bluuebunny/crossref_metadata_2025 huggingface dataset:
Loss of PKCδ results in characteristics of Sjögren’s syndrome including salivary gland dysfunction
Authors: Banninger GP , Cha S , Said MS , Pauley KM , Carter CJ , Onate M , Pauley BA , Anderson SM , Reyland ME
Published: May 2011

Oral Diseases (2011) 17, 601–609

Objectives:  Chronic infiltration of lymphocytes into the salivary and lacrimal glands of patients with Sjögren’s Syndrome (SS) leads to destruction of acinar cells and loss of exocrine function. Protein kinase C‐delta (PKCδ) is known to play a critical role in B‐cell maintenance. Mice in which the PKCδ gene has been disrupted have a loss of B‐cell tolerance, multiple organ lymphocytic infiltration, and altered apoptosis. To determine whether PKCδ contributes to the pathogenesis of SS, we quantified changes in indicators of SS in PKCδ−/− mice as a function of age. Salivary gland histology, function, the presence of autoantibodies, and cytokine expression were examined.

Materials and methods:  Submandibular glands were examined for the presence of lymphocytic infiltrates, and the type of infiltrating lymphocyte and cytokine deposition was evaluated by immunohistochemistry. Serum samples were tested by autoantibody screening, which was graded by its staining pattern and intensity. Salivary gland function was determined by saliva collection at various ages.

Results:  PKCδ−/− mice have reduced salivary gland function, B220+ B‐cell infiltration, anti‐nuclear antibody production, and elevated IFN‐γ in the salivary glands as compared to PKCδ+//+ littermates.

Conclusions:  PKCδ−/− mice have exocrine gland tissue damage indicative of a SS–like phenotype.
Globalization of Chinese Firms Theoretical Universalism or Particularism
Authors: Alon Ilan , Child John , Li Shaomin , McIntyre John R.
Published: May 2011

Research on the globalization of Chinese and other emerging markets' companies has only just begun and is on the verge of taking off. As it does so, additional thought should be given to the ontological and epistemological underpinnings of the theories attempting to capture the phenomenon. Should Western-centric theory prevail? Be adapted? Or abandoned in favour of new indigenous approaches to theorizing, based on context? Finally, should the context itself be the basis of theorizing? While the debate will not stop here, the future may hold a multiplicity of approaches, both indigenous and internationalized, for explaining emerging markets' contexts and, more specifically, for understanding internationalization of their economies and their multinationals. This article provides an overview of the debate on Chinese Theory of Business vs. Theory of Chinese Business, and highlights the contribution of three key articles utilizing a hybrid approach of adapted theory, controlling for the various multinational contexts. We conclude that no theory has a monopoly on explanation and a multi-levelj multidisciplinaiy, and, perhaps, Eastern-centric theory may prove to show great potential in future theories of emerging markets' multinationals.
Efficient ATP synthesis by thermophilic Bacillus FoF1‐ATP synthase
Authors: Soga Naoki , Kinosita Kazuhiko , Yoshida Masasuke , Suzuki Toshiharu
Published: May 2011

FoF1‐ATP synthase (FoF1) synthesizes ATP in the F1 portion when protons flow through Fo to rotate the shaft common to F1 and Fo. Rotary synthesis in isolated F1 alone has been shown by applying external torque to F1 of thermophilic origin. Proton‐driven ATP synthesis by thermophilic Bacillus PS3 FoF1 (TFoF1), however, has so far been poor in vitro, of the order of 1 s−1 or less, hampering reliable characterization. Here, by using a mutant TFoF1 lacking an inhibitory segment of the ε‐subunit, we have developed highly reproducible, simple procedures for the preparation of active proteoliposomes and for kinetic analysis of ATP synthesis, which was driven by acid–base transition and K+‐diffusion potential. The synthesis activity reached ∼ 16 s−1 at 30 °C with a Q10 temperature coefficient of 3–4 between 10 and 30 °C, suggesting a high level of activity at the physiological temperature of ∼ 60 °C. The Michaelis–Menten constants for the substrates ADP and inorganic phosphate were 13 μm and 0.55 mm, respectively, which are an order of magnitude lower than previous estimates and are suited to efficient ATP synthesis.
Comparison of the Changes in Sexual Function of Premenopausal and Postmenopausal Women Following Transvaginal Mesh Surgery
Authors: Long Cheng-Yu , Hsu Chun-Shuo , Wu Ming-Ping , Lo Tsia-Shu , Liu Cheng-Min , Tsai Eing-Mei
Published: May 2011

Introduction

The effect of transvaginal mesh (TVM) surgery on sexual function between premenopausal and postmenopausal women remains controversial.

Aim

To compare the changes in sexual function of premenopausal and postmenopausal women following TVM repair.

Methods

One hundred and fifty-two consecutive women with symptomatic pelvic organ prolapse (POP) stages II to IV were referred for TVM procedures at our hospitals. Sixty-eight women were included because they were sexually active and had complete follow-up. All subjects were divided into the premenopausal (N = 36) and postmenopausal (N = 32) groups. Preoperative and postoperative assessments included pelvic examination using the POP quantification (POP-Q) system and a personal interview with the Female Sexual Function Index (FSFI), Urogenital Distress Inventory (UDI-6), and Incontinence Impact Questionnaire (IIQ-7).

Main Outcome Measures

The FSFI, UDI-6, and IIQ-7 questionnaires.

Results

The mean age, rates of hypertension, and previous hysterectomy were significantly higher in the postmenopausal group (P < 0.05) compared with the premenopausal group. As for the POP-Q analysis, there was a significant improvement at points Aa, Ba, C, Ap, and Bp (P < 0.001) in both groups except for total vaginal length (P > 0.05). Similarly, the UDI-6 and IIQ-7 scores significantly decreased postoperatively (P < 0.01). After POP surgery, the score of the dyspareunia domain decreased significantly in the premenopausal group (P < 0.01) but was not the case for the postmenopausal group (P > 0.05). There were no significant changes in other domains and total scores in both groups (P > 0.05). However, higher rates of worsening dyspareunia and total scores were noted in the premenopausal group (P = 0.03 vs. 0.033).

Conclusion

TVM procedure is effective for the anatomical restoration of POP. However, individual domain of FSFI such as dyspareunia may worsen in the premenopausal women. Additionally, our results revealed that over one third of premenopausal women could have a worsening sexuality domain postoperatively, with significantly higher rate of deteriorated dyspareunia and total FSFI scores than postmenopausal women.
Stromanthe bahiensis sp. nov. (Marantaceae), endemic to southern Bahia State, Brazil
Authors: Yoshida‐Arns Karla Norye , Mayo Simon Joseph , Braga João Marcelo Alvarenga
Published: May 2011

Stromanthe bahiensis Yoshida‐Arns, Mayo & J. M. A. Braga sp. nov. (Marantaceae) is described as an endemic to the Atlantic Forest coast of southern Bahia State in Brazil. It is similar to S. hjalmarssonii (Körn.) Petersen, which is restricted to Central America, but differs from it by the following characteristics: petiole 14–70 cm long, leaf blade oblong‐ovate to ovate‐lanceolate, fertile bracts 18–30×2–4 mm, narrowly lanceolate to ovate‐lanceolate, sepals 4–6 mm long, corolla lobes 3.0–3.5 mm long, outer staminodes 2.0–3.5×1–2 mm, pale bluish or purplish, callose staminode 2–3×1–2 mm, cucullate staminode 2–3 mm long and ovary hirsute. The new species is described and illustrated with diagnostic characters, taxonomic comments and remarks on its conservation status.
The Cognitive Science of Visual‐Spatial Displays: Implications for Design
Authors: Hegarty Mary
Published: May 2011

This paper reviews cognitive science perspectives on the design of visual‐spatial displays and introduces the other papers in this topic. It begins by classifying different types of visual‐spatial displays, followed by a discussion of ways in which visual‐spatial displays augment cognition and an overview of the perceptual and cognitive processes involved in using displays. The paper then argues for the importance of cognitive science methods to the design of visual displays and reviews some of the main principles of display design that have emerged from these approaches to date. Cognitive scientists have had good success in characterizing the performance of well‐defined tasks with relatively simple visual displays, but many challenges remain in understanding the use of complex displays for ill‐defined tasks. Current research exemplified by the papers in this topic extends empirical approaches to new displays and domains, informs the development of general principles of graphic design, and addresses current challenges in display design raised by the recent explosion in availability of complex data sets and new technologies for visualizing and interacting with these data.
Real‐Time Monitoring of Blood Flow and Intravesical Pressure in the Rat Bladder
Authors: SAITO Motoaki , OHMASA Fumiya , TSOUNAPI Panagiota , INOUE Seiya , KINOSHITA Yukako , DIMITRIADIS Fotios , SATOH Keisuke
Published: May 2011

Objectives: Because there is little information available about blood flow in the voiding cycle of the bladder, we performed a study in which we simultaneously monitored blood flow and intravesical pressure during the micturition cycle in a rat model.

Methods: Approximately 300 g male Wistar rats were used in this study. Cystometric studies were performed according to our previous report, and simultaneously blood flow was monitored.

Results: Before the micturition reflex occurred, a significant increase in bladder blood flow was observed, and this increased blood flow continued during the micturition reflex. Under the maximum contraction pressure, blood flow rapidly decreased (within 10% compared to the max level). This low level of blood flow continued for more than half a minute.

Conclusion: Our data indicated that the blood flow in the bladder was dynamically changed during voiding. This technique may represent a strong tool to investigate bladder function under drug administrations and/or pathophysiological conditions.
Plasma D‐dimer level in the perioperative period in non‐small‐cell lung cancer
Authors: Wang Zhe , Fu Junke , Diao Dongmei , Dang Chengxue
Published: May 2011

Background:  There has been little research on perioperative hypercoagulability in non‐small‐cell lung cancer patients. The D‐dimer can be used to evaluate the hypercoagulability in cancer patients.

Methods:  Eighty‐five non‐small‐cell lung cancer patients were included in the study. The plasma D‐dimer levels during the preoperative and 3rd and 9th day postoperative period were prospectively examined and analyzed along with the clinicopathological characteristics.

Results:  The medians (interquartile range) of the preoperative, 3rd and 9th day postoperative D‐dimer levels were 1.09 (0.77) mg/L, 3.35 (2.31) mg/L and 4.1 (2.55) mg/L respectively (P= 0.00). The preoperative D‐dimer level was related with the stage (P= 0.004). The preoperative and the 3rd day postoperative D‐dimer levels were both related to patient age (P= 0.014, P= 0.034). The 3rd day postoperative D‐dimer levels were arbitrarily stratified into three groups, adenocarcinoma dominated the high and low groups while squamous cell carcinoma dominated the median one (exact P= 0.02). The pneumonectomy group did not show a higher 3rd day postoperative D‐dimer level than the lobectomy group (P= 0.064).

Conclusion:  Non‐small‐cell lung cancer patients had increasing hypercoagulability within the first 9 postoperative days. Preoperative hypercoagulability was close related with tumor stage. Heterogeneity existed among postoperative hypercoagulability.
Randomization tests for quantifying species importance to ecosystem function
Authors: Gotelli Nicholas J. , Ulrich Werner , Maestre Fernando T.
Published: May 2011

1. Quantifying the contribution of different species to ecosystem function is an important challenge. We introduce simple randomization tests (and software) for quantifying the average effect of species on ecosystem variables measured in multiple plots with and without the presence of a particular species. These randomization tests formalize the analysis of uncontrolled ‘natural experiments’ and quantify species effects in standardized deviation units.

2. We tested the method with data on ecosystem function in biological soil crust assemblages of lichens in semi‐arid gypsum outcrops in central Spain. In sixty‐three 50 cm × 50 cm sample plots, we measured the presence and percentage cover of 17 species of lichens and the levels of five important ecosystem variables (organic carbon, total nitrogen, urease activity, phosphatase activity and β‐glucosidase activity). The randomization tests revealed 13 positive and six negative associations between species presence and ecosystem function.

3. We used data from an independent microcosm experiment on ecosystem function and species composition to validate these results. Microcosms that had higher levels of organic carbon and total nitrogen also had higher average species effect scores (measured from the survey data) for the species that were present in each experimental treatment.

4. As in all natural experiments, strong species interactions, effects of unmeasured abiotic variables on species occurrence and reciprocal effects of ecosystem variables on species occurrence can potentially confound estimates of species importance. Nevertheless, the method we propose provides a simple index and statistical test of species importance that can form the basis for additional hypothesis tests and experimental studies of species occurrence and ecosystem function.
The role of eyes in early face processing: A rapid adaptation study of the inversion effect
Authors: Nemrodov Dan , Itier Roxane J.
Published: May 2011

The current study employed a rapid adaptation procedure to test the neuronal mechanisms of the face inversion effect (FIE) on the early face‐sensitive event‐related potential (ERP) component N170. Five categories of face‐related stimuli (isolated eyes, isolated mouths, eyeless faces, mouthless faces, and full faces) and houses were presented in upright and inverted orientations as adaptors for inverted full face test stimuli. Strong adaptation was found for all face‐related stimuli except mouths. The adaptation effect was larger for inverted than upright stimuli, but only when eyes were present. These results underline an important role of eyes in early face processing. A mechanism of eye‐dependent orientation sensitivity during the structural encoding stage of faces is proposed.
UNITARITY FOR THE BOSONIC NAPPI–WITTEN STRING FROM BRST VIEW
Authors: CHEN GANG , CAO ZHISHEN , WANG BIN
Published: May 2011

In this paper, we present the proof of a no-ghost theorem for the bosonic string in Nappi–Witten spacetime by the BRST-technology. The key point in this proof is to compare the characters with the signature functions, where traces are taken over the whole state space. It includes the states of Nappi–Witten string, the states of some extra unitary CFT and the conformal ghost states. Only the signature function of the Nappi–Witten string part is not trivial. Here we obtain it in a new complete basis for the states space of Nappi–Witten string. For all real number b, which is a parameter of the Nappi–Witten metric, the characters and the signature functions are exactly equivalent. Then we can state that the physical string states in Nappi–Witten group are all of non-negative norm.
EVIDENCE OF A SPIN-LIQUID PHASE IN THE FRUSTRATED HONEYCOMB LATTICE
Authors: CABRA D. C. , LAMAS C. A. , ROSALES H. D.
Published: May 2011

In the present paper, we present some new data supporting the existence of a spin-disordered phase in the Heisenberg model on the honeycomb lattice with antiferromagnetic interactions up to third neighbors along the line J2 = J3, predicted in Ref. 1. We use the Schwinger boson technique followed by a mean field decoupling and exact diagonalization for small systems to show the existence of an intermediate phase with a spin gap and short range Néel correlations in the strong quantum limit [Formula: see text].
ENTANGLEMENT OF QUANTUM SPIN SYSTEMS: A VALENCE-BOND APPROACH
Authors: CAPPONI SYLVAIN , ALET FABIEN , MAMBRINI MATTHIEU
Published: May 2011

In order to quantify entanglement between two parts of a quantum system, one of the most used estimators is the Von Neumann entropy. Unfortunately, computing this quantity for large interacting quantum spin systems remains an open issue. Faced with this difficulty, other estimators have been proposed to measure entanglement efficiently, mostly by using simulations in the valence-bond basis. We review the different proposals and try to clarify the connections between their geometric definitions and proper observables. We illustrate this analysis with new results of entanglement properties of spin-1 chains.
SPIN RESISTIVITY IN THE FRUSTRATED J1 - J2 MODEL
Authors: HOANG DANH-TAI , MAGNIN YANN , DIEP H. T.
Published: May 2011

We study in this paper the resistivity encountered by Ising itinerant spins traveling in the so-called J1 - J2 frustrated simple cubic Ising lattice. For the lattice, we take into account the interactions between nearest-neighbors and next-nearest-neighbors, J1 and J2 respectively. Itinerant spins interact with lattice spins via a distance-dependent interaction. We also take into account an interaction between itinerant spins. The lattice is frustrated in a range of J2 in which we show that it undergoes a very strong first-order transition. Using Monte Carlo simulation, we calculate the resistivity ρ of the itinerant spins and show that the first-order transition of the lattice causes a discontinuity of ρ.
PSEUDOGAP BEHAVIOR IN THE INFINITE DIMENSIONAL ATTRACTIVE HUBBARD MODEL
Authors: KOGA AKIHISA , WERNER PHILIPP
Published: May 2011

We study the attractive Hubbard model in infinite spatial dimensions by means of dynamical mean-field theory with continuous-time quantum Monte Carlo simulations. Calculating the pair potential and the spectral function, we discuss the stability of the superfluid state at low temperatures. The pseudogap behavior above the critical temperature is also addressed.
EFFECT OF BOND ALTERNATION ON ELECTRONIC ENERGY BAND STRUCTURE OF ARMCHAIR CARBON NANOTUBES
Authors: PHONG TRAN CONG , HIEU NGUYEN NGOC
Published: May 2011

The influence of the bond alternation on electronic energy band structure of armchair carbon nanotubes is studied by the tight-binding approximation. It is shown that the armchair carbon nanotubes at ground state with Kekule structure open small band gap at the Fermi level. Dependence of energy band gap of armchair carbon nanotubes with Kekule structure on their radius is considered and numerically calculated. The numerical calculations are applied to the (n, n) carbon nanotubes with n = 5, 6, 7, 8.
ELECTRONIC TRANSPORT IN GRAPHENE: QUANTUM EFFECTS AND ROLE OF LOCAL DEFECTS
Authors: TRAMBLY DE LAISSARDIÈRE GUY , MAYOU DIDIER
Published: May 2011

In this paper, we present generic properties of quantum transport in mono-layer graphene. In the scheme of the Kubo–Geenwood formula, we compute the square spreading of wave packets of a given energy with is directly related to conductivity. As a first result, we compute analytically the time-dependent diffusion for pure graphene. In addition to the semi-classical term, a second term exists that is due to matrix elements of the velocity operator between electron and hole bands. This term is related to velocity fluctuations, i.e. Zitterbewegung effect. Secondly, we study numerically the quantum diffusion in graphene with simple vacancies and pair of neighboring vacancies (divacancies), that simulate schematically oxidation, hydrogenation and other functionalizations of graphene. We analyze in particular the time-dependence of the diffusion and its dependence on energy in relation with the electronic structure. We compute also the mean free path and the semi-classical value of the conductivity as a function of energy in the limit of small concentration of defects.
SPIN TRANSPORT IN MAGNETICALLY ORDERED SYSTEMS: EFFECT OF THE LATTICE RELAXATION TIME
Authors: MAGNIN YANN , HOANG DANH-TAI , DIEP H. T.
Published: May 2011

Spin resistivity R has been shown to result mainly from the scattering of itinerant spins with magnetic impurities and lattice spins. R is proportional to the spin–spin correlation so that its behavior is very complicated near and at the magnetic phase transition of the lattice spins. For the time being there are many new experimental data on the spin resistivity going from semiconductors to superconductors. Depending on materials, various behaviors have been observed. There is however no theory so far which gives a unified mechanism for the spin resistivity in magnetic materials. Recently, we have shown Monte Carlo results for different systems. We found that the spin resistivity is very different from one material to another. In this paper, we show for the first time how the dynamic relaxation time of the lattice spins affects the resistivity of itinerant spins observed in Monte Carlo simulation.
STUDY OF THERMODYNAMIC PROPERTIES OF ZINC-BLENDE-TYPE SEMICONDUCTORS: TEMPERATURE AND PRESSURE DEPENDENCES
Authors: HIEU HO KHAC , HUNG VU VAN
Published: May 2011

Using the statistical moment method (SMM), the temperature and pressure dependences of thermodynamic quantities of zinc-blende-type semiconductors have been investigated. The analytical expressions of the nearest-neighbor distances, the change of volumes and the mean-square atomic displacements (MSDs) have been derived. Numerical calculations have been performed for a series of zinc-blende-type semiconductors: GaAs , GaP , GaSb , InAs , InP and InSb . The agreement between our calculations and both earlier other theoretical results and experimental data is a support for our new theory in investigating the temperature and pressure dependences of thermodynamic quantities of semiconductors.
RESIDUAL DECOHERENCE IN TOPOLOGICALLY PROTECTED SUPERCONDUCTING QUBITS
Authors: DOUÇOT B.
Published: May 2011

This note discusses the residual decoherence for a class of topologically protected qubits realized as small Josephson junction arrays. For static noise, such circuits present a decoherence rate which is exponentially small in the system size. However, in the presence of a dynamical coupling to an external bath, this length has to remain small enough so that no irreversible real transition to excited states can occur. When this condition is not satisfied, the rate of such transitions is computed through a generalization of the Fermi golden rule formula, adapted to this particular class of systems, which is derived here.
TWO-IMPURITY KONDO MODEL: SPIN-ORBIT INTERACTIONS AND ENTANGLEMENT
Authors: JOHANNESSON HENRIK , MROSS DAVID F. , ERIKSSON ERIK
Published: May 2011

Motivated by proposals to employ RKKY-coupled spins as building blocks in a solid-state quantum computer, we analyze how the RKKY interaction in a 2D electron gas is influenced by spin-orbit interactions. Using a two-impurity Kondo model with added Dresselhaus and Rashba spin-orbit interactions we find that spin-rotational invariance of the RKKY interaction — essential for a well-controllable two-qubit gate — is restored when tuning the Rashba coupling to have the same strength as the Dresselhaus coupling. We also discuss the critical properties of the two-impurity Kondo model in the presence of spin-orbit interactions, and extract the leading correction to the block entanglement scaling due to these interactions.
ELECTROPHONON RESONANCE IN DOPED SEMICONDUCTOR SUPERLATTICES
Authors: PHONG TRAN CONG , LAM VO THANH , HOI BUI DINH
Published: May 2011

The electrophonon resonance (EPR) effect in doped semiconductor superlattices (DSSL) are investigated by using the quantum kinetic equation (QKE) for electrons to obtain the general analytic expression for optical absorption coefficient. We also obtain an EPR condition as a function of the photon energy and plasma energy. In particular, anomalous behaviors of the EPR effect such as the splitting of EPR peaks for incident photon energy or plasma energy are discussed. This raises a possibility of detecting electric subbands in DSSLs experimentally by utilizing EPR effects.
STUDY OF IONIC CONDUCTIVITY IN CUBIC CERIA BY THE STATISTICAL MOMENT METHOD
Authors: HUNG VU VAN , TINH BUI DUC , LEE JAICHAN
Published: May 2011

We have investigated the diffusion and ionic conductivity of the cubic ceria CeO 2 using the statistical moment method (SMM) in the statistical physics. The activation energy, diffusion coefficient, pre-exponential factor and ionic conductivity are derived in closed analytic forms. The SMM calculations are performed by using the Buckingham potential for the cubic ceria. The effects of the three different potential parameter sets of the Buckingham potential and influence of dipole polarization effects on activation energy, diffusion coefficient and ionic conductivity for CeO 2 are also investigated. The present analytical formulas including the anharmonic effects of the lattice vibrations give the predicted values of these quantities, which are comparable to those of the experimental values.
EPB MODEL OF DNA AND THERMODYNAMIC EFFECTIVE BIO TIME
Authors: THANH NGO V. , VIET N. A.
Published: May 2011

Using the simple EPB model1 of DNA (the combined model of the pendulum model of Englander,2 and Peyrard–Bishop microscopic model3), we propose a bio (DNA) time measured by EPB pendulum. We have shown that the effective bio time has a thermodynamic origin which equals the ordinary (real) time in the range of room-body temperature. Furthermore, it flows slower at low temperature and much faster near the DNA melting phase transition temperature than real time.
A SOFTWARE ENVIRONMENT FOR AN ADAPTIVE HUMAN-AWARE SOFTWARE AGENT SUPPORTING ATTENTION-DEMANDING TASKS
Authors: BOSSE TIBOR , MEMON ZULFIQAR A. , OORBURG ROGIER , TREUR JAN , UMAIR MUHAMMAD , DE VOS MICHAEL
Published: May 2011

This paper presents a software environment providing human-aware ambient support for a human performing a task that demands substantial amounts of attention. The agent obtains human attention-awareness in an adaptive manner by use of a dynamical model of human attention, gaze sensoring by an eye-tracker, and information about features of the objects in the environment which is parameterised for characteristics of the human specified above. The agent uses a built-in adaptation model to adapt on the fly, the values of these parameters to the personal characteristics of the human. The software agent has been implemented in a component-based manner within the Adobe®Flex®environment, thereby also integrating the Tobii®eye-tracker. It has been applied in a setup for a task where the human has to identify enemies and allies, and eliminate the enemies.
ON CLUSTER VALIDATION FOR DETECTING THE NUMBER OF CLUSTERS IN A DATA SET
Authors: ALBALATE AMPARO , SUENDERMANN DAVID , MINKER WOLFGANG
Published: May 2011

In this article we analyse different techniques for cluster validation to detect the number of clusters in a dataset and introduce a new combination approach to cluster validation. The proposed algorithm is a combination of several validation indexes, which are used to simultaneously evaluate different partitions of a dataset generated with different clustering techniques and object distances.
CUBE DIAGRAMS AND 3-DIMENSIONAL REIDEMEISTER-LIKE MOVES FOR KNOTS
Authors: BALDRIDGE SCOTT , LOWRANCE ADAM M.
Published: May 2011

In this paper we introduce a representation of knots and links called a cube diagram. We show that a property of a cube diagram is a link invariant if and only if the property is invariant under five cube diagram moves. A knot homology is constructed from cube diagrams and shown to be equivalent to knot Floer homology.
A VOLUME FORM ON THE KHOVANOV INVARIANT
Authors: ORTIZ-NAVARRO JUAN
Published: May 2011

The Reidemeister torsion construction can be applied to the chain complex used to compute the Khovanov homology of a knot or a link. This defines a volume form on Khovanov homology. The volume form transforms correctly under Reidemeister moves to give an invariant volume on the Khovanov homology. In this paper, its construction and invariance under these moves is demonstrated. Also, some examples of the invariant are presented for particular choices for the bases of homology groups to obtain a numerical invariant of knots and links. In these examples, the algebraic torsion seen in the Khovanov chain complex when homology is computed over ℤ is recovered.
IMPROVED FEMORAL NECK FRACTURE PREDICTIONS USING ANISOTROPIC FAILURE CRITERIA MODELS
Authors: PITHIOUX MARTINE , CHABRAND PATRICK , HOCHARD CHRISTIAN , CHAMPSAUR PIERRE
Published: May 2011

Finite element models are widely used to assess long bone strength, implant stability and other clinical problems. In most of the models presented so far in the literature, the bone is taken to be isotropic, and the occurrence of failure is predicted by defining a threshold von Mises stress. However, human bone is found to show orthotropic behavior. Studies so far have focused only on the use of anisotropic criteria in orthotropic models designed to predict the occurrence of human femur failure. The aim of this study was therefore to investigate how specific finite element models for human femora combined with composite failure theories could be used to improve failure predictions in vitro. For this purpose, nine human proximal femora were tested mechanically up to failure under the loading conditions present during the one-leg stance phase in walking. Specific finite element models using various materials to represent the bone were generated for each femur. First, the bone material was modeled in the form of an isotropic brittle material, and the von Mises criterion was used to predict the occurrence of fracture. Second, the bone was modeled as a transversely isotropic brittle material with asymmetric strength characteristics, and the occurrence of fracture was predicted using the Hill and the Tsai–Wu criteria. The results obtained here show that the transversely isotropic model combined with Tsai–Wu and Hill criteria accurately predicted the fracture load (values of R2 = 0.94 and SEE = 10.3% were obtained with the Tsai–Wu criteria and R2 = 0.82 and SEE = 22.9% were obtained with the Hill criteria), while the isotropic model combined with the von Mises criterion overestimated the fracture load, although a good correlation was generally observed with the experimental results (R2 = 0.77, SEE = 30.6%).
TRANSDUCTION OF STRAIN TO CELLS SEEDED ONTO SCAFFOLDS EXPOSED TO UNIAXIAL STRETCHING: A THREE DIMENSIONAL FINITE ELEMENT STUDY
Authors: STERN AMBER RATH , STERN MATTHEW M. , VAN DYKE MARK E.
Published: May 2011

When preparing tissue engineering and regenerative medicine constructs, a commonly encountered problem is the failure of seeded cells to infiltrate the scaffold. In an increasing number of cases, constructs are being mechanically preconditioned with the expectation that preconditioning will enhance the construct's maturation and effectiveness by pre-exposing seeded cells to stimuli the tissue of interest experiences in vivo. However, whether or not mechanostimulation of a scaffold actually results in transmission of stimuli to the seeded cells remains poorly understood. The purpose of this research was to develop a model that quantifies how strain is transmitted to cells layered on a scaffold's surface compared to cells embedded within a scaffold. Three-dimensional finite element models representative of these conditions were created. When 10% strain was applied to the construct, embedded cells received the full imposed strain. However, cells growing on top of the scaffold received 5% strain within the first layer of cells, and the strain transmitted to cells in subsequent layers decreased exponentially with increasing distance from the scaffold's surface. When experimentally testing the model, strain-induced biological responses were muted in conditions where cell to scaffold contact was reduced. This research illustrates the importance of achieving cellular penetration and cell-to-scaffold contacts when mechanically conditioning tissue engineering constructs.
THE EFFECTS OF INTRA-ABDOMINAL PRESSURE ON THE STABILITY AND UNLOADING OF THE SPINE
Authors: MOKHTARZADEH HOSSEIN , FARAHMAND FARZAM , SHIRAZI-ADL ABOULFAZL , ARJMAND NAVID , MALEKIPOUR FATEMEH , PARNIANPOUR MOHAMAD
Published: May 2011

In spite of earlier experimental and modeling studies, the relative role of the intra-abdominal pressure (IAP) in spine mechanics has remained controversial. This study employs simple analytical and finite element (FE) models of the spine and its surrounding structures to investigate the contribution of IAP to spinal loading and stability. The analytical model includes the abdominal cavity surrounded by muscles, lumbar spine, rib cage and pelvic ring. The intra-abdominal cavity and its surrounding muscles are represented by a thin deformable cylindrical membrane. Muscle activation levels are simulated by changing the Young's modulus of the membrane in the direction of muscle fibers, yielding IAP values recorded under the partial Valsalva maneuver. In the FE model, the abdominal cavity is cylindrical and filled with a nearly incompressible fluid. The surrounding muscles are modeled as membrane elements with transverse isotropic material properties simulating their fiber orientation. Results indicate a good qualitative agreement between the analytical and FE models. Larger external force and/or higher levels of muscle activation generate higher IAP thereby increasing spinal stiffness. These effects are more pronounced for activation of muscles with more horizontally directed fibers, e.g., transverse abdominis (TA). The capacity of the abdominal muscles to indirectly unload and stabilize the spine by generating IAP depends mostly on their fiber orientation, and secondarily on their cross-section area.
The new foraminiferal genus Ammogloborotaloides n. gen. and subfamily Ammogloborotaloidinae n. subfam. from the Neogene of Venezuela: an example of isomorphism between agglutinated and planktonic Foraminifera
Authors: Kaminski Michael A. , Contreras Jime
Published: May 2011

Abstract. We report the occurrence of two new species of the new agglutinated foraminiferal genus Ammogloborotaloides in the Miocene of western Venezuela. These two taxa have been assigned informal names and have been known to the petroleum industry in Venezuela for many years, but have never been described. A. truncatulinoidiformis n. sp. is the type species and the second species, A. sp. 16, is left in open nomenclature. The two species of Ammogloborotaloides are strongly isomorphic with the planktonic foraminiferal species Globorotalia truncatulinoides and Globorotalia crassaformis, and illustrate the possible evolutionary connections between agglutinated benthics and the planktonic foraminifera.
Intraoperative Three-Dimensional Imaging in Selective Decompression for Lumbar Spinal Stenosis: A Useful Tool in Theory but Also in Everyday Practice?
Authors: Mauer Uwe Max , Kunz Ulrich , Schulz Chris
Published: May 2011

Background.We conducted a pilot study to investigate the value of an Iso-C3D imaging system in determining the extent of decompression of lumbar spinal stenosis during surgery. We now address the question whether this imaging has become a routine tool.Material and Methods.Ten patients who underwent unilateral decompression for lumbar spinal stenosis were intraoperatively examined using the Iso-C3D imaging system. Four years after this study, we investigated whether this intraoperative imaging modality is still being used.Results.Evaluable images were intraoperatively obtained for all patients. In two cases, the surgical procedure was changed on the basis of the images. Myelography did not provide any additional information. In the four years following the study, this intraoperative imaging technique has not been used again.Conclusion.Intraoperative imaging using the Iso-C3D system provides additional safety. It, however, has not become established as a routine procedure.
Differences in Characteristics and Treatment Received among Depressed Adolescent Psychiatric Outpatients with and without Co-Occuring Alcohol Misuse: A 1-Year Follow-Up Study
Authors: Pirkola Tiia , Pelkonen Mirjami , Karlsson Linnea , Kiviruusu Olli , Strandholm Thea , Tuisku Virpi , Ruuttu Titta , Marttunen Mauri
Published: May 2011

Objectives. We aimed at examining the differences between depressed psychiatric adolescent outpatients with and without cooccurring alcohol misuse in psychosocial background, clinical characteristics, and treatment received during one-year followup. Furthermore, we investigated factors related to nonattendance at treatment.Materials and Methods. Consecutive 156 adolescent (13–19 years) psychiatric outpatients with a unipolar depressive disorder at baseline were interviewed using structured measures at baseline and at 12 months. Alcohol misuse was defined as having an AUDIT score of 8 or more points. The outpatients received “treatment as usual” of clinically defined duration.Results. Among depressive outpatients, poor parental support, parental alcohol use and decreased attendance at treatment associated with alcohol misuse. The severity of alcohol use as measured by AUDIT-score was the strongest factor independently predicting nonattendance at treatment in multivariate analysis.Conclusions. Alcohol misuse indicates family problems, has a deleterious effect on treatment attendance, and should be taken into account when managing treatment for depressive adolescent outpatients.
Minimally Invasive Parathyroidectomy
Authors: Starker Lee F. , Fonseca Annabelle L. , Carling Tobias , Udelsman Robert
Published: May 2011

Minimally invasive parathyroidectomy (MIP) is an operative approach for the treatment of primary hyperparathyroidism (pHPT). Currently, routine use of improved preoperative localization studies, cervical block anesthesia in the conscious patient, and intraoperative parathyroid hormone analyses aid in guiding surgical therapy. MIP requires less surgical dissection causing decreased trauma to tissues, can be performed safely in the ambulatory setting, and is at least as effective as standard cervical exploration. This paper reviews advances in preoperative localization, anesthetic techniques, and intraoperative management of patients undergoing MIP for the treatment of pHPT.
Analytical Method in Solving Flow of Viscoelastic Fluid in a Porous Converging Channel
Authors: Esmaeilpour M. , Roshan Naeem , Roshan Negar , Ganji D. D.
Published: May 2011

An analytical method, called homotopy perturbation method (HPM), is used to compute an approximation to the solution of the nonlinear differential equation governing the problem of two‐dimensional and steady flow of a second‐grade fluid in a converging channel. The table and figures are presented for influencing various parameters on the velocity field. The results compare well with those obtained by the numerical method. The method is straightforward and concise, and it can also be applied to other nonlinear evolution equations in mathematical physics.
Racial and Ethnic Variation in Lipoprotein (a) Levels among Asian Indian and Chinese Patients
Authors: Banerjee Dipanjan , Wong Eric C. , Shin Jessica , Fortmann Stephen P. , Palaniappan Latha
Published: May 2011

Background. Lipoprotein (a) [Lp(a)] is an independent risk factor for cardiovascular disease (CVD) in Non-Hispanic Whites (NHW). There are known racial/ethnic differences in Lp(a) levels, and the association of Lp(a) with CVD outcomes has not been examined in Asian Americans in the USA.Objective. We hypothesized that Lp(a) levels would differ in Asian Indians and Chinese Americans when compared to NHW and that the relationship between Lp(a) and CVD outcomes would be different in these Asian racial/ethnic subgroups when compared to NHW.Methods. We studied the outpatient electronic health records of 2022 NHW, 295 Asian Indians, and 151 Chinese adults age≥18 y in Northern California in whom Lp(a) levels were assessed during routine clinical care from 2001 to 2008, excluding those who had received prescriptions for niacin (14.6%). Nonparametric methods were used to compare median Lp(a) levels. Significance was assessed at theP<.0001level to account for multiple comparisons. CVD outcomes were defined as ischemic heart disease (IHD) (265 events), stroke (122), or peripheral vascular disease (PVD) (87). We used logistic regression to determine the relationship between Lp(a) and CVD outcomes.Results. Both Asian Indians (36 nmol/L) and NHW (29 nmol/L) had higher median Lp(a) levels than Chinese (22 nmol/L,P≤.0001andP=.0032). When stratified by sex, the differences in median Lp(a) between these groups persisted in the 1761 men (AI v CH:P=.001, NHW v CH:P=.0018) but were not statistically significant in the 1130 women (AI v CH:P=.0402, NHW v CH:P=.0761). Asian Indians (OR=2.0) and Chinese (OR=4.8) exhibited a trend towards greater risk of IHD with high Lp(a) levels than NHW (OR=1.4), but no relationship was statistically significant.Conclusion. Asian Indian and NHW men have higher Lp(a) values than Chinese men, with a trend toward, similar associations in women. High Lp(a) may be more strongly associated with IHD in Asian Indians and Chinese, although we did not have a sufficient number of outcomes to confirm this. Further studies should strive to elucidate the relationship between Lp(a) levels, CVD, and race/ethnicity among Asian subgroups in the USA.
A Very Long Foreign Body in the Bladder
Authors: Imai Atsushi , Suzuki Yuichiro , Hashimoto Yasuhiro , Sasaki Atsushi , Saitoh Hisao , Ohyama Chikara
Published: May 2011

In the urinary tract, foreign body is most commonly found in the urinary bladder. But it is anatomically very difficult for a man to self-insert a long object into the urinary bladder. Here we report a case of a 49-year-old Japanese man who has inserted a 140-cm vinyl tube in the bladder for masturbation. He could not retrieve it, and the bladder foreign body remained in this position for about two years. He was referred to our hospital and open surgery was performed.
Carotid Intima Media Thickness as a Measure of Cardiovascular Disease Burden in Nigerian Africans with Hypertension and Diabetes Mellitus
Authors: Okeahialam Basil N. , Alonge Benjamin A. , Pam Stephen D. , Puepet Fabian H.
Published: May 2011

As part of a larger study of cardiovascular risk factors in nonhypertensive type 2 diabetes patients, we subjected a cohort of diabetics to B mode ultrasonography of the carotid artery to measure the intima media thickness (IMT) and compared it with values in hypertensives and apparently normal controls matched reasonably for gender and age. All groups were comparable in terms of age and gender representation. The mean (SD) of carotid IMT right and left was 0.94 mm (0.12), 0.94 mm (0.16); 0.93 mm (0.21), 0.93 mm (0.15); 0.91 mm (0.17), 0.91 mm (0.13) for diabetic, hypertensive, and normal groups, respectively. There was a nonsignificant tendency to raised IMT for the disease groups from the normal ones. Diabetic and hypertensive Nigerians are equally burdened by cardiovascular disease risk factors. Apparently normal subjects have a reasonable degree of burden suggesting the need to evaluate them for other traditional and emerging risk factors.
Thymic Self-Antigen Expression for the Design of a Negative/Tolerogenic Self-Vaccine against Type 1 Diabetes
Authors: Chentoufi Aziz Alami , Geenen Vincent
Published: May 2011

Before being able to react against infectious non-self-antigens, the immune system has to be educated in the recognition and tolerance of neuroendocrine proteins, and this critical process essentially takes place in the thymus. The development of the autoimmune diabetogenic response results from a thymus dysfunction in programming central self-tolerance to pancreatic insulin-secreting isletβcells, leading to the breakdown of immune homeostasis with an enrichment of isletβcell reactive effector T cells and a deficiency ofβcell-specific natural regulatory T cells (nTreg) in the peripheral T-lymphocyte repertoire. Insulin-like growth factor 2 (IGF-2) is the dominant member of the insulin family expressed during fetal life by the thymic epithelium under the control of the autoimmune regulator (AIRE) gene/protein. Based on the close homology and cross-tolerance between insulin, the primary T1D autoantigen, and IGF-2, the dominant self-antigen of the insulin family, a novel type of vaccination, so-called “negative/tolerogenic self-vaccination”, is currently developed for prevention and cure of T1D. If this approach were found to be effective for reprogramming immunological tolerance in T1D, it could pave the way for the design of negative self-vaccines against autoimmune endocrine diseases, as well as other organ-specific autoimmune diseases.
A New Oscillation Criterion for Forced Second‐Order Quasilinear Differential Equations
Authors: Jing Shao
Published: May 2011

By using the generalized variational principle and Riccati technique, a new oscillation criterion is established for second‐order quasilinear differential equation with an oscillatory forcing term, which improves and generalizes some of new results in the literature.
Nonlinear Mathematical Modeling in Pneumatic Servo Position Applications
Authors: Valdiero Antonio Carlos , Ritter Carla Silvane , Rios Cláudio Fernando , Rafikov Marat
Published: May 2011

This paper addresses a new methodology for servo pneumatic actuators mathematical modeling and selection from the dynamic behavior study in engineering applications. The pneumatic actuator is very common in industrial application because it has the following advantages: its maintenance is easy and simple, with relatively low cost, self‐cooling properties, good power density (power/dimension rate), fast acting with high accelerations, and installation flexibility. The proposed fifth‐order nonlinear mathematical model represents the main characteristics of this nonlinear dynamic system, as servo valve dead zone, air flow‐pressure relationship through valve orifice, air compressibility, and friction effects between contact surfaces in actuator seals. Simulation results show the dynamic performance for different pneumatic cylinders in order to see which features contribute to a better behavior of the system. The knowledge of this behavior allows an appropriate choice of pneumatic actuator, mainly contributing to the success of their precise control in several applications.
Studies of Gene Variants Related to Inflammation, Oxidative Stress, Dyslipidemia, and Obesity: Implications for a Nutrigenetic Approach
Authors: Curti Maira Ladeia R. , Jacob Patrícia , Borges Maria Carolina , Rogero Marcelo Macedo , Ferreira Sandra Roberta G.
Published: May 2011

Obesity is currently considered a serious public health issue due to its strong impact on health, economy, and quality of life. It is considered a chronic low-grade inflammation state and is directly involved in the genesis of metabolic disturbances, such as insulin resistance and dyslipidemia, which are well-known risk factors for cardiovascular disease. Furthermore, there is evidence that genetic variation that predisposes to inflammation and metabolic disturbances could interact with environmental factors, such as diet, modulating individual susceptibility to developing these conditions. This paper aims to review the possible interactions between diet and single-nucleotide polymorphisms (SNPs) in genes implicated on the inflammatory response, lipoprotein metabolism, and oxidative status. Therefore, the impact of genetic variants of the peroxisome proliferator-activated receptor-(PPAR-)gamma, tumor necrosis factor-(TNF-)alpha, interleukin (IL)-1, IL-6, apolipoprotein (Apo) A1, Apo A2, Apo A5, Apo E, glutathione peroxidases 1, 2, and 4, and selenoprotein P exposed to variations on diet composition is described.