bluuebunny/crossref_metadata_2025 huggingface dataset:
Biosynthesis of lactose and its deoxy derivatives
Authors: Zemek Jiří , Kučár Štefan , Zámocký Juraj , Augustín Jozef
Published: October 2011

The biosynthesis of lactose (O-β-D-galactopyranosyl-(1 → 4)-D-glucopyranose was investigated in a reaction catalyzed by lactosynthetase (UDP-D-galactose: D-glucose-4-β-D-galactosyltransferase) isolated from milk. The reaction donor in this reaction was UDP-D-galactose, the acceptor D-glucose or its monodeoxy derivatives. As found, monodeoxyglucose - excepting 4-deoxy-D-glucose - enter the transglycosylation reaction of biosynthesis of lactose. The affinity of the enzyme and the rate of biosynthesis of lactose and its deoxy derivatives decrease in the following order: lactose, 2G-deoxylactose, 6G-deoxylactose, 3G-deoxylactose.
Application of the turbidity ratio method in the spherical particle size determination in the range m ∈ <1.001, 1.315> and α ∈ <0.05, 100>
Authors: Sedláček Blahoslav , Verner Břetislav , Bárta Miroslav , Zimmermann Karel
Published: October 2011

Basic scattering functions were used in a novel calculation of the turbidity ratios for particles having the relative refractive index m = 1.001, 1.005 (0.005) 1.315 and the size α = 0.05 (0.05) 6.00 (0.10) 15.00 (0.50) 70.00 (1.00) 100, where α = πL/λ, L is the diameter of the spherical particle, λ = Λ/μ1 is the wavelength of light in a medium with the refractive index μ1 and Λ is the wavelength of light in vacuo. The data are tabulated for the wavelength λ = 546.1/μw = 409.357 nm, where μw is the refractive index of water. A procedure has been suggested how to extend the applicability of Tables to various refractive indices of the medium and to various turbidity ratios τa/τb obtained with the individual pairs of wavelengths λa and λb. The selection of these pairs is bound to the sequence condition λa = λ0χa and λb = λ0χb, in which b-a = δ = 1, 2, 3; a = -2, -1, 0, 1, 2, ..., b = a + δ = -1, 0, 1, 2, ...; λ0 = λa=0 = 326.675 nm; χ = 546.1 : 435.8 = 1.2531 is the quotient of the given sequence.
Note on boundary layer flows of non-Newtonian Powell-Eyring fluids
Authors: Lhotáková Šárka , Mitschka Pavel
Published: October 2011

The boundary layer equations for flow of non-Newtonian Powell-Eyring fluids past a rectangular wedge are solved exactly over a wide range of the governing parameters. The accuracy of an approximate solution of the same flow problem, based on the integral momentum theorem, is found to be sufficient for rapid engineering calculations.
Control of the adiabatic flow reactor by feeding the catalyst solution
Authors: Horák Josef , Sojková Zina , Jiráček František
Published: October 2011

Control algorithm of the operating temperature is described in the reactor, which is operated at constant temperature and composition of the inlet mixture. The temperature is controlled by dosing a constant volume of the catalyst solution. The dosing frequency is determined according to the reaction temperature (deviation of the temperature from the desired value and the sign of the derivative of temperature). The control algorithm has been verified experimentally for the laboratory reactor in unstable steady state.
Effect of admixtures on the formation of NiAl2O4 by solid phase reaction
Authors: Macák Jiří , Koutský Bohumil
Published: October 2011

The effect of silicon and of subgroups IVb-VIIIb elements on the rate of the reaction NiO + Al2O3 = NiAl2O4 proceeding in the solid phase in a powder system at 1 100-1 300 °C was examined. A remarkable accelerating effect was found for V(V) and Ti(IV), whereas retardation of the NiAl2O4 formation was observed with Mo(VI) and Cr(III). The activation energies of the reaction in the presence of the various admixtures were determined.
Determination of the aeration capacity of bubble columns by dynamic method. The influence of axial dispersion and of the start-up period
Authors: Linek Václav , Stejskal Jiří , Sinkule Jiří , Vacek Václav
Published: October 2011

A dynamic method for the determination of volumetric mass transfer coefficient of oxygen, kLa, in bubble columns using an oxygen electrode was derived on the basis of a liquid phase axial dispersion model The influence of aeration startup was studied assuming that the kLa value is position and time dependent. The conditions are defined under which the influence of aeration startup and of axial mixing of the liquid upon the steady state kLa value is negligible. A critical assessment has been made of various methods proposed for evaluation of oxygen probe responses.
The preparation and metabolic fate of tritiated Nα-acetyl[2-O-methyltyrosine]oxytocin - An inhibitor of the uterotonic action of oxytocin
Authors: Bojanovska Vera , Barth Tomislav , Černý Bohuslav , Hauzer Karel , Jošt Karel
Published: October 2011

An inhibitor of the uterotonic action of oxytocin-[CH3CO-3H] [2-O-methyltyrosine]oxytocin - having biological activity and a specific radioactivity of 3-7 Ci/mmol was prepared by the reaction of [2-O-methyltyrosine]oxytocin with 2,2'-3H2-acetanhydride. The analogue was stable in human pregnancy serum. Chymotrypsin split the Tyr(Me)-Ile and Leu-GlyNH2 peptide bonds. In the presence of subcellular fractions of homogenates of the rat uterus and mammary gland, several metabolic products were formed from the analogue.
Cooxidation reactions of ascorbic acid
Authors: Schwertnerová Eva , Wagnerová Dana M. , Vepřek-Šiška Josef
Published: October 2011

Catalytic oxidation of salicylic acid by molecular oxygen, induced by the oxidation of ascorbic acid, leads to the formation of a mixture of isomers of dihydroxybenzoic acid. The reaction is catalyzed by a series of metal chelates, especially Fe(II) and Co(II), the most marked catalytic effect having been found in the case of tetrasulphophthalocyanine of cobalt (CoTSP). The kinetics of the oxidation of ascorbic acid in the presence of salicylic acid was followed, and the formation of hydrogen peroxide as reaction intermediate was proved.
Fluorinated tricyclic neuroleptics: Synthesis and pharmacology of 8-fluoro-4-(4-methylpiperazino)-4,5-dihydrothieno[2,3-b]-1-benzothiepin
Authors: Rajšner Miroslav , Mikšík František , Metyšová Jiřina , Protiva Miroslav
Published: October 2011

A reaction of (4-fluoro-2-iodophenyl)acetic acid with 2-thiophenethiol gave the acid V which was cyclized to 8-fluorothieno[2,3-b]-1-benzothiepin-4(5H)-one (VII); two further steps led to 4-chloro-8-fluoro-4,5-dihydrothieno[2,3-b]-1-benzothiepin (IX). A substitution reaction with 1-methylpiperazine resulted in the title compound which showed a very strong central depressant and cataleptic activity, being at the same time almost inactive in the test of inhibition of apomorphine stereotypies in rats. Ethyl 2-amino-5-ethylthiopene-3-carboxylate (X) was transformed by multi-step procedures to the acids XV, XIX and XXVI out of which only the first one could be cyclized to a tricyclic ketone, i.e. 2-ethyldithieno[2,3-b; 3',2'-e]thiopyran-4-one (XX).
Components of Neopallasia pectinata
Authors: Motl Otakar , Očir Gončig
Published: October 2011

From the light petroleum extract of the above-ground part of Neopallasia pectinata (PALL.) POLYAKOV paraffins, sesquiterpenic hydrocarbons, a sesquiterpenic diol and a relatively considerable amount of eremophila-9(10),11(13)-dien-12-oic acid were isolated by chromatography. The mixture of plant phytosterols contained β-sitosterol, stigmasterol and campesterol.
The effect of acetates on the activity of cobalt bromide catalysts
Authors: Hronec Milan , Veselý Václav , Herain Jiří
Published: October 2011

With a view to assess the effect of acetates of the groups Ia and IIon the activity of cobalt bromide catalyst, oxidation of mesitylene and pseudo-cumene in a temperature range of 90 to °C has been investigated. At 100°C the acetate anions retarded the oxidation in the initial stage and increased selectivity of the oxidation of mesitylene to 3,5-dimethylbenzaldehyde, which intermediate was formed to a concentration of 42 mol%. The presence of acetates also affected distribution of isomers of aromatic dicarboxylic acids and the contents of aldehydo acids. The resultant effect of the simultaneous presence of acetate anions and nitrogen compounds on the activity of cobalt bromide catalysts depended on the nitrogen compound; with aminoacetic acid and hexamethylenediamine the oxidation rate and yields of aromatic acids were markedly increased. As conductance measurements indicated, the presence of acetates enhanced the formation of ionic forms of the complexes.
Studies on tautomerism in the triazoline dione
Authors: Beni Alireza Salimi , Dalirnasab Zeinab , Teimouri Abbas , Chermahini Alireza Najafi
Published: October 2011

The chemical properties of the triazoline dione have been extensively studied. The relative stability of three tautomers in the gas phase and solution (using PCM model) are evaluated using HF and DFT methods and compared with MP2 level using different basis sets. The results of the calculations indicate that 4H-1,2,4-triazole-3,5-dione (K form) is more stable in the gas phase than in solution. In addition, the transition states of proton transfer reaction is calculated. The vibrational frequencies and corresponding normal mode assignments of 4H-1,2,4-triazole-3,5-dione and 5-hydroxy-3H-1,2,4-triazol-3-one (E1 form) are also theoretically examined. In addition, the variation of dipole moments and charges on atoms with change of solvent is studied. Specific solvent effects with addition of one molecule of water near the electrophilic centers of three tautomers and the transition state of proton transfer assisted by a water molecule was investigated. Aggregation with water molecules does not change the order of stability of isomers, but proton transfer reaction assisted by a water molecule needs less energy than the intramolecular process.
Deterministic Distributed Vertex Coloring in Polylogarithmic Time
Authors: Barenboim Leonid , Elkin Michael
Published: October 2011

Consider an
n
-vertex graph
G
= (
V
,
E
) of maximum degree
Δ
, and suppose that each vertex
v
∈
V
hosts a processor. The processors are allowed to communicate only with their neighbors in
G
. The communication is synchronous, that is, it proceeds in discrete rounds.

In the distributed vertex coloring problem, the objective is to color
G
with
Δ
+ 1, or slightly more than
Δ
+ 1, colors using as few rounds of communication as possible. (The number of rounds of communication will be henceforth referred to as
running time
.) Efficient
randomized
algorithms for this problem are known for more than twenty years [Alon et al. 1986; Luby 1986]. Specifically, these algorithms produce a (
Δ
+ 1)-coloring within
O
(log
n
) time, with high probability. On the other hand, the best known
deterministic
algorithm that requires polylogarithmic time employs
O
(
Δ
2
) colors. This algorithm was devised in a seminal FOCS’87 paper by Linial [1987]. Its running time is
O
(log
*
n
). In the same article, Linial asked whether one can color with significantly less than
Δ
2
colors in deterministic polylogarithmic time. By now, this question of Linial became one of the most central long-standing open questions in this area.

In this article, we answer this question in the affirmative, and devise a deterministic algorithm that employs
Δ
1+
o
(1) colors, and runs in
polylogarithmic
time. Specifically, the running time of our algorithm is
O
(
f
(
Δ
)log
Δ
log
n
), for an arbitrarily slow-growing function
f
(
Δ
) =
ω
(1). We can also produce an
O
(
Δ
1+
η
)-coloring in
O
(log
Δ
log
n
)-time, for an arbitrarily small constant
η
> 0, and an
O
(
Δ
)-coloring in
O
(
Δϵ
log
n
) time, for an arbitrarily small constant
ϵ
> 0. Our results are, in fact, far more general than this. In particular, for a graph of arboricity
a
, our algorithm produces an
O
(
a
1+
η
)-coloring, for an arbitrarily small constant
η
> 0, in time
O
(log
a
log
n
).
Role of autophagy in angiogenesis in aortic endothelial cells
Authors: Du Jianhai , Teng Ru-Jeng , Guan Tongju , Eis Annie , Kaul Sushma , Konduri Girija G. , Shi Yang
Published: October 2011

Angiogenesis plays critical roles in the recovery phase of ischemic heart disease and peripheral vascular disease. An increase in autophagy is protective under hypoxic and chronic ischemic conditions. In the present study we determined the role of autophagy in angiogenesis. 3-Methyladenine (3-MA) and small interfering RNA (siRNA) against ATG5 were used to inhibit autophagy induced by nutrient deprivation of cultured bovine aortic endothelial cells (BAECs). Assays of BAECs tube formation and cell migration revealed that inhibition of autophagy by 3-MA or siRNA against ATG5 reduced angiogenesis. In contrast, induction of autophagy by overexpression of ATG5 increased BAECs tube formation and migration. Additionally, inhibiting autophagy impaired vascular endothelial growth factor (VEGF)-induced angiogenesis. However, inhibition of autophagy did not alter the expression of pro-angiogenesis factors such as VEGF, platelet-derived growth factor, or integrin αV. Furthermore, autophagy increased reactive oxygen species (ROS) formation and activated AKT phosphorylation. Inhibition of autophagy significantly decreased the production of ROS and activation of AKT but not of extracellular regulated kinase, whereas overexpression of ATG5 increased cellular ROS production and AKT activation in BAECs. Inhibition of AKT activation or ROS production significantly decreased the tube formation induced by ATG5 overexpression. Here we report a novel observation that autophagy plays an important role in angiogenesis in BAECs. Induction of autophagy promotes angiogenesis while inhibition of autophagy suppresses angiogenesis, including VEGF-induced angiogenesis. ROS production and AKT activation might be important mechanisms for mediating angiogenesis induced by autophagy. Our findings indicate that targeting autophagy may provide an important new tool for treating cardiovascular disease.
Human gene SLC41A1 encodes for the Na+/Mg2+ exchanger
Authors: Kolisek Martin , Nestler Axel , Vormann Jürgen , Schweigel-Röntgen Monika
Published: October 2011

Magnesium (Mg2+), the second most abundant divalent intracellular cation, is involved in the vast majority of intracellular processes, including the synthesis of nucleic acids, proteins, and energy metabolism. The concentration of intracellular free Mg2+ ([Mg2+]i) in mammalian cells is therefore tightly regulated to its optimum, mainly by an exchange of intracellular Mg2+ for extracellular Na+. Despite the importance of this process for cellular Mg2+ homeostasis, the gene(s) encoding for the functional Na+/Mg2+ exchanger is (are) still unknown. Here, using the fluorescent probe mag-fura 2 to measure [Mg2+]i changes, we examine Mg2+ extrusion from hSLC41A1-overexpressing human embryonic kidney (HEK)-293 cells. A three- to fourfold elevation of [Mg2+]i was accompanied by a five- to ninefold increase of Mg2+ efflux. The latter was strictly dependent on extracellular Na+ and reduced by 91% after complete replacement of Na+ with N-methyl-d-glucamine. Imipramine and quinidine, known unspecific Na+/Mg2+ exchanger inhibitors, led to a strong 88% to 100% inhibition of hSLC41A1-related Mg2+ extrusion. In addition, our data show regulation of the transport activity via phosphorylation by cAMP-dependent protein kinase A. As these are the typical characteristics of a Na+/Mg2+ exchanger, we conclude that the human SLC41A1 gene encodes for the Na+/Mg2+ exchanger, the predominant Mg2+ efflux system. Based on this finding, the analysis of Na+/Mg2+ exchanger regulation and its involvement in the pathogenesis of diseases such as Parkinson's disease and hypertension at the molecular level should now be possible.
Mitochondrial functional specialization in glycolytic and oxidative muscle fibers: tailoring the organelle for optimal function
Authors: Picard Martin , Hepple Russell T. , Burelle Yan
Published: October 2011

In skeletal muscle, two major types of muscle fibers exist: slow-twitch oxidative (type I) fibers designed for low-intensity long-lasting contractions, and fast-twitch glycolytic (type II) fibers designed for high-intensity short-duration contractions. Such a wide range of capabilities has emerged through the selection across fiber types of a narrow set of molecular characteristics suitable to achieve a specific contractile phenotype. In this article we review evidence supporting the existence of distinct functional phenotypes in mitochondria from slow and fast fibers that may be required to ensure optimal muscle function. This includes differences with respect to energy substrate preferences, regulation of oxidative phosphorylation, dynamics of reactive oxygen species, handling of Ca2+, and regulation of cell death. The potential physiological implications on muscle function and the putative mechanisms responsible for establishing and maintaining distinct mitochondrial phenotype across fiber types are also discussed.
Ion Transport by Pulmonary Epithelia
Authors: Hollenhorst Monika I. , Richter Katrin , Fronius Martin
Published: October 2011

The lung surface of air‐breathing vertebrates is formed by a continuous epithelium that is covered by a fluid layer. In the airways, this epithelium is largely pseudostratified consisting of diverse cell types such as ciliated cells, goblet cells, and undifferentiated basal cells, whereas the alveolar epithelium consists of alveolar type I and alveolar type II cells. Regulation and maintenance of the volume and viscosity of the fluid layer covering the epithelium is one of the most important functions of the epithelial barrier that forms the outer surface area of the lungs. Therefore, the epithelial cells are equipped with a wide variety of ion transport proteins, among which Na+, Cl−, and K+ channels have been identified to play a role in the regulation of the fluid layer. Malfunctions of pulmonary epithelial ion transport processes and, thus, impairment of the liquid balance in our lungs is associated with severe diseases, such as cystic fibrosis and pulmonary oedema. Due to the important role of pulmonary epithelial ion transport processes for proper lung function, the present paper summarizes the recent findings about composition, function, and ion transport properties of the airway epithelium as well as of the alveolar epithelium.
Efficacy of Esthetic Retainers: Clinical Comparison between Multistranded Wires and Direct-Bond Glass Fiber-Reinforced Composite Splints
Authors: Scribante Andrea , Sfondrini Maria Francesca , Broggini Simona , D'Allocco Marina , Gandini Paola
Published: October 2011

The purpose of this longitudinal prospective randomized study was to evaluate the reliability of two different types of orthodontic retainers in clinical use: a multistrand stainless steel wire and a polyethylene ribbon-reinforced resin composite. Moreover the level of satisfaction of the patient about the esthetic result was also analyzed by means of a Visual Analogue Scale (VAS). 34 patients (9 boys and 25 girls, mean age 14.3), in the finishing phase of orthodontic treatment, were selected for the study. Since splints were applied the number, cause, and date of splint failures were recorded for each single tooth over 12 months. Statistical analysis was performed using a paired -test, Kaplan Meier survival estimates, and the log-rank test. Kruskal Wallis test was performed to analyze VAS recordings. Differences between the bond failure rates were not statistically significant. Esthetic result of VAS was significantly higher for polyethylene ribbon-reinforced resin retainers than for stainless steel wires.
Engineering Judgment of Children Bone Fracture
Authors: Alsamhan A. , ELSingergy M. M. , Zamzam M. M. , Darwish S. M.
Published: October 2011

Supracondylar humerus fracture (SCHF) is one of the commonest elbow fractures in children. It is common injury for children with age from four to fourteen. In current study, the finite element technique is used to evaluate two techniques, namely, parallel and crossed K-wire fixation for treatment of SCHF, using K-wire fixation.
Are We Missing Post-Thrombotic Syndrome Syndrome? An Orthopaedic Perspective in Lower Limb Arthroplasty
Authors: Reidy M. , MacInnes A. , Pillai A.
Published: October 2011

2–5% of patients undergoing hip or knee arthroplasty develop a symptomatic DVT; there is evidence to suggest that without prophylaxis 40–60% of patients have a subclinical DVT. This can be reduced by around half with appropriate thromboprophylaxis; there still remains a significant incidence of subclinical DVT. Therefore, it is important to know, as orthopaedic surgeons, if our patients undergoing large joint arthroplasty are being adversely affected. Post-thrombotic syndrome (PTS) is usually associated with symptomatic DVT, and the purpose of this paper is to address if asymptomatic DVT is also associated with an increased risk of PTS. The majority of evidence gathered does not support a link; therefore, there is no evidence to warrant a change in practice to warn patients of a potential risk or to routinely screen asymptomatic patients.
Redefining Onyx HD 500 in the Flow Diversion Era
Authors: Dalyai Richard Tyler , Randazzo Ciro , Ghobrial George , Gonzalez L. Fernando , Tjoumakaris Stavropoula I. , Dumont Aaron S. , Rosenwasser Robert H. , Jabbour Pascal
Published: October 2011

We report the largest US case series results using Onyx HD-500 (EV3), a new liquid embolic agent, in the successful treatment of 21 patients with wide-neck intracranial aneurysms (mean size 4.5 mm), which are at increased risk of incomplete occlusion or recanalization with standard endovascular intervention utilizing detachable platinum coils. All aneurysms were located in the anterior circulation, and three aneurysms presented as acute subarachnoid hemorrhages. Complete aneurysm occlusion was present in 19 of 21 patients (90%). On six-month followup, one patient with an initially small residual neck progressed to total occlusion. Aneurysm recanalization was not detected in any patients on mean follow up of 8.9 months in 11 patients. Four patients experienced transient neurologic deficits in the immediate postoperative period and one in a delayed fashion. Embolization with the liquid embolic agent Onyx appears to be a safe and effective endovascular modality of treatment for wide-neck aneurysms or recurrent aneurysms that had previously failed treatment with detachable coils.
Behavioral and Physiological Responses of Ozark Zigzag Salamanders to Stimuli from an Invasive Predator: The Armadillo
Authors: Crane Adam L. , McGrane Carly E. , Mathis Alicia
Published: October 2011

When new predators invade a habitat, either through range extensions or introductions, prey may be at a high risk because they do not recognize the predators as dangerous. The nine-banded armadillo (Dasypus novemcinctus) has recently expanded its range in North America. Armadillos forage by searching soil and leaf litter, consuming invertebrates and small vertebrates, including salamanders. We tested whether Ozark zigzag salamanders (Plethodon angusticlavius) from a population coexisting with armadillos for about 30 years exhibit antipredator behavior in the presence of armadillo chemical cues and whether they can discriminate between stimuli from armadillos and a nonpredatory sympatric mammal (white-tailed deer,Odocoileus virginianus). Salamanders appeared to recognize substrate cues from armadillos as a threat because they increased escape behaviors and oxygen consumption. When exposed to airborne cues from armadillos, salamanders also exhibited an antipredator response by spending more time in an inconspicuous posture. Additionally, individually consistent behaviors across treatments for some response variables suggest the potential for a behavioral syndrome in this species.
A Review of Dual-Task Walking Deficits in People with Parkinson's Disease: Motor and Cognitive Contributions, Mechanisms, and Clinical Implications
Authors: Kelly Valerie E. , Eusterbrock Alexis J. , Shumway-Cook Anne
Published: October 2011

Gait impairments in Parkinson's disease (PD) are exacerbated under dual-task conditions requiring the simultaneous performance of cognitive or motor tasks. Dual-task walking deficits impact functional mobility, which often requires walking while performing concurrent tasks such as talking or carrying an object. The consequences of gait impairments in PD are significant and include increased disability, increased fall risk, and reduced quality of life. However, effective therapeutic interventions for dual-task walking deficits are limited. The goals of this narrative review are to describe dual-task walking deficits in people with PD, to discuss motor and cognitive factors that may contribute to these deficits, to review potential mechanisms underlying dual-task deficits, and to discuss the effect of therapeutic interventions on dual-task walking deficits in persons with PD.
Digital Ocular Fundus Imaging: A Review
Authors: Bernardes Rui , Serranho Pedro , Lobo Conceição
Published: October 2011

Ocular fundus imaging plays a key role in monitoring the health status of the human eye. Currently, a large number of imaging modalities allow the assessment and/or quantification of ocular changes from a healthy status. This review focuses on the main digital fundus imaging modality, color fundus photography, with a brief overview of complementary techniques, such as fluorescein angiography. While focusing on two-dimensional color fundus photography, the authors address the evolution from nondigital to digital imaging and its impact on diagnosis. They also compare several studies performed along the transitional path of this technology. Retinal image processing and analysis, automated disease detection and identification of the stage of diabetic retinopathy (DR) are addressed as well. The authors emphasize the problems of image segmentation, focusing on the major landmark structures of the ocular fundus: the vascular network, optic disk and the fovea. Several proposed approaches for the automatic detection of signs of disease onset and progression, such as microaneurysms, are surveyed. A thorough comparison is conducted among different studies with regard to the number of eyes/subjects, imaging modality, fundus camera used, field of view and image resolution to identify the large variation in characteristics from one study to another. Similarly, the main features of the proposed classifications and algorithms for the automatic detection of DR are compared, thereby addressing computer-aided diagnosis and computer-aided detection for use in screening programs.
Race-Ethnicity and Medical Services for Infertility
Authors: Greil Arthur L. , McQuillan Julia , Shreffler Karina M. , Johnson Katherine M. , Slauson-Blevins Kathleen S.
Published: October 2011

Evidence of group differences in reproductive control and access to reproductive health care suggests the continued existence of “stratified reproduction” in the United States. Women of color are overrepresented among people with infertility but are underrepresented among those who receive medical services. The authors employ path analysis to uncover mechanisms accounting for these differences among black, Hispanic, Asian, and non-Hispanic white women using a probability-based sample of 2,162 U.S. women. Black and Hispanic women are less likely to receive services than other women. The enabling conditions of income, education, and private insurance partially mediate the relationship between race-ethnicity and receipt of services but do not fully account for the association at all levels of service. For black and Hispanic women, social cues, enabling conditions, and predisposing conditions contribute to disparities in receipt of services. Most of the association between race-ethnicity and service receipt is indirect rather than direct.
Health Technology Assessment Implementation
Authors: Callahan Daniel
Published: October 2011

Using a 2009 American debate on a federal public health recommendation on mammography screening for women under the age of 50 as a case study, it is argued that public acceptance of health technology assessment (HTA) depends on the ethical acceptability of its recommendations. At the same time, that acceptability cannot be separated from the politics and values of the health care system of which it is part. In the United States, those values display a sharp ideological split between a conservative individual-based ethic and a liberal community-oriented ethic. A clash of this kind cannot be solved by invocation of ethical principles when it is those principles themselves that are in conflict. Inevitably HTA acceptance is threatened by this conflict as is the fate of health care reform.
A new conjugate heat transfer method to analyse a 3D steam cooled gas turbine blade with temperature-dependent material properties
Authors: Jafari M M , Atefi G , Khalesi J , Soleymani A
Published: October 2011

The erosion of the hot regions in a gas turbine is one of the most important challenges encountered by the power plants. Though several numerical simulations of the problem have been reported so far, little is known to give accurate results. In this article, the thermoelastic behaviour of a gas turbine blade with internal steam-cooled channels positioned within a three-dimensional cascade configuration has been studied. A computer code based on the conjugate heat transfer method using the simultaneous solution of Navier–Stokes and heat transfer equations has been developed. From this study, the temperature distribution along with the stress values at high temperatures has been obtained. The blade parameters such as E, α, and K were considered to be a function of the temperature. In the previous works, usually only one or two of these parameters was considered as temperature dependent and the others constant. In this article, all the blade parameters, though making the equations highly non-linear, were considered as a function of temperature. The results have been compared with the available experimental data and a good agreement is observed. According to these findings, taking the temperature dependency of materials into account increases the estimations accuracy and brings the results closer to the reality.
An improved Geneva mechanism for optimal kinematic performance
Authors: Heidari M , Atai A A , Panahi M Shariat
Published: October 2011

In this article, an alternative Geneva mechanism is presented and optimized. Unlike the original mechanism in which the driving pin operates at a fixed radius, the alternative mechanism benefits from a fixed groove cam which controls the radius of action of driving pin, resulting in continuous wheel acceleration and lower maximum velocity and acceleration. Apolynomial displacement function is adopted for the cam in the interval of engagement of driver and wheel. The problem of finding the coefficients of the polynomial is formulated as a constrained optimization problem in which the maximum acceleration of the Geneva wheel is to be minimized, while the motion of the pin is constrained to have zero velocity and zero acceleration at the beginning and end of the motion, respectively. Moreover, it is argued that since the objective function is highly sensitive to the variations of design variables, traditional search algorithms often fail to find its global optimum. To resolve this problem, a new hybrid genetic algorithm with a built-in adaptive local search is employed to find the coefficients of a polynomial that would define the optimal groove profile. The proposed approach is applied to the classical problems of designing a Geneva mechanism with four, five, and six grooves, and the results are compared with those obtained by other methods. The comparison shows that the proposed approach is capable of designing shock-free mechanisms with significantly reduced maximum angular velocity and acceleration of the Geneva wheel.
Finite element modelling of the rail gauge corner and underhead radius stresses under heavy axle load conditions
Authors: Ranjha S A , Ding K , Mutton P J , Kapoor A
Published: October 2011

Highly localized stresses generated at the gauge corner of the outer rail cause fatigue cracking. The longitudinal bending stresses in the rail underhead radius position are of special interest, as tension spikes have been identified at this location during in-track measurements under high axle load conditions. The tension spike is a result of vertical and lateral head bending on the web. This effect is highly localized and is additional to the stresses generated due to vertical and lateral bending of the whole rail profile (the so-called global bending). This study examined contact and bending stresses by modelling the rail on a discrete foundation using finite elements and by considering the loading to be a fully slipping elliptical Hertzian contact patch. The analysis revealed that the tensile longitudinal stress was highly dependent on several service conditions: the contact patch offset from the rail centreline, the ratio of lateral ( L) to vertical ( V) loads, the direction of lateral traction, foundation stiffness and seasonal temperature variations. The tension spike increases, and the depth below the contact surface at which the stresses become tensile reduces, as the contact patch offset and/or the L/ V ratio increases. Both these enhance the tendency for rolling contact fatigue cracks to turn downwards and become transverse defects. This is because an increase in tensile bending stresses together with both residual and thermally induced stresses can facilitate cracks to turn perpendicular to the tensile stresses once they reach a critical length. Shear traction towards the gauge corner was found to be the most damaging phenomenon.
Erratic control of breathing during exercise in patients with systemic lupus erythematosus: a pilot-study
Authors: do Prado DML , Gualano B , Miossi R , Lima FR , Roschel H , Borba E , Bonfá E , de Sá Pinto AL
Published: October 2011

Purpose: The aim of this study was to provide a comprehensive evaluation of the pattern and timing of breathing during incremental exercise in a sample of women living with systemic lupus erythematosus (SLE). Methods: In this cross-sectional study, 20 women with SLE without pulmonary involvement were compared with 20 gender-, body mass index- (BMI), and age-matched healthy individuals. By using a cardiopulmonary incremental exercise test, the following parameters were assessed: tidal volume (VT); breathing frequency (BF); total respiratory time (TOT); inspiratory time (TI); expiratory time (TE); inspiratory time to total time (TI/TOT); mean inspiratory flow (VT/TI); ventilatory equivalent for carbon dioxide (VE/VCO2) and end-tidal carbon dioxide pressure (PETCO2). Results: BF and BF/VT were significantly higher in patients with SLE versus controls, whereas VT, TE, TI and TOT were significantly lower in the former group ( p < 0.05). Additionally, patients with SLE presented higher VE/VCO2 and lower PETCO2 than controls ( p < 0.05), suggesting a ventilatory inefficiency. Conclusion: We reported compelling evidence of abnormal pattern and timing of breathing during incremental exercise in SLE. Considering that an erratic control of breathing may play an important role in exercise intolerance and fatigue, respiratory exercises emerge as a potential treatment for these symptoms in patients with SLE.
Lingodroids: socially grounding place names in privately grounded cognitive maps
Authors: Schulz Ruth , Wyeth Gordon , Wiles Janet
Published: October 2011

For mobile robots to communicate meaningfully about their spatial environment, they require personally constructed cognitive maps and social interactions to form languages with shared meanings. Geographic spatial concepts introduce particular problems for grounding—connecting a word to its referent in the world—because such concepts cannot be directly and solely based on sensory perceptions. In this article we investigate the grounding of geographic spatial concepts using mobile robots with cognitive maps, called Lingodroids. Languages were established through structured interactions between pairs of robots called where-are-we conversations. The robots used a novel method, termed the distributed lexicon table, to create flexible concepts. This method enabled words for locations, termed toponyms, to be grounded through experience. Their understanding of the meaning of words was demonstrated using go-to games in which the robots independently navigated to named locations. Studies in real and virtual reality worlds show that the system is effective at learning spatial language: robots learn words easily—in a single trial as children do—and the words and their meaning are sufficiently robust for use in real world tasks.
Effects of Pioglitazone on High-Fat-Diet–Induced Ventricular Remodeling and Dysfunction in Rats
Authors: Tian Ya-Qiang , Li Shou-She , Su Xu-Dong , Zhang Guang-Zhen , Zhao Jia-Jun , Li Guang-Wei , Wang Lexin
Published: October 2011

Objective: To investigate the effect of pioglitazone on high-fat (HF)-diet–induced left ventricular (LV) hypertrophy and dysfunction in rats. Methods: A total of 36 male Sprague-Dawley rats were randomly divided into 3 groups, namely, control, HF diet, and pioglitazone treatment group. High-fat diet group (HF group) animals were treated with HF diet for 30 weeks, whereas pioglitazone group was treated with HF diet for 30 weeks and pioglitazone in the last 6 weeks of the 30-week treatment. Fasting plasma free fatty acids (FFAs), serum, and myocardial triglyceride were measured. Left ventricular function was assessed by echocardiography. Renin, angiotensin II, and angiotensin types 1 and 2 (AT1/AT2) receptors in the myocardium were analyzed by immunohistochemistry and real-time polymerase chain reaction (PCR). Results: Systolic blood pressure, plasma FFA, serum, and myocardial triglyceride concentrations in HF group were higher than in control and pioglitazone groups ( P < .01). There was no significant difference in LV weight index and LV posterior wall thickness between HF and pioglitazone groups; both were higher than in the control group ( P < .01). Left ventricular ejection fraction, fraction of shortening, and cardiac index in HF group were lower than in the control and pioglitazone groups ( P < .05). Myocardial expression of angiotensin II and AT1 receptor protein in HF group was higher when compared with the control and pioglitazone groups ( P < .01). Myocardial renin and angiotensin II messenger RNA (mRNA) in HF group was also higher when compared with the control and pioglitazone groups, whereas the expression of AT2 mRNA was lower ( P < .01). Conclusion: Pioglitazone diminished HF-diet–induced LV dysfunction. These effects may be related to a reduction in blood pressure, myocardial triglycerides sedimentary, and suppression of renin–angiotensin system.
A multi-purpose earthquake simulator and a flexible development platform for actuator controller design
Authors: Nakata Narutoshi
Published: October 2011

This paper presents a multi-purpose uniaxial earthquake simulator that has been designed and developed at the Johns Hopkins University. The earthquake simulator is coupled with a flexible platform that facilitates the development of actuator control strategies to enhance accuracy in shake table tests. The development platform provides a full access to processes in control including an actuator servo control loop, enabling high-fidelity controller designs to be implemented and experimentally investigated for earthquake simulators. This paper presents construction details, hydraulic components, dynamic specifications, an integrated control and data acquisition system, and example applications of the earthquake simulator. The paper demonstrates the versatility of the earthquake simulator and the development platform that can be adopted elsewhere.
Rolling element bearing vibration modeling with applications to health monitoring
Authors: Jiang Jian , Zhang Bin
Published: October 2011

The condition monitoring of a rolling element bearing requires a thorough understanding of the bearing and online evaluation of system health. This paper presents a generic scheme for health monitoring of rolling element bearings. The approach contains vibration modeling and online fault dimension estimation. The parameters of a vibration model are obtained via offline training. A genetic algorithm is applied to a set of data with various operating conditions and fault dimensions to achieve the optimal model parameters. The trained model is then used online in parallel with a real system in service to realize model-based fault detection and diagnosis. To increase the accuracy of diagnosis, an extended Kalman filter is used to address the noises and uncertainties associated with fault dimension estimation. The proposed system is implemented on a case study of rolling element bearing health monitoring and experimental results demonstrate the efficiency of the proposed method.
Piezoelectric actuators applied to neutralize mechanical vibrations
Authors: Gallo Carlos Alberto , Tofoli Fernando Lessa , Rade Domingos Alves , Steffen Valder
Published: October 2011

Piezoelectric actuators are widely used in smart structural systems to actively control vibration and noise, and to enhance performance. Because of the highly capacitive nature of these actuators, special power amplifiers, capable of delivering high currents, are required to drive these systems. In this paper, a study to reduce the reactive energy that is necessary in such systems is carried out. This is accomplished by associating the actuator with its capacitive characteristic circuit. Also, non-idealities of the circuit performance are addressed, along with theoretical limits regarding possible power savings and practical difficulties in achieving them. The proposed converter introduces energy to correct the difference of phase between current and voltage that is supplied to the piezoelectric transducer (PZT) actuator. This process is optimized by the introduction of reactive power to the characteristic process of the PZT’s actuator circuit. Therefore the system is supposed to present an electric characteristic that is close to resistive, and is not capacitive any more.
Further study on aeroelastic response of aircraft wing with freeplay
Authors: Wang Fusheng , Huo Shihui , Yue Zhufeng , Qian Wei
Published: October 2011

The complex aeroelastic equation of an aircraft wing with freeplay nonlinearity was built and applied for aeroelastic response analysis. This took into account multiple lumped mass points and directions of the control surface using the Roger rational function approximation. The aerodynamic analysis was based on the subsonic doublet lattice method and the external program of time history analysis method was employed. The aeroelastic response results show that amplitudes of generalized displacement considering the freeplay effect is decreased compared with those not considering the freeplay effect, and influenced by freeplay stiffness coefficients. Constant and variable step length calculations of the fourth order Runge-Kutta method can influence the results and efficiency.
The Development of the Interest in Child Molestation Scale
Authors: Gannon Theresa A. , O’Connor Alisha
Published: October 2011

Although numerous research studies have been conducted to investigate apprehended child molesters’ sexual interest in children and associated concepts, very little research has been conducted to investigate community males’ sexual interest in children. In this article, the authors describe the development and preliminary validation of a new measure—the Interest in Child Molestation Scale—to assess community male’s sexual arousal, behavioral propensity toward, and enjoyment of child sexual abuse. Preliminary results show that the Interest in Child Molestation Scale holds some promising psychometric properties, representing a reasonably reliable measure of community males’ sexual interest in children. Using this scale, the authors find that a good proportion of community males (57%) did not emphatically reject an interest in child sexual abuse. The authors also find that self-reported sexual arousal to child sexual abuse that is relatively low in forcefulness was significantly related to implicit child sexualization as measured via a pen-and-paper implicit association test. The authors discuss these results with reference to possible future uses of the measure for theory and research development.
Friction–speed characteristics of elastohydrodynamically lubricated contacts with anomalous film shapes
Authors: Fu Z , Guo F , Wong P L
Published: October 2011

An optical elastohydrodynamically lubricated (EHL) test rig was modified, so that the measurement of friction and mapping of the lubricated contact could be executed simultaneously. Pure sliding tests using viscous polybutene oils were carried out with very slow entrainment speeds to achieve isothermal conditions. The experimentally obtained friction–speed curves are characterized by anomalous wave shapes with two inflection points, a peak and a valley. This deviates from the traditional Stribeck curve, which is characterized by a monotonic increasing trend from EHL regime to hydrodynamic lubrication regime. Comparing the abnormal friction–speed curve with the corresponding film shapes, the two inflection points closely relate to the appearance of a dimple at the inlet of the contact and the loss of elastic deformation of the contact surfaces, respectively. Previous numerical studies hypothesized that the anomalous EHL film shape is due to boundary slippage. The present finding of a reduction in friction with the anomalous EHL film shapes gives further support to this hypothesis.
Social injustice, human rights-based education and citizens’ direct action to promote social transformation in the Philippines
Authors: Ty Reynaldo
Published: October 2011

This article opens with a proposed framework for human rights education (HRE), which synthesizes ideas drawn from Zinn’s people’s history, Sen’s theory of justice and Freire’s critical pedagogy. A review of the literature on HRE and human rights-based learning suggests three existent interrelated models of HRE. Drawing on human rights-based programmes designed to benefit Philippine society, this article then presents case studies in which programme participants actively struggle against social injustice. As an integral part of the learning process, co-learners envision a just and peaceful society, plan for change and engage in direct social action. New volunteers are continually mobilized to participate in community service and contribute to social action that benefits and empowers hitherto oppressed people and minorities. The article concludes with a proposal for an interactive model of human rights-based learning which aims to build on the HRE framework inspired by Zinn, Sen and Freire.
Narratives in teaching and research for justice and human rights
Authors: Osler Audrey , Zhu Juanjuan
Published: October 2011

Throughout history individual and collective narratives have been used in struggles for justice. We draw on Sen’s theory of justice to examine the potential of narratives in teaching and researching for social justice. Human rights are presented as powerful ethical claims that can be critically examined by learners to consider their rights and responsibilities to others, at scales from the local to the global. One life history is used as an illustrative example to examine the Universal Declaration of Human Rights 1948 and its possible meanings for learners in China and globally. This article discusses the strengths and limitations of narratives as research and pedagogical tools in understanding justice, human rights and inequalities; in stimulating solidarity and our common humanity; and in enabling learners to explore their multiple identities. We conclude by making the case for human rights as principles for learning and living together in overlapping communities of fate.