After the test, I decided to determine the biological half-life of Cardiolite®.
“Dissection” of a Hair Dryer
Authors: Eisenstein Stan , Simpson Jeff
Published: November 2008

The electrical design of the common hair dryer is based almost entirely on relatively simple principles learned in introductory physics classes. Just as biology students dissect a frog to see the principles of anatomy in action, physics students can “dissect” a hair dryer to see how principles of electricity are used in a real system. They can discover how engineers solve problems such as how to vary between low and high heat and fan speed by simply moving the position of a single switch. Principles of alternating versus direct current, series and parallel circuits, electrical safety, voltage dividing, ac rectification, power, and measurement of resistance and continuity all come in to play.
Role of the Ser-287-Asn Replacement in the Hydrolysis Spectrum Extension of AmpC β-Lactamases in
Escherichia coli
Authors: Mammeri Hedi , Galleni Moreno , Nordmann Patrice
Published: November 2008

Two AmpC variants harboring the S287N substitution were obtained by mutagenesis from cephalosporinases representative of the phylogenetic groups A and B2 of
Escherichia coli
. Their biochemical characterization revealed that the S287N replacement led to an important increase in the catalytic efficiency toward extended-spectrum cephalosporins in the AmpC β-lactamase of group A only.
Nationwide Survey of CTX-M-Type Extended-Spectrum β-Lactamases among
Klebsiella pneumoniae
Isolates in Slovenian Hospitals
Authors: Meško Meglič K. , Koren S. , Palepou M. F. I. , Karisik E. , Livermore D. M. , Pike R. , Andlovic A. , Jeverica S. , Križan-Hergouth V. , Müller-Premru M. , Seme K. , Woodford N.
Published: November 2008

Among 177 extended-spectrum β-lactamase-producing
Klebsiella pneumoniae
isolates collected from 11 Slovenian hospitals in 2005 and 2006, 60 (34%), from eight hospitals, harbored genes for CTX-M enzymes, with
bla
CTX-M-15
detected by sequencing. These 60 isolates comprised 11 pulsed-field gel electrophoresis-defined strains, with several clusters of closely related isolates. Plasmids encoding CTX-M-15 enzyme were highly transmissible.
Inactivation of KsgA, a 16S rRNA Methyltransferase, Causes Vigorous Emergence of Mutants with High-Level Kasugamycin Resistance
Authors: Ochi Kozo , Kim Ji-Yun , Tanaka Yukinori , Wang Guojun , Masuda Kenta , Nanamiya Hideaki , Okamoto Susumu , Tokuyama Shinji , Adachi Yoshikazu , Kawamura Fujio
Published: November 2008

The methyltransferases RsmG and KsgA methylate the nucleotides G535 (RsmG) and A1518 and A1519 (KsgA) in 16S rRNA, and inactivation of the proteins by introducing mutations results in acquisition of low-level resistance to streptomycin and kasugamycin, respectively. In a
Bacillus subtilis
strain harboring a single
rrn
operon (
rrnO
), we found that spontaneous
ksgA
mutations conferring a modest level of resistance to kasugamycin occur at a high frequency of 10
−6
. More importantly, we also found that once cells acquire the
ksgA
mutations, they produce high-level kasugamycin resistance at an extraordinarily high frequency (100-fold greater frequency than that observed in the
ksgA

+

strain), a phenomenon previously reported for
rsmG
mutants. This was not the case for other antibiotic resistance mutations (Tsp
r
and Rif
r
), indicating that the high frequency of emergence of a mutation for high-level kasugamycin resistance in the genetic background of
ksgA
is not due simply to increased persistence of the
ksgA
strain. Comparative genome sequencing showed that a mutation in the
speD
gene encoding
S
-adenosylmethionine decarboxylase is responsible for the observed high-level kasugamycin resistance.
ksgA speD
double mutants showed a markedly reduced level of intracellular spermidine, underlying the mechanism of high-level resistance. A growth competition assay indicated that, unlike
rsmG
mutation, the
ksgA
mutation is disadvantageous for overall growth fitness. This study clarified the similarities and differences between
ksgA
mutation and
rsmG
mutation, both of which share a common characteristic—failure to methylate the bases of 16S rRNA. Coexistence of the
ksgA
mutation and the
rsmG
mutation allowed cell viability. We propose that the
ksgA
mutation, together with the
rsmG
mutation, may provide a novel clue to uncover a still-unknown mechanism of mutation and ribosomal function.
Relative Strengths of the Class 1 Integron Promoter Hybrid 2 and the Combinations of Strong and Hybrid 1 with an Active P2 Promoter
Authors: Papagiannitsis Costas C. , Tzouvelekis Leonidas S. , Miriagou Vivi
Published: November 2008

The relative strengths of the uncommon promoters hybrid 2, hybrid 1 with an active P2 promoter (hybrid 1+P2), and strong+P2, which drive transcription of resistance genes in class 1 integrons, were evaluated using
bla
GES-1
as a reporter gene cassette. Hybrid 2 was stronger than hybrid 1. Coupling P2 with the strong promoter and with hybrid 1 caused a measurable increase in GES-1 expression.
Neutrophils Are Essential for Rapid Clearance ofEnterococcus faeciumin Mice
Authors: Leendertse Masja , Willems Rob J. L. , Giebelen Ida A. J. , Roelofs Joris J. T. H. , Bonten Marc J. M. , van der Poll Tom
Published: November 2008

A progressive increase in infections with multiresistantEnterococcus faeciumhas been reported, especially in cancer patients and neutropenic patients. Despite its increasing importance as a nosocomial pathogen, knowledge of the pathogenesis ofE. faeciuminfections is highly limited. In this study, we investigated the role of neutrophils during peritonitis with subsequent bacteremia caused byE. faecium. Therefore, we depleted neutrophils by intraperitoneal injections of monoclonal antibody RB6-8C5. Mice were followed for 5 days, and the enterococcal outgrowth and inflammatory response were compared between neutropenic mice and immunoglobulin G-injected control mice. Neutropenic mice demonstrated a severe delay in enterococcal clearance from all cultured organs (peritoneal fluid, blood, and lung and liver tissue). In particular, neutropenic mice remained bacteremic for up to 3 days, whereas all nonneutropenic mice had cleared the bacteria from circulation by 2 days. Furthermore, neutropenic mice displayed elevated peritoneal cytokine and chemokine levels 1 day after the infection and attracted fewer macrophages into the peritoneal cavity. In the circulation, a prolonged elevation of tumor necrosis factor alpha, interleukin-6, and the acute-phase proteins serum amyloid A and complement 3 were measured in neutropenic mice. In conclusion, attraction of neutrophils to the primary site ofE. faeciuminfection is important for a rapid clearance of this bacterium, thereby attenuating a systemic inflammatory response.
Characterization ofEntamoeba histolyticaIntermediate Subunit Lectin-Specific Human Monoclonal Antibodies Generated in Transgenic Mice Expressing Human Immunoglobulin Loci
Authors: Tachibana Hiroshi , Cheng Xun-Jia , Tsukamoto Hideo , Itoh Johbu
Published: November 2008

Four fully human monoclonal antibodies (MAbs) toEntamoeba histolyticaintermediate subunit lectin (Igl) were prepared in XenoMouse mice, which are transgenic mice expressing human immunoglobulin loci. Examination of the reactivities of these MAbs to recombinant Igl1 and Igl2 ofE. histolyticashowed that XEhI-20 {immunoglobulin G2(κ) [IgG2(κ)]} and XEhI-28 [IgG2(κ)] were specific to Igl1, XEhI-B5 [IgG2(κ)] was specific to Igl2, and XEhI-H2 [IgM(κ)] was reactive with both Igls. Gene analyses revealed that the VHand VLgerm lines were VH3-48 and L2 for XEhI-20, VH3-21 and L2 for XEhI-28, VH3-33 and B3 for XEhI-B5, and VH4-4 and A19 for XEhI-H2, respectively. Flow cytometry analyses showed that the epitopes recognized by all of these MAbs were located on the surfaces of living trophozoites. Confocal microscopy demonstrated that most Igl1 and Igl2 proteins were colocalized on the surface and in the cytoplasm, but different localization patterns in intracellular vacuoles were also present. The preincubation of trophozoites with XEhI-20, XEhI-B5, and XEhI-H2 caused significant inhibition of the adherence of trophozoites to Chinese hamster ovary cells, whereas preincubation with XEhI-28 did not do so. XEhI-20, XEhI-B5, and XEhI-H2 were injected intraperitoneally into hamsters 24 h prior to intrahepatic challenge withE. histolyticatrophozoites. One week later, the mean abscess size in groups injected with one of the three MAbs was significantly smaller than that in controls injected with polyclonal IgG or IgM isolated from healthy humans. These results demonstrate that human MAbs to Igls may be applicable for immunoprophylaxis of amebiasis.
The Potassium Transporter Trk and External Potassium Modulate
Salmonella enterica
Protein Secretion and Virulence
Authors: Su Jing , Gong Hao , Lai Jeff , Main Andrew , Lu Sangwei
Published: November 2008

Potassium (K
+
) is the most abundant intracellular cation and is essential for many physiological functions of all living organisms; however, its role in the pathogenesis of human pathogens is not well understood. In this study, we characterized the functions of the bacterial Trk K
+
transport system and external K
+
in the pathogenesis of
Salmonella enterica
, a major food-borne bacterial pathogen. Here we report that Trk is important for
Salmonella
to invade and grow inside epithelial cells. It is also necessary for the full virulence of
Salmonella
in an animal infection model. Analysis of proteins of
Salmonella
indicated that Trk is involved in the expression and secretion of effector proteins of the type III secretion system (TTSS) encoded by
Salmonella
pathogenicity island 1 (SPI1) that were previously shown to be necessary for
Salmonella
invasion. In addition to the role of the Trk transporter in the pathogenesis of
Salmonella
, we discovered that external K
+
modulates the pathogenic properties of
Salmonella
by increasing the expression and secretion of effector proteins of the SPI1-encoded TTSS and by enhancing epithelial cell invasion. Our studies demonstrated that K
+
is actively involved in the pathogenesis of
Salmonella
and indicated that
Salmonella
may take advantage of the high K
+
content inside host cells and in the intestinal fluid during diarrhea to become more virulent.
Borrelia burgdorferi
Infection-Associated Surface Proteins ErpP, ErpA, and ErpC Bind Human Plasminogen
Authors: Brissette Catherine A. , Haupt Katrin , Barthel Diana , Cooley Anne E. , Bowman Amy , Skerka Christina , Wallich Reinhard , Zipfel Peter F. , Kraiczy Peter , Stevenson Brian
Published: November 2008

Host-derived plasmin plays a critical role in mammalian infection by
Borrelia burgdorferi
. The Lyme disease spirochete expresses several plasminogen-binding proteins. Bound plasminogen is converted to the serine protease plasmin and thereby may facilitate the bacterium's dissemination throughout the host by degrading extracellular matrix. In this work, we demonstrate plasminogen binding by three highly similar borrelial outer surface proteins, ErpP, ErpA, and ErpC, all of which are expressed during mammalian infection. Extensive characterization of ErpP demonstrated that this protein bound in a dose-dependent manner to lysine binding site I of plasminogen. Removal of three lysine residues from the carboxy terminus of ErpP significantly reduced binding of plasminogen, and the presence of a lysine analog, ε-aminocaproic acid, inhibited the ErpP-plasminogen interaction, thus strongly pointing to a primary role for lysine residues in plasminogen binding. Ionic interactions are not required in ErpP binding of plasminogen, as addition of excess NaCl or the polyanion heparin did not have any significant effect on binding. Plasminogen bound to ErpP could be converted to the active enzyme, plasmin. The three plasminogen-binding Erp proteins can also bind the host complement regulator factor H. Plasminogen and factor H bound simultaneously and did not compete for binding to ErpP, indicating separate binding sites for both host ligands and the ability of the borrelial surface proteins to bind both host proteins.
CHARLES CAMPBELL AT SIXTY-FIVE: A TRIBUTE TO INNOVATION AND ENDURING DEDICATION
Authors: CLARK JOHN W.
Published: November 2008

A retrospective of the career of Charles E. Campbell in condensed matter physics is presented as a tribute to his pathbreaking contributions to quantum many-body theory and his selfless dedication to the advancement of the research community associated with the Condensed Matter Workshop series.
GROUND STATE ENERGY OF BOSE-EINSTEIN CONDENSATION IN A DISORDERED SYSTEM
Authors: SA-YAKANIT VIRULH , LIM WATTANA
Published: November 2008

A modeled Bose system consisting of N particles with two-body interaction confined within volume V under inhomogeneity of the system is investigated using the Feynman path integral approach. The two-body interaction energy is assumed to be dependent on the two-parameter interacting strength a and the correlation length l. The inhomogeneity of the system or the porosity can be represented as density [Formula: see text] with interacting strength b and correlation length L. The mean field approximation on the two-body interaction in the Feynman path integrals representation is performed to obtain the one-body interaction. This approximation is equivalent to the Hartree approximation in the many-body electron gas problem. This approximation has shown that the calculation can be reduced to the effective one-body propagator. Performing the variational calculations, we obtain analytical results of the ground state energy which is in agreement with that from Bugoliubov's approach.
IMPLICATIONS OF RELATIVISTIC CONFIGURATIONS AND BAND STRUCTURES IN THE PHYSICS OF BIO-MOLECULES AND SOLIDS
Authors: FHOKRUL ISLAM M. , BOHR HENRIK G. , MALIK F. B.
Published: November 2008

Beyond the second row of elements in the Mendeleev periodic table, the consideration of the relativistic effect is important in determining proper configurations of atoms and ions, in many cases. Many important quantities of interest in determining physical and chemical properties of matter, such as the effective charge, root mean square radii, and higher moments of radii used in many calculations, e.g. in the determinations of legend stabilization bond energies depend on whether the treatment is relativistic or not. In general, these quantities for a given l-orbital having two different j-values, e.g. [Formula: see text] and [Formula: see text], differ from each other, hence, making it necessary to treat them as separate orbitals. This also necessitates characterizing bands with their j-values in many instants and not l-values, particularly for “d” and f-orbitals. For example, in Au , [Formula: see text] and [Formula: see text] are to be dealt with as two distinct bands. The observed enhancement of laser induced field emission in W, which is not understood in terms of non-relativistic band-structures, can be explained in terms of the expected relativistic band structure. Spin-orbit coupling, which is the manifestation of the relativistic effect, is a prime factor in facilitating intersystem crossing in bio-molecules.
EFFECT OF DISORDER ON THE INTERACTING FERMI GASES IN A ONE-DIMENSIONAL OPTICAL LATTICE
Authors: GAO XIANLONG , POLINI M. , TOSI M. P. , TANATAR B.
Published: November 2008

Interacting two-component Fermi gases loaded in a one-dimensional (1D) lattice and subjected to a harmonic trapping potential exhibit interesting compound phases in which fluid regions coexist with local Mott-insulator and/or band-insulator regions. Motivated by experiments on cold atoms inside disordered optical lattices, we present a theoretical study of the effects of a correlated random potential on these ground-state phases. We employ a lattice version of density-functional theory within the local-density approximation to determine the density distribution of fermions in these phases. The exchange-correlation potential is obtained from the Lieb-Wu exact solution of Fermi-Hubbard model. On-site disorder (with and without Gaussian correlations) and harmonic trap are treated as external potentials. We find that disorder has two main effects: (i) it destroys the local insulating regions if it is sufficiently strong compared with the on-site atom-atom repulsion, and (ii) it induces an anomaly in the inverse compressibility at low density from quenching of percolation. For sufficiently large disorder correlation length the enhancement in the inverse compressibility diminishes.
DYNAMIC PAIR EXCITATIONS IN ALUMINUM
Authors: BÖHM HELGA M. , HOLLER ROBERT , KROTSCHECK ECKHARD , PANHOLZER MARTIN
Published: November 2008

We present a calculation of the excitation spectrum of the electron liquid that includes time-dependent pair correlations. For the charged boson fluid these correlations provide a major mechanism for lowering the plasmon energy; here we extend that study to the much more demanding fermionic case. Based on the formalism of correlated basis functions we derive coupled equations of motion for time-dependent 1- and 2-particle correlation amplitudes. Our solution strategy for these equations ensures the fulfillment of the first two energy–weighted sum rules and, in the appropriate limit, is consistent with the bosonic version. Results are presented for the dynamic structure factor with special emphasis being put on studying the double plasmon.
DYNAMICAL PHASE TRANSITIONS IN OPINION NETWORKS: COEXISTENCE OF OPPORTUNISTS AND CONTRARIANS
Authors: KÜRTEN KARL E.
Published: November 2008

We study a model for the emergence of collective decision making, consisting of N interacting agents, whose opinions are described by Ising spin variables. In particular, we present dynamical phase transitions from ordered to chaotic behavior in the space-time evolution of the binary choice network. One focus of this study is the determination of critical parameters, where the network is placed “at the edge of chaos,” i.e., at a subtle compromise between stability and flexibility, where the system has both, the necessary stability and the potential for “evolutionary” improvements.
PROBING THE EQUATION OF STATE OF NUCLEAR MATTER IN THE NUCLEAR RAINBOW SCATTERING
Authors: KHOA DAO T. , VON OERTZEN W. , BOHLEN H. G.
Published: November 2008

We present a brief overview of the light wave interference in the atmospheric rainbow and how a similar mechanism can be observed in the elastic nucleus-nucleus scattering which gives rise to the nuclear rainbow. The latter phenomenon, observed at energies of around few tens MeV/nucleon, has been well investigated based on the basic concepts of the nuclear optical model. Given a weak absorption associated with the nuclear rainbow scattering, the observed data can be used to probe the density dependence of the effective nucleon-nucleon (NN) interaction based on the folding model study of elastic scattering. Most of the rainbow scattering data were found to be best described by a density dependent NN interaction which gives a nuclear incompressibility K ≈ 230 – 260 MeV in the Hartree-Fock calculation of nuclear matter. This result implies a rather soft equation of state of nuclear matter.
RESONANCES AND ANGULAR DISTRIBUTION IN α DECAY
Authors: KARPESHIN F. F.
Published: November 2008

Tunneling of a particles through the Coulomb barrier is consecutively treated. The effect of sharp peaks arising in the case of coincidence of the α energy with that of a quasistationary state within the barrier is elucidated. Peaks' energy depend on the α-nucleus potential. They can give rise to “anomalous” properties of some neutron resonances. The peaks can also be observed in the incoming α-nucleus channel. The method is also applied for calculation of the angular distribution of the emitted α particles from the α decay of a compound nucleus of135Pr . Next fundamental test of the theory is proposed to be the α decay of superheavies.
GIANT DIELECTRIC BEHAVIOR OF BaFe0.5Nb0.5O3 PEROVSKITE CERAMIC
Authors: INTATHA URAIWAN , EITSSAYEAM SUKUM , TUNKASIRI TAWEE
Published: November 2008

Single-phase cubic Ba ( Fe , Nb )0.5 O 3 (BFN) powder was synthesized by solid-state reaction at 1443 K for 4 hour in air. X-ray diffraction indicated that the BFN oxide mixture calcined at 1200°C crystallizes to the pure cubic perovskite phase. BFN ceramics were produced from this powder by sintering at 1623–1673 K for 4 hrs in air. Samples prepared under these conditions achieved up to 94.7% of the theoretical density. The temperature dependence of their dielectric constant and loss tangent, measured at difference frequencies, shows an increase in the dielectric constant with temperature which is probably due to disorder on the B site ion of the perovskite. Non-Debye type of relaxation phenomena has been observed in the BFN ceramics as confirmed by Cole–Cole plots. The higher value of ɛ′ at the lower frequency is explained on the basis of the Maxwell–Wagner (MW) polarization model.
THE SPIN HAMILTONIAN PARAMETERS CALCULATION OF 14N AND 15N IN NATURAL TYPE I DIAMOND
Authors: KEDKAEW CHITTRA , LIMSUWAN PICHET , THONGCHAM KANPHOT , MEEJOO SIWAPORN
Published: November 2008

The main purpose of this work is to present the ESR spectra and calculate the spin Hamiltonian parameters of 14 N and 15 N impurities in natural diamond. The ESR spectra of diamond crystal were measured on ESR spectrometer operating at X-band microwave frequency. The results of ESR spectra show that the diamond has a P1 center. This center gives rise to three strong resonance absorption peaks at θ = 90°, φ = 0° due to hyperfine interaction between electron spin and nuclear spin of 14 N . The ESR spectra of 15 N impurity consist of two satellites at the same rotation angle (φ). The effects of isolated substitution nitrogen on carbon atom produced a symmetric distortion from Td to C3V symmetry. According to this symmetry, the resonance magnetic field positions of ESR spectra for the rotation angles of 0°, 90° and 180° are almost overlap. The g-factor values and spin Hamiltonian parameters of 14 N and 15 N are: g = 2.0019, A⊥ = 29.73, A‖ = 40.24 and g = 2.0019, A⊥ = −39.90, A‖ = −57.05, respectively.
Interactive film and the multiplied self
Authors: Danylak Roman , Edmonds Ernest
Published: November 2008

Interactive film, delivered by computational processes, collapses the
self
; the singular, personal identity to which we have become accustomed is challenged by the adoption of many selves, transforming our primary experience of identity. The new medium presents us with narrative multiplicity, so that we are no longer just “John Smith,” our namesake. The combination of separate, unique, historically-evolved representational techniques, defined as
counterfeit
,
production
, and
simulation
, makes the creation of a multiplied self possible in a digitized environment. This paper will focus on Spielberg's film
Catch Me if You Can
, whose narrative describes the actions of its game-playing protagonist, Frank Abagnale Jr., who exemplifies the emerging digital man. He creates many personas in a predigital world by means of the three techniques of representation. His “art” is shown to be a precursor of interactive film, turning the world into a game of interchangeable multiple personalities. Manipulating and adopting screen media communication artefacts, Frank Abagnale Jr. creates an analogue of human-computer multimedia interaction. A comparison of similar innovations and their effects in earlier historical periods of media is also included.
Using “tilt” as an interface to control “no-button” 3-D mobile games
Authors: Gilbertson Paul , Coulton Paul , Chehimi Fadi , Vajk Tamas
Published: November 2008

Mobile phones offer considerable challenges for game developers, and not least among them is the user interface, which is primarily optimized for number entry rather than for playing games. In fact, due to the limitations one of the most desirable criteria for mobile games has the design of games controlled by a one-button interface. However, this type of interface has only been seen as applicable for casual games, where mastering the interface is de-emphasized. As a number of mobile phones are starting to appear with 3-D accelerometers, game developers have the opportunity to investigate new interface mechanisms. In this article we illustrate how accelerometers provide the possibility of a no-button mobile game. While 3-D accelerometers offer a range of possible interface mechanisms, the one that requires minimal signal processing and no external references is
motion
, and in particular,
tilt
, and as such is eminently suitable for mobile phones. In this article we explore a tilt interface for a 3-D graphics first-person driving game titled
Tunnel Run
, and compare the user experience playing the same game with a traditional phone joypad interface and with a tilt interface in two different modes. The results show that the tilt interface was experienced as fun, and certainly seemed more attractive to players, who said they would not have played this type of game otherwise.