bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Drug Adherence Rates Among Patients with Seven Different Medical Conditions
Authors: Briesacher Becky A. , Andrade Susan E. , Fouayzi Hassan , Chan K. Arnold
Published: March 2008

Study Objective. To compare drug adherence rates among patients with gout, hypercholesterolemia, hypertension, hypothyroidism, osteoporosis, seizure disorders, and type 2 diabetes mellitus by using a standardized approach.

Design. Longitudinal study

Data Source. Health care claims data from 2001–2004.

Patients. A total of 706,032 adults aged 18 years or older with at least one of the seven medical conditions and with incident use of drug therapy for that condition.

Measurements and Main Results. Drug adherence was measured as the sum of the days' supply of drug therapy over the first year observed. Covariates were age, sex, geographic residence, type of health plan, and a comorbidity score calculated by using the Hierarchical Condition Categories risk adjuster. Bivariate statistics and stratification analyses were used to assess unadjusted means and frequency distributions. Sample sizes ranged from 4984 subjects for seizure disorders to 457,395 for hypertension. During the first year of drug therapy, 72.3% of individuals with hypertension achieved adherence rates of 80% or better compared with 68.4%, 65.4%, 60.8%, 54.6%, 51.2%, or 36.8% for those with hypothyroidism, type 2 diabetes, seizure disorders, hypercholesterolemia, osteoporosis, or gout, respectively. Age younger than 60 years was associated with lower adherence across all diseases except seizure disorders. Comorbidity burden and adherence varied by disease. As comorbidity increased, adherence among subjects with osteoporosis decreased, whereas adherence among those with hypertension, hypercholesterolemia, or gout increased. Add‐on drug therapies and previous experience with taking drugs for the condition increased adherence among subjects with hypertension, type 2 diabetes, hypothyroidism, or seizure disorders but not the other conditions.

Conclusion. This uniform comparison of drug adherence revealed modest variation across six of seven diseases, with the outlier condition being gout.
Telavancin: An Antimicrobial with a Multifunctional Mechanism of Action for the Treatment of Serious Gram‐Positive Infections
Authors: Leonard Steven N. , Rybak Michael J.
Published: March 2008

Telavancin is a once‐daily lipoglycopeptide antibiotic structurally derived from vancomycin. It has broad‐spectrum activity against gram‐positive bacteria, including strains with reduced susceptibility to vancomycin. Telavancin's multifunctional mechanism of action, including inhibition of peptidoglycan synthesis and disruption of membrane potential, account for this enhanced activity as well as rapid bactericidal properties. In vitro activity has been demonstrated against a wide range of gram‐positive pathogens such as multidrug‐resistant Streptococcus pneumoniae, as well as methicillin‐resistant, glycopeptide‐intermediate, and vancomycin‐resistant Staphylococcus aureus. The agent also displays activity against many gram‐positive anaerobic organisms. Predictable linear pharmacokinetics have been demonstrated over a wide range of doses, with the most common adverse effects being taste disturbance and nausea. Clinical experience with telavancin in phase II and III studies for complicated skin and skin structure infections has shown it to have similar efficacy and tolerability compared with vancomycin and antistaphylococcal penicillins, and recently telavancin received an approvable letter from the United States Food and Drug Administration for this indication. Telavancin appears to be a promising agent for the treatment of serious infections caused by gram‐positive pathogens, including drug‐resistant pathogens. Further clinical experience will clarify its role in therapy.
Simulated light extraction from a light‐emitting diode integrated with a microlens array
Authors: Hong Jun‐Hee , Park Si‐Hyun
Published: March 2008

Abstract— Light extraction from InGaN‐based light‐emitting diodes (LEDs) on which microlens arrays were integrated using ray‐tracing methods was simulated. Enhancement of the total light extraction and beam shaping in the forward direction of the output of microlens‐integrated LEDs compared to conventional LEDs were observed. The diameter, curvature radius, and density of the microlens arrays on the LEDs were varied and the optimal conditions for external efficiency was determined.
Characterization of a SAG‐InGaN/AlGaN LED by mixed‐source HVPE with a multi‐sliding boat system
Authors: Hwang S. L. , Kim K. H. , Jeon H. S. , Lee C. H. , Hong S. H. , Heo I. H. , Yang M. , Ahn H. S. , Kim S. W. , Lee S. C. , Cho I. S. , Lim W. T. , Lee J. H. , Shee S. K.
Published: March 2008

Abstract— The selective area growth (SAG) of a InGaN/AlGaN light‐emitting diode (LED) is performed by using mixed‐source hydride vapor‐phase epitaxy (HVPE) with a multi‐sliding boat system. The SAG‐InGaN/AlGaN LED consists of a Si‐doped AlGaN cladding layer, an InGaN active layer, a Mg‐doped AlGaN cladding layer, and a Mg‐doped GaN capping layer. The carrier concentration of the n‐type AlxGa1−xN (x ∼ 16%) cladding layer depends on the amount of poly‐Si placed in the Al‐Ga source. The carrier concentration is varied from 2.0 × 1016 to 1.1 × 1017 cm−3. Electroluminescence (EL) characteristics show an emission peak wavelength at 426 nm with a full width at half‐maximum (FWHM) of approximately 0.47 eV at 20 mA. It was found that the mixed‐source HVPE method with a multi‐sliding boat system is a candidate growth method for III‐nitride LEDs.
High‐efficacy drive of spatial positive‐column‐discharge PDP with delayed D pulses
Authors: Shiga Tomokazu , Sato Taiko , Kobayashi Narue , Mikoshiba Shigeo , Asai Hideyuki , Kikuchi Naoya
Published: March 2008

Abstract— A thick‐film ceramic‐sheet PDP provides a long sustain discharge gap of 0.45 mm, enabling the use of positive column discharges. The discharges are established in the middle of the discharge space and are completely free from touching the surface of substrates. This allows for the reduction in diffusion losses of the charged particles. To further improve the efficacy, delayed D pulses are applied to the address electrodes during the sustain period. Although the pulses only draw a little current, they perturb the electric field, reducing the peak discharge current and hence resulting in higher efficacy and luminance. The efficacy and luminance increase by 35% and 38%, respectively, with the delayed D pulses. These pulses are incorporated into the contiguous‐subfield erase‐addressing drive scheme for TV application. A short gap of 70 μm between the sustain and data electrodes generates a fast‐rising discharge and allows a high‐speed addressing of 0.25 μsec. This provides 18 contiguous subfields for the full‐HD single‐scan mode, with 70% light emission duty. A luminous efficacy of 6.0 lm/W can been attained using Ne + 30% Xe 47 kPa, a sustain voltage of 320 V, and a sustain frequency of 3.3 kHz, when the luminance is 157 cd/m2. Alternatively, the panel can achieve 4.2 lm/W and 1260 cd/m2 by increasing the sustain frequency to 33 kHz.
Coatings of indium tin oxide nanoparticles on various flexible polymer substrates: Influence of surface topography and oscillatory bending on electrical properties
Authors: Königer Tobias , Münstedt Helmut
Published: March 2008

Abstract— Coatings of indium tin oxide (ITO) nanoparticles on different flexible polymer substrates were investigated with respect to the achievable sheet resistance and their electrical behavior under oscillatory bending. As substrate materials, polyethyleneterephthalate (PET), polyethylenenaphthalate (PEN), polyetheretherketone (PEEK), and polyimide (PI) were chosen, the surface resistances on the different polymer substrates were compared as a function of annealing temperature and surface topography. The surface topography, which has a strong influence on the surface resistance, was characterized by means of a white‐light confocal (WL‐CF) microscope. On the PET substrate, which exhibits the smoothest surface, the coating of ITO nanoparticles shows the lowest sheet resistance of 2 kΩ/□ for a layer thickness of 3 μm and an annealing temperature of 200°C. Furthermore, the electrical behavior of coatings of ITO nanoparticles under oscillatory bending was investigated using a special device. These coatings show a cyclic change of the conductivity which can be explained by an alternating compression and extension of crack flanks under the applied stress. Due to the growing number of cracks with increasing number of cycles, a decrease of the conductivity is observed in the bent state as well as in the balanced state. For a small bending radii, the decrease of the conductivity is stronger due to more cracks caused by the higher tensile stresses in the layer. The electrical behavior of the coatings of the annealed ITO nanoparticles on PET films under oscillatory bending was compared with commercially available sputtered ITO coatings. The annealed coatings of ITO nanoparticles demonstrate better electrical properties under oscillatory bending than coatings of sputtered ITO. The different electrical behavior under oscillatory bending can be related to differences in crack formation.
Modeling polycyclic aromatic hydrocarbon bioaccumulation and metabolism in time-variable early life-stage exposures
Authors: Mathew Rooni , McGrath Joy A , Toro Dominic M. Di
Published: March 2008

Recent laboratory investigations into the bioaccumulation and toxicity of polycyclic aromatic hydrocarbons (PAH) have focused on low-level, time-variable exposures to early life-stage fish. Polycyclic aromatic hydrocarbon body-burden residues reported in these studies were lower than critical body-burden residues predicted by the target lipid model (TLM). To understand this discrepancy, a time-variable uptake and depuration model of PAH bioaccumulation was developed. Kinetic constants were fit using measured exposure and tissue concentrations. The resulting lipid-water partition coefficients (KLW) were uncorrelated with the octanol-water partition coefficient (Kow)—a qualitatively unrealistic finding considering that numerous studies have reported a positive correlation between the two. Because PAHs are known to be metabolized, the comparison of KLW with Kow suggests that metabolism may be occurring in early life-stage fish. Therefore, the uptake and depuration model was modified to include metabolism while assuming linearity of KLW with Kow. Calculated metabolism rates were positively correlated with Kow—a finding qualitatively similar to those of other studies. The present study provides a reasonable explanation for the discrepancy between the TLM predictions and the measured toxic effect levels. Given the time-variable exposure concentrations, the maximum measured body burdens used to relate to toxic effects may be underestimated. In addition, the maximum body burden of parent PAH plus metabolites may be a better measure in relating tissue concentrations to toxic effects. Incorporating these refinements in relating body burdens to toxic effects may result in a better comparison between TLM predictions and measured effect levels.
Quantitative structure-activity relationships for kinetic parameters of polycyclic aromatic hydrocarbon biotransformation
Authors: Dimitriou-Christidis Petros , Autenrieth Robin L , Abraham Michael H
Published: March 2008

Quantitative structure-activity relationships (QSARs) were developed for three Monod-type parameters—qmax, KS, and qmax/KS—that express the kinetics of polycyclic aromatic hydrocarbon (PAH) biotransformation by Sphingomonas paucimobilis strain EPA505. The training sets contained high-quality experimental values of the kinetic parameters for 20 unsubstituted and methylated PAHs as well as values of 41 meaningful molecular descriptors. A genetic function approximation algorithm was used to develop the QSARs. Statistical evaluation of the developed QSARs showed that the relationships are statistically significant and satisfy the assumptions of linear-regression analysis. The Organization for Economic Cooperation and Development principles for (Q)SAR validation were followed to evaluate the developed QSARs, which showed that the QSARs are valid. The QSARs contain spatial, spatial and electronic, topological, and thermodynamic molecular descriptors. Whereas spatial descriptors were essential in explaining biotransformation kinetics, electronic descriptors were not. Mechanistic interpretation of the QSARs resulted in evidence that is consistent with the hypothesis of membrane transport as being the rate-limiting process in PAH biotransformation by strain EPA505. The present study demonstrates the value of QSAR not only as a predictive tool but also as a framework for understanding the mechanisms governing biodegradation at the molecular level.
Is sonication effective to improve biogas production and solids reduction in excess sludge digestion?
Authors: Braguglia C. M. , Mininni G. , Gianico A.
Published: March 2008

Results of three semi-continuous anaerobic tests were reported and discussed. Each test was carried out by two parallel anaerobic reactors fed with waste activated sludge, either as it was sampled from the sewage treatment plant of Rome North or previously disintegrated by ultra-sound treatment. Activated sludge was sonicated at the energy input of 5,000 or 2,500 kJ kg−1 dry solids corresponding to a disintegration degree of approximately 8 or 4%, respectively. Sonication proved to be effective both in increasing VS destruction and cumulative biogas production. The best increase of VS destruction (from 30 to 35%) was achieved in test #3 carried out at high organic load (10 d residence time) and low energy input (2,500 kJ kg−1 dry solids). The best increase in cumulative biogas production (from 472 to 640 NL after 67 d of tests i.e.) was obtained in test #1 at low organic load (20 d residence time) and high energy input (5,000 kJ kg−1 dry solids). Specific biogas production varied in the tests carried out with untreated sludge (0.55 – 0.67 Nm3 kg−1 VS destroyed) but was practically unchanged for all the tests with sonicated sludge (0.7 Nm3 kg−1 VS destroyed).
Polymer production by bacterial strains isolated from activated sludge treating municipal wastewater
Authors: Yan S. , Bala Subramanian S. , Tyagi R. D. , Surampalli R. Y.
Published: March 2008

Polyhydroxyalkanoates (PHAs) accumulating bacteria were isolated from activated sludge samples collected from municipal wastewater treatment plants in Quebec. Twelve bacterial strains were screened for PHA production with acetate as sole carbon source. PHA granules exhibited a strong orange fluorescence when stained with Nile blue A observed under microscope (X100x). PHA was also analyzed by Gas Chromatography Linked to Mass Spectroscopy (GCMS) to further confirm the presence and the concentration of PHA. To compare the abilities of these PHA accumulating bacterial strains, synthetic media with acetate as carbon source was prepared to accumulate PHA in 500 mL Erlenmeyer flask containing 150 of the medium. These flasks were then inoculated with the isolated bacterial strains, incubated at 25 °C for 48 hours in a rotary shaker at 220 rpm. The results showed that the bacterial strains isolated from sludge possess different abilities for accumulating PHA. The maximum PHA content of 27.50% was obtained by strain PHA-SB3. The PHB/PHV ratio of the copolymer produced in the study changed in accordance with operating time and strains.
Fouling and its reversibility in relation to flow properties and module design in aerated hollow fibre modules for membrane bioreactors
Authors: Pollet S. , Guigui C. , Cabassud C.
Published: March 2008

Nowadays, most membrane bioreactors are using membranes submerged in the biomass and aeration in the concentrate compartment to limit or to control fouling. An important issue for the design of modules or membrane bundles in MBRs is to understand how the air/liquid flow is behaving and influencing fouling and its reversibility in relationship to the module properties. This paper focuses on an innovative and very specific process, in which HF membranes are put in a cartridge outside the activated sludge tank and a recycling loop is associated to the cartridge in order to decrease concentration of foulant species at the membrane surface and mass transfer resistance. Recycling operates with a very low liquid velocity in the module (a few cm·s−1) which constitutes a specificity of this process in terms of filtration operation. The aim of this study is to characterise two-phase flow and its effects on fouling and fouling reversibility at the scale of a semi-industrial bundle of outside/in hollow fibres, and as a function of bundle properties (packing density, fibre diameter), using specific methods to characterise the flow and fouling effects. Two modules were used showing a different packing density. Filtration was operated at constant permeate flux with clay suspension at 0.65 g·l−1 in the same hydrodynamic conditions. Fouling kinetics and irreversibility were characterised by an adapted step method, and gas and liquid flows were characterised at global scale by residence time distribution analyses and gas hold-up. Fouling velocities are clearly influenced by gas velocity. The proportion of dead to total volume in the module is mainly affected by the liquid flow velocity and module design. The module with the higher fibre diameter and the lower packing density showed better performances in terms of fouling which was correlated with better flow properties.
Membrane bioreactor aeration: investigation of the velocity flow pattern
Authors: Tacke D. , Pinnekamp J. , Prieske H. , Kraume M.
Published: March 2008

Results of investigations concerning membrane bioreactor aeration are presented which were carried out at the Institute of Environmental Engineering of RWTH Aachen University (ISA) in cooperation with the Department of Chemical Engineering of the Technische Universität Berlin. In the field of industrial and municipal wastewater treatment the use of membrane bioreactors (MBR) is of increasing interest especially due to the high requirements on effluent quality nowadays. The design of aeration systems is a very important aspect of MBR development because it influences both cost of operation and filtration flux. The ISA has carried out tests concerning the velocity flow pattern in flat sheet membrane modules (developed by the A3 Water Solutions GmbH) to identify the effects of different aeration systems, aeration intensities and module constructions. The Department of Chemical Engineering is currently using the results obtained from the ADV to calibrate a numerical model which simulates two phase water and gas flow within an aerated membrane module. Optical investigations concerning the bubble distribution give a better understanding of the flow conditions in MBR. Developing a numerical tool for membrane module optimization concerning the hydrodynamics is the aim of the investigation of membrane bioreactor aeration.
A Path Analytic Model of Socio-Cultural Indicators of in-School Adolescents' Response to HIV/AIDS Preventive Practices in Nigeria
Authors: Asim Alice E. , Uwe Ekanem A. , Ekuri Emmanuel E. , Asuquo Patrick N. , Ekpiken-Ekanem Roibito Samuel
Published: March 2008

This study is a path modeling, which examines the effect and magnitude of four socio-cultural indicators on adolescents' response to HIV/AIDS preventive practices in Nigerian setting. Questionnaire data were generated from 316 fifth year students in 12 secondary schools in Cross River State, Nigeria. Result of data analysis, using path analyses procedures indicated that only three socio-cultural factors were effective in explaining adolescents' response to HIV/AIDS preventive practices. Cultural indicators and sexuality attitudes had the most significant influence on adolescents' response to HIV/AIDS preventive practices. In all, 56.5% of the total effect of the variables was direct, while 43.5% was indirect. The implications of the research findings are addressed.
Impact of the lasr wavelength and fluence on the ablation rate of aluminium
Authors: Stafe Mihai , Vladoiu Ionut , Popescu Ion
Published: March 2008

The dependence of the ablation rate of aluminium on the fluence of nanosecond laser pulses with wavelengths of 532 nm and respectively 1064 nm is investigated in atmospheric air. The fluence of the pulses is varied by changing the diameter of the irradiated area at the target surface, and the wavelength is varied by using the fundamental and the second harmonic of a Q-switched Nd-YAG laser system. The results indicate an approximately logarithmic increase of the ablation rate with the fluence for ablation rates smaller than ∼6 μm/pulse at 532 nm, and 0.3 μm/pulse at 1064 nm wavelength. The significantly smaller ablation rate at 1064 nm is due to the small optical absorptivity, the strong oxidation of the aluminium target, and to the strong attenuation of the pulses into the plasma plume at this wavelength. A jump of the ablation rate is observed at the fluence threshold value, which is ∼50 J/cm2 for the second harmonic, and ∼15 J/cm2 for the fundamental pulses. Further increasing the fluence leads to a steep increase of the ablation rate at both wavelengths, the increase of the ablation rate being approximately exponential in the case of visible pulses. The jump of the ablation rate at the threshold fluence value is due to the transition from a normal vaporization regime to a phase explosion regime, and to the change of the dimensionality of the hydrodynamics of the plasma-plume.
New results in the use of a “reverse engineering” method in cosmologies with scalar field
Authors: Vulcanov Dumitru
Published: March 2008

The method of “reverse engineering” for designing potentials in cosmologies with “quintessence” scalar field is systematically used for several types of cosmologies (through the time behavior of the scale factor). The general recipe is introduced and then applied when matter other than the scalar field is present, and for tachyonic scalar fields. The possibility of using this method for prescribing initial data in numerical simulations in cosmology is investigated.
Exact and approximate statistical approaches for the exergy of blackbody radiation
Authors: Badescu Viorel
Published: March 2008

There is a long term debate in literature about the exergy of blackbody radiation (BBR). Most authors contributing to this dispute used classical thermodynamics arguments. The objective of this paper is to propose a statistical thermodynamics approach. This gives new perspectives to previous results. Four simple statistical microscopic models are used to derive BBR exergy. They consist of combinations of quantum and classical descriptions of the state occupation number and entropy, respectively. In all four cases the BBR exergy (or exergy flux density) is given by the internal energy (or energy flux density) times an efficiency-like factor containing the environment temperature and the blackbody radiation temperature. One shows that Petela-Landsberg-Press efficiency is the “exact” result while the Jeter (Carnot) efficiency corresponds to the classical approximation. Other two (new) approximate efficiency-like factors are also reported.
Determination of thin film refractive index and thickness by means of film phase thickness
Authors: Nenkov Milen , Pencheva Tamara
Published: March 2008

A new approach for determination of refractive index dispersion n(λ) (the real part of the complex refractive index) and thickness d of thin films of negligible absorption and weak dispersion is proposed. The calculation procedure is based on determination of the phase thickness of the film in the spectral region of measured transmittance data. All points of measured spectra are included in the calculations. Barium titanate thin films are investigated in the spectral region 0.38–0.78 μm and their n(λ) and d are calculated. The approach is validated using Swanepoel’s method and it is found to be applicable for relatively thin films when measured transmittance spectra have one minimum and one maximum only.
Ultraviolet detectors based on ZnO films by thermal oxidation of Zn metallic films
Authors: Zheng Xue , Li Qing
Published: March 2008

Metallic Zn films were deposited on glass substrates by electron-beam evaporation. ZnO films were synthesized by thermal oxidation of Zn metallic films in air. At the annealing temperature of 550 °C, ZnO nanowires appeared on the surface, which mainly result from the decrease of oxidation rate. A ZnO ultraviolet photodetector was fabricated based on a metal-semiconductor-metal planar structure. The detector showed a large UV photoresponse with an increase of two orders of magnitude. It is concluded that promising UV detectors can be obtained on ZnO films by thermal oxidation of Zn metallic films. The ways of performing spectral response measurements for polycrystalline ZnO films are also discussed.
Stochastic quantization method for spinning particles in a gravitational plane wave field
Authors: Lehtihet Zehoua , Chetouani Lyazid
Published: March 2008

The exact and analytic Green functions for spinning relativistic particles in interaction with a gravitational plane wave field are obtained within the Stochastic Quantization Method of Parisi and Wu. We have separated the classical calculations from those related to the quantum fluctuations. The problem has been solved by using a perturbative treatment via the Langevin equation relying on phase and configuration spaces formulation.
Coherent control for the spherical symmetric box potential in short and intensive XUV laser fields
Authors: Barna Imre , Dombi Péter
Published: March 2008

Coherent control calculations are presented for a spherically symmetric box potential for non-resonant two photon transition probabilities. With the help of a genetic algorithm (GA), the population of the excited states are maximized and minimized. The external driving field is a superposition of three intensive extreme ultraviolet (XUV) linearly polarized laser pulses with different frequencies in the femtosecond duration range. We solved the quantum mechanical problem within the dipole approximation. Our investigation clearly shows that the dynamics of the electron current has a strong correlation with the optimized and neutralizing pulse shape.
Superconducting state parameters of La100-C
GaC binary metallic glasses
Authors: Vora Aditya
Published: March 2008

The theoretical investigations of the superconducting state parameters (SSP) viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ*, transition temperature T
C, isotope effect exponent α and effective interaction strength N
O
V of six binary La100-C
GaC (C = 16, 20, 22, 24, 26 and 28 at. %) metallic glasses have been reported using Ashcroft’s empty core (EMC) model potential for the first time. Five local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used in the present investigation to study the screening influence on the aforesaid properties. It is observed that the electron-phonon coupling strength λ and the transition temperature T
C are quite sensitive to the selection of the local field correction functions, whereas the Coulomb pseudopotential μ*, isotope effect exponent α and effective interaction strength N
O
V show weak dependences on the local field correction functions. The T
C obtained from H-local field correction function are found in qualitative agreement with available experimental data and show almost linear nature with the concentration (C) of ‘Ga’ element. A linear T
C equation is proposed by fitting the present outcomes for H-local field correction function, which is in conformity with other results for the experimental data. Also, the present results are found to be in qualitative agreement with other such earlier reported data, which confirms the superconducting phase in the metallic glasses.
The uncertainty relation expressed by means of a new entropic function
Authors: Majerník Vladimir
Published: March 2008

In this article we use a new entropic function, derived from an f-divergence between two probability distributions, for the construction of an alternative entropic uncertainty relation. After a brief review of some existing f-divergences, a new f-divergence and the corresponding entropic function, derived from it, is introduced and its useful characteristics are presented. This entropic function is then applied to construct an alternative uncertainty relation of two non-commuting observables in quantum physics. An explicit expression for such an uncertainty relation is found for the case of two observables which are the x- and z-components of the angular momentum of the spin-1/2 system.
Entanglement conditions for four-mode states via the uncertainty relations in conjunction with partial transposition
Authors: Song Lijun , Wang Xiaoguang , Yan Dong , Li Yongda
Published: March 2008

From the Heisenberg uncertainty relation in conjunction with partial transposition, we derive a class of inequalities for detecting entanglements in four-mode states. The sufficient conditions for bipartite entangled states are presented. We also discuss the generalization of the entanglement conditions via the Schrödinger-Robertson indeterminacy relation, which are in general stronger than those based on the Heisenberg uncertainty relation.
Superconducting state parameters of binary metallic glasses
Authors: Vora Aditya
Published: March 2008

Ashcroft’s empty core (EMC) model potential is used to study the superconducting state parameters (SSPs) viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ*, transition temperature T
C, isotope effect exponent αand effective interaction strength N
O
V of some binary metallic glasses based on the superconducting (S), conditional superconducting (S’) and non-superconducting (NS) elements of the periodic table. Five local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used for the first time with EMC potential in the present investigation to study the screening influence on the aforesaid properties. The T
C obtained from the H-local field correction function are in excellent agreement with available theoretical or experimental data. In the present computation, the use of the pseudo-alloy-atom model (PAA) was proposed and found successful. Present work results are in qualitative agreement with such earlier reported experimental values which confirm the superconducting phase in all metallic glasses. A strong dependency of the SSPs of the metallic glasses on the valence ‘Z’ is identified.
Particle tunneling and scattering in a three-dimensional potential with a barrier
Authors: Olkhovsky Vladislav , Petrillo Vittoria , Jakiel Jacek , Kantor Wiesław
Published: March 2008

The particle tunneling through a 3-D rectangular potential barrier has been studied. The simplest model for multiple internal reflections has been assumed. The explicit expression for all the transmission and reflection probability amplitudes have been derived, as well as the tunneling and reflection phase times.
Simple signal path technique for matching circuit in packaged semiconductor diode laser
Authors: Han J.
Published: March 2008

Improvement in frequency bandwidth of a packaged diode laser is investigated by the circuit impedance matching. To overcome the structural limitation of the electronic package for high frequencies, employing conventional lumped element impedance matching technique in conjunction with the manipulation of signal path of the package connections showed significant enhancement for 3-dB bandwidth to more than 6 GHz.
Functional brain imaging by multi-wavelength time-resolved near infrared spectroscopy
Authors: Torricelli A. , Contini D. , Pifferi A. , Spinelli L. , Cubeddu R.
Published: March 2008

We present a description of evolution of time-resolved systems developed at the Department of Physics, Politecnico di Milano for tissue oximetry and functional brain imaging. From a single source and 4-channel set-up we have upgraded to a potentially 18-sources and 64-channel device. An example of sensitivity of the latest set-up is reported for a motor task experiment. A short discussion on the next generation time-resolved instrumentation for functional studies is also presented.
Monte Carlo simulation of light propagation in adult brain: influence of tissue blood content and indocyanine green
Authors: Niederer P. , Mudra R. , Keller E.
Published: March 2008

Near-infrared spectroscopy (NIRS), applied to a human head, is a noninvasive method in neurointensive care to monitor cerebral hemodynamics and oxygenation. The method is particularly powerful when it is applied in combination with indocyanine green (ICG) as a tracer substance. In order to assess contributions to the measured optical density (OD) which are due to extracerebral circulation and disturb the clinically significant intracerebral signals, we simulated the light propagation in an anatomically representative model of the adult head derived from MRI measurements with the aid of Monte Carlo methods. Since the measured OD signal depends largely on the relative blood content in various transilluminated tissues, we weighted the calculated densities of the photon distribution under baseline conditions within the tissues with the changes and aberrations of the relative blood volumes which we expect to prevail under physiological conditions. Furthermore, the influence of the IGC dye as a tracer substance was assessed. We conclude that up to about different 70% of the measured OD signal may have its origin in the tissues of interest under optimal conditions, which is mainly due to the extrapolated high relative blood content of brain tissue along with the influence of ICG.
Bricks and pseudo MV-algebras are equivalent
Authors: Subrahmanyam N.
Published: March 2008

We will show that the bricks (of Bosbach) and the pseudo MV-algebras are each term equivalent to the class of semigroups with a pair of unary operations ^ and ˘ satisfying the equations: (âa)^b = b = b(aă)˘ and a($$
\hat b
$$
a)˘ = (bă)^b and also show that a brick is an interval [0, u] of the positive cone of a unital lattice ordered group. We further extend the notion of implications to a pseudo MV-algebra and study the algebra of such implications.
A note on normal bases of ideals in sextic algebraic number field
Authors: Dubovský Viktor , Kostra Juraj , Lazar Vladimir
Published: March 2008

Let K/Q be a cyclic tamely ramified extension of degree 6, then any ambiguous ideal of K has a normal basis.
Groups with few conjugacy classes of non-normal subgroups
Authors: Falco Maria , Giovanni Francesco , Musella Carmela
Published: March 2008

The structure of groups with finitely many non-normal subgroups is well known. In this paper, groups are investigated with finitely many conjugacy classes of non-normal subgroups with a given property. In particular, it is proved that a locally soluble group with finitely many non-trivial conjugacy classes of non-abelian subgroups has finite commutator subgroup. This result generalizes a theorem by Romalis and Sesekin on groups in which every non-abelian subgroup is normal.
Oscillation of fourth order nonlinear neutral difference equations I
Authors: Tripathy A.
Published: March 2008

Oscillatory and asymptotic behaviour of solutions of a class of nonlinear fourth order neutral difference equations of the form $$
\Delta ^2 (r(n)\Delta ^2 (y(n) + p(n)y(n - m))) + q(n)G(y(n - k)) = 0
$$ and $$
(NH) \Delta ^2 (r(n)\Delta ^2 (y(n) + p(n)y(n - m))) + q(n)G(y(n - k)) = f(n)
$$ are studied under the assumption $$
\sum\limits_{n = 0}^\infty {\tfrac{n}
{{r(n)}} = \infty }
$$, for various ranges of p(n). Sufficient conditions are obtained for the existence of bounded positive solutions of (NH).
Plant traits enabling survival in Mediterranean badlands in northeastern Spain suffering from soil erosion
Authors: Guerrero‐Campo Joaquín , Palacio Sara , Montserrat‐Martí Gabriel
Published: March 2008

Question: This study analysed the effect of severe soil erosion on species composition of plant communities by favouring species showing certain growth forms, root‐sprouting and clonal growth abilities.

Location: The study area was located between the middle Ebro Valley and the Pre‐Pyrenees (northeastern Spain).

Methods: Root‐sprouting and shoot‐rooting abilities, clonal reproduction and growth form were assessed for the 123 most common plant species from eroded lands in the study area. We obtained 260 vegetation relevés in three different substrata (gypsum outcrops, Miocene clays and Eocene marls) on areas with different degrees of soil erosion. The frequency of every plant trait in each relevé was estimated according to species presence. The effect of soil erosion on the frequency of plant attributes was assessed by correlation analyses.

Results: Bipolar, non‐clonal plants and annual species decreased their frequency with increasing soil erosion in the three substrata analyzed, whereas root‐sprouters and woody plants (mostly sub‐shrubs) increased their frequency in most of the substrata analysed.

Conclusions: Woody sub‐shrubs, root‐sprouters and clonal species are favoured in eroded lands in NE Spain. Bipolar species and annual plants might not be plastic enough to survive the high stress and frequent disturbances prevailing in such eroded areas.
Spatial structure along an altitudinal gradient in the Italian central Alps suggests competition and facilitation among coniferous species
Authors: Lingua Emanuele , Cherubini Paolo , Motta Renzo , Nola Paola
Published: March 2008

Questions:

What is the structure of the anthropogenic upper forest‐grassland ecotone and are there differences in the spatial relationships between the tree species involved?

Location:

Valfurva Valley, Italian central Alps.

Methods:

We conducted a spatial distribution and structure analysis in three 1‐ha permanent plots along an altitudinal gradient, from the treeline to the sub‐alpine forest. We reconstructed the age structure from cores from each individual with diameter > 4 cm at 50 cm height.

Results:

All tree species and age classes examined had a clumped structure. The cluster tendency was more evident at the treeline where the environmental conditions are more severe. In the sub‐alpine forest there was a repulsion between Pinus cembra and Pinus mugo but at the treeline P. cembra was frequently found downslope from P. mugo.

Conclusions:

Although human influence has been the main driving force in shaping the present forest structure, in the last few decades natural dynamics have become the predominant force acting on forest structure and processes, showing a higher magnitude as altitude increases. Our results emphasize the existence of facilitating and interfering mechanisms between different species. P. cembra seems to be favoured compared to the other tree species.
Regeneration models and plant regenerative types related to the intensity of fire in Atlantic shrubland and woodland species
Authors: Reyes Otilia , Casal Mercedes
Published: March 2008

Question: Is it possible to model the germinative and resprouting behaviour of plant species in Atlantic shrublands and woodlands in relation to fire intensity? Is it possible to recognise different functional regenerative types in these plant species?

Location: Galicia, NW Iberian Peninsula.

Methods: We explored the patterns of germination and resprouting plant responses in relation to different intensities of fire using data from 37 trees, shrubs and herbaceous species growing in Atlantic shrublands and woodlands.

Results: Synthesizing their germinative and resprouting behaviour, we created two graphical models: the Functional Germinative Model (FGM) and the Functional Sprouting Model (FSM). Integrating the germinative and resprouting responses, and taking into account fire intensity, we created the Functional Regenerative Model (FRM), which predicts the post‐fire recuperation of the populations of each species. The FRM has been validated with data from four Atlantic communities. We identified four plant functional regenerative types (PFRT) for Atlantic forest vegetation and we propose three intensities of response.

Conclusions: The extracted models (FGM, FSM and FRM) and the grouping of species in four PFRTs could be applicable to more Atlantic species, to disturbance ecology in general and to population, community and landscape management.
CFD modeling of mass transfer and stripping efficiency in FCCU strippers
Authors: Gao Jinsen , Chang Jian , Lan Xingying , Yang Yong , Lu Chunxi , Xu Chunming
Published: March 2008

This article presents an experimental and computational study of mass transfer characteristics and stripping efficiency of bubbling fluidized beds within FCCU strippers. The hydrodynamic and mass transfer characteristics are investigated experimentally. Based on the granular kinetics theory, a two‐fluid CFD model coupled with a modified Gidaspow drag model and an empirical mass transfer model has been developed and verified against the experimental results. The overall trend of the time‐averaged bed density, concentration of tracer and stripping efficiency at various superficial gas velocities were in reasonable agreement with the experimental data. It was found that stripping efficiency depends strongly on the operating conditions as well as on the internal configuration of the strippers. Increasing superficial gas velocity increases stripping efficiency. Internal baffles improve break‐up and redistribution of bubbles and enhance the gas‐solids contacting remarkably, showing a benefit for the mass transfer in the V‐baffled stripper. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Repairing the human brain after stroke: I. Mechanisms of spontaneous recovery
Authors: Cramer Steven C.
Published: March 2008

Stroke remains a leading cause of adult disability. Some degree of spontaneous behavioral recovery is usually seen in the weeks after stroke onset. Variability in recovery is substantial across human patients. Some principles have emerged; for example, recovery occurs slowest in those destined to have less successful outcomes. Animal studies have extended these observations, providing insight into a broad range of underlying molecular and physiological events. Brain mapping studies in human patients have provided observations at the systems level that often parallel findings in animals. In general, the best outcomes are associated with the greatest return toward the normal state of brain functional organization. Reorganization of surviving central nervous system elements supports behavioral recovery, for example, through changes in interhemispheric lateralization, activity of association cortices linked to injured zones, and organization of cortical representational maps. A number of factors influence events supporting stroke recovery, such as demographics, behavioral experience, and perhaps genetics. Such measures gain importance when viewed as covariates in therapeutic trials of restorative agents that target stroke recovery. Ann Neurol 2008;63:272–287
Reducing harm from tobacco smoke exposure during pregnancy
Authors: Coleman Tim
Published: March 2008

In addition to the health risks that maternal tobacco smoke exposure in pregnancy poses to women, this is a cause of substantial fetal morbidity and mortality. In pregnancy, maternal tobacco smoke exposure can arise because women either smoke or are passively exposed to environmental tobacco smoke as a consequence of other's smoking. This article discusses the scope for clinicians to help reduce both types of tobacco smoke exposure in pregnancy, with a specific focus on available and effective interventions for smoking cessation by pregnant women. Behavioral support with smoking cessation is the only intervention that has been proven to encourage smoking cessation in pregnancy and reduces smoking rates in late pregnancy by 6 to 7%. There are physiological reasons to suspect that nicotine replacement therapy (NRT) will be less or (in)effective for smoking cessation in pregnancy when compared with its use by nonpregnant smokers. However, there are also strong theoretical reasons to suspect that NRT is likely to be safer than continued smoking in pregnancy. Consequently, this article reviews evidence for the safety and effectiveness of NRT when used for smoking cessation in pregnancy and recommendations concerning the use of NRT in pregnancy are presented. Birth Defects Research (Part C) 84:73–79, 2008. © 2008 Wiley‐Liss, Inc.
Review on genetic variants and maternal smoking in the etiology of oral clefts and other birth defects
Authors: Shi Min , Wehby George L. , Murray Jeffrey C.
Published: March 2008

A spectrum of adverse pregnancy outcomes, including preterm birth, low birth weight, and birth defects has been linked with maternal smoking during pregnancy. This article includes a review of studies investigating interactions between genetic variants and maternal smoking in contributing to birth defects using oral clefting as a model birth defect. The primary gene‐smoking studies for other major birth defects are also summarized. Gene‐environment interaction studies for birth defects are still at an early stage with several mixed results, but evolving research findings have begun to document clinically and developmentally important interactions. As samples and data become increasingly available, more effort is needed in designing innovative analytical methods to study gene‐environment interactions. Birth Defects Research (Part C) 84:16–29, 2008. Published 2008 Wiley‐Liss, Inc.
In vitro assessment of reproductive toxicity of tobacco smoke and its constituents
Authors: Talbot Prudence
Published: March 2008

Epidemiological studies have repeatedly shown that reproductive processes in pregnant women are adversely affected by exposure to cigarette smoke. The potential reproductive targets of smoke during pregnancy include the ovaries, oviducts, uterus, placenta, umbilical cord, and embryo/fetus. In vitro methods for studying the effects of smoke and its individual components have been developed and applied to each of these reproductive targets. In vitro assays have been useful in determining the biological processes that are affected in the reproductive organs and in identifying the cellular and molecular targets of smoke in each organ. In vitro methods have also been used to study the mechanism of action of smoke constituents, such as nicotine, on specific processes in reproductive organs and to screen smoke solutions to identify the molecules that affect reproduction. In general, data collected in vitro have confirmed, extended, and helped explain what has been learned from epidemiological studies. This review summarizes some of the in vitro assays that have been used to study cigarette smoke's effect on the nonpregnant and pregnant female reproductive tract and spotlights examples of their applications. Birth Defects Research (Part C) 84:61–72, 2008. © 2008 Wiley‐Liss, Inc.
Einführung in die Neuausgabe von DIN 1045‐1
Authors: Fingerloos Frank , Zilch Konrad
Published: March 2008

Als ein Ergebnis der Bearbeitung des Nationalen Anhangs zur neuen europäischen Bemessungsnorm für Stahlbeton‐ und Spannbetontragwerke Eurocode 2 und unter Berücksichtigung der Erfahrungen mit der Anwendung und Auslegung der deutschen Bemessungsnorm ist Anfang 2008 eine konsolidierte Neuausgabe von DIN 1045‐1 erschienen. In diesem Beitrag werden die Änderungen und ihre Hintergründe in der Neuausgabe von DIN 1045‐1 erläutert. Behandelt werden die neu eingeführten oder geänderten Regelungen zu

– den Feuchtigkeitsklassen bei Alkali‐Kieselsäurereaktion (AKR)

– zur Betondeckung

– zur effektiven Kriechzahl

– zu den Temperaturbereichen für die Stahleigenschaften

– zur Mindestquerkrafttragfähigkeit

– zu Verbundfugen

– zur Querkrafterhöhung bei Durchstanznachweisen an Wandende und ‐ecke

– zu den Betonstahleigenschaften bei Ermüdung

– zur rissbreitenbegrenzenden Mindestbewehrung für dicke Bauteile

– zur Querbewehrung bei Übergreifungsstößen und Stützen

– zur Robustheitsbewehrung