bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Dynamics of Extracellular Accesses to the β1 and β2 Adrenoceptors Binding Sites Uncovers the Potential of Kinetic Basis of Antagonist Selectivity
Authors: Selvam Balaji , Wereszczynski Jeff , Tikhonova Irina G.
Published: April 2012

From the molecular mechanism of antagonist unbinding in the β1 and β2 adrenoceptors investigated by steered molecular dynamics, we attempt to provide further possibilities of ligand subtype and subspecies selectivity. We have simulated unbinding of β1‐selective Esmolol and β2‐selective ICI‐118551 from both receptors to the extracellular environment and found distinct molecular features of unbinding. By calculating work profiles, we show different preference in antagonist unbinding pathways between the receptors, in particular, perpendicular to the membrane pathway is favourable in the β1 adrenoceptor, whereas the lateral pathway involving helices 5, 6 and 7 is preferable in the β2 adrenoceptor. The estimated free energy change of unbinding based on the preferable pathway correlates with the experimental ligand selectivity. We then show that the non‐conserved K347 (6.58) appears to facilitate in guiding Esmolol to the extracellular surface via hydrogen bonds in the β1 adrenoceptor. In contrast, hydrophobic and aromatic interactions dominate in driving ICI‐118551 through the easiest pathway in the β2 adrenoceptor. We show how our study can stimulate design of selective antagonists and discuss other possible molecular reasons of ligand selectivity, involving sequential binding of agonists and glycosylation of the receptor extracellular surface.
Factors associated with subjective well‐being in cancer workers in Queensland
Authors: Poulsen Michael G , Poulsen Anne A , Khan Asaduzzaman , Poulsen Emma E , Khan Shanchita R
Published: April 2012

Introduction: This study aims to describe factors associated with subjective well‐being (SWB) in cancer workers in Queensland and compares results to normative data for the Australian population.

Method: This study was based on a cross‐sectional survey of 544 cancer workers in Queensland with a response rate of 54%. SWB was measured using the Personal Wellbeing Index for Adults. Multiple regression analyses were performed to identify explanatory variables, which were independently associated with SWB. Results were compared with normative Australian data.

Results: The overall mean SWB for study participants was 74.63, which was comparable to the mean of 75.02 for the Australian population (P = 0.47). Female cancer workers had significantly lower levels of SWB compared to the normative data of female Australians (74.44 compared to 75.7, P = 0.03). Multiple regression analyses showed that higher levels of SWB were associated with having 11–30 h of direct patient care hours per week, being married, no child or elder care commitments, good physical health, low levels of both psychological distress and burnout, and high levels of work engagement.

Conclusions: Cancer workers' overall levels of SWB were similar to the national mean scores. Amount of time in direct patient care was linked with SWB, with an optimal time between 11 and 30 h per week associated with high SWB. The majority of the factors significantly associated with SWB were of a personal nature such as marital status and physical and mental health. These data provide a valuable baseline for future research in this area, especially in the area of interventions to promote SWB of workers.
Monitoring by Affiliated Bankers on Board of Directors: Evidence from Corporate Financing Outcomes
Authors: Sisli‐Ciamarra Elif
Published: April 2012

Using a hand‐collected data set on boards of directors of large US nonfinancial companies, this paper investigates the effects of the presence of a creditor on a company's board. The results suggest that the presence of a creditor: 1) increases the amount of debt in a company's capital structure via an increase in private debt, 2) decreases the sensitivity of debt financing to the amount of tangible assets that a company holds, 3) decreases the cost of borrowing, and 4) reduces the pledge of collateral and financial covenants in debt contracts.
Cotinine: A Potential New Therapeutic Agent against Alzheimer's disease
Authors: Echeverria Valentina , Zeitlin Ross
Published: April 2012

Tobacco smoking has been correlated with a lower incidence of Alzheimer's disease (AD). This negative correlation has been attributed to nicotine's properties. However, the undesired side‐effects of nicotine and the absence of clear evidence of positive effects of this drug on the cognitive abilities of AD patients have decreased the enthusiasm for its therapeutic use. In this review, we discuss evidence showing that cotinine, the main metabolite of nicotine, has many of the beneficial effects but none of the negative side‐effects of its precursor. Cotinine has been shown to be neuroprotective, to improve memory in primates as well as to prevent memory loss, and to lower amyloid‐beta (Aβ)) burden in AD mice. In AD, cotinine's positive effect on memory is associated with the inhibition of Aβ aggregation, the stimulation of pro‐survival factors such as Akt, and the inhibition of pro‐apoptotic factors such as glycogen synthase kinase 3 beta (GSK3β). Because stimulation of the α7 nicotinic acetylcholine receptors (α7nAChRs) positively modulates these factors and memory, the involvement of these receptors in cotinine's effects are discussed. Because of its beneficial effects on brain function, good safety profile, and nonaddictive properties, cotinine may represent a new therapeutic agent against AD.
An Approach for Automated and Optimized Selection of Weldguns for Spot Welding in Automotive Body Shop
Authors: Gupta Ashish , Shastry Gopalakrishna K. , Hunsur Narahari K. , Cai Wayne , Tilove Robert
Published: April 2012

During process planning stage in an automotive vehicle development process (VDP), one of the tasks is to select tools such as weldguns and fixtures from large tool libraries and assign them to individual manufacturing operations. Software packages merely pick and validate individual library items to find “a solution.” Further, no design assistance is provided to configure a valid new tool. Currently, in automotive industry, the tool selection process is manual, local, and subjective. It leads to proliferation of tool variants resulting in increased cost and reduced operational flexibility. This paper proposes an approach for automated and optimized selection of tools. In the proposed approach, a tool is characterized in terms of its design parameters. The vehicle geometry is analyzed to identify “solution space,” i.e., the free space quantified in terms of bounds on the tool’s design parameters. The solution space of each manufacturing operation and the design parameters of every tool are used to generate the capability matrix (CM), which shows interoperability of tools. Using CM, tool assignment is formulated as an integer programming (IP) problem. The paper describes the algorithmic details of the proposed approach, for selection of weldguns for spot welding operation in automotive body in white (BIW) assembly shop.
Effective Dynamic Properties and Multi-Resonant Design of Acoustic Metamaterials
Authors: Zhu R. , Huang G. L. , Hu G. K.
Published: April 2012

In the study, a retrieval approach is extended to determine the effective dynamic properties of a finite multilayered acoustic metamaterial based on the theoretical reflection and transmission analysis. The accuracy of the method is verified through a comparison of wave dispersion curve predictions from the homogeneous effective medium and the exact solution. A multiresonant design is then suggested for the desirable multiple wave band gaps by using a finite acoustic metamaterial slab. Finally, the band gap behavior and kinetic energy transfer mechanism in a multilayered composite with a periodic microstructure are studied to demonstrate the difference between the Bragg scattering mechanism and the locally resonant mechanism.
Quadratic Mode Shape Components From Ground Vibration Testing
Authors: van Zyl L. H. , Mathews E. H.
Published: April 2012

Points on a vibrating structure generally move along curved paths rather than straight lines. For example, the tip of a cantilever beam vibrating in a bending mode experiences axial displacement as well as transverse displacement. The axial displacement is governed by the inextensibility of the neutral axis of the beam and is proportional to the square of the transverse displacement; hence the name “quadratic mode shape component.” Quadratic mode shape components are largely ignored in modal analysis, but there are some applications in the field of modal-basis structural analysis where the curved path of motion cannot be ignored. Examples include vibrations of rotating structures and buckling. Methods employing finite element analysis have been developed to calculate quadratic mode shape components. Ground vibration testing typically only yields the linear mode shape components. This paper explores the possibility of measuring the quadratic mode shape components in a sine-dwell ground vibration test. This is purely an additional measurement and does not affect the measured linear mode shape components or the modal parameters, i.e., modal mass, frequency, and damping ratio. The accelerometer output was modeled in detail taking into account its linear acceleration, its rotation, and gravitational acceleration. The response was correlated with the Fourier series representation of the output signal. The result was a simple expression for the quadratic mode shape component. The method was tested on a simple test piece and satisfactory results were obtained. The method requires that the accelerometers measure down to steady state and that up to the second Fourier coefficients of the output signals are calculated. The proposed method for measuring quadratic mode shape components in a sine-dwell ground vibration test seems feasible. One drawback of the method is that it is based on the measurement and processing of second harmonics in the acceleration signals and is therefore sensitive to any form of structural nonlinearity that may also cause higher harmonics in the acceleration signals. Another drawback is that only the quadratic components of individual modes can be measured, whereas coupled quadratic terms are generally also required to fully describe the motion of a point on a vibrating structure.
Modeling Three-Dimensional Plasma Arc in Gas Tungsten Arc Welding
Authors: Xu G. , Hu J. , Tsai H. L.
Published: April 2012

This article presents a three-dimensional (3D) mathematical model for the plasma arc in gas tungsten arc welding (GTAW). The velocity, pressure, temperature, electric potential, current density, and magnetic field of the plasma arc are calculated by solving the mass, momentum, and energy conservation equations coupled with electromagnetic equations. The predicted results were compared with the published experimental data and good agreements were achieved. This 3D model can be used to study a nonaxisymmetric arc that may be caused by the presence of nonaxisymmetric weld pools, joint configurations, and perturbations such as an external magnetic field. This study also provides a method to calculate 3D arc pressure, heat flux, and current density on the surface of the weld pool which, if coupled with a weld pool model, will become a complete model of GTAW.
Series Solution for Finite Displacement of Single-Loop Spatial Linkages
Authors: Milenkovic Paul
Published: April 2012

The kinematic differential equation for a spatial point trajectory accepts the time-varying instantaneous screw of a rigid body as input, the time-zero coordinates of a point on that rigid body as the initial condition and generates the space curve traced by that point over time as the solution. Applying this equation to multiple points on a rigid body derives the kinematic differential equations for a displacement matrix and for a joint screw. The solution of these differential equations in turn expresses the trajectory over the course of a finite displacement taken by a coordinate frame in the case of the displacement matrix, by a joint axis line in the case of a screw. All of the kinematic differential equations are amenable to solution by power series owing to the expression for the product of two power series. The kinematic solution for finite displacement of a single-loop spatial linkage may, hence, be expressed either in terms of displacement matrices or in terms of screws. Each method determines coefficients for joint rates by a recursive procedure that solves a sequence of linear systems of equations, but that procedure requires only a single factorization of a 6 by 6 matrix for a given initial posture of the linkage. The inverse kinematics of an 8R nonseparable redundant-joint robot, represented by one of the multiple degrees of freedom of a 9R loop, provides a numerical example of the new analytical technique.
A Co-Evolution Model for Prediction and Synthesis of New Products and Manufacturing Systems
Authors: AlGeddawy Tarek , ElMaraghy Hoda
Published: April 2012

A model for predicting the future codevelopment of new products and manufacturing systems is presented. The model incorporates a set of manufacturing co-evolution hypotheses that promote association between manufacturing systems and product variants throughout their shared evolution courses based on a biological analogy. It shows the impact of the different co-evolution states particularly the imperfect co-evolution, which can be remedied by predicting new systems and products. A novel mathematical technique for co-evolution knowledge synthesis is used to analyze the relationships between manufacturing capabilities and product features and discover the human synthesis knowledge implicit in their codevelopment. A set of rules and linear system of equations is formulated to discover such knowledge. The co-evolution model is mathematically established using Cladistics and trees reconciliation techniques that are used extensively in Biology. The model is validated by data sets of milling machine tools and the corresponding machined prismatic parts. The application of the developed model yields suggested directions for the future planning and development of the analyzed machine tools and potential new products features, products and variants that would further sustain and prolong the useful life of the current manufacturing capabilities and systems.
Classifying the Boundaries of the Wrench-Closure Workspace of Planar Parallel Cable-Driven Mechanisms by Visual Inspection
Authors: Azizian K. , Cardou P. , Moore B.
Published: April 2012

The wrench-closure workspace of parallel cable-driven mechanisms is the set of poses for which any wrench can be produced at the end-effector by a set of non-negative cable tensions. It is already known that the boundary of the constant-orientation wrench-closure workspace of a planar parallel cable-driven mechanism is composed of segments of conic sections. However, the relationship between the geometry of the mechanism and the types of these conic sections is unknown. This technical report proposes a graphical method for determining the types of these conic sections from the mechanism geometry. It is also shown that the proposed method can be applied to find the constant-orientation singularities of a 3-RPR planar parallel robot, since these conic sections correspond to the boundary segment of the analogous three-cable driven planar parallel mechanism.
Design of Statically Balanced Spatial Mechanisms With Spring Suspensions
Authors: Lin Po-Yang
Published: April 2012

This paper proposes a general approach for designing spatial statically balanced mechanisms with articular joints utilizing ideal zero-free-length springs. The proposed statically balanced mechanism can counterbalance the gravitational forces and provides a perfect static equilibrium at any configuration. The method of the paper is based on the energy approach, and a generalized coordinate system is developed to define the configuration of a spatial mechanism and to be a vector basis for the derivation of potential energy. By incorporating the gravitational forces and the spring forces into the system, the stiffness matrix of a spring-loaded mechanism is proposed. The perfect static balance is observed when the stiffness matrix is a diagonal matrix, from which, the design equations can be readily obtained. The closed-form solution of spring design parameters of a statically balanced, spatial, three-articular arm is obtained as a design example. The simulations of the conceptual design are performed by commercial computer software, and the static equilibrium of a quasi-static continuous motion is verified.
Analysis and Determination of Associated Linkage, Redundant Constraint, and Degree of Freedom of Closed Mechanisms With Redundant Constraints and/or Passive Degree of Freedom
Authors: Lu Yi , Ye Nijia , Lu Yang , Mao Bingyi , Zhai Xu , Hu Bo
Published: April 2012

The relations among the associated linkages (ALs), the redundant constraints, the passive degree of freedom (DoF), and the degree of freedom are studied systematically for the type synthesis of the closed mechanisms in this paper. First, the kinematic pairs with multidegree of freedoms are formed by combination of the basic joints with single degree of freedom in series, and the formulae are derived for the calculation of the degree of freedoms of the associated linkages, the number of the basic joints, and the valid numbers of the basic links in the associated linkages. Second, many different associated linkages and the number of basic links are derived, and the relations among the associated linkages, the redundant constraints, the passive degree of freedom, and the degree of freedoms of the closed mechanisms are analyzed. Third, some topology graphs are derived and the relative closed mechanisms with the redundant constraints and the passive degree of freedom are synthesized. Finally, the redundant constraints and the degree of freedoms of the closed mechanisms are determined.
High-indium-content InGaN quantum-well structure grown pseudomorphically on a strain-relaxed InGaN template layer
Authors: Liu Yanli , Chen Dunjun , Xue Junjun , Liu Bin , Lu Hai , Zhang Rong , Zheng Youdou , Xu Ke , Zhang Jinping , Cui Bentao , Wowchak Andrew M. , Dabiran Amir M.
Published: April 2012

A high-indium-content InGaN quantum-well structure was grown on a strain-relaxed InGaN template to reduce structural strain induced by lattice mismatch. The results show that the InGaN template, following a nanosculpting process, can maintain the good crystal quality of the underlying GaN layer and provide a new lattice parameter for pseudomorphically growing a high-indium-content quantum-well structure, and the fourth-order satellite peak of the multi-quantum-well structure is clearly distinguishable. Atom misalignment, a strain gradient, and a composition undulation along the growth direction in the quantum-well structure were not observed by high-resolution transmission electron microscopy and selected area diffraction.
p-Co3O4/n-ZnO, Obtained by PECVD, Analyzed by X-ray Photoelectron Spectroscopy
Authors: Bekermann Daniela , Gasparotto Alberto , Barreca Davide , Devi Anjana , Fischer Roland A.
Published: April 2012

The present work focuses on the X-ray Photoelectron Spectroscopy (XPS) and X-ray Excited Auger Electron Spectroscopy (XE-AES) of a Co3O4/ZnO nanosystem. The composite material was obtained via a two-step Plasma Enhanced-Chemical Vapor Deposition (PECVD) process in Ar/O2 mixtures, consisting in the initial deposition of ZnO and the subsequent growth of Co3O4 onto the pristine matrices. Zn(ketoimi)2 (ketoimi = [CH3O(CH2)3NC(CH3)=C(H)C(CH3)=O]) and Co(dpm)2 (dpm = 2,2,6,6-tetramethyl-3,5-heptanedionate) were used as zinc and cobalt precursors, respectively. In particular, strongly 〈001〉 oriented ZnO was grown at 300 °C, followed by the deposition of Co3O4 at 200 °C, applying a radio-frequency (RF) power of 20 W. Structural, morphological and compositional investigations were performed by Glancing Incidence X-ray Diffraction (GIXRD), Field Emission-Scanning Electron Microscopy (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDXS). Surface XPS and XE-AES analyses were carried out to study in detail the system O 1s, Zn 2p3/2, Zn 3p and Co 2p core levels, as well as the Zn and Co Auger peaks. The obtained results evidenced the formation of a composite material, in which ZnO and Co3O4 preserved their chemical identity.
An EPID based method for performing high accuracy calibration between an optical external marker tracking device and the LINAC reference frame
Authors: Grelewicz Zachary , Kang Hyejoo , Wiersma Rodney D.
Published: April 2012

Purpose:

With the increasing use of external 3D optical tracking cameras to guide modern radiation therapy procedures, it has become vitally important to have an accurate camera to linear accelerator (LINAC) reference frame calibration. To eliminate errors present in current calibration procedures based on the manual hand alignment of a device using the light field crosshairs and in room guidance lasers, a semiautomated quantitative calibration approach requiring only use of an electronic portal imaging device (EPID) was developed.

Methods:

A phantom comprised of seven highly IR reflective plastic BBs was placed on the LINAC treatment couch and imaged with both a 3D stereoscopic IR imager and the on board megavoltage (MV) EPID imager. Having knowledge of the optically determined 3D positions and projected EPID images of the BBs, simulated annealing was used to optimize the location of the BBs in the LINAC frame using four different optimization functions. Singular value decomposition was then used to calculate the transformation matrix between the camera and LINAC reference frames. Results were then compared to a traditional camera calibration method for overall accuracy.

Results:

Using modeled data, the simulated annealing process was able to determine the actual locations of the BBs with a RMSE of 0.23 mm. Using projection images acquired with an MV imager, the process was able to determine locations of BBs within .26 mm. The results depend on the choice of optimization function.

Conclusions:

Results show that the method can be used to provide highly accurate spatial registration between an external 3D imaging reference frame and the LINAC frame. The experimental MV imager results, while not as precise as the simulated results, exceed 1 mm accuracy and the current accepted AAPM TG‐142 standard of ≤2 mm positioning accuracy.
Suppression of Phosphoinositide 3-Kinase Signaling and Alteration of Multiple Ion Currents in Drug-Induced Long QT Syndrome
Authors: Lu Zhongju , Wu Chia-Yen C. , Jiang Ya-Ping , Ballou Lisa M. , Clausen Chris , Cohen Ira S. , Lin Richard Z.
Published: April 2012

The dangerous heart arrhythmias that are triggered as a side effect of some drugs are caused by many ion channels, prompting a rethinking of how we screen for these adverse events.
Separate But Not Equal: Giving the NOD to Innate Immunity in Leprosy
Authors: Anandasabapathy Niroshana
Published: April 2012

Different leprosy pathogen components drive distinct paths of dendritic cell development from monocytes.
Carrier and Therapeutic in One
Authors: Collier Joel H.
Published: April 2012

Spherical particles formed of long RNA polymers are taken up by cells and transformed into therapeutic short interfering RNAs.
Consciousness Reborn
Authors: Mashour George A.
Published: April 2012

PET scanning while subjects emerge from general anesthesia reveals the neural core of consciousness.
A Big Step Forward for Tiny Particles
Authors: Nahrendorf Matthias
Published: April 2012

Multimodal nanoparticles guide brain tumor staging and resection in mice.
iNKT Cells Live Off the Fat of the Land
Authors: Reznik Marina
Published: April 2012

iNKT cells link obesity-induced inflammation, insulin resistance, and hepatic steatosis.
The Origins of Cooperative Bacterial Communities
Authors: Sachs J. L. , Hollowell A. C.
Published: April 2012

Bacteria live in complex multispecies communities. Intimately interacting bacterial cells are ubiquitous on biological and mineral surfaces in all habitats. Molecular and cellular biologists have unraveled some key mechanisms that modulate bacterial interactions, but the ecology and evolution of these associations remain poorly understood. One debate has focused on the relative importance of cooperation among cells in bacterial communities. Some researchers suggest that communication and cooperation, both within and among bacterial species, have produced emergent properties that give such groups a selective advantage. Evolutionary biologists have countered that the appearance of group-level traits should be viewed with caution, as natural selection almost invariably favors selfishness. A recent theory by Morris, Lenski, and Zinser, called the Black Queen Hypothesis, gives a new perspective on this debate (J. J. Morris, R. E. Lenski, and E. R. Zinser, mBio 3(2):e00036-12, 2012). These authors present a model that reshapes a decades-old idea: cooperation among species can be automatic and based upon purely selfish traits. Moreover, this hypothesis stands in contrast to the Red Queen Hypothesis, which states that species are in constant evolutionary conflict. Two assumptions serve as the core of the Black Queen model. First, bacterial functions are often leaky, such that cells unavoidably produce resources that benefit others. Second, the receivers of such by-products will tend to delete their own costly pathways for those products, thus building dependency into the interactions. Although not explicitly required in their model, an emergent prediction is that the initiation of such dependency can favor the spread of more obligate coevolved partnerships. This new paradigm suggests that bacteria might often form interdependent cooperative interactions in communities and moreover that bacterial cooperation should leave a clear genomic signature via complementary loss of shared diffusible functions.
Digital dictation and voice transcription software enhances outpatient clinic letter production: a crossover study
Authors: Patel Kinesh , Harbord Marcus
Published: April 2012

Background

Digital voice transcription has been introduced widely in the National Health Service (NHS), though primarily in radiology departments. There has been a long-standing problem with recruitment of medical secretaries within the NHS, leading to long delays in the production of correspondence from outpatient clinics.

Objective

To determine whether use of widely available digital transcription software improves efficiency and the time taken to produce correspondence.

Methods

The project used a prospective, crossover trial design in a ‘real-world’ environment. Correspondence from clinics was transcribed after dictation by a secretary using conventional analogue audio tape or the dictation software. After a 2-week washout period the same clinics' dictations were transcribed using the other method to produce identical correspondence. The two sets of letters were compared.

Results

The mean time for the secretary to produce letters for a complete clinic using digital dictation was 66 min whereas analogue dictation took 121 min (p<0.00002). There was no difference in the number of mistakes per letter (p>0.05).

Conclusion

Voice transcription software significantly decreased the time taken to transcribe outpatient clinic letters with minimal training of secretarial staff, resulting in improved efficiency.
Emplacement ages and exhumation rates for intrusion-hosted Cu–Mo–Sb–Au mineral systems at Freegold Mountain (Yukon, Canada): assessment from U–Pb, Ar–Ar, and (U–Th)/He geochronometers
Authors: Bineli Betsi Thierry , Lentz David , McInnes Brent , Evans Noreen J.
Published: April 2012

To decipher the thermal history of mineralized systems across the Freegold Mountain area (Yukon, Canada), a combined geochronology (zircon U–Pb and hornblende, biotite, and whole rock Ar–Ar) and thermochronology (apatite and zircon (U–Th)/He) study was carried out. Previous U–Pb data combined with new U–Pb and Ar–Ar data show that intrusive bodies across the Freegold Mountain were emplaced during two protracted episodes, the first spanning from 109.6 to 98 Ma and the second between 79 and 68 Ma. Overprinting of the first intrusive event by a second magmatic hydrothermal event is suggested by a zircon U–Pb age of 108.7 ± 0.4 Ma for a chlorite-altered dyke and a whole rock Ar–Ar plateau age of 76.25 ± 0.53 Ma. Zircon (U–Th)/He data are between 66 and 89 Ma, whereas apatite (U–Th)/He data are scattered (38.7–109.9 Ma) and bracket the two magmatic emplacement events. Our combined data reveal a complex history of reheating that led to resetting of numerous chronometers. In most of the investigated magmatic hydrothermal systems, early fast cooling from igneous emplacement through hydrothermal alteration (between 900 and 200 °C) was followed by later and slower cooling accompanying post mineralization uplift and erosion (between 200 and 70 °C). Preliminary models indicate intrusive bodies associated with the Stoddart Cu–Mo ± W prospect cooled slowly (23 °C/Ma) compared with the ones spatially associated with the Revenue Au–Cu prospect (43 °C/Ma), and the similarity of the zircon U–Pb and (U–Th)/He ages from Revenue dyke further supports a rapid cooling from 700 to 180 °C. Erosion rates of 0.035–0.045 mm/year are consistent with tectonic quiescence during the Late Tertiary combined with the lack of Pleistocene glaciation in central Yukon. Such low rates of exhumation favour the formation and preservation of supergene mineralization, such as that found north of Freegold Mountain.
THERMODYNAMIC PROCESSES GENERATED BY A CLASS OF COMPLETELY POSITIVE QUANTUM OPERATIONS
Authors: ABE SUMIYOSHI , AOYAGHI YUKI
Published: April 2012

An attempt toward the operational formulation of quantum thermodynamics is made by employing the recently proposed operations forming positive operator-valued measures for generating thermodynamic processes. The quantity of heat as well as the von Neumann entropy monotonically increases under the operations. The fixed point analysis shows that repeated applications of these operations to a given system transform from its pure ground state at zero temperature to the completely random state in the high temperature limit with intermediate states being generically out of equilibrium. It is shown that the Clausius inequality can be violated along the processes, in general. A bipartite spin-1/2 system is analyzed as an explicit example.
VIRIAL THEOREM FOR ROTATING SELF-GRAVITATING BROWNIAN PARTICLES AND TWO-DIMENSIONAL POINT VORTICES
Authors: CHAVANIS PIERRE-HENRI
Published: April 2012

We derive the virial theorem for an overdamped system of rotating self-gravitating Brownian particles. We show that, in the two-dimensional case, it takes a closed form that can be used to obtain general results about the dynamics without being required to solve the Smoluchowski–Poisson system explicitly. In particular, we obtain the exact analytical expression of the mean square displacement 〈r2〉(t) of the interacting Brownian particles. We exhibit a critical temperature below which the system collapses, and above which it evaporates, and we determine how this temperature is affected by a solid rotation. We also develop an analogy between self-gravitating systems and two-dimensional point vortices. We derive a virial-like relation for point vortices at statistical equilibrium relating the angular velocity to the angular momentum and the temperature.
Separation and atropisomer isolation ofortho-halogenated tetraarylporphyrins by HPLC: Full characterization using 1D and 2D NMR
Authors: Monteiro Carlos J.P. , Pereira Mariette M. , Gonçalves Nuno P. F. , Carvalho Carla G. , Neves Ângela C.B. , Abreu Artur R. , Arnaut Luis G. , Silva Artur M.S.
Published: April 2012

The separation and isolation of the four atropisomers of ortho-halogenated tetraarylporphyrins by semi-preparative HPLC is described. Full characterization and assignment of all1H and13C resonances of 5,10,15,20-tetrakis(2-fluoro or 2-chlorophenyl)porphyrins and 5,10,15,20-tetrakis(2-fluoro or chloro-5-N-ethylsulfamoylphenyl)porphyrins by 1D and 2D NMR techniques is reported. The outcome is an unequivocal evidence of the chlorosulfonation of meso-tetra(2-haloaryl)porphyrins on the 5′-position.
Effect of β-bromo substitution on the photophysical properties ofmeso-phenyl,meso-carbazole, andmeso-triphenylamine porphyrins
Authors: Haley Joy E. , Su Weijie , Singh Kristi M. , Monahan Jennifer L. , Slagle Jonathan E. , McLean Daniel G. , Cooper Thomas M.
Published: April 2012

We present results of an experimental photophysical study of a series of novel brominated and non-brominated porphyrins that contain phenyl, carbazole, or triphenylamine in the meso-position. In addition we have looked at the effects of incorporating a zinc metal into the porphyrin system relative to the free base. Structure-property relationships are established using various absorption and emission techniques including femtosecond pump probe transient absorption and nanosecond laser flash photolysis. With slightly increasing electron donating strength (phenyl < carbazole < triphenylamine) red shifts were observed in all data. The same effect was observed upon the addition of bromine in the beta position. Due to the heavy atom affect of the bromines both the singlet and triplet excited state lifetimes were significantly shorter in the brominated porphyrins. For the T1–Tnabsorption data we observe a large absorption in the near infrared region with the brominated carbazole and triphenylamine. The largest effect of the addition of zinc was in the ground state absorption and emission where a blue shift in the data was observed. Some effects were also observed in the kinetic decays with zinc as the metal compared to the free base porphyrins.
ADAPTIVE VERSUS FUZZY CONTROL OF UNCERTAIN MECHANICAL SYSTEMS
Authors: BEHN CARSTEN , LOEPELMANN PETER
Published: April 2012

The motivation of this work is formed by the biological behavior of a receptor cell (sensory system). It is modeled as a spring-mass-damper oscillator with a spatial disturbance signal acting on the frame and an inner active element that generates a force acting on the mass. Both the system parameters and the excitation signal are supposed to be unknown. The goal is to achieve a predefined movement of the mass, such as tracking a set point trajectory or stabilization. Thus, a controller is required to act on the system using the control force as input in such a way that the desired behavior is generated. This is done by means of high-gain-stabilization. Like its biological paradigm, the receptor is in a permanent state of adaption. This means that recurring disturbances, such as wind acting on the vibrissa, are damped in order to achieve λ-stabilization. To achieve this control goal and at the same time deal with unknown systems, adaptive controllers are introduced. These adaptive control strategies are compared with an adaptive fuzzy approach.
TORSION OF FUNCTIONALLY GRADED OPEN-SECTION MEMBERS
Authors: HEMATIYAN M. R. , ESTAKHRIAN E.
Published: April 2012

There exist some approximate analytical methods for torsion analysis of homogeneous open cross-section members; however, no analytical formulation has been presented for solving a torsion problem of inhomogeneous open cross-section members yet. In this paper, an approximate analytical method for the torsion analysis of thin- to moderately thick-walled functionally graded open-section members with uniform thickness is presented. The shear modulus of rigidity is assumed to have a variation across the thickness. The cross-section is decomposed into some straight, curved and end segments. The torsion problem is then solved in each segment considering some appropriate approximations. By presenting three examples, accuracy of the presented method with respect to thickness, corner radius, and material parameters are investigated. The results show that the proposed method is useful for torsion analysis of thin- to moderately thick-walled functionally graded open-section members.
SWCNTs AS ELECTRON WITHDRAWERS IN NANOCRYSTALLINE ANATASE PHOTOCATALYSTS
Authors: TACCHINI IGNACIO , TERRADO EVA , ANSÓN-CASAOS ALEJANDRO , MARTÍNEZ M. TERESA
Published: April 2012

Single-walled carbon nanotube (SWCNT)/anatase TiO2 composite materials were prepared by successive sol–gel and hydrothermal processes. The composites contained thin SWCNT bundles embedded in aggregates of ~ 12 nm anatase crystallites. A series of SWCNT/ TiO2 photocatalysts was prepared with various SWCNT contents; a SWCNT content of ~ 8 wt.% was found to be optimal for methylene blue (MB) degradation under combined UV/visible radiation. The optimized SWCNT/ TiO2 composite demonstrated substantially higher photocatalytic activity than pure nanocrystalline anatase (5.2 times) and Degussa P-25 TiO2 powder (2.7 times). The MB degradation and mineralization processes were separately evaluated and complete decomposition of MB was shown to take place. The presence of SWCNTs caused an increase in the visible light absorbance of TiO2 ; however, SWCNT/ TiO2 composites did not show any photocatalytic activity when the UV part of the UV/visible light source was filtered. Therefore SWCNTs worked as acceptors for the TiO2 photoexcited electrons, but did not act as sensitizers for TiO2 .
EFFECTS OF ANNEALING ON THE SURFACE DEFECTS OF ZINC OXIDE NANOPARTICLES
Authors: KUMAR SURENDER , SAHARE P. D.
Published: April 2012

ZnO nanoparticles have been prepared by wet chemical method. The properties of the synthesized nanostructures are studied using X-ray diffraction, Transmission Electron Microscopy (TEM), Photoluminescence (PL), Ultraviolet-Visible absorption, Laser Raman and Fourier transform Infrared (FTIR) spectroscopy. The thermal decomposition is analyzed by Thermogravimetric (TG) and Differential Thermal Analysis (DTA). The influence of annealing on structural and optical properties of ZnO nanoparticles has been systematically investigated. The PL results demonstrated that the visible emission at 565 nm is associated with the combination of oxygen vacancies and OH group attached at the surface of ZnO nanoparticles. OH group is lessened from the surface of ZnO nanoparticles with annealing temperature and a blue-shift in visible emission peak is observed at 800°C annealing temperature.
ON ONE APPLICATION OF FOURIER ANALYSIS IN PLASTIC SURGERY
Authors: RAKHIMOV ABDUMALIK , ZAINUDDIN HISHAMUDDIN
Published: April 2012

In present paper, we discuss the spectral methods of measurement of the degree of speech and/or quality of sound by comparing the coefficient of performance indicators depending on energy distributions, ratio of energy of the fundamental tone and energy of overtones. Such a method is very efficient for string oscillation with different initial conditions and it is useful for justification of applications of Fourier analysis in plastic surgery in treatment of some medical diseases.
SOLVING COCOA POD SIGMOID GROWTH MODEL WITH NEWTON RAPHSON METHOD
Authors: CHANG ALBERT LING SHENG , MAISIN NAVIES
Published: April 2012

Cocoa pod growth modelling are useful in crop management, pest and disease management and yield forecasting. Recently, the Beta Growth Function has been used to determine the pod growth model due to its unique for the plant organ growth which is zero growth rate at both the start and end of a precisely defined growth period. Specific pod size (7cm to 10cm in length) is useful in cocoa pod borer (CPB) management for pod sleeving or pesticide spraying. The Beta Growth Function is well-fitted to the pods growth data of four different cocoa clones under non-linear function with time (t) as its independent variable which measured pod length and diameter weekly started at 8 weeks after fertilization occur until pods ripen. However, the same pod length among the clones did not indicate the same pod age since the morphological characteristics for cocoa pods vary among the clones. Depending on pod size for all the clones as guideline in CPB management did not give information on pod age, therefore it is important to study the pod age at specific pod sizes on different clones. Hence, Newton Raphson method is used to solve the non-linear equation of the Beta Growth Function of four different group of cocoa pod at specific pod size.
EFFICIENCY ANALYSIS OF CASPIAN CATTLE FEEDLOT FARMS BY DATA ENVELOPMENT ANALYSIS
Authors: ASHRAFI ALI , JAAFAR AZMI BIN , LEE LAI SOON
Published: April 2012

Data envelopment analysis (DEA) is an excellent approach for evaluating the performance of decision making units (DMUs) that use multiple inputs to produce multiple outputs. This research utilizes the DEA to analyze the operating efficiency of Caspian cattle feedlot farms in Iran. The inputs utilized by the farms are number of calve, number of labors, total metabolizable energy intake, total crude protein intake and total cost of hygiene-treatment of calve; and the output considered is total live weigh gain of calve. By using two DEA models, the efficiency score for each farm is calculated and the efficient farms are ranked.
THE CHARACTERIZATIONS OF DIFFERENT SPLICING SYSTEMS
Authors: KARIMI FARIBA , SARMIN NOR HANIZA , HENG FONG WAN
Published: April 2012

The concept of splicing system was first introduced by Head in 1987 to model the biological process of DNA recombination mathematically. This model was made on the basis of formal language theory which is a branch of applied discrete mathematics and theoretical computer science. In fact, splicing system treats DNA molecule and the recombinant behavior by restriction enzymes and ligases in the form of words and splicing rules respectively. The notion of splicing systems was taken into account from different points of view by many mathematicians. Several modified definitions have been introduced by many researchers. In this paper, some properties of different kinds of splicing systems are presented and their relationships are investigated. Furthermore, these results are illustrated by some examples.
SIMULATION OF INTERVAL CENSORED DATA IN MEDICAL AND BIOLOGICAL STUDIES
Authors: KIANI KAVEH , ARASAN JAYANTHI
Published: April 2012

This research looks at the simulation of interval censored data when the survivor function of the survival time is known and attendance probability of the subjects for follow-ups can take any number between 0 to 1. Interval censored data often arise in the medical and biological follow-up studies where the event of interest occurs somewhere between two known times. Regardless of the methods used to analyze these types of data, simulation of interval censored data is an important and challenging step toward model building and prediction of survival time. The simulation itself is rather tedious and very computer intensive due to the interval monitoring of subjects at prescheduled times and subject's incomplete attendance to follow-ups. In this paper the simulated data by the proposed method were assessed using the bias, standard error and root mean square error (RMSE) of the parameter estimates where the survival time T is assumed to follow the Gompertz distribution function.
ROUGH CLUSTERING FOR CANCER DATASETS
Authors: HERAWAN TUTUT
Published: April 2012

Cancer is becoming a leading cause of death among people in the whole world. It is confirmed that the early detection and accurate diagnosis of this disease can ensure a long survival of the patients. Expert systems and machine learning techniques are gaining popularity in this field because of the effective classification and high diagnostic capability. This paper presents the application of rough set theory for clustering two cancer datasets. These datasets are taken from UCI ML repository. The method is based on MDA technique proposed by [11]. To select a clustering attribute, the maximal degree of the rough attributes dependencies in categorical-valued information systems is used. Further, we use a divide-and-conquer method to partition/cluster the objects. The results show that MDA technique can be used to cluster to the data. Further, we present clusters visualization using two dimensional plot. The plot results provide user friendly navigation to understand the cluster obtained.
ON DISCRETE LOTKA-VOLTERRA TYPE MODELS
Authors: MUKHAMEDOV FARRUKH , SABUROV MANSOOR
Published: April 2012

The Lotka-Volterra (in short LV) model is a second order nonlinear differential equation frequently used to describe the dynamics of biological systems in which two groups of species, predators and their preys interact. One of the basic results of the LV model is that under suitable conditions the LV model can exhibit any asymptotical behavior such as equilibrium states, periodic cycles, and attractors. The discrete analogy of LV model has been considered by many researchers and has been called a quadratic LV model. In a discrete case, one of the unexpected results is that a quadratic LV model cannot exhibit a periodic cycle. In this paper we study nonlinear LV type models which include quadratic LV as a particular case. Unlike quadratic LV models, LV type models can exhibit any asymptotical behavior such as equilibrium states, periodic cycles, and attractors.
A GENETIC ALGORITHM FOR URBAN TRANSIT ROUTING PROBLEM
Authors: CHEW JOANNE SUK CHUN , LEE LAI SOON
Published: April 2012

The Urban Transit Routing Problem (UTRP) involves solving a set of transit route networks, which proved to be a highly complex multi-constrained problem. In this study, a bus route network to find an efficient network to meet customer demands given information on link travel times is considered. An evolutionary optimization technique, called Genetic Algorithm is proposed to solve the UTRP. The main objective is to minimize the passenger costs where the quality of the route sets is evaluated by a set of parameters. Initial computational experiments show that the proposed algorithm performs better than the benchmark results for Mandl's problems.
SOLVING LOCAL MINIMA PROBLEM IN BACK PROPAGATION ALGORITHM USING ADAPTIVE GAIN, ADAPTIVE MOMENTUM AND ADAPTIVE LEARNING RATE ON CLASSIFICATION PROBLEMS
Authors: HAMID NORHAMREEZA ABDUL , NAWI NAZRI MOHD , GHAZALI ROZAIDA , SALLEH MOHD NAJIB MOHD
Published: April 2012

This paper presents a new method to improve back propagation algorithm from getting stuck with local minima problem and slow convergence speeds which caused by neuron saturation in the hidden layer. In this proposed algorithm, each training pattern has its own activation functions of neurons in the hidden layer that are adjusted by the adaptation of gain parameters together with adaptive momentum and learning rate value during the learning process. The efficiency of the proposed algorithm is compared with the conventional back propagation gradient descent and the current working back propagation gradient descent with adaptive gain by means of simulation on three benchmark problems namely iris, glass and thyroid.
DETECTING CRITICAL LEAST ASSOCIATION RULES IN MEDICAL DATABASES
Authors: ABDULLAH ZAILANI , HERAWAN TUTUT , DERIS MUSTAFA MAT
Published: April 2012

Least association rules are corresponded to the rarity or irregularity relationship among itemset in database. Mining these rules is very difficult and rarely focused since it always involves with infrequent and exceptional cases. In certain medical data, detecting these rules is very critical and most valuable. However, mathematical formulation and evaluation of the new proposed measurement are not really impressive. Therefore, in this paper we applied our novel measurement called Critical Relative Support (CRS) to mine the critical least association rules from medical dataset. We also employed our scalable algorithm called Significant Least Pattern Growth algorithm (SLP-Growth) to mine the respective association rules. Experiment with two benchmarked medical datasets, Breast Cancer and Cardiac Single Proton Emission Computed Tomography (SPECT) Images proves that CRS can be used to detect to the pertinent rules and thus verify its scalability.
ON SOME NEW PROPERTIES OF CATALAN NUMBERS
Authors: RAKHIMOV ISAMIDDIN S. , MOHD ATAN KAMEL A.
Published: April 2012

It is well known that Catalan Numbers are used in Mathematical Biology as Enumerating RNA secondary structures for finite points. In this paper, we present some new properties of the Catalan Numbers.