bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetics of osteoporosis
Authors: Ralston Stuart H.
Published: April 2010

Osteoporosis is a common disease with a strong genetic component characterized by reduced bone mass and an increased risk of fragility fractures. Twin and family studies have shown that the heritability of bone mineral density and other determinants of fracture risk, such as ultrasound properties of bone, skeletal geometry, and bone turnover, is high, although heritability of fracture is modest. Many different genetic variants contribute to the regulation of these phenotypes. Most are common variants of small effect size, but there is evidence that rare variants of large effect size also contribute in some individuals. Many of the genes that regulate susceptibility to osteoporosis have been identified through studies of rare bone diseases, but genome‐wide association studies have also been successful in identifying genes that predispose to osteoporosis. Although there has been extensive progress in this area over the past 10 years, most of the genetic variants that regulate susceptibility to osteoporosis remain to be discovered.
Cbl–phosphatidylinositol 3 kinase interaction differentially regulates macrophage colony‐stimulating factor‐mediated osteoclast survival and cytoskeletal reorganization
Authors: Adapala Naga Suresh , Barbe Mary F. , Langdon Wallace Y. , Tsygankov Alexander Y. , Sanjay Archana
Published: April 2010

The Cbl protein is a key player in macrophage colony‐stimulating factor (M‐CSF)‐induced signaling. To examine the role of Cbl in M‐CSF‐mediated cellular events, we used CblYF/YF knockin mice in which the regulatory tyrosine 737, which when phosphorylated binds to the p85 subunit of phosphatidylinositol 3 kinase (PI3K), is substituted to phenylalanine. In ex vivo cultures, M‐CSF and receptor activator of nuclear factor‐κB ligand‐mediated differentiation of bone marrow precursors from CblYF/YF mice generated increased number of osteoclasts; however, osteoclast numbers in CblYF/YF cultures were unchanged with increasing doses of M‐CSF. We found that CblYF/YF osteoclasts have enhanced intrinsic ability to survive, and this response was further augmented upon exposure to M‐CSF. Treatment of osteoclasts with M‐CSF‐induced actin reorganization and lamellipodia formation in wild‐type osteoclasts; however, in CblYF/YF osteoclasts lamellipodia formation was compromised. Collectively, these results indicate that abrogation of the Cbl–PI3K interaction, although not affecting M‐CSF‐induced proliferation and differentiation of precursors, is required for regulation of survival and actin cytoskeletal reorganization of mature osteoclasts.
Biomechanical computed tomography—noninvasive bone strength analysis using clinical computed tomography scans
Authors: Keaveny Tony M.
Published: April 2010

The combination of finite element modeling, biomechanics, and clinical computed tomography (CT) scanning—biomechanical CT (BCT)—is a powerful research technique for noninvasive assessment of whole‐bone strength and is now being used in clinical research studies. Well supported by cadaver studies, the technique is providing substantial new insight into drug treatment effects, can show treatment effects earlier than dual‐energy X‐ray absorptiometry (DXA), and has shown greater sensitivity than DXA in fracture risk assessment. Because the technique can be used as an ancillary “add‐on” analysis to previously acquired CT scans containing either the hip or spine, it should be possible to implement this technology clinically in a highly cost‐effective manner. This strategy, if applied to those not previously tested by DXA, has the potential to greatly increase the number of individuals identified as being at high risk for osteoporotic fracture.
Bone turnover across the menopause transition
Authors: Nicks Kristy M. , Fowler Tristan W. , Akel Nisreen S. , Perrien Daniel S. , Suva Larry J. , Gaddy Dana
Published: April 2010

Accumulating evidence demonstrates increasing bone turnover and bone loss in women prior to menopause and decreases in serum estradiol levels. Increased follicle‐stimulating hormone levels have been correlated with some of these peri‐menopausal changes. However, decreases in gonadal inhibins of the transforming growth factor (TGF)‐β superfamily strongly correlate with increases in bone formation and resorption markers across the menopause transition and predict lumbar bone mass in peri‐menopausal women, likely as a result of direct inhibin suppression of osteoblastogenesis and osteoclastogenesis. Inhibins bind specifically to cells during osteoblastogenesis and osteoclastogenesis. They can block bone morphogenetic protein (BMP)‐stimulated osteoblast and osteoclast development as well as BMP‐stimulated SMAD1 phosphorylation, likely via inhibin–β‐glycan sequestration of BMP Type II receptor (BMPRII). Interestingly, continuous in vivo exposure to inhibin A is anabolic and protective against gonadectomy‐induced bone loss in mice, suggesting that inhibins contribute to the endocrine regulation of bone metabolism via a bimodal mechanism of action whereby cycling inhibin exposure suppresses bone turnover and continuous exposure to inhibins is anabolic.
Extracellular regulation of transforming growth factor β and bone morphogenetic protein signaling in bone
Authors: Nistala Harikiran , Lee‐Arteaga Sui , Siciliano Gabriella , Smaldone Silvia , Ramirez Francesco
Published: April 2010

Systemic and local factors regulate the activity of osteoblasts and osteoclasts during bone growth and remodeling by modulating a complex array of intracellular signaling events. Recent genetic evidence implicates extracellular fibrillin assemblies (microfibrils and elastic fibers) in imparting contextual specificity to endogenous transforming growth factor‐β and bone morphogenetic protein ligands in the forming and mature skeleton. The evidence is based on the characterization of the cellular and molecular mechanisms responsible for the unique bone manifestations that characterize mouse models of Marfan syndrome and congenital contractural arachnodactyly. Collectively, the studies indicate that fibrillin assemblies play a key role both in establishing morphogen gradients within the developing limbs and in restricting growth factors activity in remodeling bones. The latter finding is likely to improve the design of more effective therapeutic interventions in osteoporosis and of bioengineering formulations for the repair of bone fractures.
Role of mitochondrial reactive oxygen species in osteoclast differentiation
Authors: Srinivasan Satish , Koenigstein Alexander , Joseph Joy , Sun Li , Kalyanaraman B. , Zaidi Mone , Avadhani Narayan G.
Published: April 2010

Previously we showed that hypoxia‐induced mitochondrial respiratory stress in RAW 264.7 macrophages and other cells caused activation of retrograde signaling (also known as mitochondrial respiratory stress signaling) and the appearance of tartrate‐resistant acid phosphatase (TRAP)‐positive cells. In the present study, we used N‐acetyl cysteine and ascorbate (general antioxidants) and MitoQ, a mitochondria‐specific antioxidant, to investigate the role of intracellular reactive oxygen species (ROS) in osteoclast differentiation. Our results show that hypoxia‐mediated mitochondrial dysfunction, as tested by disruption of mitochondrial transmembrane potential, was suppressed by MitoQ as well as by the other antioxidants. These agents also suppressed the activation of mitochondrial retrograde signaling. Interestingly, in terms of molar concentrations, MitoQ was more than 1000‐fold more effective than general antioxidants in suppressing the receptor activator of nuclear factor‐B ligand‐induced differentiation of RAW 264.7 cells into multinucleated and TRAP‐positive osteoclasts. We propose that mitochondrial function and intramitochondrial ROS play important roles in osteoclastogenesis.
Looking beyond bone mineral density
Authors: Griffith James F. , Engelke Klaus , Genant Harry K.
Published: April 2010

Bone fracture is related to bone strength. In current clinical practice, bone mineral density (BMD) is used as the prime indicator of bone strength, not infrequently at the neglect of an even more pertinent measure of reduced bone strength, namely the radiographic presence of an insufficiency fracture. Bone strength depends not just on BMD but also on bone quality, which relates to such factors as bone architecture, turnover, mineralization, and cellularity. The high resolution available from current imaging techniques, particularly computed tomography and magnetic resonance imaging, along with advanced analytical software has greatly enhanced evaluation of bone architecture and strength. This has improved our knowledge of the pathophysiological processes behind osteoporosis and its treatment beyond that provided by BMD measurement alone. Although still in the experimental stage, these techniques will no doubt be incorporated into clinical practice, leading to a more tailored approach to the screening, monitoring, and treatment of osteoporosis.
Physiological role of alkaline phosphatase explored in hypophosphatasia
Authors: Whyte Michael P.
Published: April 2010

Hypophosphatasia (HPP) is the instructive rickets or osteomalacia caused by loss‐of‐function mutation(s) within TNSALP, the gene that encodes the “tissue nonspecific” isoenzyme of alkaline phosphatase (TNSALP). HPP reveals a critical role for this enzyme in skeletal mineralization. Increased extracellular levels of pyridoxal 5′‐phosphate and inorganic pyrophosphate (PPi) demonstrate that TNSALP is a phosphomonoester phosphohydrolase and a pyrophosphatase that hydrolyzes much lower concentrations of natural substrates than the artificial substrates of laboratory assays. Clearly, TNSALP acts at physiological pH and “alkaline phosphatase” is a misnomer. Aberrations of vitamin B6 metabolism in HPP revealed that TNSALP is an ectoenzyme. PPi excesses cause chondrocalcinosis and sometimes arthropathy. The skeletal disease is due to PPi inhibition of hydroxyapatite crystal growth extracellularly so that crystals form within matrix vesicles but fail to enlarge after these structures rupture. Trials of alkaline phosphatase replacement therapy for HPP suggest that TNSALP functions at the level of skeletal tissues.
Therapeutics for cognitive aging
Authors: Shineman Diana W. , Salthouse Timothy A. , Launer Lenore J. , Hof Patrick R. , Bartzokis George , Kleiman Robin , Luine Victoria , Buccafusco Jerry J. , Small Gary W. , Aisen Paul S. , Lowe David A. , Fillit Howard M.
Published: April 2010

This review summarizes the scientific talks presented at the conference “Therapeutics for Cognitive Aging,” hosted by the New York Academy of Sciences and the Alzheimer's Drug Discovery Foundation on May 15, 2009. Attended by scientists from industry and academia, as well as by a number of lay people—approximately 200 in all—the conference specifically tackled the many aspects of developing therapeutic interventions for cognitive impairment. Discussion also focused on how to define cognitive aging and whether it should be considered a treatable, tractable disease.
Vocation
Authors: Scholes Jeffrey
Published: April 2010

Since Martin Luther, the Protestant concept of vocation has been tied to daily work. Yet, Max Weber famously proclaimed that while vocations used to endow work with divine import, this is no longer the case; the work ethic is actually driven by secular motives. However, if popular self‐help literature is any indication, the need for work to tap transcendent meaning has not abated. ‘Vocation language’ still acts as the primary means for communicating this need. What, then, is the state of vocation in its relationship to work today? In this essay, I present a selective survey of history of the Protestant concept of vocation as it relates to the work world. Such a survey does lend credence to Weber’s straightforward contention that religion no longer animates work in the West. Yet at the same time, the history of the Protestant vocation helps explain its staying power in spite of radical changes in the meaning and nature of work.
Bog Bilberry (Vaccinium uliginosum L.) Extract Reduces Cultured Hep‐G2, Caco‐2, and 3T3‐L1 Cell Viability, Affects Cell Cycle Progression, and Has Variable Effects on Membrane Permeability
Authors: Liu Jia , Zhang Wei , Jing Hao , Popovich David G.
Published: April 2010

ABSTRACT:  Bog bilberry (Vaccinium uliginosum L.) is a blue‐pigmented edible berry related to bilberry (Vaccinium myrtillus L.) and the common blueberry (Vaccinium corymbosum). The objective of this study was to investigate the effect of a bog bilberry anthocyanin extract (BBAE) on cell growth, membrane permeability, and cell cycle of 2 malignant cancer cell lines, Caco‐2 and Hep‐G2, and a nonmalignant murine 3T3‐L1 cell line. BBAE contained 3 identified anthocyanins. The most abundant anthocyanin was cyanidin‐3‐glucoside (140.9 ± 2.6 μg/mg of dry weight), followed by malvidin‐3‐glucoside (10.3 ± 0.3 μg/mg) and malvidin‐3‐galactoside (8.1 ± 0.4 μg/mg). Hep‐G2 LC50 was calculated to be 0.563 ± 0.04 mg/mL, Caco‐2 LC50 was 0.390 ± 0.30 mg/mL and 0.214 ± 0.02 mg/mL for 3T3‐L1 cells. LDH release, a marker of membrane permeability, was significantly increased in Hep‐G2 cells and Caco‐2 cells after 48 and 72 h compared to 24 h. The increase was 21% at 48 h and 57% at 72 h in Caco‐2 cells and 66% and 139% in Hep‐G2 cells compared to 24 h. However, 3T3‐L1 cells showed an unexpected significant lower LDH activity (P ≤ 0.05) after 72 h of exposure corresponding to a 21% reduction in LDH release. BBAE treatment increased sub‐G1 in all 3 cell lines without influencing cells in the G2/M phase. BBAE treatment reduced the growth and increased the accumulation of sub‐G1 cells in 2 malignant and 1 nonmalignant cell line; however, the effect on membrane permeability differs considerably between the malignant and nonmalignant cells and may in part be due to differences in cellular membrane composition.
Screening for Alternative Antibiotics: An Investigation into the Antimicrobial Activities of Medicinal Food Plants of Mauritius
Authors: Mahomoodally M.F. , Gurib‐Fakim A. , Subratty A.H.
Published: April 2010

ABSTRACT:  The present study was designed to evaluate the antimicrobial activities of 2 endemic medicinal plants; Faujasiopsis flexuosa (Asteraceae) (FF) and Pittosporum senacia (Pittosporaceae) (PS) and 2 exotic medicinal plants, Momordica charantia (Cucurbitaceae) (MC) and Ocimum tenuiflorum (Lamiaceae) (OT) that forms part of local pharmacopoeia of Mauritius and correlate any observed activity with its phytochemical profile. Aqueous and organic fractions of the leaves, fruits, and seeds of these plants were subjected to antimicrobial testing by the disc diffusion method against 8 clinical isolates of bacteria and 2 strains of fungus. It was found that MC, OT, and FF possessed antimicrobial properties against the test organisms. The MIC for MC ranged from 0.5 to 9 mg/mL and that of FF from 2 to 10 mg/mL and the lowest MIC value (0.5 mg/mL) was recorded for the unripe fruits of MC against E. coli. On the other hand, higher concentration of the unripe MC fruit extract of 9 mg/mL was needed to be effective against a resistant strain of Staphylococcus aureus (MRSA). The antimicrobial effect against MRSA was lost upon ripening of the fruits. The methanolic extract of both MC and FF showed highest MIC values compared to the corresponding aqueous extract, which indicates the low efficacy and the need of higher doses of the plant extract. Phytochemical screening of the plants showed the presence of at least tannins, phenols, flavonoids, and alkaloids, which are known antimicrobial phyto‐compounds. In conclusion, the observed antimicrobial properties would tend to further validate the medicinal properties of these commonly used endemic medicinal and food plants of Mauritius.
Use of Lysozyme, Nisin, and EDTA Combined Treatments for Maintaining Quality of Packed Ostrich Patties
Authors: Mastromatteo Marianna , Lucera Annalisa , Sinigaglia Milena , Corbo Maria Rosaria
Published: April 2010

ABSTRACT:  The antimicrobial effectiveness of lysozyme, nisin, and ethylene diamine tetraacetic acid (EDTA) combination treatments (Mix1: 250 ppm lysozyme, 250 ppm nisin, 5 mM EDTA; Mix2: 500 ppm lysozyme, 500 ppm nisin, 5 mM EDTA) on bacterial growth of ostrich patties packaged in air, vacuum, and 2 different modified atmospheres (MAP1: 80% O2, 20% CO2; MAP2: 5% O2, 30% CO2, 65% N2) was evaluated. Moreover, the lipid oxidation was evaluated as well as color and sensory characteristics. The growth of total viable counts and lactic acid bacteria were strongly inhibited by the antimicrobial treatments in all the running time (Inhibition Index >97%) whereas for Enterobacteriaceae and Pseudomonas spp. lower inhibition indices from 12% to about 28% were observed. The lipid oxidation was more pronounced in the control respect to the treated meat patties. Moreover, the mixture at low concentration of lysozyme and nisin showed the best antioxidative effect. High concentrations of lysozyme and nisin showed the greatest color loss. Also, off‐odors for the untreated patties developed faster than the treated samples.

Practical Application: Great interest is developing in food bio‐preservation, because of the ever‐increasing needs to protect consumers' health and to valorize the naturalness and safety of food products.
Changes in the Functional Properties and Antinutritional Factors of Extruded Hard‐to‐Cook Common Beans (Phaseolus vulgaris, L.)
Authors: Batista Karla A. , Prudêncio Sandra H. , Fernandes Kátia F.
Published: April 2010

ABSTRACT:  The biochemical and functional properties of 2 hard‐to‐cook common bean cultivars (Phaseolus vulgaris, L.) were investigated after the extrusion process. Beans of BRS pontal and BRS grafite cultivars were milled and extruded at 150 °C, with a compression ratio screw of 3 : 1, 5‐mm die, and screw speed of 150 rpm. Extrudate flours were evaluated for water solubility (WS), water absorption index (WAI), oil absorption capacity (OAC), foaming capacity (FC), emulsifying activity (EA), antinutritional factors, and in vitro protein and starch digestibility. Results indicated that the extrusion significantly decreased antinutrients such as phytic acid, lectin, α‐amylase, and trypsin inhibitors, reduced the emulsifying capacity and eliminated the FC in both BRS pontal and BRS grafite cultivars. In addition, the WS, WAI, and in vitro protein and starch digestibility were improved by the extrusion process. These results indicate that it is possible to produce new extruded products with good functional and biochemical properties from these common bean cultivars.
Fermentation of Cucumbers Brined with Calcium Chloride Instead of Sodium Chloride
Authors: McFeeters Roger F. , Pérez‐Díaz Ilenys
Published: April 2010

ABSTRACT:  Waste water containing high levels of NaCl from cucumber fermentation tank yards is a continuing problem for the pickled vegetable industry. A major reduction in waste salt could be achieved if NaCl were eliminated from the cucumber fermentation process. The objectives of this project were to ferment cucumbers in brine containing CaCl2 as the only salt, to determine the course of fermentation metabolism in the absence of NaCl, and to compare firmness retention of cucumbers fermented in CaCl2 brine during subsequent storage compared to cucumbers fermented in brines containing both NaCl and CaCl2 at concentrations typically used in commercial fermentations. The major metabolite changes during fermentation without NaCl were conversion of sugars in the fresh cucumbers primarily to lactic acid which caused pH to decrease to less than 3.5. This is the same pattern that occurs when cucumbers are fermented with NaCl as the major brining salt. Lactic acid concentration and pH were stable during storage and there was no detectable production of propionic acid or butyric acid that would indicate growth of spoilage bacteria. Firmness retention in cucumbers fermented with 100 to 300 mM CaCl2 during storage at a high temperature (45 °C) was not significantly different from that obtained in fermented cucumbers with 1.03 M NaCl and 40 mM CaCl2. In closed jars, cucumber fermentations with and without NaCl in the fermentation brine were similar both in the chemical changes caused by the fermentative microorganisms and in the retention of firmness in the fermented cucumbers.
Caffeine (1, 3, 7‐trimethylxanthine) in Foods: A Comprehensive Review on Consumption, Functionality, Safety, and Regulatory Matters
Authors: Heckman Melanie A. , Weil Jorge , De Mejia Elvira Gonzalez
Published: April 2010

ABSTRACT: Caffeine ranks as one of the top most commonly consumed dietary ingredients throughout the world. It is naturally found in coffee beans, cacao beans, kola nuts, guarana berries, and tea leaves including yerba mate. The total daily intake, as well as the major source of caffeine varies globally; however, coffee and tea are the 2 most prominent sources. Soft drinks are also a common source of caffeine as well as energy drinks, a category of functional beverages. Moderate caffeine consumption is considered safe and its use as a food ingredient has been approved, within certain limits, by numerous regulatory agencies around the world. Performance benefits attributed to caffeine include physical endurance, reduction of fatigue, and enhancing mental alertness and concentration. Caffeine has also been recently linked to weight loss and consequent reduction of the overall risks for developing the metabolic syndrome. However, the caloric contribution of caffeine‐sweetened beverages needs to be considered in the overall energy balance. Despite all these benefits the potential negative effects of excessive caffeine intake should also be considered, particularly in children and pregnant women.
Uptake of Tritiated Liquids by Individual Breakfast Cereal Flakes
Authors: Medina Wenceslao T. , Laurent Sophie , Brandan Enrique , Aguilera José M.
Published: April 2010

ABSTRACT:  Surface liquid adhesion (SLA) and liquid absorption (LA) of tritiated liquids, including water and skim, low‐fat, whole, and fat‐enriched milks, by cornflakes (CF) and frosted flakes (FF) were determined by scintillation counting using water‐[3H] at 0.5 μCi/mL. SLA or the liquid adhering to individual flakes after a short immersion period was the same for CF and FF in the case of water (approximately 0.011 μL mm−2 of flake) but were always higher for CF than for FF and increased as the fat content in milks augmented. LA of individual flakes, followed for 300 s of soaking, increased with time and was always higher for CF than for FF (for the same liquid), however, data did not follow a regular pattern. Flakes showed quite compact outer surfaces and an internal porous matrix composed of air cells of various sizes separated by dense walls of different thicknesses. This heterogeneous microstructure of individual flakes may be the cause of the lack of a simple kinetics during the soaking process. Previous results obtained by soaking a mass of flakes overestimated the uptake of fluid by individual because they included the liquid occluded between the flakes.
Global patterns of marine turtle bycatch
Authors: Wallace Bryan P. , Lewison Rebecca L. , McDonald Sara L. , McDonald Richard K. , Kot Connie Y. , Kelez Shaleyla , Bjorkland Rhema K. , Finkbeiner Elena M. , Helmbrecht S’rai , Crowder Larry B.
Published: April 2010

Fisheries bycatch is a primary driver of population declines in several species of marine megafauna (e.g., elasmobranchs, mammals, seabirds, turtles). Characterizing the global bycatch seascape using data on bycatch rates across fisheries is essential for highlighting conservation priorities. We compiled a comprehensive database of reported data on marine turtle bycatch in gillnet, longline, and trawl fisheries worldwide from 1990 to 2008. The total reported global marine turtle bycatch was ∼85,000 turtles, but due to the small percentage of fishing effort observed and reported (typically <1% of total fleets), and to a global lack of bycatch information from small‐scale fisheries, this likely underestimates the true total by at least two orders of magnitude. Our synthesis also highlights an apparently universal pattern across fishing gears and regions where high bycatch rates were associated with low observed effort, which emphasizes the need for strategic bycatch data collection and reporting. This study provides the first global perspective of fisheries bycatch for marine turtles and highlights region–gear combinations that warrant urgent conservation action (e.g., gillnets, longlines, and trawls in the Mediterranean Sea and eastern Pacific Ocean) and region–gear combinations in need of enhanced observation and reporting efforts (e.g., eastern Indian Ocean gillnets, West African trawls).
Idiopathic inflammatory myopathies: diagnostic criteria, classification and epidemiological features
Authors: COX Sally , LIMAYE Vidya , HILL Catherine , BLUMBERGS Peter , ROBERTS‐THOMSON Peter
Published: April 2010

Idiopathic inflammatory myopathies (IIM) are a group of rare autoimmune disorders characterized by muscle inflammation and progressive weakness. The cause of IIM is unclear but it is believed that disease expression may be triggered by unknown factors in genetically predisposed individuals. Diagnosis is based on a combination of clinical, laboratory and electromyography findings. Muscle biopsy is the definitive diagnostic test. Research into IIM has been limited by the rarity of the disease, a somewhat insidious onset, difficulties with classification and diagnostic methods and heterogeneous study populations making cross‐study evaluations difficult. This paper reviews the diagnostic and classification criteria of the IIM and examines epidemiological studies that have been performed, focusing on demographics.
Fascicle-Scale Loading and Failure Behavior of the Achilles Tendon
Authors: Komolafe Oluseeni A. , Doehring Todd C.
Published: April 2010

Although the overall bulk properties of the Achilles tendon have been measured, there is little information detailing the properties of individual fascicles or their interactions. The knowledge of biomechanical properties at the fascicle-scale is critical in understanding the biomechanical behavior of tendons and for the construction of accurate and detailed computational models. Seven tissue samples (∼15×4×1 mm3) harvested from four freshly thawed human (all male) tendons, each sample having four to six fascicles, were tested in uniaxial tension. A sequential sectioning protocol was used to isolate interaction effects between adjacent fascicles and to obtain the loading response for a single fascicle. The specimen deformation was measured directly using a novel polarized light imaging system with digital image correlation (DIC) for marker-free deformation measurement. The modulus of the single fascicle was significantly higher compared with the intact fascicle group (single: 226 MPa (SD 179), group: 68 MPa (SD 33)). The interaction effect between the adjacent fascicles was less than 10% of the applied load and evidence of sub- and postfailure fascicle sliding was clearly visible. The DIC direct deformation measurements revealed that the modulus of single fascicles could be as much as three to four times the intact specimen. The consistently higher moduli values of the single (strongest) fascicle indicate that the overall response of the tendon may be dominated by a subset of “strongest” fascicles. Also, fascicle-to-fascicle interactions were small, which was <10% of the overall response. This knowledge is useful for developing computational models representing single fascicle and/or fascicle group mechanical behavior and provides valuable insights into fascicle-scale Achilles tendon material properties.
Theory of Fractional Order Generalized Thermoelasticity
Authors: Youssef Hamdy M.
Published: April 2010

In this work, a new model of thermoelasticity theory has been constructed in the context of a new consideration of heat conduction with fractional order, and its uniqueness theorem has been approved also. One-dimensional application for a half-space of elastic material, which is thermally shocked, has been solved by using Laplace transform and state-space techniques. According to the numerical results and its graphs, conclusion about the new theory of thermoelasticity has been constructed.
Tomography-Based Analysis of Radiative Transfer in Reacting Packed Beds Undergoing a Solid-Gas Thermochemical Transformation
Authors: Haussener Sophia , Lipiński Wojciech , Wyss Peter , Steinfeld Aldo
Published: April 2010

A reacting packed-bed undergoing a high-temperature thermochemical solid-gas transformation is considered. The steam- and dry-gasification of carbonaceous materials to syngas is selected as the model reaction. The exact 3D digital geometrical representation of the packed-bed is obtained by computer tomography and used in direct pore-level simulations to characterize its morphological and radiative transport properties as a function of the reaction extent. Two-point correlation functions and mathematical morphology operations are applied to calculate porosities, specific surfaces, particle-size distributions, and representative elementary volumes. The collision-based Monte Carlo method is applied to determine the probability distribution of attenuation path length and direction of incidence at the solid-fluid boundary, which are linked to the extinction coefficient, scattering phase function, and scattering albedo. These effective properties can be then incorporated in continuum models of the reacting packed-bed.
Heat Transport Capability and Fluid Flow Neutron Radiography of Three-Dimensional Oscillating Heat Pipes
Authors: Borgmeyer B. , Wilson C. , Winholtz R. A. , Ma H. B. , Jacobson D. , Hussey D.
Published: April 2010

An experimental investigation into the parameters affecting heat transport in two three-dimensional oscillating heat pipes (OHPs) was implemented. A three-dimensional OHP is one in which the center axis of the circular channels containing the internal working fluid do not lie in the same plane. This novel design allows for more turns in a more compact size. The OHPs in the current investigation is made of copper tubings (3.175 mm outside diameter, 1.65 mm inside diameter) wrapped in a three-dimensional fashion around two copper spreaders that act as the evaporator and condenser. The two OHPs have 10 and 20 turns in both the evaporator and condenser. The 20-turn OHP was filled to 50% of the total volume with a high performance liquid chromatography grade water. Transient and steady state temperature data were recorded at different locations for various parameters. Parameters such as heat input, operating temperature, and filling ratio were varied to determine its effect on the overall heat transport. Neutron radiography was simultaneously implemented to create images of the internal working fluid flow at a rate of 30 frames per second. Results show the average temperature drop from the evaporator to condenser decreases at higher heat inputs due to an increase in temperature throughout the condenser region due to greater oscillations. These large oscillations were visually observed using neutron radiography. As the operating temperature is increased, the thermal resistance is reduced. A decrease in filling ratio tends to create more steady fluid motion; however, the heat transfer performance is reduced.
A SIMPLIFICATION OF COMBINATORIAL LINK FLOER HOMOLOGY
Authors: BELIAKOVA ANNA
Published: April 2010

We define a new combinatorial complex computing the hat version of link Floer homology over ℤ/2ℤ, which turns out to be significantly smaller than the Manolescu–Ozsváth–Sarkar one.
ON THE INVERSE MAPPING CLASS MONOIDS
Authors: KAROUI R. , VERSHININ V. V.
Published: April 2010

Braid groups and mapping class groups have many features in common. Similarly to the notion of inverse braid monoid, inverse mapping class monoid is defined. It concerns surfaces with punctures, but among given n punctures, several can be omitted. This corresponds to braids where the number of strings is not fixed. In the paper we give the analogue of the Dehn–Nilsen–Baer theorem, propose a presentation of the inverse mapping class monoid for a punctured sphere and study the word problem. This shows that certain properties and objects based on mapping class groups may be extended to the inverse mapping class monoids. We also give analogues of Artin presentation with two generators.
AN ORIENTED MODEL FOR KHOVANOV HOMOLOGY
Authors: BLANCHET CHRISTIAN
Published: April 2010

We give an alternative presentation of Khovanov homology of links. The original construction rests on the Kauffman bracket model for the Jones polynomial, and the generators for the complex are enhanced Kauffman states. Here we use an oriented sl(2) state model allowing a natural definition of the boundary operator as twisted action of morphisms belonging to a TQFT for trivalent graphs and surfaces. Functoriality in original Khovanov homology holds up to sign. Variants of Khovanov homology fixing functoriality were obtained by Clark–Morrison–Walker [7] and also by Caprau [6]. Our construction is similar to those variants. Here we work over integers, while the previous constructions were over gaussian integers.
SIMULATION OF NONLINEAR ULTRASONIC PULSES PROPAGATING THROUGH BUBBLY LAYERS IN A LIQUID: FILTERING AND CHARACTERIZATION
Authors: VANHILLE CHRISTIAN , CAMPOS-POZUELO CLEOFÉ
Published: April 2010

This paper deals with the nonlinear propagation of ultrasonic pulses in a homogeneous medium in which a bubbly layer is placed. The medium we use is air bubbles in water. During the propagation of a pulse, the interaction of the acoustic field and bubbles vibration is assured via the coupling of a nonlinear differential system. The solution is tracked in the time domain by means of the SNOW-BL code. In the biphasic fluid, attenuation and nonlinear effects are due to the bubbles only. The study addresses to two applications: filter effects of the layer and nonlinear characterization of liquid–gas mixtures. We study the filter effects (screen effect) a layer has for some frequency ranges present in the initial ultrasonic pulses, in the linear and nonlinear regimes, i.e. for low and high pressure amplitude. One (or several) simple layer is contemplated in numerical experiments with different bubble densities, bubble sizes, layer thicknesses, for different kinds of pulse.
A SIMPLE METHOD FOR COMPUTING THE GREEN FUNCTIONS OF THE HELMHOLTZ EQUATION IN THE TWO-DIMENSIONAL IMPEDANCE HALF SPACE
Authors: CHEN Z.-S. , WAUBKE H.
Published: April 2010

Green functions of Helmholtz's equation in an impedance half space (IHS) can be computed using various methods, e.g. the method presented by S. N. Chandler-Wilde and D. C. Hothersall.1 The approach of W. L. Li, T. W. Wu and A. F. Seybert2 is simpler, but it can only be used in a mass-like IHS. In this paper, the method is reformulated so that it can also be used in a stiffness-like IHS. Numerical experiments indicate that the method yields reliable results.
The Role of Risk Related Knowledge in the Diffusion of Internet Innovations
Authors: Saleh Zakaria I. , Abushanab Emad
Published: April 2010

Several variables can influence the adoption of innovation. Human Computer Interaction research has focused on ease of use as the prime determinate of user satisfaction and adoption. This study explores the issues that influence the adoption, and further examines the knowledge of perceived risk as an influence. The study examines existing theory as it pertains to the diffusion of innovation from the perspective of the Internet, and assesses the extent to which Internet technology can be used in building long-term consumer relationships. Despite the high volume of shopping done on the Internet each day, many consumers fail to make online purchases because of continued reluctance to engage in transactions with intermediaries that are not familiar and trusted. Based on the previous studies, this study posits that perceived risk for security of online transactions is one of the factors influencing online purchasing behaviour, and has an effect on the continued use.
Unstructured Knowledge Transfer in ICT Teams
Authors: Halonen Raija , Laukkanen Elisa , Acton Thomas , Conboy Kieran
Published: April 2010

This paper investigates how unstructured knowledge transfer is managed in ICT teams. In this context, unstructured knowledge refers to knowledge that is not supported by organisational strategy or any formal structure due to its ad hoc and versatile nature. The research utilises empirical material produced for use by the organisation, thus offering a realistic picture of transferring knowledge. Before knowledge management can be supported, it is necessary to understand how it is transferred and externalised in teams. To increase required understanding, this qualitative research investigated how team members in practice utilised knowledge that was created in the team, and how they attempted to support each other to benefit from existing knowledge. In the analysis, three frameworks were used, namely SECI, CIP and ba.
Technology Adoption by Subsidiaries of a Multinational Corporation: An Actor–Network Perspective
Authors: Hilaricus Janis R.
Published: April 2010

International business (IB) and management information system (MIS) literature have focused respectively on the adoption process in multinational corporations (MNCs) and on the adoption of technology in organisations. This paper investigates the process of technology adoption in MNCs and draws on the actor–network theory (ANT) in order to understand the process of technology adoption in MNCs. A case study of a French-owned subsidiary in Brazil is utilised for the conclusions. First, through data analysis, it is discovered that people established connections that differ in being either beneficial or detrimental to technology adoption. Next, it is proposed that the decision to adopt is constantly being renegotiated, whereas previous research assumes a single adoption choice for individuals and organisations. Finally, this paper shows how boundary objects may help MNCs to cope with the conflicting pressures of global integration and national responsiveness.
Structuring Innovation in the Knowledge Management Platform: Perceptions and Practices
Authors: Alstete Jeffrey W. , Meyer John P.
Published: April 2010

This qualitative research study examined perceptions and current practices of structuring innovation in the knowledge management platform by questioning employees of companies in the greater New York metropolitan area. The 69 participants involved were enrolled in graduate-level distance learning courses offered by a fully-accredited higher education institution. Many participants in the study agreed with the premise of this paper that innovation policies can and should be structured into knowledge management systems. However, it was stated by a minority in the study group that officially setting up the innovation polices with the KM system is not truly feasible, although it is a worthy goal. Nevertheless, the concepts of innovation and knowledge are closely related, and within organisations today it is a tremendous missed opportunity if knowledge management systems are not developed and structured from the start with innovation in mind as a continual outcome.
ORDINATION ANALYSIS OFTAXUS CHINENSISVAR.MAIREIFORESTS BASED ON ARTIFICIAL NEURAL NETWORK THEORY
Authors: ZHANG JIN-TUN , RU WENMING
Published: April 2010

The artificial neural network is attractive for ecological studies for its power in analyzing and solving complicated and nonlinear matters. The Self-Organizing Feature Map (SOFM) ordination were described and applied to the analysis of Taxus chinensis var. mairei forests in Shanxi province of China in this paper. The data matrix is the important values of 128 species in 95 quadrats. The results showed that SOFM ordination displayed forest communities in species space which reflected ecological gradients successfully. Its first axis is comprehensive gradient of topographical factors and its second axis is a comprehensive gradient of soil variables. SOFM ordination also distinguished 95 quadrats into eight forest types. SOFM ordination made the interpretation of relationships between communities, species, and environments easier.
SIMULATION WITH EMBEDDED AI FOR TRANSDISCIPLINARY PROBLEM SOLVING
Authors: JÁVOR ANDRÁS
Published: April 2010

In this article, a methodology and its application in various fields is dealt with. The theoretical research work has been undertaken at the McLeod Institute of Simulation Sciences Hungarian Center and its results have been implemented in the CASSANDRA (Cognizant Adaptive Simulation System for Applications in Numerous Different Relevant Areas) simulation system. The applications covered a wide range of areas where the tool system and the methodology have been applied with success. Most of these were in the framework of international projects of the European Union.
THE CBE HARDWARE ACCELERATOR FOR NUMERICAL RELATIVITY: A SIMPLE APPROACH
Authors: KHANNA GAURAV
Published: April 2010

Hardware accelerators (such as the Cell Broadband Engine) have recently received a significant amount of attention from the computational science community because they can provide significant gains in the overall performance of many numerical simulations at a low cost. However, such accelerators usually employ a rather unfamiliar and specialized programming model that often requires advanced knowledge of their hardware design. In this article, we demonstrate an alternate and simpler approach toward managing the main complexities in the programming of the cell processor, called software caching. We apply this technique to a numerical relativity (NR) application: a time-domain, finite-difference Kerr black hole perturbation evolver, and present the performance results. We obtain gains in the overall performance of generic simulations that are close to the theoretical maximum that can be obtained through our parallelization approach.
SIMULATION AND REALITY: THE BIG PICTURE
Authors: ÖREN TUNCER
Published: April 2010

The discipline of modeling and simulation (M&S) is advancing, maturing, and is being used in more and more challenging areas. Appreciation of its comprehensive and integrative view, i.e., its big picture would be very useful for its continued and systematic growth and successful applications. The article starts with a rationale for the needs to see the big picture of M&S and ways to see the big picture. Since M&S is closely related with reality and its representations i.e., models, reality/model dichotomy is clarified. As the core of the article, detailed perceptions of M&S from different perspectives such as: purpose of use, problem to be solved, connectivity of operations, and types of knowledge processing are clarified. Then, three aspects of ways to increase the trustworthiness of M&S are outlined (i.e., validation and verification (V&V), quality assurance (QA), and failure avoidance (FA). The article ends with a discussion of M&S from the perspective of professionalism. Some recommendations or challenges are still open for implementations for the success of M&S.
IMPROVING ACCURACY AND SPEED IN REAL-TIME SIMULATION OF ELECTRIC CIRCUITS
Authors: HOWE R. M.
Published: April 2010

This article proposes a methodology for real-time simulation of electric circuits consisting of linear circuit components combined with nonlinear elements, such as diodes and electronic switches, that exhibit discontinuous behavior. The methodology consists of sub-dividing fixed numerical integration time-steps into sub-steps over which the entire circuit behaves linearly, thus permitting the simulation over each sub-step to be performed using analytic formulas. For non-real-time simulation, this has routinely been accomplished using variable-step numerical integration. In the article, we show how real-time integration can be accomplished using a linear analytic formula over each fixed integration step, where the formula coefficients are stored functions of the sub-step parameters. For example, in a single-phase diode rectifier circuit, each fixed integration step h is divided into two sub-steps, the first of duration hen over which the diode is not conducting and the second of duration h(1 - en) over which the diode is conducting, with a simple formula used to calculate the dimensionless sub-step parameter en. The output current for the n + 1 frame is then calculated with a linear formula requiring four multiplications and four additions. Three of the five coefficients required for this calculation are rather complex functions of the parameter en. However, by restricting en to N + 1 equally spaced values between 0 and 1, the 3(N + 1) possible coefficient values can be pre-computed and stored in memory, which results in a sizeable reduction in execution time for each fixed integration step. The article includes a three-phase diode rectifier example that sub-divides each fixed integration step h into three sub-steps of duration hdn, h(en - dn) and h(1 - en).
Influence of Stacking Sequences and Lattice Parameter Differences on the Microstructure of Nonpolar AlN Films Grown on (1120) 6H-SiC by Plasma-Assisted Molecular Beam Epitaxy
Authors: Vennegues Philippe , Founta Sebastien , Mariette Henri , Daudin Bruno
Published: April 2010

Thanks to close crystalline structures and low lattice mismatches, nonpolar (1120) 6H-SiC is expected to be a well-adapted substrate for the growth of nonpolar (1120) III–nitride films. We demonstrate that the local reproduction of the basal planes stacking induces the presence of numerous planar defects (1.3×106 cm-1) in AlN films deposited on (1120) 6H-SiC. Moreover, the tensile strain of AlN along the [0001] direction results in the cracking of the film for a thickness as low as 100 nm. This fragile plastic relaxation is favored because the only slip systems available for ductile plastic relaxation are pyramidal systems involving a+c dislocations which have a high activation energy.
Anisotropic Transformation of 4H-SiC Etching Shapes by High-Temperature Annealing and Its Enhancement by Ion Implantation
Authors: Kawada Yasuyuki , Tawara Takeshi , Nakamura Shun-ichi , Tsuji Takashi , Gotoh Masahide , Iwamuro Noriyuki
Published: April 2010

The transformation of 4H-SiC etching shapes by high-temperature annealing was investigated. Although the opening of the etching mask was circular, the resulting etched shape was a hexagon, dodecagon, or rounded polygon with more edges, depending on the diameter. A hexagon was transformed into a dodecagon following high-temperature annealing, and a dodecagon was transformed into a rounded polygon.
First Demonstration of Semipolar Deep Ultraviolet Light Emitting Diode on m-Plane Sapphire with AlGaN Multiple Quantum Wells
Authors: Balakrishnan Krishnan , Adivarahan Vinod , Fareed Qhalid , Lachab Mohamed , Zhang Bin , Khan Asif
Published: April 2010

We report on the first demonstration of a semipolar AlGaN based deep ultraviolet (UV) light emitting diode (LED), with a peak emission wavelength of 307 nm. The LED structure was grown on an m-plane sapphire substrate using metal organic chemical vapor deposition (MOCVD). A combination of pulsed MOCVD (PMOCVD) grown AlN and a short period AlN/AlGaN superlattice structure was found to be instrumental in achieving singular semipolar structural phase of (1122) with a defect density low enough to fabricate the light emitting device. The on-wafer optical output power of the fabricated LED was ∼20 µW at a dc pump current of 20 mA.
Optically Induced Rotation of Microcylinders Made of Photopolymerizable Nematic Liquid Crystal
Authors: Ito Kiminori , Kimura Masahiro
Published: April 2010

We report for the first time the use of photopolymerizable liquid crystals in fabricating microsized cylinders that are rotated by a circularly polarized laser beam. They were fabricated by two-photon photopolymerization from liquid crystals whose molecules had been deliberately oriented on a rubbed surface. The rotational torque showed similar oscillatory structures to those observed in the intensity of light transmitted through crossed Nikols as a function of cylinder height. From the structures, the birefringence of the cylinders was estimated and the main mechanism underlying the rotational torque transfer was determined.